Linux Virtualization - May 2017 - [PATCH net 3/3] virtio-net: enable TSO/checksum offloads for Q-in-Q vlans

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.

CC: "Michael S. Tsirkin" <mst at redhat.com>
CC: Jason Wang <jasowang at redhat.com>
CC: virtualization at lists.linux-foundation.org
Signed-off-by: Vladislav Yasevich <vyasevic at redhat.com>
---
 drivers/net/virtio_net.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 8324a5e..341fb96 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2028,6 +2028,7 @@ static const struct net_device_ops virtnet_netdev = {
 	.ndo_poll_controller = virtnet_netpoll,
 #endif
 	.ndo_xdp		= virtnet_xdp,
+	.ndo_features_check	= passthru_features_check,
 };
 
 static void virtnet_config_changed_work(struct work_struct *work)
-- 
2.7.4

On Thu, May 18, 2017 at 09:31:05AM -0400, Vladislav Yasevich
wrote:
> 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.
> 
> CC: "Michael S. Tsirkin" <mst at redhat.com>
> CC: Jason Wang <jasowang at redhat.com>
> CC: virtualization at lists.linux-foundation.org
> Signed-off-by: Vladislav Yasevich <vyasevic at redhat.com>
Acked-by: Michael S. Tsirkin <mst at redhat.com>
> ---
>  drivers/net/virtio_net.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 8324a5e..341fb96 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -2028,6 +2028,7 @@ static const struct net_device_ops virtnet_netdev = {
>  	.ndo_poll_controller = virtnet_netpoll,
>  #endif
>  	.ndo_xdp		= virtnet_xdp,
> +	.ndo_features_check	= passthru_features_check,
>  };
>  
>  static void virtnet_config_changed_work(struct work_struct *work)
> -- 
> 2.7.4

On 2017?05?18? 21:31, Vladislav Yasevich wrote:
> 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.
>
> CC: "Michael S. Tsirkin" <mst at redhat.com>
> CC: Jason Wang <jasowang at redhat.com>
> CC: virtualization at lists.linux-foundation.org
> Signed-off-by: Vladislav Yasevich <vyasevic at redhat.com>
> ---
>   drivers/net/virtio_net.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 8324a5e..341fb96 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -2028,6 +2028,7 @@ static const struct net_device_ops virtnet_netdev = {
>   	.ndo_poll_controller = virtnet_netpoll,
>   #endif
>   	.ndo_xdp		= virtnet_xdp,
> +	.ndo_features_check	= passthru_features_check,
>   };
>   
>   static void virtnet_config_changed_work(struct work_struct *work)
Acked-by: Jason Wang <jasowang at redhat.com>