From: Jason Wang <jasowang@redhat.com>
Date: Fri, 23 Oct 2015 04:57:05 +0000 (-0400)
Subject: macvtap: unbreak receiving of gro skb with frag list
X-Git-Tag: firefly_0821_release~176^2~865^2~25
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f23d538bc24a83c16127c2eb82c9cf1adc2b5149;p=firefly-linux-kernel-4.4.55.git

macvtap: unbreak receiving of gro skb with frag list

We don't have fraglist support in TAP_FEATURES. This will lead
software segmentation of gro skb with frag list. Fixes by having
frag list support in TAP_FEATURES.

With this patch single session of netperf receiving were restored from
about 5Gb/s to about 12Gb/s on mlx4.

Fixes a567dd6252 ("macvtap: simplify usage of tap_features")
Cc: Vlad Yasevich <vyasevic@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 248478c6f6e4..197c93937c2d 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -137,7 +137,7 @@ static const struct proto_ops macvtap_socket_ops;
 #define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
 		      NETIF_F_TSO6 | NETIF_F_UFO)
 #define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO)
-#define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG)
+#define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG | NETIF_F_FRAGLIST)
 
 static struct macvlan_dev *macvtap_get_vlan_rcu(const struct net_device *dev)
 {