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SubjectRe: [PATCH 35/61] KVM: x86: Handle Intel PT CPUID adjustment in VMX code
Date
Sean Christopherson <sean.j.christopherson@intel.com> writes:

> Move the Processor Trace CPUID adjustment into VMX code to eliminate
> an instance of the undesirable "unsigned f_* = *_supported ? F(*) : 0"
> pattern in the common CPUID handling code, and to pave the way toward
> eventually removing ->pt_supported().
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> ---
> arch/x86/kvm/cpuid.c | 3 +--
> arch/x86/kvm/vmx/vmx.c | 3 +++
> 2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index fc507270f3f3..f4a3655451dd 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -339,7 +339,6 @@ static int __do_cpuid_func_emulated(struct kvm_cpuid_array *array, u32 func)
>
> static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry)
> {
> - unsigned f_intel_pt = kvm_x86_ops->pt_supported() ? F(INTEL_PT) : 0;
> unsigned f_la57;
>
> /* cpuid 7.0.ebx */
> @@ -348,7 +347,7 @@ static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry)
> F(BMI2) | F(ERMS) | 0 /*INVPCID*/ | F(RTM) | 0 /*MPX*/ | F(RDSEED) |
> F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) |
> F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) |
> - F(SHA_NI) | F(AVX512BW) | F(AVX512VL) | f_intel_pt;
> + F(SHA_NI) | F(AVX512BW) | F(AVX512VL) | 0 /*INTEL_PT*/;
>
> /* cpuid 7.0.ecx*/
> const u32 kvm_cpuid_7_0_ecx_x86_features =
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 3990ba691d07..fcec3d8a0176 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -7111,6 +7111,9 @@ static void vmx_set_supported_cpuid(struct kvm_cpuid_entry2 *entry)
> cpuid_entry_set(entry, X86_FEATURE_MPX);
> if (boot_cpu_has(X86_FEATURE_INVPCID) && cpu_has_vmx_invpcid())
> cpuid_entry_set(entry, X86_FEATURE_INVPCID);
> + if (boot_cpu_has(X86_FEATURE_INTEL_PT) &&
> + vmx_pt_mode_is_host_guest())
> + cpuid_entry_set(entry, X86_FEATURE_INTEL_PT);
> if (vmx_umip_emulated())
> cpuid_entry_set(entry, X86_FEATURE_UMIP);

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

--
Vitaly

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