KVM: x86: Handle Intel PT CPUID adjustment in VMX code

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.
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/cpuid.c

@@ -331,7 +331,6 @@ 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 */
@@ -340,7 +339,7 @@ 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 =

arch/x86/kvm/vmx/vmx.c

@@ -7135,6 +7135,9 @@ 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);