Re: [PATCH v2] x86/cpu: Skip reading MSR_IA32_PLATFORM_ID in virtualized environment

[Borislav Petkov]

On Wed, May 13, 2026 at 07:02:53PM +0800, Binbin Wu wrote:
> My version treated it as a bug fix, so I tried to minimize the code change.

I didn't like

	BIT(X86_FEATURE_HYPERVISOR & 0x1f))

in your patch. I'd use BIT(31) as it does.

But, more importantly, it added yet another place where we test whether we run
on a HV. And it is high time we unified those because we run more and more on
HVs nowadays.

> There is one case not covered by setting the global x86_hypervisor_present at this point.
> Xen PV guest will not go this path, so Xen PV guest will not see the hypervisor bit.
> 
> But maybe we can just ignore Xen PV guest case today?

Nothing changes before or after this fix. So Xen PV can be handled
completely separated from this.

Thx.

-- 
Regards/Gruss,
    Boris.

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