XDP hardware hints discussion mail archive
 help / color / mirror / Atom feed
From: Stanislav Fomichev <sdf@google.com>
To: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>,
	bpf@vger.kernel.org, netdev@vger.kernel.org,
	martin.lau@kernel.org, ast@kernel.org, daniel@iogearbox.net,
	alexandr.lobakin@intel.com, larysa.zaremba@intel.com,
	xdp-hints@xdp-project.net
Subject: [xdp-hints] Re: [PATCH bpf-next V2] xdp: bpf_xdp_metadata use NODEV for no device support
Date: Fri, 17 Feb 2023 09:40:44 -0800	[thread overview]
Message-ID: <CAKH8qBujK0RnOHi3EH_KwKamEtQRYJ6izoYRBB2_2CQias0HXA@mail.gmail.com> (raw)
In-Reply-To: <514bb57b-cc3e-7b7e-c7d4-94cdf52565d6@linux.dev>

On Fri, Feb 17, 2023 at 9:39 AM Martin KaFai Lau <martin.lau@linux.dev> wrote:
>
> On 2/17/23 9:32 AM, Stanislav Fomichev wrote:
> > On 02/17, Jesper Dangaard Brouer wrote:
> >> With our XDP-hints kfunc approach, where individual drivers overload the
> >> default implementation, it can be hard for API users to determine
> >> whether or not the current device driver have this kfunc available.
> >
> >> Change the default implementations to use an errno (ENODEV), that
> >> drivers shouldn't return, to make it possible for BPF runtime to
> >> determine if bpf kfunc for xdp metadata isn't implemented by driver.
> >
> >> This is intended to ease supporting and troubleshooting setups. E.g.
> >> when users on mailing list report -19 (ENODEV) as an error, then we can
> >> immediately tell them their device driver is too old.
> >
> > I agree with the v1 comments that I'm not sure how it helps.
> > Why can't we update the doc in the same fashion and say that
> > the drivers shouldn't return EOPNOTSUPP?
> >
> > I'm fine with the change if you think it makes your/users life
> > easier. Although I don't really understand how. We can, as Toke
> > mentioned, ask the users to provide jited program dump if it's
> > mostly about user reports.
>
> and there is xdp-features also.

Yeah, I was going to suggest it, but then I wasn't sure how to
reconcile our 'kfunc is not a uapi' with xdp-features (that probably
is a uapi)?

  reply	other threads:[~2023-02-17 17:40 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-17 12:11 [xdp-hints] " Jesper Dangaard Brouer
2023-02-17 17:32 ` [xdp-hints] " Stanislav Fomichev
2023-02-17 17:38   ` Martin KaFai Lau
2023-02-17 17:40     ` Stanislav Fomichev [this message]
2023-02-17 17:55       ` Martin KaFai Lau
2023-02-17 18:01         ` Stanislav Fomichev
2023-02-17 20:49           ` Toke Høiland-Jørgensen
2023-02-18 14:01             ` Jesper Dangaard Brouer

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://lists.xdp-project.net/postorius/lists/xdp-hints.xdp-project.net/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CAKH8qBujK0RnOHi3EH_KwKamEtQRYJ6izoYRBB2_2CQias0HXA@mail.gmail.com \
    --to=sdf@google.com \
    --cc=alexandr.lobakin@intel.com \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=brouer@redhat.com \
    --cc=daniel@iogearbox.net \
    --cc=larysa.zaremba@intel.com \
    --cc=martin.lau@kernel.org \
    --cc=martin.lau@linux.dev \
    --cc=netdev@vger.kernel.org \
    --cc=xdp-hints@xdp-project.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox