diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2017-02-28 14:21:32 +0100 |
|---|---|---|
| committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2017-03-27 21:07:21 -0500 |
| commit | ce37df91f4f9a4577fb12f46b94dde93c19bd661 (patch) | |
| tree | cf0a133b80e769c8b26918d7c7de6e805e76bbfe | |
| parent | dc35a13747843688690d5779ef22f2a62dfd6d3b (diff) | |
| download | qemu-ce37df91f4f9a4577fb12f46b94dde93c19bd661.tar.gz | |
virtio: always use handle_aio_output if registered
Commit ad07cd6 ("virtio-scsi: always use dataplane path if ioeventfd is
active", 2016-10-30) and 9ffe337 ("virtio-blk: always use dataplane
path if ioeventfd is active", 2016-10-30) broke the virtio 1.0
indirect access registers.
The indirect access registers bypass the ioeventfd, so that virtio-blk
and virtio-scsi now repeatedly try to initialize dataplane instead of
triggering the guest->host EventNotifier. Detect the situation by
checking vq->handle_aio_output; if it is not NULL, trigger the
EventNotifier, which is how the device expects to get notifications
and in fact the only thread-safe manner to deliver them.
Fixes: ad07cd6
Fixes: 9ffe337
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit e49a6618400d11e51e30328dfe8d7cafce82d4bc)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
| -rw-r--r-- | hw/virtio/virtio.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 6dfc92f230..b2a477d354 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -1256,7 +1256,18 @@ static void virtio_queue_notify_vq(VirtQueue *vq) void virtio_queue_notify(VirtIODevice *vdev, int n) { - virtio_queue_notify_vq(&vdev->vq[n]); + VirtQueue *vq = &vdev->vq[n]; + + if (unlikely(!vq->vring.desc || vdev->broken)) { + return; + } + + trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); + if (vq->handle_aio_output) { + event_notifier_set(&vq->host_notifier); + } else if (vq->handle_output) { + vq->handle_output(vdev, vq); + } } uint16_t virtio_queue_vector(VirtIODevice *vdev, int n) |