From nobody Sat Feb 7 20:33:18 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52F2DC433F5 for ; Tue, 17 May 2022 15:43:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235124AbiEQPnZ (ORCPT ); Tue, 17 May 2022 11:43:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350495AbiEQPli (ORCPT ); Tue, 17 May 2022 11:41:38 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5560741312; Tue, 17 May 2022 08:41:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1652802097; x=1684338097; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Myp3GlTN5oxwIa3pW8JLbfoYhVNkfVcR8xonCn01QvI=; b=YLoCgZF0hmc5T27Ma+Xsg1daK60nfrj8L5mgtYKvDNCq0n7YkVThAt/O Zj2bWCw223eFNi1q8xF6J3oc+DDQJkFb/0oUgXArxc0qNwYtnKMvviTcv vvKzkcSREKQUGwhWzaZ8wS/HAmMVyxBFj9nSTnZK1G6xkuWtHrvkP1jR5 WyDAhu/PIcSkGCTKTM24JqXMV+PiDMve3u3qidQvOIS6hihG9q54JyQKK MyFw2eBK0KyweswBNAKN1osNGjhGC3sIFWx5A7GC/CeBHQD1VUeev5eyl BYOx6xYgRqmmyJ1cKrvvnhAWbNFiEZYW+mn1hkR5MqrFRKY2eqPY0q+B5 g==; X-IronPort-AV: E=McAfee;i="6400,9594,10350"; a="357632105" X-IronPort-AV: E=Sophos;i="5.91,233,1647327600"; d="scan'208";a="357632105" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 May 2022 08:41:34 -0700 X-IronPort-AV: E=Sophos;i="5.91,233,1647327600"; d="scan'208";a="626533575" Received: from embargo.jf.intel.com ([10.165.9.183]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 May 2022 08:41:33 -0700 From: Yang Weijiang To: pbonzini@redhat.com, jmattson@google.com, seanjc@google.com, like.xu.linux@gmail.com, vkuznets@redhat.com, kan.liang@linux.intel.com, wei.w.wang@intel.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Like Xu , Yang Weijiang Subject: [PATCH v12 07/16] KVM: vmx/pmu: Emulate MSR_ARCH_LBR_CTL for guest Arch LBR Date: Tue, 17 May 2022 11:40:51 -0400 Message-Id: <20220517154100.29983-8-weijiang.yang@intel.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220517154100.29983-1-weijiang.yang@intel.com> References: <20220517154100.29983-1-weijiang.yang@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Like Xu Arch LBR is enabled by setting MSR_ARCH_LBR_CTL.LBREn to 1. A new guest state field named "Guest IA32_LBR_CTL" is added to enhance guest LBR usage. When guest Arch LBR is enabled, a guest LBR event will be created like the model-specific LBR does. Clear guest LBR enable bit on host PMI handling so guest can see expected config. On processors that support Arch LBR, MSR_IA32_DEBUGCTLMSR[bit 0] has no meaning. It can be written to 0 or 1, but reads will always return 0. Like IA32_DEBUGCTL, IA32_ARCH_LBR_CTL msr is also preserved on INIT. Regardless of the Arch LBR or legacy LBR, when the LBR_EN bit 0 of the corresponding control MSR is set to 1, LBR recording will be enabled. Signed-off-by: Like Xu Co-developed-by: Yang Weijiang Signed-off-by: Yang Weijiang Reviewed-by: Kan Liang --- arch/x86/events/intel/lbr.c | 2 -- arch/x86/include/asm/msr-index.h | 1 + arch/x86/include/asm/vmx.h | 2 ++ arch/x86/kvm/vmx/pmu_intel.c | 57 ++++++++++++++++++++++++++++---- arch/x86/kvm/vmx/vmx.c | 12 +++++++ 5 files changed, 66 insertions(+), 8 deletions(-) diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c index 4529ce448b2e..4fe6c3b50fc3 100644 --- a/arch/x86/events/intel/lbr.c +++ b/arch/x86/events/intel/lbr.c @@ -160,8 +160,6 @@ enum { ARCH_LBR_RETURN |\ ARCH_LBR_OTHER_BRANCH) =20 -#define ARCH_LBR_CTL_MASK 0x7f000e - static void intel_pmu_lbr_filter(struct cpu_hw_events *cpuc); =20 static __always_inline bool is_lbr_call_stack_bit_set(u64 config) diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-in= dex.h index c89ca8f78462..65e90414c603 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -169,6 +169,7 @@ #define LBR_INFO_BR_TYPE (0xfull << LBR_INFO_BR_TYPE_OFFSET) =20 #define MSR_ARCH_LBR_CTL 0x000014ce +#define ARCH_LBR_CTL_MASK 0x7f000e #define ARCH_LBR_CTL_LBREN BIT(0) #define ARCH_LBR_CTL_CPL_OFFSET 1 #define ARCH_LBR_CTL_CPL (0x3ull << ARCH_LBR_CTL_CPL_OFFSET) diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h index 89d2172787c5..a84d902952ce 100644 --- a/arch/x86/include/asm/vmx.h +++ b/arch/x86/include/asm/vmx.h @@ -256,6 +256,8 @@ enum vmcs_field { GUEST_BNDCFGS_HIGH =3D 0x00002813, GUEST_IA32_RTIT_CTL =3D 0x00002814, GUEST_IA32_RTIT_CTL_HIGH =3D 0x00002815, + GUEST_IA32_LBR_CTL =3D 0x00002816, + GUEST_IA32_LBR_CTL_HIGH =3D 0x00002817, HOST_IA32_PAT =3D 0x00002c00, HOST_IA32_PAT_HIGH =3D 0x00002c01, HOST_IA32_EFER =3D 0x00002c02, diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 22d6a869ea4d..0e882e97728e 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -19,6 +19,7 @@ #include "pmu.h" =20 #define MSR_PMC_FULL_WIDTH_BIT (MSR_IA32_PMC0 - MSR_IA32_PERFCTR0) +#define KVM_ARCH_LBR_CTL_MASK (ARCH_LBR_CTL_MASK | ARCH_LBR_CTL_LBREN) =20 static struct kvm_event_hw_type_mapping intel_arch_events[] =3D { [0] =3D { 0x3c, 0x00, PERF_COUNT_HW_CPU_CYCLES }, @@ -182,7 +183,7 @@ static bool intel_pmu_is_valid_lbr_msr(struct kvm_vcpu = *vcpu, u32 index) if (!intel_pmu_lbr_is_enabled(vcpu)) return ret; =20 - if (index =3D=3D MSR_ARCH_LBR_DEPTH) { + if (index =3D=3D MSR_ARCH_LBR_DEPTH || index =3D=3D MSR_ARCH_LBR_CTL) { if (kvm_cpu_cap_has(X86_FEATURE_ARCH_LBR)) ret =3D guest_cpuid_has(vcpu, X86_FEATURE_ARCH_LBR); return ret; @@ -364,6 +365,33 @@ static bool arch_lbr_depth_is_valid(struct kvm_vcpu *v= cpu, u64 depth) return (depth =3D=3D pmu->kvm_arch_lbr_depth); } =20 +static bool arch_lbr_ctl_is_valid(struct kvm_vcpu *vcpu, u64 ctl) +{ + struct kvm_cpuid_entry2 *entry; + + if (!kvm_cpu_cap_has(X86_FEATURE_ARCH_LBR)) + return false; + + if (ctl & ~KVM_ARCH_LBR_CTL_MASK) + goto warn; + + entry =3D kvm_find_cpuid_entry(vcpu, 0x1c, 0); + if (!entry) + return false; + + if (!(entry->ebx & BIT(0)) && (ctl & ARCH_LBR_CTL_CPL)) + return false; + if (!(entry->ebx & BIT(2)) && (ctl & ARCH_LBR_CTL_STACK)) + return false; + if (!(entry->ebx & BIT(1)) && (ctl & ARCH_LBR_CTL_FILTER)) + return false; + return true; +warn: + pr_warn_ratelimited("kvm: vcpu-%d: invalid arch lbr ctl.\n", + vcpu->vcpu_id); + return false; +} + static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_i= nfo) { struct kvm_pmu *pmu =3D vcpu_to_pmu(vcpu); @@ -396,6 +424,9 @@ static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, str= uct msr_data *msr_info) case MSR_ARCH_LBR_DEPTH: msr_info->data =3D lbr_desc->records.nr; return 0; + case MSR_ARCH_LBR_CTL: + msr_info->data =3D vmcs_read64(GUEST_IA32_LBR_CTL); + return 0; default: if ((pmc =3D get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) || (pmc =3D get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) { @@ -488,6 +519,16 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, st= ruct msr_data *msr_info) */ wrmsrl(MSR_ARCH_LBR_DEPTH, lbr_desc->records.nr); return 0; + case MSR_ARCH_LBR_CTL: + if (!arch_lbr_ctl_is_valid(vcpu, data)) + break; + + vmcs_write64(GUEST_IA32_LBR_CTL, data); + + if (intel_pmu_lbr_is_enabled(vcpu) && !lbr_desc->event && + (data & ARCH_LBR_CTL_LBREN)) + intel_pmu_create_guest_lbr_event(vcpu); + return 0; default: if ((pmc =3D get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) || (pmc =3D get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) { @@ -726,12 +767,16 @@ static void intel_pmu_reset(struct kvm_vcpu *vcpu) */ static void intel_pmu_legacy_freezing_lbrs_on_pmi(struct kvm_vcpu *vcpu) { - u64 data =3D vmcs_read64(GUEST_IA32_DEBUGCTL); + u32 lbr_ctl_field =3D GUEST_IA32_DEBUGCTL; =20 - if (data & DEBUGCTLMSR_FREEZE_LBRS_ON_PMI) { - data &=3D ~DEBUGCTLMSR_LBR; - vmcs_write64(GUEST_IA32_DEBUGCTL, data); - } + if (!(vmcs_read64(GUEST_IA32_DEBUGCTL) & DEBUGCTLMSR_FREEZE_LBRS_ON_PMI)) + return; + + if (kvm_cpu_cap_has(X86_FEATURE_ARCH_LBR) && + guest_cpuid_has(vcpu, X86_FEATURE_ARCH_LBR)) + lbr_ctl_field =3D GUEST_IA32_LBR_CTL; + + vmcs_write64(lbr_ctl_field, vmcs_read64(lbr_ctl_field) & ~0x1ULL); } =20 static void intel_pmu_deliver_pmi(struct kvm_vcpu *vcpu) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 8bbcf2071faf..60f00598f3c9 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -2025,6 +2025,13 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct= msr_data *msr_info) VM_EXIT_SAVE_DEBUG_CONTROLS) get_vmcs12(vcpu)->guest_ia32_debugctl =3D data; =20 + /* + * For Arch LBR, IA32_DEBUGCTL[bit 0] has no meaning. + * It can be written to 0 or 1, but reads will always return 0. + */ + if (guest_cpuid_has(vcpu, X86_FEATURE_ARCH_LBR)) + data &=3D ~DEBUGCTLMSR_LBR; + vmcs_write64(GUEST_IA32_DEBUGCTL, data); if (intel_pmu_lbr_is_enabled(vcpu) && !to_vmx(vcpu)->lbr_desc.event && (data & DEBUGCTLMSR_LBR)) @@ -4641,6 +4648,11 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bo= ol init_event) kvm_make_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu); =20 vpid_sync_context(vmx->vpid); + + if (!init_event) { + if (static_cpu_has(X86_FEATURE_ARCH_LBR)) + vmcs_write64(GUEST_IA32_LBR_CTL, 0); + } } =20 static void vmx_enable_irq_window(struct kvm_vcpu *vcpu) --=20 2.27.0