xen-netback: accept an L4 or L3 skb hash value from the frontend

This patch adds an indication that netback is capable of handling hash
values passed from the frontend (see netif.h for details), and the code
necessary to process the additional xen_netif_extra_info segment and
set a hash on the skb.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index ac0db145270ea9b76f294c739f05e1704070daf0..f820f63b20bc3c73cb96bac1145e762b4ab02b1c 100644 (file)
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1364,6 +1364,28 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
                        }
                }
 
+               if (extras[XEN_NETIF_EXTRA_TYPE_HASH - 1].type) {
+                       struct xen_netif_extra_info *extra;
+                       u32 hash = *(u32 *)extra->u.hash.value;
+
+                       extra = &extras[XEN_NETIF_EXTRA_TYPE_HASH - 1];
+
+                       switch (extra->u.hash.type) {
+                       case XEN_NETIF_HASH_TYPE_TCPV4:
+                       case XEN_NETIF_HASH_TYPE_TCPV6:
+                               skb_set_hash(skb, hash, PKT_HASH_TYPE_L4);
+                               break;
+
+                       case XEN_NETIF_HASH_TYPE_IPV4:
+                       case XEN_NETIF_HASH_TYPE_IPV6:
+                               skb_set_hash(skb, hash, PKT_HASH_TYPE_L3);
+                               break;
+
+                       default:
+                               break;
+                       }
+               }
+
                XENVIF_TX_CB(skb)->pending_idx = pending_idx;
 
                __skb_put(skb, data_len);

diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 929a6e7e5ecfe9249569c0059516e531fb0b79eb..2fa8a16fcf0f2018c9d826fc5b87cac6c413e4c6 100644 (file)
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -335,6 +335,14 @@ static int netback_probe(struct xenbus_device *dev,
                        goto abort_transaction;
                }
 
+               /* We support hash values. */
+               err = xenbus_printf(xbt, dev->nodename,
+                                   "feature-hash", "%d", 1);
+               if (err) {
+                       message = "writing feature-hash";
+                       goto abort_transaction;
+               }
+
                err = xenbus_transaction_end(xbt, 0);
        } while (err == -EAGAIN);