i40e: fix offload of GRE tunnels

The driver still was not offloading TSO on GRE tunnels because
it forgot to set the GSO_GRE flag, causing lots of retransmits.

This fixes generic GRE traffic (like a tunnel added like below)
whereas before it would get 1Gb/s or less, now on a 10G adapter
it gets 8.7Gb/s.

ip ad ad 11.1.0.2/24 dev ens2f0
ip l set ens2f0 up
ip link add gre2 type gretap remote 11.1.0.1 local 11.1.0.2 dev ens2f0
ip l set gre2 up
ip ad ad 192.168.124.2/24 dev gre2
ping 192.168.124.1
netperf -H 192.168.124.1

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 2fdf978..dd44faf 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -8389,6 +8389,7 @@ static int i40e_config_netdev(struct i40e_vsi *vsi)
 
        netdev->hw_enc_features |= NETIF_F_IP_CSUM       |
                                  NETIF_F_GSO_UDP_TUNNEL |
+                                 NETIF_F_GSO_GRE        |
                                  NETIF_F_TSO;
 
        netdev->features = NETIF_F_SG                  |
@@ -8396,6 +8397,7 @@ static int i40e_config_netdev(struct i40e_vsi *vsi)
                           NETIF_F_SCTP_CSUM           |
                           NETIF_F_HIGHDMA             |
                           NETIF_F_GSO_UDP_TUNNEL      |
+                          NETIF_F_GSO_GRE             |
                           NETIF_F_HW_VLAN_CTAG_TX     |
                           NETIF_F_HW_VLAN_CTAG_RX     |
                           NETIF_F_HW_VLAN_CTAG_FILTER |