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 #include <linux/swap.h>
  44
  45 #include <asm/processor.h>
  46 #include <asm/io.h>
  47 #include <asm/uaccess.h>
  48 #include <asm/pgtable.h>
  49
  50 MODULE_AUTHOR("Qumranet");
  51 MODULE_LICENSE("GPL");
  52
  53 DEFINE_SPINLOCK(kvm_lock);
  54 LIST_HEAD(vm_list);
  55
  56 static cpumask_t cpus_hardware_enabled;
  57
  58 struct kmem_cache *kvm_vcpu_cache;
  59 EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
  60
  61 static __read_mostly struct preempt_ops kvm_preempt_ops;
  62
  63 struct dentry *kvm_debugfs_dir;
  64
  65 static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
  66                            unsigned long arg);
  67
  68 bool kvm_rebooting;
  69
  70 static inline int valid_vcpu(int n)
  71 {
  72         return likely(n >= 0 && n < KVM_MAX_VCPUS);
  73 }
  74
  75 /*
  76  * Switches to specified vcpu, until a matching vcpu_put()
  77  */
  78 void vcpu_load(struct kvm_vcpu *vcpu)
  79 {
  80         int cpu;
  81
  82         mutex_lock(&vcpu->mutex);
  83         cpu = get_cpu();
  84         preempt_notifier_register(&vcpu->preempt_notifier);
  85         kvm_arch_vcpu_load(vcpu, cpu);
  86         put_cpu();
  87 }
  88
  89 void vcpu_put(struct kvm_vcpu *vcpu)
  90 {
  91         preempt_disable();
  92         kvm_arch_vcpu_put(vcpu);
  93         preempt_notifier_unregister(&vcpu->preempt_notifier);
  94         preempt_enable();
  95         mutex_unlock(&vcpu->mutex);
  96 }
  97
  98 static void ack_flush(void *_completed)
  99 {
 100 }
 101
 102 void kvm_flush_remote_tlbs(struct kvm *kvm)
 103 {
 104         int i, cpu;
 105         cpumask_t cpus;
 106         struct kvm_vcpu *vcpu;
 107
 108         cpus_clear(cpus);
 109         for (i = 0; i < KVM_MAX_VCPUS; ++i) {
 110                 vcpu = kvm->vcpus[i];
 111                 if (!vcpu)
 112                         continue;
 113                 if (test_and_set_bit(KVM_REQ_TLB_FLUSH, &vcpu->requests))
 114                         continue;
 115                 cpu = vcpu->cpu;
 116                 if (cpu != -1 && cpu != raw_smp_processor_id())
 117                         cpu_set(cpu, cpus);
 118         }
 119         if (cpus_empty(cpus))
 120                 return;
 121         ++kvm->stat.remote_tlb_flush;
 122         smp_call_function_mask(cpus, ack_flush, NULL, 1);
 123 }
 124
 125 void kvm_reload_remote_mmus(struct kvm *kvm)
 126 {
 127         int i, cpu;
 128         cpumask_t cpus;
 129         struct kvm_vcpu *vcpu;
 130
 131         cpus_clear(cpus);
 132         for (i = 0; i < KVM_MAX_VCPUS; ++i) {
 133                 vcpu = kvm->vcpus[i];
 134                 if (!vcpu)
 135                         continue;
 136                 if (test_and_set_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests))
 137                         continue;
 138                 cpu = vcpu->cpu;
 139                 if (cpu != -1 && cpu != raw_smp_processor_id())
 140                         cpu_set(cpu, cpus);
 141         }
 142         if (cpus_empty(cpus))
 143                 return;
 144         smp_call_function_mask(cpus, ack_flush, NULL, 1);
 145 }
 146
 147
 148 int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
 149 {
 150         struct page *page;
 151         int r;
 152
 153         mutex_init(&vcpu->mutex);
 154         vcpu->cpu = -1;
 155         vcpu->kvm = kvm;
 156         vcpu->vcpu_id = id;
 157         init_waitqueue_head(&vcpu->wq);
 158
 159         page = alloc_page(GFP_KERNEL | __GFP_ZERO);
 160         if (!page) {
 161                 r = -ENOMEM;
 162                 goto fail;
 163         }
 164         vcpu->run = page_address(page);
 165
 166         r = kvm_arch_vcpu_init(vcpu);
 167         if (r < 0)
 168                 goto fail_free_run;
 169         return 0;
 170
 171 fail_free_run:
 172         free_page((unsigned long)vcpu->run);
 173 fail:
 174         return r;
 175 }
 176 EXPORT_SYMBOL_GPL(kvm_vcpu_init);
 177
 178 void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
 179 {
 180         kvm_arch_vcpu_uninit(vcpu);
 181         free_page((unsigned long)vcpu->run);
 182 }
 183 EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
 184
 185 static struct kvm *kvm_create_vm(void)
 186 {
 187         struct kvm *kvm = kvm_arch_create_vm();
 188
 189         if (IS_ERR(kvm))
 190                 goto out;
 191
 192         kvm->mm = current->mm;
 193         atomic_inc(&kvm->mm->mm_count);
 194         spin_lock_init(&kvm->mmu_lock);
 195         kvm_io_bus_init(&kvm->pio_bus);
 196         mutex_init(&kvm->lock);
 197         kvm_io_bus_init(&kvm->mmio_bus);
 198         init_rwsem(&kvm->slots_lock);
 199         atomic_set(&kvm->users_count, 1);
 200         spin_lock(&kvm_lock);
 201         list_add(&kvm->vm_list, &vm_list);
 202         spin_unlock(&kvm_lock);
 203 out:
 204         return kvm;
 205 }
 206
 207 /*
 208  * Free any memory in @free but not in @dont.
 209  */
 210 static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
 211                                   struct kvm_memory_slot *dont)
 212 {
 213         if (!dont || free->rmap != dont->rmap)
 214                 vfree(free->rmap);
 215
 216         if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
 217                 vfree(free->dirty_bitmap);
 218
 219         if (!dont || free->lpage_info != dont->lpage_info)
 220                 vfree(free->lpage_info);
 221
 222         free->npages = 0;
 223         free->dirty_bitmap = NULL;
 224         free->rmap = NULL;
 225         free->lpage_info = NULL;
 226 }
 227
 228 void kvm_free_physmem(struct kvm *kvm)
 229 {
 230         int i;
 231
 232         for (i = 0; i < kvm->nmemslots; ++i)
 233                 kvm_free_physmem_slot(&kvm->memslots[i], NULL);
 234 }
 235
 236 static void kvm_destroy_vm(struct kvm *kvm)
 237 {
 238         struct mm_struct *mm = kvm->mm;
 239
 240         spin_lock(&kvm_lock);
 241         list_del(&kvm->vm_list);
 242         spin_unlock(&kvm_lock);
 243         kvm_io_bus_destroy(&kvm->pio_bus);
 244         kvm_io_bus_destroy(&kvm->mmio_bus);
 245         kvm_arch_destroy_vm(kvm);
 246         mmdrop(mm);
 247 }
 248
 249 void kvm_get_kvm(struct kvm *kvm)
 250 {
 251         atomic_inc(&kvm->users_count);
 252 }
 253 EXPORT_SYMBOL_GPL(kvm_get_kvm);
 254
 255 void kvm_put_kvm(struct kvm *kvm)
 256 {
 257         if (atomic_dec_and_test(&kvm->users_count))
 258                 kvm_destroy_vm(kvm);
 259 }
 260 EXPORT_SYMBOL_GPL(kvm_put_kvm);
 261
 262
 263 static int kvm_vm_release(struct inode *inode, struct file *filp)
 264 {
 265         struct kvm *kvm = filp->private_data;
 266
 267         kvm_put_kvm(kvm);
 268         return 0;
 269 }
 270
 271 /*
 272  * Allocate some memory and give it an address in the guest physical address
 273  * space.
 274  *
 275  * Discontiguous memory is allowed, mostly for framebuffers.
 276  *
 277  * Must be called holding mmap_sem for write.
 278  */
 279 int __kvm_set_memory_region(struct kvm *kvm,
 280                             struct kvm_userspace_memory_region *mem,
 281                             int user_alloc)
 282 {
 283         int r;
 284         gfn_t base_gfn;
 285         unsigned long npages;
 286         unsigned long i;
 287         struct kvm_memory_slot *memslot;
 288         struct kvm_memory_slot old, new;
 289
 290         r = -EINVAL;
 291         /* General sanity checks */
 292         if (mem->memory_size & (PAGE_SIZE - 1))
 293                 goto out;
 294         if (mem->guest_phys_addr & (PAGE_SIZE - 1))
 295                 goto out;
 296         if (mem->slot >= KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS)
 297                 goto out;
 298         if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
 299                 goto out;
 300
 301         memslot = &kvm->memslots[mem->slot];
 302         base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
 303         npages = mem->memory_size >> PAGE_SHIFT;
 304
 305         if (!npages)
 306                 mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
 307
 308         new = old = *memslot;
 309
 310         new.base_gfn = base_gfn;
 311         new.npages = npages;
 312         new.flags = mem->flags;
 313
 314         /* Disallow changing a memory slot's size. */
 315         r = -EINVAL;
 316         if (npages && old.npages && npages != old.npages)
 317                 goto out_free;
 318
 319         /* Check for overlaps */
 320         r = -EEXIST;
 321         for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
 322                 struct kvm_memory_slot *s = &kvm->memslots[i];
 323
 324                 if (s == memslot)
 325                         continue;
 326                 if (!((base_gfn + npages <= s->base_gfn) ||
 327                       (base_gfn >= s->base_gfn + s->npages)))
 328                         goto out_free;
 329         }
 330
 331         /* Free page dirty bitmap if unneeded */
 332         if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
 333                 new.dirty_bitmap = NULL;
 334
 335         r = -ENOMEM;
 336
 337         /* Allocate if a slot is being created */
 338         if (npages && !new.rmap) {
 339                 new.rmap = vmalloc(npages * sizeof(struct page *));
 340
 341                 if (!new.rmap)
 342                         goto out_free;
 343
 344                 memset(new.rmap, 0, npages * sizeof(*new.rmap));
 345
 346                 new.user_alloc = user_alloc;
 347                 new.userspace_addr = mem->userspace_addr;
 348         }
 349         if (npages && !new.lpage_info) {
 350                 int largepages = npages / KVM_PAGES_PER_HPAGE;
 351                 if (npages % KVM_PAGES_PER_HPAGE)
 352                         largepages++;
 353                 if (base_gfn % KVM_PAGES_PER_HPAGE)
 354                         largepages++;
 355
 356                 new.lpage_info = vmalloc(largepages * sizeof(*new.lpage_info));
 357
 358                 if (!new.lpage_info)
 359                         goto out_free;
 360
 361                 memset(new.lpage_info, 0, largepages * sizeof(*new.lpage_info));
 362
 363                 if (base_gfn % KVM_PAGES_PER_HPAGE)
 364                         new.lpage_info[0].write_count = 1;
 365                 if ((base_gfn+npages) % KVM_PAGES_PER_HPAGE)
 366                         new.lpage_info[largepages-1].write_count = 1;
 367         }
 368
 369         /* Allocate page dirty bitmap if needed */
 370         if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
 371                 unsigned dirty_bytes = ALIGN(npages, BITS_PER_LONG) / 8;
 372
 373                 new.dirty_bitmap = vmalloc(dirty_bytes);
 374                 if (!new.dirty_bitmap)
 375                         goto out_free;
 376                 memset(new.dirty_bitmap, 0, dirty_bytes);
 377         }
 378
 379         if (mem->slot >= kvm->nmemslots)
 380                 kvm->nmemslots = mem->slot + 1;
 381
 382         *memslot = new;
 383
 384         r = kvm_arch_set_memory_region(kvm, mem, old, user_alloc);
 385         if (r) {
 386                 *memslot = old;
 387                 goto out_free;
 388         }
 389
 390         kvm_free_physmem_slot(&old, &new);
 391         return 0;
 392
 393 out_free:
 394         kvm_free_physmem_slot(&new, &old);
 395 out:
 396         return r;
 397
 398 }
 399 EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
 400
 401 int kvm_set_memory_region(struct kvm *kvm,
 402                           struct kvm_userspace_memory_region *mem,
 403                           int user_alloc)
 404 {
 405         int r;
 406
 407         down_write(&kvm->slots_lock);
 408         r = __kvm_set_memory_region(kvm, mem, user_alloc);
 409         up_write(&kvm->slots_lock);
 410         return r;
 411 }
 412 EXPORT_SYMBOL_GPL(kvm_set_memory_region);
 413
 414 int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
 415                                    struct
 416                                    kvm_userspace_memory_region *mem,
 417                                    int user_alloc)
 418 {
 419         if (mem->slot >= KVM_MEMORY_SLOTS)
 420                 return -EINVAL;
 421         return kvm_set_memory_region(kvm, mem, user_alloc);
 422 }
 423
 424 int kvm_get_dirty_log(struct kvm *kvm,
 425                         struct kvm_dirty_log *log, int *is_dirty)
 426 {
 427         struct kvm_memory_slot *memslot;
 428         int r, i;
 429         int n;
 430         unsigned long any = 0;
 431
 432         r = -EINVAL;
 433         if (log->slot >= KVM_MEMORY_SLOTS)
 434                 goto out;
 435
 436         memslot = &kvm->memslots[log->slot];
 437         r = -ENOENT;
 438         if (!memslot->dirty_bitmap)
 439                 goto out;
 440
 441         n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
 442
 443         for (i = 0; !any && i < n/sizeof(long); ++i)
 444                 any = memslot->dirty_bitmap[i];
 445
 446         r = -EFAULT;
 447         if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
 448                 goto out;
 449
 450         if (any)
 451                 *is_dirty = 1;
 452
 453         r = 0;
 454 out:
 455         return r;
 456 }
 457
 458 int is_error_page(struct page *page)
 459 {
 460         return page == bad_page;
 461 }
 462 EXPORT_SYMBOL_GPL(is_error_page);
 463
 464 int is_error_pfn(pfn_t pfn)
 465 {
 466         return pfn == bad_pfn;
 467 }
 468 EXPORT_SYMBOL_GPL(is_error_pfn);
 469
 470 static inline unsigned long bad_hva(void)
 471 {
 472         return PAGE_OFFSET;
 473 }
 474
 475 int kvm_is_error_hva(unsigned long addr)
 476 {
 477         return addr == bad_hva();
 478 }
 479 EXPORT_SYMBOL_GPL(kvm_is_error_hva);
 480
 481 static struct kvm_memory_slot *__gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
 482 {
 483         int i;
 484
 485         for (i = 0; i < kvm->nmemslots; ++i) {
 486                 struct kvm_memory_slot *memslot = &kvm->memslots[i];
 487
 488                 if (gfn >= memslot->base_gfn
 489                     && gfn < memslot->base_gfn + memslot->npages)
 490                         return memslot;
 491         }
 492         return NULL;
 493 }
 494
 495 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
 496 {
 497         gfn = unalias_gfn(kvm, gfn);
 498         return __gfn_to_memslot(kvm, gfn);
 499 }
 500
 501 int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
 502 {
 503         int i;
 504
 505         gfn = unalias_gfn(kvm, gfn);
 506         for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
 507                 struct kvm_memory_slot *memslot = &kvm->memslots[i];
 508
 509                 if (gfn >= memslot->base_gfn
 510                     && gfn < memslot->base_gfn + memslot->npages)
 511                         return 1;
 512         }
 513         return 0;
 514 }
 515 EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
 516
 517 unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
 518 {
 519         struct kvm_memory_slot *slot;
 520
 521         gfn = unalias_gfn(kvm, gfn);
 522         slot = __gfn_to_memslot(kvm, gfn);
 523         if (!slot)
 524                 return bad_hva();
 525         return (slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE);
 526 }
 527 EXPORT_SYMBOL_GPL(gfn_to_hva);
 528
 529 /*
 530  * Requires current->mm->mmap_sem to be held
 531  */
 532 pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
 533 {
 534         struct page *page[1];
 535         unsigned long addr;
 536         int npages;
 537         pfn_t pfn;
 538
 539         might_sleep();
 540
 541         addr = gfn_to_hva(kvm, gfn);
 542         if (kvm_is_error_hva(addr)) {
 543                 get_page(bad_page);
 544                 return page_to_pfn(bad_page);
 545         }
 546
 547         npages = get_user_pages(current, current->mm, addr, 1, 1, 1, page,
 548                                 NULL);
 549
 550         if (unlikely(npages != 1)) {
 551                 struct vm_area_struct *vma;
 552
 553                 vma = find_vma(current->mm, addr);
 554                 if (vma == NULL || addr < vma->vm_start ||
 555                     !(vma->vm_flags & VM_PFNMAP)) {
 556                         get_page(bad_page);
 557                         return page_to_pfn(bad_page);
 558                 }
 559
 560                 pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
 561                 BUG_ON(pfn_valid(pfn));
 562         } else
 563                 pfn = page_to_pfn(page[0]);
 564
 565         return pfn;
 566 }
 567
 568 EXPORT_SYMBOL_GPL(gfn_to_pfn);
 569
 570 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
 571 {
 572         pfn_t pfn;
 573
 574         pfn = gfn_to_pfn(kvm, gfn);
 575         if (pfn_valid(pfn))
 576                 return pfn_to_page(pfn);
 577
 578         WARN_ON(!pfn_valid(pfn));
 579
 580         get_page(bad_page);
 581         return bad_page;
 582 }
 583
 584 EXPORT_SYMBOL_GPL(gfn_to_page);
 585
 586 void kvm_release_page_clean(struct page *page)
 587 {
 588         kvm_release_pfn_clean(page_to_pfn(page));
 589 }
 590 EXPORT_SYMBOL_GPL(kvm_release_page_clean);
 591
 592 void kvm_release_pfn_clean(pfn_t pfn)
 593 {
 594         if (pfn_valid(pfn))
 595                 put_page(pfn_to_page(pfn));
 596 }
 597 EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
 598
 599 void kvm_release_page_dirty(struct page *page)
 600 {
 601         kvm_release_pfn_dirty(page_to_pfn(page));
 602 }
 603 EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
 604
 605 void kvm_release_pfn_dirty(pfn_t pfn)
 606 {
 607         kvm_set_pfn_dirty(pfn);
 608         kvm_release_pfn_clean(pfn);
 609 }
 610 EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
 611
 612 void kvm_set_page_dirty(struct page *page)
 613 {
 614         kvm_set_pfn_dirty(page_to_pfn(page));
 615 }
 616 EXPORT_SYMBOL_GPL(kvm_set_page_dirty);
 617
 618 void kvm_set_pfn_dirty(pfn_t pfn)
 619 {
 620         if (pfn_valid(pfn)) {
 621                 struct page *page = pfn_to_page(pfn);
 622                 if (!PageReserved(page))
 623                         SetPageDirty(page);
 624         }
 625 }
 626 EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
 627
 628 void kvm_set_pfn_accessed(pfn_t pfn)
 629 {
 630         if (pfn_valid(pfn))
 631                 mark_page_accessed(pfn_to_page(pfn));
 632 }
 633 EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
 634
 635 void kvm_get_pfn(pfn_t pfn)
 636 {
 637         if (pfn_valid(pfn))
 638                 get_page(pfn_to_page(pfn));
 639 }
 640 EXPORT_SYMBOL_GPL(kvm_get_pfn);
 641
 642 static int next_segment(unsigned long len, int offset)
 643 {
 644         if (len > PAGE_SIZE - offset)
 645                 return PAGE_SIZE - offset;
 646         else
 647                 return len;
 648 }
 649
 650 int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
 651                         int len)
 652 {
 653         int r;
 654         unsigned long addr;
 655
 656         addr = gfn_to_hva(kvm, gfn);
 657         if (kvm_is_error_hva(addr))
 658                 return -EFAULT;
 659         r = copy_from_user(data, (void __user *)addr + offset, len);
 660         if (r)
 661                 return -EFAULT;
 662         return 0;
 663 }
 664 EXPORT_SYMBOL_GPL(kvm_read_guest_page);
 665
 666 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
 667 {
 668         gfn_t gfn = gpa >> PAGE_SHIFT;
 669         int seg;
 670         int offset = offset_in_page(gpa);
 671         int ret;
 672
 673         while ((seg = next_segment(len, offset)) != 0) {
 674                 ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
 675                 if (ret < 0)
 676                         return ret;
 677                 offset = 0;
 678                 len -= seg;
 679                 data += seg;
 680                 ++gfn;
 681         }
 682         return 0;
 683 }
 684 EXPORT_SYMBOL_GPL(kvm_read_guest);
 685
 686 int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
 687                           unsigned long len)
 688 {
 689         int r;
 690         unsigned long addr;
 691         gfn_t gfn = gpa >> PAGE_SHIFT;
 692         int offset = offset_in_page(gpa);
 693
 694         addr = gfn_to_hva(kvm, gfn);
 695         if (kvm_is_error_hva(addr))
 696                 return -EFAULT;
 697         pagefault_disable();
 698         r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
 699         pagefault_enable();
 700         if (r)
 701                 return -EFAULT;
 702         return 0;
 703 }
 704 EXPORT_SYMBOL(kvm_read_guest_atomic);
 705
 706 int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
 707                          int offset, int len)
 708 {
 709         int r;
 710         unsigned long addr;
 711
 712         addr = gfn_to_hva(kvm, gfn);
 713         if (kvm_is_error_hva(addr))
 714                 return -EFAULT;
 715         r = copy_to_user((void __user *)addr + offset, data, len);
 716         if (r)
 717                 return -EFAULT;
 718         mark_page_dirty(kvm, gfn);
 719         return 0;
 720 }
 721 EXPORT_SYMBOL_GPL(kvm_write_guest_page);
 722
 723 int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
 724                     unsigned long len)
 725 {
 726         gfn_t gfn = gpa >> PAGE_SHIFT;
 727         int seg;
 728         int offset = offset_in_page(gpa);
 729         int ret;
 730
 731         while ((seg = next_segment(len, offset)) != 0) {
 732                 ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
 733                 if (ret < 0)
 734                         return ret;
 735                 offset = 0;
 736                 len -= seg;
 737                 data += seg;
 738                 ++gfn;
 739         }
 740         return 0;
 741 }
 742
 743 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
 744 {
 745         return kvm_write_guest_page(kvm, gfn, empty_zero_page, offset, len);
 746 }
 747 EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
 748
 749 int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
 750 {
 751         gfn_t gfn = gpa >> PAGE_SHIFT;
 752         int seg;
 753         int offset = offset_in_page(gpa);
 754         int ret;
 755
 756         while ((seg = next_segment(len, offset)) != 0) {
 757                 ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
 758                 if (ret < 0)
 759                         return ret;
 760                 offset = 0;
 761                 len -= seg;
 762                 ++gfn;
 763         }
 764         return 0;
 765 }
 766 EXPORT_SYMBOL_GPL(kvm_clear_guest);
 767
 768 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
 769 {
 770         struct kvm_memory_slot *memslot;
 771
 772         gfn = unalias_gfn(kvm, gfn);
 773         memslot = __gfn_to_memslot(kvm, gfn);
 774         if (memslot && memslot->dirty_bitmap) {
 775                 unsigned long rel_gfn = gfn - memslot->base_gfn;
 776
 777                 /* avoid RMW */
 778                 if (!test_bit(rel_gfn, memslot->dirty_bitmap))
 779                         set_bit(rel_gfn, memslot->dirty_bitmap);
 780         }
 781 }
 782
 783 /*
 784  * The vCPU has executed a HLT instruction with in-kernel mode enabled.
 785  */
 786 void kvm_vcpu_block(struct kvm_vcpu *vcpu)
 787 {
 788         DEFINE_WAIT(wait);
 789
 790         for (;;) {
 791                 prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
 792
 793                 if (kvm_cpu_has_interrupt(vcpu))
 794                         break;
 795                 if (kvm_cpu_has_pending_timer(vcpu))
 796                         break;
 797                 if (kvm_arch_vcpu_runnable(vcpu))
 798                         break;
 799                 if (signal_pending(current))
 800                         break;
 801
 802                 vcpu_put(vcpu);
 803                 schedule();
 804                 vcpu_load(vcpu);
 805         }
 806
 807         finish_wait(&vcpu->wq, &wait);
 808 }
 809
 810 void kvm_resched(struct kvm_vcpu *vcpu)
 811 {
 812         if (!need_resched())
 813                 return;
 814         cond_resched();
 815 }
 816 EXPORT_SYMBOL_GPL(kvm_resched);
 817
 818 static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 819 {
 820         struct kvm_vcpu *vcpu = vma->vm_file->private_data;
 821         struct page *page;
 822
 823         if (vmf->pgoff == 0)
 824                 page = virt_to_page(vcpu->run);
 825 #ifdef CONFIG_X86
 826         else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
 827                 page = virt_to_page(vcpu->arch.pio_data);
 828 #endif
 829         else
 830                 return VM_FAULT_SIGBUS;
 831         get_page(page);
 832         vmf->page = page;
 833         return 0;
 834 }
 835
 836 static struct vm_operations_struct kvm_vcpu_vm_ops = {
 837         .fault = kvm_vcpu_fault,
 838 };
 839
 840 static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
 841 {
 842         vma->vm_ops = &kvm_vcpu_vm_ops;
 843         return 0;
 844 }
 845
 846 static int kvm_vcpu_release(struct inode *inode, struct file *filp)
 847 {
 848         struct kvm_vcpu *vcpu = filp->private_data;
 849
 850         kvm_put_kvm(vcpu->kvm);
 851         return 0;
 852 }
 853
 854 static const struct file_operations kvm_vcpu_fops = {
 855         .release        = kvm_vcpu_release,
 856         .unlocked_ioctl = kvm_vcpu_ioctl,
 857         .compat_ioctl   = kvm_vcpu_ioctl,
 858         .mmap           = kvm_vcpu_mmap,
 859 };
 860
 861 /*
 862  * Allocates an inode for the vcpu.
 863  */
 864 static int create_vcpu_fd(struct kvm_vcpu *vcpu)
 865 {
 866         int fd = anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu);
 867         if (fd < 0)
 868                 kvm_put_kvm(vcpu->kvm);
 869         return fd;
 870 }
 871
 872 /*
 873  * Creates some virtual cpus.  Good luck creating more than one.
 874  */
 875 static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
 876 {
 877         int r;
 878         struct kvm_vcpu *vcpu;
 879
 880         if (!valid_vcpu(n))
 881                 return -EINVAL;
 882
 883         vcpu = kvm_arch_vcpu_create(kvm, n);
 884         if (IS_ERR(vcpu))
 885                 return PTR_ERR(vcpu);
 886
 887         preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
 888
 889         r = kvm_arch_vcpu_setup(vcpu);
 890         if (r)
 891                 goto vcpu_destroy;
 892
 893         mutex_lock(&kvm->lock);
 894         if (kvm->vcpus[n]) {
 895                 r = -EEXIST;
 896                 mutex_unlock(&kvm->lock);
 897                 goto vcpu_destroy;
 898         }
 899         kvm->vcpus[n] = vcpu;
 900         mutex_unlock(&kvm->lock);
 901
 902         /* Now it's all set up, let userspace reach it */
 903         kvm_get_kvm(kvm);
 904         r = create_vcpu_fd(vcpu);
 905         if (r < 0)
 906                 goto unlink;
 907         return r;
 908
 909 unlink:
 910         mutex_lock(&kvm->lock);
 911         kvm->vcpus[n] = NULL;
 912         mutex_unlock(&kvm->lock);
 913 vcpu_destroy:
 914         kvm_arch_vcpu_destroy(vcpu);
 915         return r;
 916 }
 917
 918 static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
 919 {
 920         if (sigset) {
 921                 sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
 922                 vcpu->sigset_active = 1;
 923                 vcpu->sigset = *sigset;
 924         } else
 925                 vcpu->sigset_active = 0;
 926         return 0;
 927 }
 928
 929 static long kvm_vcpu_ioctl(struct file *filp,
 930                            unsigned int ioctl, unsigned long arg)
 931 {
 932         struct kvm_vcpu *vcpu = filp->private_data;
 933         void __user *argp = (void __user *)arg;
 934         int r;
 935
 936         if (vcpu->kvm->mm != current->mm)
 937                 return -EIO;
 938         switch (ioctl) {
 939         case KVM_RUN:
 940                 r = -EINVAL;
 941                 if (arg)
 942                         goto out;
 943                 r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
 944                 break;
 945         case KVM_GET_REGS: {
 946                 struct kvm_regs *kvm_regs;
 947
 948                 r = -ENOMEM;
 949                 kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
 950                 if (!kvm_regs)
 951                         goto out;
 952                 r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
 953                 if (r)
 954                         goto out_free1;
 955                 r = -EFAULT;
 956                 if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
 957                         goto out_free1;
 958                 r = 0;
 959 out_free1:
 960                 kfree(kvm_regs);
 961                 break;
 962         }
 963         case KVM_SET_REGS: {
 964                 struct kvm_regs *kvm_regs;
 965
 966                 r = -ENOMEM;
 967                 kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
 968                 if (!kvm_regs)
 969                         goto out;
 970                 r = -EFAULT;
 971                 if (copy_from_user(kvm_regs, argp, sizeof(struct kvm_regs)))
 972                         goto out_free2;
 973                 r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
 974                 if (r)
 975                         goto out_free2;
 976                 r = 0;
 977 out_free2:
 978                 kfree(kvm_regs);
 979                 break;
 980         }
 981         case KVM_GET_SREGS: {
 982                 struct kvm_sregs kvm_sregs;
 983
 984                 memset(&kvm_sregs, 0, sizeof kvm_sregs);
 985                 r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, &kvm_sregs);
 986                 if (r)
 987                         goto out;
 988                 r = -EFAULT;
 989                 if (copy_to_user(argp, &kvm_sregs, sizeof kvm_sregs))
 990                         goto out;
 991                 r = 0;
 992                 break;
 993         }
 994         case KVM_SET_SREGS: {
 995                 struct kvm_sregs kvm_sregs;
 996
 997                 r = -EFAULT;
 998                 if (copy_from_user(&kvm_sregs, argp, sizeof kvm_sregs))
 999                         goto out;
1000                 r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, &kvm_sregs);
1001                 if (r)
1002                         goto out;
1003                 r = 0;
1004                 break;
1005         }
1006         case KVM_GET_MP_STATE: {
1007                 struct kvm_mp_state mp_state;
1008
1009                 r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
1010                 if (r)
1011                         goto out;
1012                 r = -EFAULT;
1013                 if (copy_to_user(argp, &mp_state, sizeof mp_state))
1014                         goto out;
1015                 r = 0;
1016                 break;
1017         }
1018         case KVM_SET_MP_STATE: {
1019                 struct kvm_mp_state mp_state;
1020
1021                 r = -EFAULT;
1022                 if (copy_from_user(&mp_state, argp, sizeof mp_state))
1023                         goto out;
1024                 r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
1025                 if (r)
1026                         goto out;
1027                 r = 0;
1028                 break;
1029         }
1030         case KVM_TRANSLATE: {
1031                 struct kvm_translation tr;
1032
1033                 r = -EFAULT;
1034                 if (copy_from_user(&tr, argp, sizeof tr))
1035                         goto out;
1036                 r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
1037                 if (r)
1038                         goto out;
1039                 r = -EFAULT;
1040                 if (copy_to_user(argp, &tr, sizeof tr))
1041                         goto out;
1042                 r = 0;
1043                 break;
1044         }
1045         case KVM_DEBUG_GUEST: {
1046                 struct kvm_debug_guest dbg;
1047
1048                 r = -EFAULT;
1049                 if (copy_from_user(&dbg, argp, sizeof dbg))
1050                         goto out;
1051                 r = kvm_arch_vcpu_ioctl_debug_guest(vcpu, &dbg);
1052                 if (r)
1053                         goto out;
1054                 r = 0;
1055                 break;
1056         }
1057         case KVM_SET_SIGNAL_MASK: {
1058                 struct kvm_signal_mask __user *sigmask_arg = argp;
1059                 struct kvm_signal_mask kvm_sigmask;
1060                 sigset_t sigset, *p;
1061
1062                 p = NULL;
1063                 if (argp) {
1064                         r = -EFAULT;
1065                         if (copy_from_user(&kvm_sigmask, argp,
1066                                            sizeof kvm_sigmask))
1067                                 goto out;
1068                         r = -EINVAL;
1069                         if (kvm_sigmask.len != sizeof sigset)
1070                                 goto out;
1071                         r = -EFAULT;
1072                         if (copy_from_user(&sigset, sigmask_arg->sigset,
1073                                            sizeof sigset))
1074                                 goto out;
1075                         p = &sigset;
1076                 }
1077                 r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
1078                 break;
1079         }
1080         case KVM_GET_FPU: {
1081                 struct kvm_fpu fpu;
1082
1083                 memset(&fpu, 0, sizeof fpu);
1084                 r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, &fpu);
1085                 if (r)
1086                         goto out;
1087                 r = -EFAULT;
1088                 if (copy_to_user(argp, &fpu, sizeof fpu))
1089                         goto out;
1090                 r = 0;
1091                 break;
1092         }
1093         case KVM_SET_FPU: {
1094                 struct kvm_fpu fpu;
1095
1096                 r = -EFAULT;
1097                 if (copy_from_user(&fpu, argp, sizeof fpu))
1098                         goto out;
1099                 r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, &fpu);
1100                 if (r)
1101                         goto out;
1102                 r = 0;
1103                 break;
1104         }
1105         default:
1106                 r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
1107         }
1108 out:
1109         return r;
1110 }
1111
1112 static long kvm_vm_ioctl(struct file *filp,
1113                            unsigned int ioctl, unsigned long arg)
1114 {
1115         struct kvm *kvm = filp->private_data;
1116         void __user *argp = (void __user *)arg;
1117         int r;
1118
1119         if (kvm->mm != current->mm)
1120                 return -EIO;
1121         switch (ioctl) {
1122         case KVM_CREATE_VCPU:
1123                 r = kvm_vm_ioctl_create_vcpu(kvm, arg);
1124                 if (r < 0)
1125                         goto out;
1126                 break;
1127         case KVM_SET_USER_MEMORY_REGION: {
1128                 struct kvm_userspace_memory_region kvm_userspace_mem;
1129
1130                 r = -EFAULT;
1131                 if (copy_from_user(&kvm_userspace_mem, argp,
1132                                                 sizeof kvm_userspace_mem))
1133                         goto out;
1134
1135                 r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem, 1);
1136                 if (r)
1137                         goto out;
1138                 break;
1139         }
1140         case KVM_GET_DIRTY_LOG: {
1141                 struct kvm_dirty_log log;
1142
1143                 r = -EFAULT;
1144                 if (copy_from_user(&log, argp, sizeof log))
1145                         goto out;
1146                 r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
1147                 if (r)
1148                         goto out;
1149                 break;
1150         }
1151         default:
1152                 r = kvm_arch_vm_ioctl(filp, ioctl, arg);
1153         }
1154 out:
1155         return r;
1156 }
1157
1158 static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1159 {
1160         struct kvm *kvm = vma->vm_file->private_data;
1161         struct page *page;
1162
1163         if (!kvm_is_visible_gfn(kvm, vmf->pgoff))
1164                 return VM_FAULT_SIGBUS;
1165         page = gfn_to_page(kvm, vmf->pgoff);
1166         if (is_error_page(page)) {
1167                 kvm_release_page_clean(page);
1168                 return VM_FAULT_SIGBUS;
1169         }
1170         vmf->page = page;
1171         return 0;
1172 }
1173
1174 static struct vm_operations_struct kvm_vm_vm_ops = {
1175         .fault = kvm_vm_fault,
1176 };
1177
1178 static int kvm_vm_mmap(struct file *file, struct vm_area_struct *vma)
1179 {
1180         vma->vm_ops = &kvm_vm_vm_ops;
1181         return 0;
1182 }
1183
1184 static const struct file_operations kvm_vm_fops = {
1185         .release        = kvm_vm_release,
1186         .unlocked_ioctl = kvm_vm_ioctl,
1187         .compat_ioctl   = kvm_vm_ioctl,
1188         .mmap           = kvm_vm_mmap,
1189 };
1190
1191 static int kvm_dev_ioctl_create_vm(void)
1192 {
1193         int fd;
1194         struct kvm *kvm;
1195
1196         kvm = kvm_create_vm();
1197         if (IS_ERR(kvm))
1198                 return PTR_ERR(kvm);
1199         fd = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm);
1200         if (fd < 0)
1201                 kvm_put_kvm(kvm);
1202
1203         return fd;
1204 }
1205
1206 static long kvm_dev_ioctl(struct file *filp,
1207                           unsigned int ioctl, unsigned long arg)
1208 {
1209         long r = -EINVAL;
1210
1211         switch (ioctl) {
1212         case KVM_GET_API_VERSION:
1213                 r = -EINVAL;
1214                 if (arg)
1215                         goto out;
1216                 r = KVM_API_VERSION;
1217                 break;
1218         case KVM_CREATE_VM:
1219                 r = -EINVAL;
1220                 if (arg)
1221                         goto out;
1222                 r = kvm_dev_ioctl_create_vm();
1223                 break;
1224         case KVM_CHECK_EXTENSION:
1225                 r = kvm_dev_ioctl_check_extension(arg);
1226                 break;
1227         case KVM_GET_VCPU_MMAP_SIZE:
1228                 r = -EINVAL;
1229                 if (arg)
1230                         goto out;
1231                 r = PAGE_SIZE;     /* struct kvm_run */
1232 #ifdef CONFIG_X86
1233                 r += PAGE_SIZE;    /* pio data page */
1234 #endif
1235                 break;
1236         case KVM_TRACE_ENABLE:
1237         case KVM_TRACE_PAUSE:
1238         case KVM_TRACE_DISABLE:
1239                 r = kvm_trace_ioctl(ioctl, arg);
1240                 break;
1241         default:
1242                 return kvm_arch_dev_ioctl(filp, ioctl, arg);
1243         }
1244 out:
1245         return r;
1246 }
1247
1248 static struct file_operations kvm_chardev_ops = {
1249         .unlocked_ioctl = kvm_dev_ioctl,
1250         .compat_ioctl   = kvm_dev_ioctl,
1251 };
1252
1253 static struct miscdevice kvm_dev = {
1254         KVM_MINOR,
1255         "kvm",
1256         &kvm_chardev_ops,
1257 };
1258
1259 static void hardware_enable(void *junk)
1260 {
1261         int cpu = raw_smp_processor_id();
1262
1263         if (cpu_isset(cpu, cpus_hardware_enabled))
1264                 return;
1265         cpu_set(cpu, cpus_hardware_enabled);
1266         kvm_arch_hardware_enable(NULL);
1267 }
1268
1269 static void hardware_disable(void *junk)
1270 {
1271         int cpu = raw_smp_processor_id();
1272
1273         if (!cpu_isset(cpu, cpus_hardware_enabled))
1274                 return;
1275         cpu_clear(cpu, cpus_hardware_enabled);
1276         kvm_arch_hardware_disable(NULL);
1277 }
1278
1279 static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
1280                            void *v)
1281 {
1282         int cpu = (long)v;
1283
1284         val &= ~CPU_TASKS_FROZEN;
1285         switch (val) {
1286         case CPU_DYING:
1287                 printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
1288                        cpu);
1289                 hardware_disable(NULL);
1290                 break;
1291         case CPU_UP_CANCELED:
1292                 printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
1293                        cpu);
1294                 smp_call_function_single(cpu, hardware_disable, NULL, 1);
1295                 break;
1296         case CPU_ONLINE:
1297                 printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
1298                        cpu);
1299                 smp_call_function_single(cpu, hardware_enable, NULL, 1);
1300                 break;
1301         }
1302         return NOTIFY_OK;
1303 }
1304
1305
1306 asmlinkage void kvm_handle_fault_on_reboot(void)
1307 {
1308         if (kvm_rebooting)
1309                 /* spin while reset goes on */
1310                 while (true)
1311                         ;
1312         /* Fault while not rebooting.  We want the trace. */
1313         BUG();
1314 }
1315 EXPORT_SYMBOL_GPL(kvm_handle_fault_on_reboot);
1316
1317 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
1318                       void *v)
1319 {
1320         if (val == SYS_RESTART) {
1321                 /*
1322                  * Some (well, at least mine) BIOSes hang on reboot if
1323                  * in vmx root mode.
1324                  */
1325                 printk(KERN_INFO "kvm: exiting hardware virtualization\n");
1326                 kvm_rebooting = true;
1327                 on_each_cpu(hardware_disable, NULL, 1);
1328         }
1329         return NOTIFY_OK;
1330 }
1331
1332 static struct notifier_block kvm_reboot_notifier = {
1333         .notifier_call = kvm_reboot,
1334         .priority = 0,
1335 };
1336
1337 void kvm_io_bus_init(struct kvm_io_bus *bus)
1338 {
1339         memset(bus, 0, sizeof(*bus));
1340 }
1341
1342 void kvm_io_bus_destroy(struct kvm_io_bus *bus)
1343 {
1344         int i;
1345
1346         for (i = 0; i < bus->dev_count; i++) {
1347                 struct kvm_io_device *pos = bus->devs[i];
1348
1349                 kvm_iodevice_destructor(pos);
1350         }
1351 }
1352
1353 struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus,
1354                                           gpa_t addr, int len, int is_write)
1355 {
1356         int i;
1357
1358         for (i = 0; i < bus->dev_count; i++) {
1359                 struct kvm_io_device *pos = bus->devs[i];
1360
1361                 if (pos->in_range(pos, addr, len, is_write))
1362                         return pos;
1363         }
1364
1365         return NULL;
1366 }
1367
1368 void kvm_io_bus_register_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev)
1369 {
1370         BUG_ON(bus->dev_count > (NR_IOBUS_DEVS-1));
1371
1372         bus->devs[bus->dev_count++] = dev;
1373 }
1374
1375 static struct notifier_block kvm_cpu_notifier = {
1376         .notifier_call = kvm_cpu_hotplug,
1377         .priority = 20, /* must be > scheduler priority */
1378 };
1379
1380 static int vm_stat_get(void *_offset, u64 *val)
1381 {
1382         unsigned offset = (long)_offset;
1383         struct kvm *kvm;
1384
1385         *val = 0;
1386         spin_lock(&kvm_lock);
1387         list_for_each_entry(kvm, &vm_list, vm_list)
1388                 *val += *(u32 *)((void *)kvm + offset);
1389         spin_unlock(&kvm_lock);
1390         return 0;
1391 }
1392
1393 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
1394
1395 static int vcpu_stat_get(void *_offset, u64 *val)
1396 {
1397         unsigned offset = (long)_offset;
1398         struct kvm *kvm;
1399         struct kvm_vcpu *vcpu;
1400         int i;
1401
1402         *val = 0;
1403         spin_lock(&kvm_lock);
1404         list_for_each_entry(kvm, &vm_list, vm_list)
1405                 for (i = 0; i < KVM_MAX_VCPUS; ++i) {
1406                         vcpu = kvm->vcpus[i];
1407                         if (vcpu)
1408                                 *val += *(u32 *)((void *)vcpu + offset);
1409                 }
1410         spin_unlock(&kvm_lock);
1411         return 0;
1412 }
1413
1414 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
1415
1416 static struct file_operations *stat_fops[] = {
1417         [KVM_STAT_VCPU] = &vcpu_stat_fops,
1418         [KVM_STAT_VM]   = &vm_stat_fops,
1419 };
1420
1421 static void kvm_init_debug(void)
1422 {
1423         struct kvm_stats_debugfs_item *p;
1424
1425         kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
1426         for (p = debugfs_entries; p->name; ++p)
1427                 p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
1428                                                 (void *)(long)p->offset,
1429                                                 stat_fops[p->kind]);
1430 }
1431
1432 static void kvm_exit_debug(void)
1433 {
1434         struct kvm_stats_debugfs_item *p;
1435
1436         for (p = debugfs_entries; p->name; ++p)
1437                 debugfs_remove(p->dentry);
1438         debugfs_remove(kvm_debugfs_dir);
1439 }
1440
1441 static int kvm_suspend(struct sys_device *dev, pm_message_t state)
1442 {
1443         hardware_disable(NULL);
1444         return 0;
1445 }
1446
1447 static int kvm_resume(struct sys_device *dev)
1448 {
1449         hardware_enable(NULL);
1450         return 0;
1451 }
1452
1453 static struct sysdev_class kvm_sysdev_class = {
1454         .name = "kvm",
1455         .suspend = kvm_suspend,
1456         .resume = kvm_resume,
1457 };
1458
1459 static struct sys_device kvm_sysdev = {
1460         .id = 0,
1461         .cls = &kvm_sysdev_class,
1462 };
1463
1464 struct page *bad_page;
1465 pfn_t bad_pfn;
1466
1467 static inline
1468 struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
1469 {
1470         return container_of(pn, struct kvm_vcpu, preempt_notifier);
1471 }
1472
1473 static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
1474 {
1475         struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
1476
1477         kvm_arch_vcpu_load(vcpu, cpu);
1478 }
1479
1480 static void kvm_sched_out(struct preempt_notifier *pn,
1481                           struct task_struct *next)
1482 {
1483         struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
1484
1485         kvm_arch_vcpu_put(vcpu);
1486 }
1487
1488 int kvm_init(void *opaque, unsigned int vcpu_size,
1489                   struct module *module)
1490 {
1491         int r;
1492         int cpu;
1493
1494         kvm_init_debug();
1495
1496         r = kvm_arch_init(opaque);
1497         if (r)
1498                 goto out_fail;
1499
1500         bad_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
1501
1502         if (bad_page == NULL) {
1503                 r = -ENOMEM;
1504                 goto out;
1505         }
1506
1507         bad_pfn = page_to_pfn(bad_page);
1508
1509         r = kvm_arch_hardware_setup();
1510         if (r < 0)
1511                 goto out_free_0;
1512
1513         for_each_online_cpu(cpu) {
1514                 smp_call_function_single(cpu,
1515                                 kvm_arch_check_processor_compat,
1516                                 &r, 1);
1517                 if (r < 0)
1518                         goto out_free_1;
1519         }
1520
1521         on_each_cpu(hardware_enable, NULL, 1);
1522         r = register_cpu_notifier(&kvm_cpu_notifier);
1523         if (r)
1524                 goto out_free_2;
1525         register_reboot_notifier(&kvm_reboot_notifier);
1526
1527         r = sysdev_class_register(&kvm_sysdev_class);
1528         if (r)
1529                 goto out_free_3;
1530
1531         r = sysdev_register(&kvm_sysdev);
1532         if (r)
1533                 goto out_free_4;
1534
1535         /* A kmem cache lets us meet the alignment requirements of fx_save. */
1536         kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size,
1537                                            __alignof__(struct kvm_vcpu),
1538                                            0, NULL);
1539         if (!kvm_vcpu_cache) {
1540                 r = -ENOMEM;
1541                 goto out_free_5;
1542         }
1543
1544         kvm_chardev_ops.owner = module;
1545
1546         r = misc_register(&kvm_dev);
1547         if (r) {
1548                 printk(KERN_ERR "kvm: misc device register failed\n");
1549                 goto out_free;
1550         }
1551
1552         kvm_preempt_ops.sched_in = kvm_sched_in;
1553         kvm_preempt_ops.sched_out = kvm_sched_out;
1554
1555         return 0;
1556
1557 out_free:
1558         kmem_cache_destroy(kvm_vcpu_cache);
1559 out_free_5:
1560         sysdev_unregister(&kvm_sysdev);
1561 out_free_4:
1562         sysdev_class_unregister(&kvm_sysdev_class);
1563 out_free_3:
1564         unregister_reboot_notifier(&kvm_reboot_notifier);
1565         unregister_cpu_notifier(&kvm_cpu_notifier);
1566 out_free_2:
1567         on_each_cpu(hardware_disable, NULL, 1);
1568 out_free_1:
1569         kvm_arch_hardware_unsetup();
1570 out_free_0:
1571         __free_page(bad_page);
1572 out:
1573         kvm_arch_exit();
1574         kvm_exit_debug();
1575 out_fail:
1576         return r;
1577 }
1578 EXPORT_SYMBOL_GPL(kvm_init);
1579
1580 void kvm_exit(void)
1581 {
1582         kvm_trace_cleanup();
1583         misc_deregister(&kvm_dev);
1584         kmem_cache_destroy(kvm_vcpu_cache);
1585         sysdev_unregister(&kvm_sysdev);
1586         sysdev_class_unregister(&kvm_sysdev_class);
1587         unregister_reboot_notifier(&kvm_reboot_notifier);
1588         unregister_cpu_notifier(&kvm_cpu_notifier);
1589         on_each_cpu(hardware_disable, NULL, 1);
1590         kvm_arch_hardware_unsetup();
1591         kvm_arch_exit();
1592         kvm_exit_debug();
1593         __free_page(bad_page);
1594 }
1595 EXPORT_SYMBOL_GPL(kvm_exit);