# -*- Mode: Python -*- # vim: filetype=python # ## # = Migration ## { 'include': 'common.json' } { 'include': 'sockets.json' } ## # @MigrationStats: # # Detailed migration status. # # @transferred: amount of bytes already transferred to the target VM # # @remaining: amount of bytes remaining to be transferred to the target VM # # @total: total amount of bytes involved in the migration process # # @duplicate: number of duplicate (zero) pages (since 1.2) # # @skipped: number of skipped zero pages (since 1.5) # # @normal: number of normal pages (since 1.2) # # @normal-bytes: number of normal bytes sent (since 1.2) # # @dirty-pages-rate: number of pages dirtied by second by the # guest (since 1.3) # # @mbps: throughput in megabits/sec. (since 1.6) # # @dirty-sync-count: number of times that dirty ram was synchronized (since 2.1) # # @postcopy-requests: The number of page requests received from the destination # (since 2.7) # # @page-size: The number of bytes per page for the various page-based # statistics (since 2.10) # # @multifd-bytes: The number of bytes sent through multifd (since 3.0) # # @pages-per-second: the number of memory pages transferred per second # (Since 4.0) # # Since: 0.14.0 ## { 'struct': 'MigrationStats', 'data': {'transferred': 'int', 'remaining': 'int', 'total': 'int' , 'duplicate': 'int', 'skipped': 'int', 'normal': 'int', 'normal-bytes': 'int', 'dirty-pages-rate' : 'int', 'mbps' : 'number', 'dirty-sync-count' : 'int', 'postcopy-requests' : 'int', 'page-size' : 'int', 'multifd-bytes' : 'uint64', 'pages-per-second' : 'uint64' } } ## # @XBZRLECacheStats: # # Detailed XBZRLE migration cache statistics # # @cache-size: XBZRLE cache size # # @bytes: amount of bytes already transferred to the target VM # # @pages: amount of pages transferred to the target VM # # @cache-miss: number of cache miss # # @cache-miss-rate: rate of cache miss (since 2.1) # # @encoding-rate: rate of encoded bytes (since 5.1) # # @overflow: number of overflows # # Since: 1.2 ## { 'struct': 'XBZRLECacheStats', 'data': {'cache-size': 'int', 'bytes': 'int', 'pages': 'int', 'cache-miss': 'int', 'cache-miss-rate': 'number', 'encoding-rate': 'number', 'overflow': 'int' } } ## # @CompressionStats: # # Detailed migration compression statistics # # @pages: amount of pages compressed and transferred to the target VM # # @busy: count of times that no free thread was available to compress data # # @busy-rate: rate of thread busy # # @compressed-size: amount of bytes after compression # # @compression-rate: rate of compressed size # # Since: 3.1 ## { 'struct': 'CompressionStats', 'data': {'pages': 'int', 'busy': 'int', 'busy-rate': 'number', 'compressed-size': 'int', 'compression-rate': 'number' } } ## # @MigrationStatus: # # An enumeration of migration status. # # @none: no migration has ever happened. # # @setup: migration process has been initiated. # # @cancelling: in the process of cancelling migration. # # @cancelled: cancelling migration is finished. # # @active: in the process of doing migration. # # @postcopy-active: like active, but now in postcopy mode. (since 2.5) # # @postcopy-paused: during postcopy but paused. (since 3.0) # # @postcopy-recover: trying to recover from a paused postcopy. (since 3.0) # # @completed: migration is finished. # # @failed: some error occurred during migration process. # # @colo: VM is in the process of fault tolerance, VM can not get into this # state unless colo capability is enabled for migration. (since 2.8) # # @pre-switchover: Paused before device serialisation. (since 2.11) # # @device: During device serialisation when pause-before-switchover is enabled # (since 2.11) # # @wait-unplug: wait for device unplug request by guest OS to be completed. # (since 4.2) # # Since: 2.3 # ## { 'enum': 'MigrationStatus', 'data': [ 'none', 'setup', 'cancelling', 'cancelled', 'active', 'postcopy-active', 'postcopy-paused', 'postcopy-recover', 'completed', 'failed', 'colo', 'pre-switchover', 'device', 'wait-unplug' ] } ## # @MigrationInfo: # # Information about current migration process. # # @status: @MigrationStatus describing the current migration status. # If this field is not returned, no migration process # has been initiated # # @ram: @MigrationStats containing detailed migration # status, only returned if status is 'active' or # 'completed'(since 1.2) # # @disk: @MigrationStats containing detailed disk migration # status, only returned if status is 'active' and it is a block # migration # # @xbzrle-cache: @XBZRLECacheStats containing detailed XBZRLE # migration statistics, only returned if XBZRLE feature is on and # status is 'active' or 'completed' (since 1.2) # # @total-time: total amount of milliseconds since migration started. # If migration has ended, it returns the total migration # time. (since 1.2) # # @downtime: only present when migration finishes correctly # total downtime in milliseconds for the guest. # (since 1.3) # # @expected-downtime: only present while migration is active # expected downtime in milliseconds for the guest in last walk # of the dirty bitmap. (since 1.3) # # @setup-time: amount of setup time in milliseconds *before* the # iterations begin but *after* the QMP command is issued. This is designed # to provide an accounting of any activities (such as RDMA pinning) which # may be expensive, but do not actually occur during the iterative # migration rounds themselves. (since 1.6) # # @cpu-throttle-percentage: percentage of time guest cpus are being # throttled during auto-converge. This is only present when auto-converge # has started throttling guest cpus. (Since 2.7) # # @error-desc: the human readable error description string, when # @status is 'failed'. Clients should not attempt to parse the # error strings. (Since 2.7) # # @postcopy-blocktime: total time when all vCPU were blocked during postcopy # live migration. This is only present when the postcopy-blocktime # migration capability is enabled. (Since 3.0) # # @postcopy-vcpu-blocktime: list of the postcopy blocktime per vCPU. This is # only present when the postcopy-blocktime migration capability # is enabled. (Since 3.0) # # @compression: migration compression statistics, only returned if compression # feature is on and status is 'active' or 'completed' (Since 3.1) # # @socket-address: Only used for tcp, to know what the real port is (Since 4.0) # # Since: 0.14.0 ## { 'struct': 'MigrationInfo', 'data': {'*status': 'MigrationStatus', '*ram': 'MigrationStats', '*disk': 'MigrationStats', '*xbzrle-cache': 'XBZRLECacheStats', '*total-time': 'int', '*expected-downtime': 'int', '*downtime': 'int', '*setup-time': 'int', '*cpu-throttle-percentage': 'int', '*error-desc': 'str', '*postcopy-blocktime' : 'uint32', '*postcopy-vcpu-blocktime': ['uint32'], '*compression': 'CompressionStats', '*socket-address': ['SocketAddress'] } } ## # @query-migrate: # # Returns information about current migration process. If migration # is active there will be another json-object with RAM migration # status and if block migration is active another one with block # migration status. # # Returns: @MigrationInfo # # Since: 0.14.0 # # Example: # # 1. Before the first migration # # -> { "execute": "query-migrate" } # <- { "return": {} } # # 2. Migration is done and has succeeded # # -> { "execute": "query-migrate" } # <- { "return": { # "status": "completed", # "total-time":12345, # "setup-time":12345, # "downtime":12345, # "ram":{ # "transferred":123, # "remaining":123, # "total":246, # "duplicate":123, # "normal":123, # "normal-bytes":123456, # "dirty-sync-count":15 # } # } # } # # 3. Migration is done and has failed # # -> { "execute": "query-migrate" } # <- { "return": { "status": "failed" } } # # 4. Migration is being performed and is not a block migration: # # -> { "execute": "query-migrate" } # <- { # "return":{ # "status":"active", # "total-time":12345, # "setup-time":12345, # "expected-downtime":12345, # "ram":{ # "transferred":123, # "remaining":123, # "total":246, # "duplicate":123, # "normal":123, # "normal-bytes":123456, # "dirty-sync-count":15 # } # } # } # # 5. Migration is being performed and is a block migration: # # -> { "execute": "query-migrate" } # <- { # "return":{ # "status":"active", # "total-time":12345, # "setup-time":12345, # "expected-downtime":12345, # "ram":{ # "total":1057024, # "remaining":1053304, # "transferred":3720, # "duplicate":123, # "normal":123, # "normal-bytes":123456, # "dirty-sync-count":15 # }, # "disk":{ # "total":20971520, # "remaining":20880384, # "transferred":91136 # } # } # } # # 6. Migration is being performed and XBZRLE is active: # # -> { "execute": "query-migrate" } # <- { # "return":{ # "status":"active", # "total-time":12345, # "setup-time":12345, # "expected-downtime":12345, # "ram":{ # "total":1057024, # "remaining":1053304, # "transferred":3720, # "duplicate":10, # "normal":3333, # "normal-bytes":3412992, # "dirty-sync-count":15 # }, # "xbzrle-cache":{ # "cache-size":67108864, # "bytes":20971520, # "pages":2444343, # "cache-miss":2244, # "cache-miss-rate":0.123, # "encoding-rate":80.1, # "overflow":34434 # } # } # } # ## { 'command': 'query-migrate', 'returns': 'MigrationInfo' } ## # @MigrationCapability: # # Migration capabilities enumeration # # @xbzrle: Migration supports xbzrle (Xor Based Zero Run Length Encoding). # This feature allows us to minimize migration traffic for certain work # loads, by sending compressed difference of the pages # # @rdma-pin-all: Controls whether or not the entire VM memory footprint is # mlock()'d on demand or all at once. Refer to docs/rdma.txt for usage. # Disabled by default. (since 2.0) # # @zero-blocks: During storage migration encode blocks of zeroes efficiently. This # essentially saves 1MB of zeroes per block on the wire. Enabling requires # source and target VM to support this feature. To enable it is sufficient # to enable the capability on the source VM. The feature is disabled by # default. (since 1.6) # # @compress: Use multiple compression threads to accelerate live migration. # This feature can help to reduce the migration traffic, by sending # compressed pages. Please note that if compress and xbzrle are both # on, compress only takes effect in the ram bulk stage, after that, # it will be disabled and only xbzrle takes effect, this can help to # minimize migration traffic. The feature is disabled by default. # (since 2.4 ) # # @events: generate events for each migration state change # (since 2.4 ) # # @auto-converge: If enabled, QEMU will automatically throttle down the guest # to speed up convergence of RAM migration. (since 1.6) # # @postcopy-ram: Start executing on the migration target before all of RAM has # been migrated, pulling the remaining pages along as needed. The # capacity must have the same setting on both source and target # or migration will not even start. NOTE: If the migration fails during # postcopy the VM will fail. (since 2.6) # # @x-colo: If enabled, migration will never end, and the state of the VM on the # primary side will be migrated continuously to the VM on secondary # side, this process is called COarse-Grain LOck Stepping (COLO) for # Non-stop Service. (since 2.8) # # @release-ram: if enabled, qemu will free the migrated ram pages on the source # during postcopy-ram migration. (since 2.9) # # @block: If enabled, QEMU will also migrate the contents of all block # devices. Default is disabled. A possible alternative uses # mirror jobs to a builtin NBD server on the destination, which # offers more flexibility. # (Since 2.10) # # @return-path: If enabled, migration will use the return path even # for precopy. (since 2.10) # # @pause-before-switchover: Pause outgoing migration before serialising device # state and before disabling block IO (since 2.11) # # @multifd: Use more than one fd for migration (since 4.0) # # @dirty-bitmaps: If enabled, QEMU will migrate named dirty bitmaps. # (since 2.12) # # @postcopy-blocktime: Calculate downtime for postcopy live migration # (since 3.0) # # @late-block-activate: If enabled, the destination will not activate block # devices (and thus take locks) immediately at the end of migration. # (since 3.0) # # @x-ignore-shared: If enabled, QEMU will not migrate shared memory (since 4.0) # # @validate-uuid: Send the UUID of the source to allow the destination # to ensure it is the same. (since 4.2) # # Since: 1.2 ## { 'enum': 'MigrationCapability', 'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks', 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram', 'block', 'return-path', 'pause-before-switchover', 'multifd', 'dirty-bitmaps', 'postcopy-blocktime', 'late-block-activate', 'x-ignore-shared', 'validate-uuid' ] } ## # @MigrationCapabilityStatus: # # Migration capability information # # @capability: capability enum # # @state: capability state bool # # Since: 1.2 ## { 'struct': 'MigrationCapabilityStatus', 'data': { 'capability' : 'MigrationCapability', 'state' : 'bool' } } ## # @migrate-set-capabilities: # # Enable/Disable the following migration capabilities (like xbzrle) # # @capabilities: json array of capability modifications to make # # Since: 1.2 # # Example: # # -> { "execute": "migrate-set-capabilities" , "arguments": # { "capabilities": [ { "capability": "xbzrle", "state": true } ] } } # ## { 'command': 'migrate-set-capabilities', 'data': { 'capabilities': ['MigrationCapabilityStatus'] } } ## # @query-migrate-capabilities: # # Returns information about the current migration capabilities status # # Returns: @MigrationCapabilitiesStatus # # Since: 1.2 # # Example: # # -> { "execute": "query-migrate-capabilities" } # <- { "return": [ # {"state": false, "capability": "xbzrle"}, # {"state": false, "capability": "rdma-pin-all"}, # {"state": false, "capability": "auto-converge"}, # {"state": false, "capability": "zero-blocks"}, # {"state": false, "capability": "compress"}, # {"state": true, "capability": "events"}, # {"state": false, "capability": "postcopy-ram"}, # {"state": false, "capability": "x-colo"} # ]} # ## { 'command': 'query-migrate-capabilities', 'returns': ['MigrationCapabilityStatus']} ## # @MultiFDCompression: # # An enumeration of multifd compression methods. # # @none: no compression. # @zlib: use zlib compression method. # @zstd: use zstd compression method. # # Since: 5.0 # ## { 'enum': 'MultiFDCompression', 'data': [ 'none', 'zlib', { 'name': 'zstd', 'if': 'defined(CONFIG_ZSTD)' } ] } ## # @BitmapMigrationBitmapAlias: # # @name: The name of the bitmap. # # @alias: An alias name for migration (for example the bitmap name on # the opposite site). # # Since: 5.2 ## { 'struct': 'BitmapMigrationBitmapAlias', 'data': { 'name': 'str', 'alias': 'str' } } ## # @BitmapMigrationNodeAlias: # # Maps a block node name and the bitmaps it has to aliases for dirty # bitmap migration. # # @node-name: A block node name. # # @alias: An alias block node name for migration (for example the # node name on the opposite site). # # @bitmaps: Mappings for the bitmaps on this node. # # Since: 5.2 ## { 'struct': 'BitmapMigrationNodeAlias', 'data': { 'node-name': 'str', 'alias': 'str', 'bitmaps': [ 'BitmapMigrationBitmapAlias' ] } } ## # @MigrationParameter: # # Migration parameters enumeration # # @announce-initial: Initial delay (in milliseconds) before sending the first # announce (Since 4.0) # # @announce-max: Maximum delay (in milliseconds) between packets in the # announcement (Since 4.0) # # @announce-rounds: Number of self-announce packets sent after migration # (Since 4.0) # # @announce-step: Increase in delay (in milliseconds) between subsequent # packets in the announcement (Since 4.0) # # @compress-level: Set the compression level to be used in live migration, # the compression level is an integer between 0 and 9, where 0 means # no compression, 1 means the best compression speed, and 9 means best # compression ratio which will consume more CPU. # # @compress-threads: Set compression thread count to be used in live migration, # the compression thread count is an integer between 1 and 255. # # @compress-wait-thread: Controls behavior when all compression threads are # currently busy. If true (default), wait for a free # compression thread to become available; otherwise, # send the page uncompressed. (Since 3.1) # # @decompress-threads: Set decompression thread count to be used in live # migration, the decompression thread count is an integer between 1 # and 255. Usually, decompression is at least 4 times as fast as # compression, so set the decompress-threads to the number about 1/4 # of compress-threads is adequate. # # @throttle-trigger-threshold: The ratio of bytes_dirty_period and bytes_xfer_period # to trigger throttling. It is expressed as percentage. # The default value is 50. (Since 5.0) # # @cpu-throttle-initial: Initial percentage of time guest cpus are throttled # when migration auto-converge is activated. The # default value is 20. (Since 2.7) # # @cpu-throttle-increment: throttle percentage increase each time # auto-converge detects that migration is not making # progress. The default value is 10. (Since 2.7) # # @cpu-throttle-tailslow: Make CPU throttling slower at tail stage # At the tail stage of throttling, the Guest is very # sensitive to CPU percentage while the @cpu-throttle # -increment is excessive usually at tail stage. # If this parameter is true, we will compute the ideal # CPU percentage used by the Guest, which may exactly make # the dirty rate match the dirty rate threshold. Then we # will choose a smaller throttle increment between the # one specified by @cpu-throttle-increment and the one # generated by ideal CPU percentage. # Therefore, it is compatible to traditional throttling, # meanwhile the throttle increment won't be excessive # at tail stage. # The default value is false. (Since 5.1) # # @tls-creds: ID of the 'tls-creds' object that provides credentials for # establishing a TLS connection over the migration data channel. # On the outgoing side of the migration, the credentials must # be for a 'client' endpoint, while for the incoming side the # credentials must be for a 'server' endpoint. Setting this # will enable TLS for all migrations. The default is unset, # resulting in unsecured migration at the QEMU level. (Since 2.7) # # @tls-hostname: hostname of the target host for the migration. This is # required when using x509 based TLS credentials and the # migration URI does not already include a hostname. For # example if using fd: or exec: based migration, the # hostname must be provided so that the server's x509 # certificate identity can be validated. (Since 2.7) # # @tls-authz: ID of the 'authz' object subclass that provides access control # checking of the TLS x509 certificate distinguished name. # This object is only resolved at time of use, so can be deleted # and recreated on the fly while the migration server is active. # If missing, it will default to denying access (Since 4.0) # # @max-bandwidth: to set maximum speed for migration. maximum speed in # bytes per second. (Since 2.8) # # @downtime-limit: set maximum tolerated downtime for migration. maximum # downtime in milliseconds (Since 2.8) # # @x-checkpoint-delay: The delay time (in ms) between two COLO checkpoints in # periodic mode. (Since 2.8) # # @block-incremental: Affects how much storage is migrated when the # block migration capability is enabled. When false, the entire # storage backing chain is migrated into a flattened image at # the destination; when true, only the active qcow2 layer is # migrated and the destination must already have access to the # same backing chain as was used on the source. (since 2.10) # # @multifd-channels: Number of channels used to migrate data in # parallel. This is the same number that the # number of sockets used for migration. The # default value is 2 (since 4.0) # # @xbzrle-cache-size: cache size to be used by XBZRLE migration. It # needs to be a multiple of the target page size # and a power of 2 # (Since 2.11) # # @max-postcopy-bandwidth: Background transfer bandwidth during postcopy. # Defaults to 0 (unlimited). In bytes per second. # (Since 3.0) # # @max-cpu-throttle: maximum cpu throttle percentage. # Defaults to 99. (Since 3.1) # # @multifd-compression: Which compression method to use. # Defaults to none. (Since 5.0) # # @multifd-zlib-level: Set the compression level to be used in live # migration, the compression level is an integer between 0 # and 9, where 0 means no compression, 1 means the best # compression speed, and 9 means best compression ratio which # will consume more CPU. # Defaults to 1. (Since 5.0) # # @multifd-zstd-level: Set the compression level to be used in live # migration, the compression level is an integer between 0 # and 20, where 0 means no compression, 1 means the best # compression speed, and 20 means best compression ratio which # will consume more CPU. # Defaults to 1. (Since 5.0) # # @block-bitmap-mapping: Maps block nodes and bitmaps on them to # aliases for the purpose of dirty bitmap migration. Such # aliases may for example be the corresponding names on the # opposite site. # The mapping must be one-to-one, but not necessarily # complete: On the source, unmapped bitmaps and all bitmaps # on unmapped nodes will be ignored. On the destination, # encountering an unmapped alias in the incoming migration # stream will result in a report, and all further bitmap # migration data will then be discarded. # Note that the destination does not know about bitmaps it # does not receive, so there is no limitation or requirement # regarding the number of bitmaps received, or how they are # named, or on which nodes they are placed. # By default (when this parameter has never been set), bitmap # names are mapped to themselves. Nodes are mapped to their # block device name if there is one, and to their node name # otherwise. (Since 5.2) # # Since: 2.4 ## { 'enum': 'MigrationParameter', 'data': ['announce-initial', 'announce-max', 'announce-rounds', 'announce-step', 'compress-level', 'compress-threads', 'decompress-threads', 'compress-wait-thread', 'throttle-trigger-threshold', 'cpu-throttle-initial', 'cpu-throttle-increment', 'cpu-throttle-tailslow', 'tls-creds', 'tls-hostname', 'tls-authz', 'max-bandwidth', 'downtime-limit', 'x-checkpoint-delay', 'block-incremental', 'multifd-channels', 'xbzrle-cache-size', 'max-postcopy-bandwidth', 'max-cpu-throttle', 'multifd-compression', 'multifd-zlib-level' ,'multifd-zstd-level', 'block-bitmap-mapping' ] } ## # @MigrateSetParameters: # # @announce-initial: Initial delay (in milliseconds) before sending the first # announce (Since 4.0) # # @announce-max: Maximum delay (in milliseconds) between packets in the # announcement (Since 4.0) # # @announce-rounds: Number of self-announce packets sent after migration # (Since 4.0) # # @announce-step: Increase in delay (in milliseconds) between subsequent # packets in the announcement (Since 4.0) # # @compress-level: compression level # # @compress-threads: compression thread count # # @compress-wait-thread: Controls behavior when all compression threads are # currently busy. If true (default), wait for a free # compression thread to become available; otherwise, # send the page uncompressed. (Since 3.1) # # @decompress-threads: decompression thread count # # @throttle-trigger-threshold: The ratio of bytes_dirty_period and bytes_xfer_period # to trigger throttling. It is expressed as percentage. # The default value is 50. (Since 5.0) # # @cpu-throttle-initial: Initial percentage of time guest cpus are # throttled when migration auto-converge is activated. # The default value is 20. (Since 2.7) # # @cpu-throttle-increment: throttle percentage increase each time # auto-converge detects that migration is not making # progress. The default value is 10. (Since 2.7) # # @cpu-throttle-tailslow: Make CPU throttling slower at tail stage # At the tail stage of throttling, the Guest is very # sensitive to CPU percentage while the @cpu-throttle # -increment is excessive usually at tail stage. # If this parameter is true, we will compute the ideal # CPU percentage used by the Guest, which may exactly make # the dirty rate match the dirty rate threshold. Then we # will choose a smaller throttle increment between the # one specified by @cpu-throttle-increment and the one # generated by ideal CPU percentage. # Therefore, it is compatible to traditional throttling, # meanwhile the throttle increment won't be excessive # at tail stage. # The default value is false. (Since 5.1) # # @tls-creds: ID of the 'tls-creds' object that provides credentials # for establishing a TLS connection over the migration data # channel. On the outgoing side of the migration, the credentials # must be for a 'client' endpoint, while for the incoming side the # credentials must be for a 'server' endpoint. Setting this # to a non-empty string enables TLS for all migrations. # An empty string means that QEMU will use plain text mode for # migration, rather than TLS (Since 2.9) # Previously (since 2.7), this was reported by omitting # tls-creds instead. # # @tls-hostname: hostname of the target host for the migration. This # is required when using x509 based TLS credentials and the # migration URI does not already include a hostname. For # example if using fd: or exec: based migration, the # hostname must be provided so that the server's x509 # certificate identity can be validated. (Since 2.7) # An empty string means that QEMU will use the hostname # associated with the migration URI, if any. (Since 2.9) # Previously (since 2.7), this was reported by omitting # tls-hostname instead. # # @max-bandwidth: to set maximum speed for migration. maximum speed in # bytes per second. (Since 2.8) # # @downtime-limit: set maximum tolerated downtime for migration. maximum # downtime in milliseconds (Since 2.8) # # @x-checkpoint-delay: the delay time between two COLO checkpoints. (Since 2.8) # # @block-incremental: Affects how much storage is migrated when the # block migration capability is enabled. When false, the entire # storage backing chain is migrated into a flattened image at # the destination; when true, only the active qcow2 layer is # migrated and the destination must already have access to the # same backing chain as was used on the source. (since 2.10) # # @multifd-channels: Number of channels used to migrate data in # parallel. This is the same number that the # number of sockets used for migration. The # default value is 2 (since 4.0) # # @xbzrle-cache-size: cache size to be used by XBZRLE migration. It # needs to be a multiple of the target page size # and a power of 2 # (Since 2.11) # # @max-postcopy-bandwidth: Background transfer bandwidth during postcopy. # Defaults to 0 (unlimited). In bytes per second. # (Since 3.0) # # @max-cpu-throttle: maximum cpu throttle percentage. # The default value is 99. (Since 3.1) # # @multifd-compression: Which compression method to use. # Defaults to none. (Since 5.0) # # @multifd-zlib-level: Set the compression level to be used in live # migration, the compression level is an integer between 0 # and 9, where 0 means no compression, 1 means the best # compression speed, and 9 means best compression ratio which # will consume more CPU. # Defaults to 1. (Since 5.0) # # @multifd-zstd-level: Set the compression level to be used in live # migration, the compression level is an integer between 0 # and 20, where 0 means no compression, 1 means the best # compression speed, and 20 means best compression ratio which # will consume more CPU. # Defaults to 1. (Since 5.0) # # @block-bitmap-mapping: Maps block nodes and bitmaps on them to # aliases for the purpose of dirty bitmap migration. Such # aliases may for example be the corresponding names on the # opposite site. # The mapping must be one-to-one, but not necessarily # complete: On the source, unmapped bitmaps and all bitmaps # on unmapped nodes will be ignored. On the destination, # encountering an unmapped alias in the incoming migration # stream will result in a report, and all further bitmap # migration data will then be discarded. # Note that the destination does not know about bitmaps it # does not receive, so there is no limitation or requirement # regarding the number of bitmaps received, or how they are # named, or on which nodes they are placed. # By default (when this parameter has never been set), bitmap # names are mapped to themselves. Nodes are mapped to their # block device name if there is one, and to their node name # otherwise. (Since 5.2) # # Since: 2.4 ## # TODO either fuse back into MigrationParameters, or make # MigrationParameters members mandatory { 'struct': 'MigrateSetParameters', 'data': { '*announce-initial': 'size', '*announce-max': 'size', '*announce-rounds': 'size', '*announce-step': 'size', '*compress-level': 'int', '*compress-threads': 'int', '*compress-wait-thread': 'bool', '*decompress-threads': 'int', '*throttle-trigger-threshold': 'int', '*cpu-throttle-initial': 'int', '*cpu-throttle-increment': 'int', '*cpu-throttle-tailslow': 'bool', '*tls-creds': 'StrOrNull', '*tls-hostname': 'StrOrNull', '*tls-authz': 'StrOrNull', '*max-bandwidth': 'int', '*downtime-limit': 'int', '*x-checkpoint-delay': 'int', '*block-incremental': 'bool', '*multifd-channels': 'int', '*xbzrle-cache-size': 'size', '*max-postcopy-bandwidth': 'size', '*max-cpu-throttle': 'int', '*multifd-compression': 'MultiFDCompression', '*multifd-zlib-level': 'int', '*multifd-zstd-level': 'int', '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } } ## # @migrate-set-parameters: # # Set various migration parameters. # # Since: 2.4 # # Example: # # -> { "execute": "migrate-set-parameters" , # "arguments": { "compress-level": 1 } } # ## { 'command': 'migrate-set-parameters', 'boxed': true, 'data': 'MigrateSetParameters' } ## # @MigrationParameters: # # The optional members aren't actually optional. # # @announce-initial: Initial delay (in milliseconds) before sending the # first announce (Since 4.0) # # @announce-max: Maximum delay (in milliseconds) between packets in the # announcement (Since 4.0) # # @announce-rounds: Number of self-announce packets sent after migration # (Since 4.0) # # @announce-step: Increase in delay (in milliseconds) between subsequent # packets in the announcement (Since 4.0) # # @compress-level: compression level # # @compress-threads: compression thread count # # @compress-wait-thread: Controls behavior when all compression threads are # currently busy. If true (default), wait for a free # compression thread to become available; otherwise, # send the page uncompressed. (Since 3.1) # # @decompress-threads: decompression thread count # # @throttle-trigger-threshold: The ratio of bytes_dirty_period and bytes_xfer_period # to trigger throttling. It is expressed as percentage. # The default value is 50. (Since 5.0) # # @cpu-throttle-initial: Initial percentage of time guest cpus are # throttled when migration auto-converge is activated. # (Since 2.7) # # @cpu-throttle-increment: throttle percentage increase each time # auto-converge detects that migration is not making # progress. (Since 2.7) # # @cpu-throttle-tailslow: Make CPU throttling slower at tail stage # At the tail stage of throttling, the Guest is very # sensitive to CPU percentage while the @cpu-throttle # -increment is excessive usually at tail stage. # If this parameter is true, we will compute the ideal # CPU percentage used by the Guest, which may exactly make # the dirty rate match the dirty rate threshold. Then we # will choose a smaller throttle increment between the # one specified by @cpu-throttle-increment and the one # generated by ideal CPU percentage. # Therefore, it is compatible to traditional throttling, # meanwhile the throttle increment won't be excessive # at tail stage. # The default value is false. (Since 5.1) # # @tls-creds: ID of the 'tls-creds' object that provides credentials # for establishing a TLS connection over the migration data # channel. On the outgoing side of the migration, the credentials # must be for a 'client' endpoint, while for the incoming side the # credentials must be for a 'server' endpoint. # An empty string means that QEMU will use plain text mode for # migration, rather than TLS (Since 2.7) # Note: 2.8 reports this by omitting tls-creds instead. # # @tls-hostname: hostname of the target host for the migration. This # is required when using x509 based TLS credentials and the # migration URI does not already include a hostname. For # example if using fd: or exec: based migration, the # hostname must be provided so that the server's x509 # certificate identity can be validated. (Since 2.7) # An empty string means that QEMU will use the hostname # associated with the migration URI, if any. (Since 2.9) # Note: 2.8 reports this by omitting tls-hostname instead. # # @tls-authz: ID of the 'authz' object subclass that provides access control # checking of the TLS x509 certificate distinguished name. (Since # 4.0) # # @max-bandwidth: to set maximum speed for migration. maximum speed in # bytes per second. (Since 2.8) # # @downtime-limit: set maximum tolerated downtime for migration. maximum # downtime in milliseconds (Since 2.8) # # @x-checkpoint-delay: the delay time between two COLO checkpoints. (Since 2.8) # # @block-incremental: Affects how much storage is migrated when the # block migration capability is enabled. When false, the entire # storage backing chain is migrated into a flattened image at # the destination; when true, only the active qcow2 layer is # migrated and the destination must already have access to the # same backing chain as was used on the source. (since 2.10) # # @multifd-channels: Number of channels used to migrate data in # parallel. This is the same number that the # number of sockets used for migration. # The default value is 2 (since 4.0) # # @xbzrle-cache-size: cache size to be used by XBZRLE migration. It # needs to be a multiple of the target page size # and a power of 2 # (Since 2.11) # # @max-postcopy-bandwidth: Background transfer bandwidth during postcopy. # Defaults to 0 (unlimited). In bytes per second. # (Since 3.0) # # @max-cpu-throttle: maximum cpu throttle percentage. # Defaults to 99. # (Since 3.1) # # @multifd-compression: Which compression method to use. # Defaults to none. (Since 5.0) # # @multifd-zlib-level: Set the compression level to be used in live # migration, the compression level is an integer between 0 # and 9, where 0 means no compression, 1 means the best # compression speed, and 9 means best compression ratio which # will consume more CPU. # Defaults to 1. (Since 5.0) # # @multifd-zstd-level: Set the compression level to be used in live # migration, the compression level is an integer between 0 # and 20, where 0 means no compression, 1 means the best # compression speed, and 20 means best compression ratio which # will consume more CPU. # Defaults to 1. (Since 5.0) # # @block-bitmap-mapping: Maps block nodes and bitmaps on them to # aliases for the purpose of dirty bitmap migration. Such # aliases may for example be the corresponding names on the # opposite site. # The mapping must be one-to-one, but not necessarily # complete: On the source, unmapped bitmaps and all bitmaps # on unmapped nodes will be ignored. On the destination, # encountering an unmapped alias in the incoming migration # stream will result in a report, and all further bitmap # migration data will then be discarded. # Note that the destination does not know about bitmaps it # does not receive, so there is no limitation or requirement # regarding the number of bitmaps received, or how they are # named, or on which nodes they are placed. # By default (when this parameter has never been set), bitmap # names are mapped to themselves. Nodes are mapped to their # block device name if there is one, and to their node name # otherwise. (Since 5.2) # # Since: 2.4 ## { 'struct': 'MigrationParameters', 'data': { '*announce-initial': 'size', '*announce-max': 'size', '*announce-rounds': 'size', '*announce-step': 'size', '*compress-level': 'uint8', '*compress-threads': 'uint8', '*compress-wait-thread': 'bool', '*decompress-threads': 'uint8', '*throttle-trigger-threshold': 'uint8', '*cpu-throttle-initial': 'uint8', '*cpu-throttle-increment': 'uint8', '*cpu-throttle-tailslow': 'bool', '*tls-creds': 'str', '*tls-hostname': 'str', '*tls-authz': 'str', '*max-bandwidth': 'size', '*downtime-limit': 'uint64', '*x-checkpoint-delay': 'uint32', '*block-incremental': 'bool' , '*multifd-channels': 'uint8', '*xbzrle-cache-size': 'size', '*max-postcopy-bandwidth': 'size', '*max-cpu-throttle': 'uint8', '*multifd-compression': 'MultiFDCompression', '*multifd-zlib-level': 'uint8', '*multifd-zstd-level': 'uint8', '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } } ## # @query-migrate-parameters: # # Returns information about the current migration parameters # # Returns: @MigrationParameters # # Since: 2.4 # # Example: # # -> { "execute": "query-migrate-parameters" } # <- { "return": { # "decompress-threads": 2, # "cpu-throttle-increment": 10, # "compress-threads": 8, # "compress-level": 1, # "cpu-throttle-initial": 20, # "max-bandwidth": 33554432, # "downtime-limit": 300 # } # } # ## { 'command': 'query-migrate-parameters', 'returns': 'MigrationParameters' } ## # @client_migrate_info: # # Set migration information for remote display. This makes the server # ask the client to automatically reconnect using the new parameters # once migration finished successfully. Only implemented for SPICE. # # @protocol: must be "spice" # @hostname: migration target hostname # @port: spice tcp port for plaintext channels # @tls-port: spice tcp port for tls-secured channels # @cert-subject: server certificate subject # # Since: 0.14.0 # # Example: # # -> { "execute": "client_migrate_info", # "arguments": { "protocol": "spice", # "hostname": "virt42.lab.kraxel.org", # "port": 1234 } } # <- { "return": {} } # ## { 'command': 'client_migrate_info', 'data': { 'protocol': 'str', 'hostname': 'str', '*port': 'int', '*tls-port': 'int', '*cert-subject': 'str' } } ## # @migrate-start-postcopy: # # Followup to a migration command to switch the migration to postcopy mode. # The postcopy-ram capability must be set on both source and destination # before the original migration command. # # Since: 2.5 # # Example: # # -> { "execute": "migrate-start-postcopy" } # <- { "return": {} } # ## { 'command': 'migrate-start-postcopy' } ## # @MIGRATION: # # Emitted when a migration event happens # # @status: @MigrationStatus describing the current migration status. # # Since: 2.4 # # Example: # # <- {"timestamp": {"seconds": 1432121972, "microseconds": 744001}, # "event": "MIGRATION", # "data": {"status": "completed"} } # ## { 'event': 'MIGRATION', 'data': {'status': 'MigrationStatus'}} ## # @MIGRATION_PASS: # # Emitted from the source side of a migration at the start of each pass # (when it syncs the dirty bitmap) # # @pass: An incrementing count (starting at 1 on the first pass) # # Since: 2.6 # # Example: # # { "timestamp": {"seconds": 1449669631, "microseconds": 239225}, # "event": "MIGRATION_PASS", "data": {"pass": 2} } # ## { 'event': 'MIGRATION_PASS', 'data': { 'pass': 'int' } } ## # @COLOMessage: # # The message transmission between Primary side and Secondary side. # # @checkpoint-ready: Secondary VM (SVM) is ready for checkpointing # # @checkpoint-request: Primary VM (PVM) tells SVM to prepare for checkpointing # # @checkpoint-reply: SVM gets PVM's checkpoint request # # @vmstate-send: VM's state will be sent by PVM. # # @vmstate-size: The total size of VMstate. # # @vmstate-received: VM's state has been received by SVM. # # @vmstate-loaded: VM's state has been loaded by SVM. # # Since: 2.8 ## { 'enum': 'COLOMessage', 'data': [ 'checkpoint-ready', 'checkpoint-request', 'checkpoint-reply', 'vmstate-send', 'vmstate-size', 'vmstate-received', 'vmstate-loaded' ] } ## # @COLOMode: # # The COLO current mode. # # @none: COLO is disabled. # # @primary: COLO node in primary side. # # @secondary: COLO node in slave side. # # Since: 2.8 ## { 'enum': 'COLOMode', 'data': [ 'none', 'primary', 'secondary'] } ## # @FailoverStatus: # # An enumeration of COLO failover status # # @none: no failover has ever happened # # @require: got failover requirement but not handled # # @active: in the process of doing failover # # @completed: finish the process of failover # # @relaunch: restart the failover process, from 'none' -> 'completed' (Since 2.9) # # Since: 2.8 ## { 'enum': 'FailoverStatus', 'data': [ 'none', 'require', 'active', 'completed', 'relaunch' ] } ## # @COLO_EXIT: # # Emitted when VM finishes COLO mode due to some errors happening or # at the request of users. # # @mode: report COLO mode when COLO exited. # # @reason: describes the reason for the COLO exit. # # Since: 3.1 # # Example: # # <- { "timestamp": {"seconds": 2032141960, "microseconds": 417172}, # "event": "COLO_EXIT", "data": {"mode": "primary", "reason": "request" } } # ## { 'event': 'COLO_EXIT', 'data': {'mode': 'COLOMode', 'reason': 'COLOExitReason' } } ## # @COLOExitReason: # # The reason for a COLO exit. # # @none: failover has never happened. This state does not occur # in the COLO_EXIT event, and is only visible in the result of # query-colo-status. # # @request: COLO exit is due to an external request. # # @error: COLO exit is due to an internal error. # # @processing: COLO is currently handling a failover (since 4.0). # # Since: 3.1 ## { 'enum': 'COLOExitReason', 'data': [ 'none', 'request', 'error' , 'processing' ] } ## # @x-colo-lost-heartbeat: # # Tell qemu that heartbeat is lost, request it to do takeover procedures. # If this command is sent to the PVM, the Primary side will exit COLO mode. # If sent to the Secondary, the Secondary side will run failover work, # then takes over server operation to become the service VM. # # Since: 2.8 # # Example: # # -> { "execute": "x-colo-lost-heartbeat" } # <- { "return": {} } # ## { 'command': 'x-colo-lost-heartbeat' } ## # @migrate_cancel: # # Cancel the current executing migration process. # # Returns: nothing on success # # Notes: This command succeeds even if there is no migration process running. # # Since: 0.14.0 # # Example: # # -> { "execute": "migrate_cancel" } # <- { "return": {} } # ## { 'command': 'migrate_cancel' } ## # @migrate-continue: # # Continue migration when it's in a paused state. # # @state: The state the migration is currently expected to be in # # Returns: nothing on success # Since: 2.11 # Example: # # -> { "execute": "migrate-continue" , "arguments": # { "state": "pre-switchover" } } # <- { "return": {} } ## { 'command': 'migrate-continue', 'data': {'state': 'MigrationStatus'} } ## # @migrate_set_downtime: # # Set maximum tolerated downtime for migration. # # @value: maximum downtime in seconds # # Features: # @deprecated: This command is deprecated. Use # 'migrate-set-parameters' instead. # # Returns: nothing on success # # Since: 0.14.0 # # Example: # # -> { "execute": "migrate_set_downtime", "arguments": { "value": 0.1 } } # <- { "return": {} } # ## { 'command': 'migrate_set_downtime', 'data': {'value': 'number'}, 'features': [ 'deprecated' ] } ## # @migrate_set_speed: # # Set maximum speed for migration. # # @value: maximum speed in bytes per second. # # Features: # @deprecated: This command is deprecated. Use # 'migrate-set-parameters' instead. # # Returns: nothing on success # # Since: 0.14.0 # # Example: # # -> { "execute": "migrate_set_speed", "arguments": { "value": 1024 } } # <- { "return": {} } # ## { 'command': 'migrate_set_speed', 'data': {'value': 'int'}, 'features': [ 'deprecated' ] } ## # @migrate-set-cache-size: # # Set cache size to be used by XBZRLE migration # # @value: cache size in bytes # # Features: # @deprecated: This command is deprecated. Use # 'migrate-set-parameters' instead. # # The size will be rounded down to the nearest power of 2. # The cache size can be modified before and during ongoing migration # # Returns: nothing on success # # Since: 1.2 # # Example: # # -> { "execute": "migrate-set-cache-size", # "arguments": { "value": 536870912 } } # <- { "return": {} } # ## { 'command': 'migrate-set-cache-size', 'data': {'value': 'int'}, 'features': [ 'deprecated' ] } ## # @query-migrate-cache-size: # # Query migration XBZRLE cache size # # Features: # @deprecated: This command is deprecated. Use # 'query-migrate-parameters' instead. # # Returns: XBZRLE cache size in bytes # # Since: 1.2 # # Example: # # -> { "execute": "query-migrate-cache-size" } # <- { "return": 67108864 } # ## { 'command': 'query-migrate-cache-size', 'returns': 'int', 'features': [ 'deprecated' ] } ## # @migrate: # # Migrates the current running guest to another Virtual Machine. # # @uri: the Uniform Resource Identifier of the destination VM # # @blk: do block migration (full disk copy) # # @inc: incremental disk copy migration # # @detach: this argument exists only for compatibility reasons and # is ignored by QEMU # # @resume: resume one paused migration, default "off". (since 3.0) # # Returns: nothing on success # # Since: 0.14.0 # # Notes: # # 1. The 'query-migrate' command should be used to check migration's progress # and final result (this information is provided by the 'status' member) # # 2. All boolean arguments default to false # # 3. The user Monitor's "detach" argument is invalid in QMP and should not # be used # # Example: # # -> { "execute": "migrate", "arguments": { "uri": "tcp:0:4446" } } # <- { "return": {} } # ## { 'command': 'migrate', 'data': {'uri': 'str', '*blk': 'bool', '*inc': 'bool', '*detach': 'bool', '*resume': 'bool' } } ## # @migrate-incoming: # # Start an incoming migration, the qemu must have been started # with -incoming defer # # @uri: The Uniform Resource Identifier identifying the source or # address to listen on # # Returns: nothing on success # # Since: 2.3 # # Notes: # # 1. It's a bad idea to use a string for the uri, but it needs to stay # compatible with -incoming and the format of the uri is already exposed # above libvirt. # # 2. QEMU must be started with -incoming defer to allow migrate-incoming to # be used. # # 3. The uri format is the same as for -incoming # # Example: # # -> { "execute": "migrate-incoming", # "arguments": { "uri": "tcp::4446" } } # <- { "return": {} } # ## { 'command': 'migrate-incoming', 'data': {'uri': 'str' } } ## # @xen-save-devices-state: # # Save the state of all devices to file. The RAM and the block devices # of the VM are not saved by this command. # # @filename: the file to save the state of the devices to as binary # data. See xen-save-devices-state.txt for a description of the binary # format. # # @live: Optional argument to ask QEMU to treat this command as part of a live # migration. Default to true. (since 2.11) # # Returns: Nothing on success # # Since: 1.1 # # Example: # # -> { "execute": "xen-save-devices-state", # "arguments": { "filename": "/tmp/save" } } # <- { "return": {} } # ## { 'command': 'xen-save-devices-state', 'data': {'filename': 'str', '*live':'bool' } } ## # @xen-set-replication: # # Enable or disable replication. # # @enable: true to enable, false to disable. # # @primary: true for primary or false for secondary. # # @failover: true to do failover, false to stop. but cannot be # specified if 'enable' is true. default value is false. # # Returns: nothing. # # Example: # # -> { "execute": "xen-set-replication", # "arguments": {"enable": true, "primary": false} } # <- { "return": {} } # # Since: 2.9 ## { 'command': 'xen-set-replication', 'data': { 'enable': 'bool', 'primary': 'bool', '*failover' : 'bool' }, 'if': 'defined(CONFIG_REPLICATION)' } ## # @ReplicationStatus: # # The result format for 'query-xen-replication-status'. # # @error: true if an error happened, false if replication is normal. # # @desc: the human readable error description string, when # @error is 'true'. # # Since: 2.9 ## { 'struct': 'ReplicationStatus', 'data': { 'error': 'bool', '*desc': 'str' }, 'if': 'defined(CONFIG_REPLICATION)' } ## # @query-xen-replication-status: # # Query replication status while the vm is running. # # Returns: A @ReplicationResult object showing the status. # # Example: # # -> { "execute": "query-xen-replication-status" } # <- { "return": { "error": false } } # # Since: 2.9 ## { 'command': 'query-xen-replication-status', 'returns': 'ReplicationStatus', 'if': 'defined(CONFIG_REPLICATION)' } ## # @xen-colo-do-checkpoint: # # Xen uses this command to notify replication to trigger a checkpoint. # # Returns: nothing. # # Example: # # -> { "execute": "xen-colo-do-checkpoint" } # <- { "return": {} } # # Since: 2.9 ## { 'command': 'xen-colo-do-checkpoint', 'if': 'defined(CONFIG_REPLICATION)' } ## # @COLOStatus: # # The result format for 'query-colo-status'. # # @mode: COLO running mode. If COLO is running, this field will return # 'primary' or 'secondary'. # # @last-mode: COLO last running mode. If COLO is running, this field # will return same like mode field, after failover we can # use this field to get last colo mode. (since 4.0) # # @reason: describes the reason for the COLO exit. # # Since: 3.1 ## { 'struct': 'COLOStatus', 'data': { 'mode': 'COLOMode', 'last-mode': 'COLOMode', 'reason': 'COLOExitReason' } } ## # @query-colo-status: # # Query COLO status while the vm is running. # # Returns: A @COLOStatus object showing the status. # # Example: # # -> { "execute": "query-colo-status" } # <- { "return": { "mode": "primary", "reason": "request" } } # # Since: 3.1 ## { 'command': 'query-colo-status', 'returns': 'COLOStatus' } ## # @migrate-recover: # # Provide a recovery migration stream URI. # # @uri: the URI to be used for the recovery of migration stream. # # Returns: nothing. # # Example: # # -> { "execute": "migrate-recover", # "arguments": { "uri": "tcp:192.168.1.200:12345" } } # <- { "return": {} } # # Since: 3.0 ## { 'command': 'migrate-recover', 'data': { 'uri': 'str' }, 'allow-oob': true } ## # @migrate-pause: # # Pause a migration. Currently it only supports postcopy. # # Returns: nothing. # # Example: # # -> { "execute": "migrate-pause" } # <- { "return": {} } # # Since: 3.0 ## { 'command': 'migrate-pause', 'allow-oob': true } ## # @UNPLUG_PRIMARY: # # Emitted from source side of a migration when migration state is # WAIT_UNPLUG. Device was unplugged by guest operating system. # Device resources in QEMU are kept on standby to be able to re-plug it in case # of migration failure. # # @device-id: QEMU device id of the unplugged device # # Since: 4.2 # # Example: # {"event": "UNPLUG_PRIMARY", "data": {"device-id": "hostdev0"} } # ## { 'event': 'UNPLUG_PRIMARY', 'data': { 'device-id': 'str' } } ## # @DirtyRateStatus: # # An enumeration of dirtyrate status. # # @unstarted: the dirtyrate thread has not been started. # # @measuring: the dirtyrate thread is measuring. # # @measured: the dirtyrate thread has measured and results are available. # # Since: 5.2 # ## { 'enum': 'DirtyRateStatus', 'data': [ 'unstarted', 'measuring', 'measured'] } ## # @DirtyRateInfo: # # Information about current dirty page rate of vm. # # @dirty-rate: @dirtyrate describing the dirty page rate of vm # in units of MB/s. # If this field returns '-1', it means querying has not # yet started or completed. # # @status: status containing dirtyrate query status includes # 'unstarted' or 'measuring' or 'measured' # # @start-time: start time in units of second for calculation # # @calc-time: time in units of second for sample dirty pages # # Since: 5.2 # ## { 'struct': 'DirtyRateInfo', 'data': {'dirty-rate': 'int64', 'status': 'DirtyRateStatus', 'start-time': 'int64', 'calc-time': 'int64'} } ## # @calc-dirty-rate: # # start calculating dirty page rate for vm # # @calc-time: time in units of second for sample dirty pages # # Since: 5.2 # # Example: # {"command": "calc-dirty-rate", "data": {"calc-time": 1} } # ## { 'command': 'calc-dirty-rate', 'data': {'calc-time': 'int64'} } ## # @query-dirty-rate: # # query dirty page rate in units of MB/s for vm # # Since: 5.2 ## { 'command': 'query-dirty-rate', 'returns': 'DirtyRateInfo' }