5 # == Block device exports
8 { 'include': 'sockets.json' }
13 # Keep this type consistent with the nbd-server-start arguments. The only
14 # intended difference is using SocketAddress instead of SocketAddressLegacy.
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)
28 { 'struct': 'NbdServerOptions',
29 'data': { 'addr': 'SocketAddress',
32 '*max-connections': 'uint32' } }
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".
42 # Keep this type consistent with the NbdServerOptions type. The only intended
43 # difference is using SocketAddressLegacy instead of SocketAddress.
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)
55 # Returns: error if the server is already running.
59 { 'command': 'nbd-server-start',
60 'data': { 'addr': 'SocketAddressLegacy',
63 '*max-connections': 'uint32' } }
66 # @BlockExportOptionsNbdBase:
68 # An NBD block export (common options shared between nbd-server-add and
69 # the NBD branch of block-export-add).
71 # @name: Export name. If unspecified, the @device parameter is used as the
72 # export name. (Since 2.12)
74 # @description: Free-form description of the export, up to 4096 bytes.
79 { 'struct': 'BlockExportOptionsNbdBase',
80 'data': { '*name': 'str', '*description': 'str' } }
83 # @BlockExportOptionsNbd:
85 # An NBD block export (distinct options used in the NBD branch of
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
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)
100 { 'struct': 'BlockExportOptionsNbd',
101 'base': 'BlockExportOptionsNbdBase',
102 'data': { '*bitmaps': ['str'], '*allocation-depth': 'bool' } }
105 # @BlockExportOptionsVhostUserBlk:
107 # A vhost-user-blk block export.
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
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
118 { 'struct': 'BlockExportOptionsVhostUserBlk',
119 'data': { 'addr': 'SocketAddress',
120 '*logical-block-size': 'size',
121 '*num-queues': 'uint16'} }
124 # @BlockExportOptionsFuse:
126 # Options for exporting a block graph node on some (file) mountpoint
129 # @mountpoint: Path on which to export the block device via FUSE.
130 # This must point to an existing regular file.
132 # @growable: Whether writes beyond the EOF should grow the block node
133 # accordingly. (default: false)
137 { 'struct': 'BlockExportOptionsFuse',
138 'data': { 'mountpoint': 'str',
139 '*growable': 'bool' },
140 'if': 'defined(CONFIG_FUSE)' }
143 # @NbdServerAddOptions:
145 # An NBD block export, per legacy nbd-server-add command.
147 # @device: The device name or node name of the node to be exported
149 # @writable: Whether clients should be able to write to the device via the
150 # NBD connection (default false).
152 # @bitmap: Also export a single dirty bitmap reachable from @device, so the
153 # NBD client can use NBD_OPT_SET_META_CONTEXT with the metadata
154 # context name "qemu:dirty-bitmap:BITMAP" to inspect the bitmap
159 { 'struct': 'NbdServerAddOptions',
160 'base': 'BlockExportOptionsNbdBase',
161 'data': { 'device': 'str',
162 '*writable': 'bool', '*bitmap': 'str' } }
167 # Export a block node to QEMU's embedded NBD server.
169 # The export name will be used as the id for the resulting block export.
172 # @deprecated: This command is deprecated. Use @block-export-add instead.
174 # Returns: error if the server is not running, or export with the same name
179 { 'command': 'nbd-server-add',
180 'data': 'NbdServerAddOptions', 'boxed': true, 'features': ['deprecated'] }
183 # @BlockExportRemoveMode:
185 # Mode for removing a block export.
187 # @safe: Remove export if there are no existing connections, fail otherwise.
189 # @hard: Drop all connections immediately and remove export.
191 # Potential additional modes to be added in the future:
193 # hide: Just hide export from new clients, leave existing connections as is.
194 # Remove export after all clients are disconnected.
196 # soft: Hide export from new clients, answer with ESHUTDOWN for all further
197 # requests from existing clients.
201 {'enum': 'BlockExportRemoveMode', 'data': ['safe', 'hard']}
204 # @nbd-server-remove:
206 # Remove NBD export by name.
208 # @name: Block export id.
210 # @mode: Mode of command operation. See @BlockExportRemoveMode description.
214 # @deprecated: This command is deprecated. Use @block-export-del instead.
217 # - the server is not running
218 # - export is not found
219 # - mode is 'safe' and there are existing connections
223 { 'command': 'nbd-server-remove',
224 'data': {'name': 'str', '*mode': 'BlockExportRemoveMode'},
225 'features': ['deprecated'] }
230 # Stop QEMU's embedded NBD server, and unregister all devices previously
231 # added via @nbd-server-add.
235 { 'command': 'nbd-server-stop' }
240 # An enumeration of block export types
243 # @vhost-user-blk: vhost-user-blk export (since 5.2)
244 # @fuse: FUSE export (since: 6.0)
248 { 'enum': 'BlockExportType',
249 'data': [ 'nbd', 'vhost-user-blk',
250 { 'name': 'fuse', 'if': 'defined(CONFIG_FUSE)' } ] }
253 # @BlockExportOptions:
255 # Describes a block export, i.e. how single node should be exported on an
256 # external interface.
258 # @id: A unique identifier for the block export (across all export types)
260 # @node-name: The node name of the block node to be exported (since: 5.2)
262 # @writable: True if clients should be able to write to the export
265 # @writethrough: If true, caches are flushed after every write request to the
266 # export before completion is signalled. (since: 5.2;
269 # @iothread: The name of the iothread object where the export will run. The
270 # default is to use the thread currently associated with the
271 # block node. (since: 5.2)
273 # @fixed-iothread: True prevents the block node from being moved to another
274 # thread while the export is active. If true and @iothread is
275 # given, export creation fails if the block node cannot be
276 # moved to the iothread. The default is false. (since: 5.2)
280 { 'union': 'BlockExportOptions',
281 'base': { 'type': 'BlockExportType',
283 '*fixed-iothread': 'bool',
287 '*writethrough': 'bool' },
288 'discriminator': 'type',
290 'nbd': 'BlockExportOptionsNbd',
291 'vhost-user-blk': 'BlockExportOptionsVhostUserBlk',
292 'fuse': { 'type': 'BlockExportOptionsFuse',
293 'if': 'defined(CONFIG_FUSE)' }
299 # Creates a new block export.
303 { 'command': 'block-export-add',
304 'data': 'BlockExportOptions', 'boxed': true }
309 # Request to remove a block export. This drops the user's reference to the
310 # export, but the export may still stay around after this command returns until
311 # the shutdown of the export has completed.
313 # @id: Block export id.
315 # @mode: Mode of command operation. See @BlockExportRemoveMode description.
318 # Returns: Error if the export is not found or @mode is 'safe' and the export
319 # is still in use (e.g. by existing client connections)
323 { 'command': 'block-export-del',
324 'data': { 'id': 'str', '*mode': 'BlockExportRemoveMode' } }
327 # @BLOCK_EXPORT_DELETED:
329 # Emitted when a block export is removed and its id can be reused.
331 # @id: Block export id.
335 { 'event': 'BLOCK_EXPORT_DELETED',
336 'data': { 'id': 'str' } }
341 # Information about a single block export.
343 # @id: The unique identifier for the block export
345 # @type: The block export type
347 # @node-name: The node name of the block node that is exported
349 # @shutting-down: True if the export is shutting down (e.g. after a
350 # block-export-del command, but before the shutdown has
355 { 'struct': 'BlockExportInfo',
356 'data': { 'id': 'str',
357 'type': 'BlockExportType',
359 'shutting-down': 'bool' } }
362 # @query-block-exports:
364 # Returns: A list of BlockExportInfo describing all block exports
368 { 'command': 'query-block-exports', 'returns': ['BlockExportInfo'] }