[PATCH 3.16.y-ckt 011/168] net/mlx4_en: Advertize encapsulation offloads features only when VXLAN tunnel is set

[Luis Henriques]

3.16.7-ckt3 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Or Gerlitz <ogerlitz at mellanox.com>

commit f4a1edd56120249198073aa4a373b77e3700ac8f upstream.

Currenly we only support Large-Send and TX checksum offloads for
encapsulated traffic of type VXLAN. We must make sure to advertize
these offloads up to the stack only when VXLAN tunnel is set.

Failing to do so, would mislead the the networking stack to assume
that the driver can offload the internal TX checksum for GRE packets
and other buggy schemes.

Reported-by: Florian Westphal <fw at strlen.de>
Signed-off-by: Or Gerlitz <ogerlitz at mellanox.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index 128f0728d97d..04b2d8e117cb 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -2312,8 +2312,16 @@ static void mlx4_en_add_vxlan_offloads(struct work_struct *work)
 	ret = mlx4_SET_PORT_VXLAN(priv->mdev->dev, priv->port,
 				  VXLAN_STEER_BY_OUTER_MAC, 1);
 out:
-	if (ret)
+	if (ret) {
 		en_err(priv, "failed setting L2 tunnel configuration ret %d\n", ret);
+		return;
+	}
+
+	/* set offloads */
+	priv->dev->hw_enc_features |= NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
+				      NETIF_F_TSO | NETIF_F_GSO_UDP_TUNNEL;
+	priv->dev->hw_features |= NETIF_F_GSO_UDP_TUNNEL;
+	priv->dev->features    |= NETIF_F_GSO_UDP_TUNNEL;
 }
 
 static void mlx4_en_del_vxlan_offloads(struct work_struct *work)
@@ -2321,6 +2329,11 @@ static void mlx4_en_del_vxlan_offloads(struct work_struct *work)
 	int ret;
 	struct mlx4_en_priv *priv = container_of(work, struct mlx4_en_priv,
 						 vxlan_del_task);
+	/* unset offloads */
+	priv->dev->hw_enc_features &= ~(NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
+				      NETIF_F_TSO | NETIF_F_GSO_UDP_TUNNEL);
+	priv->dev->hw_features &= ~NETIF_F_GSO_UDP_TUNNEL;
+	priv->dev->features    &= ~NETIF_F_GSO_UDP_TUNNEL;
 
 	ret = mlx4_SET_PORT_VXLAN(priv->mdev->dev, priv->port,
 				  VXLAN_STEER_BY_OUTER_MAC, 0);
@@ -2601,13 +2614,6 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
 	if (mdev->dev->caps.steering_mode != MLX4_STEERING_MODE_A0)
 		dev->priv_flags |= IFF_UNICAST_FLT;
 
-	if (mdev->dev->caps.tunnel_offload_mode == MLX4_TUNNEL_OFFLOAD_MODE_VXLAN) {
-		dev->hw_enc_features |= NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
-					NETIF_F_TSO | NETIF_F_GSO_UDP_TUNNEL;
-		dev->hw_features |= NETIF_F_GSO_UDP_TUNNEL;
-		dev->features    |= NETIF_F_GSO_UDP_TUNNEL;
-	}
-
 	mdev->pndev[port] = dev;
 
 	netif_carrier_off(dev);
-- 
2.1.3