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

#include <linux/frame.h>
#include <linux/highmem.h>
#include <linux/hrtimer.h>
#include <linux/kernel.h>
#include <linux/kvm_host.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mod_devicetable.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/sched/smt.h>
#include <linux/slab.h>
#include <linux/tboot.h>
#include <linux/trace_events.h>

#include <asm/apic.h>
#include <asm/asm.h>
#include <asm/cpu.h>
#include <asm/debugreg.h>
#include <asm/desc.h>
#include <asm/fpu/internal.h>
#include <asm/io.h>
#include <asm/irq_remapping.h>
#include <asm/kexec.h>
#include <asm/perf_event.h>
#include <asm/mce.h>
#include <asm/mmu_context.h>
#include <asm/mshyperv.h>
#include <asm/spec-ctrl.h>
#include <asm/virtext.h>
#include <asm/vmx.h>

#include "capabilities.h"
#include "cpuid.h"
#include "evmcs.h"
#include "irq.h"
#include "kvm_cache_regs.h"
#include "lapic.h"
#include "mmu.h"
#include "nested.h"
#include "ops.h"
#include "pmu.h"
#include "trace.h"
#include "vmcs.h"
#include "vmcs12.h"
#include "vmx.h"
#include "x86.h"

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

static const struct x86_cpu_id vmx_cpu_id[] = {
        X86_FEATURE_MATCH(X86_FEATURE_VMX),
        {}
};
MODULE_DEVICE_TABLE(x86cpu, vmx_cpu_id);

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

static bool __read_mostly enable_vnmi = 1;
module_param_named(vnmi, enable_vnmi, bool, S_IRUGO);

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

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

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

bool __read_mostly enable_ept_ad_bits = 1;
module_param_named(eptad, enable_ept_ad_bits, bool, S_IRUGO);

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

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

bool __read_mostly enable_apicv = 1;
module_param(enable_apicv, bool, S_IRUGO);

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

static u64 __read_mostly host_xss;

bool __read_mostly enable_pml = 1;
module_param_named(pml, enable_pml, bool, S_IRUGO);

#define MSR_BITMAP_MODE_X2APIC          1
#define MSR_BITMAP_MODE_X2APIC_APICV    2

#define KVM_VMX_TSC_MULTIPLIER_MAX     0xffffffffffffffffULL

/* Guest_tsc -> host_tsc conversion requires 64-bit division.  */
static int __read_mostly cpu_preemption_timer_multi;
static bool __read_mostly enable_preemption_timer = 1;
#ifdef CONFIG_X86_64
module_param_named(preemption_timer, enable_preemption_timer, bool, S_IRUGO);
#endif

#define KVM_VM_CR0_ALWAYS_OFF (X86_CR0_NW | X86_CR0_CD)
#define KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST X86_CR0_NE
#define KVM_VM_CR0_ALWAYS_ON                            \
        (KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST |      \
         X86_CR0_WP | X86_CR0_PG | X86_CR0_PE)
#define KVM_CR4_GUEST_OWNED_BITS                                      \
        (X86_CR4_PVI | X86_CR4_DE | X86_CR4_PCE | X86_CR4_OSFXSR      \
         | X86_CR4_OSXMMEXCPT | X86_CR4_LA57 | X86_CR4_TSD)

#define KVM_VM_CR4_ALWAYS_ON_UNRESTRICTED_GUEST X86_CR4_VMXE
#define KVM_PMODE_VM_CR4_ALWAYS_ON (X86_CR4_PAE | X86_CR4_VMXE)
#define KVM_RMODE_VM_CR4_ALWAYS_ON (X86_CR4_VME | X86_CR4_PAE | X86_CR4_VMXE)

#define RMODE_GUEST_OWNED_EFLAGS_BITS (~(X86_EFLAGS_IOPL | X86_EFLAGS_VM))

#define MSR_IA32_RTIT_STATUS_MASK (~(RTIT_STATUS_FILTEREN | \
        RTIT_STATUS_CONTEXTEN | RTIT_STATUS_TRIGGEREN | \
        RTIT_STATUS_ERROR | RTIT_STATUS_STOPPED | \
        RTIT_STATUS_BYTECNT))

#define MSR_IA32_RTIT_OUTPUT_BASE_MASK \
        (~((1UL << cpuid_query_maxphyaddr(vcpu)) - 1) | 0x7f)

/*
 * These 2 parameters are used to config the controls for Pause-Loop Exiting:
 * ple_gap:    upper bound on the amount of time between two successive
 *             executions of PAUSE in a loop. Also indicate if ple enabled.
 *             According to test, this time is usually smaller than 128 cycles.
 * ple_window: upper bound on the amount of time a guest is allowed to execute
 *             in a PAUSE loop. Tests indicate that most spinlocks are held for
 *             less than 2^12 cycles
 * Time is measured based on a counter that runs at the same rate as the TSC,
 * refer SDM volume 3b section 21.6.13 & 22.1.3.
 */
static unsigned int ple_gap = KVM_DEFAULT_PLE_GAP;
module_param(ple_gap, uint, 0444);

static unsigned int ple_window = KVM_VMX_DEFAULT_PLE_WINDOW;
module_param(ple_window, uint, 0444);

/* Default doubles per-vcpu window every exit. */
static unsigned int ple_window_grow = KVM_DEFAULT_PLE_WINDOW_GROW;
module_param(ple_window_grow, uint, 0444);

/* Default resets per-vcpu window every exit to ple_window. */
static unsigned int ple_window_shrink = KVM_DEFAULT_PLE_WINDOW_SHRINK;
module_param(ple_window_shrink, uint, 0444);

/* Default is to compute the maximum so we can never overflow. */
static unsigned int ple_window_max        = KVM_VMX_DEFAULT_PLE_WINDOW_MAX;
module_param(ple_window_max, uint, 0444);

/* Default is SYSTEM mode, 1 for host-guest mode */
int __read_mostly pt_mode = PT_MODE_SYSTEM;
module_param(pt_mode, int, S_IRUGO);

static DEFINE_STATIC_KEY_FALSE(vmx_l1d_should_flush);
static DEFINE_STATIC_KEY_FALSE(vmx_l1d_flush_cond);
static DEFINE_MUTEX(vmx_l1d_flush_mutex);

/* Storage for pre module init parameter parsing */
static enum vmx_l1d_flush_state __read_mostly vmentry_l1d_flush_param = VMENTER_L1D_FLUSH_AUTO;

static const struct {
        const char *option;
        bool for_parse;
} vmentry_l1d_param[] = {
        [VMENTER_L1D_FLUSH_AUTO]         = {"auto", true},
        [VMENTER_L1D_FLUSH_NEVER]        = {"never", true},
        [VMENTER_L1D_FLUSH_COND]         = {"cond", true},
        [VMENTER_L1D_FLUSH_ALWAYS]       = {"always", true},
        [VMENTER_L1D_FLUSH_EPT_DISABLED] = {"EPT disabled", false},
        [VMENTER_L1D_FLUSH_NOT_REQUIRED] = {"not required", false},
};

#define L1D_CACHE_ORDER 4
static void *vmx_l1d_flush_pages;

static int vmx_setup_l1d_flush(enum vmx_l1d_flush_state l1tf)
{
        struct page *page;
        unsigned int i;

        if (!enable_ept) {
                l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_EPT_DISABLED;
                return 0;
        }

        if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES)) {
                u64 msr;

                rdmsrl(MSR_IA32_ARCH_CAPABILITIES, msr);
                if (msr & ARCH_CAP_SKIP_VMENTRY_L1DFLUSH) {
                        l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_NOT_REQUIRED;
                        return 0;
                }
        }

        /* If set to auto use the default l1tf mitigation method */
        if (l1tf == VMENTER_L1D_FLUSH_AUTO) {
                switch (l1tf_mitigation) {
                case L1TF_MITIGATION_OFF:
                        l1tf = VMENTER_L1D_FLUSH_NEVER;
                        break;
                case L1TF_MITIGATION_FLUSH_NOWARN:
                case L1TF_MITIGATION_FLUSH:
                case L1TF_MITIGATION_FLUSH_NOSMT:
                        l1tf = VMENTER_L1D_FLUSH_COND;
                        break;
                case L1TF_MITIGATION_FULL:
                case L1TF_MITIGATION_FULL_FORCE:
                        l1tf = VMENTER_L1D_FLUSH_ALWAYS;
                        break;
                }
        } else if (l1tf_mitigation == L1TF_MITIGATION_FULL_FORCE) {
                l1tf = VMENTER_L1D_FLUSH_ALWAYS;
        }

        if (l1tf != VMENTER_L1D_FLUSH_NEVER && !vmx_l1d_flush_pages &&
            !boot_cpu_has(X86_FEATURE_FLUSH_L1D)) {
                /*
                 * This allocation for vmx_l1d_flush_pages is not tied to a VM
                 * lifetime and so should not be charged to a memcg.
                 */
                page = alloc_pages(GFP_KERNEL, L1D_CACHE_ORDER);
                if (!page)
                        return -ENOMEM;
                vmx_l1d_flush_pages = page_address(page);

                /*
                 * Initialize each page with a different pattern in
                 * order to protect against KSM in the nested
                 * virtualization case.
                 */
                for (i = 0; i < 1u << L1D_CACHE_ORDER; ++i) {
                        memset(vmx_l1d_flush_pages + i * PAGE_SIZE, i + 1,
                               PAGE_SIZE);
                }
        }

        l1tf_vmx_mitigation = l1tf;

        if (l1tf != VMENTER_L1D_FLUSH_NEVER)
                static_branch_enable(&vmx_l1d_should_flush);
        else
                static_branch_disable(&vmx_l1d_should_flush);

        if (l1tf == VMENTER_L1D_FLUSH_COND)
                static_branch_enable(&vmx_l1d_flush_cond);
        else
                static_branch_disable(&vmx_l1d_flush_cond);
        return 0;
}

static int vmentry_l1d_flush_parse(const char *s)
{
        unsigned int i;

        if (s) {
                for (i = 0; i < ARRAY_SIZE(vmentry_l1d_param); i++) {
                        if (vmentry_l1d_param[i].for_parse &&
                            sysfs_streq(s, vmentry_l1d_param[i].option))
                                return i;
                }
        }
        return -EINVAL;
}

static int vmentry_l1d_flush_set(const char *s, const struct kernel_param *kp)
{
        int l1tf, ret;

        l1tf = vmentry_l1d_flush_parse(s);
        if (l1tf < 0)
                return l1tf;

        if (!boot_cpu_has(X86_BUG_L1TF))
                return 0;

        /*
         * Has vmx_init() run already? If not then this is the pre init
         * parameter parsing. In that case just store the value and let
         * vmx_init() do the proper setup after enable_ept has been
         * established.
         */
        if (l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_AUTO) {
                vmentry_l1d_flush_param = l1tf;
                return 0;
        }

        mutex_lock(&vmx_l1d_flush_mutex);
        ret = vmx_setup_l1d_flush(l1tf);
        mutex_unlock(&vmx_l1d_flush_mutex);
        return ret;
}

static int vmentry_l1d_flush_get(char *s, const struct kernel_param *kp)
{
        if (WARN_ON_ONCE(l1tf_vmx_mitigation >= ARRAY_SIZE(vmentry_l1d_param)))
                return sprintf(s, "???\n");

        return sprintf(s, "%s\n", vmentry_l1d_param[l1tf_vmx_mitigation].option);
}

static const struct kernel_param_ops vmentry_l1d_flush_ops = {
        .set = vmentry_l1d_flush_set,
        .get = vmentry_l1d_flush_get,
};
module_param_cb(vmentry_l1d_flush, &vmentry_l1d_flush_ops, NULL, 0644);

static bool guest_state_valid(struct kvm_vcpu *vcpu);
static u32 vmx_segment_access_rights(struct kvm_segment *var);
static __always_inline void vmx_disable_intercept_for_msr(unsigned long *msr_bitmap,
                                                          u32 msr, int type);

void vmx_vmexit(void);

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

/*
 * We maintian a per-CPU linked-list of vCPU, so in wakeup_handler() we
 * can find which vCPU should be waken up.
 */
static DEFINE_PER_CPU(struct list_head, blocked_vcpu_on_cpu);
static DEFINE_PER_CPU(spinlock_t, blocked_vcpu_on_cpu_lock);

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

struct vmcs_config vmcs_config;
struct vmx_capability 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 const 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),
};

u64 host_efer;

/*
 * Though SYSCALL is only supported in 64-bit mode on Intel CPUs, kvm
 * will emulate SYSCALL in legacy mode if the vendor string in guest
 * CPUID.0:{EBX,ECX,EDX} is "AuthenticAMD" or "AMDisbetter!" To
 * support this emulation, IA32_STAR must always be included in
 * vmx_msr_index[], even in i386 builds.
 */
const u32 vmx_msr_index[] = {
#ifdef CONFIG_X86_64
        MSR_SYSCALL_MASK, MSR_LSTAR, MSR_CSTAR,
#endif
        MSR_EFER, MSR_TSC_AUX, MSR_STAR,
};

#if IS_ENABLED(CONFIG_HYPERV)
static bool __read_mostly enlightened_vmcs = true;
module_param(enlightened_vmcs, bool, 0444);

/* check_ept_pointer() should be under protection of ept_pointer_lock. */
static void check_ept_pointer_match(struct kvm *kvm)
{
        struct kvm_vcpu *vcpu;
        u64 tmp_eptp = INVALID_PAGE;
        int i;

        kvm_for_each_vcpu(i, vcpu, kvm) {
                if (!VALID_PAGE(tmp_eptp)) {
                        tmp_eptp = to_vmx(vcpu)->ept_pointer;
                } else if (tmp_eptp != to_vmx(vcpu)->ept_pointer) {
                        to_kvm_vmx(kvm)->ept_pointers_match
                                = EPT_POINTERS_MISMATCH;
                        return;
                }
        }

        to_kvm_vmx(kvm)->ept_pointers_match = EPT_POINTERS_MATCH;
}

static int kvm_fill_hv_flush_list_func(struct hv_guest_mapping_flush_list *flush,
                void *data)
{
        struct kvm_tlb_range *range = data;

        return hyperv_fill_flush_guest_mapping_list(flush, range->start_gfn,
                        range->pages);
}

static inline int __hv_remote_flush_tlb_with_range(struct kvm *kvm,
                struct kvm_vcpu *vcpu, struct kvm_tlb_range *range)
{
        u64 ept_pointer = to_vmx(vcpu)->ept_pointer;

        /*
         * FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE hypercall needs address
         * of the base of EPT PML4 table, strip off EPT configuration
         * information.
         */
        if (range)
                return hyperv_flush_guest_mapping_range(ept_pointer & PAGE_MASK,
                                kvm_fill_hv_flush_list_func, (void *)range);
        else
                return hyperv_flush_guest_mapping(ept_pointer & PAGE_MASK);
}

static int hv_remote_flush_tlb_with_range(struct kvm *kvm,
                struct kvm_tlb_range *range)
{
        struct kvm_vcpu *vcpu;
        int ret = 0, i;

        spin_lock(&to_kvm_vmx(kvm)->ept_pointer_lock);

        if (to_kvm_vmx(kvm)->ept_pointers_match == EPT_POINTERS_CHECK)
                check_ept_pointer_match(kvm);

        if (to_kvm_vmx(kvm)->ept_pointers_match != EPT_POINTERS_MATCH) {
                kvm_for_each_vcpu(i, vcpu, kvm) {
                        /* If ept_pointer is invalid pointer, bypass flush request. */
                        if (VALID_PAGE(to_vmx(vcpu)->ept_pointer))
                                ret |= __hv_remote_flush_tlb_with_range(
                                        kvm, vcpu, range);
                }
        } else {
                ret = __hv_remote_flush_tlb_with_range(kvm,
                                kvm_get_vcpu(kvm, 0), range);
        }

        spin_unlock(&to_kvm_vmx(kvm)->ept_pointer_lock);
        return ret;
}
static int hv_remote_flush_tlb(struct kvm *kvm)
{
        return hv_remote_flush_tlb_with_range(kvm, NULL);
}

#endif /* IS_ENABLED(CONFIG_HYPERV) */

/*
 * Comment's format: document - errata name - stepping - processor name.
 * Refer from
 * https://www.virtualbox.org/svn/vbox/trunk/src/VBox/VMM/VMMR0/HMR0.cpp
 */
static u32 vmx_preemption_cpu_tfms[] = {
/* 323344.pdf - BA86   - D0 - Xeon 7500 Series */
0x000206E6,
/* 323056.pdf - AAX65  - C2 - Xeon L3406 */
/* 322814.pdf - AAT59  - C2 - i7-600, i5-500, i5-400 and i3-300 Mobile */
/* 322911.pdf - AAU65  - C2 - i5-600, i3-500 Desktop and Pentium G6950 */
0x00020652,
/* 322911.pdf - AAU65  - K0 - i5-600, i3-500 Desktop and Pentium G6950 */
0x00020655,
/* 322373.pdf - AAO95  - B1 - Xeon 3400 Series */
/* 322166.pdf - AAN92  - B1 - i7-800 and i5-700 Desktop */
/*
 * 320767.pdf - AAP86  - B1 -
 * i7-900 Mobile Extreme, i7-800 and i7-700 Mobile
 */
0x000106E5,
/* 321333.pdf - AAM126 - C0 - Xeon 3500 */
0x000106A0,
/* 321333.pdf - AAM126 - C1 - Xeon 3500 */
0x000106A1,
/* 320836.pdf - AAJ124 - C0 - i7-900 Desktop Extreme and i7-900 Desktop */
0x000106A4,
 /* 321333.pdf - AAM126 - D0 - Xeon 3500 */
 /* 321324.pdf - AAK139 - D0 - Xeon 5500 */
 /* 320836.pdf - AAJ124 - D0 - i7-900 Extreme and i7-900 Desktop */
0x000106A5,
 /* Xeon E3-1220 V2 */
0x000306A8,
};

static inline bool cpu_has_broken_vmx_preemption_timer(void)
{
        u32 eax = cpuid_eax(0x00000001), i;

        /* Clear the reserved bits */
        eax &= ~(0x3U << 14 | 0xfU << 28);
        for (i = 0; i < ARRAY_SIZE(vmx_preemption_cpu_tfms); i++)
                if (eax == vmx_preemption_cpu_tfms[i])
                        return true;

        return false;
}

static inline bool cpu_need_virtualize_apic_accesses(struct kvm_vcpu *vcpu)
{
        return flexpriority_enabled && lapic_in_kernel(vcpu);
}

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

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

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

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

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

void loaded_vmcs_init(struct loaded_vmcs *loaded_vmcs)
{
        vmcs_clear(loaded_vmcs->vmcs);
        if (loaded_vmcs->shadow_vmcs && loaded_vmcs->launched)
                vmcs_clear(loaded_vmcs->shadow_vmcs);
        loaded_vmcs->cpu = -1;
        loaded_vmcs->launched = 0;
}

#ifdef CONFIG_KEXEC_CORE
/*
 * This bitmap is used to indicate whether the vmclear
 * operation is enabled on all cpus. All disabled by
 * default.
 */
static cpumask_t crash_vmclear_enabled_bitmap = CPU_MASK_NONE;

static inline void crash_enable_local_vmclear(int cpu)
{
        cpumask_set_cpu(cpu, &crash_vmclear_enabled_bitmap);
}

static inline void crash_disable_local_vmclear(int cpu)
{
        cpumask_clear_cpu(cpu, &crash_vmclear_enabled_bitmap);
}

static inline int crash_local_vmclear_enabled(int cpu)
{
        return cpumask_test_cpu(cpu, &crash_vmclear_enabled_bitmap);
}

static void crash_vmclear_local_loaded_vmcss(void)
{
        int cpu = raw_smp_processor_id();
        struct loaded_vmcs *v;

        if (!crash_local_vmclear_enabled(cpu))
                return;

        list_for_each_entry(v, &per_cpu(loaded_vmcss_on_cpu, cpu),
                            loaded_vmcss_on_cpu_link)
                vmcs_clear(v->vmcs);
}
#else
static inline void crash_enable_local_vmclear(int cpu) { }
static inline void crash_disable_local_vmclear(int cpu) { }
#endif /* CONFIG_KEXEC_CORE */

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

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

        /*
         * we should ensure updating loaded_vmcs->loaded_vmcss_on_cpu_link
         * is before setting loaded_vmcs->vcpu to -1 which is done in
         * loaded_vmcs_init. Otherwise, other cpu can see vcpu = -1 fist
         * then adds the vmcs into percpu list before it is deleted.
         */
        smp_wmb();

        loaded_vmcs_init(loaded_vmcs);
        crash_enable_local_vmclear(cpu);
}

void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs)
{
        int cpu = loaded_vmcs->cpu;

        if (cpu != -1)
                smp_call_function_single(cpu,
                         __loaded_vmcs_clear, loaded_vmcs, 1);
}

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

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

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

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

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

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

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

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

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

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

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

        eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR) |
             (1u << DB_VECTOR) | (1u << AC_VECTOR);
        /*
         * Guest access to VMware backdoor ports could legitimately
         * trigger #GP because of TSS I/O permission bitmap.
         * We intercept those #GP and allow access to them anyway
         * as VMware does.
         */
        if (enable_vmware_backdoor)
                eb |= (1u << GP_VECTOR);
        if ((vcpu->guest_debug &
             (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP)) ==
            (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP))
                eb |= 1u << BP_VECTOR;
        if (to_vmx(vcpu)->rmode.vm86_active)
                eb = ~0;
        if (enable_ept)
                eb &= ~(1u << PF_VECTOR); /* bypass_guest_pf = 0 */

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

        vmcs_write32(EXCEPTION_BITMAP, eb);
}

/*
 * Check if MSR is intercepted for currently loaded MSR bitmap.
 */
static bool msr_write_intercepted(struct kvm_vcpu *vcpu, u32 msr)
{
        unsigned long *msr_bitmap;
        int f = sizeof(unsigned long);

        if (!cpu_has_vmx_msr_bitmap())
                return true;

        msr_bitmap = to_vmx(vcpu)->loaded_vmcs->msr_bitmap;

        if (msr <= 0x1fff) {
                return !!test_bit(msr, msr_bitmap + 0x800 / f);
        } else if ((msr >= 0xc0000000) && (msr <= 0xc0001fff)) {
                msr &= 0x1fff;
                return !!test_bit(msr, msr_bitmap + 0xc00 / f);
        }

        return true;
}

static void clear_atomic_switch_msr_special(struct vcpu_vmx *vmx,
                unsigned long entry, unsigned long exit)
{
        vm_entry_controls_clearbit(vmx, entry);
        vm_exit_controls_clearbit(vmx, exit);
}

static int find_msr(struct vmx_msrs *m, unsigned int msr)
{
        unsigned int i;

        for (i = 0; i < m->nr; ++i) {
                if (m->val[i].index == msr)
                        return i;
        }
        return -ENOENT;
}

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

        switch (msr) {
        case MSR_EFER:
                if (cpu_has_load_ia32_efer()) {
                        clear_atomic_switch_msr_special(vmx,
                                        VM_ENTRY_LOAD_IA32_EFER,
                                        VM_EXIT_LOAD_IA32_EFER);
                        return;
                }
                break;
        case MSR_CORE_PERF_GLOBAL_CTRL:
                if (cpu_has_load_perf_global_ctrl()) {
                        clear_atomic_switch_msr_special(vmx,
                                        VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL,
                                        VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL);
                        return;
                }
                break;
        }
        i = find_msr(&m->guest, msr);
        if (i < 0)
                goto skip_guest;
        --m->guest.nr;
        m->guest.val[i] = m->guest.val[m->guest.nr];
        vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->guest.nr);

skip_guest:
        i = find_msr(&m->host, msr);
        if (i < 0)
                return;

        --m->host.nr;
        m->host.val[i] = m->host.val[m->host.nr];
        vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->host.nr);
}

static void add_atomic_switch_msr_special(struct vcpu_vmx *vmx,
                unsigned long entry, unsigned long exit,
                unsigned long guest_val_vmcs, unsigned long host_val_vmcs,
                u64 guest_val, u64 host_val)
{
        vmcs_write64(guest_val_vmcs, guest_val);
        if (host_val_vmcs != HOST_IA32_EFER)
                vmcs_write64(host_val_vmcs, host_val);
        vm_entry_controls_setbit(vmx, entry);
        vm_exit_controls_setbit(vmx, exit);
}

static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
                                  u64 guest_val, u64 host_val, bool entry_only)
{
        int i, j = 0;
        struct msr_autoload *m = &vmx->msr_autoload;

        switch (msr) {
        case MSR_EFER:
                if (cpu_has_load_ia32_efer()) {
                        add_atomic_switch_msr_special(vmx,
                                        VM_ENTRY_LOAD_IA32_EFER,
                                        VM_EXIT_LOAD_IA32_EFER,
                                        GUEST_IA32_EFER,
                                        HOST_IA32_EFER,
                                        guest_val, host_val);
                        return;
                }
                break;
        case MSR_CORE_PERF_GLOBAL_CTRL:
                if (cpu_has_load_perf_global_ctrl()) {
                        add_atomic_switch_msr_special(vmx,
                                        VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL,
                                        VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL,
                                        GUEST_IA32_PERF_GLOBAL_CTRL,
                                        HOST_IA32_PERF_GLOBAL_CTRL,
                                        guest_val, host_val);
                        return;
                }
                break;
        case MSR_IA32_PEBS_ENABLE:
                /* PEBS needs a quiescent period after being disabled (to write
                 * a record).  Disabling PEBS through VMX MSR swapping doesn't
                 * provide that period, so a CPU could write host's record into
                 * guest's memory.
                 */
                wrmsrl(MSR_IA32_PEBS_ENABLE, 0);
        }

        i = find_msr(&m->guest, msr);
        if (!entry_only)
                j = find_msr(&m->host, msr);

        if ((i < 0 && m->guest.nr == NR_AUTOLOAD_MSRS) ||
                (j < 0 &&  m->host.nr == NR_AUTOLOAD_MSRS)) {
                printk_once(KERN_WARNING "Not enough msr switch entries. "
                                "Can't add msr %x\n", msr);
                return;
        }
        if (i < 0) {
                i = m->guest.nr++;
                vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->guest.nr);
        }
        m->guest.val[i].index = msr;
        m->guest.val[i].value = guest_val;

        if (entry_only)
                return;

        if (j < 0) {
                j = m->host.nr++;
                vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->host.nr);
        }
        m->host.val[j].index = msr;
        m->host.val[j].value = host_val;
}

static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
{
        u64 guest_efer = vmx->vcpu.arch.efer;
        u64 ignore_bits = 0;

        if (!enable_ept) {
                /*
                 * NX is needed to handle CR0.WP=1, CR4.SMEP=1.  Testing
                 * host CPUID is more efficient than testing guest CPUID
                 * or CR4.  Host SMEP is anyway a requirement for guest SMEP.
                 */
                if (boot_cpu_has(X86_FEATURE_SMEP))
                        guest_efer |= EFER_NX;
                else if (!(guest_efer & EFER_NX))
                        ignore_bits |= EFER_NX;
        }

        /*
         * LMA and LME handled by hardware; SCE meaningless outside long mode.
         */
        ignore_bits |= 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

        /*
         * On EPT, we can't emulate NX, so we must switch EFER atomically.
         * On CPUs that support "load IA32_EFER", always switch EFER
         * atomically, since it's faster than switching it manually.
         */
        if (cpu_has_load_ia32_efer() ||
            (enable_ept && ((vmx->vcpu.arch.efer ^ host_efer) & EFER_NX))) {
                if (!(guest_efer & EFER_LMA))
                        guest_efer &= ~EFER_LME;
                if (guest_efer != host_efer)
                        add_atomic_switch_msr(vmx, MSR_EFER,
                                              guest_efer, host_efer, false);
                else
                        clear_atomic_switch_msr(vmx, MSR_EFER);
                return false;
        } else {
                clear_atomic_switch_msr(vmx, MSR_EFER);

                guest_efer &= ~ignore_bits;
                guest_efer |= host_efer & ignore_bits;

                vmx->guest_msrs[efer_offset].data = guest_efer;
                vmx->guest_msrs[efer_offset].mask = ~ignore_bits;

                return true;
        }
}

#ifdef CONFIG_X86_32
/*
 * On 32-bit kernels, VM exits still load the FS and GS bases from the
 * VMCS rather than the segment table.  KVM uses this helper to figure
 * out the current bases to poke them into the VMCS before entry.
 */
static unsigned long segment_base(u16 selector)
{
        struct desc_struct *table;
        unsigned long v;

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

        table = get_current_gdt_ro();

        if ((selector & SEGMENT_TI_MASK) == SEGMENT_LDT) {
                u16 ldt_selector = kvm_read_ldt();

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

                table = (struct desc_struct *)segment_base(ldt_selector);
        }
        v = get_desc_base(&table[selector >> 3]);
        return v;
}
#endif

static inline void pt_load_msr(struct pt_ctx *ctx, u32 addr_range)
{
        u32 i;

        wrmsrl(MSR_IA32_RTIT_STATUS, ctx->status);
        wrmsrl(MSR_IA32_RTIT_OUTPUT_BASE, ctx->output_base);
        wrmsrl(MSR_IA32_RTIT_OUTPUT_MASK, ctx->output_mask);
        wrmsrl(MSR_IA32_RTIT_CR3_MATCH, ctx->cr3_match);
        for (i = 0; i < addr_range; i++) {
                wrmsrl(MSR_IA32_RTIT_ADDR0_A + i * 2, ctx->addr_a[i]);
                wrmsrl(MSR_IA32_RTIT_ADDR0_B + i * 2, ctx->addr_b[i]);
        }
}

static inline void pt_save_msr(struct pt_ctx *ctx, u32 addr_range)
{
        u32 i;

        rdmsrl(MSR_IA32_RTIT_STATUS, ctx->status);
        rdmsrl(MSR_IA32_RTIT_OUTPUT_BASE, ctx->output_base);
        rdmsrl(MSR_IA32_RTIT_OUTPUT_MASK, ctx->output_mask);
        rdmsrl(MSR_IA32_RTIT_CR3_MATCH, ctx->cr3_match);

        for (i = 0; i < addr_range; i++) {
                rdmsrl(MSR_IA32_RTIT_ADDR0_A + i * 2, ctx->addr_a[i]);
                rdmsrl(MSR_IA32_RTIT_ADDR0_B + i * 2, ctx->addr_b[i]);
        }
}

static void pt_guest_enter(struct vcpu_vmx *vmx)
{
        if (pt_mode == PT_MODE_SYSTEM)
                return;

        /*
         * GUEST_IA32_RTIT_CTL is already set in the VMCS.
         * Save host state before VM entry.
         */
        rdmsrl(MSR_IA32_RTIT_CTL, vmx->pt_desc.host.ctl);
        if (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) {
                wrmsrl(MSR_IA32_RTIT_CTL, 0);
                pt_save_msr(&vmx->pt_desc.host, vmx->pt_desc.addr_range);
                pt_load_msr(&vmx->pt_desc.guest, vmx->pt_desc.addr_range);
        }
}

static void pt_guest_exit(struct vcpu_vmx *vmx)
{
        if (pt_mode == PT_MODE_SYSTEM)
                return;

        if (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) {
                pt_save_msr(&vmx->pt_desc.guest, vmx->pt_desc.addr_range);
                pt_load_msr(&vmx->pt_desc.host, vmx->pt_desc.addr_range);
        }

        /* Reload host state (IA32_RTIT_CTL will be cleared on VM exit). */
        wrmsrl(MSR_IA32_RTIT_CTL, vmx->pt_desc.host.ctl);
}

void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct vmcs_host_state *host_state;
#ifdef CONFIG_X86_64
        int cpu = raw_smp_processor_id();
#endif
        unsigned long fs_base, gs_base;
        u16 fs_sel, gs_sel;
        int i;

        vmx->req_immediate_exit = false;

        /*
         * Note that guest MSRs to be saved/restored can also be changed
         * when guest state is loaded. This happens when guest transitions
         * to/from long-mode by setting MSR_EFER.LMA.
         */
        if (!vmx->loaded_cpu_state || vmx->guest_msrs_dirty) {
                vmx->guest_msrs_dirty = false;
                for (i = 0; i < vmx->save_nmsrs; ++i)
                        kvm_set_shared_msr(vmx->guest_msrs[i].index,
                                           vmx->guest_msrs[i].data,
                                           vmx->guest_msrs[i].mask);

        }

        if (vmx->loaded_cpu_state)
                return;

        vmx->loaded_cpu_state = vmx->loaded_vmcs;
        host_state = &vmx->loaded_cpu_state->host_state;

        /*
         * Set host fs and gs selectors.  Unfortunately, 22.2.3 does not
         * allow segment selectors with cpl > 0 or ti == 1.
         */
        host_state->ldt_sel = kvm_read_ldt();

#ifdef CONFIG_X86_64
        savesegment(ds, host_state->ds_sel);
        savesegment(es, host_state->es_sel);

        gs_base = cpu_kernelmode_gs_base(cpu);
        if (likely(is_64bit_mm(current->mm))) {
                save_fsgs_for_kvm();
                fs_sel = current->thread.fsindex;
                gs_sel = current->thread.gsindex;
                fs_base = current->thread.fsbase;
                vmx->msr_host_kernel_gs_base = current->thread.gsbase;
        } else {
                savesegment(fs, fs_sel);
                savesegment(gs, gs_sel);
                fs_base = read_msr(MSR_FS_BASE);
                vmx->msr_host_kernel_gs_base = read_msr(MSR_KERNEL_GS_BASE);
        }

        wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base);
#else
        savesegment(fs, fs_sel);
        savesegment(gs, gs_sel);
        fs_base = segment_base(fs_sel);
        gs_base = segment_base(gs_sel);
#endif

        if (unlikely(fs_sel != host_state->fs_sel)) {
                if (!(fs_sel & 7))
                        vmcs_write16(HOST_FS_SELECTOR, fs_sel);
                else
                        vmcs_write16(HOST_FS_SELECTOR, 0);
                host_state->fs_sel = fs_sel;
        }
        if (unlikely(gs_sel != host_state->gs_sel)) {
                if (!(gs_sel & 7))
                        vmcs_write16(HOST_GS_SELECTOR, gs_sel);
                else
                        vmcs_write16(HOST_GS_SELECTOR, 0);
                host_state->gs_sel = gs_sel;
        }
        if (unlikely(fs_base != host_state->fs_base)) {
                vmcs_writel(HOST_FS_BASE, fs_base);
                host_state->fs_base = fs_base;
        }
        if (unlikely(gs_base != host_state->gs_base)) {
                vmcs_writel(HOST_GS_BASE, gs_base);
                host_state->gs_base = gs_base;
        }
}

static void vmx_prepare_switch_to_host(struct vcpu_vmx *vmx)
{
        struct vmcs_host_state *host_state;

        if (!vmx->loaded_cpu_state)
                return;

        WARN_ON_ONCE(vmx->loaded_cpu_state != vmx->loaded_vmcs);
        host_state = &vmx->loaded_cpu_state->host_state;

        ++vmx->vcpu.stat.host_state_reload;
        vmx->loaded_cpu_state = NULL;

#ifdef CONFIG_X86_64
        rdmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base);
#endif
        if (host_state->ldt_sel || (host_state->gs_sel & 7)) {
                kvm_load_ldt(host_state->ldt_sel);
#ifdef CONFIG_X86_64
                load_gs_index(host_state->gs_sel);
#else
                loadsegment(gs, host_state->gs_sel);
#endif
        }
        if (host_state->fs_sel & 7)
                loadsegment(fs, host_state->fs_sel);
#ifdef CONFIG_X86_64
        if (unlikely(host_state->ds_sel | host_state->es_sel)) {
                loadsegment(ds, host_state->ds_sel);
                loadsegment(es, host_state->es_sel);
        }
#endif
        invalidate_tss_limit();
#ifdef CONFIG_X86_64
        wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_host_kernel_gs_base);
#endif
        load_fixmap_gdt(raw_smp_processor_id());
}

#ifdef CONFIG_X86_64
static u64 vmx_read_guest_kernel_gs_base(struct vcpu_vmx *vmx)
{
        preempt_disable();
        if (vmx->loaded_cpu_state)
                rdmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base);
        preempt_enable();
        return vmx->msr_guest_kernel_gs_base;
}

static void vmx_write_guest_kernel_gs_base(struct vcpu_vmx *vmx, u64 data)
{
        preempt_disable();
        if (vmx->loaded_cpu_state)
                wrmsrl(MSR_KERNEL_GS_BASE, data);
        preempt_enable();
        vmx->msr_guest_kernel_gs_base = data;
}
#endif

static void vmx_vcpu_pi_load(struct kvm_vcpu *vcpu, int cpu)
{
        struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu);
        struct pi_desc old, new;
        unsigned int dest;

        /*
         * In case of hot-plug or hot-unplug, we may have to undo
         * vmx_vcpu_pi_put even if there is no assigned device.  And we
         * always keep PI.NDST up to date for simplicity: it makes the
         * code easier, and CPU migration is not a fast path.
         */
        if (!pi_test_sn(pi_desc) && vcpu->cpu == cpu)
                return;

        /* The full case.  */
        do {
                old.control = new.control = pi_desc->control;

                dest = cpu_physical_id(cpu);

                if (x2apic_enabled())
                        new.ndst = dest;
                else
                        new.ndst = (dest << 8) & 0xFF00;

                new.sn = 0;
        } while (cmpxchg64(&pi_desc->control, old.control,
                           new.control) != old.control);

        /*
         * Clear SN before reading the bitmap.  The VT-d firmware
         * writes the bitmap and reads SN atomically (5.2.3 in the
         * spec), so it doesn't really have a memory barrier that
         * pairs with this, but we cannot do that and we need one.
         */
        smp_mb__after_atomic();

        if (!bitmap_empty((unsigned long *)pi_desc->pir, NR_VECTORS))
                pi_set_on(pi_desc);
}

/*
 * Switches to specified vcpu, until a matching vcpu_put(), but assumes
 * vcpu mutex is already taken.
 */
void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        bool already_loaded = vmx->loaded_vmcs->cpu == cpu;

        if (!already_loaded) {
                loaded_vmcs_clear(vmx->loaded_vmcs);
                local_irq_disable();
                crash_disable_local_vmclear(cpu);

                /*
                 * Read loaded_vmcs->cpu should be before fetching
                 * loaded_vmcs->loaded_vmcss_on_cpu_link.
                 * See the comments in __loaded_vmcs_clear().
                 */
                smp_rmb();

                list_add(&vmx->loaded_vmcs->loaded_vmcss_on_cpu_link,
                         &per_cpu(loaded_vmcss_on_cpu, cpu));
                crash_enable_local_vmclear(cpu);
                local_irq_enable();
        }

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

        if (!already_loaded) {
                void *gdt = get_current_gdt_ro();
                unsigned long sysenter_esp;

                kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);

                /*
                 * Linux uses per-cpu TSS and GDT, so set these when switching
                 * processors.  See 22.2.4.
                 */
                vmcs_writel(HOST_TR_BASE,
                            (unsigned long)&get_cpu_entry_area(cpu)->tss.x86_tss);
                vmcs_writel(HOST_GDTR_BASE, (unsigned long)gdt);   /* 22.2.4 */

                /*
                 * VM exits change the host TR limit to 0x67 after a VM
                 * exit.  This is okay, since 0x67 covers everything except
                 * the IO bitmap and have have code to handle the IO bitmap
                 * being lost after a VM exit.
                 */
                BUILD_BUG_ON(IO_BITMAP_OFFSET - 1 != 0x67);

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

                vmx->loaded_vmcs->cpu = cpu;
        }

        /* Setup TSC multiplier */
        if (kvm_has_tsc_control &&
            vmx->current_tsc_ratio != vcpu->arch.tsc_scaling_ratio)
                decache_tsc_multiplier(vmx);

        vmx_vcpu_pi_load(vcpu, cpu);
        vmx->host_pkru = read_pkru();
        vmx->host_debugctlmsr = get_debugctlmsr();
}

static void vmx_vcpu_pi_put(struct kvm_vcpu *vcpu)
{
        struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu);

        if (!kvm_arch_has_assigned_device(vcpu->kvm) ||
                !irq_remapping_cap(IRQ_POSTING_CAP)  ||
                !kvm_vcpu_apicv_active(vcpu))
                return;

        /* Set SN when the vCPU is preempted */
        if (vcpu->preempted)
                pi_set_sn(pi_desc);
}

void vmx_vcpu_put(struct kvm_vcpu *vcpu)
{
        vmx_vcpu_pi_put(vcpu);

        vmx_prepare_switch_to_host(to_vmx(vcpu));
}

static bool emulation_required(struct kvm_vcpu *vcpu)
{
        return emulate_invalid_guest_state && !guest_state_valid(vcpu);
}

static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu);

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

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

void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
{
        unsigned long old_rflags = vmx_get_rflags(vcpu);

        __set_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail);
        to_vmx(vcpu)->rflags = rflags;
        if (to_vmx(vcpu)->rmode.vm86_active) {
                to_vmx(vcpu)->rmode.save_rflags = rflags;
                rflags |= X86_EFLAGS_IOPL | X86_EFLAGS_VM;
        }
        vmcs_writel(GUEST_RFLAGS, rflags);

        if ((old_rflags ^ to_vmx(vcpu)->rflags) & X86_EFLAGS_VM)
                to_vmx(vcpu)->emulation_required = emulation_required(vcpu);
}

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

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

        return ret;
}

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

        interruptibility &= ~(GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS);

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

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

static int vmx_rtit_ctl_check(struct kvm_vcpu *vcpu, u64 data)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        unsigned long value;

        /*
         * Any MSR write that attempts to change bits marked reserved will
         * case a #GP fault.
         */
        if (data & vmx->pt_desc.ctl_bitmask)
                return 1;

        /*
         * Any attempt to modify IA32_RTIT_CTL while TraceEn is set will
         * result in a #GP unless the same write also clears TraceEn.
         */
        if ((vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) &&
                ((vmx->pt_desc.guest.ctl ^ data) & ~RTIT_CTL_TRACEEN))
                return 1;

        /*
         * WRMSR to IA32_RTIT_CTL that sets TraceEn but clears this bit
         * and FabricEn would cause #GP, if
         * CPUID.(EAX=14H, ECX=0):ECX.SNGLRGNOUT[bit 2] = 0
         */
        if ((data & RTIT_CTL_TRACEEN) && !(data & RTIT_CTL_TOPA) &&
                !(data & RTIT_CTL_FABRIC_EN) &&
                !intel_pt_validate_cap(vmx->pt_desc.caps,
                                        PT_CAP_single_range_output))
                return 1;

        /*
         * MTCFreq, CycThresh and PSBFreq encodings check, any MSR write that
         * utilize encodings marked reserved will casue a #GP fault.
         */
        value = intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_mtc_periods);
        if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_mtc) &&
                        !test_bit((data & RTIT_CTL_MTC_RANGE) >>
                        RTIT_CTL_MTC_RANGE_OFFSET, &value))
                return 1;
        value = intel_pt_validate_cap(vmx->pt_desc.caps,
                                                PT_CAP_cycle_thresholds);
        if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_psb_cyc) &&
                        !test_bit((data & RTIT_CTL_CYC_THRESH) >>
                        RTIT_CTL_CYC_THRESH_OFFSET, &value))
                return 1;
        value = intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_psb_periods);
        if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_psb_cyc) &&
                        !test_bit((data & RTIT_CTL_PSB_FREQ) >>
                        RTIT_CTL_PSB_FREQ_OFFSET, &value))
                return 1;

        /*
         * If ADDRx_CFG is reserved or the encodings is >2 will
         * cause a #GP fault.
         */
        value = (data & RTIT_CTL_ADDR0) >> RTIT_CTL_ADDR0_OFFSET;
        if ((value && (vmx->pt_desc.addr_range < 1)) || (value > 2))
                return 1;
        value = (data & RTIT_CTL_ADDR1) >> RTIT_CTL_ADDR1_OFFSET;
        if ((value && (vmx->pt_desc.addr_range < 2)) || (value > 2))
                return 1;
        value = (data & RTIT_CTL_ADDR2) >> RTIT_CTL_ADDR2_OFFSET;
        if ((value && (vmx->pt_desc.addr_range < 3)) || (value > 2))
                return 1;
        value = (data & RTIT_CTL_ADDR3) >> RTIT_CTL_ADDR3_OFFSET;
        if ((value && (vmx->pt_desc.addr_range < 4)) || (value > 2))
                return 1;

        return 0;
}


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

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

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

static void vmx_clear_hlt(struct kvm_vcpu *vcpu)
{
        /*
         * Ensure that we clear the HLT state in the VMCS.  We don't need to
         * explicitly skip the instruction because if the HLT state is set,
         * then the instruction is already executing and RIP has already been
         * advanced.
         */
        if (kvm_hlt_in_guest(vcpu->kvm) &&
                        vmcs_read32(GUEST_ACTIVITY_STATE) == GUEST_ACTIVITY_HLT)
                vmcs_write32(GUEST_ACTIVITY_STATE, GUEST_ACTIVITY_ACTIVE);
}

static void vmx_queue_exception(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        unsigned nr = vcpu->arch.exception.nr;
        bool has_error_code = vcpu->arch.exception.has_error_code;
        u32 error_code = vcpu->arch.exception.error_code;
        u32 intr_info = nr | INTR_INFO_VALID_MASK;

        kvm_deliver_exception_payload(vcpu);

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

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

        WARN_ON_ONCE(vmx->emulation_required);

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

        vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, intr_info);

        vmx_clear_hlt(vcpu);
}

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

static bool vmx_invpcid_supported(void)
{
        return cpu_has_vmx_invpcid();
}

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

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

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

        save_nmsrs = 0;
#ifdef CONFIG_X86_64
        /*
         * The SYSCALL MSRs are only needed on long mode guests, and only
         * when EFER.SCE is set.
         */
        if (is_long_mode(&vmx->vcpu) && (vmx->vcpu.arch.efer & EFER_SCE)) {
                index = __find_msr_index(vmx, MSR_STAR);
                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_SYSCALL_MASK);
                if (index >= 0)
                        move_msr_up(vmx, index, save_nmsrs++);
        }
#endif
        index = __find_msr_index(vmx, MSR_EFER);
        if (index >= 0 && update_transition_efer(vmx, index))
                move_msr_up(vmx, index, save_nmsrs++);
        index = __find_msr_index(vmx, MSR_TSC_AUX);
        if (index >= 0 && guest_cpuid_has(&vmx->vcpu, X86_FEATURE_RDTSCP))
                move_msr_up(vmx, index, save_nmsrs++);

        vmx->save_nmsrs = save_nmsrs;
        vmx->guest_msrs_dirty = true;

        if (cpu_has_vmx_msr_bitmap())
                vmx_update_msr_bitmap(&vmx->vcpu);
}

static u64 vmx_read_l1_tsc_offset(struct kvm_vcpu *vcpu)
{
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);

        if (is_guest_mode(vcpu) &&
            (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING))
                return vcpu->arch.tsc_offset - vmcs12->tsc_offset;

        return vcpu->arch.tsc_offset;
}

static u64 vmx_write_l1_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)
{
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
        u64 g_tsc_offset = 0;

        /*
         * We're here if L1 chose not to trap WRMSR to TSC. According
         * to the spec, this should set L1's TSC; The offset that L1
         * set for L2 remains unchanged, and still needs to be added
         * to the newly set TSC to get L2's TSC.
         */
        if (is_guest_mode(vcpu) &&
            (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING))
                g_tsc_offset = vmcs12->tsc_offset;

        trace_kvm_write_tsc_offset(vcpu->vcpu_id,
                                   vcpu->arch.tsc_offset - g_tsc_offset,
                                   offset);
        vmcs_write64(TSC_OFFSET, offset + g_tsc_offset);
        return offset + g_tsc_offset;
}

/*
 * nested_vmx_allowed() checks whether a guest should be allowed to use VMX
 * instructions and MSRs (i.e., nested VMX). Nested VMX is disabled for
 * all guests if the "nested" module option is off, and can also be disabled
 * for a single guest by disabling its VMX cpuid bit.
 */
bool nested_vmx_allowed(struct kvm_vcpu *vcpu)
{
        return nested && guest_cpuid_has(vcpu, X86_FEATURE_VMX);
}

static inline bool vmx_feature_control_msr_valid(struct kvm_vcpu *vcpu,
                                                 uint64_t val)
{
        uint64_t valid_bits = to_vmx(vcpu)->msr_ia32_feature_control_valid_bits;

        return !(val & ~valid_bits);
}

static int vmx_get_msr_feature(struct kvm_msr_entry *msr)
{
        switch (msr->index) {
        case MSR_IA32_VMX_BASIC ... MSR_IA32_VMX_VMFUNC:
                if (!nested)
                        return 1;
                return vmx_get_vmx_msr(&vmcs_config.nested, msr->index, &msr->data);
        default:
                return 1;
        }

        return 0;
}

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

        switch (msr_info->index) {
#ifdef CONFIG_X86_64
        case MSR_FS_BASE:
                msr_info->data = vmcs_readl(GUEST_FS_BASE);
                break;
        case MSR_GS_BASE:
                msr_info->data = vmcs_readl(GUEST_GS_BASE);
                break;
        case MSR_KERNEL_GS_BASE:
                msr_info->data = vmx_read_guest_kernel_gs_base(vmx);
                break;
#endif
        case MSR_EFER:
                return kvm_get_msr_common(vcpu, msr_info);
        case MSR_IA32_SPEC_CTRL:
                if (!msr_info->host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
                        return 1;

                msr_info->data = to_vmx(vcpu)->spec_ctrl;
                break;
        case MSR_IA32_SYSENTER_CS:
                msr_info->data = vmcs_read32(GUEST_SYSENTER_CS);
                break;
        case MSR_IA32_SYSENTER_EIP:
                msr_info->data = vmcs_readl(GUEST_SYSENTER_EIP);
                break;
        case MSR_IA32_SYSENTER_ESP:
                msr_info->data = vmcs_readl(GUEST_SYSENTER_ESP);
                break;
        case MSR_IA32_BNDCFGS:
                if (!kvm_mpx_supported() ||
                    (!msr_info->host_initiated &&
                     !guest_cpuid_has(vcpu, X86_FEATURE_MPX)))
                        return 1;
                msr_info->data = vmcs_read64(GUEST_BNDCFGS);
                break;
        case MSR_IA32_MCG_EXT_CTL:
                if (!msr_info->host_initiated &&
                    !(vmx->msr_ia32_feature_control &
                      FEATURE_CONTROL_LMCE))
                        return 1;
                msr_info->data = vcpu->arch.mcg_ext_ctl;
                break;
        case MSR_IA32_FEATURE_CONTROL:
                msr_info->data = vmx->msr_ia32_feature_control;
                break;
        case MSR_IA32_VMX_BASIC ... MSR_IA32_VMX_VMFUNC:
                if (!nested_vmx_allowed(vcpu))
                        return 1;
                return vmx_get_vmx_msr(&vmx->nested.msrs, msr_info->index,
                                       &msr_info->data);
        case MSR_IA32_XSS:
                if (!vmx_xsaves_supported())
                        return 1;
                msr_info->data = vcpu->arch.ia32_xss;
                break;
        case MSR_IA32_RTIT_CTL:
                if (pt_mode != PT_MODE_HOST_GUEST)
                        return 1;
                msr_info->data = vmx->pt_desc.guest.ctl;
                break;
        case MSR_IA32_RTIT_STATUS:
                if (pt_mode != PT_MODE_HOST_GUEST)
                        return 1;
                msr_info->data = vmx->pt_desc.guest.status;
                break;
        case MSR_IA32_RTIT_CR3_MATCH:
                if ((pt_mode != PT_MODE_HOST_GUEST) ||
                        !intel_pt_validate_cap(vmx->pt_desc.caps,
                                                PT_CAP_cr3_filtering))
                        return 1;
                msr_info->data = vmx->pt_desc.guest.cr3_match;
                break;
        case MSR_IA32_RTIT_OUTPUT_BASE:
                if ((pt_mode != PT_MODE_HOST_GUEST) ||
                        (!intel_pt_validate_cap(vmx->pt_desc.caps,
                                        PT_CAP_topa_output) &&
                         !intel_pt_validate_cap(vmx->pt_desc.caps,
                                        PT_CAP_single_range_output)))
                        return 1;
                msr_info->data = vmx->pt_desc.guest.output_base;
                break;
        case MSR_IA32_RTIT_OUTPUT_MASK:
                if ((pt_mode != PT_MODE_HOST_GUEST) ||
                        (!intel_pt_validate_cap(vmx->pt_desc.caps,
                                        PT_CAP_topa_output) &&
                         !intel_pt_validate_cap(vmx->pt_desc.caps,
                                        PT_CAP_single_range_output)))
                        return 1;
                msr_info->data = vmx->pt_desc.guest.output_mask;
                break;
        case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B:
                index = msr_info->index - MSR_IA32_RTIT_ADDR0_A;
                if ((pt_mode != PT_MODE_HOST_GUEST) ||
                        (index >= 2 * intel_pt_validate_cap(vmx->pt_desc.caps,
                                        PT_CAP_num_address_ranges)))
                        return 1;
                if (index % 2)
                        msr_info->data = vmx->pt_desc.guest.addr_b[index / 2];
                else
                        msr_info->data = vmx->pt_desc.guest.addr_a[index / 2];
                break;
        case MSR_TSC_AUX:
                if (!msr_info->host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP))
                        return 1;
                /* Else, falls through */
        default:
                msr = find_msr_entry(vmx, msr_info->index);
                if (msr) {
                        msr_info->data = msr->data;
                        break;
                }
                return kvm_get_msr_common(vcpu, msr_info);
        }

        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, struct msr_data *msr_info)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct shared_msr_entry *msr;
        int ret = 0;
        u32 msr_index = msr_info->index;
        u64 data = msr_info->data;
        u32 index;

        switch (msr_index) {
        case MSR_EFER:
                ret = kvm_set_msr_common(vcpu, msr_info);
                break;
#ifdef CONFIG_X86_64
        case MSR_FS_BASE:
                vmx_segment_cache_clear(vmx);
                vmcs_writel(GUEST_FS_BASE, data);
                break;
        case MSR_GS_BASE:
                vmx_segment_cache_clear(vmx);
                vmcs_writel(GUEST_GS_BASE, data);
                break;
        case MSR_KERNEL_GS_BASE:
                vmx_write_guest_kernel_gs_base(vmx, 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_BNDCFGS:
                if (!kvm_mpx_supported() ||
                    (!msr_info->host_initiated &&
                     !guest_cpuid_has(vcpu, X86_FEATURE_MPX)))
                        return 1;
                if (is_noncanonical_address(data & PAGE_MASK, vcpu) ||
                    (data & MSR_IA32_BNDCFGS_RSVD))
                        return 1;
                vmcs_write64(GUEST_BNDCFGS, data);
                break;
        case MSR_IA32_SPEC_CTRL:
                if (!msr_info->host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
                        return 1;

                /* The STIBP bit doesn't fault even if it's not advertised */
                if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP | SPEC_CTRL_SSBD))
                        return 1;

                vmx->spec_ctrl = data;

                if (!data)
                        break;

                /*
                 * For non-nested:
                 * When it's written (to non-zero) for the first time, pass
                 * it through.
                 *
                 * For nested:
                 * The handling of the MSR bitmap for L2 guests is done in
                 * nested_vmx_merge_msr_bitmap. We should not touch the
                 * vmcs02.msr_bitmap here since it gets completely overwritten
                 * in the merging. We update the vmcs01 here for L1 as well
                 * since it will end up touching the MSR anyway now.
                 */
                vmx_disable_intercept_for_msr(vmx->vmcs01.msr_bitmap,
                                              MSR_IA32_SPEC_CTRL,
                                              MSR_TYPE_RW);
                break;
        case MSR_IA32_PRED_CMD:
                if (!msr_info->host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
                        return 1;

                if (data & ~PRED_CMD_IBPB)
                        return 1;

                if (!data)
                        break;

                wrmsrl(MSR_IA32_PRED_CMD, PRED_CMD_IBPB);

                /*
                 * For non-nested:
                 * When it's written (to non-zero) for the first time, pass
                 * it through.
                 *
                 * For nested:
                 * The handling of the MSR bitmap for L2 guests is done in
                 * nested_vmx_merge_msr_bitmap. We should not touch the
                 * vmcs02.msr_bitmap here since it gets completely overwritten
                 * in the merging.
                 */
                vmx_disable_intercept_for_msr(vmx->vmcs01.msr_bitmap, MSR_IA32_PRED_CMD,
                                              MSR_TYPE_W);
                break;
        case MSR_IA32_CR_PAT:
                if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
                        if (!kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, data))
                                return 1;
                        vmcs_write64(GUEST_IA32_PAT, data);
                        vcpu->arch.pat = data;
                        break;
                }
                ret = kvm_set_msr_common(vcpu, msr_info);
                break;
        case MSR_IA32_TSC_ADJUST:
                ret = kvm_set_msr_common(vcpu, msr_info);
                break;
        case MSR_IA32_MCG_EXT_CTL:
                if ((!msr_info->host_initiated &&
                     !(to_vmx(vcpu)->msr_ia32_feature_control &
                       FEATURE_CONTROL_LMCE)) ||
                    (data & ~MCG_EXT_CTL_LMCE_EN))
                        return 1;
                vcpu->arch.mcg_ext_ctl = data;
                break;
        case MSR_IA32_FEATURE_CONTROL:
                if (!vmx_feature_control_msr_valid(vcpu, data) ||
                    (to_vmx(vcpu)->msr_ia32_feature_control &
                     FEATURE_CONTROL_LOCKED && !msr_info->host_initiated))
                        return 1;
                vmx->msr_ia32_feature_control = data;
                if (msr_info->host_initiated && data == 0)
                        vmx_leave_nested(vcpu);
                break;
        case MSR_IA32_VMX_BASIC ... MSR_IA32_VMX_VMFUNC:
                if (!msr_info->host_initiated)
                        return 1; /* they are read-only */
                if (!nested_vmx_allowed(vcpu))
                        return 1;
                return vmx_set_vmx_msr(vcpu, msr_index, data);
        case MSR_IA32_XSS:
                if (!vmx_xsaves_supported())
                        return 1;
                /*
                 * The only supported bit as of Skylake is bit 8, but
                 * it is not supported on KVM.
                 */
                if (data != 0)
                        return 1;
                vcpu->arch.ia32_xss = data;
                if (vcpu->arch.ia32_xss != host_xss)
                        add_atomic_switch_msr(vmx, MSR_IA32_XSS,
                                vcpu->arch.ia32_xss, host_xss, false);
                else
                        clear_atomic_switch_msr(vmx, MSR_IA32_XSS);
                break;
        case MSR_IA32_RTIT_CTL:
                if ((pt_mode != PT_MODE_HOST_GUEST) ||
                        vmx_rtit_ctl_check(vcpu, data) ||
                        vmx->nested.vmxon)
                        return 1;
                vmcs_write64(GUEST_IA32_RTIT_CTL, data);
                vmx->pt_desc.guest.ctl = data;
                pt_update_intercept_for_msr(vmx);
                break;
        case MSR_IA32_RTIT_STATUS:
                if ((pt_mode != PT_MODE_HOST_GUEST) ||
                        (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) ||
                        (data & MSR_IA32_RTIT_STATUS_MASK))
                        return 1;
                vmx->pt_desc.guest.status = data;
                break;
        case MSR_IA32_RTIT_CR3_MATCH:
                if ((pt_mode != PT_MODE_HOST_GUEST) ||
                        (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) ||
                        !intel_pt_validate_cap(vmx->pt_desc.caps,
                                                PT_CAP_cr3_filtering))
                        return 1;
                vmx->pt_desc.guest.cr3_match = data;
                break;
        case MSR_IA32_RTIT_OUTPUT_BASE:
                if ((pt_mode != PT_MODE_HOST_GUEST) ||
                        (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) ||
                        (!intel_pt_validate_cap(vmx->pt_desc.caps,
                                        PT_CAP_topa_output) &&
                         !intel_pt_validate_cap(vmx->pt_desc.caps,
                                        PT_CAP_single_range_output)) ||
                        (data & MSR_IA32_RTIT_OUTPUT_BASE_MASK))
                        return 1;
                vmx->pt_desc.guest.output_base = data;
                break;
        case MSR_IA32_RTIT_OUTPUT_MASK:
                if ((pt_mode != PT_MODE_HOST_GUEST) ||
                        (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) ||
                        (!intel_pt_validate_cap(vmx->pt_desc.caps,
                                        PT_CAP_topa_output) &&
                         !intel_pt_validate_cap(vmx->pt_desc.caps,
                                        PT_CAP_single_range_output)))
                        return 1;
                vmx->pt_desc.guest.output_mask = data;
                break;
        case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B:
                index = msr_info->index - MSR_IA32_RTIT_ADDR0_A;
                if ((pt_mode != PT_MODE_HOST_GUEST) ||
                        (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) ||
                        (index >= 2 * intel_pt_validate_cap(vmx->pt_desc.caps,
                                        PT_CAP_num_address_ranges)))
                        return 1;
                if (index % 2)
                        vmx->pt_desc.guest.addr_b[index / 2] = data;
                else
                        vmx->pt_desc.guest.addr_a[index / 2] = data;
                break;

        case MSR_TSC_AUX:
                if (!msr_info->host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP))
                        return 1;
                /* Check reserved bit, higher 32 bits should be zero */
                if ((data >> 32) != 0)
                        return 1;
                /* Else, falls through */
        default:
                msr = find_msr_entry(vmx, msr_index);
                if (msr) {
                        u64 old_msr_data = msr->data;
                        msr->data = data;
                        if (msr - vmx->guest_msrs < vmx->save_nmsrs) {
                                preempt_disable();
                                ret = kvm_set_shared_msr(msr->index, msr->data,
                                                         msr->mask);
                                preempt_enable();
                                if (ret)
                                        msr->data = old_msr_data;
                        }
                        break;
                }
                ret = kvm_set_msr_common(vcpu, msr_info);
        }

        return ret;
}

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

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

static __init int vmx_disabled_by_bios(void)
{
        u64 msr;

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

        return 0;
}

static void kvm_cpu_vmxon(u64 addr)
{
        cr4_set_bits(X86_CR4_VMXE);
        intel_pt_handle_vmx(1);

        asm volatile ("vmxon %0" : : "m"(addr));
}

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

        if (cr4_read_shadow() & X86_CR4_VMXE)
                return -EBUSY;

        /*
         * This can happen if we hot-added a CPU but failed to allocate
         * VP assist page for it.
         */
        if (static_branch_unlikely(&enable_evmcs) &&
            !hv_get_vp_assist_page(cpu))
                return -EFAULT;

        INIT_LIST_HEAD(&per_cpu(loaded_vmcss_on_cpu, cpu));
        INIT_LIST_HEAD(&per_cpu(blocked_vcpu_on_cpu, cpu));
        spin_lock_init(&per_cpu(blocked_vcpu_on_cpu_lock, cpu));

        /*
         * Now we can enable the vmclear operation in kdump
         * since the loaded_vmcss_on_cpu list on this cpu
         * has been initialized.
         *
         * Though the cpu is not in VMX operation now, there
         * is no problem to enable the vmclear operation
         * for the loaded_vmcss_on_cpu list is empty!
         */
        crash_enable_local_vmclear(cpu);

        rdmsrl(MSR_IA32_FEATURE_CONTROL, old);

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

        if ((old & test_bits) != test_bits) {
                /* enable and lock */
                wrmsrl(MSR_IA32_FEATURE_CONTROL, old | test_bits);
        }
        kvm_cpu_vmxon(phys_addr);
        if (enable_ept)
                ept_sync_global();

        return 0;
}

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

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


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

        intel_pt_handle_vmx(0);
        cr4_clear_bits(X86_CR4_VMXE);
}

static void hardware_disable(void)
{
        vmclear_local_loaded_vmcss();
        kvm_cpu_vmxoff();
}

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,
                                    struct vmx_capability *vmx_cap)
{
        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;

        memset(vmcs_conf, 0, sizeof(*vmcs_conf));
        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_UNCOND_IO_EXITING |
              CPU_BASED_MOV_DR_EXITING |
              CPU_BASED_USE_TSC_OFFSETING |
              CPU_BASED_MWAIT_EXITING |
              CPU_BASED_MONITOR_EXITING |
              CPU_BASED_INVLPG_EXITING |
              CPU_BASED_RDPMC_EXITING;

        opt = CPU_BASED_TPR_SHADOW |
              CPU_BASED_USE_MSR_BITMAPS |
              CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
        if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PROCBASED_CTLS,
                                &_cpu_based_exec_control) < 0)
                return -EIO;
#ifdef CONFIG_X86_64
        if ((_cpu_based_exec_control & CPU_BASED_TPR_SHADOW))
                _cpu_based_exec_control &= ~CPU_BASED_CR8_LOAD_EXITING &
                                           ~CPU_BASED_CR8_STORE_EXITING;
#endif
        if (_cpu_based_exec_control & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) {
                min2 = 0;
                opt2 = SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
                        SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE |
                        SECONDARY_EXEC_WBINVD_EXITING |
                        SECONDARY_EXEC_ENABLE_VPID |
                        SECONDARY_EXEC_ENABLE_EPT |
                        SECONDARY_EXEC_UNRESTRICTED_GUEST |
                        SECONDARY_EXEC_PAUSE_LOOP_EXITING |
                        SECONDARY_EXEC_DESC |
                        SECONDARY_EXEC_RDTSCP |
                        SECONDARY_EXEC_ENABLE_INVPCID |
                        SECONDARY_EXEC_APIC_REGISTER_VIRT |
                        SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY |
                        SECONDARY_EXEC_SHADOW_VMCS |
                        SECONDARY_EXEC_XSAVES |
                        SECONDARY_EXEC_RDSEED_EXITING |
                        SECONDARY_EXEC_RDRAND_EXITING |
                        SECONDARY_EXEC_ENABLE_PML |
                        SECONDARY_EXEC_TSC_SCALING |
                        SECONDARY_EXEC_PT_USE_GPA |
                        SECONDARY_EXEC_PT_CONCEAL_VMX |
                        SECONDARY_EXEC_ENABLE_VMFUNC |
                        SECONDARY_EXEC_ENCLS_EXITING;
                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_exec_control & CPU_BASED_TPR_SHADOW))
                _cpu_based_2nd_exec_control &= ~(
                                SECONDARY_EXEC_APIC_REGISTER_VIRT |
                                SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE |
                                SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY);

        rdmsr_safe(MSR_IA32_VMX_EPT_VPID_CAP,
                &vmx_cap->ept, &vmx_cap->vpid);

        if (_cpu_based_2nd_exec_control & SECONDARY_EXEC_ENABLE_EPT) {
                /* CR3 accesses and invlpg don't need to cause VM Exits when EPT
                   enabled */
                _cpu_based_exec_control &= ~(CPU_BASED_CR3_LOAD_EXITING |
                                             CPU_BASED_CR3_STORE_EXITING |
                                             CPU_BASED_INVLPG_EXITING);
        } else if (vmx_cap->ept) {
                vmx_cap->ept = 0;
                pr_warn_once("EPT CAP should not exist if not support "
                                "1-setting enable EPT VM-execution control\n");
        }
        if (!(_cpu_based_2nd_exec_control & SECONDARY_EXEC_ENABLE_VPID) &&
                vmx_cap->vpid) {
                vmx_cap->vpid = 0;
                pr_warn_once("VPID CAP should not exist if not support "
                                "1-setting enable VPID VM-execution control\n");
        }

        min = VM_EXIT_SAVE_DEBUG_CONTROLS | VM_EXIT_ACK_INTR_ON_EXIT;
#ifdef CONFIG_X86_64
        min |= VM_EXIT_HOST_ADDR_SPACE_SIZE;
#endif
        opt = VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL |
              VM_EXIT_SAVE_IA32_PAT |
              VM_EXIT_LOAD_IA32_PAT |
              VM_EXIT_LOAD_IA32_EFER |
              VM_EXIT_CLEAR_BNDCFGS |
              VM_EXIT_PT_CONCEAL_PIP |
              VM_EXIT_CLEAR_IA32_RTIT_CTL;
        if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_EXIT_CTLS,
                                &_vmexit_control) < 0)
                return -EIO;

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

        if (cpu_has_broken_vmx_preemption_timer())
                _pin_based_exec_control &= ~PIN_BASED_VMX_PREEMPTION_TIMER;
        if (!(_cpu_based_2nd_exec_control &
                SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY))
                _pin_based_exec_control &= ~PIN_BASED_POSTED_INTR;

        min = VM_ENTRY_LOAD_DEBUG_CONTROLS;
        opt = VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL |
              VM_ENTRY_LOAD_IA32_PAT |
              VM_ENTRY_LOAD_IA32_EFER |
              VM_ENTRY_LOAD_BNDCFGS |
              VM_ENTRY_PT_CONCEAL_PIP |
              VM_ENTRY_LOAD_IA32_RTIT_CTL;
        if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_ENTRY_CTLS,
                                &_vmentry_control) < 0)
                return -EIO;

        /*
         * Some cpus support VM_{ENTRY,EXIT}_IA32_PERF_GLOBAL_CTRL but they
         * can't be used due to an errata where VM Exit may incorrectly clear
         * IA32_PERF_GLOBAL_CTRL[34:32].  Workaround the errata by using the
         * MSR load mechanism to switch IA32_PERF_GLOBAL_CTRL.
         */
        if (boot_cpu_data.x86 == 0x6) {
                switch (boot_cpu_data.x86_model) {
                case 26: /* AAK155 */
                case 30: /* AAP115 */
                case 37: /* AAT100 */
                case 44: /* BC86,AAY89,BD102 */
                case 46: /* BA97 */
                        _vmentry_control &= ~VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL;
                        _vmexit_control &= ~VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL;
                        pr_warn_once("kvm: VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL "
                                        "does not work properly. Using workaround\n");
                        break;
                default:
                        break;
                }
        }


        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_conf->size);
        vmcs_conf->basic_cap = vmx_msr_high & ~0x1fff;

        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;

        if (static_branch_unlikely(&enable_evmcs))
                evmcs_sanitize_exec_ctrls(vmcs_conf);

        return 0;
}

struct vmcs *alloc_vmcs_cpu(bool shadow, int cpu, gfp_t flags)
{
        int node = cpu_to_node(cpu);
        struct page *pages;
        struct vmcs *vmcs;

        pages = __alloc_pages_node(node, flags, vmcs_config.order);
        if (!pages)
                return NULL;
        vmcs = page_address(pages);
        memset(vmcs, 0, vmcs_config.size);

        /* KVM supports Enlightened VMCS v1 only */
        if (static_branch_unlikely(&enable_evmcs))
                vmcs->hdr.revision_id = KVM_EVMCS_VERSION;
        else
                vmcs->hdr.revision_id = vmcs_config.revision_id;

        if (shadow)
                vmcs->hdr.shadow_vmcs = 1;
        return vmcs;
}

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

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

int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
{
        loaded_vmcs->vmcs = alloc_vmcs(false);
        if (!loaded_vmcs->vmcs)
                return -ENOMEM;

        loaded_vmcs->shadow_vmcs = NULL;
        loaded_vmcs_init(loaded_vmcs);

        if (cpu_has_vmx_msr_bitmap()) {
                loaded_vmcs->msr_bitmap = (unsigned long *)
                                __get_free_page(GFP_KERNEL_ACCOUNT);
                if (!loaded_vmcs->msr_bitmap)
                        goto out_vmcs;
                memset(loaded_vmcs->msr_bitmap, 0xff, PAGE_SIZE);

                if (IS_ENABLED(CONFIG_HYPERV) &&
                    static_branch_unlikely(&enable_evmcs) &&
                    (ms_hyperv.nested_features & HV_X64_NESTED_MSR_BITMAP)) {
                        struct hv_enlightened_vmcs *evmcs =
                                (struct hv_enlightened_vmcs *)loaded_vmcs->vmcs;

                        evmcs->hv_enlightenments_control.msr_bitmap = 1;
                }
        }

        memset(&loaded_vmcs->host_state, 0, sizeof(struct vmcs_host_state));

        return 0;

out_vmcs:
        free_loaded_vmcs(loaded_vmcs);
        return -ENOMEM;
}

static void free_kvm_area(void)
{
        int cpu;

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

static __init int alloc_kvm_area(void)
{
        int cpu;

        for_each_possible_cpu(cpu) {
                struct vmcs *vmcs;

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

                /*
                 * When eVMCS is enabled, alloc_vmcs_cpu() sets
                 * vmcs->revision_id to KVM_EVMCS_VERSION instead of
                 * revision_id reported by MSR_IA32_VMX_BASIC.
                 *
                 * However, even though not explicitly documented by
                 * TLFS, VMXArea passed as VMXON argument should
                 * still be marked with revision_id reported by
                 * physical CPU.
                 */
                if (static_branch_unlikely(&enable_evmcs))
                        vmcs->hdr.revision_id = vmcs_config.revision_id;

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

static void fix_pmode_seg(struct kvm_vcpu *vcpu, int seg,
                struct kvm_segment *save)
{
        if (!emulate_invalid_guest_state) {
                /*
                 * CS and SS RPL should be equal during guest entry according
                 * to VMX spec, but in reality it is not always so. Since vcpu
                 * is in the middle of the transition from real mode to
                 * protected mode it is safe to assume that RPL 0 is a good
                 * default value.
                 */
                if (seg == VCPU_SREG_CS || seg == VCPU_SREG_SS)
                        save->selector &= ~SEGMENT_RPL_MASK;
                save->dpl = save->selector & SEGMENT_RPL_MASK;
                save->s = 1;
        }
        vmx_set_segment(vcpu, save, seg);
}

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

        /*
         * Update real mode segment cache. It may be not up-to-date if sement
         * register was written while vcpu was in a guest mode.
         */
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_ES], VCPU_SREG_ES);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_DS], VCPU_SREG_DS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_FS], VCPU_SREG_FS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_GS], VCPU_SREG_GS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_SS], VCPU_SREG_SS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_CS], VCPU_SREG_CS);

        vmx->rmode.vm86_active = 0;

        vmx_segment_cache_clear(vmx);

        vmx_set_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_TR], VCPU_SREG_TR);

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

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

        update_exception_bitmap(vcpu);

        fix_pmode_seg(vcpu, VCPU_SREG_CS, &vmx->rmode.segs[VCPU_SREG_CS]);
        fix_pmode_seg(vcpu, VCPU_SREG_SS, &vmx->rmode.segs[VCPU_SREG_SS]);
        fix_pmode_seg(vcpu, VCPU_SREG_ES, &vmx->rmode.segs[VCPU_SREG_ES]);
        fix_pmode_seg(vcpu, VCPU_SREG_DS, &vmx->rmode.segs[VCPU_SREG_DS]);
        fix_pmode_seg(vcpu, VCPU_SREG_FS, &vmx->rmode.segs[VCPU_SREG_FS]);
        fix_pmode_seg(vcpu, VCPU_SREG_GS, &vmx->rmode.segs[VCPU_SREG_GS]);
}

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

        var.dpl = 0x3;
        if (seg == VCPU_SREG_CS)
                var.type = 0x3;

        if (!emulate_invalid_guest_state) {
                var.selector = var.base >> 4;
                var.base = var.base & 0xffff0;
                var.limit = 0xffff;
                var.g = 0;
                var.db = 0;
                var.present = 1;
                var.s = 1;
                var.l = 0;
                var.unusable = 0;
                var.type = 0x3;
                var.avl = 0;
                if (save->base & 0xf)
                        printk_once(KERN_WARNING "kvm: segment base is not "
                                        "paragraph aligned when entering "
                                        "protected mode (seg=%d)", seg);
        }

        vmcs_write16(sf->selector, var.selector);
        vmcs_writel(sf->base, var.base);
        vmcs_write32(sf->limit, var.limit);
        vmcs_write32(sf->ar_bytes, vmx_segment_access_rights(&var));
}

static void enter_rmode(struct kvm_vcpu *vcpu)
{
        unsigned long flags;
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct kvm_vmx *kvm_vmx = to_kvm_vmx(vcpu->kvm);

        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_TR], VCPU_SREG_TR);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_ES], VCPU_SREG_ES);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_DS], VCPU_SREG_DS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_FS], VCPU_SREG_FS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_GS], VCPU_SREG_GS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_SS], VCPU_SREG_SS);
        vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_CS], VCPU_SREG_CS);

        vmx->rmode.vm86_active = 1;

        /*
         * Very old userspace does not call KVM_SET_TSS_ADDR before entering
         * vcpu. Warn the user that an update is overdue.
         */
        if (!kvm_vmx->tss_addr)
                printk_once(KERN_WARNING "kvm: KVM_SET_TSS_ADDR need to be "
                             "called before entering vcpu\n");

        vmx_segment_cache_clear(vmx);

        vmcs_writel(GUEST_TR_BASE, kvm_vmx->tss_addr);
        vmcs_write32(GUEST_TR_LIMIT, RMODE_TSS_SIZE - 1);
        vmcs_write32(GUEST_TR_AR_BYTES, 0x008b);

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

        flags |= X86_EFLAGS_IOPL | X86_EFLAGS_VM;

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

        fix_rmode_seg(VCPU_SREG_SS, &vmx->rmode.segs[VCPU_SREG_SS]);
        fix_rmode_seg(VCPU_SREG_CS, &vmx->rmode.segs[VCPU_SREG_CS]);
        fix_rmode_seg(VCPU_SREG_ES, &vmx->rmode.segs[VCPU_SREG_ES]);
        fix_rmode_seg(VCPU_SREG_DS, &vmx->rmode.segs[VCPU_SREG_DS]);
        fix_rmode_seg(VCPU_SREG_GS, &vmx->rmode.segs[VCPU_SREG_GS]);
        fix_rmode_seg(VCPU_SREG_FS, &vmx->rmode.segs[VCPU_SREG_FS]);

        kvm_mmu_reset_context(vcpu);
}

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

        if (!msr)
                return;

        vcpu->arch.efer = efer;
        if (efer & EFER_LMA) {
                vm_entry_controls_setbit(to_vmx(vcpu), VM_ENTRY_IA32E_MODE);
                msr->data = efer;
        } else {
                vm_entry_controls_clearbit(to_vmx(vcpu), VM_ENTRY_IA32E_MODE);

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

#ifdef CONFIG_X86_64

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

        vmx_segment_cache_clear(to_vmx(vcpu));

        guest_tr_ar = vmcs_read32(GUEST_TR_AR_BYTES);
        if ((guest_tr_ar & VMX_AR_TYPE_MASK) != VMX_AR_TYPE_BUSY_64_TSS) {
                pr_debug_ratelimited("%s: tss fixup for long mode. \n",
                                     __func__);
                vmcs_write32(GUEST_TR_AR_BYTES,
                             (guest_tr_ar & ~VMX_AR_TYPE_MASK)
                             | VMX_AR_TYPE_BUSY_64_TSS);
        }
        vmx_set_efer(vcpu, vcpu->arch.efer | EFER_LMA);
}

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

#endif

static void vmx_flush_tlb_gva(struct kvm_vcpu *vcpu, gva_t addr)
{
        int vpid = to_vmx(vcpu)->vpid;

        if (!vpid_sync_vcpu_addr(vpid, addr))
                vpid_sync_context(vpid);

        /*
         * If VPIDs are not supported or enabled, then the above is a no-op.
         * But we don't really need a TLB flush in that case anyway, because
         * each VM entry/exit includes an implicit flush when VPID is 0.
         */
}

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

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

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

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

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

static void ept_load_pdptrs(struct kvm_vcpu *vcpu)
{
        struct kvm_mmu *mmu = vcpu->arch.walk_mmu;

        if (!test_bit(VCPU_EXREG_PDPTR,
                      (unsigned long *)&vcpu->arch.regs_dirty))
                return;

        if (is_pae_paging(vcpu)) {
                vmcs_write64(GUEST_PDPTR0, mmu->pdptrs[0]);
                vmcs_write64(GUEST_PDPTR1, mmu->pdptrs[1]);
                vmcs_write64(GUEST_PDPTR2, mmu->pdptrs[2]);
                vmcs_write64(GUEST_PDPTR3, mmu->pdptrs[3]);
        }
}

void ept_save_pdptrs(struct kvm_vcpu *vcpu)
{
        struct kvm_mmu *mmu = vcpu->arch.walk_mmu;

        if (is_pae_paging(vcpu)) {
                mmu->pdptrs[0] = vmcs_read64(GUEST_PDPTR0);
                mmu->pdptrs[1] = vmcs_read64(GUEST_PDPTR1);
                mmu->pdptrs[2] = vmcs_read64(GUEST_PDPTR2);
                mmu->pdptrs[3] = vmcs_read64(GUEST_PDPTR3);
        }

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

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

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

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

        hw_cr0 = (cr0 & ~KVM_VM_CR0_ALWAYS_OFF);
        if (enable_unrestricted_guest)
                hw_cr0 |= KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST;
        else {
                hw_cr0 |= KVM_VM_CR0_ALWAYS_ON;

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

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

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

        if (enable_ept && !enable_unrestricted_guest)
                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;

        /* depends on vcpu->arch.cr0 to be set to a new value */
        vmx->emulation_required = emulation_required(vcpu);
}

static int get_ept_level(struct kvm_vcpu *vcpu)
{
        if (cpu_has_vmx_ept_5levels() && (cpuid_maxphyaddr(vcpu) > 48))
                return 5;
        return 4;
}

u64 construct_eptp(struct kvm_vcpu *vcpu, unsigned long root_hpa)
{
        u64 eptp = VMX_EPTP_MT_WB;

        eptp |= (get_ept_level(vcpu) == 5) ? VMX_EPTP_PWL_5 : VMX_EPTP_PWL_4;

        if (enable_ept_ad_bits &&
            (!is_guest_mode(vcpu) || nested_ept_ad_enabled(vcpu)))
                eptp |= VMX_EPTP_AD_ENABLE_BIT;
        eptp |= (root_hpa & PAGE_MASK);

        return eptp;
}

void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
{
        struct kvm *kvm = vcpu->kvm;
        unsigned long guest_cr3;
        u64 eptp;

        guest_cr3 = cr3;
        if (enable_ept) {
                eptp = construct_eptp(vcpu, cr3);
                vmcs_write64(EPT_POINTER, eptp);

                if (kvm_x86_ops->tlb_remote_flush) {
                        spin_lock(&to_kvm_vmx(kvm)->ept_pointer_lock);
                        to_vmx(vcpu)->ept_pointer = eptp;
                        to_kvm_vmx(kvm)->ept_pointers_match
                                = EPT_POINTERS_CHECK;
                        spin_unlock(&to_kvm_vmx(kvm)->ept_pointer_lock);
                }

                if (enable_unrestricted_guest || is_paging(vcpu) ||
                    is_guest_mode(vcpu))
                        guest_cr3 = kvm_read_cr3(vcpu);
                else
                        guest_cr3 = to_kvm_vmx(kvm)->ept_identity_map_addr;
                ept_load_pdptrs(vcpu);
        }

        vmcs_writel(GUEST_CR3, guest_cr3);
}

int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
        /*
         * Pass through host's Machine Check Enable value to hw_cr4, which
         * is in force while we are in guest mode.  Do not let guests control
         * this bit, even if host CR4.MCE == 0.
         */
        unsigned long hw_cr4;

        hw_cr4 = (cr4_read_shadow() & X86_CR4_MCE) | (cr4 & ~X86_CR4_MCE);
        if (enable_unrestricted_guest)
                hw_cr4 |= KVM_VM_CR4_ALWAYS_ON_UNRESTRICTED_GUEST;
        else if (to_vmx(vcpu)->rmode.vm86_active)
                hw_cr4 |= KVM_RMODE_VM_CR4_ALWAYS_ON;
        else
                hw_cr4 |= KVM_PMODE_VM_CR4_ALWAYS_ON;

        if (!boot_cpu_has(X86_FEATURE_UMIP) && vmx_umip_emulated()) {
                if (cr4 & X86_CR4_UMIP) {
                        vmcs_set_bits(SECONDARY_VM_EXEC_CONTROL,
                                SECONDARY_EXEC_DESC);
                        hw_cr4 &= ~X86_CR4_UMIP;
                } else if (!is_guest_mode(vcpu) ||
                        !nested_cpu_has2(get_vmcs12(vcpu), SECONDARY_EXEC_DESC))
                        vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL,
                                        SECONDARY_EXEC_DESC);
        }

        if (cr4 & X86_CR4_VMXE) {
                /*
                 * To use VMXON (and later other VMX instructions), a guest
                 * must first be able to turn on cr4.VMXE (see handle_vmon()).
                 * So basically the check on whether to allow nested VMX
                 * is here.  We operate under the default treatment of SMM,
                 * so VMX cannot be enabled under SMM.
                 */
                if (!nested_vmx_allowed(vcpu) || is_smm(vcpu))
                        return 1;
        }

        if (to_vmx(vcpu)->nested.vmxon && !nested_cr4_valid(vcpu, cr4))
                return 1;

        vcpu->arch.cr4 = cr4;

        if (!enable_unrestricted_guest) {
                if (enable_ept) {
                        if (!is_paging(vcpu)) {
                                hw_cr4 &= ~X86_CR4_PAE;
                                hw_cr4 |= X86_CR4_PSE;
                        } else if (!(cr4 & X86_CR4_PAE)) {
                                hw_cr4 &= ~X86_CR4_PAE;
                        }
                }

                /*
                 * SMEP/SMAP/PKU is disabled if CPU is in non-paging mode in
                 * hardware.  To emulate this behavior, SMEP/SMAP/PKU needs
                 * to be manually disabled when guest switches to non-paging
                 * mode.
                 *
                 * If !enable_unrestricted_guest, the CPU is always running
                 * with CR0.PG=1 and CR4 needs to be modified.
                 * If enable_unrestricted_guest, the CPU automatically
                 * disables SMEP/SMAP/PKU when the guest sets CR0.PG=0.
                 */
                if (!is_paging(vcpu))
                        hw_cr4 &= ~(X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE);
        }

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

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

        if (vmx->rmode.vm86_active && seg != VCPU_SREG_LDTR) {
                *var = vmx->rmode.segs[seg];
                if (seg == VCPU_SREG_TR
                    || var->selector == vmx_read_guest_seg_selector(vmx, seg))
                        return;
                var->base = vmx_read_guest_seg_base(vmx, seg);
                var->selector = vmx_read_guest_seg_selector(vmx, seg);
                return;
        }
        var->base = vmx_read_guest_seg_base(vmx, seg);
        var->limit = vmx_read_guest_seg_limit(vmx, seg);
        var->selector = vmx_read_guest_seg_selector(vmx, seg);
        ar = vmx_read_guest_seg_ar(vmx, seg);
        var->unusable = (ar >> 16) & 1;
        var->type = ar & 15;
        var->s = (ar >> 4) & 1;
        var->dpl = (ar >> 5) & 3;
        /*
         * Some userspaces do not preserve unusable property. Since usable
         * segment has to be present according to VMX spec we can use present
         * property to amend userspace bug by making unusable segment always
         * nonpresent. vmx_segment_access_rights() already marks nonpresent
         * segment as unusable.
         */
        var->present = !var->unusable;
        var->avl = (ar >> 12) & 1;
        var->l = (ar >> 13) & 1;
        var->db = (ar >> 14) & 1;
        var->g = (ar >> 15) & 1;
}

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

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

int vmx_get_cpl(struct kvm_vcpu *vcpu)
{