> -----邮件原件----- > 发件人: Wei Huang [mailto:wei.huang2@xxxxxxx] > 发送时间: 2020年5月2日 5:31 > 收件人: Li,Rongqing <lirongqing@xxxxxxxxx> > 抄送: linux-kernel@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; x86@xxxxxxxxxx; > hpa@xxxxxxxxx; bp@xxxxxxxxx; mingo@xxxxxxxxxx; tglx@xxxxxxxxxxxxx; > jmattson@xxxxxxxxxx; wanpengli@xxxxxxxxxxx; vkuznets@xxxxxxxxxx; > sean.j.christopherson@xxxxxxxxx; pbonzini@xxxxxxxxxx; xiaoyao.li@xxxxxxxxx > 主题: Re: [PATCH] [v3] kvm: x86: support APERF/MPERF registers > 重要性: 高 > > On 04/30 06:45, Li RongQing wrote: > > 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 > ^^^^ > This > > > 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. > > If we save/restore the values of aperf/mperf properly during vcpu migration > among different cores, is pinning still required? > I think it can be as a new mode, it maybe add more msr operation, like write > > > > and a per-VM capability is added to configure aperfmperf mode > > > > Signed-off-by: Li RongQing <lirongqing@xxxxxxxxx> > > Signed-off-by: Chai Wen <chaiwen@xxxxxxxxx> > > Signed-off-by: Jia Lina <jialina01@xxxxxxxxx> > > --- > > diff v2: > > support aperfmperf pass though > > move common codes to kvm_get_msr_common > > > > diff v1: > > 1. support AMD, but not test > > pt-mode doesn't work doesn't work on AMD. See below. > > > 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.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 efbbe570aa9b..c3be3b6a1717 > > 100644 > > --- a/Documentation/virt/kvm/api.rst > > +++ b/Documentation/virt/kvm/api.rst > > @@ -6109,3 +6109,13 @@ 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 42a2d0d3984a..81477f676f60 > > 100644 > > --- a/arch/x86/include/asm/kvm_host.h > > +++ b/arch/x86/include/asm/kvm_host.h > > @@ -820,6 +820,9 @@ struct kvm_vcpu_arch { > > > > /* AMD MSRC001_0015 Hardware Configuration */ > > u64 msr_hwcr; > > + > > + u64 v_mperf; > > + u64 v_aperf; > > }; > > > > struct kvm_lpage_info { > > @@ -885,6 +888,12 @@ 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 > > @@ -982,6 +991,8 @@ 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 > > 901cd1fdecd9..7a64ea2c3eef 100644 > > --- a/arch/x86/kvm/cpuid.c > > +++ b/arch/x86/kvm/cpuid.c > > @@ -124,6 +124,14 @@ 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; > > + } > > /* Update physical-address width */ > > vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); > > kvm_mmu_reset_context(vcpu); > > @@ -558,7 +566,10 @@ 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.c b/arch/x86/kvm/svm.c index > > 851e9cc79930..5646b6475049 100644 > > --- a/arch/x86/kvm/svm.c > > +++ b/arch/x86/kvm/svm.c > ^^^^^^^^^ > The latest kernel moves svm-related files to arch/x86/kvm/svm directory. You > need to update your patches. > > > @@ -2292,6 +2292,14 @@ 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, 1, 0); > > + set_msr_interception(svm->msrpm, MSR_IA32_APERF, 1, 0); > > + } else if (guest_aperfmperf_pt(vcpu->kvm)) { > > + set_msr_interception(svm->msrpm, MSR_IA32_MPERF, 0, 0); > > + set_msr_interception(svm->msrpm, MSR_IA32_APERF, 0, 0); > > + } > > The bit setting for KVM_APERFMPERF_SOFT and KVM_APERFMPERF_PT is > incorrect. set_msr_interception() takes read/write as parameters. When they > are 1, it means svm doesn't intercept this specific MSR. So, you code should > look like: > > 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); > } > > Thanks, I will fix it -Li
