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

[Jason Wang]

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.