Messages in this thread | | | Subject | Re: [PATCH net 4/9] virtio-net: correctly handle XDP_PASS for linearized packets | From | Jason Wang <> | Date | Mon, 26 Dec 2016 10:34:39 +0800 |
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On 2016年12月23日 23:57, John Fastabend wrote: > 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 <john.r.fastabend@intel.com> >> Signed-off-by: Jason Wang <jasowang@redhat.com> >> --- >> 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.
Looks not, without this and 3/9 the code will try to get buffers and build skb for a new packet instead of existed buffers.
Thanks
> > Acked-by: John Fastabend <john.r.fastabend@intel.com>
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