[PATCH net] netvsc: transfer lower device max tso size during VF transition
From: Li Tian <hidden>
Date: 2026-03-25 04:50:25
Also in:
linux-hyperv, lkml
Subsystem:
hyper-v/azure core and drivers, networking drivers, the rest · Maintainers:
"K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
When netvsc is accelerated by the lower device, we can advertise the lower device max tso size in order to get better performance. While a long-term migration to user-space bonding is planned, current users on RHEL 10 / Azure are experiencing significant performance regressions in 802.3ad environments. This patch provides a localized, safe fix within netvsc without introducing new core networking helpers. Signed-off-by: Li Tian <redacted> --- drivers/net/hyperv/netvsc_drv.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index ee5ab5ceb2be..971607c7406f 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c@@ -2428,10 +2428,14 @@ static int netvsc_vf_changed(struct net_device *vf_netdev, unsigned long event) * This value is only increased for netvsc NIC when datapath is * switched over to the VF */ - if (vf_is_up) + if (vf_is_up) { netif_set_tso_max_size(ndev, vf_netdev->tso_max_size); - else + WRITE_ONCE(ndev->gso_max_size, READ_ONCE(vf_netdev->gso_max_size)); + WRITE_ONCE(ndev->gso_ipv4_max_size, + READ_ONCE(vf_netdev->gso_ipv4_max_size)); + } else { netif_set_tso_max_size(ndev, netvsc_dev->netvsc_gso_max_size); + } } return NOTIFY_OK;
--
2.53.0