66 A vhost-user message consists of 3 header fields and a payload.
69 | request | flags | size | payload |
84 :size: 32-bit size of the payload
86 Payload  section in Message Specification
89 Depending on the request type, **payload** can be:
273 | offset | size | flags | payload |
284 :payload: Size bytes array holding the contents of the virtio
691 vhost_iotlb_msg`` as payload. For update events, the ``iotlb`` payload
696 ``iotlb`` payload has to be filled with the invalidation message type
698 expected to reply with a zero payload, non-zero otherwise.
704 payload. For miss events, the iotlb payload has to be filled with the
706 flags. For access failure event, the iotlb payload has to be filled
1063   :request payload: N/A
1064   :reply payload: ``u64``
1074   :request payload: ``u64``
1075   :reply payload: N/A
1085   :request payload: N/A
1086   :reply payload: ``u64``
1102   :request payload: ``u64``
1103   :reply payload: N/A
1118   :request payload: N/A
1119   :reply payload: N/A
1127   :request payload: N/A
1128   :reply payload: N/A
1141   :request payload: multiple memory regions description
1142   :reply payload: (postcopy only) multiple memory regions description
1165   :request payload: u64
1166   :reply payload: N/A
1178   :request payload: N/A
1179   :reply payload: N/A
1186   :request payload: vring state description
1187   :reply payload: N/A
1194   :request payload: vring address description
1195   :reply payload: N/A
1202   :request payload: vring descriptor index/indices
1203   :reply payload: N/A
1215   Consequently, the payload type is specific to the type of virt queue
1222   :request payload: vring state description
1223   :reply payload: vring descriptor index/indices
1240   Consequently, the payload type is specific to the type of virt queue
1248   The request payload's *num* field is currently reserved and must be
1254   :request payload: ``u64``
1255   :reply payload: N/A
1260   Bits (0-7) of the payload contain the vring index. Bit 8 is the
1273   :request payload: ``u64``
1274   :reply payload: N/A
1279   Bits (0-7) of the payload contain the vring index. Bit 8 is the
1292   :request payload: ``u64``
1293   :reply payload: N/A
1298   Bits (0-7) of the payload contain the vring index. Bit 8 is the
1310   :request payload: N/A
1311   :reply payload: u64
1322   :request payload: vring state description
1323   :reply payload: N/A
1333   :request payload: ``u64``
1334   :reply payload: N/A
1343   payload contain the mac address of the guest to allow the vhost user
1349   :request payload: ``u64``
1350   :reply payload: N/A
1367   :request payload: N/A
1368   :reply payload: N/A
1383   :request payload: ``struct vhost_iotlb_msg``
1384   :reply payload: ``u64``
1386   Send IOTLB messages with ``struct vhost_iotlb_msg`` as payload.
1390   zero as ``u64`` payload for success, non-zero otherwise.
1398   :request payload: vring state description
1399   :reply payload: N/A
1414   :request payload: virtio device config space
1415   :reply payload: virtio device config space
1419   virtio device configuration space, vhost-user back-end's payload size
1421   payload to indicate an error to the vhost-user front-end. The vhost-user
1428   :request payload: virtio device config space
1429   :reply payload: N/A
1441   :request payload: crypto session description
1442   :reply payload: crypto session description
1454   :request payload: ``u64``
1455   :reply payload: N/A
1467   :request payload: N/A
1468   :reply payload: userfault fd
1477   :request payload: N/A
1478   :reply payload: N/A
1489   :request payload: N/A
1490   :reply payload: ``u64``
1505   :request payload: inflight description
1506   :reply payload: N/A
1517   :request payload: inflight description
1518   :reply payload: N/A
1528   :request payload: N/A
1529   :reply payload: N/A
1538   :request payload: N/A
1539   :reply payload: N/A
1552   :request payload: vring state description
1553   :reply payload: N/A
1566   :request payload: N/A
1567   :reply payload: u64
1572   u64 payload containing the maximum number of memory slots for
1580   :request payload: N/A
1581   :reply payload: single memory region description
1585   by the front-end to the back-end. The message payload contains a memory
1604   :request payload: N/A
1605   :reply payload: single memory region description
1609   by the front-end to the back-end. The message payload contains a memory
1628   :request payload: ``u64``
1629   :reply payload: N/A
1639   :request payload: N/A
1640   :reply payload: ``u64``
1650   :request payload: ``struct VhostUserShared``
1651   :reply payload: dmabuf fd
1663   :request payload: device state transfer parameters
1664   :reply payload: ``u64``
1698   The request payload contains parameters for the subsequent data
1716   :request payload: N/A
1717   :reply payload: ``u64``
1739   :request payload: ``struct vhost_iotlb_msg``
1740   :reply payload: N/A
1742   Send IOTLB messages with ``struct vhost_iotlb_msg`` as payload.
1754   :request payload: N/A
1755   :reply payload: N/A
1769   :request payload: vring area description
1770   :reply payload: N/A
1792   :request payload: vring state description
1793   :reply payload: N/A
1806   :request payload: vring state description
1807   :reply payload: N/A
1820   :request payload: ``struct VhostUserShared``
1821   :reply payload: N/A
1838   :request payload: ``struct VhostUserShared``
1839   :reply payload: N/A
1854   :request payload: ``struct VhostUserShared``
1855   :reply payload: dmabuf fd and ``u64``
1876 back-end MUST respond with a Payload ``VhostUserMsg`` indicating success
1877 or failure. The payload should be set to zero on success or non-zero
1880 The reply payload gives QEMU a deterministic indication of the result