Re: [Qemu-devel] [PATCH uq/master v2 1/2] kvm: reset state from the CPU's reset method

[Gleb Natapov]

On Mon, Apr 08, 2013 at 04:36:47PM +0200, Andreas Färber wrote:
> Am 08.04.2013 14:19, schrieb Gleb Natapov:
> > On Tue, Apr 02, 2013 at 04:29:32PM +0300, Gleb Natapov wrote:
> >>>  static void kvm_sw_tlb_put(PowerPCCPU *cpu)
> >>>  {
> >>>      CPUPPCState *env = &cpu->env;
> >>> diff --git a/target-s390x/cpu.c b/target-s390x/cpu.c
> >>> index 23fe51f..6321384 100644
> >>> --- a/target-s390x/cpu.c
> >>> +++ b/target-s390x/cpu.c
> >>> @@ -84,6 +84,10 @@ static void s390_cpu_reset(CPUState *s)
> >>>       * after incrementing the cpu counter */
> >>>  #if !defined(CONFIG_USER_ONLY)
> >>>      s->halted = 1;
> >>> +
> >>> +    if (kvm_enabled()) {
> >>> +        kvm_arch_reset_vcpu(s);
> >> Does this compile with kvm support disabled?
> >>
> > Well, it does not:
> >   CC    s390x-softmmu/target-s390x/cpu.o
> > /users/gleb/work/qemu/target-s390x/cpu.c: In function 's390_cpu_reset':
> > /users/gleb/work/qemu/target-s390x/cpu.c:89:9: error: implicit
> > declaration of function 'kvm_arch_reset_vcpu'
> > [-Werror=implicit-function-declaration]
> > /users/gleb/work/qemu/target-s390x/cpu.c:89:9: error: nested extern
> > declaration of 'kvm_arch_reset_vcpu' [-Werror=nested-externs]
> > cc1: all warnings being treated as errors
> > 
> > I wonder if it is portable between compilers to rely on code in if(0){} to
> > be dropped in all levels of optimizations.
> 
> No, we had a previous case where --enable-debug broke if (kvm_enabled())
> {...} but regular builds worked.
> 
Can you recall what compiler was it with? 4.7.2 works with -O0.

--
                        Gleb.