All of lore.kernel.org
 help / color / mirror / Atom feed
From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: "Lorenzo Bianconi" <lorenzo@kernel.org>,
	bpf <bpf@vger.kernel.org>,
	"Network Development" <netdev@vger.kernel.org>,
	"Lorenzo Bianconi" <lorenzo.bianconi@redhat.com>,
	"David S. Miller" <davem@davemloft.net>,
	"Alexei Starovoitov" <ast@kernel.org>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	shayagr@amazon.com, "John Fastabend" <john.fastabend@gmail.com>,
	"David Ahern" <dsahern@kernel.org>,
	"Jesper Dangaard Brouer" <brouer@redhat.com>,
	"Eelco Chaudron" <echaudro@redhat.com>,
	"Jason Wang" <jasowang@redhat.com>,
	"Alexander Duyck" <alexander.duyck@gmail.com>,
	"Saeed Mahameed" <saeed@kernel.org>,
	"Fijalkowski, Maciej" <maciej.fijalkowski@intel.com>,
	"Karlsson, Magnus" <magnus.karlsson@intel.com>,
	tirthendu.sarkar@intel.com,
	"Toke Høiland-Jørgensen" <toke@redhat.com>
Subject: Re: [PATCH v14 bpf-next 00/18] mvneta: introduce XDP multi-buffer support
Date: Fri, 17 Sep 2021 12:10:34 -0700	[thread overview]
Message-ID: <CAADnVQKbrkOxfNoixUx-RLJEWULJLyhqjZ=M_X2cFG_APwNyCg@mail.gmail.com> (raw)
In-Reply-To: <20210917120053.1ec617c2@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>

On Fri, Sep 17, 2021 at 12:00 PM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Fri, 17 Sep 2021 11:43:07 -0700 Alexei Starovoitov wrote:
> > > If bpf_xdp_load_bytes() / bpf_xdp_store_bytes() works for most we
> > > can start with that. In all honesty I don't know what the exact
> > > use cases for looking at data are, either. I'm primarily worried
> > > about exposing the kernel internals too early.
> >
> > I don't mind the xdp equivalent of skb_load_bytes,
> > but skb_header_pointer() idea is superior.
> > When we did xdp with data/data_end there was no refine_retval_range
> > concept in the verifier (iirc or we just missed that opportunity).
> > We'd need something more advanced: a pointer with valid range
> > refined by input argument 'len' or NULL.
> > The verifier doesn't have such thing yet, but it fits as a combination of
> > value_or_null plus refine_retval_range.
> > The bpf_xdp_header_pointer() and bpf_skb_header_pointer()
> > would probably simplify bpf programs as well.
> > There would be no need to deal with data/data_end.
>
> What are your thoughts on inlining? Can we inline the common case
> of the header being in the "head"? Otherwise data/end comparisons
> would be faster.

Yeah. It can be inlined by the verifier.
It would still look like a call from bpf prog pov with llvm doing spill/fill
of scratched regs, but it's minor.

Also we can use the same bpf_header_pointer(ctx, ...)
helper for both xdp and skb program types. They will have different
implementation underneath, but this might make possible writing bpf
programs that could work in both xdp and skb context.
I believe cilium has fancy macros to achieve that.

  reply	other threads:[~2021-09-17 19:10 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-10 16:14 [PATCH v14 bpf-next 00/18] mvneta: introduce XDP multi-buffer support Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 01/18] net: skbuff: add size metadata to skb_shared_info for xdp Lorenzo Bianconi
2021-09-10 16:18   ` Jesper Dangaard Brouer
2021-09-10 16:14 ` [PATCH v14 bpf-next 02/18] xdp: introduce flags field in xdp_buff/xdp_frame Lorenzo Bianconi
2021-09-10 16:19   ` Jesper Dangaard Brouer
2021-09-10 16:14 ` [PATCH v14 bpf-next 03/18] net: mvneta: update mb bit before passing the xdp buffer to eBPF layer Lorenzo Bianconi
2021-09-20  8:25   ` Shay Agroskin
2021-09-20  8:37     ` Lorenzo Bianconi
2021-09-20  8:45       ` Shay Agroskin
2021-09-20  9:00         ` Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 04/18] net: mvneta: simplify mvneta_swbm_add_rx_fragment management Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 05/18] net: xdp: add xdp_update_skb_shared_info utility routine Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 06/18] net: marvell: rely on " Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 07/18] xdp: add multi-buff support to xdp_return_{buff/frame} Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 08/18] net: mvneta: add multi buffer support to XDP_TX Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 09/18] net: mvneta: enable jumbo frames for XDP Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 10/18] bpf: add multi-buff support to the bpf_xdp_adjust_tail() API Lorenzo Bianconi
2021-09-16 16:55   ` Jakub Kicinski
2021-09-17 10:02     ` Lorenzo Bianconi
2021-09-17 13:03       ` Jakub Kicinski
2021-09-10 16:14 ` [PATCH v14 bpf-next 11/18] bpf: introduce bpf_xdp_get_buff_len helper Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 12/18] bpf: add multi-buffer support to xdp copy helpers Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 13/18] bpf: move user_size out of bpf_test_init Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 14/18] bpf: introduce multibuff support to bpf_prog_test_run_xdp() Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 15/18] bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 16/18] bpf: update xdp_adjust_tail selftest to include multi-buffer Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 17/18] net: xdp: introduce bpf_xdp_adjust_data helper Lorenzo Bianconi
2021-09-10 16:14 ` [PATCH v14 bpf-next 18/18] bpf: add bpf_xdp_adjust_data selftest Lorenzo Bianconi
2021-09-16 16:55 ` [PATCH v14 bpf-next 00/18] mvneta: introduce XDP multi-buffer support Jakub Kicinski
2021-09-17 14:51   ` Lorenzo Bianconi
2021-09-17 18:33     ` Jakub Kicinski
2021-09-17 18:43       ` Alexei Starovoitov
2021-09-17 19:00         ` Jakub Kicinski
2021-09-17 19:10           ` Alexei Starovoitov [this message]
2021-09-17 22:07             ` John Fastabend
2021-09-18 11:53               ` Toke Høiland-Jørgensen
2021-09-20 18:02                 ` Jakub Kicinski
2021-09-20 21:01                   ` Toke Høiland-Jørgensen
2021-09-20 21:25                     ` Jakub Kicinski
2021-09-20 22:44                       ` Toke Høiland-Jørgensen
2021-09-21 10:03                         ` Eelco Chaudron
2021-09-28 11:48                           ` Magnus Karlsson
2021-09-29 10:36                         ` Lorenz Bauer
2021-09-29 12:25                           ` Toke Høiland-Jørgensen
2021-09-29 12:32                             ` Lorenz Bauer
2021-09-29 17:48                             ` Jakub Kicinski
2021-09-29 17:46                           ` Jakub Kicinski
2021-09-29 10:41   ` Lorenz Bauer
2021-09-29 12:10     ` Toke Høiland-Jørgensen
2021-09-29 12:38       ` Lorenz Bauer
2021-09-29 18:54         ` Alexei Starovoitov
2021-09-29 19:22           ` Jakub Kicinski
2021-09-29 20:39             ` Toke Høiland-Jørgensen
2021-10-01  9:03               ` Lorenzo Bianconi
2021-10-01 18:35                 ` Jakub Kicinski
2021-10-06  9:32                   ` Lorenzo Bianconi
2021-10-06 10:08                     ` Eelco Chaudron
2021-10-06 12:15                       ` Lorenzo Bianconi

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

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

  git send-email \
    --in-reply-to='CAADnVQKbrkOxfNoixUx-RLJEWULJLyhqjZ=M_X2cFG_APwNyCg@mail.gmail.com' \
    --to=alexei.starovoitov@gmail.com \
    --cc=alexander.duyck@gmail.com \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=brouer@redhat.com \
    --cc=daniel@iogearbox.net \
    --cc=davem@davemloft.net \
    --cc=dsahern@kernel.org \
    --cc=echaudro@redhat.com \
    --cc=jasowang@redhat.com \
    --cc=john.fastabend@gmail.com \
    --cc=kuba@kernel.org \
    --cc=lorenzo.bianconi@redhat.com \
    --cc=lorenzo@kernel.org \
    --cc=maciej.fijalkowski@intel.com \
    --cc=magnus.karlsson@intel.com \
    --cc=netdev@vger.kernel.org \
    --cc=saeed@kernel.org \
    --cc=shayagr@amazon.com \
    --cc=tirthendu.sarkar@intel.com \
    --cc=toke@redhat.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.