diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 4b09d4aa9bf4..258fc2c85301 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1179,6 +1179,9 @@ struct kvm_x86_ops { int (*mem_enc_unreg_region)(struct kvm *kvm, struct kvm_enc_region *argp); int (*get_msr_feature)(struct kvm_msr_entry *entry); + + int (*nested_enable_evmcs)(struct kvm_vcpu *vcpu, + uint16_t *vmcs_version); }; struct kvm_arch_async_pf { diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 2936c63bcc2f..47b07211c5b1 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -7036,6 +7036,13 @@ failed: return ret; } +static int nested_enable_evmcs(struct kvm_vcpu *vcpu, + uint16_t *vmcs_version) +{ + /* Intel-only feature */ + return -ENODEV; +} + static struct kvm_x86_ops svm_x86_ops __ro_after_init = { .cpu_has_kvm_support = has_svm, .disabled_by_bios = is_disabled, @@ -7165,6 +7172,8 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = { .mem_enc_op = svm_mem_enc_op, .mem_enc_reg_region = svm_register_enc_region, .mem_enc_unreg_region = svm_unregister_enc_region, + + .nested_enable_evmcs = nested_enable_evmcs, }; static int __init svm_init(void) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 509d4e34dd62..459cdaa0d1cd 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -846,6 +846,13 @@ struct nested_vmx { bool change_vmcs01_virtual_apic_mode; + /* + * Enlightened VMCS has been enabled. It does not mean that L1 has to + * use it. However, VMX features available to L1 will be limited based + * on what the enlightened VMCS supports. + */ + bool enlightened_vmcs_enabled; + /* L2 must run next, and mustn't decide to exit to L1. */ bool nested_run_pending; @@ -1589,6 +1596,34 @@ static inline void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf) {} static inline void evmcs_touch_msr_bitmap(void) {} #endif /* IS_ENABLED(CONFIG_HYPERV) */ +static int nested_enable_evmcs(struct kvm_vcpu *vcpu, + uint16_t *vmcs_version) +{ + struct vcpu_vmx *vmx = to_vmx(vcpu); + + /* We don't support disabling the feature for simplicity. */ + if (vmx->nested.enlightened_vmcs_enabled) + return 0; + + vmx->nested.enlightened_vmcs_enabled = true; + + /* + * vmcs_version represents the range of supported Enlightened VMCS + * versions: lower 8 bits is the minimal version, higher 8 bits is the + * maximum supported version. KVM supports versions from 1 to + * KVM_EVMCS_VERSION. + */ + *vmcs_version = (KVM_EVMCS_VERSION << 8) | 1; + + vmx->nested.msrs.pinbased_ctls_high &= ~EVMCS1_UNSUPPORTED_PINCTRL; + vmx->nested.msrs.entry_ctls_high &= ~EVMCS1_UNSUPPORTED_VMENTRY_CTRL; + vmx->nested.msrs.exit_ctls_high &= ~EVMCS1_UNSUPPORTED_VMEXIT_CTRL; + vmx->nested.msrs.secondary_ctls_high &= ~EVMCS1_UNSUPPORTED_2NDEXEC; + vmx->nested.msrs.vmfunc_controls &= ~EVMCS1_UNSUPPORTED_VMFUNC; + + return 0; +} + static inline bool is_exception_n(u32 intr_info, u8 vector) { return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK | @@ -14505,6 +14540,8 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = { .pre_enter_smm = vmx_pre_enter_smm, .pre_leave_smm = vmx_pre_leave_smm, .enable_smi_window = enable_smi_window, + + .nested_enable_evmcs = nested_enable_evmcs, }; static void vmx_cleanup_l1d_flush(void) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index eee871ad4ade..50f308499ce5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2913,6 +2913,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_HYPERV_EVENTFD: case KVM_CAP_HYPERV_TLBFLUSH: case KVM_CAP_HYPERV_SEND_IPI: + case KVM_CAP_HYPERV_ENLIGHTENED_VMCS: case KVM_CAP_PCI_SEGMENT: case KVM_CAP_DEBUGREGS: case KVM_CAP_X86_ROBUST_SINGLESTEP: @@ -3700,6 +3701,10 @@ static int kvm_set_guest_paused(struct kvm_vcpu *vcpu) static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu, struct kvm_enable_cap *cap) { + int r; + uint16_t vmcs_version; + void __user *user_ptr; + if (cap->flags) return -EINVAL; @@ -3712,6 +3717,16 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu, return -EINVAL; return kvm_hv_activate_synic(vcpu, cap->cap == KVM_CAP_HYPERV_SYNIC2); + case KVM_CAP_HYPERV_ENLIGHTENED_VMCS: + r = kvm_x86_ops->nested_enable_evmcs(vcpu, &vmcs_version); + if (!r) { + user_ptr = (void __user *)(uintptr_t)cap->args[0]; + if (copy_to_user(user_ptr, &vmcs_version, + sizeof(vmcs_version))) + r = -EFAULT; + } + return r; + default: return -EINVAL; } diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 97780a0277fe..a2f2b8845502 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -963,6 +963,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_PPC_NESTED_HV 160 #define KVM_CAP_HYPERV_SEND_IPI 161 #define KVM_CAP_COALESCED_PIO 162 +#define KVM_CAP_HYPERV_ENLIGHTENED_VMCS 163 #ifdef KVM_CAP_IRQ_ROUTING