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From: Yang Weijiang <weijiang.yang@intel.com>
To: pbonzini@redhat.com, jmattson@google.com, seanjc@google.com,
	like.xu.linux@gmail.com, vkuznets@redhat.com,
	wei.w.wang@intel.com, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: Yang Weijiang <weijiang.yang@intel.com>
Subject: [PATCH v8 06/15] KVM: x86/pmu: Refactor code to support guest Arch LBR
Date: Tue, 24 Aug 2021 15:56:08 +0800	[thread overview]
Message-ID: <1629791777-16430-7-git-send-email-weijiang.yang@intel.com> (raw)
In-Reply-To: <1629791777-16430-1-git-send-email-weijiang.yang@intel.com>

Take account of Arch LBR when do sanity checks before program
vPMU for guest. Pass through Arch LBR recording MSRs to guest
to gain better performance. Note, Arch LBR and Legacy LBR support
are mutually exclusive, i.e., they're not both available on one
platform.

Co-developed-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
 arch/x86/kvm/vmx/pmu_intel.c | 37 +++++++++++++++++++++++++++++-------
 arch/x86/kvm/vmx/vmx.c       |  3 +++
 2 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index db055b352de0..62cafe4ff9ad 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -176,12 +176,16 @@ static inline struct kvm_pmc *get_fw_gp_pmc(struct kvm_pmu *pmu, u32 msr)
 
 bool intel_pmu_lbr_is_compatible(struct kvm_vcpu *vcpu)
 {
+	if (kvm_cpu_cap_has(X86_FEATURE_ARCH_LBR))
+		return guest_cpuid_has(vcpu, X86_FEATURE_ARCH_LBR);
+
 	/*
 	 * As a first step, a guest could only enable LBR feature if its
 	 * cpu model is the same as the host because the LBR registers
 	 * would be pass-through to the guest and they're model specific.
 	 */
-	return boot_cpu_data.x86_model == guest_cpuid_model(vcpu);
+	return !boot_cpu_has(X86_FEATURE_ARCH_LBR) &&
+		boot_cpu_data.x86_model == guest_cpuid_model(vcpu);
 }
 
 bool intel_pmu_lbr_is_enabled(struct kvm_vcpu *vcpu)
@@ -199,12 +203,19 @@ static bool intel_pmu_is_valid_lbr_msr(struct kvm_vcpu *vcpu, u32 index)
 	if (!intel_pmu_lbr_is_enabled(vcpu))
 		return ret;
 
-	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))
+		ret = (index == MSR_LBR_SELECT) || (index == MSR_LBR_TOS);
+
+	if (!ret) {
+		ret = (index >= records->from &&
+		       index < records->from + records->nr) ||
+		      (index >= records->to &&
+		       index < records->to + records->nr);
+	}
 
 	if (!ret && records->info)
-		ret = (index >= records->info && index < records->info + records->nr);
+		ret = (index >= records->info &&
+		       index < records->info + records->nr);
 
 	return ret;
 }
@@ -743,6 +754,9 @@ 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);
 }
@@ -783,10 +797,13 @@ 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_LBR_CTL) & ARCH_LBR_CTL_LBREN) :
+		(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;
@@ -803,13 +820,19 @@ void vmx_passthrough_lbr_msrs(struct kvm_vcpu *vcpu)
 	return;
 
 warn:
+	if (kvm_cpu_cap_has(X86_FEATURE_ARCH_LBR))
+		wrmsrl(MSR_ARCH_LBR_DEPTH, lbr_desc->records.nr);
 	pr_warn_ratelimited("kvm: vcpu-%d: fail to passthrough LBR.\n",
 		vcpu->vcpu_id);
 }
 
 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_LBR_CTL) & ARCH_LBR_CTL_LBREN) :
+		(vmcs_read64(GUEST_IA32_DEBUGCTL) & DEBUGCTLMSR_LBR);
+
+	if (!lbr_enable)
 		intel_pmu_release_guest_lbr_event(vcpu);
 }
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index e8df44faf900..c15be89d6619 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -576,6 +576,9 @@ static bool is_valid_passthrough_msr(u32 msr)
 	case MSR_LBR_NHM_TO ... MSR_LBR_NHM_TO + 31:
 	case MSR_LBR_CORE_FROM ... MSR_LBR_CORE_FROM + 8:
 	case MSR_LBR_CORE_TO ... MSR_LBR_CORE_TO + 8:
+	case MSR_ARCH_LBR_FROM_0 ... MSR_ARCH_LBR_FROM_0 + 31:
+	case MSR_ARCH_LBR_TO_0 ... MSR_ARCH_LBR_TO_0 + 31:
+	case MSR_ARCH_LBR_INFO_0 ... MSR_ARCH_LBR_INFO_0 + 31:
 		/* LBR MSRs. These are handled in vmx_update_intercept_for_lbr_msrs() */
 		return true;
 	}
-- 
2.25.1


  parent reply	other threads:[~2021-08-24  7:41 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-24  7:56 [PATCH v8 00/15] Introduce Architectural LBR for vPMU Yang Weijiang
2021-08-24  7:56 ` [PATCH v8 01/15] perf/x86/intel: Fix the comment about guest LBR support on KVM Yang Weijiang
2021-08-24  7:56 ` [PATCH v8 02/15] perf/x86/lbr: Simplify the exposure check for the LBR_INFO registers Yang Weijiang
2021-08-24  7:56 ` [PATCH v8 03/15] KVM: x86: Add Arch LBR MSRs to msrs_to_save_all list Yang Weijiang
2021-08-24  7:56 ` [PATCH v8 04/15] KVM: vmx/pmu: Emulate MSR_ARCH_LBR_DEPTH for guest Arch LBR Yang Weijiang
2021-08-24  7:56 ` [PATCH v8 05/15] KVM: vmx/pmu: Emulate MSR_ARCH_LBR_CTL " Yang Weijiang
2021-08-25  7:59   ` kernel test robot
2021-08-27  1:06   ` kernel test robot
2021-08-24  7:56 ` Yang Weijiang [this message]
2021-08-24  7:56 ` [PATCH v8 07/15] KVM: x86: Refresh CPUID on writes to MSR_IA32_XSS Yang Weijiang
2021-08-24  7:56 ` [PATCH v8 08/15] KVM: x86: Report XSS as an MSR to be saved if there are supported features Yang Weijiang
2021-08-24  7:56 ` [PATCH v8 09/15] KVM: x86: Refine the matching and clearing logic for supported_xss Yang Weijiang
2021-08-24  7:56 ` [PATCH v8 10/15] KVM: x86: Add XSAVE Support for Architectural LBR Yang Weijiang
2021-08-24  7:56 ` [PATCH v8 11/15] KVM: x86/vmx: Check Arch LBR config when return perf capabilities Yang Weijiang
2021-08-24  7:56 ` [PATCH v8 12/15] KVM: nVMX: Add necessary Arch LBR settings for nested VM Yang Weijiang
2021-08-24  7:56 ` [PATCH v8 13/15] KVM: x86/vmx: Clear Arch LBREn bit before inject #DB to guest Yang Weijiang
2021-08-24  7:56 ` [PATCH v8 14/15] KVM: x86/vmx: Flip Arch LBREn bit on guest state change Yang Weijiang
2021-08-24  7:56 ` [PATCH v8 15/15] KVM: x86/cpuid: Advise Arch LBR feature in CPUID Yang Weijiang
2021-10-15  0:01   ` Sean Christopherson
2021-10-15  1:28     ` Yang Weijiang
2021-10-15  2:05       ` Like Xu
2021-10-15 14:49         ` Sean Christopherson
2021-09-07  3:26 ` [PATCH v8 00/15] Introduce Architectural LBR for vPMU Yang Weijiang

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