tuntap: initialize vlan_features
The vlan_features was zero which prevents vlan GSO packets to be transmitted to
userspace. This is suboptimal so enable this by initialize vlan_features for
tuntap.
Netperf shows better performance of guest receiving since vlan TSO works for
tuntap:
before:
netperf -H 192.168.5.4
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.5.4 ()
port 0 AF_INET : demo
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec
87380 16384 16384 10.01 2786.67
after:
netperf -H 192.168.5.4
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.5.4 ()
port 0 AF_INET : demo
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec
87380 16384 16384 10.00 8085.49
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 29538e6..316c759 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1656,6 +1656,7 @@
dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
TUN_USER_FEATURES;
dev->features = dev->hw_features;
+ dev->vlan_features = dev->features;
INIT_LIST_HEAD(&tun->disabled);
err = tun_attach(tun, file);