netdev - Re: [PATCH bpf-next 2/5] riscv, bpf: Relax restrictions on Zbb instructions

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Message-ID: <20240403-clanking-undress-b18346aa4cef@spud>
Date: Wed, 3 Apr 2024 13:29:49 +0100
From: Conor Dooley <conor@...nel.org>
To: Pu Lehui <pulehui@...weicloud.com>
Cc: Björn Töpel <bjorn@...nel.org>,
	Stefan O'Rear <sorear@...tmail.com>, bpf@...r.kernel.org,
	linux-riscv@...ts.infradead.org, netdev@...r.kernel.org,
	Alexei Starovoitov <ast@...nel.org>,
	Daniel Borkmann <daniel@...earbox.net>,
	Andrii Nakryiko <andrii@...nel.org>,
	Martin KaFai Lau <martin.lau@...ux.dev>,
	Eduard Zingerman <eddyz87@...il.com>, Song Liu <song@...nel.org>,
	Yonghong Song <yhs@...com>,
	John Fastabend <john.fastabend@...il.com>,
	KP Singh <kpsingh@...nel.org>, Stanislav Fomichev <sdf@...gle.com>,
	Hao Luo <haoluo@...gle.com>, Jiri Olsa <jolsa@...nel.org>,
	Mykola Lysenko <mykolal@...com>, Manu Bretelle <chantr4@...il.com>,
	Pu Lehui <pulehui@...wei.com>
Subject: Re: [PATCH bpf-next 2/5] riscv, bpf: Relax restrictions on Zbb
 instructions

On Wed, Apr 03, 2024 at 06:05:38PM +0800, Pu Lehui wrote:
> Hi Conor and Björn,
> 
> Thanks for your explanation. I totally agree with what you said,
> "CONFIG_RISCV_ISA_ZBB only controls whether optimizations for Zbb are built
> so that if Zbb is detected they can be used.".
> 
> Since the instructions emited by bpf jit are in kernel space, they should
> indeed be aligned in this regard.
> 
> PS: It's a bit difficult to understand this,😅 if I'm wrong please don't
> hesitate to tell me.

I think your understanding is correct. Sorry if I confused you at all!

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