Re: [PATCH] Update event idx if guest has made extra buffers during double check

["Michael S. Tsirkin" <mst@redhat.com>]

Thanks for the patch!
Yet something to improve:



subject should list the affected component, and be shorter.

On Thu, Jun 13, 2024 at 10:21:47AM +0800, thomas wrote:
> Fixes: 06b12970174 ("virtio-net: fix network stall under load")

this should come at the end. and what exactly does this
refer to? did this commit cause a regression of some sort?

> If guest has made some buffers available during double check,

what does "double check" refer to?

> but the total buffer size available is lower than @bufsize,
> notify the guest with the latest available idx(event idx)
> seen by the host.

which makes sense why?  And which changes the correct behavious of what
to a new behaviour of what which is better why?

Pls review docs/devel/submitting-a-patch.rst and follow the
process there.



> ---
>  hw/net/virtio-net.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index 9c7e85caea..23c6c8c898 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -1654,6 +1654,7 @@ static int virtio_net_has_buffers(VirtIONetQueue *q, int bufsize)
>          if (virtio_queue_empty(q->rx_vq) ||
>              (n->mergeable_rx_bufs &&
>               !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
> +            virtio_queue_set_notification(q->rx_vq, 1);
>              return 0;
>          }
>      }
> -- 
> 2.39.0