Re: [PATCH 1/2] virtio: reset region cache when on queue deletion

[Jason Wang <jasowang@redhat.com>]

On 2019/12/26 下午12:36, Yuri Benditovich wrote:
> https://bugzilla.redhat.com/show_bug.cgi?id=1708480
> Fix leak of region reference that prevents complete
> device deletion on hot unplug.


More information is needed here, the bug said only q35 can meet this 
issue. What makes q35 different here?


>
> Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
> ---
>   hw/virtio/virtio.c | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 04716b5f6c..baadec8abc 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -2340,6 +2340,11 @@ void virtio_del_queue(VirtIODevice *vdev, int n)
>       vdev->vq[n].vring.num_default = 0;
>       vdev->vq[n].handle_output = NULL;
>       vdev->vq[n].handle_aio_output = NULL;
> +    /*
> +     * with vring.num = 0 the queue will be ignored
> +     * in later loops of region cache reset
> +     */


I can't get the meaning of this comment.

Thanks


> +    virtio_virtqueue_reset_region_cache(&vdev->vq[n]);
>       g_free(vdev->vq[n].used_elems);
>   }
>