QEMU Storage Daemon QMP Reference Manual¶
Block devices¶
Block core (VM unrelated)¶
Common data types¶
IoOperationType (Enum)¶
An enumeration of the I/O operation types
Values¶
readread operation
writewrite operation
Since¶
2.1
OnOffAuto (Enum)¶
An enumeration of three options: on, off, and auto
Values¶
autoQEMU selects the value between on and off
onEnabled
offDisabled
Since¶
2.2
OnOffSplit (Enum)¶
An enumeration of three values: on, off, and split
Values¶
onEnabled
offDisabled
splitMixed
Since¶
2.6
String (Object)¶
A fat type wrapping ‘str’, to be embedded in lists.
Members¶
str:stringNot 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 different meaning.
Members¶
s:stringthe string value
n:nullno string value
Since¶
2.10
OffAutoPCIBAR (Enum)¶
An enumeration of options for specifying a PCI BAR
Values¶
offThe specified feature is disabled
autoThe PCI BAR for the feature is automatically selected
bar0PCI BAR0 is used for the feature
bar1PCI BAR1 is used for the feature
bar2PCI BAR2 is used for the feature
bar3PCI BAR3 is used for the feature
bar4PCI BAR4 is used for the feature
bar5PCI BAR5 is used for the feature
Since¶
2.12
PCIELinkSpeed (Enum)¶
An enumeration of PCIe link speeds in units of GT/s
Values¶
2_52.5GT/s
55.0GT/s
88.0GT/s
1616.0GT/s
Since¶
4.0
PCIELinkWidth (Enum)¶
An enumeration of PCIe link width
Values¶
1x1
2x2
4x4
8x8
12x12
16x16
32x32
Since¶
4.0
HostMemPolicy (Enum)¶
Host memory policy types
Values¶
defaultrestore default policy, remove any nondefault policy
preferredset the preferred host nodes for allocation
binda strict policy that restricts memory allocation to the host nodes specified
interleavememory 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¶
allthe filter is attached both to the receive and the transmit queue of the netdev (default).
rxthe filter is attached to the receive queue of the netdev, where it will receive packets sent to the netdev.
txthe 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-ctrlNot documented
alt-altNot documented
shift-shiftNot documented
meta-metaNot documented
scrolllockNot documented
ctrl-scrolllockNot documented
Since¶
4.0
HumanReadableText (Object)¶
Members¶
human-readable-text:stringFormatted 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¶
clientthe network endpoint is acting as the client
serverthe network endpoint is acting as the server
Since¶
2.5
QCryptoSecretFormat (Enum)¶
The data format that the secret is provided in
Values¶
rawraw bytes. When encoded in JSON only valid UTF-8 sequences can be used
base64arbitrary base64 encoded binary data
Since¶
2.6
QCryptoHashAlgorithm (Enum)¶
The supported algorithms for computing content digests
Values¶
md5MD5. Should not be used in any new code, legacy compat only
sha1SHA-1. Should not be used in any new code, legacy compat only
sha224SHA-224. (since 2.7)
sha256SHA-256. Current recommended strong hash.
sha384SHA-384. (since 2.7)
sha512SHA-512. (since 2.7)
ripemd160RIPEMD-160. (since 2.7)
Since¶
2.6
QCryptoCipherAlgorithm (Enum)¶
The supported algorithms for content encryption ciphers
Values¶
aes-128AES with 128 bit / 16 byte keys
aes-192AES with 192 bit / 24 byte keys
aes-256AES with 256 bit / 32 byte keys
desDES with 56 bit / 8 byte keys. Do not use except in VNC. (since 6.1)
3des3DES(EDE) with 192 bit / 24 byte keys (since 2.9)
cast5-128Cast5 with 128 bit / 16 byte keys
serpent-128Serpent with 128 bit / 16 byte keys
serpent-192Serpent with 192 bit / 24 byte keys
serpent-256Serpent with 256 bit / 32 byte keys
twofish-128Twofish with 128 bit / 16 byte keys
twofish-192Twofish with 192 bit / 24 byte keys
twofish-256Twofish with 256 bit / 32 byte keys
Since¶
2.6
QCryptoCipherMode (Enum)¶
The supported modes for content encryption ciphers
Values¶
ecbElectronic Code Book
cbcCipher Block Chaining
xtsXEX with tweaked code book and ciphertext stealing
ctrCounter (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¶
plain64-bit sector number truncated to 32-bits
plain6464-bit sector number
essiv64-bit sector number encrypted with a hash of the encryption key
Since¶
2.6
QCryptoBlockFormat (Enum)¶
The supported full disk encryption formats
Values¶
qcowQCow/QCow2 built-in AES-CBC encryption. Use only for liberating data from old images.
luksLUKS encryption format. Recommended for new images
Since¶
2.6
QCryptoBlockOptionsBase (Object)¶
The common options that apply to all full disk encryption formats
Members¶
format:QCryptoBlockFormatthe 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
QCryptoBlockOptionsQCowwhenformatis"qcow" - The members of
QCryptoBlockOptionsLUKSwhenformatis"luks"
Since¶
2.6
QCryptoBlockCreateOptions (Object)¶
The options that are available for all encryption formats when initializing a new volume
Members¶
- The members of
QCryptoBlockOptionsBase - The members of
QCryptoBlockOptionsQCowwhenformatis"qcow" - The members of
QCryptoBlockCreateOptionsLUKSwhenformatis"luks"
Since¶
2.6
QCryptoBlockInfoBase (Object)¶
The common information that applies to all full disk encryption formats
Members¶
format:QCryptoBlockFormatthe encryption format
Since¶
2.7
QCryptoBlockInfoLUKSSlot (Object)¶
Information about the LUKS block encryption key slot options
Members¶
active:booleanwhether the key slot is currently in use
key-offset:intoffset 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:QCryptoCipherAlgorithmthe cipher algorithm for data encryption
cipher-mode:QCryptoCipherModethe cipher mode for data encryption
ivgen-alg:QCryptoIVGenAlgorithmthe initialization vector generator
ivgen-hash-alg:QCryptoHashAlgorithm(optional)the initialization vector generator hash
hash-alg:QCryptoHashAlgorithmthe master key hash algorithm
payload-offset:intoffset to the payload data in bytes
master-key-iters:intnumber of PBKDF2 iterations for key material
uuid:stringunique identifier for the volume
slots:array of QCryptoBlockInfoLUKSSlotinformation about each key slot
Since¶
2.7
QCryptoBlockInfo (Object)¶
Information about the block encryption options
Members¶
- The members of
QCryptoBlockInfoBase - The members of
QCryptoBlockInfoLUKSwhenformatis"luks"
Since¶
2.7
QCryptoBlockLUKSKeyslotState (Enum)¶
Defines state of keyslots that are affected by the update
Values¶
activeThe slots contain the given password and marked as active
inactiveThe 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:QCryptoBlockLUKSKeyslotStatethe 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 password 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
QCryptoBlockAmendOptionsLUKSwhenformatis"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 option 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 unencrypted.
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
keyidis given. Ignored ifkeyidis absent.
Features¶
deprecatedMember
loadedis 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:intserial 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. (default: 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¶
deprecatedMember
loadedis 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¶
deprecatedMember
loadedis 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 version by providing the
passwordidparameter. This provides the ID of a previously created secret object containing the password for decryption.- The members of
TlsCredsProperties
Features¶
deprecatedMember
loadedis deprecated. Setting true doesn’t make sense, and false is already the default.
Since¶
2.5
Background jobs¶
JobType (Enum)¶
Type of a background job.
Values¶
commitblock commit job type, see “block-commit”
streamblock stream job type, see “block-stream”
mirrordrive mirror job type, see “drive-mirror”
backupdrive backup job type, see “drive-backup”
createimage creation job type, see “blockdev-create” (since 3.0)
amendimage options amend job type, see “x-blockdev-amend” (since 5.1)
snapshot-loadsnapshot load job type, see “snapshot-load” (since 6.0)
snapshot-savesnapshot save job type, see “snapshot-save” (since 6.0)
snapshot-deletesnapshot 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¶
undefinedErroneous, default state. Should not ever be visible.
createdThe job has been created, but not yet started.
runningThe job is currently running.
pausedThe job is running, but paused. The pause may be requested by either the QMP user or by internal processes.
readyThe job is running, but is ready for the user to signal completion. This is used for long-running jobs like mirror that are designed to run indefinitely.
standbyThe job is ready, but paused. This is nearly identical to
paused. The job may return toreadyor otherwise be canceled.waitingThe 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.
pendingThe 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-finalizeif auto-finalize was set to false. These pending changes may still fail.abortingThe 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.concludedThe 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.nullThe 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¶
cancelsee
job-cancelpausesee
job-pauseresumesee
job-resumeset-speedsee
block-job-set-speedcompletesee
job-completedismisssee
job-dismissfinalizesee
job-finalize
Since¶
2.12
JOB_STATUS_CHANGE (Event)¶
Emitted when a job transitions to a different status.
Arguments¶
id:stringThe job identifier
status:JobStatusThe new job status
Since¶
3.0
job-pause (Command)¶
Pause an active job.
This command returns immediately after marking the active job for pausing. 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:stringThe 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:stringNot 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 cancellation.
The job will cancel as soon as possible and then emit a JOB_STATUS_CHANGE event. Usually, the status will change to ABORTING, but it is possible that a job successfully completes (e.g. because it was almost done and there was no opportunity to cancel earlier than completing the job) and transitions to PENDING instead.
Arguments¶
id:stringThe job identifier.
Since¶
3.0
job-complete (Command)¶
Manually trigger completion of an active job in the READY state.
Arguments¶
id:stringThe 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 enabled.
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:stringThe 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 PENDING 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 instruct a single member job to finalize.
Arguments¶
id:stringThe 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:stringThe job identifier
type:JobTypeThe kind of job that is being performed
status:JobStatusCurrent job state/status
current-progress:intProgress made until now. The unit is arbitrary and the value can only meaningfully be used for the ratio of
current-progresstototal-progress. The value is monotonically increasing.total-progress:intEstimated
current-progressvalue 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 reason for the job failure. It should not be parsed by applications.
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¶
ipv4IPV4 family
ipv6IPV6 family
unixunix socket
vsockvsock family (since 2.8)
unknownotherwise
Since¶
2.1
InetSocketAddressBase (Object)¶
Members¶
host:stringhost part of the address
port:stringport 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 between
portandto.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:stringfilesystem path to use
abstract:boolean(optional) (If:CONFIG_LINUX)if true, this is a Linux abstract socket address.
pathwill 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:stringunique host identifier
port:stringport
Note¶
string types are used to allow for possible future hostname or service resolution support.
Since¶
2.8
InetSocketAddressWrapper (Object)¶
Members¶
data:InetSocketAddressNot documented
Since¶
1.3
UnixSocketAddressWrapper (Object)¶
Members¶
data:UnixSocketAddressNot documented
Since¶
1.3
VsockSocketAddressWrapper (Object)¶
Members¶
data:VsockSocketAddressNot documented
Since¶
2.8
StringWrapper (Object)¶
Members¶
data:StringNot documented
Since¶
1.3
SocketAddressLegacy (Object)¶
Captures the address of a socket, which could also be a named file descriptor
Members¶
type:SocketAddressTypeNot documented
- The members of
InetSocketAddressWrapperwhentypeis"inet" - The members of
UnixSocketAddressWrapperwhentypeis"unix" - The members of
VsockSocketAddressWrapperwhentypeis"vsock" - The members of
StringWrapperwhentypeis"fd"
Note¶
This type is deprecated in favor of SocketAddress. The difference between SocketAddressLegacy and SocketAddress is that the latter is has fewer {} on the wire.
Since¶
1.3
SocketAddressType (Enum)¶
Available SocketAddress types
Values¶
inetInternet address
unixUnix domain socket
vsockVMCI address
fddecimal is for file descriptor number, otherwise a file descriptor name. Named file descriptors are permitted in monitor commands, in combination with the ‘getfd’ command. Decimal file descriptors 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 descriptor
Members¶
type:SocketAddressTypeTransport type
- The members of
InetSocketAddresswhentypeis"inet" - The members of
UnixSocketAddresswhentypeis"unix" - The members of
VsockSocketAddresswhentypeis"vsock" - The members of
Stringwhentypeis"fd"
Since¶
2.9
SnapshotInfo (Object)¶
Members¶
id:stringunique snapshot id
name:stringuser chosen name
vm-state-size:intsize of the VM state
date-sec:intUTC date of the snapshot in seconds
date-nsec:intfractional part in nano seconds to be used with date-sec
vm-clock-sec:intVM clock relative to boot in seconds
vm-clock-nsec:intfractional 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 obtained through
query-replaycommand (since 5.2)
Since¶
1.3
ImageInfoSpecificQCow2EncryptionBase (Object)¶
Members¶
format:BlockdevQcow2EncryptionFormatThe encryption format
Since¶
2.10
ImageInfoSpecificQCow2Encryption (Object)¶
Members¶
- The members of
ImageInfoSpecificQCow2EncryptionBase - The members of
QCryptoBlockInfoLUKSwhenformatis"luks"
Since¶
2.10
ImageInfoSpecificQCow2 (Object)¶
Members¶
compat:stringcompatibility level
data-file:string(optional)the filename of the external data file that is stored in the image 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:intwidth of a refcount entry in bits (since 2.3)
encrypt:ImageInfoSpecificQCow2Encryption(optional)details about encryption parameters; only set if image is encrypted (since 2.10)
bitmaps:array of Qcow2BitmapInfo(optional)A list of qcow2 bitmap details (since 4.0)
compression-type:Qcow2CompressionTypethe image cluster compression method (since 5.1)
Since¶
1.7
ImageInfoSpecificVmdk (Object)¶
Members¶
create-type:stringThe create type of VMDK image
cid:intContent id of image
parent-cid:intParent VMDK image’s cid
extents:array of ImageInfoList of extent files
Since¶
1.7
ImageInfoSpecificRbd (Object)¶
Members¶
encryption-format:RbdImageEncryptionFormat(optional)Image encryption format
Since¶
6.1
ImageInfoSpecificKind (Enum)¶
Values¶
luksSince 2.7
rbdSince 6.1
qcow2Not documented
vmdkNot documented
Since¶
1.7
ImageInfoSpecificQCow2Wrapper (Object)¶
Members¶
data:ImageInfoSpecificQCow2Not documented
Since¶
1.7
ImageInfoSpecificVmdkWrapper (Object)¶
Members¶
data:ImageInfoSpecificVmdkNot documented
Since¶
6.1
ImageInfoSpecificLUKSWrapper (Object)¶
Members¶
data:QCryptoBlockInfoLUKSNot documented
Since¶
2.7
ImageInfoSpecificRbdWrapper (Object)¶
Members¶
data:ImageInfoSpecificRbdNot documented
Since¶
6.1
ImageInfoSpecific (Object)¶
A discriminated record of image format specific information structures.
Members¶
type:ImageInfoSpecificKindNot documented
- The members of
ImageInfoSpecificQCow2Wrapperwhentypeis"qcow2" - The members of
ImageInfoSpecificVmdkWrapperwhentypeis"vmdk" - The members of
ImageInfoSpecificLUKSWrapperwhentypeis"luks" - The members of
ImageInfoSpecificRbdWrapperwhentypeis"rbd"
Since¶
1.7
ImageInfo (Object)¶
Information about a QEMU image file
Members¶
filename:stringname of the image file
format:stringformat of the image file
virtual-size:intmaximum 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:stringname of the image file checked
format:stringformat of the image file checked
check-errors:intnumber 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:intvirtual (guest) offset of the first byte described by this entry
length:intthe number of bytes of the mapped virtual range
data:booleanreading the image will actually read data from a file (in particular, if
offsetis present this means that the sectors are not simply preallocated, but contain actual data in raw format)zero:booleanwhether the virtual blocks read as zeroes
depth:intnumber 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:booleantrue 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:booleantrue if writeback mode is enabled
direct:booleantrue if the host page cache is bypassed (O_DIRECT)
no-flush:booleantrue if flush requests are ignored for the device
Since¶
2.3
BlockDeviceInfo (Object)¶
Information about the backing device for a block device.
Members¶
file:stringthe filename of the backing device
node-name:string(optional)the name of the block driver node (Since 2.0)
ro:booleantrue if the backing device was open read-only
drv:stringthe 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:intnumber of files in the backing file chain (since: 1.2)
encrypted:booleantrue if the backing device is encrypted
detect_zeroes:BlockdevDetectZeroesOptionsdetect and optimize zero writes (Since 2.1)
bps:inttotal throughput limit in bytes per second is specified
bps_rd:intread throughput limit in bytes per second is specified
bps_wr:intwrite throughput limit in bytes per second is specified
iops:inttotal I/O operations per second is specified
iops_rd:intread I/O operations per second is specified
iops_wr:intwrite I/O operations per second is specified
image:ImageInfothe 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_maxburst period, in seconds. (Since 2.6)
- maximum length of the
bps_rd_max_length:int(optional)- maximum length of the
bps_rd_max burst period, in seconds. (Since 2.6)
- maximum length of the
bps_wr_max_length:int(optional)- maximum length of the
bps_wr_max burst period, in seconds. (Since 2.6)
- maximum length of the
iops_max_length:int(optional)- maximum length of the
iopsburst period, in seconds. (Since 2.6)
- maximum length of the
iops_rd_max_length:int(optional)- maximum length of the
iops_rd_max burst period, in seconds. (Since 2.6)
- maximum length of the
iops_wr_max_length:int(optional)- maximum length of the
iops_wr_max burst period, in seconds. (Since 2.6)
- maximum length of the
iops_size:int(optional)an I/O size in bytes (Since 1.7)
group:string(optional)throttle group name (Since 2.4)
cache:BlockdevCacheInfothe cache mode used for the block device (since: 2.3)
write_threshold:intconfigured 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¶
okThe last I/O operation has succeeded
failedThe last I/O operation has failed
nospaceThe 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:intnumber of dirty bytes according to the dirty bitmap
granularity:intgranularity of the dirty bitmap in bytes (since 1.4)
recording:booleantrue if the bitmap is recording new writes from the guest. Replaces
activeanddisabledstatuses. (since 4.0)busy:booleantrue if the bitmap is in-use by some operation (NBD or jobs) and cannot be modified via QMP or used by another operation. Replaces
lockedandfrozenstatuses. (since 4.0)persistent:booleantrue 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
persistentto be true;recordingandbusyto be false. This bitmap cannot be used. To remove it, useblock-dirty-bitmap-remove. (Since 4.0)
Since¶
1.3
Qcow2BitmapInfoFlags (Enum)¶
An enumeration of flags that a bitmap can report to the user.
Values¶
in-useThis 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 usage, and may contain inconsistent data.
autoThe 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:stringthe name of the bitmap
granularity:intgranularity of the bitmap in bytes
flags:array of Qcow2BitmapInfoFlagsflags of the bitmap
Since¶
4.0
BlockLatencyHistogramInfo (Object)¶
Block latency histogram.
Members¶
boundaries:array of intlist 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 intlist of io request counts corresponding to histogram intervals. len(
bins) = len(boundaries) + 1 For the example above,binsmay 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:stringThe 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:stringThis field is returned only for compatibility reasons, it should not be used (always returns ‘unknown’)
removable:booleanTrue if the device supports removable media.
locked:booleanTrue 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)BlockDeviceInfodescribing 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:intSize required for a new image file, in bytes, when copying just allocated guest-visible contents.
fully-allocated:intImage 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 bitmaps. (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:intInterval used for calculating the statistics, in seconds.
min_rd_latency_ns:intMinimum latency of read operations in the defined interval, in nanoseconds.
min_wr_latency_ns:intMinimum latency of write operations in the defined interval, in nanoseconds.
min_flush_latency_ns:intMinimum latency of flush operations in the defined interval, in nanoseconds.
max_rd_latency_ns:intMaximum latency of read operations in the defined interval, in nanoseconds.
max_wr_latency_ns:intMaximum latency of write operations in the defined interval, in nanoseconds.
max_flush_latency_ns:intMaximum latency of flush operations in the defined interval, in nanoseconds.
avg_rd_latency_ns:intAverage latency of read operations in the defined interval, in nanoseconds.
avg_wr_latency_ns:intAverage latency of write operations in the defined interval, in nanoseconds.
avg_flush_latency_ns:intAverage latency of flush operations in the defined interval, in nanoseconds.
avg_rd_queue_depth:numberAverage number of pending read operations in the defined interval.
avg_wr_queue_depth:numberAverage number of pending write operations in the defined interval.
Since¶
2.5
BlockDeviceStats (Object)¶
Statistics of a virtual block device or a block backing device.
Members¶
rd_bytes:intThe number of bytes read by the device.
wr_bytes:intThe number of bytes written by the device.
unmap_bytes:intThe number of bytes unmapped by the device (Since 4.2)
rd_operations:intThe number of read operations performed by the device.
wr_operations:intThe number of write operations performed by the device.
flush_operations:intThe number of cache flush operations performed by the device (since 0.15)
unmap_operations:intThe number of unmap operations performed by the device (Since 4.2)
rd_total_time_ns:intTotal time spent on reads in nanoseconds (since 0.15).
wr_total_time_ns:intTotal time spent on writes in nanoseconds (since 0.15).
flush_total_time_ns:intTotal time spent on cache flushes in nanoseconds (since 0.15).
unmap_total_time_ns:intTotal time spent on unmap operations in nanoseconds (Since 4.2)
wr_highest_offset:intThe 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:intNumber of read requests that have been merged into another request (Since 2.3).
wr_merged:intNumber of write requests that have been merged into another request (Since 2.3).
unmap_merged:intNumber of unmap requests that have been merged into another request (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:intThe number of failed read operations performed by the device (Since 2.5)
failed_wr_operations:intThe number of failed write operations performed by the device (Since 2.5)
failed_flush_operations:intThe number of failed flush operations performed by the device (Since 2.5)
failed_unmap_operations:intThe 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:intThe number of invalid write operations performed by the device (Since 2.5)
invalid_flush_operations:intThe number of invalid flush operations performed by the device (Since 2.5)
invalid_unmap_operations:intThe number of invalid unmap operations performed by the device (Since 4.2)
account_invalid:booleanWhether invalid operations are included in the last access statistics (Since 2.5)
account_failed:booleanWhether failed operations are included in the latency and last access statistics (Since 2.5)
timed_stats:array of BlockDeviceTimedStatsStatistics 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:intThe number of successful discard operations performed by the driver.
discard-nb-failed:intThe number of failed discard operations performed by the driver.
discard-bytes-ok:intThe number of bytes discarded by the driver.
Since¶
4.2
BlockStatsSpecificNvme (Object)¶
NVMe driver statistics
Members¶
completion-errors:intThe number of completion errors.
aligned-accesses:intThe number of aligned accesses performed by the driver.
unaligned-accesses:intThe number of unaligned accesses performed by the driver.
Since¶
5.2
BlockStatsSpecific (Object)¶
Block driver specific statistics
Members¶
driver:BlockdevDriverNot documented
- The members of
BlockStatsSpecificFilewhendriveris"file" - The members of
BlockStatsSpecificFilewhendriveris"host_device"(If:HAVE_HOST_BLOCK_DEVICE) - The members of
BlockStatsSpecificNvmewhendriveris"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 corresponding 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:BlockDeviceStatsA
BlockDeviceStatsfor 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 protocol, 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 before - query all the device backends, recursively including their “parent” and “backing”. Filter nodes that were created implicitly 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¶
reportfor guest operations, report the error to the guest; for jobs, cancel the job
ignoreignore 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.
enospcsame as
stopon ENOSPC, same asreportotherwise.stopfor guest operations, stop the virtual machine; for jobs, pause the job
autoinherit 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¶
topcopies data in the topmost image to the destination
fullcopies data from all images to the destination
noneonly copy data written from now on
incrementalonly copy data described by the dirty bitmap. (since: 2.4)
bitmaponly copy data described by the dirty bitmap. (since: 4.2) Behavior on completion is determined by the BitmapSyncMode.
Since¶
1.3
BitmapSyncMode (Enum)¶
An enumeration of possible behaviors for the synchronization of a bitmap when used for data copy operations.
Values¶
on-successThe bitmap is only synced when the operation is successful. This is the behavior always used for ‘INCREMENTAL’ backups.
neverThe bitmap is never synchronized with the operation, and is treated solely as a read-only manifest of blocks to copy.
alwaysThe 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¶
backgroundcopy data in background only.
write-blockingwhen data is written to the source, write it (synchronously) to the target as well. In addition, data is copied in background just like in
backgroundmode.
Since¶
3.0
BlockJobInfo (Object)¶
Information about a long-running block device operation.
Members¶
type:stringthe job type (‘stream’ for image streaming)
device:stringThe job identifier. Originally the device name but other values are allowed since QEMU 2.7
len:intEstimated
offsetvalue at the completion of the job. This value can arbitrarily change while the job is running, in both directions.offset:intProgress made until now. The unit is arbitrary and the value can only meaningfully be used for the ratio of
offsettolen. The value is monotonically increasing.busy:booleanfalse if the job is known to be in a quiescent state, with no pending I/O. Since 1.3.
paused:booleanwhether the job is paused or, if
busyis true, will pause itself as soon as possible. Since 1.3.speed:intthe rate limit, bytes per second
io-status:BlockDeviceIoStatusthe status of the job (since 1.3)
ready:booleantrue if the job may be completed (since 2.2)
status:JobStatusCurrent job state/status (since 2.12)
auto-finalize:booleanJob will finalize itself when PENDING, moving to the CONCLUDED state. (since 2.12)
auto-dismiss:booleanJob 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:intnew image size in bytes
Returns¶
nothing on success
If
deviceis 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¶
existingQEMU should look for an existing image file.
absolute-pathsQEMU should create a new image with absolute paths for the backing 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:stringthe 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 ‘absolute-paths’.
BlockdevSnapshot (Object)¶
Members¶
node:stringdevice or node name that will have a snapshot taken.
overlay:stringreference 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 functionality, 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 device name will be used. (Since 2.7)
device:stringthe device name or node-name of a root node which should be copied.
sync:MirrorSyncModewhat 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. (default: 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 supports 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-finalizebefore 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 autogenerated. (Since: 4.2)x-perf:BackupPerf(optional)Performance options. (Since 6.0)
Features¶
unstableMember
x-perfis 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:stringthe 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 destination. 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
modeis ‘existing’, else the format of the sourcemode:NewImageMode(optional)whether and how QEMU should create a new image, default is ‘absolute-paths’.
- The members of
BackupCommon
Since¶
1.6
BlockdevBackup (Object)¶
Members¶
target:stringthe 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
deviceis 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 ‘overlay’. 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-overlayIf 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:stringThe 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:stringThe device name or node-name of the root node that owns image-node-name.
backing-file:stringThe 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 itself. 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 resized to be the same size as top. If top is smaller than the base image, 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 yourself once the commit operation successfully completes.
Arguments¶
job-id:string(optional)identifier for the newly-created block job. If omitted, the device name will be used. (Since 2.7)
device:stringthe 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 acceptedtop-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 specified, 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 acceptedbacking-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 error.
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 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. ‘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-finalizebefore 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¶
deprecatedMembers
baseandtopare deprecated. Usebase-nodeandtop-nodeinstead.
Returns¶
Nothing on success
If
devicedoes not exist, DeviceNotFoundAny 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¶
deprecatedThis command is deprecated. Use
blockdev-backupinstead.
Returns¶
nothing on success
If
deviceis 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
deviceis 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,
"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-backendcorresponds to BlockBackend
block-jobcorresponds to BlockJob
block-drivercorresponds to BlockDriverState
Since¶
4.0
XDbgBlockGraphNode (Object)¶
Members¶
id:intBlock graph node identifier. This
idis generated only for x-debug-query-block-graph and does not relate to any other identifiers in Qemu.type:XDbgBlockGraphNodeTypeType of graph node. Can be one of block-backend, block-job or block-driver-state.
name:stringHuman 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-readA user that has the “permission” of consistent reads is guaranteed that their view of the contents of the block device is complete 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 maintained in a few situations like for intermediate nodes of a commit block job.
writeThis permission is required to change the visible disk contents.
write-unchangedThis 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 sufficient to perform an unchanging write.
resizeThis permission is required to change the size of a block node.
graph-modThis permission is required to change the node that this BdrvChild points to.
Since¶
4.0
XDbgBlockGraphEdge (Object)¶
Block Graph edge description for x-debug-query-block-graph.
Members¶
parent:intparent id
child:intchild id
name:stringname of the relation (examples are ‘file’ and ‘backing’)
perm:array of BlockPermissiongranted permissions for the parent operating on the child
shared-perm:array of BlockPermissionpermissions 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 XDbgBlockGraphNodeNot documented
edges:array of XDbgBlockGraphEdgeNot documented
Since¶
4.0
x-debug-query-block-graph (Command)¶
Get the block graph.
Features¶
unstableThis 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 format of the source.
Arguments¶
- The members of
DriveMirror
Returns¶
nothing on success
If
deviceis 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 device name will be used. (Since 2.7)
device:stringthe device name or node-name of a root node whose writes should be mirrored.
target:stringthe 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 destination. 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
modeis ‘existing’, else the format of the sourcenode-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 broken Quorum files. By default,
deviceis replaced, although implicitly created filters on it are kept. (Since 2.1)mode:NewImageMode(optional)whether and how QEMU should create a new image, default is ‘absolute-paths’.
speed:int(optional)the maximum speed, in bytes per second
sync:MirrorSyncModewhat 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 supports 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-finalizebefore 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:stringname of device/node which the bitmap is tracking
name:stringname of the dirty bitmap
Since¶
2.4
BlockDirtyBitmapAdd (Object)¶
Members¶
node:stringname of device/node which the bitmap is tracking
name:stringname of the dirty bitmap (must be less than 1024 bytes)
granularity:int(optional)the bitmap granularity, default is 64k for block-dirty-bitmap-add
persistent:boolean(optional)the bitmap is persistent, i.e. it will be saved to the corresponding 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
BlockDirtyBitmapMergeSource (Alternate)¶
Members¶
local:stringname of the bitmap, attached to the same node as target bitmap.
external:BlockDirtyBitmapbitmap with specified node
Since¶
4.1
BlockDirtyBitmapMerge (Object)¶
Members¶
node:stringname of device/node which the
targetbitmap is trackingtarget:stringname of the destination dirty bitmap
bitmaps:array of BlockDirtyBitmapMergeSourcename(s) of the source dirty bitmap(s) at
nodeand/or fully specified 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
nodeis not a valid block device or node, DeviceNotFoundIf
nameis 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
nodeis not a valid block device or node, DeviceNotFoundIf
nameis not found, GenericError with an explanationif
nameis 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 modified after this clear operation.
Returns¶
nothing on success
If
nodeis not a valid block device, DeviceNotFoundIf
nameis 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
nodeis not a valid block device, DeviceNotFoundIf
nameis 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
nodeis not a valid block device, DeviceNotFoundIf
nameis 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 checkpoints, or in simpler usages, to copy bitmaps.
Returns¶
nothing on success
If
nodeis not a valid block device, DeviceNotFoundIf any bitmap in
bitmapsortargetis not found, GenericErrorIf any of the bitmaps have different sizes or granularities, GenericError
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:stringASCII representation of SHA256 bitmap hash
Since¶
2.10
x-debug-block-dirty-bitmap-sha256 (Command)¶
Get bitmap SHA256.
Features¶
unstableThis command is meant for debugging.
Returns¶
BlockDirtyBitmapSha256 on success
If
nodeis not a valid block device, DeviceNotFoundIf
nameis 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 device name will be used. (Since 2.7)
device:stringThe device name or node-name of a root node whose writes should be mirrored.
target:stringthe 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 broken Quorum files. By default,
deviceis replaced, although implicitly created filters on it are kept.speed:int(optional)the maximum speed, in bytes per second
sync:MirrorSyncModewhat 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 supports 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 option 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-finalizebefore 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:inttotal throughput limit in bytes per second
bps_rd:intread throughput limit in bytes per second
bps_wr:intwrite throughput limit in bytes per second
iops:inttotal I/O operations per second
iops_rd:intread I/O operations per second
iops_wr:intwrite 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_maxburst period, in seconds. It must only be set ifbps_maxis set as well. Defaults to 1. (Since 2.6)bps_rd_max_length:int(optional)maximum length of the
bps_rd_maxburst period, in seconds. It must only be set ifbps_rd_maxis set as well. Defaults to 1. (Since 2.6)bps_wr_max_length:int(optional)maximum length of the
bps_wr_maxburst period, in seconds. It must only be set ifbps_wr_maxis set as well. Defaults to 1. (Since 2.6)iops_max_length:int(optional)maximum length of the
iopsburst period, in seconds. It must only be set ifiops_maxis set as well. Defaults to 1. (Since 2.6)iops_rd_max_length:int(optional)maximum length of the
iops_rd_maxburst period, in seconds. It must only be set ifiops_rd_maxis set as well. Defaults to 1. (Since 2.6)iops_wr_max_length:int(optional)maximum length of the
iops_wr_maxburst period, in seconds. It must only be set ifiops_wr_maxis 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¶
deprecatedMember
deviceis deprecated. Useidinstead.
Since¶
1.1
ThrottleLimits (Object)¶
Limit parameters for throttling. Since some limit combinations are illegal, 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-maxis 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-maxis 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-maxis 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-maxis 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-maxis 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-maxis 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¶
unstableAll members starting with x- are aliases for the same key without x- in the
limitsobject. This is not a stable interface and may be removed or changed incompatibly in the future. Uselimitsfor 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 operations 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 versions 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 backing 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 instead of modifying
device itself.
Arguments¶
job-id:string(optional)identifier for the newly-created block job. If omitted, the device name will be used. (Since 2.7)
device:stringthe device or node name of the top image
base:string(optional)the common backing file name. It cannot be set if
base-nodeorbottomis also set.base-node:string(optional)the node name of the backing file. It cannot be set if
baseorbottomis 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
baseorbase-nodeis 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 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 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 option 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-finalizebefore 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
devicedoes 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:stringThe 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:intthe maximum speed, in bytes per second, or 0 for unlimited. Defaults 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 visible when enumerated using query-block-jobs.
Note that if you issue ‘block-job-cancel’ after ‘drive-mirror’ has indicated (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 cancellation.
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:stringThe 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 automatically resumes it.
Arguments¶
device:stringThe 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:stringThe 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 device to write to the target path only. The ability to complete is signaled with a BLOCK_JOB_READY event.
This command completes an active background block operation synchronously. 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/werror arguments that were specified when starting the operation.
A cancelled or paused job cannot be completed.
Arguments¶
device:stringThe 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:stringThe 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:stringThe job identifier.
Returns¶
Nothing on success
Since¶
2.12
BlockdevDiscardOptions (Enum)¶
Determines how to handle discard requests.
Values¶
ignoreIgnore the request
unmapForward 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¶
offDisabled (default)
onEnabled
unmapEnabled and even try to unmap blocks if possible. This requires also that
BlockdevDiscardOptionsis set to unmap for this device.
Since¶
2.1
BlockdevAioOptions (Enum)¶
Selects the AIO backend to handle I/O requests
Values¶
threadsUse qemu’s thread pool
nativeUse 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¶
throttleSince 2.11
nvmeSince 2.12
copy-on-readSince 3.0
blklogwritesSince 3.0
blkreplaySince 4.2
compressSince 5.0
copy-before-writeSince 6.2
blkdebugNot documented
blkverifyNot documented
bochsNot documented
cloopNot documented
dmgNot documented
fileNot documented
ftpNot documented
ftpsNot documented
glusterNot documented
host_cdrom(If:HAVE_HOST_BLOCK_DEVICE)Not documented
host_device(If:HAVE_HOST_BLOCK_DEVICE)Not documented
httpNot documented
httpsNot documented
iscsiNot documented
luksNot documented
nbdNot documented
nfsNot documented
null-aioNot documented
null-coNot documented
parallelsNot documented
preallocateNot documented
qcowNot documented
qcow2Not documented
qedNot documented
quorumNot documented
rawNot documented
rbdNot documented
replication(If:CONFIG_REPLICATION)Not documented
sshNot documented
vdiNot documented
vhdxNot documented
vmdkNot documented
vpcNot documented
vvfatNot documented
Since¶
2.9
BlockdevOptionsFile (Object)¶
Driver specific block device options for the file backend.
Members¶
filename:stringpath 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 submission 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. (default: 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 (default: 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-onlyIf 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 allows giving QEMU write permissions only on demand when an operation actually needs write access.
unstableMember 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. Default 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:stringPCI controller address of the NVMe device in format hhhh:bb:ss.f (host:bus:slot.function)
namespace:intnamespace 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:stringdirectory 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 traditionally 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 option besides their data source.
Members¶
file:BlockdevRefreference 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 option 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 backing file stored the image file.
- The members of
BlockdevOptionsGenericFormat
Since¶
2.9
Qcow2OverlapCheckMode (Enum)¶
General overlap check modes.
Values¶
noneDo not perform any checks
constantPerform only checks which can be done in constant time and without reading anything from disk
cachedPerform only checks which can be done without reading anything from disk
allPerform 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 unintended overwriting.
Members¶
flags:Qcow2OverlapCheckFlagsset of flags for separate specification of each metadata structure type
mode:Qcow2OverlapCheckModenamed mode which chooses a specific set of flags
Since¶
2.9
BlockdevQcowEncryptionFormat (Enum)¶
Values¶
aesAES-CBC with plain64 initialization vectors
Since¶
2.10
BlockdevQcowEncryption (Object)¶
Members¶
format:BlockdevQcowEncryptionFormatNot documented
- The members of
QCryptoBlockOptionsQCowwhenformatis"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¶
aesAES-CBC with plain64 initialization vectors
luksNot documented
Since¶
2.10
BlockdevQcow2Encryption (Object)¶
Members¶
format:BlockdevQcow2EncryptionFormatNot documented
- The members of
QCryptoBlockOptionsQCowwhenformatis"aes" - The members of
QCryptoBlockOptionsLUKSwhenformatis"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, defaults 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¶
noneDon’t check the host key at all
hashCompare the host key with a given hash
known_hostsCheck the host key against the known_hosts file
Since¶
2.12
SshHostKeyCheckHashType (Enum)¶
Values¶
md5The given hash is an md5 hash
sha1The given hash is an sha1 hash
sha256The given hash is an sha256 hash
Since¶
2.12
SshHostKeyHash (Object)¶
Members¶
type:SshHostKeyCheckHashTypeThe hash algorithm used for the hash
hash:stringThe expected hash value
Since¶
2.12
SshHostKeyCheck (Object)¶
Members¶
mode:SshHostKeyCheckModeNot documented
- The members of
SshHostKeyHashwhenmodeis"hash"
Since¶
2.12
BlockdevOptionsSsh (Object)¶
Members¶
server:InetSocketAddresshost address
path:stringpath 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_tablewrite zeros to the l1 table to shrink image. (since 2.11)
l1_shrink_free_l2_clustersdiscard the l2 tables. (since 2.11)
cor_writea write due to copy-on-read (since 2.11)
cluster_alloc_spacean allocation of file space for a cluster (since 4.1)
nonetriggers once at creation of the blkdebug node (since 4.1)
l1_updateNot documented
l1_grow_alloc_tableNot documented
l1_grow_write_tableNot documented
l1_grow_activate_tableNot documented
l2_loadNot documented
l2_updateNot documented
l2_update_compressedNot documented
l2_alloc_cow_readNot documented
l2_alloc_writeNot documented
read_aioNot documented
read_backing_aioNot documented
read_compressedNot documented
write_aioNot documented
write_compressedNot documented
vmstate_loadNot documented
vmstate_saveNot documented
cow_readNot documented
cow_writeNot documented
reftable_loadNot documented
reftable_growNot documented
reftable_updateNot documented
refblock_loadNot documented
refblock_updateNot documented
refblock_update_partNot documented
refblock_allocNot documented
refblock_alloc_hookupNot documented
refblock_alloc_writeNot documented
refblock_alloc_write_blocksNot documented
refblock_alloc_write_tableNot documented
refblock_alloc_switch_tableNot documented
cluster_allocNot documented
cluster_alloc_bytesNot documented
cluster_freeNot documented
flush_to_osNot documented
flush_to_diskNot documented
pwritev_rmw_headNot documented
pwritev_rmw_after_headNot documented
pwritev_rmw_tailNot documented
pwritev_rmw_after_tailNot documented
pwritevNot documented
pwritev_zeroNot documented
pwritev_doneNot documented
empty_image_prepareNot 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:BlkdebugEventtrigger 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 injected; 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; defaults 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:BlkdebugEventtrigger event
state:int(optional)the current state identifier blkdebug needs to be in; defaults to “any”
new_state:intthe 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:BlockdevRefunderlying 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 multiple of
alignand 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
alignand 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, ofopt-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 positive multiple of
alignand 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, ofopt-discard, and of the underlying file’s request alignment (but need not be a power of 2), or 0 for default (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
imagein addition to what is necessary anyway (which depends on how the blkdebug node is used). Defaults to none. (since 5.0)unshare-child-perms:array of BlockPermission(optional)Permissions not to share on
imagein 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:BlockdevRefblock device
log:BlockdevRefblock device used to log writes to
filelog-sector-size:int(optional)sector size used in logging writes to
file, determines granularity 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:BlockdevRefblock device to be tested
raw:BlockdevRefraw image used for verification
Since¶
2.9
BlockdevOptionsBlkreplay (Object)¶
Driver specific block device options for blkreplay.
Members¶
image:BlockdevRefdisk image which should be controlled with blkreplay
Since¶
4.2
QuorumReadPattern (Enum)¶
An enumeration of quorum read patterns.
Values¶
quorumread all the children and do a quorum vote on reads
fiforead 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 BlockdevRefthe children block devices to use
vote-threshold:intthe 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:stringname of gluster volume where VM image resides
path:stringabsolute path to image file in gluster volume
server:array of SocketAddressgluster 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
IscsiTransport (Enum)¶
An enumeration of libiscsi transport types
Values¶
tcpNot documented
iserNot documented
Since¶
2.9
IscsiHeaderDigest (Enum)¶
An enumeration of header digests supported by libiscsi
Values¶
crc32cNot documented
noneNot documented
crc32c-noneNot documented
none-crc32cNot documented
Since¶
2.9
BlockdevOptionsIscsi (Object)¶
Members¶
transport:IscsiTransportThe iscsi transport type
portal:stringThe address of the iscsi portal
target:stringThe 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
useris specified.initiator-name:string(optional)The iqn name we want to identify to the target as. If this option is not specified, an initiator name is generated automatically.
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¶
cephxNot documented
noneNot documented
Since¶
3.0
RbdImageEncryptionFormat (Enum)¶
Values¶
luksNot documented
luks2Not documented
Since¶
6.1
RbdEncryptionOptionsLUKSBase (Object)¶
Members¶
key-secret:stringID of a QCryptoSecret object providing a passphrase for unlocking 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:RbdImageEncryptionFormatNot documented
- The members of
RbdEncryptionOptionsLUKSwhenformatis"luks" - The members of
RbdEncryptionOptionsLUKS2whenformatis"luks2"
Since¶
6.1
RbdEncryptionCreateOptions (Object)¶
Members¶
format:RbdImageEncryptionFormatNot documented
- The members of
RbdEncryptionCreateOptionsLUKSwhenformatis"luks" - The members of
RbdEncryptionCreateOptionsLUKS2whenformatis"luks2"
Since¶
6.1
BlockdevOptionsRbd (Object)¶
Members¶
pool:stringCeph pool name.
namespace:string(optional)Rados namespace name in the Ceph pool. (Since 5.0)
image:stringImage 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 configuration option “auth_client_required”. (Since 3.0)
key-secret:string(optional)ID of a QCryptoSecret object providing a key for cephx authentication. 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¶
primaryPrimary mode, the vm’s state will be sent to secondary QEMU.
secondarySecondary 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:ReplicationModethe 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¶
inetTCP transport
Since¶
2.9
NFSServer (Object)¶
Captures the address of the socket
Members¶
type:NFSTransporttransport type used for NFS (only TCP supported)
host:stringhost address for NFS server
Since¶
2.9
BlockdevOptionsNfs (Object)¶
Driver specific block device option for NFS
Members¶
server:NFSServerhost address
path:stringpath 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:stringURL of the image file
readahead:int(optional)Size of the read-ahead cache; must be a multiple of 512 (defaults 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 authentication (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 authentication (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=content2;” as explained by CURLOPT_COOKIE(3). Defaults to no cookies.
cookie-secret:string(optional)ID of a QCryptoSecret object providing the cookie data in a secure way. See
cookiefor 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=content2;” as explained by CURLOPT_COOKIE(3). Defaults to no cookies.
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 secure way. See
cookiefor 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:SocketAddressNBD server address
export:string(optional)export name
tls-creds:string(optional)TLS credentials ID
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-delayseconds, 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 reconnect will immediately fail. Default 0 (Since 4.2)
Features¶
unstableMember
x-dirty-bitmapis 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:stringthe name of the throttle-group object to use. It must already exist.
file:BlockdevRefreference 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
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:BlockdevRefThe target for copy-before-write operations.
- 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:BlockdevDriverblock driver name
node-name:string(optional)the node name of the new node (Since 2.0). This option is required 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 characters.
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, either generally or in certain configurations. In this case, the default value does not work and the option must be specified explicitly.
auto-read-only:boolean(optional)if true and
read-onlyis 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. depending on whether the image file is writable or whether a writing 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
BlockdevOptionsBlkdebugwhendriveris"blkdebug" - The members of
BlockdevOptionsBlklogwriteswhendriveris"blklogwrites" - The members of
BlockdevOptionsBlkverifywhendriveris"blkverify" - The members of
BlockdevOptionsBlkreplaywhendriveris"blkreplay" - The members of
BlockdevOptionsGenericFormatwhendriveris"bochs" - The members of
BlockdevOptionsGenericFormatwhendriveris"cloop" - The members of
BlockdevOptionsGenericFormatwhendriveris"compress" - The members of
BlockdevOptionsCbwwhendriveris"copy-before-write" - The members of
BlockdevOptionsCorwhendriveris"copy-on-read" - The members of
BlockdevOptionsGenericFormatwhendriveris"dmg" - The members of
BlockdevOptionsFilewhendriveris"file" - The members of
BlockdevOptionsCurlFtpwhendriveris"ftp" - The members of
BlockdevOptionsCurlFtpswhendriveris"ftps" - The members of
BlockdevOptionsGlusterwhendriveris"gluster" - The members of
BlockdevOptionsFilewhendriveris"host_cdrom"(If:HAVE_HOST_BLOCK_DEVICE) - The members of
BlockdevOptionsFilewhendriveris"host_device"(If:HAVE_HOST_BLOCK_DEVICE) - The members of
BlockdevOptionsCurlHttpwhendriveris"http" - The members of
BlockdevOptionsCurlHttpswhendriveris"https" - The members of
BlockdevOptionsIscsiwhendriveris"iscsi" - The members of
BlockdevOptionsLUKSwhendriveris"luks" - The members of
BlockdevOptionsNbdwhendriveris"nbd" - The members of
BlockdevOptionsNfswhendriveris"nfs" - The members of
BlockdevOptionsNullwhendriveris"null-aio" - The members of
BlockdevOptionsNullwhendriveris"null-co" - The members of
BlockdevOptionsNVMewhendriveris"nvme" - The members of
BlockdevOptionsGenericFormatwhendriveris"parallels" - The members of
BlockdevOptionsPreallocatewhendriveris"preallocate" - The members of
BlockdevOptionsQcow2whendriveris"qcow2" - The members of
BlockdevOptionsQcowwhendriveris"qcow" - The members of
BlockdevOptionsGenericCOWFormatwhendriveris"qed" - The members of
BlockdevOptionsQuorumwhendriveris"quorum" - The members of
BlockdevOptionsRawwhendriveris"raw" - The members of
BlockdevOptionsRbdwhendriveris"rbd" - The members of
BlockdevOptionsReplicationwhendriveris"replication"(If:CONFIG_REPLICATION) - The members of
BlockdevOptionsSshwhendriveris"ssh" - The members of
BlockdevOptionsThrottlewhendriveris"throttle" - The members of
BlockdevOptionsGenericFormatwhendriveris"vdi" - The members of
BlockdevOptionsGenericFormatwhendriveris"vhdx" - The members of
BlockdevOptionsGenericCOWFormatwhendriveris"vmdk" - The members of
BlockdevOptionsGenericFormatwhendriveris"vpc" - The members of
BlockdevOptionsVVFATwhendriveris"vvfat"
Remaining options are determined by the block driver.
Since¶
2.9
BlockdevRef (Alternate)¶
Reference to a block device.
Members¶
definition:BlockdevOptionsdefines a new block device inline
reference:stringreferences the ID of an existing block device
Since¶
2.9
BlockdevRefOrNull (Alternate)¶
Reference to a block device.
Members¶
definition:BlockdevOptionsdefines a new block device inline
reference:stringreferences the ID of an existing block device. An empty string means that no block device should be referenced. Deprecated; use null instead.
null:nullNo 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 error. 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:
A set of options (BlockdevOptions): the child is reopened with the specified set of options.
A reference to the current child: the child is reopened using its existing set of options.
A reference to a different node: the current child is replaced with the specified one.
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
unless 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 BlockdevOptionsNot 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:stringName 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:stringFilename for the new image file
size:intSize of the virtual disk in bytes
preallocation:PreallocMode(optional)Preallocation mode for the new image (default: off; allowed values: off, falloc (if CONFIG_POSIX_FALLOCATE), full (if CONFIG_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:BlockdevOptionsGlusterWhere to store the new image file
size:intSize of the virtual disk in bytes
preallocation:PreallocMode(optional)Preallocation mode for the new image (default: off; allowed values: off, falloc (if CONFIG_GLUSTERFS_FALLOCATE), full (if CONFIG_GLUSTERFS_ZEROFILL))
Since¶
2.12
BlockdevCreateOptionsLUKS (Object)¶
Driver specific image creation options for LUKS.
Members¶
file:BlockdevRefNode to create the image format on
size:intSize 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:BlockdevOptionsNfsWhere to store the new image file
size:intSize of the virtual disk in bytes
Since¶
2.12
BlockdevCreateOptionsParallels (Object)¶
Driver specific image creation options for parallels.
Members¶
file:BlockdevRefNode to create the image format on
size:intSize 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:BlockdevRefNode to create the image format on
size:intSize 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¶
v2The original QCOW2 format as introduced in qemu 0.10 (version 2)
v3The extended QCOW2 format as introduced in qemu 1.1 (version 3)
Since¶
2.12
Qcow2CompressionType (Enum)¶
Compression type used in qcow2 image file
Values¶
zlibzlib 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:BlockdevRefNode 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 (default: false; since: 4.0)
extended-l2:boolean(optional)True to make the image have extended L2 entries (default: false; since 5.2)
size:intSize 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 values: 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:BlockdevRefNode to create the image format on
size:intSize 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:BlockdevOptionsRbdWhere to store the new image file. This location cannot point to a snapshot.
size:intSize 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¶
monolithicSparseSingle file image with sparse cluster allocation
monolithicFlatSingle flat data image and a descriptor file
twoGbMaxExtentSparseData is split into 2GB (per virtual LBA) sparse extent files, in addition to a descriptor file
twoGbMaxExtentFlatData is split into 2GB (per virtual LBA) flat extent files, in addition to a descriptor file
streamOptimizedSingle file image sparse cluster allocation, optimized for streaming over network.
Since¶
4.0
BlockdevVmdkAdapterType (Enum)¶
Adapter type info for VMDK images
Values¶
ideNot documented
buslogicNot documented
lsilogicNot documented
legacyESXNot documented
Since¶
4.0
BlockdevCreateOptionsVmdk (Object)¶
Driver specific image creation options for VMDK.
Members¶
file:BlockdevRefWhere to store the new image file. This refers to the image file for monolithcSparse and streamOptimized format, or the descriptor file for other formats.
size:intSize 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 monolithicFlat, only one entry is required; for twoGbMaxExtent* formats, the number of entries required is calculated as extent_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”. Default: “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:BlockdevOptionsSshWhere to store the new image file
size:intSize of the virtual disk in bytes
Since¶
2.12
BlockdevCreateOptionsVdi (Object)¶
Driver specific image creation options for VDI.
Members¶
file:BlockdevRefNode to create the image format on
size:intSize of the virtual disk in bytes
preallocation:PreallocMode(optional)Preallocation mode for the new image (default: off; allowed values: off, metadata)
Since¶
2.12
BlockdevVhdxSubformat (Enum)¶
Values¶
dynamicGrowing image file
fixedPreallocated fixed-size image file
Since¶
2.12
BlockdevCreateOptionsVhdx (Object)¶
Driver specific image creation options for vhdx.
Members¶
file:BlockdevRefNode to create the image format on
size:intSize 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 depending 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¶
dynamicGrowing image file
fixedPreallocated fixed-size image file
Since¶
2.12
BlockdevCreateOptionsVpc (Object)¶
Driver specific image creation options for vpc (VHD).
Members¶
file:BlockdevRefNode to create the image format on
size:intSize 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:BlockdevDriverblock driver to create the image format
- The members of
BlockdevCreateOptionsFilewhendriveris"file" - The members of
BlockdevCreateOptionsGlusterwhendriveris"gluster" - The members of
BlockdevCreateOptionsLUKSwhendriveris"luks" - The members of
BlockdevCreateOptionsNfswhendriveris"nfs" - The members of
BlockdevCreateOptionsParallelswhendriveris"parallels" - The members of
BlockdevCreateOptionsQcowwhendriveris"qcow" - The members of
BlockdevCreateOptionsQcow2whendriveris"qcow2" - The members of
BlockdevCreateOptionsQedwhendriveris"qed" - The members of
BlockdevCreateOptionsRbdwhendriveris"rbd" - The members of
BlockdevCreateOptionsSshwhendriveris"ssh" - The members of
BlockdevCreateOptionsVdiwhendriveris"vdi" - The members of
BlockdevCreateOptionsVhdxwhendriveris"vhdx" - The members of
BlockdevCreateOptionsVmdkwhendriveris"vmdk" - The members of
BlockdevCreateOptionsVpcwhendriveris"vpc"
Since¶
2.12
blockdev-create (Command)¶
Starts a job to create an image format on a given node. The job is automatically finalized, but a manual job-dismiss is required.
Arguments¶
job-id:stringIdentifier for the newly created job.
options:BlockdevCreateOptionsOptions 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 encryption 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:BlockdevDriverBlock driver of the node to amend.
- The members of
BlockdevAmendOptionsLUKSwhendriveris"luks" - The members of
BlockdevAmendOptionsQcow2whendriveris"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:stringIdentifier for the newly created job.
node-name:stringName of the block node to work on
options:BlockdevAmendOptionsOptions (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¶
unstableThis command is experimental.
Since¶
5.1
BlockErrorAction (Enum)¶
An enumeration of action that has been taken when a DISK I/O occurs
Values¶
ignoreerror has been ignored
reporterror has been reported to the device
stoperror 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 image does not have a device name associated.
Arguments¶
device:stringdevice 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:stringinformative 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 access size
fatal:booleanif 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": "ide0-hd0", "node-name": "node0",
"msg": "Prevented active L1 table overwrite", "offset": 196608,
"size": 65536 },
"timestamp": { "seconds": 1378126126, "microseconds": 966463 } }
Since¶
1.7
BLOCK_IO_ERROR (Event)¶
Emitted when a disk I/O error occurs
Arguments¶
device:stringdevice 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:IoOperationTypeI/O operation
action:BlockErrorActionaction 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:stringhuman readable string describing the error cause. (This field is a debugging aid for humans, it should not be parsed by applications) (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" },
"timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
BLOCK_JOB_COMPLETED (Event)¶
Emitted when a block job has completed
Arguments¶
type:JobTypejob type
device:stringThe job identifier. Originally the device name but other values are allowed since QEMU 2.7
len:intmaximum progress value
offset:intcurrent progress value. On success this is equal to len. On failure this is less than len
speed:intrate 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 interpret 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:JobTypejob type
device:stringThe job identifier. Originally the device name but other values are allowed since QEMU 2.7
len:intmaximum progress value
offset:intcurrent progress value. On success this is equal to len. On failure this is less than len
speed:intrate 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:stringThe job identifier. Originally the device name but other values are allowed since QEMU 2.7
operation:IoOperationTypeI/O operation
action:BlockErrorActionaction 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:JobTypejob type
device:stringThe job identifier. Originally the device name but other values are allowed since QEMU 2.7
len:intmaximum progress value
offset:intcurrent progress value. On success this is equal to len. On failure this is less than len
speed:intrate 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 transaction, it will
not emit this event until the transaction has converged first.
Arguments¶
type:JobTypejob type
id:stringThe job identifier.
Since¶
2.12
Example¶
<- { "event": "BLOCK_JOB_WAITING",
"data": { "device": "drive0", "type": "mirror" },
"timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
PreallocMode (Enum)¶
Preallocation mode of QEMU image file
Values¶
offno preallocation
metadatapreallocate only for metadata
falloclike
fullpreallocation but allocate disk space by posix_fallocate() rather than writing data.fullpreallocate all data by writing it to the device to ensure disk space is really available. This data may or may not be zero, depending on the image format and storage.
fullpreallocation 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:stringgraph node name on which the threshold was exceeded.
amount-exceeded:intamount of data which exceeded the threshold, in bytes.
write-threshold:intlast configured threshold, in bytes.
Since¶
2.3
block-set-write-threshold (Command)¶
Change the write threshold for a block drive. An event will be delivered 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:stringgraph node name on which the threshold must be set.
write-threshold:intconfigured threshold for the block device, bytes. Use 0 to disable 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 useful 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:stringthe 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¶
unstableThis 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:stringthe name of the block driver node
iothread:StrOrNullthe 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 BlockBackend is already attached
Features¶
unstableThis 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¶
readread operation
writewrite operation
flushflush operation
Since¶
2.6
QUORUM_FAILURE (Event)¶
Emitted by the Quorum block driver if it fails to establish a quorum
Arguments¶
reference:stringdevice name if defined else node name
sector-num:intnumber of the first sector of the failed read operation
sectors-count:intfailed 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:QuorumOpTypequorum 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:stringthe graph node name of the block driver state
sector-num:intnumber of the first sector of the failed read operation
sectors-count:intfailed 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:stringthe device name or node-name of a root node to generate the snapshot from
name:stringthe 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 example, 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
deviceis not a valid block device, GenericErrorIf any snapshot matching
nameexists, ornameis empty, GenericErrorIf the format of the image used does not support it, BlockFormatFeatureNotSupported
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:stringthe device name or node-name of a root node to delete the snapshot 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
deviceis not a valid block device, GenericErrorIf snapshot not found, GenericError
If the format of the image used does not support it, BlockFormatFeatureNotSupported
If
idandnameare 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 SocketAddressLegacy.
Members¶
addr:SocketAddressAddress 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 resolved 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. (since 5.2; default: 0)
Since¶
4.2
nbd-server-start (Command)¶
Start an NBD server listening on the given host and port. Block
devices 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 intended difference is using SocketAddressLegacy instead of SocketAddress.
Arguments¶
addr:SocketAddressLegacyAddress 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 resolved 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. (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
deviceparameter 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 string(optional)Also export each of the named dirty bitmaps 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 each bitmap.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 context 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:SocketAddressThe vhost-user socket on which to listen. Both ‘unix’ and ‘fd’ SocketAddress types are supported. Passed fds must be UNIX domain 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¶
offDo not pass allow_other as a mount option.
onPass allow_other as a mount option.
autoTry 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:stringPath 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 accordingly. (default: false)
allow-other:FuseExportAllowOther(optional)If this is off, only qemu’s user is allowed access to this export. That cannot be changed even with chmod or chown. Enabling this option will allow other users access to the export with the FUSE mount option “allow_other”. Note that using allow_other as a non-root user requires user_allow_other to be enabled 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
NbdServerAddOptions (Object)¶
An NBD block export, per legacy nbd-server-add command.
Members¶
device:stringThe 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¶
deprecatedThis command is deprecated. Use
block-export-addinstead.
Returns¶
error if the server is not running, or export with the same name already exists.
Since¶
1.3
BlockExportRemoveMode (Enum)¶
Mode for removing a block export.
Values¶
safeRemove export if there are no existing connections, fail otherwise.
hardDrop all connections immediately and remove export.
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 further requests from existing clients.
Since¶
2.12
nbd-server-remove (Command)¶
Remove NBD export by name.
Arguments¶
name:stringBlock export id.
mode:BlockExportRemoveMode(optional)Mode of command operation. See
BlockExportRemoveModedescription. Default is ‘safe’.
Features¶
deprecatedThis command is deprecated. Use
block-export-delinstead.
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¶
nbdNBD export
vhost-user-blkvhost-user-blk export (since 5.2)
fuse(If:CONFIG_FUSE)FUSE export (since: 6.0)
Since¶
4.2
BlockExportOptions (Object)¶
Describes a block export, i.e. how single node should be exported on an external interface.
Members¶
id:stringA unique identifier for the block export (across all export types)
node-name:stringThe 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 export 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
iothreadis given, export creation fails if the block node cannot be moved to the iothread. The default is false. (since: 5.2)type:BlockExportTypeNot documented
- The members of
BlockExportOptionsNbdwhentypeis"nbd" - The members of
BlockExportOptionsVhostUserBlkwhentypeis"vhost-user-blk" - The members of
BlockExportOptionsFusewhentypeis"fuse"(If:CONFIG_FUSE)
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 returns until the shutdown of the export has completed.
Arguments¶
id:stringBlock export id.
mode:BlockExportRemoveMode(optional)Mode of command operation. See
BlockExportRemoveModedescription. 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:stringBlock export id.
Since¶
5.2
BlockExportInfo (Object)¶
Information about a single block export.
Members¶
id:stringThe unique identifier for the block export
type:BlockExportTypeThe block export type
node-name:stringThe node name of the block node that is exported
shutting-down:booleanTrue if the export is shutting down (e.g. after a block-export-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:stringthe label of the character device
filename:stringthe filename of the character device
frontend-open:booleanshows 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
encoding. 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:stringThe 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¶
utf8Data is a UTF-8 string (RFC 3629)
base64Data is Base64 encoded binary (RFC 3548)
Since¶
1.4
ringbuf-write (Command)¶
Write to a ring buffer character device.
Arguments¶
device:stringthe ring buffer character device name
data:stringdata 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:stringthe ring buffer character device name
size:inthow 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 characters, 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 truncate)
Since¶
2.6
ChardevFile (Object)¶
Configuration info for file chardevs.
Members¶
in:string(optional)The name of the input file
out:stringThe 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:stringThe 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:SocketAddressLegacysocket 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:SocketAddressLegacyremote address
local:SocketAddressLegacy(optional)local address
- The members of
ChardevCommon
Since¶
1.5
ChardevMux (Object)¶
Configuration info for mux chardevs.
Members¶
chardev:stringname 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:stringkind 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:stringname of the channel (see docs/spice-port-fqdn.txt)
- The members of
ChardevCommon
Since¶
1.5
If¶
CONFIG_SPICE
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¶
pipeSince 1.5
udpSince 1.5
muxSince 1.5
msmouseSince 1.5
wctabletSince 2.9
brailleSince 1.5
testdevSince 2.2
stdioSince 1.5
consoleSince 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
vcv1.5
ringbufSince 1.6
memorySince 1.5
fileNot documented
serialNot documented
parallelNot documented
socketNot documented
ptyNot documented
nullNot documented
Since¶
1.4
ChardevFileWrapper (Object)¶
Members¶
data:ChardevFileNot documented
Since¶
1.4
ChardevHostdevWrapper (Object)¶
Members¶
data:ChardevHostdevNot documented
Since¶
1.4
ChardevSocketWrapper (Object)¶
Members¶
data:ChardevSocketNot documented
Since¶
1.4
ChardevUdpWrapper (Object)¶
Members¶
data:ChardevUdpNot documented
Since¶
1.5
ChardevCommonWrapper (Object)¶
Members¶
data:ChardevCommonNot documented
Since¶
2.6
ChardevMuxWrapper (Object)¶
Members¶
data:ChardevMuxNot documented
Since¶
1.5
ChardevStdioWrapper (Object)¶
Members¶
data:ChardevStdioNot documented
Since¶
1.5
ChardevSpiceChannelWrapper (Object)¶
Members¶
data:ChardevSpiceChannelNot documented
Since¶
1.5
If¶
CONFIG_SPICE
ChardevSpicePortWrapper (Object)¶
Members¶
data:ChardevSpicePortNot documented
Since¶
1.5
If¶
CONFIG_SPICE
ChardevQemuVDAgentWrapper (Object)¶
Members¶
data:ChardevQemuVDAgentNot documented
Since¶
6.1
If¶
CONFIG_SPICE_PROTOCOL
ChardevVCWrapper (Object)¶
Members¶
data:ChardevVCNot documented
Since¶
1.5
ChardevRingbufWrapper (Object)¶
Members¶
data:ChardevRingbufNot documented
Since¶
1.5
ChardevBackend (Object)¶
Configuration info for the new chardev backend.
Members¶
type:ChardevBackendKindNot documented
- The members of
ChardevFileWrapperwhentypeis"file" - The members of
ChardevHostdevWrapperwhentypeis"serial" - The members of
ChardevHostdevWrapperwhentypeis"parallel" - The members of
ChardevHostdevWrapperwhentypeis"pipe" - The members of
ChardevSocketWrapperwhentypeis"socket" - The members of
ChardevUdpWrapperwhentypeis"udp" - The members of
ChardevCommonWrapperwhentypeis"pty" - The members of
ChardevCommonWrapperwhentypeis"null" - The members of
ChardevMuxWrapperwhentypeis"mux" - The members of
ChardevCommonWrapperwhentypeis"msmouse" - The members of
ChardevCommonWrapperwhentypeis"wctablet" - The members of
ChardevCommonWrapperwhentypeis"braille" - The members of
ChardevCommonWrapperwhentypeis"testdev" - The members of
ChardevStdioWrapperwhentypeis"stdio" - The members of
ChardevCommonWrapperwhentypeis"console" - The members of
ChardevSpiceChannelWrapperwhentypeis"spicevmc"(If:CONFIG_SPICE) - The members of
ChardevSpicePortWrapperwhentypeis"spiceport"(If:CONFIG_SPICE) - The members of
ChardevQemuVDAgentWrapperwhentypeis"qemu-vdagent"(If:CONFIG_SPICE_PROTOCOL) - The members of
ChardevVCWrapperwhentypeis"vc" - The members of
ChardevRingbufWrapperwhentypeis"ringbuf" - The members of
ChardevRingbufWrapperwhentypeis"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:stringthe chardev’s ID, must be unique
backend:ChardevBackendbackend 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:stringthe chardev’s ID, must exist
backend:ChardevBackendnew 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:stringthe 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:stringthe 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:stringdevice identifier of the virtio-serial port
open:booleantrue 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 monitor 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 connection, used for agreeing on particular QMP extension behaviors.
Values¶
oobQMP 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:intThe major version number.
minor:intThe minor version number.
micro:intThe micro version number.
Since¶
2.4
VersionInfo (Object)¶
A description of QEMU’s version.
Members¶
qemu:VersionTripleThe 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 release.
package:stringQEMU will always set this field to an empty string. Downstream versions of QEMU should set this to a non-empty string. The exact format depends on the downstream however it highly recommended 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:stringThe 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 every 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¶
readlineHMP monitor (human-oriented command line interface)
controlQMP 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:stringName 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-compatible across qemu versions, the introspection output is not guaranteed 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¶
builtina predefined type such as ‘int’ or ‘bool’.
enuman enumeration type
arrayan array type
objectan object type (struct or union)
alternatean alternate type
commanda QMP command
eventa QMP event
Since¶
2.5
SchemaInfo (Object)¶
Members¶
name:stringthe entity’s name, inherited from
base. The SchemaInfo is always 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 ofmeta-type.meta-type:SchemaMetaTypethe 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
SchemaInfoBuiltinwhenmeta-typeis"builtin" - The members of
SchemaInfoEnumwhenmeta-typeis"enum" - The members of
SchemaInfoArraywhenmeta-typeis"array" - The members of
SchemaInfoObjectwhenmeta-typeis"object" - The members of
SchemaInfoAlternatewhenmeta-typeis"alternate" - The members of
SchemaInfoCommandwhenmeta-typeis"command" - The members of
SchemaInfoEventwhenmeta-typeis"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:JSONTypethe 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 section 1, plus ‘int’ (split off ‘number’), plus the obvious top type ‘value’.
Values¶
stringNot documented
numberNot documented
intNot documented
booleanNot documented
nullNot documented
objectNot documented
arrayNot documented
valueNot documented
Since¶
2.5
SchemaInfoEnum (Object)¶
Additional SchemaInfo members for meta-type ‘enum’.
Members¶
members:array of SchemaInfoEnumMemberthe enum type’s members, in no particular order (since 6.2).
values:array of stringthe enumeration type’s member names, in no particular order. Redundant with
members. Just for backward compatibility.
Features¶
deprecatedMember
valuesis deprecated. Usemembersinstead.
Values of this type are JSON string on the wire.
Since¶
2.5
SchemaInfoEnumMember (Object)¶
An object member.
Members¶
name:stringthe 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:stringthe 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 SchemaInfoObjectMemberthe 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
memberswith 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
tagis present. The variants are in no particular order, and may even differ from the order of the values of the enum type of thetag.
Values of this type are JSON object on the wire.
Since¶
2.5
SchemaInfoObjectMember (Object)¶
An object member.
Members¶
name:stringthe member’s name, as defined in the QAPI schema.
type:stringthe name of the member’s type.
default:value(optional)default when used as command parameter. If absent, the parameter is mandatory. If present, the value must be null. The parameter is optional, and behavior when it’s missing is not specified here. Future extension: if present and non-null, the parameter 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:stringa value of the type tag.
type:stringthe 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 SchemaInfoAlternateMemberthe alternate type’s members, in no particular order. The members’ wire encoding is distinct, see docs/devel/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:stringthe name of the member’s type.
Since¶
2.5
SchemaInfoCommand (Object)¶
Additional SchemaInfo members for meta-type ‘command’.
Members¶
arg-type:stringthe name of the object type that provides the command’s parameters.
ret-type:stringthe 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:stringthe name of the object type that provides the event’s parameters.
Since¶
2.5
User authorization¶
QAuthZListPolicy (Enum)¶
The authorization policy result
Values¶
denydeny access
allowallow access
Since¶
4.0
QAuthZListFormat (Enum)¶
The authorization policy match format
Values¶
exactan exact string match
globstring with ? and * shell wildcard support
Since¶
4.0
QAuthZListRule (Object)¶
A single authorization rule.
Members¶
match:stringa string or glob to match against a user identity
policy:QAuthZListPolicythe result to return if
matchevaluates to trueformat:QAuthZListFormat(optional)the format of the
matchrule (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:stringFile 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 authorizations will fail until the file is next successfully loaded. (default: true if the binary was built with CONFIG_INOTIFY1, false otherwise)
Since¶
4.0
AuthZPAMProperties (Object)¶
Properties for authz-pam objects.
Members¶
service:stringPAM service name to use for authorization
Since¶
4.0
AuthZSimpleProperties (Object)¶
Properties for authz-simple objects.
Members¶
identity:stringIdentifies the allowed user. Its format depends on the network service that authorization object is associated with. For authorizing based on TLS x509 certificates, the identity must be the x509 distinguished name.
Since¶
4.0
QEMU Object Model (QOM)¶
ObjectPropertyInfo (Object)¶
Members¶
name:stringthe name of the property
type:stringthe type of the property. This will typically come in one of four forms:
A primitive type such as ‘u8’, ‘u16’, ‘bool’, ‘str’, or ‘double’. These types are mapped to the appropriate JSON type.
A child type in the form ‘child<subtype>’ where subtype is a qdev device type name. Child properties create the composition tree.
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:stringthe path within the object model. See
qom-getfor a description of this parameter.
Returns¶
a list of ObjectPropertyInfo that describe the properties of the
object.
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:stringThe path within the object model. There are two forms of supported 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:stringThe 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:stringsee
qom-getfor a description of this parameterproperty:stringthe property name to set
value:valuea value who’s type is appropriate for the property type. See
qom-getfor 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:stringthe type name found in the search
abstract:boolean(optional)the type is abstract and can’t be directly instantiated. Omitted 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:stringthe 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 included 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:stringinterface name of the host system CAN bus to connect to
canbus:stringobject 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:stringname of the character device backend to use for the primary input (incoming packets are redirected to
outdev)secondary_in:stringname of the character device backend to use for secondary input (incoming packets are only compared to the input on
primary_inand then dropped)outdev:stringname of the character device backend to use for output
iothread:stringname 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_infor comparison with an incoming packet onsecondary_inin milliseconds (default: 3000)expired_scan_cycle:int(optional)the interval at which colo-compare checks whether packets from
primaryhave 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:stringthe 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:stringthe 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¶
beforeinsert before the specified filter
behindinsert behind the specified filter
Since¶
5.0
NetfilterProperties (Object)¶
Properties for objects of classes derived from netfilter.
Members¶
netdev:stringid 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 filter is inserted at the tail of the filter list, behind any existing filters (default). “id=<id>” means the filter is inserted before or behind the filter specified by <id>, depending on the
insertproperty. (default: “tail”)insert:NetfilterInsert(optional)where to insert the filter relative to the filter given in
position. Ignored ifpositionis “head” or “tail”. (default: behind)
Since¶
2.5
FilterBufferProperties (Object)¶
Properties for filter-buffer objects.
Members¶
interval:inta 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:stringthe 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:stringthe 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:stringthe screen name as declared in the screens section of barrier.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:stringthe 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
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 otherwise)
poll-grow:int(optional)the multiplier used to increase the polling time when the algorithm 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)
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, since 6.1)
Since¶
2.0
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)
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 (default: true) (since 6.1)
size:intsize of the memory region in bytes
x-use-canonical-path-for-ramblock-id:boolean(optional)if true, the canoncial 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 example, 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 bymem-pathrequire an alignment different 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 selects 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-datais only an optimization, and QEMU might not discard file contents if it aborts unexpectedly or is terminated using SIGKILL. (default: false)mem-path:stringthe 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-pathis 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 system). 0 selects a default page size. This option is ignored if
hugetlbis 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:stringthe path to a Unix domain socket for connecting to the external helper
Since¶
2.11
QtestProperties (Object)¶
Properties for qtest objects.
Members¶
chardev:stringthe 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:stringfile descriptor name previously passed via ‘getfd’ command
devid:stringthe id of the device to be associated with the file descriptor
Since¶
6.0
RngProperties (Object)¶
Properties for objects of classes derived from rng.
Members¶
opened:boolean(optional)if true, the device is opened immediately when applying this option and will probably fail when processing the next option. Don’t use; only provided for compatibility. (default: false)
Features¶
deprecatedMember
openedis 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:stringthe name of a character device backend that provides the connection 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:intnumber 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
ObjectType (Enum)¶
Values¶
authz-listNot documented
authz-listfileNot documented
authz-pamNot documented
authz-simpleNot documented
can-busNot documented
can-host-socketcan(If:CONFIG_LINUX)Not documented
colo-compareNot documented
cryptodev-backendNot documented
cryptodev-backend-builtinNot documented
cryptodev-vhost-user(If:CONFIG_VHOST_CRYPTO)Not documented
dbus-vmstateNot documented
filter-bufferNot documented
filter-dumpNot documented
filter-mirrorNot documented
filter-redirectorNot documented
filter-replayNot documented
filter-rewriterNot documented
input-barrierNot documented
input-linux(If:CONFIG_LINUX)Not documented
iothreadNot documented
memory-backend-epc(If:CONFIG_LINUX)Not documented
memory-backend-fileNot documented
memory-backend-memfd(If:CONFIG_LINUX)Not documented
memory-backend-ramNot documented
pef-guestNot documented
pr-manager-helper(If:CONFIG_LINUX)Not documented
qtestNot documented
rng-builtinNot documented
rng-egdNot documented
rng-random(If:CONFIG_POSIX)Not documented
secretNot documented
secret_keyring(If:CONFIG_SECRET_KEYRING)Not documented
sev-guestNot documented
s390-pv-guestNot documented
throttle-groupNot documented
tls-creds-anonNot documented
tls-creds-pskNot documented
tls-creds-x509Not documented
tls-cipher-suitesNot documented
x-remote-objectNot documented
Features¶
unstableMember
x-remote-objectis experimental.
Since¶
6.0
ObjectOptions (Object)¶
Describes the options of a user creatable QOM object.
Members¶
qom-type:ObjectTypethe class name for the object to be created
id:stringthe name of the new object
- The members of
AuthZListPropertieswhenqom-typeis"authz-list" - The members of
AuthZListFilePropertieswhenqom-typeis"authz-listfile" - The members of
AuthZPAMPropertieswhenqom-typeis"authz-pam" - The members of
AuthZSimplePropertieswhenqom-typeis"authz-simple" - The members of
CanHostSocketcanPropertieswhenqom-typeis"can-host-socketcan"(If:CONFIG_LINUX) - The members of
ColoComparePropertieswhenqom-typeis"colo-compare" - The members of
CryptodevBackendPropertieswhenqom-typeis"cryptodev-backend" - The members of
CryptodevBackendPropertieswhenqom-typeis"cryptodev-backend-builtin" - The members of
CryptodevVhostUserPropertieswhenqom-typeis"cryptodev-vhost-user"(If:CONFIG_VHOST_CRYPTO) - The members of
DBusVMStatePropertieswhenqom-typeis"dbus-vmstate" - The members of
FilterBufferPropertieswhenqom-typeis"filter-buffer" - The members of
FilterDumpPropertieswhenqom-typeis"filter-dump" - The members of
FilterMirrorPropertieswhenqom-typeis"filter-mirror" - The members of
FilterRedirectorPropertieswhenqom-typeis"filter-redirector" - The members of
NetfilterPropertieswhenqom-typeis"filter-replay" - The members of
FilterRewriterPropertieswhenqom-typeis"filter-rewriter" - The members of
InputBarrierPropertieswhenqom-typeis"input-barrier" - The members of
InputLinuxPropertieswhenqom-typeis"input-linux"(If:CONFIG_LINUX) - The members of
IothreadPropertieswhenqom-typeis"iothread" - The members of
MemoryBackendEpcPropertieswhenqom-typeis"memory-backend-epc"(If:CONFIG_LINUX) - The members of
MemoryBackendFilePropertieswhenqom-typeis"memory-backend-file" - The members of
MemoryBackendMemfdPropertieswhenqom-typeis"memory-backend-memfd"(If:CONFIG_LINUX) - The members of
MemoryBackendPropertieswhenqom-typeis"memory-backend-ram" - The members of
PrManagerHelperPropertieswhenqom-typeis"pr-manager-helper"(If:CONFIG_LINUX) - The members of
QtestPropertieswhenqom-typeis"qtest" - The members of
RngPropertieswhenqom-typeis"rng-builtin" - The members of
RngEgdPropertieswhenqom-typeis"rng-egd" - The members of
RngRandomPropertieswhenqom-typeis"rng-random"(If:CONFIG_POSIX) - The members of
SecretPropertieswhenqom-typeis"secret" - The members of
SecretKeyringPropertieswhenqom-typeis"secret_keyring"(If:CONFIG_SECRET_KEYRING) - The members of
SevGuestPropertieswhenqom-typeis"sev-guest" - The members of
ThrottleGroupPropertieswhenqom-typeis"throttle-group" - The members of
TlsCredsAnonPropertieswhenqom-typeis"tls-creds-anon" - The members of
TlsCredsPskPropertieswhenqom-typeis"tls-creds-psk" - The members of
TlsCredsX509Propertieswhenqom-typeis"tls-creds-x509" - The members of
TlsCredsPropertieswhenqom-typeis"tls-cipher-suites" - The members of
RemoteObjectPropertieswhenqom-typeis"x-remote-object"
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:stringthe 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¶
individualDo 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.
groupedIf 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¶
abortSince 1.6
block-dirty-bitmap-addSince 2.5
block-dirty-bitmap-removeSince 4.2
block-dirty-bitmap-clearSince 2.5
block-dirty-bitmap-enableSince 4.0
block-dirty-bitmap-disableSince 4.0
block-dirty-bitmap-mergeSince 4.0
blockdev-backupSince 2.3
blockdev-snapshotSince 2.5
blockdev-snapshot-internal-syncSince 1.7
blockdev-snapshot-syncsince 1.1
drive-backupSince 1.6
Features¶
deprecatedMember
drive-backupis deprecated. Use memberblockdev-backupinstead.
Since¶
1.1
AbortWrapper (Object)¶
Members¶
data:AbortNot documented
Since¶
1.6
BlockDirtyBitmapAddWrapper (Object)¶
Members¶
data:BlockDirtyBitmapAddNot documented
Since¶
2.5
BlockDirtyBitmapWrapper (Object)¶
Members¶
data:BlockDirtyBitmapNot documented
Since¶
2.5
BlockDirtyBitmapMergeWrapper (Object)¶
Members¶
data:BlockDirtyBitmapMergeNot documented
Since¶
4.0
BlockdevBackupWrapper (Object)¶
Members¶
data:BlockdevBackupNot documented
Since¶
2.3
BlockdevSnapshotWrapper (Object)¶
Members¶
data:BlockdevSnapshotNot documented
Since¶
2.5
BlockdevSnapshotInternalWrapper (Object)¶
Members¶
data:BlockdevSnapshotInternalNot documented
Since¶
1.7
BlockdevSnapshotSyncWrapper (Object)¶
Members¶
data:BlockdevSnapshotSyncNot documented
Since¶
1.1
DriveBackupWrapper (Object)¶
Members¶
data:DriveBackupNot documented
Since¶
1.6
TransactionAction (Object)¶
A discriminated record of operations that can be performed with
transaction.
Members¶
type:TransactionActionKindNot documented
- The members of
AbortWrapperwhentypeis"abort" - The members of
BlockDirtyBitmapAddWrapperwhentypeis"block-dirty-bitmap-add" - The members of
BlockDirtyBitmapWrapperwhentypeis"block-dirty-bitmap-remove" - The members of
BlockDirtyBitmapWrapperwhentypeis"block-dirty-bitmap-clear" - The members of
BlockDirtyBitmapWrapperwhentypeis"block-dirty-bitmap-enable" - The members of
BlockDirtyBitmapWrapperwhentypeis"block-dirty-bitmap-disable" - The members of
BlockDirtyBitmapMergeWrapperwhentypeis"block-dirty-bitmap-merge" - The members of
BlockdevBackupWrapperwhentypeis"blockdev-backup" - The members of
BlockdevSnapshotWrapperwhentypeis"blockdev-snapshot" - The members of
BlockdevSnapshotInternalWrapperwhentypeis"blockdev-snapshot-internal-sync" - The members of
BlockdevSnapshotSyncWrapperwhentypeis"blockdev-snapshot-sync" - The members of
DriveBackupWrapperwhentypeis"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 complete or fail as a group. See
ActionCompletionModefor 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 contents 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 cannot 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 TransactionActionList of
TransactionAction; information needed for the respective operations.properties:TransactionProperties(optional)structure of additional options to control the execution of the transaction. See
TransactionPropertiesfor 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 condition, 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": {} }