Paul Durrant
2013-Oct-08 10:44 UTC
[PATCH net-next 1/5] xen-netback: add IPv6 checksum offload to guest
Check xenstore flag feature-ipv6-csum-offload to determine if a
guest is happy to accept IPv6 packets with only partial checksum.
Also check analogous feature-ip-csum-offload to determone if a
guest is happy to accept IPv4 packets with only partial checksum
as a replacement for a negated feature-no-csum-offload value and
add a comment to deprecate use of feature-no-csum-offload.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Wei Liu <wei.liuw2@citrix.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
---
drivers/net/xen-netback/common.h | 3 ++-
drivers/net/xen-netback/interface.c | 10 +++++++---
drivers/net/xen-netback/xenbus.c | 24 +++++++++++++++++++++++-
3 files changed, 32 insertions(+), 5 deletions(-)
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index 5715318..b4a9a3c 100644
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -153,7 +153,8 @@ struct xenvif {
u8 can_sg:1;
u8 gso:1;
u8 gso_prefix:1;
- u8 csum:1;
+ u8 ip_csum:1;
+ u8 ipv6_csum:1;
/* Internal feature information. */
u8 can_queue:1; /* can queue packets for receiver? */
diff --git a/drivers/net/xen-netback/interface.c
b/drivers/net/xen-netback/interface.c
index 01bb854..8e92783 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -216,8 +216,10 @@ static netdev_features_t xenvif_fix_features(struct
net_device *dev,
features &= ~NETIF_F_SG;
if (!vif->gso && !vif->gso_prefix)
features &= ~NETIF_F_TSO;
- if (!vif->csum)
+ if (!vif->ip_csum)
features &= ~NETIF_F_IP_CSUM;
+ if (!vif->ipv6_csum)
+ features &= ~NETIF_F_IPV6_CSUM;
return features;
}
@@ -306,7 +308,7 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t
domid,
vif->domid = domid;
vif->handle = handle;
vif->can_sg = 1;
- vif->csum = 1;
+ vif->ip_csum = 1;
vif->dev = dev;
vif->credit_bytes = vif->remaining_credit = ~0UL;
@@ -316,7 +318,9 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t
domid,
vif->credit_timeout.expires = jiffies;
dev->netdev_ops = &xenvif_netdev_ops;
- dev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_TSO;
+ dev->hw_features = NETIF_F_SG |
+ NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
+ NETIF_F_TSO;
dev->features = dev->hw_features;
SET_ETHTOOL_OPS(dev, &xenvif_ethtool_ops);
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index b45bce2..5e45b00 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -567,10 +567,32 @@ static int connect_rings(struct backend_info *be)
val = 0;
vif->gso_prefix = !!val;
+ /* Before feature-ipv6-csum-offload was introduced, checksum offload
+ * was turned on by a zero value in (or lack of)
+ * feature-no-csum-offload. Therefore, for compatibility, assume
+ * that if feature-ip-csum-offload is missing that IP (v4) offload
+ * is turned on. If this is not the case then the flag will be
+ * cleared when we subsequently sample feature-no-csum-offload.
+ */
+ if (xenbus_scanf(XBT_NIL, dev->otherend,
"feature-ip-csum-offload",
+ "%d", &val) < 0)
+ val = 1;
+ vif->ip_csum = !!val;
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend,
"feature-ipv6-csum-offload",
+ "%d", &val) < 0)
+ val = 0;
+ vif->ipv6_csum = !!val;
+
+ /* This is deprecated. Frontends should set IP v4 and v6 checksum
+ * offload using feature-ip-csum-offload and
+ * feature-ipv6-csum-offload respectively.
+ */
if (xenbus_scanf(XBT_NIL, dev->otherend,
"feature-no-csum-offload",
"%d", &val) < 0)
val = 0;
- vif->csum = !val;
+ if (val)
+ vif->ip_csum = 0;
/* Map the shared frame, irq etc. */
err = xenvif_connect(vif, tx_ring_ref, rx_ring_ref,
--
1.7.10.4