Re: [Qemu-devel] [PATCH 2/2] i386/kvm: lower requirements for Hyper-V frequency MSRs exposure

[Vitaly Kuznetsov]

Paolo Bonzini <address@hidden> writes:

> On 12/03/2018 16:12, Vitaly Kuznetsov wrote:
>>  
>> -        if (has_msr_hv_frequencies && tsc_is_stable_and_known(env)) {
>> +        if (has_msr_hv_frequencies && env->tsc_khz) {
>
> Should this be
>
> ((env->tsc_khz && has_msr_hv_reenlightenment) ||
>  tsc_is_stable_and_known(env))
>
> so that you don't regress on older kernels?
>

I don't actually see where the regression might come from: frequency
MSRs are supported regardless or reenlightenment/invtsc and there's
nothing wrong with exposing them but I may be missing something..

-- 
  Vitaly