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

[Jason Wang <jasowang@redhat.com>]

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