Re: [PATCH net-next v2 01/14] bpf: Introduce per-packet metadata storage for BPF programs

[Jiayuan Chen <jiayuan.chen@linux.dev>]

> diff --git a/net/Kconfig b/net/Kconfig
> index e38477393551..6d57320dfea3 100644
> --- a/net/Kconfig
> +++ b/net/Kconfig
> @@ -540,4 +540,24 @@ config NET_TEST
>   
>   	  If unsure, say N.
>   
> +config BPF_SKB_EXT
> +	bool "skb extension for BPF metadata"
> +	depends on BPF_SYSCALL
> +	select SKB_EXTENSIONS
> +	help
> +	  Enable an sk_buff extension for storing BPF metadata. This allows BPF
> +	  programs to associate arbitrary data with individual packets as they
> +	  traverse the network stack. The storage is automatically freed when
> +	  the sk_buff is freed.
> +
> +config BPF_SKB_EXT_SIZE
> +	int "Size of the BPF skb extension metadata buffer"
> +	depends on BPF_SKB_EXT
> +	range 1 256
> +	default 64
> +	help
> +	  Configures the size of the inline metadata buffer in struct
> +	  bpf_skb_ext, which is the maximum amount of data a BPF program can
> +	  store or retrieve with bpf_dynptr_from_skb_ext().
> +
>   endif   # if NET



Can we do it like this? So that enabling BPF_SKB_EXT_SIZE only is enough 
and make it easier.


config BPF_SKB_EXT_SIZE
     int "Per-packet BPF metadata in skb, in bytes (0 to disable)"
     depends on BPF_SYSCALL
     range 0 256
     default 0
     help
       Configures the size of the inline metadata buffer in struct
       ....
       The skb extension chunk is sized in units of 8 bytes, so values
       that are not a multiple of 8 just waste the remainder.

config BPF_SKB_EXT
     def_bool BPF_SKB_EXT_SIZE != 0
     select SKB_EXTENSIONS
     help
       xxx