Linux Virtualization - Nov 2013 - [PATCH V2 RFC 9/9] virtio_scsi: verify if queue is broken after virtqueue_get_buf()

Rusty,

and here is patch 9 as you suggested.

Thanks.

Heinz Graalfs (9):
  virtio_ring: change host notification API
  virtio_ring: let virtqueue_{kick()/notify()} return a bool
  virtio_net: verify if virtqueue_kick() succeeded
  virtio_test: verify if virtqueue_kick() succeeded
  virtio_ring: add new function virtqueue_is_broken()
  virtio_blk: verify if queue is broken after virtqueue_get_buf()
  virtio_console: verify if queue is broken after virtqueue_get_buf()
  virtio_net: verify if queue is broken after virtqueue_get_buf()
  virtio_scsi: verify if queue is broken after virtqueue_get_buf()

 drivers/block/virtio_blk.c             |  2 ++
 drivers/char/virtio_console.c          |  6 ++++--
 drivers/lguest/lguest_device.c         |  3 ++-
 drivers/net/virtio_net.c               | 12 +++++++-----
 drivers/remoteproc/remoteproc_virtio.c |  3 ++-
 drivers/s390/kvm/kvm_virtio.c          |  8 ++++++--
 drivers/s390/kvm/virtio_ccw.c          |  5 ++++-
 drivers/scsi/virtio_scsi.c             |  3 +++
 drivers/virtio/virtio_mmio.c           |  3 ++-
 drivers/virtio/virtio_pci.c            |  3 ++-
 drivers/virtio/virtio_ring.c           | 32 ++++++++++++++++++++++++++------
 include/linux/virtio.h                 |  6 ++++--
 include/linux/virtio_ring.h            |  2 +-
 tools/virtio/virtio_test.c             |  6 ++++--
 tools/virtio/vringh_test.c             | 13 +++++++++----
 15 files changed, 78 insertions(+), 29 deletions(-)

-- 
1.8.3.1

If virtqueue_get_buf() returned with a NULL pointer avoid a possibly
endless loop by checking for a broken virtqueue.

Signed-off-by: Heinz Graalfs <graalfs at linux.vnet.ibm.com>
---
 drivers/scsi/virtio_scsi.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 74b88ef..aa25aab 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -224,6 +224,9 @@ static void virtscsi_vq_done(struct virtio_scsi *vscsi,
 		virtqueue_disable_cb(vq);
 		while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
 			fn(vscsi, buf);
+
+		if (unlikely(virtqueue_is_broken(vq)))
+			break;
 	} while (!virtqueue_enable_cb(vq));
 	spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
 }
-- 
1.8.3.1

Heinz Graalfs <graalfs at linux.vnet.ibm.com>
writes:
> If virtqueue_get_buf() returned with a NULL pointer avoid a possibly
> endless loop by checking for a broken virtqueue.
>
> Signed-off-by: Heinz Graalfs <graalfs at linux.vnet.ibm.com>
Thanks, applied.

Cheers,
Rusty.