2.6.25-rc7

 virt

 kvm

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
new file mode 100644
index 0000000..b2e1289
--- /dev/null
+++ b/virt/kvm/kvm_main.c
@@ -0,0 +1,1401 @@
+/*
+ * 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 "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/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 <linux/kvm_para.h>
+#include <linux/pagemap.h>
+#include <linux/mman.h>
+
+#include <asm/processor.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+
+MODULE_AUTHOR("Qumranet");
+MODULE_LICENSE("GPL");
+
+DEFINE_SPINLOCK(kvm_lock);
+LIST_HEAD(vm_list);
+
+static cpumask_t cpus_hardware_enabled;
+
+struct kmem_cache *kvm_vcpu_cache;
+EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
+
+static __read_mostly struct preempt_ops kvm_preempt_ops;
+
+static struct dentry *debugfs_dir;
+
+static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
+            unsigned long arg);
+
+static inline int valid_vcpu(int n)
+{
+   return likely(n >= 0 && n < KVM_MAX_VCPUS);
+}
+
+/*
+ * Switches to specified vcpu, until a matching vcpu_put()
+ */
+void vcpu_load(struct kvm_vcpu *vcpu)
+{
+   int cpu;
+
+   mutex_lock(&vcpu->mutex);
+   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)
+{
+}
+
+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_REQ_TLB_FLUSH, &vcpu->requests))
+         continue;
+      cpu = vcpu->cpu;
+      if (cpu != -1 && cpu != raw_smp_processor_id())
+         cpu_set(cpu, cpus);
+   }
+   if (cpus_empty(cpus))
+      return;
+   ++kvm->stat.remote_tlb_flush;
+   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->kvm = kvm;
+   vcpu->vcpu_id = id;
+   init_waitqueue_head(&vcpu->wq);
+
+   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)
+{
+   kvm_arch_vcpu_uninit(vcpu);
+   free_page((unsigned long)vcpu->run);
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
+
+static struct kvm *kvm_create_vm(void)
+{
+   struct kvm *kvm = kvm_arch_create_vm();
+
+   if (IS_ERR(kvm))
+      goto out;
+
+   kvm->mm = current->mm;
+   atomic_inc(&kvm->mm->mm_count);
+   spin_lock_init(&kvm->mmu_lock);
+   kvm_io_bus_init(&kvm->pio_bus);
+   mutex_init(&kvm->lock);
+   kvm_io_bus_init(&kvm->mmio_bus);
+   init_rwsem(&kvm->slots_lock);
+   spin_lock(&kvm_lock);
+   list_add(&kvm->vm_list, &vm_list);
+   spin_unlock(&kvm_lock);
+out:
+   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)
+{
+   if (!dont || free->rmap != dont->rmap)
+      vfree(free->rmap);
+
+   if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
+      vfree(free->dirty_bitmap);
+
+   free->npages = 0;
+   free->dirty_bitmap = NULL;
+   free->rmap = NULL;
+}
+
+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 kvm_destroy_vm(struct kvm *kvm)
+{
+   struct mm_struct *mm = kvm->mm;
+
+   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);
+   kvm_arch_destroy_vm(kvm);
+   mmdrop(mm);
+}
+
+static int kvm_vm_release(struct inode *inode, struct file *filp)
+{
+   struct kvm *kvm = filp->private_data;
+
+   kvm_destroy_vm(kvm);
+   return 0;
+}
+
+/*
+ * 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;
+
+   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 + KVM_PRIVATE_MEM_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;
+
+   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_free;
+
+   /* 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_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 && !new.rmap) {
+      new.rmap = vmalloc(npages * sizeof(struct page *));
+
+      if (!new.rmap)
+         goto out_free;
+
+      memset(new.rmap, 0, npages * sizeof(*new.rmap));
+
+      new.user_alloc = user_alloc;
+      new.userspace_addr = mem->userspace_addr;
+   }
+
+   /* 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_free;
+      memset(new.dirty_bitmap, 0, dirty_bytes);
+   }
+
+   if (mem->slot >= kvm->nmemslots)
+      kvm->nmemslots = mem->slot + 1;
+
+   *memslot = new;
+
+   r = kvm_arch_set_memory_region(kvm, mem, old, user_alloc);
+   if (r) {
+      *memslot = old;
+      goto out_free;
+   }
+
+   kvm_free_physmem_slot(&old, &new);
+   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;
+
+   down_write(&kvm->slots_lock);
+   r = __kvm_set_memory_region(kvm, mem, user_alloc);
+   up_write(&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;
+   int n;
+   unsigned long any = 0;
+
+   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 (any)
+      *is_dirty = 1;
+
+   r = 0;
+out:
+   return r;
+}
+
+int is_error_page(struct page *page)
+{
+   return page == bad_page;
+}
+EXPORT_SYMBOL_GPL(is_error_page);
+
+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);
+
+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);
+}
+
+int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
+{
+   int i;
+
+   gfn = unalias_gfn(kvm, gfn);
+   for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
+      struct kvm_memory_slot *memslot = &kvm->memslots[i];
+
+      if (gfn >= memslot->base_gfn
+          && gfn < memslot->base_gfn + memslot->npages)
+         return 1;
+   }
+   return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
+
+static unsigned long gfn_to_hva(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 bad_hva();
+   return (slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE);
+}
+
+/*
+ * Requires current->mm->mmap_sem to be held
+ */
+struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
+{
+   struct page *page[1];
+   unsigned long addr;
+   int npages;
+
+   might_sleep();
+
+   addr = gfn_to_hva(kvm, gfn);
+   if (kvm_is_error_hva(addr)) {
+      get_page(bad_page);
+      return bad_page;
+   }
+
+   npages = get_user_pages(current, current->mm, addr, 1, 1, 1, page,
+            NULL);
+
+   if (npages != 1) {
+      get_page(bad_page);
+      return bad_page;
+   }
+
+   return page[0];
+}
+
+EXPORT_SYMBOL_GPL(gfn_to_page);
+
+void kvm_release_page_clean(struct page *page)
+{
+   put_page(page);
+}
+EXPORT_SYMBOL_GPL(kvm_release_page_clean);
+
+void kvm_release_page_dirty(struct page *page)
+{
+   if (!PageReserved(page))
+      SetPageDirty(page);
+   put_page(page);
+}
+EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
+
+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;
+   r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
+   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_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
+{
+   return kvm_write_guest_page(kvm, gfn, 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(struct kvm *kvm, gfn_t gfn)
+{
+   struct kvm_memory_slot *memslot;
+
+   gfn = unalias_gfn(kvm, gfn);
+   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);
+   }
+}
+
+/*
+ * The vCPU has executed a HLT instruction with in-kernel mode enabled.
+ */
+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)
+          && !kvm_arch_vcpu_runnable(vcpu)) {
+      set_current_state(TASK_INTERRUPTIBLE);
+      vcpu_put(vcpu);
+      schedule();
+      vcpu_load(vcpu);
+   }
+
+   __set_current_state(TASK_RUNNING);
+   remove_wait_queue(&vcpu->wq, &wait);
+}
+
+void kvm_resched(struct kvm_vcpu *vcpu)
+{
+   if (!need_resched())
+      return;
+   cond_resched();
+}
+EXPORT_SYMBOL_GPL(kvm_resched);
+
+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);
+   else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
+      page = virt_to_page(vcpu->arch.pio_data);
+   else
+      return VM_FAULT_SIGBUS;
+   get_page(page);
+   vmf->page = page;
+   return 0;
+}
+
+static 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;
+
+   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_arch_vcpu_create(kvm, n);
+   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->vcpus[n]) {
+      r = -EEXIST;
+      mutex_unlock(&kvm->lock);
+      goto vcpu_destroy;
+   }
+   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);
+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;
+
+   if (vcpu->kvm->mm != current->mm)
+      return -EIO;
+   switch (ioctl) {
+   case KVM_RUN:
+      r = -EINVAL;
+      if (arg)
+         goto out;
+      r = kvm_arch_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_arch_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_arch_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_arch_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_arch_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_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_DEBUG_GUEST: {
+      struct kvm_debug_guest dbg;
+
+      r = -EFAULT;
+      if (copy_from_user(&dbg, argp, sizeof dbg))
+         goto out;
+      r = kvm_arch_vcpu_ioctl_debug_guest(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, &sigset);
+      break;
+   }
+   case KVM_GET_FPU: {
+      struct kvm_fpu fpu;
+
+      memset(&fpu, 0, sizeof fpu);
+      r = kvm_arch_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_arch_vcpu_ioctl_set_fpu(vcpu, &fpu);
+      if (r)
+         goto out;
+      r = 0;
+      break;
+   }
+   default:
+      r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
+   }
+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;
+
+   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;
+   }
+   default:
+      r = kvm_arch_vm_ioctl(filp, ioctl, arg);
+   }
+out:
+   return r;
+}
+
+static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+   struct kvm *kvm = vma->vm_file->private_data;
+   struct page *page;
+
+   if (!kvm_is_visible_gfn(kvm, vmf->pgoff))
+      return VM_FAULT_SIGBUS;
+   page = gfn_to_page(kvm, vmf->pgoff);
+   if (is_error_page(page)) {
+      kvm_release_page_clean(page);
+      return VM_FAULT_SIGBUS;
+   }
+   vmf->page = page;
+   return 0;
+}
+
+static 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,
+   .compat_ioctl   = kvm_vm_ioctl,
+   .mmap           = kvm_vm_mmap,
+};
+
+static int kvm_dev_ioctl_create_vm(void)
+{
+   int fd, r;
+   struct inode *inode;
+   struct file *file;
+   struct kvm *kvm;
+
+   kvm = kvm_create_vm();
+   if (IS_ERR(kvm))
+      return PTR_ERR(kvm);
+   r = anon_inode_getfd(&fd, &inode, &file, "kvm-vm", &kvm_vm_fops, kvm);
+   if (r) {
+      kvm_destroy_vm(kvm);
+      return r;
+   }
+
+   kvm->filp = file;
+
+   return fd;
+}
+
+static long kvm_dev_ioctl(struct file *filp,
+           unsigned int ioctl, unsigned long arg)
+{
+   void __user *argp = (void __user *)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 = -EINVAL;
+      if (arg)
+         goto out;
+      r = kvm_dev_ioctl_create_vm();
+      break;
+   case KVM_CHECK_EXTENSION:
+      r = kvm_dev_ioctl_check_extension((long)argp);
+      break;
+   case KVM_GET_VCPU_MMAP_SIZE:
+      r = -EINVAL;
+      if (arg)
+         goto out;
+      r = 2 * PAGE_SIZE;
+      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,
+};
+
+static struct miscdevice kvm_dev = {
+   KVM_MINOR,
+   "kvm",
+   &kvm_chardev_ops,
+};
+
+static void hardware_enable(void *junk)
+{
+   int cpu = raw_smp_processor_id();
+
+   if (cpu_isset(cpu, cpus_hardware_enabled))
+      return;
+   cpu_set(cpu, cpus_hardware_enabled);
+   kvm_arch_hardware_enable(NULL);
+}
+
+static void hardware_disable(void *junk)
+{
+   int cpu = raw_smp_processor_id();
+
+   if (!cpu_isset(cpu, cpus_hardware_enabled))
+      return;
+   cpu_clear(cpu, cpus_hardware_enabled);
+   decache_vcpus_on_cpu(cpu);
+   kvm_arch_hardware_disable(NULL);
+}
+
+static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
+            void *v)
+{
+   int cpu = (long)v;
+
+   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_UP_CANCELED:
+      printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
+             cpu);
+      smp_call_function_single(cpu, hardware_disable, NULL, 0, 1);
+      break;
+   case CPU_ONLINE:
+      printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
+             cpu);
+      smp_call_function_single(cpu, hardware_enable, NULL, 0, 1);
+      break;
+   }
+   return NOTIFY_OK;
+}
+
+static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
+            void *v)
+{
+   if (val == SYS_RESTART) {
+      /*
+       * Some (well, at least mine) BIOSes hang on reboot if
+       * in vmx root mode.
+       */
+      printk(KERN_INFO "kvm: exiting hardware virtualization\n");
+      on_each_cpu(hardware_disable, NULL, 0, 1);
+   }
+   return NOTIFY_OK;
+}
+
+static struct notifier_block kvm_reboot_notifier = {
+   .notifier_call = kvm_reboot,
+   .priority = 0,
+};
+
+void kvm_io_bus_init(struct kvm_io_bus *bus)
+{
+   memset(bus, 0, sizeof(*bus));
+}
+
+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->devs[i];
+
+      kvm_iodevice_destructor(pos);
+   }
+}
+
+struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus, gpa_t addr)
+{
+   int i;
+
+   for (i = 0; i < bus->dev_count; i++) {
+      struct kvm_io_device *pos = bus->devs[i];
+
+      if (pos->in_range(pos, addr))
+         return pos;
+   }
+
+   return NULL;
+}
+
+void kvm_io_bus_register_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev)
+{
+   BUG_ON(bus->dev_count > (NR_IOBUS_DEVS-1));
+
+   bus->devs[bus->dev_count++] = dev;
+}
+
+static struct notifier_block kvm_cpu_notifier = {
+   .notifier_call = kvm_cpu_hotplug,
+   .priority = 20, /* must be > scheduler priority */
+};
+
+static int vm_stat_get(void *_offset, u64 *val)
+{
+   unsigned offset = (long)_offset;
+   struct kvm *kvm;
+
+   *val = 0;
+   spin_lock(&kvm_lock);
+   list_for_each_entry(kvm, &vm_list, vm_list)
+      *val += *(u32 *)((void *)kvm + offset);
+   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;
+   spin_lock(&kvm_lock);
+   list_for_each_entry(kvm, &vm_list, vm_list)
+      for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+         vcpu = kvm->vcpus[i];
+         if (vcpu)
+            *val += *(u32 *)((void *)vcpu + offset);
+      }
+   spin_unlock(&kvm_lock);
+   return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
+
+static struct file_operations *stat_fops[] = {
+   [KVM_STAT_VCPU] = &vcpu_stat_fops,
+   [KVM_STAT_VM]   = &vm_stat_fops,
+};
+
+static void kvm_init_debug(void)
+{
+   struct kvm_stats_debugfs_item *p;
+
+   debugfs_dir = debugfs_create_dir("kvm", NULL);
+   for (p = debugfs_entries; p->name; ++p)
+      p->dentry = debugfs_create_file(p->name, 0444, debugfs_dir,
+                  (void *)(long)p->offset,
+                  stat_fops[p->kind]);
+}
+
+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(debugfs_dir);
+}
+
+static int kvm_suspend(struct sys_device *dev, pm_message_t state)
+{
+   hardware_disable(NULL);
+   return 0;
+}
+
+static int kvm_resume(struct sys_device *dev)
+{
+   hardware_enable(NULL);
+   return 0;
+}
+
+static struct sysdev_class kvm_sysdev_class = {
+   .name = "kvm",
+   .suspend = kvm_suspend,
+   .resume = kvm_resume,
+};
+
+static struct sys_device kvm_sysdev = {
+   .id = 0,
+   .cls = &kvm_sysdev_class,
+};
+
+struct page *bad_page;
+
+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 int vcpu_size,
+        struct module *module)
+{
+   int r;
+   int cpu;
+
+   kvm_init_debug();
+
+   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;
+   }
+
+   r = kvm_arch_hardware_setup();
+   if (r < 0)
+      goto out_free_0;
+
+   for_each_online_cpu(cpu) {
+      smp_call_function_single(cpu,
+            kvm_arch_check_processor_compat,
+            &r, 0, 1);
+      if (r < 0)
+         goto out_free_1;
+   }
+
+   on_each_cpu(hardware_enable, NULL, 0, 1);
+   r = register_cpu_notifier(&kvm_cpu_notifier);
+   if (r)
+      goto out_free_2;
+   register_reboot_notifier(&kvm_reboot_notifier);
+
+   r = sysdev_class_register(&kvm_sysdev_class);
+   if (r)
+      goto out_free_3;
+
+   r = sysdev_register(&kvm_sysdev);
+   if (r)
+      goto out_free_4;
+
+   /* A kmem cache lets us meet the alignment requirements of fx_save. */
+   kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size,
+                  __alignof__(struct kvm_vcpu),
+                  0, NULL);
+   if (!kvm_vcpu_cache) {
+      r = -ENOMEM;
+      goto out_free_5;
+   }
+
+   kvm_chardev_ops.owner = module;
+
+   r = misc_register(&kvm_dev);
+   if (r) {
+      printk(KERN_ERR "kvm: misc device register failed\n");
+      goto out_free;
+   }
+
+   kvm_preempt_ops.sched_in = kvm_sched_in;
+   kvm_preempt_ops.sched_out = kvm_sched_out;
+
+   return 0;
+
+out_free:
+   kmem_cache_destroy(kvm_vcpu_cache);
+out_free_5:
+   sysdev_unregister(&kvm_sysdev);
+out_free_4:
+   sysdev_class_unregister(&kvm_sysdev_class);
+out_free_3:
+   unregister_reboot_notifier(&kvm_reboot_notifier);
+   unregister_cpu_notifier(&kvm_cpu_notifier);
+out_free_2:
+   on_each_cpu(hardware_disable, NULL, 0, 1);
+out_free_1:
+   kvm_arch_hardware_unsetup();
+out_free_0:
+   __free_page(bad_page);
+out:
+   kvm_arch_exit();
+   kvm_exit_debug();
+out_fail:
+   return r;
+}
+EXPORT_SYMBOL_GPL(kvm_init);
+
+void kvm_exit(void)
+{
+   misc_deregister(&kvm_dev);
+   kmem_cache_destroy(kvm_vcpu_cache);
+   sysdev_unregister(&kvm_sysdev);
+   sysdev_class_unregister(&kvm_sysdev_class);
+   unregister_reboot_notifier(&kvm_reboot_notifier);
+   unregister_cpu_notifier(&kvm_cpu_notifier);
+   on_each_cpu(hardware_disable, NULL, 0, 1);
+   kvm_arch_hardware_unsetup();
+   kvm_arch_exit();
+   kvm_exit_debug();
+   __free_page(bad_page);
+}
+EXPORT_SYMBOL_GPL(kvm_exit);