diff mbox series

[net-next,1/2] virtio-net: don't reserve space for vnet header for XDP

Message ID 20200506061633.16327-1-jasowang@redhat.com
State New
Headers show
Series [net-next,1/2] virtio-net: don't reserve space for vnet header for XDP | expand

Commit Message

Jason Wang May 6, 2020, 6:16 a.m. UTC 
We tried to reserve space for vnet header before
xdp.data_hard_start. But this is useless since the packet could be
modified by XDP which may invalidate the information stored in the
header and there's no way for XDP to know the existence of the vnet
header currently.

So let's just not reserve space for vnet header in this case.

Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/net/virtio_net.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 11f722460513..98dd75b665a5 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -684,8 +684,8 @@  static struct sk_buff *receive_small(struct net_device *dev,
 			page = xdp_page;
 		}
 
-		xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
-		xdp.data = xdp.data_hard_start + xdp_headroom;
+		xdp.data_hard_start = buf + VIRTNET_RX_PAD;
+		xdp.data = xdp.data_hard_start + xdp_headroom + vi->hdr_len;
 		xdp.data_end = xdp.data + len;
 		xdp.data_meta = xdp.data;
 		xdp.rxq = &rq->xdp_rxq;
@@ -845,7 +845,7 @@  static struct sk_buff *receive_mergeable(struct net_device *dev,
 		 * the descriptor on if we get an XDP_TX return code.
 		 */
 		data = page_address(xdp_page) + offset;
-		xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM + vi->hdr_len;
+		xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM;
 		xdp.data = data + vi->hdr_len;
 		xdp.data_end = xdp.data + (len - vi->hdr_len);
 		xdp.data_meta = xdp.data;