From patchwork Sat Jun 13 08:09:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Like Xu X-Patchwork-Id: 11602601 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2484660D for ; Sat, 13 Jun 2020 08:12:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 16778207FF for ; Sat, 13 Jun 2020 08:12:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726563AbgFMILh (ORCPT ); Sat, 13 Jun 2020 04:11:37 -0400 Received: from mga07.intel.com ([134.134.136.100]:64600 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726541AbgFMILd (ORCPT ); Sat, 13 Jun 2020 04:11:33 -0400 IronPort-SDR: 918yfGiljIrESC7/iWY7XuNlvoy1LYbQ8ocM/zK4xX6GOU3Zq2vkdDSEXjhWnYyN4W9B5GrrLz 9j3aEm2VaWIg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jun 2020 01:11:32 -0700 IronPort-SDR: IA2aq0Psj6XKnGsFTqLXpJJl3J4I5Bd0cqRpKIbdbx7qYyl+Sk6Ud0xX8CMATdQ/mD3m1pDavQ oKwJpUaNaUig== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,506,1583222400"; d="scan'208";a="474467442" Received: from sqa-gate.sh.intel.com (HELO clx-ap-likexu.tsp.org) ([10.239.48.212]) by fmsmga006.fm.intel.com with ESMTP; 13 Jun 2020 01:11:29 -0700 From: Like Xu To: Paolo Bonzini Cc: Peter Zijlstra , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , ak@linux.intel.com, wei.w.wang@intel.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Like Xu Subject: [PATCH v12 09/11] KVM: vmx/pmu: Emulate legacy freezing LBRs on virtual PMI Date: Sat, 13 Jun 2020 16:09:54 +0800 Message-Id: <20200613080958.132489-10-like.xu@linux.intel.com> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20200613080958.132489-1-like.xu@linux.intel.com> References: <20200613080958.132489-1-like.xu@linux.intel.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The current vPMU only supports Architecture Version 2. According to Intel SDM "17.4.7 Freezing LBR and Performance Counters on PMI", if IA32_DEBUGCTL.Freeze_LBR_On_PMI = 1, the LBR is frozen on the virtual PMI and the KVM would emulate to clear the LBR bit (bit 0) in IA32_DEBUGCTL. Also guest needs to re-enable IA32_DEBUGCTL.LBR to resume recording branches. Signed-off-by: Like Xu --- arch/x86/kvm/pmu.c | 5 ++++- arch/x86/kvm/pmu.h | 1 + arch/x86/kvm/vmx/pmu_intel.c | 31 +++++++++++++++++++++++++++++++ 3 files changed, 36 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index b86346903f2e..5053f4238218 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -378,8 +378,11 @@ int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data) void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu) { - if (lapic_in_kernel(vcpu)) + if (lapic_in_kernel(vcpu)) { + if (kvm_x86_ops.pmu_ops->deliver_pmi) + kvm_x86_ops.pmu_ops->deliver_pmi(vcpu); kvm_apic_local_deliver(vcpu->arch.apic, APIC_LVTPC); + } } bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr) diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h index ab85eed8a6cc..095b84392b89 100644 --- a/arch/x86/kvm/pmu.h +++ b/arch/x86/kvm/pmu.h @@ -37,6 +37,7 @@ struct kvm_pmu_ops { void (*refresh)(struct kvm_vcpu *vcpu); void (*init)(struct kvm_vcpu *vcpu); void (*reset)(struct kvm_vcpu *vcpu); + void (*deliver_pmi)(struct kvm_vcpu *vcpu); }; static inline u64 pmc_bitmask(struct kvm_pmc *pmc) diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index a78c440ebff2..85a675004cbb 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -641,6 +641,36 @@ static void intel_pmu_reset(struct kvm_vcpu *vcpu) intel_pmu_free_lbr_event(vcpu); } +/* + * Emulate LBR_On_PMI behavior for 1 < pmu.version < 4. + * + * If Freeze_LBR_On_PMI = 1, the LBR is frozen on PMI and + * the KVM emulates to clear the LBR bit (bit 0) in IA32_DEBUGCTL. + * + * Guest needs to re-enable LBR to resume branches recording. + */ +static void intel_pmu_legacy_freezing_lbrs_on_pmi(struct kvm_vcpu *vcpu) +{ + u64 data; + + data = vmcs_read64(GUEST_IA32_DEBUGCTL); + if (data & DEBUGCTLMSR_FREEZE_LBRS_ON_PMI) { + data &= ~DEBUGCTLMSR_LBR; + vmcs_write64(GUEST_IA32_DEBUGCTL, data); + } +} + +static void intel_pmu_deliver_pmi(struct kvm_vcpu *vcpu) +{ + u8 version = vcpu_to_pmu(vcpu)->version; + + if (!lbr_is_enabled(vcpu)) + return; + + if (version > 1 && version < 4) + intel_pmu_legacy_freezing_lbrs_on_pmi(vcpu); +} + struct kvm_pmu_ops intel_pmu_ops = { .find_arch_event = intel_find_arch_event, .find_fixed_event = intel_find_fixed_event, @@ -655,4 +685,5 @@ struct kvm_pmu_ops intel_pmu_ops = { .refresh = intel_pmu_refresh, .init = intel_pmu_init, .reset = intel_pmu_reset, + .deliver_pmi = intel_pmu_deliver_pmi, };