Merge branch 'veth-xdp-gro'

Ignat Korchagin says:

====================
net: veth: ability to toggle GRO and XDP independently

It is rather confusing that GRO is automatically enabled, when an XDP program
is attached to a veth interface. Moreover, it is not possible to disable GRO
on a veth, if an XDP program is attached (which might be desirable in some use
cases).

Make GRO and XDP independent for a veth interface.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/veth.c

@@ -1464,8 +1464,6 @@ static netdev_features_t veth_fix_features(struct net_device *dev,
 		if (peer_priv->_xdp_prog)
 			features &= ~NETIF_F_GSO_SOFTWARE;
 	}
-	if (priv->_xdp_prog)
-		features |= NETIF_F_GRO;
 
 	return features;
 }
@@ -1569,14 +1567,6 @@ static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 		}
 
 		if (!old_prog) {
-			if (!veth_gro_requested(dev)) {
-				/* user-space did not require GRO, but adding
-				 * XDP is supposed to get GRO working
-				 */
-				dev->features |= NETIF_F_GRO;
-				netdev_features_change(dev);
-			}
-
 			peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
 			peer->max_mtu = max_mtu;
 		}
@@ -1592,14 +1582,6 @@ static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 			if (dev->flags & IFF_UP)
 				veth_disable_xdp(dev);
 
-			/* if user-space did not require GRO, since adding XDP
-			 * enabled it, clear it now
-			 */
-			if (!veth_gro_requested(dev)) {
-				dev->features &= ~NETIF_F_GRO;
-				netdev_features_change(dev);
-			}
-
 			if (peer) {
 				peer->hw_features |= NETIF_F_GSO_SOFTWARE;
 				peer->max_mtu = ETH_MAX_MTU;

tools/testing/selftests/net/udpgro_fwd.sh

@@ -217,6 +217,7 @@ for family in 4 6; do
 	cleanup
 
 	create_ns
+	ip netns exec $NS_DST ethtool -K veth$DST generic-receive-offload on
 	ip netns exec $NS_DST ethtool -K veth$DST rx-gro-list on
 	run_test "GRO frag list" $BM_NET$DST 1 0
 	cleanup
@@ -227,6 +228,7 @@ for family in 4 6; do
 	# use NAT to circumvent GRO FWD check
 	create_ns
 	ip -n $NS_DST addr add dev veth$DST $BM_NET$DST_NAT/$SUFFIX
+	ip netns exec $NS_DST ethtool -K veth$DST generic-receive-offload on
 	ip netns exec $NS_DST ethtool -K veth$DST rx-udp-gro-forwarding on
 	ip netns exec $NS_DST $IPT -t nat -I PREROUTING -d $BM_NET$DST_NAT \
 					-j DNAT --to-destination $BM_NET$DST
@@ -240,6 +242,7 @@ for family in 4 6; do
 	cleanup
 
 	create_vxlan_pair
+	ip netns exec $NS_DST ethtool -K veth$DST generic-receive-offload on
 	ip netns exec $NS_DST ethtool -K veth$DST rx-gro-list on
 	run_test "GRO frag list over UDP tunnel" $OL_NET$DST 1 1
 	cleanup
@@ -247,6 +250,7 @@ for family in 4 6; do
 	# use NAT to circumvent GRO FWD check
 	create_vxlan_pair
 	ip -n $NS_DST addr add dev $VXDEV$DST $OL_NET$DST_NAT/$SUFFIX
+	ip netns exec $NS_DST ethtool -K veth$DST generic-receive-offload on
 	ip netns exec $NS_DST ethtool -K veth$DST rx-udp-gro-forwarding on
 	ip netns exec $NS_DST $IPT -t nat -I PREROUTING -d $OL_NET$DST_NAT \
 					-j DNAT --to-destination $OL_NET$DST

tools/testing/selftests/net/veth.sh

@@ -249,9 +249,9 @@ cleanup
 create_ns
 ip -n $NS_DST link set dev veth$DST up
 ip -n $NS_DST link set dev veth$DST xdp object ${BPF_FILE} section xdp
-chk_gro_flag "gro vs xdp while down - gro flag on" $DST on
+chk_gro_flag "gro vs xdp while down - gro flag off" $DST off
 ip -n $NS_DST link set dev veth$DST down
-chk_gro_flag "                      - after down" $DST on
+chk_gro_flag "                      - after down" $DST off
 ip -n $NS_DST link set dev veth$DST xdp off
 chk_gro_flag "                      - after xdp off" $DST off
 ip -n $NS_DST link set dev veth$DST up
@@ -260,6 +260,21 @@ ip -n $NS_SRC link set dev veth$SRC xdp object ${BPF_FILE} section xdp
 chk_gro_flag "                      - after peer xdp" $DST off
 cleanup
 
+create_ns
+ip -n $NS_DST link set dev veth$DST up
+ip -n $NS_DST link set dev veth$DST xdp object ${BPF_FILE} section xdp
+ip netns exec $NS_DST ethtool -K veth$DST generic-receive-offload on
+chk_gro_flag "gro vs xdp while down - gro flag on" $DST on
+ip -n $NS_DST link set dev veth$DST down
+chk_gro_flag "                      - after down" $DST on
+ip -n $NS_DST link set dev veth$DST xdp off
+chk_gro_flag "                      - after xdp off" $DST on
+ip -n $NS_DST link set dev veth$DST up
+chk_gro_flag "                      - after up" $DST on
+ip -n $NS_SRC link set dev veth$SRC xdp object ${BPF_FILE} section xdp
+chk_gro_flag "                      - after peer xdp" $DST on
+cleanup
+
 create_ns
 chk_channels "default channels" $DST 1 1
 
@@ -327,11 +342,14 @@ if [ $CPUS -gt 2 ]; then
 fi
 
 ip -n $NS_DST link set dev veth$DST xdp object ${BPF_FILE} section xdp 2>/dev/null
-chk_gro_flag "with xdp attached - gro flag" $DST on
+chk_gro_flag "with xdp attached - gro flag" $DST off
 chk_gro_flag "        - peer gro flag" $SRC off
 chk_tso_flag "        - tso flag" $SRC off
 chk_tso_flag "        - peer tso flag" $DST on
 ip netns exec $NS_DST ethtool -K veth$DST rx-udp-gro-forwarding on
+chk_gro "        - no aggregation" 10
+ip netns exec $NS_DST ethtool -K veth$DST generic-receive-offload on
+chk_gro_flag "        - gro flag with GRO on" $DST on
 chk_gro "        - aggregation" 1