Re: [Qemu-devel] [RFC untested PATCH] i386/cpu: make -cpu host support monitor/mwait

[Michael S. Tsirkin]

On Wed, Jun 13, 2018 at 10:55:43AM +0200, Igor Mammedov wrote:
> On Tue, 12 Jun 2018 11:49:22 -0300
> Eduardo Habkost <address@hidden> wrote:
> 
> > On Tue, Jun 12, 2018 at 03:58:03PM +0200, Igor Mammedov wrote:
> > [...]
> > > > > > +    if (xcc->host_cpuid_required && enable_cpu_pm) {
> > > > > > +        host_cpuid(5, 0, &cpu->mwait.eax, &cpu->mwait.ebx,
> > > > > > +                   &cpu->mwait.ecx, &cpu->mwait.edx);
> > > > > > +    }    
> [...]
> > > > > also max_x86_cpu_initfn() might be better place for filling it up.  
> > 
> > Why?
> I've missed 'enable_cpu_pm' which is probably a property,
> so yep it can't go into initfn.
> 
> However if we not going to migrate this state or use outside of
> cpu_x86_cpuid(), I don't see why we should add it to X86CPU state
> and keep around.
> We can query it on demand from cpu_x86_cpuid() like we do for
> PMU leaf.

We can do it but the annoying thing is that it spreads
the info around as we also need to set CPUID_EXT_MONITOR.

This way we set all the info in one place on realize.

-- 
MST