Re: [PATCH RESEND v6 1/2] x86/cpu: Add support for UMONITOR/UMWAIT/TPAUSE

[Tao Xu]

On 10/11/2019 3:41 PM, Xu, Tao3 wrote:
[...]
> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
> index 11b9c854b5..a465c893b5 100644
> --- a/target/i386/kvm.c
> +++ b/target/i386/kvm.c
> @@ -401,6 +401,12 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, 
> uint32_t function,
>           if (host_tsx_blacklisted()) {
>               ret &= ~(CPUID_7_0_EBX_RTM | CPUID_7_0_EBX_HLE);
>           }
> +    } else if (function == 7 && index == 0 && reg == R_ECX) {
> +        if (enable_cpu_pm) {
> +            ret |= CPUID_7_0_ECX_WAITPKG;
> +        } else {
> +            ret &= ~CPUID_7_0_ECX_WAITPKG;
> +        }

Hi Paolo,

I am sorry because I realize in KVM side, I keep cpuid mask WAITPKG as 0:

F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B) | 0 /*WAITPKG*/;

Therefore in QEMU side, we need to add CPUID_7_0_ECX_WAITPKG when 
enable_cpu_pm is on. Otherwise, QEMU can't get this CPUID.

Could you review this part again? Thank you very much!

Tao