Re: [Qemu-devel] [PATCH] i386: Enable IA32_MISC_ENABLE MWAIT bit when exposing mwait/monitor

[Paolo Bonzini]

On 14/05/19 08:06, Wanpeng Li wrote:
> From: Wanpeng Li <address@hidden>
> 
> The CPUID.01H:ECX[bit 3] ought to mirror the value of the MSR 
> IA32_MISC_ENABLE MWAIT bit and as userspace has control of them 
> both, it is userspace's job to configure both bits to match on 
> the initial setup.

Queued, thanks.

Paolo

> Cc: Eduardo Habkost <address@hidden>
> Cc: Paolo Bonzini <address@hidden>
> Cc: Radim Krčmář <address@hidden>
> Signed-off-by: Wanpeng Li <address@hidden>
> ---
>  target/i386/cpu.c | 3 +++
>  target/i386/cpu.h | 1 +
>  2 files changed, 4 insertions(+)
> 
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 722c551..40b6108 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -4729,6 +4729,9 @@ static void x86_cpu_reset(CPUState *s)
>  
>      env->pat = 0x0007040600070406ULL;
>      env->msr_ia32_misc_enable = MSR_IA32_MISC_ENABLE_DEFAULT;
> +    if (enable_cpu_pm) {
> +        env->msr_ia32_misc_enable |= MSR_IA32_MISC_ENABLE_MWAIT;
> +    }
>  
>      memset(env->dr, 0, sizeof(env->dr));
>      env->dr[6] = DR6_FIXED_1;
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index 0128910..b94c329 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -387,6 +387,7 @@ typedef enum X86Seg {
>  #define MSR_IA32_MISC_ENABLE            0x1a0
>  /* Indicates good rep/movs microcode on some processors: */
>  #define MSR_IA32_MISC_ENABLE_DEFAULT    1
> +#define MSR_IA32_MISC_ENABLE_MWAIT      (1ULL << 18)
>  
>  #define MSR_MTRRphysBase(reg)           (0x200 + 2 * (reg))
>  #define MSR_MTRRphysMask(reg)           (0x200 + 2 * (reg) + 1)
>