On 4/24/19 11:37 AM, Michael S. Tsirkin wrote:
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 9010938e2d71..ccc1bdd1bb1f 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -495,8 +495,8 @@ static struct send_queue *virtnet_xdp_sq(struct
> virtnet_info *vi)
> return &vi->sq[qp];
> }
>
> -static int virtnet_xdp_xmit(struct net_device *dev,
> - int n, struct xdp_frame **frames, u32 flags)
> +static int __virtnet_xdp_xmit(struct net_device *dev,
> + int n, struct xdp_frame **frames, u32 flags)
> {
> struct virtnet_info *vi = netdev_priv(dev);
> struct receive_queue *rq = vi->rq;
> @@ -569,6 +569,17 @@ static int virtnet_xdp_xmit(struct net_device *dev,
> return ret;
> }
>
> +static int virtnet_xdp_xmit(struct net_device *dev,
> + int n, struct xdp_frame **frames, u32 flags)
> +{
> + int r;
> +
> + rcu_read_lock_bh();
> + r = __virtnet_xdp_xmit(dev, n, frames, flags);
> + rcu_read_unlock_bh();
> + return r;
> +}
> +
> static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
> {
> return vi->xdp_queue_pairs ? VIRTIO_XDP_HEADROOM : 0;
> @@ -714,7 +725,7 @@ static struct sk_buff *receive_small(struct net_device
> *dev,
receive_small takes the rcu lock at the beginning.
> xdpf = convert_to_xdp_frame(&xdp);
> if (unlikely(!xdpf))
> goto err_xdp;
> - err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
> + err = __virtnet_xdp_xmit(dev, 1, &xdpf, 0);
> if (unlikely(err < 0)) {
> trace_xdp_exception(vi->dev, xdp_prog, act);
> goto err_xdp;
> @@ -887,7 +898,7 @@ static struct sk_buff *receive_mergeable(struct
> net_device *dev,
same here.
> xdpf = convert_to_xdp_frame(&xdp);
> if (unlikely(!xdpf))
> goto err_xdp;
> - err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
> + err = __virtnet_xdp_xmit(dev, 1, &xdpf, 0);
> if (unlikely(err < 0)) {
> trace_xdp_exception(vi->dev, xdp_prog, act);
> if (unlikely(xdp_page != page))
>
>
bq_xmit_all is invoking the xdp_xmit callback without taking the rcu
lock, but from the git history does not appear to have any recent changes.
