diff options
| author | David Dunn <daviddunn@google.com> | 2022-02-23 22:57:41 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-02-25 08:20:14 -0500 |
| commit | ba7bb663f5547ef474c98df99a97bb4a13c5715f (patch) | |
| tree | edf880ca47225e0903485a4ff16a55824152cdd8 /arch | |
| parent | 925088781eede43cf6616a1197c31dee451b7948 (diff) | |
KVM: x86: Provide per VM capability for disabling PMU virtualization
Add a new capability, KVM_CAP_PMU_CAPABILITY, that takes a bitmask of
settings/features to allow userspace to configure PMU virtualization on
a per-VM basis. For now, support a single flag, KVM_PMU_CAP_DISABLE,
to allow disabling PMU virtualization for a VM even when KVM is configured
with enable_pmu=true a module level.
To keep KVM simple, disallow changing VM's PMU configuration after vCPUs
have been created.
Signed-off-by: David Dunn <daviddunn@google.com>
Message-Id: <20220223225743.2703915-2-daviddunn@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/pmu.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/pmu_intel.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 18 |
4 files changed, 21 insertions, 2 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 463171e3b613..dafb5a6220cd 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1147,6 +1147,7 @@ struct kvm_arch { bool exception_payload_enabled; bool bus_lock_detection_enabled; + bool enable_pmu; /* * If exit_on_emulation_error is set, and the in-kernel instruction * emulator fails to emulate an instruction, allow userspace diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c index 5aa45f13b16d..d4de52409335 100644 --- a/arch/x86/kvm/svm/pmu.c +++ b/arch/x86/kvm/svm/pmu.c @@ -101,7 +101,7 @@ static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr, { struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu); - if (!enable_pmu) + if (!vcpu->kvm->arch.enable_pmu) return NULL; switch (msr) { diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 03fab48b149c..4e5b1eeeb77c 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -487,7 +487,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu) pmu->reserved_bits = 0xffffffff00200000ull; entry = kvm_find_cpuid_entry(vcpu, 0xa, 0); - if (!entry || !enable_pmu) + if (!entry || !vcpu->kvm->arch.enable_pmu) return; eax.full = entry->eax; edx.full = entry->edx; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 16d29d41908f..0b95c379e234 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -110,6 +110,8 @@ static u64 __read_mostly cr4_reserved_bits = CR4_RESERVED_BITS; #define KVM_EXIT_HYPERCALL_VALID_MASK (1 << KVM_HC_MAP_GPA_RANGE) +#define KVM_CAP_PMU_VALID_MASK KVM_PMU_CAP_DISABLE + #define KVM_X2APIC_API_VALID_FLAGS (KVM_X2APIC_API_USE_32BIT_IDS | \ KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK) @@ -4330,6 +4332,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) if (r < sizeof(struct kvm_xsave)) r = sizeof(struct kvm_xsave); break; + case KVM_CAP_PMU_CAPABILITY: + r = enable_pmu ? KVM_CAP_PMU_VALID_MASK : 0; + break; } default: break; @@ -6004,6 +6009,18 @@ split_irqchip_unlock: kvm->arch.exit_on_emulation_error = cap->args[0]; r = 0; break; + case KVM_CAP_PMU_CAPABILITY: + r = -EINVAL; + if (!enable_pmu || (cap->args[0] & ~KVM_CAP_PMU_VALID_MASK)) + break; + + mutex_lock(&kvm->lock); + if (!kvm->created_vcpus) { + kvm->arch.enable_pmu = !(cap->args[0] & KVM_PMU_CAP_DISABLE); + r = 0; + } + mutex_unlock(&kvm->lock); + break; default: r = -EINVAL; break; @@ -11586,6 +11603,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags); kvm->arch.guest_can_read_msr_platform_info = true; + kvm->arch.enable_pmu = enable_pmu; #if IS_ENABLED(CONFIG_HYPERV) spin_lock_init(&kvm->arch.hv_root_tdp_lock); |