linux-kernel - Re: [PATCH 51/61] KVM: x86: Use kvm_cpu

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Message-ID: <87v9nulq0v.fsf@vitty.brq.redhat.com>
Date:   Tue, 25 Feb 2020 15:06:56 +0100
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     Sean Christopherson <sean.j.christopherson@...el.com>
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 51/61] KVM: x86: Use kvm_cpu_caps to detect Intel PT support

Sean Christopherson <sean.j.christopherson@...el.com> writes:

> Check for Intel PT using kvm_cpu_cap_has() to pave the way toward
> eliminating ->pt_supported().
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
> ---
>  arch/x86/kvm/cpuid.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index a37cb6fda979..3d287fc6eb6e 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -507,7 +507,6 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
>  {
>  	struct kvm_cpuid_entry2 *entry;
>  	int r, i, max_idx;
> -	unsigned f_intel_pt = kvm_x86_ops->pt_supported() ? F(INTEL_PT) : 0;
>  
>  	/* all calls to cpuid_count() should be made on the same cpu */
>  	get_cpu();
> @@ -687,7 +686,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
>  		break;
>  	/* Intel PT */
>  	case 0x14:
> -		if (!f_intel_pt) {
> +		if (!kvm_cpu_cap_has(X86_FEATURE_INTEL_PT)) {
>  			entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
>  			break;
>  		}

Reviewed-by: Vitaly Kuznetsov <vkuznets@...hat.com>

-- 
Vitaly