root/sys/dev/virtual/nvmm/x86/nvmm_x86_vmx.c
/*
 * Copyright (c) 2018-2021 Maxime Villard, m00nbsd.net
 * All rights reserved.
 *
 * This code is part of the NVMM hypervisor.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mman.h>

#include "../nvmm.h"
#include "../nvmm_internal.h"
#include "nvmm_x86.h"
#include "nvmm_x86_internal.h"

int vmx_vmlaunch(uint64_t *gprs);
int vmx_vmresume(uint64_t *gprs);
void vmx_resume_rip(void);

struct ept_desc {
        uint64_t eptp;
        uint64_t mbz;
} __packed;

struct vpid_desc {
        uint64_t vpid;
        uint64_t addr;
} __packed;

static inline void
vmx_vmxon(paddr_t *pa)
{
        __asm volatile (
                "vmxon          %[pa];"
                "jz             vmx_insn_failvalid;"
                "jc             vmx_insn_failinvalid;"
                :
                : [pa] "m" (*pa)
                : "memory", "cc"
        );
}

static inline void
vmx_vmxoff(void)
{
        __asm volatile (
                "vmxoff;"
                "jz             vmx_insn_failvalid;"
                "jc             vmx_insn_failinvalid;"
                :
                :
                : "memory", "cc"
        );
}

static inline void
vmx_invept(uint64_t op, struct ept_desc *desc)
{
        __asm volatile (
                "invept         %[desc],%[op];"
                "jz             vmx_insn_failvalid;"
                "jc             vmx_insn_failinvalid;"
                :
                : [desc] "m" (*desc), [op] "r" (op)
                : "memory", "cc"
        );
}

static inline void
vmx_invvpid(uint64_t op, struct vpid_desc *desc)
{
        __asm volatile (
                "invvpid        %[desc],%[op];"
                "jz             vmx_insn_failvalid;"
                "jc             vmx_insn_failinvalid;"
                :
                : [desc] "m" (*desc), [op] "r" (op)
                : "memory", "cc"
        );
}

static inline uint64_t
vmx_vmread(uint64_t field)
{
        uint64_t value;

        __asm volatile (
                "vmread         %[field],%[value];"
                "jz             vmx_insn_failvalid;"
                "jc             vmx_insn_failinvalid;"
                : [value] "=r" (value)
                : [field] "r" (field)
                : "cc"
        );

        return value;
}

static inline void
vmx_vmwrite(uint64_t field, uint64_t value)
{
        __asm volatile (
                "vmwrite        %[value],%[field];"
                "jz             vmx_insn_failvalid;"
                "jc             vmx_insn_failinvalid;"
                :
                : [field] "r" (field), [value] "r" (value)
                : "cc"
        );
}

static inline paddr_t __diagused
vmx_vmptrst(void)
{
        paddr_t pa;

        __asm volatile (
                "vmptrst        %[pa];"
                :
                : [pa] "m" (*(paddr_t *)&pa)
                : "memory"
        );

        return pa;
}

static inline void
vmx_vmptrld(paddr_t *pa)
{
        __asm volatile (
                "vmptrld        %[pa];"
                "jz             vmx_insn_failvalid;"
                "jc             vmx_insn_failinvalid;"
                :
                : [pa] "m" (*pa)
                : "memory", "cc"
        );
}

static inline void
vmx_vmclear(paddr_t *pa)
{
        __asm volatile (
                "vmclear        %[pa];"
                "jz             vmx_insn_failvalid;"
                "jc             vmx_insn_failinvalid;"
                :
                : [pa] "m" (*pa)
                : "memory", "cc"
        );
}

static inline void
vmx_cli(void)
{
        __asm volatile ("cli" ::: "memory");
}

static inline void
vmx_sti(void)
{
        __asm volatile ("sti" ::: "memory");
}

#define MSR_IA32_PLATFORM_ID            0x0017

#define MSR_IA32_FEATURE_CONTROL        0x003A
#define         IA32_FEATURE_CONTROL_LOCK       __BIT(0)
#define         IA32_FEATURE_CONTROL_IN_SMX     __BIT(1)
#define         IA32_FEATURE_CONTROL_OUT_SMX    __BIT(2)

#define MSR_IA32_BIOS_SIGN_ID           0x008B

#define MSR_IA32_ARCH_CAPABILITIES      0x010A
#define         IA32_ARCH_RDCL_NO               __BIT(0)
#define         IA32_ARCH_IBRS_ALL              __BIT(1)
#define         IA32_ARCH_RSBA                  __BIT(2)
#define         IA32_ARCH_SKIP_L1DFL_VMENTRY    __BIT(3)
#define         IA32_ARCH_SSB_NO                __BIT(4)
#define         IA32_ARCH_MDS_NO                __BIT(5)
#define         IA32_ARCH_IF_PSCHANGE_MC_NO     __BIT(6)
#define         IA32_ARCH_TSX_CTRL              __BIT(7)
#define         IA32_ARCH_TAA_NO                __BIT(8)

#define MSR_IA32_FLUSH_CMD              0x010B
#define         IA32_FLUSH_CMD_L1D_FLUSH        __BIT(0)

#define MSR_IA32_MISC_ENABLE            0x01A0
#define         IA32_MISC_PERFMON_EN            __BIT(7)
#define         IA32_MISC_BTS_UNAVAIL           __BIT(11)
#define         IA32_MISC_PEBS_UNAVAIL          __BIT(12)
#define         IA32_MISC_EISST_EN              __BIT(16)
#define         IA32_MISC_MWAIT_EN              __BIT(18)

#define MSR_IA32_VMX_BASIC              0x0480
#define         IA32_VMX_BASIC_IDENT            __BITS(30,0)
#define         IA32_VMX_BASIC_DATA_SIZE        __BITS(44,32)
#define         IA32_VMX_BASIC_MEM_WIDTH        __BIT(48)
#define         IA32_VMX_BASIC_DUAL             __BIT(49)
#define         IA32_VMX_BASIC_MEM_TYPE         __BITS(53,50)
#define                 MEM_TYPE_UC             0
#define                 MEM_TYPE_WB             6
#define         IA32_VMX_BASIC_IO_REPORT        __BIT(54)
#define         IA32_VMX_BASIC_TRUE_CTLS        __BIT(55)

#define MSR_IA32_VMX_PINBASED_CTLS              0x0481
#define MSR_IA32_VMX_PROCBASED_CTLS             0x0482
#define MSR_IA32_VMX_EXIT_CTLS                  0x0483
#define MSR_IA32_VMX_ENTRY_CTLS                 0x0484
#define MSR_IA32_VMX_PROCBASED_CTLS2            0x048B

#define MSR_IA32_VMX_TRUE_PINBASED_CTLS         0x048D
#define MSR_IA32_VMX_TRUE_PROCBASED_CTLS        0x048E
#define MSR_IA32_VMX_TRUE_EXIT_CTLS             0x048F
#define MSR_IA32_VMX_TRUE_ENTRY_CTLS            0x0490

#define MSR_IA32_VMX_CR0_FIXED0                 0x0486
#define MSR_IA32_VMX_CR0_FIXED1                 0x0487
#define MSR_IA32_VMX_CR4_FIXED0                 0x0488
#define MSR_IA32_VMX_CR4_FIXED1                 0x0489

#define MSR_IA32_VMX_EPT_VPID_CAP       0x048C
#define         IA32_VMX_EPT_VPID_XO                    __BIT(0)
#define         IA32_VMX_EPT_VPID_WALKLENGTH_4          __BIT(6)
#define         IA32_VMX_EPT_VPID_UC                    __BIT(8)
#define         IA32_VMX_EPT_VPID_WB                    __BIT(14)
#define         IA32_VMX_EPT_VPID_2MB                   __BIT(16)
#define         IA32_VMX_EPT_VPID_1GB                   __BIT(17)
#define         IA32_VMX_EPT_VPID_INVEPT                __BIT(20)
#define         IA32_VMX_EPT_VPID_FLAGS_AD              __BIT(21)
#define         IA32_VMX_EPT_VPID_ADVANCED_VMEXIT_INFO  __BIT(22)
#define         IA32_VMX_EPT_VPID_SHSTK                 __BIT(23)
#define         IA32_VMX_EPT_VPID_INVEPT_CONTEXT        __BIT(25)
#define         IA32_VMX_EPT_VPID_INVEPT_ALL            __BIT(26)
#define         IA32_VMX_EPT_VPID_INVVPID               __BIT(32)
#define         IA32_VMX_EPT_VPID_INVVPID_ADDR          __BIT(40)
#define         IA32_VMX_EPT_VPID_INVVPID_CONTEXT       __BIT(41)
#define         IA32_VMX_EPT_VPID_INVVPID_ALL           __BIT(42)
#define         IA32_VMX_EPT_VPID_INVVPID_CONTEXT_NOG   __BIT(43)

/* -------------------------------------------------------------------------- */

/* 16-bit control fields */
#define VMCS_VPID                               0x00000000
#define VMCS_PIR_VECTOR                         0x00000002
#define VMCS_EPTP_INDEX                         0x00000004
/* 16-bit guest-state fields */
#define VMCS_GUEST_ES_SELECTOR                  0x00000800
#define VMCS_GUEST_CS_SELECTOR                  0x00000802
#define VMCS_GUEST_SS_SELECTOR                  0x00000804
#define VMCS_GUEST_DS_SELECTOR                  0x00000806
#define VMCS_GUEST_FS_SELECTOR                  0x00000808
#define VMCS_GUEST_GS_SELECTOR                  0x0000080A
#define VMCS_GUEST_LDTR_SELECTOR                0x0000080C
#define VMCS_GUEST_TR_SELECTOR                  0x0000080E
#define VMCS_GUEST_INTR_STATUS                  0x00000810
#define VMCS_PML_INDEX                          0x00000812
/* 16-bit host-state fields */
#define VMCS_HOST_ES_SELECTOR                   0x00000C00
#define VMCS_HOST_CS_SELECTOR                   0x00000C02
#define VMCS_HOST_SS_SELECTOR                   0x00000C04
#define VMCS_HOST_DS_SELECTOR                   0x00000C06
#define VMCS_HOST_FS_SELECTOR                   0x00000C08
#define VMCS_HOST_GS_SELECTOR                   0x00000C0A
#define VMCS_HOST_TR_SELECTOR                   0x00000C0C
/* 64-bit control fields */
#define VMCS_IO_BITMAP_A                        0x00002000
#define VMCS_IO_BITMAP_B                        0x00002002
#define VMCS_MSR_BITMAP                         0x00002004
#define VMCS_EXIT_MSR_STORE_ADDRESS             0x00002006
#define VMCS_EXIT_MSR_LOAD_ADDRESS              0x00002008
#define VMCS_ENTRY_MSR_LOAD_ADDRESS             0x0000200A
#define VMCS_EXECUTIVE_VMCS                     0x0000200C
#define VMCS_PML_ADDRESS                        0x0000200E
#define VMCS_TSC_OFFSET                         0x00002010
#define VMCS_VIRTUAL_APIC                       0x00002012
#define VMCS_APIC_ACCESS                        0x00002014
#define VMCS_PIR_DESC                           0x00002016
#define VMCS_VM_CONTROL                         0x00002018
#define VMCS_EPTP                               0x0000201A
#define         EPTP_TYPE                       __BITS(2,0)
#define                 EPTP_TYPE_UC            0
#define                 EPTP_TYPE_WB            6
#define         EPTP_WALKLEN                    __BITS(5,3)
#define         EPTP_FLAGS_AD                   __BIT(6)
#define         EPTP_SSS                        __BIT(7)
#define         EPTP_PHYSADDR                   __BITS(63,12)
#define VMCS_EOI_EXIT0                          0x0000201C
#define VMCS_EOI_EXIT1                          0x0000201E
#define VMCS_EOI_EXIT2                          0x00002020
#define VMCS_EOI_EXIT3                          0x00002022
#define VMCS_EPTP_LIST                          0x00002024
#define VMCS_VMREAD_BITMAP                      0x00002026
#define VMCS_VMWRITE_BITMAP                     0x00002028
#define VMCS_VIRTUAL_EXCEPTION                  0x0000202A
#define VMCS_XSS_EXIT_BITMAP                    0x0000202C
#define VMCS_ENCLS_EXIT_BITMAP                  0x0000202E
#define VMCS_SUBPAGE_PERM_TABLE_PTR             0x00002030
#define VMCS_TSC_MULTIPLIER                     0x00002032
#define VMCS_ENCLV_EXIT_BITMAP                  0x00002036
/* 64-bit read-only fields */
#define VMCS_GUEST_PHYSICAL_ADDRESS             0x00002400
/* 64-bit guest-state fields */
#define VMCS_LINK_POINTER                       0x00002800
#define VMCS_GUEST_IA32_DEBUGCTL                0x00002802
#define VMCS_GUEST_IA32_PAT                     0x00002804
#define VMCS_GUEST_IA32_EFER                    0x00002806
#define VMCS_GUEST_IA32_PERF_GLOBAL_CTRL        0x00002808
#define VMCS_GUEST_PDPTE0                       0x0000280A
#define VMCS_GUEST_PDPTE1                       0x0000280C
#define VMCS_GUEST_PDPTE2                       0x0000280E
#define VMCS_GUEST_PDPTE3                       0x00002810
#define VMCS_GUEST_BNDCFGS                      0x00002812
#define VMCS_GUEST_RTIT_CTL                     0x00002814
#define VMCS_GUEST_PKRS                         0x00002818
/* 64-bit host-state fields */
#define VMCS_HOST_IA32_PAT                      0x00002C00
#define VMCS_HOST_IA32_EFER                     0x00002C02
#define VMCS_HOST_IA32_PERF_GLOBAL_CTRL         0x00002C04
#define VMCS_HOST_IA32_PKRS                     0x00002C06
/* 32-bit control fields */
#define VMCS_PINBASED_CTLS                      0x00004000
#define         PIN_CTLS_INT_EXITING            __BIT(0)
#define         PIN_CTLS_NMI_EXITING            __BIT(3)
#define         PIN_CTLS_VIRTUAL_NMIS           __BIT(5)
#define         PIN_CTLS_ACTIVATE_PREEMPT_TIMER __BIT(6)
#define         PIN_CTLS_PROCESS_POSTED_INTS    __BIT(7)
#define VMCS_PROCBASED_CTLS                     0x00004002
#define         PROC_CTLS_INT_WINDOW_EXITING    __BIT(2)
#define         PROC_CTLS_USE_TSC_OFFSETTING    __BIT(3)
#define         PROC_CTLS_HLT_EXITING           __BIT(7)
#define         PROC_CTLS_INVLPG_EXITING        __BIT(9)
#define         PROC_CTLS_MWAIT_EXITING         __BIT(10)
#define         PROC_CTLS_RDPMC_EXITING         __BIT(11)
#define         PROC_CTLS_RDTSC_EXITING         __BIT(12)
#define         PROC_CTLS_RCR3_EXITING          __BIT(15)
#define         PROC_CTLS_LCR3_EXITING          __BIT(16)
#define         PROC_CTLS_RCR8_EXITING          __BIT(19)
#define         PROC_CTLS_LCR8_EXITING          __BIT(20)
#define         PROC_CTLS_USE_TPR_SHADOW        __BIT(21)
#define         PROC_CTLS_NMI_WINDOW_EXITING    __BIT(22)
#define         PROC_CTLS_DR_EXITING            __BIT(23)
#define         PROC_CTLS_UNCOND_IO_EXITING     __BIT(24)
#define         PROC_CTLS_USE_IO_BITMAPS        __BIT(25)
#define         PROC_CTLS_MONITOR_TRAP_FLAG     __BIT(27)
#define         PROC_CTLS_USE_MSR_BITMAPS       __BIT(28)
#define         PROC_CTLS_MONITOR_EXITING       __BIT(29)
#define         PROC_CTLS_PAUSE_EXITING         __BIT(30)
#define         PROC_CTLS_ACTIVATE_CTLS2        __BIT(31)
#define VMCS_EXCEPTION_BITMAP                   0x00004004
#define VMCS_PF_ERROR_MASK                      0x00004006
#define VMCS_PF_ERROR_MATCH                     0x00004008
#define VMCS_CR3_TARGET_COUNT                   0x0000400A
#define VMCS_EXIT_CTLS                          0x0000400C
#define         EXIT_CTLS_SAVE_DEBUG_CONTROLS   __BIT(2)
#define         EXIT_CTLS_HOST_LONG_MODE        __BIT(9)
#define         EXIT_CTLS_LOAD_PERFGLOBALCTRL   __BIT(12)
#define         EXIT_CTLS_ACK_INTERRUPT         __BIT(15)
#define         EXIT_CTLS_SAVE_PAT              __BIT(18)
#define         EXIT_CTLS_LOAD_PAT              __BIT(19)
#define         EXIT_CTLS_SAVE_EFER             __BIT(20)
#define         EXIT_CTLS_LOAD_EFER             __BIT(21)
#define         EXIT_CTLS_SAVE_PREEMPT_TIMER    __BIT(22)
#define         EXIT_CTLS_CLEAR_BNDCFGS         __BIT(23)
#define         EXIT_CTLS_CONCEAL_PT            __BIT(24)
#define         EXIT_CTLS_CLEAR_RTIT_CTL        __BIT(25)
#define         EXIT_CTLS_LOAD_CET              __BIT(28)
#define         EXIT_CTLS_LOAD_PKRS             __BIT(29)
#define VMCS_EXIT_MSR_STORE_COUNT               0x0000400E
#define VMCS_EXIT_MSR_LOAD_COUNT                0x00004010
#define VMCS_ENTRY_CTLS                         0x00004012
#define         ENTRY_CTLS_LOAD_DEBUG_CONTROLS  __BIT(2)
#define         ENTRY_CTLS_LONG_MODE            __BIT(9)
#define         ENTRY_CTLS_SMM                  __BIT(10)
#define         ENTRY_CTLS_DISABLE_DUAL         __BIT(11)
#define         ENTRY_CTLS_LOAD_PERFGLOBALCTRL  __BIT(13)
#define         ENTRY_CTLS_LOAD_PAT             __BIT(14)
#define         ENTRY_CTLS_LOAD_EFER            __BIT(15)
#define         ENTRY_CTLS_LOAD_BNDCFGS         __BIT(16)
#define         ENTRY_CTLS_CONCEAL_PT           __BIT(17)
#define         ENTRY_CTLS_LOAD_RTIT_CTL        __BIT(18)
#define         ENTRY_CTLS_LOAD_CET             __BIT(20)
#define         ENTRY_CTLS_LOAD_PKRS            __BIT(22)
#define VMCS_ENTRY_MSR_LOAD_COUNT               0x00004014
#define VMCS_ENTRY_INTR_INFO                    0x00004016
#define         INTR_INFO_VECTOR                __BITS(7,0)
#define         INTR_INFO_TYPE                  __BITS(10,8)
#define                 INTR_TYPE_EXT_INT       0
#define                 INTR_TYPE_NMI           2
#define                 INTR_TYPE_HW_EXC        3
#define                 INTR_TYPE_SW_INT        4
#define                 INTR_TYPE_PRIV_SW_EXC   5
#define                 INTR_TYPE_SW_EXC        6
#define                 INTR_TYPE_OTHER         7
#define         INTR_INFO_ERROR                 __BIT(11)
#define         INTR_INFO_VALID                 __BIT(31)
#define VMCS_ENTRY_EXCEPTION_ERROR              0x00004018
#define VMCS_ENTRY_INSTRUCTION_LENGTH           0x0000401A
#define VMCS_TPR_THRESHOLD                      0x0000401C
#define VMCS_PROCBASED_CTLS2                    0x0000401E
#define         PROC_CTLS2_VIRT_APIC_ACCESSES   __BIT(0)
#define         PROC_CTLS2_ENABLE_EPT           __BIT(1)
#define         PROC_CTLS2_DESC_TABLE_EXITING   __BIT(2)
#define         PROC_CTLS2_ENABLE_RDTSCP        __BIT(3)
#define         PROC_CTLS2_VIRT_X2APIC          __BIT(4)
#define         PROC_CTLS2_ENABLE_VPID          __BIT(5)
#define         PROC_CTLS2_WBINVD_EXITING       __BIT(6)
#define         PROC_CTLS2_UNRESTRICTED_GUEST   __BIT(7)
#define         PROC_CTLS2_APIC_REG_VIRT        __BIT(8)
#define         PROC_CTLS2_VIRT_INT_DELIVERY    __BIT(9)
#define         PROC_CTLS2_PAUSE_LOOP_EXITING   __BIT(10)
#define         PROC_CTLS2_RDRAND_EXITING       __BIT(11)
#define         PROC_CTLS2_INVPCID_ENABLE       __BIT(12)
#define         PROC_CTLS2_VMFUNC_ENABLE        __BIT(13)
#define         PROC_CTLS2_VMCS_SHADOWING       __BIT(14)
#define         PROC_CTLS2_ENCLS_EXITING        __BIT(15)
#define         PROC_CTLS2_RDSEED_EXITING       __BIT(16)
#define         PROC_CTLS2_PML_ENABLE           __BIT(17)
#define         PROC_CTLS2_EPT_VIOLATION        __BIT(18)
#define         PROC_CTLS2_CONCEAL_VMX_FROM_PT  __BIT(19)
#define         PROC_CTLS2_XSAVES_ENABLE        __BIT(20)
#define         PROC_CTLS2_MODE_BASED_EXEC_EPT  __BIT(22)
#define         PROC_CTLS2_SUBPAGE_PERMISSIONS  __BIT(23)
#define         PROC_CTLS2_PT_USES_GPA          __BIT(24)
#define         PROC_CTLS2_USE_TSC_SCALING      __BIT(25)
#define         PROC_CTLS2_WAIT_PAUSE_ENABLE    __BIT(26)
#define         PROC_CTLS2_ENCLV_EXITING        __BIT(28)
#define VMCS_PLE_GAP                            0x00004020
#define VMCS_PLE_WINDOW                         0x00004022
/* 32-bit read-only data fields */
#define VMCS_INSTRUCTION_ERROR                  0x00004400
#define VMCS_EXIT_REASON                        0x00004402
#define VMCS_EXIT_INTR_INFO                     0x00004404
#define VMCS_EXIT_INTR_ERRCODE                  0x00004406
#define VMCS_IDT_VECTORING_INFO                 0x00004408
#define VMCS_IDT_VECTORING_ERROR                0x0000440A
#define VMCS_EXIT_INSTRUCTION_LENGTH            0x0000440C
#define VMCS_EXIT_INSTRUCTION_INFO              0x0000440E
/* 32-bit guest-state fields */
#define VMCS_GUEST_ES_LIMIT                     0x00004800
#define VMCS_GUEST_CS_LIMIT                     0x00004802
#define VMCS_GUEST_SS_LIMIT                     0x00004804
#define VMCS_GUEST_DS_LIMIT                     0x00004806
#define VMCS_GUEST_FS_LIMIT                     0x00004808
#define VMCS_GUEST_GS_LIMIT                     0x0000480A
#define VMCS_GUEST_LDTR_LIMIT                   0x0000480C
#define VMCS_GUEST_TR_LIMIT                     0x0000480E
#define VMCS_GUEST_GDTR_LIMIT                   0x00004810
#define VMCS_GUEST_IDTR_LIMIT                   0x00004812
#define VMCS_GUEST_ES_ACCESS_RIGHTS             0x00004814
#define VMCS_GUEST_CS_ACCESS_RIGHTS             0x00004816
#define VMCS_GUEST_SS_ACCESS_RIGHTS             0x00004818
#define VMCS_GUEST_DS_ACCESS_RIGHTS             0x0000481A
#define VMCS_GUEST_FS_ACCESS_RIGHTS             0x0000481C
#define VMCS_GUEST_GS_ACCESS_RIGHTS             0x0000481E
#define VMCS_GUEST_LDTR_ACCESS_RIGHTS           0x00004820
#define VMCS_GUEST_TR_ACCESS_RIGHTS             0x00004822
#define VMCS_GUEST_INTERRUPTIBILITY             0x00004824
#define         INT_STATE_STI                   __BIT(0)
#define         INT_STATE_MOVSS                 __BIT(1)
#define         INT_STATE_SMI                   __BIT(2)
#define         INT_STATE_NMI                   __BIT(3)
#define         INT_STATE_ENCLAVE               __BIT(4)
#define VMCS_GUEST_ACTIVITY                     0x00004826
#define VMCS_GUEST_SMBASE                       0x00004828
#define VMCS_GUEST_IA32_SYSENTER_CS             0x0000482A
#define VMCS_PREEMPTION_TIMER_VALUE             0x0000482E
/* 32-bit host state fields */
#define VMCS_HOST_IA32_SYSENTER_CS              0x00004C00
/* Natural-Width control fields */
#define VMCS_CR0_MASK                           0x00006000
#define VMCS_CR4_MASK                           0x00006002
#define VMCS_CR0_SHADOW                         0x00006004
#define VMCS_CR4_SHADOW                         0x00006006
#define VMCS_CR3_TARGET0                        0x00006008
#define VMCS_CR3_TARGET1                        0x0000600A
#define VMCS_CR3_TARGET2                        0x0000600C
#define VMCS_CR3_TARGET3                        0x0000600E
/* Natural-Width read-only fields */
#define VMCS_EXIT_QUALIFICATION                 0x00006400
#define VMCS_IO_RCX                             0x00006402
#define VMCS_IO_RSI                             0x00006404
#define VMCS_IO_RDI                             0x00006406
#define VMCS_IO_RIP                             0x00006408
#define VMCS_GUEST_LINEAR_ADDRESS               0x0000640A
/* Natural-Width guest-state fields */
#define VMCS_GUEST_CR0                          0x00006800
#define VMCS_GUEST_CR3                          0x00006802
#define VMCS_GUEST_CR4                          0x00006804
#define VMCS_GUEST_ES_BASE                      0x00006806
#define VMCS_GUEST_CS_BASE                      0x00006808
#define VMCS_GUEST_SS_BASE                      0x0000680A
#define VMCS_GUEST_DS_BASE                      0x0000680C
#define VMCS_GUEST_FS_BASE                      0x0000680E
#define VMCS_GUEST_GS_BASE                      0x00006810
#define VMCS_GUEST_LDTR_BASE                    0x00006812
#define VMCS_GUEST_TR_BASE                      0x00006814
#define VMCS_GUEST_GDTR_BASE                    0x00006816
#define VMCS_GUEST_IDTR_BASE                    0x00006818
#define VMCS_GUEST_DR7                          0x0000681A
#define VMCS_GUEST_RSP                          0x0000681C
#define VMCS_GUEST_RIP                          0x0000681E
#define VMCS_GUEST_RFLAGS                       0x00006820
#define VMCS_GUEST_PENDING_DBG_EXCEPTIONS       0x00006822
#define VMCS_GUEST_IA32_SYSENTER_ESP            0x00006824
#define VMCS_GUEST_IA32_SYSENTER_EIP            0x00006826
#define VMCS_GUEST_IA32_S_CET                   0x00006828
#define VMCS_GUEST_SSP                          0x0000682A
#define VMCS_GUEST_IA32_INTR_SSP_TABLE          0x0000682C
/* Natural-Width host-state fields */
#define VMCS_HOST_CR0                           0x00006C00
#define VMCS_HOST_CR3                           0x00006C02
#define VMCS_HOST_CR4                           0x00006C04
#define VMCS_HOST_FS_BASE                       0x00006C06
#define VMCS_HOST_GS_BASE                       0x00006C08
#define VMCS_HOST_TR_BASE                       0x00006C0A
#define VMCS_HOST_GDTR_BASE                     0x00006C0C
#define VMCS_HOST_IDTR_BASE                     0x00006C0E
#define VMCS_HOST_IA32_SYSENTER_ESP             0x00006C10
#define VMCS_HOST_IA32_SYSENTER_EIP             0x00006C12
#define VMCS_HOST_RSP                           0x00006C14
#define VMCS_HOST_RIP                           0x00006C16
#define VMCS_HOST_IA32_S_CET                    0x00006C18
#define VMCS_HOST_SSP                           0x00006C1A
#define VMCS_HOST_IA32_INTR_SSP_TABLE           0x00006C1C

/* VMX basic exit reasons. */
#define VMCS_EXITCODE_EXC_NMI                   0
#define VMCS_EXITCODE_EXT_INT                   1
#define VMCS_EXITCODE_SHUTDOWN                  2
#define VMCS_EXITCODE_INIT                      3
#define VMCS_EXITCODE_SIPI                      4
#define VMCS_EXITCODE_SMI                       5
#define VMCS_EXITCODE_OTHER_SMI                 6
#define VMCS_EXITCODE_INT_WINDOW                7
#define VMCS_EXITCODE_NMI_WINDOW                8
#define VMCS_EXITCODE_TASK_SWITCH               9
#define VMCS_EXITCODE_CPUID                     10
#define VMCS_EXITCODE_GETSEC                    11
#define VMCS_EXITCODE_HLT                       12
#define VMCS_EXITCODE_INVD                      13
#define VMCS_EXITCODE_INVLPG                    14
#define VMCS_EXITCODE_RDPMC                     15
#define VMCS_EXITCODE_RDTSC                     16
#define VMCS_EXITCODE_RSM                       17
#define VMCS_EXITCODE_VMCALL                    18
#define VMCS_EXITCODE_VMCLEAR                   19
#define VMCS_EXITCODE_VMLAUNCH                  20
#define VMCS_EXITCODE_VMPTRLD                   21
#define VMCS_EXITCODE_VMPTRST                   22
#define VMCS_EXITCODE_VMREAD                    23
#define VMCS_EXITCODE_VMRESUME                  24
#define VMCS_EXITCODE_VMWRITE                   25
#define VMCS_EXITCODE_VMXOFF                    26
#define VMCS_EXITCODE_VMXON                     27
#define VMCS_EXITCODE_CR                        28
#define VMCS_EXITCODE_DR                        29
#define VMCS_EXITCODE_IO                        30
#define VMCS_EXITCODE_RDMSR                     31
#define VMCS_EXITCODE_WRMSR                     32
#define VMCS_EXITCODE_FAIL_GUEST_INVALID        33
#define VMCS_EXITCODE_FAIL_MSR_INVALID          34
#define VMCS_EXITCODE_MWAIT                     36
#define VMCS_EXITCODE_TRAP_FLAG                 37
#define VMCS_EXITCODE_MONITOR                   39
#define VMCS_EXITCODE_PAUSE                     40
#define VMCS_EXITCODE_FAIL_MACHINE_CHECK        41
#define VMCS_EXITCODE_TPR_BELOW                 43
#define VMCS_EXITCODE_APIC_ACCESS               44
#define VMCS_EXITCODE_VEOI                      45
#define VMCS_EXITCODE_GDTR_IDTR                 46
#define VMCS_EXITCODE_LDTR_TR                   47
#define VMCS_EXITCODE_EPT_VIOLATION             48
#define VMCS_EXITCODE_EPT_MISCONFIG             49
#define VMCS_EXITCODE_INVEPT                    50
#define VMCS_EXITCODE_RDTSCP                    51
#define VMCS_EXITCODE_PREEMPT_TIMEOUT           52
#define VMCS_EXITCODE_INVVPID                   53
#define VMCS_EXITCODE_WBINVD                    54
#define VMCS_EXITCODE_XSETBV                    55
#define VMCS_EXITCODE_APIC_WRITE                56
#define VMCS_EXITCODE_RDRAND                    57
#define VMCS_EXITCODE_INVPCID                   58
#define VMCS_EXITCODE_VMFUNC                    59
#define VMCS_EXITCODE_ENCLS                     60
#define VMCS_EXITCODE_RDSEED                    61
#define VMCS_EXITCODE_PAGE_LOG_FULL             62
#define VMCS_EXITCODE_XSAVES                    63
#define VMCS_EXITCODE_XRSTORS                   64
#define VMCS_EXITCODE_SPP                       66
#define VMCS_EXITCODE_UMWAIT                    67
#define VMCS_EXITCODE_TPAUSE                    68

/* -------------------------------------------------------------------------- */

static void vmx_vcpu_state_provide(struct nvmm_cpu *, uint64_t);
static void vmx_vcpu_state_commit(struct nvmm_cpu *);

/*
 * These host values are static, they do not change at runtime and are the same
 * on all CPUs. We save them here because they are not saved in the VMCS.
 */
static struct {
        uint64_t xcr0;
        uint64_t star;
        uint64_t lstar;
        uint64_t cstar;
        uint64_t sfmask;
} vmx_global_hstate __cacheline_aligned;

#define VMX_MSRLIST_STAR                0
#define VMX_MSRLIST_LSTAR               1
#define VMX_MSRLIST_CSTAR               2
#define VMX_MSRLIST_SFMASK              3
#define VMX_MSRLIST_KERNELGSBASE        4
#define VMX_MSRLIST_EXIT_NMSR           5
#define VMX_MSRLIST_L1DFLUSH            5

/* On entry, we may do +1 to include L1DFLUSH. */
static size_t vmx_msrlist_entry_nmsr __read_mostly = VMX_MSRLIST_EXIT_NMSR;

struct vmxon {
        uint32_t ident;
#define VMXON_IDENT_REVISION    __BITS(30,0)

        uint8_t data[PAGE_SIZE - 4];
} __packed;

CTASSERT(sizeof(struct vmxon) == PAGE_SIZE);

struct vmxoncpu {
        vaddr_t va;
        paddr_t pa;
};

static struct vmxoncpu vmxoncpu[OS_MAXCPUS];

struct vmcs {
        uint32_t ident;
#define VMCS_IDENT_REVISION     __BITS(30,0)
#define VMCS_IDENT_SHADOW       __BIT(31)

        uint32_t abort;
        uint8_t data[PAGE_SIZE - 8];
} __packed;

CTASSERT(sizeof(struct vmcs) == PAGE_SIZE);

struct msr_entry {
        uint32_t msr;
        uint32_t rsvd;
        uint64_t val;
} __packed;

#define VPID_MAX        0xFFFF

/* Make sure we never run out of VPIDs. */
CTASSERT(VPID_MAX-1 >= NVMM_MAX_MACHINES * NVMM_MAX_VCPUS);

static uint64_t vmx_tlb_flush_op __read_mostly;
static uint64_t vmx_ept_flush_op __read_mostly;
static uint64_t vmx_eptp_type __read_mostly;
static bool vmx_ept_has_ad __read_mostly;
static bool vmx_cpu_has_arch_cap __read_mostly;

static uint64_t vmx_pinbased_ctls __read_mostly;
static uint64_t vmx_procbased_ctls __read_mostly;
static uint64_t vmx_procbased_ctls2 __read_mostly;
static uint64_t vmx_entry_ctls __read_mostly;
static uint64_t vmx_exit_ctls __read_mostly;

static uint64_t vmx_cr0_fixed0 __read_mostly;
static uint64_t vmx_cr0_fixed1 __read_mostly;
static uint64_t vmx_cr4_fixed0 __read_mostly;
static uint64_t vmx_cr4_fixed1 __read_mostly;

#define VMX_PINBASED_CTLS_ONE   \
        (PIN_CTLS_INT_EXITING| \
         PIN_CTLS_NMI_EXITING| \
         PIN_CTLS_VIRTUAL_NMIS)

#define VMX_PINBASED_CTLS_ZERO  0

#define VMX_PROCBASED_CTLS_ONE  \
        (PROC_CTLS_USE_TSC_OFFSETTING| \
         PROC_CTLS_HLT_EXITING| \
         PROC_CTLS_MWAIT_EXITING | \
         PROC_CTLS_RDPMC_EXITING | \
         PROC_CTLS_RCR8_EXITING | \
         PROC_CTLS_LCR8_EXITING | \
         PROC_CTLS_UNCOND_IO_EXITING | /* no I/O bitmap */ \
         PROC_CTLS_USE_MSR_BITMAPS | \
         PROC_CTLS_MONITOR_EXITING | \
         PROC_CTLS_ACTIVATE_CTLS2)

#define VMX_PROCBASED_CTLS_ZERO \
        (PROC_CTLS_RCR3_EXITING| \
         PROC_CTLS_LCR3_EXITING)

#define VMX_PROCBASED_CTLS2_ONE \
        (PROC_CTLS2_ENABLE_EPT| \
         PROC_CTLS2_ENABLE_VPID| \
         PROC_CTLS2_UNRESTRICTED_GUEST)

#define VMX_PROCBASED_CTLS2_ZERO        0

#define VMX_ENTRY_CTLS_ONE      \
        (ENTRY_CTLS_LOAD_DEBUG_CONTROLS| \
         ENTRY_CTLS_LOAD_EFER| \
         ENTRY_CTLS_LOAD_PAT)

#define VMX_ENTRY_CTLS_ZERO     \
        (ENTRY_CTLS_SMM| \
         ENTRY_CTLS_DISABLE_DUAL)

#define VMX_EXIT_CTLS_ONE       \
        (EXIT_CTLS_SAVE_DEBUG_CONTROLS| \
         EXIT_CTLS_HOST_LONG_MODE| \
         EXIT_CTLS_SAVE_PAT| \
         EXIT_CTLS_LOAD_PAT| \
         EXIT_CTLS_SAVE_EFER| \
         EXIT_CTLS_LOAD_EFER)

#define VMX_EXIT_CTLS_ZERO      0

static uint8_t *vmx_asidmap __read_mostly;
static uint32_t vmx_maxasid __read_mostly;
static os_mtx_t vmx_asidlock __cacheline_aligned;

#define VMX_XCR0_MASK_DEFAULT   (XCR0_X87|XCR0_SSE)
static uint64_t vmx_xcr0_mask __read_mostly;

#define VMX_NCPUIDS     32

#define VMCS_NPAGES     1
#define VMCS_SIZE       (VMCS_NPAGES * PAGE_SIZE)

#define MSRBM_NPAGES    1
#define MSRBM_SIZE      (MSRBM_NPAGES * PAGE_SIZE)

/* Guest/host CR0 mask: bits owned by the host */
#define CR0_STATIC_MASK \
        (CR0_ET | CR0_NW | CR0_CD)

/*
 * Guest real CR0 bits that must be handled specially:
 * - CR0_ET: hardwired to 1 in modern CPUs; must always be 1
 * - CR0_NE: proper FPU error handling; must always be 1
 * - CR0_CD, CR0_NW: cache control; must be forced to 0 for performance
 */
#define CR0_FORCE_ZERO \
        (CR0_NW | CR0_CD)
#define CR0_FORCE_ONE \
        (CR0_ET | CR0_NE)

#define CR4_VALID \
        (CR4_VME |                      \
         CR4_PVI |                      \
         CR4_TSD |                      \
         CR4_DE |                       \
         CR4_PSE |                      \
         CR4_PAE |                      \
         CR4_MCE |                      \
         CR4_PGE |                      \
         CR4_PCE |                      \
         CR4_OSFXSR |                   \
         CR4_OSXMMEXCPT |               \
         CR4_UMIP |                     \
         /* CR4_LA57 excluded */        \
         /* CR4_VMXE excluded */        \
         /* CR4_SMXE excluded */        \
         CR4_FSGSBASE |                 \
         CR4_PCIDE |                    \
         CR4_OSXSAVE |                  \
         CR4_SMEP |                     \
         CR4_SMAP                       \
         /* CR4_PKE excluded */         \
         /* CR4_CET excluded */         \
         /* CR4_PKS excluded */)
#define CR4_INVALID \
        (0xFFFFFFFFFFFFFFFFULL & ~CR4_VALID)

#define EFER_TLB_FLUSH \
        (EFER_NXE|EFER_LMA|EFER_LME)
#define CR0_TLB_FLUSH \
        (CR0_PG|CR0_WP|CR0_CD|CR0_NW)
#define CR4_TLB_FLUSH \
        (CR4_PSE|CR4_PAE|CR4_PGE|CR4_PCIDE|CR4_SMEP)

/* -------------------------------------------------------------------------- */

struct vmx_machdata {
        volatile uint64_t mach_htlb_gen;
};

static const size_t vmx_vcpu_conf_sizes[NVMM_X86_VCPU_NCONF] = {
        [NVMM_VCPU_CONF_MD(NVMM_VCPU_CONF_CPUID)] =
            sizeof(struct nvmm_vcpu_conf_cpuid),
        [NVMM_VCPU_CONF_MD(NVMM_VCPU_CONF_TPR)] =
            sizeof(struct nvmm_vcpu_conf_tpr)
};

struct vmx_cpudata {
        /* General. */
        uint64_t asid;
        bool gtlb_want_flush;
        bool gtsc_want_update;
        uint64_t vcpu_htlb_gen;
        os_cpuset_t *htlb_want_flush;

        /* VMCS. */
        struct vmcs *vmcs;
        paddr_t vmcs_pa;
        size_t vmcs_refcnt;
        os_cpu_t *vmcs_cpu;
        bool vmcs_launched;

        /* MSR bitmap. */
        uint8_t *msrbm;
        paddr_t msrbm_pa;

        /* Percpu host state, absent from VMCS. */
        struct {
                uint64_t kernelgsbase;
                uint64_t drs[NVMM_X64_NDR];
#ifdef __DragonFly__
                mcontext_t hmctx;  /* TODO: remove this like NetBSD */
#endif
        } hstate;

        /* Intr state. */
        bool int_window_exit;
        bool nmi_window_exit;
        bool evt_pending;

        /* Guest state. */
        struct msr_entry *gmsr;
        paddr_t gmsr_pa;
        uint64_t gmsr_misc_enable;
        uint64_t gcr2;
        uint64_t gcr8;
        uint64_t gxcr0;
        uint64_t gprs[NVMM_X64_NGPR];
        uint64_t drs[NVMM_X64_NDR];
        uint64_t gtsc_offset;
        uint64_t gtsc_match;
        struct nvmm_x86_xsave gxsave __aligned(64);

        /* VCPU configuration. */
        bool cpuidpresent[VMX_NCPUIDS];
        struct nvmm_vcpu_conf_cpuid cpuid[VMX_NCPUIDS];
        struct nvmm_vcpu_conf_tpr tpr;
};

static const struct {
        uint64_t selector;
        uint64_t attrib;
        uint64_t limit;
        uint64_t base;
} vmx_guest_segs[NVMM_X64_NSEG] = {
        [NVMM_X64_SEG_ES] = {
                VMCS_GUEST_ES_SELECTOR,
                VMCS_GUEST_ES_ACCESS_RIGHTS,
                VMCS_GUEST_ES_LIMIT,
                VMCS_GUEST_ES_BASE
        },
        [NVMM_X64_SEG_CS] = {
                VMCS_GUEST_CS_SELECTOR,
                VMCS_GUEST_CS_ACCESS_RIGHTS,
                VMCS_GUEST_CS_LIMIT,
                VMCS_GUEST_CS_BASE
        },
        [NVMM_X64_SEG_SS] = {
                VMCS_GUEST_SS_SELECTOR,
                VMCS_GUEST_SS_ACCESS_RIGHTS,
                VMCS_GUEST_SS_LIMIT,
                VMCS_GUEST_SS_BASE
        },
        [NVMM_X64_SEG_DS] = {
                VMCS_GUEST_DS_SELECTOR,
                VMCS_GUEST_DS_ACCESS_RIGHTS,
                VMCS_GUEST_DS_LIMIT,
                VMCS_GUEST_DS_BASE
        },
        [NVMM_X64_SEG_FS] = {
                VMCS_GUEST_FS_SELECTOR,
                VMCS_GUEST_FS_ACCESS_RIGHTS,
                VMCS_GUEST_FS_LIMIT,
                VMCS_GUEST_FS_BASE
        },
        [NVMM_X64_SEG_GS] = {
                VMCS_GUEST_GS_SELECTOR,
                VMCS_GUEST_GS_ACCESS_RIGHTS,
                VMCS_GUEST_GS_LIMIT,
                VMCS_GUEST_GS_BASE
        },
        [NVMM_X64_SEG_GDT] = {
                0, /* doesn't exist */
                0, /* doesn't exist */
                VMCS_GUEST_GDTR_LIMIT,
                VMCS_GUEST_GDTR_BASE
        },
        [NVMM_X64_SEG_IDT] = {
                0, /* doesn't exist */
                0, /* doesn't exist */
                VMCS_GUEST_IDTR_LIMIT,
                VMCS_GUEST_IDTR_BASE
        },
        [NVMM_X64_SEG_LDT] = {
                VMCS_GUEST_LDTR_SELECTOR,
                VMCS_GUEST_LDTR_ACCESS_RIGHTS,
                VMCS_GUEST_LDTR_LIMIT,
                VMCS_GUEST_LDTR_BASE
        },
        [NVMM_X64_SEG_TR] = {
                VMCS_GUEST_TR_SELECTOR,
                VMCS_GUEST_TR_ACCESS_RIGHTS,
                VMCS_GUEST_TR_LIMIT,
                VMCS_GUEST_TR_BASE
        }
};

/* -------------------------------------------------------------------------- */

static uint64_t
vmx_get_revision(void)
{
        uint64_t msr;

        msr = rdmsr(MSR_IA32_VMX_BASIC);
        msr &= IA32_VMX_BASIC_IDENT;

        return msr;
}

static
OS_IPI_FUNC(vmx_vmclear_ipi)
{
        paddr_t vmcs_pa = (paddr_t)arg;
        vmx_vmclear(&vmcs_pa);
}

static void
vmx_vmclear_remote(os_cpu_t *cpu, paddr_t vmcs_pa)
{
        int bound;

        OS_ASSERT(os_preempt_disabled());

        /*
         * TODO: OSify curlwp_bind().
         */

        bound = curlwp_bind();
        os_preempt_enable();

        os_ipi_unicast(cpu, vmx_vmclear_ipi, (void *)vmcs_pa);

        os_preempt_disable();
        curlwp_bindx(bound);
}

static void
vmx_vmcs_enter(struct nvmm_cpu *vcpu)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        os_cpu_t *vmcs_cpu;

        cpudata->vmcs_refcnt++;
        if (cpudata->vmcs_refcnt > 1) {
                OS_ASSERT(os_preempt_disabled());
                OS_ASSERT(vmx_vmptrst() == cpudata->vmcs_pa);
                return;
        }

        vmcs_cpu = cpudata->vmcs_cpu;
        cpudata->vmcs_cpu = (void *)0x00FFFFFFFFFFFFFF; /* clobber */

        os_preempt_disable();

        if (vmcs_cpu == NULL) {
                /* This VMCS is loaded for the first time. */
                vmx_vmclear(&cpudata->vmcs_pa);
                cpudata->vmcs_launched = false;
        } else if (vmcs_cpu != os_curcpu()) {
                /* This VMCS is active on a remote CPU. */
                vmx_vmclear_remote(vmcs_cpu, cpudata->vmcs_pa);
                cpudata->vmcs_launched = false;
        } else {
                /* This VMCS is active on curcpu, nothing to do. */
        }

        vmx_vmptrld(&cpudata->vmcs_pa);
}

static void
vmx_vmcs_leave(struct nvmm_cpu *vcpu)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;

        OS_ASSERT(os_preempt_disabled());
        OS_ASSERT(vmx_vmptrst() == cpudata->vmcs_pa);
        OS_ASSERT(cpudata->vmcs_refcnt > 0);
        cpudata->vmcs_refcnt--;

        if (cpudata->vmcs_refcnt > 0) {
                return;
        }

        cpudata->vmcs_cpu = os_curcpu();
        os_preempt_enable();
}

static void
vmx_vmcs_destroy(struct nvmm_cpu *vcpu)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;

        OS_ASSERT(os_preempt_disabled());
        OS_ASSERT(vmx_vmptrst() == cpudata->vmcs_pa);
        OS_ASSERT(cpudata->vmcs_refcnt == 1);
        cpudata->vmcs_refcnt--;

        vmx_vmclear(&cpudata->vmcs_pa);
        os_preempt_enable();
}

/* -------------------------------------------------------------------------- */

static void
vmx_event_waitexit_enable(struct nvmm_cpu *vcpu, bool nmi)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        uint64_t ctls1;

        ctls1 = vmx_vmread(VMCS_PROCBASED_CTLS);

        if (nmi) {
                // XXX INT_STATE_NMI?
                ctls1 |= PROC_CTLS_NMI_WINDOW_EXITING;
                cpudata->nmi_window_exit = true;
        } else {
                ctls1 |= PROC_CTLS_INT_WINDOW_EXITING;
                cpudata->int_window_exit = true;
        }

        vmx_vmwrite(VMCS_PROCBASED_CTLS, ctls1);
}

static void
vmx_event_waitexit_disable(struct nvmm_cpu *vcpu, bool nmi)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        uint64_t ctls1;

        ctls1 = vmx_vmread(VMCS_PROCBASED_CTLS);

        if (nmi) {
                ctls1 &= ~PROC_CTLS_NMI_WINDOW_EXITING;
                cpudata->nmi_window_exit = false;
        } else {
                ctls1 &= ~PROC_CTLS_INT_WINDOW_EXITING;
                cpudata->int_window_exit = false;
        }

        vmx_vmwrite(VMCS_PROCBASED_CTLS, ctls1);
}

static inline bool
vmx_excp_has_rf(uint8_t vector)
{
        switch (vector) {
        case 1:         /* #DB */
        case 4:         /* #OF */
        case 8:         /* #DF */
        case 18:        /* #MC */
                return false;
        default:
                return true;
        }
}

static inline int
vmx_excp_has_error(uint8_t vector)
{
        switch (vector) {
        case 8:         /* #DF */
        case 10:        /* #TS */
        case 11:        /* #NP */
        case 12:        /* #SS */
        case 13:        /* #GP */
        case 14:        /* #PF */
        case 17:        /* #AC */
        case 21:        /* #CP */
        case 30:        /* #SX */
                return 1;
        default:
                return 0;
        }
}

static int
vmx_vcpu_inject(struct nvmm_cpu *vcpu)
{
        struct nvmm_comm_page *comm = vcpu->comm;
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        int type = 0, err = 0, ret = EINVAL;
        uint64_t rflags, info, error;
        u_int evtype;
        uint8_t vector;

        evtype = comm->event.type;
        vector = comm->event.vector;
        error = comm->event.u.excp.error;
        __insn_barrier();

        vmx_vmcs_enter(vcpu);

        switch (evtype) {
        case NVMM_VCPU_EVENT_EXCP:
                if (vector == 2 || vector >= 32)
                        goto out;
                if (vector == 3 || vector == 0)
                        goto out;
                if (vmx_excp_has_rf(vector)) {
                        rflags = vmx_vmread(VMCS_GUEST_RFLAGS);
                        vmx_vmwrite(VMCS_GUEST_RFLAGS, rflags | PSL_RF);
                }
                type = INTR_TYPE_HW_EXC;
                err = vmx_excp_has_error(vector);
                break;
        case NVMM_VCPU_EVENT_INTR:
                type = INTR_TYPE_EXT_INT;
                if (vector == 2) {
                        type = INTR_TYPE_NMI;
                        vmx_event_waitexit_enable(vcpu, true);
                }
                err = 0;
                break;
        default:
                goto out;
        }

        info =
            __SHIFTIN((uint64_t)vector, INTR_INFO_VECTOR) |
            __SHIFTIN((uint64_t)type, INTR_INFO_TYPE) |
            __SHIFTIN((uint64_t)err, INTR_INFO_ERROR) |
            __SHIFTIN((uint64_t)1, INTR_INFO_VALID);
        vmx_vmwrite(VMCS_ENTRY_INTR_INFO, info);
        vmx_vmwrite(VMCS_ENTRY_EXCEPTION_ERROR, error);

        cpudata->evt_pending = true;
        ret = 0;

out:
        vmx_vmcs_leave(vcpu);
        return ret;
}

static void
vmx_inject_ud(struct nvmm_cpu *vcpu)
{
        struct nvmm_comm_page *comm = vcpu->comm;
        int ret __diagused;

        comm->event.type = NVMM_VCPU_EVENT_EXCP;
        comm->event.vector = 6;
        comm->event.u.excp.error = 0;

        ret = vmx_vcpu_inject(vcpu);
        OS_ASSERT(ret == 0);
}

static void
vmx_inject_gp(struct nvmm_cpu *vcpu)
{
        struct nvmm_comm_page *comm = vcpu->comm;
        int ret __diagused;

        comm->event.type = NVMM_VCPU_EVENT_EXCP;
        comm->event.vector = 13;
        comm->event.u.excp.error = 0;

        ret = vmx_vcpu_inject(vcpu);
        OS_ASSERT(ret == 0);
}

static inline int
vmx_vcpu_event_commit(struct nvmm_cpu *vcpu)
{
        if (__predict_true(!vcpu->comm->event_commit)) {
                return 0;
        }
        vcpu->comm->event_commit = false;
        return vmx_vcpu_inject(vcpu);
}

static inline void
vmx_inkernel_advance(void)
{
        uint64_t rip, inslen, intstate, rflags;

        /*
         * Maybe we should also apply single-stepping and debug exceptions.
         * Matters for guest-ring3, because it can execute 'cpuid' under a
         * debugger.
         */

        inslen = vmx_vmread(VMCS_EXIT_INSTRUCTION_LENGTH);
        rip = vmx_vmread(VMCS_GUEST_RIP);
        vmx_vmwrite(VMCS_GUEST_RIP, rip + inslen);

        rflags = vmx_vmread(VMCS_GUEST_RFLAGS);
        vmx_vmwrite(VMCS_GUEST_RFLAGS, rflags & ~PSL_RF);

        intstate = vmx_vmread(VMCS_GUEST_INTERRUPTIBILITY);
        vmx_vmwrite(VMCS_GUEST_INTERRUPTIBILITY,
            intstate & ~(INT_STATE_STI|INT_STATE_MOVSS));
}

static void
vmx_exit_invalid(struct nvmm_vcpu_exit *exit, uint64_t code)
{
        exit->u.inv.hwcode = code;
        exit->reason = NVMM_VCPU_EXIT_INVALID;
}

static void
vmx_exit_exc_nmi(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    struct nvmm_vcpu_exit *exit)
{
        uint64_t qual;

        qual = vmx_vmread(VMCS_EXIT_INTR_INFO);

        if ((qual & INTR_INFO_VALID) == 0) {
                goto error;
        }
        if (__SHIFTOUT(qual, INTR_INFO_TYPE) != INTR_TYPE_NMI) {
                goto error;
        }

        exit->reason = NVMM_VCPU_EXIT_NONE;
        return;

error:
        vmx_exit_invalid(exit, VMCS_EXITCODE_EXC_NMI);
}

#define VMX_CPUID_MAX_BASIC             0x16
#define VMX_CPUID_MAX_HYPERVISOR        0x40000000
#define VMX_CPUID_MAX_EXTENDED          0x80000008
static uint32_t vmx_cpuid_max_basic __read_mostly;
static uint32_t vmx_cpuid_max_extended __read_mostly;

static void
vmx_inkernel_exec_cpuid(struct vmx_cpudata *cpudata, uint32_t eax, uint32_t ecx)
{
        cpuid_desc_t descs;

        x86_get_cpuid2(eax, ecx, &descs);
        cpudata->gprs[NVMM_X64_GPR_RAX] = descs.eax;
        cpudata->gprs[NVMM_X64_GPR_RBX] = descs.ebx;
        cpudata->gprs[NVMM_X64_GPR_RCX] = descs.ecx;
        cpudata->gprs[NVMM_X64_GPR_RDX] = descs.edx;
}

static void
vmx_inkernel_handle_cpuid(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    uint32_t eax, uint32_t ecx)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        unsigned int ncpus;
        uint32_t clevel;
        uint64_t cr4;

        if (eax < 0x40000000) {
                if (__predict_false(eax > vmx_cpuid_max_basic)) {
                        eax = vmx_cpuid_max_basic;
                        vmx_inkernel_exec_cpuid(cpudata, eax, ecx);
                }
        } else if (eax < 0x80000000) {
                if (__predict_false(eax > VMX_CPUID_MAX_HYPERVISOR)) {
                        eax = vmx_cpuid_max_basic;
                        vmx_inkernel_exec_cpuid(cpudata, eax, ecx);
                }
        } else {
                if (__predict_false(eax > vmx_cpuid_max_extended)) {
                        eax = vmx_cpuid_max_basic;
                        vmx_inkernel_exec_cpuid(cpudata, eax, ecx);
                }
        }

        switch (eax) {
        case 0x00000000:
                cpudata->gprs[NVMM_X64_GPR_RAX] = vmx_cpuid_max_basic;
                break;
        case 0x00000001:
                cpudata->gprs[NVMM_X64_GPR_RAX] &= nvmm_cpuid_00000001.eax;

                cpudata->gprs[NVMM_X64_GPR_RBX] &= ~CPUID_0_01_EBX_LOCAL_APIC_ID;
                cpudata->gprs[NVMM_X64_GPR_RBX] |= __SHIFTIN(vcpu->cpuid,
                    CPUID_0_01_EBX_LOCAL_APIC_ID);

                ncpus = os_atomic_load_uint(&mach->ncpus);
                cpudata->gprs[NVMM_X64_GPR_RBX] &= ~CPUID_0_01_EBX_HTT_CORES;
                cpudata->gprs[NVMM_X64_GPR_RBX] |= __SHIFTIN(ncpus,
                    CPUID_0_01_EBX_HTT_CORES);

                cpudata->gprs[NVMM_X64_GPR_RCX] &= nvmm_cpuid_00000001.ecx;
                cpudata->gprs[NVMM_X64_GPR_RCX] |= CPUID_0_01_ECX_RAZ;
                if (vmx_procbased_ctls2 & PROC_CTLS2_INVPCID_ENABLE) {
                        cpudata->gprs[NVMM_X64_GPR_RCX] |= CPUID_0_01_ECX_PCID;
                }

                cpudata->gprs[NVMM_X64_GPR_RDX] &= nvmm_cpuid_00000001.edx;

                /* CPUID_0_01_ECX_OSXSAVE depends on CR4. */
                cr4 = vmx_vmread(VMCS_GUEST_CR4);
                if (!(cr4 & CR4_OSXSAVE)) {
                        cpudata->gprs[NVMM_X64_GPR_RCX] &= ~CPUID_0_01_ECX_OSXSAVE;
                }
                break;
        case 0x00000002:
                break;
        case 0x00000003:
                cpudata->gprs[NVMM_X64_GPR_RAX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RBX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RCX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RDX] = 0;
                break;
        case 0x00000004: /* Deterministic Cache Parameters */
                ncpus = os_atomic_load_uint(&mach->ncpus);
                clevel = __SHIFTOUT(cpudata->gprs[NVMM_X64_GPR_RAX],
                    CPUID_0_04_EAX_CACHELEVEL);

                cpudata->gprs[NVMM_X64_GPR_RAX] &= ~CPUID_0_04_EAX_SHARING;
                if (clevel >= 3) {
                        /* L3 and above: all CPUs. */
                        cpudata->gprs[NVMM_X64_GPR_RAX] |=
                            __SHIFTIN(ncpus - 1, CPUID_0_04_EAX_SHARING);
                } else {
                        /* L2 and below: one LP per CPU. */
                        cpudata->gprs[NVMM_X64_GPR_RAX] |=
                            __SHIFTIN(0, CPUID_0_04_EAX_SHARING);
                }

                cpudata->gprs[NVMM_X64_GPR_RAX] &= ~CPUID_0_04_EAX_CORE_P_PKG;
                cpudata->gprs[NVMM_X64_GPR_RAX] |=
                    __SHIFTIN(ncpus - 1, CPUID_0_04_EAX_CORE_P_PKG);
                break;
        case 0x00000005: /* MONITOR/MWAIT */
        case 0x00000006: /* Thermal and Power Management */
                cpudata->gprs[NVMM_X64_GPR_RAX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RBX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RCX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RDX] = 0;
                break;
        case 0x00000007: /* Structured Extended Feature Flags Enumeration */
                switch (ecx) {
                case 0:
                        cpudata->gprs[NVMM_X64_GPR_RAX] = 0;
                        cpudata->gprs[NVMM_X64_GPR_RBX] &= nvmm_cpuid_00000007.ebx;
                        cpudata->gprs[NVMM_X64_GPR_RCX] &= nvmm_cpuid_00000007.ecx;
                        cpudata->gprs[NVMM_X64_GPR_RDX] &= nvmm_cpuid_00000007.edx;
                        if (vmx_procbased_ctls2 & PROC_CTLS2_INVPCID_ENABLE) {
                                cpudata->gprs[NVMM_X64_GPR_RBX] |= CPUID_0_07_EBX_INVPCID;
                        }
                        if (vmx_cpu_has_arch_cap) {
                                cpudata->gprs[NVMM_X64_GPR_RDX] |= CPUID_0_07_EDX_ARCH_CAP;
                        }
                        break;
                default:
                        cpudata->gprs[NVMM_X64_GPR_RAX] = 0;
                        cpudata->gprs[NVMM_X64_GPR_RBX] = 0;
                        cpudata->gprs[NVMM_X64_GPR_RCX] = 0;
                        cpudata->gprs[NVMM_X64_GPR_RDX] = 0;
                        break;
                }
                break;
        case 0x00000008: /* Empty */
        case 0x00000009: /* Direct Cache Access Information */
                cpudata->gprs[NVMM_X64_GPR_RAX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RBX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RCX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RDX] = 0;
                break;
        case 0x0000000A: /* Architectural Performance Monitoring */
                cpudata->gprs[NVMM_X64_GPR_RAX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RBX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RCX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RDX] = 0;
                break;
        case 0x0000000B: /* Extended Topology Enumeration */
                switch (ecx) {
                case 0: /* Threads */
                        cpudata->gprs[NVMM_X64_GPR_RAX] = 0;
                        cpudata->gprs[NVMM_X64_GPR_RBX] = 0;
                        cpudata->gprs[NVMM_X64_GPR_RCX] =
                            __SHIFTIN(ecx, CPUID_0_0B_ECX_LVLNUM) |
                            __SHIFTIN(CPUID_0_0B_ECX_LVLTYPE_SMT, CPUID_0_0B_ECX_LVLTYPE);
                        cpudata->gprs[NVMM_X64_GPR_RDX] = vcpu->cpuid;
                        break;
                case 1: /* Cores */
                        ncpus = os_atomic_load_uint(&mach->ncpus);
                        cpudata->gprs[NVMM_X64_GPR_RAX] = ilog2(ncpus);
                        cpudata->gprs[NVMM_X64_GPR_RBX] = ncpus;
                        cpudata->gprs[NVMM_X64_GPR_RCX] =
                            __SHIFTIN(ecx, CPUID_0_0B_ECX_LVLNUM) |
                            __SHIFTIN(CPUID_0_0B_ECX_LVLTYPE_CORE, CPUID_0_0B_ECX_LVLTYPE);
                        cpudata->gprs[NVMM_X64_GPR_RDX] = vcpu->cpuid;
                        break;
                default:
                        cpudata->gprs[NVMM_X64_GPR_RAX] = 0;
                        cpudata->gprs[NVMM_X64_GPR_RBX] = 0;
                        cpudata->gprs[NVMM_X64_GPR_RCX] = 0; /* LVLTYPE_INVAL */
                        cpudata->gprs[NVMM_X64_GPR_RDX] = 0;
                        break;
                }
                break;
        case 0x0000000C: /* Empty */
                cpudata->gprs[NVMM_X64_GPR_RAX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RBX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RCX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RDX] = 0;
                break;
        case 0x0000000D: /* Processor Extended State Enumeration */
                if (vmx_xcr0_mask == 0) {
                        break;
                }
                switch (ecx) {
                case 0:
                        /* Supported XCR0 bits. */
                        cpudata->gprs[NVMM_X64_GPR_RAX] = vmx_xcr0_mask & 0xFFFFFFFF;
                        cpudata->gprs[NVMM_X64_GPR_RDX] = vmx_xcr0_mask >> 32;
                        /* XSAVE size for currently enabled XCR0 features. */
                        cpudata->gprs[NVMM_X64_GPR_RBX] = nvmm_x86_xsave_size(cpudata->gxcr0);
                        /* XSAVE size for all supported XCR0 features. */
                        cpudata->gprs[NVMM_X64_GPR_RCX] = nvmm_x86_xsave_size(vmx_xcr0_mask);
                        break;
                case 1:
                        cpudata->gprs[NVMM_X64_GPR_RAX] &=
                            (CPUID_0_0D_ECX1_EAX_XSAVEOPT |
                             CPUID_0_0D_ECX1_EAX_XSAVEC |
                             CPUID_0_0D_ECX1_EAX_XGETBV);
                        cpudata->gprs[NVMM_X64_GPR_RBX] = 0;
                        cpudata->gprs[NVMM_X64_GPR_RCX] = 0;
                        cpudata->gprs[NVMM_X64_GPR_RDX] = 0;
                        break;
                default:
                        cpudata->gprs[NVMM_X64_GPR_RAX] = 0;
                        cpudata->gprs[NVMM_X64_GPR_RBX] = 0;
                        cpudata->gprs[NVMM_X64_GPR_RCX] = 0;
                        cpudata->gprs[NVMM_X64_GPR_RDX] = 0;
                        break;
                }
                break;
        case 0x0000000E: /* Empty */
        case 0x0000000F: /* Intel RDT Monitoring Enumeration */
        case 0x00000010: /* Intel RDT Allocation Enumeration */
                cpudata->gprs[NVMM_X64_GPR_RAX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RBX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RCX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RDX] = 0;
                break;
        case 0x00000011: /* Empty */
        case 0x00000012: /* Intel SGX Capability Enumeration */
        case 0x00000013: /* Empty */
        case 0x00000014: /* Intel Processor Trace Enumeration */
                cpudata->gprs[NVMM_X64_GPR_RAX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RBX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RCX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RDX] = 0;
                break;
        case 0x00000015: /* TSC and Nominal Core Crystal Clock Information */
        case 0x00000016: /* Processor Frequency Information */
                break;

        case 0x40000000: /* Hypervisor Information */
                cpudata->gprs[NVMM_X64_GPR_RAX] = VMX_CPUID_MAX_HYPERVISOR;
                cpudata->gprs[NVMM_X64_GPR_RBX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RCX] = 0;
                cpudata->gprs[NVMM_X64_GPR_RDX] = 0;
                memcpy(&cpudata->gprs[NVMM_X64_GPR_RBX], "___ ", 4);
                memcpy(&cpudata->gprs[NVMM_X64_GPR_RCX], "NVMM", 4);
                memcpy(&cpudata->gprs[NVMM_X64_GPR_RDX], " ___", 4);
                break;

        case 0x80000000:
                cpudata->gprs[NVMM_X64_GPR_RAX] = vmx_cpuid_max_extended;
                break;
        case 0x80000001:
                cpudata->gprs[NVMM_X64_GPR_RAX] &= nvmm_cpuid_80000001.eax;
                cpudata->gprs[NVMM_X64_GPR_RBX] &= nvmm_cpuid_80000001.ebx;
                cpudata->gprs[NVMM_X64_GPR_RCX] &= nvmm_cpuid_80000001.ecx;
                cpudata->gprs[NVMM_X64_GPR_RDX] &= nvmm_cpuid_80000001.edx;
                break;
        case 0x80000002: /* Processor Brand String */
        case 0x80000003: /* Processor Brand String */
        case 0x80000004: /* Processor Brand String */
        case 0x80000005: /* Reserved Zero */
        case 0x80000006: /* Cache Information */
                break;
        case 0x80000007: /* TSC Information */
                cpudata->gprs[NVMM_X64_GPR_RAX] &= nvmm_cpuid_80000007.eax;
                cpudata->gprs[NVMM_X64_GPR_RBX] &= nvmm_cpuid_80000007.ebx;
                cpudata->gprs[NVMM_X64_GPR_RCX] &= nvmm_cpuid_80000007.ecx;
                cpudata->gprs[NVMM_X64_GPR_RDX] &= nvmm_cpuid_80000007.edx;
                break;
        case 0x80000008: /* Address Sizes */
                cpudata->gprs[NVMM_X64_GPR_RAX] &= nvmm_cpuid_80000008.eax;
                cpudata->gprs[NVMM_X64_GPR_RBX] &= nvmm_cpuid_80000008.ebx;
                cpudata->gprs[NVMM_X64_GPR_RCX] &= nvmm_cpuid_80000008.ecx;
                cpudata->gprs[NVMM_X64_GPR_RDX] &= nvmm_cpuid_80000008.edx;
                break;

        default:
                break;
        }
}

static void
vmx_exit_insn(struct nvmm_vcpu_exit *exit, uint64_t reason)
{
        uint64_t inslen, rip;

        inslen = vmx_vmread(VMCS_EXIT_INSTRUCTION_LENGTH);
        rip = vmx_vmread(VMCS_GUEST_RIP);
        exit->u.insn.npc = rip + inslen;
        exit->reason = reason;
}

static void
vmx_exit_cpuid(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    struct nvmm_vcpu_exit *exit)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        struct nvmm_vcpu_conf_cpuid *cpuid;
        uint32_t eax, ecx;
        size_t i;

        eax = (cpudata->gprs[NVMM_X64_GPR_RAX] & 0xFFFFFFFF);
        ecx = (cpudata->gprs[NVMM_X64_GPR_RCX] & 0xFFFFFFFF);
        vmx_inkernel_exec_cpuid(cpudata, eax, ecx);
        vmx_inkernel_handle_cpuid(mach, vcpu, eax, ecx);

        for (i = 0; i < VMX_NCPUIDS; i++) {
                if (!cpudata->cpuidpresent[i]) {
                        continue;
                }
                cpuid = &cpudata->cpuid[i];
                if (cpuid->leaf != eax) {
                        continue;
                }

                if (cpuid->exit) {
                        vmx_exit_insn(exit, NVMM_VCPU_EXIT_CPUID);
                        return;
                }
                OS_ASSERT(cpuid->mask);

                /* del */
                cpudata->gprs[NVMM_X64_GPR_RAX] &= ~cpuid->u.mask.del.eax;
                cpudata->gprs[NVMM_X64_GPR_RBX] &= ~cpuid->u.mask.del.ebx;
                cpudata->gprs[NVMM_X64_GPR_RCX] &= ~cpuid->u.mask.del.ecx;
                cpudata->gprs[NVMM_X64_GPR_RDX] &= ~cpuid->u.mask.del.edx;

                /* set */
                cpudata->gprs[NVMM_X64_GPR_RAX] |= cpuid->u.mask.set.eax;
                cpudata->gprs[NVMM_X64_GPR_RBX] |= cpuid->u.mask.set.ebx;
                cpudata->gprs[NVMM_X64_GPR_RCX] |= cpuid->u.mask.set.ecx;
                cpudata->gprs[NVMM_X64_GPR_RDX] |= cpuid->u.mask.set.edx;

                break;
        }

        vmx_inkernel_advance();
        exit->reason = NVMM_VCPU_EXIT_NONE;
}

static void
vmx_exit_hlt(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    struct nvmm_vcpu_exit *exit)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        uint64_t rflags;

        if (cpudata->int_window_exit) {
                rflags = vmx_vmread(VMCS_GUEST_RFLAGS);
                if (rflags & PSL_I) {
                        vmx_event_waitexit_disable(vcpu, false);
                }
        }

        vmx_inkernel_advance();
        exit->reason = NVMM_VCPU_EXIT_HALTED;
}

#define VMX_QUAL_CR_NUM         __BITS(3,0)
#define VMX_QUAL_CR_TYPE        __BITS(5,4)
#define         CR_TYPE_WRITE   0
#define         CR_TYPE_READ    1
#define         CR_TYPE_CLTS    2
#define         CR_TYPE_LMSW    3
#define VMX_QUAL_CR_LMSW_OPMEM  __BIT(6)
#define VMX_QUAL_CR_GPR         __BITS(11,8)
#define VMX_QUAL_CR_LMSW_SRC    __BIT(31,16)

static inline int
vmx_check_cr(uint64_t crval, uint64_t fixed0, uint64_t fixed1)
{
        /* Bits set to 1 in fixed0 are fixed to 1. */
        if ((crval & fixed0) != fixed0) {
                return -1;
        }
        /* Bits set to 0 in fixed1 are fixed to 0. */
        if (crval & ~fixed1) {
                return -1;
        }
        return 0;
}

static int
vmx_inkernel_handle_cr0(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    uint64_t qual)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        uint64_t type, gpr, oldcr0, realcr0, fakecr0;
        uint64_t efer, ctls1;

        type = __SHIFTOUT(qual, VMX_QUAL_CR_TYPE);
        if (type != CR_TYPE_WRITE) {
                return -1;
        }

        gpr = __SHIFTOUT(qual, VMX_QUAL_CR_GPR);
        OS_ASSERT(gpr < 16);

        if (gpr == NVMM_X64_GPR_RSP) {
                fakecr0 = vmx_vmread(VMCS_GUEST_RSP);
        } else {
                fakecr0 = cpudata->gprs[gpr];
        }
        fakecr0 |= CR0_ET; /* Force ET=1 for consistency. */

        realcr0 = (fakecr0 & ~CR0_FORCE_ZERO) | CR0_FORCE_ONE;
        if (vmx_check_cr(realcr0, vmx_cr0_fixed0, vmx_cr0_fixed1) == -1) {
                return -1;
        }

        /*
         * XXX Handle 32bit PAE paging, need to set PDPTEs, fetched manually
         * from CR3.
         */

        if (realcr0 & CR0_PG) {
                ctls1 = vmx_vmread(VMCS_ENTRY_CTLS);
                efer = vmx_vmread(VMCS_GUEST_IA32_EFER);
                if (efer & EFER_LME) {
                        ctls1 |= ENTRY_CTLS_LONG_MODE;
                        efer |= EFER_LMA;
                } else {
                        ctls1 &= ~ENTRY_CTLS_LONG_MODE;
                        efer &= ~EFER_LMA;
                }
                vmx_vmwrite(VMCS_GUEST_IA32_EFER, efer);
                vmx_vmwrite(VMCS_ENTRY_CTLS, ctls1);
        }

        oldcr0 = (vmx_vmread(VMCS_CR0_SHADOW) & CR0_STATIC_MASK) |
            (vmx_vmread(VMCS_GUEST_CR0) & ~CR0_STATIC_MASK);
        if ((oldcr0 ^ fakecr0) & CR0_TLB_FLUSH) {
                cpudata->gtlb_want_flush = true;
        }

        vmx_vmwrite(VMCS_CR0_SHADOW, fakecr0);
        vmx_vmwrite(VMCS_GUEST_CR0, realcr0);
        vmx_inkernel_advance();
        return 0;
}

static int
vmx_inkernel_handle_cr4(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    uint64_t qual)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        uint64_t type, gpr, oldcr4, cr4;

        type = __SHIFTOUT(qual, VMX_QUAL_CR_TYPE);
        if (type != CR_TYPE_WRITE) {
                return -1;
        }

        gpr = __SHIFTOUT(qual, VMX_QUAL_CR_GPR);
        OS_ASSERT(gpr < 16);

        if (gpr == NVMM_X64_GPR_RSP) {
                gpr = vmx_vmread(VMCS_GUEST_RSP);
        } else {
                gpr = cpudata->gprs[gpr];
        }

        if (gpr & CR4_INVALID) {
                return -1;
        }
        cr4 = gpr | CR4_VMXE;
        if (vmx_check_cr(cr4, vmx_cr4_fixed0, vmx_cr4_fixed1) == -1) {
                return -1;
        }

        oldcr4 = vmx_vmread(VMCS_GUEST_CR4);
        if ((oldcr4 ^ gpr) & CR4_TLB_FLUSH) {
                cpudata->gtlb_want_flush = true;
        }

        vmx_vmwrite(VMCS_GUEST_CR4, cr4);
        vmx_inkernel_advance();
        return 0;
}

static int
vmx_inkernel_handle_cr8(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    uint64_t qual, struct nvmm_vcpu_exit *exit)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        uint64_t type, gpr;
        bool write;

        type = __SHIFTOUT(qual, VMX_QUAL_CR_TYPE);
        if (type == CR_TYPE_WRITE) {
                write = true;
        } else if (type == CR_TYPE_READ) {
                write = false;
        } else {
                return -1;
        }

        gpr = __SHIFTOUT(qual, VMX_QUAL_CR_GPR);
        OS_ASSERT(gpr < 16);

        if (write) {
                if (gpr == NVMM_X64_GPR_RSP) {
                        cpudata->gcr8 = vmx_vmread(VMCS_GUEST_RSP);
                } else {
                        cpudata->gcr8 = cpudata->gprs[gpr];
                }
                if (cpudata->tpr.exit_changed) {
                        exit->reason = NVMM_VCPU_EXIT_TPR_CHANGED;
                }
        } else {
                if (gpr == NVMM_X64_GPR_RSP) {
                        vmx_vmwrite(VMCS_GUEST_RSP, cpudata->gcr8);
                } else {
                        cpudata->gprs[gpr] = cpudata->gcr8;
                }
        }

        vmx_inkernel_advance();
        return 0;
}

static void
vmx_exit_cr(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    struct nvmm_vcpu_exit *exit)
{
        uint64_t qual;
        int ret;

        exit->reason = NVMM_VCPU_EXIT_NONE;

        qual = vmx_vmread(VMCS_EXIT_QUALIFICATION);

        switch (__SHIFTOUT(qual, VMX_QUAL_CR_NUM)) {
        case 0:
                ret = vmx_inkernel_handle_cr0(mach, vcpu, qual);
                break;
        case 4:
                ret = vmx_inkernel_handle_cr4(mach, vcpu, qual);
                break;
        case 8:
                ret = vmx_inkernel_handle_cr8(mach, vcpu, qual, exit);
                break;
        default:
                ret = -1;
                break;
        }

        if (ret == -1) {
                vmx_inject_gp(vcpu);
        }
}

#define VMX_QUAL_IO_SIZE        __BITS(2,0)
#define         IO_SIZE_8       0
#define         IO_SIZE_16      1
#define         IO_SIZE_32      3
#define VMX_QUAL_IO_IN          __BIT(3)
#define VMX_QUAL_IO_STR         __BIT(4)
#define VMX_QUAL_IO_REP         __BIT(5)
#define VMX_QUAL_IO_DX          __BIT(6)
#define VMX_QUAL_IO_PORT        __BITS(31,16)

#define VMX_INFO_IO_ADRSIZE     __BITS(9,7)
#define         IO_ADRSIZE_16   0
#define         IO_ADRSIZE_32   1
#define         IO_ADRSIZE_64   2
#define VMX_INFO_IO_SEG         __BITS(17,15)

static void
vmx_exit_io(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    struct nvmm_vcpu_exit *exit)
{
        uint64_t qual, info, inslen, rip;

        qual = vmx_vmread(VMCS_EXIT_QUALIFICATION);
        info = vmx_vmread(VMCS_EXIT_INSTRUCTION_INFO);

        exit->reason = NVMM_VCPU_EXIT_IO;

        exit->u.io.in = (qual & VMX_QUAL_IO_IN) != 0;
        exit->u.io.port = __SHIFTOUT(qual, VMX_QUAL_IO_PORT);

        OS_ASSERT(__SHIFTOUT(info, VMX_INFO_IO_SEG) < 6);
        exit->u.io.seg = __SHIFTOUT(info, VMX_INFO_IO_SEG);

        if (__SHIFTOUT(info, VMX_INFO_IO_ADRSIZE) == IO_ADRSIZE_64) {
                exit->u.io.address_size = 8;
        } else if (__SHIFTOUT(info, VMX_INFO_IO_ADRSIZE) == IO_ADRSIZE_32) {
                exit->u.io.address_size = 4;
        } else if (__SHIFTOUT(info, VMX_INFO_IO_ADRSIZE) == IO_ADRSIZE_16) {
                exit->u.io.address_size = 2;
        }

        if (__SHIFTOUT(qual, VMX_QUAL_IO_SIZE) == IO_SIZE_32) {
                exit->u.io.operand_size = 4;
        } else if (__SHIFTOUT(qual, VMX_QUAL_IO_SIZE) == IO_SIZE_16) {
                exit->u.io.operand_size = 2;
        } else if (__SHIFTOUT(qual, VMX_QUAL_IO_SIZE) == IO_SIZE_8) {
                exit->u.io.operand_size = 1;
        }

        exit->u.io.rep = (qual & VMX_QUAL_IO_REP) != 0;
        exit->u.io.str = (qual & VMX_QUAL_IO_STR) != 0;

        if (exit->u.io.in && exit->u.io.str) {
                exit->u.io.seg = NVMM_X64_SEG_ES;
        }

        inslen = vmx_vmread(VMCS_EXIT_INSTRUCTION_LENGTH);
        rip = vmx_vmread(VMCS_GUEST_RIP);
        exit->u.io.npc = rip + inslen;

        vmx_vcpu_state_provide(vcpu,
            NVMM_X64_STATE_GPRS | NVMM_X64_STATE_SEGS |
            NVMM_X64_STATE_CRS | NVMM_X64_STATE_MSRS);
}

static const uint64_t msr_ignore_list[] = {
        MSR_IA32_BIOS_SIGN_ID,
        MSR_IA32_PLATFORM_ID
};

static bool
vmx_inkernel_handle_msr(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    struct nvmm_vcpu_exit *exit)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        uint64_t val;
        size_t i;

        if (exit->reason == NVMM_VCPU_EXIT_RDMSR) {
                if (exit->u.rdmsr.msr == MSR_CR_PAT) {
                        val = vmx_vmread(VMCS_GUEST_IA32_PAT);
                        cpudata->gprs[NVMM_X64_GPR_RAX] = (val & 0xFFFFFFFF);
                        cpudata->gprs[NVMM_X64_GPR_RDX] = (val >> 32);
                        goto handled;
                }
                if (exit->u.rdmsr.msr == MSR_IA32_MISC_ENABLE) {
                        val = cpudata->gmsr_misc_enable;
                        cpudata->gprs[NVMM_X64_GPR_RAX] = (val & 0xFFFFFFFF);
                        cpudata->gprs[NVMM_X64_GPR_RDX] = (val >> 32);
                        goto handled;
                }
                if (exit->u.rdmsr.msr == MSR_IA32_ARCH_CAPABILITIES) {
                        if (!vmx_cpu_has_arch_cap) {
                                goto error;
                        }
                        val = rdmsr(MSR_IA32_ARCH_CAPABILITIES);
                        val &= (IA32_ARCH_RDCL_NO |
                            IA32_ARCH_SSB_NO |
                            IA32_ARCH_MDS_NO |
                            IA32_ARCH_TAA_NO);
                        cpudata->gprs[NVMM_X64_GPR_RAX] = (val & 0xFFFFFFFF);
                        cpudata->gprs[NVMM_X64_GPR_RDX] = (val >> 32);
                        goto handled;
                }
                for (i = 0; i < __arraycount(msr_ignore_list); i++) {
                        if (msr_ignore_list[i] != exit->u.rdmsr.msr)
                                continue;
                        val = 0;
                        cpudata->gprs[NVMM_X64_GPR_RAX] = (val & 0xFFFFFFFF);
                        cpudata->gprs[NVMM_X64_GPR_RDX] = (val >> 32);
                        goto handled;
                }
        } else {
                if (exit->u.wrmsr.msr == MSR_TSC) {
                        cpudata->gtsc_offset = exit->u.wrmsr.val - rdtsc();
                        cpudata->gtsc_want_update = true;
                        goto handled;
                }
                if (exit->u.wrmsr.msr == MSR_CR_PAT) {
                        val = exit->u.wrmsr.val;
                        if (__predict_false(!nvmm_x86_pat_validate(val))) {
                                goto error;
                        }
                        vmx_vmwrite(VMCS_GUEST_IA32_PAT, val);
                        goto handled;
                }
                if (exit->u.wrmsr.msr == MSR_IA32_MISC_ENABLE) {
                        /* Don't care. */
                        goto handled;
                }
                for (i = 0; i < __arraycount(msr_ignore_list); i++) {
                        if (msr_ignore_list[i] != exit->u.wrmsr.msr)
                                continue;
                        goto handled;
                }
        }

        return false;

handled:
        vmx_inkernel_advance();
        return true;

error:
        vmx_inject_gp(vcpu);
        return true;
}

static void
vmx_exit_rdmsr(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    struct nvmm_vcpu_exit *exit)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        uint64_t inslen, rip;

        exit->reason = NVMM_VCPU_EXIT_RDMSR;
        exit->u.rdmsr.msr = (cpudata->gprs[NVMM_X64_GPR_RCX] & 0xFFFFFFFF);

        if (vmx_inkernel_handle_msr(mach, vcpu, exit)) {
                exit->reason = NVMM_VCPU_EXIT_NONE;
                return;
        }

        inslen = vmx_vmread(VMCS_EXIT_INSTRUCTION_LENGTH);
        rip = vmx_vmread(VMCS_GUEST_RIP);
        exit->u.rdmsr.npc = rip + inslen;

        vmx_vcpu_state_provide(vcpu, NVMM_X64_STATE_GPRS);
}

static void
vmx_exit_wrmsr(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    struct nvmm_vcpu_exit *exit)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        uint64_t rdx, rax, inslen, rip;

        rdx = cpudata->gprs[NVMM_X64_GPR_RDX];
        rax = cpudata->gprs[NVMM_X64_GPR_RAX];

        exit->reason = NVMM_VCPU_EXIT_WRMSR;
        exit->u.wrmsr.msr = (cpudata->gprs[NVMM_X64_GPR_RCX] & 0xFFFFFFFF);
        exit->u.wrmsr.val = (rdx << 32) | (rax & 0xFFFFFFFF);

        if (vmx_inkernel_handle_msr(mach, vcpu, exit)) {
                exit->reason = NVMM_VCPU_EXIT_NONE;
                return;
        }

        inslen = vmx_vmread(VMCS_EXIT_INSTRUCTION_LENGTH);
        rip = vmx_vmread(VMCS_GUEST_RIP);
        exit->u.wrmsr.npc = rip + inslen;

        vmx_vcpu_state_provide(vcpu, NVMM_X64_STATE_GPRS);
}

static void
vmx_exit_xsetbv(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    struct nvmm_vcpu_exit *exit)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        uint64_t val;

        exit->reason = NVMM_VCPU_EXIT_NONE;

        val = (cpudata->gprs[NVMM_X64_GPR_RDX] << 32) |
            (cpudata->gprs[NVMM_X64_GPR_RAX] & 0xFFFFFFFF);

        if (__predict_false(cpudata->gprs[NVMM_X64_GPR_RCX] != 0)) {
                goto error;
        } else if (__predict_false((val & ~vmx_xcr0_mask) != 0)) {
                goto error;
        } else if (__predict_false((val & XCR0_X87) == 0)) {
                goto error;
        }

        cpudata->gxcr0 = val;

        vmx_inkernel_advance();
        return;

error:
        vmx_inject_gp(vcpu);
}

#define VMX_EPT_VIOLATION_READ          __BIT(0)
#define VMX_EPT_VIOLATION_WRITE         __BIT(1)
#define VMX_EPT_VIOLATION_EXECUTE       __BIT(2)

static void
vmx_exit_epf(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    struct nvmm_vcpu_exit *exit)
{
        uint64_t perm;
        gpaddr_t gpa;

        gpa = vmx_vmread(VMCS_GUEST_PHYSICAL_ADDRESS);

        exit->reason = NVMM_VCPU_EXIT_MEMORY;
        perm = vmx_vmread(VMCS_EXIT_QUALIFICATION);
        if (perm & VMX_EPT_VIOLATION_WRITE)
                exit->u.mem.prot = PROT_WRITE;
        else if (perm & VMX_EPT_VIOLATION_EXECUTE)
                exit->u.mem.prot = PROT_EXEC;
        else
                exit->u.mem.prot = PROT_READ;
        exit->u.mem.gpa = gpa;
        exit->u.mem.inst_len = 0;

        vmx_vcpu_state_provide(vcpu,
            NVMM_X64_STATE_GPRS | NVMM_X64_STATE_SEGS |
            NVMM_X64_STATE_CRS | NVMM_X64_STATE_MSRS);
}

/* -------------------------------------------------------------------------- */

static void
vmx_vcpu_guest_fpu_enter(struct nvmm_cpu *vcpu)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;

#if defined(__NetBSD__)
        x86_curthread_save_fpu();
#elif defined(__DragonFly__)
        /*
         * NOTE: Host FPU state depends on whether the user program used the
         *       FPU or not.  Need to use npxpush()/npxpop() to handle this.
         */
        npxpush(&cpudata->hstate.hmctx);
#endif

        x86_restore_fpu(&cpudata->gxsave, vmx_xcr0_mask);
        if (vmx_xcr0_mask != 0) {
                x86_set_xcr(0, cpudata->gxcr0);
        }
}

static void
vmx_vcpu_guest_fpu_leave(struct nvmm_cpu *vcpu)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;

        if (vmx_xcr0_mask != 0) {
                x86_set_xcr(0, vmx_global_hstate.xcr0);
        }
        x86_save_fpu(&cpudata->gxsave, vmx_xcr0_mask);

#if defined(__NetBSD__)
        x86_curthread_restore_fpu();
#elif defined(__DragonFly__)
        npxpop(&cpudata->hstate.hmctx);
#endif
}

static void
vmx_vcpu_guest_dbregs_enter(struct nvmm_cpu *vcpu)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;

        x86_curthread_save_dbregs(cpudata->hstate.drs);

        x86_set_dr7(0);

        x86_set_dr0(cpudata->drs[NVMM_X64_DR_DR0]);
        x86_set_dr1(cpudata->drs[NVMM_X64_DR_DR1]);
        x86_set_dr2(cpudata->drs[NVMM_X64_DR_DR2]);
        x86_set_dr3(cpudata->drs[NVMM_X64_DR_DR3]);
        x86_set_dr6(cpudata->drs[NVMM_X64_DR_DR6]);
}

static void
vmx_vcpu_guest_dbregs_leave(struct nvmm_cpu *vcpu)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;

        cpudata->drs[NVMM_X64_DR_DR0] = x86_get_dr0();
        cpudata->drs[NVMM_X64_DR_DR1] = x86_get_dr1();
        cpudata->drs[NVMM_X64_DR_DR2] = x86_get_dr2();
        cpudata->drs[NVMM_X64_DR_DR3] = x86_get_dr3();
        cpudata->drs[NVMM_X64_DR_DR6] = x86_get_dr6();

        x86_curthread_restore_dbregs(cpudata->hstate.drs);
}

static void
vmx_vcpu_guest_misc_enter(struct nvmm_cpu *vcpu)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;

        /* This gets restored automatically by the CPU. */
        vmx_vmwrite(VMCS_HOST_IDTR_BASE, (uint64_t)os_curcpu_idt());
        vmx_vmwrite(VMCS_HOST_FS_BASE, rdmsr(MSR_FSBASE));
        vmx_vmwrite(VMCS_HOST_CR3, x86_get_cr3());
        vmx_vmwrite(VMCS_HOST_CR4, x86_get_cr4());

        /* Save the percpu host state. */
        cpudata->hstate.kernelgsbase = rdmsr(MSR_KERNELGSBASE);
}

static void
vmx_vcpu_guest_misc_leave(struct nvmm_cpu *vcpu)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;

        /* Restore the global host state. */
        wrmsr(MSR_STAR, vmx_global_hstate.star);
        wrmsr(MSR_LSTAR, vmx_global_hstate.lstar);
        wrmsr(MSR_CSTAR, vmx_global_hstate.cstar);
        wrmsr(MSR_SFMASK, vmx_global_hstate.sfmask);

        /* Restore the percpu host state. */
        wrmsr(MSR_KERNELGSBASE, cpudata->hstate.kernelgsbase);
}

/* -------------------------------------------------------------------------- */

#define VMX_INVVPID_ADDRESS             0
#define VMX_INVVPID_CONTEXT             1
#define VMX_INVVPID_ALL                 2
#define VMX_INVVPID_CONTEXT_NOGLOBAL    3

#define VMX_INVEPT_CONTEXT              1
#define VMX_INVEPT_ALL                  2

static inline void
vmx_gtlb_catchup(struct nvmm_cpu *vcpu, int hcpu)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;

        if (vcpu->hcpu_last != hcpu) {
                cpudata->gtlb_want_flush = true;
        }
}

static inline void
vmx_htlb_catchup(struct nvmm_cpu *vcpu, int hcpu)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        struct ept_desc ept_desc;

        if (__predict_true(!os_cpuset_isset(cpudata->htlb_want_flush, hcpu))) {
                return;
        }

        ept_desc.eptp = vmx_vmread(VMCS_EPTP);
        ept_desc.mbz = 0;
        vmx_invept(vmx_ept_flush_op, &ept_desc);
        os_cpuset_clear(cpudata->htlb_want_flush, hcpu);
}

static inline uint64_t
vmx_htlb_flush(struct nvmm_machine *mach, struct vmx_cpudata *cpudata)
{
        struct ept_desc ept_desc;
        uint64_t machgen;

#if defined(__NetBSD__)
        machgen = ((struct vmx_machdata *)mach->machdata)->mach_htlb_gen;
#elif defined(__DragonFly__)
        clear_xinvltlb();
        machgen = vmspace_pmap(mach->vm)->pm_invgen;
#endif
        if (__predict_true(machgen == cpudata->vcpu_htlb_gen)) {
                return machgen;
        }

        os_cpuset_setrunning(cpudata->htlb_want_flush);

        ept_desc.eptp = vmx_vmread(VMCS_EPTP);
        ept_desc.mbz = 0;
        vmx_invept(vmx_ept_flush_op, &ept_desc);

        return machgen;
}

static inline void
vmx_htlb_flush_ack(struct vmx_cpudata *cpudata, uint64_t machgen)
{
        cpudata->vcpu_htlb_gen = machgen;
        os_cpuset_clear(cpudata->htlb_want_flush, os_curcpu_number());
}

static inline void
vmx_exit_evt(struct vmx_cpudata *cpudata)
{
        uint64_t info, err, inslen;

        cpudata->evt_pending = false;

        info = vmx_vmread(VMCS_IDT_VECTORING_INFO);
        if (__predict_true((info & INTR_INFO_VALID) == 0)) {
                return;
        }
        err = vmx_vmread(VMCS_IDT_VECTORING_ERROR);

        vmx_vmwrite(VMCS_ENTRY_INTR_INFO, info);
        vmx_vmwrite(VMCS_ENTRY_EXCEPTION_ERROR, err);

        switch (__SHIFTOUT(info, INTR_INFO_TYPE)) {
        case INTR_TYPE_SW_INT:
        case INTR_TYPE_PRIV_SW_EXC:
        case INTR_TYPE_SW_EXC:
                inslen = vmx_vmread(VMCS_EXIT_INSTRUCTION_LENGTH);
                vmx_vmwrite(VMCS_ENTRY_INSTRUCTION_LENGTH, inslen);
        }

        cpudata->evt_pending = true;
}

static int
vmx_vcpu_run(struct nvmm_machine *mach, struct nvmm_cpu *vcpu,
    struct nvmm_vcpu_exit *exit)
{
        struct nvmm_comm_page *comm = vcpu->comm;
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        struct vpid_desc vpid_desc;
        uint64_t exitcode;
        uint64_t intstate;
        uint64_t machgen;
        int hcpu, ret;
        int error = 0;
        bool launched;

        vmx_vmcs_enter(vcpu);

        vmx_vcpu_state_commit(vcpu);
        comm->state_cached = 0;

#ifndef __DragonFly__
        if (__predict_false(vmx_vcpu_event_commit(vcpu) != 0)) {
                vmx_vmcs_leave(vcpu);
                return EINVAL;
        }
#endif

        hcpu = os_curcpu_number();
        launched = cpudata->vmcs_launched;

        vmx_gtlb_catchup(vcpu, hcpu);
        vmx_htlb_catchup(vcpu, hcpu);

        if (vcpu->hcpu_last != hcpu) {
                vmx_vmwrite(VMCS_HOST_TR_SELECTOR, os_curcpu_tss_sel());
                vmx_vmwrite(VMCS_HOST_TR_BASE, (uint64_t)os_curcpu_tss());
                vmx_vmwrite(VMCS_HOST_GDTR_BASE, (uint64_t)os_curcpu_gdt());
                vmx_vmwrite(VMCS_HOST_GS_BASE, rdmsr(MSR_GSBASE));
                cpudata->gtsc_want_update = true;
                vcpu->hcpu_last = hcpu;

#ifdef __DragonFly__
                /*
                 * XXX: We aren't tracking overloaded CPUs (multiple vCPUs
                 *      scheduled on the same physical CPU) yet so there are
                 *      currently no calls to pmap_del_cpu().
                 */
                pmap_add_cpu(mach->vm, hcpu);
#endif
        }

        vmx_vcpu_guest_dbregs_enter(vcpu);
        vmx_vcpu_guest_misc_enter(vcpu);

        while (1) {
                if (cpudata->gtlb_want_flush) {
                        vpid_desc.vpid = cpudata->asid;
                        vpid_desc.addr = 0;
                        vmx_invvpid(vmx_tlb_flush_op, &vpid_desc);
                        cpudata->gtlb_want_flush = false;
                }

                if (__predict_false(cpudata->gtsc_want_update)) {
                        vmx_vmwrite(VMCS_TSC_OFFSET, cpudata->gtsc_offset);
                        cpudata->gtsc_want_update = false;
                }

                vmx_cli();
                vmx_vcpu_guest_fpu_enter(vcpu);
                machgen = vmx_htlb_flush(mach, cpudata);

#ifdef __DragonFly__
                /*
                 * Check for pending host events (e.g., interrupt, AST)
                 * to make the state safe to VM Entry.  This check must
                 * be done after the cli to avoid gd_reqflags pending
                 * races.
                 *
                 * Emulators may assume that event injection succeeds, but
                 * we have to return to process these events.  To deal with
                 * this, use ERESTART mechanics.
                 */
                if (__predict_false(mycpu->gd_reqflags & RQF_HVM_MASK)) {
                        /* INVEPT executed, so ack hTLB flush. */
                        vmx_htlb_flush_ack(cpudata, machgen);
                        vmx_vcpu_guest_fpu_leave(vcpu);
                        vmx_sti();
                        exit->reason = NVMM_VCPU_EXIT_NONE;
                        error = ERESTART;
                        break;
                }

                /*
                 * Only commit event requests when we are absolutely
                 * sure that we can issue the vmlaunch/vmresume.
                 */
                if (__predict_false(vmx_vcpu_event_commit(vcpu) != 0)) {
                        /* INVEPT executed, so ack hTLB flush. */
                        vmx_htlb_flush_ack(cpudata, machgen);
                        vmx_vcpu_guest_fpu_leave(vcpu);
                        vmx_sti();
                        exit->reason = NVMM_VCPU_EXIT_NONE;
                        error = EINVAL;
                        break;
                }
#endif

                x86_set_cr2(cpudata->gcr2);
                if (launched) {
                        ret = vmx_vmresume(cpudata->gprs);
                } else {
                        ret = vmx_vmlaunch(cpudata->gprs);
                }
                cpudata->gcr2 = x86_get_cr2();
                vmx_htlb_flush_ack(cpudata, machgen);
                vmx_vcpu_guest_fpu_leave(vcpu);
                vmx_sti();

                if (__predict_false(ret != 0)) {
                        vmx_exit_invalid(exit, -1);
                        break;
                }
                vmx_exit_evt(cpudata);

                launched = true;

                exitcode = vmx_vmread(VMCS_EXIT_REASON);
                exitcode &= __BITS(15,0);

                switch (exitcode) {
                case VMCS_EXITCODE_EXC_NMI:
                        vmx_exit_exc_nmi(mach, vcpu, exit);
                        break;
                case VMCS_EXITCODE_EXT_INT:
                        exit->reason = NVMM_VCPU_EXIT_NONE;
                        break;
                case VMCS_EXITCODE_CPUID:
                        vmx_exit_cpuid(mach, vcpu, exit);
                        break;
                case VMCS_EXITCODE_HLT:
                        vmx_exit_hlt(mach, vcpu, exit);
                        break;
                case VMCS_EXITCODE_CR:
                        vmx_exit_cr(mach, vcpu, exit);
                        break;
                case VMCS_EXITCODE_IO:
                        vmx_exit_io(mach, vcpu, exit);
                        break;
                case VMCS_EXITCODE_RDMSR:
                        vmx_exit_rdmsr(mach, vcpu, exit);
                        break;
                case VMCS_EXITCODE_WRMSR:
                        vmx_exit_wrmsr(mach, vcpu, exit);
                        break;
                case VMCS_EXITCODE_SHUTDOWN:
                        exit->reason = NVMM_VCPU_EXIT_SHUTDOWN;
                        break;
                case VMCS_EXITCODE_MONITOR:
                        vmx_exit_insn(exit, NVMM_VCPU_EXIT_MONITOR);
                        break;
                case VMCS_EXITCODE_MWAIT:
                        vmx_exit_insn(exit, NVMM_VCPU_EXIT_MWAIT);
                        break;
                case VMCS_EXITCODE_XSETBV:
                        vmx_exit_xsetbv(mach, vcpu, exit);
                        break;
                case VMCS_EXITCODE_RDPMC:
                case VMCS_EXITCODE_RDTSCP:
                case VMCS_EXITCODE_INVVPID:
                case VMCS_EXITCODE_INVEPT:
                case VMCS_EXITCODE_VMCALL:
                case VMCS_EXITCODE_VMCLEAR:
                case VMCS_EXITCODE_VMLAUNCH:
                case VMCS_EXITCODE_VMPTRLD:
                case VMCS_EXITCODE_VMPTRST:
                case VMCS_EXITCODE_VMREAD:
                case VMCS_EXITCODE_VMRESUME:
                case VMCS_EXITCODE_VMWRITE:
                case VMCS_EXITCODE_VMXOFF:
                case VMCS_EXITCODE_VMXON:
                        vmx_inject_ud(vcpu);
                        exit->reason = NVMM_VCPU_EXIT_NONE;
                        break;
                case VMCS_EXITCODE_EPT_VIOLATION:
                        vmx_exit_epf(mach, vcpu, exit);
                        break;
                case VMCS_EXITCODE_INT_WINDOW:
                        vmx_event_waitexit_disable(vcpu, false);
                        exit->reason = NVMM_VCPU_EXIT_INT_READY;
                        break;
                case VMCS_EXITCODE_NMI_WINDOW:
                        vmx_event_waitexit_disable(vcpu, true);
                        exit->reason = NVMM_VCPU_EXIT_NMI_READY;
                        break;
                default:
                        vmx_exit_invalid(exit, exitcode);
                        break;
                }

                /* If no reason to return to userland, keep rolling. */
                if (os_return_needed()) {
                        break;
                }
                if (exit->reason != NVMM_VCPU_EXIT_NONE) {
                        break;
                }
        }

        cpudata->vmcs_launched = launched;

        vmx_vcpu_guest_misc_leave(vcpu);
        vmx_vcpu_guest_dbregs_leave(vcpu);

        exit->exitstate.rflags = vmx_vmread(VMCS_GUEST_RFLAGS);
        exit->exitstate.cr8 = cpudata->gcr8;
        intstate = vmx_vmread(VMCS_GUEST_INTERRUPTIBILITY);
        exit->exitstate.int_shadow =
            (intstate & (INT_STATE_STI|INT_STATE_MOVSS)) != 0;
        exit->exitstate.int_window_exiting = cpudata->int_window_exit;
        exit->exitstate.nmi_window_exiting = cpudata->nmi_window_exit;
        exit->exitstate.evt_pending = cpudata->evt_pending;

        vmx_vmcs_leave(vcpu);

        return error;
}

/* -------------------------------------------------------------------------- */

static void
vmx_vcpu_msr_allow(uint8_t *bitmap, uint64_t msr, bool read, bool write)
{
        uint64_t byte;
        uint8_t bitoff;

        if (msr < 0x00002000) {
                /* Range 1 */
                byte = ((msr - 0x00000000) / 8) + 0;
        } else if (msr >= 0xC0000000 && msr < 0xC0002000) {
                /* Range 2 */
                byte = ((msr - 0xC0000000) / 8) + 1024;
        } else {
                panic("%s: wrong range", __func__);
        }

        bitoff = (msr & 0x7);

        if (read) {
                bitmap[byte] &= ~__BIT(bitoff);
        }
        if (write) {
                bitmap[2048 + byte] &= ~__BIT(bitoff);
        }
}

#define VMX_SEG_ATTRIB_TYPE             __BITS(3,0)
#define VMX_SEG_ATTRIB_S                __BIT(4)
#define VMX_SEG_ATTRIB_DPL              __BITS(6,5)
#define VMX_SEG_ATTRIB_P                __BIT(7)
#define VMX_SEG_ATTRIB_AVL              __BIT(12)
#define VMX_SEG_ATTRIB_L                __BIT(13)
#define VMX_SEG_ATTRIB_DEF              __BIT(14)
#define VMX_SEG_ATTRIB_G                __BIT(15)
#define VMX_SEG_ATTRIB_UNUSABLE         __BIT(16)

static void
vmx_vcpu_setstate_seg(const struct nvmm_x64_state_seg *segs, int idx)
{
        uint64_t attrib;

        attrib =
            __SHIFTIN(segs[idx].attrib.type, VMX_SEG_ATTRIB_TYPE) |
            __SHIFTIN(segs[idx].attrib.s, VMX_SEG_ATTRIB_S) |
            __SHIFTIN(segs[idx].attrib.dpl, VMX_SEG_ATTRIB_DPL) |
            __SHIFTIN(segs[idx].attrib.p, VMX_SEG_ATTRIB_P) |
            __SHIFTIN(segs[idx].attrib.avl, VMX_SEG_ATTRIB_AVL) |
            __SHIFTIN(segs[idx].attrib.l, VMX_SEG_ATTRIB_L) |
            __SHIFTIN(segs[idx].attrib.def, VMX_SEG_ATTRIB_DEF) |
            __SHIFTIN(segs[idx].attrib.g, VMX_SEG_ATTRIB_G) |
            (!segs[idx].attrib.p ? VMX_SEG_ATTRIB_UNUSABLE : 0);

        if (idx != NVMM_X64_SEG_GDT && idx != NVMM_X64_SEG_IDT) {
                vmx_vmwrite(vmx_guest_segs[idx].selector, segs[idx].selector);
                vmx_vmwrite(vmx_guest_segs[idx].attrib, attrib);
        }
        vmx_vmwrite(vmx_guest_segs[idx].limit, segs[idx].limit);
        vmx_vmwrite(vmx_guest_segs[idx].base, segs[idx].base);
}

static void
vmx_vcpu_getstate_seg(struct nvmm_x64_state_seg *segs, int idx)
{
        uint64_t selector = 0, attrib = 0, base, limit;

        if (idx != NVMM_X64_SEG_GDT && idx != NVMM_X64_SEG_IDT) {
                selector = vmx_vmread(vmx_guest_segs[idx].selector);
                attrib = vmx_vmread(vmx_guest_segs[idx].attrib);
        }
        limit = vmx_vmread(vmx_guest_segs[idx].limit);
        base = vmx_vmread(vmx_guest_segs[idx].base);

        segs[idx].selector = selector;
        segs[idx].limit = limit;
        segs[idx].base = base;
        segs[idx].attrib.type = __SHIFTOUT(attrib, VMX_SEG_ATTRIB_TYPE);
        segs[idx].attrib.s = __SHIFTOUT(attrib, VMX_SEG_ATTRIB_S);
        segs[idx].attrib.dpl = __SHIFTOUT(attrib, VMX_SEG_ATTRIB_DPL);
        segs[idx].attrib.p = __SHIFTOUT(attrib, VMX_SEG_ATTRIB_P);
        segs[idx].attrib.avl = __SHIFTOUT(attrib, VMX_SEG_ATTRIB_AVL);
        segs[idx].attrib.l = __SHIFTOUT(attrib, VMX_SEG_ATTRIB_L);
        segs[idx].attrib.def = __SHIFTOUT(attrib, VMX_SEG_ATTRIB_DEF);
        segs[idx].attrib.g = __SHIFTOUT(attrib, VMX_SEG_ATTRIB_G);
        if (attrib & VMX_SEG_ATTRIB_UNUSABLE) {
                segs[idx].attrib.p = 0;
        }
}

static inline bool
vmx_state_gtlb_flush(const struct nvmm_x64_state *state, uint64_t flags)
{
        uint64_t cr0, cr3, cr4, efer;

        if (flags & NVMM_X64_STATE_CRS) {
                cr0 = vmx_vmread(VMCS_GUEST_CR0);
                if ((cr0 ^ state->crs[NVMM_X64_CR_CR0]) & CR0_TLB_FLUSH) {
                        return true;
                }
                cr3 = vmx_vmread(VMCS_GUEST_CR3);
                if (cr3 != state->crs[NVMM_X64_CR_CR3]) {
                        return true;
                }
                cr4 = vmx_vmread(VMCS_GUEST_CR4);
                if ((cr4 ^ state->crs[NVMM_X64_CR_CR4]) & CR4_TLB_FLUSH) {
                        return true;
                }
        }

        if (flags & NVMM_X64_STATE_MSRS) {
                efer = vmx_vmread(VMCS_GUEST_IA32_EFER);
                if ((efer ^
                     state->msrs[NVMM_X64_MSR_EFER]) & EFER_TLB_FLUSH) {
                        return true;
                }
        }

        return false;
}

static void
vmx_vcpu_setstate(struct nvmm_cpu *vcpu)
{
        struct nvmm_comm_page *comm = vcpu->comm;
        const struct nvmm_x64_state *state = &comm->state;
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        struct msr_entry *gmsr = cpudata->gmsr;
        struct nvmm_x64_state_fpu *fpustate;
        uint64_t ctls1, intstate;
        uint64_t flags;

        flags = comm->state_wanted;

        vmx_vmcs_enter(vcpu);

        if (vmx_state_gtlb_flush(state, flags)) {
                cpudata->gtlb_want_flush = true;
        }

        if (flags & NVMM_X64_STATE_SEGS) {
                vmx_vcpu_setstate_seg(state->segs, NVMM_X64_SEG_CS);
                vmx_vcpu_setstate_seg(state->segs, NVMM_X64_SEG_DS);
                vmx_vcpu_setstate_seg(state->segs, NVMM_X64_SEG_ES);
                vmx_vcpu_setstate_seg(state->segs, NVMM_X64_SEG_FS);
                vmx_vcpu_setstate_seg(state->segs, NVMM_X64_SEG_GS);
                vmx_vcpu_setstate_seg(state->segs, NVMM_X64_SEG_SS);
                vmx_vcpu_setstate_seg(state->segs, NVMM_X64_SEG_GDT);
                vmx_vcpu_setstate_seg(state->segs, NVMM_X64_SEG_IDT);
                vmx_vcpu_setstate_seg(state->segs, NVMM_X64_SEG_LDT);
                vmx_vcpu_setstate_seg(state->segs, NVMM_X64_SEG_TR);
        }

        CTASSERT(sizeof(cpudata->gprs) == sizeof(state->gprs));
        if (flags & NVMM_X64_STATE_GPRS) {
                memcpy(cpudata->gprs, state->gprs, sizeof(state->gprs));

                vmx_vmwrite(VMCS_GUEST_RIP, state->gprs[NVMM_X64_GPR_RIP]);
                vmx_vmwrite(VMCS_GUEST_RSP, state->gprs[NVMM_X64_GPR_RSP]);
                vmx_vmwrite(VMCS_GUEST_RFLAGS, state->gprs[NVMM_X64_GPR_RFLAGS]);
        }

        if (flags & NVMM_X64_STATE_CRS) {
                vmx_vmwrite(VMCS_CR0_SHADOW,
                    (state->crs[NVMM_X64_CR_CR0] & CR0_STATIC_MASK) |
                    CR0_ET);
                vmx_vmwrite(VMCS_GUEST_CR0,
                    (state->crs[NVMM_X64_CR_CR0] & ~CR0_FORCE_ZERO) |
                    CR0_FORCE_ONE);

                cpudata->gcr2 = state->crs[NVMM_X64_CR_CR2];

                /* XXX We are not handling PDPTE here. */
                vmx_vmwrite(VMCS_GUEST_CR3, state->crs[NVMM_X64_CR_CR3]);

                /* CR4_VMXE is mandatory. */
                vmx_vmwrite(VMCS_GUEST_CR4,
                    (state->crs[NVMM_X64_CR_CR4] & CR4_VALID) | CR4_VMXE);

                cpudata->gcr8 = state->crs[NVMM_X64_CR_CR8];

                if (vmx_xcr0_mask != 0) {
                        /* Clear illegal XCR0 bits, set mandatory X87 bit. */
                        cpudata->gxcr0 = state->crs[NVMM_X64_CR_XCR0];
                        cpudata->gxcr0 &= vmx_xcr0_mask;
                        cpudata->gxcr0 |= XCR0_X87;
                }
        }

        CTASSERT(sizeof(cpudata->drs) == sizeof(state->drs));
        if (flags & NVMM_X64_STATE_DRS) {
                memcpy(cpudata->drs, state->drs, sizeof(state->drs));

                cpudata->drs[NVMM_X64_DR_DR6] &= 0xFFFFFFFF;
                vmx_vmwrite(VMCS_GUEST_DR7, cpudata->drs[NVMM_X64_DR_DR7]);
        }

        if (flags & NVMM_X64_STATE_MSRS) {
                gmsr[VMX_MSRLIST_STAR].val =
                    state->msrs[NVMM_X64_MSR_STAR];
                gmsr[VMX_MSRLIST_LSTAR].val =
                    state->msrs[NVMM_X64_MSR_LSTAR];
                gmsr[VMX_MSRLIST_CSTAR].val =
                    state->msrs[NVMM_X64_MSR_CSTAR];
                gmsr[VMX_MSRLIST_SFMASK].val =
                    state->msrs[NVMM_X64_MSR_SFMASK];
                gmsr[VMX_MSRLIST_KERNELGSBASE].val =
                    state->msrs[NVMM_X64_MSR_KERNELGSBASE];

                vmx_vmwrite(VMCS_GUEST_IA32_EFER,
                    state->msrs[NVMM_X64_MSR_EFER]);
                vmx_vmwrite(VMCS_GUEST_IA32_PAT,
                    state->msrs[NVMM_X64_MSR_PAT]);
                vmx_vmwrite(VMCS_GUEST_IA32_SYSENTER_CS,
                    state->msrs[NVMM_X64_MSR_SYSENTER_CS]);
                vmx_vmwrite(VMCS_GUEST_IA32_SYSENTER_ESP,
                    state->msrs[NVMM_X64_MSR_SYSENTER_ESP]);
                vmx_vmwrite(VMCS_GUEST_IA32_SYSENTER_EIP,
                    state->msrs[NVMM_X64_MSR_SYSENTER_EIP]);

                /*
                 * The emulator might NOT want to set the TSC, because doing
                 * so would destroy TSC MP-synchronization across CPUs.  Try
                 * to figure out what the emulator meant to do.
                 *
                 * If writing the last TSC value we reported via getstate or
                 * a zero value, assume that the emulator does not want to
                 * write to the TSC.
                 */
                if (state->msrs[NVMM_X64_MSR_TSC] != cpudata->gtsc_match &&
                    state->msrs[NVMM_X64_MSR_TSC] != 0) {
                        cpudata->gtsc_offset =
                            state->msrs[NVMM_X64_MSR_TSC] - rdtsc();
                        cpudata->gtsc_want_update = true;
                }

                /* ENTRY_CTLS_LONG_MODE must match EFER_LMA. */
                ctls1 = vmx_vmread(VMCS_ENTRY_CTLS);
                if (state->msrs[NVMM_X64_MSR_EFER] & EFER_LMA) {
                        ctls1 |= ENTRY_CTLS_LONG_MODE;
                } else {
                        ctls1 &= ~ENTRY_CTLS_LONG_MODE;
                }
                vmx_vmwrite(VMCS_ENTRY_CTLS, ctls1);
        }

        if (flags & NVMM_X64_STATE_INTR) {
                intstate = vmx_vmread(VMCS_GUEST_INTERRUPTIBILITY);
                intstate &= ~(INT_STATE_STI|INT_STATE_MOVSS);
                if (state->intr.int_shadow) {
                        intstate |= INT_STATE_MOVSS;
                }
                vmx_vmwrite(VMCS_GUEST_INTERRUPTIBILITY, intstate);

                if (state->intr.int_window_exiting) {
                        vmx_event_waitexit_enable(vcpu, false);
                } else {
                        vmx_event_waitexit_disable(vcpu, false);
                }

                if (state->intr.nmi_window_exiting) {
                        vmx_event_waitexit_enable(vcpu, true);
                } else {
                        vmx_event_waitexit_disable(vcpu, true);
                }
        }

        CTASSERT(sizeof(cpudata->gxsave.fpu) == sizeof(state->fpu));
        if (flags & NVMM_X64_STATE_FPU) {
                memcpy(&cpudata->gxsave.fpu, &state->fpu, sizeof(state->fpu));

                fpustate = (struct nvmm_x64_state_fpu *)&cpudata->gxsave.fpu;
                fpustate->fx_mxcsr_mask &= x86_fpu_mxcsr_mask;
                fpustate->fx_mxcsr &= fpustate->fx_mxcsr_mask;

                if (vmx_xcr0_mask != 0) {
                        /* Reset XSTATE_BV, to force a reload. */
                        cpudata->gxsave.xstate_bv = vmx_xcr0_mask;
                }
        }

        vmx_vmcs_leave(vcpu);

        comm->state_wanted = 0;
        comm->state_cached |= flags;
}

static void
vmx_vcpu_getstate(struct nvmm_cpu *vcpu)
{
        struct nvmm_comm_page *comm = vcpu->comm;
        struct nvmm_x64_state *state = &comm->state;
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        struct msr_entry *gmsr = cpudata->gmsr;
        uint64_t intstate, flags;

        flags = comm->state_wanted;

        vmx_vmcs_enter(vcpu);

        if (flags & NVMM_X64_STATE_SEGS) {
                vmx_vcpu_getstate_seg(state->segs, NVMM_X64_SEG_CS);
                vmx_vcpu_getstate_seg(state->segs, NVMM_X64_SEG_DS);
                vmx_vcpu_getstate_seg(state->segs, NVMM_X64_SEG_ES);
                vmx_vcpu_getstate_seg(state->segs, NVMM_X64_SEG_FS);
                vmx_vcpu_getstate_seg(state->segs, NVMM_X64_SEG_GS);
                vmx_vcpu_getstate_seg(state->segs, NVMM_X64_SEG_SS);
                vmx_vcpu_getstate_seg(state->segs, NVMM_X64_SEG_GDT);
                vmx_vcpu_getstate_seg(state->segs, NVMM_X64_SEG_IDT);
                vmx_vcpu_getstate_seg(state->segs, NVMM_X64_SEG_LDT);
                vmx_vcpu_getstate_seg(state->segs, NVMM_X64_SEG_TR);
        }

        CTASSERT(sizeof(cpudata->gprs) == sizeof(state->gprs));
        if (flags & NVMM_X64_STATE_GPRS) {
                memcpy(state->gprs, cpudata->gprs, sizeof(state->gprs));

                state->gprs[NVMM_X64_GPR_RIP] = vmx_vmread(VMCS_GUEST_RIP);
                state->gprs[NVMM_X64_GPR_RSP] = vmx_vmread(VMCS_GUEST_RSP);
                state->gprs[NVMM_X64_GPR_RFLAGS] = vmx_vmread(VMCS_GUEST_RFLAGS);
        }

        if (flags & NVMM_X64_STATE_CRS) {
                state->crs[NVMM_X64_CR_CR0] =
                    (vmx_vmread(VMCS_CR0_SHADOW) & CR0_STATIC_MASK) |
                    (vmx_vmread(VMCS_GUEST_CR0) & ~CR0_STATIC_MASK);
                state->crs[NVMM_X64_CR_CR2] = cpudata->gcr2;
                state->crs[NVMM_X64_CR_CR3] = vmx_vmread(VMCS_GUEST_CR3);
                state->crs[NVMM_X64_CR_CR4] = vmx_vmread(VMCS_GUEST_CR4);
                state->crs[NVMM_X64_CR_CR8] = cpudata->gcr8;
                state->crs[NVMM_X64_CR_XCR0] = cpudata->gxcr0;

                /* Hide VMXE. */
                state->crs[NVMM_X64_CR_CR4] &= ~CR4_VMXE;
        }

        CTASSERT(sizeof(cpudata->drs) == sizeof(state->drs));
        if (flags & NVMM_X64_STATE_DRS) {
                memcpy(state->drs, cpudata->drs, sizeof(state->drs));

                state->drs[NVMM_X64_DR_DR7] = vmx_vmread(VMCS_GUEST_DR7);
        }

        if (flags & NVMM_X64_STATE_MSRS) {
                state->msrs[NVMM_X64_MSR_STAR] =
                    gmsr[VMX_MSRLIST_STAR].val;
                state->msrs[NVMM_X64_MSR_LSTAR] =
                    gmsr[VMX_MSRLIST_LSTAR].val;
                state->msrs[NVMM_X64_MSR_CSTAR] =
                    gmsr[VMX_MSRLIST_CSTAR].val;
                state->msrs[NVMM_X64_MSR_SFMASK] =
                    gmsr[VMX_MSRLIST_SFMASK].val;
                state->msrs[NVMM_X64_MSR_KERNELGSBASE] =
                    gmsr[VMX_MSRLIST_KERNELGSBASE].val;
                state->msrs[NVMM_X64_MSR_EFER] =
                    vmx_vmread(VMCS_GUEST_IA32_EFER);
                state->msrs[NVMM_X64_MSR_PAT] =
                    vmx_vmread(VMCS_GUEST_IA32_PAT);
                state->msrs[NVMM_X64_MSR_SYSENTER_CS] =
                    vmx_vmread(VMCS_GUEST_IA32_SYSENTER_CS);
                state->msrs[NVMM_X64_MSR_SYSENTER_ESP] =
                    vmx_vmread(VMCS_GUEST_IA32_SYSENTER_ESP);
                state->msrs[NVMM_X64_MSR_SYSENTER_EIP] =
                    vmx_vmread(VMCS_GUEST_IA32_SYSENTER_EIP);
                state->msrs[NVMM_X64_MSR_TSC] = rdtsc() + cpudata->gtsc_offset;

                /* Save reported TSC value for later setstate check. */
                cpudata->gtsc_match = state->msrs[NVMM_X64_MSR_TSC];
        }

        if (flags & NVMM_X64_STATE_INTR) {
                intstate = vmx_vmread(VMCS_GUEST_INTERRUPTIBILITY);
                state->intr.int_shadow =
                    (intstate & (INT_STATE_STI|INT_STATE_MOVSS)) != 0;
                state->intr.int_window_exiting = cpudata->int_window_exit;
                state->intr.nmi_window_exiting = cpudata->nmi_window_exit;
                state->intr.evt_pending = cpudata->evt_pending;
        }

        CTASSERT(sizeof(cpudata->gxsave.fpu) == sizeof(state->fpu));
        if (flags & NVMM_X64_STATE_FPU) {
                memcpy(&state->fpu, &cpudata->gxsave.fpu, sizeof(state->fpu));
        }

        vmx_vmcs_leave(vcpu);

        comm->state_wanted = 0;
        comm->state_cached |= flags;
}

static void
vmx_vcpu_state_provide(struct nvmm_cpu *vcpu, uint64_t flags)
{
        vcpu->comm->state_wanted = flags;
        vmx_vcpu_getstate(vcpu);
}

static void
vmx_vcpu_state_commit(struct nvmm_cpu *vcpu)
{
        vcpu->comm->state_wanted = vcpu->comm->state_commit;
        vcpu->comm->state_commit = 0;
        vmx_vcpu_setstate(vcpu);
}

/* -------------------------------------------------------------------------- */

static void
vmx_asid_alloc(struct nvmm_cpu *vcpu)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        size_t i, oct, bit;

        os_mtx_lock(&vmx_asidlock);

        for (i = 0; i < vmx_maxasid; i++) {
                oct = i / 8;
                bit = i % 8;

                if (vmx_asidmap[oct] & __BIT(bit)) {
                        continue;
                }

                cpudata->asid = i;

                vmx_asidmap[oct] |= __BIT(bit);
                vmx_vmwrite(VMCS_VPID, i);
                os_mtx_unlock(&vmx_asidlock);
                return;
        }

        os_mtx_unlock(&vmx_asidlock);

        panic("%s: impossible", __func__);
}

static void
vmx_asid_free(struct nvmm_cpu *vcpu)
{
        size_t oct, bit;
        uint64_t asid;

        asid = vmx_vmread(VMCS_VPID);

        oct = asid / 8;
        bit = asid % 8;

        os_mtx_lock(&vmx_asidlock);
        vmx_asidmap[oct] &= ~__BIT(bit);
        os_mtx_unlock(&vmx_asidlock);
}

static void
vmx_vcpu_init(struct nvmm_machine *mach, struct nvmm_cpu *vcpu)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;
        struct vmcs *vmcs = cpudata->vmcs;
        struct msr_entry *gmsr = cpudata->gmsr;
        uint64_t rev, eptp;

        rev = vmx_get_revision();

        memset(vmcs, 0, VMCS_SIZE);
        vmcs->ident = __SHIFTIN(rev, VMCS_IDENT_REVISION);
        vmcs->abort = 0;

        vmx_vmcs_enter(vcpu);

        /* No link pointer. */
        vmx_vmwrite(VMCS_LINK_POINTER, 0xFFFFFFFFFFFFFFFFULL);

        /* Install the CTLSs. */
        vmx_vmwrite(VMCS_PINBASED_CTLS, vmx_pinbased_ctls);
        vmx_vmwrite(VMCS_PROCBASED_CTLS, vmx_procbased_ctls);
        vmx_vmwrite(VMCS_PROCBASED_CTLS2, vmx_procbased_ctls2);
        vmx_vmwrite(VMCS_ENTRY_CTLS, vmx_entry_ctls);
        vmx_vmwrite(VMCS_EXIT_CTLS, vmx_exit_ctls);

        /* Allow direct access to certain MSRs. */
        memset(cpudata->msrbm, 0xFF, MSRBM_SIZE);
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_EFER, true, true);
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_STAR, true, true);
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_LSTAR, true, true);
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_CSTAR, true, true);
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_SFMASK, true, true);
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_KERNELGSBASE, true, true);
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_SYSENTER_CS, true, true);
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_SYSENTER_ESP, true, true);
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_SYSENTER_EIP, true, true);
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_FSBASE, true, true);
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_GSBASE, true, true);
        vmx_vcpu_msr_allow(cpudata->msrbm, MSR_TSC, true, false);
        vmx_vmwrite(VMCS_MSR_BITMAP, (uint64_t)cpudata->msrbm_pa);

        /*
         * List of Guest MSRs loaded on VMENTRY, saved on VMEXIT. This
         * includes the L1D_FLUSH MSR, to mitigate L1TF.
         */
        gmsr[VMX_MSRLIST_STAR].msr = MSR_STAR;
        gmsr[VMX_MSRLIST_STAR].val = 0;
        gmsr[VMX_MSRLIST_LSTAR].msr = MSR_LSTAR;
        gmsr[VMX_MSRLIST_LSTAR].val = 0;
        gmsr[VMX_MSRLIST_CSTAR].msr = MSR_CSTAR;
        gmsr[VMX_MSRLIST_CSTAR].val = 0;
        gmsr[VMX_MSRLIST_SFMASK].msr = MSR_SFMASK;
        gmsr[VMX_MSRLIST_SFMASK].val = 0;
        gmsr[VMX_MSRLIST_KERNELGSBASE].msr = MSR_KERNELGSBASE;
        gmsr[VMX_MSRLIST_KERNELGSBASE].val = 0;
        gmsr[VMX_MSRLIST_L1DFLUSH].msr = MSR_IA32_FLUSH_CMD;
        gmsr[VMX_MSRLIST_L1DFLUSH].val = IA32_FLUSH_CMD_L1D_FLUSH;
        vmx_vmwrite(VMCS_ENTRY_MSR_LOAD_ADDRESS, cpudata->gmsr_pa);
        vmx_vmwrite(VMCS_EXIT_MSR_STORE_ADDRESS, cpudata->gmsr_pa);
        vmx_vmwrite(VMCS_ENTRY_MSR_LOAD_COUNT, vmx_msrlist_entry_nmsr);
        vmx_vmwrite(VMCS_EXIT_MSR_STORE_COUNT, VMX_MSRLIST_EXIT_NMSR);

        /* Set the CR0 mask. Any change of these bits causes a VMEXIT. */
        vmx_vmwrite(VMCS_CR0_MASK, CR0_STATIC_MASK);

        /* Force unsupported CR4 fields to zero. */
        vmx_vmwrite(VMCS_CR4_MASK, CR4_INVALID);
        vmx_vmwrite(VMCS_CR4_SHADOW, 0);

        /* Set the Host state for resuming. */
        vmx_vmwrite(VMCS_HOST_RIP, (uint64_t)(uintptr_t)vmx_resume_rip);
        vmx_vmwrite(VMCS_HOST_CS_SELECTOR, GSEL(GCODE_SEL, SEL_KPL));
        vmx_vmwrite(VMCS_HOST_SS_SELECTOR, GSEL(GDATA_SEL, SEL_KPL));
        vmx_vmwrite(VMCS_HOST_DS_SELECTOR, GSEL(GDATA_SEL, SEL_KPL));
        vmx_vmwrite(VMCS_HOST_ES_SELECTOR, GSEL(GDATA_SEL, SEL_KPL));
        vmx_vmwrite(VMCS_HOST_FS_SELECTOR, 0);
        vmx_vmwrite(VMCS_HOST_GS_SELECTOR, 0);
        vmx_vmwrite(VMCS_HOST_IA32_SYSENTER_CS, 0);
        vmx_vmwrite(VMCS_HOST_IA32_SYSENTER_ESP, 0);
        vmx_vmwrite(VMCS_HOST_IA32_SYSENTER_EIP, 0);
        vmx_vmwrite(VMCS_HOST_IA32_PAT, rdmsr(MSR_CR_PAT));
        vmx_vmwrite(VMCS_HOST_IA32_EFER, rdmsr(MSR_EFER));
        vmx_vmwrite(VMCS_HOST_CR0, x86_get_cr0() & ~CR0_TS);

        /* Generate ASID. */
        vmx_asid_alloc(vcpu);

        /* Enable Extended Paging, 4-Level. */
        eptp =
            __SHIFTIN(vmx_eptp_type, EPTP_TYPE) |
            __SHIFTIN(4-1, EPTP_WALKLEN) |
            (vmx_ept_has_ad ? EPTP_FLAGS_AD : 0) |
            os_vmspace_pdirpa(mach->vm);
        vmx_vmwrite(VMCS_EPTP, eptp);

        /* Init IA32_MISC_ENABLE. */
        cpudata->gmsr_misc_enable = rdmsr(MSR_IA32_MISC_ENABLE);
        cpudata->gmsr_misc_enable &=
            ~(IA32_MISC_PERFMON_EN|IA32_MISC_EISST_EN|IA32_MISC_MWAIT_EN);
        cpudata->gmsr_misc_enable |=
            (IA32_MISC_BTS_UNAVAIL|IA32_MISC_PEBS_UNAVAIL);

        /* Init XSAVE header. */
        cpudata->gxsave.xstate_bv = vmx_xcr0_mask;
        cpudata->gxsave.xcomp_bv = 0;

        /* Install the RESET state. */
        memcpy(&vcpu->comm->state, &nvmm_x86_reset_state,
            sizeof(nvmm_x86_reset_state));
        vcpu->comm->state_wanted = NVMM_X64_STATE_ALL;
        vcpu->comm->state_cached = 0;
        vmx_vcpu_setstate(vcpu);

        vmx_vmcs_leave(vcpu);
}

static int
vmx_vcpu_create(struct nvmm_machine *mach, struct nvmm_cpu *vcpu)
{
        struct vmx_cpudata *cpudata;
        int error;

        /* Allocate the VMX cpudata. */
        cpudata = (struct vmx_cpudata *)os_pagemem_zalloc(sizeof(*cpudata));
        if (cpudata == NULL)
                return ENOMEM;

        vcpu->cpudata = cpudata;

        /* VMCS */
        error = os_contigpa_zalloc(&cpudata->vmcs_pa,
            (vaddr_t *)&cpudata->vmcs, VMCS_NPAGES);
        if (error)
                goto error;

        /* MSR Bitmap */
        error = os_contigpa_zalloc(&cpudata->msrbm_pa,
            (vaddr_t *)&cpudata->msrbm, MSRBM_NPAGES);
        if (error)
                goto error;

        /* Guest MSR List */
        error = os_contigpa_zalloc(&cpudata->gmsr_pa,
            (vaddr_t *)&cpudata->gmsr, 1);
        if (error)
                goto error;

        os_cpuset_init(&cpudata->htlb_want_flush);

        /* Init the VCPU info. */
        vmx_vcpu_init(mach, vcpu);

        return 0;

error:
        if (cpudata->vmcs_pa) {
                os_contigpa_free(cpudata->vmcs_pa, (vaddr_t)cpudata->vmcs,
                    VMCS_NPAGES);
        }
        if (cpudata->msrbm_pa) {
                os_contigpa_free(cpudata->msrbm_pa, (vaddr_t)cpudata->msrbm,
                    MSRBM_NPAGES);
        }
        if (cpudata->gmsr_pa) {
                os_contigpa_free(cpudata->gmsr_pa, (vaddr_t)cpudata->gmsr, 1);
        }
        os_pagemem_free(cpudata, sizeof(*cpudata));
        return error;
}

static void
vmx_vcpu_destroy(struct nvmm_machine *mach, struct nvmm_cpu *vcpu)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;

        vmx_vmcs_enter(vcpu);
        vmx_asid_free(vcpu);
        vmx_vmcs_destroy(vcpu);

        os_cpuset_destroy(cpudata->htlb_want_flush);

        os_contigpa_free(cpudata->vmcs_pa, (vaddr_t)cpudata->vmcs,
            VMCS_NPAGES);
        os_contigpa_free(cpudata->msrbm_pa, (vaddr_t)cpudata->msrbm,
            MSRBM_NPAGES);
        os_contigpa_free(cpudata->gmsr_pa, (vaddr_t)cpudata->gmsr,
            1);
        os_pagemem_free(cpudata, sizeof(*cpudata));
}

/* -------------------------------------------------------------------------- */

static int
vmx_vcpu_configure_cpuid(struct vmx_cpudata *cpudata, void *data)
{
        struct nvmm_vcpu_conf_cpuid *cpuid = data;
        size_t i;

        if (__predict_false(cpuid->mask && cpuid->exit)) {
                return EINVAL;
        }
        if (__predict_false(cpuid->mask &&
            ((cpuid->u.mask.set.eax & cpuid->u.mask.del.eax) ||
             (cpuid->u.mask.set.ebx & cpuid->u.mask.del.ebx) ||
             (cpuid->u.mask.set.ecx & cpuid->u.mask.del.ecx) ||
             (cpuid->u.mask.set.edx & cpuid->u.mask.del.edx)))) {
                return EINVAL;
        }

        /* If unset, delete, to restore the default behavior. */
        if (!cpuid->mask && !cpuid->exit) {
                for (i = 0; i < VMX_NCPUIDS; i++) {
                        if (!cpudata->cpuidpresent[i]) {
                                continue;
                        }
                        if (cpudata->cpuid[i].leaf == cpuid->leaf) {
                                cpudata->cpuidpresent[i] = false;
                        }
                }
                return 0;
        }

        /* If already here, replace. */
        for (i = 0; i < VMX_NCPUIDS; i++) {
                if (!cpudata->cpuidpresent[i]) {
                        continue;
                }
                if (cpudata->cpuid[i].leaf == cpuid->leaf) {
                        memcpy(&cpudata->cpuid[i], cpuid,
                            sizeof(struct nvmm_vcpu_conf_cpuid));
                        return 0;
                }
        }

        /* Not here, insert. */
        for (i = 0; i < VMX_NCPUIDS; i++) {
                if (!cpudata->cpuidpresent[i]) {
                        cpudata->cpuidpresent[i] = true;
                        memcpy(&cpudata->cpuid[i], cpuid,
                            sizeof(struct nvmm_vcpu_conf_cpuid));
                        return 0;
                }
        }

        return ENOBUFS;
}

static int
vmx_vcpu_configure_tpr(struct vmx_cpudata *cpudata, void *data)
{
        struct nvmm_vcpu_conf_tpr *tpr = data;

        memcpy(&cpudata->tpr, tpr, sizeof(*tpr));
        return 0;
}

static int
vmx_vcpu_configure(struct nvmm_cpu *vcpu, uint64_t op, void *data)
{
        struct vmx_cpudata *cpudata = vcpu->cpudata;

        switch (op) {
        case NVMM_VCPU_CONF_MD(NVMM_VCPU_CONF_CPUID):
                return vmx_vcpu_configure_cpuid(cpudata, data);
        case NVMM_VCPU_CONF_MD(NVMM_VCPU_CONF_TPR):
                return vmx_vcpu_configure_tpr(cpudata, data);
        default:
                return EINVAL;
        }
}

/* -------------------------------------------------------------------------- */

#ifdef __NetBSD__
static void
vmx_tlb_flush(struct pmap *pm)
{
        struct nvmm_machine *mach = os_pmap_mach(pm);
        struct vmx_machdata *machdata = mach->machdata;

        os_atomic_inc_64(&machdata->mach_htlb_gen);

        /*
         * Send a dummy IPI to each CPU. The IPIs cause #VMEXITs. Afterwards the
         * VCPU loops will see that their 'vcpu_htlb_gen' is out of sync, and
         * will each flush their own TLB.
         */
        os_ipi_kickall();
}
#endif

static void
vmx_machine_create(struct nvmm_machine *mach)
{
        struct pmap *pmap = os_vmspace_pmap(mach->vm);
        struct vmx_machdata *machdata;

        /* Transform into an EPT pmap. */
#if defined(__NetBSD__)
        pmap_ept_transform(pmap);
        os_pmap_mach(pmap) = (void *)mach;
        pmap->pm_tlb_flush = vmx_tlb_flush;
#elif defined(__DragonFly__)
        pmap_ept_transform(pmap, vmx_ept_has_ad ? 0 : PMAP_EMULATE_AD_BITS);
#endif

        machdata = os_mem_zalloc(sizeof(struct vmx_machdata));
        mach->machdata = machdata;

        /* Start with an hTLB flush everywhere. */
        machdata->mach_htlb_gen = 1;
}

static void
vmx_machine_destroy(struct nvmm_machine *mach)
{
        os_mem_free(mach->machdata, sizeof(struct vmx_machdata));
}

static int
vmx_machine_configure(struct nvmm_machine *mach, uint64_t op, void *data)
{
        panic("%s: impossible", __func__);
}

/* -------------------------------------------------------------------------- */

#define CTLS_ONE_ALLOWED(msrval, bitoff) \
        ((msrval & __BIT(32 + bitoff)) != 0)
#define CTLS_ZERO_ALLOWED(msrval, bitoff) \
        ((msrval & __BIT(bitoff)) == 0)

static int
vmx_check_ctls(uint64_t msr_ctls, uint64_t msr_true_ctls, uint64_t set_one)
{
        uint64_t basic, val, true_val;
        bool has_true;
        size_t i;

        basic = rdmsr(MSR_IA32_VMX_BASIC);
        has_true = (basic & IA32_VMX_BASIC_TRUE_CTLS) != 0;

        val = rdmsr(msr_ctls);
        if (has_true) {
                true_val = rdmsr(msr_true_ctls);
        } else {
                true_val = val;
        }

        for (i = 0; i < 32; i++) {
                if (!(set_one & __BIT(i))) {
                        continue;
                }
                if (!CTLS_ONE_ALLOWED(true_val, i)) {
                        return -1;
                }
        }

        return 0;
}

static int
vmx_init_ctls(uint64_t msr_ctls, uint64_t msr_true_ctls,
    uint64_t set_one, uint64_t set_zero, uint64_t *res)
{
        uint64_t basic, val, true_val;
        bool one_allowed, zero_allowed, has_true;
        size_t i;

        basic = rdmsr(MSR_IA32_VMX_BASIC);
        has_true = (basic & IA32_VMX_BASIC_TRUE_CTLS) != 0;

        val = rdmsr(msr_ctls);
        if (has_true) {
                true_val = rdmsr(msr_true_ctls);
        } else {
                true_val = val;
        }

        for (i = 0; i < 32; i++) {
                one_allowed = CTLS_ONE_ALLOWED(true_val, i);
                zero_allowed = CTLS_ZERO_ALLOWED(true_val, i);

                if (zero_allowed && !one_allowed) {
                        if (set_one & __BIT(i))
                                return -1;
                        *res &= ~__BIT(i);
                } else if (one_allowed && !zero_allowed) {
                        if (set_zero & __BIT(i))
                                return -1;
                        *res |= __BIT(i);
                } else {
                        if (set_zero & __BIT(i)) {
                                *res &= ~__BIT(i);
                        } else if (set_one & __BIT(i)) {
                                *res |= __BIT(i);
                        } else if (!has_true) {
                                *res &= ~__BIT(i);
                        } else if (CTLS_ZERO_ALLOWED(val, i)) {
                                *res &= ~__BIT(i);
                        } else if (CTLS_ONE_ALLOWED(val, i)) {
                                *res |= __BIT(i);
                        } else {
                                return -1;
                        }
                }
        }

        return 0;
}

static bool
vmx_ident(void)
{
        cpuid_desc_t descs;
        uint64_t msr;
        int ret;

        x86_get_cpuid(0x00000001, &descs);
        if (!(descs.ecx & CPUID_0_01_ECX_VMX)) {
                return false;
        }

        msr = rdmsr(MSR_IA32_FEATURE_CONTROL);
        if ((msr & IA32_FEATURE_CONTROL_LOCK) != 0 &&
            (msr & IA32_FEATURE_CONTROL_OUT_SMX) == 0) {
                os_printf("nvmm: VMX disabled in BIOS\n");
                return false;
        }

        msr = rdmsr(MSR_IA32_VMX_BASIC);
        if ((msr & IA32_VMX_BASIC_IO_REPORT) == 0) {
                os_printf("nvmm: I/O reporting not supported\n");
                return false;
        }
        if (__SHIFTOUT(msr, IA32_VMX_BASIC_MEM_TYPE) != MEM_TYPE_WB) {
                os_printf("nvmm: WB memory not supported\n");
                return false;
        }

        /* PG and PE are reported, even if Unrestricted Guests is supported. */
        vmx_cr0_fixed0 = rdmsr(MSR_IA32_VMX_CR0_FIXED0) & ~(CR0_PG|CR0_PE);
        vmx_cr0_fixed1 = rdmsr(MSR_IA32_VMX_CR0_FIXED1) | (CR0_PG|CR0_PE);
        ret = vmx_check_cr(x86_get_cr0(), vmx_cr0_fixed0, vmx_cr0_fixed1);
        if (ret == -1) {
                os_printf("nvmm: CR0 requirements not satisfied\n");
                return false;
        }

        vmx_cr4_fixed0 = rdmsr(MSR_IA32_VMX_CR4_FIXED0);
        vmx_cr4_fixed1 = rdmsr(MSR_IA32_VMX_CR4_FIXED1);
        ret = vmx_check_cr(x86_get_cr4() | CR4_VMXE, vmx_cr4_fixed0,
            vmx_cr4_fixed1);
        if (ret == -1) {
                os_printf("nvmm: CR4 requirements not satisfied\n");
                return false;
        }

        /* Init the CTLSs right now, and check for errors. */
        ret = vmx_init_ctls(
            MSR_IA32_VMX_PINBASED_CTLS, MSR_IA32_VMX_TRUE_PINBASED_CTLS,
            VMX_PINBASED_CTLS_ONE, VMX_PINBASED_CTLS_ZERO,
            &vmx_pinbased_ctls);
        if (ret == -1) {
                os_printf("nvmm: pin-based-ctls requirements not satisfied\n");
                return false;
        }
        ret = vmx_init_ctls(
            MSR_IA32_VMX_PROCBASED_CTLS, MSR_IA32_VMX_TRUE_PROCBASED_CTLS,
            VMX_PROCBASED_CTLS_ONE, VMX_PROCBASED_CTLS_ZERO,
            &vmx_procbased_ctls);
        if (ret == -1) {
                os_printf("nvmm: proc-based-ctls requirements not satisfied\n");
                return false;
        }
        ret = vmx_init_ctls(
            MSR_IA32_VMX_PROCBASED_CTLS2, MSR_IA32_VMX_PROCBASED_CTLS2,
            VMX_PROCBASED_CTLS2_ONE, VMX_PROCBASED_CTLS2_ZERO,
            &vmx_procbased_ctls2);
        if (ret == -1) {
                os_printf("nvmm: proc-based-ctls2 requirements not satisfied\n");
                return false;
        }
        ret = vmx_check_ctls(
            MSR_IA32_VMX_PROCBASED_CTLS2, MSR_IA32_VMX_PROCBASED_CTLS2,
            PROC_CTLS2_INVPCID_ENABLE);
        if (ret != -1) {
                vmx_procbased_ctls2 |= PROC_CTLS2_INVPCID_ENABLE;
        }
        ret = vmx_init_ctls(
            MSR_IA32_VMX_ENTRY_CTLS, MSR_IA32_VMX_TRUE_ENTRY_CTLS,
            VMX_ENTRY_CTLS_ONE, VMX_ENTRY_CTLS_ZERO,
            &vmx_entry_ctls);
        if (ret == -1) {
                os_printf("nvmm: entry-ctls requirements not satisfied\n");
                return false;
        }
        ret = vmx_init_ctls(
            MSR_IA32_VMX_EXIT_CTLS, MSR_IA32_VMX_TRUE_EXIT_CTLS,
            VMX_EXIT_CTLS_ONE, VMX_EXIT_CTLS_ZERO,
            &vmx_exit_ctls);
        if (ret == -1) {
                os_printf("nvmm: exit-ctls requirements not satisfied\n");
                return false;
        }

        msr = rdmsr(MSR_IA32_VMX_EPT_VPID_CAP);
        if ((msr & IA32_VMX_EPT_VPID_WALKLENGTH_4) == 0) {
                os_printf("nvmm: 4-level page tree not supported\n");
                return false;
        }
        if ((msr & IA32_VMX_EPT_VPID_INVEPT) == 0) {
                os_printf("nvmm: INVEPT not supported\n");
                return false;
        }
        if ((msr & IA32_VMX_EPT_VPID_INVVPID) == 0) {
                os_printf("nvmm: INVVPID not supported\n");
                return false;
        }
        if ((msr & IA32_VMX_EPT_VPID_FLAGS_AD) != 0) {
                vmx_ept_has_ad = true;
        } else {
                vmx_ept_has_ad = false;
        }
#ifdef __NetBSD__
        pmap_ept_has_ad = vmx_ept_has_ad;
#endif
        if (!(msr & IA32_VMX_EPT_VPID_UC) && !(msr & IA32_VMX_EPT_VPID_WB)) {
                os_printf("nvmm: EPT UC/WB memory types not supported\n");
                return false;
        }

        vmx_cpu_has_arch_cap = false;
        x86_get_cpuid(0x00000000, &descs);
        if (descs.eax >= 7) {
                x86_get_cpuid(0x00000007, &descs);
                if (descs.edx & CPUID_0_07_EDX_ARCH_CAP) {
                        vmx_cpu_has_arch_cap = true;
                }
        }

        return true;
}

static void
vmx_init_asid(uint32_t maxasid)
{
        size_t allocsz;

        os_mtx_init(&vmx_asidlock);

        vmx_maxasid = maxasid;
        allocsz = roundup(maxasid, 8) / 8;
        vmx_asidmap = os_mem_zalloc(allocsz);

        /* ASID 0 is reserved for the host. */
        vmx_asidmap[0] |= __BIT(0);
}

static
OS_IPI_FUNC(vmx_change_cpu)
{
        bool enable = arg != NULL;
        uint64_t msr, cr4;

        if (enable) {
                msr = rdmsr(MSR_IA32_FEATURE_CONTROL);
                if ((msr & IA32_FEATURE_CONTROL_LOCK) == 0) {
                        /* Lock now, with VMX-outside-SMX enabled. */
                        wrmsr(MSR_IA32_FEATURE_CONTROL, msr |
                            IA32_FEATURE_CONTROL_LOCK |
                            IA32_FEATURE_CONTROL_OUT_SMX);
                }
        }

        if (!enable) {
                vmx_vmxoff();
        }

        cr4 = x86_get_cr4();
        if (enable) {
                cr4 |= CR4_VMXE;
        } else {
                cr4 &= ~CR4_VMXE;
        }
        x86_set_cr4(cr4);

        if (enable) {
                vmx_vmxon(&vmxoncpu[os_curcpu_number()].pa);
        }
}

static void
vmx_init_l1tf(void)
{
        cpuid_desc_t descs;
        uint64_t msr;

        x86_get_cpuid(0x00000000, &descs);
        if (descs.eax < 7) {
                return;
        }

        x86_get_cpuid(0x00000007, &descs);

        if (descs.edx & CPUID_0_07_EDX_ARCH_CAP) {
                msr = rdmsr(MSR_IA32_ARCH_CAPABILITIES);
                if (msr & IA32_ARCH_SKIP_L1DFL_VMENTRY) {
                        /* No mitigation needed. */
                        return;
                }
        }

        if (descs.edx & CPUID_0_07_EDX_L1D_FLUSH) {
                /* Enable hardware mitigation. */
                vmx_msrlist_entry_nmsr += 1;
        }
}

static void
vmx_init(void)
{
        struct vmxon *vmxon;
        uint32_t revision;
        cpuid_desc_t descs;
        os_cpu_t *cpu;
        uint64_t msr;
        paddr_t pa;
        vaddr_t va;
        int error;

        /* Init the ASID bitmap (VPID). */
        vmx_init_asid(VPID_MAX);

        /* Init the XCR0 mask. */
        vmx_xcr0_mask = VMX_XCR0_MASK_DEFAULT & x86_xsave_features;

        /* Init the max basic CPUID leaf. */
        x86_get_cpuid(0x00000000, &descs);
        vmx_cpuid_max_basic = uimin(descs.eax, VMX_CPUID_MAX_BASIC);

        /* Init the max extended CPUID leaf. */
        x86_get_cpuid(0x80000000, &descs);
        vmx_cpuid_max_extended = uimin(descs.eax, VMX_CPUID_MAX_EXTENDED);

        /* Init the TLB flush op, the EPT flush op and the EPTP type. */
        msr = rdmsr(MSR_IA32_VMX_EPT_VPID_CAP);
        if ((msr & IA32_VMX_EPT_VPID_INVVPID_CONTEXT) != 0) {
                vmx_tlb_flush_op = VMX_INVVPID_CONTEXT;
        } else {
                vmx_tlb_flush_op = VMX_INVVPID_ALL;
        }
        if ((msr & IA32_VMX_EPT_VPID_INVEPT_CONTEXT) != 0) {
                vmx_ept_flush_op = VMX_INVEPT_CONTEXT;
        } else {
                vmx_ept_flush_op = VMX_INVEPT_ALL;
        }
        if ((msr & IA32_VMX_EPT_VPID_WB) != 0) {
                vmx_eptp_type = EPTP_TYPE_WB;
        } else {
                vmx_eptp_type = EPTP_TYPE_UC;
        }

        /* Init the L1TF mitigation. */
        vmx_init_l1tf();

        /* Init the global host state. */
        if (vmx_xcr0_mask != 0) {
                vmx_global_hstate.xcr0 = x86_get_xcr(0);
        }
        vmx_global_hstate.star = rdmsr(MSR_STAR);
        vmx_global_hstate.lstar = rdmsr(MSR_LSTAR);
        vmx_global_hstate.cstar = rdmsr(MSR_CSTAR);
        vmx_global_hstate.sfmask = rdmsr(MSR_SFMASK);

        memset(vmxoncpu, 0, sizeof(vmxoncpu));
        revision = vmx_get_revision();

        OS_CPU_FOREACH(cpu) {
                error = os_contigpa_zalloc(&pa, &va, 1);
                if (error) {
                        panic("%s: out of memory", __func__);
                }
                vmxoncpu[os_cpu_number(cpu)].pa = pa;
                vmxoncpu[os_cpu_number(cpu)].va = va;

                vmxon = (struct vmxon *)vmxoncpu[os_cpu_number(cpu)].va;
                vmxon->ident = __SHIFTIN(revision, VMXON_IDENT_REVISION);
        }

        os_ipi_broadcast(vmx_change_cpu, (void *)true);
}

static void
vmx_fini_asid(void)
{
        size_t allocsz;

        allocsz = roundup(vmx_maxasid, 8) / 8;
        os_mem_free(vmx_asidmap, allocsz);

        os_mtx_destroy(&vmx_asidlock);
}

static void
vmx_fini(void)
{
        size_t i;

        os_ipi_broadcast(vmx_change_cpu, (void *)false);

        for (i = 0; i < OS_MAXCPUS; i++) {
                if (vmxoncpu[i].pa != 0)
                        os_contigpa_free(vmxoncpu[i].pa, vmxoncpu[i].va, 1);
        }

        vmx_fini_asid();
}

static void
vmx_capability(struct nvmm_capability *cap)
{
        cap->arch.mach_conf_support = 0;
        cap->arch.vcpu_conf_support =
            NVMM_CAP_ARCH_VCPU_CONF_CPUID |
            NVMM_CAP_ARCH_VCPU_CONF_TPR;
        cap->arch.xcr0_mask = vmx_xcr0_mask;
        cap->arch.mxcsr_mask = x86_fpu_mxcsr_mask;
        cap->arch.conf_cpuid_maxops = VMX_NCPUIDS;
}

const struct nvmm_impl nvmm_x86_vmx = {
        .name = "x86-vmx",
        .ident = vmx_ident,
        .init = vmx_init,
        .fini = vmx_fini,
        .capability = vmx_capability,
        .mach_conf_max = NVMM_X86_MACH_NCONF,
        .mach_conf_sizes = NULL,
        .vcpu_conf_max = NVMM_X86_VCPU_NCONF,
        .vcpu_conf_sizes = vmx_vcpu_conf_sizes,
        .state_size = sizeof(struct nvmm_x64_state),
        .machine_create = vmx_machine_create,
        .machine_destroy = vmx_machine_destroy,
        .machine_configure = vmx_machine_configure,
        .vcpu_create = vmx_vcpu_create,
        .vcpu_destroy = vmx_vcpu_destroy,
        .vcpu_configure = vmx_vcpu_configure,
        .vcpu_setstate = vmx_vcpu_setstate,
        .vcpu_getstate = vmx_vcpu_getstate,
        .vcpu_inject = vmx_vcpu_inject,
        .vcpu_run = vmx_vcpu_run
};