linux-toradex.git/drivers/vhost, branch v6.10

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2024-05-23T19:04:36+00:00

Pull virtio updates from Michael Tsirkin:
 "Several new features here:

   - virtio-net is finally supported in vduse

   - virtio (balloon and mem) interaction with suspend is improved

   - vhost-scsi now handles signals better/faster

  And fixes, cleanups all over the place"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (48 commits)
  virtio-pci: Check if is_avq is NULL
  virtio: delete vq in vp_find_vqs_msix() when request_irq() fails
  MAINTAINERS: add Eugenio Pérez as reviewer
  vhost-vdpa: Remove usage of the deprecated ida_simple_xx() API
  vp_vdpa: don't allocate unused msix vectors
  sound: virtio: drop owner assignment
  fuse: virtio: drop owner assignment
  scsi: virtio: drop owner assignment
  rpmsg: virtio: drop owner assignment
  nvdimm: virtio_pmem: drop owner assignment
  wifi: mac80211_hwsim: drop owner assignment
  vsock/virtio: drop owner assignment
  net: 9p: virtio: drop owner assignment
  net: virtio: drop owner assignment
  net: caif: virtio: drop owner assignment
  misc: nsm: drop owner assignment
  iommu: virtio: drop owner assignment
  drm/virtio: drop owner assignment
  gpio: virtio: drop owner assignment
  firmware: arm_scmi: virtio: drop owner assignment
  ...

vhost-vdpa: Remove usage of the deprecated ida_simple_xx() API

2024-05-22T12:31:18+00:00

ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

Note that the upper limit of ida_simple_get() is exclusive, but the one of
ida_alloc_max() is inclusive. So a -1 has been added when needed.

Signed-off-by: Christophe JAILLET 
Reviewed-by: Simon Horman 
Message-Id: <67c2edf49788c27d5f7a49fc701520b9fcf739b5.1713088999.git.christophe.jaillet@wanadoo.fr>
Signed-off-by: Michael S. Tsirkin 
Acked-by: Jason Wang

vhost_task: Handle SIGKILL by flushing work and exiting

2024-05-22T12:31:15+00:00

Instead of lingering until the device is closed, this has us handle
SIGKILL by:

1. marking the worker as killed so we no longer try to use it with
   new virtqueues and new flush operations.
2. setting the virtqueue to worker mapping so no new works are queued.
3. running all the exiting works.

Suggested-by: Edward Adam Davis 
Reported-and-tested-by: syzbot+98edc2df894917b3431f@syzkaller.appspotmail.com
Message-Id: 
Signed-off-by: Mike Christie 
Message-Id: <20240316004707.45557-9-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin

vhost: Release worker mutex during flushes

2024-05-22T12:31:15+00:00

In the next patches where the worker can be killed while in use, we
need to be able to take the worker mutex and kill queued works for
new IO and flushes, and set some new flags to prevent new
__vhost_vq_attach_worker calls from swapping in/out killed workers.

If we are holding the worker mutex during a flush and the flush's work
is still in the queue, the worker code that will handle the SIGKILL
cleanup won't be able to take the mutex and perform it's cleanup. So
this patch has us drop the worker mutex while waiting for the flush
to complete.

Signed-off-by: Mike Christie 
Message-Id: <20240316004707.45557-8-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin

vhost: Use virtqueue mutex for swapping worker

2024-05-22T12:31:15+00:00

__vhost_vq_attach_worker uses the vhost_dev mutex to serialize the
swapping of a virtqueue's worker. This was done for simplicity because
we are already holding that mutex.

In the next patches where the worker can be killed while in use, we need
finer grained locking because some drivers will hold the vhost_dev mutex
while flushing. However in the SIGKILL handler in the next patches, we
will need to be able to swap workers (set current one to NULL), kill
queued works and stop new flushes while flushes are in progress.

To prepare us, this has us use the virtqueue mutex for swapping workers
instead of the vhost_dev one.

Signed-off-by: Mike Christie 
Message-Id: <20240316004707.45557-7-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin

vhost_scsi: Handle vhost_vq_work_queue failures for TMFs

2024-05-22T12:31:15+00:00

vhost_vq_work_queue will never fail when queueing the TMF's response
handling because a guest can only send us TMFs when the device is fully
setup so there is always a worker at that time. In the next patches we
will modify the worker code so it handles SIGKILL by exiting before
outstanding commands/TMFs have sent their responses. In that case
vhost_vq_work_queue can fail when we try to send a response.

This has us just free the TMF's resources since at this time the guest
won't be able to get a response even if we could send it.

Signed-off-by: Mike Christie 
Message-Id: <20240316004707.45557-6-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin

vhost: Remove vhost_vq_flush

2024-05-22T12:31:15+00:00

vhost_vq_flush is no longer used so remove it.

Signed-off-by: Mike Christie 
Message-Id: <20240316004707.45557-5-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin

vhost-scsi: Use system wq to flush dev for TMFs

2024-05-22T12:31:15+00:00

We flush all the workers that are not also used by the ctl vq to make
sure that responses queued by LIO before the TMF response are sent
before the TMF response. This requires a special vhost_vq_flush
function which, in the next patches where we handle SIGKILL killing
workers while in use, will require extra locking/complexity. To avoid
that, this patch has us flush the entire device from the system work
queue, then queue up sending the response from there.

This is a little less optimal since we now flush all workers but this
will be ok since commands have already timed out and perf is not a
concern.

Signed-off-by: Mike Christie 
Message-Id: <20240316004707.45557-4-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin

vhost-scsi: Handle vhost_vq_work_queue failures for cmds

2024-05-22T12:31:15+00:00

In the next patches we will support the vhost_task being killed while in
use. The problem for vhost-scsi is that we can't free some structs until
we get responses for commands we have submitted to the target layer and
we currently process the responses from the vhost_task.

This has just drop the responses and free the command's resources. When
all commands have completed then operations like flush will be woken up
and we can complete device release and endpoint cleanup.

Signed-off-by: Mike Christie 
Message-Id: <20240316004707.45557-3-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin

vhost-scsi: Handle vhost_vq_work_queue failures for events

2024-05-22T12:31:15+00:00

Currently, we can try to queue an event's work before the vhost_task is
created. When this happens we just drop it in vhost_scsi_do_plug before
even calling vhost_vq_work_queue. During a device shutdown we do the
same thing after vhost_scsi_clear_endpoint has cleared the backends.

In the next patches we will be able to kill the vhost_task before we
have cleared the endpoint. In that case, vhost_vq_work_queue can fail
and we will leak the event's memory. This has handle the failure by
just freeing the event. This is safe to do, because
vhost_vq_work_queue will only return failure for us when the vhost_task
is killed and so userspace will not be able to handle events if we
sent them.

Signed-off-by: Mike Christie 
Message-Id: <20240316004707.45557-2-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin