[PATCH net-next] xen-netfront: convert to GRO API and advertise this feature

[Wei Liu <wei.liu2@citrix.com>]

Anirban was seeing netfront received MTU size packets, which downgraded
throughput. The following patch makes netfront use GRO API which
improves throughput for that case.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Anirban Chakraborty <abchak@juniper.net>
Cc: Ian Campbell <ian.campbell@citrix.com>
---
 drivers/net/xen-netfront.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 36808bf..5664165 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -952,7 +952,7 @@ static int handle_incoming_queue(struct net_device *dev,
 		u64_stats_update_end(&stats->syncp);
 
 		/* Pass it up. */
-		netif_receive_skb(skb);
+		napi_gro_receive(&np->napi, skb);
 	}
 
 	return packets_dropped;
@@ -1051,6 +1051,8 @@ err:
 	if (work_done < budget) {
 		int more_to_do = 0;
 
+		napi_gro_flush(napi, false);
+
 		local_irq_save(flags);
 
 		RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do);
@@ -1371,7 +1373,8 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev)
 	netif_napi_add(netdev, &np->napi, xennet_poll, 64);
 	netdev->features        = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
 				  NETIF_F_GSO_ROBUST;
-	netdev->hw_features	= NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO;
+	netdev->hw_features	= NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO |
+				  NETIF_F_GRO;
 
 	/*
          * Assume that all hw features are available for now. This set
-- 
1.7.10.4