KVM: x86: Introduce a function to initialize the PT configuration

Initialize the Intel PT configuration when cpuid update.
Include cpuid inforamtion, rtit_ctl bit mask and the number of
address ranges.
Signed-off-by: Luwei Kang <luwei.kang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/vmx.c

@@ -6744,6 +6744,75 @@ static void nested_vmx_entry_exit_ctls_update(struct kvm_vcpu *vcpu)
 	}
 }
 
+static void update_intel_pt_cfg(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	struct kvm_cpuid_entry2 *best = NULL;
+	int i;
+
+	for (i = 0; i < PT_CPUID_LEAVES; i++) {
+		best = kvm_find_cpuid_entry(vcpu, 0x14, i);
+		if (!best)
+			return;
+		vmx->pt_desc.caps[CPUID_EAX + i*PT_CPUID_REGS_NUM] = best->eax;
+		vmx->pt_desc.caps[CPUID_EBX + i*PT_CPUID_REGS_NUM] = best->ebx;
+		vmx->pt_desc.caps[CPUID_ECX + i*PT_CPUID_REGS_NUM] = best->ecx;
+		vmx->pt_desc.caps[CPUID_EDX + i*PT_CPUID_REGS_NUM] = best->edx;
+	}
+
+	/* Get the number of configurable Address Ranges for filtering */
+	vmx->pt_desc.addr_range = intel_pt_validate_cap(vmx->pt_desc.caps,
+						PT_CAP_num_address_ranges);
+
+	/* Initialize and clear the no dependency bits */
+	vmx->pt_desc.ctl_bitmask = ~(RTIT_CTL_TRACEEN | RTIT_CTL_OS |
+			RTIT_CTL_USR | RTIT_CTL_TSC_EN | RTIT_CTL_DISRETC);
+
+	/*
+	 * If CPUID.(EAX=14H,ECX=0):EBX[0]=1 CR3Filter can be set otherwise
+	 * will inject an #GP
+	 */
+	if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_cr3_filtering))
+		vmx->pt_desc.ctl_bitmask &= ~RTIT_CTL_CR3EN;
+
+	/*
+	 * If CPUID.(EAX=14H,ECX=0):EBX[1]=1 CYCEn, CycThresh and
+	 * PSBFreq can be set
+	 */
+	if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_psb_cyc))
+		vmx->pt_desc.ctl_bitmask &= ~(RTIT_CTL_CYCLEACC |
+				RTIT_CTL_CYC_THRESH | RTIT_CTL_PSB_FREQ);
+
+	/*
+	 * If CPUID.(EAX=14H,ECX=0):EBX[3]=1 MTCEn BranchEn and
+	 * MTCFreq can be set
+	 */
+	if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_mtc))
+		vmx->pt_desc.ctl_bitmask &= ~(RTIT_CTL_MTC_EN |
+				RTIT_CTL_BRANCH_EN | RTIT_CTL_MTC_RANGE);
+
+	/* If CPUID.(EAX=14H,ECX=0):EBX[4]=1 FUPonPTW and PTWEn can be set */
+	if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_ptwrite))
+		vmx->pt_desc.ctl_bitmask &= ~(RTIT_CTL_FUP_ON_PTW |
+							RTIT_CTL_PTW_EN);
+
+	/* If CPUID.(EAX=14H,ECX=0):EBX[5]=1 PwrEvEn can be set */
+	if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_power_event_trace))
+		vmx->pt_desc.ctl_bitmask &= ~RTIT_CTL_PWR_EVT_EN;
+
+	/* If CPUID.(EAX=14H,ECX=0):ECX[0]=1 ToPA can be set */
+	if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_topa_output))
+		vmx->pt_desc.ctl_bitmask &= ~RTIT_CTL_TOPA;
+
+	/* If CPUID.(EAX=14H,ECX=0):ECX[3]=1 FabircEn can be set */
+	if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_output_subsys))
+		vmx->pt_desc.ctl_bitmask &= ~RTIT_CTL_FABRIC_EN;
+
+	/* unmask address range configure area */
+	for (i = 0; i < vmx->pt_desc.addr_range; i++)
+		vmx->pt_desc.ctl_bitmask &= ~(0xf << (32 + i * 4));
+}
+
 static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -6764,6 +6833,10 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
 		nested_vmx_cr_fixed1_bits_update(vcpu);
 		nested_vmx_entry_exit_ctls_update(vcpu);
 	}
+
+	if (boot_cpu_has(X86_FEATURE_INTEL_PT) &&
+			guest_cpuid_has(vcpu, X86_FEATURE_INTEL_PT))
+		update_intel_pt_cfg(vcpu);
 }
 
 static void vmx_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry)