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

From: Larysa Zaremba <[email-masked]>
Date: Tue, 22 Aug 2023 11:07:06 +0200

On Thu, Aug 17, 2023 at 02:58:26PM -0700, Alexei Starovoitov wrote:
> 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 <[email-masked]>
> > ---
> >  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.

I have no other vendors on my current setup :/

I could send an RFC of v5 + a compile-tested implementation for some other 
vendor, so you can see, how it might look.

What do you think?