From a50af86dd49ee1851d1ccf06dd0019c05b95e297 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 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 --- drivers/net/hyperv/netvsc_drv.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index f6382150b16a..c9140c3aeb67 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -47,6 +47,10 @@ NETIF_F_TSO | \ NETIF_F_TSO6 | \ NETIF_F_HW_CSUM) + +/* 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)"); @@ -1400,6 +1404,7 @@ static int netvsc_probe(struct hv_device *dev, nvdev = net_device_ctx->nvdev; netif_set_real_num_tx_queues(net, nvdev->num_chn); netif_set_real_num_rx_queues(net, nvdev->num_chn); + netif_set_gso_max_size(net, NETVSC_GSO_MAX_SIZE); ret = register_netdev(net); if (ret != 0) { -- 2.30.2