From b51700632e0e53254733ff706e5bdca22d19dbe5 Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Tue, 21 May 2019 14:06:53 +0800 Subject: [PATCH] KVM: X86: Provide a capability to disable cstate msr read intercepts MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Allow guest reads CORE cstate when exposing host CPU power management capabilities to the guest. PKG cstate is restricted to avoid a guest to get the whole package information in multi-tenant scenario. Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Sean Christopherson Cc: Liran Alon Signed-off-by: Wanpeng Li Signed-off-by: Paolo Bonzini --- Documentation/virtual/kvm/api.txt | 1 + arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/vmx/vmx.c | 6 ++++++ arch/x86/kvm/x86.c | 5 ++++- arch/x86/kvm/x86.h | 5 +++++ include/uapi/linux/kvm.h | 4 +++- tools/include/uapi/linux/kvm.h | 4 +++- 7 files changed, 23 insertions(+), 3 deletions(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 33cd92dd6aa5..91fd86fcc49f 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -4894,6 +4894,7 @@ Valid bits in args[0] are #define KVM_X86_DISABLE_EXITS_MWAIT (1 << 0) #define KVM_X86_DISABLE_EXITS_HLT (1 << 1) #define KVM_X86_DISABLE_EXITS_PAUSE (1 << 2) +#define KVM_X86_DISABLE_EXITS_CSTATE (1 << 3) Enabling this capability on a VM provides userspace with a way to no longer intercept some instructions for improved latency in some diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 15e973d9b840..aeadbc770eb2 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -882,6 +882,7 @@ struct kvm_arch { bool mwait_in_guest; bool hlt_in_guest; bool pause_in_guest; + bool cstate_in_guest; unsigned long irq_sources_bitmap; s64 kvmclock_offset; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 0861c71a4379..da24f1858acc 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6637,6 +6637,12 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_CS, MSR_TYPE_RW); vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_ESP, MSR_TYPE_RW); vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_EIP, MSR_TYPE_RW); + if (kvm_cstate_in_guest(kvm)) { + vmx_disable_intercept_for_msr(msr_bitmap, MSR_CORE_C1_RES, MSR_TYPE_R); + vmx_disable_intercept_for_msr(msr_bitmap, MSR_CORE_C3_RESIDENCY, MSR_TYPE_R); + 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); + } 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 8aa6b5a75e7a..17e9533f51eb 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3098,7 +3098,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = KVM_CLOCK_TSC_STABLE; break; case KVM_CAP_X86_DISABLE_EXITS: - r |= KVM_X86_DISABLE_EXITS_HLT | KVM_X86_DISABLE_EXITS_PAUSE; + r |= KVM_X86_DISABLE_EXITS_HLT | KVM_X86_DISABLE_EXITS_PAUSE | + KVM_X86_DISABLE_EXITS_CSTATE; if(kvm_can_mwait_in_guest()) r |= KVM_X86_DISABLE_EXITS_MWAIT; break; @@ -4615,6 +4616,8 @@ split_irqchip_unlock: kvm->arch.hlt_in_guest = true; if (cap->args[0] & KVM_X86_DISABLE_EXITS_PAUSE) kvm->arch.pause_in_guest = true; + if (cap->args[0] & KVM_X86_DISABLE_EXITS_CSTATE) + kvm->arch.cstate_in_guest = true; r = 0; break; case KVM_CAP_MSR_PLATFORM_INFO: diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index a470ff0868c5..275b3b646023 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -333,6 +333,11 @@ static inline bool kvm_pause_in_guest(struct kvm *kvm) return kvm->arch.pause_in_guest; } +static inline bool kvm_cstate_in_guest(struct kvm *kvm) +{ + return kvm->arch.cstate_in_guest; +} + DECLARE_PER_CPU(struct kvm_vcpu *, current_vcpu); static inline void kvm_before_interrupt(struct kvm_vcpu *vcpu) diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 2fe12b40d503..c2152f3dd02d 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -696,9 +696,11 @@ struct kvm_ioeventfd { #define KVM_X86_DISABLE_EXITS_MWAIT (1 << 0) #define KVM_X86_DISABLE_EXITS_HLT (1 << 1) #define KVM_X86_DISABLE_EXITS_PAUSE (1 << 2) +#define KVM_X86_DISABLE_EXITS_CSTATE (1 << 3) #define KVM_X86_DISABLE_VALID_EXITS (KVM_X86_DISABLE_EXITS_MWAIT | \ KVM_X86_DISABLE_EXITS_HLT | \ - KVM_X86_DISABLE_EXITS_PAUSE) + KVM_X86_DISABLE_EXITS_PAUSE | \ + KVM_X86_DISABLE_EXITS_CSTATE) /* for KVM_ENABLE_CAP */ struct kvm_enable_cap { diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h index 6d4ea4b6c922..ef3303f72c46 100644 --- a/tools/include/uapi/linux/kvm.h +++ b/tools/include/uapi/linux/kvm.h @@ -696,9 +696,11 @@ struct kvm_ioeventfd { #define KVM_X86_DISABLE_EXITS_MWAIT (1 << 0) #define KVM_X86_DISABLE_EXITS_HLT (1 << 1) #define KVM_X86_DISABLE_EXITS_PAUSE (1 << 2) +#define KVM_X86_DISABLE_EXITS_CSTATE (1 << 3) #define KVM_X86_DISABLE_VALID_EXITS (KVM_X86_DISABLE_EXITS_MWAIT | \ KVM_X86_DISABLE_EXITS_HLT | \ - KVM_X86_DISABLE_EXITS_PAUSE) + KVM_X86_DISABLE_EXITS_PAUSE | \ + KVM_X86_DISABLE_EXITS_CSTATE) /* for KVM_ENABLE_CAP */ struct kvm_enable_cap { -- 2.20.1