From 33c7b0f74c57d1a3c0a623ce794d7f61e097d09c Mon Sep 17 00:00:00 2001 From: stephen hemminger Date: Tue, 6 Dec 2016 13:43:54 -0800 Subject: [PATCH] netvsc: reduce maximum GSO size [ 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/hyperv/netvsc_drv.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 409b48e1e589..7a601d8c615e 100644 --- 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 net_device *net, } goto recover; } + netif_set_gso_max_size(net, NETVSC_GSO_MAX_SIZE); out: netvsc_open(net); -- 2.34.1