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, 7 insertions, 2 deletions

diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index b4a9a3c844b2..55b8dec86233 100644
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -87,9 +87,13 @@ struct pending_tx_info {
 struct xenvif_rx_meta {
         int id;
         int size;
+        int gso_type;
         int gso_size;
 };
 
+#define GSO_BIT(type) \
+        (1 << XEN_NETIF_GSO_TYPE_ ## type)
+
 /* Discriminate from any valid pending_idx value. */
 #define INVALID_PENDING_IDX 0xFFFF
 
@@ -150,9 +154,10 @@ struct xenvif {
         u8               fe_dev_addr[6];
 
         /* Frontend feature information. */
+        int gso_mask;
+        int gso_prefix_mask;
+
         u8 can_sg:1;
-        u8 gso:1;
-        u8 gso_prefix:1;
         u8 ip_csum:1;
         u8 ipv6_csum:1;