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migration.json
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migration.json
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# -*- 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. Always zero, only provided for
# compatibility (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)
#
# @precopy-bytes: The number of bytes sent in the pre-copy phase
# (since 7.0).
#
# @downtime-bytes: The number of bytes sent while the guest is paused
# (since 7.0).
#
# @postcopy-bytes: The number of bytes sent during the post-copy phase
# (since 7.0).
#
# @dirty-sync-missed-zero-copy: Number of times dirty RAM
# synchronization could not avoid copying dirty pages. This is
# between 0 and @dirty-sync-count * @multifd-channels. (since
# 7.1)
#
# Features:
#
# @deprecated: Member @skipped is always zero since 1.5.3
#
# Since: 0.14
#
##
{ 'struct': 'MigrationStats',
'data': {'transferred': 'int', 'remaining': 'int', 'total': 'int' ,
'duplicate': 'int',
'skipped': { 'type': 'int', 'features': [ 'deprecated' ] },
'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',
'precopy-bytes': 'uint64', 'downtime-bytes': 'uint64',
'postcopy-bytes': 'uint64',
'dirty-sync-missed-zero-copy': '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': 'size', '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' ] }
##
# @VfioStats:
#
# Detailed VFIO devices migration statistics
#
# @transferred: amount of bytes transferred to the target VM by VFIO
# devices
#
# Since: 5.2
##
{ 'struct': 'VfioStats',
'data': {'transferred': 'int' } }
##
# @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. 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)
#
# @vfio: @VfioStats containing detailed VFIO devices migration
# statistics, only returned if VFIO device is present, migration
# is supported by all VFIO devices and status is 'active' or
# 'completed' (since 5.2)
#
# @blocked-reasons: A list of reasons an outgoing migration is
# blocked. Present and non-empty when migration is blocked.
# (since 6.0)
#
# @dirty-limit-throttle-time-per-round: Maximum throttle time
# (in microseconds) of virtual CPUs each dirty ring full round,
# which shows how MigrationCapability dirty-limit affects the
# guest during live migration. (Since 8.1)
#
# @dirty-limit-ring-full-time: Estimated average dirty ring full time
# (in microseconds) for each dirty ring full round. The value
# equals the dirty ring memory size divided by the average dirty
# page rate of the virtual CPU, which can be used to observe the
# average memory load of the virtual CPU indirectly. Note that
# zero means guest doesn't dirty memory. (Since 8.1)
#
# Features:
#
# @deprecated: Member @disk is deprecated because block migration is.
# Member @compression is deprecated because it is unreliable and
# untested. It is recommended to use multifd migration, which
# offers an alternative compression implementation that is
# reliable and tested.
#
# Since: 0.14
##
{ 'struct': 'MigrationInfo',
'data': {'*status': 'MigrationStatus', '*ram': 'MigrationStats',
'*disk': { 'type': 'MigrationStats', 'features': [ 'deprecated' ] },
'*vfio': 'VfioStats',
'*xbzrle-cache': 'XBZRLECacheStats',
'*total-time': 'int',
'*expected-downtime': 'int',
'*downtime': 'int',
'*setup-time': 'int',
'*cpu-throttle-percentage': 'int',
'*error-desc': 'str',
'*blocked-reasons': ['str'],
'*postcopy-blocktime': 'uint32',
'*postcopy-vcpu-blocktime': ['uint32'],
'*compression': { 'type': 'CompressionStats', 'features': [ 'deprecated' ] },
'*socket-address': ['SocketAddress'],
'*dirty-limit-throttle-time-per-round': 'uint64',
'*dirty-limit-ring-full-time': 'uint64'} }
##
# @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
#
# Examples:
#
# 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
# that is accessible on the destination machine. (since 4.0)
#
# @validate-uuid: Send the UUID of the source to allow the destination
# to ensure it is the same. (since 4.2)
#
# @background-snapshot: If enabled, the migration stream will be a
# snapshot of the VM exactly at the point when the migration
# procedure starts. The VM RAM is saved with running VM. (since
# 6.0)
#
# @zero-copy-send: Controls behavior on sending memory pages on
# migration. When true, enables a zero-copy mechanism for sending
# memory pages, if host supports it. Requires that QEMU be
# permitted to use locked memory for guest RAM pages. (since 7.1)
#
# @postcopy-preempt: If enabled, the migration process will allow
# postcopy requests to preempt precopy stream, so postcopy
# requests will be handled faster. This is a performance feature
# and should not affect the correctness of postcopy migration.
# (since 7.1)
#
# @switchover-ack: If enabled, migration will not stop the source VM
# and complete the migration until an ACK is received from the
# destination that it's OK to do so. Exactly when this ACK is
# sent depends on the migrated devices that use this feature. For
# example, a device can use it to make sure some of its data is
# sent and loaded in the destination before doing switchover.
# This can reduce downtime if devices that support this capability
# are present. 'return-path' capability must be enabled to use
# it. (since 8.1)
#
# @dirty-limit: If enabled, migration will throttle vCPUs as needed to
# keep their dirty page rate within @vcpu-dirty-limit. This can
# improve responsiveness of large guests during live migration,
# and can result in more stable read performance. Requires KVM
# with accelerator property "dirty-ring-size" set. (Since 8.1)
#
# Features:
#
# @deprecated: Member @block is deprecated. Use blockdev-mirror with
# NBD instead. Member @compress is deprecated because it is
# unreliable and untested. It is recommended to use multifd
# migration, which offers an alternative compression
# implementation that is reliable and tested.
#
# @unstable: Members @x-colo and @x-ignore-shared are experimental.
#
# Since: 1.2
##
{ 'enum': 'MigrationCapability',
'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks',
{ 'name': 'compress', 'features': [ 'deprecated' ] },
'events', 'postcopy-ram',
{ 'name': 'x-colo', 'features': [ 'unstable' ] },
'release-ram',
{ 'name': 'block', 'features': [ 'deprecated' ] },
'return-path', 'pause-before-switchover', 'multifd',
'dirty-bitmaps', 'postcopy-blocktime', 'late-block-activate',
{ 'name': 'x-ignore-shared', 'features': [ 'unstable' ] },
'validate-uuid', 'background-snapshot',
'zero-copy-send', 'postcopy-preempt', 'switchover-ack',
'dirty-limit'] }
##
# @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 } ] } }
# <- { "return": {} }
##
{ 'command': 'migrate-set-capabilities',
'data': { 'capabilities': ['MigrationCapabilityStatus'] } }
##
# @query-migrate-capabilities:
#
# Returns information about the current migration capabilities status
#
# Returns: @MigrationCapabilityStatus
#
# 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': 'CONFIG_ZSTD' } ] }
##
# @MigMode:
#
# @normal: the original form of migration. (since 8.2)
#
# @cpr-reboot: The migrate command saves state to a file, allowing one to
# quit qemu, reboot to an updated kernel, and restart an updated
# version of qemu. The caller must specify a migration URI
# that writes to and reads from a file. Unlike normal mode,
# the use of certain local storage options does not block the
# migration, but the caller must not modify guest block devices
# between the quit and restart. To avoid saving guest RAM to the
# file, the memory backend must be shared, and the @x-ignore-shared
# migration capability must be set. Guest RAM must be non-volatile
# across reboot, such as by backing it with a dax device, but this
# is not enforced. The restarted qemu arguments must match those
# used to initially start qemu, plus the -incoming option.
# (since 8.2)
##
{ 'enum': 'MigMode',
'data': [ 'normal', 'cpr-reboot' ] }
##
# @BitmapMigrationBitmapAliasTransform:
#
# @persistent: If present, the bitmap will be made persistent or
# transient depending on this parameter.
#
# Since: 6.0
##
{ 'struct': 'BitmapMigrationBitmapAliasTransform',
'data': {
'*persistent': 'bool'
} }
##
# @BitmapMigrationBitmapAlias:
#
# @name: The name of the bitmap.
#
# @alias: An alias name for migration (for example the bitmap name on
# the opposite site).
#
# @transform: Allows the modification of the migrated bitmap. (since
# 6.0)
#
# Since: 5.2
##
{ 'struct': 'BitmapMigrationBitmapAlias',
'data': {
'name': 'str',
'alias': 'str',
'*transform': 'BitmapMigrationBitmapAliasTransform'
} }
##
# @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)
#
# @avail-switchover-bandwidth: to set the available bandwidth that
# migration can use during switchover phase. NOTE! This does not
# limit the bandwidth during switchover, but only for calculations when
# making decisions to switchover. By default, this value is zero,
# which means QEMU will estimate the bandwidth automatically. This can
# be set when the estimated value is not accurate, while the user is
# able to guarantee such bandwidth is available when switching over.
# When specified correctly, this can make the switchover decision much
# more accurate. (Since 8.2)
#
# @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)
#
# @x-vcpu-dirty-limit-period: Periodic time (in milliseconds) of dirty
# limit during live migration. Should be in the range 1 to 1000ms.
# Defaults to 1000ms. (Since 8.1)
#
# @vcpu-dirty-limit: Dirtyrate limit (MB/s) during live migration.
# Defaults to 1. (Since 8.1)
#
# @mode: Migration mode. See description in @MigMode. Default is 'normal'.
# (Since 8.2)
#
# Features:
#
# @deprecated: Member @block-incremental is deprecated. Use
# blockdev-mirror with NBD instead. Members @compress-level,
# @compress-threads, @decompress-threads and @compress-wait-thread
# are deprecated because @compression is deprecated.
#
# @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period
# are experimental.
#
# Since: 2.4
##
{ 'enum': 'MigrationParameter',
'data': ['announce-initial', 'announce-max',
'announce-rounds', 'announce-step',
{ 'name': 'compress-level', 'features': [ 'deprecated' ] },
{ 'name': 'compress-threads', 'features': [ 'deprecated' ] },
{ 'name': 'decompress-threads', 'features': [ 'deprecated' ] },
{ 'name': 'compress-wait-thread', 'features': [ 'deprecated' ] },
'throttle-trigger-threshold',
'cpu-throttle-initial', 'cpu-throttle-increment',
'cpu-throttle-tailslow',
'tls-creds', 'tls-hostname', 'tls-authz', 'max-bandwidth',
'avail-switchover-bandwidth', 'downtime-limit',
{ 'name': 'x-checkpoint-delay', 'features': [ 'unstable' ] },
{ 'name': 'block-incremental', 'features': [ 'deprecated' ] },
'multifd-channels',
'xbzrle-cache-size', 'max-postcopy-bandwidth',
'max-cpu-throttle', 'multifd-compression',
'multifd-zlib-level', 'multifd-zstd-level',
'block-bitmap-mapping',
{ 'name': 'x-vcpu-dirty-limit-period', 'features': ['unstable'] },
'vcpu-dirty-limit',
'mode'] }
##
# @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)
#
# @avail-switchover-bandwidth: to set the available bandwidth that
# migration can use during switchover phase. NOTE! This does not
# limit the bandwidth during switchover, but only for calculations when
# making decisions to switchover. By default, this value is zero,
# which means QEMU will estimate the bandwidth automatically. This can
# be set when the estimated value is not accurate, while the user is
# able to guarantee such bandwidth is available when switching over.
# When specified correctly, this can make the switchover decision much
# more accurate. (Since 8.2)
#
# @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)