Re: [PATCH v5 1/2] x86/cpu: Add support for UMONITOR/UMWAIT/TPAUSE

[Paolo Bonzini]

On 29/09/19 03:57, Tao Xu wrote:
> +    } else if (function == 7 && index == 0 && reg == R_ECX) {
> +        if (enable_cpu_pm) {
> +            ret |= CPUID_7_0_ECX_WAITPKG;

This is incorrect.  You should disable WAITPKG if !enable_cpu_pm, but
you should not enable it forcefully if enable_cpu_pm is true.

Paolo

> +        } else {
> +            ret &= ~CPUID_7_0_ECX_WAITPKG;
> +        }