Patch "netvsc: reduce maximum GSO size" has been added to the 4.4-stable tree

Patch "netvsc: reduce maximum GSO size" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    netvsc: reduce maximum GSO size

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     netvsc-reduce-maximum-gso-size.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Thu Jan 12 21:36:14 CET 2017
From: stephen hemminger <stephen@networkplumber.org>
Date: Tue, 6 Dec 2016 13:43:54 -0800
Subject: netvsc: reduce maximum GSO size

From: stephen hemminger <stephen@networkplumber.org>


[ Upstream commit a50af86dd49ee1851d1ccf06dd0019c05b95e297 ]

Hyper-V (and Azure) support using NVGRE which requires some extra space
for encapsulation headers. Because of this the largest allowed TSO
packet is reduced.

For older releases, hard code a fixed reduced value.  For next release,
there is a better solution which uses result of host offload
negotiation.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/hyperv/netvsc_drv.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -40,6 +40,8 @@
 
 #include "hyperv_net.h"
 
+/* Restrict GSO size to account for NVGRE */
+#define NETVSC_GSO_MAX_SIZE	62768
 
 #define RING_SIZE_MIN 64
 static int ring_size = 128;
@@ -852,6 +854,7 @@ static int netvsc_set_channels(struct ne
 		}
 		goto recover;
 	}
+	netif_set_gso_max_size(net, NETVSC_GSO_MAX_SIZE);
 
  out:
 	netvsc_open(net);


Patches currently in stable-queue which might be from stephen@networkplumber.org are

queue-4.4/netvsc-reduce-maximum-gso-size.patch