From: Like Xu <like.xu@linux.intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
ak@linux.intel.com, wei.w.wang@intel.com, kan.liang@intel.com,
alex.shi@linux.alibaba.com, kvm@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v14 07/11] KVM: vmx/pmu: Reduce the overhead of LBR pass-through or cancellation
Date: Mon, 1 Feb 2021 13:10:35 +0800 [thread overview]
Message-ID: <20210201051039.255478-8-like.xu@linux.intel.com> (raw)
In-Reply-To: <20210201051039.255478-1-like.xu@linux.intel.com>
When the LBR records msrs has already been pass-through, there is no
need to call vmx_update_intercept_for_lbr_msrs() again and again, and
vice versa.
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
---
arch/x86/kvm/vmx/pmu_intel.c | 13 +++++++++++++
arch/x86/kvm/vmx/vmx.h | 3 +++
2 files changed, 16 insertions(+)
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 287fc14f0445..60f395e18446 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -550,6 +550,7 @@ static void intel_pmu_init(struct kvm_vcpu *vcpu)
vcpu->arch.perf_capabilities = 0;
lbr_desc->records.nr = 0;
lbr_desc->event = NULL;
+ lbr_desc->msr_passthrough = false;
}
static void intel_pmu_reset(struct kvm_vcpu *vcpu)
@@ -596,12 +597,24 @@ static void vmx_update_intercept_for_lbr_msrs(struct kvm_vcpu *vcpu, bool set)
static inline void vmx_disable_lbr_msrs_passthrough(struct kvm_vcpu *vcpu)
{
+ struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu);
+
+ if (!lbr_desc->msr_passthrough)
+ return;
+
vmx_update_intercept_for_lbr_msrs(vcpu, true);
+ lbr_desc->msr_passthrough = false;
}
static inline void vmx_enable_lbr_msrs_passthrough(struct kvm_vcpu *vcpu)
{
+ struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu);
+
+ if (lbr_desc->msr_passthrough)
+ return;
+
vmx_update_intercept_for_lbr_msrs(vcpu, false);
+ lbr_desc->msr_passthrough = true;
}
/*
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 863bb3fe73d4..4d6a2624a204 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -90,6 +90,9 @@ struct lbr_desc {
* The records may be inaccurate if the host reclaims the LBR.
*/
struct perf_event *event;
+
+ /* True if LBRs are marked as not intercepted in the MSR bitmap */
+ bool msr_passthrough;
};
/*
--
2.29.2
next prev parent reply other threads:[~2021-02-01 6:49 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-01 5:10 [PATCH v14 00/11] KVM: x86/pmu: Guest Last Branch Recording Enabling Like Xu
2021-02-01 5:10 ` [PATCH v14 01/11] KVM: x86/vmx: Make vmx_set_intercept_for_msr() non-static Like Xu
2021-02-01 5:10 ` [PATCH v14 02/11] KVM: x86/pmu: Set up IA32_PERF_CAPABILITIES if PDCM bit is available Like Xu
2021-02-02 11:48 ` Paolo Bonzini
2021-02-01 5:10 ` [PATCH v14 03/11] KVM: vmx/pmu: Add PMU_CAP_LBR_FMT check when guest LBR is enabled Like Xu
2021-02-02 12:00 ` Paolo Bonzini
2021-02-01 5:10 ` [PATCH v14 04/11] KVM: vmx/pmu: Expose DEBUGCTLMSR_LBR in the MSR_IA32_DEBUGCTLMSR Like Xu
2021-02-01 5:10 ` [PATCH v14 05/11] KVM: vmx/pmu: Create a guest LBR event when vcpu sets DEBUGCTLMSR_LBR Like Xu
2021-02-01 5:10 ` [PATCH v14 06/11] KVM: vmx/pmu: Pass-through LBR msrs when the guest LBR event is ACTIVE Like Xu
2021-02-01 5:10 ` Like Xu [this message]
2021-02-01 5:10 ` [PATCH v14 08/11] KVM: vmx/pmu: Emulate legacy freezing LBRs on virtual PMI Like Xu
2021-02-01 5:10 ` [PATCH v14 09/11] KVM: vmx/pmu: Release guest LBR event via lazy release mechanism Like Xu
2021-02-01 5:10 ` [PATCH v14 10/11] KVM: vmx/pmu: Expose LBR_FMT in the MSR_IA32_PERF_CAPABILITIES Like Xu
2021-02-01 5:10 ` [PATCH v14 11/11] selftests: kvm/x86: add test for pmu msr MSR_IA32_PERF_CAPABILITIES Like Xu
2021-02-01 6:01 ` [PATCH v14 07/11] KVM: vmx/pmu: Reduce the overhead of LBR pass-through or cancellation Like Xu
2021-02-01 6:01 ` [PATCH v14 08/11] KVM: vmx/pmu: Emulate legacy freezing LBRs on virtual PMI Like Xu
2021-02-01 6:01 ` [PATCH v14 09/11] KVM: vmx/pmu: Release guest LBR event via lazy release mechanism Like Xu
2021-02-01 6:01 ` [PATCH v14 10/11] KVM: vmx/pmu: Expose LBR_FMT in the MSR_IA32_PERF_CAPABILITIES Like Xu
2021-02-01 6:01 ` [PATCH v14 11/11] selftests: kvm/x86: add test for pmu msr MSR_IA32_PERF_CAPABILITIES Like Xu
2021-02-02 14:53 ` Paolo Bonzini
2021-02-02 12:37 ` [PATCH v14 00/11] KVM: x86/pmu: Guest Last Branch Recording Enabling Paolo Bonzini
2021-07-29 12:40 ` Liuxiangdong
2021-07-30 3:15 ` Liuxiangdong
2021-07-30 3:28 ` Like Xu
2022-09-13 23:42 ` Jim Mattson
2022-09-19 7:26 ` Like Xu
2022-09-19 18:08 ` Jim Mattson
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