From: stephen hemminger <stephen@xxxxxxxxxxxxxxxxxx>
commit a50af86dd49ee1851d1ccf06dd0019c05b95e297 upstream.
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@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Willy Tarreau <w@xxxxxx>
---
drivers/net/hyperv/netvsc_drv.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 59e9c56..4934604 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -48,6 +48,9 @@ struct net_device_context {
struct work_struct work;
};
+/* Restrict GSO size to account for NVGRE */
+#define NETVSC_GSO_MAX_SIZE 62768
+
#define RING_SIZE_MIN 64
static int ring_size = 128;
module_param(ring_size, int, S_IRUGO);
@@ -436,6 +439,7 @@ 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) {
--
2.8.0.rc2.1.gbe9624a