From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: Re: [PATCH net 4/9] virtio-net: correctly handle XDP_PASS for linearized packets Date: Fri, 23 Dec 2016 07:57:26 -0800 Message-ID: <585D4966.9060605@gmail.com> References: <1482503852-12438-1-git-send-email-jasowang@redhat.com> <1482503852-12438-5-git-send-email-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: john.r.fastabend@intel.com To: Jason Wang , mst@redhat.com, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: In-Reply-To: <1482503852-12438-5-git-send-email-jasowang@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org 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