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Date:   Fri, 12 May 2023 11:28:44 -0700
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Subject: Re: [PATCH RESEND bpf-next 09/15] xdp: Add VLAN tag hint
From:   Stanislav Fomichev <sdf@google.com>
To:     Larysa Zaremba <larysa.zaremba@intel.com>
Cc:     bpf@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Jakub Kicinski <kuba@kernel.org>,
        Martin KaFai Lau <martin.lau@linux.dev>,
        Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>, Jiri Olsa <jolsa@kernel.org>,
        Jesse Brandeburg <jesse.brandeburg@intel.com>,
        Tony Nguyen <anthony.l.nguyen@intel.com>,
        Anatoly Burakov <anatoly.burakov@intel.com>,
        Jesper Dangaard Brouer <brouer@redhat.com>,
        Alexander Lobakin <alexandr.lobakin@intel.com>,
        Magnus Karlsson <magnus.karlsson@gmail.com>,
        Maryam Tahhan <mtahhan@redhat.com>, xdp-hints@xdp-project.net,
        netdev@vger.kernel.org, intel-wired-lan@lists.osuosl.org,
        linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="utf-8"
Precedence: bulk

On 05/12, Larysa Zaremba wrote:
> Implement functionality that enables drivers to expose VLAN tag
> to XDP code.
> 
> Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>

Acked-by: Stanislav Fomichev <sdf@google.com>

> ---
>  Documentation/networking/xdp-rx-metadata.rst | 11 ++++++++-
>  include/linux/netdevice.h                    |  2 ++
>  include/net/xdp.h                            |  4 ++++
>  kernel/bpf/offload.c                         |  4 ++++
>  net/core/xdp.c                               | 24 ++++++++++++++++++++
>  5 files changed, 44 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/networking/xdp-rx-metadata.rst b/Documentation/networking/xdp-rx-metadata.rst
> index 25ce72af81c2..73a78029c596 100644
> --- a/Documentation/networking/xdp-rx-metadata.rst
> +++ b/Documentation/networking/xdp-rx-metadata.rst
> @@ -18,7 +18,16 @@ Currently, the following kfuncs are supported. In the future, as more
>  metadata is supported, this set will grow:
>  
>  .. kernel-doc:: net/core/xdp.c
> -   :identifiers: bpf_xdp_metadata_rx_timestamp bpf_xdp_metadata_rx_hash
> +   :identifiers: bpf_xdp_metadata_rx_timestamp
> +
> +.. kernel-doc:: net/core/xdp.c
> +   :identifiers: bpf_xdp_metadata_rx_hash
> +
> +.. kernel-doc:: net/core/xdp.c
> +   :identifiers: bpf_xdp_metadata_rx_ctag
> +
> +.. kernel-doc:: net/core/xdp.c
> +   :identifiers: bpf_xdp_metadata_rx_stag
>  
>  An XDP program can use these kfuncs to read the metadata into stack
>  variables for its own consumption. Or, to pass the metadata on to other
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 08fbd4622ccf..fdae37fe11f5 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -1655,6 +1655,8 @@ struct xdp_metadata_ops {
>  	int	(*xmo_rx_timestamp)(const struct xdp_md *ctx, u64 *timestamp);
>  	int	(*xmo_rx_hash)(const struct xdp_md *ctx, u32 *hash,
>  			       enum xdp_rss_hash_type *rss_type);
> +	int	(*xmo_rx_ctag)(const struct xdp_md *ctx, u16 *vlan_tag);
> +	int	(*xmo_rx_stag)(const struct xdp_md *ctx, u16 *vlan_tag);
>  };
>  
>  /**
> diff --git a/include/net/xdp.h b/include/net/xdp.h
> index 6381560efae2..2db7439fc60f 100644
> --- a/include/net/xdp.h
> +++ b/include/net/xdp.h
> @@ -389,6 +389,10 @@ void xdp_attachment_setup(struct xdp_attachment_info *info,
>  			   bpf_xdp_metadata_rx_timestamp) \
>  	XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_HASH, \
>  			   bpf_xdp_metadata_rx_hash) \
> +	XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_CTAG, \
> +			   bpf_xdp_metadata_rx_ctag) \
> +	XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_STAG, \
> +			   bpf_xdp_metadata_rx_stag) \
>  
>  enum {
>  #define XDP_METADATA_KFUNC(name, _) name,
> diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
> index d9c9f45e3529..2c6b6e82cfac 100644
> --- a/kernel/bpf/offload.c
> +++ b/kernel/bpf/offload.c
> @@ -848,6 +848,10 @@ void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id)
>  		p = ops->xmo_rx_timestamp;
>  	else if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_HASH))
>  		p = ops->xmo_rx_hash;
> +	else if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_CTAG))
> +		p = ops->xmo_rx_ctag;
> +	else if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_STAG))
> +		p = ops->xmo_rx_stag;
>  out:
>  	up_read(&bpf_devs_lock);
>  
> diff --git a/net/core/xdp.c b/net/core/xdp.c
> index 41e5ca8643ec..eff21501609f 100644
> --- a/net/core/xdp.c
> +++ b/net/core/xdp.c
> @@ -738,6 +738,30 @@ __bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, u32 *hash,
>  	return -EOPNOTSUPP;
>  }
>  
> +/**
> + * bpf_xdp_metadata_rx_ctag - Read XDP packet inner vlan tag.
> + * @ctx: XDP context pointer.
> + * @vlan_tag: Return value pointer.
> + *
> + * Returns 0 on success or ``-errno`` on error.
> + */
> +__bpf_kfunc int bpf_xdp_metadata_rx_ctag(const struct xdp_md *ctx, u16 *vlan_tag)
> +{
> +	return -EOPNOTSUPP;
> +}
> +
> +/**
> + * bpf_xdp_metadata_rx_stag - Read XDP packet outer vlan tag.
> + * @ctx: XDP context pointer.
> + * @vlan_tag: Return value pointer.
> + *
> + * Returns 0 on success or ``-errno`` on error.
> + */
> +__bpf_kfunc int bpf_xdp_metadata_rx_stag(const struct xdp_md *ctx, u16 *vlan_tag)
> +{
> +	return -EOPNOTSUPP;
> +}
> +
>  __diag_pop();
>  
>  BTF_SET8_START(xdp_metadata_kfunc_ids)
> -- 
> 2.35.3
>