From a643d6599358b6a33d1438c359aa98aeac9f4fb9 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 [bwh: Backported to 3.2: adjust filename, context] Signed-off-by: Ben Hutchings --- drivers/staging/hv/netvsc_drv.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/staging/hv/netvsc_drv.c b/drivers/staging/hv/netvsc_drv.c index 93b0e91cbf98..c993dfd8671b 100644 --- a/drivers/staging/hv/netvsc_drv.c +++ b/drivers/staging/hv/netvsc_drv.c @@ -52,6 +52,9 @@ struct net_device_context { /* Need this many pages to handle worst case fragmented packet */ #define PACKET_PAGES_HIWATER (MAX_SKB_FRAGS + 2) +/* Restrict GSO size to account for NVGRE */ +#define NETVSC_GSO_MAX_SIZE 62768 + static int ring_size = 128; module_param(ring_size, int, S_IRUGO); MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)"); @@ -363,6 +366,7 @@ static int netvsc_probe(struct hv_device *dev, SET_ETHTOOL_OPS(net, ðtool_ops); SET_NETDEV_DEV(net, &dev->device); + netif_set_gso_max_size(net, NETVSC_GSO_MAX_SIZE); ret = register_netdev(net); if (ret != 0) { -- 2.39.5