On 01/27/2017 12:40 PM, Paolo Bonzini wrote:
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 <pbonz...@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4...@amsat.org>
---
hw/virtio/virtio.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 32bf364..23fac1e 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2154,7 +2154,9 @@ void virtio_queue_set_last_avail_idx(VirtIODevice *vdev,
int n, uint16_t idx)
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)
