Re: [PATCH net-next] tun: Implement ethtool's get_channels() callback

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

Yunjian Wang wrote:
> Implement the tun .get_channels functionality. This feature is necessary
> for some tools, such as libxdp, which need to retrieve the queue count.
> 
> Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
> ---
>  drivers/net/tun.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index afa5497f7c35..7cf448ff93ee 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -3638,12 +3638,22 @@ static int tun_set_coalesce(struct net_device *dev,
>  	return 0;
>  }
>  
> +static void tun_get_channels(struct net_device *dev,
> +			     struct ethtool_channels *channels)
> +{
> +	struct tun_struct *tun = netdev_priv(dev);
> +
> +	channels->combined_count = tun->numqueues;
> +	channels->max_combined = MAX_TAP_QUEUES;

Conditional on IFF_MULTI_QUEUE?

> +}
> +
>  static const struct ethtool_ops tun_ethtool_ops = {
>  	.supported_coalesce_params = ETHTOOL_COALESCE_RX_MAX_FRAMES,
>  	.get_drvinfo	= tun_get_drvinfo,
>  	.get_msglevel	= tun_get_msglevel,
>  	.set_msglevel	= tun_set_msglevel,
>  	.get_link	= ethtool_op_get_link,
> +	.get_channels   = tun_get_channels,
>  	.get_ts_info	= ethtool_op_get_ts_info,
>  	.get_coalesce   = tun_get_coalesce,
>  	.set_coalesce   = tun_set_coalesce,
> -- 
> 2.33.0
>