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From: Stanislav Fomichev <sdf@google.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: "Toke Høiland-Jørgensen" <toke@redhat.com>,
	"Jesper Dangaard Brouer" <jbrouer@redhat.com>,
	bpf@vger.kernel.org, brouer@redhat.com, ast@kernel.org,
	daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev,
	song@kernel.org, yhs@fb.com, john.fastabend@gmail.com,
	kpsingh@kernel.org, haoluo@google.com, jolsa@kernel.org,
	"David Ahern" <dsahern@gmail.com>,
	"Willem de Bruijn" <willemb@google.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 06/11] xdp: Carry over xdp metadata into skb context
Date: Mon, 21 Nov 2022 11:41:19 -0800	[thread overview]
Message-ID: <CAKH8qBuJiLhFy5UqFaXinStfP+jRthkUDXS4KBPUpMiQLP751Q@mail.gmail.com> (raw)
In-Reply-To: <20221121104744.10e1afc8@kernel.org>

On Mon, Nov 21, 2022 at 10:47 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Mon, 21 Nov 2022 09:53:02 -0800 Stanislav Fomichev wrote:
> > > Jakub was objecting to putting it in the UAPI header, but didn't we
> > > already agree that this wasn't necessary?
> > >
> > > I.e., if we just define
> > >
> > > struct xdp_skb_metadata *bpf_xdp_metadata_export_to_skb()
> > >
> > > as a kfunc, the xdp_skb_metadata struct won't appear in any UAPI headers
> > > and will only be accessible via BTF? And we can put the actual data
> > > wherever we choose, since that bit is nicely hidden behind the kfunc,
> > > while the returned pointer still allows programs to access it.
> > >
> > > We could even make that kfunc smart enough that it checks if the field
> > > is already populated and just return the pointer to the existing data
> > > instead of re-populating it int his case (with a flag to override,
> > > maybe?).
> >
> > Even if we only expose it via btf, I think the fact that we still
> > expose a somewhat fixed layout is the problem?
> > I'm not sure the fact that we're not technically putting in the uapi
> > header is the issue here, but maybe I'm wrong?
> > Jakub?
>
> Until the device metadata access from BPF is in bpf-next the only
> opinion I have on this is something along the lines of "not right now".
>
> I may be missing some concerns / perspectives, in which case - when
> is the next "BPF office hours" meeting?

SG! Let's get back to it once we get the basic rx metadata sorted out.
I'll probably look at the tx part next though; that xdp->skb path is
of least priority for me.

  reply	other threads:[~2022-11-21 19:41 UTC|newest]

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-15  3:01 [xdp-hints] [PATCH bpf-next 00/11] xdp: hints via kfuncs Stanislav Fomichev
2022-11-15  3:02 ` [xdp-hints] [PATCH bpf-next 02/11] bpf: Introduce bpf_patch Stanislav Fomichev
2022-11-15  3:02 ` [xdp-hints] [PATCH bpf-next 03/11] bpf: Support inlined/unrolled kfuncs for xdp metadata Stanislav Fomichev
2022-11-15 16:16   ` [xdp-hints] " Toke Høiland-Jørgensen
2022-11-15 18:37     ` Stanislav Fomichev
2022-11-16 20:42   ` Jakub Kicinski
2022-11-16 20:53     ` Stanislav Fomichev
2022-11-15  3:02 ` [xdp-hints] [PATCH bpf-next 05/11] veth: Support rx timestamp metadata for xdp Stanislav Fomichev
2022-11-15 16:17   ` [xdp-hints] " Toke Høiland-Jørgensen
2022-11-15 18:37     ` Stanislav Fomichev
2022-11-15 22:46       ` Toke Høiland-Jørgensen
2022-11-16  4:09         ` Stanislav Fomichev
2022-11-16  6:38           ` John Fastabend
2022-11-16  7:47             ` Martin KaFai Lau
2022-11-16 10:08               ` Toke Høiland-Jørgensen
2022-11-16 18:20                 ` Martin KaFai Lau
2022-11-16 19:03                 ` John Fastabend
2022-11-16 20:50                   ` Stanislav Fomichev
2022-11-16 23:47                     ` John Fastabend
2022-11-17  0:19                       ` Stanislav Fomichev
2022-11-17  2:17                         ` Alexei Starovoitov
2022-11-17  2:53                           ` Stanislav Fomichev
2022-11-17  2:59                             ` Alexei Starovoitov
2022-11-17  4:18                               ` Stanislav Fomichev
2022-11-17  6:55                                 ` John Fastabend
2022-11-17 17:51                                   ` Stanislav Fomichev
2022-11-17 19:47                                     ` John Fastabend
2022-11-17 20:17                                       ` Alexei Starovoitov
2022-11-17 11:32                             ` Toke Høiland-Jørgensen
2022-11-17 16:59                               ` Alexei Starovoitov
2022-11-17 17:52                                 ` Stanislav Fomichev
2022-11-17 23:46                                   ` Toke Høiland-Jørgensen
2022-11-18  0:02                                     ` Alexei Starovoitov
2022-11-18  0:29                                       ` Toke Høiland-Jørgensen
2022-11-17 10:27                       ` Toke Høiland-Jørgensen
2022-11-15  3:02 ` [xdp-hints] [PATCH bpf-next 06/11] xdp: Carry over xdp metadata into skb context Stanislav Fomichev
2022-11-15 23:20   ` [xdp-hints] " Toke Høiland-Jørgensen
2022-11-16  3:49     ` Stanislav Fomichev
2022-11-16  9:30       ` Toke Høiland-Jørgensen
2022-11-16  4:40   ` kernel test robot
2022-11-16  7:04   ` Martin KaFai Lau
2022-11-16  9:48     ` Toke Høiland-Jørgensen
2022-11-16 20:51       ` Stanislav Fomichev
2022-11-16 20:51     ` Stanislav Fomichev
2022-11-16  8:22   ` kernel test robot
2022-11-16  9:03   ` kernel test robot
2022-11-16 13:46   ` kernel test robot
2022-11-16 21:12   ` Jakub Kicinski
2022-11-16 21:49     ` Martin KaFai Lau
2022-11-18 14:05   ` Jesper Dangaard Brouer
2022-11-18 18:18     ` Stanislav Fomichev
2022-11-19 12:31       ` Toke Høiland-Jørgensen
2022-11-21 17:53         ` Stanislav Fomichev
2022-11-21 18:47           ` Jakub Kicinski
2022-11-21 19:41             ` Stanislav Fomichev [this message]
2022-11-15  3:02 ` [xdp-hints] [PATCH bpf-next 07/11] selftests/bpf: Verify xdp_metadata xdp->af_xdp path Stanislav Fomichev
2022-11-15  3:02 ` [xdp-hints] [PATCH bpf-next 08/11] selftests/bpf: Verify xdp_metadata xdp->skb path Stanislav Fomichev
2022-11-15  3:02 ` [xdp-hints] [PATCH bpf-next 09/11] mlx4: Introduce mlx4_xdp_buff wrapper for xdp_buff Stanislav Fomichev
2022-11-15  3:02 ` [xdp-hints] [PATCH bpf-next 10/11] mxl4: Support rx timestamp metadata for xdp Stanislav Fomichev
2022-11-15 15:54 ` [xdp-hints] Re: [PATCH bpf-next 00/11] xdp: hints via kfuncs Toke Høiland-Jørgensen
2022-11-15 18:37   ` Stanislav Fomichev
2022-11-15 22:31     ` Toke Høiland-Jørgensen
2022-11-15 22:54     ` Alexei Starovoitov
2022-11-15 23:13       ` Toke Høiland-Jørgensen

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