Re: [RFC net-next 2/9] xdp: add XDP_FLAGS_GRO_DISABLED flag

[Alexander Lobakin <aleksander.lobakin@intel.com>]

From: Yan Zhai <yan@cloudflare.com>
Date: Thu, 20 Jun 2024 15:19:13 -0700

> Allow XDP program to set XDP_FLAGS_GRO_DISABLED flag in xdp_buff and
> xdp_frame, and disable GRO when building an sk_buff if this flag is set.
> 
> Signed-off-by: Yan Zhai <yan@cloudflare.com>
> ---
>  include/net/xdp.h | 38 +++++++++++++++++++++++++++++++++++++-
>  1 file changed, 37 insertions(+), 1 deletion(-)
> 
> diff --git a/include/net/xdp.h b/include/net/xdp.h
> index e6770dd40c91..cc3bce8817b0 100644
> --- a/include/net/xdp.h
> +++ b/include/net/xdp.h
> @@ -75,6 +75,7 @@ enum xdp_buff_flags {
>  	XDP_FLAGS_FRAGS_PF_MEMALLOC	= BIT(1), /* xdp paged memory is under
>  						   * pressure
>  						   */
> +	XDP_FLAGS_GRO_DISABLED          = BIT(2), /* GRO disabled */

There should be tabs, not spaces.

>  };
>  
>  struct xdp_buff {
> @@ -113,12 +114,35 @@ static __always_inline void xdp_buff_set_frag_pfmemalloc(struct xdp_buff *xdp)
>  	xdp->flags |= XDP_FLAGS_FRAGS_PF_MEMALLOC;
>  }
>  
> +static __always_inline void xdp_buff_disable_gro(struct xdp_buff *xdp)
> +{
> +	xdp->flags |= XDP_FLAGS_GRO_DISABLED;
> +}
> +
> +static __always_inline bool xdp_buff_gro_disabled(struct xdp_buff *xdp)
> +{
> +	return !!(xdp->flags & XDP_FLAGS_GRO_DISABLED);
> +}
> +
> +static __always_inline void
> +xdp_buff_fixup_skb_offloading(struct xdp_buff *xdp, struct sk_buff *skb)
> +{
> +	if (xdp_buff_gro_disabled(xdp))
> +		skb_disable_gro(skb);
> +}

I don't think this should be named "fixup". "propagate", "update",
"promote", ...?

Maybe `if` is not needed here?

	skb->gro_disabled = xdp_buff_gro_disabled(xdp)

?

> +
> +static __always_inline void
> +xdp_init_buff_minimal(struct xdp_buff *xdp)
> +{
> +	xdp->flags = 0;
> +}

"xdp_buff_clear_flags"?

> +
>  static __always_inline void
>  xdp_init_buff(struct xdp_buff *xdp, u32 frame_sz, struct xdp_rxq_info *rxq)
>  {
>  	xdp->frame_sz = frame_sz;
>  	xdp->rxq = rxq;
> -	xdp->flags = 0;
> +	xdp_init_buff_minimal(xdp);
>  }
>  
>  static __always_inline void
> @@ -187,6 +211,18 @@ static __always_inline bool xdp_frame_is_frag_pfmemalloc(struct xdp_frame *frame
>  	return !!(frame->flags & XDP_FLAGS_FRAGS_PF_MEMALLOC);
>  }
>  
> +static __always_inline bool xdp_frame_gro_disabled(struct xdp_frame *frame)
> +{
> +	return !!(frame->flags & XDP_FLAGS_GRO_DISABLED);
> +}
> +
> +static __always_inline void
> +xdp_frame_fixup_skb_offloading(struct xdp_frame *frame, struct sk_buff *skb)
> +{
> +	if (xdp_frame_gro_disabled(frame))
> +		skb_disable_gro(skb);
> +}

(same)

> +
>  #define XDP_BULK_QUEUE_SIZE	16
>  struct xdp_frame_bulk {
>  	int count;

Thanks,
Olek