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Message-Id: <1588139196-23802-1-git-send-email-lirongqing@baidu.com>
Date: Wed, 29 Apr 2020 13:46:36 +0800
From: Li RongQing <lirongqing@...du.com>
To: linux-kernel@...r.kernel.org, kvm@...r.kernel.org, x86@...nel.org,
hpa@...or.com, bp@...en8.de, mingo@...hat.com, tglx@...utronix.de,
joro@...tes.org, jmattson@...gle.com, wanpengli@...cent.com,
vkuznets@...hat.com, sean.j.christopherson@...el.com,
pbonzini@...hat.com
Subject: [PATCH][v2] kvm: x86: emulate APERF/MPERF registers
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 we should emulate aperf mperf to achieve it
the period of aperf/mperf in guest mode are accumulated as
emulated value, and add per-VM knod to enable emulate mperfaperf
diff v1:
1. support AMD
2. support per-vm capability to enable
Signed-off-by: Li RongQing <lirongqing@...du.com>
Signed-off-by: Chai Wen <chaiwen@...du.com>
Signed-off-by: Jia Lina <jialina01@...du.com>
---
Documentation/virt/kvm/api.rst | 7 +++++++
arch/x86/include/asm/kvm_host.h | 4 ++++
arch/x86/kvm/cpuid.c | 13 ++++++++++++-
arch/x86/kvm/svm.c | 6 ++++++
arch/x86/kvm/vmx/vmx.c | 6 ++++++
arch/x86/kvm/x86.c | 37 +++++++++++++++++++++++++++++++++++++
arch/x86/kvm/x86.h | 6 ++++++
include/uapi/linux/kvm.h | 1 +
8 files changed, 79 insertions(+), 1 deletion(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index efbbe570aa9b..dc4b4036e5d2 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -6109,3 +6109,10 @@ 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_MPERFAPERF
+----------------------------
+
+:Architectures: x86
+
+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..58fd3254804f 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 {
@@ -979,6 +982,7 @@ struct kvm_arch {
bool guest_can_read_msr_platform_info;
bool exception_payload_enabled;
+ bool guest_has_mperfaperf;
struct kvm_pmu_event_filter *pmu_event_filter;
struct task_struct *nx_lpage_recovery_thread;
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 901cd1fdecd9..3bdd907981b5 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_mperfaperf(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..1d157a8dba46 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4310,6 +4310,12 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
case MSR_F10H_DECFG:
msr_info->data = svm->msr_decfg;
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:
return kvm_get_msr_common(vcpu, msr_info);
}
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 91749f1254e8..b05e276e262b 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1914,6 +1914,12 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
!guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP))
return 1;
goto find_shared_msr;
+ 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:
find_shared_msr:
msr = find_msr_entry(vmx, msr_info->index);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b8124b562dea..38deb11b1544 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3435,6 +3435,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_HYPERV_ENLIGHTENED_VMCS:
r = kvm_x86_ops.nested_enable_evmcs != NULL;
break;
+ case KVM_CAP_MPERFAPERF:
+ r = boot_cpu_has(X86_FEATURE_APERFMPERF) ? 1 : 0;
+ break;
default:
break;
}
@@ -4883,6 +4886,11 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
kvm->arch.exception_payload_enabled = cap->args[0];
r = 0;
break;
+ case KVM_CAP_MPERFAPERF:
+ kvm->arch.guest_has_mperfaperf =
+ boot_cpu_has(X86_FEATURE_APERFMPERF) ? cap->args[0] : 0;
+ r = 0;
+ break;
default:
r = -EINVAL;
break;
@@ -8163,6 +8171,25 @@ void __kvm_request_immediate_exit(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(__kvm_request_immediate_exit);
+
+static void guest_enter_mperfaperf(u64 *mperf, u64 *aperf)
+{
+ rdmsrl(MSR_IA32_MPERF, *mperf);
+ rdmsrl(MSR_IA32_APERF, *aperf);
+}
+
+static void guest_exit_mperfaperf(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
@@ -8176,7 +8203,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
kvm_cpu_accept_dm_intr(vcpu);
enum exit_fastpath_completion exit_fastpath = EXIT_FASTPATH_NONE;
+ bool enable_mperfaperf = guest_has_mperfaperf(vcpu->kvm);
bool req_immediate_exit = false;
+ u64 mperf, aperf;
if (kvm_request_pending(vcpu)) {
if (kvm_check_request(KVM_REQ_GET_VMCS12_PAGES, vcpu)) {
@@ -8326,6 +8355,10 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
preempt_disable();
+ mperf = aperf = 0;
+ if (unlikely(enable_mperfaperf))
+ guest_enter_mperfaperf(&mperf, &aperf);
+
kvm_x86_ops.prepare_guest_switch(vcpu);
/*
@@ -8449,6 +8482,10 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
}
local_irq_enable();
+
+ if (unlikely(enable_mperfaperf) && mperf)
+ guest_exit_mperfaperf(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 b968acc0516f..69b66ed8d82a 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -355,6 +355,12 @@ static inline bool kvm_dr7_valid(u64 data)
return !(data >> 32);
}
+
+static inline bool guest_has_mperfaperf(struct kvm *kvm)
+{
+ return kvm->arch.guest_has_mperfaperf;
+}
+
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 428c7dde6b4b..1f9abdf0d1a9 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1017,6 +1017,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_S390_VCPU_RESETS 179
#define KVM_CAP_S390_PROTECTED 180
#define KVM_CAP_PPC_SECURE_GUEST 181
+#define KVM_CAP_MPERFAPERF 182
#ifdef KVM_CAP_IRQ_ROUTING
--
2.16.2
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