[PATCH v6 13/13] KVM: selftests: add Enlightened VMCS test

[Vitaly Kuznetsov <vkuznets@redhat.com>]

Modify test library and add eVMCS test. This includes nVMX save/restore
testing.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 tools/testing/selftests/kvm/Makefile          |    1 +
 tools/testing/selftests/kvm/include/evmcs.h   | 1098 +++++++++++++++++
 .../selftests/kvm/include/x86_64/vmx.h        |   28 +
 tools/testing/selftests/kvm/lib/x86_64/vmx.c  |   48 +-
 .../testing/selftests/kvm/x86_64/evmcs_test.c |  159 +++
 5 files changed, 1322 insertions(+), 12 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/include/evmcs.h
 create mode 100644 tools/testing/selftests/kvm/x86_64/evmcs_test.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 5e23f97ec46f..01a219229238 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -13,6 +13,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/sync_regs_test
 TEST_GEN_PROGS_x86_64 += x86_64/vmx_tsc_adjust_test
 TEST_GEN_PROGS_x86_64 += x86_64/cr4_cpuid_sync_test
 TEST_GEN_PROGS_x86_64 += x86_64/state_test
+TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test
 TEST_GEN_PROGS_x86_64 += dirty_log_test
 
 TEST_GEN_PROGS_aarch64 += dirty_log_test
diff --git a/tools/testing/selftests/kvm/include/evmcs.h b/tools/testing/selftests/kvm/include/evmcs.h
new file mode 100644
index 000000000000..4059014d93ea
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/evmcs.h
@@ -0,0 +1,1098 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * tools/testing/selftests/kvm/include/vmx.h
+ *
+ * Copyright (C) 2018, Red Hat, Inc.
+ *
+ */
+
+#ifndef SELFTEST_KVM_EVMCS_H
+#define SELFTEST_KVM_EVMCS_H
+
+#include <stdint.h>
+#include "vmx.h"
+
+#define u16 uint16_t
+#define u32 uint32_t
+#define u64 uint64_t
+
+extern bool enable_evmcs;
+
+struct hv_vp_assist_page {
+	__u32 apic_assist;
+	__u32 reserved;
+	__u64 vtl_control[2];
+	__u64 nested_enlightenments_control[2];
+	__u32 enlighten_vmentry;
+	__u64 current_nested_vmcs;
+};
+
+struct hv_enlightened_vmcs {
+	u32 revision_id;
+	u32 abort;
+
+	u16 host_es_selector;
+	u16 host_cs_selector;
+	u16 host_ss_selector;
+	u16 host_ds_selector;
+	u16 host_fs_selector;
+	u16 host_gs_selector;
+	u16 host_tr_selector;
+
+	u64 host_ia32_pat;
+	u64 host_ia32_efer;
+
+	u64 host_cr0;
+	u64 host_cr3;
+	u64 host_cr4;
+
+	u64 host_ia32_sysenter_esp;
+	u64 host_ia32_sysenter_eip;
+	u64 host_rip;
+	u32 host_ia32_sysenter_cs;
+
+	u32 pin_based_vm_exec_control;
+	u32 vm_exit_controls;
+	u32 secondary_vm_exec_control;
+
+	u64 io_bitmap_a;
+	u64 io_bitmap_b;
+	u64 msr_bitmap;
+
+	u16 guest_es_selector;
+	u16 guest_cs_selector;
+	u16 guest_ss_selector;
+	u16 guest_ds_selector;
+	u16 guest_fs_selector;
+	u16 guest_gs_selector;
+	u16 guest_ldtr_selector;
+	u16 guest_tr_selector;
+
+	u32 guest_es_limit;
+	u32 guest_cs_limit;
+	u32 guest_ss_limit;
+	u32 guest_ds_limit;
+	u32 guest_fs_limit;
+	u32 guest_gs_limit;
+	u32 guest_ldtr_limit;
+	u32 guest_tr_limit;
+	u32 guest_gdtr_limit;
+	u32 guest_idtr_limit;
+
+	u32 guest_es_ar_bytes;
+	u32 guest_cs_ar_bytes;
+	u32 guest_ss_ar_bytes;
+	u32 guest_ds_ar_bytes;
+	u32 guest_fs_ar_bytes;
+	u32 guest_gs_ar_bytes;
+	u32 guest_ldtr_ar_bytes;
+	u32 guest_tr_ar_bytes;
+
+	u64 guest_es_base;
+	u64 guest_cs_base;
+	u64 guest_ss_base;
+	u64 guest_ds_base;
+	u64 guest_fs_base;
+	u64 guest_gs_base;
+	u64 guest_ldtr_base;
+	u64 guest_tr_base;
+	u64 guest_gdtr_base;
+	u64 guest_idtr_base;
+
+	u64 padding64_1[3];
+
+	u64 vm_exit_msr_store_addr;
+	u64 vm_exit_msr_load_addr;
+	u64 vm_entry_msr_load_addr;
+
+	u64 cr3_target_value0;
+	u64 cr3_target_value1;
+	u64 cr3_target_value2;
+	u64 cr3_target_value3;
+
+	u32 page_fault_error_code_mask;
+	u32 page_fault_error_code_match;
+
+	u32 cr3_target_count;
+	u32 vm_exit_msr_store_count;
+	u32 vm_exit_msr_load_count;
+	u32 vm_entry_msr_load_count;
+
+	u64 tsc_offset;
+	u64 virtual_apic_page_addr;
+	u64 vmcs_link_pointer;
+
+	u64 guest_ia32_debugctl;
+	u64 guest_ia32_pat;
+	u64 guest_ia32_efer;
+
+	u64 guest_pdptr0;
+	u64 guest_pdptr1;
+	u64 guest_pdptr2;
+	u64 guest_pdptr3;
+
+	u64 guest_pending_dbg_exceptions;
+	u64 guest_sysenter_esp;
+	u64 guest_sysenter_eip;
+
+	u32 guest_activity_state;
+	u32 guest_sysenter_cs;
+
+	u64 cr0_guest_host_mask;
+	u64 cr4_guest_host_mask;
+	u64 cr0_read_shadow;
+	u64 cr4_read_shadow;
+	u64 guest_cr0;
+	u64 guest_cr3;
+	u64 guest_cr4;
+	u64 guest_dr7;
+
+	u64 host_fs_base;
+	u64 host_gs_base;
+	u64 host_tr_base;
+	u64 host_gdtr_base;
+	u64 host_idtr_base;
+	u64 host_rsp;
+
+	u64 ept_pointer;
+
+	u16 virtual_processor_id;
+	u16 padding16[3];
+
+	u64 padding64_2[5];
+	u64 guest_physical_address;
+
+	u32 vm_instruction_error;
+	u32 vm_exit_reason;
+	u32 vm_exit_intr_info;
+	u32 vm_exit_intr_error_code;
+	u32 idt_vectoring_info_field;
+	u32 idt_vectoring_error_code;
+	u32 vm_exit_instruction_len;
+	u32 vmx_instruction_info;
+
+	u64 exit_qualification;
+	u64 exit_io_instruction_ecx;
+	u64 exit_io_instruction_esi;
+	u64 exit_io_instruction_edi;
+	u64 exit_io_instruction_eip;
+
+	u64 guest_linear_address;
+	u64 guest_rsp;
+	u64 guest_rflags;
+
+	u32 guest_interruptibility_info;
+	u32 cpu_based_vm_exec_control;
+	u32 exception_bitmap;
+	u32 vm_entry_controls;
+	u32 vm_entry_intr_info_field;
+	u32 vm_entry_exception_error_code;
+	u32 vm_entry_instruction_len;
+	u32 tpr_threshold;
+
+	u64 guest_rip;
+
+	u32 hv_clean_fields;
+	u32 hv_padding_32;
+	u32 hv_synthetic_controls;
+	struct {
+		u32 nested_flush_hypercall:1;
+		u32 msr_bitmap:1;
+		u32 reserved:30;
+	} hv_enlightenments_control;
+	u32 hv_vp_id;
+
+	u64 hv_vm_id;
+	u64 partition_assist_page;
+	u64 padding64_4[4];
+	u64 guest_bndcfgs;
+	u64 padding64_5[7];
+	u64 xss_exit_bitmap;
+	u64 padding64_6[7];
+};
+
+#define HV_X64_MSR_VP_ASSIST_PAGE		0x40000073
+#define HV_X64_MSR_VP_ASSIST_PAGE_ENABLE	0x00000001
+#define HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT	12
+#define HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_MASK	\
+		(~((1ull << HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT) - 1))
+
+struct hv_enlightened_vmcs *current_evmcs;
+struct hv_vp_assist_page *current_vp_assist;
+
+static inline int enable_vp_assist(uint64_t vp_assist_pa, void *vp_assist)
+{
+	u64 val = (vp_assist_pa & HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_MASK) |
+		HV_X64_MSR_VP_ASSIST_PAGE_ENABLE;
+
+	wrmsr(HV_X64_MSR_VP_ASSIST_PAGE, val);
+
+	current_vp_assist = vp_assist;
+
+	enable_evmcs = true;
+
+	return 0;
+}
+
+static inline int evmcs_vmptrld(uint64_t vmcs_pa, void *vmcs)
+{
+	current_vp_assist->current_nested_vmcs = vmcs_pa;
+	current_vp_assist->enlighten_vmentry = 1;
+
+	current_evmcs = vmcs;
+
+	return 0;
+}
+
+static inline int evmcs_vmptrst(uint64_t *value)
+{
+	*value = current_vp_assist->current_nested_vmcs &
+		~HV_X64_MSR_VP_ASSIST_PAGE_ENABLE;
+
+	return 0;
+}
+
+static inline int evmcs_vmread(uint64_t encoding, uint64_t *value)
+{
+	switch (encoding) {
+	case GUEST_RIP:
+		*value = current_evmcs->guest_rip;
+		break;
+	case GUEST_RSP:
+		*value = current_evmcs->guest_rsp;
+		break;
+	case GUEST_RFLAGS:
+		*value = current_evmcs->guest_rflags;
+		break;
+	case HOST_IA32_PAT:
+		*value = current_evmcs->host_ia32_pat;
+		break;
+	case HOST_IA32_EFER:
+		*value = current_evmcs->host_ia32_efer;
+		break;
+	case HOST_CR0:
+		*value = current_evmcs->host_cr0;
+		break;
+	case HOST_CR3:
+		*value = current_evmcs->host_cr3;
+		break;
+	case HOST_CR4:
+		*value = current_evmcs->host_cr4;
+		break;
+	case HOST_IA32_SYSENTER_ESP:
+		*value = current_evmcs->host_ia32_sysenter_esp;
+		break;
+	case HOST_IA32_SYSENTER_EIP:
+		*value = current_evmcs->host_ia32_sysenter_eip;
+		break;
+	case HOST_RIP:
+		*value = current_evmcs->host_rip;
+		break;
+	case IO_BITMAP_A:
+		*value = current_evmcs->io_bitmap_a;
+		break;
+	case IO_BITMAP_B:
+		*value = current_evmcs->io_bitmap_b;
+		break;
+	case MSR_BITMAP:
+		*value = current_evmcs->msr_bitmap;
+		break;
+	case GUEST_ES_BASE:
+		*value = current_evmcs->guest_es_base;
+		break;
+	case GUEST_CS_BASE:
+		*value = current_evmcs->guest_cs_base;
+		break;
+	case GUEST_SS_BASE:
+		*value = current_evmcs->guest_ss_base;
+		break;
+	case GUEST_DS_BASE:
+		*value = current_evmcs->guest_ds_base;
+		break;
+	case GUEST_FS_BASE:
+		*value = current_evmcs->guest_fs_base;
+		break;
+	case GUEST_GS_BASE:
+		*value = current_evmcs->guest_gs_base;
+		break;
+	case GUEST_LDTR_BASE:
+		*value = current_evmcs->guest_ldtr_base;
+		break;
+	case GUEST_TR_BASE:
+		*value = current_evmcs->guest_tr_base;
+		break;
+	case GUEST_GDTR_BASE:
+		*value = current_evmcs->guest_gdtr_base;
+		break;
+	case GUEST_IDTR_BASE:
+		*value = current_evmcs->guest_idtr_base;
+		break;
+	case TSC_OFFSET:
+		*value = current_evmcs->tsc_offset;
+		break;
+	case VIRTUAL_APIC_PAGE_ADDR:
+		*value = current_evmcs->virtual_apic_page_addr;
+		break;
+	case VMCS_LINK_POINTER:
+		*value = current_evmcs->vmcs_link_pointer;
+		break;
+	case GUEST_IA32_DEBUGCTL:
+		*value = current_evmcs->guest_ia32_debugctl;
+		break;
+	case GUEST_IA32_PAT:
+		*value = current_evmcs->guest_ia32_pat;
+		break;
+	case GUEST_IA32_EFER:
+		*value = current_evmcs->guest_ia32_efer;
+		break;
+	case GUEST_PDPTR0:
+		*value = current_evmcs->guest_pdptr0;
+		break;
+	case GUEST_PDPTR1:
+		*value = current_evmcs->guest_pdptr1;
+		break;
+	case GUEST_PDPTR2:
+		*value = current_evmcs->guest_pdptr2;
+		break;
+	case GUEST_PDPTR3:
+		*value = current_evmcs->guest_pdptr3;
+		break;
+	case GUEST_PENDING_DBG_EXCEPTIONS:
+		*value = current_evmcs->guest_pending_dbg_exceptions;
+		break;
+	case GUEST_SYSENTER_ESP:
+		*value = current_evmcs->guest_sysenter_esp;
+		break;
+	case GUEST_SYSENTER_EIP:
+		*value = current_evmcs->guest_sysenter_eip;
+		break;
+	case CR0_GUEST_HOST_MASK:
+		*value = current_evmcs->cr0_guest_host_mask;
+		break;
+	case CR4_GUEST_HOST_MASK:
+		*value = current_evmcs->cr4_guest_host_mask;
+		break;
+	case CR0_READ_SHADOW:
+		*value = current_evmcs->cr0_read_shadow;
+		break;
+	case CR4_READ_SHADOW:
+		*value = current_evmcs->cr4_read_shadow;
+		break;
+	case GUEST_CR0:
+		*value = current_evmcs->guest_cr0;
+		break;
+	case GUEST_CR3:
+		*value = current_evmcs->guest_cr3;
+		break;
+	case GUEST_CR4:
+		*value = current_evmcs->guest_cr4;
+		break;
+	case GUEST_DR7:
+		*value = current_evmcs->guest_dr7;
+		break;
+	case HOST_FS_BASE:
+		*value = current_evmcs->host_fs_base;
+		break;
+	case HOST_GS_BASE:
+		*value = current_evmcs->host_gs_base;
+		break;
+	case HOST_TR_BASE:
+		*value = current_evmcs->host_tr_base;
+		break;
+	case HOST_GDTR_BASE:
+		*value = current_evmcs->host_gdtr_base;
+		break;
+	case HOST_IDTR_BASE:
+		*value = current_evmcs->host_idtr_base;
+		break;
+	case HOST_RSP:
+		*value = current_evmcs->host_rsp;
+		break;
+	case EPT_POINTER:
+		*value = current_evmcs->ept_pointer;
+		break;
+	case GUEST_BNDCFGS:
+		*value = current_evmcs->guest_bndcfgs;
+		break;
+	case XSS_EXIT_BITMAP:
+		*value = current_evmcs->xss_exit_bitmap;
+		break;
+	case GUEST_PHYSICAL_ADDRESS:
+		*value = current_evmcs->guest_physical_address;
+		break;
+	case EXIT_QUALIFICATION:
+		*value = current_evmcs->exit_qualification;
+		break;
+	case GUEST_LINEAR_ADDRESS:
+		*value = current_evmcs->guest_linear_address;
+		break;
+	case VM_EXIT_MSR_STORE_ADDR:
+		*value = current_evmcs->vm_exit_msr_store_addr;
+		break;
+	case VM_EXIT_MSR_LOAD_ADDR:
+		*value = current_evmcs->vm_exit_msr_load_addr;
+		break;
+	case VM_ENTRY_MSR_LOAD_ADDR:
+		*value = current_evmcs->vm_entry_msr_load_addr;
+		break;
+	case CR3_TARGET_VALUE0:
+		*value = current_evmcs->cr3_target_value0;
+		break;
+	case CR3_TARGET_VALUE1:
+		*value = current_evmcs->cr3_target_value1;
+		break;
+	case CR3_TARGET_VALUE2:
+		*value = current_evmcs->cr3_target_value2;
+		break;
+	case CR3_TARGET_VALUE3:
+		*value = current_evmcs->cr3_target_value3;
+		break;
+	case TPR_THRESHOLD:
+		*value = current_evmcs->tpr_threshold;
+		break;
+	case GUEST_INTERRUPTIBILITY_INFO:
+		*value = current_evmcs->guest_interruptibility_info;
+		break;
+	case CPU_BASED_VM_EXEC_CONTROL:
+		*value = current_evmcs->cpu_based_vm_exec_control;
+		break;
+	case EXCEPTION_BITMAP:
+		*value = current_evmcs->exception_bitmap;
+		break;
+	case VM_ENTRY_CONTROLS:
+		*value = current_evmcs->vm_entry_controls;
+		break;
+	case VM_ENTRY_INTR_INFO_FIELD:
+		*value = current_evmcs->vm_entry_intr_info_field;
+		break;
+	case VM_ENTRY_EXCEPTION_ERROR_CODE:
+		*value = current_evmcs->vm_entry_exception_error_code;
+		break;
+	case VM_ENTRY_INSTRUCTION_LEN:
+		*value = current_evmcs->vm_entry_instruction_len;
+		break;
+	case HOST_IA32_SYSENTER_CS:
+		*value = current_evmcs->host_ia32_sysenter_cs;
+		break;
+	case PIN_BASED_VM_EXEC_CONTROL:
+		*value = current_evmcs->pin_based_vm_exec_control;
+		break;
+	case VM_EXIT_CONTROLS:
+		*value = current_evmcs->vm_exit_controls;
+		break;
+	case SECONDARY_VM_EXEC_CONTROL:
+		*value = current_evmcs->secondary_vm_exec_control;
+		break;
+	case GUEST_ES_LIMIT:
+		*value = current_evmcs->guest_es_limit;
+		break;
+	case GUEST_CS_LIMIT:
+		*value = current_evmcs->guest_cs_limit;
+		break;
+	case GUEST_SS_LIMIT:
+		*value = current_evmcs->guest_ss_limit;
+		break;
+	case GUEST_DS_LIMIT:
+		*value = current_evmcs->guest_ds_limit;
+		break;
+	case GUEST_FS_LIMIT:
+		*value = current_evmcs->guest_fs_limit;
+		break;
+	case GUEST_GS_LIMIT:
+		*value = current_evmcs->guest_gs_limit;
+		break;
+	case GUEST_LDTR_LIMIT:
+		*value = current_evmcs->guest_ldtr_limit;
+		break;
+	case GUEST_TR_LIMIT:
+		*value = current_evmcs->guest_tr_limit;
+		break;
+	case GUEST_GDTR_LIMIT:
+		*value = current_evmcs->guest_gdtr_limit;
+		break;
+	case GUEST_IDTR_LIMIT:
+		*value = current_evmcs->guest_idtr_limit;
+		break;
+	case GUEST_ES_AR_BYTES:
+		*value = current_evmcs->guest_es_ar_bytes;
+		break;
+	case GUEST_CS_AR_BYTES:
+		*value = current_evmcs->guest_cs_ar_bytes;
+		break;
+	case GUEST_SS_AR_BYTES:
+		*value = current_evmcs->guest_ss_ar_bytes;
+		break;
+	case GUEST_DS_AR_BYTES:
+		*value = current_evmcs->guest_ds_ar_bytes;
+		break;
+	case GUEST_FS_AR_BYTES:
+		*value = current_evmcs->guest_fs_ar_bytes;
+		break;
+	case GUEST_GS_AR_BYTES:
+		*value = current_evmcs->guest_gs_ar_bytes;
+		break;
+	case GUEST_LDTR_AR_BYTES:
+		*value = current_evmcs->guest_ldtr_ar_bytes;
+		break;
+	case GUEST_TR_AR_BYTES:
+		*value = current_evmcs->guest_tr_ar_bytes;
+		break;
+	case GUEST_ACTIVITY_STATE:
+		*value = current_evmcs->guest_activity_state;
+		break;
+	case GUEST_SYSENTER_CS:
+		*value = current_evmcs->guest_sysenter_cs;
+		break;
+	case VM_INSTRUCTION_ERROR:
+		*value = current_evmcs->vm_instruction_error;
+		break;
+	case VM_EXIT_REASON:
+		*value = current_evmcs->vm_exit_reason;
+		break;
+	case VM_EXIT_INTR_INFO:
+		*value = current_evmcs->vm_exit_intr_info;
+		break;
+	case VM_EXIT_INTR_ERROR_CODE:
+		*value = current_evmcs->vm_exit_intr_error_code;
+		break;
+	case IDT_VECTORING_INFO_FIELD:
+		*value = current_evmcs->idt_vectoring_info_field;
+		break;
+	case IDT_VECTORING_ERROR_CODE:
+		*value = current_evmcs->idt_vectoring_error_code;
+		break;
+	case VM_EXIT_INSTRUCTION_LEN:
+		*value = current_evmcs->vm_exit_instruction_len;
+		break;
+	case VMX_INSTRUCTION_INFO:
+		*value = current_evmcs->vmx_instruction_info;
+		break;
+	case PAGE_FAULT_ERROR_CODE_MASK:
+		*value = current_evmcs->page_fault_error_code_mask;
+		break;
+	case PAGE_FAULT_ERROR_CODE_MATCH:
+		*value = current_evmcs->page_fault_error_code_match;
+		break;
+	case CR3_TARGET_COUNT:
+		*value = current_evmcs->cr3_target_count;
+		break;
+	case VM_EXIT_MSR_STORE_COUNT:
+		*value = current_evmcs->vm_exit_msr_store_count;
+		break;
+	case VM_EXIT_MSR_LOAD_COUNT:
+		*value = current_evmcs->vm_exit_msr_load_count;
+		break;
+	case VM_ENTRY_MSR_LOAD_COUNT:
+		*value = current_evmcs->vm_entry_msr_load_count;
+		break;
+	case HOST_ES_SELECTOR:
+		*value = current_evmcs->host_es_selector;
+		break;
+	case HOST_CS_SELECTOR:
+		*value = current_evmcs->host_cs_selector;
+		break;
+	case HOST_SS_SELECTOR:
+		*value = current_evmcs->host_ss_selector;
+		break;
+	case HOST_DS_SELECTOR:
+		*value = current_evmcs->host_ds_selector;
+		break;
+	case HOST_FS_SELECTOR:
+		*value = current_evmcs->host_fs_selector;
+		break;
+	case HOST_GS_SELECTOR:
+		*value = current_evmcs->host_gs_selector;
+		break;
+	case HOST_TR_SELECTOR:
+		*value = current_evmcs->host_tr_selector;
+		break;
+	case GUEST_ES_SELECTOR:
+		*value = current_evmcs->guest_es_selector;
+		break;
+	case GUEST_CS_SELECTOR:
+		*value = current_evmcs->guest_cs_selector;
+		break;
+	case GUEST_SS_SELECTOR:
+		*value = current_evmcs->guest_ss_selector;
+		break;
+	case GUEST_DS_SELECTOR:
+		*value = current_evmcs->guest_ds_selector;
+		break;
+	case GUEST_FS_SELECTOR:
+		*value = current_evmcs->guest_fs_selector;
+		break;
+	case GUEST_GS_SELECTOR:
+		*value = current_evmcs->guest_gs_selector;
+		break;
+	case GUEST_LDTR_SELECTOR:
+		*value = current_evmcs->guest_ldtr_selector;
+		break;
+	case GUEST_TR_SELECTOR:
+		*value = current_evmcs->guest_tr_selector;
+		break;
+	case VIRTUAL_PROCESSOR_ID:
+		*value = current_evmcs->virtual_processor_id;
+		break;
+	default: return 1;
+	}
+
+	return 0;
+}
+
+static inline int evmcs_vmwrite(uint64_t encoding, uint64_t value)
+{
+	switch (encoding) {
+	case GUEST_RIP:
+		current_evmcs->guest_rip = value;
+		break;
+	case GUEST_RSP:
+		current_evmcs->guest_rsp = value;
+		break;
+	case GUEST_RFLAGS:
+		current_evmcs->guest_rflags = value;
+		break;
+	case HOST_IA32_PAT:
+		current_evmcs->host_ia32_pat = value;
+		break;
+	case HOST_IA32_EFER:
+		current_evmcs->host_ia32_efer = value;
+		break;
+	case HOST_CR0:
+		current_evmcs->host_cr0 = value;
+		break;
+	case HOST_CR3:
+		current_evmcs->host_cr3 = value;
+		break;
+	case HOST_CR4:
+		current_evmcs->host_cr4 = value;
+		break;
+	case HOST_IA32_SYSENTER_ESP:
+		current_evmcs->host_ia32_sysenter_esp = value;
+		break;
+	case HOST_IA32_SYSENTER_EIP:
+		current_evmcs->host_ia32_sysenter_eip = value;
+		break;
+	case HOST_RIP:
+		current_evmcs->host_rip = value;
+		break;
+	case IO_BITMAP_A:
+		current_evmcs->io_bitmap_a = value;
+		break;
+	case IO_BITMAP_B:
+		current_evmcs->io_bitmap_b = value;
+		break;
+	case MSR_BITMAP:
+		current_evmcs->msr_bitmap = value;
+		break;
+	case GUEST_ES_BASE:
+		current_evmcs->guest_es_base = value;
+		break;
+	case GUEST_CS_BASE:
+		current_evmcs->guest_cs_base = value;
+		break;
+	case GUEST_SS_BASE:
+		current_evmcs->guest_ss_base = value;
+		break;
+	case GUEST_DS_BASE:
+		current_evmcs->guest_ds_base = value;
+		break;
+	case GUEST_FS_BASE:
+		current_evmcs->guest_fs_base = value;
+		break;
+	case GUEST_GS_BASE:
+		current_evmcs->guest_gs_base = value;
+		break;
+	case GUEST_LDTR_BASE:
+		current_evmcs->guest_ldtr_base = value;
+		break;
+	case GUEST_TR_BASE:
+		current_evmcs->guest_tr_base = value;
+		break;
+	case GUEST_GDTR_BASE:
+		current_evmcs->guest_gdtr_base = value;
+		break;
+	case GUEST_IDTR_BASE:
+		current_evmcs->guest_idtr_base = value;
+		break;
+	case TSC_OFFSET:
+		current_evmcs->tsc_offset = value;
+		break;
+	case VIRTUAL_APIC_PAGE_ADDR:
+		current_evmcs->virtual_apic_page_addr = value;
+		break;
+	case VMCS_LINK_POINTER:
+		current_evmcs->vmcs_link_pointer = value;
+		break;
+	case GUEST_IA32_DEBUGCTL:
+		current_evmcs->guest_ia32_debugctl = value;
+		break;
+	case GUEST_IA32_PAT:
+		current_evmcs->guest_ia32_pat = value;
+		break;
+	case GUEST_IA32_EFER:
+		current_evmcs->guest_ia32_efer = value;
+		break;
+	case GUEST_PDPTR0:
+		current_evmcs->guest_pdptr0 = value;
+		break;
+	case GUEST_PDPTR1:
+		current_evmcs->guest_pdptr1 = value;
+		break;
+	case GUEST_PDPTR2:
+		current_evmcs->guest_pdptr2 = value;
+		break;
+	case GUEST_PDPTR3:
+		current_evmcs->guest_pdptr3 = value;
+		break;
+	case GUEST_PENDING_DBG_EXCEPTIONS:
+		current_evmcs->guest_pending_dbg_exceptions = value;
+		break;
+	case GUEST_SYSENTER_ESP:
+		current_evmcs->guest_sysenter_esp = value;
+		break;
+	case GUEST_SYSENTER_EIP:
+		current_evmcs->guest_sysenter_eip = value;
+		break;
+	case CR0_GUEST_HOST_MASK:
+		current_evmcs->cr0_guest_host_mask = value;
+		break;
+	case CR4_GUEST_HOST_MASK:
+		current_evmcs->cr4_guest_host_mask = value;
+		break;
+	case CR0_READ_SHADOW:
+		current_evmcs->cr0_read_shadow = value;
+		break;
+	case CR4_READ_SHADOW:
+		current_evmcs->cr4_read_shadow = value;
+		break;
+	case GUEST_CR0:
+		current_evmcs->guest_cr0 = value;
+		break;
+	case GUEST_CR3:
+		current_evmcs->guest_cr3 = value;
+		break;
+	case GUEST_CR4:
+		current_evmcs->guest_cr4 = value;
+		break;
+	case GUEST_DR7:
+		current_evmcs->guest_dr7 = value;
+		break;
+	case HOST_FS_BASE:
+		current_evmcs->host_fs_base = value;
+		break;
+	case HOST_GS_BASE:
+		current_evmcs->host_gs_base = value;
+		break;
+	case HOST_TR_BASE:
+		current_evmcs->host_tr_base = value;
+		break;
+	case HOST_GDTR_BASE:
+		current_evmcs->host_gdtr_base = value;
+		break;
+	case HOST_IDTR_BASE:
+		current_evmcs->host_idtr_base = value;
+		break;
+	case HOST_RSP:
+		current_evmcs->host_rsp = value;
+		break;
+	case EPT_POINTER:
+		current_evmcs->ept_pointer = value;
+		break;
+	case GUEST_BNDCFGS:
+		current_evmcs->guest_bndcfgs = value;
+		break;
+	case XSS_EXIT_BITMAP:
+		current_evmcs->xss_exit_bitmap = value;
+		break;
+	case GUEST_PHYSICAL_ADDRESS:
+		current_evmcs->guest_physical_address = value;
+		break;
+	case EXIT_QUALIFICATION:
+		current_evmcs->exit_qualification = value;
+		break;
+	case GUEST_LINEAR_ADDRESS:
+		current_evmcs->guest_linear_address = value;
+		break;
+	case VM_EXIT_MSR_STORE_ADDR:
+		current_evmcs->vm_exit_msr_store_addr = value;
+		break;
+	case VM_EXIT_MSR_LOAD_ADDR:
+		current_evmcs->vm_exit_msr_load_addr = value;
+		break;
+	case VM_ENTRY_MSR_LOAD_ADDR:
+		current_evmcs->vm_entry_msr_load_addr = value;
+		break;
+	case CR3_TARGET_VALUE0:
+		current_evmcs->cr3_target_value0 = value;
+		break;
+	case CR3_TARGET_VALUE1:
+		current_evmcs->cr3_target_value1 = value;
+		break;
+	case CR3_TARGET_VALUE2:
+		current_evmcs->cr3_target_value2 = value;
+		break;
+	case CR3_TARGET_VALUE3:
+		current_evmcs->cr3_target_value3 = value;
+		break;
+	case TPR_THRESHOLD:
+		current_evmcs->tpr_threshold = value;
+		break;
+	case GUEST_INTERRUPTIBILITY_INFO:
+		current_evmcs->guest_interruptibility_info = value;
+		break;
+	case CPU_BASED_VM_EXEC_CONTROL:
+		current_evmcs->cpu_based_vm_exec_control = value;
+		break;
+	case EXCEPTION_BITMAP:
+		current_evmcs->exception_bitmap = value;
+		break;
+	case VM_ENTRY_CONTROLS:
+		current_evmcs->vm_entry_controls = value;
+		break;
+	case VM_ENTRY_INTR_INFO_FIELD:
+		current_evmcs->vm_entry_intr_info_field = value;
+		break;
+	case VM_ENTRY_EXCEPTION_ERROR_CODE:
+		current_evmcs->vm_entry_exception_error_code = value;
+		break;
+	case VM_ENTRY_INSTRUCTION_LEN:
+		current_evmcs->vm_entry_instruction_len = value;
+		break;
+	case HOST_IA32_SYSENTER_CS:
+		current_evmcs->host_ia32_sysenter_cs = value;
+		break;
+	case PIN_BASED_VM_EXEC_CONTROL:
+		current_evmcs->pin_based_vm_exec_control = value;
+		break;
+	case VM_EXIT_CONTROLS:
+		current_evmcs->vm_exit_controls = value;
+		break;
+	case SECONDARY_VM_EXEC_CONTROL:
+		current_evmcs->secondary_vm_exec_control = value;
+		break;
+	case GUEST_ES_LIMIT:
+		current_evmcs->guest_es_limit = value;
+		break;
+	case GUEST_CS_LIMIT:
+		current_evmcs->guest_cs_limit = value;
+		break;
+	case GUEST_SS_LIMIT:
+		current_evmcs->guest_ss_limit = value;
+		break;
+	case GUEST_DS_LIMIT:
+		current_evmcs->guest_ds_limit = value;
+		break;
+	case GUEST_FS_LIMIT:
+		current_evmcs->guest_fs_limit = value;
+		break;
+	case GUEST_GS_LIMIT:
+		current_evmcs->guest_gs_limit = value;
+		break;
+	case GUEST_LDTR_LIMIT:
+		current_evmcs->guest_ldtr_limit = value;
+		break;
+	case GUEST_TR_LIMIT:
+		current_evmcs->guest_tr_limit = value;
+		break;
+	case GUEST_GDTR_LIMIT:
+		current_evmcs->guest_gdtr_limit = value;
+		break;
+	case GUEST_IDTR_LIMIT:
+		current_evmcs->guest_idtr_limit = value;
+		break;
+	case GUEST_ES_AR_BYTES:
+		current_evmcs->guest_es_ar_bytes = value;
+		break;
+	case GUEST_CS_AR_BYTES:
+		current_evmcs->guest_cs_ar_bytes = value;
+		break;
+	case GUEST_SS_AR_BYTES:
+		current_evmcs->guest_ss_ar_bytes = value;
+		break;
+	case GUEST_DS_AR_BYTES:
+		current_evmcs->guest_ds_ar_bytes = value;
+		break;
+	case GUEST_FS_AR_BYTES:
+		current_evmcs->guest_fs_ar_bytes = value;
+		break;
+	case GUEST_GS_AR_BYTES:
+		current_evmcs->guest_gs_ar_bytes = value;
+		break;
+	case GUEST_LDTR_AR_BYTES:
+		current_evmcs->guest_ldtr_ar_bytes = value;
+		break;
+	case GUEST_TR_AR_BYTES:
+		current_evmcs->guest_tr_ar_bytes = value;
+		break;
+	case GUEST_ACTIVITY_STATE:
+		current_evmcs->guest_activity_state = value;
+		break;
+	case GUEST_SYSENTER_CS:
+		current_evmcs->guest_sysenter_cs = value;
+		break;
+	case VM_INSTRUCTION_ERROR:
+		current_evmcs->vm_instruction_error = value;
+		break;
+	case VM_EXIT_REASON:
+		current_evmcs->vm_exit_reason = value;
+		break;
+	case VM_EXIT_INTR_INFO:
+		current_evmcs->vm_exit_intr_info = value;
+		break;
+	case VM_EXIT_INTR_ERROR_CODE:
+		current_evmcs->vm_exit_intr_error_code = value;
+		break;
+	case IDT_VECTORING_INFO_FIELD:
+		current_evmcs->idt_vectoring_info_field = value;
+		break;
+	case IDT_VECTORING_ERROR_CODE:
+		current_evmcs->idt_vectoring_error_code = value;
+		break;
+	case VM_EXIT_INSTRUCTION_LEN:
+		current_evmcs->vm_exit_instruction_len = value;
+		break;
+	case VMX_INSTRUCTION_INFO:
+		current_evmcs->vmx_instruction_info = value;
+		break;
+	case PAGE_FAULT_ERROR_CODE_MASK:
+		current_evmcs->page_fault_error_code_mask = value;
+		break;
+	case PAGE_FAULT_ERROR_CODE_MATCH:
+		current_evmcs->page_fault_error_code_match = value;
+		break;
+	case CR3_TARGET_COUNT:
+		current_evmcs->cr3_target_count = value;
+		break;
+	case VM_EXIT_MSR_STORE_COUNT:
+		current_evmcs->vm_exit_msr_store_count = value;
+		break;
+	case VM_EXIT_MSR_LOAD_COUNT:
+		current_evmcs->vm_exit_msr_load_count = value;
+		break;
+	case VM_ENTRY_MSR_LOAD_COUNT:
+		current_evmcs->vm_entry_msr_load_count = value;
+		break;
+	case HOST_ES_SELECTOR:
+		current_evmcs->host_es_selector = value;
+		break;
+	case HOST_CS_SELECTOR:
+		current_evmcs->host_cs_selector = value;
+		break;
+	case HOST_SS_SELECTOR:
+		current_evmcs->host_ss_selector = value;
+		break;
+	case HOST_DS_SELECTOR:
+		current_evmcs->host_ds_selector = value;
+		break;
+	case HOST_FS_SELECTOR:
+		current_evmcs->host_fs_selector = value;
+		break;
+	case HOST_GS_SELECTOR:
+		current_evmcs->host_gs_selector = value;
+		break;
+	case HOST_TR_SELECTOR:
+		current_evmcs->host_tr_selector = value;
+		break;
+	case GUEST_ES_SELECTOR:
+		current_evmcs->guest_es_selector = value;
+		break;
+	case GUEST_CS_SELECTOR:
+		current_evmcs->guest_cs_selector = value;
+		break;
+	case GUEST_SS_SELECTOR:
+		current_evmcs->guest_ss_selector = value;
+		break;
+	case GUEST_DS_SELECTOR:
+		current_evmcs->guest_ds_selector = value;
+		break;
+	case GUEST_FS_SELECTOR:
+		current_evmcs->guest_fs_selector = value;
+		break;
+	case GUEST_GS_SELECTOR:
+		current_evmcs->guest_gs_selector = value;
+		break;
+	case GUEST_LDTR_SELECTOR:
+		current_evmcs->guest_ldtr_selector = value;
+		break;
+	case GUEST_TR_SELECTOR:
+		current_evmcs->guest_tr_selector = value;
+		break;
+	case VIRTUAL_PROCESSOR_ID:
+		current_evmcs->virtual_processor_id = value;
+		break;
+	default: return 1;
+	}
+
+	return 0;
+}
+
+static inline int evmcs_vmlaunch(void)
+{
+	int ret;
+
+	current_evmcs->hv_clean_fields = 0;
+
+	__asm__ __volatile__("push %%rbp;"
+			     "push %%rcx;"
+			     "push %%rdx;"
+			     "push %%rsi;"
+			     "push %%rdi;"
+			     "push $0;"
+			     "mov %%rsp, (%[host_rsp]);"
+			     "lea 1f(%%rip), %%rax;"
+			     "mov %%rax, (%[host_rip]);"
+			     "vmlaunch;"
+			     "incq (%%rsp);"
+			     "1: pop %%rax;"
+			     "pop %%rdi;"
+			     "pop %%rsi;"
+			     "pop %%rdx;"
+			     "pop %%rcx;"
+			     "pop %%rbp;"
+			     : [ret]"=&a"(ret)
+			     : [host_rsp]"r"
+			       ((uint64_t)&current_evmcs->host_rsp),
+			       [host_rip]"r"
+			       ((uint64_t)&current_evmcs->host_rip)
+			     : "memory", "cc", "rbx", "r8", "r9", "r10",
+			       "r11", "r12", "r13", "r14", "r15");
+	return ret;
+}
+
+/*
+ * No guest state (e.g. GPRs) is established by this vmresume.
+ */
+static inline int evmcs_vmresume(void)
+{
+	int ret;
+
+	current_evmcs->hv_clean_fields = 0;
+
+	__asm__ __volatile__("push %%rbp;"
+			     "push %%rcx;"
+			     "push %%rdx;"
+			     "push %%rsi;"
+			     "push %%rdi;"
+			     "push $0;"
+			     "mov %%rsp, (%[host_rsp]);"
+			     "lea 1f(%%rip), %%rax;"
+			     "mov %%rax, (%[host_rip]);"
+			     "vmresume;"
+			     "incq (%%rsp);"
+			     "1: pop %%rax;"
+			     "pop %%rdi;"
+			     "pop %%rsi;"
+			     "pop %%rdx;"
+			     "pop %%rcx;"
+			     "pop %%rbp;"
+			     : [ret]"=&a"(ret)
+			     : [host_rsp]"r"
+			       ((uint64_t)&current_evmcs->host_rsp),
+			       [host_rip]"r"
+			       ((uint64_t)&current_evmcs->host_rip)
+			     : "memory", "cc", "rbx", "r8", "r9", "r10",
+			       "r11", "r12", "r13", "r14", "r15");
+	return ret;
+}
+
+#endif /* !SELFTEST_KVM_EVMCS_H */
diff --git a/tools/testing/selftests/kvm/include/x86_64/vmx.h b/tools/testing/selftests/kvm/include/x86_64/vmx.h
index 4bbee8560292..c9bd935b939c 100644
--- a/tools/testing/selftests/kvm/include/x86_64/vmx.h
+++ b/tools/testing/selftests/kvm/include/x86_64/vmx.h
@@ -339,6 +339,8 @@ struct vmx_msr_entry {
 	uint64_t value;
 } __attribute__ ((aligned(16)));
 
+#include "evmcs.h"
+
 static inline int vmxon(uint64_t phys)
 {
 	uint8_t ret;
@@ -372,6 +374,9 @@ static inline int vmptrld(uint64_t vmcs_pa)
 {
 	uint8_t ret;
 
+	if (enable_evmcs)
+		return -1;
+
 	__asm__ __volatile__ ("vmptrld %[pa]; setna %[ret]"
 		: [ret]"=rm"(ret)
 		: [pa]"m"(vmcs_pa)
@@ -385,6 +390,9 @@ static inline int vmptrst(uint64_t *value)
 	uint64_t tmp;
 	uint8_t ret;
 
+	if (enable_evmcs)
+		return evmcs_vmptrst(value);
+
 	__asm__ __volatile__("vmptrst %[value]; setna %[ret]"
 		: [value]"=m"(tmp), [ret]"=rm"(ret)
 		: : "cc", "memory");
@@ -411,6 +419,9 @@ static inline int vmlaunch(void)
 {
 	int ret;
 
+	if (enable_evmcs)
+		return evmcs_vmlaunch();
+
 	__asm__ __volatile__("push %%rbp;"
 			     "push %%rcx;"
 			     "push %%rdx;"
@@ -443,6 +454,9 @@ static inline int vmresume(void)
 {
 	int ret;
 
+	if (enable_evmcs)
+		return evmcs_vmresume();
+
 	__asm__ __volatile__("push %%rbp;"
 			     "push %%rcx;"
 			     "push %%rdx;"
@@ -482,6 +496,9 @@ static inline int vmread(uint64_t encoding, uint64_t *value)
 	uint64_t tmp;
 	uint8_t ret;
 
+	if (enable_evmcs)
+		return evmcs_vmread(encoding, value);
+
 	__asm__ __volatile__("vmread %[encoding], %[value]; setna %[ret]"
 		: [value]"=rm"(tmp), [ret]"=rm"(ret)
 		: [encoding]"r"(encoding)
@@ -506,6 +523,9 @@ static inline int vmwrite(uint64_t encoding, uint64_t value)
 {
 	uint8_t ret;
 
+	if (enable_evmcs)
+		return evmcs_vmwrite(encoding, value);
+
 	__asm__ __volatile__ ("vmwrite %[value], %[encoding]; setna %[ret]"
 		: [ret]"=rm"(ret)
 		: [value]"rm"(value), [encoding]"r"(encoding)
@@ -543,6 +563,14 @@ struct vmx_pages {
 	void *vmwrite_hva;
 	uint64_t vmwrite_gpa;
 	void *vmwrite;
+
+	void *vp_assist_hva;
+	uint64_t vp_assist_gpa;
+	void *vp_assist;
+
+	void *enlightened_vmcs_hva;
+	uint64_t enlightened_vmcs_gpa;
+	void *enlightened_vmcs;
 };
 
 struct vmx_pages *vcpu_alloc_vmx(struct kvm_vm *vm, vm_vaddr_t *p_vmx_gva);
diff --git a/tools/testing/selftests/kvm/lib/x86_64/vmx.c b/tools/testing/selftests/kvm/lib/x86_64/vmx.c
index cc356da9b3d8..771ba6bf751c 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/vmx.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/vmx.c
@@ -13,6 +13,8 @@
 #include "processor.h"
 #include "vmx.h"
 
+bool enable_evmcs;
+
 /* Allocate memory regions for nested VMX tests.
  *
  * Input Args:
@@ -62,6 +64,20 @@ vcpu_alloc_vmx(struct kvm_vm *vm, vm_vaddr_t *p_vmx_gva)
 	vmx->vmwrite_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->vmwrite);
 	memset(vmx->vmwrite_hva, 0, getpagesize());
 
+	/* Setup of a region of guest memory for the VP Assist page. */
+	vmx->vp_assist = (void *)vm_vaddr_alloc(vm, getpagesize(),
+						0x10000, 0, 0);
+	vmx->vp_assist_hva = addr_gva2hva(vm, (uintptr_t)vmx->vp_assist);
+	vmx->vp_assist_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->vp_assist);
+
+	/* Setup of a region of guest memory for the enlightened VMCS. */
+	vmx->enlightened_vmcs = (void *)vm_vaddr_alloc(vm, getpagesize(),
+						       0x10000, 0, 0);
+	vmx->enlightened_vmcs_hva =
+		addr_gva2hva(vm, (uintptr_t)vmx->enlightened_vmcs);
+	vmx->enlightened_vmcs_gpa =
+		addr_gva2gpa(vm, (uintptr_t)vmx->enlightened_vmcs);
+
 	*p_vmx_gva = vmx_gva;
 	return vmx;
 }
@@ -112,18 +128,26 @@ bool prepare_for_vmx_operation(struct vmx_pages *vmx)
 
 bool load_vmcs(struct vmx_pages *vmx)
 {
-	/* Load a VMCS. */
-	*(uint32_t *)(vmx->vmcs) = vmcs_revision();
-	if (vmclear(vmx->vmcs_gpa))
-		return false;
-
-	if (vmptrld(vmx->vmcs_gpa))
-		return false;
-
-	/* Setup shadow VMCS, do not load it yet. */
-	*(uint32_t *)(vmx->shadow_vmcs) = vmcs_revision() | 0x80000000ul;
-	if (vmclear(vmx->shadow_vmcs_gpa))
-		return false;
+	if (!enable_evmcs) {
+		/* Load a VMCS. */
+		*(uint32_t *)(vmx->vmcs) = vmcs_revision();
+		if (vmclear(vmx->vmcs_gpa))
+			return false;
+
+		if (vmptrld(vmx->vmcs_gpa))
+			return false;
+
+		/* Setup shadow VMCS, do not load it yet. */
+		*(uint32_t *)(vmx->shadow_vmcs) =
+			vmcs_revision() | 0x80000000ul;
+		if (vmclear(vmx->shadow_vmcs_gpa))
+			return false;
+	} else {
+		if (evmcs_vmptrld(vmx->enlightened_vmcs_gpa,
+				  vmx->enlightened_vmcs))
+			return false;
+		current_evmcs->revision_id = vmcs_revision();
+	}
 
 	return true;
 }
diff --git a/tools/testing/selftests/kvm/x86_64/evmcs_test.c b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
new file mode 100644
index 000000000000..126aaf3da12e
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018, Red Hat, Inc.
+ *
+ * Tests for Enlightened VMCS, including nested guest state.
+ */
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include "test_util.h"
+
+#include "kvm_util.h"
+
+#include "vmx.h"
+
+#define VCPU_ID		5
+
+static bool have_nested_state;
+
+void l2_guest_code(void)
+{
+	GUEST_SYNC(6);
+
+	GUEST_SYNC(7);
+
+	/* Done, exit to L1 and never come back.  */
+	vmcall();
+}
+
+void l1_guest_code(struct vmx_pages *vmx_pages)
+{
+#define L2_GUEST_STACK_SIZE 64
+	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
+
+	enable_vp_assist(vmx_pages->vp_assist_gpa, vmx_pages->vp_assist);
+
+	GUEST_ASSERT(vmx_pages->vmcs_gpa);
+	GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
+	GUEST_SYNC(3);
+	GUEST_ASSERT(load_vmcs(vmx_pages));
+	GUEST_ASSERT(vmptrstz() == vmx_pages->enlightened_vmcs_gpa);
+
+	GUEST_SYNC(4);
+	GUEST_ASSERT(vmptrstz() == vmx_pages->enlightened_vmcs_gpa);
+
+	prepare_vmcs(vmx_pages, l2_guest_code,
+		     &l2_guest_stack[L2_GUEST_STACK_SIZE]);
+
+	GUEST_SYNC(5);
+	GUEST_ASSERT(vmptrstz() == vmx_pages->enlightened_vmcs_gpa);
+	GUEST_ASSERT(!vmlaunch());
+	GUEST_ASSERT(vmptrstz() == vmx_pages->enlightened_vmcs_gpa);
+	GUEST_SYNC(8);
+	GUEST_ASSERT(!vmresume());
+	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
+	GUEST_SYNC(9);
+}
+
+void guest_code(struct vmx_pages *vmx_pages)
+{
+	GUEST_SYNC(1);
+	GUEST_SYNC(2);
+
+	if (vmx_pages)
+		l1_guest_code(vmx_pages);
+
+	GUEST_DONE();
+}
+
+int main(int argc, char *argv[])
+{
+	struct vmx_pages *vmx_pages = NULL;
+	vm_vaddr_t vmx_pages_gva = 0;
+
+	struct kvm_regs regs1, regs2;
+	struct kvm_vm *vm;
+	struct kvm_run *run;
+	struct kvm_x86_state *state;
+	struct ucall uc;
+	int stage;
+	uint16_t evmcs_ver;
+	struct kvm_enable_cap enable_evmcs_cap = {
+		.cap = KVM_CAP_HYPERV_ENLIGHTENED_VMCS,
+		 .args[0] = (unsigned long)&evmcs_ver
+	};
+
+	struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1);
+
+	/* Create VM */
+	vm = vm_create_default(VCPU_ID, 0, guest_code);
+
+	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
+
+	vcpu_ioctl(vm, VCPU_ID, KVM_ENABLE_CAP, &enable_evmcs_cap);
+
+	run = vcpu_state(vm, VCPU_ID);
+
+	vcpu_regs_get(vm, VCPU_ID, &regs1);
+
+	if (kvm_check_cap(KVM_CAP_NESTED_STATE)) {
+		vmx_pages = vcpu_alloc_vmx(vm, &vmx_pages_gva);
+		vcpu_args_set(vm, VCPU_ID, 1, vmx_pages_gva);
+	} else {
+		printf("will skip nested state checks\n");
+		vcpu_args_set(vm, VCPU_ID, 1, 0);
+	}
+
+	for (stage = 1;; stage++) {
+		_vcpu_run(vm, VCPU_ID);
+		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+			    "Unexpected exit reason: %u (%s),\n",
+			    run->exit_reason,
+			    exit_reason_str(run->exit_reason));
+
+		memset(&regs1, 0, sizeof(regs1));
+		vcpu_regs_get(vm, VCPU_ID, &regs1);
+		switch (get_ucall(vm, VCPU_ID, &uc)) {
+		case UCALL_ABORT:
+			TEST_ASSERT(false, "%s at %s:%d", (const char *)uc.args[0],
+				    __FILE__, uc.args[1]);
+			/* NOT REACHED */
+		case UCALL_SYNC:
+			break;
+		case UCALL_DONE:
+			goto done;
+		default:
+			TEST_ASSERT(false, "Unknown ucall 0x%x.", uc.cmd);
+		}
+
+		/* UCALL_SYNC is handled here.  */
+		TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
+			    uc.args[1] == stage, "Unexpected register values vmexit #%lx, got %lx",
+			    stage, (ulong)uc.args[1]);
+
+		state = vcpu_save_state(vm, VCPU_ID);
+		kvm_vm_release(vm);
+
+		/* Restore state in a new VM.  */
+		kvm_vm_restart(vm, O_RDWR);
+		vm_vcpu_add(vm, VCPU_ID, 0, 0);
+		vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
+		vcpu_load_state(vm, VCPU_ID, state);
+		run = vcpu_state(vm, VCPU_ID);
+		free(state);
+
+		memset(&regs2, 0, sizeof(regs2));
+		vcpu_regs_get(vm, VCPU_ID, &regs2);
+		TEST_ASSERT(!memcmp(&regs1, &regs2, sizeof(regs2)),
+			    "Unexpected register values after vcpu_load_state; rdi: %lx rsi: %lx",
+			    (ulong) regs2.rdi, (ulong) regs2.rsi);
+	}
+
+done:
+	kvm_vm_free(vm);
+}
-- 
2.17.1