Subject: Re: [PATCH v2 bpf-next 13/22] xsk: report ZC multi-buffer capability via xdp_features

From: Simon Horman <[email-masked]>
Date: Tue, 30 May 2023 13:55:45 +0200

On Mon, May 29, 2023 at 05:50:15PM +0200, Maciej Fijalkowski wrote:
> Introduce new xdp_feature NETDEV_XDP_ACT_NDO_ZC_SG that will be used to
> find out if user space that wants to do ZC multi-buffer will be able to
> do so against underlying ZC driver.
> 
> Signed-off-by: Maciej Fijalkowski <[email-masked]>
> ---
>  include/uapi/linux/netdev.h | 4 ++--
>  net/xdp/xsk_buff_pool.c     | 6 ++++++
>  2 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
> index 639524b59930..bfca07224f7b 100644
> --- a/include/uapi/linux/netdev.h
> +++ b/include/uapi/linux/netdev.h
> @@ -33,8 +33,8 @@ enum netdev_xdp_act {
>  	NETDEV_XDP_ACT_HW_OFFLOAD = 16,
>  	NETDEV_XDP_ACT_RX_SG = 32,
>  	NETDEV_XDP_ACT_NDO_XMIT_SG = 64,
> -
> -	NETDEV_XDP_ACT_MASK = 127,
> +	NETDEV_XDP_ACT_NDO_ZC_SG = 128,

Hi Maciej,

Please consider adding NETDEV_XDP_ACT_NDO_ZC_SG to the Kernel doc
a just above netdev_xdp_act.

> +	NETDEV_XDP_ACT_MASK = 255,
>  };
>  
>  enum {

...