From patchwork Sat May 30 04:35:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li RongQing X-Patchwork-Id: 11579937 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 3469C739 for ; Sat, 30 May 2020 04:37:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0ECF5206DA for ; Sat, 30 May 2020 04:37:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725912AbgE3EgT (ORCPT ); Sat, 30 May 2020 00:36:19 -0400 Received: from mx140-tc.baidu.com ([61.135.168.140]:54397 "EHLO tc-sys-mailedm03.tc.baidu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725776AbgE3EgS (ORCPT ); Sat, 30 May 2020 00:36:18 -0400 Received: from localhost (cp01-cos-dev01.cp01.baidu.com [10.92.119.46]) by tc-sys-mailedm03.tc.baidu.com (Postfix) with ESMTP id 0EC444500032; Sat, 30 May 2020 12:35:53 +0800 (CST) From: Li RongQing To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, hpa@zytor.com, bp@alien8.de, mingo@redhat.com, tglx@linutronix.de, jmattson@google.com, wanpengli@tencent.com, vkuznets@redhat.com, sean.j.christopherson@intel.com, pbonzini@redhat.com, xiaoyao.li@intel.com, wei.huang2@amd.com, lirongqing@baidu.com Subject: [PATCH][v5] KVM: X86: support APERF/MPERF registers Date: Sat, 30 May 2020 12:35:53 +0800 Message-Id: <1590813353-11775-1-git-send-email-lirongqing@baidu.com> X-Mailer: git-send-email 1.7.1 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Guest kernel reports a fixed cpu frequency in /proc/cpuinfo, this is confused to user when turbo is enable, and aperf/mperf can be used to show current cpu frequency after 7d5905dc14a "(x86 / CPU: Always show current CPU frequency in /proc/cpuinfo)" so guest should support aperf/mperf capability This patch implements aperf/mperf by three mode: none, software emulation, and pass-through None: default mode, guest does not support aperf/mperf Software emulation: the period of aperf/mperf in guest mode are accumulated as emulated value Pass-though: it is only suitable for KVM_HINTS_REALTIME, Because that hint guarantees we have a 1:1 vCPU:CPU binding and guaranteed no over-commit. And a per-VM capability is added to configure aperfmperf mode Signed-off-by: Li RongQing Signed-off-by: Chai Wen Signed-off-by: Jia Lina diff v4: fix maybe-uninitialized warning diff v3: fix interception of MSR_IA32_MPERF/APERF in svm diff v2: support aperfmperf pass though move common codes to kvm_get_msr_common diff v1: 1. support AMD, but not test 2. support per-vm capability to enable Documentation/virt/kvm/api.rst | 10 ++++++++++ arch/x86/include/asm/kvm_host.h | 11 +++++++++++ arch/x86/kvm/cpuid.c | 13 ++++++++++++- arch/x86/kvm/svm/svm.c | 8 ++++++++ arch/x86/kvm/vmx/vmx.c | 6 ++++++ arch/x86/kvm/x86.c | 42 +++++++++++++++++++++++++++++++++++++++++ arch/x86/kvm/x86.h | 15 +++++++++++++++ include/uapi/linux/kvm.h | 1 + 8 files changed, 105 insertions(+), 1 deletion(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index d871dacb984e..f854f4da6fd8 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6126,3 +6126,13 @@ KVM can therefore start protected VMs. This capability governs the KVM_S390_PV_COMMAND ioctl and the KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected guests when the state change is invalid. + +8.23 KVM_CAP_APERFMPERF +---------------------------- + +:Architectures: x86 +:Parameters: args[0] is aperfmperf mode; + 0 for not support, 1 for software emulation, 2 for pass-through +:Returns: 0 on success; -1 on error + +This capability indicates that KVM supports APERF and MPERF MSR registers diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index fd78bd44b2d6..14643f8af9c4 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -824,6 +824,9 @@ struct kvm_vcpu_arch { /* AMD MSRC001_0015 Hardware Configuration */ u64 msr_hwcr; + + u64 v_mperf; + u64 v_aperf; }; struct kvm_lpage_info { @@ -889,6 +892,12 @@ enum kvm_irqchip_mode { KVM_IRQCHIP_SPLIT, /* created with KVM_CAP_SPLIT_IRQCHIP */ }; +enum kvm_aperfmperf_mode { + KVM_APERFMPERF_NONE, + KVM_APERFMPERF_SOFT, /* software emulate aperfmperf */ + KVM_APERFMPERF_PT, /* pass-through aperfmperf to guest */ +}; + #define APICV_INHIBIT_REASON_DISABLE 0 #define APICV_INHIBIT_REASON_HYPERV 1 #define APICV_INHIBIT_REASON_NESTED 2 @@ -986,6 +995,8 @@ struct kvm_arch { struct kvm_pmu_event_filter *pmu_event_filter; struct task_struct *nx_lpage_recovery_thread; + + enum kvm_aperfmperf_mode aperfmperf_mode; }; struct kvm_vm_stat { diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index cd708b0b460a..c960dda4251b 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -122,6 +122,14 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu) MSR_IA32_MISC_ENABLE_MWAIT); } + best = kvm_find_cpuid_entry(vcpu, 6, 0); + if (best) { + if (guest_has_aperfmperf(vcpu->kvm) && + boot_cpu_has(X86_FEATURE_APERFMPERF)) + best->ecx |= 1; + else + best->ecx &= ~1; + } /* Note, maxphyaddr must be updated before tdp_level. */ vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); vcpu->arch.tdp_level = kvm_x86_ops.get_tdp_level(vcpu); @@ -557,7 +565,10 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) case 6: /* Thermal management */ entry->eax = 0x4; /* allow ARAT */ entry->ebx = 0; - entry->ecx = 0; + if (boot_cpu_has(X86_FEATURE_APERFMPERF)) + entry->ecx = 0x1; + else + entry->ecx = 0x0; entry->edx = 0; break; /* function 7 has additional index. */ diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index e9c0fb68387d..1d38fe3afc0d 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1200,6 +1200,14 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu) svm->msrpm = page_address(msrpm_pages); svm_vcpu_init_msrpm(svm->msrpm); + if (guest_aperfmperf_soft(vcpu->kvm)) { + set_msr_interception(svm->msrpm, MSR_IA32_MPERF, 0, 0); + set_msr_interception(svm->msrpm, MSR_IA32_APERF, 0, 0); + } else if (guest_aperfmperf_pt(vcpu->kvm)) { + set_msr_interception(svm->msrpm, MSR_IA32_MPERF, 1, 0); + set_msr_interception(svm->msrpm, MSR_IA32_APERF, 1, 0); + } + svm->nested.msrpm = page_address(nested_msrpm_pages); svm_vcpu_init_msrpm(svm->nested.msrpm); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 0ea5a225a579..18d02e95db04 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6916,6 +6916,12 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu) vmx_disable_intercept_for_msr(msr_bitmap, MSR_CORE_C6_RESIDENCY, MSR_TYPE_R); vmx_disable_intercept_for_msr(msr_bitmap, MSR_CORE_C7_RESIDENCY, MSR_TYPE_R); } + + if (guest_aperfmperf_pt(vcpu->kvm)) { + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_MPERF, MSR_TYPE_R); + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_APERF, MSR_TYPE_R); + } + vmx->msr_bitmap_mode = 0; vmx->loaded_vmcs = &vmx->vmcs01; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8ac69c16f153..de6406d51722 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3271,6 +3271,12 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_K7_HWCR: msr_info->data = vcpu->arch.msr_hwcr; break; + case MSR_IA32_MPERF: + msr_info->data = vcpu->arch.v_mperf; + break; + case MSR_IA32_APERF: + msr_info->data = vcpu->arch.v_aperf; + break; default: if (kvm_pmu_is_valid_msr(vcpu, msr_info->index)) return kvm_pmu_get_msr(vcpu, msr_info->index, &msr_info->data); @@ -3480,6 +3486,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_HYPERV_ENLIGHTENED_VMCS: r = kvm_x86_ops.nested_ops->enable_evmcs != NULL; break; + case KVM_CAP_APERFMPERF: + r = boot_cpu_has(X86_FEATURE_APERFMPERF) ? 1 : 0; + break; default: break; } @@ -4930,6 +4939,11 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, kvm->arch.exception_payload_enabled = cap->args[0]; r = 0; break; + case KVM_CAP_APERFMPERF: + kvm->arch.aperfmperf_mode = + boot_cpu_has(X86_FEATURE_APERFMPERF) ? cap->args[0] : 0; + r = 0; + break; default: r = -EINVAL; break; @@ -8217,6 +8231,25 @@ void __kvm_request_immediate_exit(struct kvm_vcpu *vcpu) } EXPORT_SYMBOL_GPL(__kvm_request_immediate_exit); + +static void guest_enter_aperfmperf(u64 *mperf, u64 *aperf) +{ + rdmsrl(MSR_IA32_MPERF, *mperf); + rdmsrl(MSR_IA32_APERF, *aperf); +} + +static void guest_exit_aperfmperf(struct kvm_vcpu *vcpu, + u64 mperf, u64 aperf) +{ + u64 perf; + + rdmsrl(MSR_IA32_MPERF, perf); + vcpu->arch.v_mperf += perf - mperf; + + rdmsrl(MSR_IA32_APERF, perf); + vcpu->arch.v_aperf += perf - aperf; +} + /* * Returns 1 to let vcpu_run() continue the guest execution loop without * exiting to the userspace. Otherwise, the value will be returned to the @@ -8230,6 +8263,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_cpu_accept_dm_intr(vcpu); fastpath_t exit_fastpath; + bool enable_aperfmperf = guest_aperfmperf_soft(vcpu->kvm); + u64 uninitialized_var(mperf), uninitialized_var(aperf); bool req_immediate_exit = false; if (kvm_request_pending(vcpu)) { @@ -8393,6 +8428,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) preempt_disable(); + if (unlikely(enable_aperfmperf)) + guest_enter_aperfmperf(&mperf, &aperf); + kvm_x86_ops.prepare_guest_switch(vcpu); /* @@ -8514,6 +8552,10 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) } local_irq_enable(); + + if (unlikely(enable_aperfmperf)) + guest_exit_aperfmperf(vcpu, mperf, aperf); + preempt_enable(); vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index 6eb62e97e59f..8216f697c53c 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -361,6 +361,21 @@ static inline bool kvm_dr7_valid(u64 data) return !(data >> 32); } +static inline bool guest_has_aperfmperf(struct kvm *kvm) +{ + return kvm->arch.aperfmperf_mode != KVM_APERFMPERF_NONE; +} + +static inline bool guest_aperfmperf_soft(struct kvm *kvm) +{ + return kvm->arch.aperfmperf_mode == KVM_APERFMPERF_SOFT; +} + +static inline bool guest_aperfmperf_pt(struct kvm *kvm) +{ + return kvm->arch.aperfmperf_mode == KVM_APERFMPERF_PT; +} + void kvm_load_guest_xsave_state(struct kvm_vcpu *vcpu); void kvm_load_host_xsave_state(struct kvm_vcpu *vcpu); u64 kvm_spec_ctrl_valid_bits(struct kvm_vcpu *vcpu); diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index ac9eba0289d1..57285a53078d 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1018,6 +1018,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_S390_PROTECTED 180 #define KVM_CAP_PPC_SECURE_GUEST 181 #define KVM_CAP_HALT_POLL 182 +#define KVM_CAP_APERFMPERF 183 #ifdef KVM_CAP_IRQ_ROUTING