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Date:   Sat, 24 Dec 2022 14:22:57 +0800
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Subject: Re: [RFC PATCH RESEND bpf-next 0/4] Support bpf trampoline for RV64
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To:     =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= <bjorn@kernel.org>,
        bpf@vger.kernel.org, linux-riscv@lists.infradead.org,
        linux-kernel@vger.kernel.org
Cc:     Luke Nelson <luke.r.nels@gmail.com>, Xi Wang <xi.wang@gmail.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <martin.lau@linux.dev>,
        Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
        Stanislav Fomichev <sdf@google.com>,
        Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Pu Lehui <pulehui@huawei.com>
References: <20221220021319.1655871-1-pulehui@huaweicloud.com>
 <87ili3a8zy.fsf@all.your.base.are.belong.to.us>
From:   Pu Lehui <pulehui@huaweicloud.com>
In-Reply-To: <87ili3a8zy.fsf@all.your.base.are.belong.to.us>
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On 2022/12/22 21:00, Björn Töpel wrote:
> Pu Lehui <pulehui@huaweicloud.com> writes:
> 
>> BPF trampoline is the critical infrastructure of the bpf
>> subsystem, acting as a mediator between kernel functions
>> and BPF programs. Numerous important features, such as
>> using ebpf program for zero overhead kernel introspection,
>> rely on this key component. We can't wait to support bpf
>> trampoline on RV64. The implementation of bpf trampoline
>> was closely to x86 and arm64 for future development.
> 
> Thank you for working on this! BPF trampoline is the "missing piece"
> from getting proper kfunc support.
> 
> Unfortunately, I wont be able to do a proper review until next week.
> 

Take your time, it might take several rounds of optimization. Yep, riscv 
bpf will look more complete when bpf trampoline and kfunc are supported.

Anyway, have a nice christmas holidays.????

Lehui

> 
> Happy holidays,
> Björn