[PATCH 4.4 20/53] virtio-net: enable TSO/checksum offloads for Q-in-Q vlans

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Vlad Yasevich <vyasevich@xxxxxxxxx>


[ Upstream commit 2836b4f224d4fd7d1a2b23c3eecaf0f0ae199a74 ]

Since virtio does not provide it's own ndo_features_check handler,
TSO, and now checksum offload, are disabled for stacked vlans.
Re-enable the support and let the host take care of it.  This
restores/improves Guest-to-Guest performance over Q-in-Q vlans.

Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Vladislav Yasevich <vyasevic@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/virtio_net.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1415,6 +1415,7 @@ static const struct net_device_ops virtn
 #ifdef CONFIG_NET_RX_BUSY_POLL
 	.ndo_busy_poll		= virtnet_busy_poll,
 #endif
+	.ndo_features_check	= passthru_features_check,
 };
 
 static void virtnet_config_changed_work(struct work_struct *work)