[PATCH V2 net 0/3] Fix checksum issues with Q-in-Q vlans

[Vladislav Yasevich <vyasevich@gmail.com>]

TCP checksum appear broken on a lot of devices that
advertise NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM.  This problem
becomes very visible/reproducable since the series
commit afb0bc972b526 ("Merge branch 'stacked_vlan_tso'").

In particular, the issue appeared consistently on bnx2 and be2net
drivers (not all drivers were tested).

This short series corrects this by disabling checksum offload
support on packets sent through Q-in-Q vlans if the underlying HW only
enables IP specific checksum features.  We currently 'assume' that
any drivers setting NETIF_F_HW_CSUM can correclty pass checksum offsets
to HW.  It is up to individual drivers to enable it properly through
ndo_features_check if they have some support for Q-in-Q vlans.

Additionally, be2net driver was fixed to make the proper call.

While looking at the drivers, it was also found that virtio-net ended
up disabling accelerations, which is unnecessary.  

V2: Instead of disabling checksuming for all devices, only devices using
    NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM are now affected by this change.
    For drivers using NETIF_F_HW_CSUM, we will continue to use checksum
    offloading.  If any drivers are found to be broken, they would need
    be fixed individually.

Vladislav Yasevich (3):
  vlan: Fix tcp checksum offloads in Q-in-Q vlans
  be2net: Fix offload features for Q-in-Q packets
  virtio-net: enable TSO/checksum offloads for Q-in-Q vlans

 drivers/net/ethernet/emulex/benet/be_main.c |  4 +++-
 drivers/net/virtio_net.c                    |  1 +
 include/linux/if_vlan.h                     | 10 ++++++++--
 3 files changed, 12 insertions(+), 3 deletions(-)

-- 
2.7.4