Re: [PATCH net] bonding: do not report NETDEV_XDP_ACT_XSK_ZEROCOPY

["Toke Høiland-Jørgensen" <toke@redhat.com>]

Magnus Karlsson <magnus.karlsson@gmail.com> writes:

> From: Magnus Karlsson <magnus.karlsson@intel.com>
>
> Do not report the XDP capability NETDEV_XDP_ACT_XSK_ZEROCOPY as the
> bonding driver does not support XDP and AF_XDP in zero-copy mode even
> if the real NIC drivers do.
>
> Fixes: cb9e6e584d58 ("bonding: add xdp_features support")
> Reported-by: Prashant Batra <prbatra.mail@gmail.com>
> Link: https://lore.kernel.org/all/CAJ8uoz2ieZCopgqTvQ9ZY6xQgTbujmC6XkMTamhp68O-h_-rLg@mail.gmail.com/T/
> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
> ---
>  drivers/net/bonding/bond_main.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 4e0600c7b050..79a37bed097b 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -1819,6 +1819,8 @@ void bond_xdp_set_features(struct net_device *bond_dev)
>  	bond_for_each_slave(bond, slave, iter)
>  		val &= slave->dev->xdp_features;
>  
> +	val &= ~NETDEV_XDP_ACT_XSK_ZEROCOPY;
> +
>  	xdp_set_features_flag(bond_dev, val);
>  }
>  
> @@ -5910,8 +5912,10 @@ void bond_setup(struct net_device *bond_dev)
>  		bond_dev->features |= BOND_XFRM_FEATURES;
>  #endif /* CONFIG_XFRM_OFFLOAD */
>  
> -	if (bond_xdp_check(bond))
> +	if (bond_xdp_check(bond)) {
>  		bond_dev->xdp_features = NETDEV_XDP_ACT_MASK;
> +		bond_dev->xdp_features &= ~NETDEV_XDP_ACT_XSK_ZEROCOPY;
> +	}

Shouldn't we rather drop this assignment completely? It makes no sense
to default to all features, it should default to none...

-Toke