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>
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 02cb00b..f035899 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -577,15 +577,40 @@
val = 0;
vif->can_sg = !!val;
+ vif->gso_mask = 0;
+ vif->gso_prefix_mask = 0;
+
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4",
"%d", &val) < 0)
val = 0;
- vif->gso = !!val;
+ if (val)
+ vif->gso_mask |= GSO_BIT(TCPV4);
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4-prefix",
"%d", &val) < 0)
val = 0;
- vif->gso_prefix = !!val;
+ if (val)
+ vif->gso_prefix_mask |= GSO_BIT(TCPV4);
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6",
+ "%d", &val) < 0)
+ val = 0;
+ if (val)
+ vif->gso_mask |= GSO_BIT(TCPV6);
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6-prefix",
+ "%d", &val) < 0)
+ val = 0;
+ if (val)
+ vif->gso_prefix_mask |= GSO_BIT(TCPV6);
+
+ if (vif->gso_mask & vif->gso_prefix_mask) {
+ xenbus_dev_fatal(dev, err,
+ "%s: gso and gso prefix flags are not "
+ "mutually exclusive",
+ dev->otherend);
+ return -EOPNOTSUPP;
+ }
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
"%d", &val) < 0)