Re: [PATCH v14 8/9] KVM: x86: virtualize cpuid faulting

Jim Mattson <[email protected]> Fri, 27 Jul 2018 14:30:24 -0700
Newsgroups gmane.linux.kernel,gmane.linux.uml.devel,gmane.linux.uml.user,gmane.linux.file-systems,gmane.comp.emulators.kvm.devel
Message-ID <CALMp9eQ3VOOdQpZ2=rqB1W3=RnyZXDxrqXgADsDZ0eSH_8r9tQ@mail.gmail.com>
On Fri, Jul 27, 2018 at 2:05 PM, Andy Lutomirski <[email protected]> wrote:
> Does KVM *have* a concept of "maximum non-turbo frequency" of the
> guest that it would make sense to expose here?  If so, presumably the
> right solution is to expose it.

KVM has the concept of a guest's invariant TSC frequency. The Maximum
Non-Turbo Ratio is just some fraction of that. Sadly, the fraction is
100 MHz, 133.33MHz, or the "scalable bus frequency" from some other
MSR, depending on microarchitecture.