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From: Yang Weijiang <weijiang.yang@intel.com>
To: pbonzini@redhat.com, seanjc@google.com, kvm@vger.kernel.org
Cc: like.xu.linux@gmail.com, kan.liang@linux.intel.com,
	wei.w.wang@intel.com, linux-kernel@vger.kernel.org
Subject: [PATCH 04/15] KVM: PMU: disable LBR handling if architectural LBR is available
Date: Wed, 31 Aug 2022 18:34:27 -0400	[thread overview]
Message-ID: <20220831223438.413090-5-weijiang.yang@intel.com> (raw)
In-Reply-To: <20220831223438.413090-1-weijiang.yang@intel.com>

From: Paolo Bonzini <pbonzini@redhat.com>

Traditional LBR is absent on CPU models that have architectural LBR, so
disable all processing of traditional LBR MSRs if they are not there.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/pmu_intel.c | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index c399637a3a79..89cb75bb0280 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -174,19 +174,23 @@ static inline struct kvm_pmc *get_fw_gp_pmc(struct kvm_pmu *pmu, u32 msr)
 static bool intel_pmu_is_valid_lbr_msr(struct kvm_vcpu *vcpu, u32 index)
 {
 	struct x86_pmu_lbr *records = vcpu_to_lbr_records(vcpu);
-	bool ret = false;
 
 	if (!intel_pmu_lbr_is_enabled(vcpu))
-		return ret;
+		return false;
 
-	ret = (index == MSR_LBR_SELECT) || (index == MSR_LBR_TOS) ||
-		(index >= records->from && index < records->from + records->nr) ||
-		(index >= records->to && index < records->to + records->nr);
+	if (!guest_cpuid_has(vcpu, X86_FEATURE_ARCH_LBR) &&
+	    (index == MSR_LBR_SELECT || index == MSR_LBR_TOS))
+		return true;
 
-	if (!ret && records->info)
-		ret = (index >= records->info && index < records->info + records->nr);
+	if ((index >= records->from && index < records->from + records->nr) ||
+	    (index >= records->to && index < records->to + records->nr))
+		return true;
 
-	return ret;
+	if (records->info && index >= records->info &&
+	    index < records->info + records->nr)
+		return true;
+
+	return false;
 }
 
 static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
@@ -703,6 +707,9 @@ static void vmx_update_intercept_for_lbr_msrs(struct kvm_vcpu *vcpu, bool set)
 			vmx_set_intercept_for_msr(vcpu, lbr->info + i, MSR_TYPE_RW, set);
 	}
 
+	if (guest_cpuid_has(vcpu, X86_FEATURE_ARCH_LBR))
+		return;
+
 	vmx_set_intercept_for_msr(vcpu, MSR_LBR_SELECT, MSR_TYPE_RW, set);
 	vmx_set_intercept_for_msr(vcpu, MSR_LBR_TOS, MSR_TYPE_RW, set);
 }
@@ -743,10 +750,12 @@ void vmx_passthrough_lbr_msrs(struct kvm_vcpu *vcpu)
 {
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 	struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu);
+	bool lbr_enable = !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_LBR) &&
+		(vmcs_read64(GUEST_IA32_DEBUGCTL) & DEBUGCTLMSR_LBR);
 
 	if (!lbr_desc->event) {
 		vmx_disable_lbr_msrs_passthrough(vcpu);
-		if (vmcs_read64(GUEST_IA32_DEBUGCTL) & DEBUGCTLMSR_LBR)
+		if (lbr_enable)
 			goto warn;
 		if (test_bit(INTEL_PMC_IDX_FIXED_VLBR, pmu->pmc_in_use))
 			goto warn;
@@ -769,7 +778,10 @@ void vmx_passthrough_lbr_msrs(struct kvm_vcpu *vcpu)
 
 static void intel_pmu_cleanup(struct kvm_vcpu *vcpu)
 {
-	if (!(vmcs_read64(GUEST_IA32_DEBUGCTL) & DEBUGCTLMSR_LBR))
+	bool lbr_enable = !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_LBR) &&
+		(vmcs_read64(GUEST_IA32_DEBUGCTL) & DEBUGCTLMSR_LBR);
+
+	if (!lbr_enable)
 		intel_pmu_release_guest_lbr_event(vcpu);
 }
 
-- 
2.27.0


  parent reply	other threads:[~2022-09-01  1:37 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-31 22:34 [PATCH 00/15] Introduce Architectural LBR for vPMU Yang Weijiang
2022-08-31 22:34 ` [PATCH 01/15] perf/x86/lbr: Simplify the exposure check for the LBR_INFO registers Yang Weijiang
2022-09-01 14:19   ` Sean Christopherson
2022-09-02  3:05     ` Yang, Weijiang
2022-08-31 22:34 ` [PATCH 02/15] KVM: x86: Report XSS as an MSR to be saved if there are supported features Yang Weijiang
2022-08-31 22:34 ` [PATCH 03/15] KVM: x86: Refresh CPUID on writes to MSR_IA32_XSS Yang Weijiang
2022-08-31 22:34 ` Yang Weijiang [this message]
2022-08-31 22:34 ` [PATCH 05/15] KVM: vmx/pmu: Emulate MSR_ARCH_LBR_DEPTH for guest Arch LBR Yang Weijiang
2022-08-31 22:34 ` [PATCH 06/15] KVM: vmx/pmu: Emulate MSR_ARCH_LBR_CTL " Yang Weijiang
2022-08-31 22:34 ` [PATCH 07/15] KVM: VMX: Support passthrough of architectural LBRs Yang Weijiang
2022-09-01 14:20   ` Sean Christopherson
2022-09-02  3:04     ` Yang, Weijiang
2022-08-31 22:34 ` [PATCH 08/15] KVM: x86: Add Arch LBR MSRs to msrs_to_save_all list Yang Weijiang
2022-08-31 22:34 ` [PATCH 09/15] KVM: x86: Refine the matching and clearing logic for supported_xss Yang Weijiang
2022-08-31 22:34 ` [PATCH 10/15] KVM: x86/vmx: Check Arch LBR config when return perf capabilities Yang Weijiang
2022-08-31 22:34 ` [PATCH 11/15] KVM: x86: Add XSAVE Support for Architectural LBR Yang Weijiang
2022-08-31 22:34 ` [PATCH 12/15] KVM: x86/vmx: Clear Arch LBREn bit before inject #DB to guest Yang Weijiang
2022-08-31 22:34 ` [PATCH 13/15] KVM: x86/vmx: Flip Arch LBREn bit on guest state change Yang Weijiang
2022-08-31 22:34 ` [PATCH 14/15] KVM: x86: Add Arch LBR data MSR access interface Yang Weijiang
2022-08-31 22:34 ` [PATCH 15/15] KVM: x86/cpuid: Advertise Arch LBR feature in CPUID Yang Weijiang
2022-09-01 14:23 ` [PATCH 00/15] Introduce Architectural LBR for vPMU Sean Christopherson
2022-09-02  3:44   ` Yang, Weijiang
2022-10-21  2:14     ` Yang, Weijiang
2022-10-30  6:06       ` Yang, Weijiang

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