xen-netback: use hash value from the frontend

My recent patch to include/xen/interface/io/netif.h defines a new extra
info type that can be used to pass hash values between backend and guest
frontend.

This patch adds code to xen-netback to use the value in a hash extra
info fragment passed from the guest frontend in a transmit-side
(i.e. netback receive side) packet to set the skb hash accordingly.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 9d6bd86..edbae0b 100644 (file)
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1510,6 +1510,33 @@ 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;
+                       enum pkt_hash_types type = PKT_HASH_TYPE_NONE;
+
+                       extra = &extras[XEN_NETIF_EXTRA_TYPE_HASH - 1];
+
+                       switch (extra->u.hash.type) {
+                       case _XEN_NETIF_CTRL_HASH_TYPE_IPV4:
+                       case _XEN_NETIF_CTRL_HASH_TYPE_IPV6:
+                               type = PKT_HASH_TYPE_L3;
+                               break;
+
+                       case _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP:
+                       case _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP:
+                               type = PKT_HASH_TYPE_L4;
+                               break;
+
+                       default:
+                               break;
+                       }
+
+                       if (type != PKT_HASH_TYPE_NONE)
+                               skb_set_hash(skb,
+                                            *(u32 *)extra->u.hash.value,
+                                            type);
+               }
+
                XENVIF_TX_CB(skb)->pending_idx = pending_idx;
 
                __skb_put(skb, data_len);