From: Jason Wang <jasowang@redhat.com>
Date: Thu, 22 Nov 2018 14:36:31 +0800
Subject: virtio-net: fail XDP set if guest csum is negotiated
Git-commit: 18ba58e1c234ea1a2d9835ac8c1735d965ce4640
Patch-mainline: v4.20-rc4
References: networking-stable-18_12_03

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@redhat.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Pavel Popa <pashinho1990@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/net/virtio_net.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1891,8 +1891,9 @@ static int virtnet_xdp_set(struct net_de
 	if (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;
 	}