Re: VMX Preemption Timer appears to be buggy on SKX, CLX, and ICX

[Xiaoyao Li]

On 6/13/2026 6:51 AM, Jim Mattson wrote:
> On Thu, Jun 4, 2026 at 10:56 PM Chao Gao <chao.gao@xxxxxxxxx> wrote:
> > On Thu, Jun 04, 2026 at 10:34:40PM -0700, Jim Mattson wrote:
> ...
> > > With respect to EMR, you wrote previously, "A mitigation for this
> > > erratum is for software to program the VMX preemption timer for values
> > > below 2^25 * CPUID.15H:EBX[31:0] / CPUID.15H:EAX[31:0]."
> > >
> > > My question is whether the exponent, 25, is a fixed value for all
> > > CPUs, regardless of their IA32_VMX_MISC[4:0]. It sounds like you are
> > > saying that the exponent may depend on IA32_VMX_MISC[4:0].
> >
> > Let me double-check this with the internal team and get back to you.
>
> Have you discovered anything?

Chao is on vacation, let's wait one more week.