QEMU-STORAGE-DAEMON-QMP-REF(7) QEMU QEMU-STORAGE-DAEMON-QMP-REF(7)
NAME
qemu-storage-daemon-qmp-ref - QEMU Storage Daemon QMP Reference Manual
Contents
• QEMU Storage Daemon QMP Reference Manual
• Block devices
• Block core (VM unrelated)
• Common data types
• IoOperationType (Enum)
• OnOffAuto (Enum)
• OnOffSplit (Enum)
• String (Object)
• StrOrNull (Alternate)
• OffAutoPCIBAR (Enum)
• PCIELinkSpeed (Enum)
• PCIELinkWidth (Enum)
• HostMemPolicy (Enum)
• NetFilterDirection (Enum)
• GrabToggleKeys (Enum)
• HumanReadableText (Object)
• Cryptography
• QCryptoTLSCredsEndpoint (Enum)
• QCryptoSecretFormat (Enum)
• QCryptoHashAlgorithm (Enum)
• QCryptoCipherAlgorithm (Enum)
• QCryptoCipherMode (Enum)
• QCryptoIVGenAlgorithm (Enum)
• QCryptoBlockFormat (Enum)
• QCryptoBlockOptionsBase (Object)
• QCryptoBlockOptionsQCow (Object)
• QCryptoBlockOptionsLUKS (Object)
• QCryptoBlockCreateOptionsLUKS (Object)
• QCryptoBlockOpenOptions (Object)
• QCryptoBlockCreateOptions (Object)
• QCryptoBlockInfoBase (Object)
• QCryptoBlockInfoLUKSSlot (Object)
• QCryptoBlockInfoLUKS (Object)
• QCryptoBlockInfo (Object)
• QCryptoBlockLUKSKeyslotState (Enum)
• QCryptoBlockAmendOptionsLUKS (Object)
• QCryptoBlockAmendOptions (Object)
• SecretCommonProperties (Object)
• SecretProperties (Object)
• SecretKeyringProperties (Object)
• TlsCredsProperties (Object)
• TlsCredsAnonProperties (Object)
• TlsCredsPskProperties (Object)
• TlsCredsX509Properties (Object)
• QCryptoAkCipherAlgorithm (Enum)
• QCryptoAkCipherKeyType (Enum)
• QCryptoRSAPaddingAlgorithm (Enum)
• QCryptoAkCipherOptionsRSA (Object)
• QCryptoAkCipherOptions (Object)
• Background jobs
• Socket data types
• NetworkAddressFamily (Enum)
• InetSocketAddressBase (Object)
• InetSocketAddress (Object)
• UnixSocketAddress (Object)
• VsockSocketAddress (Object)
• InetSocketAddressWrapper (Object)
• UnixSocketAddressWrapper (Object)
• VsockSocketAddressWrapper (Object)
• StringWrapper (Object)
• SocketAddressLegacy (Object)
• SocketAddressType (Enum)
• SocketAddress (Object)
• SnapshotInfo (Object)
• ImageInfoSpecificQCow2EncryptionBase (Object)
• ImageInfoSpecificQCow2Encryption (Object)
• ImageInfoSpecificQCow2 (Object)
• ImageInfoSpecificVmdk (Object)
• ImageInfoSpecificRbd (Object)
• ImageInfoSpecificKind (Enum)
• ImageInfoSpecificQCow2Wrapper (Object)
• ImageInfoSpecificVmdkWrapper (Object)
• ImageInfoSpecificLUKSWrapper (Object)
• ImageInfoSpecificRbdWrapper (Object)
• ImageInfoSpecific (Object)
• ImageInfo (Object)
• ImageCheck (Object)
• MapEntry (Object)
• BlockdevCacheInfo (Object)
• BlockDeviceInfo (Object)
• BlockDeviceIoStatus (Enum)
• BlockDirtyInfo (Object)
• Qcow2BitmapInfoFlags (Enum)
• Qcow2BitmapInfo (Object)
• BlockLatencyHistogramInfo (Object)
• BlockInfo (Object)
• BlockMeasureInfo (Object)
• query-block (Command)
• BlockDeviceTimedStats (Object)
• BlockDeviceStats (Object)
• BlockStatsSpecificFile (Object)
• BlockStatsSpecificNvme (Object)
• BlockStatsSpecific (Object)
• BlockStats (Object)
• query-blockstats (Command)
• BlockdevOnError (Enum)
• MirrorSyncMode (Enum)
• BitmapSyncMode (Enum)
• MirrorCopyMode (Enum)
• BlockJobInfo (Object)
• query-block-jobs (Command)
• block_resize (Command)
• NewImageMode (Enum)
• BlockdevSnapshotSync (Object)
• BlockdevSnapshot (Object)
• BackupPerf (Object)
• BackupCommon (Object)
• DriveBackup (Object)
• BlockdevBackup (Object)
• blockdev-snapshot-sync (Command)
• blockdev-snapshot (Command)
• change-backing-file (Command)
• block-commit (Command)
• drive-backup (Command)
• blockdev-backup (Command)
• query-named-block-nodes (Command)
• XDbgBlockGraphNodeType (Enum)
• XDbgBlockGraphNode (Object)
• BlockPermission (Enum)
• XDbgBlockGraphEdge (Object)
• XDbgBlockGraph (Object)
• x-debug-query-block-graph (Command)
• drive-mirror (Command)
• DriveMirror (Object)
• BlockDirtyBitmap (Object)
• BlockDirtyBitmapAdd (Object)
• BlockDirtyBitmapOrStr (Alternate)
• BlockDirtyBitmapMerge (Object)
• block-dirty-bitmap-add (Command)
• block-dirty-bitmap-remove (Command)
• block-dirty-bitmap-clear (Command)
• block-dirty-bitmap-enable (Command)
• block-dirty-bitmap-disable (Command)
• block-dirty-bitmap-merge (Command)
• BlockDirtyBitmapSha256 (Object)
• x-debug-block-dirty-bitmap-sha256 (Command)
• blockdev-mirror (Command)
• BlockIOThrottle (Object)
• ThrottleLimits (Object)
• ThrottleGroupProperties (Object)
• block-stream (Command)
• block-job-set-speed (Command)
• block-job-cancel (Command)
• block-job-pause (Command)
• block-job-resume (Command)
• block-job-complete (Command)
• block-job-dismiss (Command)
• block-job-finalize (Command)
• BlockdevDiscardOptions (Enum)
• BlockdevDetectZeroesOptions (Enum)
• BlockdevAioOptions (Enum)
• BlockdevCacheOptions (Object)
• BlockdevDriver (Enum)
• BlockdevOptionsFile (Object)
• BlockdevOptionsNull (Object)
• BlockdevOptionsNVMe (Object)
• BlockdevOptionsVVFAT (Object)
• BlockdevOptionsGenericFormat (Object)
• BlockdevOptionsLUKS (Object)
• BlockdevOptionsGenericCOWFormat (Object)
• Qcow2OverlapCheckMode (Enum)
• Qcow2OverlapCheckFlags (Object)
• Qcow2OverlapChecks (Alternate)
• BlockdevQcowEncryptionFormat (Enum)
• BlockdevQcowEncryption (Object)
• BlockdevOptionsQcow (Object)
• BlockdevQcow2EncryptionFormat (Enum)
• BlockdevQcow2Encryption (Object)
• BlockdevOptionsPreallocate (Object)
• BlockdevOptionsQcow2 (Object)
• SshHostKeyCheckMode (Enum)
• SshHostKeyCheckHashType (Enum)
• SshHostKeyHash (Object)
• SshHostKeyCheck (Object)
• BlockdevOptionsSsh (Object)
• BlkdebugEvent (Enum)
• BlkdebugIOType (Enum)
• BlkdebugInjectErrorOptions (Object)
• BlkdebugSetStateOptions (Object)
• BlockdevOptionsBlkdebug (Object)
• BlockdevOptionsBlklogwrites (Object)
• BlockdevOptionsBlkverify (Object)
• BlockdevOptionsBlkreplay (Object)
• QuorumReadPattern (Enum)
• BlockdevOptionsQuorum (Object)
• BlockdevOptionsGluster (Object)
• BlockdevOptionsIoUring (Object)
• BlockdevOptionsNvmeIoUring (Object)
• BlockdevOptionsVirtioBlkVfioPci (Object)
• BlockdevOptionsVirtioBlkVhostUser (Object)
• BlockdevOptionsVirtioBlkVhostVdpa (Object)
• IscsiTransport (Enum)
• IscsiHeaderDigest (Enum)
• BlockdevOptionsIscsi (Object)
• RbdAuthMode (Enum)
• RbdImageEncryptionFormat (Enum)
• RbdEncryptionOptionsLUKSBase (Object)
• RbdEncryptionCreateOptionsLUKSBase (Object)
• RbdEncryptionOptionsLUKS (Object)
• RbdEncryptionOptionsLUKS2 (Object)
• RbdEncryptionCreateOptionsLUKS (Object)
• RbdEncryptionCreateOptionsLUKS2 (Object)
• RbdEncryptionOptions (Object)
• RbdEncryptionCreateOptions (Object)
• BlockdevOptionsRbd (Object)
• ReplicationMode (Enum)
• BlockdevOptionsReplication (Object)
• NFSTransport (Enum)
• NFSServer (Object)
• BlockdevOptionsNfs (Object)
• BlockdevOptionsCurlBase (Object)
• BlockdevOptionsCurlHttp (Object)
• BlockdevOptionsCurlHttps (Object)
• BlockdevOptionsCurlFtp (Object)
• BlockdevOptionsCurlFtps (Object)
• BlockdevOptionsNbd (Object)
• BlockdevOptionsRaw (Object)
• BlockdevOptionsThrottle (Object)
• BlockdevOptionsCor (Object)
• OnCbwError (Enum)
• BlockdevOptionsCbw (Object)
• BlockdevOptions (Object)
• BlockdevRef (Alternate)
• BlockdevRefOrNull (Alternate)
• blockdev-add (Command)
• blockdev-reopen (Command)
• blockdev-del (Command)
• BlockdevCreateOptionsFile (Object)
• BlockdevCreateOptionsGluster (Object)
• BlockdevCreateOptionsLUKS (Object)
• BlockdevCreateOptionsNfs (Object)
• BlockdevCreateOptionsParallels (Object)
• BlockdevCreateOptionsQcow (Object)
• BlockdevQcow2Version (Enum)
• Qcow2CompressionType (Enum)
• BlockdevCreateOptionsQcow2 (Object)
• BlockdevCreateOptionsQed (Object)
• BlockdevCreateOptionsRbd (Object)
• BlockdevVmdkSubformat (Enum)
• BlockdevVmdkAdapterType (Enum)
• BlockdevCreateOptionsVmdk (Object)
• BlockdevCreateOptionsSsh (Object)
• BlockdevCreateOptionsVdi (Object)
• BlockdevVhdxSubformat (Enum)
• BlockdevCreateOptionsVhdx (Object)
• BlockdevVpcSubformat (Enum)
• BlockdevCreateOptionsVpc (Object)
• BlockdevCreateOptions (Object)
• blockdev-create (Command)
• BlockdevAmendOptionsLUKS (Object)
• BlockdevAmendOptionsQcow2 (Object)
• BlockdevAmendOptions (Object)
• x-blockdev-amend (Command)
• BlockErrorAction (Enum)
• BLOCK_IMAGE_CORRUPTED (Event)
• BLOCK_IO_ERROR (Event)
• BLOCK_JOB_COMPLETED (Event)
• BLOCK_JOB_CANCELLED (Event)
• BLOCK_JOB_ERROR (Event)
• BLOCK_JOB_READY (Event)
• BLOCK_JOB_PENDING (Event)
• PreallocMode (Enum)
• BLOCK_WRITE_THRESHOLD (Event)
• block-set-write-threshold (Command)
• x-blockdev-change (Command)
• x-blockdev-set-iothread (Command)
• QuorumOpType (Enum)
• QUORUM_FAILURE (Event)
• QUORUM_REPORT_BAD (Event)
• BlockdevSnapshotInternal (Object)
• blockdev-snapshot-internal-sync (Command)
• blockdev-snapshot-delete-internal-sync (Command)
• Block device exports
• Character devices
• ChardevInfo (Object)
• query-chardev (Command)
• ChardevBackendInfo (Object)
• query-chardev-backends (Command)
• DataFormat (Enum)
• ringbuf-write (Command)
• ringbuf-read (Command)
• ChardevCommon (Object)
• ChardevFile (Object)
• ChardevHostdev (Object)
• ChardevSocket (Object)
• ChardevUdp (Object)
• ChardevMux (Object)
• ChardevStdio (Object)
• ChardevSpiceChannel (Object)
• ChardevSpicePort (Object)
• ChardevDBus (Object)
• ChardevVC (Object)
• ChardevRingbuf (Object)
• ChardevQemuVDAgent (Object)
• ChardevBackendKind (Enum)
• ChardevFileWrapper (Object)
• ChardevHostdevWrapper (Object)
• ChardevSocketWrapper (Object)
• ChardevUdpWrapper (Object)
• ChardevCommonWrapper (Object)
• ChardevMuxWrapper (Object)
• ChardevStdioWrapper (Object)
• ChardevSpiceChannelWrapper (Object)
• ChardevSpicePortWrapper (Object)
• ChardevQemuVDAgentWrapper (Object)
• ChardevDBusWrapper (Object)
• ChardevVCWrapper (Object)
• ChardevRingbufWrapper (Object)
• ChardevBackend (Object)
• ChardevReturn (Object)
• chardev-add (Command)
• chardev-change (Command)
• chardev-remove (Command)
• chardev-send-break (Command)
• VSERPORT_CHANGE (Event)
• QMP monitor control
• qmp_capabilities (Command)
• QMPCapability (Enum)
• VersionTriple (Object)
• VersionInfo (Object)
• query-version (Command)
• CommandInfo (Object)
• query-commands (Command)
• quit (Command)
• MonitorMode (Enum)
• MonitorOptions (Object)
• QMP introspection
• query-qmp-schema (Command)
• SchemaMetaType (Enum)
• SchemaInfo (Object)
• SchemaInfoBuiltin (Object)
• JSONType (Enum)
• SchemaInfoEnum (Object)
• SchemaInfoEnumMember (Object)
• SchemaInfoArray (Object)
• SchemaInfoObject (Object)
• SchemaInfoObjectMember (Object)
• SchemaInfoObjectVariant (Object)
• SchemaInfoAlternate (Object)
• SchemaInfoAlternateMember (Object)
• SchemaInfoCommand (Object)
• SchemaInfoEvent (Object)
• User authorization
• QAuthZListPolicy (Enum)
• QAuthZListFormat (Enum)
• QAuthZListRule (Object)
• AuthZListProperties (Object)
• AuthZListFileProperties (Object)
• AuthZPAMProperties (Object)
• AuthZSimpleProperties (Object)
• QEMU Object Model (QOM)
• ObjectPropertyInfo (Object)
• qom-list (Command)
• qom-get (Command)
• qom-set (Command)
• ObjectTypeInfo (Object)
• qom-list-types (Command)
• qom-list-properties (Command)
• CanHostSocketcanProperties (Object)
• ColoCompareProperties (Object)
• CryptodevBackendProperties (Object)
• CryptodevVhostUserProperties (Object)
• DBusVMStateProperties (Object)
• NetfilterInsert (Enum)
• NetfilterProperties (Object)
• FilterBufferProperties (Object)
• FilterDumpProperties (Object)
• FilterMirrorProperties (Object)
• FilterRedirectorProperties (Object)
• FilterRewriterProperties (Object)
• InputBarrierProperties (Object)
• InputLinuxProperties (Object)
• EventLoopBaseProperties (Object)
• IothreadProperties (Object)
• MainLoopProperties (Object)
• MemoryBackendProperties (Object)
• MemoryBackendFileProperties (Object)
• MemoryBackendMemfdProperties (Object)
• MemoryBackendEpcProperties (Object)
• PrManagerHelperProperties (Object)
• QtestProperties (Object)
• RemoteObjectProperties (Object)
• VfioUserServerProperties (Object)
• RngProperties (Object)
• RngEgdProperties (Object)
• RngRandomProperties (Object)
• SevGuestProperties (Object)
• ThreadContextProperties (Object)
• ObjectType (Enum)
• ObjectOptions (Object)
• object-add (Command)
• object-del (Command)
• Transactions
• Abort (Object)
• ActionCompletionMode (Enum)
• TransactionActionKind (Enum)
• AbortWrapper (Object)
• BlockDirtyBitmapAddWrapper (Object)
• BlockDirtyBitmapWrapper (Object)
• BlockDirtyBitmapMergeWrapper (Object)
• BlockdevBackupWrapper (Object)
• BlockdevSnapshotWrapper (Object)
• BlockdevSnapshotInternalWrapper (Object)
• BlockdevSnapshotSyncWrapper (Object)
• DriveBackupWrapper (Object)
• TransactionAction (Object)
• TransactionProperties (Object)
• transaction (Command)
BLOCK DEVICES
Block core (VM unrelated)
COMMON DATA TYPES
IoOperationType (Enum)
An enumeration of the I/O operation types
Values
read read operation
write write operation
Since
2.1
OnOffAuto (Enum)
An enumeration of three options: on, off, and auto
Values
auto QEMU selects the value between on and off
on Enabled
off Disabled
Since
2.2
OnOffSplit (Enum)
An enumeration of three values: on, off, and split
Values
on Enabled
off Disabled
split Mixed
Since
2.6
String (Object)
A fat type wrapping 'str', to be embedded in lists.
Members
str: string
Not documented
Since
1.2
StrOrNull (Alternate)
This is a string value or the explicit lack of a string (null pointer
in C). Intended for cases when 'optional absent' already has a differ-
ent meaning.
Members
s: string
the string value
n: null
no string value
Since
2.10
OffAutoPCIBAR (Enum)
An enumeration of options for specifying a PCI BAR
Values
off The specified feature is disabled
auto The PCI BAR for the feature is automatically selected
bar0 PCI BAR0 is used for the feature
bar1 PCI BAR1 is used for the feature
bar2 PCI BAR2 is used for the feature
bar3 PCI BAR3 is used for the feature
bar4 PCI BAR4 is used for the feature
bar5 PCI BAR5 is used for the feature
Since
2.12
PCIELinkSpeed (Enum)
An enumeration of PCIe link speeds in units of GT/s
Values
2_5 2.5GT/s
5 5.0GT/s
8 8.0GT/s
16 16.0GT/s
Since
4.0
PCIELinkWidth (Enum)
An enumeration of PCIe link width
Values
1 x1
2 x2
4 x4
8 x8
12 x12
16 x16
32 x32
Since
4.0
HostMemPolicy (Enum)
Host memory policy types
Values
default
restore default policy, remove any nondefault policy
preferred
set the preferred host nodes for allocation
bind a strict policy that restricts memory allocation to the host
nodes specified
interleave
memory allocations are interleaved across the set of host nodes
specified
Since
2.1
NetFilterDirection (Enum)
Indicates whether a netfilter is attached to a netdev's transmit queue
or receive queue or both.
Values
all the filter is attached both to the receive and the transmit
queue of the netdev (default).
rx the filter is attached to the receive queue of the netdev, where
it will receive packets sent to the netdev.
tx the filter is attached to the transmit queue of the netdev,
where it will receive packets sent by the netdev.
Since
2.5
GrabToggleKeys (Enum)
Keys to toggle input-linux between host and guest.
Values
ctrl-ctrl
Not documented
alt-alt
Not documented
shift-shift
Not documented
meta-meta
Not documented
scrolllock
Not documented
ctrl-scrolllock
Not documented
Since
4.0
HumanReadableText (Object)
Members
human-readable-text: string
Formatted output intended for humans.
Since
6.2
CRYPTOGRAPHY
QCryptoTLSCredsEndpoint (Enum)
The type of network endpoint that will be using the credentials. Most
types of credential require different setup / structures depending on
whether they will be used in a server versus a client.
Values
client the network endpoint is acting as the client
server the network endpoint is acting as the server
Since
2.5
QCryptoSecretFormat (Enum)
The data format that the secret is provided in
Values
raw raw bytes. When encoded in JSON only valid UTF-8 sequences can
be used
base64 arbitrary base64 encoded binary data
Since
2.6
QCryptoHashAlgorithm (Enum)
The supported algorithms for computing content digests
Values
md5 MD5. Should not be used in any new code, legacy compat only
sha1 SHA-1. Should not be used in any new code, legacy compat only
sha224 SHA-224. (since 2.7)
sha256 SHA-256. Current recommended strong hash.
sha384 SHA-384. (since 2.7)
sha512 SHA-512. (since 2.7)
ripemd160
RIPEMD-160. (since 2.7)
Since
2.6
QCryptoCipherAlgorithm (Enum)
The supported algorithms for content encryption ciphers
Values
aes-128
AES with 128 bit / 16 byte keys
aes-192
AES with 192 bit / 24 byte keys
aes-256
AES with 256 bit / 32 byte keys
des DES with 56 bit / 8 byte keys. Do not use except in VNC. (since
6.1)
3des 3DES(EDE) with 192 bit / 24 byte keys (since 2.9)
cast5-128
Cast5 with 128 bit / 16 byte keys
serpent-128
Serpent with 128 bit / 16 byte keys
serpent-192
Serpent with 192 bit / 24 byte keys
serpent-256
Serpent with 256 bit / 32 byte keys
twofish-128
Twofish with 128 bit / 16 byte keys
twofish-192
Twofish with 192 bit / 24 byte keys
twofish-256
Twofish with 256 bit / 32 byte keys
Since
2.6
QCryptoCipherMode (Enum)
The supported modes for content encryption ciphers
Values
ecb Electronic Code Book
cbc Cipher Block Chaining
xts XEX with tweaked code book and ciphertext stealing
ctr Counter (Since 2.8)
Since
2.6
QCryptoIVGenAlgorithm (Enum)
The supported algorithms for generating initialization vectors for full
disk encryption. The 'plain' generator should not be used for disks
with sector numbers larger than 2^32, except where compatibility with
pre-existing Linux dm-crypt volumes is required.
Values
plain 64-bit sector number truncated to 32-bits
plain64
64-bit sector number
essiv 64-bit sector number encrypted with a hash of the encryption key
Since
2.6
QCryptoBlockFormat (Enum)
The supported full disk encryption formats
Values
qcow QCow/QCow2 built-in AES-CBC encryption. Use only for liberating
data from old images.
luks LUKS encryption format. Recommended for new images
Since
2.6
QCryptoBlockOptionsBase (Object)
The common options that apply to all full disk encryption formats
Members
format: QCryptoBlockFormat
the encryption format
Since
2.6
QCryptoBlockOptionsQCow (Object)
The options that apply to QCow/QCow2 AES-CBC encryption format
Members
key-secret: string (optional)
the ID of a QCryptoSecret object providing the decryption key.
Mandatory except when probing image for metadata only.
Since
2.6
QCryptoBlockOptionsLUKS (Object)
The options that apply to LUKS encryption format
Members
key-secret: string (optional)
the ID of a QCryptoSecret object providing the decryption key.
Mandatory except when probing image for metadata only.
Since
2.6
QCryptoBlockCreateOptionsLUKS (Object)
The options that apply to LUKS encryption format initialization
Members
cipher-alg: QCryptoCipherAlgorithm (optional)
the cipher algorithm for data encryption Currently defaults to
'aes-256'.
cipher-mode: QCryptoCipherMode (optional)
the cipher mode for data encryption Currently defaults to 'xts'
ivgen-alg: QCryptoIVGenAlgorithm (optional)
the initialization vector generator Currently defaults to
'plain64'
ivgen-hash-alg: QCryptoHashAlgorithm (optional)
the initialization vector generator hash Currently defaults to
'sha256'
hash-alg: QCryptoHashAlgorithm (optional)
the master key hash algorithm Currently defaults to 'sha256'
iter-time: int (optional)
number of milliseconds to spend in PBKDF passphrase processing.
Currently defaults to 2000. (since 2.8)
The members of QCryptoBlockOptionsLUKS
Since
2.6
QCryptoBlockOpenOptions (Object)
The options that are available for all encryption formats when opening
an existing volume
Members
The members of QCryptoBlockOptionsBase
The members of QCryptoBlockOptionsQCow when format is "qcow"
The members of QCryptoBlockOptionsLUKS when format is "luks"
Since
2.6
QCryptoBlockCreateOptions (Object)
The options that are available for all encryption formats when initial-
izing a new volume
Members
The members of QCryptoBlockOptionsBase
The members of QCryptoBlockOptionsQCow when format is "qcow"
The members of QCryptoBlockCreateOptionsLUKS when format is "luks"
Since
2.6
QCryptoBlockInfoBase (Object)
The common information that applies to all full disk encryption formats
Members
format: QCryptoBlockFormat
the encryption format
Since
2.7
QCryptoBlockInfoLUKSSlot (Object)
Information about the LUKS block encryption key slot options
Members
active: boolean
whether the key slot is currently in use
key-offset: int
offset to the key material in bytes
iters: int (optional)
number of PBKDF2 iterations for key material
stripes: int (optional)
number of stripes for splitting key material
Since
2.7
QCryptoBlockInfoLUKS (Object)
Information about the LUKS block encryption options
Members
cipher-alg: QCryptoCipherAlgorithm
the cipher algorithm for data encryption
cipher-mode: QCryptoCipherMode
the cipher mode for data encryption
ivgen-alg: QCryptoIVGenAlgorithm
the initialization vector generator
ivgen-hash-alg: QCryptoHashAlgorithm (optional)
the initialization vector generator hash
hash-alg: QCryptoHashAlgorithm
the master key hash algorithm
payload-offset: int
offset to the payload data in bytes
master-key-iters: int
number of PBKDF2 iterations for key material
uuid: string
unique identifier for the volume
slots: array of QCryptoBlockInfoLUKSSlot
information about each key slot
Since
2.7
QCryptoBlockInfo (Object)
Information about the block encryption options
Members
The members of QCryptoBlockInfoBase
The members of QCryptoBlockInfoLUKS when format is "luks"
Since
2.7
QCryptoBlockLUKSKeyslotState (Enum)
Defines state of keyslots that are affected by the update
Values
active The slots contain the given password and marked as active
inactive
The slots are erased (contain garbage) and marked as inactive
Since
5.1
QCryptoBlockAmendOptionsLUKS (Object)
This struct defines the update parameters that activate/de-activate set
of keyslots
Members
state: QCryptoBlockLUKSKeyslotState
the desired state of the keyslots
new-secret: string (optional)
The ID of a QCryptoSecret object providing the password to be
written into added active keyslots
old-secret: string (optional)
Optional (for deactivation only) If given will deactivate all
keyslots that match password located in QCryptoSecret with this
ID
iter-time: int (optional)
Optional (for activation only) Number of milliseconds to spend
in PBKDF passphrase processing for the newly activated keyslot.
Currently defaults to 2000.
keyslot: int (optional)
Optional. ID of the keyslot to activate/deactivate. For keyslot
activation, keyslot should not be active already (this is unsafe
to update an active keyslot), but possible if 'force' parameter
is given. If keyslot is not given, first free keyslot will be
written.
For keyslot deactivation, this parameter specifies the exact
keyslot to deactivate
secret: string (optional)
Optional. The ID of a QCryptoSecret object providing the pass-
word to use to retrieve current master key. Defaults to the
same secret that was used to open the image
Since
5.1
QCryptoBlockAmendOptions (Object)
The options that are available for all encryption formats when amending
encryption settings
Members
The members of QCryptoBlockOptionsBase
The members of QCryptoBlockAmendOptionsLUKS when format is "luks"
Since
5.1
SecretCommonProperties (Object)
Properties for objects of classes derived from secret-common.
Members
loaded: boolean (optional)
if true, the secret is loaded immediately when applying this op-
tion and will probably fail when processing the next option.
Don't use; only provided for compatibility. (default: false)
format: QCryptoSecretFormat (optional)
the data format that the secret is provided in (default: raw)
keyid: string (optional)
the name of another secret that should be used to decrypt the
provided data. If not present, the data is assumed to be unen-
crypted.
iv: string (optional)
the random initialization vector used for encryption of this
particular secret. Should be a base64 encrypted string of the
16-byte IV. Mandatory if keyid is given. Ignored if keyid is ab-
sent.
Features
deprecated
Member loaded is deprecated. Setting true doesn't make sense,
and false is already the default.
Since
2.6
SecretProperties (Object)
Properties for secret objects.
Either data or file must be provided, but not both.
Members
data: string (optional)
the associated with the secret from
file: string (optional)
the filename to load the data associated with the secret from
The members of SecretCommonProperties
Since
2.6
SecretKeyringProperties (Object)
Properties for secret_keyring objects.
Members
serial: int
serial number that identifies a key to get from the kernel
The members of SecretCommonProperties
Since
5.1
TlsCredsProperties (Object)
Properties for objects of classes derived from tls-creds.
Members
verify-peer: boolean (optional)
if true the peer credentials will be verified once the handshake
is completed. This is a no-op for anonymous credentials. (de-
fault: true)
dir: string (optional)
the path of the directory that contains the credential files
endpoint: QCryptoTLSCredsEndpoint (optional)
whether the QEMU network backend that uses the credentials will
be acting as a client or as a server (default: client)
priority: string (optional)
a gnutls priority string as described at
https://gnutls.org/manual/html_node/Priority-Strings.html
Since
2.5
TlsCredsAnonProperties (Object)
Properties for tls-creds-anon objects.
Members
loaded: boolean (optional)
if true, the credentials are loaded immediately when applying
this option and will ignore options that are processed later.
Don't use; only provided for compatibility. (default: false)
The members of TlsCredsProperties
Features
deprecated
Member loaded is deprecated. Setting true doesn't make sense,
and false is already the default.
Since
2.5
TlsCredsPskProperties (Object)
Properties for tls-creds-psk objects.
Members
loaded: boolean (optional)
if true, the credentials are loaded immediately when applying
this option and will ignore options that are processed later.
Don't use; only provided for compatibility. (default: false)
username: string (optional)
the username which will be sent to the server. For clients
only. If absent, "qemu" is sent and the property will read back
as an empty string.
The members of TlsCredsProperties
Features
deprecated
Member loaded is deprecated. Setting true doesn't make sense,
and false is already the default.
Since
3.0
TlsCredsX509Properties (Object)
Properties for tls-creds-x509 objects.
Members
loaded: boolean (optional)
if true, the credentials are loaded immediately when applying
this option and will ignore options that are processed later.
Don't use; only provided for compatibility. (default: false)
sanity-check: boolean (optional)
if true, perform some sanity checks before using the credentials
(default: true)
passwordid: string (optional)
For the server-key.pem and client-key.pem files which contain
sensitive private keys, it is possible to use an encrypted ver-
sion by providing the passwordid parameter. This provides the
ID of a previously created secret object containing the password
for decryption.
The members of TlsCredsProperties
Features
deprecated
Member loaded is deprecated. Setting true doesn't make sense,
and false is already the default.
Since
2.5
QCryptoAkCipherAlgorithm (Enum)
The supported algorithms for asymmetric encryption ciphers
Values
rsa RSA algorithm
Since
7.1
QCryptoAkCipherKeyType (Enum)
The type of asymmetric keys.
Values
public Not documented
private
Not documented
Since
7.1
QCryptoRSAPaddingAlgorithm (Enum)
The padding algorithm for RSA.
Values
raw no padding used
pkcs1 pkcs1#v1.5
Since
7.1
QCryptoAkCipherOptionsRSA (Object)
Specific parameters for RSA algorithm.
Members
hash-alg: QCryptoHashAlgorithm
QCryptoHashAlgorithm
padding-alg: QCryptoRSAPaddingAlgorithm
QCryptoRSAPaddingAlgorithm
Since
7.1
QCryptoAkCipherOptions (Object)
The options that are available for all asymmetric key algorithms when
creating a new QCryptoAkCipher.
Members
alg: QCryptoAkCipherAlgorithm
Not documented
The members of QCryptoAkCipherOptionsRSA when alg is "rsa"
Since
7.1
Background jobs
JobType (Enum)
Type of a background job.
Values
commit block commit job type, see "block-commit"
stream block stream job type, see "block-stream"
mirror drive mirror job type, see "drive-mirror"
backup drive backup job type, see "drive-backup"
create image creation job type, see "blockdev-create" (since 3.0)
amend image options amend job type, see "x-blockdev-amend" (since 5.1)
snapshot-load
snapshot load job type, see "snapshot-load" (since 6.0)
snapshot-save
snapshot save job type, see "snapshot-save" (since 6.0)
snapshot-delete
snapshot delete job type, see "snapshot-delete" (since 6.0)
Since
1.7
JobStatus (Enum)
Indicates the present state of a given job in its lifetime.
Values
undefined
Erroneous, default state. Should not ever be visible.
created
The job has been created, but not yet started.
running
The job is currently running.
paused The job is running, but paused. The pause may be requested by
either the QMP user or by internal processes.
ready The job is running, but is ready for the user to signal comple-
tion. This is used for long-running jobs like mirror that are
designed to run indefinitely.
standby
The job is ready, but paused. This is nearly identical to
paused. The job may return to ready or otherwise be canceled.
waiting
The job is waiting for other jobs in the transaction to converge
to the waiting state. This status will likely not be visible for
the last job in a transaction.
pending
The job has finished its work, but has finalization steps that
it needs to make prior to completing. These changes will require
manual intervention via job-finalize if auto-finalize was set to
false. These pending changes may still fail.
aborting
The job is in the process of being aborted, and will finish with
an error. The job will afterwards report that it is concluded.
This status may not be visible to the management process.
concluded
The job has finished all work. If auto-dismiss was set to false,
the job will remain in the query list until it is dismissed via
job-dismiss.
null The job is in the process of being dismantled. This state should
not ever be visible externally.
Since
2.12
JobVerb (Enum)
Represents command verbs that can be applied to a job.
Values
cancel see job-cancel
pause see job-pause
resume see job-resume
set-speed
see block-job-set-speed
complete
see job-complete
dismiss
see job-dismiss
finalize
see job-finalize
Since
2.12
JOB_STATUS_CHANGE (Event)
Emitted when a job transitions to a different status.
Arguments
id: string
The job identifier
status: JobStatus
The new job status
Since
3.0
job-pause (Command)
Pause an active job.
This command returns immediately after marking the active job for paus-
ing. Pausing an already paused job is an error.
The job will pause as soon as possible, which means transitioning into
the PAUSED state if it was RUNNING, or into STANDBY if it was READY.
The corresponding JOB_STATUS_CHANGE event will be emitted.
Cancelling a paused job automatically resumes it.
Arguments
id: string
The job identifier.
Since
3.0
job-resume (Command)
Resume a paused job.
This command returns immediately after resuming a paused job. Resuming
an already running job is an error.
id : The job identifier.
Arguments
id: string
Not documented
Since
3.0
job-cancel (Command)
Instruct an active background job to cancel at the next opportunity.
This command returns immediately after marking the active job for can-
cellation.
The job will cancel as soon as possible and then emit a JOB_STA-
TUS_CHANGE event. Usually, the status will change to ABORTING, but it
is possible that a job successfully completes (e.g. because it was al-
most done and there was no opportunity to cancel earlier than complet-
ing the job) and transitions to PENDING instead.
Arguments
id: string
The job identifier.
Since
3.0
job-complete (Command)
Manually trigger completion of an active job in the READY state.
Arguments
id: string
The job identifier.
Since
3.0
job-dismiss (Command)
Deletes a job that is in the CONCLUDED state. This command only needs
to be run explicitly for jobs that don't have automatic dismiss en-
abled.
This command will refuse to operate on any job that has not yet reached
its terminal state, JOB_STATUS_CONCLUDED. For jobs that make use of
JOB_READY event, job-cancel or job-complete will still need to be used
as appropriate.
Arguments
id: string
The job identifier.
Since
3.0
job-finalize (Command)
Instructs all jobs in a transaction (or a single job if it is not part
of any transaction) to finalize any graph changes and do any necessary
cleanup. This command requires that all involved jobs are in the PEND-
ING state.
For jobs in a transaction, instructing one job to finalize will force
ALL jobs in the transaction to finalize, so it is only necessary to in-
struct a single member job to finalize.
Arguments
id: string
The identifier of any job in the transaction, or of a job that
is not part of any transaction.
Since
3.0
JobInfo (Object)
Information about a job.
Members
id: string
The job identifier
type: JobType
The kind of job that is being performed
status: JobStatus
Current job state/status
current-progress: int
Progress made until now. The unit is arbitrary and the value can
only meaningfully be used for the ratio of current-progress to
total-progress. The value is monotonically increasing.
total-progress: int
Estimated current-progress value at the completion of the job.
This value can arbitrarily change while the job is running, in
both directions.
error: string (optional)
If this field is present, the job failed; if it is still missing
in the CONCLUDED state, this indicates successful completion.
The value is a human-readable error message to describe the rea-
son for the job failure. It should not be parsed by applica-
tions.
Since
3.0
query-jobs (Command)
Return information about jobs.
Returns
a list with a JobInfo for each active job
Since
3.0
SOCKET DATA TYPES
NetworkAddressFamily (Enum)
The network address family
Values
ipv4 IPV4 family
ipv6 IPV6 family
unix unix socket
vsock vsock family (since 2.8)
unknown
otherwise
Since
2.1
InetSocketAddressBase (Object)
Members
host: string
host part of the address
port: string
port part of the address
InetSocketAddress (Object)
Captures a socket address or address range in the Internet namespace.
Members
numeric: boolean (optional)
true if the host/port are guaranteed to be numeric, false if
name resolution should be attempted. Defaults to false. (Since
2.9)
to: int (optional)
If present, this is range of possible addresses, with port be-
tween port and to.
ipv4: boolean (optional)
whether to accept IPv4 addresses, default try both IPv4 and IPv6
ipv6: boolean (optional)
whether to accept IPv6 addresses, default try both IPv4 and IPv6
keep-alive: boolean (optional)
enable keep-alive when connecting to this socket. Not supported
for passive sockets. (Since 4.2)
mptcp: boolean (optional) (If: HAVE_IPPROTO_MPTCP)
enable multi-path TCP. (Since 6.1)
The members of InetSocketAddressBase
Since
1.3
UnixSocketAddress (Object)
Captures a socket address in the local ("Unix socket") namespace.
Members
path: string
filesystem path to use
abstract: boolean (optional) (If: CONFIG_LINUX)
if true, this is a Linux abstract socket address. path will be
prefixed by a null byte, and optionally padded with null bytes.
Defaults to false. (Since 5.1)
tight: boolean (optional) (If: CONFIG_LINUX)
if false, pad an abstract socket address with enough null bytes
to make it fill struct sockaddr_un member sun_path. Defaults to
true. (Since 5.1)
Since
1.3
VsockSocketAddress (Object)
Captures a socket address in the vsock namespace.
Members
cid: string
unique host identifier
port: string
port
Note
string types are used to allow for possible future hostname or service
resolution support.
Since
2.8
InetSocketAddressWrapper (Object)
Members
data: InetSocketAddress
Not documented
Since
1.3
UnixSocketAddressWrapper (Object)
Members
data: UnixSocketAddress
Not documented
Since
1.3
VsockSocketAddressWrapper (Object)
Members
data: VsockSocketAddress
Not documented
Since
2.8
StringWrapper (Object)
Members
data: String
Not documented
Since
1.3
SocketAddressLegacy (Object)
Captures the address of a socket, which could also be a named file de-
scriptor
Members
type: SocketAddressType
Not documented
The members of InetSocketAddressWrapper when type is "inet"
The members of UnixSocketAddressWrapper when type is "unix"
The members of VsockSocketAddressWrapper when type is "vsock"
The members of StringWrapper when type is "fd"
Note
This type is deprecated in favor of SocketAddress. The difference be-
tween SocketAddressLegacy and SocketAddress is that the latter has
fewer {} on the wire.
Since
1.3
SocketAddressType (Enum)
Available SocketAddress types
Values
inet Internet address
unix Unix domain socket
vsock VMCI address
fd decimal is for file descriptor number, otherwise a file descrip-
tor name. Named file descriptors are permitted in monitor com-
mands, in combination with the 'getfd' command. Decimal file de-
scriptors are permitted at startup or other contexts where no
monitor context is active.
Since
2.9
SocketAddress (Object)
Captures the address of a socket, which could also be a named file de-
scriptor
Members
type: SocketAddressType
Transport type
The members of InetSocketAddress when type is "inet"
The members of UnixSocketAddress when type is "unix"
The members of VsockSocketAddress when type is "vsock"
The members of String when type is "fd"
Since
2.9
SnapshotInfo (Object)
Members
id: string
unique snapshot id
name: string
user chosen name
vm-state-size: int
size of the VM state
date-sec: int
UTC date of the snapshot in seconds
date-nsec: int
fractional part in nano seconds to be used with date-sec
vm-clock-sec: int
VM clock relative to boot in seconds
vm-clock-nsec: int
fractional part in nano seconds to be used with vm-clock-sec
icount: int (optional)
Current instruction count. Appears when execution record/replay
is enabled. Used for "time-traveling" to match the moment in the
recorded execution with the snapshots. This counter may be ob-
tained through query-replay command (since 5.2)
Since
1.3
ImageInfoSpecificQCow2EncryptionBase (Object)
Members
format: BlockdevQcow2EncryptionFormat
The encryption format
Since
2.10
ImageInfoSpecificQCow2Encryption (Object)
Members
The members of ImageInfoSpecificQCow2EncryptionBase
The members of QCryptoBlockInfoLUKS when format is "luks"
Since
2.10
ImageInfoSpecificQCow2 (Object)
Members
compat: string
compatibility level
data-file: string (optional)
the filename of the external data file that is stored in the im-
age and used as a default for opening the image (since: 4.0)
data-file-raw: boolean (optional)
True if the external data file must stay valid as a standalone
(read-only) raw image without looking at qcow2 metadata (since:
4.0)
extended-l2: boolean (optional)
true if the image has extended L2 entries; only valid for compat
>= 1.1 (since 5.2)
lazy-refcounts: boolean (optional)
on or off; only valid for compat >= 1.1
corrupt: boolean (optional)
true if the image has been marked corrupt; only valid for compat
>= 1.1 (since 2.2)
refcount-bits: int
width of a refcount entry in bits (since 2.3)
encrypt: ImageInfoSpecificQCow2Encryption (optional)
details about encryption parameters; only set if image is en-
crypted (since 2.10)
bitmaps: array of Qcow2BitmapInfo (optional)
A list of qcow2 bitmap details (since 4.0)
compression-type: Qcow2CompressionType
the image cluster compression method (since 5.1)
Since
1.7
ImageInfoSpecificVmdk (Object)
Members
create-type: string
The create type of VMDK image
cid: int
Content id of image
parent-cid: int
Parent VMDK image's cid
extents: array of ImageInfo
List of extent files
Since
1.7
ImageInfoSpecificRbd (Object)
Members
encryption-format: RbdImageEncryptionFormat (optional)
Image encryption format
Since
6.1
ImageInfoSpecificKind (Enum)
Values
luks Since 2.7
rbd Since 6.1
qcow2 Not documented
vmdk Not documented
Since
1.7
ImageInfoSpecificQCow2Wrapper (Object)
Members
data: ImageInfoSpecificQCow2
Not documented
Since
1.7
ImageInfoSpecificVmdkWrapper (Object)
Members
data: ImageInfoSpecificVmdk
Not documented
Since
6.1
ImageInfoSpecificLUKSWrapper (Object)
Members
data: QCryptoBlockInfoLUKS
Not documented
Since
2.7
ImageInfoSpecificRbdWrapper (Object)
Members
data: ImageInfoSpecificRbd
Not documented
Since
6.1
ImageInfoSpecific (Object)
A discriminated record of image format specific information structures.
Members
type: ImageInfoSpecificKind
Not documented
The members of ImageInfoSpecificQCow2Wrapper when type is "qcow2"
The members of ImageInfoSpecificVmdkWrapper when type is "vmdk"
The members of ImageInfoSpecificLUKSWrapper when type is "luks"
The members of ImageInfoSpecificRbdWrapper when type is "rbd"
Since
1.7
ImageInfo (Object)
Information about a QEMU image file
Members
filename: string
name of the image file
format: string
format of the image file
virtual-size: int
maximum capacity in bytes of the image
actual-size: int (optional)
actual size on disk in bytes of the image
dirty-flag: boolean (optional)
true if image is not cleanly closed
cluster-size: int (optional)
size of a cluster in bytes
encrypted: boolean (optional)
true if the image is encrypted
compressed: boolean (optional)
true if the image is compressed (Since 1.7)
backing-filename: string (optional)
name of the backing file
full-backing-filename: string (optional)
full path of the backing file
backing-filename-format: string (optional)
the format of the backing file
snapshots: array of SnapshotInfo (optional)
list of VM snapshots
backing-image: ImageInfo (optional)
info of the backing image (since 1.6)
format-specific: ImageInfoSpecific (optional)
structure supplying additional format-specific information
(since 1.7)
Since
1.3
ImageCheck (Object)
Information about a QEMU image file check
Members
filename: string
name of the image file checked
format: string
format of the image file checked
check-errors: int
number of unexpected errors occurred during check
image-end-offset: int (optional)
offset (in bytes) where the image ends, this field is present if
the driver for the image format supports it
corruptions: int (optional)
number of corruptions found during the check if any
leaks: int (optional)
number of leaks found during the check if any
corruptions-fixed: int (optional)
number of corruptions fixed during the check if any
leaks-fixed: int (optional)
number of leaks fixed during the check if any
total-clusters: int (optional)
total number of clusters, this field is present if the driver
for the image format supports it
allocated-clusters: int (optional)
total number of allocated clusters, this field is present if the
driver for the image format supports it
fragmented-clusters: int (optional)
total number of fragmented clusters, this field is present if
the driver for the image format supports it
compressed-clusters: int (optional)
total number of compressed clusters, this field is present if
the driver for the image format supports it
Since
1.4
MapEntry (Object)
Mapping information from a virtual block range to a host file range
Members
start: int
virtual (guest) offset of the first byte described by this entry
length: int
the number of bytes of the mapped virtual range
data: boolean
reading the image will actually read data from a file (in par-
ticular, if offset is present this means that the sectors are
not simply preallocated, but contain actual data in raw format)
zero: boolean
whether the virtual blocks read as zeroes
depth: int
number of layers (0 = top image, 1 = top image's backing file,
..., n - 1 = bottom image (where n is the number of images in
the chain)) before reaching one for which the range is allocated
present: boolean
true if this layer provides the data, false if adding a backing
layer could impact this region (since 6.1)
offset: int (optional)
if present, the image file stores the data for this range in raw
format at the given (host) offset
filename: string (optional)
filename that is referred to by offset
Since
2.6
BlockdevCacheInfo (Object)
Cache mode information for a block device
Members
writeback: boolean
true if writeback mode is enabled
direct: boolean
true if the host page cache is bypassed (O_DIRECT)
no-flush: boolean
true if flush requests are ignored for the device
Since
2.3
BlockDeviceInfo (Object)
Information about the backing device for a block device.
Members
file: string
the filename of the backing device
node-name: string (optional)
the name of the block driver node (Since 2.0)
ro: boolean
true if the backing device was open read-only
drv: string
the name of the block format used to open the backing device. As
of 0.14 this can be: 'blkdebug', 'bochs', 'cloop', 'cow', 'dmg',
'file', 'file', 'ftp', 'ftps', 'host_cdrom', 'host_device',
'http', 'https', 'luks', 'nbd', 'parallels', 'qcow', 'qcow2',
'raw', 'vdi', 'vmdk', 'vpc', 'vvfat' 2.2: 'archipelago' added,
'cow' dropped 2.3: 'host_floppy' deprecated 2.5: 'host_floppy'
dropped 2.6: 'luks' added 2.8: 'replication' added, 'tftp'
dropped 2.9: 'archipelago' dropped
backing_file: string (optional)
the name of the backing file (for copy-on-write)
backing_file_depth: int
number of files in the backing file chain (since: 1.2)
encrypted: boolean
true if the backing device is encrypted
detect_zeroes: BlockdevDetectZeroesOptions
detect and optimize zero writes (Since 2.1)
bps: int
total throughput limit in bytes per second is specified
bps_rd: int
read throughput limit in bytes per second is specified
bps_wr: int
write throughput limit in bytes per second is specified
iops: int
total I/O operations per second is specified
iops_rd: int
read I/O operations per second is specified
iops_wr: int
write I/O operations per second is specified
image: ImageInfo
the info of image used (since: 1.6)
bps_max: int (optional)
total throughput limit during bursts,
in bytes (Since 1.7)
bps_rd_max: int (optional)
read throughput limit during bursts,
in bytes (Since 1.7)
bps_wr_max: int (optional)
write throughput limit during bursts,
in bytes (Since 1.7)
iops_max: int (optional)
total I/O operations per second during bursts,
in bytes (Since 1.7)
iops_rd_max: int (optional)
read I/O operations per second during bursts,
in bytes (Since 1.7)
iops_wr_max: int (optional)
write I/O operations per second during bursts,
in bytes (Since 1.7)
bps_max_length: int (optional)
maximum length of the bps_max burst
period, in seconds. (Since 2.6)
bps_rd_max_length: int (optional)
maximum length of the bps_rd_max
burst period, in seconds. (Since 2.6)
bps_wr_max_length: int (optional)
maximum length of the bps_wr_max
burst period, in seconds. (Since 2.6)
iops_max_length: int (optional)
maximum length of the iops burst
period, in seconds. (Since 2.6)
iops_rd_max_length: int (optional)
maximum length of the iops_rd_max
burst period, in seconds. (Since 2.6)
iops_wr_max_length: int (optional)
maximum length of the iops_wr_max
burst period, in seconds. (Since 2.6)
iops_size: int (optional)
an I/O size in bytes (Since 1.7)
group: string (optional)
throttle group name (Since 2.4)
cache: BlockdevCacheInfo
the cache mode used for the block device (since: 2.3)
write_threshold: int
configured write threshold for the device. 0 if disabled.
(Since 2.3)
dirty-bitmaps: array of BlockDirtyInfo (optional)
dirty bitmaps information (only present if node has one or more
dirty bitmaps) (Since 4.2)
Since
0.14
BlockDeviceIoStatus (Enum)
An enumeration of block device I/O status.
Values
ok The last I/O operation has succeeded
failed The last I/O operation has failed
nospace
The last I/O operation has failed due to a no-space condition
Since
1.0
BlockDirtyInfo (Object)
Block dirty bitmap information.
Members
name: string (optional)
the name of the dirty bitmap (Since 2.4)
count: int
number of dirty bytes according to the dirty bitmap
granularity: int
granularity of the dirty bitmap in bytes (since 1.4)
recording: boolean
true if the bitmap is recording new writes from the guest. Re-
places active and disabled statuses. (since 4.0)
busy: boolean
true if the bitmap is in-use by some operation (NBD or jobs) and
cannot be modified via QMP or used by another operation. Re-
places locked and frozen statuses. (since 4.0)
persistent: boolean
true if the bitmap was stored on disk, is scheduled to be stored
on disk, or both. (since 4.0)
inconsistent: boolean (optional)
true if this is a persistent bitmap that was improperly stored.
Implies persistent to be true; recording and busy to be false.
This bitmap cannot be used. To remove it, use block-dirty-bit-
map-remove. (Since 4.0)
Since
1.3
Qcow2BitmapInfoFlags (Enum)
An enumeration of flags that a bitmap can report to the user.
Values
in-use This flag is set by any process actively modifying the qcow2
file, and cleared when the updated bitmap is flushed to the
qcow2 image. The presence of this flag in an offline image
means that the bitmap was not saved correctly after its last us-
age, and may contain inconsistent data.
auto The bitmap must reflect all changes of the virtual disk by any
application that would write to this qcow2 file.
Since
4.0
Qcow2BitmapInfo (Object)
Qcow2 bitmap information.
Members
name: string
the name of the bitmap
granularity: int
granularity of the bitmap in bytes
flags: array of Qcow2BitmapInfoFlags
flags of the bitmap
Since
4.0
BlockLatencyHistogramInfo (Object)
Block latency histogram.
Members
boundaries: array of int
list of interval boundary values in nanoseconds, all greater
than zero and in ascending order. For example, the list [10,
50, 100] produces the following histogram intervals: [0, 10),
[10, 50), [50, 100), [100, +inf).
bins: array of int
list of io request counts corresponding to histogram intervals.
len(bins) = len(boundaries) + 1 For the example above, bins may
be something like [3, 1, 5, 2], and corresponding histogram
looks like:
5| *
4| *
3| * *
2| * * *
1| * * * *
+------------------
10 50 100
Since
4.0
BlockInfo (Object)
Block device information. This structure describes a virtual device
and the backing device associated with it.
Members
device: string
The device name associated with the virtual device.
qdev: string (optional)
The qdev ID, or if no ID is assigned, the QOM path of the block
device. (since 2.10)
type: string
This field is returned only for compatibility reasons, it should
not be used (always returns 'unknown')
removable: boolean
True if the device supports removable media.
locked: boolean
True if the guest has locked this device from having its media
removed
tray_open: boolean (optional)
True if the device's tray is open (only present if it has a
tray)
io-status: BlockDeviceIoStatus (optional)
BlockDeviceIoStatus. Only present if the device supports it and
the VM is configured to stop on errors (supported device models:
virtio-blk, IDE, SCSI except scsi-generic)
inserted: BlockDeviceInfo (optional)
BlockDeviceInfo describing the device if media is present
Since
0.14
BlockMeasureInfo (Object)
Image file size calculation information. This structure describes the
size requirements for creating a new image file.
The size requirements depend on the new image file format. File size
always equals virtual disk size for the 'raw' format, even for sparse
POSIX files. Compact formats such as 'qcow2' represent unallocated and
zero regions efficiently so file size may be smaller than virtual disk
size.
The values are upper bounds that are guaranteed to fit the new image
file. Subsequent modification, such as internal snapshot or further
bitmap creation, may require additional space and is not covered here.
Members
required: int
Size required for a new image file, in bytes, when copying just
allocated guest-visible contents.
fully-allocated: int
Image file size, in bytes, once data has been written to all
sectors, when copying just guest-visible contents.
bitmaps: int (optional)
Additional size required if all the top-level bitmap metadata in
the source image were to be copied to the destination, present
only when source and destination both support persistent bit-
maps. (since 5.1)
Since
2.10
query-block (Command)
Get a list of BlockInfo for all virtual block devices.
Returns
a list of BlockInfo describing each virtual block device. Filter nodes
that were created implicitly are skipped over.
Since
0.14
Example
-> { "execute": "query-block" }
<- {
"return":[
{
"io-status": "ok",
"device":"ide0-hd0",
"locked":false,
"removable":false,
"inserted":{
"ro":false,
"drv":"qcow2",
"encrypted":false,
"file":"disks/test.qcow2",
"backing_file_depth":1,
"bps":1000000,
"bps_rd":0,
"bps_wr":0,
"iops":1000000,
"iops_rd":0,
"iops_wr":0,
"bps_max": 8000000,
"bps_rd_max": 0,
"bps_wr_max": 0,
"iops_max": 0,
"iops_rd_max": 0,
"iops_wr_max": 0,
"iops_size": 0,
"detect_zeroes": "on",
"write_threshold": 0,
"image":{
"filename":"disks/test.qcow2",
"format":"qcow2",
"virtual-size":2048000,
"backing_file":"base.qcow2",
"full-backing-filename":"disks/base.qcow2",
"backing-filename-format":"qcow2",
"snapshots":[
{
"id": "1",
"name": "snapshot1",
"vm-state-size": 0,
"date-sec": 10000200,
"date-nsec": 12,
"vm-clock-sec": 206,
"vm-clock-nsec": 30
}
],
"backing-image":{
"filename":"disks/base.qcow2",
"format":"qcow2",
"virtual-size":2048000
}
}
},
"qdev": "ide_disk",
"type":"unknown"
},
{
"io-status": "ok",
"device":"ide1-cd0",
"locked":false,
"removable":true,
"qdev": "/machine/unattached/device[23]",
"tray_open": false,
"type":"unknown"
},
{
"device":"floppy0",
"locked":false,
"removable":true,
"qdev": "/machine/unattached/device[20]",
"type":"unknown"
},
{
"device":"sd0",
"locked":false,
"removable":true,
"type":"unknown"
}
]
}
BlockDeviceTimedStats (Object)
Statistics of a block device during a given interval of time.
Members
interval_length: int
Interval used for calculating the statistics, in seconds.
min_rd_latency_ns: int
Minimum latency of read operations in the defined interval, in
nanoseconds.
min_wr_latency_ns: int
Minimum latency of write operations in the defined interval, in
nanoseconds.
min_flush_latency_ns: int
Minimum latency of flush operations in the defined interval, in
nanoseconds.
max_rd_latency_ns: int
Maximum latency of read operations in the defined interval, in
nanoseconds.
max_wr_latency_ns: int
Maximum latency of write operations in the defined interval, in
nanoseconds.
max_flush_latency_ns: int
Maximum latency of flush operations in the defined interval, in
nanoseconds.
avg_rd_latency_ns: int
Average latency of read operations in the defined interval, in
nanoseconds.
avg_wr_latency_ns: int
Average latency of write operations in the defined interval, in
nanoseconds.
avg_flush_latency_ns: int
Average latency of flush operations in the defined interval, in
nanoseconds.
avg_rd_queue_depth: number
Average number of pending read operations in the defined inter-
val.
avg_wr_queue_depth: number
Average number of pending write operations in the defined inter-
val.
Since
2.5
BlockDeviceStats (Object)
Statistics of a virtual block device or a block backing device.
Members
rd_bytes: int
The number of bytes read by the device.
wr_bytes: int
The number of bytes written by the device.
unmap_bytes: int
The number of bytes unmapped by the device (Since 4.2)
rd_operations: int
The number of read operations performed by the device.
wr_operations: int
The number of write operations performed by the device.
flush_operations: int
The number of cache flush operations performed by the device
(since 0.15)
unmap_operations: int
The number of unmap operations performed by the device (Since
4.2)
rd_total_time_ns: int
Total time spent on reads in nanoseconds (since 0.15).
wr_total_time_ns: int
Total time spent on writes in nanoseconds (since 0.15).
flush_total_time_ns: int
Total time spent on cache flushes in nanoseconds (since 0.15).
unmap_total_time_ns: int
Total time spent on unmap operations in nanoseconds (Since 4.2)
wr_highest_offset: int
The offset after the greatest byte written to the device. The
intended use of this information is for growable sparse files
(like qcow2) that are used on top of a physical device.
rd_merged: int
Number of read requests that have been merged into another re-
quest (Since 2.3).
wr_merged: int
Number of write requests that have been merged into another re-
quest (Since 2.3).
unmap_merged: int
Number of unmap requests that have been merged into another re-
quest (Since 4.2)
idle_time_ns: int (optional)
Time since the last I/O operation, in nanoseconds. If the field
is absent it means that there haven't been any operations yet
(Since 2.5).
failed_rd_operations: int
The number of failed read operations performed by the device
(Since 2.5)
failed_wr_operations: int
The number of failed write operations performed by the device
(Since 2.5)
failed_flush_operations: int
The number of failed flush operations performed by the device
(Since 2.5)
failed_unmap_operations: int
The number of failed unmap operations performed by the device
(Since 4.2)
invalid_rd_operations: int
The number of invalid read operations
performed by the device (Since 2.5)
invalid_wr_operations: int
The number of invalid write operations performed by the device
(Since 2.5)
invalid_flush_operations: int
The number of invalid flush operations performed by the device
(Since 2.5)
invalid_unmap_operations: int
The number of invalid unmap operations performed by the device
(Since 4.2)
account_invalid: boolean
Whether invalid operations are included in the last access sta-
tistics (Since 2.5)
account_failed: boolean
Whether failed operations are included in the latency and last
access statistics (Since 2.5)
timed_stats: array of BlockDeviceTimedStats
Statistics specific to the set of previously defined intervals
of time (Since 2.5)
rd_latency_histogram: BlockLatencyHistogramInfo (optional)
BlockLatencyHistogramInfo. (Since 4.0)
wr_latency_histogram: BlockLatencyHistogramInfo (optional)
BlockLatencyHistogramInfo. (Since 4.0)
flush_latency_histogram: BlockLatencyHistogramInfo (optional)
BlockLatencyHistogramInfo. (Since 4.0)
Since
0.14
BlockStatsSpecificFile (Object)
File driver statistics
Members
discard-nb-ok: int
The number of successful discard operations performed by the
driver.
discard-nb-failed: int
The number of failed discard operations performed by the driver.
discard-bytes-ok: int
The number of bytes discarded by the driver.
Since
4.2
BlockStatsSpecificNvme (Object)
NVMe driver statistics
Members
completion-errors: int
The number of completion errors.
aligned-accesses: int
The number of aligned accesses performed by the driver.
unaligned-accesses: int
The number of unaligned accesses performed by the driver.
Since
5.2
BlockStatsSpecific (Object)
Block driver specific statistics
Members
driver: BlockdevDriver
Not documented
The members of BlockStatsSpecificFile when driver is "file"
The members of BlockStatsSpecificFile when driver is "host_device" (If:
HAVE_HOST_BLOCK_DEVICE)
The members of BlockStatsSpecificNvme when driver is "nvme"
Since
4.2
BlockStats (Object)
Statistics of a virtual block device or a block backing device.
Members
device: string (optional)
If the stats are for a virtual block device, the name corre-
sponding to the virtual block device.
node-name: string (optional)
The node name of the device. (Since 2.3)
qdev: string (optional)
The qdev ID, or if no ID is assigned, the QOM path of the block
device. (since 3.0)
stats: BlockDeviceStats
A BlockDeviceStats for the device.
driver-specific: BlockStatsSpecific (optional)
Optional driver-specific stats. (Since 4.2)
parent: BlockStats (optional)
This describes the file block device if it has one. Contains
recursively the statistics of the underlying protocol (e.g. the
host file for a qcow2 image). If there is no underlying proto-
col, this field is omitted
backing: BlockStats (optional)
This describes the backing block device if it has one. (Since
2.0)
Since
0.14
query-blockstats (Command)
Query the BlockStats for all virtual block devices.
Arguments
query-nodes: boolean (optional)
If true, the command will query all the block nodes that have a
node name, in a list which will include "parent" information,
but not "backing". If false or omitted, the behavior is as be-
fore - query all the device backends, recursively including
their "parent" and "backing". Filter nodes that were created im-
plicitly are skipped over in this mode. (Since 2.3)
Returns
A list of BlockStats for each virtual block devices.
Since
0.14
Example
-> { "execute": "query-blockstats" }
<- {
"return":[
{
"device":"ide0-hd0",
"parent":{
"stats":{
"wr_highest_offset":3686448128,
"wr_bytes":9786368,
"wr_operations":751,
"rd_bytes":122567168,
"rd_operations":36772
"wr_total_times_ns":313253456
"rd_total_times_ns":3465673657
"flush_total_times_ns":49653
"flush_operations":61,
"rd_merged":0,
"wr_merged":0,
"idle_time_ns":2953431879,
"account_invalid":true,
"account_failed":false
}
},
"stats":{
"wr_highest_offset":2821110784,
"wr_bytes":9786368,
"wr_operations":692,
"rd_bytes":122739200,
"rd_operations":36604
"flush_operations":51,
"wr_total_times_ns":313253456
"rd_total_times_ns":3465673657
"flush_total_times_ns":49653,
"rd_merged":0,
"wr_merged":0,
"idle_time_ns":2953431879,
"account_invalid":true,
"account_failed":false
},
"qdev": "/machine/unattached/device[23]"
},
{
"device":"ide1-cd0",
"stats":{
"wr_highest_offset":0,
"wr_bytes":0,
"wr_operations":0,
"rd_bytes":0,
"rd_operations":0
"flush_operations":0,
"wr_total_times_ns":0
"rd_total_times_ns":0
"flush_total_times_ns":0,
"rd_merged":0,
"wr_merged":0,
"account_invalid":false,
"account_failed":false
},
"qdev": "/machine/unattached/device[24]"
},
{
"device":"floppy0",
"stats":{
"wr_highest_offset":0,
"wr_bytes":0,
"wr_operations":0,
"rd_bytes":0,
"rd_operations":0
"flush_operations":0,
"wr_total_times_ns":0
"rd_total_times_ns":0
"flush_total_times_ns":0,
"rd_merged":0,
"wr_merged":0,
"account_invalid":false,
"account_failed":false
},
"qdev": "/machine/unattached/device[16]"
},
{
"device":"sd0",
"stats":{
"wr_highest_offset":0,
"wr_bytes":0,
"wr_operations":0,
"rd_bytes":0,
"rd_operations":0
"flush_operations":0,
"wr_total_times_ns":0
"rd_total_times_ns":0
"flush_total_times_ns":0,
"rd_merged":0,
"wr_merged":0,
"account_invalid":false,
"account_failed":false
}
}
]
}
BlockdevOnError (Enum)
An enumeration of possible behaviors for errors on I/O operations. The
exact meaning depends on whether the I/O was initiated by a guest or by
a block job
Values
report for guest operations, report the error to the guest; for jobs,
cancel the job
ignore ignore the error, only report a QMP event (BLOCK_IO_ERROR or
BLOCK_JOB_ERROR). The backup, mirror and commit block jobs retry
the failing request later and may still complete successfully.
The stream block job continues to stream and will complete with
an error.
enospc same as stop on ENOSPC, same as report otherwise.
stop for guest operations, stop the virtual machine; for jobs, pause
the job
auto inherit the error handling policy of the backend (since: 2.7)
Since
1.3
MirrorSyncMode (Enum)
An enumeration of possible behaviors for the initial synchronization
phase of storage mirroring.
Values
top copies data in the topmost image to the destination
full copies data from all images to the destination
none only copy data written from now on
incremental
only copy data described by the dirty bitmap. (since: 2.4)
bitmap only copy data described by the dirty bitmap. (since: 4.2) Be-
havior on completion is determined by the BitmapSyncMode.
Since
1.3
BitmapSyncMode (Enum)
An enumeration of possible behaviors for the synchronization of a bit-
map when used for data copy operations.
Values
on-success
The bitmap is only synced when the operation is successful.
This is the behavior always used for 'INCREMENTAL' backups.
never The bitmap is never synchronized with the operation, and is
treated solely as a read-only manifest of blocks to copy.
always The bitmap is always synchronized with the operation, regardless
of whether or not the operation was successful.
Since
4.2
MirrorCopyMode (Enum)
An enumeration whose values tell the mirror block job when to trigger
writes to the target.
Values
background
copy data in background only.
write-blocking
when data is written to the source, write it (synchronously) to
the target as well. In addition, data is copied in background
just like in background mode.
Since
3.0
BlockJobInfo (Object)
Information about a long-running block device operation.
Members
type: string
the job type ('stream' for image streaming)
device: string
The job identifier. Originally the device name but other values
are allowed since QEMU 2.7
len: int
Estimated offset value at the completion of the job. This value
can arbitrarily change while the job is running, in both direc-
tions.
offset: int
Progress made until now. The unit is arbitrary and the value can
only meaningfully be used for the ratio of offset to len. The
value is monotonically increasing.
busy: boolean
false if the job is known to be in a quiescent state, with no
pending I/O. Since 1.3.
paused: boolean
whether the job is paused or, if busy is true, will pause itself
as soon as possible. Since 1.3.
speed: int
the rate limit, bytes per second
io-status: BlockDeviceIoStatus
the status of the job (since 1.3)
ready: boolean
true if the job may be completed (since 2.2)
status: JobStatus
Current job state/status (since 2.12)
auto-finalize: boolean
Job will finalize itself when PENDING, moving to the CONCLUDED
state. (since 2.12)
auto-dismiss: boolean
Job will dismiss itself when CONCLUDED, moving to the NULL state
and disappearing from the query list. (since 2.12)
error: string (optional)
Error information if the job did not complete successfully. Not
set if the job completed successfully. (since 2.12.1)
Since
1.1
query-block-jobs (Command)
Return information about long-running block device operations.
Returns
a list of BlockJobInfo for each active block job
Since
1.1
block_resize (Command)
Resize a block image while a guest is running.
Either device or node-name must be set but not both.
Arguments
device: string (optional)
the name of the device to get the image resized
node-name: string (optional)
graph node name to get the image resized (Since 2.0)
size: int
new image size in bytes
Returns
• nothing on success
• If device is not a valid block device, DeviceNotFound
Since
0.14
Example
-> { "execute": "block_resize",
"arguments": { "device": "scratch", "size": 1073741824 } }
<- { "return": {} }
NewImageMode (Enum)
An enumeration that tells QEMU how to set the backing file path in a
new image file.
Values
existing
QEMU should look for an existing image file.
absolute-paths
QEMU should create a new image with absolute paths for the back-
ing file. If there is no backing file available, the new image
will not be backed either.
Since
1.1
BlockdevSnapshotSync (Object)
Either device or node-name must be set but not both.
Members
device: string (optional)
the name of the device to take a snapshot of.
node-name: string (optional)
graph node name to generate the snapshot from (Since 2.0)
snapshot-file: string
the target of the new overlay image. If the file exists, or if
it is a device, the overlay will be created in the existing
file/device. Otherwise, a new file will be created.
snapshot-node-name: string (optional)
the graph node name of the new image (Since 2.0)
format: string (optional)
the format of the overlay image, default is 'qcow2'.
mode: NewImageMode (optional)
whether and how QEMU should create a new image, default is 'ab-
solute-paths'.
BlockdevSnapshot (Object)
Members
node: string
device or node name that will have a snapshot taken.
overlay: string
reference to the existing block device that will become the
overlay of node, as part of taking the snapshot. It must not
have a current backing file (this can be achieved by passing
"backing": null to blockdev-add).
Since
2.5
BackupPerf (Object)
Optional parameters for backup. These parameters don't affect function-
ality, but may significantly affect performance.
Members
use-copy-range: boolean (optional)
Use copy offloading. Default false.
max-workers: int (optional)
Maximum number of parallel requests for the sustained background
copying process. Doesn't influence copy-before-write operations.
Default 64.
max-chunk: int (optional)
Maximum request length for the sustained background copying
process. Doesn't influence copy-before-write operations. 0
means unlimited. If max-chunk is non-zero then it should not be
less than job cluster size which is calculated as maximum of
target image cluster size and 64k. Default 0.
Since
6.0
BackupCommon (Object)
Members
job-id: string (optional)
identifier for the newly-created block job. If omitted, the de-
vice name will be used. (Since 2.7)
device: string
the device name or node-name of a root node which should be
copied.
sync: MirrorSyncMode
what parts of the disk image should be copied to the destination
(all the disk, only the sectors allocated in the topmost image,
from a dirty bitmap, or only new I/O).
speed: int (optional)
the maximum speed, in bytes per second. The default is 0, for
unlimited.
bitmap: string (optional)
The name of a dirty bitmap to use. Must be present if sync is
"bitmap" or "incremental". Can be present if sync is "full" or
"top". Must not be present otherwise. (Since 2.4
(drive-backup), 3.1 (blockdev-backup))
bitmap-mode: BitmapSyncMode (optional)
Specifies the type of data the bitmap should contain after the
operation concludes. Must be present if a bitmap was provided,
Must NOT be present otherwise. (Since 4.2)
compress: boolean (optional)
true to compress data, if the target format supports it. (de-
fault: false) (since 2.8)
on-source-error: BlockdevOnError (optional)
the action to take on an error on the source, default 'report'.
'stop' and 'enospc' can only be used if the block device sup-
ports io-status (see BlockInfo).
on-target-error: BlockdevOnError (optional)
the action to take on an error on the target, default 'report'
(no limitations, since this applies to a different block device
than device).
auto-finalize: boolean (optional)
When false, this job will wait in a PENDING state after it has
finished its work, waiting for block-job-finalize before making
any block graph changes. When true, this job will automatically
perform its abort or commit actions. Defaults to true. (Since
2.12)
auto-dismiss: boolean (optional)
When false, this job will wait in a CONCLUDED state after it has
completely ceased all work, and awaits block-job-dismiss. When
true, this job will automatically disappear from the query list
without user intervention. Defaults to true. (Since 2.12)
filter-node-name: string (optional)
the node name that should be assigned to the filter driver that
the backup job inserts into the graph above node specified by
drive. If this option is not given, a node name is autogener-
ated. (Since: 4.2)
x-perf: BackupPerf (optional)
Performance options. (Since 6.0)
Features
unstable
Member x-perf is experimental.
Note
on-source-error and on-target-error only affect background I/O. If an
error occurs during a guest write request, the device's rerror/werror
actions will be used.
Since
4.2
DriveBackup (Object)
Members
target: string
the target of the new image. If the file exists, or if it is a
device, the existing file/device will be used as the new desti-
nation. If it does not exist, a new file will be created.
format: string (optional)
the format of the new destination, default is to probe if mode
is 'existing', else the format of the source
mode: NewImageMode (optional)
whether and how QEMU should create a new image, default is 'ab-
solute-paths'.
The members of BackupCommon
Since
1.6
BlockdevBackup (Object)
Members
target: string
the device name or node-name of the backup target node.
The members of BackupCommon
Since
2.3
blockdev-snapshot-sync (Command)
Takes a synchronous snapshot of a block device.
For the arguments, see the documentation of BlockdevSnapshotSync.
Returns
• nothing on success
• If device is not a valid block device, DeviceNotFound
Since
0.14
Example
-> { "execute": "blockdev-snapshot-sync",
"arguments": { "device": "ide-hd0",
"snapshot-file":
"/some/place/my-image",
"format": "qcow2" } }
<- { "return": {} }
blockdev-snapshot (Command)
Takes a snapshot of a block device.
Take a snapshot, by installing 'node' as the backing image of 'over-
lay'. Additionally, if 'node' is associated with a block device, the
block device changes to using 'overlay' as its new active image.
For the arguments, see the documentation of BlockdevSnapshot.
Features
allow-write-only-overlay
If present, the check whether this operation is safe was relaxed
so that it can be used to change backing file of a destination
of a blockdev-mirror. (since 5.0)
Since
2.5
Example
-> { "execute": "blockdev-add",
"arguments": { "driver": "qcow2",
"node-name": "node1534",
"file": { "driver": "file",
"filename": "hd1.qcow2" },
"backing": null } }
<- { "return": {} }
-> { "execute": "blockdev-snapshot",
"arguments": { "node": "ide-hd0",
"overlay": "node1534" } }
<- { "return": {} }
change-backing-file (Command)
Change the backing file in the image file metadata. This does not
cause QEMU to reopen the image file to reparse the backing filename (it
may, however, perform a reopen to change permissions from r/o -> r/w ->
r/o, if needed). The new backing file string is written into the image
file metadata, and the QEMU internal strings are updated.
Arguments
image-node-name: string
The name of the block driver state node of the image to modify.
The "device" argument is used to verify "image-node-name" is in
the chain described by "device".
device: string
The device name or node-name of the root node that owns im-
age-node-name.
backing-file: string
The string to write as the backing file. This string is not
validated, so care should be taken when specifying the string or
the image chain may not be able to be reopened again.
Returns
• Nothing on success
• If "device" does not exist or cannot be determined, DeviceNotFound
Since
2.1
block-commit (Command)
Live commit of data from overlay image nodes into backing nodes - i.e.,
writes data between 'top' and 'base' into 'base'.
If top == base, that is an error. If top has no overlays on top of it,
or if it is in use by a writer, the job will not be completed by it-
self. The user needs to complete the job with the block-job-complete
command after getting the ready event. (Since 2.0)
If the base image is smaller than top, then the base image will be re-
sized to be the same size as top. If top is smaller than the base im-
age, the base will not be truncated. If you want the base image size
to match the size of the smaller top, you can safely truncate it your-
self once the commit operation successfully completes.
Arguments
job-id: string (optional)
identifier for the newly-created block job. If omitted, the de-
vice name will be used. (Since 2.7)
device: string
the device name or node-name of a root node
base-node: string (optional)
The node name of the backing image to write data into. If not
specified, this is the deepest backing image. (since: 3.1)
base: string (optional)
Same as base-node, except that it is a file name rather than a
node name. This must be the exact filename string that was used
to open the node; other strings, even if addressing the same
file, are not accepted
top-node: string (optional)
The node name of the backing image within the image chain which
contains the topmost data to be committed down. If not speci-
fied, this is the active layer. (since: 3.1)
top: string (optional)
Same as top-node, except that it is a file name rather than a
node name. This must be the exact filename string that was used
to open the node; other strings, even if addressing the same
file, are not accepted
backing-file: string (optional)
The backing file string to write into the overlay image of
'top'. If 'top' does not have an overlay image, or if 'top' is
in use by a writer, specifying a backing file string is an er-
ror.
This filename is not validated. If a pathname string is such
that it cannot be resolved by QEMU, that means that subsequent
QMP or HMP commands must use node-names for the image in ques-
tion, as filename lookup methods will fail.
If not specified, QEMU will automatically determine the backing
file string to use, or error out if there is no obvious choice.
Care should be taken when specifying the string, to specify a
valid filename or protocol. (Since 2.1)
speed: int (optional)
the maximum speed, in bytes per second
on-error: BlockdevOnError (optional)
the action to take on an error. 'ignore' means that the request
should be retried. (default: report; Since: 5.0)
filter-node-name: string (optional)
the node name that should be assigned to the filter driver that
the commit job inserts into the graph above top. If this option
is not given, a node name is autogenerated. (Since: 2.9)
auto-finalize: boolean (optional)
When false, this job will wait in a PENDING state after it has
finished its work, waiting for block-job-finalize before making
any block graph changes. When true, this job will automatically
perform its abort or commit actions. Defaults to true. (Since
3.1)
auto-dismiss: boolean (optional)
When false, this job will wait in a CONCLUDED state after it has
completely ceased all work, and awaits block-job-dismiss. When
true, this job will automatically disappear from the query list
without user intervention. Defaults to true. (Since 3.1)
Features
deprecated
Members base and top are deprecated. Use base-node and top-node
instead.
Returns
• Nothing on success
• If device does not exist, DeviceNotFound
• Any other error returns a GenericError.
Since
1.3
Example
-> { "execute": "block-commit",
"arguments": { "device": "virtio0",
"top": "/tmp/snap1.qcow2" } }
<- { "return": {} }
drive-backup (Command)
Start a point-in-time copy of a block device to a new destination. The
status of ongoing drive-backup operations can be checked with
query-block-jobs where the BlockJobInfo.type field has the value
'backup'. The operation can be stopped before it has completed using
the block-job-cancel command.
Arguments
The members of DriveBackup
Features
deprecated
This command is deprecated. Use blockdev-backup instead.
Returns
• nothing on success
• If device is not a valid block device, GenericError
Since
1.6
Example
-> { "execute": "drive-backup",
"arguments": { "device": "drive0",
"sync": "full",
"target": "backup.img" } }
<- { "return": {} }
blockdev-backup (Command)
Start a point-in-time copy of a block device to a new destination. The
status of ongoing blockdev-backup operations can be checked with
query-block-jobs where the BlockJobInfo.type field has the value
'backup'. The operation can be stopped before it has completed using
the block-job-cancel command.
Arguments
The members of BlockdevBackup
Returns
• nothing on success
• If device is not a valid block device, DeviceNotFound
Since
2.3
Example
-> { "execute": "blockdev-backup",
"arguments": { "device": "src-id",
"sync": "full",
"target": "tgt-id" } }
<- { "return": {} }
query-named-block-nodes (Command)
Get the named block driver list
Arguments
flat: boolean (optional)
Omit the nested data about backing image ("backing-image" key)
if true. Default is false (Since 5.0)
Returns
the list of BlockDeviceInfo
Since
2.0
Example
-> { "execute": "query-named-block-nodes" }
<- { "return": [ { "ro":false,
"drv":"qcow2",
"encrypted":false,
"file":"disks/test.qcow2",
"node-name": "my-node",
"backing_file_depth":1,
"detect_zeroes":"off",
"bps":1000000,
"bps_rd":0,
"bps_wr":0,
"iops":1000000,
"iops_rd":0,
"iops_wr":0,
"bps_max": 8000000,
"bps_rd_max": 0,
"bps_wr_max": 0,
"iops_max": 0,
"iops_rd_max": 0,
"iops_wr_max": 0,
"iops_size": 0,
"write_threshold": 0,
"image":{
"filename":"disks/test.qcow2",
"format":"qcow2",
"virtual-size":2048000,
"backing_file":"base.qcow2",
"full-backing-filename":"disks/base.qcow2",
"backing-filename-format":"qcow2",
"snapshots":[
{
"id": "1",
"name": "snapshot1",
"vm-state-size": 0,
"date-sec": 10000200,
"date-nsec": 12,
"vm-clock-sec": 206,
"vm-clock-nsec": 30
}
],
"backing-image":{
"filename":"disks/base.qcow2",
"format":"qcow2",
"virtual-size":2048000
}
} } ] }
XDbgBlockGraphNodeType (Enum)
Values
block-backend
corresponds to BlockBackend
block-job
corresponds to BlockJob
block-driver
corresponds to BlockDriverState
Since
4.0
XDbgBlockGraphNode (Object)
Members
id: int
Block graph node identifier. This id is generated only for x-de-
bug-query-block-graph and does not relate to any other identi-
fiers in Qemu.
type: XDbgBlockGraphNodeType
Type of graph node. Can be one of block-backend, block-job or
block-driver-state.
name: string
Human readable name of the node. Corresponds to node-name for
block-driver-state nodes; is not guaranteed to be unique in the
whole graph (with block-jobs and block-backends).
Since
4.0
BlockPermission (Enum)
Enum of base block permissions.
Values
consistent-read
A user that has the "permission" of consistent reads is guaran-
teed that their view of the contents of the block device is com-
plete and self-consistent, representing the contents of a disk
at a specific point. For most block devices (including their
backing files) this is true, but the property cannot be main-
tained in a few situations like for intermediate nodes of a com-
mit block job.
write This permission is required to change the visible disk contents.
write-unchanged
This permission (which is weaker than BLK_PERM_WRITE) is both
enough and required for writes to the block node when the caller
promises that the visible disk content doesn't change. As the
BLK_PERM_WRITE permission is strictly stronger, either is suffi-
cient to perform an unchanging write.
resize This permission is required to change the size of a block node.
Since
4.0
XDbgBlockGraphEdge (Object)
Block Graph edge description for x-debug-query-block-graph.
Members
parent: int
parent id
child: int
child id
name: string
name of the relation (examples are 'file' and 'backing')
perm: array of BlockPermission
granted permissions for the parent operating on the child
shared-perm: array of BlockPermission
permissions that can still be granted to other users of the
child while it is still attached to this parent
Since
4.0
XDbgBlockGraph (Object)
Block Graph - list of nodes and list of edges.
Members
nodes: array of XDbgBlockGraphNode
Not documented
edges: array of XDbgBlockGraphEdge
Not documented
Since
4.0
x-debug-query-block-graph (Command)
Get the block graph.
Features
unstable
This command is meant for debugging.
Since
4.0
drive-mirror (Command)
Start mirroring a block device's writes to a new destination. target
specifies the target of the new image. If the file exists, or if it is
a device, it will be used as the new destination for writes. If it does
not exist, a new file will be created. format specifies the format of
the mirror image, default is to probe if mode='existing', else the for-
mat of the source.
Arguments
The members of DriveMirror
Returns
• nothing on success
• If device is not a valid block device, GenericError
Since
1.3
Example
-> { "execute": "drive-mirror",
"arguments": { "device": "ide-hd0",
"target": "/some/place/my-image",
"sync": "full",
"format": "qcow2" } }
<- { "return": {} }
DriveMirror (Object)
A set of parameters describing drive mirror setup.
Members
job-id: string (optional)
identifier for the newly-created block job. If omitted, the de-
vice name will be used. (Since 2.7)
device: string
the device name or node-name of a root node whose writes should
be mirrored.
target: string
the target of the new image. If the file exists, or if it is a
device, the existing file/device will be used as the new desti-
nation. If it does not exist, a new file will be created.
format: string (optional)
the format of the new destination, default is to probe if mode
is 'existing', else the format of the source
node-name: string (optional)
the new block driver state node name in the graph (Since 2.1)
replaces: string (optional)
with sync=full graph node name to be replaced by the new image
when a whole image copy is done. This can be used to repair bro-
ken Quorum files. By default, device is replaced, although im-
plicitly created filters on it are kept. (Since 2.1)
mode: NewImageMode (optional)
whether and how QEMU should create a new image, default is 'ab-
solute-paths'.
speed: int (optional)
the maximum speed, in bytes per second
sync: MirrorSyncMode
what parts of the disk image should be copied to the destination
(all the disk, only the sectors allocated in the topmost image,
or only new I/O).
granularity: int (optional)
granularity of the dirty bitmap, default is 64K if the image
format doesn't have clusters, 4K if the clusters are smaller
than that, else the cluster size. Must be a power of 2 between
512 and 64M (since 1.4).
buf-size: int (optional)
maximum amount of data in flight from source to target (since
1.4).
on-source-error: BlockdevOnError (optional)
the action to take on an error on the source, default 'report'.
'stop' and 'enospc' can only be used if the block device sup-
ports io-status (see BlockInfo).
on-target-error: BlockdevOnError (optional)
the action to take on an error on the target, default 'report'
(no limitations, since this applies to a different block device
than device).
unmap: boolean (optional)
Whether to try to unmap target sectors where source has only
zero. If true, and target unallocated sectors will read as zero,
target image sectors will be unmapped; otherwise, zeroes will be
written. Both will result in identical contents. Default is
true. (Since 2.4)
copy-mode: MirrorCopyMode (optional)
when to copy data to the destination; defaults to 'background'
(Since: 3.0)
auto-finalize: boolean (optional)
When false, this job will wait in a PENDING state after it has
finished its work, waiting for block-job-finalize before making
any block graph changes. When true, this job will automatically
perform its abort or commit actions. Defaults to true. (Since
3.1)
auto-dismiss: boolean (optional)
When false, this job will wait in a CONCLUDED state after it has
completely ceased all work, and awaits block-job-dismiss. When
true, this job will automatically disappear from the query list
without user intervention. Defaults to true. (Since 3.1)
Since
1.3
BlockDirtyBitmap (Object)
Members
node: string
name of device/node which the bitmap is tracking
name: string
name of the dirty bitmap
Since
2.4
BlockDirtyBitmapAdd (Object)
Members
node: string
name of device/node which the bitmap is tracking
name: string
name of the dirty bitmap (must be less than 1024 bytes)
granularity: int (optional)
the bitmap granularity, default is 64k for block-dirty-bit-
map-add
persistent: boolean (optional)
the bitmap is persistent, i.e. it will be saved to the corre-
sponding block device image file on its close. For now only
Qcow2 disks support persistent bitmaps. Default is false for
block-dirty-bitmap-add. (Since: 2.10)
disabled: boolean (optional)
the bitmap is created in the disabled state, which means that it
will not track drive changes. The bitmap may be enabled with
block-dirty-bitmap-enable. Default is false. (Since: 4.0)
Since
2.4
BlockDirtyBitmapOrStr (Alternate)
Members
local: string
name of the bitmap, attached to the same node as target bitmap.
external: BlockDirtyBitmap
bitmap with specified node
Since
4.1
BlockDirtyBitmapMerge (Object)
Members
node: string
name of device/node which the target bitmap is tracking
target: string
name of the destination dirty bitmap
bitmaps: array of BlockDirtyBitmapOrStr
name(s) of the source dirty bitmap(s) at node and/or fully spec-
ified BlockDirtyBitmap elements. The latter are supported since
4.1.
Since
4.0
block-dirty-bitmap-add (Command)
Create a dirty bitmap with a name on the node, and start tracking the
writes.
Returns
• nothing on success
• If node is not a valid block device or node, DeviceNotFound
• If name is already taken, GenericError with an explanation
Since
2.4
Example
-> { "execute": "block-dirty-bitmap-add",
"arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }
block-dirty-bitmap-remove (Command)
Stop write tracking and remove the dirty bitmap that was created with
block-dirty-bitmap-add. If the bitmap is persistent, remove it from its
storage too.
Returns
• nothing on success
• If node is not a valid block device or node, DeviceNotFound
• If name is not found, GenericError with an explanation
• if name is frozen by an operation, GenericError
Since
2.4
Example
-> { "execute": "block-dirty-bitmap-remove",
"arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }
block-dirty-bitmap-clear (Command)
Clear (reset) a dirty bitmap on the device, so that an incremental
backup from this point in time forward will only backup clusters modi-
fied after this clear operation.
Returns
• nothing on success
• If node is not a valid block device, DeviceNotFound
• If name is not found, GenericError with an explanation
Since
2.4
Example
-> { "execute": "block-dirty-bitmap-clear",
"arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }
block-dirty-bitmap-enable (Command)
Enables a dirty bitmap so that it will begin tracking disk changes.
Returns
• nothing on success
• If node is not a valid block device, DeviceNotFound
• If name is not found, GenericError with an explanation
Since
4.0
Example
-> { "execute": "block-dirty-bitmap-enable",
"arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }
block-dirty-bitmap-disable (Command)
Disables a dirty bitmap so that it will stop tracking disk changes.
Returns
• nothing on success
• If node is not a valid block device, DeviceNotFound
• If name is not found, GenericError with an explanation
Since
4.0
Example
-> { "execute": "block-dirty-bitmap-disable",
"arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }
block-dirty-bitmap-merge (Command)
Merge dirty bitmaps listed in bitmaps to the target dirty bitmap.
Dirty bitmaps in bitmaps will be unchanged, except if it also appears
as the target bitmap. Any bits already set in target will still be set
after the merge, i.e., this operation does not clear the target. On
error, target is unchanged.
The resulting bitmap will count as dirty any clusters that were dirty
in any of the source bitmaps. This can be used to achieve backup check-
points, or in simpler usages, to copy bitmaps.
Returns
• nothing on success
• If node is not a valid block device, DeviceNotFound
• If any bitmap in bitmaps or target is not found, GenericError
• If any of the bitmaps have different sizes or granularities, Gener-
icError
Since
4.0
Example
-> { "execute": "block-dirty-bitmap-merge",
"arguments": { "node": "drive0", "target": "bitmap0",
"bitmaps": ["bitmap1"] } }
<- { "return": {} }
BlockDirtyBitmapSha256 (Object)
SHA256 hash of dirty bitmap data
Members
sha256: string
ASCII representation of SHA256 bitmap hash
Since
2.10
x-debug-block-dirty-bitmap-sha256 (Command)
Get bitmap SHA256.
Features
unstable
This command is meant for debugging.
Returns
• BlockDirtyBitmapSha256 on success
• If node is not a valid block device, DeviceNotFound
• If name is not found or if hashing has failed, GenericError with an
explanation
Since
2.10
blockdev-mirror (Command)
Start mirroring a block device's writes to a new destination.
Arguments
job-id: string (optional)
identifier for the newly-created block job. If omitted, the de-
vice name will be used. (Since 2.7)
device: string
The device name or node-name of a root node whose writes should
be mirrored.
target: string
the id or node-name of the block device to mirror to. This
mustn't be attached to guest.
replaces: string (optional)
with sync=full graph node name to be replaced by the new image
when a whole image copy is done. This can be used to repair bro-
ken Quorum files. By default, device is replaced, although im-
plicitly created filters on it are kept.
speed: int (optional)
the maximum speed, in bytes per second
sync: MirrorSyncMode
what parts of the disk image should be copied to the destination
(all the disk, only the sectors allocated in the topmost image,
or only new I/O).
granularity: int (optional)
granularity of the dirty bitmap, default is 64K if the image
format doesn't have clusters, 4K if the clusters are smaller
than that, else the cluster size. Must be a power of 2 between
512 and 64M
buf-size: int (optional)
maximum amount of data in flight from source to target
on-source-error: BlockdevOnError (optional)
the action to take on an error on the source, default 'report'.
'stop' and 'enospc' can only be used if the block device sup-
ports io-status (see BlockInfo).
on-target-error: BlockdevOnError (optional)
the action to take on an error on the target, default 'report'
(no limitations, since this applies to a different block device
than device).
filter-node-name: string (optional)
the node name that should be assigned to the filter driver that
the mirror job inserts into the graph above device. If this op-
tion is not given, a node name is autogenerated. (Since: 2.9)
copy-mode: MirrorCopyMode (optional)
when to copy data to the destination; defaults to 'background'
(Since: 3.0)
auto-finalize: boolean (optional)
When false, this job will wait in a PENDING state after it has
finished its work, waiting for block-job-finalize before making
any block graph changes. When true, this job will automatically
perform its abort or commit actions. Defaults to true. (Since
3.1)
auto-dismiss: boolean (optional)
When false, this job will wait in a CONCLUDED state after it has
completely ceased all work, and awaits block-job-dismiss. When
true, this job will automatically disappear from the query list
without user intervention. Defaults to true. (Since 3.1)
Returns
nothing on success.
Since
2.6
Example
-> { "execute": "blockdev-mirror",
"arguments": { "device": "ide-hd0",
"target": "target0",
"sync": "full" } }
<- { "return": {} }
BlockIOThrottle (Object)
A set of parameters describing block throttling.
Members
device: string (optional)
Block device name
id: string (optional)
The name or QOM path of the guest device (since: 2.8)
bps: int
total throughput limit in bytes per second
bps_rd: int
read throughput limit in bytes per second
bps_wr: int
write throughput limit in bytes per second
iops: int
total I/O operations per second
iops_rd: int
read I/O operations per second
iops_wr: int
write I/O operations per second
bps_max: int (optional)
total throughput limit during bursts, in bytes (Since 1.7)
bps_rd_max: int (optional)
read throughput limit during bursts, in bytes (Since 1.7)
bps_wr_max: int (optional)
write throughput limit during bursts, in bytes (Since 1.7)
iops_max: int (optional)
total I/O operations per second during bursts, in bytes (Since
1.7)
iops_rd_max: int (optional)
read I/O operations per second during bursts, in bytes (Since
1.7)
iops_wr_max: int (optional)
write I/O operations per second during bursts, in bytes (Since
1.7)
bps_max_length: int (optional)
maximum length of the bps_max burst period, in seconds. It must
only be set if bps_max is set as well. Defaults to 1. (Since
2.6)
bps_rd_max_length: int (optional)
maximum length of the bps_rd_max burst period, in seconds. It
must only be set if bps_rd_max is set as well. Defaults to 1.
(Since 2.6)
bps_wr_max_length: int (optional)
maximum length of the bps_wr_max burst period, in seconds. It
must only be set if bps_wr_max is set as well. Defaults to 1.
(Since 2.6)
iops_max_length: int (optional)
maximum length of the iops burst period, in seconds. It must
only be set if iops_max is set as well. Defaults to 1. (Since
2.6)
iops_rd_max_length: int (optional)
maximum length of the iops_rd_max burst period, in seconds. It
must only be set if iops_rd_max is set as well. Defaults to 1.
(Since 2.6)
iops_wr_max_length: int (optional)
maximum length of the iops_wr_max burst period, in seconds. It
must only be set if iops_wr_max is set as well. Defaults to 1.
(Since 2.6)
iops_size: int (optional)
an I/O size in bytes (Since 1.7)
group: string (optional)
throttle group name (Since 2.4)
Features
deprecated
Member device is deprecated. Use id instead.
Since
1.1
ThrottleLimits (Object)
Limit parameters for throttling. Since some limit combinations are il-
legal, limits should always be set in one transaction. All fields are
optional. When setting limits, if a field is missing the current value
is not changed.
Members
iops-total: int (optional)
limit total I/O operations per second
iops-total-max: int (optional)
I/O operations burst
iops-total-max-length: int (optional)
length of the iops-total-max burst period, in seconds It must
only be set if iops-total-max is set as well.
iops-read: int (optional)
limit read operations per second
iops-read-max: int (optional)
I/O operations read burst
iops-read-max-length: int (optional)
length of the iops-read-max burst period, in seconds It must
only be set if iops-read-max is set as well.
iops-write: int (optional)
limit write operations per second
iops-write-max: int (optional)
I/O operations write burst
iops-write-max-length: int (optional)
length of the iops-write-max burst period, in seconds It must
only be set if iops-write-max is set as well.
bps-total: int (optional)
limit total bytes per second
bps-total-max: int (optional)
total bytes burst
bps-total-max-length: int (optional)
length of the bps-total-max burst period, in seconds. It must
only be set if bps-total-max is set as well.
bps-read: int (optional)
limit read bytes per second
bps-read-max: int (optional)
total bytes read burst
bps-read-max-length: int (optional)
length of the bps-read-max burst period, in seconds It must only
be set if bps-read-max is set as well.
bps-write: int (optional)
limit write bytes per second
bps-write-max: int (optional)
total bytes write burst
bps-write-max-length: int (optional)
length of the bps-write-max burst period, in seconds It must
only be set if bps-write-max is set as well.
iops-size: int (optional)
when limiting by iops max size of an I/O in bytes
Since
2.11
ThrottleGroupProperties (Object)
Properties for throttle-group objects.
Members
limits: ThrottleLimits (optional)
limits to apply for this throttle group
x-iops-total: int (optional)
Not documented
x-iops-total-max: int (optional)
Not documented
x-iops-total-max-length: int (optional)
Not documented
x-iops-read: int (optional)
Not documented
x-iops-read-max: int (optional)
Not documented
x-iops-read-max-length: int (optional)
Not documented
x-iops-write: int (optional)
Not documented
x-iops-write-max: int (optional)
Not documented
x-iops-write-max-length: int (optional)
Not documented
x-bps-total: int (optional)
Not documented
x-bps-total-max: int (optional)
Not documented
x-bps-total-max-length: int (optional)
Not documented
x-bps-read: int (optional)
Not documented
x-bps-read-max: int (optional)
Not documented
x-bps-read-max-length: int (optional)
Not documented
x-bps-write: int (optional)
Not documented
x-bps-write-max: int (optional)
Not documented
x-bps-write-max-length: int (optional)
Not documented
x-iops-size: int (optional)
Not documented
Features
unstable
All members starting with x- are aliases for the same key with-
out x- in the limits object. This is not a stable interface and
may be removed or changed incompatibly in the future. Use lim-
its for a supported stable interface.
Since
2.11
block-stream (Command)
Copy data from a backing file into a block device.
The block streaming operation is performed in the background until the
entire backing file has been copied. This command returns immediately
once streaming has started. The status of ongoing block streaming op-
erations can be checked with query-block-jobs. The operation can be
stopped before it has completed using the block-job-cancel command.
The node that receives the data is called the top image, can be located
in any part of the chain (but always above the base image; see below)
and can be specified using its device or node name. Earlier qemu ver-
sions only allowed 'device' to name the top level node; presence of the
'base-node' parameter during introspection can be used as a witness of
the enhanced semantics of 'device'.
If a base file is specified then sectors are not copied from that base
file and its backing chain. This can be used to stream a subset of the
backing file chain instead of flattening the entire image. When
streaming completes the image file will have the base file as its back-
ing file, unless that node was changed while the job was running. In
that case, base's parent's backing (or filtered, whichever exists)
child (i.e., base at the beginning of the job) will be the new backing
file.
On successful completion the image file is updated to drop the backing
file and the BLOCK_JOB_COMPLETED event is emitted.
In case device is a filter node, block-stream modifies the first
non-filter overlay node below it to point to the new backing node in-
stead of modifying device itself.
Arguments
job-id: string (optional)
identifier for the newly-created block job. If omitted, the de-
vice name will be used. (Since 2.7)
device: string
the device or node name of the top image
base: string (optional)
the common backing file name. It cannot be set if base-node or
bottom is also set.
base-node: string (optional)
the node name of the backing file. It cannot be set if base or
bottom is also set. (Since 2.8)
bottom: string (optional)
the last node in the chain that should be streamed into top. It
cannot be set if base or base-node is also set. It cannot be
filter node. (Since 6.0)
backing-file: string (optional)
The backing file string to write into the top image. This file-
name is not validated.
If a pathname string is such that it cannot be resolved by QEMU,
that means that subsequent QMP or HMP commands must use
node-names for the image in question, as filename lookup methods
will fail.
If not specified, QEMU will automatically determine the backing
file string to use, or error out if there is no obvious choice.
Care should be taken when specifying the string, to specify a
valid filename or protocol. (Since 2.1)
speed: int (optional)
the maximum speed, in bytes per second
on-error: BlockdevOnError (optional)
the action to take on an error (default report). 'stop' and
'enospc' can only be used if the block device supports io-status
(see BlockInfo). Since 1.3.
filter-node-name: string (optional)
the node name that should be assigned to the filter driver that
the stream job inserts into the graph above device. If this op-
tion is not given, a node name is autogenerated. (Since: 6.0)
auto-finalize: boolean (optional)
When false, this job will wait in a PENDING state after it has
finished its work, waiting for block-job-finalize before making
any block graph changes. When true, this job will automatically
perform its abort or commit actions. Defaults to true. (Since
3.1)
auto-dismiss: boolean (optional)
When false, this job will wait in a CONCLUDED state after it has
completely ceased all work, and awaits block-job-dismiss. When
true, this job will automatically disappear from the query list
without user intervention. Defaults to true. (Since 3.1)
Returns
• Nothing on success.
• If device does not exist, DeviceNotFound.
Since
1.1
Example
-> { "execute": "block-stream",
"arguments": { "device": "virtio0",
"base": "/tmp/master.qcow2" } }
<- { "return": {} }
block-job-set-speed (Command)
Set maximum speed for a background block operation.
This command can only be issued when there is an active block job.
Throttling can be disabled by setting the speed to 0.
Arguments
device: string
The job identifier. This used to be a device name (hence the
name of the parameter), but since QEMU 2.7 it can have other
values.
speed: int
the maximum speed, in bytes per second, or 0 for unlimited. De-
faults to 0.
Returns
• Nothing on success
• If no background operation is active on this device, DeviceNotActive
Since
1.1
block-job-cancel (Command)
Stop an active background block operation.
This command returns immediately after marking the active background
block operation for cancellation. It is an error to call this command
if no operation is in progress.
The operation will cancel as soon as possible and then emit the
BLOCK_JOB_CANCELLED event. Before that happens the job is still visi-
ble when enumerated using query-block-jobs.
Note that if you issue 'block-job-cancel' after 'drive-mirror' has in-
dicated (via the event BLOCK_JOB_READY) that the source and destination
are synchronized, then the event triggered by this command changes to
BLOCK_JOB_COMPLETED, to indicate that the mirroring has ended and the
destination now has a point-in-time copy tied to the time of the can-
cellation.
For streaming, the image file retains its backing file unless the
streaming operation happens to complete just as it is being cancelled.
A new streaming operation can be started at a later time to finish
copying all data from the backing file.
Arguments
device: string
The job identifier. This used to be a device name (hence the
name of the parameter), but since QEMU 2.7 it can have other
values.
force: boolean (optional)
If true, and the job has already emitted the event
BLOCK_JOB_READY, abandon the job immediately (even if it is
paused) instead of waiting for the destination to complete its
final synchronization (since 1.3)
Returns
• Nothing on success
• If no background operation is active on this device, DeviceNotActive
Since
1.1
block-job-pause (Command)
Pause an active background block operation.
This command returns immediately after marking the active background
block operation for pausing. It is an error to call this command if no
operation is in progress or if the job is already paused.
The operation will pause as soon as possible. No event is emitted when
the operation is actually paused. Cancelling a paused job automati-
cally resumes it.
Arguments
device: string
The job identifier. This used to be a device name (hence the
name of the parameter), but since QEMU 2.7 it can have other
values.
Returns
• Nothing on success
• If no background operation is active on this device, DeviceNotActive
Since
1.3
block-job-resume (Command)
Resume an active background block operation.
This command returns immediately after resuming a paused background
block operation. It is an error to call this command if no operation
is in progress or if the job is not paused.
This command also clears the error status of the job.
Arguments
device: string
The job identifier. This used to be a device name (hence the
name of the parameter), but since QEMU 2.7 it can have other
values.
Returns
• Nothing on success
• If no background operation is active on this device, DeviceNotActive
Since
1.3
block-job-complete (Command)
Manually trigger completion of an active background block operation.
This is supported for drive mirroring, where it also switches the de-
vice to write to the target path only. The ability to complete is sig-
naled with a BLOCK_JOB_READY event.
This command completes an active background block operation syn-
chronously. The ordering of this command's return with the
BLOCK_JOB_COMPLETED event is not defined. Note that if an I/O error
occurs during the processing of this command: 1) the command itself
will fail; 2) the error will be processed according to the rerror/wer-
ror arguments that were specified when starting the operation.
A cancelled or paused job cannot be completed.
Arguments
device: string
The job identifier. This used to be a device name (hence the
name of the parameter), but since QEMU 2.7 it can have other
values.
Returns
• Nothing on success
• If no background operation is active on this device, DeviceNotActive
Since
1.3
block-job-dismiss (Command)
For jobs that have already concluded, remove them from the
block-job-query list. This command only needs to be run for jobs which
were started with QEMU 2.12+ job lifetime management semantics.
This command will refuse to operate on any job that has not yet reached
its terminal state, JOB_STATUS_CONCLUDED. For jobs that make use of the
BLOCK_JOB_READY event, block-job-cancel or block-job-complete will
still need to be used as appropriate.
Arguments
id: string
The job identifier.
Returns
Nothing on success
Since
2.12
block-job-finalize (Command)
Once a job that has manual=true reaches the pending state, it can be
instructed to finalize any graph changes and do any necessary cleanup
via this command. For jobs in a transaction, instructing one job to
finalize will force ALL jobs in the transaction to finalize, so it is
only necessary to instruct a single member job to finalize.
Arguments
id: string
The job identifier.
Returns
Nothing on success
Since
2.12
BlockdevDiscardOptions (Enum)
Determines how to handle discard requests.
Values
ignore Ignore the request
unmap Forward as an unmap request
Since
2.9
BlockdevDetectZeroesOptions (Enum)
Describes the operation mode for the automatic conversion of plain zero
writes by the OS to driver specific optimized zero write commands.
Values
off Disabled (default)
on Enabled
unmap Enabled and even try to unmap blocks if possible. This requires
also that BlockdevDiscardOptions is set to unmap for this de-
vice.
Since
2.1
BlockdevAioOptions (Enum)
Selects the AIO backend to handle I/O requests
Values
threads
Use qemu's thread pool
native Use native AIO backend (only Linux and Windows)
io_uring (If: CONFIG_LINUX_IO_URING)
Use linux io_uring (since 5.0)
Since
2.9
BlockdevCacheOptions (Object)
Includes cache-related options for block devices
Members
direct: boolean (optional)
enables use of O_DIRECT (bypass the host page cache; default:
false)
no-flush: boolean (optional)
ignore any flush requests for the device (default: false)
Since
2.9
BlockdevDriver (Enum)
Drivers that are supported in block device operations.
Values
throttle
Since 2.11
nvme Since 2.12
copy-on-read
Since 3.0
blklogwrites
Since 3.0
blkreplay
Since 4.2
compress
Since 5.0
copy-before-write
Since 6.2
snapshot-access
Since 7.0
blkdebug
Not documented
blkverify
Not documented
bochs Not documented
cloop Not documented
dmg Not documented
file Not documented
ftp Not documented
ftps Not documented
gluster
Not documented
host_cdrom (If: HAVE_HOST_BLOCK_DEVICE)
Not documented
host_device (If: HAVE_HOST_BLOCK_DEVICE)
Not documented
http Not documented
https Not documented
io_uring (If: CONFIG_BLKIO)
Not documented
iscsi Not documented
luks Not documented
nbd Not documented
nfs Not documented
null-aio
Not documented
null-co
Not documented
nvme-io_uring (If: CONFIG_BLKIO)
Not documented
parallels
Not documented
preallocate
Not documented
qcow Not documented
qcow2 Not documented
qed Not documented
quorum Not documented
raw Not documented
rbd Not documented
replication (If: CONFIG_REPLICATION)
Not documented
ssh Not documented
vdi Not documented
vhdx Not documented
virtio-blk-vfio-pci (If: CONFIG_BLKIO)
Not documented
virtio-blk-vhost-user (If: CONFIG_BLKIO)
Not documented
virtio-blk-vhost-vdpa (If: CONFIG_BLKIO)
Not documented
vmdk Not documented
vpc Not documented
vvfat Not documented
Since
2.9
BlockdevOptionsFile (Object)
Driver specific block device options for the file backend.
Members
filename: string
path to the image file
pr-manager: string (optional)
the id for the object that will handle persistent reservations
for this device (default: none, forward the commands via SG_IO;
since 2.11)
aio: BlockdevAioOptions (optional)
AIO backend (default: threads) (since: 2.8)
aio-max-batch: int (optional)
maximum number of requests to batch together into a single sub-
mission in the AIO backend. The smallest value between this and
the aio-max-batch value of the IOThread object is chosen. 0
means that the AIO backend will handle it automatically. (de-
fault: 0, since 6.2)
locking: OnOffAuto (optional)
whether to enable file locking. If set to 'auto', only enable
when Open File Descriptor (OFD) locking API is available (de-
fault: auto, since 2.10)
drop-cache: boolean (optional) (If: CONFIG_LINUX)
invalidate page cache during live migration. This prevents
stale data on the migration destination with cache.direct=off.
Currently only supported on Linux hosts. (default: on, since:
4.0)
x-check-cache-dropped: boolean (optional)
whether to check that page cache was dropped on live migration.
May cause noticeable delays if the image file is large, do not
use in production. (default: off) (since: 3.0)
Features
dynamic-auto-read-only
If present, enabled auto-read-only means that the driver will
open the image read-only at first, dynamically reopen the image
file read-write when the first writer is attached to the node
and reopen read-only when the last writer is detached. This al-
lows giving QEMU write permissions only on demand when an opera-
tion actually needs write access.
unstable
Member x-check-cache-dropped is meant for debugging.
Since
2.9
BlockdevOptionsNull (Object)
Driver specific block device options for the null backend.
Members
size: int (optional)
size of the device in bytes.
latency-ns: int (optional)
emulated latency (in nanoseconds) in processing requests. De-
fault to zero which completes requests immediately. (Since 2.4)
read-zeroes: boolean (optional)
if true, reads from the device produce zeroes; if false, the
buffer is left unchanged. (default: false; since: 4.1)
Since
2.9
BlockdevOptionsNVMe (Object)
Driver specific block device options for the NVMe backend.
Members
device: string
PCI controller address of the NVMe device in format hhhh:bb:ss.f
(host:bus:slot.function)
namespace: int
namespace number of the device, starting from 1.
Note that the PCI device must have been unbound from any host kernel
driver before instructing QEMU to add the blockdev.
Since
2.12
BlockdevOptionsVVFAT (Object)
Driver specific block device options for the vvfat protocol.
Members
dir: string
directory to be exported as FAT image
fat-type: int (optional)
FAT type: 12, 16 or 32
floppy: boolean (optional)
whether to export a floppy image (true) or partitioned hard disk
(false; default)
label: string (optional)
set the volume label, limited to 11 bytes. FAT16 and FAT32 tra-
ditionally have some restrictions on labels, which are ignored
by most operating systems. Defaults to "QEMU VVFAT". (since
2.4)
rw: boolean (optional)
whether to allow write operations (default: false)
Since
2.9
BlockdevOptionsGenericFormat (Object)
Driver specific block device options for image format that have no op-
tion besides their data source.
Members
file: BlockdevRef
reference to or definition of the data source block device
Since
2.9
BlockdevOptionsLUKS (Object)
Driver specific block device options for LUKS.
Members
key-secret: string (optional)
the ID of a QCryptoSecret object providing the decryption key
(since 2.6). Mandatory except when doing a metadata-only probe
of the image.
The members of BlockdevOptionsGenericFormat
Since
2.9
BlockdevOptionsGenericCOWFormat (Object)
Driver specific block device options for image format that have no op-
tion besides their data source and an optional backing file.
Members
backing: BlockdevRefOrNull (optional)
reference to or definition of the backing file block device,
null disables the backing file entirely. Defaults to the back-
ing file stored the image file.
The members of BlockdevOptionsGenericFormat
Since
2.9
Qcow2OverlapCheckMode (Enum)
General overlap check modes.
Values
none Do not perform any checks
constant
Perform only checks which can be done in constant time and with-
out reading anything from disk
cached Perform only checks which can be done without reading anything
from disk
all Perform all available overlap checks
Since
2.9
Qcow2OverlapCheckFlags (Object)
Structure of flags for each metadata structure. Setting a field to
'true' makes qemu guard that structure against unintended overwriting.
The default value is chosen according to the template given.
Members
template: Qcow2OverlapCheckMode (optional)
Specifies a template mode which can be adjusted using the other
flags, defaults to 'cached'
bitmap-directory: boolean (optional)
since 3.0
main-header: boolean (optional)
Not documented
active-l1: boolean (optional)
Not documented
active-l2: boolean (optional)
Not documented
refcount-table: boolean (optional)
Not documented
refcount-block: boolean (optional)
Not documented
snapshot-table: boolean (optional)
Not documented
inactive-l1: boolean (optional)
Not documented
inactive-l2: boolean (optional)
Not documented
Since
2.9
Qcow2OverlapChecks (Alternate)
Specifies which metadata structures should be guarded against unin-
tended overwriting.
Members
flags: Qcow2OverlapCheckFlags
set of flags for separate specification of each metadata struc-
ture type
mode: Qcow2OverlapCheckMode
named mode which chooses a specific set of flags
Since
2.9
BlockdevQcowEncryptionFormat (Enum)
Values
aes AES-CBC with plain64 initialization vectors
Since
2.10
BlockdevQcowEncryption (Object)
Members
format: BlockdevQcowEncryptionFormat
Not documented
The members of QCryptoBlockOptionsQCow when format is "aes"
Since
2.10
BlockdevOptionsQcow (Object)
Driver specific block device options for qcow.
Members
encrypt: BlockdevQcowEncryption (optional)
Image decryption options. Mandatory for encrypted images, except
when doing a metadata-only probe of the image.
The members of BlockdevOptionsGenericCOWFormat
Since
2.10
BlockdevQcow2EncryptionFormat (Enum)
Values
aes AES-CBC with plain64 initialization vectors
luks Not documented
Since
2.10
BlockdevQcow2Encryption (Object)
Members
format: BlockdevQcow2EncryptionFormat
Not documented
The members of QCryptoBlockOptionsQCow when format is "aes"
The members of QCryptoBlockOptionsLUKS when format is "luks"
Since
2.10
BlockdevOptionsPreallocate (Object)
Filter driver intended to be inserted between format and protocol node
and do preallocation in protocol node on write.
Members
prealloc-align: int (optional)
on preallocation, align file length to this number, default
1048576 (1M)
prealloc-size: int (optional)
how much to preallocate, default 134217728 (128M)
The members of BlockdevOptionsGenericFormat
Since
6.0
BlockdevOptionsQcow2 (Object)
Driver specific block device options for qcow2.
Members
lazy-refcounts: boolean (optional)
whether to enable the lazy refcounts feature (default is taken
from the image file)
pass-discard-request: boolean (optional)
whether discard requests to the qcow2 device should be forwarded
to the data source
pass-discard-snapshot: boolean (optional)
whether discard requests for the data source should be issued
when a snapshot operation (e.g. deleting a snapshot) frees
clusters in the qcow2 file
pass-discard-other: boolean (optional)
whether discard requests for the data source should be issued on
other occasions where a cluster gets freed
overlap-check: Qcow2OverlapChecks (optional)
which overlap checks to perform for writes to the image, de-
faults to 'cached' (since 2.2)
cache-size: int (optional)
the maximum total size of the L2 table and refcount block caches
in bytes (since 2.2)
l2-cache-size: int (optional)
the maximum size of the L2 table cache in bytes (since 2.2)
l2-cache-entry-size: int (optional)
the size of each entry in the L2 cache in bytes. It must be a
power of two between 512 and the cluster size. The default value
is the cluster size (since 2.12)
refcount-cache-size: int (optional)
the maximum size of the refcount block cache in bytes (since
2.2)
cache-clean-interval: int (optional)
clean unused entries in the L2 and refcount caches. The interval
is in seconds. The default value is 600 on supporting platforms,
and 0 on other platforms. 0 disables this feature. (since 2.5)
encrypt: BlockdevQcow2Encryption (optional)
Image decryption options. Mandatory for encrypted images, except
when doing a metadata-only probe of the image. (since 2.10)
data-file: BlockdevRef (optional)
reference to or definition of the external data file. This may
only be specified for images that require an external data file.
If it is not specified for such an image, the data file name is
loaded from the image file. (since 4.0)
The members of BlockdevOptionsGenericCOWFormat
Since
2.9
SshHostKeyCheckMode (Enum)
Values
none Don't check the host key at all
hash Compare the host key with a given hash
known_hosts
Check the host key against the known_hosts file
Since
2.12
SshHostKeyCheckHashType (Enum)
Values
md5 The given hash is an md5 hash
sha1 The given hash is an sha1 hash
sha256 The given hash is an sha256 hash
Since
2.12
SshHostKeyHash (Object)
Members
type: SshHostKeyCheckHashType
The hash algorithm used for the hash
hash: string
The expected hash value
Since
2.12
SshHostKeyCheck (Object)
Members
mode: SshHostKeyCheckMode
Not documented
The members of SshHostKeyHash when mode is "hash"
Since
2.12
BlockdevOptionsSsh (Object)
Members
server: InetSocketAddress
host address
path: string
path to the image on the host
user: string (optional)
user as which to connect, defaults to current local user name
host-key-check: SshHostKeyCheck (optional)
Defines how and what to check the host key against (default:
known_hosts)
Since
2.9
BlkdebugEvent (Enum)
Trigger events supported by blkdebug.
Values
l1_shrink_write_table
write zeros to the l1 table to shrink image. (since 2.11)
l1_shrink_free_l2_clusters
discard the l2 tables. (since 2.11)
cor_write
a write due to copy-on-read (since 2.11)
cluster_alloc_space
an allocation of file space for a cluster (since 4.1)
none triggers once at creation of the blkdebug node (since 4.1)
l1_update
Not documented
l1_grow_alloc_table
Not documented
l1_grow_write_table
Not documented
l1_grow_activate_table
Not documented
l2_load
Not documented
l2_update
Not documented
l2_update_compressed
Not documented
l2_alloc_cow_read
Not documented
l2_alloc_write
Not documented
read_aio
Not documented
read_backing_aio
Not documented
read_compressed
Not documented
write_aio
Not documented
write_compressed
Not documented
vmstate_load
Not documented
vmstate_save
Not documented
cow_read
Not documented
cow_write
Not documented
reftable_load
Not documented
reftable_grow
Not documented
reftable_update
Not documented
refblock_load
Not documented
refblock_update
Not documented
refblock_update_part
Not documented
refblock_alloc
Not documented
refblock_alloc_hookup
Not documented
refblock_alloc_write
Not documented
refblock_alloc_write_blocks
Not documented
refblock_alloc_write_table
Not documented
refblock_alloc_switch_table
Not documented
cluster_alloc
Not documented
cluster_alloc_bytes
Not documented
cluster_free
Not documented
flush_to_os
Not documented
flush_to_disk
Not documented
pwritev_rmw_head
Not documented
pwritev_rmw_after_head
Not documented
pwritev_rmw_tail
Not documented
pwritev_rmw_after_tail
Not documented
pwritev
Not documented
pwritev_zero
Not documented
pwritev_done
Not documented
empty_image_prepare
Not documented
Since
2.9
BlkdebugIOType (Enum)
Kinds of I/O that blkdebug can inject errors in.
Values
read .bdrv_co_preadv()
write .bdrv_co_pwritev()
write-zeroes
.bdrv_co_pwrite_zeroes()
discard
.bdrv_co_pdiscard()
flush .bdrv_co_flush_to_disk()
block-status
.bdrv_co_block_status()
Since
4.1
BlkdebugInjectErrorOptions (Object)
Describes a single error injection for blkdebug.
Members
event: BlkdebugEvent
trigger event
state: int (optional)
the state identifier blkdebug needs to be in to actually trigger
the event; defaults to "any"
iotype: BlkdebugIOType (optional)
the type of I/O operations on which this error should be in-
jected; defaults to "all read, write, write-zeroes, discard, and
flush operations" (since: 4.1)
errno: int (optional)
error identifier (errno) to be returned; defaults to EIO
sector: int (optional)
specifies the sector index which has to be affected in order to
actually trigger the event; defaults to "any sector"
once: boolean (optional)
disables further events after this one has been triggered; de-
faults to false
immediately: boolean (optional)
fail immediately; defaults to false
Since
2.9
BlkdebugSetStateOptions (Object)
Describes a single state-change event for blkdebug.
Members
event: BlkdebugEvent
trigger event
state: int (optional)
the current state identifier blkdebug needs to be in; defaults
to "any"
new_state: int
the state identifier blkdebug is supposed to assume if this
event is triggered
Since
2.9
BlockdevOptionsBlkdebug (Object)
Driver specific block device options for blkdebug.
Members
image: BlockdevRef
underlying raw block device (or image file)
config: string (optional)
filename of the configuration file
align: int (optional)
required alignment for requests in bytes, must be positive power
of 2, or 0 for default
max-transfer: int (optional)
maximum size for I/O transfers in bytes, must be positive multi-
ple of align and of the underlying file's request alignment (but
need not be a power of 2), or 0 for default (since 2.10)
opt-write-zero: int (optional)
preferred alignment for write zero requests in bytes, must be
positive multiple of align and of the underlying file's request
alignment (but need not be a power of 2), or 0 for default
(since 2.10)
max-write-zero: int (optional)
maximum size for write zero requests in bytes, must be positive
multiple of align, of opt-write-zero, and of the underlying
file's request alignment (but need not be a power of 2), or 0
for default (since 2.10)
opt-discard: int (optional)
preferred alignment for discard requests in bytes, must be posi-
tive multiple of align and of the underlying file's request
alignment (but need not be a power of 2), or 0 for default
(since 2.10)
max-discard: int (optional)
maximum size for discard requests in bytes, must be positive
multiple of align, of opt-discard, and of the underlying file's
request alignment (but need not be a power of 2), or 0 for de-
fault (since 2.10)
inject-error: array of BlkdebugInjectErrorOptions (optional)
array of error injection descriptions
set-state: array of BlkdebugSetStateOptions (optional)
array of state-change descriptions
take-child-perms: array of BlockPermission (optional)
Permissions to take on image in addition to what is necessary
anyway (which depends on how the blkdebug node is used). De-
faults to none. (since 5.0)
unshare-child-perms: array of BlockPermission (optional)
Permissions not to share on image in addition to what cannot be
shared anyway (which depends on how the blkdebug node is used).
Defaults to none. (since 5.0)
Since
2.9
BlockdevOptionsBlklogwrites (Object)
Driver specific block device options for blklogwrites.
Members
file: BlockdevRef
block device
log: BlockdevRef
block device used to log writes to file
log-sector-size: int (optional)
sector size used in logging writes to file, determines granular-
ity of offsets and sizes of writes (default: 512)
log-append: boolean (optional)
append to an existing log (default: false)
log-super-update-interval: int (optional)
interval of write requests after which the log super block is
updated to disk (default: 4096)
Since
3.0
BlockdevOptionsBlkverify (Object)
Driver specific block device options for blkverify.
Members
test: BlockdevRef
block device to be tested
raw: BlockdevRef
raw image used for verification
Since
2.9
BlockdevOptionsBlkreplay (Object)
Driver specific block device options for blkreplay.
Members
image: BlockdevRef
disk image which should be controlled with blkreplay
Since
4.2
QuorumReadPattern (Enum)
An enumeration of quorum read patterns.
Values
quorum read all the children and do a quorum vote on reads
fifo read only from the first child that has not failed
Since
2.9
BlockdevOptionsQuorum (Object)
Driver specific block device options for Quorum
Members
blkverify: boolean (optional)
true if the driver must print content mismatch
set to false by default
children: array of BlockdevRef
the children block devices to use
vote-threshold: int
the vote limit under which a read will fail
rewrite-corrupted: boolean (optional)
rewrite corrupted data when quorum is reached (Since 2.1)
read-pattern: QuorumReadPattern (optional)
choose read pattern and set to quorum by default (Since 2.2)
Since
2.9
BlockdevOptionsGluster (Object)
Driver specific block device options for Gluster
Members
volume: string
name of gluster volume where VM image resides
path: string
absolute path to image file in gluster volume
server: array of SocketAddress
gluster servers description
debug: int (optional)
libgfapi log level (default '4' which is Error) (Since 2.8)
logfile: string (optional)
libgfapi log file (default /dev/stderr) (Since 2.8)
Since
2.9
BlockdevOptionsIoUring (Object)
Driver specific block device options for the io_uring backend.
Members
filename: string
path to the image file
Since
7.2
If
CONFIG_BLKIO
BlockdevOptionsNvmeIoUring (Object)
Driver specific block device options for the nvme-io_uring backend.
Members
path: string
path to the NVMe namespace's character device (e.g. /dev/ng0n1).
Since
7.2
If
CONFIG_BLKIO
BlockdevOptionsVirtioBlkVfioPci (Object)
Driver specific block device options for the virtio-blk-vfio-pci back-
end.
Members
path: string
path to the PCI device's sysfs directory (e.g. /sys/bus/pci/de-
vices/0000:00:01.0).
Since
7.2
If
CONFIG_BLKIO
BlockdevOptionsVirtioBlkVhostUser (Object)
Driver specific block device options for the virtio-blk-vhost-user
backend.
Members
path: string
path to the vhost-user UNIX domain socket.
Since
7.2
If
CONFIG_BLKIO
BlockdevOptionsVirtioBlkVhostVdpa (Object)
Driver specific block device options for the virtio-blk-vhost-vdpa
backend.
Members
path: string
path to the vhost-vdpa character device.
Since
7.2
If
CONFIG_BLKIO
IscsiTransport (Enum)
An enumeration of libiscsi transport types
Values
tcp Not documented
iser Not documented
Since
2.9
IscsiHeaderDigest (Enum)
An enumeration of header digests supported by libiscsi
Values
crc32c Not documented
none Not documented
crc32c-none
Not documented
none-crc32c
Not documented
Since
2.9
BlockdevOptionsIscsi (Object)
Members
transport: IscsiTransport
The iscsi transport type
portal: string
The address of the iscsi portal
target: string
The target iqn name
lun: int (optional)
LUN to connect to. Defaults to 0.
user: string (optional)
User name to log in with. If omitted, no CHAP authentication is
performed.
password-secret: string (optional)
The ID of a QCryptoSecret object providing the password for the
login. This option is required if user is specified.
initiator-name: string (optional)
The iqn name we want to identify to the target as. If this op-
tion is not specified, an initiator name is generated automati-
cally.
header-digest: IscsiHeaderDigest (optional)
The desired header digest. Defaults to none-crc32c.
timeout: int (optional)
Timeout in seconds after which a request will timeout. 0 means
no timeout and is the default.
Driver specific block device options for iscsi
Since
2.9
RbdAuthMode (Enum)
Values
cephx Not documented
none Not documented
Since
3.0
RbdImageEncryptionFormat (Enum)
Values
luks Not documented
luks2 Not documented
Since
6.1
RbdEncryptionOptionsLUKSBase (Object)
Members
key-secret: string
ID of a QCryptoSecret object providing a passphrase for unlock-
ing the encryption
Since
6.1
RbdEncryptionCreateOptionsLUKSBase (Object)
Members
cipher-alg: QCryptoCipherAlgorithm (optional)
The encryption algorithm
The members of RbdEncryptionOptionsLUKSBase
Since
6.1
RbdEncryptionOptionsLUKS (Object)
Members
The members of RbdEncryptionOptionsLUKSBase
Since
6.1
RbdEncryptionOptionsLUKS2 (Object)
Members
The members of RbdEncryptionOptionsLUKSBase
Since
6.1
RbdEncryptionCreateOptionsLUKS (Object)
Members
The members of RbdEncryptionCreateOptionsLUKSBase
Since
6.1
RbdEncryptionCreateOptionsLUKS2 (Object)
Members
The members of RbdEncryptionCreateOptionsLUKSBase
Since
6.1
RbdEncryptionOptions (Object)
Members
format: RbdImageEncryptionFormat
Not documented
The members of RbdEncryptionOptionsLUKS when format is "luks"
The members of RbdEncryptionOptionsLUKS2 when format is "luks2"
Since
6.1
RbdEncryptionCreateOptions (Object)
Members
format: RbdImageEncryptionFormat
Not documented
The members of RbdEncryptionCreateOptionsLUKS when format is "luks"
The members of RbdEncryptionCreateOptionsLUKS2 when format is "luks2"
Since
6.1
BlockdevOptionsRbd (Object)
Members
pool: string
Ceph pool name.
namespace: string (optional)
Rados namespace name in the Ceph pool. (Since 5.0)
image: string
Image name in the Ceph pool.
conf: string (optional)
path to Ceph configuration file. Values in the configuration
file will be overridden by options specified via QAPI.
snapshot: string (optional)
Ceph snapshot name.
encrypt: RbdEncryptionOptions (optional)
Image encryption options. (Since 6.1)
user: string (optional)
Ceph id name.
auth-client-required: array of RbdAuthMode (optional)
Acceptable authentication modes. This maps to Ceph configura-
tion option "auth_client_required". (Since 3.0)
key-secret: string (optional)
ID of a QCryptoSecret object providing a key for cephx authenti-
cation. This maps to Ceph configuration option "key". (Since
3.0)
server: array of InetSocketAddressBase (optional)
Monitor host address and port. This maps to the "mon_host" Ceph
option.
Since
2.9
ReplicationMode (Enum)
An enumeration of replication modes.
Values
primary
Primary mode, the vm's state will be sent to secondary QEMU.
secondary
Secondary mode, receive the vm's state from primary QEMU.
Since
2.9
If
CONFIG_REPLICATION
BlockdevOptionsReplication (Object)
Driver specific block device options for replication
Members
mode: ReplicationMode
the replication mode
top-id: string (optional)
In secondary mode, node name or device ID of the root node who
owns the replication node chain. Must not be given in primary
mode.
The members of BlockdevOptionsGenericFormat
Since
2.9
If
CONFIG_REPLICATION
NFSTransport (Enum)
An enumeration of NFS transport types
Values
inet TCP transport
Since
2.9
NFSServer (Object)
Captures the address of the socket
Members
type: NFSTransport
transport type used for NFS (only TCP supported)
host: string
host address for NFS server
Since
2.9
BlockdevOptionsNfs (Object)
Driver specific block device option for NFS
Members
server: NFSServer
host address
path: string
path of the image on the host
user: int (optional)
UID value to use when talking to the server (defaults to 65534
on Windows and getuid() on unix)
group: int (optional)
GID value to use when talking to the server (defaults to 65534
on Windows and getgid() in unix)
tcp-syn-count: int (optional)
number of SYNs during the session establishment (defaults to
libnfs default)
readahead-size: int (optional)
set the readahead size in bytes (defaults to libnfs default)
page-cache-size: int (optional)
set the pagecache size in bytes (defaults to libnfs default)
debug: int (optional)
set the NFS debug level (max 2) (defaults to libnfs default)
Since
2.9
BlockdevOptionsCurlBase (Object)
Driver specific block device options shared by all protocols supported
by the curl backend.
Members
url: string
URL of the image file
readahead: int (optional)
Size of the read-ahead cache; must be a multiple of 512 (de-
faults to 256 kB)
timeout: int (optional)
Timeout for connections, in seconds (defaults to 5)
username: string (optional)
Username for authentication (defaults to none)
password-secret: string (optional)
ID of a QCryptoSecret object providing a password for authenti-
cation (defaults to no password)
proxy-username: string (optional)
Username for proxy authentication (defaults to none)
proxy-password-secret: string (optional)
ID of a QCryptoSecret object providing a password for proxy au-
thentication (defaults to no password)
Since
2.9
BlockdevOptionsCurlHttp (Object)
Driver specific block device options for HTTP connections over the curl
backend. URLs must start with "http://".
Members
cookie: string (optional)
List of cookies to set; format is "name1=content1; name2=con-
tent2;" as explained by CURLOPT_COOKIE(3). Defaults to no cook-
ies.
cookie-secret: string (optional)
ID of a QCryptoSecret object providing the cookie data in a se-
cure way. See cookie for the format. (since 2.10)
The members of BlockdevOptionsCurlBase
Since
2.9
BlockdevOptionsCurlHttps (Object)
Driver specific block device options for HTTPS connections over the
curl backend. URLs must start with "https://".
Members
cookie: string (optional)
List of cookies to set; format is "name1=content1; name2=con-
tent2;" as explained by CURLOPT_COOKIE(3). Defaults to no cook-
ies.
sslverify: boolean (optional)
Whether to verify the SSL certificate's validity (defaults to
true)
cookie-secret: string (optional)
ID of a QCryptoSecret object providing the cookie data in a se-
cure way. See cookie for the format. (since 2.10)
The members of BlockdevOptionsCurlBase
Since
2.9
BlockdevOptionsCurlFtp (Object)
Driver specific block device options for FTP connections over the curl
backend. URLs must start with "ftp://".
Members
The members of BlockdevOptionsCurlBase
Since
2.9
BlockdevOptionsCurlFtps (Object)
Driver specific block device options for FTPS connections over the curl
backend. URLs must start with "ftps://".
Members
sslverify: boolean (optional)
Whether to verify the SSL certificate's validity (defaults to
true)
The members of BlockdevOptionsCurlBase
Since
2.9
BlockdevOptionsNbd (Object)
Driver specific block device options for NBD.
Members
server: SocketAddress
NBD server address
export: string (optional)
export name
tls-creds: string (optional)
TLS credentials ID
tls-hostname: string (optional)
TLS hostname override for certificate validation (Since 7.0)
x-dirty-bitmap: string (optional)
A metadata context name such as "qemu:dirty-bitmap:NAME" or
"qemu:allocation-depth" to query in place of the traditional
"base:allocation" block status (see NBD_OPT_LIST_META_CONTEXT in
the NBD protocol; and yes, naming this option x-context would
have made more sense) (since 3.0)
reconnect-delay: int (optional)
On an unexpected disconnect, the nbd client tries to connect
again until succeeding or encountering a serious error. During
the first reconnect-delay seconds, all requests are paused and
will be rerun on a successful reconnect. After that time, any
delayed requests and all future requests before a successful re-
connect will immediately fail. Default 0 (Since 4.2)
open-timeout: int (optional)
In seconds. If zero, the nbd driver tries the connection only
once, and fails to open if the connection fails. If non-zero,
the nbd driver will repeat connection attempts until successful
or until open-timeout seconds have elapsed. Default 0 (Since
7.0)
Features
unstable
Member x-dirty-bitmap is experimental.
Since
2.9
BlockdevOptionsRaw (Object)
Driver specific block device options for the raw driver.
Members
offset: int (optional)
position where the block device starts
size: int (optional)
the assumed size of the device
The members of BlockdevOptionsGenericFormat
Since
2.9
BlockdevOptionsThrottle (Object)
Driver specific block device options for the throttle driver
Members
throttle-group: string
the name of the throttle-group object to use. It must already
exist.
file: BlockdevRef
reference to or definition of the data source block device
Since
2.11
BlockdevOptionsCor (Object)
Driver specific block device options for the copy-on-read driver.
Members
bottom: string (optional)
The name of a non-filter node (allocation-bearing layer) that
limits the COR operations in the backing chain (inclusive), so
that no data below this node will be copied by this filter. If
option is absent, the limit is not applied, so that data from
all backing layers may be copied.
The members of BlockdevOptionsGenericFormat
Since
6.0
OnCbwError (Enum)
An enumeration of possible behaviors for copy-before-write operation
failures.
Values
break-guest-write
report the error to the guest. This way, the guest will not be
able to overwrite areas that cannot be backed up, so the backup
process remains valid.
break-snapshot
continue guest write. Doing so will make the provided snapshot
state invalid and any backup or export process based on it will
finally fail.
Since
7.1
BlockdevOptionsCbw (Object)
Driver specific block device options for the copy-before-write driver,
which does so called copy-before-write operations: when data is written
to the filter, the filter first reads corresponding blocks from its
file child and copies them to target child. After successfully copying,
the write request is propagated to file child. If copying fails, the
original write request is failed too and no data is written to file
child.
Members
target: BlockdevRef
The target for copy-before-write operations.
bitmap: BlockDirtyBitmap (optional)
If specified, copy-before-write filter will do copy-before-write
operations only for dirty regions of the bitmap. Bitmap size
must be equal to length of file and target child of the filter.
Note also, that bitmap is used only to initialize internal bit-
map of the process, so further modifications (or removing) of
specified bitmap doesn't influence the filter. (Since 7.0)
on-cbw-error: OnCbwError (optional)
Behavior on failure of copy-before-write operation. Default is
break-guest-write. (Since 7.1)
cbw-timeout: int (optional)
Zero means no limit. Non-zero sets the timeout in seconds for
copy-before-write operation. When a timeout occurs, the respec-
tive copy-before-write operation will fail, and the on-cbw-error
parameter will decide how this failure is handled. Default 0.
(Since 7.1)
The members of BlockdevOptionsGenericFormat
Since
6.2
BlockdevOptions (Object)
Options for creating a block device. Many options are available for
all block devices, independent of the block driver:
Members
driver: BlockdevDriver
block driver name
node-name: string (optional)
the node name of the new node (Since 2.0). This option is re-
quired on the top level of blockdev-add. Valid node names start
with an alphabetic character and may contain only alphanumeric
characters, '-', '.' and '_'. Their maximum length is 31 charac-
ters.
discard: BlockdevDiscardOptions (optional)
discard-related options (default: ignore)
cache: BlockdevCacheOptions (optional)
cache-related options
read-only: boolean (optional)
whether the block device should be read-only (default: false).
Note that some block drivers support only read-only access, ei-
ther generally or in certain configurations. In this case, the
default value does not work and the option must be specified ex-
plicitly.
auto-read-only: boolean (optional)
if true and read-only is false, QEMU may automatically decide
not to open the image read-write as requested, but fall back to
read-only instead (and switch between the modes later), e.g. de-
pending on whether the image file is writable or whether a writ-
ing user is attached to the node (default: false, since 3.1)
detect-zeroes: BlockdevDetectZeroesOptions (optional)
detect and optimize zero writes (Since 2.1) (default: off)
force-share: boolean (optional)
force share all permission on added nodes. Requires
read-only=true. (Since 2.10)
The members of BlockdevOptionsBlkdebug when driver is "blkdebug"
The members of BlockdevOptionsBlklogwrites when driver is "blklog-
writes"
The members of BlockdevOptionsBlkverify when driver is "blkverify"
The members of BlockdevOptionsBlkreplay when driver is "blkreplay"
The members of BlockdevOptionsGenericFormat when driver is "bochs"
The members of BlockdevOptionsGenericFormat when driver is "cloop"
The members of BlockdevOptionsGenericFormat when driver is "compress"
The members of BlockdevOptionsCbw when driver is "copy-before-write"
The members of BlockdevOptionsCor when driver is "copy-on-read"
The members of BlockdevOptionsGenericFormat when driver is "dmg"
The members of BlockdevOptionsFile when driver is "file"
The members of BlockdevOptionsCurlFtp when driver is "ftp"
The members of BlockdevOptionsCurlFtps when driver is "ftps"
The members of BlockdevOptionsGluster when driver is "gluster"
The members of BlockdevOptionsFile when driver is "host_cdrom" (If:
HAVE_HOST_BLOCK_DEVICE)
The members of BlockdevOptionsFile when driver is "host_device" (If:
HAVE_HOST_BLOCK_DEVICE)
The members of BlockdevOptionsCurlHttp when driver is "http"
The members of BlockdevOptionsCurlHttps when driver is "https"
The members of BlockdevOptionsIoUring when driver is "io_uring" (If:
CONFIG_BLKIO)
The members of BlockdevOptionsIscsi when driver is "iscsi"
The members of BlockdevOptionsLUKS when driver is "luks"
The members of BlockdevOptionsNbd when driver is "nbd"
The members of BlockdevOptionsNfs when driver is "nfs"
The members of BlockdevOptionsNull when driver is "null-aio"
The members of BlockdevOptionsNull when driver is "null-co"
The members of BlockdevOptionsNVMe when driver is "nvme"
The members of BlockdevOptionsNvmeIoUring when driver is "nvme-io_ur-
ing" (If: CONFIG_BLKIO)
The members of BlockdevOptionsGenericFormat when driver is "parallels"
The members of BlockdevOptionsPreallocate when driver is "preallocate"
The members of BlockdevOptionsQcow2 when driver is "qcow2"
The members of BlockdevOptionsQcow when driver is "qcow"
The members of BlockdevOptionsGenericCOWFormat when driver is "qed"
The members of BlockdevOptionsQuorum when driver is "quorum"
The members of BlockdevOptionsRaw when driver is "raw"
The members of BlockdevOptionsRbd when driver is "rbd"
The members of BlockdevOptionsReplication when driver is "replication"
(If: CONFIG_REPLICATION)
The members of BlockdevOptionsGenericFormat when driver is "snap-
shot-access"
The members of BlockdevOptionsSsh when driver is "ssh"
The members of BlockdevOptionsThrottle when driver is "throttle"
The members of BlockdevOptionsGenericFormat when driver is "vdi"
The members of BlockdevOptionsGenericFormat when driver is "vhdx"
The members of BlockdevOptionsVirtioBlkVfioPci when driver is "vir-
tio-blk-vfio-pci" (If: CONFIG_BLKIO)
The members of BlockdevOptionsVirtioBlkVhostUser when driver is "vir-
tio-blk-vhost-user" (If: CONFIG_BLKIO)
The members of BlockdevOptionsVirtioBlkVhostVdpa when driver is "vir-
tio-blk-vhost-vdpa" (If: CONFIG_BLKIO)
The members of BlockdevOptionsGenericCOWFormat when driver is "vmdk"
The members of BlockdevOptionsGenericFormat when driver is "vpc"
The members of BlockdevOptionsVVFAT when driver is "vvfat"
Remaining options are determined by the block driver.
Since
2.9
BlockdevRef (Alternate)
Reference to a block device.
Members
definition: BlockdevOptions
defines a new block device inline
reference: string
references the ID of an existing block device
Since
2.9
BlockdevRefOrNull (Alternate)
Reference to a block device.
Members
definition: BlockdevOptions
defines a new block device inline
reference: string
references the ID of an existing block device. An empty string
means that no block device should be referenced. Deprecated;
use null instead.
null: null
No block device should be referenced (since 2.10)
Since
2.9
blockdev-add (Command)
Creates a new block device.
Arguments
The members of BlockdevOptions
Since
2.9
Example
1.
-> { "execute": "blockdev-add",
"arguments": {
"driver": "qcow2",
"node-name": "test1",
"file": {
"driver": "file",
"filename": "test.qcow2"
}
}
}
<- { "return": {} }
2.
-> { "execute": "blockdev-add",
"arguments": {
"driver": "qcow2",
"node-name": "node0",
"discard": "unmap",
"cache": {
"direct": true
},
"file": {
"driver": "file",
"filename": "/tmp/test.qcow2"
},
"backing": {
"driver": "raw",
"file": {
"driver": "file",
"filename": "/dev/fdset/4"
}
}
}
}
<- { "return": {} }
blockdev-reopen (Command)
Reopens one or more block devices using the given set of options. Any
option not specified will be reset to its default value regardless of
its previous status. If an option cannot be changed or a particular
driver does not support reopening then the command will return an er-
ror. All devices in the list are reopened in one transaction, so if one
of them fails then the whole transaction is cancelled.
The command receives a list of block devices to reopen. For each one of
them, the top-level node-name option (from BlockdevOptions) must be
specified and is used to select the block device to be reopened. Other
node-name options must be either omitted or set to the current name of
the appropriate node. This command won't change any node name and any
attempt to do it will result in an error.
In the case of options that refer to child nodes, the behavior of this
command depends on the value:
1. A set of options (BlockdevOptions): the child is reopened with
the specified set of options.
2. A reference to the current child: the child is reopened using its
existing set of options.
3. A reference to a different node: the current child is replaced
with the specified one.
4. NULL: the current child (if any) is detached.
Options (1) and (2) are supported in all cases. Option (3) is supported
for file and backing, and option (4) for backing only.
Unlike with blockdev-add, the backing option must always be present un-
less the node being reopened does not have a backing file and its image
does not have a default backing file name as part of its metadata.
Arguments
options: array of BlockdevOptions
Not documented
Since
6.1
blockdev-del (Command)
Deletes a block device that has been added using blockdev-add. The
command will fail if the node is attached to a device or is otherwise
being used.
Arguments
node-name: string
Name of the graph node to delete.
Since
2.9
Example
-> { "execute": "blockdev-add",
"arguments": {
"driver": "qcow2",
"node-name": "node0",
"file": {
"driver": "file",
"filename": "test.qcow2"
}
}
}
<- { "return": {} }
-> { "execute": "blockdev-del",
"arguments": { "node-name": "node0" }
}
<- { "return": {} }
BlockdevCreateOptionsFile (Object)
Driver specific image creation options for file.
Members
filename: string
Filename for the new image file
size: int
Size of the virtual disk in bytes
preallocation: PreallocMode (optional)
Preallocation mode for the new image (default: off; allowed val-
ues: off, falloc (if CONFIG_POSIX_FALLOCATE), full (if CON-
FIG_POSIX))
nocow: boolean (optional)
Turn off copy-on-write (valid only on btrfs; default: off)
extent-size-hint: int (optional)
Extent size hint to add to the image file; 0 for not adding an
extent size hint (default: 1 MB, since 5.1)
Since
2.12
BlockdevCreateOptionsGluster (Object)
Driver specific image creation options for gluster.
Members
location: BlockdevOptionsGluster
Where to store the new image file
size: int
Size of the virtual disk in bytes
preallocation: PreallocMode (optional)
Preallocation mode for the new image (default: off; allowed val-
ues: off, falloc (if CONFIG_GLUSTERFS_FALLOCATE), full (if CON-
FIG_GLUSTERFS_ZEROFILL))
Since
2.12
BlockdevCreateOptionsLUKS (Object)
Driver specific image creation options for LUKS.
Members
file: BlockdevRef
Node to create the image format on
size: int
Size of the virtual disk in bytes
preallocation: PreallocMode (optional)
Preallocation mode for the new image (since: 4.2) (default: off;
allowed values: off, metadata, falloc, full)
The members of QCryptoBlockCreateOptionsLUKS
Since
2.12
BlockdevCreateOptionsNfs (Object)
Driver specific image creation options for NFS.
Members
location: BlockdevOptionsNfs
Where to store the new image file
size: int
Size of the virtual disk in bytes
Since
2.12
BlockdevCreateOptionsParallels (Object)
Driver specific image creation options for parallels.
Members
file: BlockdevRef
Node to create the image format on
size: int
Size of the virtual disk in bytes
cluster-size: int (optional)
Cluster size in bytes (default: 1 MB)
Since
2.12
BlockdevCreateOptionsQcow (Object)
Driver specific image creation options for qcow.
Members
file: BlockdevRef
Node to create the image format on
size: int
Size of the virtual disk in bytes
backing-file: string (optional)
File name of the backing file if a backing file should be used
encrypt: QCryptoBlockCreateOptions (optional)
Encryption options if the image should be encrypted
Since
2.12
BlockdevQcow2Version (Enum)
Values
v2 The original QCOW2 format as introduced in qemu 0.10 (version 2)
v3 The extended QCOW2 format as introduced in qemu 1.1 (version 3)
Since
2.12
Qcow2CompressionType (Enum)
Compression type used in qcow2 image file
Values
zlib zlib compression, see <http://zlib.net/>
zstd (If: CONFIG_ZSTD)
zstd compression, see <http://github.com/facebook/zstd>
Since
5.1
BlockdevCreateOptionsQcow2 (Object)
Driver specific image creation options for qcow2.
Members
file: BlockdevRef
Node to create the image format on
data-file: BlockdevRef (optional)
Node to use as an external data file in which all guest data is
stored so that only metadata remains in the qcow2 file (since:
4.0)
data-file-raw: boolean (optional)
True if the external data file must stay valid as a standalone
(read-only) raw image without looking at qcow2 metadata (de-
fault: false; since: 4.0)
extended-l2: boolean (optional)
True to make the image have extended L2 entries (default: false;
since 5.2)
size: int
Size of the virtual disk in bytes
version: BlockdevQcow2Version (optional)
Compatibility level (default: v3)
backing-file: string (optional)
File name of the backing file if a backing file should be used
backing-fmt: BlockdevDriver (optional)
Name of the block driver to use for the backing file
encrypt: QCryptoBlockCreateOptions (optional)
Encryption options if the image should be encrypted
cluster-size: int (optional)
qcow2 cluster size in bytes (default: 65536)
preallocation: PreallocMode (optional)
Preallocation mode for the new image (default: off; allowed val-
ues: off, falloc, full, metadata)
lazy-refcounts: boolean (optional)
True if refcounts may be updated lazily (default: off)
refcount-bits: int (optional)
Width of reference counts in bits (default: 16)
compression-type: Qcow2CompressionType (optional)
The image cluster compression method (default: zlib, since 5.1)
Since
2.12
BlockdevCreateOptionsQed (Object)
Driver specific image creation options for qed.
Members
file: BlockdevRef
Node to create the image format on
size: int
Size of the virtual disk in bytes
backing-file: string (optional)
File name of the backing file if a backing file should be used
backing-fmt: BlockdevDriver (optional)
Name of the block driver to use for the backing file
cluster-size: int (optional)
Cluster size in bytes (default: 65536)
table-size: int (optional)
L1/L2 table size (in clusters)
Since
2.12
BlockdevCreateOptionsRbd (Object)
Driver specific image creation options for rbd/Ceph.
Members
location: BlockdevOptionsRbd
Where to store the new image file. This location cannot point to
a snapshot.
size: int
Size of the virtual disk in bytes
cluster-size: int (optional)
RBD object size
encrypt: RbdEncryptionCreateOptions (optional)
Image encryption options. (Since 6.1)
Since
2.12
BlockdevVmdkSubformat (Enum)
Subformat options for VMDK images
Values
monolithicSparse
Single file image with sparse cluster allocation
monolithicFlat
Single flat data image and a descriptor file
twoGbMaxExtentSparse
Data is split into 2GB (per virtual LBA) sparse extent files, in
addition to a descriptor file
twoGbMaxExtentFlat
Data is split into 2GB (per virtual LBA) flat extent files, in
addition to a descriptor file
streamOptimized
Single file image sparse cluster allocation, optimized for
streaming over network.
Since
4.0
BlockdevVmdkAdapterType (Enum)
Adapter type info for VMDK images
Values
ide Not documented
buslogic
Not documented
lsilogic
Not documented
legacyESX
Not documented
Since
4.0
BlockdevCreateOptionsVmdk (Object)
Driver specific image creation options for VMDK.
Members
file: BlockdevRef
Where to store the new image file. This refers to the image file
for monolithcSparse and streamOptimized format, or the descrip-
tor file for other formats.
size: int
Size of the virtual disk in bytes
extents: array of BlockdevRef (optional)
Where to store the data extents. Required for monolithcFlat,
twoGbMaxExtentSparse and twoGbMaxExtentFlat formats. For mono-
lithicFlat, only one entry is required; for twoGbMaxExtent* for-
mats, the number of entries required is calculated as ex-
tent_number = virtual_size / 2GB. Providing more extents than
will be used is an error.
subformat: BlockdevVmdkSubformat (optional)
The subformat of the VMDK image. Default: "monolithicSparse".
backing-file: string (optional)
The path of backing file. Default: no backing file is used.
adapter-type: BlockdevVmdkAdapterType (optional)
The adapter type used to fill in the descriptor. Default: ide.
hwversion: string (optional)
Hardware version. The meaningful options are "4" or "6". De-
fault: "4".
toolsversion: string (optional)
VMware guest tools version. Default: "2147483647" (Since 6.2)
zeroed-grain: boolean (optional)
Whether to enable zeroed-grain feature for sparse subformats.
Default: false.
Since
4.0
BlockdevCreateOptionsSsh (Object)
Driver specific image creation options for SSH.
Members
location: BlockdevOptionsSsh
Where to store the new image file
size: int
Size of the virtual disk in bytes
Since
2.12
BlockdevCreateOptionsVdi (Object)
Driver specific image creation options for VDI.
Members
file: BlockdevRef
Node to create the image format on
size: int
Size of the virtual disk in bytes
preallocation: PreallocMode (optional)
Preallocation mode for the new image (default: off; allowed val-
ues: off, metadata)
Since
2.12
BlockdevVhdxSubformat (Enum)
Values
dynamic
Growing image file
fixed Preallocated fixed-size image file
Since
2.12
BlockdevCreateOptionsVhdx (Object)
Driver specific image creation options for vhdx.
Members
file: BlockdevRef
Node to create the image format on
size: int
Size of the virtual disk in bytes
log-size: int (optional)
Log size in bytes, must be a multiple of 1 MB (default: 1 MB)
block-size: int (optional)
Block size in bytes, must be a multiple of 1 MB and not larger
than 256 MB (default: automatically choose a block size depend-
ing on the image size)
subformat: BlockdevVhdxSubformat (optional)
vhdx subformat (default: dynamic)
block-state-zero: boolean (optional)
Force use of payload blocks of type 'ZERO'. Non-standard, but
default. Do not set to 'off' when using 'qemu-img convert' with
subformat=dynamic.
Since
2.12
BlockdevVpcSubformat (Enum)
Values
dynamic
Growing image file
fixed Preallocated fixed-size image file
Since
2.12
BlockdevCreateOptionsVpc (Object)
Driver specific image creation options for vpc (VHD).
Members
file: BlockdevRef
Node to create the image format on
size: int
Size of the virtual disk in bytes
subformat: BlockdevVpcSubformat (optional)
vhdx subformat (default: dynamic)
force-size: boolean (optional)
Force use of the exact byte size instead of rounding to the next
size that can be represented in CHS geometry (default: false)
Since
2.12
BlockdevCreateOptions (Object)
Options for creating an image format on a given node.
Members
driver: BlockdevDriver
block driver to create the image format
The members of BlockdevCreateOptionsFile when driver is "file"
The members of BlockdevCreateOptionsGluster when driver is "gluster"
The members of BlockdevCreateOptionsLUKS when driver is "luks"
The members of BlockdevCreateOptionsNfs when driver is "nfs"
The members of BlockdevCreateOptionsParallels when driver is "paral-
lels"
The members of BlockdevCreateOptionsQcow when driver is "qcow"
The members of BlockdevCreateOptionsQcow2 when driver is "qcow2"
The members of BlockdevCreateOptionsQed when driver is "qed"
The members of BlockdevCreateOptionsRbd when driver is "rbd"
The members of BlockdevCreateOptionsSsh when driver is "ssh"
The members of BlockdevCreateOptionsVdi when driver is "vdi"
The members of BlockdevCreateOptionsVhdx when driver is "vhdx"
The members of BlockdevCreateOptionsVmdk when driver is "vmdk"
The members of BlockdevCreateOptionsVpc when driver is "vpc"
Since
2.12
blockdev-create (Command)
Starts a job to create an image format on a given node. The job is au-
tomatically finalized, but a manual job-dismiss is required.
Arguments
job-id: string
Identifier for the newly created job.
options: BlockdevCreateOptions
Options for the image creation.
Since
3.0
BlockdevAmendOptionsLUKS (Object)
Driver specific image amend options for LUKS.
Members
The members of QCryptoBlockAmendOptionsLUKS
Since
5.1
BlockdevAmendOptionsQcow2 (Object)
Driver specific image amend options for qcow2. For now, only encryp-
tion options can be amended
encrypt Encryption options to be amended
Members
encrypt: QCryptoBlockAmendOptions (optional)
Not documented
Since
5.1
BlockdevAmendOptions (Object)
Options for amending an image format
Members
driver: BlockdevDriver
Block driver of the node to amend.
The members of BlockdevAmendOptionsLUKS when driver is "luks"
The members of BlockdevAmendOptionsQcow2 when driver is "qcow2"
Since
5.1
x-blockdev-amend (Command)
Starts a job to amend format specific options of an existing open block
device The job is automatically finalized, but a manual job-dismiss is
required.
Arguments
job-id: string
Identifier for the newly created job.
node-name: string
Name of the block node to work on
options: BlockdevAmendOptions
Options (driver specific)
force: boolean (optional)
Allow unsafe operations, format specific For luks that allows
erase of the last active keyslot (permanent loss of data), and
replacement of an active keyslot (possible loss of data if IO
error happens)
Features
unstable
This command is experimental.
Since
5.1
BlockErrorAction (Enum)
An enumeration of action that has been taken when a DISK I/O occurs
Values
ignore error has been ignored
report error has been reported to the device
stop error caused VM to be stopped
Since
2.1
BLOCK_IMAGE_CORRUPTED (Event)
Emitted when a disk image is being marked corrupt. The image can be
identified by its device or node name. The 'device' field is always
present for compatibility reasons, but it can be empty ("") if the im-
age does not have a device name associated.
Arguments
device: string
device name. This is always present for compatibility reasons,
but it can be empty ("") if the image does not have a device
name associated.
node-name: string (optional)
node name (Since: 2.4)
msg: string
informative message for human consumption, such as the kind of
corruption being detected. It should not be parsed by machine as
it is not guaranteed to be stable
offset: int (optional)
if the corruption resulted from an image access, this is the
host's access offset into the image
size: int (optional)
if the corruption resulted from an image access, this is the ac-
cess size
fatal: boolean
if set, the image is marked corrupt and therefore unusable after
this event and must be repaired (Since 2.2; before, every
BLOCK_IMAGE_CORRUPTED event was fatal)
Note
If action is "stop", a STOP event will eventually follow the
BLOCK_IO_ERROR event.
Example
<- { "event": "BLOCK_IMAGE_CORRUPTED",
"data": { "device": "", "node-name": "drive", "fatal": false,
"msg": "L2 table offset 0x2a2a2a00 unaligned (L1 index: 0)" },
"timestamp": { "seconds": 1648243240, "microseconds": 906060 } }
Since
1.7
BLOCK_IO_ERROR (Event)
Emitted when a disk I/O error occurs
Arguments
device: string
device name. This is always present for compatibility reasons,
but it can be empty ("") if the image does not have a device
name associated.
node-name: string (optional)
node name. Note that errors may be reported for the root node
that is directly attached to a guest device rather than for the
node where the error occurred. The node name is not present if
the drive is empty. (Since: 2.8)
operation: IoOperationType
I/O operation
action: BlockErrorAction
action that has been taken
nospace: boolean (optional)
true if I/O error was caused due to a no-space condition. This
key is only present if query-block's io-status is present,
please see query-block documentation for more information
(since: 2.2)
reason: string
human readable string describing the error cause. (This field
is a debugging aid for humans, it should not be parsed by appli-
cations) (since: 2.2)
Note
If action is "stop", a STOP event will eventually follow the
BLOCK_IO_ERROR event
Since
0.13
Example
<- { "event": "BLOCK_IO_ERROR",
"data": { "device": "ide0-hd1",
"node-name": "#block212",
"operation": "write",
"action": "stop",
"reason": "No space left on device" },
"timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
BLOCK_JOB_COMPLETED (Event)
Emitted when a block job has completed
Arguments
type: JobType
job type
device: string
The job identifier. Originally the device name but other values
are allowed since QEMU 2.7
len: int
maximum progress value
offset: int
current progress value. On success this is equal to len. On
failure this is less than len
speed: int
rate limit, bytes per second
error: string (optional)
error message. Only present on failure. This field contains a
human-readable error message. There are no semantics other than
that streaming has failed and clients should not try to inter-
pret the error string
Since
1.1
Example
<- { "event": "BLOCK_JOB_COMPLETED",
"data": { "type": "stream", "device": "virtio-disk0",
"len": 10737418240, "offset": 10737418240,
"speed": 0 },
"timestamp": { "seconds": 1267061043, "microseconds": 959568 } }
BLOCK_JOB_CANCELLED (Event)
Emitted when a block job has been cancelled
Arguments
type: JobType
job type
device: string
The job identifier. Originally the device name but other values
are allowed since QEMU 2.7
len: int
maximum progress value
offset: int
current progress value. On success this is equal to len. On
failure this is less than len
speed: int
rate limit, bytes per second
Since
1.1
Example
<- { "event": "BLOCK_JOB_CANCELLED",
"data": { "type": "stream", "device": "virtio-disk0",
"len": 10737418240, "offset": 134217728,
"speed": 0 },
"timestamp": { "seconds": 1267061043, "microseconds": 959568 } }
BLOCK_JOB_ERROR (Event)
Emitted when a block job encounters an error
Arguments
device: string
The job identifier. Originally the device name but other values
are allowed since QEMU 2.7
operation: IoOperationType
I/O operation
action: BlockErrorAction
action that has been taken
Since
1.3
Example
<- { "event": "BLOCK_JOB_ERROR",
"data": { "device": "ide0-hd1",
"operation": "write",
"action": "stop" },
"timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
BLOCK_JOB_READY (Event)
Emitted when a block job is ready to complete
Arguments
type: JobType
job type
device: string
The job identifier. Originally the device name but other values
are allowed since QEMU 2.7
len: int
maximum progress value
offset: int
current progress value. On success this is equal to len. On
failure this is less than len
speed: int
rate limit, bytes per second
Note
The "ready to complete" status is always reset by a BLOCK_JOB_ERROR
event
Since
1.3
Example
<- { "event": "BLOCK_JOB_READY",
"data": { "device": "drive0", "type": "mirror", "speed": 0,
"len": 2097152, "offset": 2097152 },
"timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
BLOCK_JOB_PENDING (Event)
Emitted when a block job is awaiting explicit authorization to finalize
graph changes via block-job-finalize. If this job is part of a transac-
tion, it will not emit this event until the transaction has converged
first.
Arguments
type: JobType
job type
id: string
The job identifier.
Since
2.12
Example
<- { "event": "BLOCK_JOB_PENDING",
"data": { "type": "mirror", "id": "backup_1" },
"timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
PreallocMode (Enum)
Preallocation mode of QEMU image file
Values
off no preallocation
metadata
preallocate only for metadata
falloc like full preallocation but allocate disk space by posix_fallo-
cate() rather than writing data.
full preallocate all data by writing it to the device to ensure disk
space is really available. This data may or may not be zero, de-
pending on the image format and storage. full preallocation
also sets up metadata correctly.
Since
2.2
BLOCK_WRITE_THRESHOLD (Event)
Emitted when writes on block device reaches or exceeds the configured
write threshold. For thin-provisioned devices, this means the device
should be extended to avoid pausing for disk exhaustion. The event is
one shot. Once triggered, it needs to be re-registered with another
block-set-write-threshold command.
Arguments
node-name: string
graph node name on which the threshold was exceeded.
amount-exceeded: int
amount of data which exceeded the threshold, in bytes.
write-threshold: int
last configured threshold, in bytes.
Since
2.3
block-set-write-threshold (Command)
Change the write threshold for a block drive. An event will be deliv-
ered if a write to this block drive crosses the configured threshold.
The threshold is an offset, thus must be non-negative. Default is no
write threshold. Setting the threshold to zero disables it.
This is useful to transparently resize thin-provisioned drives without
the guest OS noticing.
Arguments
node-name: string
graph node name on which the threshold must be set.
write-threshold: int
configured threshold for the block device, bytes. Use 0 to dis-
able the threshold.
Since
2.3
Example
-> { "execute": "block-set-write-threshold",
"arguments": { "node-name": "mydev",
"write-threshold": 17179869184 } }
<- { "return": {} }
x-blockdev-change (Command)
Dynamically reconfigure the block driver state graph. It can be used to
add, remove, insert or replace a graph node. Currently only the Quorum
driver implements this feature to add or remove its child. This is use-
ful to fix a broken quorum child.
If node is specified, it will be inserted under parent. child may not
be specified in this case. If both parent and child are specified but
node is not, child will be detached from parent.
Arguments
parent: string
the id or name of the parent node.
child: string (optional)
the name of a child under the given parent node.
node: string (optional)
the name of the node that will be added.
Features
unstable
This command is experimental, and its API is not stable. It
does not support all kinds of operations, all kinds of children,
nor all block drivers.
FIXME Removing children from a quorum node means introducing
gaps in the child indices. This cannot be represented in the
'children' list of BlockdevOptionsQuorum, as returned by
.bdrv_refresh_filename().
Warning: The data in a new quorum child MUST be consistent with
that of the rest of the array.
Since
2.7
Example
1. Add a new node to a quorum
-> { "execute": "blockdev-add",
"arguments": {
"driver": "raw",
"node-name": "new_node",
"file": { "driver": "file",
"filename": "test.raw" } } }
<- { "return": {} }
-> { "execute": "x-blockdev-change",
"arguments": { "parent": "disk1",
"node": "new_node" } }
<- { "return": {} }
2. Delete a quorum's node
-> { "execute": "x-blockdev-change",
"arguments": { "parent": "disk1",
"child": "children.1" } }
<- { "return": {} }
x-blockdev-set-iothread (Command)
Move node and its children into the iothread. If iothread is null then
move node and its children into the main loop.
The node must not be attached to a BlockBackend.
Arguments
node-name: string
the name of the block driver node
iothread: StrOrNull
the name of the IOThread object or null for the main loop
force: boolean (optional)
true if the node and its children should be moved when a Block-
Backend is already attached
Features
unstable
This command is experimental and intended for test cases that
need control over IOThreads only.
Since
2.12
Example
1. Move a node into an IOThread
-> { "execute": "x-blockdev-set-iothread",
"arguments": { "node-name": "disk1",
"iothread": "iothread0" } }
<- { "return": {} }
2. Move a node into the main loop
-> { "execute": "x-blockdev-set-iothread",
"arguments": { "node-name": "disk1",
"iothread": null } }
<- { "return": {} }
QuorumOpType (Enum)
An enumeration of the quorum operation types
Values
read read operation
write write operation
flush flush operation
Since
2.6
QUORUM_FAILURE (Event)
Emitted by the Quorum block driver if it fails to establish a quorum
Arguments
reference: string
device name if defined else node name
sector-num: int
number of the first sector of the failed read operation
sectors-count: int
failed read operation sector count
Note
This event is rate-limited.
Since
2.0
Example
<- { "event": "QUORUM_FAILURE",
"data": { "reference": "usr1", "sector-num": 345435, "sectors-count": 5 },
"timestamp": { "seconds": 1344522075, "microseconds": 745528 } }
QUORUM_REPORT_BAD (Event)
Emitted to report a corruption of a Quorum file
Arguments
type: QuorumOpType
quorum operation type (Since 2.6)
error: string (optional)
error message. Only present on failure. This field contains a
human-readable error message. There are no semantics other than
that the block layer reported an error and clients should not
try to interpret the error string.
node-name: string
the graph node name of the block driver state
sector-num: int
number of the first sector of the failed read operation
sectors-count: int
failed read operation sector count
Note
This event is rate-limited.
Since
2.0
Example
1. Read operation
{ "event": "QUORUM_REPORT_BAD",
"data": { "node-name": "node0", "sector-num": 345435, "sectors-count": 5,
"type": "read" },
"timestamp": { "seconds": 1344522075, "microseconds": 745528 } }
2. Flush operation
{ "event": "QUORUM_REPORT_BAD",
"data": { "node-name": "node0", "sector-num": 0, "sectors-count": 2097120,
"type": "flush", "error": "Broken pipe" },
"timestamp": { "seconds": 1456406829, "microseconds": 291763 } }
BlockdevSnapshotInternal (Object)
Members
device: string
the device name or node-name of a root node to generate the
snapshot from
name: string
the name of the internal snapshot to be created
Notes
In transaction, if name is empty, or any snapshot matching name exists,
the operation will fail. Only some image formats support it, for exam-
ple, qcow2, and rbd.
Since
1.7
blockdev-snapshot-internal-sync (Command)
Synchronously take an internal snapshot of a block device, when the
format of the image used supports it. If the name is an empty string,
or a snapshot with name already exists, the operation will fail.
For the arguments, see the documentation of BlockdevSnapshotInternal.
Returns
• nothing on success
• If device is not a valid block device, GenericError
• If any snapshot matching name exists, or name is empty, GenericError
• If the format of the image used does not support it, BlockFormatFea-
tureNotSupported
Since
1.7
Example
-> { "execute": "blockdev-snapshot-internal-sync",
"arguments": { "device": "ide-hd0",
"name": "snapshot0" }
}
<- { "return": {} }
blockdev-snapshot-delete-internal-sync (Command)
Synchronously delete an internal snapshot of a block device, when the
format of the image used support it. The snapshot is identified by name
or id or both. One of the name or id is required. Return SnapshotInfo
for the successfully deleted snapshot.
Arguments
device: string
the device name or node-name of a root node to delete the snap-
shot from
id: string (optional)
optional the snapshot's ID to be deleted
name: string (optional)
optional the snapshot's name to be deleted
Returns
• SnapshotInfo on success
• If device is not a valid block device, GenericError
• If snapshot not found, GenericError
• If the format of the image used does not support it, BlockFormatFea-
tureNotSupported
• If id and name are both not specified, GenericError
Since
1.7
Example
-> { "execute": "blockdev-snapshot-delete-internal-sync",
"arguments": { "device": "ide-hd0",
"name": "snapshot0" }
}
<- { "return": {
"id": "1",
"name": "snapshot0",
"vm-state-size": 0,
"date-sec": 1000012,
"date-nsec": 10,
"vm-clock-sec": 100,
"vm-clock-nsec": 20,
"icount": 220414
}
}
Block device exports
NbdServerOptions (Object)
Keep this type consistent with the nbd-server-start arguments. The only
intended difference is using SocketAddress instead of SocketAddressLe-
gacy.
Members
addr: SocketAddress
Address on which to listen.
tls-creds: string (optional)
ID of the TLS credentials object (since 2.6).
tls-authz: string (optional)
ID of the QAuthZ authorization object used to validate the
client's x509 distinguished name. This object is is only re-
solved at time of use, so can be deleted and recreated on the
fly while the NBD server is active. If missing, it will default
to denying access (since 4.0).
max-connections: int (optional)
The maximum number of connections to allow at the same time, 0
for unlimited. Setting this to 1 also stops the server from ad-
vertising multiple client support (since 5.2; default: 0)
Since
4.2
nbd-server-start (Command)
Start an NBD server listening on the given host and port. Block de-
vices can then be exported using nbd-server-add. The NBD server will
present them as named exports; for example, another QEMU instance could
refer to them as "nbd:HOST:PORT:exportname=NAME".
Keep this type consistent with the NbdServerOptions type. The only in-
tended difference is using SocketAddressLegacy instead of SocketAd-
dress.
Arguments
addr: SocketAddressLegacy
Address on which to listen.
tls-creds: string (optional)
ID of the TLS credentials object (since 2.6).
tls-authz: string (optional)
ID of the QAuthZ authorization object used to validate the
client's x509 distinguished name. This object is is only re-
solved at time of use, so can be deleted and recreated on the
fly while the NBD server is active. If missing, it will default
to denying access (since 4.0).
max-connections: int (optional)
The maximum number of connections to allow at the same time, 0
for unlimited. Setting this to 1 also stops the server from ad-
vertising multiple client support (since 5.2; default: 0).
Returns
error if the server is already running.
Since
1.3
BlockExportOptionsNbdBase (Object)
An NBD block export (common options shared between nbd-server-add and
the NBD branch of block-export-add).
Members
name: string (optional)
Export name. If unspecified, the device parameter is used as the
export name. (Since 2.12)
description: string (optional)
Free-form description of the export, up to 4096 bytes. (Since
5.0)
Since
5.0
BlockExportOptionsNbd (Object)
An NBD block export (distinct options used in the NBD branch of
block-export-add).
Members
bitmaps: array of BlockDirtyBitmapOrStr (optional)
Also export each of the named dirty bitmaps reachable from de-
vice, so the NBD client can use NBD_OPT_SET_META_CONTEXT with
the metadata context name "qemu:dirty-bitmap:BITMAP" to inspect
each bitmap. Since 7.1 bitmap may be specified by node/name
pair.
allocation-depth: boolean (optional)
Also export the allocation depth map for device, so the NBD
client can use NBD_OPT_SET_META_CONTEXT with the metadata con-
text name "qemu:allocation-depth" to inspect allocation details.
(since 5.2)
The members of BlockExportOptionsNbdBase
Since
5.2
BlockExportOptionsVhostUserBlk (Object)
A vhost-user-blk block export.
Members
addr: SocketAddress
The vhost-user socket on which to listen. Both 'unix' and 'fd'
SocketAddress types are supported. Passed fds must be UNIX do-
main sockets.
logical-block-size: int (optional)
Logical block size in bytes. Defaults to 512 bytes.
num-queues: int (optional)
Number of request virtqueues. Must be greater than 0. Defaults
to 1.
Since
5.2
FuseExportAllowOther (Enum)
Possible allow_other modes for FUSE exports.
Values
off Do not pass allow_other as a mount option.
on Pass allow_other as a mount option.
auto Try mounting with allow_other first, and if that fails, retry
without allow_other.
Since
6.1
BlockExportOptionsFuse (Object)
Options for exporting a block graph node on some (file) mountpoint as a
raw image.
Members
mountpoint: string
Path on which to export the block device via FUSE. This must
point to an existing regular file.
growable: boolean (optional)
Whether writes beyond the EOF should grow the block node accord-
ingly. (default: false)
allow-other: FuseExportAllowOther (optional)
If this is off, only qemu's user is allowed access to this ex-
port. That cannot be changed even with chmod or chown. En-
abling this option will allow other users access to the export
with the FUSE mount option "allow_other". Note that using al-
low_other as a non-root user requires user_allow_other to be en-
abled in the global fuse.conf configuration file. In auto mode
(the default), the FUSE export driver will first attempt to
mount the export with allow_other, and if that fails, try again
without. (since 6.1; default: auto)
Since
6.0
If
CONFIG_FUSE
BlockExportOptionsVduseBlk (Object)
A vduse-blk block export.
Members
name: string
the name of VDUSE device (must be unique across the host).
num-queues: int (optional)
the number of virtqueues. Defaults to 1.
queue-size: int (optional)
the size of virtqueue. Defaults to 256.
logical-block-size: int (optional)
Logical block size in bytes. Range [512, PAGE_SIZE] and must be
power of 2. Defaults to 512 bytes.
serial: string (optional)
the serial number of virtio block device. Defaults to empty
string.
Since
7.1
NbdServerAddOptions (Object)
An NBD block export, per legacy nbd-server-add command.
Members
device: string
The device name or node name of the node to be exported
writable: boolean (optional)
Whether clients should be able to write to the device via the
NBD connection (default false).
bitmap: string (optional)
Also export a single dirty bitmap reachable from device, so the
NBD client can use NBD_OPT_SET_META_CONTEXT with the metadata
context name "qemu:dirty-bitmap:BITMAP" to inspect the bitmap
(since 4.0).
The members of BlockExportOptionsNbdBase
Since
5.0
nbd-server-add (Command)
Export a block node to QEMU's embedded NBD server.
The export name will be used as the id for the resulting block export.
Arguments
The members of NbdServerAddOptions
Features
deprecated
This command is deprecated. Use block-export-add instead.
Returns
error if the server is not running, or export with the same name al-
ready exists.
Since
1.3
BlockExportRemoveMode (Enum)
Mode for removing a block export.
Values
safe Remove export if there are no existing connections, fail other-
wise.
hard Drop all connections immediately and remove export.
TODO
Potential additional modes to be added in the future:
hide: Just hide export from new clients, leave existing connections as
is. Remove export after all clients are disconnected.
soft: Hide export from new clients, answer with ESHUTDOWN for all fur-
ther requests from existing clients.
Since
2.12
nbd-server-remove (Command)
Remove NBD export by name.
Arguments
name: string
Block export id.
mode: BlockExportRemoveMode (optional)
Mode of command operation. See BlockExportRemoveMode descrip-
tion. Default is 'safe'.
Features
deprecated
This command is deprecated. Use block-export-del instead.
Returns
error if
• the server is not running
• export is not found
• mode is 'safe' and there are existing connections
Since
2.12
nbd-server-stop (Command)
Stop QEMU's embedded NBD server, and unregister all devices previously
added via nbd-server-add.
Since
1.3
BlockExportType (Enum)
An enumeration of block export types
Values
nbd NBD export
vhost-user-blk (If: CONFIG_VHOST_USER_BLK_SERVER)
vhost-user-blk export (since 5.2)
fuse (If: CONFIG_FUSE)
FUSE export (since: 6.0)
vduse-blk (If: CONFIG_VDUSE_BLK_EXPORT)
vduse-blk export (since 7.1)
Since
4.2
BlockExportOptions (Object)
Describes a block export, i.e. how single node should be exported on an
external interface.
Members
id: string
A unique identifier for the block export (across all export
types)
node-name: string
The node name of the block node to be exported (since: 5.2)
writable: boolean (optional)
True if clients should be able to write to the export (default
false)
writethrough: boolean (optional)
If true, caches are flushed after every write request to the ex-
port before completion is signalled. (since: 5.2; default:
false)
iothread: string (optional)
The name of the iothread object where the export will run. The
default is to use the thread currently associated with the block
node. (since: 5.2)
fixed-iothread: boolean (optional)
True prevents the block node from being moved to another thread
while the export is active. If true and iothread is given, ex-
port creation fails if the block node cannot be moved to the io-
thread. The default is false. (since: 5.2)
type: BlockExportType
Not documented
The members of BlockExportOptionsNbd when type is "nbd"
The members of BlockExportOptionsVhostUserBlk when type is
"vhost-user-blk" (If: CONFIG_VHOST_USER_BLK_SERVER)
The members of BlockExportOptionsFuse when type is "fuse" (If: CON-
FIG_FUSE)
The members of BlockExportOptionsVduseBlk when type is "vduse-blk" (If:
CONFIG_VDUSE_BLK_EXPORT)
Since
4.2
block-export-add (Command)
Creates a new block export.
Arguments
The members of BlockExportOptions
Since
5.2
block-export-del (Command)
Request to remove a block export. This drops the user's reference to
the export, but the export may still stay around after this command re-
turns until the shutdown of the export has completed.
Arguments
id: string
Block export id.
mode: BlockExportRemoveMode (optional)
Mode of command operation. See BlockExportRemoveMode descrip-
tion. Default is 'safe'.
Returns
Error if the export is not found or mode is 'safe' and the export is
still in use (e.g. by existing client connections)
Since
5.2
BLOCK_EXPORT_DELETED (Event)
Emitted when a block export is removed and its id can be reused.
Arguments
id: string
Block export id.
Since
5.2
BlockExportInfo (Object)
Information about a single block export.
Members
id: string
The unique identifier for the block export
type: BlockExportType
The block export type
node-name: string
The node name of the block node that is exported
shutting-down: boolean
True if the export is shutting down (e.g. after a block-ex-
port-del command, but before the shutdown has completed)
Since
5.2
query-block-exports (Command)
Returns
A list of BlockExportInfo describing all block exports
Since
5.2
CHARACTER DEVICES
ChardevInfo (Object)
Information about a character device.
Members
label: string
the label of the character device
filename: string
the filename of the character device
frontend-open: boolean
shows whether the frontend device attached to this backend (eg.
with the chardev=... option) is in open or closed state (since
2.1)
Notes
filename is encoded using the QEMU command line character device encod-
ing. See the QEMU man page for details.
Since
0.14
query-chardev (Command)
Returns information about current character devices.
Returns
a list of ChardevInfo
Since
0.14
Example
-> { "execute": "query-chardev" }
<- {
"return": [
{
"label": "charchannel0",
"filename": "unix:/var/lib/libvirt/qemu/seabios.rhel6.agent,server=on",
"frontend-open": false
},
{
"label": "charmonitor",
"filename": "unix:/var/lib/libvirt/qemu/seabios.rhel6.monitor,server=on",
"frontend-open": true
},
{
"label": "charserial0",
"filename": "pty:/dev/pts/2",
"frontend-open": true
}
]
}
ChardevBackendInfo (Object)
Information about a character device backend
Members
name: string
The backend name
Since
2.0
query-chardev-backends (Command)
Returns information about character device backends.
Returns
a list of ChardevBackendInfo
Since
2.0
Example
-> { "execute": "query-chardev-backends" }
<- {
"return":[
{
"name":"udp"
},
{
"name":"tcp"
},
{
"name":"unix"
},
{
"name":"spiceport"
}
]
}
DataFormat (Enum)
An enumeration of data format.
Values
utf8 Data is a UTF-8 string (RFC 3629)
base64 Data is Base64 encoded binary (RFC 3548)
Since
1.4
ringbuf-write (Command)
Write to a ring buffer character device.
Arguments
device: string
the ring buffer character device name
data: string
data to write
format: DataFormat (optional)
data encoding (default 'utf8').
• base64: data must be base64 encoded text. Its binary decoding
gets written.
• utf8: data's UTF-8 encoding is written
• data itself is always Unicode regardless of format, like any
other string.
Returns
Nothing on success
Since
1.4
Example
-> { "execute": "ringbuf-write",
"arguments": { "device": "foo",
"data": "abcdefgh",
"format": "utf8" } }
<- { "return": {} }
ringbuf-read (Command)
Read from a ring buffer character device.
Arguments
device: string
the ring buffer character device name
size: int
how many bytes to read at most
format: DataFormat (optional)
data encoding (default 'utf8').
• base64: the data read is returned in base64 encoding.
• utf8: the data read is interpreted as UTF-8. Bug: can screw
up when the buffer contains invalid UTF-8 sequences, NUL char-
acters, after the ring buffer lost data, and when reading
stops because the size limit is reached.
• The return value is always Unicode regardless of format, like
any other string.
Returns
data read from the device
Since
1.4
Example
-> { "execute": "ringbuf-read",
"arguments": { "device": "foo",
"size": 1000,
"format": "utf8" } }
<- { "return": "abcdefgh" }
ChardevCommon (Object)
Configuration shared across all chardev backends
Members
logfile: string (optional)
The name of a logfile to save output
logappend: boolean (optional)
true to append instead of truncate (default to false to trun-
cate)
Since
2.6
ChardevFile (Object)
Configuration info for file chardevs.
Members
in: string (optional)
The name of the input file
out: string
The name of the output file
append: boolean (optional)
Open the file in append mode (default false to truncate) (Since
2.6)
The members of ChardevCommon
Since
1.4
ChardevHostdev (Object)
Configuration info for device and pipe chardevs.
Members
device: string
The name of the special file for the device, i.e. /dev/ttyS0 on
Unix or COM1: on Windows
The members of ChardevCommon
Since
1.4
ChardevSocket (Object)
Configuration info for (stream) socket chardevs.
Members
addr: SocketAddressLegacy
socket address to listen on (server=true) or connect to
(server=false)
tls-creds: string (optional)
the ID of the TLS credentials object (since 2.6)
tls-authz: string (optional)
the ID of the QAuthZ authorization object against which the
client's x509 distinguished name will be validated. This object
is only resolved at time of use, so can be deleted and recreated
on the fly while the chardev server is active. If missing, it
will default to denying access (since 4.0)
server: boolean (optional)
create server socket (default: true)
wait: boolean (optional)
wait for incoming connection on server sockets (default: false).
Silently ignored with server: false. This use is deprecated.
nodelay: boolean (optional)
set TCP_NODELAY socket option (default: false)
telnet: boolean (optional)
enable telnet protocol on server sockets (default: false)
tn3270: boolean (optional)
enable tn3270 protocol on server sockets (default: false)
(Since: 2.10)
websocket: boolean (optional)
enable websocket protocol on server sockets (default: false)
(Since: 3.1)
reconnect: int (optional)
For a client socket, if a socket is disconnected, then attempt a
reconnect after the given number of seconds. Setting this to
zero disables this function. (default: 0) (Since: 2.2)
The members of ChardevCommon
Since
1.4
ChardevUdp (Object)
Configuration info for datagram socket chardevs.
Members
remote: SocketAddressLegacy
remote address
local: SocketAddressLegacy (optional)
local address
The members of ChardevCommon
Since
1.5
ChardevMux (Object)
Configuration info for mux chardevs.
Members
chardev: string
name of the base chardev.
The members of ChardevCommon
Since
1.5
ChardevStdio (Object)
Configuration info for stdio chardevs.
Members
signal: boolean (optional)
Allow signals (such as SIGINT triggered by ^C) be delivered to
qemu. Default: true.
The members of ChardevCommon
Since
1.5
ChardevSpiceChannel (Object)
Configuration info for spice vm channel chardevs.
Members
type: string
kind of channel (for example vdagent).
The members of ChardevCommon
Since
1.5
If
CONFIG_SPICE
ChardevSpicePort (Object)
Configuration info for spice port chardevs.
Members
fqdn: string
name of the channel (see docs/spice-port-fqdn.txt)
The members of ChardevCommon
Since
1.5
If
CONFIG_SPICE
ChardevDBus (Object)
Configuration info for DBus chardevs.
Members
name: string
name of the channel (following docs/spice-port-fqdn.txt)
The members of ChardevCommon
Since
7.0
If
CONFIG_DBUS_DISPLAY
ChardevVC (Object)
Configuration info for virtual console chardevs.
Members
width: int (optional)
console width, in pixels
height: int (optional)
console height, in pixels
cols: int (optional)
console width, in chars
rows: int (optional)
console height, in chars
The members of ChardevCommon
Since
1.5
ChardevRingbuf (Object)
Configuration info for ring buffer chardevs.
Members
size: int (optional)
ring buffer size, must be power of two, default is 65536
The members of ChardevCommon
Since
1.5
ChardevQemuVDAgent (Object)
Configuration info for qemu vdagent implementation.
Members
mouse: boolean (optional)
enable/disable mouse, default is enabled.
clipboard: boolean (optional)
enable/disable clipboard, default is disabled.
The members of ChardevCommon
Since
6.1
If
CONFIG_SPICE_PROTOCOL
ChardevBackendKind (Enum)
Values
pipe Since 1.5
udp Since 1.5
mux Since 1.5
msmouse
Since 1.5
wctablet
Since 2.9
braille
Since 1.5
testdev
Since 2.2
stdio Since 1.5
console
Since 1.5
spicevmc (If: CONFIG_SPICE)
Since 1.5
spiceport (If: CONFIG_SPICE)
Since 1.5
qemu-vdagent (If: CONFIG_SPICE_PROTOCOL)
Since 6.1
dbus (If: CONFIG_DBUS_DISPLAY)
Since 7.0
vc v1.5
ringbuf
Since 1.6
memory Since 1.5
file Not documented
serial Not documented
parallel
Not documented
socket Not documented
pty Not documented
null Not documented
Since
1.4
ChardevFileWrapper (Object)
Members
data: ChardevFile
Not documented
Since
1.4
ChardevHostdevWrapper (Object)
Members
data: ChardevHostdev
Not documented
Since
1.4
ChardevSocketWrapper (Object)
Members
data: ChardevSocket
Not documented
Since
1.4
ChardevUdpWrapper (Object)
Members
data: ChardevUdp
Not documented
Since
1.5
ChardevCommonWrapper (Object)
Members
data: ChardevCommon
Not documented
Since
2.6
ChardevMuxWrapper (Object)
Members
data: ChardevMux
Not documented
Since
1.5
ChardevStdioWrapper (Object)
Members
data: ChardevStdio
Not documented
Since
1.5
ChardevSpiceChannelWrapper (Object)
Members
data: ChardevSpiceChannel
Not documented
Since
1.5
If
CONFIG_SPICE
ChardevSpicePortWrapper (Object)
Members
data: ChardevSpicePort
Not documented
Since
1.5
If
CONFIG_SPICE
ChardevQemuVDAgentWrapper (Object)
Members
data: ChardevQemuVDAgent
Not documented
Since
6.1
If
CONFIG_SPICE_PROTOCOL
ChardevDBusWrapper (Object)
Members
data: ChardevDBus
Not documented
Since
7.0
If
CONFIG_DBUS_DISPLAY
ChardevVCWrapper (Object)
Members
data: ChardevVC
Not documented
Since
1.5
ChardevRingbufWrapper (Object)
Members
data: ChardevRingbuf
Not documented
Since
1.5
ChardevBackend (Object)
Configuration info for the new chardev backend.
Members
type: ChardevBackendKind
Not documented
The members of ChardevFileWrapper when type is "file"
The members of ChardevHostdevWrapper when type is "serial"
The members of ChardevHostdevWrapper when type is "parallel"
The members of ChardevHostdevWrapper when type is "pipe"
The members of ChardevSocketWrapper when type is "socket"
The members of ChardevUdpWrapper when type is "udp"
The members of ChardevCommonWrapper when type is "pty"
The members of ChardevCommonWrapper when type is "null"
The members of ChardevMuxWrapper when type is "mux"
The members of ChardevCommonWrapper when type is "msmouse"
The members of ChardevCommonWrapper when type is "wctablet"
The members of ChardevCommonWrapper when type is "braille"
The members of ChardevCommonWrapper when type is "testdev"
The members of ChardevStdioWrapper when type is "stdio"
The members of ChardevCommonWrapper when type is "console"
The members of ChardevSpiceChannelWrapper when type is "spicevmc" (If:
CONFIG_SPICE)
The members of ChardevSpicePortWrapper when type is "spiceport" (If:
CONFIG_SPICE)
The members of ChardevQemuVDAgentWrapper when type is "qemu-vdagent"
(If: CONFIG_SPICE_PROTOCOL)
The members of ChardevDBusWrapper when type is "dbus" (If: CON-
FIG_DBUS_DISPLAY)
The members of ChardevVCWrapper when type is "vc"
The members of ChardevRingbufWrapper when type is "ringbuf"
The members of ChardevRingbufWrapper when type is "memory"
Since
1.4
ChardevReturn (Object)
Return info about the chardev backend just created.
Members
pty: string (optional)
name of the slave pseudoterminal device, present if and only if
a chardev of type 'pty' was created
Since
1.4
chardev-add (Command)
Add a character device backend
Arguments
id: string
the chardev's ID, must be unique
backend: ChardevBackend
backend type and parameters
Returns
ChardevReturn.
Since
1.4
Example
-> { "execute" : "chardev-add",
"arguments" : { "id" : "foo",
"backend" : { "type" : "null", "data" : {} } } }
<- { "return": {} }
-> { "execute" : "chardev-add",
"arguments" : { "id" : "bar",
"backend" : { "type" : "file",
"data" : { "out" : "/tmp/bar.log" } } } }
<- { "return": {} }
-> { "execute" : "chardev-add",
"arguments" : { "id" : "baz",
"backend" : { "type" : "pty", "data" : {} } } }
<- { "return": { "pty" : "/dev/pty/42" } }
chardev-change (Command)
Change a character device backend
Arguments
id: string
the chardev's ID, must exist
backend: ChardevBackend
new backend type and parameters
Returns
ChardevReturn.
Since
2.10
Example
-> { "execute" : "chardev-change",
"arguments" : { "id" : "baz",
"backend" : { "type" : "pty", "data" : {} } } }
<- { "return": { "pty" : "/dev/pty/42" } }
-> {"execute" : "chardev-change",
"arguments" : {
"id" : "charchannel2",
"backend" : {
"type" : "socket",
"data" : {
"addr" : {
"type" : "unix" ,
"data" : {
"path" : "/tmp/charchannel2.socket"
}
},
"server" : true,
"wait" : false }}}}
<- {"return": {}}
chardev-remove (Command)
Remove a character device backend
Arguments
id: string
the chardev's ID, must exist and not be in use
Returns
Nothing on success
Since
1.4
Example
-> { "execute": "chardev-remove", "arguments": { "id" : "foo" } }
<- { "return": {} }
chardev-send-break (Command)
Send a break to a character device
Arguments
id: string
the chardev's ID, must exist
Returns
Nothing on success
Since
2.10
Example
-> { "execute": "chardev-send-break", "arguments": { "id" : "foo" } }
<- { "return": {} }
VSERPORT_CHANGE (Event)
Emitted when the guest opens or closes a virtio-serial port.
Arguments
id: string
device identifier of the virtio-serial port
open: boolean
true if the guest has opened the virtio-serial port
Note
This event is rate-limited.
Since
2.1
Example
<- { "event": "VSERPORT_CHANGE",
"data": { "id": "channel0", "open": true },
"timestamp": { "seconds": 1401385907, "microseconds": 422329 } }
QMP MONITOR CONTROL
qmp_capabilities (Command)
Enable QMP capabilities.
Arguments:
Arguments
enable: array of QMPCapability (optional)
An optional list of QMPCapability values to enable. The client
must not enable any capability that is not mentioned in the QMP
greeting message. If the field is not provided, it means no QMP
capabilities will be enabled. (since 2.12)
Example
-> { "execute": "qmp_capabilities",
"arguments": { "enable": [ "oob" ] } }
<- { "return": {} }
Notes
This command is valid exactly when first connecting: it must be issued
before any other command will be accepted, and will fail once the moni-
tor is accepting other commands. (see qemu docs/interop/qmp-spec.txt)
The QMP client needs to explicitly enable QMP capabilities, otherwise
all the QMP capabilities will be turned off by default.
Since
0.13
QMPCapability (Enum)
Enumeration of capabilities to be advertised during initial client con-
nection, used for agreeing on particular QMP extension behaviors.
Values
oob QMP ability to support out-of-band requests. (Please refer to
qmp-spec.txt for more information on OOB)
Since
2.12
VersionTriple (Object)
A three-part version number.
Members
major: int
The major version number.
minor: int
The minor version number.
micro: int
The micro version number.
Since
2.4
VersionInfo (Object)
A description of QEMU's version.
Members
qemu: VersionTriple
The version of QEMU. By current convention, a micro version of
50 signifies a development branch. A micro version greater than
or equal to 90 signifies a release candidate for the next minor
version. A micro version of less than 50 signifies a stable re-
lease.
package: string
QEMU will always set this field to an empty string. Downstream
versions of QEMU should set this to a non-empty string. The ex-
act format depends on the downstream however it highly recom-
mended that a unique name is used.
Since
0.14
query-version (Command)
Returns the current version of QEMU.
Returns
A VersionInfo object describing the current version of QEMU.
Since
0.14
Example
-> { "execute": "query-version" }
<- {
"return":{
"qemu":{
"major":0,
"minor":11,
"micro":5
},
"package":""
}
}
CommandInfo (Object)
Information about a QMP command
Members
name: string
The command name
Since
0.14
query-commands (Command)
Return a list of supported QMP commands by this server
Returns
A list of CommandInfo for all supported commands
Since
0.14
Example
-> { "execute": "query-commands" }
<- {
"return":[
{
"name":"query-balloon"
},
{
"name":"system_powerdown"
}
]
}
Note
This example has been shortened as the real response is too long.
quit (Command)
This command will cause the QEMU process to exit gracefully. While ev-
ery attempt is made to send the QMP response before terminating, this
is not guaranteed. When using this interface, a premature EOF would
not be unexpected.
Since
0.14
Example
-> { "execute": "quit" }
<- { "return": {} }
MonitorMode (Enum)
An enumeration of monitor modes.
Values
readline
HMP monitor (human-oriented command line interface)
control
QMP monitor (JSON-based machine interface)
Since
5.0
MonitorOptions (Object)
Options to be used for adding a new monitor.
Members
id: string (optional)
Name of the monitor
mode: MonitorMode (optional)
Selects the monitor mode (default: readline in the system
emulator, control in qemu-storage-daemon)
pretty: boolean (optional)
Enables pretty printing (QMP only)
chardev: string
Name of a character device to expose the monitor on
Since
5.0
QMP INTROSPECTION
query-qmp-schema (Command)
Command query-qmp-schema exposes the QMP wire ABI as an array of
SchemaInfo. This lets QMP clients figure out what commands and events
are available in this QEMU, and their parameters and results.
However, the SchemaInfo can't reflect all the rules and restrictions
that apply to QMP. It's interface introspection (figuring out what's
there), not interface specification. The specification is in the QAPI
schema.
Furthermore, while we strive to keep the QMP wire format backwards-com-
patible across qemu versions, the introspection output is not guaran-
teed to have the same stability. For example, one version of qemu may
list an object member as an optional non-variant, while another lists
the same member only through the object's variants; or the type of a
member may change from a generic string into a specific enum or from
one specific type into an alternate that includes the original type
alongside something else.
Returns
array of SchemaInfo, where each element describes an entity in the ABI:
command, event, type, ...
The order of the various SchemaInfo is unspecified; however, all names
are guaranteed to be unique (no name will be duplicated with different
meta-types).
Note
the QAPI schema is also used to help define internal interfaces, by
defining QAPI types. These are not part of the QMP wire ABI, and
therefore not returned by this command.
Since
2.5
SchemaMetaType (Enum)
This is a SchemaInfo's meta type, i.e. the kind of entity it describes.
Values
builtin
a predefined type such as 'int' or 'bool'.
enum an enumeration type
array an array type
object an object type (struct or union)
alternate
an alternate type
command
a QMP command
event a QMP event
Since
2.5
SchemaInfo (Object)
Members
name: string
the entity's name, inherited from base. The SchemaInfo is al-
ways referenced by this name. Commands and events have the name
defined in the QAPI schema. Unlike command and event names,
type names are not part of the wire ABI. Consequently, type
names are meaningless strings here, although they are still
guaranteed unique regardless of meta-type.
meta-type: SchemaMetaType
the entity's meta type, inherited from base.
features: array of string (optional)
names of features associated with the entity, in no particular
order. (since 4.1 for object types, 4.2 for commands, 5.0 for
the rest)
The members of SchemaInfoBuiltin when meta-type is "builtin"
The members of SchemaInfoEnum when meta-type is "enum"
The members of SchemaInfoArray when meta-type is "array"
The members of SchemaInfoObject when meta-type is "object"
The members of SchemaInfoAlternate when meta-type is "alternate"
The members of SchemaInfoCommand when meta-type is "command"
The members of SchemaInfoEvent when meta-type is "event"
Additional members depend on the value of meta-type.
Since
2.5
SchemaInfoBuiltin (Object)
Additional SchemaInfo members for meta-type 'builtin'.
Members
json-type: JSONType
the JSON type used for this type on the wire.
Since
2.5
JSONType (Enum)
The four primitive and two structured types according to RFC 8259 sec-
tion 1, plus 'int' (split off 'number'), plus the obvious top type
'value'.
Values
string Not documented
number Not documented
int Not documented
boolean
Not documented
null Not documented
object Not documented
array Not documented
value Not documented
Since
2.5
SchemaInfoEnum (Object)
Additional SchemaInfo members for meta-type 'enum'.
Members
members: array of SchemaInfoEnumMember
the enum type's members, in no particular order (since 6.2).
values: array of string
the enumeration type's member names, in no particular order.
Redundant with members. Just for backward compatibility.
Features
deprecated
Member values is deprecated. Use members instead.
Values of this type are JSON string on the wire.
Since
2.5
SchemaInfoEnumMember (Object)
An object member.
Members
name: string
the member's name, as defined in the QAPI schema.
features: array of string (optional)
names of features associated with the member, in no particular
order.
Since
6.2
SchemaInfoArray (Object)
Additional SchemaInfo members for meta-type 'array'.
Members
element-type: string
the array type's element type.
Values of this type are JSON array on the wire.
Since
2.5
SchemaInfoObject (Object)
Additional SchemaInfo members for meta-type 'object'.
Members
members: array of SchemaInfoObjectMember
the object type's (non-variant) members, in no particular order.
tag: string (optional)
the name of the member serving as type tag. An element of mem-
bers with this name must exist.
variants: array of SchemaInfoObjectVariant (optional)
variant members, i.e. additional members that depend on the type
tag's value. Present exactly when tag is present. The variants
are in no particular order, and may even differ from the order
of the values of the enum type of the tag.
Values of this type are JSON object on the wire.
Since
2.5
SchemaInfoObjectMember (Object)
An object member.
Members
name: string
the member's name, as defined in the QAPI schema.
type: string
the name of the member's type.
default: value (optional)
default when used as command parameter. If absent, the parame-
ter is mandatory. If present, the value must be null. The pa-
rameter is optional, and behavior when it's missing is not spec-
ified here. Future extension: if present and non-null, the pa-
rameter is optional, and defaults to this value.
features: array of string (optional)
names of features associated with the member, in no particular
order. (since 5.0)
Since
2.5
SchemaInfoObjectVariant (Object)
The variant members for a value of the type tag.
Members
case: string
a value of the type tag.
type: string
the name of the object type that provides the variant members
when the type tag has value case.
Since
2.5
SchemaInfoAlternate (Object)
Additional SchemaInfo members for meta-type 'alternate'.
Members
members: array of SchemaInfoAlternateMember
the alternate type's members, in no particular order. The mem-
bers' wire encoding is distinct, see docs/de-
vel/qapi-code-gen.txt section Alternate types.
On the wire, this can be any of the members.
Since
2.5
SchemaInfoAlternateMember (Object)
An alternate member.
Members
type: string
the name of the member's type.
Since
2.5
SchemaInfoCommand (Object)
Additional SchemaInfo members for meta-type 'command'.
Members
arg-type: string
the name of the object type that provides the command's parame-
ters.
ret-type: string
the name of the command's result type.
allow-oob: boolean (optional)
whether the command allows out-of-band execution, defaults to
false (Since: 2.12)
TODO
success-response (currently irrelevant, because it's QGA, not QMP)
Since
2.5
SchemaInfoEvent (Object)
Additional SchemaInfo members for meta-type 'event'.
Members
arg-type: string
the name of the object type that provides the event's parame-
ters.
Since
2.5
USER AUTHORIZATION
QAuthZListPolicy (Enum)
The authorization policy result
Values
deny deny access
allow allow access
Since
4.0
QAuthZListFormat (Enum)
The authorization policy match format
Values
exact an exact string match
glob string with ? and * shell wildcard support
Since
4.0
QAuthZListRule (Object)
A single authorization rule.
Members
match: string
a string or glob to match against a user identity
policy: QAuthZListPolicy
the result to return if match evaluates to true
format: QAuthZListFormat (optional)
the format of the match rule (default 'exact')
Since
4.0
AuthZListProperties (Object)
Properties for authz-list objects.
Members
policy: QAuthZListPolicy (optional)
Default policy to apply when no rule matches (default: deny)
rules: array of QAuthZListRule (optional)
Authorization rules based on matching user
Since
4.0
AuthZListFileProperties (Object)
Properties for authz-listfile objects.
Members
filename: string
File name to load the configuration from. The file must contain
valid JSON for AuthZListProperties.
refresh: boolean (optional)
If true, inotify is used to monitor the file, automatically
reloading changes. If an error occurs during reloading, all au-
thorizations will fail until the file is next successfully
loaded. (default: true if the binary was built with CONFIG_INO-
TIFY1, false otherwise)
Since
4.0
AuthZPAMProperties (Object)
Properties for authz-pam objects.
Members
service: string
PAM service name to use for authorization
Since
4.0
AuthZSimpleProperties (Object)
Properties for authz-simple objects.
Members
identity: string
Identifies the allowed user. Its format depends on the network
service that authorization object is associated with. For autho-
rizing based on TLS x509 certificates, the identity must be the
x509 distinguished name.
Since
4.0
QEMU OBJECT MODEL (QOM)
ObjectPropertyInfo (Object)
Members
name: string
the name of the property
type: string
the type of the property. This will typically come in one of
four forms:
1. A primitive type such as 'u8', 'u16', 'bool', 'str', or 'dou-
ble'. These types are mapped to the appropriate JSON type.
2. A child type in the form 'child<subtype>' where subtype is a
qdev device type name. Child properties create the composi-
tion tree.
3. A link type in the form 'link<subtype>' where subtype is a
qdev device type name. Link properties form the device model
graph.
description: string (optional)
if specified, the description of the property.
default-value: value (optional)
the default value, if any (since 5.0)
Since
1.2
qom-list (Command)
This command will list any properties of a object given a path in the
object model.
Arguments
path: string
the path within the object model. See qom-get for a description
of this parameter.
Returns
a list of ObjectPropertyInfo that describe the properties of the ob-
ject.
Since
1.2
Example
-> { "execute": "qom-list",
"arguments": { "path": "/chardevs" } }
<- { "return": [ { "name": "type", "type": "string" },
{ "name": "parallel0", "type": "child<chardev-vc>" },
{ "name": "serial0", "type": "child<chardev-vc>" },
{ "name": "mon0", "type": "child<chardev-stdio>" } ] }
qom-get (Command)
This command will get a property from a object model path and return
the value.
Arguments
path: string
The path within the object model. There are two forms of sup-
ported paths--absolute and partial paths.
Absolute paths are derived from the root object and can follow
child<> or link<> properties. Since they can follow link<>
properties, they can be arbitrarily long. Absolute paths look
like absolute filenames and are prefixed with a leading slash.
Partial paths look like relative filenames. They do not begin
with a prefix. The matching rules for partial paths are subtle
but designed to make specifying objects easy. At each level of
the composition tree, the partial path is matched as an absolute
path. The first match is not returned. At least two matches
are searched for. A successful result is only returned if only
one match is found. If more than one match is found, a flag is
return to indicate that the match was ambiguous.
property: string
The property name to read
Returns
The property value. The type depends on the property type. child<> and
link<> properties are returned as #str pathnames. All integer property
types (u8, u16, etc) are returned as #int.
Since
1.2
Example
1. Use absolute path
-> { "execute": "qom-get",
"arguments": { "path": "/machine/unattached/device[0]",
"property": "hotplugged" } }
<- { "return": false }
2. Use partial path
-> { "execute": "qom-get",
"arguments": { "path": "unattached/sysbus",
"property": "type" } }
<- { "return": "System" }
qom-set (Command)
This command will set a property from a object model path.
Arguments
path: string
see qom-get for a description of this parameter
property: string
the property name to set
value: value
a value who's type is appropriate for the property type. See
qom-get for a description of type mapping.
Since
1.2
Example
-> { "execute": "qom-set",
"arguments": { "path": "/machine",
"property": "graphics",
"value": false } }
<- { "return": {} }
ObjectTypeInfo (Object)
This structure describes a search result from qom-list-types
Members
name: string
the type name found in the search
abstract: boolean (optional)
the type is abstract and can't be directly instantiated. Omit-
ted if false. (since 2.10)
parent: string (optional)
Name of parent type, if any (since 2.10)
Since
1.1
qom-list-types (Command)
This command will return a list of types given search parameters
Arguments
implements: string (optional)
if specified, only return types that implement this type name
abstract: boolean (optional)
if true, include abstract types in the results
Returns
a list of ObjectTypeInfo or an empty list if no results are found
Since
1.1
qom-list-properties (Command)
List properties associated with a QOM object.
Arguments
typename: string
the type name of an object
Note
objects can create properties at runtime, for example to describe links
between different devices and/or objects. These properties are not in-
cluded in the output of this command.
Returns
a list of ObjectPropertyInfo describing object properties
Since
2.12
CanHostSocketcanProperties (Object)
Properties for can-host-socketcan objects.
Members
if: string
interface name of the host system CAN bus to connect to
canbus: string
object ID of the can-bus object to connect to the host interface
Since
2.12
ColoCompareProperties (Object)
Properties for colo-compare objects.
Members
primary_in: string
name of the character device backend to use for the primary in-
put (incoming packets are redirected to outdev)
secondary_in: string
name of the character device backend to use for secondary input
(incoming packets are only compared to the input on primary_in
and then dropped)
outdev: string
name of the character device backend to use for output
iothread: string
name of the iothread to run in
notify_dev: string (optional)
name of the character device backend to be used to communicate
with the remote colo-frame (only for Xen COLO)
compare_timeout: int (optional)
the maximum time to hold a packet from primary_in for comparison
with an incoming packet on secondary_in in milliseconds (de-
fault: 3000)
expired_scan_cycle: int (optional)
the interval at which colo-compare checks whether packets from
primary have timed out, in milliseconds (default: 3000)
max_queue_size: int (optional)
the maximum number of packets to keep in the queue for comparing
with incoming packets from secondary_in. If the queue is full
and additional packets are received, the additional packets are
dropped. (default: 1024)
vnet_hdr_support: boolean (optional)
if true, vnet header support is enabled (default: false)
Since
2.8
CryptodevBackendProperties (Object)
Properties for cryptodev-backend and cryptodev-backend-builtin objects.
Members
queues: int (optional)
the number of queues for the cryptodev backend. Ignored for
cryptodev-backend and must be 1 for cryptodev-backend-builtin.
(default: 1)
Since
2.8
CryptodevVhostUserProperties (Object)
Properties for cryptodev-vhost-user objects.
Members
chardev: string
the name of a Unix domain socket character device that connects
to the vhost-user server
The members of CryptodevBackendProperties
Since
2.12
DBusVMStateProperties (Object)
Properties for dbus-vmstate objects.
Members
addr: string
the name of the DBus bus to connect to
id-list: string (optional)
a comma separated list of DBus IDs of helpers whose data should
be included in the VM state on migration
Since
5.0
NetfilterInsert (Enum)
Indicates where to insert a netfilter relative to a given other filter.
Values
before insert before the specified filter
behind insert behind the specified filter
Since
5.0
NetfilterProperties (Object)
Properties for objects of classes derived from netfilter.
Members
netdev: string
id of the network device backend to filter
queue: NetFilterDirection (optional)
indicates which queue(s) to filter (default: all)
status: string (optional)
indicates whether the filter is enabled ("on") or disabled
("off") (default: "on")
position: string (optional)
specifies where the filter should be inserted in the filter
list. "head" means the filter is inserted at the head of the
filter list, before any existing filters. "tail" means the fil-
ter is inserted at the tail of the filter list, behind any ex-
isting filters (default). "id=<id>" means the filter is in-
serted before or behind the filter specified by <id>, depending
on the insert property. (default: "tail")
insert: NetfilterInsert (optional)
where to insert the filter relative to the filter given in posi-
tion. Ignored if position is "head" or "tail". (default: be-
hind)
Since
2.5
FilterBufferProperties (Object)
Properties for filter-buffer objects.
Members
interval: int
a non-zero interval in microseconds. All packets arriving in
the given interval are delayed until the end of the interval.
The members of NetfilterProperties
Since
2.5
FilterDumpProperties (Object)
Properties for filter-dump objects.
Members
file: string
the filename where the dumped packets should be stored
maxlen: int (optional)
maximum number of bytes in a packet that are stored (default:
65536)
The members of NetfilterProperties
Since
2.5
FilterMirrorProperties (Object)
Properties for filter-mirror objects.
Members
outdev: string
the name of a character device backend to which all incoming
packets are mirrored
vnet_hdr_support: boolean (optional)
if true, vnet header support is enabled (default: false)
The members of NetfilterProperties
Since
2.6
FilterRedirectorProperties (Object)
Properties for filter-redirector objects.
At least one of indev or outdev must be present. If both are present,
they must not refer to the same character device backend.
Members
indev: string (optional)
the name of a character device backend from which packets are
received and redirected to the filtered network device
outdev: string (optional)
the name of a character device backend to which all incoming
packets are redirected
vnet_hdr_support: boolean (optional)
if true, vnet header support is enabled (default: false)
The members of NetfilterProperties
Since
2.6
FilterRewriterProperties (Object)
Properties for filter-rewriter objects.
Members
vnet_hdr_support: boolean (optional)
if true, vnet header support is enabled (default: false)
The members of NetfilterProperties
Since
2.8
InputBarrierProperties (Object)
Properties for input-barrier objects.
Members
name: string
the screen name as declared in the screens section of bar-
rier.conf
server: string (optional)
hostname of the Barrier server (default: "localhost")
port: string (optional)
TCP port of the Barrier server (default: "24800")
x-origin: string (optional)
x coordinate of the leftmost pixel on the guest screen (default:
"0")
y-origin: string (optional)
y coordinate of the topmost pixel on the guest screen (default:
"0")
width: string (optional)
the width of secondary screen in pixels (default: "1920")
height: string (optional)
the height of secondary screen in pixels (default: "1080")
Since
4.2
InputLinuxProperties (Object)
Properties for input-linux objects.
Members
evdev: string
the path of the host evdev device to use
grab_all: boolean (optional)
if true, grab is toggled for all devices (e.g. both keyboard and
mouse) instead of just one device (default: false)
repeat: boolean (optional)
enables auto-repeat events (default: false)
grab-toggle: GrabToggleKeys (optional)
the key or key combination that toggles device grab (default:
ctrl-ctrl)
Since
2.6
EventLoopBaseProperties (Object)
Common properties for event loops
Members
aio-max-batch: int (optional)
maximum number of requests in a batch for the AIO engine, 0
means that the engine will use its default. (default: 0)
thread-pool-min: int (optional)
minimum number of threads reserved in the thread pool (de-
fault:0)
thread-pool-max: int (optional)
maximum number of threads the thread pool can contain (de-
fault:64)
Since
7.1
IothreadProperties (Object)
Properties for iothread objects.
Members
poll-max-ns: int (optional)
the maximum number of nanoseconds to busy wait for events. 0
means polling is disabled (default: 32768 on POSIX hosts, 0 oth-
erwise)
poll-grow: int (optional)
the multiplier used to increase the polling time when the algo-
rithm detects it is missing events due to not polling long
enough. 0 selects a default behaviour (default: 0)
poll-shrink: int (optional)
the divisor used to decrease the polling time when the algorithm
detects it is spending too long polling without encountering
events. 0 selects a default behaviour (default: 0)
The members of EventLoopBaseProperties
The aio-max-batch option is available since 6.1.
Since
2.0
MainLoopProperties (Object)
Properties for the main-loop object.
Members
The members of EventLoopBaseProperties
Since
7.1
MemoryBackendProperties (Object)
Properties for objects of classes derived from memory-backend.
Members
merge: boolean (optional)
if true, mark the memory as mergeable (default depends on the
machine type)
dump: boolean (optional)
if true, include the memory in core dumps (default depends on
the machine type)
host-nodes: array of int (optional)
the list of NUMA host nodes to bind the memory to
policy: HostMemPolicy (optional)
the NUMA policy (default: 'default')
prealloc: boolean (optional)
if true, preallocate memory (default: false)
prealloc-threads: int (optional)
number of CPU threads to use for prealloc (default: 1)
prealloc-context: string (optional)
thread context to use for creation of preallocation threads (de-
fault: none) (since 7.2)
share: boolean (optional)
if false, the memory is private to QEMU; if true, it is shared
(default: false)
reserve: boolean (optional)
if true, reserve swap space (or huge pages) if applicable (de-
fault: true) (since 6.1)
size: int
size of the memory region in bytes
x-use-canonical-path-for-ramblock-id: boolean (optional)
if true, the canonical path is used for ramblock-id. Disable
this for 4.0 machine types or older to allow migration with
newer QEMU versions. (default: false generally, but true for
machine types <= 4.0)
Note
prealloc=true and reserve=false cannot be set at the same time. With
reserve=true, the behavior depends on the operating system: for exam-
ple, Linux will not reserve swap space for shared file mappings -- "not
applicable". In contrast, reserve=false will bail out if it cannot be
configured accordingly.
Since
2.1
MemoryBackendFileProperties (Object)
Properties for memory-backend-file objects.
Members
align: int (optional)
the base address alignment when QEMU mmap(2)s mem-path. Some
backend stores specified by mem-path require an alignment dif-
ferent than the default one used by QEMU, e.g. the device DAX
/dev/dax0.0 requires 2M alignment rather than 4K. In such cases,
users can specify the required alignment via this option. 0 se-
lects a default alignment (currently the page size). (default:
0)
discard-data: boolean (optional)
if true, the file contents can be destroyed when QEMU exits, to
avoid unnecessarily flushing data to the backing file. Note that
discard-data is only an optimization, and QEMU might not discard
file contents if it aborts unexpectedly or is terminated using
SIGKILL. (default: false)
mem-path: string
the path to either a shared memory or huge page filesystem mount
pmem: boolean (optional) (If: CONFIG_LIBPMEM)
specifies whether the backing file specified by mem-path is in
host persistent memory that can be accessed using the SNIA NVM
programming model (e.g. Intel NVDIMM).
readonly: boolean (optional)
if true, the backing file is opened read-only; if false, it is
opened read-write. (default: false)
The members of MemoryBackendProperties
Since
2.1
MemoryBackendMemfdProperties (Object)
Properties for memory-backend-memfd objects.
The share boolean option is true by default with memfd.
Members
hugetlb: boolean (optional)
if true, the file to be created resides in the hugetlbfs
filesystem (default: false)
hugetlbsize: int (optional)
the hugetlb page size on systems that support multiple hugetlb
page sizes (it must be a power of 2 value supported by the sys-
tem). 0 selects a default page size. This option is ignored if
hugetlb is false. (default: 0)
seal: boolean (optional)
if true, create a sealed-file, which will block further resizing
of the memory (default: true)
The members of MemoryBackendProperties
Since
2.12
MemoryBackendEpcProperties (Object)
Properties for memory-backend-epc objects.
The share boolean option is true by default with epc
The merge boolean option is false by default with epc
The dump boolean option is false by default with epc
Members
The members of MemoryBackendProperties
Since
6.2
PrManagerHelperProperties (Object)
Properties for pr-manager-helper objects.
Members
path: string
the path to a Unix domain socket for connecting to the external
helper
Since
2.11
QtestProperties (Object)
Properties for qtest objects.
Members
chardev: string
the chardev to be used to receive qtest commands on.
log: string (optional)
the path to a log file
Since
6.0
RemoteObjectProperties (Object)
Properties for x-remote-object objects.
Members
fd: string
file descriptor name previously passed via 'getfd' command
devid: string
the id of the device to be associated with the file descriptor
Since
6.0
VfioUserServerProperties (Object)
Properties for x-vfio-user-server objects.
Members
socket: SocketAddress
socket to be used by the libvfio-user library
device: string
the ID of the device to be emulated at the server
Since
7.1
RngProperties (Object)
Properties for objects of classes derived from rng.
Members
opened: boolean (optional)
if true, the device is opened immediately when applying this op-
tion and will probably fail when processing the next option.
Don't use; only provided for compatibility. (default: false)
Features
deprecated
Member opened is deprecated. Setting true doesn't make sense,
and false is already the default.
Since
1.3
RngEgdProperties (Object)
Properties for rng-egd objects.
Members
chardev: string
the name of a character device backend that provides the connec-
tion to the RNG daemon
The members of RngProperties
Since
1.3
RngRandomProperties (Object)
Properties for rng-random objects.
Members
filename: string (optional)
the filename of the device on the host to obtain entropy from
(default: "/dev/urandom")
The members of RngProperties
Since
1.3
SevGuestProperties (Object)
Properties for sev-guest objects.
Members
sev-device: string (optional)
SEV device to use (default: "/dev/sev")
dh-cert-file: string (optional)
guest owners DH certificate (encoded with base64)
session-file: string (optional)
guest owners session parameters (encoded with base64)
policy: int (optional)
SEV policy value (default: 0x1)
handle: int (optional)
SEV firmware handle (default: 0)
cbitpos: int (optional)
C-bit location in page table entry (default: 0)
reduced-phys-bits: int
number of bits in physical addresses that become unavailable
when SEV is enabled
kernel-hashes: boolean (optional)
if true, add hashes of kernel/initrd/cmdline to a designated
guest firmware page for measured boot with -kernel (default:
false) (since 6.2)
Since
2.12
ThreadContextProperties (Object)
Properties for thread context objects.
Members
cpu-affinity: array of int (optional)
the list of host CPU numbers used as CPU affinity for all
threads created in the thread context (default: QEMU main thread
CPU affinity)
node-affinity: array of int (optional)
the list of host node numbers that will be resolved to a list of
host CPU numbers used as CPU affinity. This is a shortcut for
specifying the list of host CPU numbers belonging to the host
nodes manually by setting cpu-affinity. (default: QEMU main
thread affinity)
Since
7.2
ObjectType (Enum)
Values
authz-list
Not documented
authz-listfile
Not documented
authz-pam
Not documented
authz-simple
Not documented
can-bus
Not documented
can-host-socketcan (If: CONFIG_LINUX)
Not documented
colo-compare
Not documented
cryptodev-backend
Not documented
cryptodev-backend-builtin
Not documented
cryptodev-backend-lkcf
Not documented
cryptodev-vhost-user (If: CONFIG_VHOST_CRYPTO)
Not documented
dbus-vmstate
Not documented
filter-buffer
Not documented
filter-dump
Not documented
filter-mirror
Not documented
filter-redirector
Not documented
filter-replay
Not documented
filter-rewriter
Not documented
input-barrier
Not documented
input-linux (If: CONFIG_LINUX)
Not documented
iothread
Not documented
main-loop
Not documented
memory-backend-epc (If: CONFIG_LINUX)
Not documented
memory-backend-file
Not documented
memory-backend-memfd (If: CONFIG_LINUX)
Not documented
memory-backend-ram
Not documented
pef-guest
Not documented
pr-manager-helper (If: CONFIG_LINUX)
Not documented
qtest Not documented
rng-builtin
Not documented
rng-egd
Not documented
rng-random (If: CONFIG_POSIX)
Not documented
secret Not documented
secret_keyring (If: CONFIG_SECRET_KEYRING)
Not documented
sev-guest
Not documented
thread-context
Not documented
s390-pv-guest
Not documented
throttle-group
Not documented
tls-creds-anon
Not documented
tls-creds-psk
Not documented
tls-creds-x509
Not documented
tls-cipher-suites
Not documented
x-remote-object
Not documented
x-vfio-user-server
Not documented
Features
unstable
Member x-remote-object is experimental.
Since
6.0
ObjectOptions (Object)
Describes the options of a user creatable QOM object.
Members
qom-type: ObjectType
the class name for the object to be created
id: string
the name of the new object
The members of AuthZListProperties when qom-type is "authz-list"
The members of AuthZListFileProperties when qom-type is "authz-list-
file"
The members of AuthZPAMProperties when qom-type is "authz-pam"
The members of AuthZSimpleProperties when qom-type is "authz-simple"
The members of CanHostSocketcanProperties when qom-type is
"can-host-socketcan" (If: CONFIG_LINUX)
The members of ColoCompareProperties when qom-type is "colo-compare"
The members of CryptodevBackendProperties when qom-type is "cryp-
todev-backend"
The members of CryptodevBackendProperties when qom-type is "cryp-
todev-backend-builtin"
The members of CryptodevBackendProperties when qom-type is "cryp-
todev-backend-lkcf"
The members of CryptodevVhostUserProperties when qom-type is "cryp-
todev-vhost-user" (If: CONFIG_VHOST_CRYPTO)
The members of DBusVMStateProperties when qom-type is "dbus-vmstate"
The members of FilterBufferProperties when qom-type is "filter-buffer"
The members of FilterDumpProperties when qom-type is "filter-dump"
The members of FilterMirrorProperties when qom-type is "filter-mirror"
The members of FilterRedirectorProperties when qom-type is "fil-
ter-redirector"
The members of NetfilterProperties when qom-type is "filter-replay"
The members of FilterRewriterProperties when qom-type is "fil-
ter-rewriter"
The members of InputBarrierProperties when qom-type is "input-barrier"
The members of InputLinuxProperties when qom-type is "input-linux" (If:
CONFIG_LINUX)
The members of IothreadProperties when qom-type is "iothread"
The members of MainLoopProperties when qom-type is "main-loop"
The members of MemoryBackendEpcProperties when qom-type is "mem-
ory-backend-epc" (If: CONFIG_LINUX)
The members of MemoryBackendFileProperties when qom-type is "mem-
ory-backend-file"
The members of MemoryBackendMemfdProperties when qom-type is "mem-
ory-backend-memfd" (If: CONFIG_LINUX)
The members of MemoryBackendProperties when qom-type is "memory-back-
end-ram"
The members of PrManagerHelperProperties when qom-type is "pr-man-
ager-helper" (If: CONFIG_LINUX)
The members of QtestProperties when qom-type is "qtest"
The members of RngProperties when qom-type is "rng-builtin"
The members of RngEgdProperties when qom-type is "rng-egd"
The members of RngRandomProperties when qom-type is "rng-random" (If:
CONFIG_POSIX)
The members of SecretProperties when qom-type is "secret"
The members of SecretKeyringProperties when qom-type is "se-
cret_keyring" (If: CONFIG_SECRET_KEYRING)
The members of SevGuestProperties when qom-type is "sev-guest"
The members of ThreadContextProperties when qom-type is "thread-con-
text"
The members of ThrottleGroupProperties when qom-type is "throt-
tle-group"
The members of TlsCredsAnonProperties when qom-type is "tls-creds-anon"
The members of TlsCredsPskProperties when qom-type is "tls-creds-psk"
The members of TlsCredsX509Properties when qom-type is "tls-creds-x509"
The members of TlsCredsProperties when qom-type is "tls-cipher-suites"
The members of RemoteObjectProperties when qom-type is "x-remote-ob-
ject"
The members of VfioUserServerProperties when qom-type is
"x-vfio-user-server"
Since
6.0
object-add (Command)
Create a QOM object.
Arguments
The members of ObjectOptions
Returns
Nothing on success Error if qom-type is not a valid class name
Since
2.0
Example
-> { "execute": "object-add",
"arguments": { "qom-type": "rng-random", "id": "rng1",
"filename": "/dev/hwrng" } }
<- { "return": {} }
object-del (Command)
Remove a QOM object.
Arguments
id: string
the name of the QOM object to remove
Returns
Nothing on success Error if id is not a valid id for a QOM object
Since
2.0
Example
-> { "execute": "object-del", "arguments": { "id": "rng1" } }
<- { "return": {} }
TRANSACTIONS
Abort (Object)
This action can be used to test transaction failure.
Since
1.6
ActionCompletionMode (Enum)
An enumeration of Transactional completion modes.
Values
individual
Do not attempt to cancel any other Actions if any Actions fail
after the Transaction request succeeds. All Actions that can
complete successfully will do so without waiting on others.
This is the default.
grouped
If any Action fails after the Transaction succeeds, cancel all
Actions. Actions do not complete until all Actions are ready to
complete. May be rejected by Actions that do not support this
completion mode.
Since
2.5
TransactionActionKind (Enum)
Values
abort Since 1.6
block-dirty-bitmap-add
Since 2.5
block-dirty-bitmap-remove
Since 4.2
block-dirty-bitmap-clear
Since 2.5
block-dirty-bitmap-enable
Since 4.0
block-dirty-bitmap-disable
Since 4.0
block-dirty-bitmap-merge
Since 4.0
blockdev-backup
Since 2.3
blockdev-snapshot
Since 2.5
blockdev-snapshot-internal-sync
Since 1.7
blockdev-snapshot-sync
since 1.1
drive-backup
Since 1.6
Features
deprecated
Member drive-backup is deprecated. Use member blockdev-backup
instead.
Since
1.1
AbortWrapper (Object)
Members
data: Abort
Not documented
Since
1.6
BlockDirtyBitmapAddWrapper (Object)
Members
data: BlockDirtyBitmapAdd
Not documented
Since
2.5
BlockDirtyBitmapWrapper (Object)
Members
data: BlockDirtyBitmap
Not documented
Since
2.5
BlockDirtyBitmapMergeWrapper (Object)
Members
data: BlockDirtyBitmapMerge
Not documented
Since
4.0
BlockdevBackupWrapper (Object)
Members
data: BlockdevBackup
Not documented
Since
2.3
BlockdevSnapshotWrapper (Object)
Members
data: BlockdevSnapshot
Not documented
Since
2.5
BlockdevSnapshotInternalWrapper (Object)
Members
data: BlockdevSnapshotInternal
Not documented
Since
1.7
BlockdevSnapshotSyncWrapper (Object)
Members
data: BlockdevSnapshotSync
Not documented
Since
1.1
DriveBackupWrapper (Object)
Members
data: DriveBackup
Not documented
Since
1.6
TransactionAction (Object)
A discriminated record of operations that can be performed with trans-
action.
Members
type: TransactionActionKind
Not documented
The members of AbortWrapper when type is "abort"
The members of BlockDirtyBitmapAddWrapper when type is
"block-dirty-bitmap-add"
The members of BlockDirtyBitmapWrapper when type is "block-dirty-bit-
map-remove"
The members of BlockDirtyBitmapWrapper when type is "block-dirty-bit-
map-clear"
The members of BlockDirtyBitmapWrapper when type is "block-dirty-bit-
map-enable"
The members of BlockDirtyBitmapWrapper when type is "block-dirty-bit-
map-disable"
The members of BlockDirtyBitmapMergeWrapper when type is
"block-dirty-bitmap-merge"
The members of BlockdevBackupWrapper when type is "blockdev-backup"
The members of BlockdevSnapshotWrapper when type is "blockdev-snapshot"
The members of BlockdevSnapshotInternalWrapper when type is "block-
dev-snapshot-internal-sync"
The members of BlockdevSnapshotSyncWrapper when type is "blockdev-snap-
shot-sync"
The members of DriveBackupWrapper when type is "drive-backup"
Since
1.1
TransactionProperties (Object)
Optional arguments to modify the behavior of a Transaction.
Members
completion-mode: ActionCompletionMode (optional)
Controls how jobs launched asynchronously by Actions will com-
plete or fail as a group. See ActionCompletionMode for details.
Since
2.5
transaction (Command)
Executes a number of transactionable QMP commands atomically. If any
operation fails, then the entire set of actions will be abandoned and
the appropriate error returned.
For external snapshots, the dictionary contains the device, the file to
use for the new snapshot, and the format. The default format, if not
specified, is qcow2.
Each new snapshot defaults to being created by QEMU (wiping any con-
tents if the file already exists), but it is also possible to reuse an
externally-created file. In the latter case, you should ensure that
the new image file has the same contents as the current one; QEMU can-
not perform any meaningful check. Typically this is achieved by using
the current image file as the backing file for the new image.
On failure, the original disks pre-snapshot attempt will be used.
For internal snapshots, the dictionary contains the device and the
snapshot's name. If an internal snapshot matching name already exists,
the request will be rejected. Only some image formats support it, for
example, qcow2, and rbd,
On failure, qemu will try delete the newly created internal snapshot in
the transaction. When an I/O error occurs during deletion, the user
needs to fix it later with qemu-img or other command.
Arguments
actions: array of TransactionAction
List of TransactionAction; information needed for the respective
operations.
properties: TransactionProperties (optional)
structure of additional options to control the execution of the
transaction. See TransactionProperties for additional detail.
Returns
nothing on success
Errors depend on the operations of the transaction
Note
The transaction aborts on the first failure. Therefore, there will be
information on only one failed operation returned in an error condi-
tion, and subsequent actions will not have been attempted.
Since
1.1
Example
-> { "execute": "transaction",
"arguments": { "actions": [
{ "type": "blockdev-snapshot-sync", "data" : { "device": "ide-hd0",
"snapshot-file": "/some/place/my-image",
"format": "qcow2" } },
{ "type": "blockdev-snapshot-sync", "data" : { "node-name": "myfile",
"snapshot-file": "/some/place/my-image2",
"snapshot-node-name": "node3432",
"mode": "existing",
"format": "qcow2" } },
{ "type": "blockdev-snapshot-sync", "data" : { "device": "ide-hd1",
"snapshot-file": "/some/place/my-image2",
"mode": "existing",
"format": "qcow2" } },
{ "type": "blockdev-snapshot-internal-sync", "data" : {
"device": "ide-hd2",
"name": "snapshot0" } } ] } }
<- { "return": {} }
COPYRIGHT
2024, The QEMU Project Developers
7.2.11 May 09, 2024 QEMU-STORAGE-DAEMON-QMP-REF(7)
Generated by dwww version 1.15 on Thu Jun 27 16:23:17 CEST 2024.