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From: Like Xu <like.xu@linux.intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Jim Mattson <jmattson@google.com>,
	kvm@vger.kernel.org
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Joerg Roedel <joro@8bytes.org>,
	linux-kernel@vger.kernel.org, Like Xu <like.xu@linux.intel.com>
Subject: [PATCH v13 09/10] KVM: vmx/pmu: Expose LBR_FMT in the MSR_IA32_PERF_CAPABILITIES
Date: Sun, 26 Jul 2020 23:32:28 +0800	[thread overview]
Message-ID: <20200726153229.27149-11-like.xu@linux.intel.com> (raw)
In-Reply-To: <20200726153229.27149-1-like.xu@linux.intel.com>

Userspace could enable guest LBR feature when the exactly supported
LBR format value is initialized to the MSR_IA32_PERF_CAPABILITIES
and the LBR is also compatible with vPMU version and host cpu model.

Signed-off-by: Like Xu <like.xu@linux.intel.com>
---
 arch/x86/kvm/vmx/capabilities.h |  9 ++++++++-
 arch/x86/kvm/vmx/vmx.c          | 10 ++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index f17ab6cf152e..5829f4e9a7e0 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -378,7 +378,14 @@ static inline u64 vmx_get_perf_capabilities(void)
 	 * Since counters are virtualized, KVM would support full
 	 * width counting unconditionally, even if the host lacks it.
 	 */
-	return PMU_CAP_FW_WRITES;
+	u64 perf_cap = PMU_CAP_FW_WRITES;
+
+	if (boot_cpu_has(X86_FEATURE_PDCM))
+		rdmsrl(MSR_IA32_PERF_CAPABILITIES, perf_cap);
+
+	perf_cap |= perf_cap & PMU_CAP_LBR_FMT;
+
+	return perf_cap;
 }
 
 static inline u64 vmx_supported_debugctl(void)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index b72fbbef56fa..6d8b1d98ae1d 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2251,6 +2251,16 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		if ((data >> 32) != 0)
 			return 1;
 		goto find_shared_msr;
+	case MSR_IA32_PERF_CAPABILITIES:
+		if (data & PMU_CAP_LBR_FMT) {
+			if ((data & PMU_CAP_LBR_FMT) !=
+			    (vmx_get_perf_capabilities() & PMU_CAP_LBR_FMT))
+				return 1;
+			if (!intel_pmu_lbr_is_compatible(vcpu))
+				return 1;
+		}
+		ret = kvm_set_msr_common(vcpu, msr_info);
+		break;
 
 	default:
 	find_shared_msr:
-- 
2.21.3


  parent reply	other threads:[~2020-07-26 15:35 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-26 15:32 [PATCH v13 00/10] Guest Last Branch Recording Enabling (KVM part) Like Xu
2020-07-26 15:32 ` [PATCH v13 01/10] KVM: x86: Move common set/get handler of MSR_IA32_DEBUGCTLMSR to VMX Like Xu
2020-07-26 15:32 ` [PATCH] target/i386: add -cpu,lbr=true support to enable guest LBR Like Xu
2020-09-24 22:05   ` Eduardo Habkost
     [not found]     ` <958128c6-39e8-96fe-34d8-7be1888f4144@intel.com>
2020-09-28 15:41       ` Eduardo Habkost
2020-09-29  6:24         ` Xu, Like
2020-07-26 15:32 ` [PATCH v13 02/10] KVM: x86/vmx: Make vmx_set_intercept_for_msr() non-static and expose it Like Xu
2020-09-29  3:13   ` Sean Christopherson
2020-09-29  7:12     ` Xu, Like
2020-07-26 15:32 ` [PATCH v13 03/10] KVM: vmx/pmu: Initialize vcpu perf_capabilities once in intel_pmu_init() Like Xu
2020-07-26 15:32 ` [PATCH v13 04/10] KVM: vmx/pmu: Clear PMU_CAP_LBR_FMT when guest LBR is disabled Like Xu
2020-07-26 15:32 ` [PATCH v13 05/10] KVM: vmx/pmu: Create a guest LBR event when vcpu sets DEBUGCTLMSR_LBR Like Xu
2020-07-26 15:32 ` [PATCH v13 06/10] KVM: vmx/pmu: Pass-through LBR msrs to when the guest LBR event is ACTIVE Like Xu
2020-07-26 15:32 ` [PATCH v13 07/10] KVM: vmx/pmu: Reduce the overhead of LBR pass-through or cancellation Like Xu
2020-07-26 15:32 ` [PATCH v13 08/10] KVM: vmx/pmu: Emulate legacy freezing LBRs on virtual PMI Like Xu
2020-07-26 15:32 ` Like Xu [this message]
2020-07-26 15:32 ` [PATCH v13 10/10] KVM: vmx/pmu: Release guest LBR event via lazy release mechanism Like Xu
2020-08-14  8:48 ` [PATCH v13 00/10] Guest Last Branch Recording Enabling (KVM part) Xu, Like
2020-09-04  1:57   ` Xu, Like
2020-09-30  2:23   ` Xu, Like

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