Re: [Xen-devel] [PATCH V6 5/5] x86/hvm: pkeys, add pkeys support for cpuid handling

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 19.01.16 at 08:30, <huaitong.han@xxxxxxxxx> wrote:
> --- a/xen/arch/x86/hvm/hvm.c
> +++ b/xen/arch/x86/hvm/hvm.c
> @@ -4566,7 +4566,7 @@ void hvm_cpuid(unsigned int input, unsigned int *eax, 
> unsigned int *ebx,
>              __clear_bit(X86_FEATURE_APIC & 31, edx);
>  
>          /* Fix up OSXSAVE. */
> -        if ( cpu_has_xsave )
> +        if ( *ecx & cpufeat_mask(X86_FEATURE_XSAVE) )
>              *ecx |= (v->arch.hvm_vcpu.guest_cr[4] & X86_CR4_OSXSAVE) ?
>                       cpufeat_mask(X86_FEATURE_OSXSAVE) : 0;

Imo this change (aiming at consistency) would better be mentioned
in the commit message, to avoid the impression of an unintended /
unrelated change.

> @@ -4579,21 +4579,31 @@ void hvm_cpuid(unsigned int input, unsigned int *eax, 
> unsigned int *ebx,
>              *edx &= ~cpufeat_mask(X86_FEATURE_PSE36);
>          break;
>      case 0x7:
> -        if ( (count == 0) && !cpu_has_smep )
> -            *ebx &= ~cpufeat_mask(X86_FEATURE_SMEP);
> +        if ( count == 0 )
> +        {
> +            if ( !cpu_has_smep )
> +                *ebx &= ~cpufeat_mask(X86_FEATURE_SMEP);
>  
> -        if ( (count == 0) && !cpu_has_smap )
> -            *ebx &= ~cpufeat_mask(X86_FEATURE_SMAP);
> +            if ( !cpu_has_smap )
> +                *ebx &= ~cpufeat_mask(X86_FEATURE_SMAP);
>  
> -        /* Don't expose MPX to hvm when VMX support is not available */
> -        if ( (count == 0) &&
> -             (!(vmx_vmexit_control & VM_EXIT_CLEAR_BNDCFGS) ||
> -              !(vmx_vmentry_control & VM_ENTRY_LOAD_BNDCFGS)) )
> -            *ebx &= ~cpufeat_mask(X86_FEATURE_MPX);
> +            /* Don't expose MPX to hvm when VMX support is not available. */
> +            if ( !(vmx_vmexit_control & VM_EXIT_CLEAR_BNDCFGS) ||
> +                    !(vmx_vmentry_control & VM_ENTRY_LOAD_BNDCFGS) )
> +                *ebx &= ~cpufeat_mask(X86_FEATURE_MPX);
>  
> -        /* Don't expose INVPCID to non-hap hvm. */
> -        if ( (count == 0) && !hap_enabled(d) )
> -            *ebx &= ~cpufeat_mask(X86_FEATURE_INVPCID);
> +            if ( !hap_enabled(d) )
> +            {
> +                /* Don't expose INVPCID to non-hap hvm. */
> +                *ebx &= ~cpufeat_mask(X86_FEATURE_INVPCID);
> +                /* X86_FEATURE_PKU is not yet implemented for shadow paging. 
> */
> +                *ecx &= ~cpufeat_mask(X86_FEATURE_PKU);
> +            }
> +
> +            if ( (*ecx & cpufeat_mask(X86_FEATURE_PKU)) &&
> +                    (v->arch.hvm_vcpu.guest_cr[4] & X86_CR4_PKE) )

Indentation. But this whole hunk needs re-basing anyway.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel