If the vring has not been set up, it is not necessary for vring_used_idx
to do anything (as is already the case when the caller is virtio_load).
This is harmless for now, but it will be a problem when the
MemoryRegionCache has not been set up.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
void virtio_queue_update_used_idx(VirtIODevice *vdev, int n)
{
- vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]);
+ if (vdev->vq[n].vring.desc) {
+ vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]);
+ }
}
void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n)