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

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

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

quoted

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.fastabend@gmail.com>
Signed-off-by: Jason Wang <redacted>
---

[...]

quoted

@@ -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.

quoted

+			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.