Re: [Qemu-devel] Virtualising qmp_query_cpus() arch specifics

[Andreas Färber]

Am 09.07.2015 um 08:36 schrieb Peter Crosthwaite:
> Hi All,
> 
> So for my multi-arch work, one of the eventual requirements is to
> remove all #define TARGET_FOO from core code. I came across this in
> cpus.c/qmp_query_cpus():
> 
> #if defined(TARGET_I386)
>         X86CPU *x86_cpu = X86_CPU(cpu);
>         CPUX86State *env = &x86_cpu->env;
> #elif defined(TARGET_PPC)
>         PowerPCCPU *ppc_cpu = POWERPC_CPU(cpu);
>         CPUPPCState *env = &ppc_cpu->env;
> ...
> 
> #if defined(TARGET_I386)
>         info->value->has_pc = true;
>         info->value->pc = env->eip + env->segs[R_CS].base;
> #elif defined(TARGET_PPC)
>         info->value->has_nip = true;
>         info->value->nip = env->nip;
> ...
> 
> This should probably be a QOM CPU virtual function. What makes me
> uneasy about it however, is a direct implementation means the QAPI
> autogenerated CPUInfoList struct would need to be exposed to
> target-foo/cpu.c. Is this ok or an abstraction fail? Do we need some
> other other minimal struct to communicate between target-foo and QMP
> with these particulars? Any third options?

Wouldn't that just be a get_pc() matching your set_pc() hook?

Unfortunately there's name differences above, pc vs. nip. Maybe we can
just use a generic field and keep #ifdef stuff only as legacy compat?

Cheers,
Andreas

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