On Mon, Mar 06, 2023 at 12:15:35PM +0800, Xuan Zhuo wrote:
> If the queue of xdp xmit is not an independent queue, then when the xdp
> xmit used all the desc, the xmit from the __dev_queue_xmit() may encounter
> the following error.
>
> net ens4: Unexpected TXQ (0) queue failure: -28
>
> This patch adds a check whether sq is full in XDP Xmit.
>
> Reported-by: Yichun Zhang <yichun@xxxxxxxxxxxxx>
> Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
> ---
> drivers/net/virtio_net.c | 25 +++++++++++++++----------
> 1 file changed, 15 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 777de0ec0b1b..3001b9a548e5 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -302,6 +302,8 @@ struct padded_vnet_hdr {
>
> static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf);
> static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
> +static void check_sq_full(struct virtnet_info *vi, struct net_device *dev,
> + struct send_queue *sq);
>
> static bool is_xdp_frame(void *ptr)
> {
> @@ -341,6 +343,16 @@ static int rxq2vq(int rxq)
> return rxq * 2;
> }
>
I'd really rather we ordered functions reasonably so declarations
are not needed.
> +static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
> +{
> + if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
> + return false;
> + else if (q < vi->curr_queue_pairs)
> + return true;
> + else
> + return false;
> +}
> +
> static inline struct virtio_net_hdr_mrg_rxbuf *skb_vnet_hdr(struct sk_buff *skb)
> {
> return (struct virtio_net_hdr_mrg_rxbuf *)skb->cb;
> @@ -686,6 +698,9 @@ static int virtnet_xdp_xmit(struct net_device *dev,
> }
> ret = nxmit;
>
> + if (!is_xdp_raw_buffer_queue(vi, sq - vi->sq))
> + check_sq_full(vi, dev, sq);
> +
> if (flags & XDP_XMIT_FLUSH) {
> if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq))
> kicks = 1;
> @@ -1784,16 +1799,6 @@ static void check_sq_full(struct virtnet_info *vi, struct net_device *dev,
> }
> }
>
> -static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
> -{
> - if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
> - return false;
> - else if (q < vi->curr_queue_pairs)
> - return true;
> - else
> - return false;
> -}
> -
> static void virtnet_poll_cleantx(struct receive_queue *rq)
> {
> struct virtnet_info *vi = rq->vq->vdev->priv;
> --
> 2.32.0.3.g01195cf9f
