wireguard: device: support big tcp GSO

Advertise GSO_MAX_SIZE as TSO max size in order support BIG TCP for wireguard.
This helps to improve wireguard performance a bit when enabled as it allows
wireguard to aggregate larger skbs in wg_packet_consume_data_done() via
napi_gro_receive(), but also allows the stack to build larger skbs on xmit
where the driver then segments them before encryption inside wg_xmit().
We've seen a 15% improvement in TCP stream performance.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://patch.msgid.link/20241117212030.629159-5-Jason@zx2c4.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/wireguard/device.c b/drivers/net/wireguard/device.c
index a2ba71fbbed46954bd176c621af066b1b82878c5..6cf173a008e782c8254d45bbd250202fc215da5a 100644 (file)
--- a/drivers/net/wireguard/device.c
+++ b/drivers/net/wireguard/device.c
@@ -302,6 +302,8 @@ static void wg_setup(struct net_device *dev)
        /* We need to keep the dst around in case of icmp replies. */
        netif_keep_dst(dev);
 
+       netif_set_tso_max_size(dev, GSO_MAX_SIZE);
+
        wg->dev = dev;
 }