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docs: vhost-user: clean up request/reply description 

It is not necessary to mention which side is sending/receiving
each payload; it is more interesting to say which is the request
and which is the reply.  This also matches what vhost-user-gpu.rst
already does.

While at it, ensure that all messages list both the request and
the reply payload.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210226143413.188046-2-pbonzini@redhat.com>
Message-Id: <20220321153037.3622127-5-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
This commit is contained in:
Paolo Bonzini 2022-03-21 15:30:28 +00:00 committed by Michael S. Tsirkin
parent 6ca6d8ee9d
commit 43725d4844
1 changed files with 95 additions and 68 deletions
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163
docs/interop/vhost-user.rst
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@ -866,8 +866,8 @@ Master message types
``VHOST_USER_GET_FEATURES``
:id: 1
:equivalent ioctl: ``VHOST_GET_FEATURES``
:master payload: N/A
:slave payload: ``u64``
:request payload: N/A
:reply payload: ``u64``
Get from the underlying vhost implementation the features bitmask.
Feature bit ``VHOST_USER_F_PROTOCOL_FEATURES`` signals slave support
@ -877,7 +877,8 @@ Master message types
``VHOST_USER_SET_FEATURES``
:id: 2
:equivalent ioctl: ``VHOST_SET_FEATURES``
:master payload: ``u64``
:request payload: ``u64``
:reply payload: N/A
Enable features in the underlying vhost implementation using a
bitmask. Feature bit ``VHOST_USER_F_PROTOCOL_FEATURES`` signals
@ -887,8 +888,8 @@ Master message types
``VHOST_USER_GET_PROTOCOL_FEATURES``
:id: 15
:equivalent ioctl: ``VHOST_GET_FEATURES``
:master payload: N/A
:slave payload: ``u64``
:request payload: N/A
:reply payload: ``u64``
Get the protocol feature bitmask from the underlying vhost
implementation. Only legal if feature bit
@ -903,7 +904,8 @@ Master message types
``VHOST_USER_SET_PROTOCOL_FEATURES``
:id: 16
:equivalent ioctl: ``VHOST_SET_FEATURES``
:master payload: ``u64``
:request payload: ``u64``
:reply payload: N/A
Enable protocol features in the underlying vhost implementation.
@ -917,7 +919,8 @@ Master message types
``VHOST_USER_SET_OWNER``
:id: 3
:equivalent ioctl: ``VHOST_SET_OWNER``
:master payload: N/A
:request payload: N/A
:reply payload: N/A
Issued when a new connection is established. It sets the current
*master* as an owner of the session. This can be used on the *slave*
@ -925,7 +928,8 @@ Master message types
``VHOST_USER_RESET_OWNER``
:id: 4
:master payload: N/A
:request payload: N/A
:reply payload: N/A
.. admonition:: Deprecated
@ -938,8 +942,8 @@ Master message types
``VHOST_USER_SET_MEM_TABLE``
:id: 5
:equivalent ioctl: ``VHOST_SET_MEM_TABLE``
:master payload: memory regions description
:slave payload: (postcopy only) memory regions description
:request payload: memory regions description
:reply payload: (postcopy only) memory regions description
Sets the memory map regions on the slave so it can translate the
vring addresses. In the ancillary data there is an array of file
@ -962,8 +966,8 @@ Master message types
``VHOST_USER_SET_LOG_BASE``
:id: 6
:equivalent ioctl: ``VHOST_SET_LOG_BASE``
:master payload: u64
:slave payload: N/A
:request payload: u64
:reply payload: N/A
Sets logging shared memory space.
@ -975,44 +979,48 @@ Master message types
``VHOST_USER_SET_LOG_FD``
:id: 7
:equivalent ioctl: ``VHOST_SET_LOG_FD``
:master payload: N/A
:request payload: N/A
:reply payload: N/A
Sets the logging file descriptor, which is passed as ancillary data.
``VHOST_USER_SET_VRING_NUM``
:id: 8
:equivalent ioctl: ``VHOST_SET_VRING_NUM``
:master payload: vring state description
:request payload: vring state description
:reply payload: N/A
Set the size of the queue.
``VHOST_USER_SET_VRING_ADDR``
:id: 9
:equivalent ioctl: ``VHOST_SET_VRING_ADDR``
:master payload: vring address description
:slave payload: N/A
:request payload: vring address description
:reply payload: N/A
Sets the addresses of the different aspects of the vring.
``VHOST_USER_SET_VRING_BASE``
:id: 10
:equivalent ioctl: ``VHOST_SET_VRING_BASE``
:master payload: vring state description
:request payload: vring state description
:reply payload: N/A
Sets the base offset in the available vring.
``VHOST_USER_GET_VRING_BASE``
:id: 11
:equivalent ioctl: ``VHOST_USER_GET_VRING_BASE``
:master payload: vring state description
:slave payload: vring state description
:request payload: vring state description
:reply payload: vring state description
Get the available vring base offset.
``VHOST_USER_SET_VRING_KICK``
:id: 12
:equivalent ioctl: ``VHOST_SET_VRING_KICK``
:master payload: ``u64``
:request payload: ``u64``
:reply payload: N/A
Set the event file descriptor for adding buffers to the vring. It is
passed in the ancillary data.
@ -1030,7 +1038,8 @@ Master message types
``VHOST_USER_SET_VRING_CALL``
:id: 13
:equivalent ioctl: ``VHOST_SET_VRING_CALL``
:master payload: ``u64``
:request payload: ``u64``
:reply payload: N/A
Set the event file descriptor to signal when buffers are used. It is
passed in the ancillary data.
@ -1048,7 +1057,8 @@ Master message types
``VHOST_USER_SET_VRING_ERR``
:id: 14
:equivalent ioctl: ``VHOST_SET_VRING_ERR``
:master payload: ``u64``
:request payload: ``u64``
:reply payload: N/A
Set the event file descriptor to signal when error occurs. It is
passed in the ancillary data.
@ -1065,8 +1075,8 @@ Master message types
``VHOST_USER_GET_QUEUE_NUM``
:id: 17
:equivalent ioctl: N/A
:master payload: N/A
:slave payload: u64
:request payload: N/A
:reply payload: u64
Query how many queues the backend supports.
@ -1077,7 +1087,8 @@ Master message types
``VHOST_USER_SET_VRING_ENABLE``
:id: 18
:equivalent ioctl: N/A
:master payload: vring state description
:request payload: vring state description
:reply payload: N/A
Signal slave to enable or disable corresponding vring.
@ -1087,7 +1098,8 @@ Master message types
``VHOST_USER_SEND_RARP``
:id: 19
:equivalent ioctl: N/A
:master payload: ``u64``
:request payload: ``u64``
:reply payload: N/A
Ask vhost user backend to broadcast a fake RARP to notify the migration
is terminated for guest that does not support GUEST_ANNOUNCE.
@ -1102,7 +1114,8 @@ Master message types
``VHOST_USER_NET_SET_MTU``
:id: 20
:equivalent ioctl: N/A
:master payload: ``u64``
:request payload: ``u64``
:reply payload: N/A
Set host MTU value exposed to the guest.
@ -1119,7 +1132,8 @@ Master message types
``VHOST_USER_SET_SLAVE_REQ_FD``
:id: 21
:equivalent ioctl: N/A
:master payload: N/A
:request payload: N/A
:reply payload: N/A
Set the socket file descriptor for slave initiated requests. It is passed
in the ancillary data.
@ -1134,8 +1148,8 @@ Master message types
``VHOST_USER_IOTLB_MSG``
:id: 22
:equivalent ioctl: N/A (equivalent to ``VHOST_IOTLB_MSG`` message type)
:master payload: ``struct vhost_iotlb_msg``
:slave payload: ``u64``
:request payload: ``struct vhost_iotlb_msg``
:reply payload: ``u64``
Send IOTLB messages with ``struct vhost_iotlb_msg`` as payload.
@ -1149,7 +1163,8 @@ Master message types
``VHOST_USER_SET_VRING_ENDIAN``
:id: 23
:equivalent ioctl: ``VHOST_SET_VRING_ENDIAN``
:master payload: vring state description
:request payload: vring state description
:reply payload: N/A
Set the endianness of a VQ for legacy devices. Little-endian is
indicated with state.num set to 0 and big-endian is indicated with
@ -1164,8 +1179,8 @@ Master message types
``VHOST_USER_GET_CONFIG``
:id: 24
:equivalent ioctl: N/A
:master payload: virtio device config space
:slave payload: virtio device config space
:request payload: virtio device config space
:reply payload: virtio device config space
When ``VHOST_USER_PROTOCOL_F_CONFIG`` is negotiated, this message is
submitted by the vhost-user master to fetch the contents of the
@ -1178,8 +1193,8 @@ Master message types
``VHOST_USER_SET_CONFIG``
:id: 25
:equivalent ioctl: N/A
:master payload: virtio device config space
:slave payload: N/A
:request payload: virtio device config space
:reply payload: N/A
When ``VHOST_USER_PROTOCOL_F_CONFIG`` is negotiated, this message is
submitted by the vhost-user master when the Guest changes the virtio
@ -1191,8 +1206,8 @@ Master message types
``VHOST_USER_CREATE_CRYPTO_SESSION``
:id: 26
:equivalent ioctl: N/A
:master payload: crypto session description
:slave payload: crypto session description
:request payload: crypto session description
:reply payload: crypto session description
Create a session for crypto operation. The server side must return
the session id, 0 or positive for success, negative for failure.
@ -1204,7 +1219,8 @@ Master message types
``VHOST_USER_CLOSE_CRYPTO_SESSION``
:id: 27
:equivalent ioctl: N/A
:master payload: ``u64``
:request payload: ``u64``
:reply payload: N/A
Close a session for crypto operation which was previously
created by ``VHOST_USER_CREATE_CRYPTO_SESSION``.
@ -1216,8 +1232,8 @@ Master message types
``VHOST_USER_POSTCOPY_ADVISE``
:id: 28
:master payload: N/A
:slave payload: userfault fd
:request payload: N/A
:reply payload: userfault fd
When ``VHOST_USER_PROTOCOL_F_PAGEFAULT`` is supported, the master
advises slave that a migration with postcopy enabled is underway,
@ -1226,7 +1242,8 @@ Master message types
``VHOST_USER_POSTCOPY_LISTEN``
:id: 29
:master payload: N/A
:request payload: N/A
:reply payload: N/A
Master advises slave that a transition to postcopy mode has
happened. The slave must ensure that shared memory is registered
@ -1237,10 +1254,11 @@ Master message types
``VHOST_USER_POSTCOPY_END``
:id: 30
:slave payload: ``u64``
:request payload: N/A
:reply payload: ``u64``
Master advises that postcopy migration has now completed. The slave
must disable the userfaultfd. The response is an acknowledgement
must disable the userfaultfd. The reply is an acknowledgement
only.
When ``VHOST_USER_PROTOCOL_F_PAGEFAULT`` is supported, this message
@ -1252,7 +1270,8 @@ Master message types
``VHOST_USER_GET_INFLIGHT_FD``
:id: 31
:equivalent ioctl: N/A
:master payload: inflight description
:request payload: inflight description
:reply payload: N/A
When ``VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD`` protocol feature has
been successfully negotiated, this message is submitted by master to
@ -1263,7 +1282,8 @@ Master message types
``VHOST_USER_SET_INFLIGHT_FD``
:id: 32
:equivalent ioctl: N/A
:master payload: inflight description
:request payload: inflight description
:reply payload: N/A
When ``VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD`` protocol feature has
been successfully negotiated, this message is submitted by master to
@ -1273,7 +1293,8 @@ Master message types
``VHOST_USER_GPU_SET_SOCKET``
:id: 33
:equivalent ioctl: N/A
:master payload: N/A
:request payload: N/A
:reply payload: N/A
Sets the GPU protocol socket file descriptor, which is passed as
ancillary data. The GPU protocol is used to inform the master of
@ -1282,8 +1303,8 @@ Master message types
``VHOST_USER_RESET_DEVICE``
:id: 34
:equivalent ioctl: N/A
:master payload: N/A
:slave payload: N/A
:request payload: N/A
:reply payload: N/A
Ask the vhost user backend to disable all rings and reset all
internal device state to the initial state, ready to be
@ -1296,8 +1317,8 @@ Master message types
``VHOST_USER_VRING_KICK``
:id: 35
:equivalent ioctl: N/A
:slave payload: vring state description
:master payload: N/A
:request payload: vring state description
:reply payload: N/A
When the ``VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS`` protocol
feature has been successfully negotiated, this message may be
@ -1310,7 +1331,8 @@ Master message types
``VHOST_USER_GET_MAX_MEM_SLOTS``
:id: 36
:equivalent ioctl: N/A
:slave payload: u64
:request payload: N/A
:reply payload: u64
When the ``VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS`` protocol
feature has been successfully negotiated, this message is submitted
@ -1323,7 +1345,8 @@ Master message types
``VHOST_USER_ADD_MEM_REG``
:id: 37
:equivalent ioctl: N/A
:slave payload: single memory region description
:request payload: N/A
:reply payload: single memory region description
When the ``VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS`` protocol
feature has been successfully negotiated, this message is submitted
@ -1346,7 +1369,8 @@ Master message types
``VHOST_USER_REM_MEM_REG``
:id: 38
:equivalent ioctl: N/A
:slave payload: single memory region description
:request payload: N/A
:reply payload: single memory region description
When the ``VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS`` protocol
feature has been successfully negotiated, this message is submitted
@ -1369,8 +1393,8 @@ Master message types
``VHOST_USER_SET_STATUS``
:id: 39
:equivalent ioctl: VHOST_VDPA_SET_STATUS
:slave payload: N/A
:master payload: ``u64``
:request payload: ``u64``
:reply payload: N/A
When the ``VHOST_USER_PROTOCOL_F_STATUS`` protocol feature has been
successfully negotiated, this message is submitted by the master to
@ -1380,8 +1404,8 @@ Master message types
``VHOST_USER_GET_STATUS``
:id: 40
:equivalent ioctl: VHOST_VDPA_GET_STATUS
:slave payload: ``u64``
:master payload: N/A
:request payload: N/A
:reply payload: ``u64``
When the ``VHOST_USER_PROTOCOL_F_STATUS`` protocol feature has been
successfully negotiated, this message is submitted by the master to
@ -1392,11 +1416,14 @@ Master message types
Slave message types
-------------------
For this type of message, the request is sent by the slave and the reply
is sent by the master.
``VHOST_USER_SLAVE_IOTLB_MSG``
:id: 1
:equivalent ioctl: N/A (equivalent to ``VHOST_IOTLB_MSG`` message type)
:slave payload: ``struct vhost_iotlb_msg``
:master payload: N/A
:request payload: ``struct vhost_iotlb_msg``
:reply payload: N/A
Send IOTLB messages with ``struct vhost_iotlb_msg`` as payload.
Slave sends such requests to notify of an IOTLB miss, or an IOTLB
@ -1410,8 +1437,8 @@ Slave message types
``VHOST_USER_SLAVE_CONFIG_CHANGE_MSG``
:id: 2
:equivalent ioctl: N/A
:slave payload: N/A
:master payload: N/A
:request payload: N/A
:reply payload: N/A
When ``VHOST_USER_PROTOCOL_F_CONFIG`` is negotiated, vhost-user
slave sends such messages to notify that the virtio device's
@ -1425,8 +1452,8 @@ Slave message types
``VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG``
:id: 3
:equivalent ioctl: N/A
:slave payload: vring area description
:master payload: N/A
:request payload: vring area description
:reply payload: N/A
Sets host notifier for a specified queue. The queue index is
contained in the ``u64`` field of the vring area description. The
@ -1448,8 +1475,8 @@ Slave message types
``VHOST_USER_SLAVE_VRING_CALL``
:id: 4
:equivalent ioctl: N/A
:slave payload: vring state description
:master payload: N/A
:request payload: vring state description
:reply payload: N/A
When the ``VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS`` protocol
feature has been successfully negotiated, this message may be
@ -1462,8 +1489,8 @@ Slave message types
``VHOST_USER_SLAVE_VRING_ERR``
:id: 5
:equivalent ioctl: N/A
:slave payload: vring state description
:master payload: N/A
:request payload: vring state description
:reply payload: N/A
When the ``VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS`` protocol
feature has been successfully negotiated, this message may be
@ -1489,7 +1516,7 @@ client MUST respond with a Payload ``VhostUserMsg`` indicating success
or failure. The payload should be set to zero on success or non-zero
on failure, unless the message already has an explicit reply body.
The response payload gives QEMU a deterministic indication of the result
The reply payload gives QEMU a deterministic indication of the result
of the command. Today, QEMU is expected to terminate the main vhost-user
loop upon receiving such errors. In future, qemu could be taught to be more
resilient for selective requests.