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root/arch/x86/kvm/vmx.c

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DEFINITIONS

This source file includes following definitions.
  1. to_vmx
  2. load_msrs
  3. save_msrs
  4. is_page_fault
  5. is_no_device
  6. is_invalid_opcode
  7. is_external_interrupt
  8. cpu_has_vmx_msr_bitmap
  9. cpu_has_vmx_tpr_shadow
  10. vm_need_tpr_shadow
  11. cpu_has_secondary_exec_ctrls
  12. cpu_has_vmx_virtualize_apic_accesses
  13. cpu_has_vmx_invept_individual_addr
  14. cpu_has_vmx_invept_context
  15. cpu_has_vmx_invept_global
  16. cpu_has_vmx_ept
  17. vm_need_ept
  18. vm_need_virtualize_apic_accesses
  19. cpu_has_vmx_vpid
  20. cpu_has_virtual_nmis
  21. __find_msr_index
  22. __invvpid
  23. __invept
  24. find_msr_entry
  25. vmcs_clear
  26. __vcpu_clear
  27. vcpu_clear
  28. vpid_sync_vcpu_all
  29. ept_sync_global
  30. ept_sync_context
  31. ept_sync_individual_addr
  32. vmcs_readl
  33. vmcs_read16
  34. vmcs_read32
  35. vmcs_read64
  36. vmwrite_error
  37. vmcs_writel
  38. vmcs_write16
  39. vmcs_write32
  40. vmcs_write64
  41. vmcs_clear_bits
  42. vmcs_set_bits
  43. update_exception_bitmap
  44. reload_tss
  45. load_transition_efer
  46. reload_host_efer
  47. vmx_save_host_state
  48. __vmx_load_host_state
  49. vmx_load_host_state
  50. vmx_vcpu_load
  51. vmx_vcpu_put
  52. vmx_fpu_activate
  53. vmx_fpu_deactivate
  54. vmx_get_rflags
  55. vmx_set_rflags
  56. skip_emulated_instruction
  57. vmx_queue_exception
  58. vmx_exception_injected
  59. move_msr_up
  60. setup_msrs
  61. guest_read_tsc
  62. guest_write_tsc
  63. vmx_get_msr
  64. vmx_set_msr
  65. vcpu_load_rsp_rip
  66. vcpu_put_rsp_rip
  67. set_guest_debug
  68. vmx_get_irq
  69. cpu_has_kvm_support
  70. vmx_disabled_by_bios
  71. hardware_enable
  72. vmclear_local_vcpus
  73. hardware_disable
  74. adjust_vmx_controls
  75. setup_vmcs_config
  76. alloc_vmcs_cpu
  77. alloc_vmcs
  78. free_vmcs
  79. free_kvm_area
  80. alloc_kvm_area
  81. hardware_setup
  82. hardware_unsetup
  83. fix_pmode_dataseg
  84. enter_pmode
  85. rmode_tss_base
  86. fix_rmode_seg
  87. enter_rmode
  88. enter_lmode
  89. exit_lmode
  90. vmx_flush_tlb
  91. vmx_decache_cr4_guest_bits
  92. ept_load_pdptrs
  93. ept_update_paging_mode_cr0
  94. ept_update_paging_mode_cr4
  95. vmx_set_cr0
  96. construct_eptp
  97. vmx_set_cr3
  98. vmx_set_cr4
  99. vmx_set_efer
  100. vmx_get_segment_base
  101. vmx_get_segment
  102. vmx_get_cpl
  103. vmx_segment_access_rights
  104. vmx_set_segment
  105. vmx_get_cs_db_l_bits
  106. vmx_get_idt
  107. vmx_set_idt
  108. vmx_get_gdt
  109. vmx_set_gdt
  110. init_rmode_tss
  111. init_rmode_identity_map
  112. seg_setup
  113. alloc_apic_access_page
  114. alloc_identity_pagetable
  115. allocate_vpid
  116. vmx_disable_intercept_for_msr
  117. vmx_vcpu_setup
  118. init_rmode
  119. vmx_vcpu_reset
  120. vmx_inject_irq
  121. vmx_inject_nmi
  122. kvm_do_inject_irq
  123. do_interrupt_requests
  124. vmx_set_tss_addr
  125. kvm_guest_debug_pre
  126. handle_rmode_exception
  127. handle_exception
  128. handle_external_interrupt
  129. handle_triple_fault
  130. handle_io
  131. vmx_patch_hypercall
  132. handle_cr
  133. handle_dr
  134. handle_cpuid
  135. handle_rdmsr
  136. handle_wrmsr
  137. handle_tpr_below_threshold
  138. handle_interrupt_window
  139. handle_halt
  140. handle_vmcall
  141. handle_wbinvd
  142. handle_apic_access
  143. handle_task_switch
  144. handle_ept_violation
  145. handle_nmi_window
  146. kvm_handle_exit
  147. update_tpr_threshold
  148. enable_irq_window
  149. enable_nmi_window
  150. vmx_nmi_enabled
  151. vmx_irq_enabled
  152. enable_intr_window
  153. vmx_intr_assist
  154. fixup_rmode_irq
  155. vmx_vcpu_run
  156. vmx_free_vmcs
  157. vmx_free_vcpu
  158. vmx_create_vcpu
  159. vmx_check_processor_compat
  160. get_ept_level
  161. vmx_init
  162. vmx_exit

/*
 * 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.
 *
 * 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 "vmx.h"
#include "mmu.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 <asm/io.h>
#include <asm/desc.h>

#define __ex(x) __kvm_handle_fault_on_reboot(x)

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

static int bypass_guest_pf = 1;
module_param(bypass_guest_pf, bool, 0);

static int enable_vpid = 1;
module_param(enable_vpid, bool, 0);

static int flexpriority_enabled = 1;
module_param(flexpriority_enabled, bool, 0);

static int enable_ept = 1;
module_param(enable_ept, bool, 0);

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

struct vcpu_vmx {
        struct kvm_vcpu       vcpu;
        struct list_head      local_vcpus_link;
        int                   launched;
        u8                    fail;
        u32                   idt_vectoring_info;
        struct kvm_msr_entry *guest_msrs;
        struct kvm_msr_entry *host_msrs;
        int                   nmsrs;
        int                   save_nmsrs;
        int                   msr_offset_efer;
#ifdef CONFIG_X86_64
        int                   msr_offset_kernel_gs_base;
#endif
        struct vmcs          *vmcs;
        struct {
                int           loaded;
                u16           fs_sel, gs_sel, ldt_sel;
                int           gs_ldt_reload_needed;
                int           fs_reload_needed;
                int           guest_efer_loaded;
        } host_state;
        struct {
                struct {
                        bool pending;
                        u8 vector;
                        unsigned rip;
                } irq;
        } rmode;
        int vpid;
};

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

static int init_rmode(struct kvm *kvm);
static u64 construct_eptp(unsigned long root_hpa);

static DEFINE_PER_CPU(struct vmcs *, vmxarea);
static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
static DEFINE_PER_CPU(struct list_head, vcpus_on_cpu);

static struct page *vmx_io_bitmap_a;
static struct page *vmx_io_bitmap_b;
static struct page *vmx_msr_bitmap;

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;

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),
};

/*
 * Keep MSR_K6_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, MSR_KERNEL_GS_BASE,
#endif
        MSR_EFER, MSR_K6_STAR,
};
#define NR_VMX_MSR ARRAY_SIZE(vmx_msr_index)

static void load_msrs(struct kvm_msr_entry *e, int n)
{
        int i;

        for (i = 0; i < n; ++i)
                wrmsrl(e[i].index, e[i].data);
}

static void save_msrs(struct kvm_msr_entry *e, int n)
{
        int i;

        for (i = 0; i < n; ++i)
                rdmsrl(e[i].index, e[i].data);
}

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

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

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

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

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

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

static inline int 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 flexpriority_enabled
                && (vmcs_config.cpu_based_2nd_exec_ctrl &
                    SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES);
}

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

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

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

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

static inline int vm_need_ept(void)
{
        return (cpu_has_vmx_ept() && enable_ept);
}

static inline int vm_need_virtualize_apic_accesses(struct kvm *kvm)
{
        return ((cpu_has_vmx_virtualize_apic_accesses()) &&
                (irqchip_in_kernel(kvm)));
}

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

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

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

        for (i = 0; i < vmx->nmsrs; ++i)
                if (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 kvm_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"
                      : "=g"(error) : "a"(&phys_addr), "m"(phys_addr)
                      : "cc", "memory");
        if (error)
                printk(KERN_ERR "kvm: vmclear fail: %p/%llx\n",
                       vmcs, phys_addr);
}

static void __vcpu_clear(void *arg)
{
        struct vcpu_vmx *vmx = arg;
        int cpu = raw_smp_processor_id();

        if (vmx->vcpu.cpu == cpu)
                vmcs_clear(vmx->vmcs);
        if (per_cpu(current_vmcs, cpu) == vmx->vmcs)
                per_cpu(current_vmcs, cpu) = NULL;
        rdtscll(vmx->vcpu.arch.host_tsc);
        list_del(&vmx->local_vcpus_link);
        vmx->vcpu.cpu = -1;
        vmx->launched = 0;
}

static void vcpu_clear(struct vcpu_vmx *vmx)
{
        if (vmx->vcpu.cpu == -1)
                return;
        smp_call_function_single(vmx->vcpu.cpu, __vcpu_clear, vmx, 1);
}

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

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

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 (vm_need_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 (vm_need_ept()) {
                if (cpu_has_vmx_invept_individual_addr())
                        __invept(VMX_EPT_EXTENT_INDIVIDUAL_ADDR,
                                        eptp, gpa);
                else
                        ept_sync_context(eptp);
        }
}

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

        asm volatile (__ex(ASM_VMX_VMREAD_RDX_RAX)
                      : "=a"(value) : "d"(field) : "cc");
        return value;
}

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

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

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

        eb = (1u << PF_VECTOR) | (1u << UD_VECTOR);
        if (!vcpu->fpu_active)
                eb |= 1u << NM_VECTOR;
        if (vcpu->guest_debug.enabled)
                eb |= 1u << 1;
        if (vcpu->arch.rmode.active)
                eb = ~0;
        if (vm_need_ept())
                eb &= ~(1u << PF_VECTOR); /* bypass_guest_pf = 0 */
        vmcs_write32(EXCEPTION_BITMAP, eb);
}

static void reload_tss(void)
{
        /*
         * VT restores TR but not its size.  Useless.
         */
        struct descriptor_table gdt;
        struct desc_struct *descs;

        kvm_get_gdt(&gdt);
        descs = (void *)gdt.base;
        descs[GDT_ENTRY_TSS].type = 9; /* available TSS */
        load_TR_desc();
}

static void load_transition_efer(struct vcpu_vmx *vmx)
{
        int efer_offset = vmx->msr_offset_efer;
        u64 host_efer = vmx->host_msrs[efer_offset].data;
        u64 guest_efer = vmx->guest_msrs[efer_offset].data;
        u64 ignore_bits;

        if (efer_offset < 0)
                return;
        /*
         * 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
        if ((guest_efer & ~ignore_bits) == (host_efer & ~ignore_bits))
                return;

        vmx->host_state.guest_efer_loaded = 1;
        guest_efer &= ~ignore_bits;
        guest_efer |= host_efer & ignore_bits;
        wrmsrl(MSR_EFER, guest_efer);
        vmx->vcpu.stat.efer_reload++;
}

static void reload_host_efer(struct vcpu_vmx *vmx)
{
        if (vmx->host_state.guest_efer_loaded) {
                vmx->host_state.guest_efer_loaded = 0;
                load_msrs(vmx->host_msrs + vmx->msr_offset_efer, 1);
        }
}

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

        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;
        vmx->host_state.fs_sel = kvm_read_fs();
        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;
        }
        vmx->host_state.gs_sel = kvm_read_gs();
        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
        if (is_long_mode(&vmx->vcpu))
                save_msrs(vmx->host_msrs +
                          vmx->msr_offset_kernel_gs_base, 1);

#endif
        load_msrs(vmx->guest_msrs, vmx->save_nmsrs);
        load_transition_efer(vmx);
}

static void __vmx_load_host_state(struct vcpu_vmx *vmx)
{
        unsigned long flags;

        if (!vmx->host_state.loaded)
                return;

        ++vmx->vcpu.stat.host_state_reload;
        vmx->host_state.loaded = 0;
        if (vmx->host_state.fs_reload_needed)
                kvm_load_fs(vmx->host_state.fs_sel);
        if (vmx->host_state.gs_ldt_reload_needed) {
                kvm_load_ldt(vmx->host_state.ldt_sel);
                /*
                 * If we have to reload gs, we must take care to
                 * preserve our gs base.
                 */
                local_irq_save(flags);
                kvm_load_gs(vmx->host_state.gs_sel);
#ifdef CONFIG_X86_64
                wrmsrl(MSR_GS_BASE, vmcs_readl(HOST_GS_BASE));
#endif
                local_irq_restore(flags);
        }
        reload_tss();
        save_msrs(vmx->guest_msrs, vmx->save_nmsrs);
        load_msrs(vmx->host_msrs, vmx->save_nmsrs);
        reload_host_efer(vmx);
}

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(vmx->vmcs);
        u64 tsc_this, delta, new_offset;

        if (vcpu->cpu != cpu) {
                vcpu_clear(vmx);
                kvm_migrate_timers(vcpu);
                vpid_sync_vcpu_all(vmx);
                local_irq_disable();
                list_add(&vmx->local_vcpus_link,
                         &per_cpu(vcpus_on_cpu, cpu));
                local_irq_enable();
        }

        if (per_cpu(current_vmcs, cpu) != vmx->vmcs) {
                u8 error;

                per_cpu(current_vmcs, cpu) = vmx->vmcs;
                asm volatile (__ex(ASM_VMX_VMPTRLD_RAX) "; setna %0"
                              : "=g"(error) : "a"(&phys_addr), "m"(phys_addr)
                              : "cc");
                if (error)
                        printk(KERN_ERR "kvm: vmptrld %p/%llx fail\n",
                               vmx->vmcs, phys_addr);
        }

        if (vcpu->cpu != cpu) {
                struct descriptor_table dt;
                unsigned long sysenter_esp;

                vcpu->cpu = cpu;
                /*
                 * 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 */
                kvm_get_gdt(&dt);
                vmcs_writel(HOST_GDTR_BASE, dt.base);   /* 22.2.4 */

                rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp);
                vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */

                /*
                 * Make sure the time stamp counter is monotonous.
                 */
                rdtscll(tsc_this);
                if (tsc_this < vcpu->arch.host_tsc) {
                        delta = vcpu->arch.host_tsc - tsc_this;
                        new_offset = vmcs_read64(TSC_OFFSET) + delta;
                        vmcs_write64(TSC_OFFSET, new_offset);
                }
        }
}

static void vmx_vcpu_put(struct kvm_vcpu *vcpu)
{
        __vmx_load_host_state(to_vmx(vcpu));
}

static void vmx_fpu_activate(struct kvm_vcpu *vcpu)
{
        if (vcpu->fpu_active)
                return;
        vcpu->fpu_active = 1;
        vmcs_clear_bits(GUEST_CR0, X86_CR0_TS);
        if (vcpu->arch.cr0 & X86_CR0_TS)
                vmcs_set_bits(GUEST_CR0, X86_CR0_TS);
        update_exception_bitmap(vcpu);
}

static void vmx_fpu_deactivate(struct kvm_vcpu *vcpu)
{
        if (!vcpu->fpu_active)
                return;
        vcpu->fpu_active = 0;
        vmcs_set_bits(GUEST_CR0, X86_CR0_TS);
        update_exception_bitmap(vcpu);
}

static unsigned long vmx_get_rflags(struct kvm_vcpu *vcpu)
{
        return vmcs_readl(GUEST_RFLAGS);
}

static void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
{
        if (vcpu->arch.rmode.active)
                rflags |= X86_EFLAGS_IOPL | X86_EFLAGS_VM;
        vmcs_writel(GUEST_RFLAGS, rflags);
}

static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
{
        unsigned long rip;
        u32 interruptibility;

        rip = vmcs_readl(GUEST_RIP);
        rip += vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
        vmcs_writel(GUEST_RIP, rip);

        /*
         * We emulated an instruction, so temporary interrupt blocking
         * should be removed, if set.
         */
        interruptibility = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);
        if (interruptibility & 3)
                vmcs_write32(GUEST_INTERRUPTIBILITY_INFO,
                             interruptibility & ~3);
        vcpu->arch.interrupt_window_open = 1;
}

static void vmx_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
                                bool has_error_code, u32 error_code)
{
        vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
                     nr | INTR_TYPE_EXCEPTION
                     | (has_error_code ? INTR_INFO_DELIVER_CODE_MASK : 0)
                     | INTR_INFO_VALID_MASK);
        if (has_error_code)
                vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE, error_code);
}

static bool vmx_exception_injected(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        return !(vmx->idt_vectoring_info & VECTORING_INFO_VALID_MASK);
}

/*
 * Swap MSR entry in host/guest MSR entry array.
 */
#ifdef CONFIG_X86_64
static void move_msr_up(struct vcpu_vmx *vmx, int from, int to)
{
        struct kvm_msr_entry tmp;

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

/*
 * 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;

        vmx_load_host_state(vmx);
        save_nmsrs = 0;
#ifdef CONFIG_X86_64
        if (is_long_mode(&vmx->vcpu)) {
                int index;

                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_KERNEL_GS_BASE);
                if (index >= 0)
                        move_msr_up(vmx, index, save_nmsrs++);
                /*
                 * MSR_K6_STAR is only needed on long mode guests, and only
                 * if efer.sce is enabled.
                 */
                index = __find_msr_index(vmx, MSR_K6_STAR);
                if ((index >= 0) && (vmx->vcpu.arch.shadow_efer & EFER_SCE))
                        move_msr_up(vmx, index, save_nmsrs++);
        }
#endif
        vmx->save_nmsrs = save_nmsrs;

#ifdef CONFIG_X86_64
        vmx->msr_offset_kernel_gs_base =
                __find_msr_index(vmx, MSR_KERNEL_GS_BASE);
#endif
        vmx->msr_offset_efer = __find_msr_index(vmx, MSR_EFER);
}

/*
 * 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;
}

/*
 * writes 'guest_tsc' into guest's timestamp counter "register"
 * guest_tsc = host_tsc + tsc_offset ==> tsc_offset = guest_tsc - host_tsc
 */
static void guest_write_tsc(u64 guest_tsc)
{
        u64 host_tsc;

        rdtscll(host_tsc);
        vmcs_write64(TSC_OFFSET, guest_tsc - host_tsc);
}

/*
 * 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 kvm_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_EFER:
                return kvm_get_msr_common(vcpu, msr_index, pdata);
#endif
        case MSR_IA32_TIME_STAMP_COUNTER:
                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;
        default:
                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 kvm_msr_entry *msr;
        int ret = 0;

        switch (msr_index) {
#ifdef CONFIG_X86_64
        case MSR_EFER:
                vmx_load_host_state(vmx);
                ret = kvm_set_msr_common(vcpu, msr_index, data);
                break;
        case MSR_FS_BASE:
                vmcs_writel(GUEST_FS_BASE, data);
                break;
        case MSR_GS_BASE:
                vmcs_writel(GUEST_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_TIME_STAMP_COUNTER:
                guest_write_tsc(data);
                break;
        case MSR_P6_PERFCTR0:
        case MSR_P6_PERFCTR1:
        case MSR_P6_EVNTSEL0:
        case MSR_P6_EVNTSEL1:
                /*
                 * Just discard all writes to the performance counters; this
                 * should keep both older linux and windows 64-bit guests
                 * happy
                 */
                pr_unimpl(vcpu, "unimplemented perfctr wrmsr: 0x%x data 0x%llx\n", msr_index, data);

                break;
        default:
                vmx_load_host_state(vmx);
                msr = find_msr_entry(vmx, msr_index);
                if (msr) {
                        msr->data = data;
                        break;
                }
                ret = kvm_set_msr_common(vcpu, msr_index, data);
        }

        return ret;
}

/*
 * Sync the rsp and rip registers into the vcpu structure.  This allows
 * registers to be accessed by indexing vcpu->arch.regs.
 */
static void vcpu_load_rsp_rip(struct kvm_vcpu *vcpu)
{
        vcpu->arch.regs[VCPU_REGS_RSP] = vmcs_readl(GUEST_RSP);
        vcpu->arch.rip = vmcs_readl(GUEST_RIP);
}

/*
 * Syncs rsp and rip back into the vmcs.  Should be called after possible
 * modification.
 */
static void vcpu_put_rsp_rip(struct kvm_vcpu *vcpu)
{
        vmcs_writel(GUEST_RSP, vcpu->arch.regs[VCPU_REGS_RSP]);
        vmcs_writel(GUEST_RIP, vcpu->arch.rip);
}

static int set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_debug_guest *dbg)
{
        unsigned long dr7 = 0x400;
        int old_singlestep;

        old_singlestep = vcpu->guest_debug.singlestep;

        vcpu->guest_debug.enabled = dbg->enabled;
        if (vcpu->guest_debug.enabled) {
                int i;

                dr7 |= 0x200;  /* exact */
                for (i = 0; i < 4; ++i) {
                        if (!dbg->breakpoints[i].enabled)
                                continue;
                        vcpu->guest_debug.bp[i] = dbg->breakpoints[i].address;
                        dr7 |= 2 << (i*2);    /* global enable */
                        dr7 |= 0 << (i*4+16); /* execution breakpoint */
                }

                vcpu->guest_debug.singlestep = dbg->singlestep;
        } else
                vcpu->guest_debug.singlestep = 0;

        if (old_singlestep && !vcpu->guest_debug.singlestep) {
                unsigned long flags;

                flags = vmcs_readl(GUEST_RFLAGS);
                flags &= ~(X86_EFLAGS_TF | X86_EFLAGS_RF);
                vmcs_writel(GUEST_RFLAGS, flags);
        }

        update_exception_bitmap(vcpu);
        vmcs_writel(GUEST_DR7, dr7);

        return 0;
}

static int vmx_get_irq(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 idtv_info_field;

        idtv_info_field = vmx->idt_vectoring_info;
        if (idtv_info_field & INTR_INFO_VALID_MASK) {
                if (is_external_interrupt(idtv_info_field))
                        return idtv_info_field & VECTORING_INFO_VECTOR_MASK;
                else
                        printk(KERN_DEBUG "pending exception: not handled yet\n");
        }
        return -1;
}

static __init int cpu_has_kvm_support(void)
{
        unsigned long ecx = cpuid_ecx(1);
        return test_bit(5, &ecx); /* CPUID.1:ECX.VMX[bit 5] -> VT */
}

static __init int vmx_disabled_by_bios(void)
{
        u64 msr;

        rdmsrl(MSR_IA32_FEATURE_CONTROL, msr);
        return (msr & (MSR_IA32_FEATURE_CONTROL_LOCKED |
                       MSR_IA32_FEATURE_CONTROL_VMXON_ENABLED))
            == MSR_IA32_FEATURE_CONTROL_LOCKED;
        /* locked but not enabled */
}

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

        INIT_LIST_HEAD(&per_cpu(vcpus_on_cpu, cpu));
        rdmsrl(MSR_IA32_FEATURE_CONTROL, old);
        if ((old & (MSR_IA32_FEATURE_CONTROL_LOCKED |
                    MSR_IA32_FEATURE_CONTROL_VMXON_ENABLED))
            != (MSR_IA32_FEATURE_CONTROL_LOCKED |
                MSR_IA32_FEATURE_CONTROL_VMXON_ENABLED))
                /* enable and lock */
                wrmsrl(MSR_IA32_FEATURE_CONTROL, old |
                       MSR_IA32_FEATURE_CONTROL_LOCKED |
                       MSR_IA32_FEATURE_CONTROL_VMXON_ENABLED);
        write_cr4(read_cr4() | X86_CR4_VMXE); /* FIXME: not cpu hotplug safe */
        asm volatile (ASM_VMX_VMXON_RAX
                      : : "a"(&phys_addr), "m"(phys_addr)
                      : "memory", "cc");
}

static void vmclear_local_vcpus(void)
{
        int cpu = raw_smp_processor_id();
        struct vcpu_vmx *vmx, *n;

        list_for_each_entry_safe(vmx, n, &per_cpu(vcpus_on_cpu, cpu),
                                 local_vcpus_link)
                __vcpu_clear(vmx);
}

static void hardware_disable(void *garbage)
{
        vmclear_local_vcpus();
        asm volatile (__ex(ASM_VMX_VMXOFF) : : : "cc");
        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 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;
        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;
                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 don't need to cause VM Exits when EPT enabled */
                min &= ~(CPU_BASED_CR3_LOAD_EXITING |
                         CPU_BASED_CR3_STORE_EXITING);
                if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PROCBASED_CTLS,
                                        &_cpu_based_exec_control) < 0)
                        return -EIO;
                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 = 0;
        if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_EXIT_CTLS,
                                &_vmexit_control) < 0)
                return -EIO;

        min = opt = 0;
        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;

        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_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);
}

static void free_kvm_area(void)
{
        int cpu;

        for_each_online_cpu(cpu)
                free_vmcs(per_cpu(vmxarea, cpu));
}

static __init int alloc_kvm_area(void)
{
        int cpu;

        for_each_online_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);

        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;

        vcpu->arch.rmode.active = 0;

        vmcs_writel(GUEST_TR_BASE, vcpu->arch.rmode.tr.base);
        vmcs_write32(GUEST_TR_LIMIT, vcpu->arch.rmode.tr.limit);
        vmcs_write32(GUEST_TR_AR_BYTES, vcpu->arch.rmode.tr.ar);

        flags = vmcs_readl(GUEST_RFLAGS);
        flags &= ~(X86_EFLAGS_IOPL | X86_EFLAGS_VM);
        flags |= (vcpu->arch.rmode.save_iopl << IOPL_SHIFT);
        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);

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

        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) {
                gfn_t base_gfn = kvm->memslots[0].base_gfn +
                                 kvm->memslots[0].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 & 0xfffff);
        vmcs_write32(sf->limit, 0xffff);
        vmcs_write32(sf->ar_bytes, 0xf3);
}

static void enter_rmode(struct kvm_vcpu *vcpu)
{
        unsigned long flags;

        vcpu->arch.rmode.active = 1;

        vcpu->arch.rmode.tr.base = vmcs_readl(GUEST_TR_BASE);
        vmcs_writel(GUEST_TR_BASE, rmode_tss_base(vcpu->kvm));

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

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

        flags = vmcs_readl(GUEST_RFLAGS);
        vcpu->arch.rmode.save_iopl
                = (flags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;

        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);

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

        kvm_mmu_reset_context(vcpu);
        init_rmode(vcpu->kvm);
}

#ifdef CONFIG_X86_64

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

        guest_tr_ar = vmcs_read32(GUEST_TR_AR_BYTES);
        if ((guest_tr_ar & AR_TYPE_MASK) != AR_TYPE_BUSY_64_TSS) {
                printk(KERN_DEBUG "%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);
        }

        vcpu->arch.shadow_efer |= EFER_LMA;

        find_msr_entry(to_vmx(vcpu), MSR_EFER)->data |= EFER_LMA | EFER_LME;
        vmcs_write32(VM_ENTRY_CONTROLS,
                     vmcs_read32(VM_ENTRY_CONTROLS)
                     | VM_ENTRY_IA32E_MODE);
}

static void exit_lmode(struct kvm_vcpu *vcpu)
{
        vcpu->arch.shadow_efer &= ~EFER_LMA;

        vmcs_write32(VM_ENTRY_CONTROLS,
                     vmcs_read32(VM_ENTRY_CONTROLS)
                     & ~VM_ENTRY_IA32E_MODE);
}

#endif

static void vmx_flush_tlb(struct kvm_vcpu *vcpu)
{
        vpid_sync_vcpu_all(to_vmx(vcpu));
        if (vm_need_ept())
                ept_sync_context(construct_eptp(vcpu->arch.mmu.root_hpa));
}

static void vmx_decache_cr4_guest_bits(struct kvm_vcpu *vcpu)
{
        vcpu->arch.cr4 &= KVM_GUEST_CR4_MASK;
        vcpu->arch.cr4 |= vmcs_readl(GUEST_CR4) & ~KVM_GUEST_CR4_MASK;
}

static void ept_load_pdptrs(struct kvm_vcpu *vcpu)
{
        if (is_paging(vcpu) && is_pae(vcpu) && !is_long_mode(vcpu)) {
                if (!load_pdptrs(vcpu, vcpu->arch.cr3)) {
                        printk(KERN_ERR "EPT: Fail to load pdptrs!\n");
                        return;
                }
                vmcs_write64(GUEST_PDPTR0, vcpu->arch.pdptrs[0]);
                vmcs_write64(GUEST_PDPTR1, vcpu->arch.pdptrs[1]);
                vmcs_write64(GUEST_PDPTR2, vcpu->arch.pdptrs[2]);
                vmcs_write64(GUEST_PDPTR3, vcpu->arch.pdptrs[3]);
        }
}

static void 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 (!(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, vcpu->arch.cr4);
                *hw_cr0 |= X86_CR0_PE | X86_CR0_PG;
                *hw_cr0 &= ~X86_CR0_WP;
        } 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, vcpu->arch.cr4);
                if (!(vcpu->arch.cr0 & X86_CR0_WP))
                        *hw_cr0 &= ~X86_CR0_WP;
        }
}

static void ept_update_paging_mode_cr4(unsigned long *hw_cr4,
                                        struct kvm_vcpu *vcpu)
{
        if (!is_paging(vcpu)) {
                *hw_cr4 &= ~X86_CR4_PAE;
                *hw_cr4 |= X86_CR4_PSE;
        } else if (!(vcpu->arch.cr4 & X86_CR4_PAE))
                *hw_cr4 &= ~X86_CR4_PAE;
}

static void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
{
        unsigned long hw_cr0 = (cr0 & ~KVM_GUEST_CR0_MASK) |
                                KVM_VM_CR0_ALWAYS_ON;

        vmx_fpu_deactivate(vcpu);

        if (vcpu->arch.rmode.active && (cr0 & X86_CR0_PE))
                enter_pmode(vcpu);

        if (!vcpu->arch.rmode.active && !(cr0 & X86_CR0_PE))
                enter_rmode(vcpu);

#ifdef CONFIG_X86_64
        if (vcpu->arch.shadow_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 (vm_need_ept())
                ept_update_paging_mode_cr0(&hw_cr0, cr0, vcpu);

        vmcs_writel(CR0_READ_SHADOW, cr0);
        vmcs_writel(GUEST_CR0, hw_cr0);
        vcpu->arch.cr0 = cr0;

        if (!(cr0 & X86_CR0_TS) || !(cr0 & X86_CR0_PE))
                vmx_fpu_activate(vcpu);
}

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 (vm_need_ept()) {
                eptp = construct_eptp(cr3);
                vmcs_write64(EPT_POINTER, eptp);
                ept_sync_context(eptp);
                ept_load_pdptrs(vcpu);
                guest_cr3 = is_paging(vcpu) ? vcpu->arch.cr3 :
                        VMX_EPT_IDENTITY_PAGETABLE_ADDR;
        }

        vmx_flush_tlb(vcpu);
        vmcs_writel(GUEST_CR3, guest_cr3);
        if (vcpu->arch.cr0 & X86_CR0_PE)
                vmx_fpu_deactivate(vcpu);
}

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

        vcpu->arch.cr4 = cr4;
        if (vm_need_ept())
                ept_update_paging_mode_cr4(&hw_cr4, vcpu);

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

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

        vcpu->arch.shadow_efer = efer;
        if (!msr)
                return;
        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);
}

static u64 vmx_get_segment_base(struct kvm_vcpu *vcpu, int seg)
{
        struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg];

        return vmcs_readl(sf->base);
}

static void vmx_get_segment(struct kvm_vcpu *vcpu,
                            struct kvm_segment *var, int seg)
{
        struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg];
        u32 ar;

        var->base = vmcs_readl(sf->base);
        var->limit = vmcs_read32(sf->limit);
        var->selector = vmcs_read16(sf->selector);
        ar = vmcs_read32(sf->ar_bytes);
        if (ar & AR_UNUSABLE_MASK)
                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 int vmx_get_cpl(struct kvm_vcpu *vcpu)
{
        struct kvm_segment kvm_seg;

        if (!(vcpu->arch.cr0 & X86_CR0_PE)) /* if real mode */
                return 0;

        if (vmx_get_rflags(vcpu) & X86_EFLAGS_VM) /* if virtual 8086 */
                return 3;

        vmx_get_segment(vcpu, &kvm_seg, VCPU_SREG_CS);
        return kvm_seg.selector & 3;
}

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;
                ar |= (var->db & 1) << 14;
                ar |= (var->g & 1) << 15;
        }
        if (ar == 0) /* a 0 value means unusable */
                ar = AR_UNUSABLE_MASK;

        return ar;
}

static void vmx_set_segment(struct kvm_vcpu *vcpu,
                            struct kvm_segment *var, int seg)
{
        struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg];
        u32 ar;

        if (vcpu->arch.rmode.active && seg == VCPU_SREG_TR) {
                vcpu->arch.rmode.tr.selector = var->selector;
                vcpu->arch.rmode.tr.base = var->base;
                vcpu->arch.rmode.tr.limit = var->limit;
                vcpu->arch.rmode.tr.ar = vmx_segment_access_rights(var);
                return;
        }
        vmcs_writel(sf->base, var->base);
        vmcs_write32(sf->limit, var->limit);
        vmcs_write16(sf->selector, var->selector);
        if (vcpu->arch.rmode.active && var->s) {
                /*
                 * Hack real-mode segments into vm86 compatibility.
                 */
                if (var->base == 0xffff0000 && var->selector == 0xf000)
                        vmcs_writel(sf->base, 0xf0000);
                ar = 0xf3;
        } else
                ar = vmx_segment_access_rights(var);
        vmcs_write32(sf->ar_bytes, ar);
}

static void vmx_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l)
{
        u32 ar = vmcs_read32(GUEST_CS_AR_BYTES);

        *db = (ar >> 14) & 1;
        *l = (ar >> 13) & 1;
}

static void vmx_get_idt(struct kvm_vcpu *vcpu, struct descriptor_table *dt)
{
        dt->limit = vmcs_read32(GUEST_IDTR_LIMIT);
        dt->base = vmcs_readl(GUEST_IDTR_BASE);
}

static void vmx_set_idt(struct kvm_vcpu *vcpu, struct descriptor_table *dt)
{
        vmcs_write32(GUEST_IDTR_LIMIT, dt->limit);
        vmcs_writel(GUEST_IDTR_BASE, dt->base);
}

static void vmx_get_gdt(struct kvm_vcpu *vcpu, struct descriptor_table *dt)
{
        dt->limit = vmcs_read32(GUEST_GDTR_LIMIT);
        dt->base = vmcs_readl(GUEST_GDTR_BASE);
}

static void vmx_set_gdt(struct kvm_vcpu *vcpu, struct descriptor_table *dt)
{
        vmcs_write32(GUEST_GDTR_LIMIT, dt->limit);
        vmcs_writel(GUEST_GDTR_BASE, dt->base);
}

static int init_rmode_tss(struct kvm *kvm)
{
        gfn_t fn = rmode_tss_base(kvm) >> PAGE_SHIFT;
        u16 data = 0;
        int ret = 0;
        int r;

        r = kvm_clear_guest_page(kvm, fn, 0, PAGE_SIZE);
        if (r < 0)
                goto out;
        data = TSS_BASE_SIZE + TSS_REDIRECTION_SIZE;
        r = kvm_write_guest_page(kvm, fn++, &data, 0x66, sizeof(u16));
        if (r < 0)
                goto out;
        r = kvm_clear_guest_page(kvm, fn++, 0, PAGE_SIZE);
        if (r < 0)
                goto out;
        r = kvm_clear_guest_page(kvm, fn, 0, PAGE_SIZE);
        if (r < 0)
                goto out;
        data = ~0;
        r = kvm_write_guest_page(kvm, fn, &data,
                                 RMODE_TSS_SIZE - 2 * PAGE_SIZE - 1,
                                 sizeof(u8));
        if (r < 0)
                goto out;

        ret = 1;
out:
        return ret;
}

static int init_rmode_identity_map(struct kvm *kvm)
{
        int i, r, ret;
        pfn_t identity_map_pfn;
        u32 tmp;

        if (!vm_need_ept())
                return 1;
        if (unlikely(!kvm->arch.ept_identity_pagetable)) {
                printk(KERN_ERR "EPT: identity-mapping pagetable "
                        "haven't been allocated!\n");
                return 0;
        }
        if (likely(kvm->arch.ept_identity_pagetable_done))
                return 1;
        ret = 0;
        identity_map_pfn = VMX_EPT_IDENTITY_PAGETABLE_ADDR >> PAGE_SHIFT;
        r = kvm_clear_guest_page(kvm, identity_map_pfn, 0, PAGE_SIZE);
        if (r < 0)
                goto out;
        /* Set up identity-mapping pagetable for EPT in real mode */
        for (i = 0; i < PT32_ENT_PER_PAGE; i++) {
                tmp = (i << 22) + (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER |
                        _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_PSE);
                r = kvm_write_guest_page(kvm, identity_map_pfn,
                                &tmp, i * sizeof(tmp), sizeof(tmp));
                if (r < 0)
                        goto out;
        }
        kvm->arch.ept_identity_pagetable_done = true;
        ret = 1;
out:
        return ret;
}

static void seg_setup(int seg)
{
        struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg];

        vmcs_write16(sf->selector, 0);
        vmcs_writel(sf->base, 0);
        vmcs_write32(sf->limit, 0xffff);
        vmcs_write32(sf->ar_bytes, 0x93);
}

static int alloc_apic_access_page(struct kvm *kvm)
{
        struct kvm_userspace_memory_region kvm_userspace_mem;
        int r = 0;

        down_write(&kvm->slots_lock);
        if (kvm->arch.apic_access_page)
                goto out;
        kvm_userspace_mem.slot = APIC_ACCESS_PAGE_PRIVATE_MEMSLOT;
        kvm_userspace_mem.flags = 0;
        kvm_userspace_mem.guest_phys_addr = 0xfee00000ULL;
        kvm_userspace_mem.memory_size = PAGE_SIZE;
        r = __kvm_set_memory_region(kvm, &kvm_userspace_mem, 0);
        if (r)
                goto out;

        down_read(&current->mm->mmap_sem);
        kvm->arch.apic_access_page = gfn_to_page(kvm, 0xfee00);
        up_read(&current->mm->mmap_sem);
out:
        up_write(&kvm->slots_lock);
        return r;
}

static int alloc_identity_pagetable(struct kvm *kvm)
{
        struct kvm_userspace_memory_region kvm_userspace_mem;
        int r = 0;

        down_write(&kvm->slots_lock);
        if (kvm->arch.ept_identity_pagetable)
                goto out;
        kvm_userspace_mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;
        kvm_userspace_mem.flags = 0;
        kvm_userspace_mem.guest_phys_addr = VMX_EPT_IDENTITY_PAGETABLE_ADDR;
        kvm_userspace_mem.memory_size = PAGE_SIZE;
        r = __kvm_set_memory_region(kvm, &kvm_userspace_mem, 0);
        if (r)
                goto out;

        down_read(&current->mm->mmap_sem);
        kvm->arch.ept_identity_pagetable = gfn_to_page(kvm,
                        VMX_EPT_IDENTITY_PAGETABLE_ADDR >> PAGE_SHIFT);
        up_read(&current->mm->mmap_sem);
out:
        up_write(&kvm->slots_lock);
        return r;
}

static void allocate_vpid(struct vcpu_vmx *vmx)
{
        int vpid;

        vmx->vpid = 0;
        if (!enable_vpid || !cpu_has_vmx_vpid())
                return;
        spin_lock(&vmx_vpid_lock);
        vpid = find_first_zero_bit(vmx_vpid_bitmap, VMX_NR_VPIDS);
        if (vpid < VMX_NR_VPIDS) {
                vmx->vpid = vpid;
                __set_bit(vpid, vmx_vpid_bitmap);
        }
        spin_unlock(&vmx_vpid_lock);
}

static void vmx_disable_intercept_for_msr(struct page *msr_bitmap, u32 msr)
{
        void *va;

        if (!cpu_has_vmx_msr_bitmap())
                return;

        /*
         * See Intel PRM Vol. 3, 20.6.9 (MSR-Bitmap Address). Early manuals
         * have the write-low and read-high bitmap offsets the wrong way round.
         * We can control MSRs 0x00000000-0x00001fff and 0xc0000000-0xc0001fff.
         */
        va = kmap(msr_bitmap);
        if (msr <= 0x1fff) {
                __clear_bit(msr, va + 0x000); /* read-low */
                __clear_bit(msr, va + 0x800); /* write-low */
        } else if ((msr >= 0xc0000000) && (msr <= 0xc0001fff)) {
                msr &= 0x1fff;
                __clear_bit(msr, va + 0x400); /* read-high */
                __clear_bit(msr, va + 0xc00); /* write-high */
        }
        kunmap(msr_bitmap);
}

/*
 * Sets up the vmcs for emulated real mode.
 */
static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
{
        u32 host_sysenter_cs;
        u32 junk;
        unsigned long a;
        struct descriptor_table dt;
        int i;
        unsigned long kvm_vmx_return;
        u32 exec_control;

        /* I/O */
        vmcs_write64(IO_BITMAP_A, page_to_phys(vmx_io_bitmap_a));
        vmcs_write64(IO_BITMAP_B, page_to_phys(vmx_io_bitmap_b));

        if (cpu_has_vmx_msr_bitmap())
                vmcs_write64(MSR_BITMAP, page_to_phys(vmx_msr_bitmap));

        vmcs_write64(VMCS_LINK_POINTER, -1ull); /* 22.3.1.5 */

        /* Control */
        vmcs_write32(PIN_BASED_VM_EXEC_CONTROL,
                vmcs_config.pin_based_exec_ctrl);

        exec_control = vmcs_config.cpu_based_exec_ctrl;
        if (!vm_need_tpr_shadow(vmx->vcpu.kvm)) {
                exec_control &= ~CPU_BASED_TPR_SHADOW;
#ifdef CONFIG_X86_64
                exec_control |= CPU_BASED_CR8_STORE_EXITING |
                                CPU_BASED_CR8_LOAD_EXITING;
#endif
        }
        if (!vm_need_ept())
                exec_control |= CPU_BASED_CR3_STORE_EXITING |
                                CPU_BASED_CR3_LOAD_EXITING;
        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, exec_control);

        if (cpu_has_secondary_exec_ctrls()) {
                exec_control = vmcs_config.cpu_based_2nd_exec_ctrl;
                if (!vm_need_virtualize_apic_accesses(vmx->vcpu.kvm))
                        exec_control &=
                                ~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
                if (vmx->vpid == 0)
                        exec_control &= ~SECONDARY_EXEC_ENABLE_VPID;
                if (!vm_need_ept())
                        exec_control &= ~SECONDARY_EXEC_ENABLE_EPT;
                vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
        }

        vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK, !!bypass_guest_pf);
        vmcs_write32(PAGE_FAULT_ERROR_CODE_MATCH, !!bypass_guest_pf);
        vmcs_write32(CR3_TARGET_COUNT, 0);           /* 22.2.1 */

        vmcs_writel(HOST_CR0, read_cr0());  /* 22.2.3 */
        vmcs_writel(HOST_CR4, read_cr4());  /* 22.2.3, 22.2.5 */
        vmcs_writel(HOST_CR3, read_cr3());  /* 22.2.3  FIXME: shadow tables */

        vmcs_write16(HOST_CS_SELECTOR, __KERNEL_CS);  /* 22.2.4 */
        vmcs_write16(HOST_DS_SELECTOR, __KERNEL_DS);  /* 22.2.4 */
        vmcs_write16(HOST_ES_SELECTOR, __KERNEL_DS);  /* 22.2.4 */
        vmcs_write16(HOST_FS_SELECTOR, kvm_read_fs());    /* 22.2.4 */
        vmcs_write16(HOST_GS_SELECTOR, kvm_read_gs());    /* 22.2.4 */
        vmcs_write16(HOST_SS_SELECTOR, __KERNEL_DS);  /* 22.2.4 */
#ifdef CONFIG_X86_64
        rdmsrl(MSR_FS_BASE, a);
        vmcs_writel(HOST_FS_BASE, a); /* 22.2.4 */
        rdmsrl(MSR_GS_BASE, a);
        vmcs_writel(HOST_GS_BASE, a); /* 22.2.4 */
#else
        vmcs_writel(HOST_FS_BASE, 0); /* 22.2.4 */
        vmcs_writel(HOST_GS_BASE, 0); /* 22.2.4 */
#endif

        vmcs_write16(HOST_TR_SELECTOR, GDT_ENTRY_TSS*8);  /* 22.2.4 */

        kvm_get_idt(&dt);
        vmcs_writel(HOST_IDTR_BASE, dt.base);   /* 22.2.4 */

        asm("mov $.Lkvm_vmx_return, %0" : "=r"(kvm_vmx_return));
        vmcs_writel(HOST_RIP, kvm_vmx_return); /* 22.2.5 */
        vmcs_write32(VM_EXIT_MSR_STORE_COUNT, 0);
        vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, 0);
        vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, 0);

        rdmsr(MSR_IA32_SYSENTER_CS, host_sysenter_cs, junk);
        vmcs_write32(HOST_IA32_SYSENTER_CS, host_sysenter_cs);
        rdmsrl(MSR_IA32_SYSENTER_ESP, a);
        vmcs_writel(HOST_IA32_SYSENTER_ESP, a);   /* 22.2.3 */
        rdmsrl(MSR_IA32_SYSENTER_EIP, a);
        vmcs_writel(HOST_IA32_SYSENTER_EIP, a);   /* 22.2.3 */

        for (i = 0; i < NR_VMX_MSR; ++i) {
                u32 index = vmx_msr_index[i];
                u32 data_low, data_high;
                u64 data;
                int j = vmx->nmsrs;

                if (rdmsr_safe(index, &data_low, &data_high) < 0)
                        continue;
                if (wrmsr_safe(index, data_low, data_high) < 0)
                        continue;
                data = data_low | ((u64)data_high << 32);
                vmx->host_msrs[j].index = index;
                vmx->host_msrs[j].reserved = 0;
                vmx->host_msrs[j].data = data;
                vmx->guest_msrs[j] = vmx->host_msrs[j];
                ++vmx->nmsrs;
        }

        vmcs_write32(VM_EXIT_CONTROLS, vmcs_config.vmexit_ctrl);

        /* 22.2.1, 20.8.1 */
        vmcs_write32(VM_ENTRY_CONTROLS, vmcs_config.vmentry_ctrl);

        vmcs_writel(CR0_GUEST_HOST_MASK, ~0UL);
        vmcs_writel(CR4_GUEST_HOST_MASK, KVM_GUEST_CR4_MASK);


        return 0;
}

static int init_rmode(struct kvm *kvm)
{
        if (!init_rmode_tss(kvm))
                return 0;
        if (!init_rmode_identity_map(kvm))
                return 0;
        return 1;
}

static int vmx_vcpu_reset(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u64 msr;
        int ret;

        down_read(&vcpu->kvm->slots_lock);
        if (!init_rmode(vmx->vcpu.kvm)) {
                ret = -ENOMEM;
                goto out;
        }

        vmx->vcpu.arch.rmode.active = 0;

        vmx->vcpu.arch.regs[VCPU_REGS_RDX] = get_rdx_init_val();
        kvm_set_cr8(&vmx->vcpu, 0);
        msr = 0xfee00000 | MSR_IA32_APICBASE_ENABLE;
        if (vmx->vcpu.vcpu_id == 0)
                msr |= MSR_IA32_APICBASE_BSP;
        kvm_set_apic_base(&vmx->vcpu, msr);

        fx_init(&vmx->vcpu);

        /*
         * GUEST_CS_BASE should really be 0xffff0000, but VT vm86 mode
         * insists on having GUEST_CS_BASE == GUEST_CS_SELECTOR << 4.  Sigh.
         */
        if (vmx->vcpu.vcpu_id == 0) {
                vmcs_write16(GUEST_CS_SELECTOR, 0xf000);
                vmcs_writel(GUEST_CS_BASE, 0x000f0000);
        } else {
                vmcs_write16(GUEST_CS_SELECTOR, vmx->vcpu.arch.sipi_vector << 8);
                vmcs_writel(GUEST_CS_BASE, vmx->vcpu.arch.sipi_vector << 12);
        }
        vmcs_write32(GUEST_CS_LIMIT, 0xffff);
        vmcs_write32(GUEST_CS_AR_BYTES, 0x9b);

        seg_setup(VCPU_SREG_DS);
        seg_setup(VCPU_SREG_ES);
        seg_setup(VCPU_SREG_FS);
        seg_setup(VCPU_SREG_GS);
        seg_setup(VCPU_SREG_SS);

        vmcs_write16(GUEST_TR_SELECTOR, 0);
        vmcs_writel(GUEST_TR_BASE, 0);
        vmcs_write32(GUEST_TR_LIMIT, 0xffff);
        vmcs_write32(GUEST_TR_AR_BYTES, 0x008b);

        vmcs_write16(GUEST_LDTR_SELECTOR, 0);
        vmcs_writel(GUEST_LDTR_BASE, 0);
        vmcs_write32(GUEST_LDTR_LIMIT, 0xffff);
        vmcs_write32(GUEST_LDTR_AR_BYTES, 0x00082);

        vmcs_write32(GUEST_SYSENTER_CS, 0);
        vmcs_writel(GUEST_SYSENTER_ESP, 0);
        vmcs_writel(GUEST_SYSENTER_EIP, 0);

        vmcs_writel(GUEST_RFLAGS, 0x02);
        if (vmx->vcpu.vcpu_id == 0)
                vmcs_writel(GUEST_RIP, 0xfff0);
        else
                vmcs_writel(GUEST_RIP, 0);
        vmcs_writel(GUEST_RSP, 0);

        /* todo: dr0 = dr1 = dr2 = dr3 = 0; dr6 = 0xffff0ff0 */
        vmcs_writel(GUEST_DR7, 0x400);

        vmcs_writel(GUEST_GDTR_BASE, 0);
        vmcs_write32(GUEST_GDTR_LIMIT, 0xffff);

        vmcs_writel(GUEST_IDTR_BASE, 0);
        vmcs_write32(GUEST_IDTR_LIMIT, 0xffff);

        vmcs_write32(GUEST_ACTIVITY_STATE, 0);
        vmcs_write32(GUEST_INTERRUPTIBILITY_INFO, 0);
        vmcs_write32(GUEST_PENDING_DBG_EXCEPTIONS, 0);

        guest_write_tsc(0);

        /* Special registers */
        vmcs_write64(GUEST_IA32_DEBUGCTL, 0);

        setup_msrs(vmx);

        vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, 0);  /* 22.2.1 */

        if (cpu_has_vmx_tpr_shadow()) {
                vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, 0);
                if (vm_need_tpr_shadow(vmx->vcpu.kvm))
                        vmcs_write64(VIRTUAL_APIC_PAGE_ADDR,
                                page_to_phys(vmx->vcpu.arch.apic->regs_page));
                vmcs_write32(TPR_THRESHOLD, 0);
        }

        if (vm_need_virtualize_apic_accesses(vmx->vcpu.kvm))
                vmcs_write64(APIC_ACCESS_ADDR,
                             page_to_phys(vmx->vcpu.kvm->arch.apic_access_page));

        if (vmx->vpid != 0)
                vmcs_write16(VIRTUAL_PROCESSOR_ID, vmx->vpid);

        vmx->vcpu.arch.cr0 = 0x60000010;
        vmx_set_cr0(&vmx->vcpu, vmx->vcpu.arch.cr0); /* enter rmode */
        vmx_set_cr4(&vmx->vcpu, 0);
        vmx_set_efer(&vmx->vcpu, 0);
        vmx_fpu_activate(&vmx->vcpu);
        update_exception_bitmap(&vmx->vcpu);

        vpid_sync_vcpu_all(vmx);

        ret = 0;

out:
        up_read(&vcpu->kvm->slots_lock);
        return ret;
}

static void vmx_inject_irq(struct kvm_vcpu *vcpu, int irq)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        KVMTRACE_1D(INJ_VIRQ, vcpu, (u32)irq, handler);

        if (vcpu->arch.rmode.active) {
                vmx->rmode.irq.pending = true;
                vmx->rmode.irq.vector = irq;
                vmx->rmode.irq.rip = vmcs_readl(GUEST_RIP);
                vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
                             irq | INTR_TYPE_SOFT_INTR | INTR_INFO_VALID_MASK);
                vmcs_write32(VM_ENTRY_INSTRUCTION_LEN, 1);
                vmcs_writel(GUEST_RIP, vmx->rmode.irq.rip - 1);
                return;
        }
        vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
                        irq | INTR_TYPE_EXT_INTR | INTR_INFO_VALID_MASK);
}

static void vmx_inject_nmi(struct kvm_vcpu *vcpu)
{
        vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
                        INTR_TYPE_NMI_INTR | INTR_INFO_VALID_MASK | NMI_VECTOR);
        vcpu->arch.nmi_pending = 0;
}

static void kvm_do_inject_irq(struct kvm_vcpu *vcpu)
{
        int word_index = __ffs(vcpu->arch.irq_summary);
        int bit_index = __ffs(vcpu->arch.irq_pending[word_index]);
        int irq = word_index * BITS_PER_LONG + bit_index;

        clear_bit(bit_index, &vcpu->arch.irq_pending[word_index]);
        if (!vcpu->arch.irq_pending[word_index])
                clear_bit(word_index, &vcpu->arch.irq_summary);
        vmx_inject_irq(vcpu, irq);
}


static void do_interrupt_requests(struct kvm_vcpu *vcpu,
                                       struct kvm_run *kvm_run)
{
        u32 cpu_based_vm_exec_control;

        vcpu->arch.interrupt_window_open =
                ((vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF) &&
                 (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & 3) == 0);

        if (vcpu->arch.interrupt_window_open &&
            vcpu->arch.irq_summary &&
            !(vmcs_read32(VM_ENTRY_INTR_INFO_FIELD) & INTR_INFO_VALID_MASK))
                /*
                 * If interrupts enabled, and not blocked by sti or mov ss. Good.
                 */
                kvm_do_inject_irq(vcpu);

        cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
        if (!vcpu->arch.interrupt_window_open &&
            (vcpu->arch.irq_summary || kvm_run->request_interrupt_window))
                /*
                 * Interrupts blocked.  Wait for unblock.
                 */
                cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING;
        else
                cpu_based_vm_exec_control &= ~CPU_BASED_VIRTUAL_INTR_PENDING;
        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
}

static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr)
{
        int ret;
        struct kvm_userspace_memory_region tss_mem = {
                .slot = 8,
                .guest_phys_addr = addr,
                .memory_size = PAGE_SIZE * 3,
                .flags = 0,
        };

        ret = kvm_set_memory_region(kvm, &tss_mem, 0);
        if (ret)
                return ret;
        kvm->arch.tss_addr = addr;
        return 0;
}

static void kvm_guest_debug_pre(struct kvm_vcpu *vcpu)
{
        struct kvm_guest_debug *dbg = &vcpu->guest_debug;

        set_debugreg(dbg->bp[0], 0);
        set_debugreg(dbg->bp[1], 1);
        set_debugreg(dbg->bp[2], 2);
        set_debugreg(dbg->bp[3], 3);

        if (dbg->singlestep) {
                unsigned long flags;

                flags = vmcs_readl(GUEST_RFLAGS);
                flags |= X86_EFLAGS_TF | X86_EFLAGS_RF;
                vmcs_writel(GUEST_RFLAGS, flags);
        }
}

static int handle_rmode_exception(struct kvm_vcpu *vcpu,
                                  int vec, u32 err_code)
{
        if (!vcpu->arch.rmode.active)
                return 0;

        /*
         * Instruction with address size override prefix opcode 0x67
         * Cause the #SS fault with 0 error code in VM86 mode.
         */
        if (((vec == GP_VECTOR) || (vec == SS_VECTOR)) && err_code == 0)
                if (emulate_instruction(vcpu, NULL, 0, 0, 0) == EMULATE_DONE)
                        return 1;
        return 0;
}

static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 intr_info, error_code;
        unsigned long cr2, rip;
        u32 vect_info;
        enum emulation_result er;

        vect_info = vmx->idt_vectoring_info;
        intr_info = vmcs_read32(VM_EXIT_INTR_INFO);

        if ((vect_info & VECTORING_INFO_VALID_MASK) &&
                                                !is_page_fault(intr_info))
                printk(KERN_ERR "%s: unexpected, vectoring info 0x%x "
                       "intr info 0x%x\n", __func__, vect_info, intr_info);

        if (!irqchip_in_kernel(vcpu->kvm) && is_external_interrupt(vect_info)) {
                int irq = vect_info & VECTORING_INFO_VECTOR_MASK;
                set_bit(irq, vcpu->arch.irq_pending);
                set_bit(irq / BITS_PER_LONG, &vcpu->arch.irq_summary);
        }

        if ((intr_info & INTR_INFO_INTR_TYPE_MASK) == 0x200) /* nmi */
                return 1;  /* already handled by vmx_vcpu_run() */

        if (is_no_device(intr_info)) {
                vmx_fpu_activate(vcpu);
                return 1;
        }

        if (is_invalid_opcode(intr_info)) {
                er = emulate_instruction(vcpu, kvm_run, 0, 0, EMULTYPE_TRAP_UD);
                if (er != EMULATE_DONE)
                        kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }

        error_code = 0;
        rip = vmcs_readl(GUEST_RIP);
        if (intr_info & INTR_INFO_DELIVER_CODE_MASK)
                error_code = vmcs_read32(VM_EXIT_INTR_ERROR_CODE);
        if (is_page_fault(intr_info)) {
                /* EPT won't cause page fault directly */
                if (vm_need_ept())
                        BUG();
                cr2 = vmcs_readl(EXIT_QUALIFICATION);
                KVMTRACE_3D(PAGE_FAULT, vcpu, error_code, (u32)cr2,
                            (u32)((u64)cr2 >> 32), handler);
                if (vect_info & VECTORING_INFO_VALID_MASK)
                        kvm_mmu_unprotect_page_virt(vcpu, cr2);
                return kvm_mmu_page_fault(vcpu, cr2, error_code);
        }

        if (vcpu->arch.rmode.active &&
            handle_rmode_exception(vcpu, intr_info & INTR_INFO_VECTOR_MASK,
                                                                error_code)) {
                if (vcpu->arch.halt_request) {
                        vcpu->arch.halt_request = 0;
                        return kvm_emulate_halt(vcpu);
                }
                return 1;
        }

        if ((intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK)) ==
            (INTR_TYPE_EXCEPTION | 1)) {
                kvm_run->exit_reason = KVM_EXIT_DEBUG;
                return 0;
        }
        kvm_run->exit_reason = KVM_EXIT_EXCEPTION;
        kvm_run->ex.exception = intr_info & INTR_INFO_VECTOR_MASK;
        kvm_run->ex.error_code = error_code;
        return 0;
}

static int handle_external_interrupt(struct kvm_vcpu *vcpu,
                                     struct kvm_run *kvm_run)
{
        ++vcpu->stat.irq_exits;
        KVMTRACE_1D(INTR, vcpu, vmcs_read32(VM_EXIT_INTR_INFO), handler);
        return 1;
}

static int handle_triple_fault(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        kvm_run->exit_reason = KVM_EXIT_SHUTDOWN;
        return 0;
}

static int handle_io(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        unsigned long exit_qualification;
        int size, down, in, string, rep;
        unsigned port;

        ++vcpu->stat.io_exits;
        exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        string = (exit_qualification & 16) != 0;

        if (string) {
                if (emulate_instruction(vcpu,
                                        kvm_run, 0, 0, 0) == EMULATE_DO_MMIO)
                        return 0;
                return 1;
        }

        size = (exit_qualification & 7) + 1;
        in = (exit_qualification & 8) != 0;
        down = (vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_DF) != 0;
        rep = (exit_qualification & 32) != 0;
        port = exit_qualification >> 16;

        return kvm_emulate_pio(vcpu, kvm_run, in, size, port);
}

static void
vmx_patch_hypercall(struct kvm_vcpu *vcpu, unsigned char *hypercall)
{
        /*
         * Patch in the VMCALL instruction:
         */
        hypercall[0] = 0x0f;
        hypercall[1] = 0x01;
        hypercall[2] = 0xc1;
}

static int handle_cr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        unsigned long exit_qualification;
        int cr;
        int reg;

        exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        cr = exit_qualification & 15;
        reg = (exit_qualification >> 8) & 15;
        switch ((exit_qualification >> 4) & 3) {
        case 0: /* mov to cr */
                KVMTRACE_3D(CR_WRITE, vcpu, (u32)cr, (u32)vcpu->arch.regs[reg],
                            (u32)((u64)vcpu->arch.regs[reg] >> 32), handler);
                switch (cr) {
                case 0:
                        vcpu_load_rsp_rip(vcpu);
                        kvm_set_cr0(vcpu, vcpu->arch.regs[reg]);
                        skip_emulated_instruction(vcpu);
                        return 1;
                case 3:
                        vcpu_load_rsp_rip(vcpu);
                        kvm_set_cr3(vcpu, vcpu->arch.regs[reg]);
                        skip_emulated_instruction(vcpu);
                        return 1;
                case 4:
                        vcpu_load_rsp_rip(vcpu);
                        kvm_set_cr4(vcpu, vcpu->arch.regs[reg]);
                        skip_emulated_instruction(vcpu);
                        return 1;
                case 8:
                        vcpu_load_rsp_rip(vcpu);
                        kvm_set_cr8(vcpu, vcpu->arch.regs[reg]);
                        skip_emulated_instruction(vcpu);
                        if (irqchip_in_kernel(vcpu->kvm))
                                return 1;
                        kvm_run->exit_reason = KVM_EXIT_SET_TPR;
                        return 0;
                };
                break;
        case 2: /* clts */
                vcpu_load_rsp_rip(vcpu);
                vmx_fpu_deactivate(vcpu);
                vcpu->arch.cr0 &= ~X86_CR0_TS;
                vmcs_writel(CR0_READ_SHADOW, vcpu->arch.cr0);
                vmx_fpu_activate(vcpu);
                KVMTRACE_0D(CLTS, vcpu, handler);
                skip_emulated_instruction(vcpu);
                return 1;
        case 1: /*mov from cr*/
                switch (cr) {
                case 3:
                        vcpu_load_rsp_rip(vcpu);
                        vcpu->arch.regs[reg] = vcpu->arch.cr3;
                        vcpu_put_rsp_rip(vcpu);
                        KVMTRACE_3D(CR_READ, vcpu, (u32)cr,
                                    (u32)vcpu->arch.regs[reg],
                                    (u32)((u64)vcpu->arch.regs[reg] >> 32),
                                    handler);
                        skip_emulated_instruction(vcpu);
                        return 1;
                case 8:
                        vcpu_load_rsp_rip(vcpu);
                        vcpu->arch.regs[reg] = kvm_get_cr8(vcpu);
                        vcpu_put_rsp_rip(vcpu);
                        KVMTRACE_2D(CR_READ, vcpu, (u32)cr,
                                    (u32)vcpu->arch.regs[reg], handler);
                        skip_emulated_instruction(vcpu);
                        return 1;
                }
                break;
        case 3: /* lmsw */
                kvm_lmsw(vcpu, (exit_qualification >> LMSW_SOURCE_DATA_SHIFT) & 0x0f);

                skip_emulated_instruction(vcpu);
                return 1;
        default:
                break;
        }
        kvm_run->exit_reason = 0;
        pr_unimpl(vcpu, "unhandled control register: op %d cr %d\n",
               (int)(exit_qualification >> 4) & 3, cr);
        return 0;
}

static int handle_dr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        unsigned long exit_qualification;
        unsigned long val;
        int dr, reg;

        /*
         * FIXME: this code assumes the host is debugging the guest.
         *        need to deal with guest debugging itself too.
         */
        exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        dr = exit_qualification & 7;
        reg = (exit_qualification >> 8) & 15;
        vcpu_load_rsp_rip(vcpu);
        if (exit_qualification & 16) {
                /* mov from dr */
                switch (dr) {
                case 6:
                        val = 0xffff0ff0;
                        break;
                case 7:
                        val = 0x400;
                        break;
                default:
                        val = 0;
                }
                vcpu->arch.regs[reg] = val;
                KVMTRACE_2D(DR_READ, vcpu, (u32)dr, (u32)val, handler);
        } else {
                /* mov to dr */
        }
        vcpu_put_rsp_rip(vcpu);
        skip_emulated_instruction(vcpu);
        return 1;
}

static int handle_cpuid(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        kvm_emulate_cpuid(vcpu);
        return 1;
}

static int handle_rdmsr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        u32 ecx = vcpu->arch.regs[VCPU_REGS_RCX];
        u64 data;

        if (vmx_get_msr(vcpu, ecx, &data)) {
                kvm_inject_gp(vcpu, 0);
                return 1;
        }

        KVMTRACE_3D(MSR_READ, vcpu, ecx, (u32)data, (u32)(data >> 32),
                    handler);

        /* FIXME: handling of bits 32:63 of rax, rdx */
        vcpu->arch.regs[VCPU_REGS_RAX] = data & -1u;
        vcpu->arch.regs[VCPU_REGS_RDX] = (data >> 32) & -1u;
        skip_emulated_instruction(vcpu);
        return 1;
}

static int handle_wrmsr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        u32 ecx = vcpu->arch.regs[VCPU_REGS_RCX];
        u64 data = (vcpu->arch.regs[VCPU_REGS_RAX] & -1u)
                | ((u64)(vcpu->arch.regs[VCPU_REGS_RDX] & -1u) << 32);

        KVMTRACE_3D(MSR_WRITE, vcpu, ecx, (u32)data, (u32)(data >> 32),
                    handler);

        if (vmx_set_msr(vcpu, ecx, data) != 0) {
                kvm_inject_gp(vcpu, 0);
                return 1;
        }

        skip_emulated_instruction(vcpu);
        return 1;
}

static int handle_tpr_below_threshold(struct kvm_vcpu *vcpu,
                                      struct kvm_run *kvm_run)
{
        return 1;
}

static int handle_interrupt_window(struct kvm_vcpu *vcpu,
                                   struct kvm_run *kvm_run)
{
        u32 cpu_based_vm_exec_control;

        /* clear pending irq */
        cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
        cpu_based_vm_exec_control &= ~CPU_BASED_VIRTUAL_INTR_PENDING;
        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);

        KVMTRACE_0D(PEND_INTR, vcpu, handler);

        /*
         * If the user space waits to inject interrupts, exit as soon as
         * possible
         */
        if (kvm_run->request_interrupt_window &&
            !vcpu->arch.irq_summary) {
                kvm_run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
                ++vcpu->stat.irq_window_exits;
                return 0;
        }
        return 1;
}

static int handle_halt(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        skip_emulated_instruction(vcpu);
        return kvm_emulate_halt(vcpu);
}

static int handle_vmcall(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        skip_emulated_instruction(vcpu);
        kvm_emulate_hypercall(vcpu);
        return 1;
}

static int handle_wbinvd(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        skip_emulated_instruction(vcpu);
        /* TODO: Add support for VT-d/pass-through device */
        return 1;
}

static int handle_apic_access(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        u64 exit_qualification;
        enum emulation_result er;
        unsigned long offset;

        exit_qualification = vmcs_read64(EXIT_QUALIFICATION);
        offset = exit_qualification & 0xffful;

        er = emulate_instruction(vcpu, kvm_run, 0, 0, 0);

        if (er !=  EMULATE_DONE) {
                printk(KERN_ERR
                       "Fail to handle apic access vmexit! Offset is 0x%lx\n",
                       offset);
                return -ENOTSUPP;
        }
        return 1;
}

static int handle_task_switch(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        unsigned long exit_qualification;
        u16 tss_selector;
        int reason;

        exit_qualification = vmcs_readl(EXIT_QUALIFICATION);

        reason = (u32)exit_qualification >> 30;
        tss_selector = exit_qualification;

        return kvm_task_switch(vcpu, tss_selector, reason);
}

static int handle_ept_violation(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        u64 exit_qualification;
        enum emulation_result er;
        gpa_t gpa;
        unsigned long hva;
        int gla_validity;
        int r;

        exit_qualification = vmcs_read64(EXIT_QUALIFICATION);

        if (exit_qualification & (1 << 6)) {
                printk(KERN_ERR "EPT: GPA exceeds GAW!\n");
                return -ENOTSUPP;
        }

        gla_validity = (exit_qualification >> 7) & 0x3;
        if (gla_validity != 0x3 && gla_validity != 0x1 && gla_validity != 0) {
                printk(KERN_ERR "EPT: Handling EPT violation failed!\n");
                printk(KERN_ERR "EPT: GPA: 0x%lx, GVA: 0x%lx\n",
                        (long unsigned int)vmcs_read64(GUEST_PHYSICAL_ADDRESS),
                        (long unsigned int)vmcs_read64(GUEST_LINEAR_ADDRESS));
                printk(KERN_ERR "EPT: Exit qualification is 0x%lx\n",
                        (long unsigned int)exit_qualification);
                kvm_run->exit_reason = KVM_EXIT_UNKNOWN;
                kvm_run->hw.hardware_exit_reason = 0;
                return -ENOTSUPP;
        }

        gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
        hva = gfn_to_hva(vcpu->kvm, gpa >> PAGE_SHIFT);
        if (!kvm_is_error_hva(hva)) {
                r = kvm_mmu_page_fault(vcpu, gpa & PAGE_MASK, 0);
                if (r < 0) {
                        printk(KERN_ERR "EPT: Not enough memory!\n");
                        return -ENOMEM;
                }
                return 1;
        } else {
                /* must be MMIO */
                er = emulate_instruction(vcpu, kvm_run, 0, 0, 0);

                if (er == EMULATE_FAIL) {
                        printk(KERN_ERR
                         "EPT: Fail to handle EPT violation vmexit!er is %d\n",
                         er);
                        printk(KERN_ERR "EPT: GPA: 0x%lx, GVA: 0x%lx\n",
                         (long unsigned int)vmcs_read64(GUEST_PHYSICAL_ADDRESS),
                         (long unsigned int)vmcs_read64(GUEST_LINEAR_ADDRESS));
                        printk(KERN_ERR "EPT: Exit qualification is 0x%lx\n",
                                (long unsigned int)exit_qualification);
                        return -ENOTSUPP;
                } else if (er == EMULATE_DO_MMIO)
                        return 0;
        }
        return 1;
}

static int handle_nmi_window(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        u32 cpu_based_vm_exec_control;

        /* clear pending NMI */
        cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
        cpu_based_vm_exec_control &= ~CPU_BASED_VIRTUAL_NMI_PENDING;
        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
        ++vcpu->stat.nmi_window_exits;

        return 1;
}

/*
 * The exit handlers return 1 if the exit was handled fully and guest execution
 * may resume.  Otherwise they set the kvm_run parameter to indicate what needs
 * to be done to userspace and return 0.
 */
static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu,
                                      struct kvm_run *kvm_run) = {
        [EXIT_REASON_EXCEPTION_NMI]           = handle_exception,
        [EXIT_REASON_EXTERNAL_INTERRUPT]      = handle_external_interrupt,
        [EXIT_REASON_TRIPLE_FAULT]            = handle_triple_fault,
        [EXIT_REASON_NMI_WINDOW]              = handle_nmi_window,
        [EXIT_REASON_IO_INSTRUCTION]          = handle_io,
        [EXIT_REASON_CR_ACCESS]               = handle_cr,
        [EXIT_REASON_DR_ACCESS]               = handle_dr,
        [EXIT_REASON_CPUID]                   = handle_cpuid,
        [EXIT_REASON_MSR_READ]                = handle_rdmsr,
        [EXIT_REASON_MSR_WRITE]               = handle_wrmsr,
        [EXIT_REASON_PENDING_INTERRUPT]       = handle_interrupt_window,
        [EXIT_REASON_HLT]                     = handle_halt,
        [EXIT_REASON_VMCALL]                  = handle_vmcall,
        [EXIT_REASON_TPR_BELOW_THRESHOLD]     = handle_tpr_below_threshold,
        [EXIT_REASON_APIC_ACCESS]             = handle_apic_access,
        [EXIT_REASON_WBINVD]                  = handle_wbinvd,
        [EXIT_REASON_TASK_SWITCH]             = handle_task_switch,
        [EXIT_REASON_EPT_VIOLATION]           = handle_ept_violation,
};

static const int kvm_vmx_max_exit_handlers =
        ARRAY_SIZE(kvm_vmx_exit_handlers);

/*
 * The guest has exited.  See if we can fix it or if we need userspace
 * assistance.
 */
static int kvm_handle_exit(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
{
        u32 exit_reason = vmcs_read32(VM_EXIT_REASON);
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 vectoring_info = vmx->idt_vectoring_info;

        KVMTRACE_3D(VMEXIT, vcpu, exit_reason, (u32)vmcs_readl(GUEST_RIP),
                    (u32)((u64)vmcs_readl(GUEST_RIP) >> 32), entryexit);

        /* Access CR3 don't cause VMExit in paging mode, so we need
         * to sync with guest real CR3. */
        if (vm_need_ept() && is_paging(vcpu)) {
                vcpu->arch.cr3 = vmcs_readl(GUEST_CR3);
                ept_load_pdptrs(vcpu);
        }

        if (unlikely(vmx->fail)) {
                kvm_run->exit_reason = KVM_EXIT_FAIL_ENTRY;
                kvm_run->fail_entry.hardware_entry_failure_reason
                        = vmcs_read32(VM_INSTRUCTION_ERROR);
                return 0;
        }

        if ((vectoring_info & VECTORING_INFO_VALID_MASK) &&
                        (exit_reason != EXIT_REASON_EXCEPTION_NMI &&
                        exit_reason != EXIT_REASON_EPT_VIOLATION))
                printk(KERN_WARNING "%s: unexpected, valid vectoring info and "
                       "exit reason is 0x%x\n", __func__, exit_reason);
        if (exit_reason < kvm_vmx_max_exit_handlers
            && kvm_vmx_exit_handlers[exit_reason])
                return kvm_vmx_exit_handlers[exit_reason](vcpu, kvm_run);
        else {
                kvm_run->exit_reason = KVM_EXIT_UNKNOWN;
                kvm_run->hw.hardware_exit_reason = exit_reason;
        }
        return 0;
}

static void update_tpr_threshold(struct kvm_vcpu *vcpu)
{
        int max_irr, tpr;

        if (!vm_need_tpr_shadow(vcpu->kvm))
                return;

        if (!kvm_lapic_enabled(vcpu) ||
            ((max_irr = kvm_lapic_find_highest_irr(vcpu)) == -1)) {
                vmcs_write32(TPR_THRESHOLD, 0);
                return;
        }

        tpr = (kvm_lapic_get_cr8(vcpu) & 0x0f) << 4;
        vmcs_write32(TPR_THRESHOLD, (max_irr > tpr) ? tpr >> 4 : max_irr >> 4);
}

static void enable_irq_window(struct kvm_vcpu *vcpu)
{
        u32 cpu_based_vm_exec_control;

        cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
        cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING;
        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
}

static void enable_nmi_window(struct kvm_vcpu *vcpu)
{
        u32 cpu_based_vm_exec_control;

        if (!cpu_has_virtual_nmis())
                return;

        cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);
        cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_NMI_PENDING;
        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
}

static int vmx_nmi_enabled(struct kvm_vcpu *vcpu)
{
        u32 guest_intr = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);
        return !(guest_intr & (GUEST_INTR_STATE_NMI |
                               GUEST_INTR_STATE_MOV_SS |
                               GUEST_INTR_STATE_STI));
}

static int vmx_irq_enabled(struct kvm_vcpu *vcpu)
{
        u32 guest_intr = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);
        return (!(guest_intr & (GUEST_INTR_STATE_MOV_SS |
                               GUEST_INTR_STATE_STI)) &&
                (vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF));
}

static void enable_intr_window(struct kvm_vcpu *vcpu)
{
        if (vcpu->arch.nmi_pending)
                enable_nmi_window(vcpu);
        else if (kvm_cpu_has_interrupt(vcpu))
                enable_irq_window(vcpu);
}

static void vmx_intr_assist(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 idtv_info_field, intr_info_field, exit_intr_info_field;
        int vector;

        update_tpr_threshold(vcpu);

        intr_info_field = vmcs_read32(VM_ENTRY_INTR_INFO_FIELD);
        exit_intr_info_field = vmcs_read32(VM_EXIT_INTR_INFO);
        idtv_info_field = vmx->idt_vectoring_info;
        if (intr_info_field & INTR_INFO_VALID_MASK) {
                if (idtv_info_field & INTR_INFO_VALID_MASK) {
                        /* TODO: fault when IDT_Vectoring */
                        if (printk_ratelimit())
                                printk(KERN_ERR "Fault when IDT_Vectoring\n");
                }
                enable_intr_window(vcpu);
                return;
        }
        if (unlikely(idtv_info_field & INTR_INFO_VALID_MASK)) {
                if ((idtv_info_field & VECTORING_INFO_TYPE_MASK)
                    == INTR_TYPE_EXT_INTR
                    && vcpu->arch.rmode.active) {
                        u8 vect = idtv_info_field & VECTORING_INFO_VECTOR_MASK;

                        vmx_inject_irq(vcpu, vect);
                        enable_intr_window(vcpu);
                        return;
                }

                KVMTRACE_1D(REDELIVER_EVT, vcpu, idtv_info_field, handler);

                /*
                 * SDM 3: 25.7.1.2
                 * Clear bit "block by NMI" before VM entry if a NMI delivery
                 * faulted.
                 */
                if ((idtv_info_field & VECTORING_INFO_TYPE_MASK)
                    == INTR_TYPE_NMI_INTR && cpu_has_virtual_nmis())
                        vmcs_write32(GUEST_INTERRUPTIBILITY_INFO,
                                vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) &
                                ~GUEST_INTR_STATE_NMI);

                vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, idtv_info_field
                                & ~INTR_INFO_RESVD_BITS_MASK);
                vmcs_write32(VM_ENTRY_INSTRUCTION_LEN,
                                vmcs_read32(VM_EXIT_INSTRUCTION_LEN));

                if (unlikely(idtv_info_field & INTR_INFO_DELIVER_CODE_MASK))
                        vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE,
                                vmcs_read32(IDT_VECTORING_ERROR_CODE));
                enable_intr_window(vcpu);
                return;
        }
        if (cpu_has_virtual_nmis()) {
                /*
                 * SDM 3: 25.7.1.2
                 * Re-set bit "block by NMI" before VM entry if vmexit caused by
                 * a guest IRET fault.
                 */
                if ((exit_intr_info_field & INTR_INFO_UNBLOCK_NMI) &&
                    (exit_intr_info_field & INTR_INFO_VECTOR_MASK) != 8)
                        vmcs_write32(GUEST_INTERRUPTIBILITY_INFO,
                                vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) |
                                GUEST_INTR_STATE_NMI);
                else if (vcpu->arch.nmi_pending) {
                        if (vmx_nmi_enabled(vcpu))
                                vmx_inject_nmi(vcpu);
                        enable_intr_window(vcpu);
                        return;
                }

        }
        if (!kvm_cpu_has_interrupt(vcpu))
                return;
        if (vmx_irq_enabled(vcpu)) {
                vector = kvm_cpu_get_interrupt(vcpu);
                vmx_inject_irq(vcpu, vector);
                kvm_timer_intr_post(vcpu, vector);
        } else
                enable_irq_window(vcpu);
}

/*
 * Failure to inject an interrupt should give us the information
 * in IDT_VECTORING_INFO_FIELD.  However, if the failure occurs
 * when fetching the interrupt redirection bitmap in the real-mode
 * tss, this doesn't happen.  So we do it ourselves.
 */
static void fixup_rmode_irq(struct vcpu_vmx *vmx)
{
        vmx->rmode.irq.pending = 0;
        if (vmcs_readl(GUEST_RIP) + 1 != vmx->rmode.irq.rip)
                return;
        vmcs_writel(GUEST_RIP, vmx->rmode.irq.rip);
        if (vmx->idt_vectoring_info & VECTORING_INFO_VALID_MASK) {
                vmx->idt_vectoring_info &= ~VECTORING_INFO_TYPE_MASK;
                vmx->idt_vectoring_info |= INTR_TYPE_EXT_INTR;
                return;
        }
        vmx->idt_vectoring_info =
                VECTORING_INFO_VALID_MASK
                | INTR_TYPE_EXT_INTR
                | vmx->rmode.irq.vector;
}

static void vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 intr_info;

        /*
         * Loading guest fpu may have cleared host cr0.ts
         */
        vmcs_writel(HOST_CR0, read_cr0());

        asm(
                /* Store host registers */
#ifdef CONFIG_X86_64
                "push %%rdx; push %%rbp;"
                "push %%rcx \n\t"
#else
                "push %%edx; push %%ebp;"
                "push %%ecx \n\t"
#endif
                __ex(ASM_VMX_VMWRITE_RSP_RDX) "\n\t"
                /* Check if vmlaunch of vmresume is needed */
                "cmpl $0, %c[launched](%0) \n\t"
                /* Load guest registers.  Don't clobber flags. */
#ifdef CONFIG_X86_64
                "mov %c[cr2](%0), %%rax \n\t"
                "mov %%rax, %%cr2 \n\t"
                "mov %c[rax](%0), %%rax \n\t"
                "mov %c[rbx](%0), %%rbx \n\t"
                "mov %c[rdx](%0), %%rdx \n\t"
                "mov %c[rsi](%0), %%rsi \n\t"
                "mov %c[rdi](%0), %%rdi \n\t"
                "mov %c[rbp](%0), %%rbp \n\t"
                "mov %c[r8](%0),  %%r8  \n\t"
                "mov %c[r9](%0),  %%r9  \n\t"
                "mov %c[r10](%0), %%r10 \n\t"
                "mov %c[r11](%0), %%r11 \n\t"
                "mov %c[r12](%0), %%r12 \n\t"
                "mov %c[r13](%0), %%r13 \n\t"
                "mov %c[r14](%0), %%r14 \n\t"
                "mov %c[r15](%0), %%r15 \n\t"
                "mov %c[rcx](%0), %%rcx \n\t" /* kills %0 (rcx) */
#else
                "mov %c[cr2](%0), %%eax \n\t"
                "mov %%eax,   %%cr2 \n\t"
                "mov %c[rax](%0), %%eax \n\t"
                "mov %c[rbx](%0), %%ebx \n\t"
                "mov %c[rdx](%0), %%edx \n\t"
                "mov %c[rsi](%0), %%esi \n\t"
                "mov %c[rdi](%0), %%edi \n\t"
                "mov %c[rbp](%0), %%ebp \n\t"
                "mov %c[rcx](%0), %%ecx \n\t" /* kills %0 (ecx) */
#endif
                /* Enter guest mode */
                "jne .Llaunched \n\t"
                __ex(ASM_VMX_VMLAUNCH) "\n\t"
                "jmp .Lkvm_vmx_return \n\t"
                ".Llaunched: " __ex(ASM_VMX_VMRESUME) "\n\t"
                ".Lkvm_vmx_return: "
                /* Save guest registers, load host registers, keep flags */
#ifdef CONFIG_X86_64
                "xchg %0,     (%%rsp) \n\t"
                "mov %%rax, %c[rax](%0) \n\t"
                "mov %%rbx, %c[rbx](%0) \n\t"
                "pushq (%%rsp); popq %c[rcx](%0) \n\t"
                "mov %%rdx, %c[rdx](%0) \n\t"
                "mov %%rsi, %c[rsi](%0) \n\t"
                "mov %%rdi, %c[rdi](%0) \n\t"
                "mov %%rbp, %c[rbp](%0) \n\t"
                "mov %%r8,  %c[r8](%0) \n\t"
                "mov %%r9,  %c[r9](%0) \n\t"
                "mov %%r10, %c[r10](%0) \n\t"
                "mov %%r11, %c[r11](%0) \n\t"
                "mov %%r12, %c[r12](%0) \n\t"
                "mov %%r13, %c[r13](%0) \n\t"
                "mov %%r14, %c[r14](%0) \n\t"
                "mov %%r15, %c[r15](%0) \n\t"
                "mov %%cr2, %%rax   \n\t"
                "mov %%rax, %c[cr2](%0) \n\t"

                "pop  %%rbp; pop  %%rbp; pop  %%rdx \n\t"
#else
                "xchg %0, (%%esp) \n\t"
                "mov %%eax, %c[rax](%0) \n\t"
                "mov %%ebx, %c[rbx](%0) \n\t"
                "pushl (%%esp); popl %c[rcx](%0) \n\t"
                "mov %%edx, %c[rdx](%0) \n\t"
                "mov %%esi, %c[rsi](%0) \n\t"
                "mov %%edi, %c[rdi](%0) \n\t"
                "mov %%ebp, %c[rbp](%0) \n\t"
                "mov %%cr2, %%eax  \n\t"
                "mov %%eax, %c[cr2](%0) \n\t"

                "pop %%ebp; pop %%ebp; pop %%edx \n\t"
#endif
                "setbe %c[fail](%0) \n\t"
              : : "c"(vmx), "d"((unsigned long)HOST_RSP),
                [launched]"i"(offsetof(struct vcpu_vmx, launched)),
                [fail]"i"(offsetof(struct vcpu_vmx, fail)),
                [rax]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RAX])),
                [rbx]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RBX])),
                [rcx]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RCX])),
                [rdx]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RDX])),
                [rsi]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RSI])),
                [rdi]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RDI])),
                [rbp]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RBP])),
#ifdef CONFIG_X86_64
                [r8]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R8])),
                [r9]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R9])),
                [r10]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R10])),
                [r11]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R11])),
                [r12]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R12])),
                [r13]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R13])),
                [r14]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R14])),
                [r15]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_R15])),
#endif
                [cr2]"i"(offsetof(struct vcpu_vmx, vcpu.arch.cr2))
              : "cc", "memory"
#ifdef CONFIG_X86_64
                , "rbx", "rdi", "rsi"
                , "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15"
#else
                , "ebx", "edi", "rsi"
#endif
              );

        vmx->idt_vectoring_info = vmcs_read32(IDT_VECTORING_INFO_FIELD);
        if (vmx->rmode.irq.pending)
                fixup_rmode_irq(vmx);

        vcpu->arch.interrupt_window_open =
                (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) &
                 (GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS)) == 0;

        asm("mov %0, %%ds; mov %0, %%es" : : "r"(__USER_DS));
        vmx->launched = 1;

        intr_info = vmcs_read32(VM_EXIT_INTR_INFO);

        /* We need to handle NMIs before interrupts are enabled */
        if ((intr_info & INTR_INFO_INTR_TYPE_MASK) == 0x200 &&
            (intr_info & INTR_INFO_VALID_MASK)) {
                KVMTRACE_0D(NMI, vcpu, handler);
                asm("int $2");
        }
}

static void vmx_free_vmcs(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (vmx->vmcs) {
                vcpu_clear(vmx);
                free_vmcs(vmx->vmcs);
                vmx->vmcs = NULL;
        }
}

static void vmx_free_vcpu(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        spin_lock(&vmx_vpid_lock);
        if (vmx->vpid != 0)
                __clear_bit(vmx->vpid, vmx_vpid_bitmap);
        spin_unlock(&vmx_vpid_lock);
        vmx_free_vmcs(vcpu);
        kfree(vmx->host_msrs);
        kfree(vmx->guest_msrs);
        kvm_vcpu_uninit(vcpu);
        kmem_cache_free(kvm_vcpu_cache, vmx);
}

static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
{
        int err;
        struct vcpu_vmx *vmx = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
        int cpu;

        if (!vmx)
                return ERR_PTR(-ENOMEM);

        allocate_vpid(vmx);

        err = kvm_vcpu_init(&vmx->vcpu, kvm, id);
        if (err)
                goto free_vcpu;

        vmx->guest_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL);
        if (!vmx->guest_msrs) {
                err = -ENOMEM;
                goto uninit_vcpu;
        }

        vmx->host_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL);
        if (!vmx->host_msrs)
                goto free_guest_msrs;

        vmx->vmcs = alloc_vmcs();
        if (!vmx->vmcs)
                goto free_msrs;

        vmcs_clear(vmx->vmcs);

        cpu = get_cpu();
        vmx_vcpu_load(&vmx->vcpu, cpu);
        err = vmx_vcpu_setup(vmx);
        vmx_vcpu_put(&vmx->vcpu);
        put_cpu();
        if (err)
                goto free_vmcs;
        if (vm_need_virtualize_apic_accesses(kvm))
                if (alloc_apic_access_page(kvm) != 0)
                        goto free_vmcs;

        if (vm_need_ept())
                if (alloc_identity_pagetable(kvm) != 0)
                        goto free_vmcs;

        return &vmx->vcpu;

free_vmcs:
        free_vmcs(vmx->vmcs);
free_msrs:
        kfree(vmx->host_msrs);
free_guest_msrs:
        kfree(vmx->guest_msrs);
uninit_vcpu:
        kvm_vcpu_uninit(&vmx->vcpu);
free_vcpu:
        kmem_cache_free(kvm_vcpu_cache, vmx);
        return ERR_PTR(err);
}

static void __init vmx_check_processor_compat(void *rtn)
{
        struct vmcs_config vmcs_conf;

        *(int *)rtn = 0;
        if (setup_vmcs_config(&vmcs_conf) < 0)
                *(int *)rtn = -EIO;
        if (memcmp(&vmcs_config, &vmcs_conf, sizeof(struct vmcs_config)) != 0) {
                printk(KERN_ERR "kvm: CPU %d feature inconsistency!\n",
                                smp_processor_id());
                *(int *)rtn = -EIO;
        }
}

static int get_ept_level(void)
{
        return VMX_EPT_DEFAULT_GAW + 1;
}

static struct kvm_x86_ops vmx_x86_ops = {
        .cpu_has_kvm_support = cpu_has_kvm_support,
        .disabled_by_bios = vmx_disabled_by_bios,
        .hardware_setup = hardware_setup,
        .hardware_unsetup = hardware_unsetup,
        .check_processor_compatibility = vmx_check_processor_compat,
        .hardware_enable = hardware_enable,
        .hardware_disable = hardware_disable,
        .cpu_has_accelerated_tpr = cpu_has_vmx_virtualize_apic_accesses,

        .vcpu_create = vmx_create_vcpu,
        .vcpu_free = vmx_free_vcpu,
        .vcpu_reset = vmx_vcpu_reset,

        .prepare_guest_switch = vmx_save_host_state,
        .vcpu_load = vmx_vcpu_load,
        .vcpu_put = vmx_vcpu_put,

        .set_guest_debug = set_guest_debug,
        .guest_debug_pre = kvm_guest_debug_pre,
        .get_msr = vmx_get_msr,
        .set_msr = vmx_set_msr,
        .get_segment_base = vmx_get_segment_base,
        .get_segment = vmx_get_segment,
        .set_segment = vmx_set_segment,
        .get_cpl = vmx_get_cpl,
        .get_cs_db_l_bits = vmx_get_cs_db_l_bits,
        .decache_cr4_guest_bits = vmx_decache_cr4_guest_bits,
        .set_cr0 = vmx_set_cr0,
        .set_cr3 = vmx_set_cr3,
        .set_cr4 = vmx_set_cr4,
        .set_efer = vmx_set_efer,
        .get_idt = vmx_get_idt,
        .set_idt = vmx_set_idt,
        .get_gdt = vmx_get_gdt,
        .set_gdt = vmx_set_gdt,
        .cache_regs = vcpu_load_rsp_rip,
        .decache_regs = vcpu_put_rsp_rip,
        .get_rflags = vmx_get_rflags,
        .set_rflags = vmx_set_rflags,

        .tlb_flush = vmx_flush_tlb,

        .run = vmx_vcpu_run,
        .handle_exit = kvm_handle_exit,
        .skip_emulated_instruction = skip_emulated_instruction,
        .patch_hypercall = vmx_patch_hypercall,
        .get_irq = vmx_get_irq,
        .set_irq = vmx_inject_irq,
        .queue_exception = vmx_queue_exception,
        .exception_injected = vmx_exception_injected,
        .inject_pending_irq = vmx_intr_assist,
        .inject_pending_vectors = do_interrupt_requests,

        .set_tss_addr = vmx_set_tss_addr,
        .get_tdp_level = get_ept_level,
};

static int __init vmx_init(void)
{
        void *va;
        int r;

        vmx_io_bitmap_a = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
        if (!vmx_io_bitmap_a)
                return -ENOMEM;

        vmx_io_bitmap_b = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
        if (!vmx_io_bitmap_b) {
                r = -ENOMEM;
                goto out;
        }

        vmx_msr_bitmap = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
        if (!vmx_msr_bitmap) {
                r = -ENOMEM;
                goto out1;
        }

        /*
         * Allow direct access to the PC debug port (it is often used for I/O
         * delays, but the vmexits simply slow things down).
         */
        va = kmap(vmx_io_bitmap_a);
        memset(va, 0xff, PAGE_SIZE);
        clear_bit(0x80, va);
        kunmap(vmx_io_bitmap_a);

        va = kmap(vmx_io_bitmap_b);
        memset(va, 0xff, PAGE_SIZE);
        kunmap(vmx_io_bitmap_b);

        va = kmap(vmx_msr_bitmap);
        memset(va, 0xff, PAGE_SIZE);
        kunmap(vmx_msr_bitmap);

        set_bit(0, vmx_vpid_bitmap); /* 0 is reserved for host */

        r = kvm_init(&vmx_x86_ops, sizeof(struct vcpu_vmx), THIS_MODULE);
        if (r)
                goto out2;

        vmx_disable_intercept_for_msr(vmx_msr_bitmap, MSR_FS_BASE);
        vmx_disable_intercept_for_msr(vmx_msr_bitmap, MSR_GS_BASE);
        vmx_disable_intercept_for_msr(vmx_msr_bitmap, MSR_IA32_SYSENTER_CS);
        vmx_disable_intercept_for_msr(vmx_msr_bitmap, MSR_IA32_SYSENTER_ESP);
        vmx_disable_intercept_for_msr(vmx_msr_bitmap, MSR_IA32_SYSENTER_EIP);

        if (vm_need_ept()) {
                bypass_guest_pf = 0;
                kvm_mmu_set_base_ptes(VMX_EPT_READABLE_MASK |
                        VMX_EPT_WRITABLE_MASK |
                        VMX_EPT_DEFAULT_MT << VMX_EPT_MT_EPTE_SHIFT);
                kvm_mmu_set_mask_ptes(0ull, 0ull, 0ull, 0ull,
                                VMX_EPT_EXECUTABLE_MASK);
                kvm_enable_tdp();
        } else
                kvm_disable_tdp();

        if (bypass_guest_pf)
                kvm_mmu_set_nonpresent_ptes(~0xffeull, 0ull);

        ept_sync_global();

        return 0;

out2:
        __free_page(vmx_msr_bitmap);
out1:
        __free_page(vmx_io_bitmap_b);
out:
        __free_page(vmx_io_bitmap_a);
        return r;
}

static void __exit vmx_exit(void)
{
        __free_page(vmx_msr_bitmap);
        __free_page(vmx_io_bitmap_b);
        __free_page(vmx_io_bitmap_a);

        kvm_exit();
}

module_init(vmx_init)
module_exit(vmx_exit)

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