arch/x86/kvm/vmx.c

/*
 * Kernel-based Virtual Machine driver for Linux
 *
 * This module enables machines with Intel VT-x extensions to run virtual
 * machines without emulation or binary translation.
 *
 * Copyright (C) 2006 Qumranet, Inc.
 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
 *
 * Authors:
 *   Avi Kivity   <avi@qumranet.com>
 *   Yaniv Kamay  <yaniv@qumranet.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 *
 */

#include "irq.h"
#include "mmu.h"
#include "cpuid.h"

#include <linux/kvm_host.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/sched.h>
#include <linux/moduleparam.h>
#include <linux/ftrace_event.h>
#include <linux/slab.h>
#include <linux/tboot.h>
#include "kvm_cache_regs.h"
#include "x86.h"

#include <asm/io.h>
#include <asm/desc.h>
#include <asm/vmx.h>
#include <asm/virtext.h>
#include <asm/mce.h>
#include <asm/i387.h>
#include <asm/xcr.h>
#include <asm/perf_event.h>

#include "trace.h"

#define __ex(x) __kvm_handle_fault_on_reboot(x)
#define __ex_clear(x, reg) \
	____kvm_handle_fault_on_reboot(x, "xor " reg " , " reg)

MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");

static bool __read_mostly enable_vpid = 1;
module_param_named(vpid, enable_vpid, bool, 0444);

static bool __read_mostly flexpriority_enabled = 1;
module_param_named(flexpriority, flexpriority_enabled, bool, S_IRUGO);

static bool __read_mostly enable_ept = 1;
module_param_named(ept, enable_ept, bool, S_IRUGO);

static bool __read_mostly enable_unrestricted_guest = 1;
module_param_named(unrestricted_guest,
			enable_unrestricted_guest, bool, S_IRUGO);

static bool __read_mostly emulate_invalid_guest_state = 0;
module_param(emulate_invalid_guest_state, bool, S_IRUGO);

static bool __read_mostly vmm_exclusive = 1;
module_param(vmm_exclusive, bool, S_IRUGO);

static bool __read_mostly fasteoi = 1;
module_param(fasteoi, bool, S_IRUGO);

/*
 * If nested=1, nested virtualization is supported, i.e., guests may use
 * VMX and be a hypervisor for its own guests. If nested=0, guests may not
 * use VMX instructions.
 */
static bool __read_mostly nested = 0;
module_param(nested, bool, S_IRUGO);

#define KVM_GUEST_CR0_MASK_UNRESTRICTED_GUEST				\
	(X86_CR0_WP | X86_CR0_NE | X86_CR0_NW | X86_CR0_CD)
#define KVM_GUEST_CR0_MASK						\
	(KVM_GUEST_CR0_MASK_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE)
#define KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST				\
	(X86_CR0_WP | X86_CR0_NE)
#define KVM_VM_CR0_ALWAYS_ON						\
	(KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE)
#define KVM_CR4_GUEST_OWNED_BITS				      \
	(X86_CR4_PVI | X86_CR4_DE | X86_CR4_PCE | X86_CR4_OSFXSR      \
	 | X86_CR4_OSXMMEXCPT)

#define KVM_PMODE_VM_CR4_ALWAYS_ON (X86_CR4_PAE | X86_CR4_VMXE)
#define KVM_RMODE_VM_CR4_ALWAYS_ON (X86_CR4_VME | X86_CR4_PAE | X86_CR4_VMXE)

#define RMODE_GUEST_OWNED_EFLAGS_BITS (~(X86_EFLAGS_IOPL | X86_EFLAGS_VM))

/*
 * These 2 parameters are used to config the controls for Pause-Loop Exiting:
 * ple_gap:    upper bound on the amount of time between two successive
 *             executions of PAUSE in a loop. Also indicate if ple enabled.
 *             According to test, this time is usually smaller than 128 cycles.
 * ple_window: upper bound on the amount of time a guest is allowed to execute
 *             in a PAUSE loop. Tests indicate that most spinlocks are held for
 *             less than 2^12 cycles
 * Time is measured based on a counter that runs at the same rate as the TSC,
 * refer SDM volume 3b section 21.6.13 & 22.1.3.
 */
#define KVM_VMX_DEFAULT_PLE_GAP    128
#define KVM_VMX_DEFAULT_PLE_WINDOW 4096
static int ple_gap = KVM_VMX_DEFAULT_PLE_GAP;
module_param(ple_gap, int, S_IRUGO);

static int ple_window = KVM_VMX_DEFAULT_PLE_WINDOW;
module_param(ple_window, int, S_IRUGO);

#define NR_AUTOLOAD_MSRS 8
#define VMCS02_POOL_SIZE 1

struct vmcs {
	u32 revision_id;
	u32 abort;
	char data[0];
};

/*
 * Track a VMCS that may be loaded on a certain CPU. If it is (cpu!=-1), also
 * remember whether it was VMLAUNCHed, and maintain a linked list of all VMCSs
 * loaded on this CPU (so we can clear them if the CPU goes down).
 */
struct loaded_vmcs {
	struct vmcs *vmcs;
	int cpu;
	int launched;
	struct list_head loaded_vmcss_on_cpu_link;
};

struct shared_msr_entry {
	unsigned index;
	u64 data;
	u64 mask;
};

/*
 * struct vmcs12 describes the state that our guest hypervisor (L1) keeps for a
 * single nested guest (L2), hence the name vmcs12. Any VMX implementation has
 * a VMCS structure, and vmcs12 is our emulated VMX's VMCS. This structure is
 * stored in guest memory specified by VMPTRLD, but is opaque to the guest,
 * which must access it using VMREAD/VMWRITE/VMCLEAR instructions.
 * More than one of these structures may exist, if L1 runs multiple L2 guests.
 * nested_vmx_run() will use the data here to build a vmcs02: a VMCS for the
 * underlying hardware which will be used to run L2.
 * This structure is packed to ensure that its layout is identical across
 * machines (necessary for live migration).
 * If there are changes in this struct, VMCS12_REVISION must be changed.
 */
typedef u64 natural_width;
struct __packed vmcs12 {
	/* According to the Intel spec, a VMCS region must start with the
	 * following two fields. Then follow implementation-specific data.
	 */
	u32 revision_id;
	u32 abort;

	u32 launch_state; /* set to 0 by VMCLEAR, to 1 by VMLAUNCH */
	u32 padding[7]; /* room for future expansion */

	u64 io_bitmap_a;
	u64 io_bitmap_b;
	u64 msr_bitmap;
	u64 vm_exit_msr_store_addr;
	u64 vm_exit_msr_load_addr;
	u64 vm_entry_msr_load_addr;
	u64 tsc_offset;
	u64 virtual_apic_page_addr;
	u64 apic_access_addr;
	u64 ept_pointer;
	u64 guest_physical_address;
	u64 vmcs_link_pointer;
	u64 guest_ia32_debugctl;
	u64 guest_ia32_pat;
	u64 guest_ia32_efer;
	u64 guest_ia32_perf_global_ctrl;
	u64 guest_pdptr0;
	u64 guest_pdptr1;
	u64 guest_pdptr2;
	u64 guest_pdptr3;
	u64 host_ia32_pat;
	u64 host_ia32_efer;
	u64 host_ia32_perf_global_ctrl;
	u64 padding64[8]; /* room for future expansion */
	/*
	 * To allow migration of L1 (complete with its L2 guests) between
	 * machines of different natural widths (32 or 64 bit), we cannot have
	 * unsigned long fields with no explict size. We use u64 (aliased
	 * natural_width) instead. Luckily, x86 is little-endian.
	 */
	natural_width cr0_guest_host_mask;
	natural_width cr4_guest_host_mask;
	natural_width cr0_read_shadow;
	natural_width cr4_read_shadow;
	natural_width cr3_target_value0;
	natural_width cr3_target_value1;
	natural_width cr3_target_value2;
	natural_width cr3_target_value3;
	natural_width exit_qualification;
	natural_width guest_linear_address;
	natural_width guest_cr0;
	natural_width guest_cr3;
	natural_width guest_cr4;
	natural_width guest_es_base;
	natural_width guest_cs_base;
	natural_width guest_ss_base;
	natural_width guest_ds_base;
	natural_width guest_fs_base;
	natural_width guest_gs_base;
	natural_width guest_ldtr_base;
	natural_width guest_tr_base;
	natural_width guest_gdtr_base;
	natural_width guest_idtr_base;
	natural_width guest_dr7;
	natural_width guest_rsp;
	natural_width guest_rip;
	natural_width guest_rflags;
	natural_width guest_pending_dbg_exceptions;
	natural_width guest_sysenter_esp;
	natural_width guest_sysenter_eip;
	natural_width host_cr0;
	natural_width host_cr3;
	natural_width host_cr4;
	natural_width host_fs_base;
	natural_width host_gs_base;
	natural_width host_tr_base;
	natural_width host_gdtr_base;
	natural_width host_idtr_base;
	natural_width host_ia32_sysenter_esp;
	natural_width host_ia32_sysenter_eip;
	natural_width host_rsp;
	natural_width host_rip;
	natural_width paddingl[8]; /* room for future expansion */
	u32 pin_based_vm_exec_control;
	u32 cpu_based_vm_exec_control;
	u32 exception_bitmap;
	u32 page_fault_error_code_mask;
	u32 page_fault_error_code_match;
	u32 cr3_target_count;
	u32 vm_exit_controls;
	u32 vm_exit_msr_store_count;
	u32 vm_exit_msr_load_count;
	u32 vm_entry_controls;
	u32 vm_entry_msr_load_count;
	u32 vm_entry_intr_info_field;
	u32 vm_entry_exception_error_code;
	u32 vm_entry_instruction_len;
	u32 tpr_threshold;
	u32 secondary_vm_exec_control;
	u32 vm_instruction_error;
	u32 vm_exit_reason;
	u32 vm_exit_intr_info;
	u32 vm_exit_intr_error_code;
	u32 idt_vectoring_info_field;
	u32 idt_vectoring_error_code;
	u32 vm_exit_instruction_len;
	u32 vmx_instruction_info;
	u32 guest_es_limit;
	u32 guest_cs_limit;
	u32 guest_ss_limit;
	u32 guest_ds_limit;
	u32 guest_fs_limit;
	u32 guest_gs_limit;
	u32 guest_ldtr_limit;
	u32 guest_tr_limit;
	u32 guest_gdtr_limit;
	u32 guest_idtr_limit;
	u32 guest_es_ar_bytes;
	u32 guest_cs_ar_bytes;
	u32 guest_ss_ar_bytes;
	u32 guest_ds_ar_bytes;
	u32 guest_fs_ar_bytes;
	u32 guest_gs_ar_bytes;
	u32 guest_ldtr_ar_bytes;
	u32 guest_tr_ar_bytes;
	u32 guest_interruptibility_info;
	u32 guest_activity_state;
	u32 guest_sysenter_cs;
	u32 host_ia32_sysenter_cs;
	u32 padding32[8]; /* room for future expansion */
	u16 virtual_processor_id;
	u16 guest_es_selector;
	u16 guest_cs_selector;
	u16 guest_ss_selector;
	u16 guest_ds_selector;
	u16 guest_fs_selector;
	u16 guest_gs_selector;
	u16 guest_ldtr_selector;
	u16 guest_tr_selector;
	u16 host_es_selector;
	u16 host_cs_selector;
	u16 host_ss_selector;
	u16 host_ds_selector;
	u16 host_fs_selector;
	u16 host_gs_selector;
	u16 host_tr_selector;
};

/*
 * VMCS12_REVISION is an arbitrary id that should be changed if the content or
 * layout of struct vmcs12 is changed. MSR_IA32_VMX_BASIC returns this id, and
 * VMPTRLD verifies that the VMCS region that L1 is loading contains this id.
 */
#define VMCS12_REVISION 0x11e57ed0

/*
 * VMCS12_SIZE is the number of bytes L1 should allocate for the VMXON region
 * and any VMCS region. Although only sizeof(struct vmcs12) are used by the
 * current implementation, 4K are reserved to avoid future complications.
 */
#define VMCS12_SIZE 0x1000

/* Used to remember the last vmcs02 used for some recently used vmcs12s */
struct vmcs02_list {
	struct list_head list;
	gpa_t vmptr;
	struct loaded_vmcs vmcs02;
};

/*
 * The nested_vmx structure is part of vcpu_vmx, and holds information we need
 * for correct emulation of VMX (i.e., nested VMX) on this vcpu.
 */
struct nested_vmx {
	/* Has the level1 guest done vmxon? */
	bool vmxon;

	/* The guest-physical address of the current VMCS L1 keeps for L2 */
	gpa_t current_vmptr;
	/* The host-usable pointer to the above */
	struct page *current_vmcs12_page;
	struct vmcs12 *current_vmcs12;

	/* vmcs02_list cache of VMCSs recently used to run L2 guests */
	struct list_head vmcs02_pool;
	int vmcs02_num;
	u64 vmcs01_tsc_offset;
	/* L2 must run next, and mustn't decide to exit to L1. */
	bool nested_run_pending;
	/*
	 * Guest pages referred to in vmcs02 with host-physical pointers, so
	 * we must keep them pinned while L2 runs.
	 */
	struct page *apic_access_page;
};

struct vcpu_vmx {
	struct kvm_vcpu       vcpu;
	unsigned long         host_rsp;
	u8                    fail;
	u8                    cpl;
	bool                  nmi_known_unmasked;
	u32                   exit_intr_info;
	u32                   idt_vectoring_info;
	ulong                 rflags;
	struct shared_msr_entry *guest_msrs;
	int                   nmsrs;
	int                   save_nmsrs;
#ifdef CONFIG_X86_64
	u64 		      msr_host_kernel_gs_base;
	u64 		      msr_guest_kernel_gs_base;
#endif
	/*
	 * loaded_vmcs points to the VMCS currently used in this vcpu. For a
	 * non-nested (L1) guest, it always points to vmcs01. For a nested
	 * guest (L2), it points to a different VMCS.
	 */
	struct loaded_vmcs    vmcs01;
	struct loaded_vmcs   *loaded_vmcs;
	bool                  __launched; /* temporary, used in vmx_vcpu_run */
	struct msr_autoload {
		unsigned nr;
		struct vmx_msr_entry guest[NR_AUTOLOAD_MSRS];
		struct vmx_msr_entry host[NR_AUTOLOAD_MSRS];
	} msr_autoload;
	struct {
		int           loaded;
		u16           fs_sel, gs_sel, ldt_sel;
		int           gs_ldt_reload_needed;
		int           fs_reload_needed;
	} host_state;
	struct {
		int vm86_active;
		ulong save_rflags;
		struct kvm_save_segment {
			u16 selector;
			unsigned long base;
			u32 limit;
			u32 ar;
		} tr, es, ds, fs, gs;
	} rmode;
	struct {
		u32 bitmask; /* 4 bits per segment (1 bit per field) */
		struct kvm_save_segment seg[8];
	} segment_cache;
	int vpid;
	bool emulation_required;

	/* Support for vnmi-less CPUs */
	int soft_vnmi_blocked;
	ktime_t entry_time;
	s64 vnmi_blocked_time;
	u32 exit_reason;

	bool rdtscp_enabled;

	/* Support for a guest hypervisor (nested VMX) */
	struct nested_vmx nested;
};

enum segment_cache_field {
	SEG_FIELD_SEL = 0,
	SEG_FIELD_BASE = 1,
	SEG_FIELD_LIMIT = 2,
	SEG_FIELD_AR = 3,

	SEG_FIELD_NR = 4
};

static inline struct vcpu_vmx *to_vmx(struct kvm_vcpu *vcpu)
{
	return container_of(vcpu, struct vcpu_vmx, vcpu);
}

#define VMCS12_OFFSET(x) offsetof(struct vmcs12, x)
#define FIELD(number, name)	[number] = VMCS12_OFFSET(name)
#define FIELD64(number, name)	[number] = VMCS12_OFFSET(name), \
				[number##_HIGH] = VMCS12_OFFSET(name)+4

static unsigned short vmcs_field_to_offset_table[] = {
	FIELD(VIRTUAL_PROCESSOR_ID, virtual_processor_id),
	FIELD(GUEST_ES_SELECTOR, guest_es_selector),
	FIELD(GUEST_CS_SELECTOR, guest_cs_selector),
	FIELD(GUEST_SS_SELECTOR, guest_ss_selector),
	FIELD(GUEST_DS_SELECTOR, guest_ds_selector),
	FIELD(GUEST_FS_SELECTOR, guest_fs_selector),
	FIELD(GUEST_GS_SELECTOR, guest_gs_selector),
	FIELD(GUEST_LDTR_SELECTOR, guest_ldtr_selector),
	FIELD(GUEST_TR_SELECTOR, guest_tr_selector),
	FIELD(HOST_ES_SELECTOR, host_es_selector),
	FIELD(HOST_CS_SELECTOR, host_cs_selector),
	FIELD(HOST_SS_SELECTOR, host_ss_selector),
	FIELD(HOST_DS_SELECTOR, host_ds_selector),
	FIELD(HOST_FS_SELECTOR, host_fs_selector),
	FIELD(HOST_GS_SELECTOR, host_gs_selector),
	FIELD(HOST_TR_SELECTOR, host_tr_selector),
	FIELD64(IO_BITMAP_A, io_bitmap_a),
	FIELD64(IO_BITMAP_B, io_bitmap_b),
	FIELD64(MSR_BITMAP, msr_bitmap),
	FIELD64(VM_EXIT_MSR_STORE_ADDR, vm_exit_msr_store_addr),
	FIELD64(VM_EXIT_MSR_LOAD_ADDR, vm_exit_msr_load_addr),
	FIELD64(VM_ENTRY_MSR_LOAD_ADDR, vm_entry_msr_load_addr),
	FIELD64(TSC_OFFSET, tsc_offset),
	FIELD64(VIRTUAL_APIC_PAGE_ADDR, virtual_apic_page_addr),
	FIELD64(APIC_ACCESS_ADDR, apic_access_addr),
	FIELD64(EPT_POINTER, ept_pointer),
	FIELD64(GUEST_PHYSICAL_ADDRESS, guest_physical_address),
	FIELD64(VMCS_LINK_POINTER, vmcs_link_pointer),
	FIELD64(GUEST_IA32_DEBUGCTL, guest_ia32_debugctl),
	FIELD64(GUEST_IA32_PAT, guest_ia32_pat),
	FIELD64(GUEST_IA32_EFER, guest_ia32_efer),
	FIELD64(GUEST_IA32_PERF_GLOBAL_CTRL, guest_ia32_perf_global_ctrl),
	FIELD64(GUEST_PDPTR0, guest_pdptr0),
	FIELD64(GUEST_PDPTR1, guest_pdptr1),
	FIELD64(GUEST_PDPTR2, guest_pdptr2),
	FIELD64(GUEST_PDPTR3, guest_pdptr3),
	FIELD64(HOST_IA32_PAT, host_ia32_pat),
	FIELD64(HOST_IA32_EFER, host_ia32_efer),
	FIELD64(HOST_IA32_PERF_GLOBAL_CTRL, host_ia32_perf_global_ctrl),
	FIELD(PIN_BASED_VM_EXEC_CONTROL, pin_based_vm_exec_control),
	FIELD(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control),
	FIELD(EXCEPTION_BITMAP, exception_bitmap),
	FIELD(PAGE_FAULT_ERROR_CODE_MASK, page_fault_error_code_mask),
	FIELD(PAGE_FAULT_ERROR_CODE_MATCH, page_fault_error_code_match),
	FIELD(CR3_TARGET_COUNT, cr3_target_count),
	FIELD(VM_EXIT_CONTROLS, vm_exit_controls),
	FIELD(VM_EXIT_MSR_STORE_COUNT, vm_exit_msr_store_count),
	FIELD(VM_EXIT_MSR_LOAD_COUNT, vm_exit_msr_load_count),
	FIELD(VM_ENTRY_CONTROLS, vm_entry_controls),
	FIELD(VM_ENTRY_MSR_LOAD_COUNT, vm_entry_msr_load_count),
	FIELD(VM_ENTRY_INTR_INFO_FIELD, vm_entry_intr_info_field),
	FIELD(VM_ENTRY_EXCEPTION_ERROR_CODE, vm_entry_exception_error_code),
	FIELD(VM_ENTRY_INSTRUCTION_LEN, vm_entry_instruction_len),
	FIELD(TPR_THRESHOLD, tpr_threshold),
	FIELD(SECONDARY_VM_EXEC_CONTROL, secondary_vm_exec_control),
	FIELD(VM_INSTRUCTION_ERROR, vm_instruction_error),
	FIELD(VM_EXIT_REASON, vm_exit_reason),
	FIELD(VM_EXIT_INTR_INFO, vm_exit_intr_info),
	FIELD(VM_EXIT_INTR_ERROR_CODE, vm_exit_intr_error_code),
	FIELD(IDT_VECTORING_INFO_FIELD, idt_vectoring_info_field),
	FIELD(IDT_VECTORING_ERROR_CODE, idt_vectoring_error_code),
	FIELD(VM_EXIT_INSTRUCTION_LEN, vm_exit_instruction_len),
	FIELD(VMX_INSTRUCTION_INFO, vmx_instruction_info),
	FIELD(GUEST_ES_LIMIT, guest_es_limit),
	FIELD(GUEST_CS_LIMIT, guest_cs_limit),
	FIELD(GUEST_SS_LIMIT, guest_ss_limit),
	FIELD(GUEST_DS_LIMIT, guest_ds_limit),
	FIELD(GUEST_FS_LIMIT, guest_fs_limit),
	FIELD(GUEST_GS_LIMIT, guest_gs_limit),
	FIELD(GUEST_LDTR_LIMIT, guest_ldtr_limit),
	FIELD(GUEST_TR_LIMIT, guest_tr_limit),
	FIELD(GUEST_GDTR_LIMIT, guest_gdtr_limit),
	FIELD(GUEST_IDTR_LIMIT, guest_idtr_limit),
	FIELD(GUEST_ES_AR_BYTES, guest_es_ar_bytes),
	FIELD(GUEST_CS_AR_BYTES, guest_cs_ar_bytes),
	FIELD(GUEST_SS_AR_BYTES, guest_ss_ar_bytes),
	FIELD(GUEST_DS_AR_BYTES, guest_ds_ar_bytes),
	FIELD(GUEST_FS_AR_BYTES, guest_fs_ar_bytes),
	FIELD(GUEST_GS_AR_BYTES, guest_gs_ar_bytes),
	FIELD(GUEST_LDTR_AR_BYTES, guest_ldtr_ar_bytes),
	FIELD(GUEST_TR_AR_BYTES, guest_tr_ar_bytes),
	FIELD(GUEST_INTERRUPTIBILITY_INFO, guest_interruptibility_info),
	FIELD(GUEST_ACTIVITY_STATE, guest_activity_state),
	FIELD(GUEST_SYSENTER_CS, guest_sysenter_cs),
	FIELD(HOST_IA32_SYSENTER_CS, host_ia32_sysenter_cs),
	FIELD(CR0_GUEST_HOST_MASK, cr0_guest_host_mask),
	FIELD(CR4_GUEST_HOST_MASK, cr4_guest_host_mask),
	FIELD(CR0_READ_SHADOW, cr0_read_shadow),
	FIELD(CR4_READ_SHADOW, cr4_read_shadow),
	FIELD(CR3_TARGET_VALUE0, cr3_target_value0),
	FIELD(CR3_TARGET_VALUE1, cr3_target_value1),
	FIELD(CR3_TARGET_VALUE2, cr3_target_value2),
	FIELD(CR3_TARGET_VALUE3, cr3_target_value3),
	FIELD(EXIT_QUALIFICATION, exit_qualification),
	FIELD(GUEST_LINEAR_ADDRESS, guest_linear_address),
	FIELD(GUEST_CR0, guest_cr0),
	FIELD(GUEST_CR3, guest_cr3),
	FIELD(GUEST_CR4, guest_cr4),
	FIELD(GUEST_ES_BASE, guest_es_base),
	FIELD(GUEST_CS_BASE, guest_cs_base),
	FIELD(GUEST_SS_BASE, guest_ss_base),
	FIELD(GUEST_DS_BASE, guest_ds_base),
	FIELD(GUEST_FS_BASE, guest_fs_base),
	FIELD(GUEST_GS_BASE, guest_gs_base),
	FIELD(GUEST_LDTR_BASE, guest_ldtr_base),
	FIELD(GUEST_TR_BASE, guest_tr_base),
	FIELD(GUEST_GDTR_BASE, guest_gdtr_base),
	FIELD(GUEST_IDTR_BASE, guest_idtr_base),
	FIELD(GUEST_DR7, guest_dr7),
	FIELD(GUEST_RSP, guest_rsp),
	FIELD(GUEST_RIP, guest_rip),
	FIELD(GUEST_RFLAGS, guest_rflags),
	FIELD(GUEST_PENDING_DBG_EXCEPTIONS, guest_pending_dbg_exceptions),
	FIELD(GUEST_SYSENTER_ESP, guest_sysenter_esp),
	FIELD(GUEST_SYSENTER_EIP, guest_sysenter_eip),
	FIELD(HOST_CR0, host_cr0),
	FIELD(HOST_CR3, host_cr3),
	FIELD(HOST_CR4, host_cr4),
	FIELD(HOST_FS_BASE, host_fs_base),
	FIELD(HOST_GS_BASE, host_gs_base),
	FIELD(HOST_TR_BASE, host_tr_base),
	FIELD(HOST_GDTR_BASE, host_gdtr_base),
	FIELD(HOST_IDTR_BASE, host_idtr_base),
	FIELD(HOST_IA32_SYSENTER_ESP, host_ia32_sysenter_esp),
	FIELD(HOST_IA32_SYSENTER_EIP, host_ia32_sysenter_eip),
	FIELD(HOST_RSP, host_rsp),
	FIELD(HOST_RIP, host_rip),
};
static const int max_vmcs_field = ARRAY_SIZE(vmcs_field_to_offset_table);

static inline short vmcs_field_to_offset(unsigned long field)
{
	if (field >= max_vmcs_field || vmcs_field_to_offset_table[field] == 0)
		return -1;
	return vmcs_field_to_offset_table[field];
}

static inline struct vmcs12 *get_vmcs12(struct kvm_vcpu *vcpu)
{
	return to_vmx(vcpu)->nested.current_vmcs12;
}

static struct page *nested_get_page(struct kvm_vcpu *vcpu, gpa_t addr)
{
	struct page *page = gfn_to_page(vcpu->kvm, addr >> PAGE_SHIFT);
	if (is_error_page(page)) {
		kvm_release_page_clean(page);
		return NULL;
	}
	return page;
}

static void nested_release_page(struct page *page)
{
	kvm_release_page_dirty(page);
}

static void nested_release_page_clean(struct page *page)
{
	kvm_release_page_clean(page);
}

static u64 construct_eptp(unsigned long root_hpa);
static void kvm_cpu_vmxon(u64 addr);
static void kvm_cpu_vmxoff(void);
static void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3);
static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr);

static DEFINE_PER_CPU(struct vmcs *, vmxarea);
static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
/*
 * We maintain a per-CPU linked-list of VMCS loaded on that CPU. This is needed
 * when a CPU is brought down, and we need to VMCLEAR all VMCSs loaded on it.
 */
static DEFINE_PER_CPU(struct list_head, loaded_vmcss_on_cpu);
static DEFINE_PER_CPU(struct desc_ptr, host_gdt);

static unsigned long *vmx_io_bitmap_a;
static unsigned long *vmx_io_bitmap_b;
static unsigned long *vmx_msr_bitmap_legacy;
static unsigned long *vmx_msr_bitmap_longmode;

static bool cpu_has_load_ia32_efer;
static bool cpu_has_load_perf_global_ctrl;

static DECLARE_BITMAP(vmx_vpid_bitmap, VMX_NR_VPIDS);
static DEFINE_SPINLOCK(vmx_vpid_lock);

static struct vmcs_config {
	int size;
	int order;
	u32 revision_id;
	u32 pin_based_exec_ctrl;
	u32 cpu_based_exec_ctrl;
	u32 cpu_based_2nd_exec_ctrl;
	u32 vmexit_ctrl;
	u32 vmentry_ctrl;
} vmcs_config;

static struct vmx_capability {
	u32 ept;
	u32 vpid;
} vmx_capability;

#define VMX_SEGMENT_FIELD(seg)					\
	[VCPU_SREG_##seg] = {                                   \
		.selector = GUEST_##seg##_SELECTOR,		\
		.base = GUEST_##seg##_BASE,		   	\
		.limit = GUEST_##seg##_LIMIT,		   	\
		.ar_bytes = GUEST_##seg##_AR_BYTES,	   	\
	}

static struct kvm_vmx_segment_field {
	unsigned selector;
	unsigned base;
	unsigned limit;
	unsigned ar_bytes;
} kvm_vmx_segment_fields[] = {
	VMX_SEGMENT_FIELD(CS),
	VMX_SEGMENT_FIELD(DS),
	VMX_SEGMENT_FIELD(ES),
	VMX_SEGMENT_FIELD(FS),
	VMX_SEGMENT_FIELD(GS),
	VMX_SEGMENT_FIELD(SS),
	VMX_SEGMENT_FIELD(TR),
	VMX_SEGMENT_FIELD(LDTR),
};

static u64 host_efer;

static void ept_save_pdptrs(struct kvm_vcpu *vcpu);

/*
 * Keep MSR_STAR at the end, as setup_msrs() will try to optimize it
 * away by decrementing the array size.
 */
static const u32 vmx_msr_index[] = {
#ifdef CONFIG_X86_64
	MSR_SYSCALL_MASK, MSR_LSTAR, MSR_CSTAR,
#endif
	MSR_EFER, MSR_TSC_AUX, MSR_STAR,
};
#define NR_VMX_MSR ARRAY_SIZE(vmx_msr_index)

static inline bool is_page_fault(u32 intr_info)
{
	return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK |
			     INTR_INFO_VALID_MASK)) ==
		(INTR_TYPE_HARD_EXCEPTION | PF_VECTOR | INTR_INFO_VALID_MASK);
}

static inline bool is_no_device(u32 intr_info)
{
	return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK |
			     INTR_INFO_VALID_MASK)) ==
		(INTR_TYPE_HARD_EXCEPTION | NM_VECTOR | INTR_INFO_VALID_MASK);
}

static inline bool is_invalid_opcode(u32 intr_info)
{
	return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK |
			     INTR_INFO_VALID_MASK)) ==
		(INTR_TYPE_HARD_EXCEPTION | UD_VECTOR | INTR_INFO_VALID_MASK);
}

static inline bool is_external_interrupt(u32 intr_info)
{
	return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VALID_MASK))
		== (INTR_TYPE_EXT_INTR | INTR_INFO_VALID_MASK);
}

static inline bool is_machine_check(u32 intr_info)
{
	return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK |
			     INTR_INFO_VALID_MASK)) ==
		(INTR_TYPE_HARD_EXCEPTION | MC_VECTOR | INTR_INFO_VALID_MASK);
}

static inline bool cpu_has_vmx_msr_bitmap(void)
{
	return vmcs_config.cpu_based_exec_ctrl & CPU_BASED_USE_MSR_BITMAPS;
}

static inline bool cpu_has_vmx_tpr_shadow(void)
{
	return vmcs_config.cpu_based_exec_ctrl & CPU_BASED_TPR_SHADOW;
}

static inline bool vm_need_tpr_shadow(struct kvm *kvm)
{
	return (cpu_has_vmx_tpr_shadow()) && (irqchip_in_kernel(kvm));
}

static inline bool cpu_has_secondary_exec_ctrls(void)
{
	return vmcs_config.cpu_based_exec_ctrl &
		CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
}

static inline bool cpu_has_vmx_virtualize_apic_accesses(void)
{
	return vmcs_config.cpu_based_2nd_exec_ctrl &
		SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
}

static inline bool cpu_has_vmx_flexpriority(void)
{
	return cpu_has_vmx_tpr_shadow() &&
		cpu_has_vmx_virtualize_apic_accesses();
}

static inline bool cpu_has_vmx_ept_execute_only(void)
{
	return vmx_capability.ept & VMX_EPT_EXECUTE_ONLY_BIT;
}

static inline bool cpu_has_vmx_eptp_uncacheable(void)
{
	return vmx_capability.ept & VMX_EPTP_UC_BIT;
}

static inline bool cpu_has_vmx_eptp_writeback(void)
{
	return vmx_capability.ept & VMX_EPTP_WB_BIT;
}

static inline bool cpu_has_vmx_ept_2m_page(void)
{
	return vmx_capability.ept & VMX_EPT_2MB_PAGE_BIT;
}

static inline bool cpu_has_vmx_ept_1g_page(void)
{
	return vmx_capability.ept & VMX_EPT_1GB_PAGE_BIT;
}

static inline bool cpu_has_vmx_ept_4levels(void)
{
	return vmx_capability.ept & VMX_EPT_PAGE_WALK_4_BIT;
}

static inline bool cpu_has_vmx_invept_individual_addr(void)
{
	return vmx_capability.ept & VMX_EPT_EXTENT_INDIVIDUAL_BIT;
}

static inline bool cpu_has_vmx_invept_context(void)
{
	return vmx_capability.ept & VMX_EPT_EXTENT_CONTEXT_BIT;
}

static inline bool cpu_has_vmx_invept_global(void)
{
	return vmx_capability.ept & VMX_EPT_EXTENT_GLOBAL_BIT;
}

static inline bool cpu_has_vmx_invvpid_single(void)
{
	return vmx_capability.vpid & VMX_VPID_EXTENT_SINGLE_CONTEXT_BIT;
}

static inline bool cpu_has_vmx_invvpid_global(void)
{
	return vmx_capability.vpid & VMX_VPID_EXTENT_GLOBAL_CONTEXT_BIT;
}

static inline bool cpu_has_vmx_ept(void)
{
	return vmcs_config.cpu_based_2nd_exec_ctrl &
		SECONDARY_EXEC_ENABLE_EPT;
}

static inline bool cpu_has_vmx_unrestricted_guest(void)
{
	return vmcs_config.cpu_based_2nd_exec_ctrl &
		SECONDARY_EXEC_UNRESTRICTED_GUEST;
}

static inline bool cpu_has_vmx_ple(void)
{
	return vmcs_config.cpu_based_2nd_exec_ctrl &
		SECONDARY_EXEC_PAUSE_LOOP_EXITING;
}

static inline bool vm_need_virtualize_apic_accesses(struct kvm *kvm)
{
	return flexpriority_enabled && irqchip_in_kernel(kvm);
}

static inline bool cpu_has_vmx_vpid(void)
{
	return vmcs_config.cpu_based_2nd_exec_ctrl &
		SECONDARY_EXEC_ENABLE_VPID;
}

static inline bool cpu_has_vmx_rdtscp(void)
{
	return vmcs_config.cpu_based_2nd_exec_ctrl &
		SECONDARY_EXEC_RDTSCP;
}

static inline bool cpu_has_virtual_nmis(void)
{
	return vmcs_config.pin_based_exec_ctrl & PIN_BASED_VIRTUAL_NMIS;
}

static inline bool cpu_has_vmx_wbinvd_exit(void)
{
	return vmcs_config.cpu_based_2nd_exec_ctrl &
		SECONDARY_EXEC_WBINVD_EXITING;
}

static inline bool report_flexpriority(void)
{
	return flexpriority_enabled;
}

static inline bool nested_cpu_has(struct vmcs12 *vmcs12, u32 bit)
{
	return vmcs12->cpu_based_vm_exec_control & bit;
}

static inline bool nested_cpu_has2(struct vmcs12 *vmcs12, u32 bit)
{
	return (vmcs12->cpu_based_vm_exec_control &
			CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) &&
		(vmcs12->secondary_vm_exec_control & bit);
}

static inline bool nested_cpu_has_virtual_nmis(struct vmcs12 *vmcs12,
	struct kvm_vcpu *vcpu)
{
	return vmcs12->pin_based_vm_exec_control & PIN_BASED_VIRTUAL_NMIS;
}

static inline bool is_exception(u32 intr_info)
{
	return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VALID_MASK))
		== (INTR_TYPE_HARD_EXCEPTION | INTR_INFO_VALID_MASK);
}

static void nested_vmx_vmexit(struct kvm_vcpu *vcpu);
static void nested_vmx_entry_failure(struct kvm_vcpu *vcpu,
			struct vmcs12 *vmcs12,
			u32 reason, unsigned long qualification);

static int __find_msr_index(struct vcpu_vmx *vmx, u32 msr)
{
	int i;

	for (i = 0; i < vmx->nmsrs; ++i)
		if (vmx_msr_index[vmx->guest_msrs[i].index] == msr)
			return i;
	return -1;
}

static inline void __invvpid(int ext, u16 vpid, gva_t gva)
{
    struct {
	u64 vpid : 16;
	u64 rsvd : 48;
	u64 gva;
    } operand = { vpid, 0, gva };

    asm volatile (__ex(ASM_VMX_INVVPID)
		  /* CF==1 or ZF==1 --> rc = -1 */
		  "; ja 1f ; ud2 ; 1:"
		  : : "a"(&operand), "c"(ext) : "cc", "memory");
}

static inline void __invept(int ext, u64 eptp, gpa_t gpa)
{
	struct {
		u64 eptp, gpa;
	} operand = {eptp, gpa};

	asm volatile (__ex(ASM_VMX_INVEPT)
			/* CF==1 or ZF==1 --> rc = -1 */
			"; ja 1f ; ud2 ; 1:\n"
			: : "a" (&operand), "c" (ext) : "cc", "memory");
}

static struct shared_msr_entry *find_msr_entry(struct vcpu_vmx *vmx, u32 msr)
{
	int i;

	i = __find_msr_index(vmx, msr);
	if (i >= 0)
		return &vmx->guest_msrs[i];
	return NULL;
}

static void vmcs_clear(struct vmcs *vmcs)
{
	u64 phys_addr = __pa(vmcs);
	u8 error;

	asm volatile (__ex(ASM_VMX_VMCLEAR_RAX) "; setna %0"
		      : "=qm"(error) : "a"(&phys_addr), "m"(phys_addr)
		      : "cc", "memory");
	if (error)
		printk(KERN_ERR "kvm: vmclear fail: %p/%llx\n",
		       vmcs, phys_addr);
}

static inline void loaded_vmcs_init(struct loaded_vmcs *loaded_vmcs)
{
	vmcs_clear(loaded_vmcs->vmcs);
	loaded_vmcs->cpu = -1;
	loaded_vmcs->launched = 0;
}

static void vmcs_load(struct vmcs *vmcs)
{
	u64 phys_addr = __pa(vmcs);
	u8 error;

	asm volatile (__ex(ASM_VMX_VMPTRLD_RAX) "; setna %0"
			: "=qm"(error) : "a"(&phys_addr), "m"(phys_addr)
			: "cc", "memory");
	if (error)
		printk(KERN_ERR "kvm: vmptrld %p/%llx failed\n",
		       vmcs, phys_addr);
}

static void __loaded_vmcs_clear(void *arg)
{
	struct loaded_vmcs *loaded_vmcs = arg;
	int cpu = raw_smp_processor_id();

	if (loaded_vmcs->cpu != cpu)
		return; /* vcpu migration can race with cpu offline */
	if (per_cpu(current_vmcs, cpu) == loaded_vmcs->vmcs)
		per_cpu(current_vmcs, cpu) = NULL;
	list_del(&loaded_vmcs->loaded_vmcss_on_cpu_link);
	loaded_vmcs_init(loaded_vmcs);
}

static void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs)
{
	if (loaded_vmcs->cpu != -1)
		smp_call_function_single(
			loaded_vmcs->cpu, __loaded_vmcs_clear, loaded_vmcs, 1);
}

static inline void vpid_sync_vcpu_single(struct vcpu_vmx *vmx)
{
	if (vmx->vpid == 0)
		return;

	if (cpu_has_vmx_invvpid_single())
		__invvpid(VMX_VPID_EXTENT_SINGLE_CONTEXT, vmx->vpid, 0);
}

static inline void vpid_sync_vcpu_global(void)
{
	if (cpu_has_vmx_invvpid_global())
		__invvpid(VMX_VPID_EXTENT_ALL_CONTEXT, 0, 0);
}

static inline void vpid_sync_context(struct vcpu_vmx *vmx)
{
	if (cpu_has_vmx_invvpid_single())
		vpid_sync_vcpu_single(vmx);
	else
		vpid_sync_vcpu_global();
}

static inline void ept_sync_global(void)
{
	if (cpu_has_vmx_invept_global())
		__invept(VMX_EPT_EXTENT_GLOBAL, 0, 0);
}

static inline void ept_sync_context(u64 eptp)
{
	if (enable_ept) {
		if (cpu_has_vmx_invept_context())
			__invept(VMX_EPT_EXTENT_CONTEXT, eptp, 0);
		else
			ept_sync_global();
	}
}

static inline void ept_sync_individual_addr(u64 eptp, gpa_t gpa)
{
	if (enable_ept) {
		if (cpu_has_vmx_invept_individual_addr())
			__invept(VMX_EPT_EXTENT_INDIVIDUAL_ADDR,
					eptp, gpa);
		else
			ept_sync_context(eptp);
	}
}

static __always_inline unsigned long vmcs_readl(unsigned long field)
{
	unsigned long value;

	asm volatile (__ex_clear(ASM_VMX_VMREAD_RDX_RAX, "%0")
		      : "=a"(value) : "d"(field) : "cc");
	return value;
}

static __always_inline u16 vmcs_read16(unsigned long field)
{
	return vmcs_readl(field);
}

static __always_inline u32 vmcs_read32(unsigned long field)
{
	return vmcs_readl(field);
}

static __always_inline u64 vmcs_read64(unsigned long field)
{
#ifdef CONFIG_X86_64
	return vmcs_readl(field);
#else
	return vmcs_readl(field) | ((u64)vmcs_readl(field+1) << 32);
#endif
}

static noinline void vmwrite_error(unsigned long field, unsigned long value)
{
	printk(KERN_ERR "vmwrite error: reg %lx value %lx (err %d)\n",
	       field, value, vmcs_read32(VM_INSTRUCTION_ERROR));
	dump_stack();
}

static void vmcs_writel(unsigned long field, unsigned long value)
{
	u8 error;

	asm volatile (__ex(ASM_VMX_VMWRITE_RAX_RDX) "; setna %0"
		       : "=q"(error) : "a"(value), "d"(field) : "cc");
	if (unlikely(error))
		vmwrite_error(field, value);
}

static void vmcs_write16(unsigned long field, u16 value)
{
	vmcs_writel(field, value);
}

static void vmcs_write32(unsigned long field, u32 value)
{
	vmcs_writel(field, value);
}

static void vmcs_write64(unsigned long field, u64 value)
{
	vmcs_writel(field, value);
#ifndef CONFIG_X86_64
	asm volatile ("");
	vmcs_writel(field+1, value >> 32);
#endif
}

static void vmcs_clear_bits(unsigned long field, u32 mask)
{
	vmcs_writel(field, vmcs_readl(field) & ~mask);
}

static void vmcs_set_bits(unsigned long field, u32 mask)
{
	vmcs_writel(field, vmcs_readl(field) | mask);
}

static void vmx_segment_cache_clear(struct vcpu_vmx *vmx)
{
	vmx->segment_cache.bitmask = 0;
}

static bool vmx_segment_cache_test_set(struct vcpu_vmx *vmx, unsigned seg,
				       unsigned field)
{
	bool ret;
	u32 mask = 1 << (seg * SEG_FIELD_NR + field);

	if (!(vmx->vcpu.arch.regs_avail & (1 << VCPU_EXREG_SEGMENTS))) {
		vmx->vcpu.arch.regs_avail |= (1 << VCPU_EXREG_SEGMENTS);
		vmx->segment_cache.bitmask = 0;
	}
	ret = vmx->segment_cache.bitmask & mask;
	vmx->segment_cache.bitmask |= mask;
	return ret;
}

static u16 vmx_read_guest_seg_selector(struct vcpu_vmx *vmx, unsigned seg)
{
	u16 *p = &vmx->segment_cache.seg[seg].selector;

	if (!vmx_segment_cache_test_set(vmx, seg, SEG_FIELD_SEL))
		*p = vmcs_read16(kvm_vmx_segment_fields[seg].selector);
	return *p;
}

static ulong vmx_read_guest_seg_base(struct vcpu_vmx *vmx, unsigned seg)
{
	ulong *p = &vmx->segment_cache.seg[seg].base;

	if (!vmx_segment_cache_test_set(vmx, seg, SEG_FIELD_BASE))
		*p = vmcs_readl(kvm_vmx_segment_fields[seg].base);
	return *p;
}

static u32 vmx_read_guest_seg_limit(struct vcpu_vmx *vmx, unsigned seg)
{
	u32 *p = &vmx->segment_cache.seg[seg].limit;

	if (!vmx_segment_cache_test_set(vmx, seg, SEG_FIELD_LIMIT))
		*p = vmcs_read32(kvm_vmx_segment_fields[seg].limit);
	return *p;
}

static u32 vmx_read_guest_seg_ar(struct vcpu_vmx *vmx, unsigned seg)
{
	u32 *p = &vmx->segment_cache.seg[seg].ar;

	if (!vmx_segment_cache_test_set(vmx, seg, SEG_FIELD_AR))
		*p = vmcs_read32(kvm_vmx_segment_fields[seg].ar_bytes);
	return *p;
}

static void update_exception_bitmap(struct kvm_vcpu *vcpu)
{
	u32 eb;

	eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR) |
	     (1u << NM_VECTOR) | (1u << DB_VECTOR);
	if ((vcpu->guest_debug &
	     (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP)) ==
	    (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP))
		eb |= 1u << BP_VECTOR;
	if (to_vmx(vcpu)->rmode.vm86_active)
		eb = ~0;
	if (enable_ept)
		eb &= ~(1u << PF_VECTOR); /* bypass_guest_pf = 0 */
	if (vcpu->fpu_active)
		eb &= ~(1u << NM_VECTOR);

	/* When we are running a nested L2 guest and L1 specified for it a
	 * certain exception bitmap, we must trap the same exceptions and pass
	 * them to L1. When running L2, we will only handle the exceptions
	 * specified above if L1 did not want them.
	 */
	if (is_guest_mode(vcpu))
		eb |= get_vmcs12(vcpu)->exception_bitmap;

	vmcs_write32(EXCEPTION_BITMAP, eb);
}

static void clear_atomic_switch_msr_special(unsigned long entry,
		unsigned long exit)
{
	vmcs_clear_bits(VM_ENTRY_CONTROLS, entry);
	vmcs_clear_bits(VM_EXIT_CONTROLS, exit);
}

static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
{
	unsigned i;
	struct msr_autoload *m = &vmx->msr_autoload;

	switch (msr) {
	case MSR_EFER:
		if (cpu_has_load_ia32_efer) {
			clear_atomic_switch_msr_special(VM_ENTRY_LOAD_IA32_EFER,
					VM_EXIT_LOAD_IA32_EFER);
			return;
		}
		break;
	case MSR_CORE_PERF_GLOBAL_CTRL:
		if (cpu_has_load_perf_global_ctrl) {
			clear_atomic_switch_msr_special(
					VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL,
					VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL);
			return;
		}
		break;
	}

	for (i = 0; i < m->nr; ++i)
		if (m->guest[i].index == msr)
			break;

	if (i == m->nr)
		return;
	--m->nr;
	m->guest[i] = m->guest[m->nr];
	m->host[i] = m->host[m->nr];
	vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->nr);
	vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->nr);
}

static void add_atomic_switch_msr_special(unsigned long entry,
		unsigned long exit, unsigned long guest_val_vmcs,
		unsigned long host_val_vmcs, u64 guest_val, u64 host_val)
{
	vmcs_write64(guest_val_vmcs, guest_val);
	vmcs_write64(host_val_vmcs, host_val);
	vmcs_set_bits(VM_ENTRY_CONTROLS, entry);
	vmcs_set_bits(VM_EXIT_CONTROLS, exit);
}

static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
				  u64 guest_val, u64 host_val)
{
	unsigned i;
	struct msr_autoload *m = &vmx->msr_autoload;

	switch (msr) {
	case MSR_EFER:
		if (cpu_has_load_ia32_efer) {
			add_atomic_switch_msr_special(VM_ENTRY_LOAD_IA32_EFER,
					VM_EXIT_LOAD_IA32_EFER,
					GUEST_IA32_EFER,
					HOST_IA32_EFER,
					guest_val, host_val);
			return;
		}
		break;
	case MSR_CORE_PERF_GLOBAL_CTRL:
		if (cpu_has_load_perf_global_ctrl) {
			add_atomic_switch_msr_special(
					VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL,
					VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL,
					GUEST_IA32_PERF_GLOBAL_CTRL,
					HOST_IA32_PERF_GLOBAL_CTRL,
					guest_val, host_val);
			return;
		}
		break;
	}

	for (i = 0; i < m->nr; ++i)
		if (m->guest[i].index == msr)
			break;

	if (i == NR_AUTOLOAD_MSRS) {
		printk_once(KERN_WARNING"Not enough mst switch entries. "
				"Can't add msr %x\n", msr);
		return;
	} else if (i == m->nr) {
		++m->nr;
		vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->nr);
		vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->nr);
	}

	m->guest[i].index = msr;
	m->guest[i].value = guest_val;
	m->host[i].index = msr;
	m->host[i].value = host_val;
}

static void reload_tss(void)
{
	/*
	 * VT restores TR but not its size.  Useless.
	 */
	struct desc_ptr *gdt = &__get_cpu_var(host_gdt);
	struct desc_struct *descs;

	descs = (void *)gdt->address;
	descs[GDT_ENTRY_TSS].type = 9; /* available TSS */
	load_TR_desc();
}

static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
{
	u64 guest_efer;
	u64 ignore_bits;

	guest_efer = vmx->vcpu.arch.efer;

	/*
	 * NX is emulated; LMA and LME handled by hardware; SCE meaninless
	 * outside long mode
	 */
	ignore_bits = EFER_NX | EFER_SCE;
#ifdef CONFIG_X86_64
	ignore_bits |= EFER_LMA | EFER_LME;
	/* SCE is meaningful only in long mode on Intel */
	if (guest_efer & EFER_LMA)
		ignore_bits &= ~(u64)EFER_SCE;
#endif
	guest_efer &= ~ignore_bits;
	guest_efer |= host_efer & ignore_bits;
	vmx->guest_msrs[efer_offset].data = guest_efer;
	vmx->guest_msrs[efer_offset].mask = ~ignore_bits;

	clear_atomic_switch_msr(vmx, MSR_EFER);
	/* On ept, can't emulate nx, and must switch nx atomically */
	if (enable_ept && ((vmx->vcpu.arch.efer ^ host_efer) & EFER_NX)) {
		guest_efer = vmx->vcpu.arch.efer;
		if (!(guest_efer & EFER_LMA))
			guest_efer &= ~EFER_LME;
		add_atomic_switch_msr(vmx, MSR_EFER, guest_efer, host_efer);
		return false;
	}

	return true;
}

static unsigned long segment_base(u16 selector)
{
	struct desc_ptr *gdt = &__get_cpu_var(host_gdt);
	struct desc_struct *d;
	unsigned long table_base;
	unsigned long v;

	if (!(selector & ~3))
		return 0;

	table_base = gdt->address;

	if (selector & 4) {           /* from ldt */
		u16 ldt_selector = kvm_read_ldt();

		if (!(ldt_selector & ~3))
			return 0;

		table_base = segment_base(ldt_selector);
	}
	d = (struct desc_struct *)(table_base + (selector & ~7));
	v = get_desc_base(d);
#ifdef CONFIG_X86_64
       if (d->s == 0 && (d->type == 2 || d->type == 9 || d->type == 11))
               v |= ((unsigned long)((struct ldttss_desc64 *)d)->base3) << 32;
#endif
	return v;
}

static inline unsigned long kvm_read_tr_base(void)
{
	u16 tr;
	asm("str %0" : "=g"(tr));
	return segment_base(tr);
}

static void vmx_save_host_state(struct kvm_vcpu *vcpu)
{
	struct vcpu_vmx *vmx = to_vmx(vcpu);
	int i;

	if (vmx->host_state.loaded)
		return;

	vmx->host_state.loaded = 1;
	/*
	 * Set host fs and gs selectors.  Unfortunately, 22.2.3 does not
	 * allow segment selectors with cpl > 0 or ti == 1.
	 */
	vmx->host_state.ldt_sel = kvm_read_ldt();
	vmx->host_state.gs_ldt_reload_needed = vmx->host_state.ldt_sel;
	savesegment(fs, vmx->host_state.fs_sel);
	if (!(vmx->host_state.fs_sel & 7)) {
		vmcs_write16(HOST_FS_SELECTOR, vmx->host_state.fs_sel);
		vmx->host_state.fs_reload_needed = 0;
	} else {
		vmcs_write16(HOST_FS_SELECTOR, 0);
		vmx->host_state.fs_reload_needed = 1;
	}
	savesegment(gs, vmx->host_state.gs_sel);
	if (!(vmx->host_state.gs_sel & 7))
		vmcs_write16(HOST_GS_SELECTOR, vmx->host_state.gs_sel);
	else {
		vmcs_write16(HOST_GS_SELECTOR, 0);
		vmx->host_state.gs_ldt_reload_needed = 1;
	}

#ifdef CONFIG_X86_64
	vmcs_writel(HOST_FS_BASE, read_msr(MSR_FS_BASE));
	vmcs_writel(HOST_GS_BASE, read_msr(MSR_GS_BASE));
#else
	vmcs_writel(HOST_FS_BASE, segment_base(vmx->host_state.fs_sel));
	vmcs_writel(HOST_GS_BASE, segment_base(vmx->host_state.gs_sel));
#endif

#ifdef CONFIG_X86_64
	rdmsrl(MSR_KERNEL_GS_BASE, vmx->msr_host_kernel_gs_base);
	if (is_long_mode(&vmx->vcpu))
		wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base);
#endif
	for (i = 0; i < vmx->save_nmsrs; ++i)
		kvm_set_shared_msr(vmx->guest_msrs[i].index,
				   vmx->guest_msrs[i].data,
				   vmx->guest_msrs[i].mask);
}

static void __vmx_load_host_state(struct vcpu_vmx *vmx)
{
	if (!vmx->host_state.loaded)
		return;

	++vmx->vcpu.stat.host_state_reload;
	vmx->host_state.loaded = 0;
#ifdef CONFIG_X86_64
	if (is_long_mode(&vmx->vcpu))
		rdmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base);
#endif
	if (vmx->host_state.gs_ldt_reload_needed) {
		kvm_load_ldt(vmx->host_state.ldt_sel);
#ifdef CONFIG_X86_64
		load_gs_index(vmx->host_state.gs_sel);
#else
		loadsegment(gs, vmx->host_state.gs_sel);
#endif
	}
	if (vmx->host_state.fs_reload_needed)
		loadsegment(fs, vmx->host_state.fs_sel);
	reload_tss();
#ifdef CONFIG_X86_64
	wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_host_kernel_gs_base);
#endif
	if (user_has_fpu())
		clts();
	load_gdt(&__get_cpu_var(host_gdt));
}

static void vmx_load_host_state(struct vcpu_vmx *vmx)
{
	preempt_disable();
	__vmx_load_host_state(vmx);
	preempt_enable();
}

/*
 * Switches to specified vcpu, until a matching vcpu_put(), but assumes
 * vcpu mutex is already taken.
 */
static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
	struct vcpu_vmx *vmx = to_vmx(vcpu);
	u64 phys_addr = __pa(per_cpu(vmxarea, cpu));

	if (!vmm_exclusive)
		kvm_cpu_vmxon(phys_addr);
	else if (vmx->loaded_vmcs->cpu != cpu)
		loaded_vmcs_clear(vmx->loaded_vmcs);

	if (per_cpu(current_vmcs, cpu) != vmx->loaded_vmcs->vmcs) {
		per_cpu(current_vmcs, cpu) = vmx->loaded_vmcs->vmcs;
		vmcs_load(vmx->loaded_vmcs->vmcs);
	}

	if (vmx->loaded_vmcs->cpu != cpu) {
		struct desc_ptr *gdt = &__get_cpu_var(host_gdt);
		unsigned long sysenter_esp;

		kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
		local_irq_disable();
		list_add(&vmx->loaded_vmcs->loaded_vmcss_on_cpu_link,
			 &per_cpu(loaded_vmcss_on_cpu, cpu));
		local_irq_enable();

		/*
		 * Linux uses per-cpu TSS and GDT, so set these when switching
		 * processors.
		 */
		vmcs_writel(HOST_TR_BASE, kvm_read_tr_base()); /* 22.2.4 */
		vmcs_writel(HOST_GDTR_BASE, gdt->address);   /* 22.2.4 */

		rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp);
		vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */
		vmx->loaded_vmcs->cpu = cpu;
	}
}

static void vmx_vcpu_put(struct kvm_vcpu *vcpu)
{
	__vmx_load_host_state(to_vmx(vcpu));
	if (!vmm_exclusive) {
		__loaded_vmcs_clear(to_vmx(vcpu)->loaded_vmcs);
		vcpu->cpu = -1;
		kvm_cpu_vmxoff();
	}
}

static void vmx_fpu_activate(struct kvm_vcpu *vcpu)
{
	ulong cr0;

	if (vcpu->fpu_active)
		return;
	vcpu->fpu_active = 1;
	cr0 = vmcs_readl(GUEST_CR0);
	cr0 &= ~(X86_CR0_TS | X86_CR0_MP);
	cr0 |= kvm_read_cr0_bits(vcpu, X86_CR0_TS | X86_CR0_MP);
	vmcs_writel(GUEST_CR0, cr0);
	update_exception_bitmap(vcpu);
	vcpu->arch.cr0_guest_owned_bits = X86_CR0_TS;
	if (is_guest_mode(vcpu))
		vcpu->arch.cr0_guest_owned_bits &=
			~get_vmcs12(vcpu)->cr0_guest_host_mask;
	vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits);
}

static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu);

/*
 * Return the cr0 value that a nested guest would read. This is a combination
 * of the real cr0 used to run the guest (guest_cr0), and the bits shadowed by
 * its hypervisor (cr0_read_shadow).
 */
static inline unsigned long nested_read_cr0(struct vmcs12 *fields)
{
	return (fields->guest_cr0 & ~fields->cr0_guest_host_mask) |
		(fields->cr0_read_shadow & fields->cr0_guest_host_mask);
}
static inline unsigned long nested_read_cr4(struct vmcs12 *fields)
{
	return (fields->guest_cr4 & ~fields->cr4_guest_host_mask) |
		(fields->cr4_read_shadow & fields->cr4_guest_host_mask);
}

static void vmx_fpu_deactivate(struct kvm_vcpu *vcpu)
{
	/* Note that there is no vcpu->fpu_active = 0 here. The caller must
	 * set this *before* calling this function.
	 */
	vmx_decache_cr0_guest_bits(vcpu);
	vmcs_set_bits(GUEST_CR0, X86_CR0_TS | X86_CR0_MP);
	update_exception_bitmap(vcpu);
	vcpu->arch.cr0_guest_owned_bits = 0;
	vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits);
	if (is_guest_mode(vcpu)) {
		/*
		 * L1's specified read shadow might not contain the TS bit,
		 * so now that we turned on shadowing of this bit, we need to
		 * set this bit of the shadow. Like in nested_vmx_run we need
		 * nested_read_cr0(vmcs12), but vmcs12->guest_cr0 is not yet
		 * up-to-date here because we just decached cr0.TS (and we'll
		 * only update vmcs12->guest_cr0 on nested exit).
		 */
		struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
		vmcs12->guest_cr0 = (vmcs12->guest_cr0 & ~X86_CR0_TS) |
			(vcpu->arch.cr0 & X86_CR0_TS);
		vmcs_writel(CR0_READ_SHADOW, nested_read_cr0(vmcs12));
	} else
		vmcs_writel(CR0_READ_SHADOW, vcpu->arch.cr0);
}

static unsigned long vmx_get_rflags(struct kvm_vcpu *vcpu)
{
	unsigned long rflags, save_rflags;

	if (!test_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail)) {
		__set_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail);
		rflags = vmcs_readl(GUEST_RFLAGS);
		if (to_vmx(vcpu)->rmode.vm86_active) {
			rflags &= RMODE_GUEST_OWNED_EFLAGS_BITS;
			save_rflags = to_vmx(vcpu)->rmode.save_rflags;
			rflags |= save_rflags & ~RMODE_GUEST_OWNED_EFLAGS_BITS;
		}
		to_vmx(vcpu)->rflags = rflags;
	}
	return to_vmx(vcpu)->rflags;
}

static void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
{
	__set_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail);
	__clear_bit(VCPU_EXREG_CPL, (ulong *)&vcpu->arch.regs_avail);
	to_vmx(vcpu)->rflags = rflags;
	if (to_vmx(vcpu)->rmode.vm86_active) {
		to_vmx(vcpu)->rmode.save_rflags = rflags;
		rflags |= X86_EFLAGS_IOPL | X86_EFLAGS_VM;
	}
	vmcs_writel(GUEST_RFLAGS, rflags);
}

static u32 vmx_get_interrupt_shadow(struct kvm_vcpu *vcpu, int mask)
{
	u32 interruptibility = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);
	int ret = 0;

	if (interruptibility & GUEST_INTR_STATE_STI)
		ret |= KVM_X86_SHADOW_INT_STI;
	if (interruptibility & GUEST_INTR_STATE_MOV_SS)
		ret |= KVM_X86_SHADOW_INT_MOV_SS;

	return ret & mask;
}

static void vmx_set_interrupt_shadow(struct kvm_vcpu *vcpu, int mask)
{
	u32 interruptibility_old = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);
	u32 interruptibility = interruptibility_old;

	interruptibility &= ~(GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS);

	if (mask & KVM_X86_SHADOW_INT_MOV_SS)
		interruptibility |= GUEST_INTR_STATE_MOV_SS;
	else if (mask & KVM_X86_SHADOW_INT_STI)
		interruptibility |= GUEST_INTR_STATE_STI;

	if ((interruptibility != interruptibility_old))
		vmcs_write32(GUEST_INTERRUPTIBILITY_INFO, interruptibility);
}

static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
{
	unsigned long rip;

	rip = kvm_rip_read(vcpu);
	rip += vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
	kvm_rip_write(vcpu, rip);

	/* skipping an emulated instruction also counts */
	vmx_set_interrupt_shadow(vcpu, 0);
}

/*
 * KVM wants to inject page-faults which it got to the guest. This function
 * checks whether in a nested guest, we need to inject them to L1 or L2.
 * This function assumes it is called with the exit reason in vmcs02 being
 * a #PF exception (this is the only case in which KVM injects a #PF when L2
 * is running).
 */
static int nested_pf_handled(struct kvm_vcpu *vcpu)
{
	struct vmcs12 *vmcs12 = get_vmcs12(vcpu);

	/* TODO: also check PFEC_MATCH/MASK, not just EB.PF. */
	if (!(vmcs12->exception_bitmap & (1u << PF_VECTOR)))
		return 0;

	nested_vmx_vmexit(vcpu);
	return 1;
}

static void vmx_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
				bool has_error_code, u32 error_code,
				bool reinject)
{
	struct vcpu_vmx *vmx = to_vmx(vcpu);
	u32 intr_info = nr | INTR_INFO_VALID_MASK;

	if (nr == PF_VECTOR && is_guest_mode(vcpu) &&
		nested_pf_handled(vcpu))
		return;

	if (has_error_code) {
		vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE, error_code);
		intr_info |= INTR_INFO_DELIVER_CODE_MASK;
	}

	if (vmx->rmode.vm86_active) {
		int inc_eip = 0;
		if (kvm_exception_is_soft(nr))
			inc_eip = vcpu->arch.event_exit_inst_len;
		if (kvm_inject_realmode_interrupt(vcpu, nr, inc_eip) != EMULATE_DONE)
			kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
		return;
	}

	if (kvm_exception_is_soft(nr)) {
		vmcs_write32(VM_ENTRY_INSTRUCTION_LEN,
			     vmx->vcpu.arch.event_exit_inst_len);
		intr_info |= INTR_TYPE_SOFT_EXCEPTION;
	} else
		intr_info |= INTR_TYPE_HARD_EXCEPTION;

	vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, intr_info);
}

static bool vmx_rdtscp_supported(void)
{
	return cpu_has_vmx_rdtscp();
}

/*
 * Swap MSR entry in host/guest MSR entry array.
 */
static void move_msr_up(struct vcpu_vmx *vmx, int from, int to)
{
	struct shared_msr_entry tmp;

	tmp = vmx->guest_msrs[to];
	vmx->guest_msrs[to] = vmx->guest_msrs[from];
	vmx->guest_msrs[from] = tmp;
}

/*
 * Set up the vmcs to automatically save and restore system
 * msrs.  Don't touch the 64-bit msrs if the guest is in legacy
 * mode, as fiddling with msrs is very expensive.
 */
static void setup_msrs(struct vcpu_vmx *vmx)
{
	int save_nmsrs, index;
	unsigned long *msr_bitmap;

	save_nmsrs = 0;
#ifdef CONFIG_X86_64
	if (is_long_mode(&vmx->vcpu)) {
		index = __find_msr_index(vmx, MSR_SYSCALL_MASK);
		if (index >= 0)
			move_msr_up(vmx, index, save_nmsrs++);
		index = __find_msr_index(vmx, MSR_LSTAR);
		if (index >= 0)
			move_msr_up(vmx, index, save_nmsrs++);
		index = __find_msr_index(vmx, MSR_CSTAR);
		if (index >= 0)
			move_msr_up(vmx, index, save_nmsrs++);
		index = __find_msr_index(vmx, MSR_TSC_AUX);
		if (index >= 0 && vmx->rdtscp_enabled)
			move_msr_up(vmx, index, save_nmsrs++);
		/*
		 * MSR_STAR is only needed on long mode guests, and only
		 * if efer.sce is enabled.
		 */
		index = __find_msr_index(vmx, MSR_STAR);
		if ((index >= 0) && (vmx->vcpu.arch.efer & EFER_SCE))
			move_msr_up(vmx, index, save_nmsrs++);
	}
#endif
	index = __find_msr_index(vmx, MSR_EFER);
	if (index >= 0 && update_transition_efer(vmx, index))
		move_msr_up(vmx, index, save_nmsrs++);

	vmx->save_nmsrs = save_nmsrs;

	if (cpu_has_vmx_msr_bitmap()) {
		if (is_long_mode(&vmx->vcpu))
			msr_bitmap = vmx_msr_bitmap_longmode;
		else
			msr_bitmap = vmx_msr_bitmap_legacy;

		vmcs_write64(MSR_BITMAP, __pa(msr_bitmap));
	}
}

/*
 * reads and returns guest's timestamp counter "register"
 * guest_tsc = host_tsc + tsc_offset    -- 21.3
 */
static u64 guest_read_tsc(void)
{
	u64 host_tsc, tsc_offset;

	rdtscll(host_tsc);
	tsc_offset = vmcs_read64(TSC_OFFSET);
	return host_tsc + tsc_offset;
}

/*
 * Like guest_read_tsc, but always returns L1's notion of the timestamp
 * counter, even if a nested guest (L2) is currently running.
 */
u64 vmx_read_l1_tsc(struct kvm_vcpu *vcpu)
{
	u64 host_tsc, tsc_offset;

	rdtscll(host_tsc);
	tsc_offset = is_guest_mode(vcpu) ?
		to_vmx(vcpu)->nested.vmcs01_tsc_offset :
		vmcs_read64(TSC_OFFSET);
	return host_tsc + tsc_offset;
}

/*
 * Engage any workarounds for mis-matched TSC rates.  Currently limited to
 * software catchup for faster rates on slower CPUs.
 */
static void vmx_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)
{
	if (!scale)
		return;

	if (user_tsc_khz > tsc_khz) {
		vcpu->arch.tsc_catchup = 1;
		vcpu->arch.tsc_always_catchup = 1;
	} else
		WARN(1, "user requested TSC rate below hardware speed\n");
}

/*
 * writes 'offset' into guest's timestamp counter offset register
 */
static void vmx_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)
{
	if (is_guest_mode(vcpu)) {
		/*
		 * We're here if L1 chose not to trap WRMSR to TSC. According
		 * to the spec, this should set L1's TSC; The offset that L1
		 * set for L2 remains unchanged, and still needs to be added
		 * to the newly set TSC to get L2's TSC.
		 */
		struct vmcs12 *vmcs12;
		to_vmx(vcpu)->nested.vmcs01_tsc_offset = offset;
		/* recalculate vmcs02.TSC_OFFSET: */
		vmcs12 = get_vmcs12(vcpu);
		vmcs_write64(TSC_OFFSET, offset +
			(nested_cpu_has(vmcs12, CPU_BASED_USE_TSC_OFFSETING) ?
			 vmcs12->tsc_offset : 0));
	} else {
		vmcs_write64(TSC_OFFSET, offset);
	}
}

static void vmx_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment, bool host)
{
	u64 offset = vmcs_read64(TSC_OFFSET);
	vmcs_write64(TSC_OFFSET, offset + adjustment);
	if (is_guest_mode(vcpu)) {
		/* Even when running L2, the adjustment needs to apply to L1 */
		to_vmx(vcpu)->nested.vmcs01_tsc_offset += adjustment;
	}
}

static u64 vmx_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
{
	return target_tsc - native_read_tsc();
}

static bool guest_cpuid_has_vmx(struct kvm_vcpu *vcpu)
{
	struct kvm_cpuid_entry2 *best = kvm_find_cpuid_entry(vcpu, 1, 0);
	return best && (best->ecx & (1 << (X86_FEATURE_VMX & 31)));
}

/*
 * nested_vmx_allowed() checks whether a guest should be allowed to use VMX
 * instructions and MSRs (i.e., nested VMX). Nested VMX is disabled for
 * all guests if the "nested" module option is off, and can also be disabled
 * for a single guest by disabling its VMX cpuid bit.
 */
static inline bool nested_vmx_allowed(struct kvm_vcpu *vcpu)
{
	return nested && guest_cpuid_has_vmx(vcpu);
}

/*
 * nested_vmx_setup_ctls_msrs() sets up variables containing the values to be
 * returned for the various VMX controls MSRs when nested VMX is enabled.
 * The same values should also be used to verify that vmcs12 control fields are
 * valid during nested entry from L1 to L2.
 * Each of these control msrs has a low and high 32-bit half: A low bit is on
 * if the corresponding bit in the (32-bit) control field *must* be on, and a
 * bit in the high half is on if the corresponding bit in the control field
 * may be on. See also vmx_control_verify().
 * TODO: allow these variables to be modified (downgraded) by module options
 * or other means.
 */
static u32 nested_vmx_procbased_ctls_low, nested_vmx_procbased_ctls_high;
static u32 nested_vmx_secondary_ctls_low, nested_vmx_secondary_ctls_high;
static u32 nested_vmx_pinbased_ctls_low, nested_vmx_pinbased_ctls_high;
static u32 nested_vmx_exit_ctls_low, nested_vmx_exit_ctls_high;
static u32 nested_vmx_entry_ctls_low, nested_vmx_entry_ctls_high;
static __init void nested_vmx_setup_ctls_msrs(void)
{
	/*
	 * Note that as a general rule, the high half of the MSRs (bits in
	 * the control fields which may be 1) should be initialized by the
	 * intersection of the underlying hardware's MSR (i.e., features which
	 * can be supported) and the list of features we want to expose -
	 * because they are known to be properly supported in our code.
	 * Also, usually, the low half of the MSRs (bits which must be 1) can
	 * be set to 0, meaning that L1 may turn off any of these bits. The
	 * reason is that if one of these bits is necessary, it will appear
	 * in vmcs01 and prepare_vmcs02, when it bitwise-or's the control
	 * fields of vmcs01 and vmcs02, will turn these bits off - and
	 * nested_vmx_exit_handled() will not pass related exits to L1.
	 * These rules have exceptions below.
	 */

	/* pin-based controls */
	/*
	 * According to the Intel spec, if bit 55 of VMX_BASIC is off (as it is
	 * in our case), bits 1, 2 and 4 (i.e., 0x16) must be 1 in this MSR.
	 */
	nested_vmx_pinbased_ctls_low = 0x16 ;
	nested_vmx_pinbased_ctls_high = 0x16 |
		PIN_BASED_EXT_INTR_MASK | PIN_BASED_NMI_EXITING |
		PIN_BASED_VIRTUAL_NMIS;

	/* exit controls */
	nested_vmx_exit_ctls_low = 0;
	/* Note that guest use of VM_EXIT_ACK_INTR_ON_EXIT is not supported. */
#ifdef CONFIG_X86_64
	nested_vmx_exit_ctls_high = VM_EXIT_HOST_ADDR_SPACE_SIZE;
#else
	nested_vmx_exit_ctls_high = 0;
#endif

	/* entry controls */
	rdmsr(MSR_IA32_VMX_ENTRY_CTLS,
		nested_vmx_entry_ctls_low, nested_vmx_entry_ctls_high);
	nested_vmx_entry_ctls_low = 0;
	nested_vmx_entry_ctls_high &=
		VM_ENTRY_LOAD_IA32_PAT | VM_ENTRY_IA32E_MODE;

	/* cpu-based controls */
	rdmsr(MSR_IA32_VMX_PROCBASED_CTLS,
		nested_vmx_procbased_ctls_low, nested_vmx_procbased_ctls_high);
	nested_vmx_procbased_ctls_low = 0;
	nested_vmx_procbased_ctls_high &=
		CPU_BASED_VIRTUAL_INTR_PENDING | CPU_BASED_USE_TSC_OFFSETING |
		CPU_BASED_HLT_EXITING | CPU_BASED_INVLPG_EXITING |
		CPU_BASED_MWAIT_EXITING | CPU_BASED_CR3_LOAD_EXITING |
		CPU_BASED_CR3_STORE_EXITING |
#ifdef CONFIG_X86_64
		CPU_BASED_CR8_LOAD_EXITING | CPU_BASED_CR8_STORE_EXITING |
#endif
		CPU_BASED_MOV_DR_EXITING | CPU_BASED_UNCOND_IO_EXITING |
		CPU_BASED_USE_IO_BITMAPS | CPU_BASED_MONITOR_EXITING |
		CPU_BASED_RDPMC_EXITING |
		CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
	/*
	 * We can allow some features even when not supported by the
	 * hardware. For example, L1 can specify an MSR bitmap - and we
	 * can use it to avoid exits to L1 - even when L0 runs L2
	 * without MSR bitmaps.
	 */
	nested_vmx_procbased_ctls_high |= CPU_BASED_USE_MSR_BITMAPS;

	/* secondary cpu-based controls */
	rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
		nested_vmx_secondary_ctls_low, nested_vmx_secondary_ctls_high);
	nested_vmx_secondary_ctls_low = 0;
	nested_vmx_secondary_ctls_high &=
		SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
}

static inline bool vmx_control_verify(u32 control, u32 low, u32 high)
{
	/*
	 * Bits 0 in high must be 0, and bits 1 in low must be 1.
	 */
	return ((control & high) | low) == control;
}

static inline u64 vmx_control_msr(u32 low, u32 high)
{
	return low | ((u64)high << 32);
}

/*
 * If we allow our guest to use VMX instructions (i.e., nested VMX), we should
 * also let it use VMX-specific MSRs.
 * vmx_get_vmx_msr() and vmx_set_vmx_msr() return 1 when we handled a
 * VMX-specific MSR, or 0 when we haven't (and the caller should handle it
 * like all other MSRs).
 */
static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
{
	if (!nested_vmx_allowed(vcpu) && msr_index >= MSR_IA32_VMX_BASIC &&
		     msr_index <= MSR_IA32_VMX_TRUE_ENTRY_CTLS) {
		/*
		 * According to the spec, processors which do not support VMX
		 * should throw a #GP(0) when VMX capability MSRs are read.
		 */
		kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
		return 1;
	}

	switch (msr_index) {
	case MSR_IA32_FEATURE_CONTROL:
		*pdata = 0;
		break;
	case MSR_IA32_VMX_BASIC:
		/*
		 * This MSR reports some information about VMX support. We
		 * should return information about the VMX we emulate for the
		 * guest, and the VMCS structure we give it - not about the
		 * VMX support of the underlying hardware.
		 */
		*pdata = VMCS12_REVISION |
			   ((u64)VMCS12_SIZE << VMX_BASIC_VMCS_SIZE_SHIFT) |
			   (VMX_BASIC_MEM_TYPE_WB << VMX_BASIC_MEM_TYPE_SHIFT);
		break;
	case MSR_IA32_VMX_TRUE_PINBASED_CTLS:
	case MSR_IA32_VMX_PINBASED_CTLS:
		*pdata = vmx_control_msr(nested_vmx_pinbased_ctls_low,
					nested_vmx_pinbased_ctls_high);
		break;
	case MSR_IA32_VMX_TRUE_PROCBASED_CTLS:
	case MSR_IA32_VMX_PROCBASED_CTLS:
		*pdata = vmx_control_msr(nested_vmx_procbased_ctls_low,
					nested_vmx_procbased_ctls_high);
		break;
	case MSR_IA32_VMX_TRUE_EXIT_CTLS:
	case MSR_IA32_VMX_EXIT_CTLS:
		*pdata = vmx_control_msr(nested_vmx_exit_ctls_low,
					nested_vmx_exit_ctls_high);
		break;
	case MSR_IA32_VMX_TRUE_ENTRY_CTLS:
	case MSR_IA32_VMX_ENTRY_CTLS:
		*pdata = vmx_control_msr(nested_vmx_entry_ctls_low,
					nested_vmx_entry_ctls_high);
		break;
	case MSR_IA32_VMX_MISC:
		*pdata = 0;
		break;
	/*
	 * These MSRs specify bits which the guest must keep fixed (on or off)
	 * while L1 is in VMXON mode (in L1's root mode, or running an L2).
	 * We picked the standard core2 setting.
	 */
#define VMXON_CR0_ALWAYSON	(X86_CR0_PE | X86_CR0_PG | X86_CR0_NE)
#define VMXON_CR4_ALWAYSON	X86_CR4_VMXE
	case MSR_IA32_VMX_CR0_FIXED0:
		*pdata = VMXON_CR0_ALWAYSON;
		break;
	case MSR_IA32_VMX_CR0_FIXED1:
		*pdata = -1ULL;
		break;
	case MSR_IA32_VMX_CR4_FIXED0:
		*pdata = VMXON_CR4_ALWAYSON;
		break;
	case MSR_IA32_VMX_CR4_FIXED1:
		*pdata = -1ULL;
		break;
	case MSR_IA32_VMX_VMCS_ENUM:
		*pdata = 0x1f;
		break;
	case MSR_IA32_VMX_PROCBASED_CTLS2:
		*pdata = vmx_control_msr(nested_vmx_secondary_ctls_low,
					nested_vmx_secondary_ctls_high);
		break;
	case MSR_IA32_VMX_EPT_VPID_CAP:
		/* Currently, no nested ept or nested vpid */
		*pdata = 0;
		break;
	default:
		return 0;
	}

	return 1;
}

static int vmx_set_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
{
	if (!nested_vmx_allowed(vcpu))
		return 0;

	if (msr_index == MSR_IA32_FEATURE_CONTROL)
		/* TODO: the right thing. */
		return 1;
	/*
	 * No need to treat VMX capability MSRs specially: If we don't handle
	 * them, handle_wrmsr will #GP(0), which is correct (they are readonly)
	 */
	return 0;
}

/*
 * Reads an msr value (of 'msr_index') into 'pdata'.
 * Returns 0 on success, non-0 otherwise.
 * Assumes vcpu_load() was already called.
 */
static int vmx_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
{
	u64 data;
	struct shared_msr_entry *msr;

	if (!pdata) {
		printk(KERN_ERR "BUG: get_msr called with NULL pdata\n");
		return -EINVAL;
	}

	switch (msr_index) {
#ifdef CONFIG_X86_64
	case MSR_FS_BASE:
		data = vmcs_readl(GUEST_FS_BASE);
		break;
	case MSR_GS_BASE:
		data = vmcs_readl(GUEST_GS_BASE);
		break;
	case MSR_KERNEL_GS_BASE:
		vmx_load_host_state(to_vmx(vcpu));
		data = to_vmx(vcpu)->msr_guest_kernel_gs_base;
		break;
#endif
	case MSR_EFER:
		return kvm_get_msr_common(vcpu, msr_index, pdata);
	case MSR_IA32_TSC:
		data = guest_read_tsc();
		break;
	case MSR_IA32_SYSENTER_CS:
		data = vmcs_read32(GUEST_SYSENTER_CS);
		break;
	case MSR_IA32_SYSENTER_EIP:
		data = vmcs_readl(GUEST_SYSENTER_EIP);
		break;
	case MSR_IA32_SYSENTER_ESP:
		data = vmcs_readl(GUEST_SYSENTER_ESP);
		break;
	case MSR_TSC_AUX:
		if (!to_vmx(vcpu)->rdtscp_enabled)
			return 1;
		/* Otherwise falls through */
	default:
		if (vmx_get_vmx_msr(vcpu, msr_index, pdata))
			return 0;
		msr = find_msr_entry(to_vmx(vcpu), msr_index);
		if (msr) {
			data = msr->data;
			break;
		}
		return kvm_get_msr_common(vcpu, msr_index, pdata);
	}

	*pdata = data;
	return 0;
}

/*
 * Writes msr value into into the appropriate "register".
 * Returns 0 on success, non-0 otherwise.
 * Assumes vcpu_load() was already called.
 */
static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
{
	struct vcpu_vmx *vmx = to_vmx(vcpu);
	struct shared_msr_entry *msr;
	int ret = 0;

	switch (msr_index) {
	case MSR_EFER:
		ret = kvm_set_msr_common(vcpu, msr_index, data);
		break;
#ifdef CONFIG_X86_64
	case MSR_FS_BASE:
		vmx_segment_cache_clear(vmx);
		vmcs_writel(GUEST_FS_BASE, data);
		break;
	case MSR_GS_BASE:
		vmx_segment_cache_clear(vmx);
		vmcs_writel(GUEST_GS_BASE, data);
		break;
	case MSR_KERNEL_GS_BASE:
		vmx_load_host_state(vmx);
		vmx->msr_guest_kernel_gs_base = data;
		break;
#endif
	case MSR_IA32_SYSENTER_CS:
		vmcs_write32(GUEST_SYSENTER_CS, data);
		break;
	case MSR_IA32_SYSENTER_EIP:
		vmcs_writel(GUEST_SYSENTER_EIP, data);
		break;
	case MSR_IA32_SYSENTER_ESP:
		vmcs_writel(GUEST_SYSENTER_ESP, data);
		break;
	case MSR_IA32_TSC:
		kvm_write_tsc(vcpu, data);
		break;
	case MSR_IA32_CR_PAT:
		if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
			vmcs_write64(GUEST_IA32_PAT, data);
			vcpu->arch.pat = data;
			break;
		}
		ret = kvm_set_msr_common(vcpu, msr_index, data);
		break;
	case MSR_TSC_AUX:
		if (!vmx->rdtscp_enabled)
			return 1;
		/* Check reserved bit, higher 32 bits should be zero */
		if ((data >> 32) != 0)
			return 1;
		/* Otherwise falls through */
	default:
		if (vmx_set_vmx_msr(vcpu, msr_index, data))
			break;
		msr = find_msr_entry(vmx, msr_index);
		if (msr) {
			msr->data = data;
			if (msr - vmx->guest_msrs < vmx->save_nmsrs)
				kvm_set_shared_msr(msr->index, msr->data,
						   msr->mask);
			break;
		}
		ret = kvm_set_msr_common(vcpu, msr_index, data);
	}

	return ret;
}

static void vmx_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
{
	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
	switch (reg) {
	case VCPU_REGS_RSP:
		vcpu->arch.regs[VCPU_REGS_RSP] = vmcs_readl(GUEST_RSP);
		break;
	case VCPU_REGS_RIP:
		vcpu->arch.regs[VCPU_REGS_RIP] = vmcs_readl(GUEST_RIP);
		break;
	case VCPU_EXREG_PDPTR:
		if (enable_ept)
			ept_save_pdptrs(vcpu);
		break;
	default:
		break;
	}
}

static void set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)
{
	if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
		vmcs_writel(GUEST_DR7, dbg->arch.debugreg[7]);
	else
		vmcs_writel(GUEST_DR7, vcpu->arch.dr7);

	update_exception_bitmap(vcpu);
}

static __init int cpu_has_kvm_support(void)
{
	return cpu_has_vmx();
}

static __init int vmx_disabled_by_bios(void)
{
	u64 msr;

	rdmsrl(MSR_IA32_FEATURE_CONTROL, msr);
	if (msr & FEATURE_CONTROL_LOCKED) {
		/* launched w/ TXT and VMX disabled */
		if (!(msr & FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX)
			&& tboot_enabled())
			return 1;
		/* launched w/o TXT and VMX only enabled w/ TXT */
		if (!(msr & FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX)
			&& (msr & FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX)
			&& !tboot_enabled()) {
			printk(KERN_WARNING "kvm: disable TXT in the BIOS or "
				"activate TXT before enabling KVM\n");
			return 1;
		}
		/* launched w/o TXT and VMX disabled */
		if (!(msr & FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX)
			&& !tboot_enabled())
			return 1;
	}

	return 0;
}

static void kvm_cpu_vmxon(u64 addr)
{
	asm volatile (ASM_VMX_VMXON_RAX
			: : "a"(&addr), "m"(addr)
			: "memory", "cc");
}

static int hardware_enable(void *garbage)
{
	int cpu = raw_smp_processor_id();
	u64 phys_addr = __pa(per_cpu(vmxarea, cpu));
	u64 old, test_bits;

	if (read_cr4() & X86_CR4_VMXE)
		return -EBUSY;

	INIT_LIST_HEAD(&per_cpu(loaded_vmcss_on_cpu, cpu));
	rdmsrl(MSR_IA32_FEATURE_CONTROL, old);

	test_bits = FEATURE_CONTROL_LOCKED;
	test_bits |= FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX;
	if (tboot_enabled())
		test_bits |= FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX;

	if ((old & test_bits) != test_bits) {
		/* enable and lock */
		wrmsrl(MSR_IA32_FEATURE_CONTROL, old | test_bits);
	}
	write_cr4(read_cr4() | X86_CR4_VMXE); /* FIXME: not cpu hotplug safe */

	if (vmm_exclusive) {
		kvm_cpu_vmxon(phys_addr);
		ept_sync_global();
	}

	store_gdt(&__get_cpu_var(host_gdt));

	return 0;
}

static void vmclear_local_loaded_vmcss(void)
{
	int cpu = raw_smp_processor_id();
	struct loaded_vmcs *v, *n;

	list_for_each_entry_safe(v, n, &per_cpu(loaded_vmcss_on_cpu, cpu),
				 loaded_vmcss_on_cpu_link)
		__loaded_vmcs_clear(v);
}


/* Just like cpu_vmxoff(), but with the __kvm_handle_fault_on_reboot()
 * tricks.
 */
static void kvm_cpu_vmxoff(void)
{
	asm volatile (__ex(ASM_VMX_VMXOFF) : : : "cc");
}

static void hardware_disable(void *garbage)
{
	if (vmm_exclusive) {
		vmclear_local_loaded_vmcss();
		kvm_cpu_vmxoff();
	}
	write_cr4(read_cr4() & ~X86_CR4_VMXE);
}

static __init int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt,
				      u32 msr, u32 *result)
{
	u32 vmx_msr_low, vmx_msr_high;
	u32 ctl = ctl_min | ctl_opt;

	rdmsr(msr, vmx_msr_low, vmx_msr_high);

	ctl &= vmx_msr_high; /* bit == 0 in high word ==> must be zero */
	ctl |= vmx_msr_low;  /* bit == 1 in low word  ==> must be one  */

	/* Ensure minimum (required) set of control bits are supported. */
	if (ctl_min & ~ctl)
		return -EIO;

	*result = ctl;
	return 0;
}

static __init bool allow_1_setting(u32 msr, u32 ctl)
{
	u32 vmx_msr_low, vmx_msr_high;

	rdmsr(msr, vmx_msr_low, vmx_msr_high);
	return vmx_msr_high & ctl;
}

static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf)
{
	u32 vmx_msr_low, vmx_msr_high;
	u32 min, opt, min2, opt2;
	u32 _pin_based_exec_control = 0;
	u32 _cpu_based_exec_control = 0;
	u32 _cpu_based_2nd_exec_control = 0;
	u32 _vmexit_control = 0;
	u32 _vmentry_control = 0;

	min = PIN_BASED_EXT_INTR_MASK | PIN_BASED_NMI_EXITING;
	opt = PIN_BASED_VIRTUAL_NMIS;
	if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PINBASED_CTLS,
				&_pin_based_exec_control) < 0)
		return -EIO;

	min = CPU_BASED_HLT_EXITING |
#ifdef CONFIG_X86_64
	      CPU_BASED_CR8_LOAD_EXITING |
	      CPU_BASED_CR8_STORE_EXITING |
#endif
	      CPU_BASED_CR3_LOAD_EXITING |
	      CPU_BASED_CR3_STORE_EXITING |
	      CPU_BASED_USE_IO_BITMAPS |
	      CPU_BASED_MOV_DR_EXITING |
	      CPU_BASED_USE_TSC_OFFSETING |
	      CPU_BASED_MWAIT_EXITING |
	      CPU_BASED_MONITOR_EXITING |
	      CPU_BASED_INVLPG_EXITING |
	      CPU_BASED_RDPMC_EXITING;

	opt = CPU_BASED_TPR_SHADOW |
	      CPU_BASED_USE_MSR_BITMAPS |
	      CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
	if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PROCBASED_CTLS,
				&_cpu_based_exec_control) < 0)
		return -EIO;
#ifdef CONFIG_X86_64
	if ((_cpu_based_exec_control & CPU_BASED_TPR_SHADOW))
		_cpu_based_exec_control &= ~CPU_BASED_CR8_LOAD_EXITING &
					   ~CPU_BASED_CR8_STORE_EXITING;
#endif
	if (_cpu_based_exec_control & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) {
		min2 = 0;
		opt2 = SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
			SECONDARY_EXEC_WBINVD_EXITING |
			SECONDARY_EXEC_ENABLE_VPID |
			SECONDARY_EXEC_ENABLE_EPT |
			SECONDARY_EXEC_UNRESTRICTED_GUEST |
			SECONDARY_EXEC_PAUSE_LOOP_EXITING |
			SECONDARY_EXEC_RDTSCP;
		if (adjust_vmx_controls(min2, opt2,
					MSR_IA32_VMX_PROCBASED_CTLS2,
					&_cpu_based_2nd_exec_control) < 0)
			return -EIO;
	}
#ifndef CONFIG_X86_64
	if (!(_cpu_based_2nd_exec_control &
				SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES))
		_cpu_based_exec_control &= ~CPU_BASED_TPR_SHADOW;
#endif
	if (_cpu_based_2nd_exec_control & SECONDARY_EXEC_ENABLE_EPT) {
		/* CR3 accesses and invlpg don't need to cause VM Exits when EPT
		   enabled */
		_cpu_based_exec_control &= ~(CPU_BASED_CR3_LOAD_EXITING |
					     CPU_BASED_CR3_STORE_EXITING |
					     CPU_BASED_INVLPG_EXITING);
		rdmsr(MSR_IA32_VMX_EPT_VPID_CAP,
		      vmx_capability.ept, vmx_capability.vpid);
	}

	min = 0;
#ifdef CONFIG_X86_64
	min |= VM_EXIT_HOST_ADDR_SPACE_SIZE;
#endif
	opt = VM_EXIT_SAVE_IA32_PAT | VM_EXIT_LOAD_IA32_PAT;
	if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_EXIT_CTLS,
				&_vmexit_control) < 0)
		return -EIO;

	min = 0;
	opt = VM_ENTRY_LOAD_IA32_PAT;
	if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_ENTRY_CTLS,
				&_vmentry_control) < 0)
		return -EIO;

	rdmsr(MSR_IA32_VMX_BASIC, vmx_msr_low, vmx_msr_high);

	/* IA-32 SDM Vol 3B: VMCS size is never greater than 4kB. */
	if ((vmx_msr_high & 0x1fff) > PAGE_SIZE)
		return -EIO;

#ifdef CONFIG_X86_64
	/* IA-32 SDM Vol 3B: 64-bit CPUs always have VMX_BASIC_MSR[48]==0. */
	if (vmx_msr_high & (1u<<16))
		return -EIO;
#endif

	/* Require Write-Back (WB) memory type for VMCS accesses. */
	if (((vmx_msr_high >> 18) & 15) != 6)
		return -EIO;

	vmcs_conf->size = vmx_msr_high & 0x1fff;
	vmcs_conf->order = get_order(vmcs_config.size);
	vmcs_conf->revision_id = vmx_msr_low;

	vmcs_conf->pin_based_exec_ctrl = _pin_based_exec_control;
	vmcs_conf->cpu_based_exec_ctrl = _cpu_based_exec_control;
	vmcs_conf->cpu_based_2nd_exec_ctrl = _cpu_based_2nd_exec_control;
	vmcs_conf->vmexit_ctrl         = _vmexit_control;
	vmcs_conf->vmentry_ctrl        = _vmentry_control;

	cpu_has_load_ia32_efer =
		allow_1_setting(MSR_IA32_VMX_ENTRY_CTLS,
				VM_ENTRY_LOAD_IA32_EFER)
		&& allow_1_setting(MSR_IA32_VMX_EXIT_CTLS,
				   VM_EXIT_LOAD_IA32_EFER);

	cpu_has_load_perf_global_ctrl =
		allow_1_setting(MSR_IA32_VMX_ENTRY_CTLS,
				VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL)
		&& allow_1_setting(MSR_IA32_VMX_EXIT_CTLS,
				   VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL);

	/*
	 * Some cpus support VM_ENTRY_(LOAD|SAVE)_IA32_PERF_GLOBAL_CTRL
	 * but due to arrata below it can't be used. Workaround is to use
	 * msr load mechanism to switch IA32_PERF_GLOBAL_CTRL.
	 *
	 * VM Exit May Incorrectly Clear IA32_PERF_GLOBAL_CTRL [34:32]
	 *
	 * AAK155             (model 26)
	 * AAP115             (model 30)
	 * AAT100             (model 37)
	 * BC86,AAY89,BD102   (model 44)
	 * BA97               (model 46)
	 *
	 */
	if (cpu_has_load_perf_global_ctrl && boot_cpu_data.x86 == 0x6) {
		switch (boot_cpu_data.x86_model) {
		case 26:
		case 30:
		case 37:
		case 44:
		case 46:
			cpu_has_load_perf_global_ctrl = false;
			printk_once(KERN_WARNING"kvm: VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL "
					"does not work properly. Using workaround\n");
			break;
		default:
			break;
		}
	}

	return 0;
}

static struct vmcs *alloc_vmcs_cpu(int cpu)
{
	int node = cpu_to_node(cpu);
	struct page *pages;
	struct vmcs *vmcs;

	pages = alloc_pages_exact_node(node, GFP_KERNEL, vmcs_config.order);
	if (!pages)
		return NULL;
	vmcs = page_address(pages);
	memset(vmcs, 0, vmcs_config.size);
	vmcs->revision_id = vmcs_config.revision_id; /* vmcs revision id */
	return vmcs;
}

static struct vmcs *alloc_vmcs(void)
{
	return alloc_vmcs_cpu(raw_smp_processor_id());
}

static void free_vmcs(struct vmcs *vmcs)
{
	free_pages((unsigned long)vmcs, vmcs_config.order);
}

/*
 * Free a VMCS, but before that VMCLEAR it on the CPU where it was last loaded
 */
static void free_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
{
	if (!loaded_vmcs->vmcs)
		return;
	loaded_vmcs_clear(loaded_vmcs);
	free_vmcs(loaded_vmcs->vmcs);
	loaded_vmcs->vmcs = NULL;
}

static void free_kvm_area(void)
{
	int cpu;

	for_each_possible_cpu(cpu) {
		free_vmcs(per_cpu(vmxarea, cpu));
		per_cpu(vmxarea, cpu) = NULL;
	}
}

static __init int alloc_kvm_area(void)
{
	int cpu;

	for_each_possible_cpu(cpu) {
		struct vmcs *vmcs;

		vmcs = alloc_vmcs_cpu(cpu);
		if (!vmcs) {
			free_kvm_area();
			return -ENOMEM;
		}

		per_cpu(vmxarea, cpu) = vmcs;
	}
	return 0;
}

static __init int hardware_setup(void)
{
	if (setup_vmcs_config(&vmcs_config) < 0)
		return -EIO;

	if (boot_cpu_has(X86_FEATURE_NX))
		kvm_enable_efer_bits(EFER_NX);

	if (!cpu_has_vmx_vpid())
		enable_vpid = 0;

	if (!cpu_has_vmx_ept() ||
	    !cpu_has_vmx_ept_4levels()) {
		enable_ept = 0;
		enable_unrestricted_guest = 0;
	}

	if (!cpu_has_vmx_unrestricted_guest())
		enable_unrestricted_guest = 0;

	if (!cpu_has_vmx_flexpriority())
		flexpriority_enabled = 0;

	if (!cpu_has_vmx_tpr_shadow())
		kvm_x86_ops->update_cr8_intercept = NULL;

	if (enable_ept && !cpu_has_vmx_ept_2m_page())
		kvm_disable_largepages();

	if (!cpu_has_vmx_ple())
		ple_gap = 0;

	if (nested)
		nested_vmx_setup_ctls_msrs();

	return alloc_kvm_area();
}

static __exit void hardware_unsetup(void)
{
	free_kvm_area();
}

static void fix_pmode_dataseg(int seg, struct kvm_save_segment *save)
{
	struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg];

	if (vmcs_readl(sf->base) == save->base && (save->base & AR_S_MASK)) {
		vmcs_write16(sf->selector, save->selector);
		vmcs_writel(sf->base, save->base);
		vmcs_write32(sf->limit, save->limit);
		vmcs_write32(sf->ar_bytes, save->ar);
	} else {
		u32 dpl = (vmcs_read16(sf->selector) & SELECTOR_RPL_MASK)
			<< AR_DPL_SHIFT;
		vmcs_write32(sf->ar_bytes, 0x93 | dpl);
	}
}

static void enter_pmode(struct kvm_vcpu *vcpu)
{
	unsigned long flags;
	struct vcpu_vmx *vmx = to_vmx(vcpu);

	vmx->emulation_required = 1;
	vmx->rmode.vm86_active = 0;

	vmx_segment_cache_clear(vmx);

	vmcs_write16(GUEST_TR_SELECTOR, vmx->rmode.tr.selector);
	vmcs_writel(GUEST_TR_BASE, vmx->rmode.tr.base);
	vmcs_write32(GUEST_TR_LIMIT, vmx->rmode.tr.limit);
	vmcs_write32(GUEST_TR_AR_BYTES, vmx->rmode.tr.ar);

	flags = vmcs_readl(GUEST_RFLAGS);
	flags &= RMODE_GUEST_OWNED_EFLAGS_BITS;
	flags |= vmx->rmode.save_rflags & ~RMODE_GUEST_OWNED_EFLAGS_BITS;
	vmcs_writel(GUEST_RFLAGS, flags);

	vmcs_writel(GUEST_CR4, (vmcs_readl(GUEST_CR4) & ~X86_CR4_VME) |
			(vmcs_readl(CR4_READ_SHADOW) & X86_CR4_VME));

	update_exception_bitmap(vcpu);

	if (emulate_invalid_guest_state)
		return;

	fix_pmode_dataseg(VCPU_SREG_ES, &vmx->rmode.es);
	fix_pmode_dataseg(VCPU_SREG_DS, &vmx->rmode.ds);
	fix_pmode_dataseg(VCPU_SREG_GS, &vmx->rmode.gs);
	fix_pmode_dataseg(VCPU_SREG_FS, &vmx->rmode.fs);

	vmx_segment_cache_clear(vmx);

	vmcs_write16(GUEST_SS_SELECTOR, 0);
	vmcs_write32(GUEST_SS_AR_BYTES, 0x93);

	vmcs_write16(GUEST_CS_SELECTOR,
		     vmcs_read16(GUEST_CS_SELECTOR) & ~SELECTOR_RPL_MASK);
	vmcs_write32(GUEST_CS_AR_BYTES, 0x9b);
}

static gva_t rmode_tss_base(struct kvm *kvm)
{
	if (!kvm->arch.tss_addr) {
		struct kvm_memslots *slots;
		struct kvm_memory_slot *slot;
		gfn_t base_gfn;

		slots = kvm_memslots(kvm);
		slot = id_to_memslot(slots, 0);
		base_gfn = slot->base_gfn + slot->npages - 3;

		return base_gfn << PAGE_SHIFT;
	}
	return kvm->arch.tss_addr;
}

static void fix_rmode_seg(int seg, struct kvm_save_segment *save)
{
	struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg];

	save->selector = vmcs_read16(sf->selector);
	save->base = vmcs_readl(sf->base);
	save->limit = vmcs_read32(sf->limit);
	save->ar = vmcs_read32(sf->ar_bytes);
	vmcs_write16(sf->selector, save->base >> 4);
	vmcs_write32(sf->base, save->base & 0xffff0);
	vmcs_write32(sf->limit, 0xffff);
	vmcs_write32(sf->ar_bytes, 0xf3);
	if (save->base & 0xf)
		printk_once(KERN_WARNING "kvm: segment base is not paragraph"
			    " aligned when entering protected mode (seg=%d)",
			    seg);
}

static void enter_rmode(struct kvm_vcpu *vcpu)
{
	unsigned long flags;
	struct vcpu_vmx *vmx = to_vmx(vcpu);

	if (enable_unrestricted_guest)
		return;

	vmx->emulation_required = 1;
	vmx->rmode.vm86_active = 1;

	/*
	 * Very old userspace does not call KVM_SET_TSS_ADDR before entering
	 * vcpu. Call it here with phys address pointing 16M below 4G.
	 */
	if (!vcpu->kvm->arch.tss_addr) {
		printk_once(KERN_WARNING "kvm: KVM_SET_TSS_ADDR need to be "
			     "called before entering vcpu\n");
		srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
		vmx_set_tss_addr(vcpu->kvm, 0xfeffd000);
		vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
	}

	vmx_segment_cache_clear(vmx);

	vmx->rmode.tr.selector = vmcs_read16(GUEST_TR_SELECTOR);
	vmx->rmode.tr.base = vmcs_readl(GUEST_TR_BASE);
	vmcs_writel(GUEST_TR_BASE, rmode_tss_base(vcpu->kvm));

	vmx->rmode.tr.limit = vmcs_read32(GUEST_TR_LIMIT);
	vmcs_write32(GUEST_TR_LIMIT, RMODE_TSS_SIZE - 1);

	vmx->rmode.tr.ar = vmcs_read32(GUEST_TR_AR_BYTES);
	vmcs_write32(GUEST_TR_AR_BYTES, 0x008b);

	flags = vmcs_readl(GUEST_RFLAGS);
	vmx->rmode.save_rflags = flags;

	flags |= X86_EFLAGS_IOPL | X86_EFLAGS_VM;

	vmcs_writel(GUEST_RFLAGS, flags);
	vmcs_writel(GUEST_CR4, vmcs_readl(GUEST_CR4) | X86_CR4_VME);
	update_exception_bitmap(vcpu);

	if (emulate_invalid_guest_state)
		goto continue_rmode;

	vmcs_write16(GUEST_SS_SELECTOR, vmcs_readl(GUEST_SS_BASE) >> 4);
	vmcs_write32(GUEST_SS_LIMIT, 0xffff);
	vmcs_write32(GUEST_SS_AR_BYTES, 0xf3);

	vmcs_write32(GUEST_CS_AR_BYTES, 0xf3);
	vmcs_write32(GUEST_CS_LIMIT, 0xffff);
	if (vmcs_readl(GUEST_CS_BASE) == 0xffff0000)
		vmcs_writel(GUEST_CS_BASE, 0xf0000);
	vmcs_write16(GUEST_CS_SELECTOR, vmcs_readl(GUEST_CS_BASE) >> 4);

	fix_rmode_seg(VCPU_SREG_ES, &vmx->rmode.es);
	fix_rmode_seg(VCPU_SREG_DS, &vmx->rmode.ds);
	fix_rmode_seg(VCPU_SREG_GS, &vmx->rmode.gs);
	fix_rmode_seg(VCPU_SREG_FS, &vmx->rmode.fs);

continue_rmode:
	kvm_mmu_reset_context(vcpu);
}

static void vmx_set_efer(struct kvm_vcpu *vcpu, u64 efer)
{
	struct vcpu_vmx *vmx = to_vmx(vcpu);
	struct shared_msr_entry *msr = find_msr_entry(vmx, MSR_EFER);

	if (!msr)
		return;

	/*
	 * Force kernel_gs_base reloading before EFER changes, as control
	 * of this msr depends on is_long_mode().
	 */
	vmx_load_host_state(to_vmx(vcpu));
	vcpu->arch.efer = efer;
	if (efer & EFER_LMA) {
		vmcs_write32(VM_ENTRY_CONTROLS,
			     vmcs_read32(VM_ENTRY_CONTROLS) |
			     VM_ENTRY_IA32E_MODE);
		msr->data = efer;
	} else {
		vmcs_write32(VM_ENTRY_CONTROLS,
			     vmcs_read32(VM_ENTRY_CONTROLS) &
			     ~VM_ENTRY_IA32E_MODE);

		msr->data = efer & ~EFER_LME;
	}
	setup_msrs(vmx);
}

#ifdef CONFIG_X86_64

static void enter_lmode(struct kvm_vcpu *vcpu)
{
	u32 guest_tr_ar;

	vmx_segment_cache_clear(to_vmx(vcpu));

	guest_tr_ar = vmcs_read32(GUEST_TR_AR_BYTES);
	if ((guest_tr_ar & AR_TYPE_MASK) != AR_TYPE_BUSY_64_TSS) {
		pr_debug_ratelimited("%s: tss fixup for long mode. \n",
				     __func__);
		vmcs_write32(GUEST_TR_AR_BYTES,
			     (guest_tr_ar & ~AR_TYPE_MASK)
			     | AR_TYPE_BUSY_64_TSS);
	}
	vmx_set_efer(vcpu, vcpu->arch.efer | EFER_LMA);
}

static void exit_lmode(struct kvm_vcpu *vcpu)
{
	vmcs_write32(VM_ENTRY_CONTROLS,
		     vmcs_read32(VM_ENTRY_CONTROLS)
		     & ~VM_ENTRY_IA32E_MODE);
	vmx_set_efer(vcpu, vcpu->arch.efer & ~EFER_LMA);
}

#endif

static void vmx_flush_tlb(struct kvm_vcpu *vcpu)
{
	vpid_sync_context(to_vmx(vcpu));
	if (enable_ept) {
		if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
			return;
		ept_sync_context(construct_eptp(vcpu->arch.mmu.root_hpa));
	}
}

static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu)
{
	ulong cr0_guest_owned_bits = vcpu->arch.cr0_guest_owned_bits;

	vcpu->arch.cr0 &= ~cr0_guest_owned_bits;
	vcpu->arch.cr0 |= vmcs_readl(GUEST_CR0) & cr0_guest_owned_bits;
}

static void vmx_decache_cr3(struct kvm_vcpu *vcpu)
{
	if (enable_ept && is_paging(vcpu))
		vcpu->arch.cr3 = vmcs_readl(GUEST_CR3);
	__set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);
}

static void vmx_decache_cr4_guest_bits(struct kvm_vcpu *vcpu)
{
	ulong cr4_guest_owned_bits = vcpu->arch.cr4_guest_owned_bits;

	vcpu->arch.cr4 &= ~cr4_guest_owned_bits;
	vcpu->arch.cr4 |= vmcs_readl(GUEST_CR4) & cr4_guest_owned_bits;
}

static void ept_load_pdptrs(struct kvm_vcpu *vcpu)
{
	if (!test_bit(VCPU_EXREG_PDPTR,
		      (unsigned long *)&vcpu->arch.regs_dirty))
		return;

	if (is_paging(vcpu) && is_pae(vcpu) && !is_long_mode(vcpu)) {
		vmcs_write64(GUEST_PDPTR0, vcpu->arch.mmu.pdptrs[0]);
		vmcs_write64(GUEST_PDPTR1, vcpu->arch.mmu.pdptrs[1]);
		vmcs_write64(GUEST_PDPTR2, vcpu->arch.mmu.pdptrs[2]);
		vmcs_write64(GUEST_PDPTR3, vcpu->arch.mmu.pdptrs[3]);
	}
}

static void ept_save_pdptrs(struct kvm_vcpu *vcpu)
{
	if (is_paging(vcpu) && is_pae(vcpu) && !is_long_mode(vcpu)) {
		vcpu->arch.mmu.pdptrs[0] = vmcs_read64(GUEST_PDPTR0);
		vcpu->arch.mmu.pdptrs[1] = vmcs_read64(GUEST_PDPTR1);
		vcpu->arch.mmu.pdptrs[2] = vmcs_read64(GUEST_PDPTR2);
		vcpu->arch.mmu.pdptrs[3] = vmcs_read64(GUEST_PDPTR3);
	}

	__set_bit(VCPU_EXREG_PDPTR,
		  (unsigned long *)&vcpu->arch.regs_avail);
	__set_bit(VCPU_EXREG_PDPTR,
		  (unsigned long *)&vcpu->arch.regs_dirty);
}

static int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4);

static void ept_update_paging_mode_cr0(unsigned long *hw_cr0,
					unsigned long cr0,
					struct kvm_vcpu *vcpu)
{
	if (!test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail))
		vmx_decache_cr3(vcpu);
	if (!(cr0 & X86_CR0_PG)) {
		/* From paging/starting to nonpaging */
		vmcs_write32(CPU_BASED_VM_EXEC_CONTROL,
			     vmcs_read32(CPU_BASED_VM_EXEC_CONTROL) |
			     (CPU_BASED_CR3_LOAD_EXITING |
			      CPU_BASED_CR3_STORE_EXITING));
		vcpu->arch.cr0 = cr0;
		vmx_set_cr4(vcpu, kvm_read_cr4(vcpu));
	} else if (!is_paging(vcpu)) {
		/* From nonpaging to paging */
		vmcs_write32(CPU_BASED_VM_EXEC_CONTROL,
			     vmcs_read32(CPU_BASED_VM_EXEC_CONTROL) &
			     ~(CPU_BASED_CR3_LOAD_EXITING |
			       CPU_BASED_CR3_STORE_EXITING));
		vcpu->arch.cr0 = cr0;
		vmx_set_cr4(vcpu, kvm_read_cr4(vcpu));
	}

	if (!(cr0 & X86_CR0_WP))
		*hw_cr0 &= ~X86_CR0_WP;
}

static void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
{
	struct vcpu_vmx *vmx = to_vmx(vcpu);
	unsigned long hw_cr0;

	if (enable_unrestricted_guest)
		hw_cr0 = (cr0 & ~KVM_GUEST_CR0_MASK_UNRESTRICTED_GUEST)
			| KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST;
	else
		hw_cr0 = (cr0 & ~KVM_GUEST_CR0_MASK) | KVM_VM_CR0_ALWAYS_ON;

	if (vmx->rmode.vm86_active && (cr0 & X86_CR0_PE))
		enter_pmode(vcpu);

	if (!vmx->rmode.vm86_active && !(cr0 & X86_CR0_PE))
		enter_rmode(vcpu);

#ifdef CONFIG_X86_64
	if (vcpu->arch.efer & EFER_LME) {
		if (!is_paging(vcpu) && (cr0 & X86_CR0_PG))
			enter_lmode(vcpu);
		if (is_paging(vcpu) && !(cr0 & X86_CR0_PG))
			exit_lmode(vcpu);
	}
#endif

	if (enable_ept)
		ept_update_paging_mode_cr0(&hw_cr0, cr0, vcpu);

	if (!vcpu->fpu_active)
		hw_cr0 |= X86_CR0_TS | X86_CR0_MP;

	vmcs_writel(CR0_READ_SHADOW, cr0);
	vmcs_writel(GUEST_CR0, hw_cr0);
	vcpu->arch.cr0 = cr0;
	__clear_bit(VCPU_EXREG_CPL, (ulong *)&vcpu->arch.regs_avail);
}

static u64 construct_eptp(unsigned long root_hpa)
{
	u64 eptp;

	/* TODO write the value reading from MSR */
	eptp = VMX_EPT_DEFAULT_MT |
		VMX_EPT_DEFAULT_GAW << VMX_EPT_GAW_EPTP_SHIFT;
	eptp |= (root_hpa & PAGE_MASK);

	return eptp;
}

static void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
{
	unsigned long guest_cr3;
	u64 eptp;

	guest_cr3 = cr3;
	if (enable_ept) {
		eptp = construct_eptp(cr3);
		vmcs_write64(EPT_POINTER, eptp);
		guest_cr3 = is_paging(vcpu) ? kvm_read_cr3(vcpu) :
			vcpu->kvm->arch.ept_identity_map_addr;
		ept_load_pdptrs(vcpu);
	}

	vmx_flush_tlb(vcpu);
	vmcs_writel(GUEST_CR3, guest_cr3);
}

static int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
	unsigned long hw_cr4 = cr4 | (to_vmx(vcpu)->rmode.vm86_active ?
		    KVM_RMODE_VM_CR4_ALWAYS_ON : KVM_PMODE_VM_CR4_ALWAYS_ON);

	if (cr4 & X86_CR4_VMXE) {
		/*
		 * To use VMXON (and later other VMX instructions), a guest
		 * must first be able to turn on cr4.VMXE (see handle_vmon()).
		 * So basically the check on whether to allow nested VMX
		 * is here.
		 */
		if (!nested_vmx_allowed(vcpu))
			return 1;
	} else if (to_vmx(vcpu)->nested.vmxon)
		return 1;

	vcpu->arch.cr4 = cr4;
	if (enable_ept) {
		if (!is_paging(vcpu)) {
			hw_cr4 &= ~X86_CR4_PAE;
			hw_cr4 |= X86_CR4_PSE;
		} else if (!(cr4 & X86_CR4_PAE)) {
			hw_cr4 &= ~X86_CR4_PAE;
		}
	}

	vmcs_writel(CR4_READ_SHADOW, cr4);
	vmcs_writel(GUEST_CR4, hw_cr4);
	return 0;
}

static void vmx_get_segment(struct kvm_vcpu *vcpu,
			    struct kvm_segment *var, int seg)
{
	struct vcpu_vmx *vmx = to_vmx(vcpu);
	struct kvm_save_segment *save;
	u32 ar;

	if (vmx->rmode.vm86_active
	    && (seg == VCPU_SREG_TR || seg == VCPU_SREG_ES
		|| seg == VCPU_SREG_DS || seg == VCPU_SREG_FS
		|| seg == VCPU_SREG_GS)
	    && !emulate_invalid_guest_state) {
		switch (seg) {
		case VCPU_SREG_TR: save = &vmx->rmode.tr; break;
		case VCPU_SREG_ES: save = &vmx->rmode.es; break;
		case VCPU_SREG_DS: save = &vmx->rmode.ds; break;
		case VCPU_SREG_FS: save = &vmx->rmode.fs; break;
		case VCPU_SREG_GS: save = &vmx->rmode.gs; break;
		default: BUG();
		}
		var->selector = save->selector;
		var->base = save->base;
		var->limit = save->limit;
		ar = save->ar;
		if (seg == VCPU_SREG_TR
		    || var->selector == vmx_read_guest_seg_selector(vmx, seg))
			goto use_saved_rmode_seg;
	}
	var->base = vmx_read_guest_seg_base(vmx, seg);
	var->limit = vmx_read_guest_seg_limit(vmx, seg);
	var->selector = vmx_read_guest_seg_selector(vmx, seg);
	ar = vmx_read_guest_seg_ar(vmx, seg);
use_saved_rmode_seg:
	if ((ar & AR_UNUSABLE_MASK) && !emulate_invalid_guest_state)
		ar = 0;
	var->type = ar & 15;
	var->s = (ar >> 4) & 1;
	var->dpl = (ar >> 5) & 3;
	var->present = (ar >> 7) & 1;
	var->avl = (ar >> 12) & 1;
	var->l = (ar >> 13) & 1;
	var->db = (ar >> 14) & 1;
	var->g = (ar >> 15) & 1;
	var->unusable = (ar >> 16) & 1;
}

static u64 vmx_get_segment_base(struct kvm_vcpu *vcpu, int seg)
{
	struct kvm_segment s;

	if (to_vmx(vcpu)->rmode.vm86_active) {
		vmx_get_segment(vcpu, &s, seg);
		return s.base;
	}
	return vmx_read_guest_seg_base(to_vmx(vcpu), seg);
}

static int __vmx_get_cpl(struct kvm_vcpu *vcpu)
{
	if (!is_protmode(vcpu))
		return 0;

	if (!is_long_mode(vcpu)
	    && (kvm_get_rflags(vcpu) & X86_EFLAGS_VM)) /* if virtual 8086 */
		return 3;

	return vmx_read_guest_seg_selector(to_vmx(vcpu), VCPU_SREG_CS) & 3;
}

static int vmx_get_cpl(struct kvm_vcpu *vcpu)
{
	if (!test_bit(VCPU_EXREG_CPL, (ulong *)&vcpu->arch.regs_avail)) {
		__set_bit(VCPU_EXREG_CPL, (ulong *)&vcpu->arch.regs_avail);
		to_vmx(vcpu)->cpl = __vmx_get_cpl(vcpu);
	}
	return to_vmx(vcpu)->cpl;
}


static u32 vmx_segment_access_rights(struct kvm_segment *var)
{
	u32 ar;

	if (var->unusable)
		ar = 1 << 16;
	else {
		ar = var->type & 15;
		ar |= (var->s & 1) << 4;
		ar |= (var->dpl & 3) << 5;
		ar |= (var->present & 1) << 7;
		ar |= (var->avl & 1) << 12;
		ar |= (var->l & 1) << 13;