[PATCH 3.12 36/72] macvtap: unbreak receiving of gro skb with frag list

From: Jiri Slaby
Date: Mon Nov 23 2015 - 08:12:20 EST


From: Jason Wang <jasowang@xxxxxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

[ Upstream commit f23d538bc24a83c16127c2eb82c9cf1adc2b5149 ]

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@xxxxxxxxxx>
Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/net/macvtap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 393873fb792e..ee53a9d06e8e 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -69,7 +69,7 @@ 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)

/*
* RCU usage:
--
2.6.3

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