Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965622AbcLWP5m (ORCPT ); Fri, 23 Dec 2016 10:57:42 -0500 Received: from mail-pg0-f66.google.com ([74.125.83.66]:36811 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757573AbcLWP5j (ORCPT ); Fri, 23 Dec 2016 10:57:39 -0500 Subject: Re: [PATCH net 4/9] virtio-net: correctly handle XDP_PASS for linearized packets To: Jason Wang , mst@redhat.com, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <1482503852-12438-1-git-send-email-jasowang@redhat.com> <1482503852-12438-5-git-send-email-jasowang@redhat.com> Cc: john.r.fastabend@intel.com From: John Fastabend Message-ID: <585D4966.9060605@gmail.com> Date: Fri, 23 Dec 2016 07:57:26 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <1482503852-12438-5-git-send-email-jasowang@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1475 Lines: 41 On 16-12-23 06:37 AM, Jason Wang wrote: > When XDP_PASS were determined for linearized packets, we try to get > new buffers in the virtqueue and build skbs from them. This is wrong, > we should create skbs based on existed buffers instead. Fixing them by > creating skb based on xdp_page. > > With this patch "ping 192.168.100.4 -s 3900 -M do" works for XDP_PASS. > > Cc: John Fastabend > Signed-off-by: Jason Wang > --- > drivers/net/virtio_net.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 58ad40e..470293e 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -578,8 +578,14 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > act = do_xdp_prog(vi, rq, xdp_prog, xdp_page, offset, len); > switch (act) { > case XDP_PASS: > - if (unlikely(xdp_page != page)) > - __free_pages(xdp_page, 0); > + /* We can only create skb based on xdp_page. */ > + if (unlikely(xdp_page != page)) { > + rcu_read_unlock(); > + put_page(page); > + head_skb = page_to_skb(vi, rq, xdp_page, > + 0, len, PAGE_SIZE); > + return head_skb; > + } > break; > case XDP_TX: > if (unlikely(xdp_page != page)) > Great thanks. This was likely working before because of the memory leak fixed in 3/9. Acked-by: John Fastabend