@@ -865,8 +865,8 @@ 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
@@ -876,7 +876,8 @@ 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
@@ -886,8 +887,8 @@ 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
@@ -902,7 +903,8 @@ 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.
@@ -916,7 +918,8 @@ 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*
@@ -924,7 +927,8 @@ Master message types
``VHOST_USER_RESET_OWNER``
:id: 4
- :master payload: N/A
+ :request payload: N/A
+ :reply payload: N/A
.. admonition:: Deprecated
@@ -937,8 +941,8 @@ 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
@@ -961,8 +965,8 @@ 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.
@@ -974,44 +978,48 @@ 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.
@@ -1029,7 +1037,8 @@ 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.
@@ -1047,7 +1056,8 @@ 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.
@@ -1064,8 +1074,8 @@ 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.
@@ -1076,7 +1086,8 @@ 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.
@@ -1086,7 +1097,8 @@ 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.
@@ -1101,7 +1113,8 @@ 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.
@@ -1118,7 +1131,8 @@ 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.
@@ -1133,8 +1147,8 @@ 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.
@@ -1148,7 +1162,8 @@ 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
@@ -1163,8 +1178,8 @@ 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
@@ -1177,8 +1192,8 @@ 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
@@ -1190,8 +1205,8 @@ 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.
@@ -1203,7 +1218,8 @@ 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``.
@@ -1215,8 +1231,8 @@ 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,
@@ -1225,7 +1241,8 @@ 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
@@ -1236,10 +1253,11 @@ 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
@@ -1251,7 +1269,8 @@ 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
@@ -1262,7 +1281,8 @@ 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
@@ -1272,7 +1292,8 @@ 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
@@ -1281,8 +1302,8 @@ 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
@@ -1295,8 +1316,8 @@ 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
@@ -1309,7 +1330,8 @@ 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
@@ -1322,7 +1344,8 @@ 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
@@ -1337,7 +1360,8 @@ 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
@@ -1352,8 +1376,8 @@ 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
@@ -1363,8 +1387,8 @@ 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
@@ -1375,11 +1399,14 @@ 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
@@ -1393,8 +1420,8 @@ 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
@@ -1408,8 +1435,8 @@ 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
@@ -1431,8 +1458,8 @@ 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
@@ -1445,8 +1472,8 @@ 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
@@ -1472,7 +1499,7 @@ 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.