xen-netback: enable IPv6 TCP GSO to the guest

This patch adds code to handle SKB_GSO_TCPV6 skbs and construct appropriate
extra or prefix segments to pass the large packet to the frontend. New
xenstore flags, feature-gso-tcpv6 and feature-gso-tcpv6-prefix, are sampled
to determine if the frontend is capable of handling such packets.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index cb0d8ea3d9f2..e4aa26748f80 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -214,8 +214,10 @@ static netdev_features_t xenvif_fix_features(struct net_device *dev,
 
         if (!vif->can_sg)
                 features &= ~NETIF_F_SG;
-        if (!vif->gso && !vif->gso_prefix)
+        if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV4))
                 features &= ~NETIF_F_TSO;
+        if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV6))
+                features &= ~NETIF_F_TSO6;
         if (!vif->ip_csum)
                 features &= ~NETIF_F_IP_CSUM;
         if (!vif->ipv6_csum)
@@ -320,7 +322,7 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
         dev->netdev_ops = &xenvif_netdev_ops;
         dev->hw_features = NETIF_F_SG |
                 NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
-                NETIF_F_TSO;
+                NETIF_F_TSO | NETIF_F_TSO6;
         dev->features = dev->hw_features | NETIF_F_RXCSUM;
         SET_ETHTOOL_OPS(dev, &xenvif_ethtool_ops);