[PATCH AUTOSEL 4.14 32/35] virtio-net: fail XDP set if guest csum is negotiated

[Sasha Levin]

From: Jason Wang <jasowang@xxxxxxxxxx>

[ Upstream commit 18ba58e1c234ea1a2d9835ac8c1735d965ce4640 ]

We don't support partial csumed packet since its metadata will be lost
or incorrect during XDP processing. So fail the XDP set if guest_csum
feature is negotiated.

Fixes: f600b6905015 ("virtio_net: Add XDP support")
Reported-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
Cc: Pavel Popa <pashinho1990@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/virtio_net.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 2ffa7b290591..0e8e3be50332 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1966,8 +1966,9 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 	    && (virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO4) ||
 	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_TSO6) ||
 	        virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_ECN) ||
-		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO))) {
-		NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing LRO, disable LRO first");
+		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_UFO) ||
+		virtio_has_feature(vi->vdev, VIRTIO_NET_F_GUEST_CSUM))) {
+		NL_SET_ERR_MSG_MOD(extack, "Can't set XDP while host is implementing LRO/CSUM, disable LRO/CSUM first");
 		return -EOPNOTSUPP;
 	}
 
-- 
2.17.1