Re: [PATCH v4 16/17] kvm: x86: Add support IA32_CORE_CAPABILITY MSR

[Xiaoyao Li]

On Fri, 2019-03-08 at 08:54 +0100, Paolo Bonzini wrote:
> On 08/03/19 07:10, Xiaoyao Li wrote:
> > > so that non-virtualizable features are hidden and
> > > 
> > > 	if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT))
> > > 		data |= CORE_CAP_SPLIT_LOCK_DETECT;
> > > 
> > > so that userspace gets "for free" the FMS list that will be added
> > > later to the kernel.
> > 
> > I think it's redundant. Because there is no case that
> > rdmsrl_safe(MSR_IA32_CORE_CAPABILITY, &data) shows no split lock detection
> > while
> > boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT).
> 
> There will be when the kernel will add a list of FMS values that have
> split lock detection but lack the core capabilities MSR.  Or at least
> that is what Fenghua said in the cover letter.
> 
> Paolo

Got it.
Thanks for your explanation.