[PATCH bpf-next 0/3] Use bpf_prog_pack for RV64 bpf trampoline

[Björn Töpel]

Pu Lehui <pulehui at huaweicloud.com> writes:

> We used bpf_prog_pack to aggregate bpf programs into huge page to
> relieve the iTLB pressure on the system. We can apply it to bpf
> trampoline, as Song had been implemented it in core and x86 [0]. This
> patch is going to use bpf_prog_pack to RV64 bpf trampoline. Since Song
> and Puranjay have done a lot of work for bpf_prog_pack on RV64,
> implementing this function will be easy. But one thing to mention is
> that emit_call in RV64 will generate the maximum number of instructions
> during dry run, but during real patching it may be optimized to 1
> instruction due to distance. This is no problem as it does not overflow
> the allocated RO image.
>
> Tests about regular trampoline and struct_ops trampoline have passed, as
> well as "test_verifier" with no failure cases.
>
> Link: https://lore.kernel.org/all/20231206224054.492250-1-song@kernel.org [0]

Tested-by: Björn Töpel <bjorn at rivosinc.com> #riscv