From 859e40055c19ceb8b8215f3269e57075023b72b4 Mon Sep 17 00:00:00 2001 From: Wang Zhan Date: Wed, 16 Sep 2026 14:58:44 +0800 Subject: [PATCH] openvswitch: raise internal port TSO limit Set the internal port TSO limit to GSO_MAX_SIZE (512 KB), as for loopback and veth. This allows the admin/user to set a GSO limit up to this value, to use BIG TCP for traffic routed through the internal port. Only the capability limit changes: the IPv4 and IPv6 GSO and GRO limits remain at 64 KiB until changed by the administrator. Validation used a same-host test with a temporary OVS bridge, a veth pair, and a network namespace: TCP client -> OVS internal -> OVS bridge -> veth -> TCP server The veth endpoints were BIG TCP capable throughout the test, and only the OVS internal port limits changed between 64 KiB and 524280 bytes. A single iperf3 3.19 TCP flow, run separately over IPv4 and IPv6 with six alternating runs per state (`-t 15 -O 5`, fixed CPU affinity and port tuple), increased throughput by 18.1% for IPv4 and 34.7% for IPv6: protocol BIG TCP off BIG TCP on CV off / on TCP/IPv4 65.567 Gbps 77.420 Gbps 1.12% / 0.37% TCP/IPv6 55.355 Gbps 74.568 Gbps 1.20% / 0.68% Assisted-by: LLM Signed-off-by: Wang Zhan Reviewed-by: Ilya Maximets Reviewed-by: Eelco Chaudron Link: https://patch.msgid.link/20260916065844.1380155-1-wang.zhan@smartx.com Signed-off-by: Paolo Abeni --- net/openvswitch/vport-internal_dev.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/openvswitch/vport-internal_dev.c b/net/openvswitch/vport-internal_dev.c index 125d310871e9..77a16d5ebd54 100644 --- a/net/openvswitch/vport-internal_dev.c +++ b/net/openvswitch/vport-internal_dev.c @@ -117,6 +117,8 @@ static void do_setup(struct net_device *netdev) netdev->features |= NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX; netdev->hw_features = netdev->features; + netif_set_tso_max_size(netdev, GSO_MAX_SIZE); + eth_hw_addr_random(netdev); }