diff options
| -rw-r--r-- | Documentation/virt/kvm/api.rst | 22 | ||||
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 3 | ||||
| -rw-r--r-- | arch/x86/include/uapi/asm/kvm.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 9 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 8 |
6 files changed, 39 insertions, 8 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index edc070c6e19b..061ec93d9ecb 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -8107,6 +8107,28 @@ KVM_X86_QUIRK_SLOT_ZAP_ALL By default, for KVM_X86_DEFAULT_VM VMs, KVM or moved memslot isn't reachable, i.e KVM _may_ invalidate only SPTEs related to the memslot. + +KVM_X86_QUIRK_STUFF_FEATURE_MSRS By default, at vCPU creation, KVM sets the + vCPU's MSR_IA32_PERF_CAPABILITIES (0x345), + MSR_IA32_ARCH_CAPABILITIES (0x10a), + MSR_PLATFORM_INFO (0xce), and all VMX MSRs + (0x480..0x492) to the maximal capabilities + supported by KVM. KVM also sets + MSR_IA32_UCODE_REV (0x8b) to an arbitrary + value (which is different for Intel vs. + AMD). Lastly, when guest CPUID is set (by + userspace), KVM modifies select VMX MSR + fields to force consistency between guest + CPUID and L2's effective ISA. When this + quirk is disabled, KVM zeroes the vCPU's MSR + values (with two exceptions, see below), + i.e. treats the feature MSRs like CPUID + leaves and gives userspace full control of + the vCPU model definition. This quirk does + not affect VMX MSRs CR0/CR4_FIXED1 (0x487 + and 0x489), as KVM does now allow them to + be set by userspace (KVM sets them based on + guest CPUID, for safety purposes). =================================== ============================================ 7.32 KVM_CAP_MAX_VCPU_ID diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 3ae90df0a177..dbe0ea509642 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -2360,7 +2360,8 @@ int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages); KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT | \ KVM_X86_QUIRK_FIX_HYPERCALL_INSN | \ KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS | \ - KVM_X86_QUIRK_SLOT_ZAP_ALL) + KVM_X86_QUIRK_SLOT_ZAP_ALL | \ + KVM_X86_QUIRK_STUFF_FEATURE_MSRS) /* * KVM previously used a u32 field in kvm_run to indicate the hypercall was diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h index a8debbf2f702..88585c1de416 100644 --- a/arch/x86/include/uapi/asm/kvm.h +++ b/arch/x86/include/uapi/asm/kvm.h @@ -440,6 +440,7 @@ struct kvm_sync_regs { #define KVM_X86_QUIRK_FIX_HYPERCALL_INSN (1 << 5) #define KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS (1 << 6) #define KVM_X86_QUIRK_SLOT_ZAP_ALL (1 << 7) +#define KVM_X86_QUIRK_STUFF_FEATURE_MSRS (1 << 8) #define KVM_STATE_NESTED_FORMAT_VMX 0 #define KVM_STATE_NESTED_FORMAT_SVM 1 diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 50f6b0e03d04..237e72b8a999 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1390,7 +1390,9 @@ static void __svm_vcpu_reset(struct kvm_vcpu *vcpu) svm_vcpu_init_msrpm(vcpu, svm->msrpm); svm_init_osvw(vcpu); - vcpu->arch.microcode_version = 0x01000065; + + if (kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_STUFF_FEATURE_MSRS)) + vcpu->arch.microcode_version = 0x01000065; svm->tsc_ratio_msr = kvm_caps.default_tsc_scaling_ratio; svm->nmi_masked = false; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 115ec4617a5f..f0326927d4e1 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4572,7 +4572,8 @@ vmx_adjust_secondary_exec_control(struct vcpu_vmx *vmx, u32 *exec_control, * Update the nested MSR settings so that a nested VMM can/can't set * controls for features that are/aren't exposed to the guest. */ - if (nested) { + if (nested && + kvm_check_has_quirk(vmx->vcpu.kvm, KVM_X86_QUIRK_STUFF_FEATURE_MSRS)) { /* * All features that can be added or removed to VMX MSRs must * be supported in the first place for nested virtualization. @@ -4862,7 +4863,8 @@ static void __vmx_vcpu_reset(struct kvm_vcpu *vcpu) init_vmcs(vmx); - if (nested) + if (nested && + kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_STUFF_FEATURE_MSRS)) memcpy(&vmx->nested.msrs, &vmcs_config.nested, sizeof(vmx->nested.msrs)); vcpu_setup_sgx_lepubkeyhash(vcpu); @@ -4875,7 +4877,8 @@ static void __vmx_vcpu_reset(struct kvm_vcpu *vcpu) vmx->nested.hv_evmcs_vmptr = EVMPTR_INVALID; #endif - vcpu->arch.microcode_version = 0x100000000ULL; + if (kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_STUFF_FEATURE_MSRS)) + vcpu->arch.microcode_version = 0x100000000ULL; vmx->msr_ia32_feature_control_valid_bits = FEAT_CTL_LOCKED; /* diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 16804637ba97..34a7359d2bf3 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -12314,9 +12314,11 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) kvm_async_pf_hash_reset(vcpu); - vcpu->arch.arch_capabilities = kvm_get_arch_capabilities(); - vcpu->arch.msr_platform_info = MSR_PLATFORM_INFO_CPUID_FAULT; - vcpu->arch.perf_capabilities = kvm_caps.supported_perf_cap; + if (kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_STUFF_FEATURE_MSRS)) { + vcpu->arch.arch_capabilities = kvm_get_arch_capabilities(); + vcpu->arch.msr_platform_info = MSR_PLATFORM_INFO_CPUID_FAULT; + vcpu->arch.perf_capabilities = kvm_caps.supported_perf_cap; + } kvm_pmu_init(vcpu); vcpu->arch.pending_external_vector = -1; |