virt/kvm/kvm_main.c

   1 /*
   2  * Kernel-based Virtual Machine driver for Linux
   3  *
   4  * This module enables machines with Intel VT-x extensions to run virtual
   5  * machines without emulation or binary translation.
   6  *
   7  * Copyright (C) 2006 Qumranet, Inc.
   8  *
   9  * Authors:
  10  *   Avi Kivity   <avi@qumranet.com>
  11  *   Yaniv Kamay  <yaniv@qumranet.com>
  12  *
  13  * This work is licensed under the terms of the GNU GPL, version 2.  See
  14  * the COPYING file in the top-level directory.
  15  *
  16  */
  17
  18 #include "iodev.h"
  19
  20 #include <linux/kvm_host.h>
  21 #include <linux/kvm.h>
  22 #include <linux/module.h>
  23 #include <linux/errno.h>
  24 #include <linux/percpu.h>
  25 #include <linux/gfp.h>
  26 #include <linux/mm.h>
  27 #include <linux/miscdevice.h>
  28 #include <linux/vmalloc.h>
  29 #include <linux/reboot.h>
  30 #include <linux/debugfs.h>
  31 #include <linux/highmem.h>
  32 #include <linux/file.h>
  33 #include <linux/sysdev.h>
  34 #include <linux/cpu.h>
  35 #include <linux/sched.h>
  36 #include <linux/cpumask.h>
  37 #include <linux/smp.h>
  38 #include <linux/anon_inodes.h>
  39 #include <linux/profile.h>
  40 #include <linux/kvm_para.h>
  41 #include <linux/pagemap.h>
  42 #include <linux/mman.h>
  43
  44 #include <asm/processor.h>
  45 #include <asm/io.h>
  46 #include <asm/uaccess.h>
  47 #include <asm/pgtable.h>
  48
  49 MODULE_AUTHOR("Qumranet");
  50 MODULE_LICENSE("GPL");
  51
  52 DEFINE_SPINLOCK(kvm_lock);
  53 LIST_HEAD(vm_list);
  54
  55 static cpumask_t cpus_hardware_enabled;
  56
  57 struct kmem_cache *kvm_vcpu_cache;
  58 EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
  59
  60 static __read_mostly struct preempt_ops kvm_preempt_ops;
  61
  62 static struct dentry *debugfs_dir;
  63
  64 static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
  65                            unsigned long arg);
  66
  67 static inline int valid_vcpu(int n)
  68 {
  69         return likely(n >= 0 && n < KVM_MAX_VCPUS);
  70 }
  71
  72 /*
  73  * Switches to specified vcpu, until a matching vcpu_put()
  74  */
  75 void vcpu_load(struct kvm_vcpu *vcpu)
  76 {
  77         int cpu;
  78
  79         mutex_lock(&vcpu->mutex);
  80         cpu = get_cpu();
  81         preempt_notifier_register(&vcpu->preempt_notifier);
  82         kvm_arch_vcpu_load(vcpu, cpu);
  83         put_cpu();
  84 }
  85
  86 void vcpu_put(struct kvm_vcpu *vcpu)
  87 {
  88         preempt_disable();
  89         kvm_arch_vcpu_put(vcpu);
  90         preempt_notifier_unregister(&vcpu->preempt_notifier);
  91         preempt_enable();
  92         mutex_unlock(&vcpu->mutex);
  93 }
  94
  95 static void ack_flush(void *_completed)
  96 {
  97 }
  98
  99 void kvm_flush_remote_tlbs(struct kvm *kvm)
 100 {
 101         int i, cpu;
 102         cpumask_t cpus;
 103         struct kvm_vcpu *vcpu;
 104
 105         cpus_clear(cpus);
 106         for (i = 0; i < KVM_MAX_VCPUS; ++i) {
 107                 vcpu = kvm->vcpus[i];
 108                 if (!vcpu)
 109                         continue;
 110                 if (test_and_set_bit(KVM_REQ_TLB_FLUSH, &vcpu->requests))
 111                         continue;
 112                 cpu = vcpu->cpu;
 113                 if (cpu != -1 && cpu != raw_smp_processor_id())
 114                         cpu_set(cpu, cpus);
 115         }
 116         if (cpus_empty(cpus))
 117                 return;
 118         ++kvm->stat.remote_tlb_flush;
 119         smp_call_function_mask(cpus, ack_flush, NULL, 1);
 120 }
 121
 122 int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
 123 {
 124         struct page *page;
 125         int r;
 126
 127         mutex_init(&vcpu->mutex);
 128         vcpu->cpu = -1;
 129         vcpu->kvm = kvm;
 130         vcpu->vcpu_id = id;
 131         init_waitqueue_head(&vcpu->wq);
 132
 133         page = alloc_page(GFP_KERNEL | __GFP_ZERO);
 134         if (!page) {
 135                 r = -ENOMEM;
 136                 goto fail;
 137         }
 138         vcpu->run = page_address(page);
 139
 140         r = kvm_arch_vcpu_init(vcpu);
 141         if (r < 0)
 142                 goto fail_free_run;
 143         return 0;
 144
 145 fail_free_run:
 146         free_page((unsigned long)vcpu->run);
 147 fail:
 148         return r;
 149 }
 150 EXPORT_SYMBOL_GPL(kvm_vcpu_init);
 151
 152 void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
 153 {
 154         kvm_arch_vcpu_uninit(vcpu);
 155         free_page((unsigned long)vcpu->run);
 156 }
 157 EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
 158
 159 static struct kvm *kvm_create_vm(void)
 160 {
 161         struct kvm *kvm = kvm_arch_create_vm();
 162
 163         if (IS_ERR(kvm))
 164                 goto out;
 165
 166         kvm->mm = current->mm;
 167         atomic_inc(&kvm->mm->mm_count);
 168         spin_lock_init(&kvm->mmu_lock);
 169         kvm_io_bus_init(&kvm->pio_bus);
 170         mutex_init(&kvm->lock);
 171         kvm_io_bus_init(&kvm->mmio_bus);
 172         init_rwsem(&kvm->slots_lock);
 173         spin_lock(&kvm_lock);
 174         list_add(&kvm->vm_list, &vm_list);
 175         spin_unlock(&kvm_lock);
 176 out:
 177         return kvm;
 178 }
 179
 180 /*
 181  * Free any memory in @free but not in @dont.
 182  */
 183 static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
 184                                   struct kvm_memory_slot *dont)
 185 {
 186         if (!dont || free->rmap != dont->rmap)
 187                 vfree(free->rmap);
 188
 189         if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
 190                 vfree(free->dirty_bitmap);
 191
 192         free->npages = 0;
 193         free->dirty_bitmap = NULL;
 194         free->rmap = NULL;
 195 }
 196
 197 void kvm_free_physmem(struct kvm *kvm)
 198 {
 199         int i;
 200
 201         for (i = 0; i < kvm->nmemslots; ++i)
 202                 kvm_free_physmem_slot(&kvm->memslots[i], NULL);
 203 }
 204
 205 static void kvm_destroy_vm(struct kvm *kvm)
 206 {
 207         struct mm_struct *mm = kvm->mm;
 208
 209         spin_lock(&kvm_lock);
 210         list_del(&kvm->vm_list);
 211         spin_unlock(&kvm_lock);
 212         kvm_io_bus_destroy(&kvm->pio_bus);
 213         kvm_io_bus_destroy(&kvm->mmio_bus);
 214         kvm_arch_destroy_vm(kvm);
 215         mmdrop(mm);
 216 }
 217
 218 static int kvm_vm_release(struct inode *inode, struct file *filp)
 219 {
 220         struct kvm *kvm = filp->private_data;
 221
 222         kvm_destroy_vm(kvm);
 223         return 0;
 224 }
 225
 226 /*
 227  * Allocate some memory and give it an address in the guest physical address
 228  * space.
 229  *
 230  * Discontiguous memory is allowed, mostly for framebuffers.
 231  *
 232  * Must be called holding mmap_sem for write.
 233  */
 234 int __kvm_set_memory_region(struct kvm *kvm,
 235                             struct kvm_userspace_memory_region *mem,
 236                             int user_alloc)
 237 {
 238         int r;
 239         gfn_t base_gfn;
 240         unsigned long npages;
 241         unsigned long i;
 242         struct kvm_memory_slot *memslot;
 243         struct kvm_memory_slot old, new;
 244
 245         r = -EINVAL;
 246         /* General sanity checks */
 247         if (mem->memory_size & (PAGE_SIZE - 1))
 248                 goto out;
 249         if (mem->guest_phys_addr & (PAGE_SIZE - 1))
 250                 goto out;
 251         if (mem->slot >= KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS)
 252                 goto out;
 253         if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
 254                 goto out;
 255
 256         memslot = &kvm->memslots[mem->slot];
 257         base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
 258         npages = mem->memory_size >> PAGE_SHIFT;
 259
 260         if (!npages)
 261                 mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
 262
 263         new = old = *memslot;
 264
 265         new.base_gfn = base_gfn;
 266         new.npages = npages;
 267         new.flags = mem->flags;
 268
 269         /* Disallow changing a memory slot's size. */
 270         r = -EINVAL;
 271         if (npages && old.npages && npages != old.npages)
 272                 goto out_free;
 273
 274         /* Check for overlaps */
 275         r = -EEXIST;
 276         for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
 277                 struct kvm_memory_slot *s = &kvm->memslots[i];
 278
 279                 if (s == memslot)
 280                         continue;
 281                 if (!((base_gfn + npages <= s->base_gfn) ||
 282                       (base_gfn >= s->base_gfn + s->npages)))
 283                         goto out_free;
 284         }
 285
 286         /* Free page dirty bitmap if unneeded */
 287         if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
 288                 new.dirty_bitmap = NULL;
 289
 290         r = -ENOMEM;
 291
 292         /* Allocate if a slot is being created */
 293         if (npages && !new.rmap) {
 294                 new.rmap = vmalloc(npages * sizeof(struct page *));
 295
 296                 if (!new.rmap)
 297                         goto out_free;
 298
 299                 memset(new.rmap, 0, npages * sizeof(*new.rmap));
 300
 301                 new.user_alloc = user_alloc;
 302                 new.userspace_addr = mem->userspace_addr;
 303         }
 304
 305         /* Allocate page dirty bitmap if needed */
 306         if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
 307                 unsigned dirty_bytes = ALIGN(npages, BITS_PER_LONG) / 8;
 308
 309                 new.dirty_bitmap = vmalloc(dirty_bytes);
 310                 if (!new.dirty_bitmap)
 311                         goto out_free;
 312                 memset(new.dirty_bitmap, 0, dirty_bytes);
 313         }
 314
 315         if (mem->slot >= kvm->nmemslots)
 316                 kvm->nmemslots = mem->slot + 1;
 317
 318         *memslot = new;
 319
 320         r = kvm_arch_set_memory_region(kvm, mem, old, user_alloc);
 321         if (r) {
 322                 *memslot = old;
 323                 goto out_free;
 324         }
 325
 326         kvm_free_physmem_slot(&old, &new);
 327         return 0;
 328
 329 out_free:
 330         kvm_free_physmem_slot(&new, &old);
 331 out:
 332         return r;
 333
 334 }
 335 EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
 336
 337 int kvm_set_memory_region(struct kvm *kvm,
 338                           struct kvm_userspace_memory_region *mem,
 339                           int user_alloc)
 340 {
 341         int r;
 342
 343         down_write(&kvm->slots_lock);
 344         r = __kvm_set_memory_region(kvm, mem, user_alloc);
 345         up_write(&kvm->slots_lock);
 346         return r;
 347 }
 348 EXPORT_SYMBOL_GPL(kvm_set_memory_region);
 349
 350 int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
 351                                    struct
 352                                    kvm_userspace_memory_region *mem,
 353                                    int user_alloc)
 354 {
 355         if (mem->slot >= KVM_MEMORY_SLOTS)
 356                 return -EINVAL;
 357         return kvm_set_memory_region(kvm, mem, user_alloc);
 358 }
 359
 360 int kvm_get_dirty_log(struct kvm *kvm,
 361                         struct kvm_dirty_log *log, int *is_dirty)
 362 {
 363         struct kvm_memory_slot *memslot;
 364         int r, i;
 365         int n;
 366         unsigned long any = 0;
 367
 368         r = -EINVAL;
 369         if (log->slot >= KVM_MEMORY_SLOTS)
 370                 goto out;
 371
 372         memslot = &kvm->memslots[log->slot];
 373         r = -ENOENT;
 374         if (!memslot->dirty_bitmap)
 375                 goto out;
 376
 377         n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
 378
 379         for (i = 0; !any && i < n/sizeof(long); ++i)
 380                 any = memslot->dirty_bitmap[i];
 381
 382         r = -EFAULT;
 383         if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
 384                 goto out;
 385
 386         if (any)
 387                 *is_dirty = 1;
 388
 389         r = 0;
 390 out:
 391         return r;
 392 }
 393
 394 int is_error_page(struct page *page)
 395 {
 396         return page == bad_page;
 397 }
 398 EXPORT_SYMBOL_GPL(is_error_page);
 399
 400 static inline unsigned long bad_hva(void)
 401 {
 402         return PAGE_OFFSET;
 403 }
 404
 405 int kvm_is_error_hva(unsigned long addr)
 406 {
 407         return addr == bad_hva();
 408 }
 409 EXPORT_SYMBOL_GPL(kvm_is_error_hva);
 410
 411 static struct kvm_memory_slot *__gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
 412 {
 413         int i;
 414
 415         for (i = 0; i < kvm->nmemslots; ++i) {
 416                 struct kvm_memory_slot *memslot = &kvm->memslots[i];
 417
 418                 if (gfn >= memslot->base_gfn
 419                     && gfn < memslot->base_gfn + memslot->npages)
 420                         return memslot;
 421         }
 422         return NULL;
 423 }
 424
 425 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
 426 {
 427         gfn = unalias_gfn(kvm, gfn);
 428         return __gfn_to_memslot(kvm, gfn);
 429 }
 430
 431 int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
 432 {
 433         int i;
 434
 435         gfn = unalias_gfn(kvm, gfn);
 436         for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
 437                 struct kvm_memory_slot *memslot = &kvm->memslots[i];
 438
 439                 if (gfn >= memslot->base_gfn
 440                     && gfn < memslot->base_gfn + memslot->npages)
 441                         return 1;
 442         }
 443         return 0;
 444 }
 445 EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
 446
 447 static unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
 448 {
 449         struct kvm_memory_slot *slot;
 450
 451         gfn = unalias_gfn(kvm, gfn);
 452         slot = __gfn_to_memslot(kvm, gfn);
 453         if (!slot)
 454                 return bad_hva();
 455         return (slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE);
 456 }
 457
 458 /*
 459  * Requires current->mm->mmap_sem to be held
 460  */
 461 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
 462 {
 463         struct page *page[1];
 464         unsigned long addr;
 465         int npages;
 466
 467         might_sleep();
 468
 469         addr = gfn_to_hva(kvm, gfn);
 470         if (kvm_is_error_hva(addr)) {
 471                 get_page(bad_page);
 472                 return bad_page;
 473         }
 474
 475         npages = get_user_pages(current, current->mm, addr, 1, 1, 1, page,
 476                                 NULL);
 477
 478         if (npages != 1) {
 479                 get_page(bad_page);
 480                 return bad_page;
 481         }
 482
 483         return page[0];
 484 }
 485
 486 EXPORT_SYMBOL_GPL(gfn_to_page);
 487
 488 void kvm_release_page_clean(struct page *page)
 489 {
 490         put_page(page);
 491 }
 492 EXPORT_SYMBOL_GPL(kvm_release_page_clean);
 493
 494 void kvm_release_page_dirty(struct page *page)
 495 {
 496         if (!PageReserved(page))
 497                 SetPageDirty(page);
 498         put_page(page);
 499 }
 500 EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
 501
 502 static int next_segment(unsigned long len, int offset)
 503 {
 504         if (len > PAGE_SIZE - offset)
 505                 return PAGE_SIZE - offset;
 506         else
 507                 return len;
 508 }
 509
 510 int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
 511                         int len)
 512 {
 513         int r;
 514         unsigned long addr;
 515
 516         addr = gfn_to_hva(kvm, gfn);
 517         if (kvm_is_error_hva(addr))
 518                 return -EFAULT;
 519         r = copy_from_user(data, (void __user *)addr + offset, len);
 520         if (r)
 521                 return -EFAULT;
 522         return 0;
 523 }
 524 EXPORT_SYMBOL_GPL(kvm_read_guest_page);
 525
 526 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
 527 {
 528         gfn_t gfn = gpa >> PAGE_SHIFT;
 529         int seg;
 530         int offset = offset_in_page(gpa);
 531         int ret;
 532
 533         while ((seg = next_segment(len, offset)) != 0) {
 534                 ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
 535                 if (ret < 0)
 536                         return ret;
 537                 offset = 0;
 538                 len -= seg;
 539                 data += seg;
 540                 ++gfn;
 541         }
 542         return 0;
 543 }
 544 EXPORT_SYMBOL_GPL(kvm_read_guest);
 545
 546 int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
 547                           unsigned long len)
 548 {
 549         int r;
 550         unsigned long addr;
 551         gfn_t gfn = gpa >> PAGE_SHIFT;
 552         int offset = offset_in_page(gpa);
 553
 554         addr = gfn_to_hva(kvm, gfn);
 555         if (kvm_is_error_hva(addr))
 556                 return -EFAULT;
 557         r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
 558         if (r)
 559                 return -EFAULT;
 560         return 0;
 561 }
 562 EXPORT_SYMBOL(kvm_read_guest_atomic);
 563
 564 int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
 565                          int offset, int len)
 566 {
 567         int r;
 568         unsigned long addr;
 569
 570         addr = gfn_to_hva(kvm, gfn);
 571         if (kvm_is_error_hva(addr))
 572                 return -EFAULT;
 573         r = copy_to_user((void __user *)addr + offset, data, len);
 574         if (r)
 575                 return -EFAULT;
 576         mark_page_dirty(kvm, gfn);
 577         return 0;
 578 }
 579 EXPORT_SYMBOL_GPL(kvm_write_guest_page);
 580
 581 int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
 582                     unsigned long len)
 583 {
 584         gfn_t gfn = gpa >> PAGE_SHIFT;
 585         int seg;
 586         int offset = offset_in_page(gpa);
 587         int ret;
 588
 589         while ((seg = next_segment(len, offset)) != 0) {
 590                 ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
 591                 if (ret < 0)
 592                         return ret;
 593                 offset = 0;
 594                 len -= seg;
 595                 data += seg;
 596                 ++gfn;
 597         }
 598         return 0;
 599 }
 600
 601 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
 602 {
 603         return kvm_write_guest_page(kvm, gfn, empty_zero_page, offset, len);
 604 }
 605 EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
 606
 607 int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
 608 {
 609         gfn_t gfn = gpa >> PAGE_SHIFT;
 610         int seg;
 611         int offset = offset_in_page(gpa);
 612         int ret;
 613
 614         while ((seg = next_segment(len, offset)) != 0) {
 615                 ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
 616                 if (ret < 0)
 617                         return ret;
 618                 offset = 0;
 619                 len -= seg;
 620                 ++gfn;
 621         }
 622         return 0;
 623 }
 624 EXPORT_SYMBOL_GPL(kvm_clear_guest);
 625
 626 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
 627 {
 628         struct kvm_memory_slot *memslot;
 629
 630         gfn = unalias_gfn(kvm, gfn);
 631         memslot = __gfn_to_memslot(kvm, gfn);
 632         if (memslot && memslot->dirty_bitmap) {
 633                 unsigned long rel_gfn = gfn - memslot->base_gfn;
 634
 635                 /* avoid RMW */
 636                 if (!test_bit(rel_gfn, memslot->dirty_bitmap))
 637                         set_bit(rel_gfn, memslot->dirty_bitmap);
 638         }
 639 }
 640
 641 /*
 642  * The vCPU has executed a HLT instruction with in-kernel mode enabled.
 643  */
 644 void kvm_vcpu_block(struct kvm_vcpu *vcpu)
 645 {
 646         DECLARE_WAITQUEUE(wait, current);
 647
 648         add_wait_queue(&vcpu->wq, &wait);
 649
 650         /*
 651          * We will block until either an interrupt or a signal wakes us up
 652          */
 653         while (!kvm_cpu_has_interrupt(vcpu)
 654                && !signal_pending(current)
 655                && !kvm_arch_vcpu_runnable(vcpu)) {
 656                 set_current_state(TASK_INTERRUPTIBLE);
 657                 vcpu_put(vcpu);
 658                 schedule();
 659                 vcpu_load(vcpu);
 660         }
 661
 662         __set_current_state(TASK_RUNNING);
 663         remove_wait_queue(&vcpu->wq, &wait);
 664 }
 665
 666 void kvm_resched(struct kvm_vcpu *vcpu)
 667 {
 668         if (!need_resched())
 669                 return;
 670         cond_resched();
 671 }
 672 EXPORT_SYMBOL_GPL(kvm_resched);
 673
 674 static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 675 {
 676         struct kvm_vcpu *vcpu = vma->vm_file->private_data;
 677         struct page *page;
 678
 679         if (vmf->pgoff == 0)
 680                 page = virt_to_page(vcpu->run);
 681         else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
 682                 page = virt_to_page(vcpu->arch.pio_data);
 683         else
 684                 return VM_FAULT_SIGBUS;
 685         get_page(page);
 686         vmf->page = page;
 687         return 0;
 688 }
 689
 690 static struct vm_operations_struct kvm_vcpu_vm_ops = {
 691         .fault = kvm_vcpu_fault,
 692 };
 693
 694 static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
 695 {
 696         vma->vm_ops = &kvm_vcpu_vm_ops;
 697         return 0;
 698 }
 699
 700 static int kvm_vcpu_release(struct inode *inode, struct file *filp)
 701 {
 702         struct kvm_vcpu *vcpu = filp->private_data;
 703
 704         fput(vcpu->kvm->filp);
 705         return 0;
 706 }
 707
 708 static struct file_operations kvm_vcpu_fops = {
 709         .release        = kvm_vcpu_release,
 710         .unlocked_ioctl = kvm_vcpu_ioctl,
 711         .compat_ioctl   = kvm_vcpu_ioctl,
 712         .mmap           = kvm_vcpu_mmap,
 713 };
 714
 715 /*
 716  * Allocates an inode for the vcpu.
 717  */
 718 static int create_vcpu_fd(struct kvm_vcpu *vcpu)
 719 {
 720         int fd, r;
 721         struct inode *inode;
 722         struct file *file;
 723
 724         r = anon_inode_getfd(&fd, &inode, &file,
 725                              "kvm-vcpu", &kvm_vcpu_fops, vcpu);
 726         if (r)
 727                 return r;
 728         atomic_inc(&vcpu->kvm->filp->f_count);
 729         return fd;
 730 }
 731
 732 /*
 733  * Creates some virtual cpus.  Good luck creating more than one.
 734  */
 735 static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
 736 {
 737         int r;
 738         struct kvm_vcpu *vcpu;
 739
 740         if (!valid_vcpu(n))
 741                 return -EINVAL;
 742
 743         vcpu = kvm_arch_vcpu_create(kvm, n);
 744         if (IS_ERR(vcpu))
 745                 return PTR_ERR(vcpu);
 746
 747         preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
 748
 749         r = kvm_arch_vcpu_setup(vcpu);
 750         if (r)
 751                 goto vcpu_destroy;
 752
 753         mutex_lock(&kvm->lock);
 754         if (kvm->vcpus[n]) {
 755                 r = -EEXIST;
 756                 mutex_unlock(&kvm->lock);
 757                 goto vcpu_destroy;
 758         }
 759         kvm->vcpus[n] = vcpu;
 760         mutex_unlock(&kvm->lock);
 761
 762         /* Now it's all set up, let userspace reach it */
 763         r = create_vcpu_fd(vcpu);
 764         if (r < 0)
 765                 goto unlink;
 766         return r;
 767
 768 unlink:
 769         mutex_lock(&kvm->lock);
 770         kvm->vcpus[n] = NULL;
 771         mutex_unlock(&kvm->lock);
 772 vcpu_destroy:
 773         kvm_arch_vcpu_destroy(vcpu);
 774         return r;
 775 }
 776
 777 static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
 778 {
 779         if (sigset) {
 780                 sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
 781                 vcpu->sigset_active = 1;
 782                 vcpu->sigset = *sigset;
 783         } else
 784                 vcpu->sigset_active = 0;
 785         return 0;
 786 }
 787
 788 static long kvm_vcpu_ioctl(struct file *filp,
 789                            unsigned int ioctl, unsigned long arg)
 790 {
 791         struct kvm_vcpu *vcpu = filp->private_data;
 792         void __user *argp = (void __user *)arg;
 793         int r;
 794
 795         if (vcpu->kvm->mm != current->mm)
 796                 return -EIO;
 797         switch (ioctl) {
 798         case KVM_RUN:
 799                 r = -EINVAL;
 800                 if (arg)
 801                         goto out;
 802                 r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
 803                 break;
 804         case KVM_GET_REGS: {
 805                 struct kvm_regs kvm_regs;
 806
 807                 memset(&kvm_regs, 0, sizeof kvm_regs);
 808                 r = kvm_arch_vcpu_ioctl_get_regs(vcpu, &kvm_regs);
 809                 if (r)
 810                         goto out;
 811                 r = -EFAULT;
 812                 if (copy_to_user(argp, &kvm_regs, sizeof kvm_regs))
 813                         goto out;
 814                 r = 0;
 815                 break;
 816         }
 817         case KVM_SET_REGS: {
 818                 struct kvm_regs kvm_regs;
 819
 820                 r = -EFAULT;
 821                 if (copy_from_user(&kvm_regs, argp, sizeof kvm_regs))
 822                         goto out;
 823                 r = kvm_arch_vcpu_ioctl_set_regs(vcpu, &kvm_regs);
 824                 if (r)
 825                         goto out;
 826                 r = 0;
 827                 break;
 828         }
 829         case KVM_GET_SREGS: {
 830                 struct kvm_sregs kvm_sregs;
 831
 832                 memset(&kvm_sregs, 0, sizeof kvm_sregs);
 833                 r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, &kvm_sregs);
 834                 if (r)
 835                         goto out;
 836                 r = -EFAULT;
 837                 if (copy_to_user(argp, &kvm_sregs, sizeof kvm_sregs))
 838                         goto out;
 839                 r = 0;
 840                 break;
 841         }
 842         case KVM_SET_SREGS: {
 843                 struct kvm_sregs kvm_sregs;
 844
 845                 r = -EFAULT;
 846                 if (copy_from_user(&kvm_sregs, argp, sizeof kvm_sregs))
 847                         goto out;
 848                 r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, &kvm_sregs);
 849                 if (r)
 850                         goto out;
 851                 r = 0;
 852                 break;
 853         }
 854         case KVM_TRANSLATE: {
 855                 struct kvm_translation tr;
 856
 857                 r = -EFAULT;
 858                 if (copy_from_user(&tr, argp, sizeof tr))
 859                         goto out;
 860                 r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
 861                 if (r)
 862                         goto out;
 863                 r = -EFAULT;
 864                 if (copy_to_user(argp, &tr, sizeof tr))
 865                         goto out;
 866                 r = 0;
 867                 break;
 868         }
 869         case KVM_DEBUG_GUEST: {
 870                 struct kvm_debug_guest dbg;
 871
 872                 r = -EFAULT;
 873                 if (copy_from_user(&dbg, argp, sizeof dbg))
 874                         goto out;
 875                 r = kvm_arch_vcpu_ioctl_debug_guest(vcpu, &dbg);
 876                 if (r)
 877                         goto out;
 878                 r = 0;
 879                 break;
 880         }
 881         case KVM_SET_SIGNAL_MASK: {
 882                 struct kvm_signal_mask __user *sigmask_arg = argp;
 883                 struct kvm_signal_mask kvm_sigmask;
 884                 sigset_t sigset, *p;
 885
 886                 p = NULL;
 887                 if (argp) {
 888                         r = -EFAULT;
 889                         if (copy_from_user(&kvm_sigmask, argp,
 890                                            sizeof kvm_sigmask))
 891                                 goto out;
 892                         r = -EINVAL;
 893                         if (kvm_sigmask.len != sizeof sigset)
 894                                 goto out;
 895                         r = -EFAULT;
 896                         if (copy_from_user(&sigset, sigmask_arg->sigset,
 897                                            sizeof sigset))
 898                                 goto out;
 899                         p = &sigset;
 900                 }
 901                 r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
 902                 break;
 903         }
 904         case KVM_GET_FPU: {
 905                 struct kvm_fpu fpu;
 906
 907                 memset(&fpu, 0, sizeof fpu);
 908                 r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, &fpu);
 909                 if (r)
 910                         goto out;
 911                 r = -EFAULT;
 912                 if (copy_to_user(argp, &fpu, sizeof fpu))
 913                         goto out;
 914                 r = 0;
 915                 break;
 916         }
 917         case KVM_SET_FPU: {
 918                 struct kvm_fpu fpu;
 919
 920                 r = -EFAULT;
 921                 if (copy_from_user(&fpu, argp, sizeof fpu))
 922                         goto out;
 923                 r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, &fpu);
 924                 if (r)
 925                         goto out;
 926                 r = 0;
 927                 break;
 928         }
 929         default:
 930                 r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
 931         }
 932 out:
 933         return r;
 934 }
 935
 936 static long kvm_vm_ioctl(struct file *filp,
 937                            unsigned int ioctl, unsigned long arg)
 938 {
 939         struct kvm *kvm = filp->private_data;
 940         void __user *argp = (void __user *)arg;
 941         int r;
 942
 943         if (kvm->mm != current->mm)
 944                 return -EIO;
 945         switch (ioctl) {
 946         case KVM_CREATE_VCPU:
 947                 r = kvm_vm_ioctl_create_vcpu(kvm, arg);
 948                 if (r < 0)
 949                         goto out;
 950                 break;
 951         case KVM_SET_USER_MEMORY_REGION: {
 952                 struct kvm_userspace_memory_region kvm_userspace_mem;
 953
 954                 r = -EFAULT;
 955                 if (copy_from_user(&kvm_userspace_mem, argp,
 956                                                 sizeof kvm_userspace_mem))
 957                         goto out;
 958
 959                 r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem, 1);
 960                 if (r)
 961                         goto out;
 962                 break;
 963         }
 964         case KVM_GET_DIRTY_LOG: {
 965                 struct kvm_dirty_log log;
 966
 967                 r = -EFAULT;
 968                 if (copy_from_user(&log, argp, sizeof log))
 969                         goto out;
 970                 r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
 971                 if (r)
 972                         goto out;
 973                 break;
 974         }
 975         default:
 976                 r = kvm_arch_vm_ioctl(filp, ioctl, arg);
 977         }
 978 out:
 979         return r;
 980 }
 981
 982 static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 983 {
 984         struct kvm *kvm = vma->vm_file->private_data;
 985         struct page *page;
 986
 987         if (!kvm_is_visible_gfn(kvm, vmf->pgoff))
 988                 return VM_FAULT_SIGBUS;
 989         page = gfn_to_page(kvm, vmf->pgoff);
 990         if (is_error_page(page)) {
 991                 kvm_release_page_clean(page);
 992                 return VM_FAULT_SIGBUS;
 993         }
 994         vmf->page = page;
 995         return 0;
 996 }
 997
 998 static struct vm_operations_struct kvm_vm_vm_ops = {
 999         .fault = kvm_vm_fault,
1000 };
1001
1002 static int kvm_vm_mmap(struct file *file, struct vm_area_struct *vma)
1003 {
1004         vma->vm_ops = &kvm_vm_vm_ops;
1005         return 0;
1006 }
1007
1008 static struct file_operations kvm_vm_fops = {
1009         .release        = kvm_vm_release,
1010         .unlocked_ioctl = kvm_vm_ioctl,
1011         .compat_ioctl   = kvm_vm_ioctl,
1012         .mmap           = kvm_vm_mmap,
1013 };
1014
1015 static int kvm_dev_ioctl_create_vm(void)
1016 {
1017         int fd, r;
1018         struct inode *inode;
1019         struct file *file;
1020         struct kvm *kvm;
1021
1022         kvm = kvm_create_vm();
1023         if (IS_ERR(kvm))
1024                 return PTR_ERR(kvm);
1025         r = anon_inode_getfd(&fd, &inode, &file, "kvm-vm", &kvm_vm_fops, kvm);
1026         if (r) {
1027                 kvm_destroy_vm(kvm);
1028                 return r;
1029         }
1030
1031         kvm->filp = file;
1032
1033         return fd;
1034 }
1035
1036 static long kvm_dev_ioctl(struct file *filp,
1037                           unsigned int ioctl, unsigned long arg)
1038 {
1039         void __user *argp = (void __user *)arg;
1040         long r = -EINVAL;
1041
1042         switch (ioctl) {
1043         case KVM_GET_API_VERSION:
1044                 r = -EINVAL;
1045                 if (arg)
1046                         goto out;
1047                 r = KVM_API_VERSION;
1048                 break;
1049         case KVM_CREATE_VM:
1050                 r = -EINVAL;
1051                 if (arg)
1052                         goto out;
1053                 r = kvm_dev_ioctl_create_vm();
1054                 break;
1055         case KVM_CHECK_EXTENSION:
1056                 r = kvm_dev_ioctl_check_extension((long)argp);
1057                 break;
1058         case KVM_GET_VCPU_MMAP_SIZE:
1059                 r = -EINVAL;
1060                 if (arg)
1061                         goto out;
1062                 r = 2 * PAGE_SIZE;
1063                 break;
1064         default:
1065                 return kvm_arch_dev_ioctl(filp, ioctl, arg);
1066         }
1067 out:
1068         return r;
1069 }
1070
1071 static struct file_operations kvm_chardev_ops = {
1072         .unlocked_ioctl = kvm_dev_ioctl,
1073         .compat_ioctl   = kvm_dev_ioctl,
1074 };
1075
1076 static struct miscdevice kvm_dev = {
1077         KVM_MINOR,
1078         "kvm",
1079         &kvm_chardev_ops,
1080 };
1081
1082 static void hardware_enable(void *junk)
1083 {
1084         int cpu = raw_smp_processor_id();
1085
1086         if (cpu_isset(cpu, cpus_hardware_enabled))
1087                 return;
1088         cpu_set(cpu, cpus_hardware_enabled);
1089         kvm_arch_hardware_enable(NULL);
1090 }
1091
1092 static void hardware_disable(void *junk)
1093 {
1094         int cpu = raw_smp_processor_id();
1095
1096         if (!cpu_isset(cpu, cpus_hardware_enabled))
1097                 return;
1098         cpu_clear(cpu, cpus_hardware_enabled);
1099         decache_vcpus_on_cpu(cpu);
1100         kvm_arch_hardware_disable(NULL);
1101 }
1102
1103 static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
1104                            void *v)
1105 {
1106         int cpu = (long)v;
1107
1108         val &= ~CPU_TASKS_FROZEN;
1109         switch (val) {
1110         case CPU_DYING:
1111                 printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
1112                        cpu);
1113                 hardware_disable(NULL);
1114                 break;
1115         case CPU_UP_CANCELED:
1116                 printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
1117                        cpu);
1118                 smp_call_function_single(cpu, hardware_disable, NULL, 0, 1);
1119                 break;
1120         case CPU_ONLINE:
1121                 printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
1122                        cpu);
1123                 smp_call_function_single(cpu, hardware_enable, NULL, 0, 1);
1124                 break;
1125         }
1126         return NOTIFY_OK;
1127 }
1128
1129 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
1130                       void *v)
1131 {
1132         if (val == SYS_RESTART) {
1133                 /*
1134                  * Some (well, at least mine) BIOSes hang on reboot if
1135                  * in vmx root mode.
1136                  */
1137                 printk(KERN_INFO "kvm: exiting hardware virtualization\n");
1138                 on_each_cpu(hardware_disable, NULL, 0, 1);
1139         }
1140         return NOTIFY_OK;
1141 }
1142
1143 static struct notifier_block kvm_reboot_notifier = {
1144         .notifier_call = kvm_reboot,
1145         .priority = 0,
1146 };
1147
1148 void kvm_io_bus_init(struct kvm_io_bus *bus)
1149 {
1150         memset(bus, 0, sizeof(*bus));
1151 }
1152
1153 void kvm_io_bus_destroy(struct kvm_io_bus *bus)
1154 {
1155         int i;
1156
1157         for (i = 0; i < bus->dev_count; i++) {
1158                 struct kvm_io_device *pos = bus->devs[i];
1159
1160                 kvm_iodevice_destructor(pos);
1161         }
1162 }
1163
1164 struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus, gpa_t addr)
1165 {
1166         int i;
1167
1168         for (i = 0; i < bus->dev_count; i++) {
1169                 struct kvm_io_device *pos = bus->devs[i];
1170
1171                 if (pos->in_range(pos, addr))
1172                         return pos;
1173         }
1174
1175         return NULL;
1176 }
1177
1178 void kvm_io_bus_register_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev)
1179 {
1180         BUG_ON(bus->dev_count > (NR_IOBUS_DEVS-1));
1181
1182         bus->devs[bus->dev_count++] = dev;
1183 }
1184
1185 static struct notifier_block kvm_cpu_notifier = {
1186         .notifier_call = kvm_cpu_hotplug,
1187         .priority = 20, /* must be > scheduler priority */
1188 };
1189
1190 static int vm_stat_get(void *_offset, u64 *val)
1191 {
1192         unsigned offset = (long)_offset;
1193         struct kvm *kvm;
1194
1195         *val = 0;
1196         spin_lock(&kvm_lock);
1197         list_for_each_entry(kvm, &vm_list, vm_list)
1198                 *val += *(u32 *)((void *)kvm + offset);
1199         spin_unlock(&kvm_lock);
1200         return 0;
1201 }
1202
1203 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
1204
1205 static int vcpu_stat_get(void *_offset, u64 *val)
1206 {
1207         unsigned offset = (long)_offset;
1208         struct kvm *kvm;
1209         struct kvm_vcpu *vcpu;
1210         int i;
1211
1212         *val = 0;
1213         spin_lock(&kvm_lock);
1214         list_for_each_entry(kvm, &vm_list, vm_list)
1215                 for (i = 0; i < KVM_MAX_VCPUS; ++i) {
1216                         vcpu = kvm->vcpus[i];
1217                         if (vcpu)
1218                                 *val += *(u32 *)((void *)vcpu + offset);
1219                 }
1220         spin_unlock(&kvm_lock);
1221         return 0;
1222 }
1223
1224 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
1225
1226 static struct file_operations *stat_fops[] = {
1227         [KVM_STAT_VCPU] = &vcpu_stat_fops,
1228         [KVM_STAT_VM]   = &vm_stat_fops,
1229 };
1230
1231 static void kvm_init_debug(void)
1232 {
1233         struct kvm_stats_debugfs_item *p;
1234
1235         debugfs_dir = debugfs_create_dir("kvm", NULL);
1236         for (p = debugfs_entries; p->name; ++p)
1237                 p->dentry = debugfs_create_file(p->name, 0444, debugfs_dir,
1238                                                 (void *)(long)p->offset,
1239                                                 stat_fops[p->kind]);
1240 }
1241
1242 static void kvm_exit_debug(void)
1243 {
1244         struct kvm_stats_debugfs_item *p;
1245
1246         for (p = debugfs_entries; p->name; ++p)
1247                 debugfs_remove(p->dentry);
1248         debugfs_remove(debugfs_dir);
1249 }
1250
1251 static int kvm_suspend(struct sys_device *dev, pm_message_t state)
1252 {
1253         hardware_disable(NULL);
1254         return 0;
1255 }
1256
1257 static int kvm_resume(struct sys_device *dev)
1258 {
1259         hardware_enable(NULL);
1260         return 0;
1261 }
1262
1263 static struct sysdev_class kvm_sysdev_class = {
1264         .name = "kvm",
1265         .suspend = kvm_suspend,
1266         .resume = kvm_resume,
1267 };
1268
1269 static struct sys_device kvm_sysdev = {
1270         .id = 0,
1271         .cls = &kvm_sysdev_class,
1272 };
1273
1274 struct page *bad_page;
1275
1276 static inline
1277 struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
1278 {
1279         return container_of(pn, struct kvm_vcpu, preempt_notifier);
1280 }
1281
1282 static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
1283 {
1284         struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
1285
1286         kvm_arch_vcpu_load(vcpu, cpu);
1287 }
1288
1289 static void kvm_sched_out(struct preempt_notifier *pn,
1290                           struct task_struct *next)
1291 {
1292         struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
1293
1294         kvm_arch_vcpu_put(vcpu);
1295 }
1296
1297 int kvm_init(void *opaque, unsigned int vcpu_size,
1298                   struct module *module)
1299 {
1300         int r;
1301         int cpu;
1302
1303         kvm_init_debug();
1304
1305         r = kvm_arch_init(opaque);
1306         if (r)
1307                 goto out_fail;
1308
1309         bad_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
1310
1311         if (bad_page == NULL) {
1312                 r = -ENOMEM;
1313                 goto out;
1314         }
1315
1316         r = kvm_arch_hardware_setup();
1317         if (r < 0)
1318                 goto out_free_0;
1319
1320         for_each_online_cpu(cpu) {
1321                 smp_call_function_single(cpu,
1322                                 kvm_arch_check_processor_compat,
1323                                 &r, 0, 1);
1324                 if (r < 0)
1325                         goto out_free_1;
1326         }
1327
1328         on_each_cpu(hardware_enable, NULL, 0, 1);
1329         r = register_cpu_notifier(&kvm_cpu_notifier);
1330         if (r)
1331                 goto out_free_2;
1332         register_reboot_notifier(&kvm_reboot_notifier);
1333
1334         r = sysdev_class_register(&kvm_sysdev_class);
1335         if (r)
1336                 goto out_free_3;
1337
1338         r = sysdev_register(&kvm_sysdev);
1339         if (r)
1340                 goto out_free_4;
1341
1342         /* A kmem cache lets us meet the alignment requirements of fx_save. */
1343         kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size,
1344                                            __alignof__(struct kvm_vcpu),
1345                                            0, NULL);
1346         if (!kvm_vcpu_cache) {
1347                 r = -ENOMEM;
1348                 goto out_free_5;
1349         }
1350
1351         kvm_chardev_ops.owner = module;
1352
1353         r = misc_register(&kvm_dev);
1354         if (r) {
1355                 printk(KERN_ERR "kvm: misc device register failed\n");
1356                 goto out_free;
1357         }
1358
1359         kvm_preempt_ops.sched_in = kvm_sched_in;
1360         kvm_preempt_ops.sched_out = kvm_sched_out;
1361
1362         return 0;
1363
1364 out_free:
1365         kmem_cache_destroy(kvm_vcpu_cache);
1366 out_free_5:
1367         sysdev_unregister(&kvm_sysdev);
1368 out_free_4:
1369         sysdev_class_unregister(&kvm_sysdev_class);
1370 out_free_3:
1371         unregister_reboot_notifier(&kvm_reboot_notifier);
1372         unregister_cpu_notifier(&kvm_cpu_notifier);
1373 out_free_2:
1374         on_each_cpu(hardware_disable, NULL, 0, 1);
1375 out_free_1:
1376         kvm_arch_hardware_unsetup();
1377 out_free_0:
1378         __free_page(bad_page);
1379 out:
1380         kvm_arch_exit();
1381         kvm_exit_debug();
1382 out_fail:
1383         return r;
1384 }
1385 EXPORT_SYMBOL_GPL(kvm_init);
1386
1387 void kvm_exit(void)
1388 {
1389         misc_deregister(&kvm_dev);
1390         kmem_cache_destroy(kvm_vcpu_cache);
1391         sysdev_unregister(&kvm_sysdev);
1392         sysdev_class_unregister(&kvm_sysdev_class);
1393         unregister_reboot_notifier(&kvm_reboot_notifier);
1394         unregister_cpu_notifier(&kvm_cpu_notifier);
1395         on_each_cpu(hardware_disable, NULL, 0, 1);
1396         kvm_arch_hardware_unsetup();
1397         kvm_arch_exit();
1398         kvm_exit_debug();
1399         __free_page(bad_page);
1400 }
1401 EXPORT_SYMBOL_GPL(kvm_exit);