[PATCH bpf-next v1 0/4] Support bpf trampoline for RV64

[Pu Lehui]

On 2023/2/15 22:45, Björn Töpel wrote:
> Hi Lehui,
> 
> Pu Lehui <pulehui at 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. Since RV64 does not support ftrace
>> direct call yet, the current RV64 bpf trampoline is only
>> used in bpf context.
> 
> Thanks a lot for continuing this work. I agree with you that it's
> valuable to have BPF trampoline support, even without proper direct call
> support (we'll get there soon). The trampoline enables kfunc calls. On
> that note; I don't see that you enable "bpf_jit_supports_kfunc_call()"
> anywhere in the series.  With BPF trampoline support, the RISC-V BPF
> finally can support kfunc calls!
> 
> I'd add the following to bpf_jit_comp64.c:
> 

happy to hear that，let's make it more completeable.

> bool bpf_jit_supports_kfunc_call(void)
> {
>          return true;
> }
> 
> :-)
> 
> I'll do a review ASAP.
> 
> 
> Björn