| From 5f4aefe233b6b2553fab7dfdfd441c026a04377a Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Wed, 13 Mar 2024 19:37:58 +0100 |
| Subject: net: veth: do not manipulate GRO when using XDP |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| From: Ignat Korchagin <ignat@cloudflare.com> |
| |
| [ Upstream commit d7db7775ea2e31502d46427f5efd385afc4ff1eb ] |
| |
| Commit d3256efd8e8b ("veth: allow enabling NAPI even without XDP") tried to fix |
| the fact that GRO was not possible without XDP, because veth did not use NAPI |
| without XDP. However, it also introduced the behaviour that GRO is always |
| enabled, when XDP is enabled. |
| |
| While it might be desired for most cases, it is confusing for the user at best |
| as the GRO flag suddenly changes, when an XDP program is attached. It also |
| introduces some complexities in state management as was partially addressed in |
| commit fe9f801355f0 ("net: veth: clear GRO when clearing XDP even when down"). |
| |
| But the biggest problem is that it is not possible to disable GRO at all, when |
| an XDP program is attached, which might be needed for some use cases. |
| |
| Fix this by not touching the GRO flag on XDP enable/disable as the code already |
| supports switching to NAPI if either GRO or XDP is requested. |
| |
| Link: https://lore.kernel.org/lkml/20240311124015.38106-1-ignat@cloudflare.com/ |
| Fixes: d3256efd8e8b ("veth: allow enabling NAPI even without XDP") |
| Fixes: fe9f801355f0 ("net: veth: clear GRO when clearing XDP even when down") |
| Signed-off-by: Ignat Korchagin <ignat@cloudflare.com> |
| Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/net/veth.c | 18 ------------------ |
| 1 file changed, 18 deletions(-) |
| |
| diff --git a/drivers/net/veth.c b/drivers/net/veth.c |
| index a2e80278eb2f9..2f3fd287378fd 100644 |
| --- a/drivers/net/veth.c |
| +++ b/drivers/net/veth.c |
| @@ -1533,8 +1533,6 @@ static netdev_features_t veth_fix_features(struct net_device *dev, |
| if (peer_priv->_xdp_prog) |
| features &= ~NETIF_F_GSO_SOFTWARE; |
| } |
| - if (priv->_xdp_prog) |
| - features |= NETIF_F_GRO; |
| |
| return features; |
| } |
| @@ -1638,14 +1636,6 @@ static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog, |
| } |
| |
| if (!old_prog) { |
| - if (!veth_gro_requested(dev)) { |
| - /* user-space did not require GRO, but adding |
| - * XDP is supposed to get GRO working |
| - */ |
| - dev->features |= NETIF_F_GRO; |
| - netdev_features_change(dev); |
| - } |
| - |
| peer->hw_features &= ~NETIF_F_GSO_SOFTWARE; |
| peer->max_mtu = max_mtu; |
| } |
| @@ -1661,14 +1651,6 @@ static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog, |
| if (dev->flags & IFF_UP) |
| veth_disable_xdp(dev); |
| |
| - /* if user-space did not require GRO, since adding XDP |
| - * enabled it, clear it now |
| - */ |
| - if (!veth_gro_requested(dev)) { |
| - dev->features &= ~NETIF_F_GRO; |
| - netdev_features_change(dev); |
| - } |
| - |
| if (peer) { |
| peer->hw_features |= NETIF_F_GSO_SOFTWARE; |
| peer->max_mtu = ETH_MAX_MTU; |
| -- |
| 2.43.0 |
| |
