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Diffstat (limited to 'docs')
| -rw-r--r-- | docs/interop/vhost-user.rst | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst index 5a070adbc1..415bb47a19 100644 --- a/docs/interop/vhost-user.rst +++ b/docs/interop/vhost-user.rst @@ -1440,6 +1440,18 @@ Front-end message types query the back-end for its device status as defined in the Virtio specification. +``VHOST_USER_GET_SHARED_OBJECT`` + :id: 41 + :equivalent ioctl: N/A + :request payload: ``struct VhostUserShared`` + :reply payload: dmabuf fd + + When the ``VHOST_USER_PROTOCOL_F_SHARED_OBJECT`` protocol + feature has been successfully negotiated, and the UUID is found + in the exporters cache, this message is submitted by the front-end + to retrieve a given dma-buf fd from a given back-end, determined by + the requested UUID. Back-end will reply passing the fd when the operation + is successful, or no fd otherwise. Back-end message types ---------------------- @@ -1528,6 +1540,51 @@ is sent by the front-end. The state.num field is currently reserved and must be set to 0. +``VHOST_USER_BACKEND_SHARED_OBJECT_ADD`` + :id: 6 + :equivalent ioctl: N/A + :request payload: ``struct VhostUserShared`` + :reply payload: N/A + + When the ``VHOST_USER_PROTOCOL_F_SHARED_OBJECT`` protocol + feature has been successfully negotiated, this message can be submitted + by the backends to add themselves as exporters to the virtio shared lookup + table. The back-end device gets associated with a UUID in the shared table. + The back-end is responsible of keeping its own table with exported dma-buf fds. + When another back-end tries to import the resource associated with the UUID, + it will send a message to the front-end, which will act as a proxy to the + exporter back-end. If ``VHOST_USER_PROTOCOL_F_REPLY_ACK`` is negotiated, and + the back-end sets the ``VHOST_USER_NEED_REPLY`` flag, the front-end must + respond with zero when operation is successfully completed, or non-zero + otherwise. + +``VHOST_USER_BACKEND_SHARED_OBJECT_REMOVE`` + :id: 7 + :equivalent ioctl: N/A + :request payload: ``struct VhostUserShared`` + :reply payload: N/A + + When the ``VHOST_USER_PROTOCOL_F_SHARED_OBJECT`` protocol + feature has been successfully negotiated, this message can be submitted + by the backend to remove themselves from to the virtio-dmabuf shared + table API. The shared table will remove the back-end device associated with + the UUID. If ``VHOST_USER_PROTOCOL_F_REPLY_ACK`` is negotiated, and the + back-end sets the ``VHOST_USER_NEED_REPLY`` flag, the front-end must respond + with zero when operation is successfully completed, or non-zero otherwise. + +``VHOST_USER_BACKEND_SHARED_OBJECT_LOOKUP`` + :id: 8 + :equivalent ioctl: N/A + :request payload: ``struct VhostUserShared`` + :reply payload: dmabuf fd and ``u64`` + + When the ``VHOST_USER_PROTOCOL_F_SHARED_OBJECT`` protocol + feature has been successfully negotiated, this message can be submitted + by the backends to retrieve a given dma-buf fd from the virtio-dmabuf + shared table given a UUID. Frontend will reply passing the fd and a zero + when the operation is successful, or non-zero otherwise. Note that if the + operation fails, no fd is sent to the backend. + .. _reply_ack: VHOST_USER_PROTOCOL_F_REPLY_ACK |