On Fri, 08/12 16:32, Stefan Hajnoczi wrote: > 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. > > Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> > --- > hw/virtio/virtio.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 15ee3a7..4df8274 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -1648,6 +1648,20 @@ 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 believe a comma is missing here /
Fam > + i, vdev->vq[i].vring.num, > + vdev->vq[i].last_avail_idx, > + vdev->vq[i].used_idx); > + return -1; > + } > } > } > > -- > 2.7.4 > >