/*
 * Kernel-based Virtual Machine driver for Linux
 *
 * derived from drivers/kvm/kvm_main.c
 *
 * Copyright (C) 2006 Qumranet, Inc.
 * Copyright (C) 2008 Qumranet, Inc.
 * Copyright IBM Corporation, 2008
 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
 *
 * Authors:
 *   Avi Kivity   <avi@qumranet.com>
 *   Yaniv Kamay  <yaniv@qumranet.com>
 *   Amit Shah    <amit.shah@qumranet.com>
 *   Ben-Ami Yassour <benami@il.ibm.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/kvm_host.h>
#include "irq.h"
#include "mmu.h"
#include "i8254.h"
#include "tss.h"
#include "kvm_cache_regs.h"
#include "x86.h"

#include <linux/clocksource.h>
#include <linux/interrupt.h>
#include <linux/kvm.h>
#include <linux/fs.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/mman.h>
#include <linux/highmem.h>
#include <linux/iommu.h>
#include <linux/intel-iommu.h>
#include <linux/cpufreq.h>
#include <linux/user-return-notifier.h>
#include <linux/srcu.h>
#include <linux/slab.h>
#include <linux/perf_event.h>
#include <linux/uaccess.h>
#include <linux/hash.h>
#include <linux/pci.h>
#include <trace/events/kvm.h>

#define CREATE_TRACE_POINTS
#include "trace.h"

#include <asm/debugreg.h>
#include <asm/msr.h>
#include <asm/desc.h>
#include <asm/mtrr.h>
#include <asm/mce.h>
#include <asm/i387.h>
#include <asm/xcr.h>
#include <asm/pvclock.h>
#include <asm/div64.h>

#define MAX_IO_MSRS 256
#define KVM_MAX_MCE_BANKS 32
#define KVM_MCE_CAP_SUPPORTED (MCG_CTL_P | MCG_SER_P)

#define emul_to_vcpu(ctxt) \
        container_of(ctxt, struct kvm_vcpu, arch.emulate_ctxt)

/* EFER defaults:
 * - enable syscall per default because its emulated by KVM
 * - enable LME and LMA per default on 64 bit KVM
 */
#ifdef CONFIG_X86_64
static
u64 __read_mostly efer_reserved_bits = ~((u64)(EFER_SCE | EFER_LME | EFER_LMA));
#else
static u64 __read_mostly efer_reserved_bits = ~((u64)EFER_SCE);
#endif

#define VM_STAT(x) offsetof(struct kvm, stat.x), KVM_STAT_VM
#define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU

static void update_cr8_intercept(struct kvm_vcpu *vcpu);
static int kvm_dev_ioctl_get_supported_cpuid(struct kvm_cpuid2 *cpuid,
                                    struct kvm_cpuid_entry2 __user *entries);
static void process_nmi(struct kvm_vcpu *vcpu);

struct kvm_x86_ops *kvm_x86_ops;
EXPORT_SYMBOL_GPL(kvm_x86_ops);

int ignore_msrs = 0;
module_param_named(ignore_msrs, ignore_msrs, bool, S_IRUGO | S_IWUSR);

bool kvm_has_tsc_control;
EXPORT_SYMBOL_GPL(kvm_has_tsc_control);
u32  kvm_max_guest_tsc_khz;
EXPORT_SYMBOL_GPL(kvm_max_guest_tsc_khz);

#define KVM_NR_SHARED_MSRS 16

struct kvm_shared_msrs_global {
        int nr;
        u32 msrs[KVM_NR_SHARED_MSRS];
};

struct kvm_shared_msrs {
        struct user_return_notifier urn;
        bool registered;
        struct kvm_shared_msr_values {
                u64 host;
                u64 curr;
        } values[KVM_NR_SHARED_MSRS];
};

static struct kvm_shared_msrs_global __read_mostly shared_msrs_global;
static DEFINE_PER_CPU(struct kvm_shared_msrs, shared_msrs);

struct kvm_stats_debugfs_item debugfs_entries[] = {
        { "pf_fixed", VCPU_STAT(pf_fixed) },
        { "pf_guest", VCPU_STAT(pf_guest) },
        { "tlb_flush", VCPU_STAT(tlb_flush) },
        { "invlpg", VCPU_STAT(invlpg) },
        { "exits", VCPU_STAT(exits) },
        { "io_exits", VCPU_STAT(io_exits) },
        { "mmio_exits", VCPU_STAT(mmio_exits) },
        { "signal_exits", VCPU_STAT(signal_exits) },
        { "irq_window", VCPU_STAT(irq_window_exits) },
        { "nmi_window", VCPU_STAT(nmi_window_exits) },
        { "halt_exits", VCPU_STAT(halt_exits) },
        { "halt_wakeup", VCPU_STAT(halt_wakeup) },
        { "hypercalls", VCPU_STAT(hypercalls) },
        { "request_irq", VCPU_STAT(request_irq_exits) },
        { "irq_exits", VCPU_STAT(irq_exits) },
        { "host_state_reload", VCPU_STAT(host_state_reload) },
        { "efer_reload", VCPU_STAT(efer_reload) },
        { "fpu_reload", VCPU_STAT(fpu_reload) },
        { "insn_emulation", VCPU_STAT(insn_emulation) },
        { "insn_emulation_fail", VCPU_STAT(insn_emulation_fail) },
        { "irq_injections", VCPU_STAT(irq_injections) },
        { "nmi_injections", VCPU_STAT(nmi_injections) },
        { "mmu_shadow_zapped", VM_STAT(mmu_shadow_zapped) },
        { "mmu_pte_write", VM_STAT(mmu_pte_write) },
        { "mmu_pte_updated", VM_STAT(mmu_pte_updated) },
        { "mmu_pde_zapped", VM_STAT(mmu_pde_zapped) },
        { "mmu_flooded", VM_STAT(mmu_flooded) },
        { "mmu_recycled", VM_STAT(mmu_recycled) },
        { "mmu_cache_miss", VM_STAT(mmu_cache_miss) },
        { "mmu_unsync", VM_STAT(mmu_unsync) },
        { "remote_tlb_flush", VM_STAT(remote_tlb_flush) },
        { "largepages", VM_STAT(lpages) },
        { NULL }
};

u64 __read_mostly host_xcr0;

int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt);

static inline void kvm_async_pf_hash_reset(struct kvm_vcpu *vcpu)
{
        int i;
        for (i = 0; i < roundup_pow_of_two(ASYNC_PF_PER_VCPU); i++)
                vcpu->arch.apf.gfns[i] = ~0;
}

static void kvm_on_user_return(struct user_return_notifier *urn)
{
        unsigned slot;
        struct kvm_shared_msrs *locals
                = container_of(urn, struct kvm_shared_msrs, urn);
        struct kvm_shared_msr_values *values;

        for (slot = 0; slot < shared_msrs_global.nr; ++slot) {
                values = &locals->values[slot];
                if (values->host != values->curr) {
                        wrmsrl(shared_msrs_global.msrs[slot], values->host);
                        values->curr = values->host;
                }
        }
        locals->registered = false;
        user_return_notifier_unregister(urn);
}

static void shared_msr_update(unsigned slot, u32 msr)
{
        struct kvm_shared_msrs *smsr;
        u64 value;

        smsr = &__get_cpu_var(shared_msrs);
        /* only read, and nobody should modify it at this time,
         * so don't need lock */
        if (slot >= shared_msrs_global.nr) {
                printk(KERN_ERR "kvm: invalid MSR slot!");
                return;
        }
        rdmsrl_safe(msr, &value);
        smsr->values[slot].host = value;
        smsr->values[slot].curr = value;
}

void kvm_define_shared_msr(unsigned slot, u32 msr)
{
        if (slot >= shared_msrs_global.nr)
                shared_msrs_global.nr = slot + 1;
        shared_msrs_global.msrs[slot] = msr;
        /* we need ensured the shared_msr_global have been updated */
        smp_wmb();
}
EXPORT_SYMBOL_GPL(kvm_define_shared_msr);

static void kvm_shared_msr_cpu_online(void)
{
        unsigned i;

        for (i = 0; i < shared_msrs_global.nr; ++i)
                shared_msr_update(i, shared_msrs_global.msrs[i]);
}

void kvm_set_shared_msr(unsigned slot, u64 value, u64 mask)
{
        struct kvm_shared_msrs *smsr = &__get_cpu_var(shared_msrs);

        if (((value ^ smsr->values[slot].curr) & mask) == 0)
                return;
        smsr->values[slot].curr = value;
        wrmsrl(shared_msrs_global.msrs[slot], value);
        if (!smsr->registered) {
                smsr->urn.on_user_return = kvm_on_user_return;
                user_return_notifier_register(&smsr->urn);
                smsr->registered = true;
        }
}
EXPORT_SYMBOL_GPL(kvm_set_shared_msr);

static void drop_user_return_notifiers(void *ignore)
{
        struct kvm_shared_msrs *smsr = &__get_cpu_var(shared_msrs);

        if (smsr->registered)
                kvm_on_user_return(&smsr->urn);
}

u64 kvm_get_apic_base(struct kvm_vcpu *vcpu)
{
        if (irqchip_in_kernel(vcpu->kvm))
                return vcpu->arch.apic_base;
        else
                return vcpu->arch.apic_base;
}
EXPORT_SYMBOL_GPL(kvm_get_apic_base);

void kvm_set_apic_base(struct kvm_vcpu *vcpu, u64 data)
{
        /* TODO: reserve bits check */
        if (irqchip_in_kernel(vcpu->kvm))
                kvm_lapic_set_base(vcpu, data);
        else
                vcpu->arch.apic_base = data;
}
EXPORT_SYMBOL_GPL(kvm_set_apic_base);

#define EXCPT_BENIGN            0
#define EXCPT_CONTRIBUTORY      1
#define EXCPT_PF                2

static int exception_class(int vector)
{
        switch (vector) {
        case PF_VECTOR:
                return EXCPT_PF;
        case DE_VECTOR:
        case TS_VECTOR:
        case NP_VECTOR:
        case SS_VECTOR:
        case GP_VECTOR:
                return EXCPT_CONTRIBUTORY;
        default:
                break;
        }
        return EXCPT_BENIGN;
}

static void kvm_multiple_exception(struct kvm_vcpu *vcpu,
                unsigned nr, bool has_error, u32 error_code,
                bool reinject)
{
        u32 prev_nr;
        int class1, class2;

        kvm_make_request(KVM_REQ_EVENT, vcpu);

        if (!vcpu->arch.exception.pending) {
        queue:
                vcpu->arch.exception.pending = true;
                vcpu->arch.exception.has_error_code = has_error;
                vcpu->arch.exception.nr = nr;
                vcpu->arch.exception.error_code = error_code;
                vcpu->arch.exception.reinject = reinject;
                return;
        }

        /* to check exception */
        prev_nr = vcpu->arch.exception.nr;
        if (prev_nr == DF_VECTOR) {
                /* triple fault -> shutdown */
                kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
                return;
        }
        class1 = exception_class(prev_nr);
        class2 = exception_class(nr);
        if ((class1 == EXCPT_CONTRIBUTORY && class2 == EXCPT_CONTRIBUTORY)
                || (class1 == EXCPT_PF && class2 != EXCPT_BENIGN)) {
                /* generate double fault per SDM Table 5-5 */
                vcpu->arch.exception.pending = true;
                vcpu->arch.exception.has_error_code = true;
                vcpu->arch.exception.nr = DF_VECTOR;
                vcpu->arch.exception.error_code = 0;
        } else
                /* replace previous exception with a new one in a hope
                   that instruction re-execution will regenerate lost
                   exception */
                goto queue;
}

void kvm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr)
{
        kvm_multiple_exception(vcpu, nr, false, 0, false);
}
EXPORT_SYMBOL_GPL(kvm_queue_exception);

void kvm_requeue_exception(struct kvm_vcpu *vcpu, unsigned nr)
{
        kvm_multiple_exception(vcpu, nr, false, 0, true);
}
EXPORT_SYMBOL_GPL(kvm_requeue_exception);

void kvm_complete_insn_gp(struct kvm_vcpu *vcpu, int err)
{
        if (err)
                kvm_inject_gp(vcpu, 0);
        else
                kvm_x86_ops->skip_emulated_instruction(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_complete_insn_gp);

void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault)
{
        ++vcpu->stat.pf_guest;
        vcpu->arch.cr2 = fault->address;
        kvm_queue_exception_e(vcpu, PF_VECTOR, fault->error_code);
}
EXPORT_SYMBOL_GPL(kvm_inject_page_fault);

void kvm_propagate_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault)
{
        if (mmu_is_nested(vcpu) && !fault->nested_page_fault)
                vcpu->arch.nested_mmu.inject_page_fault(vcpu, fault);
        else
                vcpu->arch.mmu.inject_page_fault(vcpu, fault);
}

void kvm_inject_nmi(struct kvm_vcpu *vcpu)
{
        atomic_inc(&vcpu->arch.nmi_queued);
        kvm_make_request(KVM_REQ_NMI, vcpu);
}
EXPORT_SYMBOL_GPL(kvm_inject_nmi);

void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code)
{
        kvm_multiple_exception(vcpu, nr, true, error_code, false);
}
EXPORT_SYMBOL_GPL(kvm_queue_exception_e);

void kvm_requeue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code)
{
        kvm_multiple_exception(vcpu, nr, true, error_code, true);
}
EXPORT_SYMBOL_GPL(kvm_requeue_exception_e);

/*
 * Checks if cpl <= required_cpl; if true, return true.  Otherwise queue
 * a #GP and return false.
 */
bool kvm_require_cpl(struct kvm_vcpu *vcpu, int required_cpl)
{
        if (kvm_x86_ops->get_cpl(vcpu) <= required_cpl)
                return true;
        kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
        return false;
}
EXPORT_SYMBOL_GPL(kvm_require_cpl);

/*
 * This function will be used to read from the physical memory of the currently
 * running guest. The difference to kvm_read_guest_page is that this function
 * can read from guest physical or from the guest's guest physical memory.
 */
int kvm_read_guest_page_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
                            gfn_t ngfn, void *data, int offset, int len,
                            u32 access)
{
        gfn_t real_gfn;
        gpa_t ngpa;

        ngpa     = gfn_to_gpa(ngfn);
        real_gfn = mmu->translate_gpa(vcpu, ngpa, access);
        if (real_gfn == UNMAPPED_GVA)
                return -EFAULT;

        real_gfn = gpa_to_gfn(real_gfn);

        return kvm_read_guest_page(vcpu->kvm, real_gfn, data, offset, len);
}
EXPORT_SYMBOL_GPL(kvm_read_guest_page_mmu);

int kvm_read_nested_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn,
                               void *data, int offset, int len, u32 access)
{
        return kvm_read_guest_page_mmu(vcpu, vcpu->arch.walk_mmu, gfn,
                                       data, offset, len, access);
}

/*
 * Load the pae pdptrs.  Return true is they are all valid.
 */
int load_pdptrs(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, unsigned long cr3)
{
        gfn_t pdpt_gfn = cr3 >> PAGE_SHIFT;
        unsigned offset = ((cr3 & (PAGE_SIZE-1)) >> 5) << 2;
        int i;
        int ret;
        u64 pdpte[ARRAY_SIZE(mmu->pdptrs)];

        ret = kvm_read_guest_page_mmu(vcpu, mmu, pdpt_gfn, pdpte,
                                      offset * sizeof(u64), sizeof(pdpte),
                                      PFERR_USER_MASK|PFERR_WRITE_MASK);
        if (ret < 0) {
                ret = 0;
                goto out;
        }
        for (i = 0; i < ARRAY_SIZE(pdpte); ++i) {
                if (is_present_gpte(pdpte[i]) &&
                    (pdpte[i] & vcpu->arch.mmu.rsvd_bits_mask[0][2])) {
                        ret = 0;
                        goto out;
                }
        }
        ret = 1;

        memcpy(mmu->pdptrs, pdpte, sizeof(mmu->pdptrs));
        __set_bit(VCPU_EXREG_PDPTR,
                  (unsigned long *)&vcpu->arch.regs_avail);
        __set_bit(VCPU_EXREG_PDPTR,
                  (unsigned long *)&vcpu->arch.regs_dirty);
out:

        return ret;
}
EXPORT_SYMBOL_GPL(load_pdptrs);

static bool pdptrs_changed(struct kvm_vcpu *vcpu)
{
        u64 pdpte[ARRAY_SIZE(vcpu->arch.walk_mmu->pdptrs)];
        bool changed = true;
        int offset;
        gfn_t gfn;
        int r;

        if (is_long_mode(vcpu) || !is_pae(vcpu))
                return false;

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

        gfn = (kvm_read_cr3(vcpu) & ~31u) >> PAGE_SHIFT;
        offset = (kvm_read_cr3(vcpu) & ~31u) & (PAGE_SIZE - 1);
        r = kvm_read_nested_guest_page(vcpu, gfn, pdpte, offset, sizeof(pdpte),
                                       PFERR_USER_MASK | PFERR_WRITE_MASK);
        if (r < 0)
                goto out;
        changed = memcmp(pdpte, vcpu->arch.walk_mmu->pdptrs, sizeof(pdpte)) != 0;
out:

        return changed;
}

int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
{
        unsigned long old_cr0 = kvm_read_cr0(vcpu);
        unsigned long update_bits = X86_CR0_PG | X86_CR0_WP |
                                    X86_CR0_CD | X86_CR0_NW;

        cr0 |= X86_CR0_ET;

#ifdef CONFIG_X86_64
        if (cr0 & 0xffffffff00000000UL)
                return 1;
#endif

        cr0 &= ~CR0_RESERVED_BITS;

        if ((cr0 & X86_CR0_NW) && !(cr0 & X86_CR0_CD))
                return 1;

        if ((cr0 & X86_CR0_PG) && !(cr0 & X86_CR0_PE))
                return 1;

        if (!is_paging(vcpu) && (cr0 & X86_CR0_PG)) {
#ifdef CONFIG_X86_64
                if ((vcpu->arch.efer & EFER_LME)) {
                        int cs_db, cs_l;

                        if (!is_pae(vcpu))
                                return 1;
                        kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
                        if (cs_l)
                                return 1;
                } else
#endif
                if (is_pae(vcpu) && !load_pdptrs(vcpu, vcpu->arch.walk_mmu,
                                                 kvm_read_cr3(vcpu)))
                        return 1;
        }

        kvm_x86_ops->set_cr0(vcpu, cr0);

        if ((cr0 ^ old_cr0) & X86_CR0_PG) {
                kvm_clear_async_pf_completion_queue(vcpu);
                kvm_async_pf_hash_reset(vcpu);
        }

        if ((cr0 ^ old_cr0) & update_bits)
                kvm_mmu_reset_context(vcpu);
        return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_cr0);

void kvm_lmsw(struct kvm_vcpu *vcpu, unsigned long msw)
{
        (void)kvm_set_cr0(vcpu, kvm_read_cr0_bits(vcpu, ~0x0eul) | (msw & 0x0f));
}
EXPORT_SYMBOL_GPL(kvm_lmsw);

int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
{
        u64 xcr0;

        /* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now  */
        if (index != XCR_XFEATURE_ENABLED_MASK)
                return 1;
        xcr0 = xcr;
        if (kvm_x86_ops->get_cpl(vcpu) != 0)
                return 1;
        if (!(xcr0 & XSTATE_FP))
                return 1;
        if ((xcr0 & XSTATE_YMM) && !(xcr0 & XSTATE_SSE))
                return 1;
        if (xcr0 & ~host_xcr0)
                return 1;
        vcpu->arch.xcr0 = xcr0;
        vcpu->guest_xcr0_loaded = 0;
        return 0;
}

int kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
{
        if (__kvm_set_xcr(vcpu, index, xcr)) {
                kvm_inject_gp(vcpu, 0);
                return 1;
        }
        return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_xcr);

static bool guest_cpuid_has_xsave(struct kvm_vcpu *vcpu)
{
        struct kvm_cpuid_entry2 *best;

        best = kvm_find_cpuid_entry(vcpu, 1, 0);
        return best && (best->ecx & bit(X86_FEATURE_XSAVE));
}

static bool guest_cpuid_has_smep(struct kvm_vcpu *vcpu)
{
        struct kvm_cpuid_entry2 *best;

        best = kvm_find_cpuid_entry(vcpu, 7, 0);
        return best && (best->ebx & bit(X86_FEATURE_SMEP));
}

static bool guest_cpuid_has_fsgsbase(struct kvm_vcpu *vcpu)
{
        struct kvm_cpuid_entry2 *best;

        best = kvm_find_cpuid_entry(vcpu, 7, 0);
        return best && (best->ebx & bit(X86_FEATURE_FSGSBASE));
}

static void update_cpuid(struct kvm_vcpu *vcpu)
{
        struct kvm_cpuid_entry2 *best;
        struct kvm_lapic *apic = vcpu->arch.apic;

        best = kvm_find_cpuid_entry(vcpu, 1, 0);
        if (!best)
                return;

        /* Update OSXSAVE bit */
        if (cpu_has_xsave && best->function == 0x1) {
                best->ecx &= ~(bit(X86_FEATURE_OSXSAVE));
                if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
                        best->ecx |= bit(X86_FEATURE_OSXSAVE);
        }

        if (apic) {
                if (best->ecx & bit(X86_FEATURE_TSC_DEADLINE_TIMER))
                        apic->lapic_timer.timer_mode_mask = 3 << 17;
                else
                        apic->lapic_timer.timer_mode_mask = 1 << 17;
        }
}

int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
        unsigned long old_cr4 = kvm_read_cr4(vcpu);
        unsigned long pdptr_bits = X86_CR4_PGE | X86_CR4_PSE |
                                   X86_CR4_PAE | X86_CR4_SMEP;
        if (cr4 & CR4_RESERVED_BITS)
                return 1;

        if (!guest_cpuid_has_xsave(vcpu) && (cr4 & X86_CR4_OSXSAVE))
                return 1;

        if (!guest_cpuid_has_smep(vcpu) && (cr4 & X86_CR4_SMEP))
                return 1;

        if (!guest_cpuid_has_fsgsbase(vcpu) && (cr4 & X86_CR4_RDWRGSFS))
                return 1;

        if (is_long_mode(vcpu)) {
                if (!(cr4 & X86_CR4_PAE))
                        return 1;
        } else if (is_paging(vcpu) && (cr4 & X86_CR4_PAE)
                   && ((cr4 ^ old_cr4) & pdptr_bits)
                   && !load_pdptrs(vcpu, vcpu->arch.walk_mmu,
                                   kvm_read_cr3(vcpu)))
                return 1;

        if (kvm_x86_ops->set_cr4(vcpu, cr4))
                return 1;

        if ((cr4 ^ old_cr4) & pdptr_bits)
                kvm_mmu_reset_context(vcpu);

        if ((cr4 ^ old_cr4) & X86_CR4_OSXSAVE)
                update_cpuid(vcpu);

        return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_cr4);

int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
{
        if (cr3 == kvm_read_cr3(vcpu) && !pdptrs_changed(vcpu)) {
                kvm_mmu_sync_roots(vcpu);
                kvm_mmu_flush_tlb(vcpu);
                return 0;
        }

        if (is_long_mode(vcpu)) {
                if (cr3 & CR3_L_MODE_RESERVED_BITS)
                        return 1;
        } else {
                if (is_pae(vcpu)) {
                        if (cr3 & CR3_PAE_RESERVED_BITS)
                                return 1;
                        if (is_paging(vcpu) &&
                            !load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3))
                                return 1;
                }
                /*
                 * We don't check reserved bits in nonpae mode, because
                 * this isn't enforced, and VMware depends on this.
                 */
        }

        /*
         * Does the new cr3 value map to physical memory? (Note, we
         * catch an invalid cr3 even in real-mode, because it would
         * cause trouble later on when we turn on paging anyway.)
         *
         * A real CPU would silently accept an invalid cr3 and would
         * attempt to use it - with largely undefined (and often hard
         * to debug) behavior on the guest side.
         */
        if (unlikely(!gfn_to_memslot(vcpu->kvm, cr3 >> PAGE_SHIFT)))
                return 1;
        vcpu->arch.cr3 = cr3;
        __set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);
        vcpu->arch.mmu.new_cr3(vcpu);
        return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_cr3);

int kvm_set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8)
{
        if (cr8 & CR8_RESERVED_BITS)
                return 1;
        if (irqchip_in_kernel(vcpu->kvm))
                kvm_lapic_set_tpr(vcpu, cr8);
        else
                vcpu->arch.cr8 = cr8;
        return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_cr8);

unsigned long kvm_get_cr8(struct kvm_vcpu *vcpu)
{
        if (irqchip_in_kernel(vcpu->kvm))
                return kvm_lapic_get_cr8(vcpu);
        else
                return vcpu->arch.cr8;
}
EXPORT_SYMBOL_GPL(kvm_get_cr8);

static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
{
        switch (dr) {
        case 0 ... 3:
                vcpu->arch.db[dr] = val;
                if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP))
                        vcpu->arch.eff_db[dr] = val;
                break;
        case 4:
                if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
                        return 1; /* #UD */
                /* fall through */
        case 6:
                if (val & 0xffffffff00000000ULL)
                        return -1; /* #GP */
                vcpu->arch.dr6 = (val & DR6_VOLATILE) | DR6_FIXED_1;
                break;
        case 5:
                if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
                        return 1; /* #UD */
                /* fall through */
        default: /* 7 */
                if (val & 0xffffffff00000000ULL)
                        return -1; /* #GP */
                vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1;
                if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) {
                        kvm_x86_ops->set_dr7(vcpu, vcpu->arch.dr7);
                        vcpu->arch.switch_db_regs = (val & DR7_BP_EN_MASK);
                }
                break;
        }

        return 0;
}

int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
{
        int res;

        res = __kvm_set_dr(vcpu, dr, val);
        if (res > 0)
                kvm_queue_exception(vcpu, UD_VECTOR);
        else if (res < 0)
                kvm_inject_gp(vcpu, 0);

        return res;
}
EXPORT_SYMBOL_GPL(kvm_set_dr);

static int _kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
{
        switch (dr) {
        case 0 ... 3:
                *val = vcpu->arch.db[dr];
                break;
        case 4:
                if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
                        return 1;
                /* fall through */
        case 6:
                *val = vcpu->arch.dr6;
                break;
        case 5:
                if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))
                        return 1;
                /* fall through */
        default: /* 7 */
                *val = vcpu->arch.dr7;
                break;
        }

        return 0;
}

int kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
{
        if (_kvm_get_dr(vcpu, dr, val)) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }
        return 0;
}
EXPORT_SYMBOL_GPL(kvm_get_dr);

/*
 * List of msr numbers which we expose to userspace through KVM_GET_MSRS
 * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
 *
 * This list is modified at module load time to reflect the
 * capabilities of the host cpu. This capabilities test skips MSRs that are
 * kvm-specific. Those are put in the beginning of the list.
 */

#define KVM_SAVE_MSRS_BEGIN     9
static u32 msrs_to_save[] = {
        MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,
        MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW,
        HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL,
        HV_X64_MSR_APIC_ASSIST_PAGE, MSR_KVM_ASYNC_PF_EN, MSR_KVM_STEAL_TIME,
        MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
        MSR_STAR,
#ifdef CONFIG_X86_64
        MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
#endif
        MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA
};

static unsigned num_msrs_to_save;

static u32 emulated_msrs[] = {
        MSR_IA32_TSCDEADLINE,
        MSR_IA32_MISC_ENABLE,
        MSR_IA32_MCG_STATUS,
        MSR_IA32_MCG_CTL,
};

static int set_efer(struct kvm_vcpu *vcpu, u64 efer)
{
        u64 old_efer = vcpu->arch.efer;

        if (efer & efer_reserved_bits)
                return 1;

        if (is_paging(vcpu)
            && (vcpu->arch.efer & EFER_LME) != (efer & EFER_LME))
                return 1;

        if (efer & EFER_FFXSR) {
                struct kvm_cpuid_entry2 *feat;

                feat = kvm_find_cpuid_entry(vcpu, 0x80000001, 0);
                if (!feat || !(feat->edx & bit(X86_FEATURE_FXSR_OPT)))
                        return 1;
        }

        if (efer & EFER_SVME) {
                struct kvm_cpuid_entry2 *feat;

                feat = kvm_find_cpuid_entry(vcpu, 0x80000001, 0);
                if (!feat || !(feat->ecx & bit(X86_FEATURE_SVM)))
                        return 1;
        }

        efer &= ~EFER_LMA;
        efer |= vcpu->arch.efer & EFER_LMA;

        kvm_x86_ops->set_efer(vcpu, efer);

        vcpu->arch.mmu.base_role.nxe = (efer & EFER_NX) && !tdp_enabled;

        /* Update reserved bits */
        if ((efer ^ old_efer) & EFER_NX)
                kvm_mmu_reset_context(vcpu);

        return 0;
}

void kvm_enable_efer_bits(u64 mask)
{
       efer_reserved_bits &= ~mask;
}
EXPORT_SYMBOL_GPL(kvm_enable_efer_bits);


/*
 * Writes msr value into into the appropriate "register".
 * Returns 0 on success, non-0 otherwise.
 * Assumes vcpu_load() was already called.
 */
int kvm_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
{
        return kvm_x86_ops->set_msr(vcpu, msr_index, data);
}

/*
 * Adapt set_msr() to msr_io()'s calling convention
 */
static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
{
        return kvm_set_msr(vcpu, index, *data);
}

static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock)
{
        int version;
        int r;
        struct pvclock_wall_clock wc;
        struct timespec boot;

        if (!wall_clock)
                return;

        r = kvm_read_guest(kvm, wall_clock, &version, sizeof(version));
        if (r)
                return;

        if (version & 1)
                ++version;  /* first time write, random junk */

        ++version;

        kvm_write_guest(kvm, wall_clock, &version, sizeof(version));

        /*
         * The guest calculates current wall clock time by adding
         * system time (updated by kvm_guest_time_update below) to the
         * wall clock specified here.  guest system time equals host
         * system time for us, thus we must fill in host boot time here.
         */
        getboottime(&boot);

        wc.sec = boot.tv_sec;
        wc.nsec = boot.tv_nsec;
        wc.version = version;

        kvm_write_guest(kvm, wall_clock, &wc, sizeof(wc));

        version++;
        kvm_write_guest(kvm, wall_clock, &version, sizeof(version));
}

static uint32_t div_frac(uint32_t dividend, uint32_t divisor)
{
        uint32_t quotient, remainder;

        /* Don't try to replace with do_div(), this one calculates
         * "(dividend << 32) / divisor" */
        __asm__ ( "divl %4"
                  : "=a" (quotient), "=d" (remainder)
                  : "0" (0), "1" (dividend), "r" (divisor) );
        return quotient;
}

static void kvm_get_time_scale(uint32_t scaled_khz, uint32_t base_khz,
                               s8 *pshift, u32 *pmultiplier)
{
        uint64_t scaled64;
        int32_t  shift = 0;
        uint64_t tps64;
        uint32_t tps32;

        tps64 = base_khz * 1000LL;
        scaled64 = scaled_khz * 1000LL;
        while (tps64 > scaled64*2 || tps64 & 0xffffffff00000000ULL) {
                tps64 >>= 1;
                shift--;
        }

        tps32 = (uint32_t)tps64;
        while (tps32 <= scaled64 || scaled64 & 0xffffffff00000000ULL) {
                if (scaled64 & 0xffffffff00000000ULL || tps32 & 0x80000000)
                        scaled64 >>= 1;
                else
                        tps32 <<= 1;
                shift++;
        }

        *pshift = shift;
        *pmultiplier = div_frac(scaled64, tps32);

        pr_debug("%s: base_khz %u => %u, shift %d, mul %u\n",
                 __func__, base_khz, scaled_khz, shift, *pmultiplier);
}

static inline u64 get_kernel_ns(void)
{
        struct timespec ts;

        WARN_ON(preemptible());
        ktime_get_ts(&ts);
        monotonic_to_bootbased(&ts);
        return timespec_to_ns(&ts);
}

static DEFINE_PER_CPU(unsigned long, cpu_tsc_khz);
unsigned long max_tsc_khz;

static inline int kvm_tsc_changes_freq(void)
{
        int cpu = get_cpu();
        int ret = !boot_cpu_has(X86_FEATURE_CONSTANT_TSC) &&
                  cpufreq_quick_get(cpu) != 0;
        put_cpu();
        return ret;
}

u64 vcpu_tsc_khz(struct kvm_vcpu *vcpu)
{
        if (vcpu->arch.virtual_tsc_khz)
                return vcpu->arch.virtual_tsc_khz;
        else
                return __this_cpu_read(cpu_tsc_khz);
}

static inline u64 nsec_to_cycles(struct kvm_vcpu *vcpu, u64 nsec)
{
        u64 ret;

        WARN_ON(preemptible());
        if (kvm_tsc_changes_freq())
                printk_once(KERN_WARNING
                 "kvm: unreliable cycle conversion on adjustable rate TSC\n");
        ret = nsec * vcpu_tsc_khz(vcpu);
        do_div(ret, USEC_PER_SEC);
        return ret;
}

static void kvm_init_tsc_catchup(struct kvm_vcpu *vcpu, u32 this_tsc_khz)
{
        /* Compute a scale to convert nanoseconds in TSC cycles */
        kvm_get_time_scale(this_tsc_khz, NSEC_PER_SEC / 1000,
                           &vcpu->arch.tsc_catchup_shift,
                           &vcpu->arch.tsc_catchup_mult);
}

static u64 compute_guest_tsc(struct kvm_vcpu *vcpu, s64 kernel_ns)
{
        u64 tsc = pvclock_scale_delta(kernel_ns-vcpu->arch.last_tsc_nsec,
                                      vcpu->arch.tsc_catchup_mult,
                                      vcpu->arch.tsc_catchup_shift);
        tsc += vcpu->arch.last_tsc_write;
        return tsc;
}

void kvm_write_tsc(struct kvm_vcpu *vcpu, u64 data)
{
        struct kvm *kvm = vcpu->kvm;
        u64 offset, ns, elapsed;
        unsigned long flags;
        s64 sdiff;

        raw_spin_lock_irqsave(&kvm->arch.tsc_write_lock, flags);
        offset = kvm_x86_ops->compute_tsc_offset(vcpu, data);
        ns = get_kernel_ns();
        elapsed = ns - kvm->arch.last_tsc_nsec;
        sdiff = data - kvm->arch.last_tsc_write;
        if (sdiff < 0)
                sdiff = -sdiff;

        /*
         * Special case: close write to TSC within 5 seconds of
         * another CPU is interpreted as an attempt to synchronize
         * The 5 seconds is to accommodate host load / swapping as
         * well as any reset of TSC during the boot process.
         *
         * In that case, for a reliable TSC, we can match TSC offsets,
         * or make a best guest using elapsed value.
         */
        if (sdiff < nsec_to_cycles(vcpu, 5ULL * NSEC_PER_SEC) &&
            elapsed < 5ULL * NSEC_PER_SEC) {
                if (!check_tsc_unstable()) {
                        offset = kvm->arch.last_tsc_offset;
                        pr_debug("kvm: matched tsc offset for %llu\n", data);
                } else {
                        u64 delta = nsec_to_cycles(vcpu, elapsed);
                        offset += delta;
                        pr_debug("kvm: adjusted tsc offset by %llu\n", delta);
                }
                ns = kvm->arch.last_tsc_nsec;
        }
        kvm->arch.last_tsc_nsec = ns;
        kvm->arch.last_tsc_write = data;
        kvm->arch.last_tsc_offset = offset;
        kvm_x86_ops->write_tsc_offset(vcpu, offset);
        raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags);

        /* Reset of TSC must disable overshoot protection below */
        vcpu->arch.hv_clock.tsc_timestamp = 0;
        vcpu->arch.last_tsc_write = data;
        vcpu->arch.last_tsc_nsec = ns;
}
EXPORT_SYMBOL_GPL(kvm_write_tsc);

static int kvm_guest_time_update(struct kvm_vcpu *v)
{
        unsigned long flags;
        struct kvm_vcpu_arch *vcpu = &v->arch;
        void *shared_kaddr;
        unsigned long this_tsc_khz;
        s64 kernel_ns, max_kernel_ns;
        u64 tsc_timestamp;

        /* Keep irq disabled to prevent changes to the clock */
        local_irq_save(flags);
        tsc_timestamp = kvm_x86_ops->read_l1_tsc(v);
        kernel_ns = get_kernel_ns();
        this_tsc_khz = vcpu_tsc_khz(v);
        if (unlikely(this_tsc_khz == 0)) {
                local_irq_restore(flags);
                kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
                return 1;
        }

        /*
         * We may have to catch up the TSC to match elapsed wall clock
         * time for two reasons, even if kvmclock is used.
         *   1) CPU could have been running below the maximum TSC rate
         *   2) Broken TSC compensation resets the base at each VCPU
         *      entry to avoid unknown leaps of TSC even when running
         *      again on the same CPU.  This may cause apparent elapsed
         *      time to disappear, and the guest to stand still or run
         *      very slowly.
         */
        if (vcpu->tsc_catchup) {
                u64 tsc = compute_guest_tsc(v, kernel_ns);
                if (tsc > tsc_timestamp) {
                        kvm_x86_ops->adjust_tsc_offset(v, tsc - tsc_timestamp);
                        tsc_timestamp = tsc;
                }
        }

        local_irq_restore(flags);

        if (!vcpu->time_page)
                return 0;

        /*
         * Time as measured by the TSC may go backwards when resetting the base
         * tsc_timestamp.  The reason for this is that the TSC resolution is
         * higher than the resolution of the other clock scales.  Thus, many
         * possible measurments of the TSC correspond to one measurement of any
         * other clock, and so a spread of values is possible.  This is not a
         * problem for the computation of the nanosecond clock; with TSC rates
         * around 1GHZ, there can only be a few cycles which correspond to one
         * nanosecond value, and any path through this code will inevitably
         * take longer than that.  However, with the kernel_ns value itself,
         * the precision may be much lower, down to HZ granularity.  If the
         * first sampling of TSC against kernel_ns ends in the low part of the
         * range, and the second in the high end of the range, we can get:
         *
         * (TSC - offset_low) * S + kns_old > (TSC - offset_high) * S + kns_new
         *
         * As the sampling errors potentially range in the thousands of cycles,
         * it is possible such a time value has already been observed by the
         * guest.  To protect against this, we must compute the system time as
         * observed by the guest and ensure the new system time is greater.
         */
        max_kernel_ns = 0;
        if (vcpu->hv_clock.tsc_timestamp && vcpu->last_guest_tsc) {
                max_kernel_ns = vcpu->last_guest_tsc -
                                vcpu->hv_clock.tsc_timestamp;
                max_kernel_ns = pvclock_scale_delta(max_kernel_ns,
                                    vcpu->hv_clock.tsc_to_system_mul,
                                    vcpu->hv_clock.tsc_shift);
                max_kernel_ns += vcpu->last_kernel_ns;
        }

        if (unlikely(vcpu->hw_tsc_khz != this_tsc_khz)) {
                kvm_get_time_scale(NSEC_PER_SEC / 1000, this_tsc_khz,
                                   &vcpu->hv_clock.tsc_shift,
                                   &vcpu->hv_clock.tsc_to_system_mul);
                vcpu->hw_tsc_khz = this_tsc_khz;
        }

        if (max_kernel_ns > kernel_ns)
                kernel_ns = max_kernel_ns;

        /* With all the info we got, fill in the values */
        vcpu->hv_clock.tsc_timestamp = tsc_timestamp;
        vcpu->hv_clock.system_time = kernel_ns + v->kvm->arch.kvmclock_offset;
        vcpu->last_kernel_ns = kernel_ns;
        vcpu->last_guest_tsc = tsc_timestamp;
        vcpu->hv_clock.flags = 0;

        /*
         * The interface expects us to write an even number signaling that the
         * update is finished. Since the guest won't see the intermediate
         * state, we just increase by 2 at the end.
         */
        vcpu->hv_clock.version += 2;

        shared_kaddr = kmap_atomic(vcpu->time_page, KM_USER0);

        memcpy(shared_kaddr + vcpu->time_offset, &vcpu->hv_clock,
               sizeof(vcpu->hv_clock));

        kunmap_atomic(shared_kaddr, KM_USER0);

        mark_page_dirty(v->kvm, vcpu->time >> PAGE_SHIFT);
        return 0;
}

static bool msr_mtrr_valid(unsigned msr)
{
        switch (msr) {
        case 0x200 ... 0x200 + 2 * KVM_NR_VAR_MTRR - 1:
        case MSR_MTRRfix64K_00000:
        case MSR_MTRRfix16K_80000:
        case MSR_MTRRfix16K_A0000:
        case MSR_MTRRfix4K_C0000:
        case MSR_MTRRfix4K_C8000:
        case MSR_MTRRfix4K_D0000:
        case MSR_MTRRfix4K_D8000:
        case MSR_MTRRfix4K_E0000:
        case MSR_MTRRfix4K_E8000:
        case MSR_MTRRfix4K_F0000:
        case MSR_MTRRfix4K_F8000:
        case MSR_MTRRdefType:
        case MSR_IA32_CR_PAT:
                return true;
        case 0x2f8:
                return true;
        }
        return false;
}

static bool valid_pat_type(unsigned t)
{
        return t < 8 && (1 << t) & 0xf3; /* 0, 1, 4, 5, 6, 7 */
}

static bool valid_mtrr_type(unsigned t)
{
        return t < 8 && (1 << t) & 0x73; /* 0, 1, 4, 5, 6 */
}

static bool mtrr_valid(struct kvm_vcpu *vcpu, u32 msr, u64 data)
{
        int i;

        if (!msr_mtrr_valid(msr))
                return false;

        if (msr == MSR_IA32_CR_PAT) {
                for (i = 0; i < 8; i++)
                        if (!valid_pat_type((data >> (i * 8)) & 0xff))
                                return false;
                return true;
        } else if (msr == MSR_MTRRdefType) {
                if (data & ~0xcff)
                        return false;
                return valid_mtrr_type(data & 0xff);
        } else if (msr >= MSR_MTRRfix64K_00000 && msr <= MSR_MTRRfix4K_F8000) {
                for (i = 0; i < 8 ; i++)
                        if (!valid_mtrr_type((data >> (i * 8)) & 0xff))
                                return false;
                return true;
        }

        /* variable MTRRs */
        return valid_mtrr_type(data & 0xff);
}

static int set_msr_mtrr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
{
        u64 *p = (u64 *)&vcpu->arch.mtrr_state.fixed_ranges;

        if (!mtrr_valid(vcpu, msr, data))
                return 1;

        if (msr == MSR_MTRRdefType) {
                vcpu->arch.mtrr_state.def_type = data;
                vcpu->arch.mtrr_state.enabled = (data & 0xc00) >> 10;
        } else if (msr == MSR_MTRRfix64K_00000)
                p[0] = data;
        else if (msr == MSR_MTRRfix16K_80000 || msr == MSR_MTRRfix16K_A0000)
                p[1 + msr - MSR_MTRRfix16K_80000] = data;
        else if (msr >= MSR_MTRRfix4K_C0000 && msr <= MSR_MTRRfix4K_F8000)
                p[3 + msr - MSR_MTRRfix4K_C0000] = data;
        else if (msr == MSR_IA32_CR_PAT)
                vcpu->arch.pat = data;
        else {  /* Variable MTRRs */
                int idx, is_mtrr_mask;
                u64 *pt;

                idx = (msr - 0x200) / 2;
                is_mtrr_mask = msr - 0x200 - 2 * idx;
                if (!is_mtrr_mask)
                        pt =
                          (u64 *)&vcpu->arch.mtrr_state.var_ranges[idx].base_lo;
                else
                        pt =
                          (u64 *)&vcpu->arch.mtrr_state.var_ranges[idx].mask_lo;
                *pt = data;
        }

        kvm_mmu_reset_context(vcpu);
        return 0;
}

static int set_msr_mce(struct kvm_vcpu *vcpu, u32 msr, u64 data)
{
        u64 mcg_cap = vcpu->arch.mcg_cap;
        unsigned bank_num = mcg_cap & 0xff;

        switch (msr) {
        case MSR_IA32_MCG_STATUS:
                vcpu->arch.mcg_status = data;
                break;
        case MSR_IA32_MCG_CTL:
                if (!(mcg_cap & MCG_CTL_P))
                        return 1;
                if (data != 0 && data != ~(u64)0)
                        return -1;
                vcpu->arch.mcg_ctl = data;
                break;
        default:
                if (msr >= MSR_IA32_MC0_CTL &&
                    msr < MSR_IA32_MC0_CTL + 4 * bank_num) {
                        u32 offset = msr - MSR_IA32_MC0_CTL;
                        /* only 0 or all 1s can be written to IA32_MCi_CTL
                         * some Linux kernels though clear bit 10 in bank 4 to
                         * workaround a BIOS/GART TBL issue on AMD K8s, ignore
                         * this to avoid an uncatched #GP in the guest
                         */
                        if ((offset & 0x3) == 0 &&
                            data != 0 && (data | (1 << 10)) != ~(u64)0)
                                return -1;
                        vcpu->arch.mce_banks[offset] = data;
                        break;
                }
                return 1;
        }
        return 0;
}

static int xen_hvm_config(struct kvm_vcpu *vcpu, u64 data)
{
        struct kvm *kvm = vcpu->kvm;
        int lm = is_long_mode(vcpu);
        u8 *blob_addr = lm ? (u8 *)(long)kvm->arch.xen_hvm_config.blob_addr_64
                : (u8 *)(long)kvm->arch.xen_hvm_config.blob_addr_32;
        u8 blob_size = lm ? kvm->arch.xen_hvm_config.blob_size_64
                : kvm->arch.xen_hvm_config.blob_size_32;
        u32 page_num = data & ~PAGE_MASK;
        u64 page_addr = data & PAGE_MASK;
        u8 *page;
        int r;

        r = -E2BIG;
        if (page_num >= blob_size)
                goto out;
        r = -ENOMEM;
        page = kzalloc(PAGE_SIZE, GFP_KERNEL);
        if (!page)
                goto out;
        r = -EFAULT;
        if (copy_from_user(page, blob_addr + (page_num * PAGE_SIZE), PAGE_SIZE))
                goto out_free;
        if (kvm_write_guest(kvm, page_addr, page, PAGE_SIZE))
                goto out_free;
        r = 0;
out_free:
        kfree(page);
out:
        return r;
}

static bool kvm_hv_hypercall_enabled(struct kvm *kvm)
{
        return kvm->arch.hv_hypercall & HV_X64_MSR_HYPERCALL_ENABLE;
}

static bool kvm_hv_msr_partition_wide(u32 msr)
{
        bool r = false;
        switch (msr) {
        case HV_X64_MSR_GUEST_OS_ID:
        case HV_X64_MSR_HYPERCALL:
                r = true;
                break;
        }

        return r;
}

static int set_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data)
{
        struct kvm *kvm = vcpu->kvm;

        switch (msr) {
        case HV_X64_MSR_GUEST_OS_ID:
                kvm->arch.hv_guest_os_id = data;
                /* setting guest os id to zero disables hypercall page */
                if (!kvm->arch.hv_guest_os_id)
                        kvm->arch.hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
                break;
        case HV_X64_MSR_HYPERCALL: {
                u64 gfn;
                unsigned long addr;
                u8 instructions[4];

                /* if guest os id is not set hypercall should remain disabled */
                if (!kvm->arch.hv_guest_os_id)
                        break;
                if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
                        kvm->arch.hv_hypercall = data;
                        break;
                }
                gfn = data >> HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT;
                addr = gfn_to_hva(kvm, gfn);
                if (kvm_is_error_hva(addr))
                        return 1;
                kvm_x86_ops->patch_hypercall(vcpu, instructions);
                ((unsigned char *)instructions)[3] = 0xc3; /* ret */
                if (__copy_to_user((void __user *)addr, instructions, 4))
                        return 1;
                kvm->arch.hv_hypercall = data;
                break;
        }
        default:
                pr_unimpl(vcpu, "HYPER-V unimplemented wrmsr: 0x%x "
                          "data 0x%llx\n", msr, data);
                return 1;
        }
        return 0;
}

static int set_msr_hyperv(struct kvm_vcpu *vcpu, u32 msr, u64 data)
{
        switch (msr) {
        case HV_X64_MSR_APIC_ASSIST_PAGE: {
                unsigned long addr;

                if (!(data & HV_X64_MSR_APIC_ASSIST_PAGE_ENABLE)) {
                        vcpu->arch.hv_vapic = data;
                        break;
                }
                addr = gfn_to_hva(vcpu->kvm, data >>
                                  HV_X64_MSR_APIC_ASSIST_PAGE_ADDRESS_SHIFT);
                if (kvm_is_error_hva(addr))
                        return 1;
                if (__clear_user((void __user *)addr, PAGE_SIZE))
                        return 1;
                vcpu->arch.hv_vapic = data;
                break;
        }
        case HV_X64_MSR_EOI:
                return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
        case HV_X64_MSR_ICR:
                return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
        case HV_X64_MSR_TPR:
                return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
        default:
                pr_unimpl(vcpu, "HYPER-V unimplemented wrmsr: 0x%x "
                          "data 0x%llx\n", msr, data);
                return 1;
        }

        return 0;
}

static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data)
{
        gpa_t gpa = data & ~0x3f;

        /* Bits 2:5 are resrved, Should be zero */
        if (data & 0x3c)
                return 1;

        vcpu->arch.apf.msr_val = data;

        if (!(data & KVM_ASYNC_PF_ENABLED)) {
                kvm_clear_async_pf_completion_queue(vcpu);
                kvm_async_pf_hash_reset(vcpu);
                return 0;
        }

        if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.apf.data, gpa))
                return 1;

        vcpu->arch.apf.send_user_only = !(data & KVM_ASYNC_PF_SEND_ALWAYS);
        kvm_async_pf_wakeup_all(vcpu);
        return 0;
}

static void kvmclock_reset(struct kvm_vcpu *vcpu)
{
        if (vcpu->arch.time_page) {
                kvm_release_page_dirty(vcpu->arch.time_page);
                vcpu->arch.time_page = NULL;
        }
}

static void accumulate_steal_time(struct kvm_vcpu *vcpu)
{
        u64 delta;

        if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
                return;

        delta = current->sched_info.run_delay - vcpu->arch.st.last_steal;
        vcpu->arch.st.last_steal = current->sched_info.run_delay;
        vcpu->arch.st.accum_steal = delta;
}

static void record_steal_time(struct kvm_vcpu *vcpu)
{
        if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
                return;

        if (unlikely(kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
                &vcpu->arch.st.steal, sizeof(struct kvm_steal_time))))
                return;

        vcpu->arch.st.steal.steal += vcpu->arch.st.accum_steal;
        vcpu->arch.st.steal.version += 2;
        vcpu->arch.st.accum_steal = 0;

        kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
                &vcpu->arch.st.steal, sizeof(struct kvm_steal_time));
}

int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
{
        switch (msr) {
        case MSR_EFER:
                return set_efer(vcpu, data);
        case MSR_K7_HWCR:
                data &= ~(u64)0x40;     /* ignore flush filter disable */
                data &= ~(u64)0x100;    /* ignore ignne emulation enable */
                if (data != 0) {
                        pr_unimpl(vcpu, "unimplemented HWCR wrmsr: 0x%llx\n",
                                data);
                        return 1;
                }
                break;
        case MSR_FAM10H_MMIO_CONF_BASE:
                if (data != 0) {
                        pr_unimpl(vcpu, "unimplemented MMIO_CONF_BASE wrmsr: "
                                "0x%llx\n", data);
                        return 1;
                }
                break;
        case MSR_AMD64_NB_CFG:
                break;
        case MSR_IA32_DEBUGCTLMSR:
                if (!data) {
                        /* We support the non-activated case already */
                        break;
                } else if (data & ~(DEBUGCTLMSR_LBR | DEBUGCTLMSR_BTF)) {
                        /* Values other than LBR and BTF are vendor-specific,
                           thus reserved and should throw a #GP */
                        return 1;
                }
                pr_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n",
                        __func__, data);
                break;
        case MSR_IA32_UCODE_REV:
        case MSR_IA32_UCODE_WRITE:
        case MSR_VM_HSAVE_PA:
        case MSR_AMD64_PATCH_LOADER:
                break;
        case 0x200 ... 0x2ff:
                return set_msr_mtrr(vcpu, msr, data);
        case MSR_IA32_APICBASE:
                kvm_set_apic_base(vcpu, data);
                break;
        case APIC_BASE_MSR ... APIC_BASE_MSR + 0x3ff:
                return kvm_x2apic_msr_write(vcpu, msr, data);
        case MSR_IA32_TSCDEADLINE:
                kvm_set_lapic_tscdeadline_msr(vcpu, data);
                break;
        case MSR_IA32_MISC_ENABLE:
                vcpu->arch.ia32_misc_enable_msr = data;
                break;
        case MSR_KVM_WALL_CLOCK_NEW:
        case MSR_KVM_WALL_CLOCK:
                vcpu->kvm->arch.wall_clock = data;
                kvm_write_wall_clock(vcpu->kvm, data);
                break;
        case MSR_KVM_SYSTEM_TIME_NEW:
        case MSR_KVM_SYSTEM_TIME: {
                kvmclock_reset(vcpu);

                vcpu->arch.time = data;
                kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);

                /* we verify if the enable bit is set... */
                if (!(data & 1))
                        break;

                /* ...but clean it before doing the actual write */
                vcpu->arch.time_offset = data & ~(PAGE_MASK | 1);

                vcpu->arch.time_page =
                                gfn_to_page(vcpu->kvm, data >> PAGE_SHIFT);

                if (is_error_page(vcpu->arch.time_page)) {
                        kvm_release_page_clean(vcpu->arch.time_page);
                        vcpu->arch.time_page = NULL;
                }
                break;
        }
        case MSR_KVM_ASYNC_PF_EN:
                if (kvm_pv_enable_async_pf(vcpu, data))
                        return 1;
                break;
        case MSR_KVM_STEAL_TIME:

                if (unlikely(!sched_info_on()))
                        return 1;

                if (data & KVM_STEAL_RESERVED_MASK)
                        return 1;

                if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.st.stime,
                                                        data & KVM_STEAL_VALID_BITS))
                        return 1;

                vcpu->arch.st.msr_val = data;

                if (!(data & KVM_MSR_ENABLED))
                        break;

                vcpu->arch.st.last_steal = current->sched_info.run_delay;

                preempt_disable();
                accumulate_steal_time(vcpu);
                preempt_enable();

                kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu);

                break;

        case MSR_IA32_MCG_CTL:
        case MSR_IA32_MCG_STATUS:
        case MSR_IA32_MC0_CTL ... MSR_IA32_MC0_CTL + 4 * KVM_MAX_MCE_BANKS - 1:
                return set_msr_mce(vcpu, msr, data);

        /* Performance counters are not protected by a CPUID bit,
         * so we should check all of them in the generic path for the sake of
         * cross vendor migration.
         * Writing a zero into the event select MSRs disables them,
         * which we perfectly emulate ;-). Any other value should be at least
         * reported, some guests depend on them.
         */
        case MSR_P6_EVNTSEL0:
        case MSR_P6_EVNTSEL1:
        case MSR_K7_EVNTSEL0:
        case MSR_K7_EVNTSEL1:
        case MSR_K7_EVNTSEL2:
        case MSR_K7_EVNTSEL3:
                if (data != 0)
                        pr_unimpl(vcpu, "unimplemented perfctr wrmsr: "
                                "0x%x data 0x%llx\n", msr, data);
                break;
        /* at least RHEL 4 unconditionally writes to the perfctr registers,
         * so we ignore writes to make it happy.
         */
        case MSR_P6_PERFCTR0:
        case MSR_P6_PERFCTR1:
        case MSR_K7_PERFCTR0:
        case MSR_K7_PERFCTR1:
        case MSR_K7_PERFCTR2:
        case MSR_K7_PERFCTR3:
                pr_unimpl(vcpu, "unimplemented perfctr wrmsr: "
                        "0x%x data 0x%llx\n", msr, data);
                break;
        case MSR_K7_CLK_CTL:
                /*
                 * Ignore all writes to this no longer documented MSR.
                 * Writes are only relevant for old K7 processors,
                 * all pre-dating SVM, but a recommended workaround from
                 * AMD for these chips. It is possible to speicify the
                 * affected processor models on the command line, hence
                 * the need to ignore the workaround.
                 */
                break;
        case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15:
                if (kvm_hv_msr_partition_wide(msr)) {
                        int r;
                        mutex_lock(&vcpu->kvm->lock);
                        r = set_msr_hyperv_pw(vcpu, msr, data);
                        mutex_unlock(&vcpu->kvm->lock);
                        return r;
                } else
                        return set_msr_hyperv(vcpu, msr, data);
                break;
        case MSR_IA32_BBL_CR_CTL3:
                /* Drop writes to this legacy MSR -- see rdmsr
                 * counterpart for further detail.
                 */
                pr_unimpl(vcpu, "ignored wrmsr: 0x%x data %llx\n", msr, data);
                break;
        default:
                if (msr && (msr == vcpu->kvm->arch.xen_hvm_config.msr))
                        return xen_hvm_config(vcpu, data);
                if (!ignore_msrs) {
                        pr_unimpl(vcpu, "unhandled wrmsr: 0x%x data %llx\n",
                                msr, data);
                        return 1;
                } else {
                        pr_unimpl(vcpu, "ignored wrmsr: 0x%x data %llx\n",
                                msr, data);
                        break;
                }
        }
        return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_msr_common);


/*
 * Reads an msr value (of 'msr_index') into 'pdata'.
 * Returns 0 on success, non-0 otherwise.
 * Assumes vcpu_load() was already called.
 */
int kvm_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
{
        return kvm_x86_ops->get_msr(vcpu, msr_index, pdata);
}

static int get_msr_mtrr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
{
        u64 *p = (u64 *)&vcpu->arch.mtrr_state.fixed_ranges;

        if (!msr_mtrr_valid(msr))
                return 1;

        if (msr == MSR_MTRRdefType)
                *pdata = vcpu->arch.mtrr_state.def_type +
                         (vcpu->arch.mtrr_state.enabled << 10);
        else if (msr == MSR_MTRRfix64K_00000)
                *pdata = p[0];
        else if (msr == MSR_MTRRfix16K_80000 || msr == MSR_MTRRfix16K_A0000)
                *pdata = p[1 + msr - MSR_MTRRfix16K_80000];
        else if (msr >= MSR_MTRRfix4K_C0000 && msr <= MSR_MTRRfix4K_F8000)
                *pdata = p[3 + msr - MSR_MTRRfix4K_C0000];
        else if (msr == MSR_IA32_CR_PAT)
                *pdata = vcpu->arch.pat;
        else {  /* Variable MTRRs */
                int idx, is_mtrr_mask;
                u64 *pt;

                idx = (msr - 0x200) / 2;
                is_mtrr_mask = msr - 0x200 - 2 * idx;
                if (!is_mtrr_mask)
                        pt =
                          (u64 *)&vcpu->arch.mtrr_state.var_ranges[idx].base_lo;
                else
                        pt =
                          (u64 *)&vcpu->arch.mtrr_state.var_ranges[idx].mask_lo;
                *pdata = *pt;
        }

        return 0;
}

static int get_msr_mce(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
{
        u64 data;
        u64 mcg_cap = vcpu->arch.mcg_cap;
        unsigned bank_num = mcg_cap & 0xff;

        switch (msr) {
        case MSR_IA32_P5_MC_ADDR:
        case MSR_IA32_P5_MC_TYPE:
                data = 0;
                break;
        case MSR_IA32_MCG_CAP:
                data = vcpu->arch.mcg_cap;
                break;
        case MSR_IA32_MCG_CTL:
                if (!(mcg_cap & MCG_CTL_P))
                        return 1;
                data = vcpu->arch.mcg_ctl;
                break;
        case MSR_IA32_MCG_STATUS:
                data = vcpu->arch.mcg_status;
                break;
        default:
                if (msr >= MSR_IA32_MC0_CTL &&
                    msr < MSR_IA32_MC0_CTL + 4 * bank_num) {
                        u32 offset = msr - MSR_IA32_MC0_CTL;
                        data = vcpu->arch.mce_banks[offset];
                        break;
                }
                return 1;
        }
        *pdata = data;
        return 0;
}

static int get_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
{
        u64 data = 0;
        struct kvm *kvm = vcpu->kvm;

        switch (msr) {
        case HV_X64_MSR_GUEST_OS_ID:
                data = kvm->arch.hv_guest_os_id;
                break;
        case HV_X64_MSR_HYPERCALL:
                data = kvm->arch.hv_hypercall;
                break;
        default:
                pr_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
                return 1;
        }

        *pdata = data;
        return 0;
}

static int get_msr_hyperv(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
{
        u64 data = 0;

        switch (msr) {
        case HV_X64_MSR_VP_INDEX: {
                int r;
                struct kvm_vcpu *v;
                kvm_for_each_vcpu(r, v, vcpu->kvm)
                        if (v == vcpu)
                                data = r;
                break;
        }
        case HV_X64_MSR_EOI:
                return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);
        case HV_X64_MSR_ICR:
                return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);
        case HV_X64_MSR_TPR:
                return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);
        case HV_X64_MSR_APIC_ASSIST_PAGE:
                data = vcpu->arch.hv_vapic;
                break;
        default:
                pr_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
                return 1;
        }
        *pdata = data;
        return 0;
}

int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
{
        u64 data;

        switch (msr) {
        case MSR_IA32_PLATFORM_ID:
        case MSR_IA32_EBL_CR_POWERON:
        case MSR_IA32_DEBUGCTLMSR:
        case MSR_IA32_LASTBRANCHFROMIP:
        case MSR_IA32_LASTBRANCHTOIP:
        case MSR_IA32_LASTINTFROMIP:
        case MSR_IA32_LASTINTTOIP:
        case MSR_K8_SYSCFG:
        case MSR_K7_HWCR:
        case MSR_VM_HSAVE_PA:
        case MSR_P6_PERFCTR0:
        case MSR_P6_PERFCTR1:
        case MSR_P6_EVNTSEL0:
        case MSR_P6_EVNTSEL1:
        case MSR_K7_EVNTSEL0:
        case MSR_K7_PERFCTR0:
        case MSR_K8_INT_PENDING_MSG:
        case MSR_AMD64_NB_CFG:
        case MSR_FAM10H_MMIO_CONF_BASE:
                data = 0;
                break;
        case MSR_IA32_UCODE_REV:
                data = 0x100000000ULL;
                break;
        case MSR_MTRRcap:
                data = 0x500 | KVM_NR_VAR_MTRR;
                break;
        case 0x200 ... 0x2ff:
                return get_msr_mtrr(vcpu, msr, pdata);
        case 0xcd: /* fsb frequency */
                data = 3;
                break;
                /*
                 * MSR_EBC_FREQUENCY_ID
                 * Conservative value valid for even the basic CPU models.
                 * Models 0,1: 000 in bits 23:21 indicating a bus speed of
                 * 100MHz, model 2 000 in bits 18:16 indicating 100MHz,
                 * and 266MHz for model 3, or 4. Set Core Clock
                 * Frequency to System Bus Frequency Ratio to 1 (bits
                 * 31:24) even though these are only valid for CPU
                 * models > 2, however guests may end up dividing or
                 * multiplying by zero otherwise.
                 */
        case MSR_EBC_FREQUENCY_ID:
                data = 1 << 24;
                break;
        case MSR_IA32_APICBASE:
                data = kvm_get_apic_base(vcpu);
                break;
        case APIC_BASE_MSR ... APIC_BASE_MSR + 0x3ff:
                return kvm_x2apic_msr_read(vcpu, msr, pdata);
                break;
        case MSR_IA32_TSCDEADLINE:
                data = kvm_get_lapic_tscdeadline_msr(vcpu);
                break;
        case MSR_IA32_MISC_ENABLE:
                data = vcpu->arch.ia32_misc_enable_msr;
                break;
        case MSR_IA32_PERF_STATUS:
                /* TSC increment by tick */
                data = 1000ULL;
                /* CPU multiplier */
                data |= (((uint64_t)4ULL) << 40);
                break;
        case MSR_EFER:
                data = vcpu->arch.efer;
                break;
        case MSR_KVM_WALL_CLOCK:
        case MSR_KVM_WALL_CLOCK_NEW:
                data = vcpu->kvm->arch.wall_clock;
                break;
        case MSR_KVM_SYSTEM_TIME:
        case MSR_KVM_SYSTEM_TIME_NEW:
                data = vcpu->arch.time;
                break;
        case MSR_KVM_ASYNC_PF_EN:
                data = vcpu->arch.apf.msr_val;
                break;
        case MSR_KVM_STEAL_TIME:
                data = vcpu->arch.st.msr_val;
                break;
        case MSR_IA32_P5_MC_ADDR:
        case MSR_IA32_P5_MC_TYPE:
        case MSR_IA32_MCG_CAP:
        case MSR_IA32_MCG_CTL:
        case MSR_IA32_MCG_STATUS:
        case MSR_IA32_MC0_CTL ... MSR_IA32_MC0_CTL + 4 * KVM_MAX_MCE_BANKS - 1:
                return get_msr_mce(vcpu, msr, pdata);
        case MSR_K7_CLK_CTL:
                /*
                 * Provide expected ramp-up count for K7. All other
                 * are set to zero, indicating minimum divisors for
                 * every field.
                 *
                 * This prevents guest kernels on AMD host with CPU
                 * type 6, model 8 and higher from exploding due to
                 * the rdmsr failing.
                 */
                data = 0x20000000;
                break;
        case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15:
                if (kvm_hv_msr_partition_wide(msr)) {
                        int r;
                        mutex_lock(&vcpu->kvm->lock);
                        r = get_msr_hyperv_pw(vcpu, msr, pdata);
                        mutex_unlock(&vcpu->kvm->lock);
                        return r;
                } else
                        return get_msr_hyperv(vcpu, msr, pdata);
                break;
        case MSR_IA32_BBL_CR_CTL3:
                /* This legacy MSR exists but isn't fully documented in current
                 * silicon.  It is however accessed by winxp in very narrow
                 * scenarios where it sets bit #19, itself documented as
                 * a "reserved" bit.  Best effort attempt to source coherent
                 * read data here should the balance of the register be
                 * interpreted by the guest:
                 *
                 * L2 cache control register 3: 64GB range, 256KB size,
                 * enabled, latency 0x1, configured
                 */
                data = 0xbe702111;
                break;
        default:
                if (!ignore_msrs) {
                        pr_unimpl(vcpu, "unhandled rdmsr: 0x%x\n", msr);
                        return 1;
                } else {
                        pr_unimpl(vcpu, "ignored rdmsr: 0x%x\n", msr);
                        data = 0;
                }
                break;
        }
        *pdata = data;
        return 0;
}
EXPORT_SYMBOL_GPL(kvm_get_msr_common);

/*
 * Read or write a bunch of msrs. All parameters are kernel addresses.
 *
 * @return number of msrs set successfully.
 */

static int __msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs *msrs,
                    struct kvm_msr_entry *entries,
                    int (*do_msr)(struct kvm_vcpu *vcpu,
                                  unsigned index, u64 *data))
{
        int i, idx;

        idx = srcu_read_lock(&vcpu->kvm->srcu);
        for (i = 0; i < msrs->nmsrs; ++i)
                if (do_msr(vcpu, entries[i].index, &entries[i].data))
                        break;
        srcu_read_unlock(&vcpu->kvm->srcu, idx);

        return i;
}

/*
 * Read or write a bunch of msrs. Parameters are user addresses.
 *
 * @return number of msrs set successfully.
 */
static int msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs __user *user_msrs,
                  int (*do_msr)(struct kvm_vcpu *vcpu,
                                unsigned index, u64 *data),
                  int writeback)
{
        struct kvm_msrs msrs;
        struct kvm_msr_entry *entries;
        int r, n;
        unsigned size;

        r = -EFAULT;
        if (copy_from_user(&msrs, user_msrs, sizeof msrs))
                goto out;

        r = -E2BIG;
        if (msrs.nmsrs >= MAX_IO_MSRS)
                goto out;

        r = -ENOMEM;
        size = sizeof(struct kvm_msr_entry) * msrs.nmsrs;
        entries = kmalloc(size, GFP_KERNEL);
        if (!entries)
                goto out;

        r = -EFAULT;
        if (copy_from_user(entries, user_msrs->entries, size))
                goto out_free;

        r = n = __msr_io(vcpu, &msrs, entries, do_msr);
        if (r < 0)
                goto out_free;

        r = -EFAULT;
        if (writeback && copy_to_user(user_msrs->entries, entries, size))
                goto out_free;

        r = n;

out_free:
        kfree(entries);
out:
        return r;
}

int kvm_dev_ioctl_check_extension(long ext)
{
        int r;

        switch (ext) {
        case KVM_CAP_IRQCHIP:
        case KVM_CAP_HLT:
        case KVM_CAP_MMU_SHADOW_CACHE_CONTROL:
        case KVM_CAP_SET_TSS_ADDR:
        case KVM_CAP_EXT_CPUID:
        case KVM_CAP_CLOCKSOURCE:
        case KVM_CAP_PIT:
        case KVM_CAP_NOP_IO_DELAY:
        case KVM_CAP_MP_STATE:
        case KVM_CAP_SYNC_MMU:
        case KVM_CAP_USER_NMI:
        case KVM_CAP_REINJECT_CONTROL:
        case KVM_CAP_IRQ_INJECT_STATUS:
        case KVM_CAP_ASSIGN_DEV_IRQ:
        case KVM_CAP_IRQFD:
        case KVM_CAP_IOEVENTFD:
        case KVM_CAP_PIT2:
        case KVM_CAP_PIT_STATE2:
        case KVM_CAP_SET_IDENTITY_MAP_ADDR:
        case KVM_CAP_XEN_HVM:
        case KVM_CAP_ADJUST_CLOCK:
        case KVM_CAP_VCPU_EVENTS:
        case KVM_CAP_HYPERV:
        case KVM_CAP_HYPERV_VAPIC:
        case KVM_CAP_HYPERV_SPIN:
        case KVM_CAP_PCI_SEGMENT:
        case KVM_CAP_DEBUGREGS:
        case KVM_CAP_X86_ROBUST_SINGLESTEP:
        case KVM_CAP_XSAVE:
        case KVM_CAP_ASYNC_PF:
        case KVM_CAP_GET_TSC_KHZ:
                r = 1;
                break;
        case KVM_CAP_COALESCED_MMIO:
                r = KVM_COALESCED_MMIO_PAGE_OFFSET;
                break;
        case KVM_CAP_VAPIC:
                r = !kvm_x86_ops->cpu_has_accelerated_tpr();
                break;
        case KVM_CAP_NR_VCPUS:
                r = KVM_SOFT_MAX_VCPUS;
                break;
        case KVM_CAP_MAX_VCPUS:
                r = KVM_MAX_VCPUS;
                break;
        case KVM_CAP_NR_MEMSLOTS:
                r = KVM_MEMORY_SLOTS;
                break;
        case KVM_CAP_PV_MMU:    /* obsolete */
                r = 0;
                break;
        case KVM_CAP_IOMMU:
                r = iommu_present(&pci_bus_type);
                break;
        case KVM_CAP_MCE:
                r = KVM_MAX_MCE_BANKS;
                break;
        case KVM_CAP_XCRS:
                r = cpu_has_xsave;
                break;
        case KVM_CAP_TSC_CONTROL:
                r = kvm_has_tsc_control;
                break;
        case KVM_CAP_TSC_DEADLINE_TIMER:
                r = boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER);
                break;
        default:
                r = 0;
                break;
        }
        return r;

}

long kvm_arch_dev_ioctl(struct file *filp,
                        unsigned int ioctl, unsigned long arg)
{
        void __user *argp = (void __user *)arg;
        long r;

        switch (ioctl) {
        case KVM_GET_MSR_INDEX_LIST: {
                struct kvm_msr_list __user *user_msr_list = argp;
                struct kvm_msr_list msr_list;
                unsigned n;

                r = -EFAULT;
                if (copy_from_user(&msr_list, user_msr_list, sizeof msr_list))
                        goto out;
                n = msr_list.nmsrs;
                msr_list.nmsrs = num_msrs_to_save + ARRAY_SIZE(emulated_msrs);
                if (copy_to_user(user_msr_list, &msr_list, sizeof msr_list))
                        goto out;
                r = -E2BIG;
                if (n < msr_list.nmsrs)
                        goto out;
                r = -EFAULT;
                if (copy_to_user(user_msr_list->indices, &msrs_to_save,
                                 num_msrs_to_save * sizeof(u32)))
                        goto out;
                if (copy_to_user(user_msr_list->indices + num_msrs_to_save,
                                 &emulated_msrs,
                                 ARRAY_SIZE(emulated_msrs) * sizeof(u32)))
                        goto out;
                r = 0;
                break;
        }
        case KVM_GET_SUPPORTED_CPUID: {
                struct kvm_cpuid2 __user *cpuid_arg = argp;
                struct kvm_cpuid2 cpuid;

                r = -EFAULT;
                if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid))
                        goto out;
                r = kvm_dev_ioctl_get_supported_cpuid(&cpuid,
                                                      cpuid_arg->entries);
                if (r)
                        goto out;

                r = -EFAULT;
                if (copy_to_user(cpuid_arg, &cpuid, sizeof cpuid))
                        goto out;
                r = 0;
                break;
        }
        case KVM_X86_GET_MCE_CAP_SUPPORTED: {
                u64 mce_cap;

                mce_cap = KVM_MCE_CAP_SUPPORTED;
                r = -EFAULT;
                if (copy_to_user(argp, &mce_cap, sizeof mce_cap))
                        goto out;
                r = 0;
                break;
        }
        default:
                r = -EINVAL;
        }
out:
        return r;
}

static void wbinvd_ipi(void *garbage)
{
        wbinvd();
}

static bool need_emulate_wbinvd(struct kvm_vcpu *vcpu)
{
        return vcpu->kvm->arch.iommu_domain &&
                !(vcpu->kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY);
}

void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
        /* Address WBINVD may be executed by guest */
        if (need_emulate_wbinvd(vcpu)) {
                if (kvm_x86_ops->has_wbinvd_exit())
                        cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask);
                else if (vcpu->cpu != -1 && vcpu->cpu != cpu)
                        smp_call_function_single(vcpu->cpu,
                                        wbinvd_ipi, NULL, 1);
        }

        kvm_x86_ops->vcpu_load(vcpu, cpu);
        if (unlikely(vcpu->cpu != cpu) || check_tsc_unstable()) {
                /* Make sure TSC doesn't go backwards */
                s64 tsc_delta;
                u64 tsc;

                tsc = kvm_x86_ops->read_l1_tsc(vcpu);
                tsc_delta = !vcpu->arch.last_guest_tsc ? 0 :
                             tsc - vcpu->arch.last_guest_tsc;

                if (tsc_delta < 0)
                        mark_tsc_unstable("KVM discovered backwards TSC");
                if (check_tsc_unstable()) {
                        kvm_x86_ops->adjust_tsc_offset(vcpu, -tsc_delta);
                        vcpu->arch.tsc_catchup = 1;
                }
                kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
                if (vcpu->cpu != cpu)
                        kvm_migrate_timers(vcpu);
                vcpu->cpu = cpu;
        }

        accumulate_steal_time(vcpu);
        kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu);
}

void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
        kvm_x86_ops->vcpu_put(vcpu);
        kvm_put_guest_fpu(vcpu);
        vcpu->arch.last_guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu);
}

static int is_efer_nx(void)
{
        unsigned long long efer = 0;

        rdmsrl_safe(MSR_EFER, &efer);
        return efer & EFER_NX;
}

static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
{
        int i;
        struct kvm_cpuid_entry2 *e, *entry;

        entry = NULL;
        for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
                e = &vcpu->arch.cpuid_entries[i];
                if (e->function == 0x80000001) {
                        entry = e;
                        break;
                }
        }
        if (entry && (entry->edx & (1 << 20)) && !is_efer_nx()) {
                entry->edx &= ~(1 << 20);
                printk(KERN_INFO "kvm: guest NX capability removed\n");
        }
}

/* when an old userspace process fills a new kernel module */
static int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
                                    struct kvm_cpuid *cpuid,
                                    struct kvm_cpuid_entry __user *entries)
{
        int r, i;
        struct kvm_cpuid_entry *cpuid_entries;

        r = -E2BIG;
        if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
                goto out;
        r = -ENOMEM;
        cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent);
        if (!cpuid_entries)
                goto out;
        r = -EFAULT;
        if (copy_from_user(cpuid_entries, entries,
                           cpuid->nent * sizeof(struct kvm_cpuid_entry)))
                goto out_free;
        for (i = 0; i < cpuid->nent; i++) {
                vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
                vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
                vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
                vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
                vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
                vcpu->arch.cpuid_entries[i].index = 0;
                vcpu->arch.cpuid_entries[i].flags = 0;
                vcpu->arch.cpuid_entries[i].padding[0] = 0;
                vcpu->arch.cpuid_entries[i].padding[1] = 0;
                vcpu->arch.cpuid_entries[i].padding[2] = 0;
        }
        vcpu->arch.cpuid_nent = cpuid->nent;
        cpuid_fix_nx_cap(vcpu);
        r = 0;
        kvm_apic_set_version(vcpu);
        kvm_x86_ops->cpuid_update(vcpu);
        update_cpuid(vcpu);

out_free:
        vfree(cpuid_entries);
out:
        return r;
}

static int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
                                     struct kvm_cpuid2 *cpuid,
                                     struct kvm_cpuid_entry2 __user *entries)
{
        int r;

        r = -E2BIG;
        if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
                goto out;
        r = -EFAULT;
        if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
                           cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
                goto out;
        vcpu->arch.cpuid_nent = cpuid->nent;
        kvm_apic_set_version(vcpu);
        kvm_x86_ops->cpuid_update(vcpu);
        update_cpuid(vcpu);
        return 0;

out:
        return r;
}

static int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
                                     struct kvm_cpuid2 *cpuid,
                                     struct kvm_cpuid_entry2 __user *entries)
{
        int r;

        r = -E2BIG;
        if (cpuid->nent < vcpu->arch.cpuid_nent)
                goto out;
        r = -EFAULT;
        if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
                         vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
                goto out;
        return 0;

out:
        cpuid->nent = vcpu->arch.cpuid_nent;
        return r;
}

static void cpuid_mask(u32 *word, int wordnum)
{
        *word &= boot_cpu_data.x86_capability[wordnum];
}

static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
                           u32 index)
{
        entry->function = function;
        entry->index = index;
        cpuid_count(entry->function, entry->index,
                    &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
        entry->flags = 0;
}

static bool supported_xcr0_bit(unsigned bit)
{
        u64 mask = ((u64)1 << bit);

        return mask & (XSTATE_FP | XSTATE_SSE | XSTATE_YMM) & host_xcr0;
}

#define F(x) bit(X86_FEATURE_##x)

static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
                         u32 index, int *nent, int maxnent)
{
        unsigned f_nx = is_efer_nx() ? F(NX) : 0;
#ifdef CONFIG_X86_64
        unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
                                ? F(GBPAGES) : 0;
        unsigned f_lm = F(LM);
#else
        unsigned f_gbpages = 0;
        unsigned f_lm = 0;
#endif
        unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;

        /* cpuid 1.edx */
        const u32 kvm_supported_word0_x86_features =
                F(FPU) | F(VME) | F(DE) | F(PSE) |
                F(TSC) | F(MSR) | F(PAE) | F(MCE) |
                F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
                F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
                F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLSH) |
                0 /* Reserved, DS, ACPI */ | F(MMX) |
                F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
                0 /* HTT, TM, Reserved, PBE */;
        /* cpuid 0x80000001.edx */
        const u32 kvm_supported_word1_x86_features =
                F(FPU) | F(VME) | F(DE) | F(PSE) |
                F(TSC) | F(MSR) | F(PAE) | F(MCE) |
                F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
                F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
                F(PAT) | F(PSE36) | 0 /* Reserved */ |
                f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
                F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
                0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
        /* cpuid 1.ecx */
        const u32 kvm_supported_word4_x86_features =
                F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
                0 /* DS-CPL, VMX, SMX, EST */ |
                0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
                0 /* Reserved */ | F(CX16) | 0 /* xTPR Update, PDCM */ |
                0 /* Reserved, DCA */ | F(XMM4_1) |
                F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
                0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
                F(F16C) | F(RDRAND);
        /* cpuid 0x80000001.ecx */
        const u32 kvm_supported_word6_x86_features =
                F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
                F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
                F(3DNOWPREFETCH) | 0 /* OSVW */ | 0 /* IBS */ | F(XOP) |
                0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);

        /* cpuid 0xC0000001.edx */
        const u32 kvm_supported_word5_x86_features =
                F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
                F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
                F(PMM) | F(PMM_EN);

        /* cpuid 7.0.ebx */
        const u32 kvm_supported_word9_x86_features =
                F(SMEP) | F(FSGSBASE) | F(ERMS);

        /* all calls to cpuid_count() should be made on the same cpu */
        get_cpu();
        do_cpuid_1_ent(entry, function, index);
        ++*nent;

        switch (function) {
        case 0:
                entry->eax = min(entry->eax, (u32)0xd);
                break;
        case 1:
                entry->edx &= kvm_supported_word0_x86_features;
                cpuid_mask(&entry->edx, 0);
                entry->ecx &= kvm_supported_word4_x86_features;
                cpuid_mask(&entry->ecx, 4);
                /* we support x2apic emulation even if host does not support
                 * it since we emulate x2apic in software */
                entry->ecx |= F(X2APIC);
                break;
        /* function 2 entries are STATEFUL. That is, repeated cpuid commands
         * may return different values. This forces us to get_cpu() before
         * issuing the first command, and also to emulate this annoying behavior
         * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
        case 2: {
                int t, times = entry->eax & 0xff;

                entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
                entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
                for (t = 1; t < times && *nent < maxnent; ++t) {
                        do_cpuid_1_ent(&entry[t], function, 0);
                        entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
                        ++*nent;
                }
                break;
        }
        /* function 4 has additional index. */
        case 4: {
                int i, cache_type;

                entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
                /* read more entries until cache_type is zero */
                for (i = 1; *nent < maxnent; ++i) {
                        cache_type = entry[i - 1].eax & 0x1f;
                        if (!cache_type)
                                break;
                        do_cpuid_1_ent(&entry[i], function, i);
                        entry[i].flags |=
                               KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
                        ++*nent;
                }
                break;
        }
        case 7: {
                entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
                /* Mask ebx against host capbability word 9 */
                if (index == 0) {
                        entry->ebx &= kvm_supported_word9_x86_features;
                        cpuid_mask(&entry->ebx, 9);
                } else
                        entry->ebx = 0;
                entry->eax = 0;
                entry->ecx = 0;
                entry->edx = 0;
                break;
        }
        case 9:
                break;
        /* function 0xb has additional index. */
        case 0xb: {
                int i, level_type;

                entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
                /* read more entries until level_type is zero */
                for (i = 1; *nent < maxnent; ++i) {
                        level_type = entry[i - 1].ecx & 0xff00;
                        if (!level_type)
                                break;
                        do_cpuid_1_ent(&entry[i], function, i);
                        entry[i].flags |=
                               KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
                        ++*nent;
                }
                break;
        }
        case 0xd: {
                int idx, i;

                entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
                for (idx = 1, i = 1; *nent < maxnent && idx < 64; ++idx) {
                        do_cpuid_1_ent(&entry[i], function, idx);
                        if (entry[i].eax == 0 || !supported_xcr0_bit(idx))
                                continue;
                        entry[i].flags |=
                               KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
                        ++*nent;
                        ++i;
                }
                break;
        }
        case KVM_CPUID_SIGNATURE: {
                char signature[12] = "KVMKVMKVM\0\0";
                u32 *sigptr = (u32 *)signature;
                entry->eax = 0;
                entry->ebx = sigptr[0];
                entry->ecx = sigptr[1];
                entry->edx = sigptr[2];
                break;
        }
        case KVM_CPUID_FEATURES:
                entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
                             (1 << KVM_FEATURE_NOP_IO_DELAY) |
                             (1 << KVM_FEATURE_CLOCKSOURCE2) |
                             (1 << KVM_FEATURE_ASYNC_PF) |
                             (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT);

                if (sched_info_on())
                        entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);

                entry->ebx = 0;
                entry->ecx = 0;
                entry->edx = 0;
                break;
        case 0x80000000:
                entry->eax = min(entry->eax, 0x8000001a);
                break;
        case 0x80000001:
                entry->edx &= kvm_supported_word1_x86_features;
                cpuid_mask(&entry->edx, 1);
                entry->ecx &= kvm_supported_word6_x86_features;
                cpuid_mask(&entry->ecx, 6);
                break;
        case 0x80000008: {
                unsigned g_phys_as = (entry->eax >> 16) & 0xff;
                unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
                unsigned phys_as = entry->eax & 0xff;

                if (!g_phys_as)
                        g_phys_as = phys_as;
                entry->eax = g_phys_as | (virt_as << 8);
                entry->ebx = entry->edx = 0;
                break;
        }
        case 0x80000019:
                entry->ecx = entry->edx = 0;
                break;
        case 0x8000001a:
                break;
        case 0x8000001d:
                break;
        /*Add support for Centaur's CPUID instruction*/
        case 0xC0000000:
                /*Just support up to 0xC0000004 now*/
                entry->eax = min(entry->eax, 0xC0000004);
                break;
        case 0xC0000001:
                entry->edx &= kvm_supported_word5_x86_features;
                cpuid_mask(&entry->edx, 5);
                break;
        case 3: /* Processor serial number */
        case 5: /* MONITOR/MWAIT */
        case 6: /* Thermal management */
        case 0xA: /* Architectural Performance Monitoring */
        case 0x80000007: /* Advanced power management */
        case 0xC0000002:
        case 0xC0000003:
        case 0xC0000004:
        default:
                entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
                break;
        }

        kvm_x86_ops->set_supported_cpuid(function, entry);

        put_cpu();
}

#undef F

static int kvm_dev_ioctl_get_supported_cpuid(struct kvm_cpuid2 *cpuid,
                                     struct kvm_cpuid_entry2 __user *entries)
{
        struct kvm_cpuid_entry2 *cpuid_entries;
        int limit, nent = 0, r = -E2BIG;
        u32 func;

        if (cpuid->nent < 1)
                goto out;
        if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
                cpuid->nent = KVM_MAX_CPUID_ENTRIES;
        r = -ENOMEM;
        cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
        if (!cpuid_entries)
                goto out;

        do_cpuid_ent(&cpuid_entries[0], 0, 0, &nent, cpuid->nent);
        limit = cpuid_entries[0].eax;
        for (func = 1; func <= limit && nent < cpuid->nent; ++func)
                do_cpuid_ent(&cpuid_entries[nent], func, 0,
                             &nent, cpuid->nent);
        r = -E2BIG;
        if (nent >= cpuid->nent)
                goto out_free;

        do_cpuid_ent(&cpuid_entries[nent], 0x80000000, 0, &nent, cpuid->nent);
        limit = cpuid_entries[nent - 1].eax;
        for (func = 0x80000001; func <= limit && nent < cpuid->nent; ++func)
                do_cpuid_ent(&cpuid_entries[nent], func, 0,
                             &nent, cpuid->nent);



        r = -E2BIG;
        if (nent >= cpuid->nent)
                goto out_free;

        /* Add support for Centaur's CPUID instruction. */
        if (boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR) {
                do_cpuid_ent(&cpuid_entries[nent], 0xC0000000, 0,
                                &nent, cpuid->nent);

                r = -E2BIG;
                if (nent >= cpuid->nent)
                        goto out_free;

                limit = cpuid_entries[nent - 1].eax;
                for (func = 0xC0000001;
                        func <= limit && nent < cpuid->nent; ++func)
                        do_cpuid_ent(&cpuid_entries[nent], func, 0,
                                        &nent, cpuid->nent);

                r = -E2BIG;
                if (nent >= cpuid->nent)
                        goto out_free;
        }

        do_cpuid_ent(&cpuid_entries[nent], KVM_CPUID_SIGNATURE, 0, &nent,
                     cpuid->nent);

        r = -E2BIG;
        if (nent >= cpuid->nent)
                goto out_free;

        do_cpuid_ent(&cpuid_entries[nent], KVM_CPUID_FEATURES, 0, &nent,
                     cpuid->nent);

        r = -E2BIG;
        if (nent >= cpuid->nent)
                goto out_free;

        r = -EFAULT;
        if (copy_to_user(entries, cpuid_entries,
                         nent * sizeof(struct kvm_cpuid_entry2)))
                goto out_free;
        cpuid->nent = nent;
        r = 0;

out_free:
        vfree(cpuid_entries);
out:
        return r;
}

static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
                                    struct kvm_lapic_state *s)
{
        memcpy(s->regs, vcpu->arch.apic->regs, sizeof *s);

        return 0;
}

static int kvm_vcpu_ioctl_set_lapic(struct kvm_vcpu *vcpu,
                                    struct kvm_lapic_state *s)
{
        memcpy(vcpu->arch.apic->regs, s->regs, sizeof *s);
        kvm_apic_post_state_restore(vcpu);
        update_cr8_intercept(vcpu);

        return 0;
}

static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
                                    struct kvm_interrupt *irq)
{
        if (irq->irq < 0 || irq->irq >= 256)
                return -EINVAL;
        if (irqchip_in_kernel(vcpu->kvm))
                return -ENXIO;

        kvm_queue_interrupt(vcpu, irq->irq, false);
        kvm_make_request(KVM_REQ_EVENT, vcpu);

        return 0;
}

static int kvm_vcpu_ioctl_nmi(struct kvm_vcpu *vcpu)
{
        kvm_inject_nmi(vcpu);

        return 0;
}

static int vcpu_ioctl_tpr_access_reporting(struct kvm_vcpu *vcpu,
                                           struct kvm_tpr_access_ctl *tac)
{
        if (tac->flags)
                return -EINVAL;
        vcpu->arch.tpr_access_reporting = !!tac->enabled;
        return 0;
}

static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu,
                                        u64 mcg_cap)
{
        int r;
        unsigned bank_num = mcg_cap & 0xff, bank;

        r = -EINVAL;
        if (!bank_num || bank_num >= KVM_MAX_MCE_BANKS)
                goto out;
        if (mcg_cap & ~(KVM_MCE_CAP_SUPPORTED | 0xff | 0xff0000))
                goto out;
        r = 0;
        vcpu->arch.mcg_cap = mcg_cap;
        /* Init IA32_MCG_CTL to all 1s */
        if (mcg_cap & MCG_CTL_P)
                vcpu->arch.mcg_ctl = ~(u64)0;
        /* Init IA32_MCi_CTL to all 1s */
        for (bank = 0; bank < bank_num; bank++)
                vcpu->arch.mce_banks[bank*4] = ~(u64)0;
out:
        return r;
}

static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,
                                      struct kvm_x86_mce *mce)
{
        u64 mcg_cap = vcpu->arch.mcg_cap;
        unsigned bank_num = mcg_cap & 0xff;
        u64 *banks = vcpu->arch.mce_banks;

        if (mce->bank >= bank_num || !(mce->status & MCI_STATUS_VAL))
                return -EINVAL;
        /*
         * if IA32_MCG_CTL is not all 1s, the uncorrected error
         * reporting is disabled
         */
        if ((mce->status & MCI_STATUS_UC) && (mcg_cap & MCG_CTL_P) &&
            vcpu->arch.mcg_ctl != ~(u64)0)
                return 0;
        banks += 4 * mce->bank;
        /*
         * if IA32_MCi_CTL is not all 1s, the uncorrected error
         * reporting is disabled for the bank
         */
        if ((mce->status & MCI_STATUS_UC) && banks[0] != ~(u64)0)
                return 0;
        if (mce->status & MCI_STATUS_UC) {
                if ((vcpu->arch.mcg_status & MCG_STATUS_MCIP) ||
                    !kvm_read_cr4_bits(vcpu, X86_CR4_MCE)) {
                        kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
                        return 0;
                }
                if (banks[1] & MCI_STATUS_VAL)
                        mce->status |= MCI_STATUS_OVER;
                banks[2] = mce->addr;
                banks[3] = mce->misc;
                vcpu->arch.mcg_status = mce->mcg_status;
                banks[1] = mce->status;
                kvm_queue_exception(vcpu, MC_VECTOR);
        } else if (!(banks[1] & MCI_STATUS_VAL)
                   || !(banks[1] & MCI_STATUS_UC)) {
                if (banks[1] & MCI_STATUS_VAL)
                        mce->status |= MCI_STATUS_OVER;
                banks[2] = mce->addr;
                banks[3] = mce->misc;
                banks[1] = mce->status;
        } else
                banks[1] |= MCI_STATUS_OVER;
        return 0;
}

static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
                                               struct kvm_vcpu_events *events)
{
        process_nmi(vcpu);
        events->exception.injected =
                vcpu->arch.exception.pending &&
                !kvm_exception_is_soft(vcpu->arch.exception.nr);
        events->exception.nr = vcpu->arch.exception.nr;
        events->exception.has_error_code = vcpu->arch.exception.has_error_code;
        events->exception.pad = 0;
        events->exception.error_code = vcpu->arch.exception.error_code;

        events->interrupt.injected =
                vcpu->arch.interrupt.pending && !vcpu->arch.interrupt.soft;
        events->interrupt.nr = vcpu->arch.interrupt.nr;
        events->interrupt.soft = 0;
        events->interrupt.shadow =
                kvm_x86_ops->get_interrupt_shadow(vcpu,
                        KVM_X86_SHADOW_INT_MOV_SS | KVM_X86_SHADOW_INT_STI);

        events->nmi.injected = vcpu->arch.nmi_injected;
        events->nmi.pending = vcpu->arch.nmi_pending != 0;
        events->nmi.masked = kvm_x86_ops->get_nmi_mask(vcpu);
        events->nmi.pad = 0;

        events->sipi_vector = vcpu->arch.sipi_vector;

        events->flags = (KVM_VCPUEVENT_VALID_NMI_PENDING
                         | KVM_VCPUEVENT_VALID_SIPI_VECTOR
                         | KVM_VCPUEVENT_VALID_SHADOW);
        memset(&events->reserved, 0, sizeof(events->reserved));
}

static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
                                              struct kvm_vcpu_events *events)
{
        if (events->flags & ~(KVM_VCPUEVENT_VALID_NMI_PENDING
                              | KVM_VCPUEVENT_VALID_SIPI_VECTOR
                              | KVM_VCPUEVENT_VALID_SHADOW))
                return -EINVAL;

        process_nmi(vcpu);
        vcpu->arch.exception.pending = events->exception.injected;
        vcpu->arch.exception.nr = events->exception.nr;
        vcpu->arch.exception.has_error_code = events->exception.has_error_code;
        vcpu->arch.exception.error_code = events->exception.error_code;

        vcpu->arch.interrupt.pending = events->interrupt.injected;
        vcpu->arch.interrupt.nr = events->interrupt.nr;
        vcpu->arch.interrupt.soft = events->interrupt.soft;
        if (events->flags & KVM_VCPUEVENT_VALID_SHADOW)
                kvm_x86_ops->set_interrupt_shadow(vcpu,
                                                  events->interrupt.shadow);

        vcpu->arch.nmi_injected = events->nmi.injected;
        if (events->flags & KVM_VCPUEVENT_VALID_NMI_PENDING)
                vcpu->arch.nmi_pending = events->nmi.pending;
        kvm_x86_ops->set_nmi_mask(vcpu, events->nmi.masked);

        if (events->flags & KVM_VCPUEVENT_VALID_SIPI_VECTOR)
                vcpu->arch.sipi_vector = events->sipi_vector;

        kvm_make_request(KVM_REQ_EVENT, vcpu);

        return 0;
}

static void kvm_vcpu_ioctl_x86_get_debugregs(struct kvm_vcpu *vcpu,
                                             struct kvm_debugregs *dbgregs)
{
        memcpy(dbgregs->db, vcpu->arch.db, sizeof(vcpu->arch.db));
        dbgregs->dr6 = vcpu->arch.dr6;
        dbgregs->dr7 = vcpu->arch.dr7;
        dbgregs->flags = 0;
        memset(&dbgregs->reserved, 0, sizeof(dbgregs->reserved));
}

static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu,
                                            struct kvm_debugregs *dbgregs)
{
        if (dbgregs->flags)
                return -EINVAL;

        memcpy(vcpu->arch.db, dbgregs->db, sizeof(vcpu->arch.db));
        vcpu->arch.dr6 = dbgregs->dr6;
        vcpu->arch.dr7 = dbgregs->dr7;

        return 0;
}

static void kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu,
                                         struct kvm_xsave *guest_xsave)
{
        if (cpu_has_xsave)
                memcpy(guest_xsave->region,
                        &vcpu->arch.guest_fpu.state->xsave,
                        xstate_size);
        else {
                memcpy(guest_xsave->region,
                        &vcpu->arch.guest_fpu.state->fxsave,
                        sizeof(struct i387_fxsave_struct));
                *(u64 *)&guest_xsave->region[XSAVE_HDR_OFFSET / sizeof(u32)] =
                        XSTATE_FPSSE;
        }
}

static int kvm_vcpu_ioctl_x86_set_xsave(struct kvm_vcpu *vcpu,
                                        struct kvm_xsave *guest_xsave)
{
        u64 xstate_bv =
                *(u64 *)&guest_xsave->region[XSAVE_HDR_OFFSET / sizeof(u32)];

        if (cpu_has_xsave)
                memcpy(&vcpu->arch.guest_fpu.state->xsave,
                        guest_xsave->region, xstate_size);
        else {
                if (xstate_bv & ~XSTATE_FPSSE)
                        return -EINVAL;
                memcpy(&vcpu->arch.guest_fpu.state->fxsave,
                        guest_xsave->region, sizeof(struct i387_fxsave_struct));
        }
        return 0;
}

static void kvm_vcpu_ioctl_x86_get_xcrs(struct kvm_vcpu *vcpu,
                                        struct kvm_xcrs *guest_xcrs)
{
        if (!cpu_has_xsave) {
                guest_xcrs->nr_xcrs = 0;
                return;
        }

        guest_xcrs->nr_xcrs = 1;
        guest_xcrs->flags = 0;
        guest_xcrs->xcrs[0].xcr = XCR_XFEATURE_ENABLED_MASK;
        guest_xcrs->xcrs[0].value = vcpu->arch.xcr0;
}

static int kvm_vcpu_ioctl_x86_set_xcrs(struct kvm_vcpu *vcpu,
                                       struct kvm_xcrs *guest_xcrs)
{
        int i, r = 0;

        if (!cpu_has_xsave)
                return -EINVAL;

        if (guest_xcrs->nr_xcrs > KVM_MAX_XCRS || guest_xcrs->flags)
                return -EINVAL;

        for (i = 0; i < guest_xcrs->nr_xcrs; i++)
                /* Only support XCR0 currently */
                if (guest_xcrs->xcrs[0].xcr == XCR_XFEATURE_ENABLED_MASK) {
                        r = __kvm_set_xcr(vcpu, XCR_XFEATURE_ENABLED_MASK,
                                guest_xcrs->xcrs[0].value);