From: "Toke Høiland-Jørgensen" <toke@redhat•com>
To: Jamal Hadi Salim <jhs@mojatatu•com>,
Willem de Bruijn <willemb@google•com>
Cc: Stanislav Fomichev <sdf@google•com>,
Jamal Hadi Salim <hadi@mojatatu•com>,
Jiri Pirko <jiri@resnulli•us>, Jakub Kicinski <kuba@kernel•org>,
netdev@vger•kernel.org, kernel@mojatatu•com,
deb.chatterjee@intel•com, anjali.singhai@intel•com,
namrata.limaye@intel•com, khalidm@nvidia•com, tom@sipanda•io,
pratyush@sipanda•io, xiyou.wangcong@gmail•com,
davem@davemloft•net, edumazet@google•com, pabeni@redhat•com,
vladbu@nvidia•com, simon.horman@corigine•com,
stefanc@marvell•com, seong.kim@amd•com, mattyk@nvidia•com,
dan.daly@intel•com, john.andy.fingerhut@intel•com
Subject: Re: [PATCH net-next RFC 00/20] Introducing P4TC
Date: Sun, 29 Jan 2023 23:14:18 +0100 [thread overview]
Message-ID: <87zga1xa2t.fsf@toke.dk> (raw)
In-Reply-To: <CAM0EoMmMd9SSxCV8p5WfmOnGqF+bOrOAOdAw9JGMC-=70Y8qzA@mail.gmail.com>
Jamal Hadi Salim <jhs@mojatatu•com> writes:
>> > We use the skip_sw and skip_hw knobs in tc to indicate whether a
>> > policy is targeting hw or sw. Not sure if you are familiar with it but its
>> > been around (and deployed) for a few years now. So a P4 program
>> > policy can target either.
>>
>> I know. So the only reason the kernel ABI needs to be extended with P4
>> objects is to be able to pass the same commands to hardware. The whole
>> kernel dataplane could be implemented as a BPF program, correct?
>>
>
> It's more than an ABI (although that is important as well).
> It is about reuse of the infra which provides a transparent symbiosis
> between hardware offload and software that has matured over time: For
> example, you can take a pipeline or a table or actions (lately) and
> split them between hardware and software transparently, etc. To
> re-iterate, we are reusing and plugging into a proven and deployed
> mechanism which enables our goal (of HW + SW scripting of arbitrary
> P4-enabled datapaths which are functionally equivalent).
But you're doing this in a way that completely ignores the existing
ecosystem for creating programmable software datapaths in the kernel
(i.e., eBPF/XDP) in favour of adding *yet another* interpreter to the
kernel.
In particular, completely excluding the XDP from this is misguided.
Programmable networking in Linux operates at three layers:
- HW: for stuff that's supported and practical there
- XDP: software fast-path for high-performance bits that can't go into HW
- TC/rest of stack: SW slow path for functional equivalence
I can see P4 playing a role as a higher-level data plane definition
language even for Linux SW stacks, but let's have it integrate with the
full ecosystem, not be its own little island in a corner...
-Toke
next prev parent reply other threads:[~2023-01-29 22:15 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-24 17:03 [PATCH net-next RFC 00/20] Introducing P4TC Jamal Hadi Salim
2023-01-26 23:30 ` Jakub Kicinski
2023-01-27 13:33 ` Jamal Hadi Salim
2023-01-27 17:18 ` Jakub Kicinski
2023-01-27 19:42 ` Jamal Hadi Salim
2023-01-28 1:34 ` Singhai, Anjali
2023-01-28 21:17 ` Tom Herbert
2023-01-29 2:09 ` Stephen Hemminger
2023-01-30 3:09 ` Singhai, Anjali
2023-01-30 17:05 ` Tom Herbert
2023-01-27 18:26 ` Jiri Pirko
2023-01-27 20:04 ` Jamal Hadi Salim
2023-01-27 22:26 ` sdf
2023-01-27 23:06 ` Tom Herbert
2023-01-28 0:47 ` Stanislav Fomichev
2023-01-28 1:32 ` Tom Herbert
2023-01-27 23:27 ` Jamal Hadi Salim
2023-01-28 0:47 ` Stanislav Fomichev
2023-01-28 13:37 ` Willem de Bruijn
2023-01-28 15:10 ` Jamal Hadi Salim
2023-01-28 15:33 ` Willem de Bruijn
2023-01-29 5:39 ` John Fastabend
2023-01-29 11:11 ` Jamal Hadi Salim
2023-01-29 11:19 ` Jamal Hadi Salim
2023-01-30 4:30 ` John Fastabend
2023-01-30 10:13 ` Jiri Pirko
2023-01-30 11:26 ` Toke Høiland-Jørgensen
2023-01-30 14:06 ` Jamal Hadi Salim
2023-01-30 14:42 ` Andrew Lunn
2023-01-30 15:31 ` Jamal Hadi Salim
2023-01-30 17:04 ` Toke Høiland-Jørgensen
2023-01-30 19:02 ` Jamal Hadi Salim
2023-01-30 20:21 ` Toke Høiland-Jørgensen
2023-01-30 21:10 ` John Fastabend
2023-01-30 21:20 ` Toke Høiland-Jørgensen
2023-01-30 22:53 ` Jamal Hadi Salim
2023-01-30 23:24 ` Singhai, Anjali
2023-01-31 0:06 ` John Fastabend
2023-01-31 0:26 ` Jamal Hadi Salim
2023-01-31 4:12 ` Jakub Kicinski
2023-01-31 10:27 ` Jamal Hadi Salim
2023-01-31 10:30 ` Jamal Hadi Salim
2023-01-31 19:10 ` Jakub Kicinski
2023-01-31 22:32 ` Jamal Hadi Salim
2023-01-31 22:36 ` Jakub Kicinski
2023-01-31 22:50 ` Jamal Hadi Salim
2023-01-30 23:32 ` John Fastabend
2023-01-31 12:17 ` Toke Høiland-Jørgensen
2023-01-31 12:37 ` Jiri Pirko
2023-01-31 14:38 ` Jiri Pirko
2023-01-31 17:01 ` Toke Høiland-Jørgensen
2023-01-31 22:23 ` Jamal Hadi Salim
2023-01-31 22:53 ` Toke Høiland-Jørgensen
2023-01-31 23:31 ` Jamal Hadi Salim
2023-02-01 18:08 ` Toke Høiland-Jørgensen
2023-02-02 18:50 ` Jamal Hadi Salim
2023-02-02 23:34 ` Tom Herbert
2023-01-30 22:41 ` Tom Herbert
2023-02-14 17:07 ` Edward Cree
2023-02-14 20:44 ` Jamal Hadi Salim
2023-02-16 20:24 ` Jamal Hadi Salim
2023-01-29 11:02 ` Jamal Hadi Salim
2023-01-29 22:14 ` Toke Høiland-Jørgensen [this message]
2023-01-28 13:41 ` Jamal Hadi Salim
2023-01-27 23:02 ` Daniel Borkmann
2023-01-27 23:57 ` Jamal Hadi Salim
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