On Fri, Jul 27, 2018 at 2:30 PM, Jim Mattson <jmattson@xxxxxxxxxx> wrote: > On Fri, Jul 27, 2018 at 2:05 PM, Andy Lutomirski <luto@xxxxxxxxxx> 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. Which is problematic, unless KVM wants to start deciding what the base clock is. There's MSR_FSB_FREQ, which is supported on Atom only, IIRC. I really wish Intel would get its act together.
