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From: Larysa Zaremba <larysa.zaremba@intel.com>
To: John Fastabend <john.fastabend@gmail.com>
Cc: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net,
	andrii@kernel.org, martin.lau@linux.dev, song@kernel.org,
	yhs@fb.com, kpsingh@kernel.org, sdf@google.com,
	haoluo@google.com, jolsa@kernel.org,
	David Ahern <dsahern@gmail.com>, Jakub Kicinski <kuba@kernel.org>,
	Willem de Bruijn <willemb@google.com>,
	Jesper Dangaard Brouer <brouer@redhat.com>,
	Anatoly Burakov <anatoly.burakov@intel.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
Subject: [xdp-hints] Re: [PATCH bpf-next v2 09/20] xdp: Add VLAN tag hint
Date: Tue, 4 Jul 2023 10:23:05 +0200	[thread overview]
Message-ID: <ZKPW6azl0Ak27wSO@lincoln> (raw)
In-Reply-To: <64a32c661648e_628d32085f@john.notmuch>

On Mon, Jul 03, 2023 at 01:15:34PM -0700, John Fastabend wrote:
> Larysa Zaremba wrote:
> > Implement functionality that enables drivers to expose VLAN tag
> > to XDP code.
> > 
> > Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
> > ---
> >  Documentation/networking/xdp-rx-metadata.rst |  8 +++++++-
> >  include/linux/netdevice.h                    |  2 ++
> >  include/net/xdp.h                            |  2 ++
> >  kernel/bpf/offload.c                         |  2 ++
> >  net/core/xdp.c                               | 20 ++++++++++++++++++++
> >  5 files changed, 33 insertions(+), 1 deletion(-)
> > 
> > diff --git a/Documentation/networking/xdp-rx-metadata.rst b/Documentation/networking/xdp-rx-metadata.rst
> > index 25ce72af81c2..ea6dd79a21d3 100644
> > --- a/Documentation/networking/xdp-rx-metadata.rst
> > +++ b/Documentation/networking/xdp-rx-metadata.rst
> > @@ -18,7 +18,13 @@ 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_vlan_tag
> >  
> >  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 b828c7a75be2..4fa4380e6d89 100644
> > --- a/include/linux/netdevice.h
> > +++ b/include/linux/netdevice.h
> > @@ -1658,6 +1658,8 @@ 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_vlan_tag)(const struct xdp_md *ctx, u16 *vlan_tag,
> > +				   __be16 *vlan_proto);
> >  };
> >  
> >  /**
> > diff --git a/include/net/xdp.h b/include/net/xdp.h
> > index 6381560efae2..89c58f56ffc6 100644
> > --- a/include/net/xdp.h
> > +++ b/include/net/xdp.h
> > @@ -389,6 +389,8 @@ 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_VLAN_TAG, \
> > +			   bpf_xdp_metadata_rx_vlan_tag) \
> >  
> >  enum {
> >  #define XDP_METADATA_KFUNC(name, _) name,
> > diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
> > index 8a26cd8814c1..986e7becfd42 100644
> > --- a/kernel/bpf/offload.c
> > +++ b/kernel/bpf/offload.c
> > @@ -848,6 +848,8 @@ 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_VLAN_TAG))
> > +		p = ops->xmo_rx_vlan_tag;
> >  out:
> >  	up_read(&bpf_devs_lock);
> >  
> > diff --git a/net/core/xdp.c b/net/core/xdp.c
> > index 41e5ca8643ec..f6262c90e45f 100644
> > --- a/net/core/xdp.c
> > +++ b/net/core/xdp.c
> > @@ -738,6 +738,26 @@ __bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, u32 *hash,
> >  	return -EOPNOTSUPP;
> >  }
> >  
> > +/**
> > + * bpf_xdp_metadata_rx_vlan_tag - Get XDP packet outermost VLAN tag with protocol
> > + * @ctx: XDP context pointer.
> > + * @vlan_tag: Destination pointer for VLAN tag
> > + * @vlan_proto: Destination pointer for VLAN protocol identifier in network byte order.
> > + *
> > + * In case of success, vlan_tag contains VLAN tag, including 12 least significant bytes
> > + * containing VLAN ID, vlan_proto contains protocol identifier.
> 
> Above is a bit confusing to me at least.
> 
> The vlan tag would be both the 16bit TPID and 16bit TCI. What fields
> are to be included here? The VlanID or the full 16bit TCI meaning the
> PCP+DEI+VID?

It contains PCP+DEI+VID, in patch 16 ("selftests/bpf: Add flags and new hints to 
xdp_hw_metadata") this is more clear, because the tag is parsed.

What about rephrasing it this way:

In case of success, vlan_proto contains VLAN protocol identifier (TPID), 
vlan_tag contains the remaining 16 bits of a 802.1Q tag (PCP+DEI+VID).

> I think by "including 12 least significant bytes" you
> mean bits,

Yes, my bad.

> but also not clear about those 4 other bits.
> 
> I can likely figure it out in next patches from implementation but
> would be nice to clean up docs.
> 
> > + *
> > + * Return:
> > + * * Returns 0 on success or ``-errno`` on error.
> > + * * ``-EOPNOTSUPP`` : device driver doesn't implement kfunc
> > + * * ``-ENODATA``    : VLAN tag was not stripped or is not available
> > + */
> > +__bpf_kfunc int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx, u16 *vlan_tag,
> > +					     __be16 *vlan_proto)
> > +{
> > +	return -EOPNOTSUPP;
> > +}
> > +
> >  __diag_pop();
> >  
> >  BTF_SET8_START(xdp_metadata_kfunc_ids)
> > -- 
> > 2.41.0
> > 
> 
> 
> 

  reply	other threads:[~2023-07-04  8:27 UTC|newest]

Thread overview: 66+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-03 18:12 [xdp-hints] [PATCH bpf-next v2 00/20] XDP metadata via kfuncs for ice Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 01/20] ice: make RX hash reading code more reusable Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 02/20] ice: make RX HW timestamp " Larysa Zaremba
2023-07-04 10:04   ` [xdp-hints] " Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 03/20] ice: make RX checksum checking " Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 04/20] ice: Make ptype internal to descriptor info processing Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 05/20] ice: Introduce ice_xdp_buff Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 06/20] ice: Support HW timestamp hint Larysa Zaremba
2023-07-05 17:30   ` [xdp-hints] " Stanislav Fomichev
2023-07-06 14:22     ` Larysa Zaremba
2023-07-06 16:39       ` Stanislav Fomichev
2023-07-10 15:49         ` Larysa Zaremba
2023-07-10 18:12           ` Stanislav Fomichev
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 07/20] ice: Support RX hash XDP hint Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 08/20] ice: Support XDP hints in AF_XDP ZC mode Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 09/20] xdp: Add VLAN tag hint Larysa Zaremba
2023-07-03 20:15   ` [xdp-hints] " John Fastabend
2023-07-04  8:23     ` Larysa Zaremba [this message]
2023-07-04 10:23       ` Jesper Dangaard Brouer
2023-07-04 11:02         ` Larysa Zaremba
2023-07-04 14:18           ` Jesper Dangaard Brouer
2023-07-06 14:46             ` Larysa Zaremba
2023-07-07 13:57               ` Jesper Dangaard Brouer
2023-07-07 17:58                 ` Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 10/20] ice: Implement " Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 11/20] ice: use VLAN proto from ring packet context in skb path Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 12/20] xdp: Add checksum level hint Larysa Zaremba
2023-07-03 20:38   ` [xdp-hints] " John Fastabend
2023-07-04  9:24     ` Larysa Zaremba
2023-07-04 10:39       ` Jesper Dangaard Brouer
2023-07-04 11:19         ` Larysa Zaremba
2023-07-06  5:50           ` John Fastabend
2023-07-06  9:04             ` Jesper Dangaard Brouer
2023-07-06 12:38               ` Larysa Zaremba
2023-07-06 12:49                 ` Larysa Zaremba
2023-07-10 16:58                   ` Alexander Lobakin
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 13/20] ice: Implement " Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 14/20] selftests/bpf: Allow VLAN packets in xdp_hw_metadata Larysa Zaremba
2023-07-05 17:31   ` [xdp-hints] " Stanislav Fomichev
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 15/20] net, xdp: allow metadata > 32 Larysa Zaremba
2023-07-03 21:06   ` [xdp-hints] " John Fastabend
2023-07-06 14:51     ` Larysa Zaremba
2023-07-10 14:01       ` Alexander Lobakin
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 16/20] selftests/bpf: Add flags and new hints to xdp_hw_metadata Larysa Zaremba
2023-07-04 11:03   ` [xdp-hints] " Jesper Dangaard Brouer
2023-07-04 11:04     ` Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 17/20] veth: Implement VLAN tag and checksum level XDP hint Larysa Zaremba
2023-07-05 17:25   ` [xdp-hints] " Stanislav Fomichev
2023-07-06  9:57     ` Jesper Dangaard Brouer
2023-07-06 10:15       ` Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 18/20] selftests/bpf: Use AF_INET for TX in xdp_metadata Larysa Zaremba
2023-07-05 17:39   ` [xdp-hints] " Stanislav Fomichev
2023-07-06 14:11     ` Larysa Zaremba
2023-07-06 17:25       ` Stanislav Fomichev
2023-07-06 17:27       ` Stanislav Fomichev
2023-07-07  8:33         ` Larysa Zaremba
2023-07-07 16:49           ` Stanislav Fomichev
2023-07-07 16:58             ` Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 19/20] selftests/bpf: Check VLAN tag and proto " Larysa Zaremba
2023-07-05 17:41   ` [xdp-hints] " Stanislav Fomichev
2023-07-06 10:10   ` Jesper Dangaard Brouer
2023-07-06 10:13     ` Larysa Zaremba
2023-07-03 18:12 ` [xdp-hints] [PATCH bpf-next v2 20/20] selftests/bpf: check checksum level " Larysa Zaremba
2023-07-05 17:41   ` [xdp-hints] " Stanislav Fomichev
2023-07-06 10:25   ` Jesper Dangaard Brouer
2023-07-06 12:02     ` Larysa Zaremba

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