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

[Paolo Bonzini]

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?

Paolo

>              env->features[FEAT_HYPERV_EAX] |= HV_ACCESS_FREQUENCY_MSRS;
>              env->features[FEAT_HYPERV_EDX] |= HV_FREQUENCY_MSRS_AVAILABLE;
>          }