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

#include "kvm.h"
#include "x86_emulate.h"
#include "segment_descriptor.h"
#include "irq.h"

#include <linux/kvm.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/percpu.h>
#include <linux/gfp.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/vmalloc.h>
#include <linux/reboot.h>
#include <linux/debugfs.h>
#include <linux/highmem.h>
#include <linux/file.h>
#include <linux/sysdev.h>
#include <linux/cpu.h>
#include <linux/sched.h>
#include <linux/cpumask.h>
#include <linux/smp.h>
#include <linux/anon_inodes.h>
#include <linux/profile.h>

#include <asm/processor.h>
#include <asm/msr.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/desc.h>

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

static DEFINE_SPINLOCK(kvm_lock);
static LIST_HEAD(vm_list);

static cpumask_t cpus_hardware_enabled;

struct kvm_x86_ops *kvm_x86_ops;
struct kmem_cache *kvm_vcpu_cache;
EXPORT_SYMBOL_GPL(kvm_vcpu_cache);

static __read_mostly struct preempt_ops kvm_preempt_ops;

#define STAT_OFFSET(x) offsetof(struct kvm_vcpu, stat.x)

static struct kvm_stats_debugfs_item {
        const char *name;
        int offset;
        struct dentry *dentry;
} debugfs_entries[] = {
        { "pf_fixed", STAT_OFFSET(pf_fixed) },
        { "pf_guest", STAT_OFFSET(pf_guest) },
        { "tlb_flush", STAT_OFFSET(tlb_flush) },
        { "invlpg", STAT_OFFSET(invlpg) },
        { "exits", STAT_OFFSET(exits) },
        { "io_exits", STAT_OFFSET(io_exits) },
        { "mmio_exits", STAT_OFFSET(mmio_exits) },
        { "signal_exits", STAT_OFFSET(signal_exits) },
        { "irq_window", STAT_OFFSET(irq_window_exits) },
        { "halt_exits", STAT_OFFSET(halt_exits) },
        { "halt_wakeup", STAT_OFFSET(halt_wakeup) },
        { "request_irq", STAT_OFFSET(request_irq_exits) },
        { "irq_exits", STAT_OFFSET(irq_exits) },
        { "light_exits", STAT_OFFSET(light_exits) },
        { "efer_reload", STAT_OFFSET(efer_reload) },
        { NULL }
};

static struct dentry *debugfs_dir;

#define MAX_IO_MSRS 256

#define CR0_RESERVED_BITS                                               \
        (~(unsigned long)(X86_CR0_PE | X86_CR0_MP | X86_CR0_EM | X86_CR0_TS \
                          | X86_CR0_ET | X86_CR0_NE | X86_CR0_WP | X86_CR0_AM \
                          | X86_CR0_NW | X86_CR0_CD | X86_CR0_PG))
#define CR4_RESERVED_BITS                                               \
        (~(unsigned long)(X86_CR4_VME | X86_CR4_PVI | X86_CR4_TSD | X86_CR4_DE\
                          | X86_CR4_PSE | X86_CR4_PAE | X86_CR4_MCE     \
                          | X86_CR4_PGE | X86_CR4_PCE | X86_CR4_OSFXSR  \
                          | X86_CR4_OSXMMEXCPT | X86_CR4_VMXE))

#define CR8_RESERVED_BITS (~(unsigned long)X86_CR8_TPR)
#define EFER_RESERVED_BITS 0xfffffffffffff2fe

#ifdef CONFIG_X86_64
// LDT or TSS descriptor in the GDT. 16 bytes.
struct segment_descriptor_64 {
        struct segment_descriptor s;
        u32 base_higher;
        u32 pad_zero;
};

#endif

static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
                           unsigned long arg);

unsigned long segment_base(u16 selector)
{
        struct descriptor_table gdt;
        struct segment_descriptor *d;
        unsigned long table_base;
        typedef unsigned long ul;
        unsigned long v;

        if (selector == 0)
                return 0;

        asm ("sgdt %0" : "=m"(gdt));
        table_base = gdt.base;

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

                asm ("sldt %0" : "=g"(ldt_selector));
                table_base = segment_base(ldt_selector);
        }
        d = (struct segment_descriptor *)(table_base + (selector & ~7));
        v = d->base_low | ((ul)d->base_mid << 16) | ((ul)d->base_high << 24);
#ifdef CONFIG_X86_64
        if (d->system == 0
            && (d->type == 2 || d->type == 9 || d->type == 11))
                v |= ((ul)((struct segment_descriptor_64 *)d)->base_higher) << 32;
#endif
        return v;
}
EXPORT_SYMBOL_GPL(segment_base);

static inline int valid_vcpu(int n)
{
        return likely(n >= 0 && n < KVM_MAX_VCPUS);
}

void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
{
        if (!vcpu->fpu_active || vcpu->guest_fpu_loaded)
                return;

        vcpu->guest_fpu_loaded = 1;
        fx_save(&vcpu->host_fx_image);
        fx_restore(&vcpu->guest_fx_image);
}
EXPORT_SYMBOL_GPL(kvm_load_guest_fpu);

void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
{
        if (!vcpu->guest_fpu_loaded)
                return;

        vcpu->guest_fpu_loaded = 0;
        fx_save(&vcpu->guest_fx_image);
        fx_restore(&vcpu->host_fx_image);
}
EXPORT_SYMBOL_GPL(kvm_put_guest_fpu);

/*
 * Switches to specified vcpu, until a matching vcpu_put()
 */
static void vcpu_load(struct kvm_vcpu *vcpu)
{
        int cpu;

        mutex_lock(&vcpu->mutex);
        cpu = get_cpu();
        preempt_notifier_register(&vcpu->preempt_notifier);
        kvm_x86_ops->vcpu_load(vcpu, cpu);
        put_cpu();
}

static void vcpu_put(struct kvm_vcpu *vcpu)
{
        preempt_disable();
        kvm_x86_ops->vcpu_put(vcpu);
        preempt_notifier_unregister(&vcpu->preempt_notifier);
        preempt_enable();
        mutex_unlock(&vcpu->mutex);
}

static void ack_flush(void *_completed)
{
}

void kvm_flush_remote_tlbs(struct kvm *kvm)
{
        int i, cpu;
        cpumask_t cpus;
        struct kvm_vcpu *vcpu;

        cpus_clear(cpus);
        for (i = 0; i < KVM_MAX_VCPUS; ++i) {
                vcpu = kvm->vcpus[i];
                if (!vcpu)
                        continue;
                if (test_and_set_bit(KVM_TLB_FLUSH, &vcpu->requests))
                        continue;
                cpu = vcpu->cpu;
                if (cpu != -1 && cpu != raw_smp_processor_id())
                        cpu_set(cpu, cpus);
        }
        smp_call_function_mask(cpus, ack_flush, NULL, 1);
}

int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
{
        struct page *page;
        int r;

        mutex_init(&vcpu->mutex);
        vcpu->cpu = -1;
        vcpu->mmu.root_hpa = INVALID_PAGE;
        vcpu->kvm = kvm;
        vcpu->vcpu_id = id;
        if (!irqchip_in_kernel(kvm) || id == 0)
                vcpu->mp_state = VCPU_MP_STATE_RUNNABLE;
        else
                vcpu->mp_state = VCPU_MP_STATE_UNINITIALIZED;
        init_waitqueue_head(&vcpu->wq);

        page = alloc_page(GFP_KERNEL | __GFP_ZERO);
        if (!page) {
                r = -ENOMEM;
                goto fail;
        }
        vcpu->run = page_address(page);

        page = alloc_page(GFP_KERNEL | __GFP_ZERO);
        if (!page) {
                r = -ENOMEM;
                goto fail_free_run;
        }
        vcpu->pio_data = page_address(page);

        r = kvm_mmu_create(vcpu);
        if (r < 0)
                goto fail_free_pio_data;

        return 0;

fail_free_pio_data:
        free_page((unsigned long)vcpu->pio_data);
fail_free_run:
        free_page((unsigned long)vcpu->run);
fail:
        return -ENOMEM;
}
EXPORT_SYMBOL_GPL(kvm_vcpu_init);

void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
{
        kvm_mmu_destroy(vcpu);
        if (vcpu->apic)
                hrtimer_cancel(&vcpu->apic->timer.dev);
        kvm_free_apic(vcpu->apic);
        free_page((unsigned long)vcpu->pio_data);
        free_page((unsigned long)vcpu->run);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);

static struct kvm *kvm_create_vm(void)
{
        struct kvm *kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);

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

        kvm_io_bus_init(&kvm->pio_bus);
        mutex_init(&kvm->lock);
        INIT_LIST_HEAD(&kvm->active_mmu_pages);
        kvm_io_bus_init(&kvm->mmio_bus);
        spin_lock(&kvm_lock);
        list_add(&kvm->vm_list, &vm_list);
        spin_unlock(&kvm_lock);
        return kvm;
}

/*
 * Free any memory in @free but not in @dont.
 */
static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
                                  struct kvm_memory_slot *dont)
{
        int i;

        if (!dont || free->phys_mem != dont->phys_mem)
                if (free->phys_mem) {
                        for (i = 0; i < free->npages; ++i)
                                if (free->phys_mem[i])
                                        __free_page(free->phys_mem[i]);
                        vfree(free->phys_mem);
                }

        if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
                vfree(free->dirty_bitmap);

        free->phys_mem = NULL;
        free->npages = 0;
        free->dirty_bitmap = NULL;
}

static void kvm_free_physmem(struct kvm *kvm)
{
        int i;

        for (i = 0; i < kvm->nmemslots; ++i)
                kvm_free_physmem_slot(&kvm->memslots[i], NULL);
}

static void free_pio_guest_pages(struct kvm_vcpu *vcpu)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(vcpu->pio.guest_pages); ++i)
                if (vcpu->pio.guest_pages[i]) {
                        __free_page(vcpu->pio.guest_pages[i]);
                        vcpu->pio.guest_pages[i] = NULL;
                }
}

static void kvm_unload_vcpu_mmu(struct kvm_vcpu *vcpu)
{
        vcpu_load(vcpu);
        kvm_mmu_unload(vcpu);
        vcpu_put(vcpu);
}

static void kvm_free_vcpus(struct kvm *kvm)
{
        unsigned int i;

        /*
         * Unpin any mmu pages first.
         */
        for (i = 0; i < KVM_MAX_VCPUS; ++i)
                if (kvm->vcpus[i])
                        kvm_unload_vcpu_mmu(kvm->vcpus[i]);
        for (i = 0; i < KVM_MAX_VCPUS; ++i) {
                if (kvm->vcpus[i]) {
                        kvm_x86_ops->vcpu_free(kvm->vcpus[i]);
                        kvm->vcpus[i] = NULL;
                }
        }

}

static void kvm_destroy_vm(struct kvm *kvm)
{
        spin_lock(&kvm_lock);
        list_del(&kvm->vm_list);
        spin_unlock(&kvm_lock);
        kvm_io_bus_destroy(&kvm->pio_bus);
        kvm_io_bus_destroy(&kvm->mmio_bus);
        kfree(kvm->vpic);
        kfree(kvm->vioapic);
        kvm_free_vcpus(kvm);
        kvm_free_physmem(kvm);
        kfree(kvm);
}

static int kvm_vm_release(struct inode *inode, struct file *filp)
{
        struct kvm *kvm = filp->private_data;

        kvm_destroy_vm(kvm);
        return 0;
}

static void inject_gp(struct kvm_vcpu *vcpu)
{
        kvm_x86_ops->inject_gp(vcpu, 0);
}

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

        mutex_lock(&vcpu->kvm->lock);
        page = gfn_to_page(vcpu->kvm, pdpt_gfn);
        if (!page) {
                ret = 0;
                goto out;
        }

        pdpt = kmap_atomic(page, KM_USER0);
        memcpy(pdpte, pdpt+offset, sizeof(pdpte));
        kunmap_atomic(pdpt, KM_USER0);

        for (i = 0; i < ARRAY_SIZE(pdpte); ++i) {
                if ((pdpte[i] & 1) && (pdpte[i] & 0xfffffff0000001e6ull)) {
                        ret = 0;
                        goto out;
                }
        }
        ret = 1;

        memcpy(vcpu->pdptrs, pdpte, sizeof(vcpu->pdptrs));
out:
        mutex_unlock(&vcpu->kvm->lock);

        return ret;
}

void set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
{
        if (cr0 & CR0_RESERVED_BITS) {
                printk(KERN_DEBUG "set_cr0: 0x%lx #GP, reserved bits 0x%lx\n",
                       cr0, vcpu->cr0);
                inject_gp(vcpu);
                return;
        }

        if ((cr0 & X86_CR0_NW) && !(cr0 & X86_CR0_CD)) {
                printk(KERN_DEBUG "set_cr0: #GP, CD == 0 && NW == 1\n");
                inject_gp(vcpu);
                return;
        }

        if ((cr0 & X86_CR0_PG) && !(cr0 & X86_CR0_PE)) {
                printk(KERN_DEBUG "set_cr0: #GP, set PG flag "
                       "and a clear PE flag\n");
                inject_gp(vcpu);
                return;
        }

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

                        if (!is_pae(vcpu)) {
                                printk(KERN_DEBUG "set_cr0: #GP, start paging "
                                       "in long mode while PAE is disabled\n");
                                inject_gp(vcpu);
                                return;
                        }
                        kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
                        if (cs_l) {
                                printk(KERN_DEBUG "set_cr0: #GP, start paging "
                                       "in long mode while CS.L == 1\n");
                                inject_gp(vcpu);
                                return;

                        }
                } else
#endif
                if (is_pae(vcpu) && !load_pdptrs(vcpu, vcpu->cr3)) {
                        printk(KERN_DEBUG "set_cr0: #GP, pdptrs "
                               "reserved bits\n");
                        inject_gp(vcpu);
                        return;
                }

        }

        kvm_x86_ops->set_cr0(vcpu, cr0);
        vcpu->cr0 = cr0;

        mutex_lock(&vcpu->kvm->lock);
        kvm_mmu_reset_context(vcpu);
        mutex_unlock(&vcpu->kvm->lock);
        return;
}
EXPORT_SYMBOL_GPL(set_cr0);

void lmsw(struct kvm_vcpu *vcpu, unsigned long msw)
{
        set_cr0(vcpu, (vcpu->cr0 & ~0x0ful) | (msw & 0x0f));
}
EXPORT_SYMBOL_GPL(lmsw);

void set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
        if (cr4 & CR4_RESERVED_BITS) {
                printk(KERN_DEBUG "set_cr4: #GP, reserved bits\n");
                inject_gp(vcpu);
                return;
        }

        if (is_long_mode(vcpu)) {
                if (!(cr4 & X86_CR4_PAE)) {
                        printk(KERN_DEBUG "set_cr4: #GP, clearing PAE while "
                               "in long mode\n");
                        inject_gp(vcpu);
                        return;
                }
        } else if (is_paging(vcpu) && !is_pae(vcpu) && (cr4 & X86_CR4_PAE)
                   && !load_pdptrs(vcpu, vcpu->cr3)) {
                printk(KERN_DEBUG "set_cr4: #GP, pdptrs reserved bits\n");
                inject_gp(vcpu);
                return;
        }

        if (cr4 & X86_CR4_VMXE) {
                printk(KERN_DEBUG "set_cr4: #GP, setting VMXE\n");
                inject_gp(vcpu);
                return;
        }
        kvm_x86_ops->set_cr4(vcpu, cr4);
        vcpu->cr4 = cr4;
        mutex_lock(&vcpu->kvm->lock);
        kvm_mmu_reset_context(vcpu);
        mutex_unlock(&vcpu->kvm->lock);
}
EXPORT_SYMBOL_GPL(set_cr4);

void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
{
        if (is_long_mode(vcpu)) {
                if (cr3 & CR3_L_MODE_RESERVED_BITS) {
                        printk(KERN_DEBUG "set_cr3: #GP, reserved bits\n");
                        inject_gp(vcpu);
                        return;
                }
        } else {
                if (is_pae(vcpu)) {
                        if (cr3 & CR3_PAE_RESERVED_BITS) {
                                printk(KERN_DEBUG
                                       "set_cr3: #GP, reserved bits\n");
                                inject_gp(vcpu);
                                return;
                        }
                        if (is_paging(vcpu) && !load_pdptrs(vcpu, cr3)) {
                                printk(KERN_DEBUG "set_cr3: #GP, pdptrs "
                                       "reserved bits\n");
                                inject_gp(vcpu);
                                return;
                        }
                } else {
                        if (cr3 & CR3_NONPAE_RESERVED_BITS) {
                                printk(KERN_DEBUG
                                       "set_cr3: #GP, reserved bits\n");
                                inject_gp(vcpu);
                                return;
                        }
                }
        }

        mutex_lock(&vcpu->kvm->lock);
        /*
         * 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)))
                inject_gp(vcpu);
        else {
                vcpu->cr3 = cr3;
                vcpu->mmu.new_cr3(vcpu);
        }
        mutex_unlock(&vcpu->kvm->lock);
}
EXPORT_SYMBOL_GPL(set_cr3);

void set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8)
{
        if (cr8 & CR8_RESERVED_BITS) {
                printk(KERN_DEBUG "set_cr8: #GP, reserved bits 0x%lx\n", cr8);
                inject_gp(vcpu);
                return;
        }
        if (irqchip_in_kernel(vcpu->kvm))
                kvm_lapic_set_tpr(vcpu, cr8);
        else
                vcpu->cr8 = cr8;
}
EXPORT_SYMBOL_GPL(set_cr8);

unsigned long get_cr8(struct kvm_vcpu *vcpu)
{
        if (irqchip_in_kernel(vcpu->kvm))
                return kvm_lapic_get_cr8(vcpu);
        else
                return vcpu->cr8;
}
EXPORT_SYMBOL_GPL(get_cr8);

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

void fx_init(struct kvm_vcpu *vcpu)
{
        unsigned after_mxcsr_mask;

        /* Initialize guest FPU by resetting ours and saving into guest's */
        preempt_disable();
        fx_save(&vcpu->host_fx_image);
        fpu_init();
        fx_save(&vcpu->guest_fx_image);
        fx_restore(&vcpu->host_fx_image);
        preempt_enable();

        vcpu->cr0 |= X86_CR0_ET;
        after_mxcsr_mask = offsetof(struct i387_fxsave_struct, st_space);
        vcpu->guest_fx_image.mxcsr = 0x1f80;
        memset((void *)&vcpu->guest_fx_image + after_mxcsr_mask,
               0, sizeof(struct i387_fxsave_struct) - after_mxcsr_mask);
}
EXPORT_SYMBOL_GPL(fx_init);

/*
 * Allocate some memory and give it an address in the guest physical address
 * space.
 *
 * Discontiguous memory is allowed, mostly for framebuffers.
 */
static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
                                          struct kvm_memory_region *mem)
{
        int r;
        gfn_t base_gfn;
        unsigned long npages;
        unsigned long i;
        struct kvm_memory_slot *memslot;
        struct kvm_memory_slot old, new;

        r = -EINVAL;
        /* General sanity checks */
        if (mem->memory_size & (PAGE_SIZE - 1))
                goto out;
        if (mem->guest_phys_addr & (PAGE_SIZE - 1))
                goto out;
        if (mem->slot >= KVM_MEMORY_SLOTS)
                goto out;
        if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
                goto out;

        memslot = &kvm->memslots[mem->slot];
        base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
        npages = mem->memory_size >> PAGE_SHIFT;

        if (!npages)
                mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;

        mutex_lock(&kvm->lock);

        new = old = *memslot;

        new.base_gfn = base_gfn;
        new.npages = npages;
        new.flags = mem->flags;

        /* Disallow changing a memory slot's size. */
        r = -EINVAL;
        if (npages && old.npages && npages != old.npages)
                goto out_unlock;

        /* Check for overlaps */
        r = -EEXIST;
        for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
                struct kvm_memory_slot *s = &kvm->memslots[i];

                if (s == memslot)
                        continue;
                if (!((base_gfn + npages <= s->base_gfn) ||
                      (base_gfn >= s->base_gfn + s->npages)))
                        goto out_unlock;
        }

        /* Deallocate if slot is being removed */
        if (!npages)
                new.phys_mem = NULL;

        /* Free page dirty bitmap if unneeded */
        if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
                new.dirty_bitmap = NULL;

        r = -ENOMEM;

        /* Allocate if a slot is being created */
        if (npages && !new.phys_mem) {
                new.phys_mem = vmalloc(npages * sizeof(struct page *));

                if (!new.phys_mem)
                        goto out_unlock;

                memset(new.phys_mem, 0, npages * sizeof(struct page *));
                for (i = 0; i < npages; ++i) {
                        new.phys_mem[i] = alloc_page(GFP_HIGHUSER
                                                     | __GFP_ZERO);
                        if (!new.phys_mem[i])
                                goto out_unlock;
                        set_page_private(new.phys_mem[i],0);
                }
        }

        /* Allocate page dirty bitmap if needed */
        if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
                unsigned dirty_bytes = ALIGN(npages, BITS_PER_LONG) / 8;

                new.dirty_bitmap = vmalloc(dirty_bytes);
                if (!new.dirty_bitmap)
                        goto out_unlock;
                memset(new.dirty_bitmap, 0, dirty_bytes);
        }

        if (mem->slot >= kvm->nmemslots)
                kvm->nmemslots = mem->slot + 1;

        *memslot = new;

        kvm_mmu_slot_remove_write_access(kvm, mem->slot);
        kvm_flush_remote_tlbs(kvm);

        mutex_unlock(&kvm->lock);

        kvm_free_physmem_slot(&old, &new);
        return 0;

out_unlock:
        mutex_unlock(&kvm->lock);
        kvm_free_physmem_slot(&new, &old);
out:
        return r;
}

/*
 * Get (and clear) the dirty memory log for a memory slot.
 */
static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
                                      struct kvm_dirty_log *log)
{
        struct kvm_memory_slot *memslot;
        int r, i;
        int n;
        unsigned long any = 0;

        mutex_lock(&kvm->lock);

        r = -EINVAL;
        if (log->slot >= KVM_MEMORY_SLOTS)
                goto out;

        memslot = &kvm->memslots[log->slot];
        r = -ENOENT;
        if (!memslot->dirty_bitmap)
                goto out;

        n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;

        for (i = 0; !any && i < n/sizeof(long); ++i)
                any = memslot->dirty_bitmap[i];

        r = -EFAULT;
        if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
                goto out;

        /* If nothing is dirty, don't bother messing with page tables. */
        if (any) {
                kvm_mmu_slot_remove_write_access(kvm, log->slot);
                kvm_flush_remote_tlbs(kvm);
                memset(memslot->dirty_bitmap, 0, n);
        }

        r = 0;

out:
        mutex_unlock(&kvm->lock);
        return r;
}

/*
 * Set a new alias region.  Aliases map a portion of physical memory into
 * another portion.  This is useful for memory windows, for example the PC
 * VGA region.
 */
static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
                                         struct kvm_memory_alias *alias)
{
        int r, n;
        struct kvm_mem_alias *p;

        r = -EINVAL;
        /* General sanity checks */
        if (alias->memory_size & (PAGE_SIZE - 1))
                goto out;
        if (alias->guest_phys_addr & (PAGE_SIZE - 1))
                goto out;
        if (alias->slot >= KVM_ALIAS_SLOTS)
                goto out;
        if (alias->guest_phys_addr + alias->memory_size
            < alias->guest_phys_addr)
                goto out;
        if (alias->target_phys_addr + alias->memory_size
            < alias->target_phys_addr)
                goto out;

        mutex_lock(&kvm->lock);

        p = &kvm->aliases[alias->slot];
        p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT;
        p->npages = alias->memory_size >> PAGE_SHIFT;
        p->target_gfn = alias->target_phys_addr >> PAGE_SHIFT;

        for (n = KVM_ALIAS_SLOTS; n > 0; --n)
                if (kvm->aliases[n - 1].npages)
                        break;
        kvm->naliases = n;

        kvm_mmu_zap_all(kvm);

        mutex_unlock(&kvm->lock);

        return 0;

out:
        return r;
}

static int kvm_vm_ioctl_get_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
{
        int r;

        r = 0;
        switch (chip->chip_id) {
        case KVM_IRQCHIP_PIC_MASTER:
                memcpy (&chip->chip.pic,
                        &pic_irqchip(kvm)->pics[0],
                        sizeof(struct kvm_pic_state));
                break;
        case KVM_IRQCHIP_PIC_SLAVE:
                memcpy (&chip->chip.pic,
                        &pic_irqchip(kvm)->pics[1],
                        sizeof(struct kvm_pic_state));
                break;
        case KVM_IRQCHIP_IOAPIC:
                memcpy (&chip->chip.ioapic,
                        ioapic_irqchip(kvm),
                        sizeof(struct kvm_ioapic_state));
                break;
        default:
                r = -EINVAL;
                break;
        }
        return r;
}

static int kvm_vm_ioctl_set_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
{
        int r;

        r = 0;
        switch (chip->chip_id) {
        case KVM_IRQCHIP_PIC_MASTER:
                memcpy (&pic_irqchip(kvm)->pics[0],
                        &chip->chip.pic,
                        sizeof(struct kvm_pic_state));
                break;
        case KVM_IRQCHIP_PIC_SLAVE:
                memcpy (&pic_irqchip(kvm)->pics[1],
                        &chip->chip.pic,
                        sizeof(struct kvm_pic_state));
                break;
        case KVM_IRQCHIP_IOAPIC:
                memcpy (ioapic_irqchip(kvm),
                        &chip->chip.ioapic,
                        sizeof(struct kvm_ioapic_state));
                break;
        default:
                r = -EINVAL;
                break;
        }
        kvm_pic_update_irq(pic_irqchip(kvm));
        return r;
}

static gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn)
{
        int i;
        struct kvm_mem_alias *alias;

        for (i = 0; i < kvm->naliases; ++i) {
                alias = &kvm->aliases[i];
                if (gfn >= alias->base_gfn
                    && gfn < alias->base_gfn + alias->npages)
                        return alias->target_gfn + gfn - alias->base_gfn;
        }
        return gfn;
}

static struct kvm_memory_slot *__gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
{
        int i;

        for (i = 0; i < kvm->nmemslots; ++i) {
                struct kvm_memory_slot *memslot = &kvm->memslots[i];

                if (gfn >= memslot->base_gfn
                    && gfn < memslot->base_gfn + memslot->npages)
                        return memslot;
        }
        return NULL;
}

struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
{
        gfn = unalias_gfn(kvm, gfn);
        return __gfn_to_memslot(kvm, gfn);
}

struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
{
        struct kvm_memory_slot *slot;

        gfn = unalias_gfn(kvm, gfn);
        slot = __gfn_to_memslot(kvm, gfn);
        if (!slot)
                return NULL;
        return slot->phys_mem[gfn - slot->base_gfn];
}
EXPORT_SYMBOL_GPL(gfn_to_page);

/* WARNING: Does not work on aliased pages. */
void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
{
        struct kvm_memory_slot *memslot;

        memslot = __gfn_to_memslot(kvm, gfn);
        if (memslot && memslot->dirty_bitmap) {
                unsigned long rel_gfn = gfn - memslot->base_gfn;

                /* avoid RMW */
                if (!test_bit(rel_gfn, memslot->dirty_bitmap))
                        set_bit(rel_gfn, memslot->dirty_bitmap);
        }
}

int emulator_read_std(unsigned long addr,
                             void *val,
                             unsigned int bytes,
                             struct kvm_vcpu *vcpu)
{
        void *data = val;

        while (bytes) {
                gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
                unsigned offset = addr & (PAGE_SIZE-1);
                unsigned tocopy = min(bytes, (unsigned)PAGE_SIZE - offset);
                unsigned long pfn;
                struct page *page;
                void *page_virt;

                if (gpa == UNMAPPED_GVA)
                        return X86EMUL_PROPAGATE_FAULT;
                pfn = gpa >> PAGE_SHIFT;
                page = gfn_to_page(vcpu->kvm, pfn);
                if (!page)
                        return X86EMUL_UNHANDLEABLE;
                page_virt = kmap_atomic(page, KM_USER0);

                memcpy(data, page_virt + offset, tocopy);

                kunmap_atomic(page_virt, KM_USER0);

                bytes -= tocopy;
                data += tocopy;
                addr += tocopy;
        }

        return X86EMUL_CONTINUE;
}
EXPORT_SYMBOL_GPL(emulator_read_std);

static int emulator_write_std(unsigned long addr,
                              const void *val,
                              unsigned int bytes,
                              struct kvm_vcpu *vcpu)
{
        pr_unimpl(vcpu, "emulator_write_std: addr %lx n %d\n", addr, bytes);
        return X86EMUL_UNHANDLEABLE;
}

/*
 * Only apic need an MMIO device hook, so shortcut now..
 */
static struct kvm_io_device *vcpu_find_pervcpu_dev(struct kvm_vcpu *vcpu,
                                                gpa_t addr)
{
        struct kvm_io_device *dev;

        if (vcpu->apic) {
                dev = &vcpu->apic->dev;
                if (dev->in_range(dev, addr))
                        return dev;
        }
        return NULL;
}

static struct kvm_io_device *vcpu_find_mmio_dev(struct kvm_vcpu *vcpu,
                                                gpa_t addr)
{
        struct kvm_io_device *dev;

        dev = vcpu_find_pervcpu_dev(vcpu, addr);
        if (dev == NULL)
                dev = kvm_io_bus_find_dev(&vcpu->kvm->mmio_bus, addr);
        return dev;
}

static struct kvm_io_device *vcpu_find_pio_dev(struct kvm_vcpu *vcpu,
                                               gpa_t addr)
{
        return kvm_io_bus_find_dev(&vcpu->kvm->pio_bus, addr);
}

static int emulator_read_emulated(unsigned long addr,
                                  void *val,
                                  unsigned int bytes,
                                  struct kvm_vcpu *vcpu)
{
        struct kvm_io_device *mmio_dev;
        gpa_t                 gpa;

        if (vcpu->mmio_read_completed) {
                memcpy(val, vcpu->mmio_data, bytes);
                vcpu->mmio_read_completed = 0;
                return X86EMUL_CONTINUE;
        } else if (emulator_read_std(addr, val, bytes, vcpu)
                   == X86EMUL_CONTINUE)
                return X86EMUL_CONTINUE;

        gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
        if (gpa == UNMAPPED_GVA)
                return X86EMUL_PROPAGATE_FAULT;

        /*
         * Is this MMIO handled locally?
         */
        mmio_dev = vcpu_find_mmio_dev(vcpu, gpa);
        if (mmio_dev) {
                kvm_iodevice_read(mmio_dev, gpa, bytes, val);
                return X86EMUL_CONTINUE;
        }

        vcpu->mmio_needed = 1;
        vcpu->mmio_phys_addr = gpa;
        vcpu->mmio_size = bytes;
        vcpu->mmio_is_write = 0;

        return X86EMUL_UNHANDLEABLE;
}

static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
                               const void *val, int bytes)
{
        struct page *page;
        void *virt;

        if (((gpa + bytes - 1) >> PAGE_SHIFT) != (gpa >> PAGE_SHIFT))
                return 0;
        page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
        if (!page)
                return 0;
        mark_page_dirty(vcpu->kvm, gpa >> PAGE_SHIFT);
        virt = kmap_atomic(page, KM_USER0);
        kvm_mmu_pte_write(vcpu, gpa, val, bytes);
        memcpy(virt + offset_in_page(gpa), val, bytes);
        kunmap_atomic(virt, KM_USER0);
        return 1;
}

static int emulator_write_emulated_onepage(unsigned long addr,
                                           const void *val,
                                           unsigned int bytes,
                                           struct kvm_vcpu *vcpu)
{
        struct kvm_io_device *mmio_dev;
        gpa_t                 gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);

        if (gpa == UNMAPPED_GVA) {
                kvm_x86_ops->inject_page_fault(vcpu, addr, 2);
                return X86EMUL_PROPAGATE_FAULT;
        }

        if (emulator_write_phys(vcpu, gpa, val, bytes))
                return X86EMUL_CONTINUE;

        /*
         * Is this MMIO handled locally?
         */
        mmio_dev = vcpu_find_mmio_dev(vcpu, gpa);
        if (mmio_dev) {
                kvm_iodevice_write(mmio_dev, gpa, bytes, val);
                return X86EMUL_CONTINUE;
        }

        vcpu->mmio_needed = 1;
        vcpu->mmio_phys_addr = gpa;
        vcpu->mmio_size = bytes;
        vcpu->mmio_is_write = 1;
        memcpy(vcpu->mmio_data, val, bytes);

        return X86EMUL_CONTINUE;
}

int emulator_write_emulated(unsigned long addr,
                                   const void *val,
                                   unsigned int bytes,
                                   struct kvm_vcpu *vcpu)
{
        /* Crossing a page boundary? */
        if (((addr + bytes - 1) ^ addr) & PAGE_MASK) {
                int rc, now;

                now = -addr & ~PAGE_MASK;
                rc = emulator_write_emulated_onepage(addr, val, now, vcpu);
                if (rc != X86EMUL_CONTINUE)
                        return rc;
                addr += now;
                val += now;
                bytes -= now;
        }
        return emulator_write_emulated_onepage(addr, val, bytes, vcpu);
}
EXPORT_SYMBOL_GPL(emulator_write_emulated);

static int emulator_cmpxchg_emulated(unsigned long addr,
                                     const void *old,
                                     const void *new,
                                     unsigned int bytes,
                                     struct kvm_vcpu *vcpu)
{
        static int reported;

        if (!reported) {
                reported = 1;
                printk(KERN_WARNING "kvm: emulating exchange as write\n");
        }
        return emulator_write_emulated(addr, new, bytes, vcpu);
}

static unsigned long get_segment_base(struct kvm_vcpu *vcpu, int seg)
{
        return kvm_x86_ops->get_segment_base(vcpu, seg);
}

int emulate_invlpg(struct kvm_vcpu *vcpu, gva_t address)
{
        return X86EMUL_CONTINUE;
}

int emulate_clts(struct kvm_vcpu *vcpu)
{
        kvm_x86_ops->set_cr0(vcpu, vcpu->cr0 & ~X86_CR0_TS);
        return X86EMUL_CONTINUE;
}

int emulator_get_dr(struct x86_emulate_ctxt* ctxt, int dr, unsigned long *dest)
{
        struct kvm_vcpu *vcpu = ctxt->vcpu;

        switch (dr) {
        case 0 ... 3:
                *dest = kvm_x86_ops->get_dr(vcpu, dr);
                return X86EMUL_CONTINUE;
        default:
                pr_unimpl(vcpu, "%s: unexpected dr %u\n", __FUNCTION__, dr);
                return X86EMUL_UNHANDLEABLE;
        }
}

int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr, unsigned long value)
{
        unsigned long mask = (ctxt->mode == X86EMUL_MODE_PROT64) ? ~0ULL : ~0U;
        int exception;

        kvm_x86_ops->set_dr(ctxt->vcpu, dr, value & mask, &exception);
        if (exception) {
                /* FIXME: better handling */
                return X86EMUL_UNHANDLEABLE;
        }
        return X86EMUL_CONTINUE;
}

void kvm_report_emulation_failure(struct kvm_vcpu *vcpu, const char *context)
{
        static int reported;
        u8 opcodes[4];
        unsigned long rip = vcpu->rip;
        unsigned long rip_linear;

        rip_linear = rip + get_segment_base(vcpu, VCPU_SREG_CS);

        if (reported)
                return;

        emulator_read_std(rip_linear, (void *)opcodes, 4, vcpu);

        printk(KERN_ERR "emulation failed (%s) rip %lx %02x %02x %02x %02x\n",
               context, rip, opcodes[0], opcodes[1], opcodes[2], opcodes[3]);
        reported = 1;
}
EXPORT_SYMBOL_GPL(kvm_report_emulation_failure);

struct x86_emulate_ops emulate_ops = {
        .read_std            = emulator_read_std,
        .write_std           = emulator_write_std,
        .read_emulated       = emulator_read_emulated,
        .write_emulated      = emulator_write_emulated,
        .cmpxchg_emulated    = emulator_cmpxchg_emulated,
};

int emulate_instruction(struct kvm_vcpu *vcpu,
                        struct kvm_run *run,
                        unsigned long cr2,
                        u16 error_code)
{
        struct x86_emulate_ctxt emulate_ctxt;
        int r;
        int cs_db, cs_l;

        vcpu->mmio_fault_cr2 = cr2;
        kvm_x86_ops->cache_regs(vcpu);

        kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);

        emulate_ctxt.vcpu = vcpu;
        emulate_ctxt.eflags = kvm_x86_ops->get_rflags(vcpu);
        emulate_ctxt.cr2 = cr2;
        emulate_ctxt.mode = (emulate_ctxt.eflags & X86_EFLAGS_VM)
                ? X86EMUL_MODE_REAL : cs_l
                ? X86EMUL_MODE_PROT64 : cs_db
                ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;

        if (emulate_ctxt.mode == X86EMUL_MODE_PROT64) {
                emulate_ctxt.cs_base = 0;
                emulate_ctxt.ds_base = 0;
                emulate_ctxt.es_base = 0;
                emulate_ctxt.ss_base = 0;
        } else {
                emulate_ctxt.cs_base = get_segment_base(vcpu, VCPU_SREG_CS);
                emulate_ctxt.ds_base = get_segment_base(vcpu, VCPU_SREG_DS);
                emulate_ctxt.es_base = get_segment_base(vcpu, VCPU_SREG_ES);
                emulate_ctxt.ss_base = get_segment_base(vcpu, VCPU_SREG_SS);
        }

        emulate_ctxt.gs_base = get_segment_base(vcpu, VCPU_SREG_GS);
        emulate_ctxt.fs_base = get_segment_base(vcpu, VCPU_SREG_FS);

        vcpu->mmio_is_write = 0;
        vcpu->pio.string = 0;
        r = x86_emulate_memop(&emulate_ctxt, &emulate_ops);
        if (vcpu->pio.string)
                return EMULATE_DO_MMIO;

        if ((r || vcpu->mmio_is_write) && run) {
                run->exit_reason = KVM_EXIT_MMIO;
                run->mmio.phys_addr = vcpu->mmio_phys_addr;
                memcpy(run->mmio.data, vcpu->mmio_data, 8);
                run->mmio.len = vcpu->mmio_size;
                run->mmio.is_write = vcpu->mmio_is_write;
        }

        if (r) {
                if (kvm_mmu_unprotect_page_virt(vcpu, cr2))
                        return EMULATE_DONE;
                if (!vcpu->mmio_needed) {
                        kvm_report_emulation_failure(vcpu, "mmio");
                        return EMULATE_FAIL;
                }
                return EMULATE_DO_MMIO;
        }

        kvm_x86_ops->decache_regs(vcpu);
        kvm_x86_ops->set_rflags(vcpu, emulate_ctxt.eflags);

        if (vcpu->mmio_is_write) {
                vcpu->mmio_needed = 0;
                return EMULATE_DO_MMIO;
        }

        return EMULATE_DONE;
}
EXPORT_SYMBOL_GPL(emulate_instruction);

/*
 * The vCPU has executed a HLT instruction with in-kernel mode enabled.
 */
static void kvm_vcpu_block(struct kvm_vcpu *vcpu)
{
        DECLARE_WAITQUEUE(wait, current);

        add_wait_queue(&vcpu->wq, &wait);

        /*
         * We will block until either an interrupt or a signal wakes us up
         */
        while (!kvm_cpu_has_interrupt(vcpu)
               && !signal_pending(current)
               && vcpu->mp_state != VCPU_MP_STATE_RUNNABLE
               && vcpu->mp_state != VCPU_MP_STATE_SIPI_RECEIVED) {
                set_current_state(TASK_INTERRUPTIBLE);
                vcpu_put(vcpu);
                schedule();
                vcpu_load(vcpu);
        }

        __set_current_state(TASK_RUNNING);
        remove_wait_queue(&vcpu->wq, &wait);
}

int kvm_emulate_halt(struct kvm_vcpu *vcpu)
{
        ++vcpu->stat.halt_exits;
        if (irqchip_in_kernel(vcpu->kvm)) {
                vcpu->mp_state = VCPU_MP_STATE_HALTED;
                kvm_vcpu_block(vcpu);
                if (vcpu->mp_state != VCPU_MP_STATE_RUNNABLE)
                        return -EINTR;
                return 1;
        } else {
                vcpu->run->exit_reason = KVM_EXIT_HLT;
                return 0;
        }
}
EXPORT_SYMBOL_GPL(kvm_emulate_halt);

int kvm_hypercall(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
        unsigned long nr, a0, a1, a2, a3, a4, a5, ret;

        kvm_x86_ops->cache_regs(vcpu);
        ret = -KVM_EINVAL;
#ifdef CONFIG_X86_64
        if (is_long_mode(vcpu)) {
                nr = vcpu->regs[VCPU_REGS_RAX];
                a0 = vcpu->regs[VCPU_REGS_RDI];
                a1 = vcpu->regs[VCPU_REGS_RSI];
                a2 = vcpu->regs[VCPU_REGS_RDX];
                a3 = vcpu->regs[VCPU_REGS_RCX];
                a4 = vcpu->regs[VCPU_REGS_R8];
                a5 = vcpu->regs[VCPU_REGS_R9];
        } else
#endif
        {
                nr = vcpu->regs[VCPU_REGS_RBX] & -1u;
                a0 = vcpu->regs[VCPU_REGS_RAX] & -1u;
                a1 = vcpu->regs[VCPU_REGS_RCX] & -1u;
                a2 = vcpu->regs[VCPU_REGS_RDX] & -1u;
                a3 = vcpu->regs[VCPU_REGS_RSI] & -1u;
                a4 = vcpu->regs[VCPU_REGS_RDI] & -1u;
                a5 = vcpu->regs[VCPU_REGS_RBP] & -1u;
        }
        switch (nr) {
        default:
                run->hypercall.nr = nr;
                run->hypercall.args[0] = a0;
                run->hypercall.args[1] = a1;
                run->hypercall.args[2] = a2;
                run->hypercall.args[3] = a3;
                run->hypercall.args[4] = a4;
                run->hypercall.args[5] = a5;
                run->hypercall.ret = ret;
                run->hypercall.longmode = is_long_mode(vcpu);
                kvm_x86_ops->decache_regs(vcpu);
                return 0;
        }
        vcpu->regs[VCPU_REGS_RAX] = ret;
        kvm_x86_ops->decache_regs(vcpu);
        return 1;
}
EXPORT_SYMBOL_GPL(kvm_hypercall);

static u64 mk_cr_64(u64 curr_cr, u32 new_val)
{
        return (curr_cr & ~((1ULL << 32) - 1)) | new_val;
}

void realmode_lgdt(struct kvm_vcpu *vcpu, u16 limit, unsigned long base)
{
        struct descriptor_table dt = { limit, base };

        kvm_x86_ops->set_gdt(vcpu, &dt);
}

void realmode_lidt(struct kvm_vcpu *vcpu, u16 limit, unsigned long base)
{
        struct descriptor_table dt = { limit, base };

        kvm_x86_ops->set_idt(vcpu, &dt);
}

void realmode_lmsw(struct kvm_vcpu *vcpu, unsigned long msw,
                   unsigned long *rflags)
{
        lmsw(vcpu, msw);
        *rflags = kvm_x86_ops->get_rflags(vcpu);
}

unsigned long realmode_get_cr(struct kvm_vcpu *vcpu, int cr)
{
        kvm_x86_ops->decache_cr4_guest_bits(vcpu);
        switch (cr) {
        case 0:
                return vcpu->cr0;
        case 2:
                return vcpu->cr2;
        case 3:
                return vcpu->cr3;
        case 4:
                return vcpu->cr4;
        default:
                vcpu_printf(vcpu, "%s: unexpected cr %u\n", __FUNCTION__, cr);
                return 0;
        }
}

void realmode_set_cr(struct kvm_vcpu *vcpu, int cr, unsigned long val,
                     unsigned long *rflags)
{
        switch (cr) {
        case 0:
                set_cr0(vcpu, mk_cr_64(vcpu->cr0, val));
                *rflags = kvm_x86_ops->get_rflags(vcpu);
                break;
        case 2:
                vcpu->cr2 = val;
                break;
        case 3:
                set_cr3(vcpu, val);
                break;
        case 4:
                set_cr4(vcpu, mk_cr_64(vcpu->cr4, val));
                break;
        default:
                vcpu_printf(vcpu, "%s: unexpected cr %u\n", __FUNCTION__, cr);
        }
}

/*
 * Register the para guest with the host:
 */
static int vcpu_register_para(struct kvm_vcpu *vcpu, gpa_t para_state_gpa)
{
        struct kvm_vcpu_para_state *para_state;
        hpa_t para_state_hpa, hypercall_hpa;
        struct page *para_state_page;
        unsigned char *hypercall;
        gpa_t hypercall_gpa;

        printk(KERN_DEBUG "kvm: guest trying to enter paravirtual mode\n");
        printk(KERN_DEBUG ".... para_state_gpa: %08Lx\n", para_state_gpa);

        /*
         * Needs to be page aligned:
         */
        if (para_state_gpa != PAGE_ALIGN(para_state_gpa))
                goto err_gp;

        para_state_hpa = gpa_to_hpa(vcpu, para_state_gpa);
        printk(KERN_DEBUG ".... para_state_hpa: %08Lx\n", para_state_hpa);
        if (is_error_hpa(para_state_hpa))
                goto err_gp;

        mark_page_dirty(vcpu->kvm, para_state_gpa >> PAGE_SHIFT);
        para_state_page = pfn_to_page(para_state_hpa >> PAGE_SHIFT);
        para_state = kmap(para_state_page);

        printk(KERN_DEBUG "....  guest version: %d\n", para_state->guest_version);
        printk(KERN_DEBUG "....           size: %d\n", para_state->size);

        para_state->host_version = KVM_PARA_API_VERSION;
        /*
         * We cannot support guests that try to register themselves
         * with a newer API version than the host supports:
         */
        if (para_state->guest_version > KVM_PARA_API_VERSION) {
                para_state->ret = -KVM_EINVAL;
                goto err_kunmap_skip;
        }

        hypercall_gpa = para_state->hypercall_gpa;
        hypercall_hpa = gpa_to_hpa(vcpu, hypercall_gpa);
        printk(KERN_DEBUG ".... hypercall_hpa: %08Lx\n", hypercall_hpa);
        if (is_error_hpa(hypercall_hpa)) {
                para_state->ret = -KVM_EINVAL;
                goto err_kunmap_skip;
        }

        printk(KERN_DEBUG "kvm: para guest successfully registered.\n");
        vcpu->para_state_page = para_state_page;
        vcpu->para_state_gpa = para_state_gpa;
        vcpu->hypercall_gpa = hypercall_gpa;

        mark_page_dirty(vcpu->kvm, hypercall_gpa >> PAGE_SHIFT);
        hypercall = kmap_atomic(pfn_to_page(hypercall_hpa >> PAGE_SHIFT),
                                KM_USER1) + (hypercall_hpa & ~PAGE_MASK);
        kvm_x86_ops->patch_hypercall(vcpu, hypercall);
        kunmap_atomic(hypercall, KM_USER1);

        para_state->ret = 0;
err_kunmap_skip:
        kunmap(para_state_page);
        return 0;
err_gp:
        return 1;
}

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

        switch (msr) {
        case 0xc0010010: /* SYSCFG */
        case 0xc0010015: /* HWCR */
        case MSR_IA32_PLATFORM_ID:
        case MSR_IA32_P5_MC_ADDR:
        case MSR_IA32_P5_MC_TYPE:
        case MSR_IA32_MC0_CTL:
        case MSR_IA32_MCG_STATUS:
        case MSR_IA32_MCG_CAP:
        case MSR_IA32_MC0_MISC:
        case MSR_IA32_MC0_MISC+4:
        case MSR_IA32_MC0_MISC+8:
        case MSR_IA32_MC0_MISC+12:
        case MSR_IA32_MC0_MISC+16:
        case MSR_IA32_UCODE_REV:
        case MSR_IA32_PERF_STATUS:
        case MSR_IA32_EBL_CR_POWERON:
                /* MTRR registers */
        case 0xfe:
        case 0x200 ... 0x2ff:
                data = 0;
                break;
        case 0xcd: /* fsb frequency */
                data = 3;
                break;
        case MSR_IA32_APICBASE:
                data = kvm_get_apic_base(vcpu);
                break;
        case MSR_IA32_MISC_ENABLE:
                data = vcpu->ia32_misc_enable_msr;
                break;
#ifdef CONFIG_X86_64
        case MSR_EFER:
                data = vcpu->shadow_efer;
                break;
#endif
        default:
                pr_unimpl(vcpu, "unhandled rdmsr: 0x%x\n", msr);
                return 1;
        }
        *pdata = data;
        return 0;
}
EXPORT_SYMBOL_GPL(kvm_get_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);
}

#ifdef CONFIG_X86_64

static void set_efer(struct kvm_vcpu *vcpu, u64 efer)
{
        if (efer & EFER_RESERVED_BITS) {
                printk(KERN_DEBUG "set_efer: 0x%llx #GP, reserved bits\n",
                       efer);
                inject_gp(vcpu);
                return;
        }

        if (is_paging(vcpu)
            && (vcpu->shadow_efer & EFER_LME) != (efer & EFER_LME)) {
                printk(KERN_DEBUG "set_efer: #GP, change LME while paging\n");
                inject_gp(vcpu);
                return;
        }

        kvm_x86_ops->set_efer(vcpu, efer);

        efer &= ~EFER_LMA;
        efer |= vcpu->shadow_efer & EFER_LMA;

        vcpu->shadow_efer = efer;
}

#endif

int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
{
        switch (msr) {
#ifdef CONFIG_X86_64
        case MSR_EFER:
                set_efer(vcpu, data);
                break;
#endif
        case MSR_IA32_MC0_STATUS:
                pr_unimpl(vcpu, "%s: MSR_IA32_MC0_STATUS 0x%llx, nop\n",
                       __FUNCTION__, data);
                break;
        case MSR_IA32_MCG_STATUS:
                pr_unimpl(vcpu, "%s: MSR_IA32_MCG_STATUS 0x%llx, nop\n",
                        __FUNCTION__, data);
                break;
        case MSR_IA32_UCODE_REV:
        case MSR_IA32_UCODE_WRITE:
        case 0x200 ... 0x2ff: /* MTRRs */
                break;
        case MSR_IA32_APICBASE:
                kvm_set_apic_base(vcpu, data);
                break;
        case MSR_IA32_MISC_ENABLE:
                vcpu->ia32_misc_enable_msr = data;
                break;
        /*
         * This is the 'probe whether the host is KVM' logic:
         */
        case MSR_KVM_API_MAGIC:
                return vcpu_register_para(vcpu, data);

        default:
                pr_unimpl(vcpu, "unhandled wrmsr: 0x%x\n", msr);
                return 1;
        }
        return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_msr_common);

/*
 * 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);
}

void kvm_resched(struct kvm_vcpu *vcpu)
{
        if (!need_resched())
                return;
        cond_resched();
}
EXPORT_SYMBOL_GPL(kvm_resched);

void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
{
        int i;
        u32 function;
        struct kvm_cpuid_entry *e, *best;

        kvm_x86_ops->cache_regs(vcpu);
        function = vcpu->regs[VCPU_REGS_RAX];
        vcpu->regs[VCPU_REGS_RAX] = 0;
        vcpu->regs[VCPU_REGS_RBX] = 0;
        vcpu->regs[VCPU_REGS_RCX] = 0;
        vcpu->regs[VCPU_REGS_RDX] = 0;
        best = NULL;
        for (i = 0; i < vcpu->cpuid_nent; ++i) {
                e = &vcpu->cpuid_entries[i];
                if (e->function == function) {
                        best = e;
                        break;
                }
                /*
                 * Both basic or both extended?
                 */
                if (((e->function ^ function) & 0x80000000) == 0)
                        if (!best || e->function > best->function)
                                best = e;
        }
        if (best) {
                vcpu->regs[VCPU_REGS_RAX] = best->eax;
                vcpu->regs[VCPU_REGS_RBX] = best->ebx;
                vcpu->regs[VCPU_REGS_RCX] = best->ecx;
                vcpu->regs[VCPU_REGS_RDX] = best->edx;
        }
        kvm_x86_ops->decache_regs(vcpu);
        kvm_x86_ops->skip_emulated_instruction(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);

static int pio_copy_data(struct kvm_vcpu *vcpu)
{
        void *p = vcpu->pio_data;
        void *q;
        unsigned bytes;
        int nr_pages = vcpu->pio.guest_pages[1] ? 2 : 1;

        q = vmap(vcpu->pio.guest_pages, nr_pages, VM_READ|VM_WRITE,
                 PAGE_KERNEL);
        if (!q) {
                free_pio_guest_pages(vcpu);
                return -ENOMEM;
        }
        q += vcpu->pio.guest_page_offset;
        bytes = vcpu->pio.size * vcpu->pio.cur_count;
        if (vcpu->pio.in)
                memcpy(q, p, bytes);
        else
                memcpy(p, q, bytes);
        q -= vcpu->pio.guest_page_offset;
        vunmap(q);
        free_pio_guest_pages(vcpu);
        return 0;
}

static int complete_pio(struct kvm_vcpu *vcpu)
{
        struct kvm_pio_request *io = &vcpu->pio;
        long delta;
        int r;

        kvm_x86_ops->cache_regs(vcpu);

        if (!io->string) {
                if (io->in)
                        memcpy(&vcpu->regs[VCPU_REGS_RAX], vcpu->pio_data,
                               io->size);
        } else {
                if (io->in) {
                        r = pio_copy_data(vcpu);
                        if (r) {
                                kvm_x86_ops->cache_regs(vcpu);
                                return r;
                        }
                }

                delta = 1;
                if (io->rep) {
                        delta *= io->cur_count;
                        /*
                         * The size of the register should really depend on
                         * current address size.
                         */
                        vcpu->regs[VCPU_REGS_RCX] -= delta;
                }
                if (io->down)
                        delta = -delta;
                delta *= io->size;
                if (io->in)
                        vcpu->regs[VCPU_REGS_RDI] += delta;
                else
                        vcpu->regs[VCPU_REGS_RSI] += delta;
        }

        kvm_x86_ops->decache_regs(vcpu);

        io->count -= io->cur_count;
        io->cur_count = 0;

        return 0;
}

static void kernel_pio(struct kvm_io_device *pio_dev,
                       struct kvm_vcpu *vcpu,
                       void *pd)
{
        /* TODO: String I/O for in kernel device */

        mutex_lock(&vcpu->kvm->lock);
        if (vcpu->pio.in)
                kvm_iodevice_read(pio_dev, vcpu->pio.port,
                                  vcpu->pio.size,
                                  pd);
        else
                kvm_iodevice_write(pio_dev, vcpu->pio.port,
                                   vcpu->pio.size,
                                   pd);
        mutex_unlock(&vcpu->kvm->lock);
}

static void pio_string_write(struct kvm_io_device *pio_dev,
                             struct kvm_vcpu *vcpu)
{
        struct kvm_pio_request *io = &vcpu->pio;
        void *pd = vcpu->pio_data;
        int i;

        mutex_lock(&vcpu->kvm->lock);
        for (i = 0; i < io->cur_count; i++) {
                kvm_iodevice_write(pio_dev, io->port,
                                   io->size,
                                   pd);
                pd += io->size;
        }
        mutex_unlock(&vcpu->kvm->lock);
}

int kvm_emulate_pio (struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
                  int size, unsigned port)
{
        struct kvm_io_device *pio_dev;

        vcpu->run->exit_reason = KVM_EXIT_IO;
        vcpu->run->io.direction = in ? KVM_EXIT_IO_IN : KVM_EXIT_IO_OUT;
        vcpu->run->io.size = vcpu->pio.size = size;
        vcpu->run->io.data_offset = KVM_PIO_PAGE_OFFSET * PAGE_SIZE;
        vcpu->run->io.count = vcpu->pio.count = vcpu->pio.cur_count = 1;
        vcpu->run->io.port = vcpu->pio.port = port;
        vcpu->pio.in = in;
        vcpu->pio.string = 0;
        vcpu->pio.down = 0;
        vcpu->pio.guest_page_offset = 0;
        vcpu->pio.rep = 0;

        kvm_x86_ops->cache_regs(vcpu);
        memcpy(vcpu->pio_data, &vcpu->regs[VCPU_REGS_RAX], 4);
        kvm_x86_ops->decache_regs(vcpu);

        kvm_x86_ops->skip_emulated_instruction(vcpu);

        pio_dev = vcpu_find_pio_dev(vcpu, port);
        if (pio_dev) {
                kernel_pio(pio_dev, vcpu, vcpu->pio_data);
                complete_pio(vcpu);
                return 1;
        }
        return 0;
}
EXPORT_SYMBOL_GPL(kvm_emulate_pio);

int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
                  int size, unsigned long count, int down,
                  gva_t address, int rep, unsigned port)
{
        unsigned now, in_page;
        int i, ret = 0;
        int nr_pages = 1;
        struct page *page;
        struct kvm_io_device *pio_dev;

        vcpu->run->exit_reason = KVM_EXIT_IO;
        vcpu->run->io.direction = in ? KVM_EXIT_IO_IN : KVM_EXIT_IO_OUT;
        vcpu->run->io.size = vcpu->pio.size = size;
        vcpu->run->io.data_offset = KVM_PIO_PAGE_OFFSET * PAGE_SIZE;
        vcpu->run->io.count = vcpu->pio.count = vcpu->pio.cur_count = count;
        vcpu->run->io.port = vcpu->pio.port = port;
        vcpu->pio.in = in;
        vcpu->pio.string = 1;
        vcpu->pio.down = down;
        vcpu->pio.guest_page_offset = offset_in_page(address);
        vcpu->pio.rep = rep;

        if (!count) {
                kvm_x86_ops->skip_emulated_instruction(vcpu);
                return 1;
        }

        if (!down)
                in_page = PAGE_SIZE - offset_in_page(address);
        else
                in_page = offset_in_page(address) + size;
        now = min(count, (unsigned long)in_page / size);
        if (!now) {
                /*
                 * String I/O straddles page boundary.  Pin two guest pages
                 * so that we satisfy atomicity constraints.  Do just one
                 * transaction to avoid complexity.
                 */
                nr_pages = 2;
                now = 1;
        }
        if (down) {
                /*
                 * String I/O in reverse.  Yuck.  Kill the guest, fix later.
                 */
                pr_unimpl(vcpu, "guest string pio down\n");
                inject_gp(vcpu);
                return 1;
        }
        vcpu->run->io.count = now;
        vcpu->pio.cur_count = now;

        if (vcpu->pio.cur_count == vcpu->pio.count)
                kvm_x86_ops->skip_emulated_instruction(vcpu);

        for (i = 0; i < nr_pages; ++i) {
                mutex_lock(&vcpu->kvm->lock);
                page = gva_to_page(vcpu, address + i * PAGE_SIZE);
                if (page)
                        get_page(page);
                vcpu->pio.guest_pages[i] = page;
                mutex_unlock(&vcpu->kvm->lock);
                if (!page) {
                        inject_gp(vcpu);
                        free_pio_guest_pages(vcpu);
                        return 1;
                }
        }

        pio_dev = vcpu_find_pio_dev(vcpu, port);
        if (!vcpu->pio.in) {
                /* string PIO write */
                ret = pio_copy_data(vcpu);
                if (ret >= 0 && pio_dev) {
                        pio_string_write(pio_dev, vcpu);
                        complete_pio(vcpu);
                        if (vcpu->pio.count == 0)
                                ret = 1;
                }
        } else if (pio_dev)
                pr_unimpl(vcpu, "no string pio read support yet, "
                       "port %x size %d count %ld\n",
                        port, size, count);

        return ret;
}
EXPORT_SYMBOL_GPL(kvm_emulate_pio_string);

/*
 * Check if userspace requested an interrupt window, and that the
 * interrupt window is open.
 *
 * No need to exit to userspace if we already have an interrupt queued.
 */
static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu,
                                          struct kvm_run *kvm_run)
{
        return (!vcpu->irq_summary &&
                kvm_run->request_interrupt_window &&
                vcpu->interrupt_window_open &&
                (kvm_x86_ops->get_rflags(vcpu) & X86_EFLAGS_IF));
}

static void post_kvm_run_save(struct kvm_vcpu *vcpu,
                              struct kvm_run *kvm_run)
{
        kvm_run->if_flag = (kvm_x86_ops->get_rflags(vcpu) & X86_EFLAGS_IF) != 0;
        kvm_run->cr8 = get_cr8(vcpu);
        kvm_run->apic_base = kvm_get_apic_base(vcpu);
        if (irqchip_in_kernel(vcpu->kvm))
                kvm_run->ready_for_interrupt_injection = 1;
        else
                kvm_run->ready_for_interrupt_injection =
                                        (vcpu->interrupt_window_open &&
                                         vcpu->irq_summary == 0);
}

static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        int r;

        if (unlikely(vcpu->mp_state == VCPU_MP_STATE_SIPI_RECEIVED)) {
                printk("vcpu %d received sipi with vector # %x\n",
                       vcpu->vcpu_id, vcpu->sipi_vector);
                kvm_lapic_reset(vcpu);
                kvm_x86_ops->vcpu_reset(vcpu);
                vcpu->mp_state = VCPU_MP_STATE_RUNNABLE;
        }

preempted:
        if (vcpu->guest_debug.enabled)
                kvm_x86_ops->guest_debug_pre(vcpu);

again:
        r = kvm_mmu_reload(vcpu);
        if (unlikely(r))
                goto out;

        preempt_disable();

        kvm_x86_ops->prepare_guest_switch(vcpu);
        kvm_load_guest_fpu(vcpu);

        local_irq_disable();

        if (signal_pending(current)) {
                local_irq_enable();
                preempt_enable();
                r = -EINTR;
                kvm_run->exit_reason = KVM_EXIT_INTR;
                ++vcpu->stat.signal_exits;
                goto out;
        }

        if (irqchip_in_kernel(vcpu->kvm))
                kvm_x86_ops->inject_pending_irq(vcpu);
        else if (!vcpu->mmio_read_completed)
                kvm_x86_ops->inject_pending_vectors(vcpu, kvm_run);

        vcpu->guest_mode = 1;
        kvm_guest_enter();

        if (vcpu->requests)
                if (test_and_clear_bit(KVM_TLB_FLUSH, &vcpu->requests))
                        kvm_x86_ops->tlb_flush(vcpu);

        kvm_x86_ops->run(vcpu, kvm_run);

        vcpu->guest_mode = 0;
        local_irq_enable();

        ++vcpu->stat.exits;

        /*
         * We must have an instruction between local_irq_enable() and
         * kvm_guest_exit(), so the timer interrupt isn't delayed by
         * the interrupt shadow.  The stat.exits increment will do nicely.
         * But we need to prevent reordering, hence this barrier():
         */
        barrier();

        kvm_guest_exit();

        preempt_enable();

        /*
         * Profile KVM exit RIPs:
         */
        if (unlikely(prof_on == KVM_PROFILING)) {
                kvm_x86_ops->cache_regs(vcpu);
                profile_hit(KVM_PROFILING, (void *)vcpu->rip);
        }

        r = kvm_x86_ops->handle_exit(kvm_run, vcpu);

        if (r > 0) {
                if (dm_request_for_irq_injection(vcpu, kvm_run)) {
                        r = -EINTR;
                        kvm_run->exit_reason = KVM_EXIT_INTR;
                        ++vcpu->stat.request_irq_exits;
                        goto out;
                }
                if (!need_resched()) {
                        ++vcpu->stat.light_exits;
                        goto again;
                }
        }

out:
        if (r > 0) {
                kvm_resched(vcpu);
                goto preempted;
        }

        post_kvm_run_save(vcpu, kvm_run);

        return r;
}


static int kvm_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
        int r;
        sigset_t sigsaved;

        vcpu_load(vcpu);

        if (unlikely(vcpu->mp_state == VCPU_MP_STATE_UNINITIALIZED)) {
                kvm_vcpu_block(vcpu);
                vcpu_put(vcpu);
                return -EAGAIN;
        }

        if (vcpu->sigset_active)
                sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);

        /* re-sync apic's tpr */
        if (!irqchip_in_kernel(vcpu->kvm))
                set_cr8(vcpu, kvm_run->cr8);

        if (vcpu->pio.cur_count) {
                r = complete_pio(vcpu);
                if (r)
                        goto out;
        }

        if (vcpu->mmio_needed) {
                memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);
                vcpu->mmio_read_completed = 1;
                vcpu->mmio_needed = 0;
                r = emulate_instruction(vcpu, kvm_run,
                                        vcpu->mmio_fault_cr2, 0);
                if (r == EMULATE_DO_MMIO) {
                        /*
                         * Read-modify-write.  Back to userspace.
                         */
                        r = 0;
                        goto out;
                }
        }

        if (kvm_run->exit_reason == KVM_EXIT_HYPERCALL) {
                kvm_x86_ops->cache_regs(vcpu);
                vcpu->regs[VCPU_REGS_RAX] = kvm_run->hypercall.ret;
                kvm_x86_ops->decache_regs(vcpu);
        }

        r = __vcpu_run(vcpu, kvm_run);

out:
        if (vcpu->sigset_active)
                sigprocmask(SIG_SETMASK, &sigsaved, NULL);

        vcpu_put(vcpu);
        return r;
}

static int kvm_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu,
                                   struct kvm_regs *regs)
{
        vcpu_load(vcpu);

        kvm_x86_ops->cache_regs(vcpu);

        regs->rax = vcpu->regs[VCPU_REGS_RAX];
        regs->rbx = vcpu->regs[VCPU_REGS_RBX];
        regs->rcx = vcpu->regs[VCPU_REGS_RCX];
        regs->rdx = vcpu->regs[VCPU_REGS_RDX];
        regs->rsi = vcpu->regs[VCPU_REGS_RSI];
        regs->rdi = vcpu->regs[VCPU_REGS_RDI];
        regs->rsp = vcpu->regs[VCPU_REGS_RSP];
        regs->rbp = vcpu->regs[VCPU_REGS_RBP];
#ifdef CONFIG_X86_64
        regs->r8 = vcpu->regs[VCPU_REGS_R8];
        regs->r9 = vcpu->regs[VCPU_REGS_R9];
        regs->r10 = vcpu->regs[VCPU_REGS_R10];
        regs->r11 = vcpu->regs[VCPU_REGS_R11];
        regs->r12 = vcpu->regs[VCPU_REGS_R12];
        regs->r13 = vcpu->regs[VCPU_REGS_R13];
        regs->r14 = vcpu->regs[VCPU_REGS_R14];
        regs->r15 = vcpu->regs[VCPU_REGS_R15];
#endif

        regs->rip = vcpu->rip;
        regs->rflags = kvm_x86_ops->get_rflags(vcpu);

        /*
         * Don't leak debug flags in case they were set for guest debugging
         */
        if (vcpu->guest_debug.enabled && vcpu->guest_debug.singlestep)
                regs->rflags &= ~(X86_EFLAGS_TF | X86_EFLAGS_RF);

        vcpu_put(vcpu);

        return 0;
}

static int kvm_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu,
                                   struct kvm_regs *regs)
{
        vcpu_load(vcpu);

        vcpu->regs[VCPU_REGS_RAX] = regs->rax;
        vcpu->regs[VCPU_REGS_RBX] = regs->rbx;
        vcpu->regs[VCPU_REGS_RCX] = regs->rcx;
        vcpu->regs[VCPU_REGS_RDX] = regs->rdx;
        vcpu->regs[VCPU_REGS_RSI] = regs->rsi;
        vcpu->regs[VCPU_REGS_RDI] = regs->rdi;
        vcpu->regs[VCPU_REGS_RSP] = regs->rsp;
        vcpu->regs[VCPU_REGS_RBP] = regs->rbp;
#ifdef CONFIG_X86_64
        vcpu->regs[VCPU_REGS_R8] = regs->r8;
        vcpu->regs[VCPU_REGS_R9] = regs->r9;
        vcpu->regs[VCPU_REGS_R10] = regs->r10;
        vcpu->regs[VCPU_REGS_R11] = regs->r11;
        vcpu->regs[VCPU_REGS_R12] = regs->r12;
        vcpu->regs[VCPU_REGS_R13] = regs->r13;
        vcpu->regs[VCPU_REGS_R14] = regs->r14;
        vcpu->regs[VCPU_REGS_R15] = regs->r15;
#endif

        vcpu->rip = regs->rip;
        kvm_x86_ops->set_rflags(vcpu, regs->rflags);

        kvm_x86_ops->decache_regs(vcpu);

        vcpu_put(vcpu);

        return 0;
}

static void get_segment(struct kvm_vcpu *vcpu,
                        struct kvm_segment *var, int seg)
{
        return kvm_x86_ops->get_segment(vcpu, var, seg);
}

static int kvm_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
                                    struct kvm_sregs *sregs)
{
        struct descriptor_table dt;
        int pending_vec;

        vcpu_load(vcpu);

        get_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
        get_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
        get_segment(vcpu, &sregs->es, VCPU_SREG_ES);
        get_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
        get_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
        get_segment(vcpu, &sregs->ss, VCPU_SREG_SS);

        get_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
        get_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);

        kvm_x86_ops->get_idt(vcpu, &dt);
        sregs->idt.limit = dt.limit;
        sregs->idt.base = dt.base;
        kvm_x86_ops->get_gdt(vcpu, &dt);
        sregs->gdt.limit = dt.limit;
        sregs->gdt.base = dt.base;

        kvm_x86_ops->decache_cr4_guest_bits(vcpu);
        sregs->cr0 = vcpu->cr0;
        sregs->cr2 = vcpu->cr2;
        sregs->cr3 = vcpu->cr3;
        sregs->cr4 = vcpu->cr4;
        sregs->cr8 = get_cr8(vcpu);
        sregs->efer = vcpu->shadow_efer;
        sregs->apic_base = kvm_get_apic_base(vcpu);

        if (irqchip_in_kernel(vcpu->kvm)) {
                memset(sregs->interrupt_bitmap, 0,
                       sizeof sregs->interrupt_bitmap);
                pending_vec = kvm_x86_ops->get_irq(vcpu);
                if (pending_vec >= 0)
                        set_bit(pending_vec, (unsigned long *)sregs->interrupt_bitmap);
        } else
                memcpy(sregs->interrupt_bitmap, vcpu->irq_pending,
                       sizeof sregs->interrupt_bitmap);

        vcpu_put(vcpu);

        return 0;
}

static void set_segment(struct kvm_vcpu *vcpu,
                        struct kvm_segment *var, int seg)
{
        return kvm_x86_ops->set_segment(vcpu, var, seg);
}

static int kvm_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
                                    struct kvm_sregs *sregs)
{
        int mmu_reset_needed = 0;
        int i, pending_vec, max_bits;
        struct descriptor_table dt;

        vcpu_load(vcpu);

        dt.limit = sregs->idt.limit;
        dt.base = sregs->idt.base;
        kvm_x86_ops->set_idt(vcpu, &dt);
        dt.limit = sregs->gdt.limit;
        dt.base = sregs->gdt.base;
        kvm_x86_ops->set_gdt(vcpu, &dt);

        vcpu->cr2 = sregs->cr2;
        mmu_reset_needed |= vcpu->cr3 != sregs->cr3;
        vcpu->cr3 = sregs->cr3;

        set_cr8(vcpu, sregs->cr8);

        mmu_reset_needed |= vcpu->shadow_efer != sregs->efer;
#ifdef CONFIG_X86_64
        kvm_x86_ops->set_efer(vcpu, sregs->efer);
#endif
        kvm_set_apic_base(vcpu, sregs->apic_base);

        kvm_x86_ops->decache_cr4_guest_bits(vcpu);

        mmu_reset_needed |= vcpu->cr0 != sregs->cr0;
        vcpu->cr0 = sregs->cr0;
        kvm_x86_ops->set_cr0(vcpu, sregs->cr0);

        mmu_reset_needed |= vcpu->cr4 != sregs->cr4;
        kvm_x86_ops->set_cr4(vcpu, sregs->cr4);
        if (!is_long_mode(vcpu) && is_pae(vcpu))
                load_pdptrs(vcpu, vcpu->cr3);

        if (mmu_reset_needed)
                kvm_mmu_reset_context(vcpu);

        if (!irqchip_in_kernel(vcpu->kvm)) {
                memcpy(vcpu->irq_pending, sregs->interrupt_bitmap,
                       sizeof vcpu->irq_pending);
                vcpu->irq_summary = 0;
                for (i = 0; i < ARRAY_SIZE(vcpu->irq_pending); ++i)
                        if (vcpu->irq_pending[i])
                                __set_bit(i, &vcpu->irq_summary);
        } else {
                max_bits = (sizeof sregs->interrupt_bitmap) << 3;
                pending_vec = find_first_bit(
                        (const unsigned long *)sregs->interrupt_bitmap,
                        max_bits);
                /* Only pending external irq is handled here */
                if (pending_vec < max_bits) {
                        kvm_x86_ops->set_irq(vcpu, pending_vec);
                        printk("Set back pending irq %d\n", pending_vec);
                }
        }

        set_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
        set_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
        set_segment(vcpu, &sregs->es, VCPU_SREG_ES);
        set_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
        set_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
        set_segment(vcpu, &sregs->ss, VCPU_SREG_SS);

        set_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
        set_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);

        vcpu_put(vcpu);

        return 0;
}

void kvm_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l)
{
        struct kvm_segment cs;

        get_segment(vcpu, &cs, VCPU_SREG_CS);
        *db = cs.db;
        *l = cs.l;
}
EXPORT_SYMBOL_GPL(kvm_get_cs_db_l_bits);

/*
 * 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.
 */
static u32 msrs_to_save[] = {
        MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
        MSR_K6_STAR,
#ifdef CONFIG_X86_64
        MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
#endif
        MSR_IA32_TIME_STAMP_COUNTER,
};

static unsigned num_msrs_to_save;

static u32 emulated_msrs[] = {
        MSR_IA32_MISC_ENABLE,
};

static __init void kvm_init_msr_list(void)
{
        u32 dummy[2];
        unsigned i, j;

        for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) {
                if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0)
                        continue;
                if (j < i)
                        msrs_to_save[j] = msrs_to_save[i];
                j++;
        }
        num_msrs_to_save = j;
}

/*
 * 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);
}

/*
 * 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;

        vcpu_load(vcpu);

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

        vcpu_put(vcpu);

        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 = vmalloc(size);
        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:
        vfree(entries);
out:
        return r;
}

/*
 * Translate a guest virtual address to a guest physical address.
 */
static int kvm_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
                                    struct kvm_translation *tr)
{
        unsigned long vaddr = tr->linear_address;
        gpa_t gpa;

        vcpu_load(vcpu);
        mutex_lock(&vcpu->kvm->lock);
        gpa = vcpu->mmu.gva_to_gpa(vcpu, vaddr);
        tr->physical_address = gpa;
        tr->valid = gpa != UNMAPPED_GVA;
        tr->writeable = 1;
        tr->usermode = 0;
        mutex_unlock(&vcpu->kvm->lock);
        vcpu_put(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;
        vcpu_load(vcpu);

        set_bit(irq->irq, vcpu->irq_pending);
        set_bit(irq->irq / BITS_PER_LONG, &vcpu->irq_summary);

        vcpu_put(vcpu);

        return 0;
}

static int kvm_vcpu_ioctl_debug_guest(struct kvm_vcpu *vcpu,
                                      struct kvm_debug_guest *dbg)
{
        int r;

        vcpu_load(vcpu);

        r = kvm_x86_ops->set_guest_debug(vcpu, dbg);

        vcpu_put(vcpu);

        return r;
}

static struct page *kvm_vcpu_nopage(struct vm_area_struct *vma,
                                    unsigned long address,
                                    int *type)
{
        struct kvm_vcpu *vcpu = vma->vm_file->private_data;
        unsigned long pgoff;
        struct page *page;

        pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
        if (pgoff == 0)
                page = virt_to_page(vcpu->run);
        else if (pgoff == KVM_PIO_PAGE_OFFSET)
                page = virt_to_page(vcpu->pio_data);
        else
                return NOPAGE_SIGBUS;
        get_page(page);
        if (type != NULL)
                *type = VM_FAULT_MINOR;

        return page;
}

static struct vm_operations_struct kvm_vcpu_vm_ops = {
        .nopage = kvm_vcpu_nopage,
};

static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
{
        vma->vm_ops = &kvm_vcpu_vm_ops;
        return 0;
}

static int kvm_vcpu_release(struct inode *inode, struct file *filp)
{
        struct kvm_vcpu *vcpu = filp->private_data;

        fput(vcpu->kvm->filp);
        return 0;
}

static struct file_operations kvm_vcpu_fops = {
        .release        = kvm_vcpu_release,
        .unlocked_ioctl = kvm_vcpu_ioctl,
        .compat_ioctl   = kvm_vcpu_ioctl,
        .mmap           = kvm_vcpu_mmap,
};

/*
 * Allocates an inode for the vcpu.
 */
static int create_vcpu_fd(struct kvm_vcpu *vcpu)
{
        int fd, r;
        struct inode *inode;
        struct file *file;

        r = anon_inode_getfd(&fd, &inode, &file,
                             "kvm-vcpu", &kvm_vcpu_fops, vcpu);
        if (r)
                return r;
        atomic_inc(&vcpu->kvm->filp->f_count);
        return fd;
}

/*
 * Creates some virtual cpus.  Good luck creating more than one.
 */
static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
{
        int r;
        struct kvm_vcpu *vcpu;

        if (!valid_vcpu(n))
                return -EINVAL;

        vcpu = kvm_x86_ops->vcpu_create(kvm, n);
        if (IS_ERR(vcpu))
                return PTR_ERR(vcpu);

        preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);

        /* We do fxsave: this must be aligned. */
        BUG_ON((unsigned long)&vcpu->host_fx_image & 0xF);

        vcpu_load(vcpu);
        r = kvm_mmu_setup(vcpu);
        vcpu_put(vcpu);
        if (r < 0)
                goto free_vcpu;

        mutex_lock(&kvm->lock);
        if (kvm->vcpus[n]) {
                r = -EEXIST;
                mutex_unlock(&kvm->lock);
                goto mmu_unload;
        }
        kvm->vcpus[n] = vcpu;
        mutex_unlock(&kvm->lock);

        /* Now it's all set up, let userspace reach it */
        r = create_vcpu_fd(vcpu);
        if (r < 0)
                goto unlink;
        return r;

unlink:
        mutex_lock(&kvm->lock);
        kvm->vcpus[n] = NULL;
        mutex_unlock(&kvm->lock);

mmu_unload:
        vcpu_load(vcpu);
        kvm_mmu_unload(vcpu);
        vcpu_put(vcpu);

free_vcpu:
        kvm_x86_ops->vcpu_free(vcpu);
        return r;
}

static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
{
        u64 efer;
        int i;
        struct kvm_cpuid_entry *e, *entry;

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

static int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
                                    struct kvm_cpuid *cpuid,
                                    struct kvm_cpuid_entry __user *entries)
{
        int r;

        r = -E2BIG;
        if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
                goto out;
        r = -EFAULT;
        if (copy_from_user(&vcpu->cpuid_entries, entries,
                           cpuid->nent * sizeof(struct kvm_cpuid_entry)))
                goto out;
        vcpu->cpuid_nent = cpuid->nent;
        cpuid_fix_nx_cap(vcpu);
        return 0;

out:
        return r;
}

static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
{
        if (sigset) {
                sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
                vcpu->sigset_active = 1;
                vcpu->sigset = *sigset;
        } else
                vcpu->sigset_active = 0;
        return 0;
}

/*
 * fxsave fpu state.  Taken from x86_64/processor.h.  To be killed when
 * we have asm/x86/processor.h
 */
struct fxsave {
        u16     cwd;
        u16     swd;
        u16     twd;
        u16     fop;
        u64     rip;
        u64     rdp;
        u32     mxcsr;
        u32     mxcsr_mask;
        u32     st_space[32];   /* 8*16 bytes for each FP-reg = 128 bytes */
#ifdef CONFIG_X86_64
        u32     xmm_space[64];  /* 16*16 bytes for each XMM-reg = 256 bytes */
#else
        u32     xmm_space[32];  /* 8*16 bytes for each XMM-reg = 128 bytes */
#endif
};

static int kvm_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
        struct fxsave *fxsave = (struct fxsave *)&vcpu->guest_fx_image;

        vcpu_load(vcpu);

        memcpy(fpu->fpr, fxsave->st_space, 128);
        fpu->fcw = fxsave->cwd;
        fpu->fsw = fxsave->swd;
        fpu->ftwx = fxsave->twd;
        fpu->last_opcode = fxsave->fop;
        fpu->last_ip = fxsave->rip;
        fpu->last_dp = fxsave->rdp;
        memcpy(fpu->xmm, fxsave->xmm_space, sizeof fxsave->xmm_space);

        vcpu_put(vcpu);

        return 0;
}

static int kvm_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
        struct fxsave *fxsave = (struct fxsave *)&vcpu->guest_fx_image;

        vcpu_load(vcpu);

        memcpy(fxsave->st_space, fpu->fpr, 128);
        fxsave->cwd = fpu->fcw;
        fxsave->swd = fpu->fsw;
        fxsave->twd = fpu->ftwx;
        fxsave->fop = fpu->last_opcode;
        fxsave->rip = fpu->last_ip;
        fxsave->rdp = fpu->last_dp;
        memcpy(fxsave->xmm_space, fpu->xmm, sizeof fxsave->xmm_space);

        vcpu_put(vcpu);

        return 0;
}

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

        return 0;
}

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

        return 0;
}

static long kvm_vcpu_ioctl(struct file *filp,
                           unsigned int ioctl, unsigned long arg)
{
        struct kvm_vcpu *vcpu = filp->private_data;
        void __user *argp = (void __user *)arg;
        int r = -EINVAL;

        switch (ioctl) {
        case KVM_RUN:
                r = -EINVAL;
                if (arg)
                        goto out;
                r = kvm_vcpu_ioctl_run(vcpu, vcpu->run);
                break;
        case KVM_GET_REGS: {
                struct kvm_regs kvm_regs;

                memset(&kvm_regs, 0, sizeof kvm_regs);
                r = kvm_vcpu_ioctl_get_regs(vcpu, &kvm_regs);
                if (r)
                        goto out;
                r = -EFAULT;
                if (copy_to_user(argp, &kvm_regs, sizeof kvm_regs))
                        goto out;
                r = 0;
                break;
        }
        case KVM_SET_REGS: {
                struct kvm_regs kvm_regs;

                r = -EFAULT;
                if (copy_from_user(&kvm_regs, argp, sizeof kvm_regs))
                        goto out;
                r = kvm_vcpu_ioctl_set_regs(vcpu, &kvm_regs);
                if (r)
                        goto out;
                r = 0;
                break;
        }
        case KVM_GET_SREGS: {
                struct kvm_sregs kvm_sregs;

                memset(&kvm_sregs, 0, sizeof kvm_sregs);
                r = kvm_vcpu_ioctl_get_sregs(vcpu, &kvm_sregs);
                if (r)
                        goto out;
                r = -EFAULT;
                if (copy_to_user(argp, &kvm_sregs, sizeof kvm_sregs))
                        goto out;
                r = 0;
                break;
        }
        case KVM_SET_SREGS: {
                struct kvm_sregs kvm_sregs;

                r = -EFAULT;
                if (copy_from_user(&kvm_sregs, argp, sizeof kvm_sregs))
                        goto out;
                r = kvm_vcpu_ioctl_set_sregs(vcpu, &kvm_sregs);
                if (r)
                        goto out;
                r = 0;
                break;
        }
        case KVM_TRANSLATE: {
                struct kvm_translation tr;

                r = -EFAULT;
                if (copy_from_user(&tr, argp, sizeof tr))
                        goto out;
                r = kvm_vcpu_ioctl_translate(vcpu, &tr);
                if (r)
                        goto out;
                r = -EFAULT;
                if (copy_to_user(argp, &tr, sizeof tr))
                        goto out;
                r = 0;
                break;
        }
        case KVM_INTERRUPT: {
                struct kvm_interrupt irq;

                r = -EFAULT;
                if (copy_from_user(&irq, argp, sizeof irq))
                        goto out;
                r = kvm_vcpu_ioctl_interrupt(vcpu, &irq);
                if (r)
                        goto out;
                r = 0;
                break;
        }
        case KVM_DEBUG_GUEST: {
                struct kvm_debug_guest dbg;

                r = -EFAULT;
                if (copy_from_user(&dbg, argp, sizeof dbg))
                        goto out;
                r = kvm_vcpu_ioctl_debug_guest(vcpu, &dbg);
                if (r)
                        goto out;
                r = 0;
                break;
        }
        case KVM_GET_MSRS:
                r = msr_io(vcpu, argp, kvm_get_msr, 1);
                break;
        case KVM_SET_MSRS:
                r = msr_io(vcpu, argp, do_set_msr, 0);
                break;
        case KVM_SET_CPUID: {
                struct kvm_cpuid __user *cpuid_arg = argp;
                struct kvm_cpuid cpuid;

                r = -EFAULT;
                if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid))
                        goto out;
                r = kvm_vcpu_ioctl_set_cpuid(vcpu, &cpuid, cpuid_arg->entries);
                if (r)
                        goto out;
                break;
        }
        case KVM_SET_SIGNAL_MASK: {
                struct kvm_signal_mask __user *sigmask_arg = argp;
                struct kvm_signal_mask kvm_sigmask;
                sigset_t sigset, *p;

                p = NULL;
                if (argp) {
                        r = -EFAULT;
                        if (copy_from_user(&kvm_sigmask, argp,
                                           sizeof kvm_sigmask))
                                goto out;
                        r = -EINVAL;
                        if (kvm_sigmask.len != sizeof sigset)
                                goto out;
                        r = -EFAULT;
                        if (copy_from_user(&sigset, sigmask_arg->sigset,
                                           sizeof sigset))
                                goto out;
                        p = &sigset;
                }
                r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
                break;
        }
        case KVM_GET_FPU: {
                struct kvm_fpu fpu;

                memset(&fpu, 0, sizeof fpu);
                r = kvm_vcpu_ioctl_get_fpu(vcpu, &fpu);
                if (r)
                        goto out;
                r = -EFAULT;
                if (copy_to_user(argp, &fpu, sizeof fpu))
                        goto out;
                r = 0;
                break;
        }
        case KVM_SET_FPU: {
                struct kvm_fpu fpu;

                r = -EFAULT;
                if (copy_from_user(&fpu, argp, sizeof fpu))
                        goto out;
                r = kvm_vcpu_ioctl_set_fpu(vcpu, &fpu);
                if (r)
                        goto out;
                r = 0;
                break;
        }
        case KVM_GET_LAPIC: {
                struct kvm_lapic_state lapic;

                memset(&lapic, 0, sizeof lapic);
                r = kvm_vcpu_ioctl_get_lapic(vcpu, &lapic);
                if (r)
                        goto out;
                r = -EFAULT;
                if (copy_to_user(argp, &lapic, sizeof lapic))
                        goto out;
                r = 0;
                break;
        }
        case KVM_SET_LAPIC: {
                struct kvm_lapic_state lapic;

                r = -EFAULT;
                if (copy_from_user(&lapic, argp, sizeof lapic))
                        goto out;
                r = kvm_vcpu_ioctl_set_lapic(vcpu, &lapic);;
                if (r)
                        goto out;
                r = 0;
                break;
        }
        default:
                ;
        }
out:
        return r;
}

static long kvm_vm_ioctl(struct file *filp,
                           unsigned int ioctl, unsigned long arg)
{
        struct kvm *kvm = filp->private_data;
        void __user *argp = (void __user *)arg;
        int r = -EINVAL;

        switch (ioctl) {
        case KVM_CREATE_VCPU: