Macvlan always turns on offload features that have sofware
fallback (NETIF_GSO_SOFTWARE). This allows much higher guest-guest
communications over macvtap.
However, macvtap does not turn on these features for vlan tagged traffic.
As a result, depending on the HW that mactap is configured on, the
performance of guest-guest communication over a vlan is very
inconsistent. If the HW supports TSO/UFO over vlans, then the
performance will be fine. If not, the the performance will suffer
greatly since the VM may continue using TSO/UFO, and will force the host
segment the traffic and possibly overlow the macvtap queue.
This patch adds the always on offloads to vlan_features. This
makes sure that any vlan tagged traffic between 2 guest will not
be segmented needlessly.
Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
70957eaecc