docs/interop/vhost-user.rst

200   areas within this region must be mapped / unmapped only when required by the
445 * While a ring is stopped, the back-end must not process the ring at
450 * started and disabled: The back-end must process the ring without
452   in the disabled state the back-end must not supply any new RX packets,
453   but must process and discard any TX packets.
455 * started and enabled: The back-end must process the ring normally, i.e.
459 must start a ring upon receiving a kick (that is, detecting that file
469 back-end must enable all rings immediately.
472 must support changing some configuration aspects on the fly.
480 not processing any vring (because they are stopped), the device must:
518 Front-ends must not rely on the ``VHOST_USER_PROTOCOL_F_MQ`` protocol feature for
566 the bit offset of the last byte of the ring must fall within the size
575 further update must be done before rings are restarted.
578 been received from the source host, and care must be taken to avoid
626 The nature of the channel is implementation-defined, but it must
629 end must read all of this data (until encountering the end of file) and
634   channel, the source front-end must transfer it to the destination
639   from the channel, the destination back-end must deserialize its
643 Seamlessly resuming operation means that the migration must be
694 flags. Addresses and size must be within vhost memory regions set via
1095    Back-ends that report ``VHOST_USER_F_PROTOCOL_FEATURES`` must
1112    Back-ends that report ``VHOST_USER_F_PROTOCOL_FEATURES`` must support
1151   regions to the front-end.  The back-end must have mmap'd the regions but
1248   The request payload's *num* field is currently reserved and must be
1360   If ``VHOST_USER_PROTOCOL_F_REPLY_ACK`` is negotiated, the back-end must
1377   ``VHOST_USER_PROTOCOL_F_REPLY_ACK`` is negotiated, the back-end must
1420   MUST match the front-end's request, vhost-user back-end uses zero length of
1434   on the destination host. The vhost-user back-end must check the flags
1435   field, and back-ends MUST NOT accept SET_CONFIG for read-only
1444   Create a session for crypto operation. The back-end must return
1472   the back-end must open a userfaultfd for later use.  Note that at this
1481   happened.  The back-end must ensure that shared memory is registered
1493   must disable the userfaultfd. The reply is an acknowledgement
1561   The state.num field is currently reserved and must be set to 0.
1587   the back-end device must map in. When the
1611   the back-end device must unmap. When the
1623   passed, the back-end MUST close it without using it otherwise.
1670   must create a file descriptor that is provided to the respectively
1671   other side, allowing access to the channel.  This FD must behave as
1674   * For the writing end, it must allow writing the whole back-end state
1678   * For the reading end, it must allow reading the whole back-end state
1688   front-end as ancillary data of the reply.  If so, the front-end must
1706   When this flag is not set, the front-end must use the returned file
1707   descriptor as its end of the transfer channel.  The back-end must not
1746   must respond with zero when operation is successfully completed, or
1763   ``VHOST_USER_NEED_REPLY`` flag, the front-end must respond with zero when
1801   The state.num field is currently reserved and must be set to 0.
1815   The state.num field is currently reserved and must be set to 0.
1831   the back-end sets the ``VHOST_USER_NEED_REPLY`` flag, the front-end must
1848   back-end sets the ``VHOST_USER_NEED_REPLY`` flag, the front-end must respond
1876 back-end MUST respond with a Payload ``VhostUserMsg`` indicating success
1914 The back-end program must not daemonize itself, but it may be
1922 The back-end program must end (as quickly and cleanly as possible) when