Re: [PATCH net] veth: Update XDP feature set when bringing up device

[Paolo Abeni <pabeni@redhat.com>]

Hi,

On Mon, 2023-09-11 at 15:58 +0200, Toke Høiland-Jørgensen wrote:
> There's an early return in veth_set_features() if the device is in a down
> state, which leads to the XDP feature flags not being updated when enabling
> GRO while the device is down. Which in turn leads to XDP_REDIRECT not
> working, because the redirect code now checks the flags.
> 
> Fix this by updating the feature flags after bringing the device up.
> 
> Before this patch:
> 
> NETDEV_XDP_ACT_BASIC:		yes
> NETDEV_XDP_ACT_REDIRECT:	yes
> NETDEV_XDP_ACT_NDO_XMIT:	no
> NETDEV_XDP_ACT_XSK_ZEROCOPY:	no
> NETDEV_XDP_ACT_HW_OFFLOAD:	no
> NETDEV_XDP_ACT_RX_SG:		yes
> NETDEV_XDP_ACT_NDO_XMIT_SG:	no
> 
> After this patch:
> 
> NETDEV_XDP_ACT_BASIC:		yes
> NETDEV_XDP_ACT_REDIRECT:	yes
> NETDEV_XDP_ACT_NDO_XMIT:	yes
> NETDEV_XDP_ACT_XSK_ZEROCOPY:	no
> NETDEV_XDP_ACT_HW_OFFLOAD:	no
> NETDEV_XDP_ACT_RX_SG:		yes
> NETDEV_XDP_ACT_NDO_XMIT_SG:	yes
> 
> Fixes: fccca038f300 ("veth: take into account device reconfiguration for xdp_features flag")
> Fixes: 66c0e13ad236 ("drivers: net: turn on XDP features")
> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
> ---
>  drivers/net/veth.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/veth.c b/drivers/net/veth.c
> index 9c6f4f83f22b..0deefd1573cf 100644
> --- a/drivers/net/veth.c
> +++ b/drivers/net/veth.c
> @@ -1446,6 +1446,8 @@ static int veth_open(struct net_device *dev)
>  		netif_carrier_on(peer);
>  	}
>  
> +	veth_set_xdp_features(dev);
> +
>  	return 0;
>  }

The patch LGTM, thanks!

I think it would be nice to add some specific self-tests here. Could
you please consider following-up with them?

Thanks,

Paolo