[PATCH bpf-next v2] riscv, bpf: Add kfunc support for RV64

[Pu Lehui]

On 2023/2/21 15:02, Björn Töpel wrote:
> Pu Lehui <pulehui at huaweicloud.com> writes:
> 
>> On 2023/2/20 22:34, Björn Töpel wrote:
>>> Pu Lehui <pulehui at huaweicloud.com> writes:
>>>
>>>> From: Pu Lehui <pulehui at huawei.com>
>>>>
>>>> As another important missing piece of RV64 JIT, kfunc allow bpf programs
>>>> call kernel functions. For now, RV64 is sufficient to enable it.
>>>
>>> Thanks Lehui!
>>>
>>> Maybe we can reword/massage the commit message a bit? What do you think
>>> about something like:
>>>
>>> "Now that the BPF trampoline is supported by RISC-V, it is possible to
>>> use BPF programs with kfunc calls.
>>>
>>
>> kfunc and bpf trampoline are functionally independent. kfunc [1], like
>> bpf helper functions, allows bpf programs to call exported kernel
>> functions, while bpf trampoline provides a more efficient way than
>> kprobe to act as a mediator between kernel functions and bpf programs,
>> and between bpf programs.
>>
>> In fact, it was already supported before the bpf trampoline
>> implementation, I just turned it on.
> 
> Good point. I guess my (incorrect) kfunc mental model was that
> struct_ops and kfunc were tightly coupled. (Then again, w/o struct_ops
> working kfunc is a bit half-working in my view.)
> 
> Fair enough. I'm still a bit confused about the commit message, but
> happy with the patch.
>  > Acked-by: Björn Töpel <bjorn at rivosinc.com>

Thanks Bjorn, will rewrite commit message to make more sense, and send 
new soon.