diff options
| author | Stefan Hajnoczi <stefanha@redhat.com> | 2016-08-15 13:54:15 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2016-08-23 19:20:10 +0300 |
| commit | bccdef6b1a204db0f41ffb6e24ce373e4d7890d4 (patch) | |
| tree | 1472d6b917593c467287fbc7436490381fd9ff81 /hw/virtio | |
| parent | 6bbbb0ac136102098a70b97ab0c07bc7bf53131c (diff) | |
virtio: recalculate vq->inuse after migration
The vq->inuse field is not migrated. Many devices don't hold
VirtQueueElements across migration so it doesn't matter that vq->inuse
starts at 0 on the destination QEMU.
At least virtio-serial, virtio-blk, and virtio-balloon migrate while
holding VirtQueueElements. For these devices we need to recalculate
vq->inuse upon load so the value is correct.
Cc: qemu-stable@nongnu.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/virtio')
| -rw-r--r-- | hw/virtio/virtio.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 15ee3a71fa..6105c6eb62 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -1648,6 +1648,21 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) } vdev->vq[i].used_idx = vring_used_idx(&vdev->vq[i]); vdev->vq[i].shadow_avail_idx = vring_avail_idx(&vdev->vq[i]); + + /* + * Some devices migrate VirtQueueElements that have been popped + * from the avail ring but not yet returned to the used ring. + */ + vdev->vq[i].inuse = vdev->vq[i].last_avail_idx - + vdev->vq[i].used_idx; + if (vdev->vq[i].inuse > vdev->vq[i].vring.num) { + error_report("VQ %d size 0x%x < last_avail_idx 0x%x - " + "used_idx 0x%x", + i, vdev->vq[i].vring.num, + vdev->vq[i].last_avail_idx, + vdev->vq[i].used_idx); + return -1; + } } } |