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

From: Jason Wang
Date: Fri Sep 22 2017 - 00:06:33 EST




On 2017å09æ21æ 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.fastabend@xxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
[...]

@@ -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.