Re: [PATCH net-next 3/3] virtio-net: support XDP_REDIRECT

[Jason Wang]

On 2017年09月21日 06:02, John Fastabend wrote:

On 09/19/2017 02:42 AM, Jason Wang wrote:

This patch tries to add XDP_REDIRECT for virtio-net. The changes are
not complex as we could use exist XDP_TX helpers for most of the
work. The rest is passing the XDP_TX to NAPI handler for implementing
batching.

Cc: John Fastabend <john.fastab...@gmail.com>
Signed-off-by: Jason Wang <jasow...@redhat.com>
---

[...]

@@ -678,12 +711,20 @@ static struct sk_buff *receive_mergeable(struct 
net_device *dev,
                        }
                        break;
                case XDP_TX:
-                       if (unlikely(!virtnet_xdp_xmit(vi, &xdp)))
+                       if (unlikely(!__virtnet_xdp_xmit(vi, &xdp)))
                                trace_xdp_exception(vi->dev, xdp_prog, act);
+                       else
+                               *xdp_xmit = true;
                        if (unlikely(xdp_page != page))
                                goto err_xdp;
                        rcu_read_unlock();
                        goto xdp_xmit;
+               case XDP_REDIRECT:
+                       err = xdp_do_redirect(dev, &xdp, xdp_prog);
+                       if (err)
+                               *xdp_xmit = true;

Is this a typo? Should above be

                        if (!err)
                                *xdp_xmit = true;

this would match the pattern in receive_small and also make more sense.

Right, will post a fix.

+                       rcu_read_unlock();
+                       goto xdp_xmit;
                default:
                        bpf_warn_invalid_xdp_action(act);
                case XDP_ABORTED:
@@ -788,7 +829,7 @@ static struct sk_buff *receive_mergeable(struct net_device 
*dev,
  }

[...]

Otherwise looks good to me thanks for doing this.

.John

Thanks for the reviewing.