[PATCH net] veth: add vlan features

[Flavio Leitner <fbl@redhat.com>]

The veth device doesn't provide the vlan features,
so TSO for example is disabled and that causes
performance issues when using tagged traffic.

The test topology looks like this:

    br0                     br1
  /   \                  /     \
vnet  veth0.10 ----- veth1.10   vnet
VM                               VM

The netperf results with current veth driver:
MIGRATED TCP STREAM TEST from 192.168.1.1 ()
port 0 AF_INET to 192.168.1.2 () port 0 AF_INET
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 87380  16384  16384    10.01    2210.22

Now after applying the proposed patch:
MIGRATED TCP STREAM TEST from 192.168.1.1 ()
port 0 AF_INET to 192.168.1.2 () port 0 AF_INET
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 87380  16384  16384    10.00    13067.47

Signed-off-by: Flavio Leitner <fbl@redhat.com>
---
 drivers/net/veth.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index da86652..eee1f19 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -269,6 +269,7 @@ static void veth_setup(struct net_device *dev)
 	dev->ethtool_ops = &veth_ethtool_ops;
 	dev->features |= NETIF_F_LLTX;
 	dev->features |= VETH_FEATURES;
+	dev->vlan_features = dev->features;
 	dev->destructor = veth_dev_free;
 
 	dev->hw_features = VETH_FEATURES;
-- 
1.8.3.1