On 2017年06月28日 10:02, Michael S. Tsirkin wrote:

On Wed, Jun 28, 2017 at 09:54:03AM +0800, Jason Wang wrote:

quoted

We should allow csumed packet for small buffer, otherwise XDP_PASS
won't work correctly.

Fixes commit bb91accf2733 ("virtio-net: XDP support for small buffers")
Signed-off-by: Jason Wang <jasowang@redhat.com>

The issue would be VIRTIO_NET_HDR_F_DATA_VALID might be set.
What do you think?

I think it's safe. For XDP_PASS, it work like in the past. For XDP_TX, 
we zero the vnet header. For adjusting header, XDP prog should deal with 
csum.

Thanks

quoted

---
The patch is needed for -stable.
---
  drivers/net/virtio_net.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 143d8a9..499fcc9 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c

@@ -413,7 +413,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
  		void *orig_data;
  		u32 act;
  
-		if (unlikely(hdr->hdr.gso_type || hdr->hdr.flags))
+		if (unlikely(hdr->hdr.gso_type))
  			goto err_xdp;
  
  		xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;

-- 
2.7.4

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