passt, branch vhost-user-migration

vhost-user: Report to front-end we support VHOST_USER_PROTOCOL_F_DEVICE_STATE

2024-12-19T11:10:15+00:00

Report to front-end that we support device state commands:
VHOST_USER_CHECK_DEVICE_STATE
VHOST_USER_SET_LOG_BASE

These feature is needed to transfer backend state using frontend
channel.

Signed-off-by: Laurent Vivier

vhost-user: add VHOST_USER_SET_DEVICE_STATE_FD command

2024-12-19T11:08:20+00:00

Set the file descriptor to use to transfer the
backend device state during migration.

Signed-off-by: Laurent Vivier

vhost-user: add VHOST_USER_CHECK_DEVICE_STATE command

2024-12-19T11:08:20+00:00

After transferring the back-end’s internal state during migration,
check whether the back-end was able to successfully fully process
the state.

The value returned indicates success or error;
0 is success, any non-zero value is an error.

Signed-off-by: Laurent Vivier

vhost-user: Report to front-end we support VHOST_USER_PROTOCOL_F_LOG_SHMFD

2024-12-19T11:08:20+00:00

This features allows QEMU to be migrated. We need also to report
VHOST_F_LOG_ALL.

This protocol feature reports we can log the page update and
implement VHOST_USER_SET_LOG_BASE and VHOST_USER_SET_LOG_FD.

Signed-off-by: Laurent Vivier

vhost-user: add VHOST_USER_SET_LOG_BASE command

2024-12-19T11:08:20+00:00

Sets logging shared memory space.

When the back-end has VHOST_USER_PROTOCOL_F_LOG_SHMFD protocol feature,
the log memory fd is provided in the ancillary data of
VHOST_USER_SET_LOG_BASE message, the size and offset of shared memory
area provided in the message.

Signed-off-by: Laurent Vivier

vhost-user: Pass vu_dev to more virtio functions

2024-12-19T11:08:20+00:00

vu_dev will be needed to log page update.

Add the parameter to:

  vring_used_write()
  vu_queue_fill_by_index()
  vu_queue_fill()
  vring_used_idx_set()
  vu_queue_flush()

The new parameter is unused for now.

Signed-off-by: Laurent Vivier

vhost-user: add VHOST_USER_SET_LOG_FD command

2024-12-19T11:08:20+00:00

VHOST_USER_SET_LOG_FD is an optional message with an eventfd
in ancillary data, it may be used to inform the front-end that the
log has been modified.

Signed-off-by: Laurent Vivier

vhost-user: update protocol features and commands list

2024-12-19T11:08:20+00:00

vhost-user protocol specification has been updated with
feature flags and commands we will need to implement migration.

Signed-off-by: Laurent Vivier

virtio: Use const pointer for vu_dev

2024-12-19T11:07:46+00:00

We don't modify the structure in some virtio functions.

Signed-off-by: Laurent Vivier 
Reviewed-by: David Gibson

README: Mark vhost-user as supported

2024-12-12T09:50:48+00:00

Signed-off-by: Stefano Brivio