x86.c

	struct kvm_vcpu *vcpu = filp->private_data;
	void __user *argp = (void __user *)arg;
	int r;
	struct kvm_lapic_state *lapic = NULL;

	switch (ioctl) {
	case KVM_GET_LAPIC: {
		r = -EINVAL;
		if (!vcpu->arch.apic)
			goto out;
		lapic = kzalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL);

		r = -ENOMEM;
		if (!lapic)
			goto out;
		r = kvm_vcpu_ioctl_get_lapic(vcpu, lapic);
		if (r)
			goto out;
		r = -EFAULT;
		if (copy_to_user(argp, lapic, sizeof(struct kvm_lapic_state)))
			goto out;
		r = 0;
		break;
	}
	case KVM_SET_LAPIC: {
		r = -EINVAL;
		if (!vcpu->arch.apic)
			goto out;
		lapic = kmalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL);
		r = -ENOMEM;
		if (!lapic)
			goto out;
		r = -EFAULT;
		if (copy_from_user(lapic, argp, sizeof(struct kvm_lapic_state)))
			goto out;
		r = kvm_vcpu_ioctl_set_lapic(vcpu, lapic);
		if (r)
			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_NMI: {
		r = kvm_vcpu_ioctl_nmi(vcpu);
		if (r)
			goto out;
		r = 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_CPUID2: {
		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_vcpu_ioctl_set_cpuid2(vcpu, &cpuid,
					      cpuid_arg->entries);
		if (r)
			goto out;
		break;
	}
	case KVM_GET_CPUID2: {
		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_vcpu_ioctl_get_cpuid2(vcpu, &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_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_TPR_ACCESS_REPORTING: {
		struct kvm_tpr_access_ctl tac;

		r = -EFAULT;
		if (copy_from_user(&tac, argp, sizeof tac))
			goto out;
		r = vcpu_ioctl_tpr_access_reporting(vcpu, &tac);
		if (r)
			goto out;
		r = -EFAULT;
		if (copy_to_user(argp, &tac, sizeof tac))
			goto out;
		r = 0;
		break;
	};
	case KVM_SET_VAPIC_ADDR: {
		struct kvm_vapic_addr va;

		r = -EINVAL;
		if (!irqchip_in_kernel(vcpu->kvm))
			goto out;
		r = -EFAULT;
		if (copy_from_user(&va, argp, sizeof va))
			goto out;
		r = 0;
		kvm_lapic_set_vapic_addr(vcpu, va.vapic_addr);
		break;
	}
	case KVM_X86_SETUP_MCE: {
		u64 mcg_cap;

		r = -EFAULT;
		if (copy_from_user(&mcg_cap, argp, sizeof mcg_cap))
			goto out;
		r = kvm_vcpu_ioctl_x86_setup_mce(vcpu, mcg_cap);
		break;
	}
	case KVM_X86_SET_MCE: {
		struct kvm_x86_mce mce;

		r = -EFAULT;
		if (copy_from_user(&mce, argp, sizeof mce))
			goto out;
		r = kvm_vcpu_ioctl_x86_set_mce(vcpu, &mce);
		break;
	}
	case KVM_GET_VCPU_EVENTS: {
		struct kvm_vcpu_events events;

		kvm_vcpu_ioctl_x86_get_vcpu_events(vcpu, &events);

		r = -EFAULT;
		if (copy_to_user(argp, &events, sizeof(struct kvm_vcpu_events)))
			break;
		r = 0;
		break;
	}
	case KVM_SET_VCPU_EVENTS: {
		struct kvm_vcpu_events events;

		r = -EFAULT;
		if (copy_from_user(&events, argp, sizeof(struct kvm_vcpu_events)))
			break;

		r = kvm_vcpu_ioctl_x86_set_vcpu_events(vcpu, &events);
		break;
	}
	default:
		r = -EINVAL;
	}
out:
	kfree(lapic);
	return r;
}

static int kvm_vm_ioctl_set_tss_addr(struct kvm *kvm, unsigned long addr)
{
	int ret;

	if (addr > (unsigned int)(-3 * PAGE_SIZE))
		return -1;
	ret = kvm_x86_ops->set_tss_addr(kvm, addr);
	return ret;
}

static int kvm_vm_ioctl_set_identity_map_addr(struct kvm *kvm,
					      u64 ident_addr)
{
	kvm->arch.ept_identity_map_addr = ident_addr;
	return 0;
}

static int kvm_vm_ioctl_set_nr_mmu_pages(struct kvm *kvm,
					  u32 kvm_nr_mmu_pages)
{
	if (kvm_nr_mmu_pages < KVM_MIN_ALLOC_MMU_PAGES)
		return -EINVAL;

	down_write(&kvm->slots_lock);
	spin_lock(&kvm->mmu_lock);

	kvm_mmu_change_mmu_pages(kvm, kvm_nr_mmu_pages);
	kvm->arch.n_requested_mmu_pages = kvm_nr_mmu_pages;

	spin_unlock(&kvm->mmu_lock);
	up_write(&kvm->slots_lock);
	return 0;
}

static int kvm_vm_ioctl_get_nr_mmu_pages(struct kvm *kvm)
{
	return kvm->arch.n_alloc_mmu_pages;
}

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

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

/*
 * 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;

	down_write(&kvm->slots_lock);
	spin_lock(&kvm->mmu_lock);

	p = &kvm->arch.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->arch.aliases[n - 1].npages)
			break;
	kvm->arch.naliases = n;

	spin_unlock(&kvm->mmu_lock);
	kvm_mmu_zap_all(kvm);

	up_write(&kvm->slots_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:
		r = kvm_get_ioapic(kvm, &chip->chip.ioapic);
		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:
		spin_lock(&pic_irqchip(kvm)->lock);
		memcpy(&pic_irqchip(kvm)->pics[0],
			&chip->chip.pic,
			sizeof(struct kvm_pic_state));
		spin_unlock(&pic_irqchip(kvm)->lock);
		break;
	case KVM_IRQCHIP_PIC_SLAVE:
		spin_lock(&pic_irqchip(kvm)->lock);
		memcpy(&pic_irqchip(kvm)->pics[1],
			&chip->chip.pic,
			sizeof(struct kvm_pic_state));
		spin_unlock(&pic_irqchip(kvm)->lock);
		break;
	case KVM_IRQCHIP_IOAPIC:
		r = kvm_set_ioapic(kvm, &chip->chip.ioapic);
		break;
	default:
		r = -EINVAL;
		break;
	}
	kvm_pic_update_irq(pic_irqchip(kvm));
	return r;
}

static int kvm_vm_ioctl_get_pit(struct kvm *kvm, struct kvm_pit_state *ps)
{
	int r = 0;

	mutex_lock(&kvm->arch.vpit->pit_state.lock);
	memcpy(ps, &kvm->arch.vpit->pit_state, sizeof(struct kvm_pit_state));
	mutex_unlock(&kvm->arch.vpit->pit_state.lock);
	return r;
}

static int kvm_vm_ioctl_set_pit(struct kvm *kvm, struct kvm_pit_state *ps)
{
	int r = 0;

	mutex_lock(&kvm->arch.vpit->pit_state.lock);
	memcpy(&kvm->arch.vpit->pit_state, ps, sizeof(struct kvm_pit_state));
	kvm_pit_load_count(kvm, 0, ps->channels[0].count, 0);
	mutex_unlock(&kvm->arch.vpit->pit_state.lock);
	return r;
}

static int kvm_vm_ioctl_get_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps)
{
	int r = 0;

	mutex_lock(&kvm->arch.vpit->pit_state.lock);
	memcpy(ps->channels, &kvm->arch.vpit->pit_state.channels,
		sizeof(ps->channels));
	ps->flags = kvm->arch.vpit->pit_state.flags;
	mutex_unlock(&kvm->arch.vpit->pit_state.lock);
	return r;
}

static int kvm_vm_ioctl_set_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps)
{
	int r = 0, start = 0;
	u32 prev_legacy, cur_legacy;
	mutex_lock(&kvm->arch.vpit->pit_state.lock);
	prev_legacy = kvm->arch.vpit->pit_state.flags & KVM_PIT_FLAGS_HPET_LEGACY;
	cur_legacy = ps->flags & KVM_PIT_FLAGS_HPET_LEGACY;
	if (!prev_legacy && cur_legacy)
		start = 1;
	memcpy(&kvm->arch.vpit->pit_state.channels, &ps->channels,
	       sizeof(kvm->arch.vpit->pit_state.channels));
	kvm->arch.vpit->pit_state.flags = ps->flags;
	kvm_pit_load_count(kvm, 0, kvm->arch.vpit->pit_state.channels[0].count, start);
	mutex_unlock(&kvm->arch.vpit->pit_state.lock);
	return r;
}

static int kvm_vm_ioctl_reinject(struct kvm *kvm,
				 struct kvm_reinject_control *control)
{
	if (!kvm->arch.vpit)
		return -ENXIO;
	mutex_lock(&kvm->arch.vpit->pit_state.lock);
	kvm->arch.vpit->pit_state.pit_timer.reinject = control->pit_reinject;
	mutex_unlock(&kvm->arch.vpit->pit_state.lock);
	return 0;
}

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

	down_write(&kvm->slots_lock);

	r = kvm_get_dirty_log(kvm, log, &is_dirty);
	if (r)
		goto out;

	/* If nothing is dirty, don't bother messing with page tables. */
	if (is_dirty) {
		spin_lock(&kvm->mmu_lock);
		kvm_mmu_slot_remove_write_access(kvm, log->slot);
		spin_unlock(&kvm->mmu_lock);
		memslot = &kvm->memslots[log->slot];
		n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
		memset(memslot->dirty_bitmap, 0, n);
	}
	r = 0;
out:
	up_write(&kvm->slots_lock);
	return r;
}

long kvm_arch_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 = -ENOTTY;
	/*
	 * This union makes it completely explicit to gcc-3.x
	 * that these two variables' stack usage should be
	 * combined, not added together.
	 */
	union {
		struct kvm_pit_state ps;
		struct kvm_pit_state2 ps2;
		struct kvm_memory_alias alias;
		struct kvm_pit_config pit_config;
	} u;

	switch (ioctl) {
	case KVM_SET_TSS_ADDR:
		r = kvm_vm_ioctl_set_tss_addr(kvm, arg);
		if (r < 0)
			goto out;
		break;
	case KVM_SET_IDENTITY_MAP_ADDR: {
		u64 ident_addr;

		r = -EFAULT;
		if (copy_from_user(&ident_addr, argp, sizeof ident_addr))
			goto out;
		r = kvm_vm_ioctl_set_identity_map_addr(kvm, ident_addr);
		if (r < 0)
			goto out;
		break;
	}
	case KVM_SET_MEMORY_REGION: {
		struct kvm_memory_region kvm_mem;
		struct kvm_userspace_memory_region kvm_userspace_mem;

		r = -EFAULT;
		if (copy_from_user(&kvm_mem, argp, sizeof kvm_mem))
			goto out;
		kvm_userspace_mem.slot = kvm_mem.slot;
		kvm_userspace_mem.flags = kvm_mem.flags;
		kvm_userspace_mem.guest_phys_addr = kvm_mem.guest_phys_addr;
		kvm_userspace_mem.memory_size = kvm_mem.memory_size;
		r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem, 0);
		if (r)
			goto out;
		break;
	}
	case KVM_SET_NR_MMU_PAGES:
		r = kvm_vm_ioctl_set_nr_mmu_pages(kvm, arg);
		if (r)
			goto out;
		break;
	case KVM_GET_NR_MMU_PAGES:
		r = kvm_vm_ioctl_get_nr_mmu_pages(kvm);
		break;
	case KVM_SET_MEMORY_ALIAS:
		r = -EFAULT;
		if (copy_from_user(&u.alias, argp, sizeof(struct kvm_memory_alias)))
			goto out;
		r = kvm_vm_ioctl_set_memory_alias(kvm, &u.alias);
		if (r)
			goto out;
		break;
	case KVM_CREATE_IRQCHIP: {
		struct kvm_pic *vpic;

		mutex_lock(&kvm->lock);
		r = -EEXIST;
		if (kvm->arch.vpic)
			goto create_irqchip_unlock;
		r = -ENOMEM;
		vpic = kvm_create_pic(kvm);
		if (vpic) {
			r = kvm_ioapic_init(kvm);
			if (r) {
				kfree(vpic);
				goto create_irqchip_unlock;
			}
		} else
			goto create_irqchip_unlock;
		smp_wmb();
		kvm->arch.vpic = vpic;
		smp_wmb();
		r = kvm_setup_default_irq_routing(kvm);
		if (r) {
			mutex_lock(&kvm->irq_lock);
			kfree(kvm->arch.vpic);
			kfree(kvm->arch.vioapic);
			kvm->arch.vpic = NULL;
			kvm->arch.vioapic = NULL;
			mutex_unlock(&kvm->irq_lock);
		}
	create_irqchip_unlock:
		mutex_unlock(&kvm->lock);
		break;
	}
	case KVM_CREATE_PIT:
		u.pit_config.flags = KVM_PIT_SPEAKER_DUMMY;
		goto create_pit;
	case KVM_CREATE_PIT2:
		r = -EFAULT;
		if (copy_from_user(&u.pit_config, argp,
				   sizeof(struct kvm_pit_config)))
			goto out;
	create_pit:
		down_write(&kvm->slots_lock);
		r = -EEXIST;
		if (kvm->arch.vpit)
			goto create_pit_unlock;
		r = -ENOMEM;
		kvm->arch.vpit = kvm_create_pit(kvm, u.pit_config.flags);
		if (kvm->arch.vpit)
			r = 0;
	create_pit_unlock:
		up_write(&kvm->slots_lock);
		break;
	case KVM_IRQ_LINE_STATUS:
	case KVM_IRQ_LINE: {
		struct kvm_irq_level irq_event;

		r = -EFAULT;
		if (copy_from_user(&irq_event, argp, sizeof irq_event))
			goto out;
		if (irqchip_in_kernel(kvm)) {
			__s32 status;
			status = kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID,
					irq_event.irq, irq_event.level);
			if (ioctl == KVM_IRQ_LINE_STATUS) {
				irq_event.status = status;
				if (copy_to_user(argp, &irq_event,
							sizeof irq_event))
					goto out;
			}
			r = 0;
		}
		break;
	}
	case KVM_GET_IRQCHIP: {
		/* 0: PIC master, 1: PIC slave, 2: IOAPIC */
		struct kvm_irqchip *chip = kmalloc(sizeof(*chip), GFP_KERNEL);

		r = -ENOMEM;
		if (!chip)
			goto out;
		r = -EFAULT;
		if (copy_from_user(chip, argp, sizeof *chip))
			goto get_irqchip_out;
		r = -ENXIO;
		if (!irqchip_in_kernel(kvm))
			goto get_irqchip_out;
		r = kvm_vm_ioctl_get_irqchip(kvm, chip);
		if (r)
			goto get_irqchip_out;
		r = -EFAULT;
		if (copy_to_user(argp, chip, sizeof *chip))
			goto get_irqchip_out;
		r = 0;
	get_irqchip_out:
		kfree(chip);
		if (r)
			goto out;
		break;
	}
	case KVM_SET_IRQCHIP: {
		/* 0: PIC master, 1: PIC slave, 2: IOAPIC */
		struct kvm_irqchip *chip = kmalloc(sizeof(*chip), GFP_KERNEL);

		r = -ENOMEM;
		if (!chip)
			goto out;
		r = -EFAULT;
		if (copy_from_user(chip, argp, sizeof *chip))
			goto set_irqchip_out;
		r = -ENXIO;
		if (!irqchip_in_kernel(kvm))
			goto set_irqchip_out;
		r = kvm_vm_ioctl_set_irqchip(kvm, chip);
		if (r)
			goto set_irqchip_out;
		r = 0;
	set_irqchip_out:
		kfree(chip);
		if (r)
			goto out;
		break;
	}
	case KVM_GET_PIT: {
		r = -EFAULT;
		if (copy_from_user(&u.ps, argp, sizeof(struct kvm_pit_state)))
			goto out;
		r = -ENXIO;
		if (!kvm->arch.vpit)
			goto out;
		r = kvm_vm_ioctl_get_pit(kvm, &u.ps);
		if (r)
			goto out;
		r = -EFAULT;
		if (copy_to_user(argp, &u.ps, sizeof(struct kvm_pit_state)))
			goto out;
		r = 0;
		break;
	}
	case KVM_SET_PIT: {
		r = -EFAULT;
		if (copy_from_user(&u.ps, argp, sizeof u.ps))
			goto out;
		r = -ENXIO;
		if (!kvm->arch.vpit)
			goto out;
		r = kvm_vm_ioctl_set_pit(kvm, &u.ps);
		if (r)
			goto out;
		r = 0;
		break;
	}
	case KVM_GET_PIT2: {
		r = -ENXIO;
		if (!kvm->arch.vpit)
			goto out;
		r = kvm_vm_ioctl_get_pit2(kvm, &u.ps2);
		if (r)
			goto out;
		r = -EFAULT;
		if (copy_to_user(argp, &u.ps2, sizeof(u.ps2)))
			goto out;
		r = 0;
		break;
	}
	case KVM_SET_PIT2: {
		r = -EFAULT;
		if (copy_from_user(&u.ps2, argp, sizeof(u.ps2)))
			goto out;
		r = -ENXIO;
		if (!kvm->arch.vpit)
			goto out;
		r = kvm_vm_ioctl_set_pit2(kvm, &u.ps2);
		if (r)
			goto out;
		r = 0;
		break;
	}
	case KVM_REINJECT_CONTROL: {
		struct kvm_reinject_control control;
		r =  -EFAULT;
		if (copy_from_user(&control, argp, sizeof(control)))
			goto out;
		r = kvm_vm_ioctl_reinject(kvm, &control);
		if (r)
			goto out;
		r = 0;
		break;
	}
	case KVM_XEN_HVM_CONFIG: {
		r = -EFAULT;
		if (copy_from_user(&kvm->arch.xen_hvm_config, argp,
				   sizeof(struct kvm_xen_hvm_config)))
			goto out;
		r = -EINVAL;
		if (kvm->arch.xen_hvm_config.flags)
			goto out;
		r = 0;
		break;
	}
	case KVM_SET_CLOCK: {
		struct timespec now;
		struct kvm_clock_data user_ns;
		u64 now_ns;
		s64 delta;

		r = -EFAULT;
		if (copy_from_user(&user_ns, argp, sizeof(user_ns)))
			goto out;

		r = -EINVAL;
		if (user_ns.flags)
			goto out;

		r = 0;
		ktime_get_ts(&now);
		now_ns = timespec_to_ns(&now);
		delta = user_ns.clock - now_ns;
		kvm->arch.kvmclock_offset = delta;
		break;
	}
	case KVM_GET_CLOCK: {
		struct timespec now;
		struct kvm_clock_data user_ns;
		u64 now_ns;

		ktime_get_ts(&now);
		now_ns = timespec_to_ns(&now);
		user_ns.clock = kvm->arch.kvmclock_offset + now_ns;
		user_ns.flags = 0;

		r = -EFAULT;
		if (copy_to_user(argp, &user_ns, sizeof(user_ns)))
			goto out;
		r = 0;
		break;
	}

	default:
		;
	}
out:
	return r;
}

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

	/* skip the first msrs in the list. KVM-specific */
	for (i = j = KVM_SAVE_MSRS_BEGIN; 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;
}

static int vcpu_mmio_write(struct kvm_vcpu *vcpu, gpa_t addr, int len,
			   const void *v)
{
	if (vcpu->arch.apic &&
	    !kvm_iodevice_write(&vcpu->arch.apic->dev, addr, len, v))
		return 0;

	return kvm_io_bus_write(&vcpu->kvm->mmio_bus, addr, len, v);
}

static int vcpu_mmio_read(struct kvm_vcpu *vcpu, gpa_t addr, int len, void *v)
{
	if (vcpu->arch.apic &&
	    !kvm_iodevice_read(&vcpu->arch.apic->dev, addr, len, v))
		return 0;

	return kvm_io_bus_read(&vcpu->kvm->mmio_bus, addr, len, v);
}

static int kvm_read_guest_virt(gva_t addr, void *val, unsigned int bytes,
			       struct kvm_vcpu *vcpu)
{
	void *data = val;
	int r = X86EMUL_CONTINUE;

	while (bytes) {
		gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
		unsigned offset = addr & (PAGE_SIZE-1);
		unsigned toread = min(bytes, (unsigned)PAGE_SIZE - offset);
		int ret;

		if (gpa == UNMAPPED_GVA) {
			r = X86EMUL_PROPAGATE_FAULT;
			goto out;
		}
		ret = kvm_read_guest(vcpu->kvm, gpa, data, toread);
		if (ret < 0) {
			r = X86EMUL_UNHANDLEABLE;
			goto out;
		}

		bytes -= toread;
		data += toread;
		addr += toread;
	}
out:
	return r;
}

static int kvm_write_guest_virt(gva_t addr, void *val, unsigned int bytes,
				struct kvm_vcpu *vcpu)
{
	void *data = val;
	int r = X86EMUL_CONTINUE;

	while (bytes) {
		gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
		unsigned offset = addr & (PAGE_SIZE-1);
		unsigned towrite = min(bytes, (unsigned)PAGE_SIZE - offset);
		int ret;

		if (gpa == UNMAPPED_GVA) {
			r = X86EMUL_PROPAGATE_FAULT;
			goto out;
		}
		ret = kvm_write_guest(vcpu->kvm, gpa, data, towrite);
		if (ret < 0) {
			r = X86EMUL_UNHANDLEABLE;
			goto out;
		}

		bytes -= towrite;
		data += towrite;
		addr += towrite;
	}
out:
	return r;
}


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

	if (vcpu->mmio_read_completed) {
		memcpy(val, vcpu->mmio_data, bytes);
		trace_kvm_mmio(KVM_TRACE_MMIO_READ, bytes,
			       vcpu->mmio_phys_addr, *(u64 *)val);
		vcpu->mmio_read_completed = 0;
		return X86EMUL_CONTINUE;
	}

	gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);

	/* For APIC access vmexit */
	if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
		goto mmio;

	if (kvm_read_guest_virt(addr, val, bytes, vcpu)
				== X86EMUL_CONTINUE)
		return X86EMUL_CONTINUE;
	if (gpa == UNMAPPED_GVA)
		return X86EMUL_PROPAGATE_FAULT;

mmio:
	/*
	 * Is this MMIO handled locally?
	 */
	if (!vcpu_mmio_read(vcpu, gpa, bytes, val)) {
		trace_kvm_mmio(KVM_TRACE_MMIO_READ, bytes, gpa, *(u64 *)val);
		return X86EMUL_CONTINUE;
	}

	trace_kvm_mmio(KVM_TRACE_MMIO_READ_UNSATISFIED, bytes, gpa, 0);

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

	return X86EMUL_UNHANDLEABLE;
}

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

	ret = kvm_write_guest(vcpu->kvm, gpa, val, bytes);
	if (ret < 0)
		return 0;
	kvm_mmu_pte_write(vcpu, gpa, val, bytes, 1);
	return 1;
}

static int emulator_write_emulated_onepage(unsigned long addr,
					   const void *val,
					   unsigned int bytes,
					   struct kvm_vcpu *vcpu)
{
	gpa_t                 gpa;

	gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);

	if (gpa == UNMAPPED_GVA) {
		kvm_inject_page_fault(vcpu, addr, 2);
		return X86EMUL_PROPAGATE_FAULT;
	}

	/* For APIC access vmexit */
	if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
		goto mmio;

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

mmio:
	trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, bytes, gpa, *(u64 *)val);
	/*
	 * Is this MMIO handled locally?
	 */
	if (!vcpu_mmio_write(vcpu, 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)
{
	printk_once(KERN_WARNING "kvm: emulating exchange as write\n");
#ifndef CONFIG_X86_64
	/* guests cmpxchg8b have to be emulated atomically */
	if (bytes == 8) {
		gpa_t gpa;
		struct page *page;
		char *kaddr;
		u64 val;

		gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);

		if (gpa == UNMAPPED_GVA ||
		   (gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
			goto emul_write;

		if (((gpa + bytes - 1) & PAGE_MASK) != (gpa & PAGE_MASK))
			goto emul_write;

		val = *(u64 *)new;

		page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);

		kaddr = kmap_atomic(page, KM_USER0);
		set_64bit((u64 *)(kaddr + offset_in_page(gpa)), val);
		kunmap_atomic(kaddr, KM_USER0);
		kvm_release_page_dirty(page);
	}
emul_write:
#endif

	return emulator_write_emulated(addr, new, bytes, vcpu);
}