From: Jerin Jacob <jerinjacobk@gmail.com>
To: Daniel Borkmann <daniel@iogearbox.net>
Cc: Thomas Monjalon <thomas@monjalon.net>,
Steve Capper <Steve.Capper@arm.com>,
"Ananyev, Konstantin" <konstantin.ananyev@intel.com>,
Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>,
Rodolph Perfetta <Rodolph.Perfetta@arm.com>,
"jerinj@marvell.com" <jerinj@marvell.com>,
dpdk-dev <dev@dpdk.org>,
"Gavin Hu (Arm Technology China)" <Gavin.Hu@arm.com>,
nd <nd@arm.com>, Alexei Starovoitov <ast@kernel.org>,
Quentin Monnet <quentin.monnet@netronome.com>,
john.fastabend@gmail.com
Subject: Re: [dpdk-dev] [PATCH 0/8] eBPF arm64 JIT support
Date: Fri, 4 Oct 2019 20:13:01 +0530 [thread overview]
Message-ID: <CALBAE1PYX4VsuMc5s17opLxgM2uD0JE5NGX-awLqqXJPJ7gffw@mail.gmail.com> (raw)
In-Reply-To: <5231837e-3813-0eeb-1c87-5b7072cf8c18@iogearbox.net>
On Fri, Oct 4, 2019 at 7:39 PM Daniel Borkmann <daniel@iogearbox.net> wrote:
>
> On 10/4/19 12:53 PM, Thomas Monjalon wrote:
> > 04/10/2019 11:54, Steve Capper:
> >> I'd recommend also reaching out the BPF maintainers:
> >> BPF JIT for ARM64
> >> M: Daniel Borkmann <daniel@iogearbox.net>
> >> M: Alexei Starovoitov <ast@kernel.org>
> >> M: Zi Shen Lim <zlim.lnx@gmail.com>
> >> L: netdev@vger.kernel.org
> >> L: bpf@vger.kernel.org
> >> S: Supported
> >> F: arch/arm64/net/
> >>
> >> As they will have much better knowledge of the state of play and will be
> >> better able to advise.
> >
> > As far as I know Alexei and Daniel are OK with the idea.
> > But better to let them reply here.
> >
> > I suggest we think about a way to package the kernel BPF JIT
> > for userspace usage (not only DPDK) as a library.
> > I don't understand why the DPDK JIT should be different
> > or optimized differently.
>
> That would be great indeed as both projects would benefit from a shared
> JIT instead of reimplementing everything twice. I never looked into DPDK
> too much, but I presume the idea would be as well to take the LLVM (or
> bpf-gcc) generated object file and load it into a BPF 'engine' that sits
> in user space on top of DPDK? Presumably loader could be libbpf here as
> well since it already knows how to parse the ELF, perform the relocations
> etc. The only difference would be that you have a different context and
> different helpers? Is that the goal eventually?
>
> > The only real issue I see is the need for a dual licensing BSD-GPL.
>
> This might be one avenue if all kernel JIT contributors would be on board.
> Another option I'm wondering could be to extend the bpf() syscall in order
> to pass down a description of context and helper mappings e.g. via BTF and
> let everything go through the verifier in the kernel the usual way (I presume
> one goal might be that you want to assure that the generated BPF code passes
> the safety checks before running the prog), then have it JITed and extract
> the generated image in order to use it from user space. Kernel would have
> to make sure it never actually allows attaching this program in the kernel.
> Generated opcodes can already be retrieved today (see below). Such infra
> could potentially help bpf-gcc folks as well as they expressed desire to
> have some sort of a simulator for their gcc BPF test suite.. and it would
> allow for consistent behavior of the BPF runtime. Just a thought.
This idea looks good. This can remove the verifier code also from DPDK.
A couple of downsides I can think of,
# We may need to extend the kernel verifier to understand the user-space address
and its symbols for CALL and MEM access operations.
# DPDK supports FreeBSD and Windows OS as well
# Need a different treatment for old Linux kernels.
>
>
next prev parent reply other threads:[~2019-10-04 14:43 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-03 10:59 jerinj
2019-09-03 10:59 ` [dpdk-dev] [PATCH 1/8] bpf/arm64: add build infrastructure jerinj
2019-09-03 10:59 ` [dpdk-dev] [PATCH 2/8] bpf/arm64: add prologue and epilogue jerinj
2019-09-03 10:59 ` [dpdk-dev] [PATCH 3/8] bpf/arm64: add basic arithmetic operations jerinj
2019-09-03 10:59 ` [dpdk-dev] [PATCH 4/8] bpf/arm64: add logical operations jerinj
2019-09-03 10:59 ` [dpdk-dev] [PATCH 5/8] bpf/arm64: add byte swap operations jerinj
2019-09-03 10:59 ` [dpdk-dev] [PATCH 6/8] bpf/arm64: add load and store operations jerinj
2019-09-03 10:59 ` [dpdk-dev] [PATCH 7/8] bpf/arm64: add atomic-exchange-and-add operation jerinj
2019-10-18 13:16 ` David Marchand
2019-09-03 10:59 ` [dpdk-dev] [PATCH 8/8] bpf/arm64: add branch operation jerinj
2019-09-24 17:03 ` [dpdk-dev] [PATCH 0/8] eBPF arm64 JIT support Ananyev, Konstantin
2019-10-12 12:22 ` Thomas Monjalon
2019-10-03 12:51 ` Thomas Monjalon
2019-10-03 13:07 ` Jerin Jacob
2019-10-03 15:05 ` Ananyev, Konstantin
2019-10-04 4:55 ` Honnappa Nagarahalli
2019-10-04 9:54 ` Steve Capper
2019-10-04 10:53 ` Thomas Monjalon
2019-10-04 14:09 ` Daniel Borkmann
2019-10-04 14:43 ` Jerin Jacob [this message]
2019-10-05 0:00 ` Daniel Borkmann
2019-10-05 14:39 ` Jerin Jacob
2019-10-07 11:57 ` Ananyev, Konstantin
2019-10-24 4:22 ` Jerin Jacob
2020-04-06 11:05 ` Ananyev, Konstantin
2019-10-04 15:39 ` Jerin Jacob
2019-10-07 12:33 ` Thomas Monjalon
2019-10-07 13:00 ` Jerin Jacob
2019-10-07 18:04 ` Thomas Monjalon
2019-10-07 19:29 ` Jerin Jacob
2019-10-07 20:15 ` Thomas Monjalon
2019-10-08 6:57 ` Jerin Jacob
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