From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D63CC433ED for ; Mon, 10 May 2021 08:16:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 571E361364 for ; Mon, 10 May 2021 08:16:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230266AbhEJIR3 (ORCPT ); Mon, 10 May 2021 04:17:29 -0400 Received: from mga12.intel.com ([192.55.52.136]:42733 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230059AbhEJIR1 (ORCPT ); Mon, 10 May 2021 04:17:27 -0400 IronPort-SDR: p6CaiEjTqd14lmXSKLp/xmoF/w+sIqWqZS8j94U+U8sSNqYZ0CoVndvehzav1CtvcxX9VHfAnz ZYi5VMiG1pnQ== X-IronPort-AV: E=McAfee;i="6200,9189,9979"; a="178727732" X-IronPort-AV: E=Sophos;i="5.82,287,1613462400"; d="scan'208";a="178727732" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 May 2021 01:16:23 -0700 IronPort-SDR: japnT3lCwIskFFI4B6fLq4ZJgVi0nPAgNQgTDCT2ndxFkTQJ6HSfMMiqKBTRKGcYgIML4o2aqd uIDwWdIyxToA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,287,1613462400"; d="scan'208";a="408250850" Received: from clx-ap-likexu.sh.intel.com ([10.239.48.108]) by orsmga002.jf.intel.com with ESMTP; 10 May 2021 01:16:20 -0700 From: Like Xu To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , weijiang.yang@intel.com, wei.w.wang@intel.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RESEND PATCH v4 03/10] KVM: vmx/pmu: Add MSR_ARCH_LBR_DEPTH emulation for Arch LBR Date: Mon, 10 May 2021 16:15:27 +0800 Message-Id: <20210510081535.94184-4-like.xu@linux.intel.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210510081535.94184-1-like.xu@linux.intel.com> References: <20210510081535.94184-1-like.xu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The number of Arch LBR entries available for recording operations is dictated by the value in MSR_ARCH_LBR_DEPTH.DEPTH. The supported LBR depth values can be found in CPUID.(EAX=01CH, ECX=0):EAX[7:0] and for each bit "n" set in this field, the MSR_ARCH_LBR_DEPTH.DEPTH value of "8*(n+1)" is supported. On a guest write to MSR_ARCH_LBR_DEPTH, all LBR entries are reset to 0. KVM emulates the reset behavior by introducing lbr_desc->arch_lbr_reset. KVM writes the guest requested value to the native ARCH_LBR_DEPTH MSR (this is safe because the two values will be the same) when the Arch LBR records MSRs are pass-through to the guest. Signed-off-by: Like Xu --- arch/x86/kvm/vmx/pmu_intel.c | 43 ++++++++++++++++++++++++++++++++++++ arch/x86/kvm/vmx/vmx.h | 3 +++ 2 files changed, 46 insertions(+) diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 9efc1a6b8693..d9c9cb6c9a4b 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -220,6 +220,9 @@ static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr) case MSR_CORE_PERF_GLOBAL_OVF_CTRL: ret = pmu->version > 1; break; + case MSR_ARCH_LBR_DEPTH: + ret = guest_cpuid_has(vcpu, X86_FEATURE_ARCH_LBR); + break; default: ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) || get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0) || @@ -250,6 +253,7 @@ static inline void intel_pmu_release_guest_lbr_event(struct kvm_vcpu *vcpu) if (lbr_desc->event) { perf_event_release_kernel(lbr_desc->event); lbr_desc->event = NULL; + lbr_desc->arch_lbr_reset = false; vcpu_to_pmu(vcpu)->event_count--; } } @@ -348,10 +352,26 @@ static bool intel_pmu_handle_lbr_msrs_access(struct kvm_vcpu *vcpu, return true; } +/* + * Check if the requested depth values is supported + * based on the bits [0:7] of the guest cpuid.1c.eax. + */ +static bool arch_lbr_depth_is_valid(struct kvm_vcpu *vcpu, u64 depth) +{ + struct kvm_cpuid_entry2 *best; + + best = kvm_find_cpuid_entry(vcpu, 0x1c, 0); + if (best && depth && (depth < 65) && !(depth & 7)) + return best->eax & BIT_ULL(depth / 8 - 1); + + return false; +} + static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) { struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); struct kvm_pmc *pmc; + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); u32 msr = msr_info->index; switch (msr) { @@ -367,6 +387,9 @@ static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_CORE_PERF_GLOBAL_OVF_CTRL: msr_info->data = pmu->global_ovf_ctrl; return 0; + case MSR_ARCH_LBR_DEPTH: + msr_info->data = lbr_desc->records.nr; + return 0; default: if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) || (pmc = get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) { @@ -393,6 +416,7 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) { struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); struct kvm_pmc *pmc; + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); u32 msr = msr_info->index; u64 data = msr_info->data; @@ -427,6 +451,12 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) return 0; } break; + case MSR_ARCH_LBR_DEPTH: + if (!arch_lbr_depth_is_valid(vcpu, data)) + return 1; + lbr_desc->records.nr = data; + lbr_desc->arch_lbr_reset = true; + return 0; default: if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) || (pmc = get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) { @@ -566,6 +596,7 @@ static void intel_pmu_init(struct kvm_vcpu *vcpu) lbr_desc->records.nr = 0; lbr_desc->event = NULL; lbr_desc->msr_passthrough = false; + lbr_desc->arch_lbr_reset = false; } static void intel_pmu_reset(struct kvm_vcpu *vcpu) @@ -623,6 +654,15 @@ static void intel_pmu_deliver_pmi(struct kvm_vcpu *vcpu) intel_pmu_legacy_freezing_lbrs_on_pmi(vcpu); } +static void intel_pmu_arch_lbr_reset(struct kvm_vcpu *vcpu) +{ + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); + + /* On a software write to IA32_LBR_DEPTH, all LBR entries are reset to 0. */ + wrmsrl(MSR_ARCH_LBR_DEPTH, lbr_desc->records.nr); + lbr_desc->arch_lbr_reset = false; +} + static void vmx_update_intercept_for_lbr_msrs(struct kvm_vcpu *vcpu, bool set) { struct x86_pmu_lbr *lbr = vcpu_to_lbr_records(vcpu); @@ -654,6 +694,9 @@ static inline void vmx_enable_lbr_msrs_passthrough(struct kvm_vcpu *vcpu) { struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); + if (unlikely(lbr_desc->arch_lbr_reset)) + intel_pmu_arch_lbr_reset(vcpu); + if (lbr_desc->msr_passthrough) return; diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 16e4e457ba23..cc362e2d3eaa 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -116,6 +116,9 @@ struct lbr_desc { /* True if LBRs are marked as not intercepted in the MSR bitmap */ bool msr_passthrough; + + /* Reset all LBR entries on a guest write to MSR_ARCH_LBR_DEPTH */ + bool arch_lbr_reset; }; /* -- 2.31.1