diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 933a3d749a..8357218ae6 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -93,7 +93,7 @@ struct VirtQueue uint16_t queue_index; - int inuse; + unsigned int inuse; uint16_t vector; VirtIOHandleOutput handle_output; @@ -1878,9 +1878,11 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) /* * Some devices migrate VirtQueueElements that have been popped * from the avail ring but not yet returned to the used ring. + * Since max ring size < UINT16_MAX it's safe to use modulo + * UINT16_MAX + 1 subtraction. */ - vdev->vq[i].inuse = vdev->vq[i].last_avail_idx - - vdev->vq[i].used_idx; + vdev->vq[i].inuse = (uint16_t)(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",