Re: [PATCH net 3/5] bonding: Fix feature propagation of NETIF_F_GSO_ENCAP_ALL

[Hangbin Liu <liuhangbin@gmail.com>]

On Tue, Dec 10, 2024 at 03:12:43PM +0100, Daniel Borkmann wrote:
> Drivers like mlx5 expose NIC's vlan_features such as
> NETIF_F_GSO_UDP_TUNNEL & NETIF_F_GSO_UDP_TUNNEL_CSUM which are
> later not propagated when the underlying devices are bonded and
> a vlan device created on top of the bond.
> 
> Right now, the more cumbersome workaround for this is to create
> the vlan on top of the mlx5 and then enslave the vlan devices
> to a bond.
> 
> To fix this, add NETIF_F_GSO_ENCAP_ALL to BOND_VLAN_FEATURES
> such that bond_compute_features() can probe and propagate the
> vlan_features from the slave devices up to the vlan device.
> 
> Given the following bond:
> 
>   # ethtool -i enp2s0f{0,1}np{0,1}
>   driver: mlx5_core
>   [...]
> 
>   # ethtool -k enp2s0f0np0 | grep udp
>   tx-udp_tnl-segmentation: on
>   tx-udp_tnl-csum-segmentation: on
>   tx-udp-segmentation: on
>   rx-udp_tunnel-port-offload: on
>   rx-udp-gro-forwarding: off
> 
>   # ethtool -k enp2s0f1np1 | grep udp
>   tx-udp_tnl-segmentation: on
>   tx-udp_tnl-csum-segmentation: on
>   tx-udp-segmentation: on
>   rx-udp_tunnel-port-offload: on
>   rx-udp-gro-forwarding: off
> 
>   # ethtool -k bond0 | grep udp
>   tx-udp_tnl-segmentation: on
>   tx-udp_tnl-csum-segmentation: on
>   tx-udp-segmentation: on
>   rx-udp_tunnel-port-offload: off [fixed]
>   rx-udp-gro-forwarding: off
> 
> Before:
> 
>   # ethtool -k bond0.100 | grep udp
>   tx-udp_tnl-segmentation: off [requested on]
>   tx-udp_tnl-csum-segmentation: off [requested on]
>   tx-udp-segmentation: on
>   rx-udp_tunnel-port-offload: off [fixed]
>   rx-udp-gro-forwarding: off
> 
> After:
> 
>   # ethtool -k bond0.100 | grep udp
>   tx-udp_tnl-segmentation: on
>   tx-udp_tnl-csum-segmentation: on
>   tx-udp-segmentation: on
>   rx-udp_tunnel-port-offload: off [fixed]
>   rx-udp-gro-forwarding: off
> 
> Various users have run into this reporting performance issues when
> configuring Cilium in vxlan tunneling mode and having the combination
> of bond & vlan for the core devices connecting the Kubernetes cluster
> to the outside world.
> 
> Fixes: a9b3ace44c7d ("bonding: fix vlan_features computing")
> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Nikolay Aleksandrov <razor@blackwall.org>
> Cc: Ido Schimmel <idosch@idosch.org>
> Cc: Jiri Pirko <jiri@nvidia.com>
> ---
>  drivers/net/bonding/bond_main.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 320dd71392ef..7b78c2bada81 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -1534,6 +1534,7 @@ static netdev_features_t bond_fix_features(struct net_device *dev,
>  
>  #define BOND_VLAN_FEATURES	(NETIF_F_HW_CSUM | NETIF_F_SG | \
>  				 NETIF_F_FRAGLIST | NETIF_F_GSO_SOFTWARE | \
> +				 NETIF_F_GSO_ENCAP_ALL | \
>  				 NETIF_F_HIGHDMA | NETIF_F_LRO)
>  
>  #define BOND_ENC_FEATURES	(NETIF_F_HW_CSUM | NETIF_F_SG | \
> -- 
> 2.43.0
> 
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>