1 files changed, 2809 insertions, 0 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
new file mode 100644
index 00000000..9739b533
--- /dev/null
+++ b/virt/kvm/kvm_main.c
@@ -0,0 +1,2809 @@
+/*
+ * Kernel-based Virtual Machine driver for Linux
+ *
+ * This module enables machines with Intel VT-x extensions to run virtual
+ * machines without emulation or binary translation.
+ *
+ * Copyright (C) 2006 Qumranet, Inc.
+ * Copyright 2010 Red Hat, Inc. and/or its affiliates.
+ *
+ * Authors:
+ *   Avi Kivity   <avi@qumranet.com>
+ *   Yaniv Kamay  <yaniv@qumranet.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "iodev.h"
+
+#include <linux/kvm_host.h>
+#include <linux/kvm.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/percpu.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/syscore_ops.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 <linux/kvm_para.h>
+#include <linux/pagemap.h>
+#include <linux/mman.h>
+#include <linux/swap.h>
+#include <linux/bitops.h>
+#include <linux/spinlock.h>
+#include <linux/compat.h>
+#include <linux/srcu.h>
+#include <linux/hugetlb.h>
+#include <linux/slab.h>
+#include <linux/sort.h>
+#include <linux/bsearch.h>
+
+#include <asm/processor.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+
+#include "coalesced_mmio.h"
+#include "async_pf.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/kvm.h>
+
+MODULE_AUTHOR("Qumranet");
+MODULE_LICENSE("GPL");
+
+/*
+ * Ordering of locks:
+ *
+ * 		kvm->lock --> kvm->slots_lock --> kvm->irq_lock
+ */
+
+DEFINE_RAW_SPINLOCK(kvm_lock);
+LIST_HEAD(vm_list);
+
+static cpumask_var_t cpus_hardware_enabled;
+static int kvm_usage_count = 0;
+static atomic_t hardware_enable_failed;
+
+struct kmem_cache *kvm_vcpu_cache;
+EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
+
+static __read_mostly struct preempt_ops kvm_preempt_ops;
+
+struct dentry *kvm_debugfs_dir;
+
+static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
+			   unsigned long arg);
+#ifdef CONFIG_COMPAT
+static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl,
+				  unsigned long arg);
+#endif
+static int hardware_enable_all(void);
+static void hardware_disable_all(void);
+
+static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
+
+bool kvm_rebooting;
+EXPORT_SYMBOL_GPL(kvm_rebooting);
+
+static bool largepages_enabled = true;
+
+static struct page *hwpoison_page;
+static pfn_t hwpoison_pfn;
+
+struct page *fault_page;
+pfn_t fault_pfn;
+
+inline int kvm_is_mmio_pfn(pfn_t pfn)
+{
+	if (pfn_valid(pfn)) {
+		int reserved;
+		struct page *tail = pfn_to_page(pfn);
+		struct page *head = compound_trans_head(tail);
+		reserved = PageReserved(head);
+		if (head != tail) {
+			/*
+			 * "head" is not a dangling pointer
+			 * (compound_trans_head takes care of that)
+			 * but the hugepage may have been splitted
+			 * from under us (and we may not hold a
+			 * reference count on the head page so it can
+			 * be reused before we run PageReferenced), so
+			 * we've to check PageTail before returning
+			 * what we just read.
+			 */
+			smp_rmb();
+			if (PageTail(tail))
+				return reserved;
+		}
+		return PageReserved(tail);
+	}
+
+	return true;
+}
+
+/*
+ * Switches to specified vcpu, until a matching vcpu_put()
+ */
+void vcpu_load(struct kvm_vcpu *vcpu)
+{
+	int cpu;
+
+	mutex_lock(&vcpu->mutex);
+	if (unlikely(vcpu->pid != current->pids[PIDTYPE_PID].pid)) {
+		/* The thread running this VCPU changed. */
+		struct pid *oldpid = vcpu->pid;
+		struct pid *newpid = get_task_pid(current, PIDTYPE_PID);
+		rcu_assign_pointer(vcpu->pid, newpid);
+		synchronize_rcu();
+		put_pid(oldpid);
+	}
+	cpu = get_cpu();
+	preempt_notifier_register(&vcpu->preempt_notifier);
+	kvm_arch_vcpu_load(vcpu, cpu);
+	put_cpu();
+}
+
+void vcpu_put(struct kvm_vcpu *vcpu)
+{
+	preempt_disable();
+	kvm_arch_vcpu_put(vcpu);
+	preempt_notifier_unregister(&vcpu->preempt_notifier);
+	preempt_enable();
+	mutex_unlock(&vcpu->mutex);
+}
+
+static void ack_flush(void *_completed)
+{
+}
+
+static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
+{
+	int i, cpu, me;
+	cpumask_var_t cpus;
+	bool called = true;
+	struct kvm_vcpu *vcpu;
+
+	zalloc_cpumask_var(&cpus, GFP_ATOMIC);
+
+	me = get_cpu();
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		kvm_make_request(req, vcpu);
+		cpu = vcpu->cpu;
+
+		/* Set ->requests bit before we read ->mode */
+		smp_mb();
+
+		if (cpus != NULL && cpu != -1 && cpu != me &&
+		      kvm_vcpu_exiting_guest_mode(vcpu) != OUTSIDE_GUEST_MODE)
+			cpumask_set_cpu(cpu, cpus);
+	}
+	if (unlikely(cpus == NULL))
+		smp_call_function_many(cpu_online_mask, ack_flush, NULL, 1);
+	else if (!cpumask_empty(cpus))
+		smp_call_function_many(cpus, ack_flush, NULL, 1);
+	else
+		called = false;
+	put_cpu();
+	free_cpumask_var(cpus);
+	return called;
+}
+
+void kvm_flush_remote_tlbs(struct kvm *kvm)
+{
+	long dirty_count = kvm->tlbs_dirty;
+
+	smp_mb();
+	if (make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
+		++kvm->stat.remote_tlb_flush;
+	cmpxchg(&kvm->tlbs_dirty, dirty_count, 0);
+}
+
+void kvm_reload_remote_mmus(struct kvm *kvm)
+{
+	make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD);
+}
+
+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->kvm = kvm;
+	vcpu->vcpu_id = id;
+	vcpu->pid = NULL;
+	init_waitqueue_head(&vcpu->wq);
+	kvm_async_pf_vcpu_init(vcpu);
+
+	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+	if (!page) {
+		r = -ENOMEM;
+		goto fail;
+	}
+	vcpu->run = page_address(page);
+
+	r = kvm_arch_vcpu_init(vcpu);
+	if (r < 0)
+		goto fail_free_run;
+	return 0;
+
+fail_free_run:
+	free_page((unsigned long)vcpu->run);
+fail:
+	return r;
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_init);
+
+void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
+{
+	put_pid(vcpu->pid);
+	kvm_arch_vcpu_uninit(vcpu);
+	free_page((unsigned long)vcpu->run);
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
+
+#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
+static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
+{
+	return container_of(mn, struct kvm, mmu_notifier);
+}
+
+static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
+					     struct mm_struct *mm,
+					     unsigned long address)
+{
+	struct kvm *kvm = mmu_notifier_to_kvm(mn);
+	int need_tlb_flush, idx;
+
+	/*
+	 * When ->invalidate_page runs, the linux pte has been zapped
+	 * already but the page is still allocated until
+	 * ->invalidate_page returns. So if we increase the sequence
+	 * here the kvm page fault will notice if the spte can't be
+	 * established because the page is going to be freed. If
+	 * instead the kvm page fault establishes the spte before
+	 * ->invalidate_page runs, kvm_unmap_hva will release it
+	 * before returning.
+	 *
+	 * The sequence increase only need to be seen at spin_unlock
+	 * time, and not at spin_lock time.
+	 *
+	 * Increasing the sequence after the spin_unlock would be
+	 * unsafe because the kvm page fault could then establish the
+	 * pte after kvm_unmap_hva returned, without noticing the page
+	 * is going to be freed.
+	 */
+	idx = srcu_read_lock(&kvm->srcu);
+	spin_lock(&kvm->mmu_lock);
+
+	kvm->mmu_notifier_seq++;
+	need_tlb_flush = kvm_unmap_hva(kvm, address) | kvm->tlbs_dirty;
+	/* we've to flush the tlb before the pages can be freed */
+	if (need_tlb_flush)
+		kvm_flush_remote_tlbs(kvm);
+
+	spin_unlock(&kvm->mmu_lock);
+	srcu_read_unlock(&kvm->srcu, idx);
+}
+
+static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
+					struct mm_struct *mm,
+					unsigned long address,
+					pte_t pte)
+{
+	struct kvm *kvm = mmu_notifier_to_kvm(mn);
+	int idx;
+
+	idx = srcu_read_lock(&kvm->srcu);
+	spin_lock(&kvm->mmu_lock);
+	kvm->mmu_notifier_seq++;
+	kvm_set_spte_hva(kvm, address, pte);
+	spin_unlock(&kvm->mmu_lock);
+	srcu_read_unlock(&kvm->srcu, idx);
+}
+
+static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
+						    struct mm_struct *mm,
+						    unsigned long start,
+						    unsigned long end)
+{
+	struct kvm *kvm = mmu_notifier_to_kvm(mn);
+	int need_tlb_flush = 0, idx;
+
+	idx = srcu_read_lock(&kvm->srcu);
+	spin_lock(&kvm->mmu_lock);
+	/*
+	 * The count increase must become visible at unlock time as no
+	 * spte can be established without taking the mmu_lock and
+	 * count is also read inside the mmu_lock critical section.
+	 */
+	kvm->mmu_notifier_count++;
+	for (; start < end; start += PAGE_SIZE)
+		need_tlb_flush |= kvm_unmap_hva(kvm, start);
+	need_tlb_flush |= kvm->tlbs_dirty;
+	/* we've to flush the tlb before the pages can be freed */
+	if (need_tlb_flush)
+		kvm_flush_remote_tlbs(kvm);
+
+	spin_unlock(&kvm->mmu_lock);
+	srcu_read_unlock(&kvm->srcu, idx);
+}
+
+static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
+						  struct mm_struct *mm,
+						  unsigned long start,
+						  unsigned long end)
+{
+	struct kvm *kvm = mmu_notifier_to_kvm(mn);
+
+	spin_lock(&kvm->mmu_lock);
+	/*
+	 * This sequence increase will notify the kvm page fault that
+	 * the page that is going to be mapped in the spte could have
+	 * been freed.
+	 */
+	kvm->mmu_notifier_seq++;
+	smp_wmb();
+	/*
+	 * The above sequence increase must be visible before the
+	 * below count decrease, which is ensured by the smp_wmb above
+	 * in conjunction with the smp_rmb in mmu_notifier_retry().
+	 */
+	kvm->mmu_notifier_count--;
+	spin_unlock(&kvm->mmu_lock);
+
+	BUG_ON(kvm->mmu_notifier_count < 0);
+}
+
+static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
+					      struct mm_struct *mm,
+					      unsigned long address)
+{
+	struct kvm *kvm = mmu_notifier_to_kvm(mn);
+	int young, idx;
+
+	idx = srcu_read_lock(&kvm->srcu);
+	spin_lock(&kvm->mmu_lock);
+
+	young = kvm_age_hva(kvm, address);
+	if (young)
+		kvm_flush_remote_tlbs(kvm);
+
+	spin_unlock(&kvm->mmu_lock);
+	srcu_read_unlock(&kvm->srcu, idx);
+
+	return young;
+}
+
+static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
+				       struct mm_struct *mm,
+				       unsigned long address)
+{
+	struct kvm *kvm = mmu_notifier_to_kvm(mn);
+	int young, idx;
+
+	idx = srcu_read_lock(&kvm->srcu);
+	spin_lock(&kvm->mmu_lock);
+	young = kvm_test_age_hva(kvm, address);
+	spin_unlock(&kvm->mmu_lock);
+	srcu_read_unlock(&kvm->srcu, idx);
+
+	return young;
+}
+
+static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
+				     struct mm_struct *mm)
+{
+	struct kvm *kvm = mmu_notifier_to_kvm(mn);
+	int idx;
+
+	idx = srcu_read_lock(&kvm->srcu);
+	kvm_arch_flush_shadow(kvm);
+	srcu_read_unlock(&kvm->srcu, idx);
+}
+
+static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
+	.invalidate_page	= kvm_mmu_notifier_invalidate_page,
+	.invalidate_range_start	= kvm_mmu_notifier_invalidate_range_start,
+	.invalidate_range_end	= kvm_mmu_notifier_invalidate_range_end,
+	.clear_flush_young	= kvm_mmu_notifier_clear_flush_young,
+	.test_young		= kvm_mmu_notifier_test_young,
+	.change_pte		= kvm_mmu_notifier_change_pte,
+	.release		= kvm_mmu_notifier_release,
+};
+
+static int kvm_init_mmu_notifier(struct kvm *kvm)
+{
+	kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
+	return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
+}
+
+#else  /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */
+
+static int kvm_init_mmu_notifier(struct kvm *kvm)
+{
+	return 0;
+}
+
+#endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
+
+static void kvm_init_memslots_id(struct kvm *kvm)
+{
+	int i;
+	struct kvm_memslots *slots = kvm->memslots;
+
+	for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
+		slots->id_to_index[i] = slots->memslots[i].id = i;
+}
+
+static struct kvm *kvm_create_vm(unsigned long type)
+{
+	int r, i;
+	struct kvm *kvm = kvm_arch_alloc_vm();
+
+	if (!kvm)
+		return ERR_PTR(-ENOMEM);
+
+	r = kvm_arch_init_vm(kvm, type);
+	if (r)
+		goto out_err_nodisable;
+
+	r = hardware_enable_all();
+	if (r)
+		goto out_err_nodisable;
+
+#ifdef CONFIG_HAVE_KVM_IRQCHIP
+	INIT_HLIST_HEAD(&kvm->mask_notifier_list);
+	INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
+#endif
+
+	r = -ENOMEM;
+	kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
+	if (!kvm->memslots)
+		goto out_err_nosrcu;
+	kvm_init_memslots_id(kvm);
+	if (init_srcu_struct(&kvm->srcu))
+		goto out_err_nosrcu;
+	for (i = 0; i < KVM_NR_BUSES; i++) {
+		kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus),
+					GFP_KERNEL);
+		if (!kvm->buses[i])
+			goto out_err;
+	}
+
+	spin_lock_init(&kvm->mmu_lock);
+	kvm->mm = current->mm;
+	atomic_inc(&kvm->mm->mm_count);
+	kvm_eventfd_init(kvm);
+	mutex_init(&kvm->lock);
+	mutex_init(&kvm->irq_lock);
+	mutex_init(&kvm->slots_lock);
+	atomic_set(&kvm->users_count, 1);
+
+	r = kvm_init_mmu_notifier(kvm);
+	if (r)
+		goto out_err;
+
+	raw_spin_lock(&kvm_lock);
+	list_add(&kvm->vm_list, &vm_list);
+	raw_spin_unlock(&kvm_lock);
+
+	return kvm;
+
+out_err:
+	cleanup_srcu_struct(&kvm->srcu);
+out_err_nosrcu:
+	hardware_disable_all();
+out_err_nodisable:
+	for (i = 0; i < KVM_NR_BUSES; i++)
+		kfree(kvm->buses[i]);
+	kfree(kvm->memslots);
+	kvm_arch_free_vm(kvm);
+	return ERR_PTR(r);
+}
+
+static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
+{
+	if (!memslot->dirty_bitmap)
+		return;
+
+	if (2 * kvm_dirty_bitmap_bytes(memslot) > PAGE_SIZE)
+		vfree(memslot->dirty_bitmap_head);
+	else
+		kfree(memslot->dirty_bitmap_head);
+
+	memslot->dirty_bitmap = NULL;
+	memslot->dirty_bitmap_head = NULL;
+}
+
+/*
+ * 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)
+{
+	if (!dont || free->rmap != dont->rmap)
+		vfree(free->rmap);
+
+	if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
+		kvm_destroy_dirty_bitmap(free);
+
+	kvm_arch_free_memslot(free, dont);
+
+	free->npages = 0;
+	free->rmap = NULL;
+}
+
+void kvm_free_physmem(struct kvm *kvm)
+{
+	struct kvm_memslots *slots = kvm->memslots;
+	struct kvm_memory_slot *memslot;
+
+	kvm_for_each_memslot(memslot, slots)
+		kvm_free_physmem_slot(memslot, NULL);
+
+	kfree(kvm->memslots);
+}
+
+static void kvm_destroy_vm(struct kvm *kvm)
+{
+	int i;
+	struct mm_struct *mm = kvm->mm;
+
+	kvm_arch_sync_events(kvm);
+	raw_spin_lock(&kvm_lock);
+	list_del(&kvm->vm_list);
+	raw_spin_unlock(&kvm_lock);
+	kvm_free_irq_routing(kvm);
+	for (i = 0; i < KVM_NR_BUSES; i++)
+		kvm_io_bus_destroy(kvm->buses[i]);
+	kvm_coalesced_mmio_free(kvm);
+#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
+	mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
+#else
+	kvm_arch_flush_shadow(kvm);
+#endif
+	kvm_arch_destroy_vm(kvm);
+	kvm_free_physmem(kvm);
+	cleanup_srcu_struct(&kvm->srcu);
+	kvm_arch_free_vm(kvm);
+	hardware_disable_all();
+	mmdrop(mm);
+}
+
+void kvm_get_kvm(struct kvm *kvm)
+{
+	atomic_inc(&kvm->users_count);
+}
+EXPORT_SYMBOL_GPL(kvm_get_kvm);
+
+void kvm_put_kvm(struct kvm *kvm)
+{
+	if (atomic_dec_and_test(&kvm->users_count))
+		kvm_destroy_vm(kvm);
+}
+EXPORT_SYMBOL_GPL(kvm_put_kvm);
+
+
+static int kvm_vm_release(struct inode *inode, struct file *filp)
+{
+	struct kvm *kvm = filp->private_data;
+
+	kvm_irqfd_release(kvm);
+
+	kvm_put_kvm(kvm);
+	return 0;
+}
+
+/*
+ * Allocation size is twice as large as the actual dirty bitmap size.
+ * This makes it possible to do double buffering: see x86's
+ * kvm_vm_ioctl_get_dirty_log().
+ */
+static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
+{
+#ifndef CONFIG_S390
+	unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
+
+	if (dirty_bytes > PAGE_SIZE)
+		memslot->dirty_bitmap = vzalloc(dirty_bytes);
+	else
+		memslot->dirty_bitmap = kzalloc(dirty_bytes, GFP_KERNEL);
+
+	if (!memslot->dirty_bitmap)
+		return -ENOMEM;
+
+	memslot->dirty_bitmap_head = memslot->dirty_bitmap;
+	memslot->nr_dirty_pages = 0;
+#endif /* !CONFIG_S390 */
+	return 0;
+}
+
+static int cmp_memslot(const void *slot1, const void *slot2)
+{
+	struct kvm_memory_slot *s1, *s2;
+
+	s1 = (struct kvm_memory_slot *)slot1;
+	s2 = (struct kvm_memory_slot *)slot2;
+
+	if (s1->npages < s2->npages)
+		return 1;
+	if (s1->npages > s2->npages)
+		return -1;
+
+	return 0;
+}
+
+/*
+ * Sort the memslots base on its size, so the larger slots
+ * will get better fit.
+ */
+static void sort_memslots(struct kvm_memslots *slots)
+{
+	int i;
+
+	sort(slots->memslots, KVM_MEM_SLOTS_NUM,
+	      sizeof(struct kvm_memory_slot), cmp_memslot, NULL);
+
+	for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
+		slots->id_to_index[slots->memslots[i].id] = i;
+}
+
+void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new)
+{
+	if (new) {
+		int id = new->id;
+		struct kvm_memory_slot *old = id_to_memslot(slots, id);
+		unsigned long npages = old->npages;
+
+		*old = *new;
+		if (new->npages != npages)
+			sort_memslots(slots);
+	}
+
+	slots->generation++;
+}
+
+/*
+ * Allocate some memory and give it an address in the guest physical address
+ * space.
+ *
+ * Discontiguous memory is allowed, mostly for framebuffers.
+ *
+ * Must be called holding mmap_sem for write.
+ */
+int __kvm_set_memory_region(struct kvm *kvm,
+			    struct kvm_userspace_memory_region *mem,
+			    int user_alloc)
+{
+	int r;
+	gfn_t base_gfn;
+	unsigned long npages;
+	unsigned long i;
+	struct kvm_memory_slot *memslot;
+	struct kvm_memory_slot old, new;
+	struct kvm_memslots *slots, *old_memslots;
+
+	r = -EINVAL;
+	/* General sanity checks */
+	if (mem->memory_size & (PAGE_SIZE - 1))
+		goto out;
+	if (mem->guest_phys_addr & (PAGE_SIZE - 1))
+		goto out;
+	/* We can read the guest memory with __xxx_user() later on. */
+	if (user_alloc &&
+	    ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
+	     !access_ok(VERIFY_WRITE,
+			(void __user *)(unsigned long)mem->userspace_addr,
+			mem->memory_size)))
+		goto out;
+	if (mem->slot >= KVM_MEM_SLOTS_NUM)
+		goto out;
+	if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
+		goto out;
+
+	memslot = id_to_memslot(kvm->memslots, mem->slot);
+	base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
+	npages = mem->memory_size >> PAGE_SHIFT;
+
+	r = -EINVAL;
+	if (npages > KVM_MEM_MAX_NR_PAGES)
+		goto out;
+
+	if (!npages)
+		mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
+
+	new = old = *memslot;
+
+	new.id = mem->slot;
+	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_free;
+
+	/* Check for overlaps */
+	r = -EEXIST;
+	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
+		struct kvm_memory_slot *s = &kvm->memslots->memslots[i];
+
+		if (s == memslot || !s->npages)
+			continue;
+		if (!((base_gfn + npages <= s->base_gfn) ||
+		      (base_gfn >= s->base_gfn + s->npages)))
+			goto out_free;
+	}
+
+	/* 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 && !old.npages) {
+		new.user_alloc = user_alloc;
+		new.userspace_addr = mem->userspace_addr;
+#ifndef CONFIG_S390
+		new.rmap = vzalloc(npages * sizeof(*new.rmap));
+		if (!new.rmap)
+			goto out_free;
+#endif /* not defined CONFIG_S390 */
+		if (kvm_arch_create_memslot(&new, npages))
+			goto out_free;
+	}
+
+	/* Allocate page dirty bitmap if needed */
+	if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
+		if (kvm_create_dirty_bitmap(&new) < 0)
+			goto out_free;
+		/* destroy any largepage mappings for dirty tracking */
+	}
+
+	if (!npages) {
+		struct kvm_memory_slot *slot;
+
+		r = -ENOMEM;
+		slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
+				GFP_KERNEL);
+		if (!slots)
+			goto out_free;
+		slot = id_to_memslot(slots, mem->slot);
+		slot->flags |= KVM_MEMSLOT_INVALID;
+
+		update_memslots(slots, NULL);
+
+		old_memslots = kvm->memslots;
+		rcu_assign_pointer(kvm->memslots, slots);
+		synchronize_srcu_expedited(&kvm->srcu);
+		/* From this point no new shadow pages pointing to a deleted
+		 * memslot will be created.
+		 *
+		 * validation of sp->gfn happens in:
+		 * 	- gfn_to_hva (kvm_read_guest, gfn_to_pfn)
+		 * 	- kvm_is_visible_gfn (mmu_check_roots)
+		 */
+		kvm_arch_flush_shadow(kvm);
+		kfree(old_memslots);
+	}
+
+	r = kvm_arch_prepare_memory_region(kvm, &new, old, mem, user_alloc);
+	if (r)
+		goto out_free;
+
+	/* map/unmap the pages in iommu page table */
+	if (npages) {
+		r = kvm_iommu_map_pages(kvm, &new);
+		if (r)
+			goto out_free;
+	} else
+		kvm_iommu_unmap_pages(kvm, &old);
+
+	r = -ENOMEM;
+	slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
+			GFP_KERNEL);
+	if (!slots)
+		goto out_free;
+
+	/* actual memory is freed via old in kvm_free_physmem_slot below */
+	if (!npages) {
+		new.rmap = NULL;
+		new.dirty_bitmap = NULL;
+		memset(&new.arch, 0, sizeof(new.arch));
+	}
+
+	update_memslots(slots, &new);
+	old_memslots = kvm->memslots;
+	rcu_assign_pointer(kvm->memslots, slots);
+	synchronize_srcu_expedited(&kvm->srcu);
+
+	kvm_arch_commit_memory_region(kvm, mem, old, user_alloc);
+
+	/*
+	 * If the new memory slot is created, we need to clear all
+	 * mmio sptes.
+	 */
+	if (npages && old.base_gfn != mem->guest_phys_addr >> PAGE_SHIFT)
+		kvm_arch_flush_shadow(kvm);
+
+	kvm_free_physmem_slot(&old, &new);
+	kfree(old_memslots);
+
+	return 0;
+
+out_free:
+	kvm_free_physmem_slot(&new, &old);
+out:
+	return r;
+
+}
+EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
+
+int kvm_set_memory_region(struct kvm *kvm,
+			  struct kvm_userspace_memory_region *mem,
+			  int user_alloc)
+{
+	int r;
+
+	mutex_lock(&kvm->slots_lock);
+	r = __kvm_set_memory_region(kvm, mem, user_alloc);
+	mutex_unlock(&kvm->slots_lock);
+	return r;
+}
+EXPORT_SYMBOL_GPL(kvm_set_memory_region);
+
+int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
+				   struct
+				   kvm_userspace_memory_region *mem,
+				   int user_alloc)
+{
+	if (mem->slot >= KVM_MEMORY_SLOTS)
+		return -EINVAL;
+	return kvm_set_memory_region(kvm, mem, user_alloc);
+}
+
+int kvm_get_dirty_log(struct kvm *kvm,
+			struct kvm_dirty_log *log, int *is_dirty)
+{
+	struct kvm_memory_slot *memslot;
+	int r, i;
+	unsigned long n;
+	unsigned long any = 0;
+
+	r = -EINVAL;
+	if (log->slot >= KVM_MEMORY_SLOTS)
+		goto out;
+
+	memslot = id_to_memslot(kvm->memslots, log->slot);
+	r = -ENOENT;
+	if (!memslot->dirty_bitmap)
+		goto out;
+
+	n = kvm_dirty_bitmap_bytes(memslot);
+
+	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 (any)
+		*is_dirty = 1;
+
+	r = 0;
+out:
+	return r;
+}
+
+bool kvm_largepages_enabled(void)
+{
+	return largepages_enabled;
+}
+
+void kvm_disable_largepages(void)
+{
+	largepages_enabled = false;
+}
+EXPORT_SYMBOL_GPL(kvm_disable_largepages);
+
+int is_error_page(struct page *page)
+{
+	return page == bad_page || page == hwpoison_page || page == fault_page;
+}
+EXPORT_SYMBOL_GPL(is_error_page);
+
+int is_error_pfn(pfn_t pfn)
+{
+	return pfn == bad_pfn || pfn == hwpoison_pfn || pfn == fault_pfn;
+}
+EXPORT_SYMBOL_GPL(is_error_pfn);
+
+int is_hwpoison_pfn(pfn_t pfn)
+{
+	return pfn == hwpoison_pfn;
+}
+EXPORT_SYMBOL_GPL(is_hwpoison_pfn);
+
+int is_fault_pfn(pfn_t pfn)
+{
+	return pfn == fault_pfn;
+}
+EXPORT_SYMBOL_GPL(is_fault_pfn);
+
+int is_noslot_pfn(pfn_t pfn)
+{
+	return pfn == bad_pfn;
+}
+EXPORT_SYMBOL_GPL(is_noslot_pfn);
+
+int is_invalid_pfn(pfn_t pfn)
+{
+	return pfn == hwpoison_pfn || pfn == fault_pfn;
+}
+EXPORT_SYMBOL_GPL(is_invalid_pfn);
+
+static inline unsigned long bad_hva(void)
+{
+	return PAGE_OFFSET;
+}
+
+int kvm_is_error_hva(unsigned long addr)
+{
+	return addr == bad_hva();
+}
+EXPORT_SYMBOL_GPL(kvm_is_error_hva);
+
+struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
+{
+	return __gfn_to_memslot(kvm_memslots(kvm), gfn);
+}
+EXPORT_SYMBOL_GPL(gfn_to_memslot);
+
+int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
+{
+	struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn);
+
+	if (!memslot || memslot->id >= KVM_MEMORY_SLOTS ||
+	      memslot->flags & KVM_MEMSLOT_INVALID)
+		return 0;
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
+
+unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn)
+{
+	struct vm_area_struct *vma;
+	unsigned long addr, size;
+
+	size = PAGE_SIZE;
+
+	addr = gfn_to_hva(kvm, gfn);
+	if (kvm_is_error_hva(addr))
+		return PAGE_SIZE;
+
+	down_read(&current->mm->mmap_sem);
+	vma = find_vma(current->mm, addr);
+	if (!vma)
+		goto out;
+
+	size = vma_kernel_pagesize(vma);
+
+out:
+	up_read(&current->mm->mmap_sem);
+
+	return size;
+}
+
+static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
+				     gfn_t *nr_pages)
+{
+	if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
+		return bad_hva();
+
+	if (nr_pages)
+		*nr_pages = slot->npages - (gfn - slot->base_gfn);
+
+	return gfn_to_hva_memslot(slot, gfn);
+}
+
+unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
+{
+	return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL);
+}
+EXPORT_SYMBOL_GPL(gfn_to_hva);
+
+static pfn_t get_fault_pfn(void)
+{
+	get_page(fault_page);
+	return fault_pfn;
+}
+
+int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm,
+	unsigned long start, int write, struct page **page)
+{
+	int flags = FOLL_TOUCH | FOLL_NOWAIT | FOLL_HWPOISON | FOLL_GET;
+
+	if (write)
+		flags |= FOLL_WRITE;
+
+	return __get_user_pages(tsk, mm, start, 1, flags, page, NULL, NULL);
+}
+
+static inline int check_user_page_hwpoison(unsigned long addr)
+{
+	int rc, flags = FOLL_TOUCH | FOLL_HWPOISON | FOLL_WRITE;
+
+	rc = __get_user_pages(current, current->mm, addr, 1,
+			      flags, NULL, NULL, NULL);
+	return rc == -EHWPOISON;
+}
+
+static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic,
+			bool *async, bool write_fault, bool *writable)
+{
+	struct page *page[1];
+	int npages = 0;
+	pfn_t pfn;
+
+	/* we can do it either atomically or asynchronously, not both */
+	BUG_ON(atomic && async);
+
+	BUG_ON(!write_fault && !writable);
+
+	if (writable)
+		*writable = true;
+
+	if (atomic || async)
+		npages = __get_user_pages_fast(addr, 1, 1, page);
+
+	if (unlikely(npages != 1) && !atomic) {
+		might_sleep();
+
+		if (writable)
+			*writable = write_fault;
+
+		if (async) {
+			down_read(&current->mm->mmap_sem);
+			npages = get_user_page_nowait(current, current->mm,
+						     addr, write_fault, page);
+			up_read(&current->mm->mmap_sem);
+		} else
+			npages = get_user_pages_fast(addr, 1, write_fault,
+						     page);
+
+		/* map read fault as writable if possible */
+		if (unlikely(!write_fault) && npages == 1) {
+			struct page *wpage[1];
+
+			npages = __get_user_pages_fast(addr, 1, 1, wpage);
+			if (npages == 1) {
+				*writable = true;
+				put_page(page[0]);
+				page[0] = wpage[0];
+			}
+			npages = 1;
+		}
+	}
+
+	if (unlikely(npages != 1)) {
+		struct vm_area_struct *vma;
+
+		if (atomic)
+			return get_fault_pfn();
+
+		down_read(&current->mm->mmap_sem);
+		if (npages == -EHWPOISON ||
+			(!async && check_user_page_hwpoison(addr))) {
+			up_read(&current->mm->mmap_sem);
+			get_page(hwpoison_page);
+			return page_to_pfn(hwpoison_page);
+		}
+
+		vma = find_vma_intersection(current->mm, addr, addr+1);
+
+		if (vma == NULL)
+			pfn = get_fault_pfn();
+		else if ((vma->vm_flags & VM_PFNMAP)) {
+			pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) +
+				vma->vm_pgoff;
+			BUG_ON(!kvm_is_mmio_pfn(pfn));
+		} else {
+			if (async && (vma->vm_flags & VM_WRITE))
+				*async = true;
+			pfn = get_fault_pfn();
+		}
+		up_read(&current->mm->mmap_sem);
+	} else
+		pfn = page_to_pfn(page[0]);
+
+	return pfn;
+}
+
+pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr)
+{
+	return hva_to_pfn(kvm, addr, true, NULL, true, NULL);
+}
+EXPORT_SYMBOL_GPL(hva_to_pfn_atomic);
+
+static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async,
+			  bool write_fault, bool *writable)
+{
+	unsigned long addr;
+
+	if (async)
+		*async = false;
+
+	addr = gfn_to_hva(kvm, gfn);
+	if (kvm_is_error_hva(addr)) {
+		get_page(bad_page);
+		return page_to_pfn(bad_page);
+	}
+
+	return hva_to_pfn(kvm, addr, atomic, async, write_fault, writable);
+}
+
+pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn)
+{
+	return __gfn_to_pfn(kvm, gfn, true, NULL, true, NULL);
+}
+EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic);
+
+pfn_t gfn_to_pfn_async(struct kvm *kvm, gfn_t gfn, bool *async,
+		       bool write_fault, bool *writable)
+{
+	return __gfn_to_pfn(kvm, gfn, false, async, write_fault, writable);
+}
+EXPORT_SYMBOL_GPL(gfn_to_pfn_async);
+
+pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
+{
+	return __gfn_to_pfn(kvm, gfn, false, NULL, true, NULL);
+}
+EXPORT_SYMBOL_GPL(gfn_to_pfn);
+
+pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
+		      bool *writable)
+{
+	return __gfn_to_pfn(kvm, gfn, false, NULL, write_fault, writable);
+}
+EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);
+
+pfn_t gfn_to_pfn_memslot(struct kvm *kvm,
+			 struct kvm_memory_slot *slot, gfn_t gfn)
+{
+	unsigned long addr = gfn_to_hva_memslot(slot, gfn);
+	return hva_to_pfn(kvm, addr, false, NULL, true, NULL);
+}
+
+int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages,
+								  int nr_pages)
+{
+	unsigned long addr;
+	gfn_t entry;
+
+	addr = gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, &entry);
+	if (kvm_is_error_hva(addr))
+		return -1;
+
+	if (entry < nr_pages)
+		return 0;
+
+	return __get_user_pages_fast(addr, nr_pages, 1, pages);
+}
+EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
+
+struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
+{
+	pfn_t pfn;
+
+	pfn = gfn_to_pfn(kvm, gfn);
+	if (!kvm_is_mmio_pfn(pfn))
+		return pfn_to_page(pfn);
+
+	WARN_ON(kvm_is_mmio_pfn(pfn));
+
+	get_page(bad_page);
+	return bad_page;
+}
+
+EXPORT_SYMBOL_GPL(gfn_to_page);
+
+void kvm_release_page_clean(struct page *page)
+{
+	kvm_release_pfn_clean(page_to_pfn(page));
+}
+EXPORT_SYMBOL_GPL(kvm_release_page_clean);
+
+void kvm_release_pfn_clean(pfn_t pfn)
+{
+	if (!kvm_is_mmio_pfn(pfn))
+		put_page(pfn_to_page(pfn));
+}
+EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
+
+void kvm_release_page_dirty(struct page *page)
+{
+	kvm_release_pfn_dirty(page_to_pfn(page));
+}
+EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
+
+void kvm_release_pfn_dirty(pfn_t pfn)
+{
+	kvm_set_pfn_dirty(pfn);
+	kvm_release_pfn_clean(pfn);
+}
+EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
+
+void kvm_set_page_dirty(struct page *page)
+{
+	kvm_set_pfn_dirty(page_to_pfn(page));
+}
+EXPORT_SYMBOL_GPL(kvm_set_page_dirty);
+
+void kvm_set_pfn_dirty(pfn_t pfn)
+{
+	if (!kvm_is_mmio_pfn(pfn)) {
+		struct page *page = pfn_to_page(pfn);
+		if (!PageReserved(page))
+			SetPageDirty(page);
+	}
+}
+EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
+
+void kvm_set_pfn_accessed(pfn_t pfn)
+{
+	if (!kvm_is_mmio_pfn(pfn))
+		mark_page_accessed(pfn_to_page(pfn));
+}
+EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
+
+void kvm_get_pfn(pfn_t pfn)
+{
+	if (!kvm_is_mmio_pfn(pfn))
+		get_page(pfn_to_page(pfn));
+}
+EXPORT_SYMBOL_GPL(kvm_get_pfn);
+
+static int next_segment(unsigned long len, int offset)
+{
+	if (len > PAGE_SIZE - offset)
+		return PAGE_SIZE - offset;
+	else
+		return len;
+}
+
+int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
+			int len)
+{
+	int r;
+	unsigned long addr;
+
+	addr = gfn_to_hva(kvm, gfn);
+	if (kvm_is_error_hva(addr))
+		return -EFAULT;
+	r = __copy_from_user(data, (void __user *)addr + offset, len);
+	if (r)
+		return -EFAULT;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_read_guest_page);
+
+int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
+{
+	gfn_t gfn = gpa >> PAGE_SHIFT;
+	int seg;
+	int offset = offset_in_page(gpa);
+	int ret;
+
+	while ((seg = next_segment(len, offset)) != 0) {
+		ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
+		if (ret < 0)
+			return ret;
+		offset = 0;
+		len -= seg;
+		data += seg;
+		++gfn;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_read_guest);
+
+int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
+			  unsigned long len)
+{
+	int r;
+	unsigned long addr;
+	gfn_t gfn = gpa >> PAGE_SHIFT;
+	int offset = offset_in_page(gpa);
+
+	addr = gfn_to_hva(kvm, gfn);
+	if (kvm_is_error_hva(addr))
+		return -EFAULT;
+	pagefault_disable();
+	r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
+	pagefault_enable();
+	if (r)
+		return -EFAULT;
+	return 0;
+}
+EXPORT_SYMBOL(kvm_read_guest_atomic);
+
+int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
+			 int offset, int len)
+{
+	int r;
+	unsigned long addr;
+
+	addr = gfn_to_hva(kvm, gfn);
+	if (kvm_is_error_hva(addr))
+		return -EFAULT;
+	r = __copy_to_user((void __user *)addr + offset, data, len);
+	if (r)
+		return -EFAULT;
+	mark_page_dirty(kvm, gfn);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_write_guest_page);
+
+int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
+		    unsigned long len)
+{
+	gfn_t gfn = gpa >> PAGE_SHIFT;
+	int seg;
+	int offset = offset_in_page(gpa);
+	int ret;
+
+	while ((seg = next_segment(len, offset)) != 0) {
+		ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
+		if (ret < 0)
+			return ret;
+		offset = 0;
+		len -= seg;
+		data += seg;
+		++gfn;
+	}
+	return 0;
+}
+
+int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+			      gpa_t gpa)
+{
+	struct kvm_memslots *slots = kvm_memslots(kvm);
+	int offset = offset_in_page(gpa);
+	gfn_t gfn = gpa >> PAGE_SHIFT;
+
+	ghc->gpa = gpa;
+	ghc->generation = slots->generation;
+	ghc->memslot = gfn_to_memslot(kvm, gfn);
+	ghc->hva = gfn_to_hva_many(ghc->memslot, gfn, NULL);
+	if (!kvm_is_error_hva(ghc->hva))
+		ghc->hva += offset;
+	else
+		return -EFAULT;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
+
+int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+			   void *data, unsigned long len)
+{
+	struct kvm_memslots *slots = kvm_memslots(kvm);
+	int r;
+
+	if (slots->generation != ghc->generation)
+		kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa);
+
+	if (kvm_is_error_hva(ghc->hva))
+		return -EFAULT;
+
+	r = __copy_to_user((void __user *)ghc->hva, data, len);
+	if (r)
+		return -EFAULT;
+	mark_page_dirty_in_slot(kvm, ghc->memslot, ghc->gpa >> PAGE_SHIFT);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
+
+int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+			   void *data, unsigned long len)
+{
+	struct kvm_memslots *slots = kvm_memslots(kvm);
+	int r;
+
+	if (slots->generation != ghc->generation)
+		kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa);
+
+	if (kvm_is_error_hva(ghc->hva))
+		return -EFAULT;
+
+	r = __copy_from_user(data, (void __user *)ghc->hva, len);
+	if (r)
+		return -EFAULT;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_read_guest_cached);
+
+int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
+{
+	return kvm_write_guest_page(kvm, gfn, (const void *) empty_zero_page,
+				    offset, len);
+}
+EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
+
+int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
+{
+	gfn_t gfn = gpa >> PAGE_SHIFT;
+	int seg;
+	int offset = offset_in_page(gpa);
+	int ret;
+
+        while ((seg = next_segment(len, offset)) != 0) {
+		ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
+		if (ret < 0)
+			return ret;
+		offset = 0;
+		len -= seg;
+		++gfn;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_clear_guest);
+
+void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot,
+			     gfn_t gfn)
+{
+	if (memslot && memslot->dirty_bitmap) {
+		unsigned long rel_gfn = gfn - memslot->base_gfn;
+
+		if (!test_and_set_bit_le(rel_gfn, memslot->dirty_bitmap))
+			memslot->nr_dirty_pages++;
+	}
+}
+
+void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
+{
+	struct kvm_memory_slot *memslot;
+
+	memslot = gfn_to_memslot(kvm, gfn);
+	mark_page_dirty_in_slot(kvm, memslot, gfn);
+}
+
+/*
+ * The vCPU has executed a HLT instruction with in-kernel mode enabled.
+ */
+void kvm_vcpu_block(struct kvm_vcpu *vcpu)
+{
+	DEFINE_WAIT(wait);
+
+	for (;;) {
+		prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
+
+		if (kvm_arch_vcpu_runnable(vcpu)) {
+			kvm_make_request(KVM_REQ_UNHALT, vcpu);
+			break;
+		}
+		if (kvm_cpu_has_pending_timer(vcpu))
+			break;
+		if (signal_pending(current))
+			break;
+
+		schedule();
+	}
+
+	finish_wait(&vcpu->wq, &wait);
+}
+
+void kvm_resched(struct kvm_vcpu *vcpu)
+{
+	if (!need_resched())
+		return;
+	cond_resched();
+}
+EXPORT_SYMBOL_GPL(kvm_resched);
+
+void kvm_vcpu_on_spin(struct kvm_vcpu *me)
+{
+	struct kvm *kvm = me->kvm;
+	struct kvm_vcpu *vcpu;
+	int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
+	int yielded = 0;
+	int pass;
+	int i;
+
+	/*
+	 * We boost the priority of a VCPU that is runnable but not
+	 * currently running, because it got preempted by something
+	 * else and called schedule in __vcpu_run.  Hopefully that
+	 * VCPU is holding the lock that we need and will release it.
+	 * We approximate round-robin by starting at the last boosted VCPU.
+	 */
+	for (pass = 0; pass < 2 && !yielded; pass++) {
+		kvm_for_each_vcpu(i, vcpu, kvm) {
+			struct task_struct *task = NULL;
+			struct pid *pid;
+			if (!pass && i < last_boosted_vcpu) {
+				i = last_boosted_vcpu;
+				continue;
+			} else if (pass && i > last_boosted_vcpu)
+				break;
+			if (vcpu == me)
+				continue;
+			if (waitqueue_active(&vcpu->wq))
+				continue;
+			rcu_read_lock();
+			pid = rcu_dereference(vcpu->pid);
+			if (pid)
+				task = get_pid_task(vcpu->pid, PIDTYPE_PID);
+			rcu_read_unlock();
+			if (!task)
+				continue;
+			if (task->flags & PF_VCPU) {
+				put_task_struct(task);
+				continue;
+			}
+			if (yield_to(task, 1)) {
+				put_task_struct(task);
+				kvm->last_boosted_vcpu = i;
+				yielded = 1;
+				break;
+			}
+			put_task_struct(task);
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
+
+static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct kvm_vcpu *vcpu = vma->vm_file->private_data;
+	struct page *page;
+
+	if (vmf->pgoff == 0)
+		page = virt_to_page(vcpu->run);
+#ifdef CONFIG_X86
+	else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
+		page = virt_to_page(vcpu->arch.pio_data);
+#endif
+#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+	else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
+		page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
+#endif
+	else
+		return kvm_arch_vcpu_fault(vcpu, vmf);
+	get_page(page);
+	vmf->page = page;
+	return 0;
+}
+
+static const struct vm_operations_struct kvm_vcpu_vm_ops = {
+	.fault = kvm_vcpu_fault,
+};
+
+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;
+
+	kvm_put_kvm(vcpu->kvm);
+	return 0;
+}
+
+static struct file_operations kvm_vcpu_fops = {
+	.release        = kvm_vcpu_release,
+	.unlocked_ioctl = kvm_vcpu_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl   = kvm_vcpu_compat_ioctl,
+#endif
+	.mmap           = kvm_vcpu_mmap,
+	.llseek		= noop_llseek,
+};
+
+/*
+ * Allocates an inode for the vcpu.
+ */
+static int create_vcpu_fd(struct kvm_vcpu *vcpu)
+{
+	return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR);
+}
+
+/*
+ * Creates some virtual cpus.  Good luck creating more than one.
+ */
+static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
+{
+	int r;
+	struct kvm_vcpu *vcpu, *v;
+
+	vcpu = kvm_arch_vcpu_create(kvm, id);
+	if (IS_ERR(vcpu))
+		return PTR_ERR(vcpu);
+
+	preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
+
+	r = kvm_arch_vcpu_setup(vcpu);
+	if (r)
+		goto vcpu_destroy;
+
+	mutex_lock(&kvm->lock);
+	if (!kvm_vcpu_compatible(vcpu)) {
+		r = -EINVAL;
+		goto unlock_vcpu_destroy;
+	}
+	if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
+		r = -EINVAL;
+		goto unlock_vcpu_destroy;
+	}
+
+	kvm_for_each_vcpu(r, v, kvm)
+		if (v->vcpu_id == id) {
+			r = -EEXIST;
+			goto unlock_vcpu_destroy;
+		}
+
+	BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
+
+	/* Now it's all set up, let userspace reach it */
+	kvm_get_kvm(kvm);
+	r = create_vcpu_fd(vcpu);
+	if (r < 0) {
+		kvm_put_kvm(kvm);
+		goto unlock_vcpu_destroy;
+	}
+
+	kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
+	smp_wmb();
+	atomic_inc(&kvm->online_vcpus);
+
+	mutex_unlock(&kvm->lock);
+	return r;
+
+unlock_vcpu_destroy:
+	mutex_unlock(&kvm->lock);
+vcpu_destroy:
+	kvm_arch_vcpu_destroy(vcpu);
+	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;
+}
+
+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;
+	struct kvm_fpu *fpu = NULL;
+	struct kvm_sregs *kvm_sregs = NULL;
+
+	if (vcpu->kvm->mm != current->mm)
+		return -EIO;
+
+#if defined(CONFIG_S390) || defined(CONFIG_PPC)
+	/*
+	 * Special cases: vcpu ioctls that are asynchronous to vcpu execution,
+	 * so vcpu_load() would break it.
+	 */
+	if (ioctl == KVM_S390_INTERRUPT || ioctl == KVM_INTERRUPT)
+		return kvm_arch_vcpu_ioctl(filp, ioctl, arg);
+#endif
+
+
+	vcpu_load(vcpu);
+	switch (ioctl) {
+	case KVM_RUN:
+		r = -EINVAL;
+		if (arg)
+			goto out;
+		r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
+		trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
+		break;
+	case KVM_GET_REGS: {
+		struct kvm_regs *kvm_regs;
+
+		r = -ENOMEM;
+		kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
+		if (!kvm_regs)
+			goto out;
+		r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
+		if (r)
+			goto out_free1;
+		r = -EFAULT;
+		if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
+			goto out_free1;
+		r = 0;
+out_free1:
+		kfree(kvm_regs);
+		break;
+	}
+	case KVM_SET_REGS: {
+		struct kvm_regs *kvm_regs;
+
+		r = -ENOMEM;
+		kvm_regs = memdup_user(argp, sizeof(*kvm_regs));
+		if (IS_ERR(kvm_regs)) {
+			r = PTR_ERR(kvm_regs);
+			goto out;
+		}
+		r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
+		if (r)
+			goto out_free2;
+		r = 0;
+out_free2:
+		kfree(kvm_regs);
+		break;
+	}
+	case KVM_GET_SREGS: {
+		kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
+		r = -ENOMEM;
+		if (!kvm_sregs)
+			goto out;
+		r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs);
+		if (r)
+			goto out;
+		r = -EFAULT;
+		if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs)))
+			goto out;
+		r = 0;
+		break;
+	}
+	case KVM_SET_SREGS: {
+		kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs));
+		if (IS_ERR(kvm_sregs)) {
+			r = PTR_ERR(kvm_sregs);
+			goto out;
+		}
+		r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs);
+		if (r)
+			goto out;
+		r = 0;
+		break;
+	}
+	case KVM_GET_MP_STATE: {
+		struct kvm_mp_state mp_state;
+
+		r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
+		if (r)
+			goto out;
+		r = -EFAULT;
+		if (copy_to_user(argp, &mp_state, sizeof mp_state))
+			goto out;
+		r = 0;
+		break;
+	}
+	case KVM_SET_MP_STATE: {
+		struct kvm_mp_state mp_state;
+
+		r = -EFAULT;
+		if (copy_from_user(&mp_state, argp, sizeof mp_state))
+			goto out;
+		r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
+		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_arch_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_SET_GUEST_DEBUG: {
+		struct kvm_guest_debug dbg;
+
+		r = -EFAULT;
+		if (copy_from_user(&dbg, argp, sizeof dbg))
+			goto out;
+		r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg);
+		if (r)
+			goto out;
+		r = 0;
+		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, p);
+		break;
+	}
+	case KVM_GET_FPU: {
+		fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
+		r = -ENOMEM;
+		if (!fpu)
+			goto out;
+		r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
+		if (r)
+			goto out;
+		r = -EFAULT;
+		if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu)))
+			goto out;
+		r = 0;
+		break;
+	}
+	case KVM_SET_FPU: {
+		fpu = memdup_user(argp, sizeof(*fpu));
+		if (IS_ERR(fpu)) {
+			r = PTR_ERR(fpu);
+			goto out;
+		}
+		r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
+		if (r)
+			goto out;
+		r = 0;
+		break;
+	}
+	default:
+		r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
+	}
+out:
+	vcpu_put(vcpu);
+	kfree(fpu);
+	kfree(kvm_sregs);
+	return r;
+}
+
+#ifdef CONFIG_COMPAT
+static long kvm_vcpu_compat_ioctl(struct file *filp,
+				  unsigned int ioctl, unsigned long arg)
+{
+	struct kvm_vcpu *vcpu = filp->private_data;
+	void __user *argp = compat_ptr(arg);
+	int r;
+
+	if (vcpu->kvm->mm != current->mm)
+		return -EIO;
+
+	switch (ioctl) {
+	case KVM_SET_SIGNAL_MASK: {
+		struct kvm_signal_mask __user *sigmask_arg = argp;
+		struct kvm_signal_mask kvm_sigmask;
+		compat_sigset_t csigset;
+		sigset_t sigset;
+
+		if (argp) {
+			r = -EFAULT;
+			if (copy_from_user(&kvm_sigmask, argp,
+					   sizeof kvm_sigmask))
+				goto out;
+			r = -EINVAL;
+			if (kvm_sigmask.len != sizeof csigset)
+				goto out;
+			r = -EFAULT;
+			if (copy_from_user(&csigset, sigmask_arg->sigset,
+					   sizeof csigset))
+				goto out;
+		}
+		sigset_from_compat(&sigset, &csigset);
+		r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
+		break;
+	}
+	default:
+		r = kvm_vcpu_ioctl(filp, ioctl, arg);
+	}
+
+out:
+	return r;
+}
+#endif
+
+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;
+
+	if (kvm->mm != current->mm)
+		return -EIO;
+	switch (ioctl) {
+	case KVM_CREATE_VCPU:
+		r = kvm_vm_ioctl_create_vcpu(kvm, arg);
+		if (r < 0)
+			goto out;
+		break;
+	case KVM_SET_USER_MEMORY_REGION: {
+		struct kvm_userspace_memory_region kvm_userspace_mem;
+
+		r = -EFAULT;
+		if (copy_from_user(&kvm_userspace_mem, argp,
+						sizeof kvm_userspace_mem))
+			goto out;
+
+		r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem, 1);
+		if (r)
+			goto out;
+		break;
+	}
+	case KVM_GET_DIRTY_LOG: {
+		struct kvm_dirty_log log;
+
+		r = -EFAULT;
+		if (copy_from_user(&log, argp, sizeof log))
+			goto out;
+		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
+		if (r)
+			goto out;
+		break;
+	}
+#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+	case KVM_REGISTER_COALESCED_MMIO: {
+		struct kvm_coalesced_mmio_zone zone;
+		r = -EFAULT;
+		if (copy_from_user(&zone, argp, sizeof zone))
+			goto out;
+		r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
+		if (r)
+			goto out;
+		r = 0;
+		break;
+	}
+	case KVM_UNREGISTER_COALESCED_MMIO: {
+		struct kvm_coalesced_mmio_zone zone;
+		r = -EFAULT;
+		if (copy_from_user(&zone, argp, sizeof zone))
+			goto out;
+		r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
+		if (r)
+			goto out;
+		r = 0;
+		break;
+	}
+#endif
+	case KVM_IRQFD: {
+		struct kvm_irqfd data;
+
+		r = -EFAULT;
+		if (copy_from_user(&data, argp, sizeof data))
+			goto out;
+		r = kvm_irqfd(kvm, data.fd, data.gsi, data.flags);
+		break;
+	}
+	case KVM_IOEVENTFD: {
+		struct kvm_ioeventfd data;
+
+		r = -EFAULT;
+		if (copy_from_user(&data, argp, sizeof data))
+			goto out;
+		r = kvm_ioeventfd(kvm, &data);
+		break;
+	}
+#ifdef CONFIG_KVM_APIC_ARCHITECTURE
+	case KVM_SET_BOOT_CPU_ID:
+		r = 0;
+		mutex_lock(&kvm->lock);
+		if (atomic_read(&kvm->online_vcpus) != 0)
+			r = -EBUSY;
+		else
+			kvm->bsp_vcpu_id = arg;
+		mutex_unlock(&kvm->lock);
+		break;
+#endif
+	default:
+		r = kvm_arch_vm_ioctl(filp, ioctl, arg);
+		if (r == -ENOTTY)
+			r = kvm_vm_ioctl_assigned_device(kvm, ioctl, arg);
+	}
+out:
+	return r;
+}
+
+#ifdef CONFIG_COMPAT
+struct compat_kvm_dirty_log {
+	__u32 slot;
+	__u32 padding1;
+	union {
+		compat_uptr_t dirty_bitmap; /* one bit per page */
+		__u64 padding2;
+	};
+};
+
+static long kvm_vm_compat_ioctl(struct file *filp,
+			   unsigned int ioctl, unsigned long arg)
+{
+	struct kvm *kvm = filp->private_data;
+	int r;
+
+	if (kvm->mm != current->mm)
+		return -EIO;
+	switch (ioctl) {
+	case KVM_GET_DIRTY_LOG: {
+		struct compat_kvm_dirty_log compat_log;
+		struct kvm_dirty_log log;
+
+		r = -EFAULT;
+		if (copy_from_user(&compat_log, (void __user *)arg,
+				   sizeof(compat_log)))
+			goto out;
+		log.slot	 = compat_log.slot;
+		log.padding1	 = compat_log.padding1;
+		log.padding2	 = compat_log.padding2;
+		log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
+
+		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
+		if (r)
+			goto out;
+		break;
+	}
+	default:
+		r = kvm_vm_ioctl(filp, ioctl, arg);
+	}
+
+out:
+	return r;
+}
+#endif
+
+static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct page *page[1];
+	unsigned long addr;
+	int npages;
+	gfn_t gfn = vmf->pgoff;
+	struct kvm *kvm = vma->vm_file->private_data;
+
+	addr = gfn_to_hva(kvm, gfn);
+	if (kvm_is_error_hva(addr))
+		return VM_FAULT_SIGBUS;
+
+	npages = get_user_pages(current, current->mm, addr, 1, 1, 0, page,
+				NULL);
+	if (unlikely(npages != 1))
+		return VM_FAULT_SIGBUS;
+
+	vmf->page = page[0];
+	return 0;
+}
+
+static const struct vm_operations_struct kvm_vm_vm_ops = {
+	.fault = kvm_vm_fault,
+};
+
+static int kvm_vm_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	vma->vm_ops = &kvm_vm_vm_ops;
+	return 0;
+}
+
+static struct file_operations kvm_vm_fops = {
+	.release        = kvm_vm_release,
+	.unlocked_ioctl = kvm_vm_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl   = kvm_vm_compat_ioctl,
+#endif
+	.mmap           = kvm_vm_mmap,
+	.llseek		= noop_llseek,
+};
+
+static int kvm_dev_ioctl_create_vm(unsigned long type)
+{
+	int r;
+	struct kvm *kvm;
+
+	kvm = kvm_create_vm(type);
+	if (IS_ERR(kvm))
+		return PTR_ERR(kvm);
+#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+	r = kvm_coalesced_mmio_init(kvm);
+	if (r < 0) {
+		kvm_put_kvm(kvm);
+		return r;
+	}
+#endif
+	r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
+	if (r < 0)
+		kvm_put_kvm(kvm);
+
+	return r;
+}
+
+static long kvm_dev_ioctl_check_extension_generic(long arg)
+{
+	switch (arg) {
+	case KVM_CAP_USER_MEMORY:
+	case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
+	case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
+#ifdef CONFIG_KVM_APIC_ARCHITECTURE
+	case KVM_CAP_SET_BOOT_CPU_ID:
+#endif
+	case KVM_CAP_INTERNAL_ERROR_DATA:
+		return 1;
+#ifdef CONFIG_HAVE_KVM_IRQCHIP
+	case KVM_CAP_IRQ_ROUTING:
+		return KVM_MAX_IRQ_ROUTES;
+#endif
+	default:
+		break;
+	}
+	return kvm_dev_ioctl_check_extension(arg);
+}
+
+static long kvm_dev_ioctl(struct file *filp,
+			  unsigned int ioctl, unsigned long arg)
+{
+	long r = -EINVAL;
+
+	switch (ioctl) {
+	case KVM_GET_API_VERSION:
+		r = -EINVAL;
+		if (arg)
+			goto out;
+		r = KVM_API_VERSION;
+		break;
+	case KVM_CREATE_VM:
+		r = kvm_dev_ioctl_create_vm(arg);
+		break;
+	case KVM_CHECK_EXTENSION:
+		r = kvm_dev_ioctl_check_extension_generic(arg);
+		break;
+	case KVM_GET_VCPU_MMAP_SIZE:
+		r = -EINVAL;
+		if (arg)
+			goto out;
+		r = PAGE_SIZE;     /* struct kvm_run */
+#ifdef CONFIG_X86
+		r += PAGE_SIZE;    /* pio data page */
+#endif
+#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+		r += PAGE_SIZE;    /* coalesced mmio ring page */
+#endif
+		break;
+	case KVM_TRACE_ENABLE:
+	case KVM_TRACE_PAUSE:
+	case KVM_TRACE_DISABLE:
+		r = -EOPNOTSUPP;
+		break;
+	default:
+		return kvm_arch_dev_ioctl(filp, ioctl, arg);
+	}
+out:
+	return r;
+}
+
+static struct file_operations kvm_chardev_ops = {
+	.unlocked_ioctl = kvm_dev_ioctl,
+	.compat_ioctl   = kvm_dev_ioctl,
+	.llseek		= noop_llseek,
+};
+
+static struct miscdevice kvm_dev = {
+	KVM_MINOR,
+	"kvm",
+	&kvm_chardev_ops,
+};
+
+static void hardware_enable_nolock(void *junk)
+{
+	int cpu = raw_smp_processor_id();
+	int r;
+
+	if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
+		return;
+
+	cpumask_set_cpu(cpu, cpus_hardware_enabled);
+
+	r = kvm_arch_hardware_enable(NULL);
+
+	if (r) {
+		cpumask_clear_cpu(cpu, cpus_hardware_enabled);
+		atomic_inc(&hardware_enable_failed);
+		printk(KERN_INFO "kvm: enabling virtualization on "
+				 "CPU%d failed\n", cpu);
+	}
+}
+
+static void hardware_enable(void *junk)
+{
+	raw_spin_lock(&kvm_lock);
+	hardware_enable_nolock(junk);
+	raw_spin_unlock(&kvm_lock);
+}
+
+static void hardware_disable_nolock(void *junk)
+{
+	int cpu = raw_smp_processor_id();
+
+	if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
+		return;
+	cpumask_clear_cpu(cpu, cpus_hardware_enabled);
+	kvm_arch_hardware_disable(NULL);
+}
+
+static void hardware_disable(void *junk)
+{
+	raw_spin_lock(&kvm_lock);
+	hardware_disable_nolock(junk);
+	raw_spin_unlock(&kvm_lock);
+}
+
+static void hardware_disable_all_nolock(void)
+{
+	BUG_ON(!kvm_usage_count);
+
+	kvm_usage_count--;
+	if (!kvm_usage_count)
+		on_each_cpu(hardware_disable_nolock, NULL, 1);
+}
+
+static void hardware_disable_all(void)
+{
+	raw_spin_lock(&kvm_lock);
+	hardware_disable_all_nolock();
+	raw_spin_unlock(&kvm_lock);
+}
+
+static int hardware_enable_all(void)
+{
+	int r = 0;
+
+	raw_spin_lock(&kvm_lock);
+
+	kvm_usage_count++;
+	if (kvm_usage_count == 1) {
+		atomic_set(&hardware_enable_failed, 0);
+		on_each_cpu(hardware_enable_nolock, NULL, 1);
+
+		if (atomic_read(&hardware_enable_failed)) {
+			hardware_disable_all_nolock();
+			r = -EBUSY;
+		}
+	}
+
+	raw_spin_unlock(&kvm_lock);
+
+	return r;
+}
+
+static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
+			   void *v)
+{
+	int cpu = (long)v;
+
+	if (!kvm_usage_count)
+		return NOTIFY_OK;
+
+	val &= ~CPU_TASKS_FROZEN;
+	switch (val) {
+	case CPU_DYING:
+		printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
+		       cpu);
+		hardware_disable(NULL);
+		break;
+	case CPU_STARTING:
+		printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
+		       cpu);
+		hardware_enable(NULL);
+		break;
+	}
+	return NOTIFY_OK;
+}
+
+
+asmlinkage void kvm_spurious_fault(void)
+{
+	/* Fault while not rebooting.  We want the trace. */
+	BUG();
+}
+EXPORT_SYMBOL_GPL(kvm_spurious_fault);
+
+static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
+		      void *v)
+{
+	/*
+	 * Some (well, at least mine) BIOSes hang on reboot if
+	 * in vmx root mode.
+	 *
+	 * And Intel TXT required VMX off for all cpu when system shutdown.
+	 */
+	printk(KERN_INFO "kvm: exiting hardware virtualization\n");
+	kvm_rebooting = true;
+	on_each_cpu(hardware_disable_nolock, NULL, 1);
+	return NOTIFY_OK;
+}
+
+static struct notifier_block kvm_reboot_notifier = {
+	.notifier_call = kvm_reboot,
+	.priority = 0,
+};
+
+static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
+{
+	int i;
+
+	for (i = 0; i < bus->dev_count; i++) {
+		struct kvm_io_device *pos = bus->range[i].dev;
+
+		kvm_iodevice_destructor(pos);
+	}
+	kfree(bus);
+}
+
+int kvm_io_bus_sort_cmp(const void *p1, const void *p2)
+{
+	const struct kvm_io_range *r1 = p1;
+	const struct kvm_io_range *r2 = p2;
+
+	if (r1->addr < r2->addr)
+		return -1;
+	if (r1->addr + r1->len > r2->addr + r2->len)
+		return 1;
+	return 0;
+}
+
+int kvm_io_bus_insert_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev,
+			  gpa_t addr, int len)
+{
+	if (bus->dev_count == NR_IOBUS_DEVS)
+		return -ENOSPC;
+
+	bus->range[bus->dev_count++] = (struct kvm_io_range) {
+		.addr = addr,
+		.len = len,
+		.dev = dev,
+	};
+
+	sort(bus->range, bus->dev_count, sizeof(struct kvm_io_range),
+		kvm_io_bus_sort_cmp, NULL);
+
+	return 0;
+}
+
+int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus,
+			     gpa_t addr, int len)
+{
+	struct kvm_io_range *range, key;
+	int off;
+
+	key = (struct kvm_io_range) {
+		.addr = addr,
+		.len = len,
+	};
+
+	range = bsearch(&key, bus->range, bus->dev_count,
+			sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp);
+	if (range == NULL)
+		return -ENOENT;
+
+	off = range - bus->range;
+
+	while (off > 0 && kvm_io_bus_sort_cmp(&key, &bus->range[off-1]) == 0)
+		off--;
+
+	return off;
+}
+
+/* kvm_io_bus_write - called under kvm->slots_lock */
+int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
+		     int len, const void *val)
+{
+	int idx;
+	struct kvm_io_bus *bus;
+	struct kvm_io_range range;
+
+	range = (struct kvm_io_range) {
+		.addr = addr,
+		.len = len,
+	};
+
+	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
+	idx = kvm_io_bus_get_first_dev(bus, addr, len);
+	if (idx < 0)
+		return -EOPNOTSUPP;
+
+	while (idx < bus->dev_count &&
+		kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) {
+		if (!kvm_iodevice_write(bus->range[idx].dev, addr, len, val))
+			return 0;
+		idx++;
+	}
+
+	return -EOPNOTSUPP;
+}
+
+/* kvm_io_bus_read - called under kvm->slots_lock */
+int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
+		    int len, void *val)
+{
+	int idx;
+	struct kvm_io_bus *bus;
+	struct kvm_io_range range;
+
+	range = (struct kvm_io_range) {
+		.addr = addr,
+		.len = len,
+	};
+
+	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
+	idx = kvm_io_bus_get_first_dev(bus, addr, len);
+	if (idx < 0)
+		return -EOPNOTSUPP;
+
+	while (idx < bus->dev_count &&
+		kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) {
+		if (!kvm_iodevice_read(bus->range[idx].dev, addr, len, val))
+			return 0;
+		idx++;
+	}
+
+	return -EOPNOTSUPP;
+}
+
+/* Caller must hold slots_lock. */
+int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
+			    int len, struct kvm_io_device *dev)
+{
+	struct kvm_io_bus *new_bus, *bus;
+
+	bus = kvm->buses[bus_idx];
+	if (bus->dev_count > NR_IOBUS_DEVS-1)
+		return -ENOSPC;
+
+	new_bus = kmemdup(bus, sizeof(struct kvm_io_bus), GFP_KERNEL);
+	if (!new_bus)
+		return -ENOMEM;
+	kvm_io_bus_insert_dev(new_bus, dev, addr, len);
+	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
+	synchronize_srcu_expedited(&kvm->srcu);
+	kfree(bus);
+
+	return 0;
+}
+
+/* Caller must hold slots_lock. */
+int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
+			      struct kvm_io_device *dev)
+{
+	int i, r;
+	struct kvm_io_bus *new_bus, *bus;
+
+	bus = kvm->buses[bus_idx];
+
+	new_bus = kmemdup(bus, sizeof(*bus), GFP_KERNEL);
+	if (!new_bus)
+		return -ENOMEM;
+
+	r = -ENOENT;
+	for (i = 0; i < new_bus->dev_count; i++)
+		if (new_bus->range[i].dev == dev) {
+			r = 0;
+			new_bus->dev_count--;
+			new_bus->range[i] = new_bus->range[new_bus->dev_count];
+			sort(new_bus->range, new_bus->dev_count,
+			     sizeof(struct kvm_io_range),
+			     kvm_io_bus_sort_cmp, NULL);
+			break;
+		}
+
+	if (r) {
+		kfree(new_bus);
+		return r;
+	}
+
+	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
+	synchronize_srcu_expedited(&kvm->srcu);
+	kfree(bus);
+	return r;
+}
+
+static struct notifier_block kvm_cpu_notifier = {
+	.notifier_call = kvm_cpu_hotplug,
+};
+
+static int vm_stat_get(void *_offset, u64 *val)
+{
+	unsigned offset = (long)_offset;
+	struct kvm *kvm;
+
+	*val = 0;
+	raw_spin_lock(&kvm_lock);
+	list_for_each_entry(kvm, &vm_list, vm_list)
+		*val += *(u32 *)((void *)kvm + offset);
+	raw_spin_unlock(&kvm_lock);
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
+
+static int vcpu_stat_get(void *_offset, u64 *val)
+{
+	unsigned offset = (long)_offset;
+	struct kvm *kvm;
+	struct kvm_vcpu *vcpu;
+	int i;
+
+	*val = 0;
+	raw_spin_lock(&kvm_lock);
+	list_for_each_entry(kvm, &vm_list, vm_list)
+		kvm_for_each_vcpu(i, vcpu, kvm)
+			*val += *(u32 *)((void *)vcpu + offset);
+
+	raw_spin_unlock(&kvm_lock);
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
+
+static const struct file_operations *stat_fops[] = {
+	[KVM_STAT_VCPU] = &vcpu_stat_fops,
+	[KVM_STAT_VM]   = &vm_stat_fops,
+};
+
+static int kvm_init_debug(void)
+{
+	int r = -EFAULT;
+	struct kvm_stats_debugfs_item *p;
+
+	kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
+	if (kvm_debugfs_dir == NULL)
+		goto out;
+
+	for (p = debugfs_entries; p->name; ++p) {
+		p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
+						(void *)(long)p->offset,
+						stat_fops[p->kind]);
+		if (p->dentry == NULL)
+			goto out_dir;
+	}
+
+	return 0;
+
+out_dir:
+	debugfs_remove_recursive(kvm_debugfs_dir);
+out:
+	return r;
+}
+
+static void kvm_exit_debug(void)
+{
+	struct kvm_stats_debugfs_item *p;
+
+	for (p = debugfs_entries; p->name; ++p)
+		debugfs_remove(p->dentry);
+	debugfs_remove(kvm_debugfs_dir);
+}
+
+static int kvm_suspend(void)
+{
+	if (kvm_usage_count)
+		hardware_disable_nolock(NULL);
+	return 0;
+}
+
+static void kvm_resume(void)
+{
+	if (kvm_usage_count) {
+		WARN_ON(raw_spin_is_locked(&kvm_lock));
+		hardware_enable_nolock(NULL);
+	}
+}
+
+static struct syscore_ops kvm_syscore_ops = {
+	.suspend = kvm_suspend,
+	.resume = kvm_resume,
+};
+
+struct page *bad_page;
+pfn_t bad_pfn;
+
+static inline
+struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
+{
+	return container_of(pn, struct kvm_vcpu, preempt_notifier);
+}
+
+static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
+{
+	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
+
+	kvm_arch_vcpu_load(vcpu, cpu);
+}
+
+static void kvm_sched_out(struct preempt_notifier *pn,
+			  struct task_struct *next)
+{
+	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
+
+	kvm_arch_vcpu_put(vcpu);
+}
+
+int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
+		  struct module *module)
+{
+	int r;
+	int cpu;
+
+	r = kvm_arch_init(opaque);
+	if (r)
+		goto out_fail;
+
+	bad_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+
+	if (bad_page == NULL) {
+		r = -ENOMEM;
+		goto out;
+	}
+
+	bad_pfn = page_to_pfn(bad_page);
+
+	hwpoison_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+
+	if (hwpoison_page == NULL) {
+		r = -ENOMEM;
+		goto out_free_0;
+	}
+
+	hwpoison_pfn = page_to_pfn(hwpoison_page);
+
+	fault_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+
+	if (fault_page == NULL) {
+		r = -ENOMEM;
+		goto out_free_0;
+	}
+
+	fault_pfn = page_to_pfn(fault_page);
+
+	if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
+		r = -ENOMEM;
+		goto out_free_0;
+	}
+
+	r = kvm_arch_hardware_setup();
+	if (r < 0)
+		goto out_free_0a;
+
+	for_each_online_cpu(cpu) {
+		smp_call_function_single(cpu,
+				kvm_arch_check_processor_compat,
+				&r, 1);
+		if (r < 0)
+			goto out_free_1;
+	}
+
+	r = register_cpu_notifier(&kvm_cpu_notifier);
+	if (r)
+		goto out_free_2;
+	register_reboot_notifier(&kvm_reboot_notifier);
+
+	/* A kmem cache lets us meet the alignment requirements of fx_save. */
+	if (!vcpu_align)
+		vcpu_align = __alignof__(struct kvm_vcpu);
+	kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size, vcpu_align,
+					   0, NULL);
+	if (!kvm_vcpu_cache) {
+		r = -ENOMEM;
+		goto out_free_3;
+	}
+
+	r = kvm_async_pf_init();
+	if (r)
+		goto out_free;
+
+	kvm_chardev_ops.owner = module;
+	kvm_vm_fops.owner = module;
+	kvm_vcpu_fops.owner = module;
+
+	r = misc_register(&kvm_dev);
+	if (r) {
+		printk(KERN_ERR "kvm: misc device register failed\n");
+		goto out_unreg;
+	}
+
+	register_syscore_ops(&kvm_syscore_ops);
+
+	kvm_preempt_ops.sched_in = kvm_sched_in;
+	kvm_preempt_ops.sched_out = kvm_sched_out;
+
+	r = kvm_init_debug();
+	if (r) {
+		printk(KERN_ERR "kvm: create debugfs files failed\n");
+		goto out_undebugfs;
+	}
+
+	return 0;
+
+out_undebugfs:
+	unregister_syscore_ops(&kvm_syscore_ops);
+out_unreg:
+	kvm_async_pf_deinit();
+out_free:
+	kmem_cache_destroy(kvm_vcpu_cache);
+out_free_3:
+	unregister_reboot_notifier(&kvm_reboot_notifier);
+	unregister_cpu_notifier(&kvm_cpu_notifier);
+out_free_2:
+out_free_1:
+	kvm_arch_hardware_unsetup();
+out_free_0a:
+	free_cpumask_var(cpus_hardware_enabled);
+out_free_0:
+	if (fault_page)
+		__free_page(fault_page);
+	if (hwpoison_page)
+		__free_page(hwpoison_page);
+	__free_page(bad_page);
+out:
+	kvm_arch_exit();
+out_fail:
+	return r;
+}
+EXPORT_SYMBOL_GPL(kvm_init);
+
+void kvm_exit(void)
+{
+	kvm_exit_debug();
+	misc_deregister(&kvm_dev);
+	kmem_cache_destroy(kvm_vcpu_cache);
+	kvm_async_pf_deinit();
+	unregister_syscore_ops(&kvm_syscore_ops);
+	unregister_reboot_notifier(&kvm_reboot_notifier);
+	unregister_cpu_notifier(&kvm_cpu_notifier);
+	on_each_cpu(hardware_disable_nolock, NULL, 1);
+	kvm_arch_hardware_unsetup();
+	kvm_arch_exit();
+	free_cpumask_var(cpus_hardware_enabled);
+	__free_page(hwpoison_page);
+	__free_page(bad_page);
+}
+EXPORT_SYMBOL_GPL(kvm_exit);