Re: [Qemu-devel] [PATCH v2 3/4] i386/kvm: introduce tsc_is_stable_and_known()

[David Hildenbrand]

On 07.08.2017 10:57, Ladi Prosek wrote:
> Move the "is TSC stable and known" condition to a reusable helper.
> 
> Signed-off-by: Ladi Prosek <address@hidden>
> ---
>  target/i386/kvm.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
> index 15d56ae..2dc01c9 100644
> --- a/target/i386/kvm.c
> +++ b/target/i386/kvm.c
> @@ -611,6 +611,15 @@ static int kvm_arch_set_tsc_khz(CPUState *cs)
>      return 0;
>  }
>  
> +static bool tsc_is_stable_and_known(CPUX86State *env)
> +{
> +    if (!env->tsc_khz) {
> +        return false;
> +    }
> +    return (env->features[FEAT_8000_0007_EDX] & CPUID_APM_INVTSC)
> +        || env->user_tsc_khz;
> +}> +
>  static int hyperv_handle_properties(CPUState *cs)
>  {
>      X86CPU *cpu = X86_CPU(cs);
> @@ -986,9 +995,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
>          && cpu->expose_kvm
>          && kvm_base == KVM_CPUID_SIGNATURE
>          /* TSC clock must be stable and known for this feature. */
> -        && ((env->features[FEAT_8000_0007_EDX] & CPUID_APM_INVTSC)
> -            || env->user_tsc_khz != 0)
> -        && env->tsc_khz != 0) {
> +        && tsc_is_stable_and_known(env)) {
>  
>          c = &cpuid_data.entries[cpuid_i++];
>          c->function = KVM_CPUID_SIGNATURE | 0x10;
> 

Reviewed-by: David Hildenbrand <address@hidden>

-- 

Thanks,

David