Hi Jerin, > > > > > > > > > > bpf_validate does not allow to execute RTE_BPF_ARG_PTR_STACK for > > > > > no reason. > > > > > > > > I believe there is a reason, > > > > ARG_PTR_STACK is reserved for memory within BPF program internal > > > > stack only. > > > > User that calls BPF program should never pass parameter with that type. > > > > > > OK. > > > Shouldn't we remove that from public header file > > > (lib/librte_bpf/rte_bpf.h) then ? > > > > Probably... or might be just put extra comments to mark it as internal? > > The reason I left it here, so we can add new public values for enum here, > > before RTE_BPF_ARG_PTR_STACK. > > Of course in theory we can use for RTE_BPF_ARG_PTR_STACK some > > reserved value instead. > > > > > > > > > If the user allocates parameter for bpf function on the stack, he > > > > can still use RTE_BPF_ARG_PTR for it. > > > > > > I see the _stack_ is only allocated under RTE_BPF_ARG_PTR_STACK checks > > in bpf_validate.c. > > > Can you check? I agree that stack should be allocated for > > RTE_BPF_ARG_PTR as well. > > > > Not sure I understand your query here... > > Each BPF program can use up to MAX_BPF_STACK_SIZE bytes for stack. > > Though to avoid JIT to allocate unused space for the stack, in > > bpf_validate.c > > we figure out does given BPF program really allocate things on the stack and > > if yes, how many bytes is needed. > > This info is stored in rte_bpf.stack_sz and can be used later by the JIT. > > Let say for x86 jit is used in emit_prolog(). > > I thought, stack will be allocated only when user gives > RTE_BPF_ARG_PTR_STACK. > I tested following program with RTE_BPF_ARG_PTR. It allocates stacks > Properly. So everything is good. > > stdw [r10-64], 0xab > mov r0, 0 > exit > > I will modify this patch to following to avoid any confusion to user: > 1) Change RTE_BPF_ARG_PTR_STACK to RTE_BPF_ARG_RESERVED in public header file > 2) In the implementation #define RTE_BPF_ARG_RESERVED BPF_ARG_PTR_STACK > > Is it OK?
Yes, sounds like a good approach to me. Thanks Konstantin
