qemu/qapi/block-export.json
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   1# -*- Mode: Python -*-
   2# vim: filetype=python
   3
   4##
   5# == Block device exports
   6##
   7
   8{ 'include': 'sockets.json' }
   9
  10##
  11# @NbdServerOptions:
  12#
  13# Keep this type consistent with the nbd-server-start arguments. The only
  14# intended difference is using SocketAddress instead of SocketAddressLegacy.
  15#
  16# @addr: Address on which to listen.
  17# @tls-creds: ID of the TLS credentials object (since 2.6).
  18# @tls-authz: ID of the QAuthZ authorization object used to validate
  19#             the client's x509 distinguished name. This object is
  20#             is only resolved at time of use, so can be deleted and
  21#             recreated on the fly while the NBD server is active.
  22#             If missing, it will default to denying access (since 4.0).
  23# @max-connections: The maximum number of connections to allow at the same
  24#                   time, 0 for unlimited. (since 5.2; default: 0)
  25#
  26# Since: 4.2
  27##
  28{ 'struct': 'NbdServerOptions',
  29  'data': { 'addr': 'SocketAddress',
  30            '*tls-creds': 'str',
  31            '*tls-authz': 'str',
  32            '*max-connections': 'uint32' } }
  33
  34##
  35# @nbd-server-start:
  36#
  37# Start an NBD server listening on the given host and port.  Block
  38# devices can then be exported using @nbd-server-add.  The NBD
  39# server will present them as named exports; for example, another
  40# QEMU instance could refer to them as "nbd:HOST:PORT:exportname=NAME".
  41#
  42# Keep this type consistent with the NbdServerOptions type. The only intended
  43# difference is using SocketAddressLegacy instead of SocketAddress.
  44#
  45# @addr: Address on which to listen.
  46# @tls-creds: ID of the TLS credentials object (since 2.6).
  47# @tls-authz: ID of the QAuthZ authorization object used to validate
  48#             the client's x509 distinguished name. This object is
  49#             is only resolved at time of use, so can be deleted and
  50#             recreated on the fly while the NBD server is active.
  51#             If missing, it will default to denying access (since 4.0).
  52# @max-connections: The maximum number of connections to allow at the same
  53#                   time, 0 for unlimited. (since 5.2; default: 0)
  54#
  55# Returns: error if the server is already running.
  56#
  57# Since: 1.3
  58##
  59{ 'command': 'nbd-server-start',
  60  'data': { 'addr': 'SocketAddressLegacy',
  61            '*tls-creds': 'str',
  62            '*tls-authz': 'str',
  63            '*max-connections': 'uint32' } }
  64
  65##
  66# @BlockExportOptionsNbdBase:
  67#
  68# An NBD block export (common options shared between nbd-server-add and
  69# the NBD branch of block-export-add).
  70#
  71# @name: Export name. If unspecified, the @device parameter is used as the
  72#        export name. (Since 2.12)
  73#
  74# @description: Free-form description of the export, up to 4096 bytes.
  75#               (Since 5.0)
  76#
  77# Since: 5.0
  78##
  79{ 'struct': 'BlockExportOptionsNbdBase',
  80  'data': { '*name': 'str', '*description': 'str' } }
  81
  82##
  83# @BlockExportOptionsNbd:
  84#
  85# An NBD block export (distinct options used in the NBD branch of
  86# block-export-add).
  87#
  88# @bitmaps: Also export each of the named dirty bitmaps reachable from
  89#           @device, so the NBD client can use NBD_OPT_SET_META_CONTEXT with
  90#           the metadata context name "qemu:dirty-bitmap:BITMAP" to inspect
  91#           each bitmap.
  92#
  93# @allocation-depth: Also export the allocation depth map for @device, so
  94#                    the NBD client can use NBD_OPT_SET_META_CONTEXT with
  95#                    the metadata context name "qemu:allocation-depth" to
  96#                    inspect allocation details. (since 5.2)
  97#
  98# Since: 5.2
  99##
 100{ 'struct': 'BlockExportOptionsNbd',
 101  'base': 'BlockExportOptionsNbdBase',
 102  'data': { '*bitmaps': ['str'], '*allocation-depth': 'bool' } }
 103
 104##
 105# @BlockExportOptionsVhostUserBlk:
 106#
 107# A vhost-user-blk block export.
 108#
 109# @addr: The vhost-user socket on which to listen. Both 'unix' and 'fd'
 110#        SocketAddress types are supported. Passed fds must be UNIX domain
 111#        sockets.
 112# @logical-block-size: Logical block size in bytes. Defaults to 512 bytes.
 113# @num-queues: Number of request virtqueues. Must be greater than 0. Defaults
 114#              to 1.
 115#
 116# Since: 5.2
 117##
 118{ 'struct': 'BlockExportOptionsVhostUserBlk',
 119  'data': { 'addr': 'SocketAddress',
 120            '*logical-block-size': 'size',
 121            '*num-queues': 'uint16'} }
 122
 123##
 124# @FuseExportAllowOther:
 125#
 126# Possible allow_other modes for FUSE exports.
 127#
 128# @off: Do not pass allow_other as a mount option.
 129#
 130# @on: Pass allow_other as a mount option.
 131#
 132# @auto: Try mounting with allow_other first, and if that fails, retry
 133#        without allow_other.
 134#
 135# Since: 6.1
 136##
 137{ 'enum': 'FuseExportAllowOther',
 138  'data': ['off', 'on', 'auto'] }
 139
 140##
 141# @BlockExportOptionsFuse:
 142#
 143# Options for exporting a block graph node on some (file) mountpoint
 144# as a raw image.
 145#
 146# @mountpoint: Path on which to export the block device via FUSE.
 147#              This must point to an existing regular file.
 148#
 149# @growable: Whether writes beyond the EOF should grow the block node
 150#            accordingly. (default: false)
 151#
 152# @allow-other: If this is off, only qemu's user is allowed access to
 153#               this export.  That cannot be changed even with chmod or
 154#               chown.
 155#               Enabling this option will allow other users access to
 156#               the export with the FUSE mount option "allow_other".
 157#               Note that using allow_other as a non-root user requires
 158#               user_allow_other to be enabled in the global fuse.conf
 159#               configuration file.
 160#               In auto mode (the default), the FUSE export driver will
 161#               first attempt to mount the export with allow_other, and
 162#               if that fails, try again without.
 163#               (since 6.1; default: auto)
 164#
 165# Since: 6.0
 166##
 167{ 'struct': 'BlockExportOptionsFuse',
 168  'data': { 'mountpoint': 'str',
 169            '*growable': 'bool',
 170            '*allow-other': 'FuseExportAllowOther' },
 171  'if': 'defined(CONFIG_FUSE)' }
 172
 173##
 174# @NbdServerAddOptions:
 175#
 176# An NBD block export, per legacy nbd-server-add command.
 177#
 178# @device: The device name or node name of the node to be exported
 179#
 180# @writable: Whether clients should be able to write to the device via the
 181#            NBD connection (default false).
 182#
 183# @bitmap: Also export a single dirty bitmap reachable from @device, so the
 184#          NBD client can use NBD_OPT_SET_META_CONTEXT with the metadata
 185#          context name "qemu:dirty-bitmap:BITMAP" to inspect the bitmap
 186#          (since 4.0).
 187#
 188# Since: 5.0
 189##
 190{ 'struct': 'NbdServerAddOptions',
 191  'base': 'BlockExportOptionsNbdBase',
 192  'data': { 'device': 'str',
 193            '*writable': 'bool', '*bitmap': 'str' } }
 194
 195##
 196# @nbd-server-add:
 197#
 198# Export a block node to QEMU's embedded NBD server.
 199#
 200# The export name will be used as the id for the resulting block export.
 201#
 202# Features:
 203# @deprecated: This command is deprecated. Use @block-export-add instead.
 204#
 205# Returns: error if the server is not running, or export with the same name
 206#          already exists.
 207#
 208# Since: 1.3
 209##
 210{ 'command': 'nbd-server-add',
 211  'data': 'NbdServerAddOptions', 'boxed': true, 'features': ['deprecated'] }
 212
 213##
 214# @BlockExportRemoveMode:
 215#
 216# Mode for removing a block export.
 217#
 218# @safe: Remove export if there are no existing connections, fail otherwise.
 219#
 220# @hard: Drop all connections immediately and remove export.
 221#
 222# Potential additional modes to be added in the future:
 223#
 224# hide: Just hide export from new clients, leave existing connections as is.
 225# Remove export after all clients are disconnected.
 226#
 227# soft: Hide export from new clients, answer with ESHUTDOWN for all further
 228# requests from existing clients.
 229#
 230# Since: 2.12
 231##
 232{'enum': 'BlockExportRemoveMode', 'data': ['safe', 'hard']}
 233
 234##
 235# @nbd-server-remove:
 236#
 237# Remove NBD export by name.
 238#
 239# @name: Block export id.
 240#
 241# @mode: Mode of command operation. See @BlockExportRemoveMode description.
 242#        Default is 'safe'.
 243#
 244# Features:
 245# @deprecated: This command is deprecated. Use @block-export-del instead.
 246#
 247# Returns: error if
 248#            - the server is not running
 249#            - export is not found
 250#            - mode is 'safe' and there are existing connections
 251#
 252# Since: 2.12
 253##
 254{ 'command': 'nbd-server-remove',
 255  'data': {'name': 'str', '*mode': 'BlockExportRemoveMode'},
 256  'features': ['deprecated'] }
 257
 258##
 259# @nbd-server-stop:
 260#
 261# Stop QEMU's embedded NBD server, and unregister all devices previously
 262# added via @nbd-server-add.
 263#
 264# Since: 1.3
 265##
 266{ 'command': 'nbd-server-stop' }
 267
 268##
 269# @BlockExportType:
 270#
 271# An enumeration of block export types
 272#
 273# @nbd: NBD export
 274# @vhost-user-blk: vhost-user-blk export (since 5.2)
 275# @fuse: FUSE export (since: 6.0)
 276#
 277# Since: 4.2
 278##
 279{ 'enum': 'BlockExportType',
 280  'data': [ 'nbd', 'vhost-user-blk',
 281            { 'name': 'fuse', 'if': 'defined(CONFIG_FUSE)' } ] }
 282
 283##
 284# @BlockExportOptions:
 285#
 286# Describes a block export, i.e. how single node should be exported on an
 287# external interface.
 288#
 289# @id: A unique identifier for the block export (across all export types)
 290#
 291# @node-name: The node name of the block node to be exported (since: 5.2)
 292#
 293# @writable: True if clients should be able to write to the export
 294#            (default false)
 295#
 296# @writethrough: If true, caches are flushed after every write request to the
 297#                export before completion is signalled. (since: 5.2;
 298#                default: false)
 299#
 300# @iothread: The name of the iothread object where the export will run. The
 301#            default is to use the thread currently associated with the
 302#            block node. (since: 5.2)
 303#
 304# @fixed-iothread: True prevents the block node from being moved to another
 305#                  thread while the export is active. If true and @iothread is
 306#                  given, export creation fails if the block node cannot be
 307#                  moved to the iothread. The default is false. (since: 5.2)
 308#
 309# Since: 4.2
 310##
 311{ 'union': 'BlockExportOptions',
 312  'base': { 'type': 'BlockExportType',
 313            'id': 'str',
 314            '*fixed-iothread': 'bool',
 315            '*iothread': 'str',
 316            'node-name': 'str',
 317            '*writable': 'bool',
 318            '*writethrough': 'bool' },
 319  'discriminator': 'type',
 320  'data': {
 321      'nbd': 'BlockExportOptionsNbd',
 322      'vhost-user-blk': 'BlockExportOptionsVhostUserBlk',
 323      'fuse': { 'type': 'BlockExportOptionsFuse',
 324                'if': 'defined(CONFIG_FUSE)' }
 325   } }
 326
 327##
 328# @block-export-add:
 329#
 330# Creates a new block export.
 331#
 332# Since: 5.2
 333##
 334{ 'command': 'block-export-add',
 335  'data': 'BlockExportOptions', 'boxed': true }
 336
 337##
 338# @block-export-del:
 339#
 340# Request to remove a block export. This drops the user's reference to the
 341# export, but the export may still stay around after this command returns until
 342# the shutdown of the export has completed.
 343#
 344# @id: Block export id.
 345#
 346# @mode: Mode of command operation. See @BlockExportRemoveMode description.
 347#        Default is 'safe'.
 348#
 349# Returns: Error if the export is not found or @mode is 'safe' and the export
 350#          is still in use (e.g. by existing client connections)
 351#
 352# Since: 5.2
 353##
 354{ 'command': 'block-export-del',
 355  'data': { 'id': 'str', '*mode': 'BlockExportRemoveMode' } }
 356
 357##
 358# @BLOCK_EXPORT_DELETED:
 359#
 360# Emitted when a block export is removed and its id can be reused.
 361#
 362# @id: Block export id.
 363#
 364# Since: 5.2
 365##
 366{ 'event': 'BLOCK_EXPORT_DELETED',
 367  'data': { 'id': 'str' } }
 368
 369##
 370# @BlockExportInfo:
 371#
 372# Information about a single block export.
 373#
 374# @id: The unique identifier for the block export
 375#
 376# @type: The block export type
 377#
 378# @node-name: The node name of the block node that is exported
 379#
 380# @shutting-down: True if the export is shutting down (e.g. after a
 381#                 block-export-del command, but before the shutdown has
 382#                 completed)
 383#
 384# Since:  5.2
 385##
 386{ 'struct': 'BlockExportInfo',
 387  'data': { 'id': 'str',
 388            'type': 'BlockExportType',
 389            'node-name': 'str',
 390            'shutting-down': 'bool' } }
 391
 392##
 393# @query-block-exports:
 394#
 395# Returns: A list of BlockExportInfo describing all block exports
 396#
 397# Since: 5.2
 398##
 399{ 'command': 'query-block-exports', 'returns': ['BlockExportInfo'] }
 400