On 2018年07月09日 15:22, Tiwei Bie wrote:
@@ -1059,9 +1059,19 @@ static bool virtqueue_kick_prepare_packed(struct
virtqueue *_vq)
* suppressions. */
virtio_mb(vq->weak_barriers);
+ old = vq->next_avail_idx - vq->num_added;
+ new = vq->next_avail_idx;
+ vq->num_added = 0;
+
snapshot = *(u32 *)vq->vring_packed.device;
I think we should use READ_ONCE() to prevent compiler from re-reading.
+ off_wrap = virtio16_to_cpu(_vq->vdev, (__virtio16)(snapshot & 0xffff));
flags = virtio16_to_cpu(_vq->vdev, (__virtio16)(snapshot >> 16)) & 0x3;
+ wrap_counter = off_wrap >> 15;
+ event_idx = off_wrap & ~(1 << 15);
+ if (wrap_counter != vq->avail_wrap_counter)
+ event_idx -= vq->vring_packed.num;
Thanks
_______________________________________________
Virtualization mailing list
[email protected]
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
