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 # @NbdServerAddOptions:
126 # An NBD block export, per legacy nbd-server-add command.
128 # @device: The device name or node name of the node to be exported
130 # @writable: Whether clients should be able to write to the device via the
131 # NBD connection (default false).
133 # @bitmap: Also export a single dirty bitmap reachable from @device, so the
134 # NBD client can use NBD_OPT_SET_META_CONTEXT with the metadata
135 # context name "qemu:dirty-bitmap:BITMAP" to inspect the bitmap
140 { 'struct': 'NbdServerAddOptions',
141 'base': 'BlockExportOptionsNbdBase',
142 'data': { 'device': 'str',
143 '*writable': 'bool', '*bitmap': 'str' } }
148 # Export a block node to QEMU's embedded NBD server.
150 # The export name will be used as the id for the resulting block export.
153 # @deprecated: This command is deprecated. Use @block-export-add instead.
155 # Returns: error if the server is not running, or export with the same name
160 { 'command': 'nbd-server-add',
161 'data': 'NbdServerAddOptions', 'boxed': true, 'features': ['deprecated'] }
164 # @BlockExportRemoveMode:
166 # Mode for removing a block export.
168 # @safe: Remove export if there are no existing connections, fail otherwise.
170 # @hard: Drop all connections immediately and remove export.
172 # Potential additional modes to be added in the future:
174 # hide: Just hide export from new clients, leave existing connections as is.
175 # Remove export after all clients are disconnected.
177 # soft: Hide export from new clients, answer with ESHUTDOWN for all further
178 # requests from existing clients.
182 {'enum': 'BlockExportRemoveMode', 'data': ['safe', 'hard']}
185 # @nbd-server-remove:
187 # Remove NBD export by name.
189 # @name: Block export id.
191 # @mode: Mode of command operation. See @BlockExportRemoveMode description.
195 # @deprecated: This command is deprecated. Use @block-export-del instead.
198 # - the server is not running
199 # - export is not found
200 # - mode is 'safe' and there are existing connections
204 { 'command': 'nbd-server-remove',
205 'data': {'name': 'str', '*mode': 'BlockExportRemoveMode'},
206 'features': ['deprecated'] }
211 # Stop QEMU's embedded NBD server, and unregister all devices previously
212 # added via @nbd-server-add.
216 { 'command': 'nbd-server-stop' }
221 # An enumeration of block export types
224 # @vhost-user-blk: vhost-user-blk export (since 5.2)
228 { 'enum': 'BlockExportType',
229 'data': [ 'nbd', 'vhost-user-blk' ] }
232 # @BlockExportOptions:
234 # Describes a block export, i.e. how single node should be exported on an
235 # external interface.
237 # @id: A unique identifier for the block export (across all export types)
239 # @node-name: The node name of the block node to be exported (since: 5.2)
241 # @writable: True if clients should be able to write to the export
244 # @writethrough: If true, caches are flushed after every write request to the
245 # export before completion is signalled. (since: 5.2;
248 # @iothread: The name of the iothread object where the export will run. The
249 # default is to use the thread currently associated with the
250 # block node. (since: 5.2)
252 # @fixed-iothread: True prevents the block node from being moved to another
253 # thread while the export is active. If true and @iothread is
254 # given, export creation fails if the block node cannot be
255 # moved to the iothread. The default is false. (since: 5.2)
259 { 'union': 'BlockExportOptions',
260 'base': { 'type': 'BlockExportType',
262 '*fixed-iothread': 'bool',
266 '*writethrough': 'bool' },
267 'discriminator': 'type',
269 'nbd': 'BlockExportOptionsNbd',
270 'vhost-user-blk': 'BlockExportOptionsVhostUserBlk'
276 # Creates a new block export.
280 { 'command': 'block-export-add',
281 'data': 'BlockExportOptions', 'boxed': true }
286 # Request to remove a block export. This drops the user's reference to the
287 # export, but the export may still stay around after this command returns until
288 # the shutdown of the export has completed.
290 # @id: Block export id.
292 # @mode: Mode of command operation. See @BlockExportRemoveMode description.
295 # Returns: Error if the export is not found or @mode is 'safe' and the export
296 # is still in use (e.g. by existing client connections)
300 { 'command': 'block-export-del',
301 'data': { 'id': 'str', '*mode': 'BlockExportRemoveMode' } }
304 # @BLOCK_EXPORT_DELETED:
306 # Emitted when a block export is removed and its id can be reused.
308 # @id: Block export id.
312 { 'event': 'BLOCK_EXPORT_DELETED',
313 'data': { 'id': 'str' } }
318 # Information about a single block export.
320 # @id: The unique identifier for the block export
322 # @type: The block export type
324 # @node-name: The node name of the block node that is exported
326 # @shutting-down: True if the export is shutting down (e.g. after a
327 # block-export-del command, but before the shutdown has
332 { 'struct': 'BlockExportInfo',
333 'data': { 'id': 'str',
334 'type': 'BlockExportType',
336 'shutting-down': 'bool' } }
339 # @query-block-exports:
341 # Returns: A list of BlockExportInfo describing all block exports
345 { 'command': 'query-block-exports', 'returns': ['BlockExportInfo'] }