[xdp-hints] Re: [PATCH bpf-next v5 13/21] ice: Implement checksum hint

[Alexei Starovoitov <alexei.starovoitov@gmail.com>]

On Fri, Aug 11, 2023 at 06:15:01PM +0200, Larysa Zaremba wrote:
> Implement .xmo_rx_csum callback to allow XDP code to determine,
> whether HW has validated any checksums.
> 
> Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_txrx_lib.c | 26 +++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
> index 6ae57a98a4d8..f11a245705bc 100644
> --- a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
> +++ b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c
> @@ -660,8 +660,34 @@ static int ice_xdp_rx_vlan_tag(const struct xdp_md *ctx, u16 *vlan_tci,
>  	return 0;
>  }
>  
> +/**
> + * ice_xdp_rx_csum - RX checksum XDP hint handler
> + * @ctx: XDP buff pointer
> + * @csum_status: status destination address
> + * @csum: not used
> + */
> +static int ice_xdp_rx_csum(const struct xdp_md *ctx,
> +			   enum xdp_csum_status *csum_status, __wsum *csum)
> +{
> +	const struct ice_xdp_buff *xdp_ext = (void *)ctx;
> +	const union ice_32b_rx_flex_desc *eop_desc;
> +	enum ice_rx_csum_status status;
> +	u16 ptype;
> +
> +	eop_desc = xdp_ext->pkt_ctx.eop_desc;
> +	ptype = ice_get_ptype(eop_desc);
> +
> +	status = ice_get_rx_csum_status(eop_desc, ptype);
> +	if (status & ICE_RX_CSUM_FAIL)
> +		return -ENODATA;
> +
> +	*csum_status = XDP_CHECKSUM_VERIFIED;
> +	return 0;
> +}
> +
>  const struct xdp_metadata_ops ice_xdp_md_ops = {
>  	.xmo_rx_timestamp		= ice_xdp_rx_hw_ts,
>  	.xmo_rx_hash			= ice_xdp_rx_hash,
>  	.xmo_rx_vlan_tag		= ice_xdp_rx_vlan_tag,
> +	.xmo_rx_csum			= ice_xdp_rx_csum,

timestamp hint is implemented by igc, mlx4, mlx5, stmmac
hash hint is implemneted by igc, mlx4, mlx5.
With above csum and vlan hints will be in ice only.
I'd like to see at least one more driver to implement them as well to make sure
the proposed API works for other vendors.