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  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
   9  *
  10  * Authors:
  11  *   Avi Kivity   <avi@qumranet.com>
  12  *   Yaniv Kamay  <yaniv@qumranet.com>
  13  *
  14  * This work is licensed under the terms of the GNU GPL, version 2.  See
  15  * the COPYING file in the top-level directory.
  16  *
  17  */
  18
  19 #include "iodev.h"
  20
  21 #include <linux/kvm_host.h>
  22 #include <linux/kvm.h>
  23 #include <linux/module.h>
  24 #include <linux/errno.h>
  25 #include <linux/percpu.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/syscore_ops.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 #include <linux/bitops.h>
  45 #include <linux/spinlock.h>
  46 #include <linux/compat.h>
  47 #include <linux/srcu.h>
  48 #include <linux/hugetlb.h>
  49 #include <linux/slab.h>
  50 #include <linux/sort.h>
  51 #include <linux/bsearch.h>
  52
  53 #include <asm/processor.h>
  54 #include <asm/io.h>
  55 #include <asm/uaccess.h>
  56 #include <asm/pgtable.h>
  57
  58 #include "coalesced_mmio.h"
  59 #include "async_pf.h"
  60
  61 #define CREATE_TRACE_POINTS
  62 #include <trace/events/kvm.h>
  63
  64 MODULE_AUTHOR("Qumranet");
  65 MODULE_LICENSE("GPL");
  66
  67 /*
  68  * Ordering of locks:
  69  *
  70  *              kvm->lock --> kvm->slots_lock --> kvm->irq_lock
  71  */
  72
  73 DEFINE_RAW_SPINLOCK(kvm_lock);
  74 LIST_HEAD(vm_list);
  75
  76 static cpumask_var_t cpus_hardware_enabled;
  77 static int kvm_usage_count = 0;
  78 static atomic_t hardware_enable_failed;
  79
  80 struct kmem_cache *kvm_vcpu_cache;
  81 EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
  82
  83 static __read_mostly struct preempt_ops kvm_preempt_ops;
  84
  85 struct dentry *kvm_debugfs_dir;
  86
  87 static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
  88                            unsigned long arg);
  89 #ifdef CONFIG_COMPAT
  90 static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl,
  91                                   unsigned long arg);
  92 #endif
  93 static int hardware_enable_all(void);
  94 static void hardware_disable_all(void);
  95
  96 static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
  97
  98 bool kvm_rebooting;
  99 EXPORT_SYMBOL_GPL(kvm_rebooting);
 100
 101 static bool largepages_enabled = true;
 102
 103 bool kvm_is_mmio_pfn(pfn_t pfn)
 104 {
 105         if (pfn_valid(pfn)) {
 106                 int reserved;
 107                 struct page *tail = pfn_to_page(pfn);
 108                 struct page *head = compound_trans_head(tail);
 109                 reserved = PageReserved(head);
 110                 if (head != tail) {
 111                         /*
 112                          * "head" is not a dangling pointer
 113                          * (compound_trans_head takes care of that)
 114                          * but the hugepage may have been splitted
 115                          * from under us (and we may not hold a
 116                          * reference count on the head page so it can
 117                          * be reused before we run PageReferenced), so
 118                          * we've to check PageTail before returning
 119                          * what we just read.
 120                          */
 121                         smp_rmb();
 122                         if (PageTail(tail))
 123                                 return reserved;
 124                 }
 125                 return PageReserved(tail);
 126         }
 127
 128         return true;
 129 }
 130
 131 /*
 132  * Switches to specified vcpu, until a matching vcpu_put()
 133  */
 134 int vcpu_load(struct kvm_vcpu *vcpu)
 135 {
 136         int cpu;
 137
 138         if (mutex_lock_killable(&vcpu->mutex))
 139                 return -EINTR;
 140         if (unlikely(vcpu->pid != current->pids[PIDTYPE_PID].pid)) {
 141                 /* The thread running this VCPU changed. */
 142                 struct pid *oldpid = vcpu->pid;
 143                 struct pid *newpid = get_task_pid(current, PIDTYPE_PID);
 144                 rcu_assign_pointer(vcpu->pid, newpid);
 145                 synchronize_rcu();
 146                 put_pid(oldpid);
 147         }
 148         cpu = get_cpu();
 149         preempt_notifier_register(&vcpu->preempt_notifier);
 150         kvm_arch_vcpu_load(vcpu, cpu);
 151         put_cpu();
 152         return 0;
 153 }
 154
 155 void vcpu_put(struct kvm_vcpu *vcpu)
 156 {
 157         preempt_disable();
 158         kvm_arch_vcpu_put(vcpu);
 159         preempt_notifier_unregister(&vcpu->preempt_notifier);
 160         preempt_enable();
 161         mutex_unlock(&vcpu->mutex);
 162 }
 163
 164 static void ack_flush(void *_completed)
 165 {
 166 }
 167
 168 static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
 169 {
 170         int i, cpu, me;
 171         cpumask_var_t cpus;
 172         bool called = true;
 173         struct kvm_vcpu *vcpu;
 174
 175         zalloc_cpumask_var(&cpus, GFP_ATOMIC);
 176
 177         me = get_cpu();
 178         kvm_for_each_vcpu(i, vcpu, kvm) {
 179                 kvm_make_request(req, vcpu);
 180                 cpu = vcpu->cpu;
 181
 182                 /* Set ->requests bit before we read ->mode */
 183                 smp_mb();
 184
 185                 if (cpus != NULL && cpu != -1 && cpu != me &&
 186                       kvm_vcpu_exiting_guest_mode(vcpu) != OUTSIDE_GUEST_MODE)
 187                         cpumask_set_cpu(cpu, cpus);
 188         }
 189         if (unlikely(cpus == NULL))
 190                 smp_call_function_many(cpu_online_mask, ack_flush, NULL, 1);
 191         else if (!cpumask_empty(cpus))
 192                 smp_call_function_many(cpus, ack_flush, NULL, 1);
 193         else
 194                 called = false;
 195         put_cpu();
 196         free_cpumask_var(cpus);
 197         return called;
 198 }
 199
 200 void kvm_flush_remote_tlbs(struct kvm *kvm)
 201 {
 202         long dirty_count = kvm->tlbs_dirty;
 203
 204         smp_mb();
 205         if (make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
 206                 ++kvm->stat.remote_tlb_flush;
 207         cmpxchg(&kvm->tlbs_dirty, dirty_count, 0);
 208 }
 209
 210 void kvm_reload_remote_mmus(struct kvm *kvm)
 211 {
 212         make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD);
 213 }
 214
 215 void kvm_make_mclock_inprogress_request(struct kvm *kvm)
 216 {
 217         make_all_cpus_request(kvm, KVM_REQ_MCLOCK_INPROGRESS);
 218 }
 219
 220 void kvm_make_update_eoibitmap_request(struct kvm *kvm)
 221 {
 222         make_all_cpus_request(kvm, KVM_REQ_EOIBITMAP);
 223 }
 224
 225 int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
 226 {
 227         struct page *page;
 228         int r;
 229
 230         mutex_init(&vcpu->mutex);
 231         vcpu->cpu = -1;
 232         vcpu->kvm = kvm;
 233         vcpu->vcpu_id = id;
 234         vcpu->pid = NULL;
 235         init_waitqueue_head(&vcpu->wq);
 236         kvm_async_pf_vcpu_init(vcpu);
 237
 238         page = alloc_page(GFP_KERNEL | __GFP_ZERO);
 239         if (!page) {
 240                 r = -ENOMEM;
 241                 goto fail;
 242         }
 243         vcpu->run = page_address(page);
 244
 245         kvm_vcpu_set_in_spin_loop(vcpu, false);
 246         kvm_vcpu_set_dy_eligible(vcpu, false);
 247
 248         r = kvm_arch_vcpu_init(vcpu);
 249         if (r < 0)
 250                 goto fail_free_run;
 251         return 0;
 252
 253 fail_free_run:
 254         free_page((unsigned long)vcpu->run);
 255 fail:
 256         return r;
 257 }
 258 EXPORT_SYMBOL_GPL(kvm_vcpu_init);
 259
 260 void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
 261 {
 262         put_pid(vcpu->pid);
 263         kvm_arch_vcpu_uninit(vcpu);
 264         free_page((unsigned long)vcpu->run);
 265 }
 266 EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
 267
 268 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
 269 static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
 270 {
 271         return container_of(mn, struct kvm, mmu_notifier);
 272 }
 273
 274 static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
 275                                              struct mm_struct *mm,
 276                                              unsigned long address)
 277 {
 278         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 279         int need_tlb_flush, idx;
 280
 281         /*
 282          * When ->invalidate_page runs, the linux pte has been zapped
 283          * already but the page is still allocated until
 284          * ->invalidate_page returns. So if we increase the sequence
 285          * here the kvm page fault will notice if the spte can't be
 286          * established because the page is going to be freed. If
 287          * instead the kvm page fault establishes the spte before
 288          * ->invalidate_page runs, kvm_unmap_hva will release it
 289          * before returning.
 290          *
 291          * The sequence increase only need to be seen at spin_unlock
 292          * time, and not at spin_lock time.
 293          *
 294          * Increasing the sequence after the spin_unlock would be
 295          * unsafe because the kvm page fault could then establish the
 296          * pte after kvm_unmap_hva returned, without noticing the page
 297          * is going to be freed.
 298          */
 299         idx = srcu_read_lock(&kvm->srcu);
 300         spin_lock(&kvm->mmu_lock);
 301
 302         kvm->mmu_notifier_seq++;
 303         need_tlb_flush = kvm_unmap_hva(kvm, address) | kvm->tlbs_dirty;
 304         /* we've to flush the tlb before the pages can be freed */
 305         if (need_tlb_flush)
 306                 kvm_flush_remote_tlbs(kvm);
 307
 308         spin_unlock(&kvm->mmu_lock);
 309         srcu_read_unlock(&kvm->srcu, idx);
 310 }
 311
 312 static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
 313                                         struct mm_struct *mm,
 314                                         unsigned long address,
 315                                         pte_t pte)
 316 {
 317         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 318         int idx;
 319
 320         idx = srcu_read_lock(&kvm->srcu);
 321         spin_lock(&kvm->mmu_lock);
 322         kvm->mmu_notifier_seq++;
 323         kvm_set_spte_hva(kvm, address, pte);
 324         spin_unlock(&kvm->mmu_lock);
 325         srcu_read_unlock(&kvm->srcu, idx);
 326 }
 327
 328 static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
 329                                                     struct mm_struct *mm,
 330                                                     unsigned long start,
 331                                                     unsigned long end)
 332 {
 333         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 334         int need_tlb_flush = 0, idx;
 335
 336         idx = srcu_read_lock(&kvm->srcu);
 337         spin_lock(&kvm->mmu_lock);
 338         /*
 339          * The count increase must become visible at unlock time as no
 340          * spte can be established without taking the mmu_lock and
 341          * count is also read inside the mmu_lock critical section.
 342          */
 343         kvm->mmu_notifier_count++;
 344         need_tlb_flush = kvm_unmap_hva_range(kvm, start, end);
 345         need_tlb_flush |= kvm->tlbs_dirty;
 346         /* we've to flush the tlb before the pages can be freed */
 347         if (need_tlb_flush)
 348                 kvm_flush_remote_tlbs(kvm);
 349
 350         spin_unlock(&kvm->mmu_lock);
 351         srcu_read_unlock(&kvm->srcu, idx);
 352 }
 353
 354 static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
 355                                                   struct mm_struct *mm,
 356                                                   unsigned long start,
 357                                                   unsigned long end)
 358 {
 359         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 360
 361         spin_lock(&kvm->mmu_lock);
 362         /*
 363          * This sequence increase will notify the kvm page fault that
 364          * the page that is going to be mapped in the spte could have
 365          * been freed.
 366          */
 367         kvm->mmu_notifier_seq++;
 368         smp_wmb();
 369         /*
 370          * The above sequence increase must be visible before the
 371          * below count decrease, which is ensured by the smp_wmb above
 372          * in conjunction with the smp_rmb in mmu_notifier_retry().
 373          */
 374         kvm->mmu_notifier_count--;
 375         spin_unlock(&kvm->mmu_lock);
 376
 377         BUG_ON(kvm->mmu_notifier_count < 0);
 378 }
 379
 380 static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
 381                                               struct mm_struct *mm,
 382                                               unsigned long address)
 383 {
 384         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 385         int young, idx;
 386
 387         idx = srcu_read_lock(&kvm->srcu);
 388         spin_lock(&kvm->mmu_lock);
 389
 390         young = kvm_age_hva(kvm, address);
 391         if (young)
 392                 kvm_flush_remote_tlbs(kvm);
 393
 394         spin_unlock(&kvm->mmu_lock);
 395         srcu_read_unlock(&kvm->srcu, idx);
 396
 397         return young;
 398 }
 399
 400 static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
 401                                        struct mm_struct *mm,
 402                                        unsigned long address)
 403 {
 404         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 405         int young, idx;
 406
 407         idx = srcu_read_lock(&kvm->srcu);
 408         spin_lock(&kvm->mmu_lock);
 409         young = kvm_test_age_hva(kvm, address);
 410         spin_unlock(&kvm->mmu_lock);
 411         srcu_read_unlock(&kvm->srcu, idx);
 412
 413         return young;
 414 }
 415
 416 static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
 417                                      struct mm_struct *mm)
 418 {
 419         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 420         int idx;
 421
 422         idx = srcu_read_lock(&kvm->srcu);
 423         kvm_arch_flush_shadow_all(kvm);
 424         srcu_read_unlock(&kvm->srcu, idx);
 425 }
 426
 427 static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
 428         .invalidate_page        = kvm_mmu_notifier_invalidate_page,
 429         .invalidate_range_start = kvm_mmu_notifier_invalidate_range_start,
 430         .invalidate_range_end   = kvm_mmu_notifier_invalidate_range_end,
 431         .clear_flush_young      = kvm_mmu_notifier_clear_flush_young,
 432         .test_young             = kvm_mmu_notifier_test_young,
 433         .change_pte             = kvm_mmu_notifier_change_pte,
 434         .release                = kvm_mmu_notifier_release,
 435 };
 436
 437 static int kvm_init_mmu_notifier(struct kvm *kvm)
 438 {
 439         kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
 440         return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
 441 }
 442
 443 #else  /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */
 444
 445 static int kvm_init_mmu_notifier(struct kvm *kvm)
 446 {
 447         return 0;
 448 }
 449
 450 #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
 451
 452 static void kvm_init_memslots_id(struct kvm *kvm)
 453 {
 454         int i;
 455         struct kvm_memslots *slots = kvm->memslots;
 456
 457         for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
 458                 slots->id_to_index[i] = slots->memslots[i].id = i;
 459 }
 460
 461 static struct kvm *kvm_create_vm(unsigned long type)
 462 {
 463         int r, i;
 464         struct kvm *kvm = kvm_arch_alloc_vm();
 465
 466         if (!kvm)
 467                 return ERR_PTR(-ENOMEM);
 468
 469         r = kvm_arch_init_vm(kvm, type);
 470         if (r)
 471                 goto out_err_nodisable;
 472
 473         r = hardware_enable_all();
 474         if (r)
 475                 goto out_err_nodisable;
 476
 477 #ifdef CONFIG_HAVE_KVM_IRQCHIP
 478         INIT_HLIST_HEAD(&kvm->mask_notifier_list);
 479         INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
 480 #endif
 481
 482         BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX);
 483
 484         r = -ENOMEM;
 485         kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
 486         if (!kvm->memslots)
 487                 goto out_err_nosrcu;
 488         kvm_init_memslots_id(kvm);
 489         if (init_srcu_struct(&kvm->srcu))
 490                 goto out_err_nosrcu;
 491         for (i = 0; i < KVM_NR_BUSES; i++) {
 492                 kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus),
 493                                         GFP_KERNEL);
 494                 if (!kvm->buses[i])
 495                         goto out_err;
 496         }
 497
 498         spin_lock_init(&kvm->mmu_lock);
 499         kvm->mm = current->mm;
 500         atomic_inc(&kvm->mm->mm_count);
 501         kvm_eventfd_init(kvm);
 502         mutex_init(&kvm->lock);
 503         mutex_init(&kvm->irq_lock);
 504         mutex_init(&kvm->slots_lock);
 505         atomic_set(&kvm->users_count, 1);
 506
 507         r = kvm_init_mmu_notifier(kvm);
 508         if (r)
 509                 goto out_err;
 510
 511         raw_spin_lock(&kvm_lock);
 512         list_add(&kvm->vm_list, &vm_list);
 513         raw_spin_unlock(&kvm_lock);
 514
 515         return kvm;
 516
 517 out_err:
 518         cleanup_srcu_struct(&kvm->srcu);
 519 out_err_nosrcu:
 520         hardware_disable_all();
 521 out_err_nodisable:
 522         for (i = 0; i < KVM_NR_BUSES; i++)
 523                 kfree(kvm->buses[i]);
 524         kfree(kvm->memslots);
 525         kvm_arch_free_vm(kvm);
 526         return ERR_PTR(r);
 527 }
 528
 529 /*
 530  * Avoid using vmalloc for a small buffer.
 531  * Should not be used when the size is statically known.
 532  */
 533 void *kvm_kvzalloc(unsigned long size)
 534 {
 535         if (size > PAGE_SIZE)
 536                 return vzalloc(size);
 537         else
 538                 return kzalloc(size, GFP_KERNEL);
 539 }
 540
 541 void kvm_kvfree(const void *addr)
 542 {
 543         if (is_vmalloc_addr(addr))
 544                 vfree(addr);
 545         else
 546                 kfree(addr);
 547 }
 548
 549 static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
 550 {
 551         if (!memslot->dirty_bitmap)
 552                 return;
 553
 554         kvm_kvfree(memslot->dirty_bitmap);
 555         memslot->dirty_bitmap = NULL;
 556 }
 557
 558 /*
 559  * Free any memory in @free but not in @dont.
 560  */
 561 static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
 562                                   struct kvm_memory_slot *dont)
 563 {
 564         if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
 565                 kvm_destroy_dirty_bitmap(free);
 566
 567         kvm_arch_free_memslot(free, dont);
 568
 569         free->npages = 0;
 570 }
 571
 572 void kvm_free_physmem(struct kvm *kvm)
 573 {
 574         struct kvm_memslots *slots = kvm->memslots;
 575         struct kvm_memory_slot *memslot;
 576
 577         kvm_for_each_memslot(memslot, slots)
 578                 kvm_free_physmem_slot(memslot, NULL);
 579
 580         kfree(kvm->memslots);
 581 }
 582
 583 static void kvm_destroy_vm(struct kvm *kvm)
 584 {
 585         int i;
 586         struct mm_struct *mm = kvm->mm;
 587
 588         kvm_arch_sync_events(kvm);
 589         raw_spin_lock(&kvm_lock);
 590         list_del(&kvm->vm_list);
 591         raw_spin_unlock(&kvm_lock);
 592         kvm_free_irq_routing(kvm);
 593         for (i = 0; i < KVM_NR_BUSES; i++)
 594                 kvm_io_bus_destroy(kvm->buses[i]);
 595         kvm_coalesced_mmio_free(kvm);
 596 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
 597         mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
 598 #else
 599         kvm_arch_flush_shadow_all(kvm);
 600 #endif
 601         kvm_arch_destroy_vm(kvm);
 602         kvm_free_physmem(kvm);
 603         cleanup_srcu_struct(&kvm->srcu);
 604         kvm_arch_free_vm(kvm);
 605         hardware_disable_all();
 606         mmdrop(mm);
 607 }
 608
 609 void kvm_get_kvm(struct kvm *kvm)
 610 {
 611         atomic_inc(&kvm->users_count);
 612 }
 613 EXPORT_SYMBOL_GPL(kvm_get_kvm);
 614
 615 void kvm_put_kvm(struct kvm *kvm)
 616 {
 617         if (atomic_dec_and_test(&kvm->users_count))
 618                 kvm_destroy_vm(kvm);
 619 }
 620 EXPORT_SYMBOL_GPL(kvm_put_kvm);
 621
 622
 623 static int kvm_vm_release(struct inode *inode, struct file *filp)
 624 {
 625         struct kvm *kvm = filp->private_data;
 626
 627         kvm_irqfd_release(kvm);
 628
 629         kvm_put_kvm(kvm);
 630         return 0;
 631 }
 632
 633 /*
 634  * Allocation size is twice as large as the actual dirty bitmap size.
 635  * See x86's kvm_vm_ioctl_get_dirty_log() why this is needed.
 636  */
 637 static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
 638 {
 639 #ifndef CONFIG_S390
 640         unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
 641
 642         memslot->dirty_bitmap = kvm_kvzalloc(dirty_bytes);
 643         if (!memslot->dirty_bitmap)
 644                 return -ENOMEM;
 645
 646 #endif /* !CONFIG_S390 */
 647         return 0;
 648 }
 649
 650 static int cmp_memslot(const void *slot1, const void *slot2)
 651 {
 652         struct kvm_memory_slot *s1, *s2;
 653
 654         s1 = (struct kvm_memory_slot *)slot1;
 655         s2 = (struct kvm_memory_slot *)slot2;
 656
 657         if (s1->npages < s2->npages)
 658                 return 1;
 659         if (s1->npages > s2->npages)
 660                 return -1;
 661
 662         return 0;
 663 }
 664
 665 /*
 666  * Sort the memslots base on its size, so the larger slots
 667  * will get better fit.
 668  */
 669 static void sort_memslots(struct kvm_memslots *slots)
 670 {
 671         int i;
 672
 673         sort(slots->memslots, KVM_MEM_SLOTS_NUM,
 674               sizeof(struct kvm_memory_slot), cmp_memslot, NULL);
 675
 676         for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
 677                 slots->id_to_index[slots->memslots[i].id] = i;
 678 }
 679
 680 void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new,
 681                      u64 last_generation)
 682 {
 683         if (new) {
 684                 int id = new->id;
 685                 struct kvm_memory_slot *old = id_to_memslot(slots, id);
 686                 unsigned long npages = old->npages;
 687
 688                 *old = *new;
 689                 if (new->npages != npages)
 690                         sort_memslots(slots);
 691         }
 692
 693         slots->generation = last_generation + 1;
 694 }
 695
 696 static int check_memory_region_flags(struct kvm_userspace_memory_region *mem)
 697 {
 698         u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES;
 699
 700 #ifdef KVM_CAP_READONLY_MEM
 701         valid_flags |= KVM_MEM_READONLY;
 702 #endif
 703
 704         if (mem->flags & ~valid_flags)
 705                 return -EINVAL;
 706
 707         return 0;
 708 }
 709
 710 static struct kvm_memslots *install_new_memslots(struct kvm *kvm,
 711                 struct kvm_memslots *slots, struct kvm_memory_slot *new)
 712 {
 713         struct kvm_memslots *old_memslots = kvm->memslots;
 714
 715         update_memslots(slots, new, kvm->memslots->generation);
 716         rcu_assign_pointer(kvm->memslots, slots);
 717         synchronize_srcu_expedited(&kvm->srcu);
 718         return old_memslots;
 719 }
 720
 721 /*
 722  * KVM_SET_USER_MEMORY_REGION ioctl allows the following operations:
 723  * - create a new memory slot
 724  * - delete an existing memory slot
 725  * - modify an existing memory slot
 726  *   -- move it in the guest physical memory space
 727  *   -- just change its flags
 728  *
 729  * Since flags can be changed by some of these operations, the following
 730  * differentiation is the best we can do for __kvm_set_memory_region():
 731  */
 732 enum kvm_mr_change {
 733         KVM_MR_CREATE,
 734         KVM_MR_DELETE,
 735         KVM_MR_MOVE,
 736         KVM_MR_FLAGS_ONLY,
 737 };
 738
 739 /*
 740  * Allocate some memory and give it an address in the guest physical address
 741  * space.
 742  *
 743  * Discontiguous memory is allowed, mostly for framebuffers.
 744  *
 745  * Must be called holding mmap_sem for write.
 746  */
 747 int __kvm_set_memory_region(struct kvm *kvm,
 748                             struct kvm_userspace_memory_region *mem,
 749                             bool user_alloc)
 750 {
 751         int r;
 752         gfn_t base_gfn;
 753         unsigned long npages;
 754         struct kvm_memory_slot *slot;
 755         struct kvm_memory_slot old, new;
 756         struct kvm_memslots *slots = NULL, *old_memslots;
 757         enum kvm_mr_change change;
 758
 759         r = check_memory_region_flags(mem);
 760         if (r)
 761                 goto out;
 762
 763         r = -EINVAL;
 764         /* General sanity checks */
 765         if (mem->memory_size & (PAGE_SIZE - 1))
 766                 goto out;
 767         if (mem->guest_phys_addr & (PAGE_SIZE - 1))
 768                 goto out;
 769         /* We can read the guest memory with __xxx_user() later on. */
 770         if (user_alloc &&
 771             ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
 772              !access_ok(VERIFY_WRITE,
 773                         (void __user *)(unsigned long)mem->userspace_addr,
 774                         mem->memory_size)))
 775                 goto out;
 776         if (mem->slot >= KVM_MEM_SLOTS_NUM)
 777                 goto out;
 778         if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
 779                 goto out;
 780
 781         slot = id_to_memslot(kvm->memslots, mem->slot);
 782         base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
 783         npages = mem->memory_size >> PAGE_SHIFT;
 784
 785         r = -EINVAL;
 786         if (npages > KVM_MEM_MAX_NR_PAGES)
 787                 goto out;
 788
 789         if (!npages)
 790                 mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
 791
 792         new = old = *slot;
 793
 794         new.id = mem->slot;
 795         new.base_gfn = base_gfn;
 796         new.npages = npages;
 797         new.flags = mem->flags;
 798
 799         r = -EINVAL;
 800         if (npages) {
 801                 if (!old.npages)
 802                         change = KVM_MR_CREATE;
 803                 else { /* Modify an existing slot. */
 804                         if ((mem->userspace_addr != old.userspace_addr) ||
 805                             (npages != old.npages) ||
 806                             ((new.flags ^ old.flags) & KVM_MEM_READONLY))
 807                                 goto out;
 808
 809                         if (base_gfn != old.base_gfn)
 810                                 change = KVM_MR_MOVE;
 811                         else if (new.flags != old.flags)
 812                                 change = KVM_MR_FLAGS_ONLY;
 813                         else { /* Nothing to change. */
 814                                 r = 0;
 815                                 goto out;
 816                         }
 817                 }
 818         } else if (old.npages) {
 819                 change = KVM_MR_DELETE;
 820         } else /* Modify a non-existent slot: disallowed. */
 821                 goto out;
 822
 823         if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) {
 824                 /* Check for overlaps */
 825                 r = -EEXIST;
 826                 kvm_for_each_memslot(slot, kvm->memslots) {
 827                         if ((slot->id >= KVM_USER_MEM_SLOTS) ||
 828                             (slot->id == mem->slot))
 829                                 continue;
 830                         if (!((base_gfn + npages <= slot->base_gfn) ||
 831                               (base_gfn >= slot->base_gfn + slot->npages)))
 832                                 goto out;
 833                 }
 834         }
 835
 836         /* Free page dirty bitmap if unneeded */
 837         if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
 838                 new.dirty_bitmap = NULL;
 839
 840         r = -ENOMEM;
 841         if (change == KVM_MR_CREATE) {
 842                 new.userspace_addr = mem->userspace_addr;
 843
 844                 if (kvm_arch_create_memslot(&new, npages))
 845                         goto out_free;
 846         }
 847
 848         /* Allocate page dirty bitmap if needed */
 849         if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
 850                 if (kvm_create_dirty_bitmap(&new) < 0)
 851                         goto out_free;
 852         }
 853
 854         if ((change == KVM_MR_DELETE) || (change == KVM_MR_MOVE)) {
 855                 r = -ENOMEM;
 856                 slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
 857                                 GFP_KERNEL);
 858                 if (!slots)
 859                         goto out_free;
 860                 slot = id_to_memslot(slots, mem->slot);
 861                 slot->flags |= KVM_MEMSLOT_INVALID;
 862
 863                 old_memslots = install_new_memslots(kvm, slots, NULL);
 864
 865                 /* slot was deleted or moved, clear iommu mapping */
 866                 kvm_iommu_unmap_pages(kvm, &old);
 867                 /* From this point no new shadow pages pointing to a deleted,
 868                  * or moved, memslot will be created.
 869                  *
 870                  * validation of sp->gfn happens in:
 871                  *      - gfn_to_hva (kvm_read_guest, gfn_to_pfn)
 872                  *      - kvm_is_visible_gfn (mmu_check_roots)
 873                  */
 874                 kvm_arch_flush_shadow_memslot(kvm, slot);
 875                 slots = old_memslots;
 876         }
 877
 878         r = kvm_arch_prepare_memory_region(kvm, &new, old, mem, user_alloc);
 879         if (r)
 880                 goto out_slots;
 881
 882         r = -ENOMEM;
 883         /*
 884          * We can re-use the old_memslots from above, the only difference
 885          * from the currently installed memslots is the invalid flag.  This
 886          * will get overwritten by update_memslots anyway.
 887          */
 888         if (!slots) {
 889                 slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
 890                                 GFP_KERNEL);
 891                 if (!slots)
 892                         goto out_free;
 893         }
 894
 895         /*
 896          * IOMMU mapping:  New slots need to be mapped.  Old slots need to be
 897          * un-mapped and re-mapped if their base changes.  Since base change
 898          * unmapping is handled above with slot deletion, mapping alone is
 899          * needed here.  Anything else the iommu might care about for existing
 900          * slots (size changes, userspace addr changes and read-only flag
 901          * changes) is disallowed above, so any other attribute changes getting
 902          * here can be skipped.
 903          */
 904         if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) {
 905                 r = kvm_iommu_map_pages(kvm, &new);
 906                 if (r)
 907                         goto out_slots;
 908         }
 909
 910         /* actual memory is freed via old in kvm_free_physmem_slot below */
 911         if (change == KVM_MR_DELETE) {
 912                 new.dirty_bitmap = NULL;
 913                 memset(&new.arch, 0, sizeof(new.arch));
 914         }
 915
 916         old_memslots = install_new_memslots(kvm, slots, &new);
 917
 918         kvm_arch_commit_memory_region(kvm, mem, old, user_alloc);
 919
 920         kvm_free_physmem_slot(&old, &new);
 921         kfree(old_memslots);
 922
 923         return 0;
 924
 925 out_slots:
 926         kfree(slots);
 927 out_free:
 928         kvm_free_physmem_slot(&new, &old);
 929 out:
 930         return r;
 931 }
 932 EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
 933
 934 int kvm_set_memory_region(struct kvm *kvm,
 935                           struct kvm_userspace_memory_region *mem,
 936                           bool user_alloc)
 937 {
 938         int r;
 939
 940         mutex_lock(&kvm->slots_lock);
 941         r = __kvm_set_memory_region(kvm, mem, user_alloc);
 942         mutex_unlock(&kvm->slots_lock);
 943         return r;
 944 }
 945 EXPORT_SYMBOL_GPL(kvm_set_memory_region);
 946
 947 int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
 948                                    struct
 949                                    kvm_userspace_memory_region *mem,
 950                                    bool user_alloc)
 951 {
 952         if (mem->slot >= KVM_USER_MEM_SLOTS)
 953                 return -EINVAL;
 954         return kvm_set_memory_region(kvm, mem, user_alloc);
 955 }
 956
 957 int kvm_get_dirty_log(struct kvm *kvm,
 958                         struct kvm_dirty_log *log, int *is_dirty)
 959 {
 960         struct kvm_memory_slot *memslot;
 961         int r, i;
 962         unsigned long n;
 963         unsigned long any = 0;
 964
 965         r = -EINVAL;
 966         if (log->slot >= KVM_USER_MEM_SLOTS)
 967                 goto out;
 968
 969         memslot = id_to_memslot(kvm->memslots, log->slot);
 970         r = -ENOENT;
 971         if (!memslot->dirty_bitmap)
 972                 goto out;
 973
 974         n = kvm_dirty_bitmap_bytes(memslot);
 975
 976         for (i = 0; !any && i < n/sizeof(long); ++i)
 977                 any = memslot->dirty_bitmap[i];
 978
 979         r = -EFAULT;
 980         if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
 981                 goto out;
 982
 983         if (any)
 984                 *is_dirty = 1;
 985
 986         r = 0;
 987 out:
 988         return r;
 989 }
 990
 991 bool kvm_largepages_enabled(void)
 992 {
 993         return largepages_enabled;
 994 }
 995
 996 void kvm_disable_largepages(void)
 997 {
 998         largepages_enabled = false;
 999 }
1000 EXPORT_SYMBOL_GPL(kvm_disable_largepages);
1001
1002 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
1003 {
1004         return __gfn_to_memslot(kvm_memslots(kvm), gfn);
1005 }
1006 EXPORT_SYMBOL_GPL(gfn_to_memslot);
1007
1008 int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
1009 {
1010         struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn);
1011
1012         if (!memslot || memslot->id >= KVM_USER_MEM_SLOTS ||
1013               memslot->flags & KVM_MEMSLOT_INVALID)
1014                 return 0;
1015
1016         return 1;
1017 }
1018 EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
1019
1020 unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn)
1021 {
1022         struct vm_area_struct *vma;
1023         unsigned long addr, size;
1024
1025         size = PAGE_SIZE;
1026
1027         addr = gfn_to_hva(kvm, gfn);
1028         if (kvm_is_error_hva(addr))
1029                 return PAGE_SIZE;
1030
1031         down_read(&current->mm->mmap_sem);
1032         vma = find_vma(current->mm, addr);
1033         if (!vma)
1034                 goto out;
1035
1036         size = vma_kernel_pagesize(vma);
1037
1038 out:
1039         up_read(&current->mm->mmap_sem);
1040
1041         return size;
1042 }
1043
1044 static bool memslot_is_readonly(struct kvm_memory_slot *slot)
1045 {
1046         return slot->flags & KVM_MEM_READONLY;
1047 }
1048
1049 static unsigned long __gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
1050                                        gfn_t *nr_pages, bool write)
1051 {
1052         if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
1053                 return KVM_HVA_ERR_BAD;
1054
1055         if (memslot_is_readonly(slot) && write)
1056                 return KVM_HVA_ERR_RO_BAD;
1057
1058         if (nr_pages)
1059                 *nr_pages = slot->npages - (gfn - slot->base_gfn);
1060
1061         return __gfn_to_hva_memslot(slot, gfn);
1062 }
1063
1064 static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
1065                                      gfn_t *nr_pages)
1066 {
1067         return __gfn_to_hva_many(slot, gfn, nr_pages, true);
1068 }
1069
1070 unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot,
1071                                  gfn_t gfn)
1072 {
1073         return gfn_to_hva_many(slot, gfn, NULL);
1074 }
1075 EXPORT_SYMBOL_GPL(gfn_to_hva_memslot);
1076
1077 unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
1078 {
1079         return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL);
1080 }
1081 EXPORT_SYMBOL_GPL(gfn_to_hva);
1082
1083 /*
1084  * The hva returned by this function is only allowed to be read.
1085  * It should pair with kvm_read_hva() or kvm_read_hva_atomic().
1086  */
1087 static unsigned long gfn_to_hva_read(struct kvm *kvm, gfn_t gfn)
1088 {
1089         return __gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL, false);
1090 }
1091
1092 static int kvm_read_hva(void *data, void __user *hva, int len)
1093 {
1094         return __copy_from_user(data, hva, len);
1095 }
1096
1097 static int kvm_read_hva_atomic(void *data, void __user *hva, int len)
1098 {
1099         return __copy_from_user_inatomic(data, hva, len);
1100 }
1101
1102 int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm,
1103         unsigned long start, int write, struct page **page)
1104 {
1105         int flags = FOLL_TOUCH | FOLL_NOWAIT | FOLL_HWPOISON | FOLL_GET;
1106
1107         if (write)
1108                 flags |= FOLL_WRITE;
1109
1110         return __get_user_pages(tsk, mm, start, 1, flags, page, NULL, NULL);
1111 }
1112
1113 static inline int check_user_page_hwpoison(unsigned long addr)
1114 {
1115         int rc, flags = FOLL_TOUCH | FOLL_HWPOISON | FOLL_WRITE;
1116
1117         rc = __get_user_pages(current, current->mm, addr, 1,
1118                               flags, NULL, NULL, NULL);
1119         return rc == -EHWPOISON;
1120 }
1121
1122 /*
1123  * The atomic path to get the writable pfn which will be stored in @pfn,
1124  * true indicates success, otherwise false is returned.
1125  */
1126 static bool hva_to_pfn_fast(unsigned long addr, bool atomic, bool *async,
1127                             bool write_fault, bool *writable, pfn_t *pfn)
1128 {
1129         struct page *page[1];
1130         int npages;
1131
1132         if (!(async || atomic))
1133                 return false;
1134
1135         /*
1136          * Fast pin a writable pfn only if it is a write fault request
1137          * or the caller allows to map a writable pfn for a read fault
1138          * request.
1139          */
1140         if (!(write_fault || writable))
1141                 return false;
1142
1143         npages = __get_user_pages_fast(addr, 1, 1, page);
1144         if (npages == 1) {
1145                 *pfn = page_to_pfn(page[0]);
1146
1147                 if (writable)
1148                         *writable = true;
1149                 return true;
1150         }
1151
1152         return false;
1153 }
1154
1155 /*
1156  * The slow path to get the pfn of the specified host virtual address,
1157  * 1 indicates success, -errno is returned if error is detected.
1158  */
1159 static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault,
1160                            bool *writable, pfn_t *pfn)
1161 {
1162         struct page *page[1];
1163         int npages = 0;
1164
1165         might_sleep();
1166
1167         if (writable)
1168                 *writable = write_fault;
1169
1170         if (async) {
1171                 down_read(&current->mm->mmap_sem);
1172                 npages = get_user_page_nowait(current, current->mm,
1173                                               addr, write_fault, page);
1174                 up_read(&current->mm->mmap_sem);
1175         } else
1176                 npages = get_user_pages_fast(addr, 1, write_fault,
1177                                              page);
1178         if (npages != 1)
1179                 return npages;
1180
1181         /* map read fault as writable if possible */
1182         if (unlikely(!write_fault) && writable) {
1183                 struct page *wpage[1];
1184
1185                 npages = __get_user_pages_fast(addr, 1, 1, wpage);
1186                 if (npages == 1) {
1187                         *writable = true;
1188                         put_page(page[0]);
1189                         page[0] = wpage[0];
1190                 }
1191
1192                 npages = 1;
1193         }
1194         *pfn = page_to_pfn(page[0]);
1195         return npages;
1196 }
1197
1198 static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault)
1199 {
1200         if (unlikely(!(vma->vm_flags & VM_READ)))
1201                 return false;
1202
1203         if (write_fault && (unlikely(!(vma->vm_flags & VM_WRITE))))
1204                 return false;
1205
1206         return true;
1207 }
1208
1209 /*
1210  * Pin guest page in memory and return its pfn.
1211  * @addr: host virtual address which maps memory to the guest
1212  * @atomic: whether this function can sleep
1213  * @async: whether this function need to wait IO complete if the
1214  *         host page is not in the memory
1215  * @write_fault: whether we should get a writable host page
1216  * @writable: whether it allows to map a writable host page for !@write_fault
1217  *
1218  * The function will map a writable host page for these two cases:
1219  * 1): @write_fault = true
1220  * 2): @write_fault = false && @writable, @writable will tell the caller
1221  *     whether the mapping is writable.
1222  */
1223 static pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
1224                         bool write_fault, bool *writable)
1225 {
1226         struct vm_area_struct *vma;
1227         pfn_t pfn = 0;
1228         int npages;
1229
1230         /* we can do it either atomically or asynchronously, not both */
1231         BUG_ON(atomic && async);
1232
1233         if (hva_to_pfn_fast(addr, atomic, async, write_fault, writable, &pfn))
1234                 return pfn;
1235
1236         if (atomic)
1237                 return KVM_PFN_ERR_FAULT;
1238
1239         npages = hva_to_pfn_slow(addr, async, write_fault, writable, &pfn);
1240         if (npages == 1)
1241                 return pfn;
1242
1243         down_read(&current->mm->mmap_sem);
1244         if (npages == -EHWPOISON ||
1245               (!async && check_user_page_hwpoison(addr))) {
1246                 pfn = KVM_PFN_ERR_HWPOISON;
1247                 goto exit;
1248         }
1249
1250         vma = find_vma_intersection(current->mm, addr, addr + 1);
1251
1252         if (vma == NULL)
1253                 pfn = KVM_PFN_ERR_FAULT;
1254         else if ((vma->vm_flags & VM_PFNMAP)) {
1255                 pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) +
1256                         vma->vm_pgoff;
1257                 BUG_ON(!kvm_is_mmio_pfn(pfn));
1258         } else {
1259                 if (async && vma_is_valid(vma, write_fault))
1260                         *async = true;
1261                 pfn = KVM_PFN_ERR_FAULT;
1262         }
1263 exit:
1264         up_read(&current->mm->mmap_sem);
1265         return pfn;
1266 }
1267
1268 static pfn_t
1269 __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic,
1270                      bool *async, bool write_fault, bool *writable)
1271 {
1272         unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault);
1273
1274         if (addr == KVM_HVA_ERR_RO_BAD)
1275                 return KVM_PFN_ERR_RO_FAULT;
1276
1277         if (kvm_is_error_hva(addr))
1278                 return KVM_PFN_NOSLOT;
1279
1280         /* Do not map writable pfn in the readonly memslot. */
1281         if (writable && memslot_is_readonly(slot)) {
1282                 *writable = false;
1283                 writable = NULL;
1284         }
1285
1286         return hva_to_pfn(addr, atomic, async, write_fault,
1287                           writable);
1288 }
1289
1290 static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async,
1291                           bool write_fault, bool *writable)
1292 {
1293         struct kvm_memory_slot *slot;
1294
1295         if (async)
1296                 *async = false;
1297
1298         slot = gfn_to_memslot(kvm, gfn);
1299
1300         return __gfn_to_pfn_memslot(slot, gfn, atomic, async, write_fault,
1301                                     writable);
1302 }
1303
1304 pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn)
1305 {
1306         return __gfn_to_pfn(kvm, gfn, true, NULL, true, NULL);
1307 }
1308 EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic);
1309
1310 pfn_t gfn_to_pfn_async(struct kvm *kvm, gfn_t gfn, bool *async,
1311                        bool write_fault, bool *writable)
1312 {
1313         return __gfn_to_pfn(kvm, gfn, false, async, write_fault, writable);
1314 }
1315 EXPORT_SYMBOL_GPL(gfn_to_pfn_async);
1316
1317 pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
1318 {
1319         return __gfn_to_pfn(kvm, gfn, false, NULL, true, NULL);
1320 }
1321 EXPORT_SYMBOL_GPL(gfn_to_pfn);
1322
1323 pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
1324                       bool *writable)
1325 {
1326         return __gfn_to_pfn(kvm, gfn, false, NULL, write_fault, writable);
1327 }
1328 EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);
1329
1330 pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
1331 {
1332         return __gfn_to_pfn_memslot(slot, gfn, false, NULL, true, NULL);
1333 }
1334
1335 pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn)
1336 {
1337         return __gfn_to_pfn_memslot(slot, gfn, true, NULL, true, NULL);
1338 }
1339 EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic);
1340
1341 int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages,
1342                                                                   int nr_pages)
1343 {
1344         unsigned long addr;
1345         gfn_t entry;
1346
1347         addr = gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, &entry);
1348         if (kvm_is_error_hva(addr))
1349                 return -1;
1350
1351         if (entry < nr_pages)
1352                 return 0;
1353
1354         return __get_user_pages_fast(addr, nr_pages, 1, pages);
1355 }
1356 EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
1357
1358 static struct page *kvm_pfn_to_page(pfn_t pfn)
1359 {
1360         if (is_error_noslot_pfn(pfn))
1361                 return KVM_ERR_PTR_BAD_PAGE;
1362
1363         if (kvm_is_mmio_pfn(pfn)) {
1364                 WARN_ON(1);
1365                 return KVM_ERR_PTR_BAD_PAGE;
1366         }
1367
1368         return pfn_to_page(pfn);
1369 }
1370
1371 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
1372 {
1373         pfn_t pfn;
1374
1375         pfn = gfn_to_pfn(kvm, gfn);
1376
1377         return kvm_pfn_to_page(pfn);
1378 }
1379
1380 EXPORT_SYMBOL_GPL(gfn_to_page);
1381
1382 void kvm_release_page_clean(struct page *page)
1383 {
1384         WARN_ON(is_error_page(page));
1385
1386         kvm_release_pfn_clean(page_to_pfn(page));
1387 }
1388 EXPORT_SYMBOL_GPL(kvm_release_page_clean);
1389
1390 void kvm_release_pfn_clean(pfn_t pfn)
1391 {
1392         if (!is_error_noslot_pfn(pfn) && !kvm_is_mmio_pfn(pfn))
1393                 put_page(pfn_to_page(pfn));
1394 }
1395 EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
1396
1397 void kvm_release_page_dirty(struct page *page)
1398 {
1399         WARN_ON(is_error_page(page));
1400
1401         kvm_release_pfn_dirty(page_to_pfn(page));
1402 }
1403 EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
1404
1405 void kvm_release_pfn_dirty(pfn_t pfn)
1406 {
1407         kvm_set_pfn_dirty(pfn);
1408         kvm_release_pfn_clean(pfn);
1409 }
1410 EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
1411
1412 void kvm_set_page_dirty(struct page *page)
1413 {
1414         kvm_set_pfn_dirty(page_to_pfn(page));
1415 }
1416 EXPORT_SYMBOL_GPL(kvm_set_page_dirty);
1417
1418 void kvm_set_pfn_dirty(pfn_t pfn)
1419 {
1420         if (!kvm_is_mmio_pfn(pfn)) {
1421                 struct page *page = pfn_to_page(pfn);
1422                 if (!PageReserved(page))
1423                         SetPageDirty(page);
1424         }
1425 }
1426 EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
1427
1428 void kvm_set_pfn_accessed(pfn_t pfn)
1429 {
1430         if (!kvm_is_mmio_pfn(pfn))
1431                 mark_page_accessed(pfn_to_page(pfn));
1432 }
1433 EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
1434
1435 void kvm_get_pfn(pfn_t pfn)
1436 {
1437         if (!kvm_is_mmio_pfn(pfn))
1438                 get_page(pfn_to_page(pfn));
1439 }
1440 EXPORT_SYMBOL_GPL(kvm_get_pfn);
1441
1442 static int next_segment(unsigned long len, int offset)
1443 {
1444         if (len > PAGE_SIZE - offset)
1445                 return PAGE_SIZE - offset;
1446         else
1447                 return len;
1448 }
1449
1450 int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
1451                         int len)
1452 {
1453         int r;
1454         unsigned long addr;
1455
1456         addr = gfn_to_hva_read(kvm, gfn);
1457         if (kvm_is_error_hva(addr))
1458                 return -EFAULT;
1459         r = kvm_read_hva(data, (void __user *)addr + offset, len);
1460         if (r)
1461                 return -EFAULT;
1462         return 0;
1463 }
1464 EXPORT_SYMBOL_GPL(kvm_read_guest_page);
1465
1466 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
1467 {
1468         gfn_t gfn = gpa >> PAGE_SHIFT;
1469         int seg;
1470         int offset = offset_in_page(gpa);
1471         int ret;
1472
1473         while ((seg = next_segment(len, offset)) != 0) {
1474                 ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
1475                 if (ret < 0)
1476                         return ret;
1477                 offset = 0;
1478                 len -= seg;
1479                 data += seg;
1480                 ++gfn;
1481         }
1482         return 0;
1483 }
1484 EXPORT_SYMBOL_GPL(kvm_read_guest);
1485
1486 int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
1487                           unsigned long len)
1488 {
1489         int r;
1490         unsigned long addr;
1491         gfn_t gfn = gpa >> PAGE_SHIFT;
1492         int offset = offset_in_page(gpa);
1493
1494         addr = gfn_to_hva_read(kvm, gfn);
1495         if (kvm_is_error_hva(addr))
1496                 return -EFAULT;
1497         pagefault_disable();
1498         r = kvm_read_hva_atomic(data, (void __user *)addr + offset, len);
1499         pagefault_enable();
1500         if (r)
1501                 return -EFAULT;
1502         return 0;
1503 }
1504 EXPORT_SYMBOL(kvm_read_guest_atomic);
1505
1506 int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
1507                          int offset, int len)
1508 {
1509         int r;
1510         unsigned long addr;
1511
1512         addr = gfn_to_hva(kvm, gfn);
1513         if (kvm_is_error_hva(addr))
1514                 return -EFAULT;
1515         r = __copy_to_user((void __user *)addr + offset, data, len);
1516         if (r)
1517                 return -EFAULT;
1518         mark_page_dirty(kvm, gfn);
1519         return 0;
1520 }
1521 EXPORT_SYMBOL_GPL(kvm_write_guest_page);
1522
1523 int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
1524                     unsigned long len)
1525 {
1526         gfn_t gfn = gpa >> PAGE_SHIFT;
1527         int seg;
1528         int offset = offset_in_page(gpa);
1529         int ret;
1530
1531         while ((seg = next_segment(len, offset)) != 0) {
1532                 ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
1533                 if (ret < 0)
1534                         return ret;
1535                 offset = 0;
1536                 len -= seg;
1537                 data += seg;
1538                 ++gfn;
1539         }
1540         return 0;
1541 }
1542
1543 int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1544                               gpa_t gpa, unsigned long len)
1545 {
1546         struct kvm_memslots *slots = kvm_memslots(kvm);
1547         int offset = offset_in_page(gpa);
1548         gfn_t start_gfn = gpa >> PAGE_SHIFT;
1549         gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT;
1550         gfn_t nr_pages_needed = end_gfn - start_gfn + 1;
1551         gfn_t nr_pages_avail;
1552
1553         ghc->gpa = gpa;
1554         ghc->generation = slots->generation;
1555         ghc->len = len;
1556         ghc->memslot = gfn_to_memslot(kvm, start_gfn);
1557         ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, &nr_pages_avail);
1558         if (!kvm_is_error_hva(ghc->hva) && nr_pages_avail >= nr_pages_needed) {
1559                 ghc->hva += offset;
1560         } else {
1561                 /*
1562                  * If the requested region crosses two memslots, we still
1563                  * verify that the entire region is valid here.
1564                  */
1565                 while (start_gfn <= end_gfn) {
1566                         ghc->memslot = gfn_to_memslot(kvm, start_gfn);
1567                         ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn,
1568                                                    &nr_pages_avail);
1569                         if (kvm_is_error_hva(ghc->hva))
1570                                 return -EFAULT;
1571                         start_gfn += nr_pages_avail;
1572                 }
1573                 /* Use the slow path for cross page reads and writes. */
1574                 ghc->memslot = NULL;
1575         }
1576         return 0;
1577 }
1578 EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
1579
1580 int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1581                            void *data, unsigned long len)
1582 {
1583         struct kvm_memslots *slots = kvm_memslots(kvm);
1584         int r;
1585
1586         BUG_ON(len > ghc->len);
1587
1588         if (slots->generation != ghc->generation)
1589                 kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa, ghc->len);
1590
1591         if (unlikely(!ghc->memslot))
1592                 return kvm_write_guest(kvm, ghc->gpa, data, len);
1593
1594         if (kvm_is_error_hva(ghc->hva))
1595                 return -EFAULT;
1596
1597         r = __copy_to_user((void __user *)ghc->hva, data, len);
1598         if (r)
1599                 return -EFAULT;
1600         mark_page_dirty_in_slot(kvm, ghc->memslot, ghc->gpa >> PAGE_SHIFT);
1601
1602         return 0;
1603 }
1604 EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
1605
1606 int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1607                            void *data, unsigned long len)
1608 {
1609         struct kvm_memslots *slots = kvm_memslots(kvm);
1610         int r;
1611
1612         BUG_ON(len > ghc->len);
1613
1614         if (slots->generation != ghc->generation)
1615                 kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa, ghc->len);
1616
1617         if (unlikely(!ghc->memslot))
1618                 return kvm_read_guest(kvm, ghc->gpa, data, len);
1619
1620         if (kvm_is_error_hva(ghc->hva))
1621                 return -EFAULT;
1622
1623         r = __copy_from_user(data, (void __user *)ghc->hva, len);
1624         if (r)
1625                 return -EFAULT;
1626
1627         return 0;
1628 }
1629 EXPORT_SYMBOL_GPL(kvm_read_guest_cached);
1630
1631 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
1632 {
1633         return kvm_write_guest_page(kvm, gfn, (const void *) empty_zero_page,
1634                                     offset, len);
1635 }
1636 EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
1637
1638 int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
1639 {
1640         gfn_t gfn = gpa >> PAGE_SHIFT;
1641         int seg;
1642         int offset = offset_in_page(gpa);
1643         int ret;
1644
1645         while ((seg = next_segment(len, offset)) != 0) {
1646                 ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
1647                 if (ret < 0)
1648                         return ret;
1649                 offset = 0;
1650                 len -= seg;
1651                 ++gfn;
1652         }
1653         return 0;
1654 }
1655 EXPORT_SYMBOL_GPL(kvm_clear_guest);
1656
1657 void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot,
1658                              gfn_t gfn)
1659 {
1660         if (memslot && memslot->dirty_bitmap) {
1661                 unsigned long rel_gfn = gfn - memslot->base_gfn;
1662
1663                 set_bit_le(rel_gfn, memslot->dirty_bitmap);
1664         }
1665 }
1666
1667 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
1668 {
1669         struct kvm_memory_slot *memslot;
1670
1671         memslot = gfn_to_memslot(kvm, gfn);
1672         mark_page_dirty_in_slot(kvm, memslot, gfn);
1673 }
1674
1675 /*
1676  * The vCPU has executed a HLT instruction with in-kernel mode enabled.
1677  */
1678 void kvm_vcpu_block(struct kvm_vcpu *vcpu)
1679 {
1680         DEFINE_WAIT(wait);
1681
1682         for (;;) {
1683                 prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
1684
1685                 if (kvm_arch_vcpu_runnable(vcpu)) {
1686                         kvm_make_request(KVM_REQ_UNHALT, vcpu);
1687                         break;
1688                 }
1689                 if (kvm_cpu_has_pending_timer(vcpu))
1690                         break;
1691                 if (signal_pending(current))
1692                         break;
1693
1694                 schedule();
1695         }
1696
1697         finish_wait(&vcpu->wq, &wait);
1698 }
1699
1700 #ifndef CONFIG_S390
1701 /*
1702  * Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode.
1703  */
1704 void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
1705 {
1706         int me;
1707         int cpu = vcpu->cpu;
1708         wait_queue_head_t *wqp;
1709
1710         wqp = kvm_arch_vcpu_wq(vcpu);
1711         if (waitqueue_active(wqp)) {
1712                 wake_up_interruptible(wqp);
1713                 ++vcpu->stat.halt_wakeup;
1714         }
1715
1716         me = get_cpu();
1717         if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu))
1718                 if (kvm_arch_vcpu_should_kick(vcpu))
1719                         smp_send_reschedule(cpu);
1720         put_cpu();
1721 }
1722 #endif /* !CONFIG_S390 */
1723
1724 void kvm_resched(struct kvm_vcpu *vcpu)
1725 {
1726         if (!need_resched())
1727                 return;
1728         cond_resched();
1729 }
1730 EXPORT_SYMBOL_GPL(kvm_resched);
1731
1732 bool kvm_vcpu_yield_to(struct kvm_vcpu *target)
1733 {
1734         struct pid *pid;
1735         struct task_struct *task = NULL;
1736         bool ret = false;
1737
1738         rcu_read_lock();
1739         pid = rcu_dereference(target->pid);
1740         if (pid)
1741                 task = get_pid_task(target->pid, PIDTYPE_PID);
1742         rcu_read_unlock();
1743         if (!task)
1744                 return ret;
1745         if (task->flags & PF_VCPU) {
1746                 put_task_struct(task);
1747                 return ret;
1748         }
1749         ret = yield_to(task, 1);
1750         put_task_struct(task);
1751
1752         return ret;
1753 }
1754 EXPORT_SYMBOL_GPL(kvm_vcpu_yield_to);
1755
1756 #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
1757 /*
1758  * Helper that checks whether a VCPU is eligible for directed yield.
1759  * Most eligible candidate to yield is decided by following heuristics:
1760  *
1761  *  (a) VCPU which has not done pl-exit or cpu relax intercepted recently
1762  *  (preempted lock holder), indicated by @in_spin_loop.
1763  *  Set at the beiginning and cleared at the end of interception/PLE handler.
1764  *
1765  *  (b) VCPU which has done pl-exit/ cpu relax intercepted but did not get
1766  *  chance last time (mostly it has become eligible now since we have probably
1767  *  yielded to lockholder in last iteration. This is done by toggling
1768  *  @dy_eligible each time a VCPU checked for eligibility.)
1769  *
1770  *  Yielding to a recently pl-exited/cpu relax intercepted VCPU before yielding
1771  *  to preempted lock-holder could result in wrong VCPU selection and CPU
1772  *  burning. Giving priority for a potential lock-holder increases lock
1773  *  progress.
1774  *
1775  *  Since algorithm is based on heuristics, accessing another VCPU data without
1776  *  locking does not harm. It may result in trying to yield to  same VCPU, fail
1777  *  and continue with next VCPU and so on.
1778  */
1779 bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu)
1780 {
1781         bool eligible;
1782
1783         eligible = !vcpu->spin_loop.in_spin_loop ||
1784                         (vcpu->spin_loop.in_spin_loop &&
1785                          vcpu->spin_loop.dy_eligible);
1786
1787         if (vcpu->spin_loop.in_spin_loop)
1788                 kvm_vcpu_set_dy_eligible(vcpu, !vcpu->spin_loop.dy_eligible);
1789
1790         return eligible;
1791 }
1792 #endif
1793
1794 void kvm_vcpu_on_spin(struct kvm_vcpu *me)
1795 {
1796         struct kvm *kvm = me->kvm;
1797         struct kvm_vcpu *vcpu;
1798         int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
1799         int yielded = 0;
1800         int try = 3;
1801         int pass;
1802         int i;
1803
1804         kvm_vcpu_set_in_spin_loop(me, true);
1805         /*
1806          * We boost the priority of a VCPU that is runnable but not
1807          * currently running, because it got preempted by something
1808          * else and called schedule in __vcpu_run.  Hopefully that
1809          * VCPU is holding the lock that we need and will release it.
1810          * We approximate round-robin by starting at the last boosted VCPU.
1811          */
1812         for (pass = 0; pass < 2 && !yielded && try; pass++) {
1813                 kvm_for_each_vcpu(i, vcpu, kvm) {
1814                         if (!pass && i <= last_boosted_vcpu) {
1815                                 i = last_boosted_vcpu;
1816                                 continue;
1817                         } else if (pass && i > last_boosted_vcpu)
1818                                 break;
1819                         if (vcpu == me)
1820                                 continue;
1821                         if (waitqueue_active(&vcpu->wq))
1822                                 continue;
1823                         if (!kvm_vcpu_eligible_for_directed_yield(vcpu))
1824                                 continue;
1825
1826                         yielded = kvm_vcpu_yield_to(vcpu);
1827                         if (yielded > 0) {
1828                                 kvm->last_boosted_vcpu = i;
1829                                 break;
1830                         } else if (yielded < 0) {
1831                                 try--;
1832                                 if (!try)
1833                                         break;
1834                         }
1835                 }
1836         }
1837         kvm_vcpu_set_in_spin_loop(me, false);
1838
1839         /* Ensure vcpu is not eligible during next spinloop */
1840         kvm_vcpu_set_dy_eligible(me, false);
1841 }
1842 EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
1843
1844 static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1845 {
1846         struct kvm_vcpu *vcpu = vma->vm_file->private_data;
1847         struct page *page;
1848
1849         if (vmf->pgoff == 0)
1850                 page = virt_to_page(vcpu->run);
1851 #ifdef CONFIG_X86
1852         else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
1853                 page = virt_to_page(vcpu->arch.pio_data);
1854 #endif
1855 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1856         else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
1857                 page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
1858 #endif
1859         else
1860                 return kvm_arch_vcpu_fault(vcpu, vmf);
1861         get_page(page);
1862         vmf->page = page;
1863         return 0;
1864 }
1865
1866 static const struct vm_operations_struct kvm_vcpu_vm_ops = {
1867         .fault = kvm_vcpu_fault,
1868 };
1869
1870 static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
1871 {
1872         vma->vm_ops = &kvm_vcpu_vm_ops;
1873         return 0;
1874 }
1875
1876 static int kvm_vcpu_release(struct inode *inode, struct file *filp)
1877 {
1878         struct kvm_vcpu *vcpu = filp->private_data;
1879
1880         kvm_put_kvm(vcpu->kvm);
1881         return 0;
1882 }
1883
1884 static struct file_operations kvm_vcpu_fops = {
1885         .release        = kvm_vcpu_release,
1886         .unlocked_ioctl = kvm_vcpu_ioctl,
1887 #ifdef CONFIG_COMPAT
1888         .compat_ioctl   = kvm_vcpu_compat_ioctl,
1889 #endif
1890         .mmap           = kvm_vcpu_mmap,
1891         .llseek         = noop_llseek,
1892 };
1893
1894 /*
1895  * Allocates an inode for the vcpu.
1896  */
1897 static int create_vcpu_fd(struct kvm_vcpu *vcpu)
1898 {
1899         return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR);
1900 }
1901
1902 /*
1903  * Creates some virtual cpus.  Good luck creating more than one.
1904  */
1905 static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
1906 {
1907         int r;
1908         struct kvm_vcpu *vcpu, *v;
1909
1910         vcpu = kvm_arch_vcpu_create(kvm, id);
1911         if (IS_ERR(vcpu))
1912                 return PTR_ERR(vcpu);
1913
1914         preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
1915
1916         r = kvm_arch_vcpu_setup(vcpu);
1917         if (r)
1918                 goto vcpu_destroy;
1919
1920         mutex_lock(&kvm->lock);
1921         if (!kvm_vcpu_compatible(vcpu)) {
1922                 r = -EINVAL;
1923                 goto unlock_vcpu_destroy;
1924         }
1925         if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
1926                 r = -EINVAL;
1927                 goto unlock_vcpu_destroy;
1928         }
1929
1930         kvm_for_each_vcpu(r, v, kvm)
1931                 if (v->vcpu_id == id) {
1932                         r = -EEXIST;
1933                         goto unlock_vcpu_destroy;
1934                 }
1935
1936         BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
1937
1938         /* Now it's all set up, let userspace reach it */
1939         kvm_get_kvm(kvm);
1940         r = create_vcpu_fd(vcpu);
1941         if (r < 0) {
1942                 kvm_put_kvm(kvm);
1943                 goto unlock_vcpu_destroy;
1944         }
1945
1946         kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
1947         smp_wmb();
1948         atomic_inc(&kvm->online_vcpus);
1949
1950         mutex_unlock(&kvm->lock);
1951         kvm_arch_vcpu_postcreate(vcpu);
1952         return r;
1953
1954 unlock_vcpu_destroy:
1955         mutex_unlock(&kvm->lock);
1956 vcpu_destroy:
1957         kvm_arch_vcpu_destroy(vcpu);
1958         return r;
1959 }
1960
1961 static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
1962 {
1963         if (sigset) {
1964                 sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
1965                 vcpu->sigset_active = 1;
1966                 vcpu->sigset = *sigset;
1967         } else
1968                 vcpu->sigset_active = 0;
1969         return 0;
1970 }
1971
1972 static long kvm_vcpu_ioctl(struct file *filp,
1973                            unsigned int ioctl, unsigned long arg)
1974 {
1975         struct kvm_vcpu *vcpu = filp->private_data;
1976         void __user *argp = (void __user *)arg;
1977         int r;
1978         struct kvm_fpu *fpu = NULL;
1979         struct kvm_sregs *kvm_sregs = NULL;
1980
1981         if (vcpu->kvm->mm != current->mm)
1982                 return -EIO;
1983
1984 #if defined(CONFIG_S390) || defined(CONFIG_PPC) || defined(CONFIG_MIPS)
1985         /*
1986          * Special cases: vcpu ioctls that are asynchronous to vcpu execution,
1987          * so vcpu_load() would break it.
1988          */
1989         if (ioctl == KVM_S390_INTERRUPT || ioctl == KVM_INTERRUPT)
1990                 return kvm_arch_vcpu_ioctl(filp, ioctl, arg);
1991 #endif
1992
1993
1994         r = vcpu_load(vcpu);
1995         if (r)
1996                 return r;
1997         switch (ioctl) {
1998         case KVM_RUN:
1999                 r = -EINVAL;
2000                 if (arg)
2001                         goto out;
2002                 r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
2003                 trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
2004                 break;
2005         case KVM_GET_REGS: {
2006                 struct kvm_regs *kvm_regs;
2007
2008                 r = -ENOMEM;
2009                 kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
2010                 if (!kvm_regs)
2011                         goto out;
2012                 r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
2013                 if (r)
2014                         goto out_free1;
2015                 r = -EFAULT;
2016                 if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
2017                         goto out_free1;
2018                 r = 0;
2019 out_free1:
2020                 kfree(kvm_regs);
2021                 break;
2022         }
2023         case KVM_SET_REGS: {
2024                 struct kvm_regs *kvm_regs;
2025
2026                 r = -ENOMEM;
2027                 kvm_regs = memdup_user(argp, sizeof(*kvm_regs));
2028                 if (IS_ERR(kvm_regs)) {
2029                         r = PTR_ERR(kvm_regs);
2030                         goto out;
2031                 }
2032                 r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
2033                 kfree(kvm_regs);
2034                 break;
2035         }
2036         case KVM_GET_SREGS: {
2037                 kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
2038                 r = -ENOMEM;
2039                 if (!kvm_sregs)
2040                         goto out;
2041                 r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs);
2042                 if (r)
2043                         goto out;
2044                 r = -EFAULT;
2045                 if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs)))
2046                         goto out;
2047                 r = 0;
2048                 break;
2049         }
2050         case KVM_SET_SREGS: {
2051                 kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs));
2052                 if (IS_ERR(kvm_sregs)) {
2053                         r = PTR_ERR(kvm_sregs);
2054                         kvm_sregs = NULL;
2055                         goto out;
2056                 }
2057                 r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs);
2058                 break;
2059         }
2060         case KVM_GET_MP_STATE: {
2061                 struct kvm_mp_state mp_state;
2062
2063                 r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
2064                 if (r)
2065                         goto out;
2066                 r = -EFAULT;
2067                 if (copy_to_user(argp, &mp_state, sizeof mp_state))
2068                         goto out;
2069                 r = 0;
2070                 break;
2071         }
2072         case KVM_SET_MP_STATE: {
2073                 struct kvm_mp_state mp_state;
2074
2075                 r = -EFAULT;
2076                 if (copy_from_user(&mp_state, argp, sizeof mp_state))
2077                         goto out;
2078                 r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
2079                 break;
2080         }
2081         case KVM_TRANSLATE: {
2082                 struct kvm_translation tr;
2083
2084                 r = -EFAULT;
2085                 if (copy_from_user(&tr, argp, sizeof tr))
2086                         goto out;
2087                 r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
2088                 if (r)
2089                         goto out;
2090                 r = -EFAULT;
2091                 if (copy_to_user(argp, &tr, sizeof tr))
2092                         goto out;
2093                 r = 0;
2094                 break;
2095         }
2096         case KVM_SET_GUEST_DEBUG: {
2097                 struct kvm_guest_debug dbg;
2098
2099                 r = -EFAULT;
2100                 if (copy_from_user(&dbg, argp, sizeof dbg))
2101                         goto out;
2102                 r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg);
2103                 break;
2104         }
2105         case KVM_SET_SIGNAL_MASK: {
2106                 struct kvm_signal_mask __user *sigmask_arg = argp;
2107                 struct kvm_signal_mask kvm_sigmask;
2108                 sigset_t sigset, *p;
2109
2110                 p = NULL;
2111                 if (argp) {
2112                         r = -EFAULT;
2113                         if (copy_from_user(&kvm_sigmask, argp,
2114                                            sizeof kvm_sigmask))
2115                                 goto out;
2116                         r = -EINVAL;
2117                         if (kvm_sigmask.len != sizeof sigset)
2118                                 goto out;
2119                         r = -EFAULT;
2120                         if (copy_from_user(&sigset, sigmask_arg->sigset,
2121                                            sizeof sigset))
2122                                 goto out;
2123                         p = &sigset;
2124                 }
2125                 r = kvm_vcpu_ioctl_set_sigmask(vcpu, p);
2126                 break;
2127         }
2128         case KVM_GET_FPU: {
2129                 fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
2130                 r = -ENOMEM;
2131                 if (!fpu)
2132                         goto out;
2133                 r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
2134                 if (r)
2135                         goto out;
2136                 r = -EFAULT;
2137                 if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu)))
2138                         goto out;
2139                 r = 0;
2140                 break;
2141         }
2142         case KVM_SET_FPU: {
2143                 fpu = memdup_user(argp, sizeof(*fpu));
2144                 if (IS_ERR(fpu)) {
2145                         r = PTR_ERR(fpu);
2146                         fpu = NULL;
2147                         goto out;
2148                 }
2149                 r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
2150                 break;
2151         }
2152         default:
2153                 r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
2154         }
2155 out:
2156         vcpu_put(vcpu);
2157         kfree(fpu);
2158         kfree(kvm_sregs);
2159         return r;
2160 }
2161
2162 #ifdef CONFIG_COMPAT
2163 static long kvm_vcpu_compat_ioctl(struct file *filp,
2164                                   unsigned int ioctl, unsigned long arg)
2165 {
2166         struct kvm_vcpu *vcpu = filp->private_data;
2167         void __user *argp = compat_ptr(arg);
2168         int r;
2169
2170         if (vcpu->kvm->mm != current->mm)
2171                 return -EIO;
2172
2173         switch (ioctl) {
2174         case KVM_SET_SIGNAL_MASK: {
2175                 struct kvm_signal_mask __user *sigmask_arg = argp;
2176                 struct kvm_signal_mask kvm_sigmask;
2177                 compat_sigset_t csigset;
2178                 sigset_t sigset;
2179
2180                 if (argp) {
2181                         r = -EFAULT;
2182                         if (copy_from_user(&kvm_sigmask, argp,
2183                                            sizeof kvm_sigmask))
2184                                 goto out;
2185                         r = -EINVAL;
2186                         if (kvm_sigmask.len != sizeof csigset)
2187                                 goto out;
2188                         r = -EFAULT;
2189                         if (copy_from_user(&csigset, sigmask_arg->sigset,
2190                                            sizeof csigset))
2191                                 goto out;
2192                         sigset_from_compat(&sigset, &csigset);
2193                         r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
2194                 } else
2195                         r = kvm_vcpu_ioctl_set_sigmask(vcpu, NULL);
2196                 break;
2197         }
2198         default:
2199                 r = kvm_vcpu_ioctl(filp, ioctl, arg);
2200         }
2201
2202 out:
2203         return r;
2204 }
2205 #endif
2206
2207 static long kvm_vm_ioctl(struct file *filp,
2208                            unsigned int ioctl, unsigned long arg)
2209 {
2210         struct kvm *kvm = filp->private_data;
2211         void __user *argp = (void __user *)arg;
2212         int r;
2213
2214         if (kvm->mm != current->mm)
2215                 return -EIO;
2216         switch (ioctl) {
2217         case KVM_CREATE_VCPU:
2218                 r = kvm_vm_ioctl_create_vcpu(kvm, arg);
2219                 break;
2220         case KVM_SET_USER_MEMORY_REGION: {
2221                 struct kvm_userspace_memory_region kvm_userspace_mem;
2222
2223                 r = -EFAULT;
2224                 if (copy_from_user(&kvm_userspace_mem, argp,
2225                                                 sizeof kvm_userspace_mem))
2226                         goto out;
2227
2228                 r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem, true);
2229                 break;
2230         }
2231         case KVM_GET_DIRTY_LOG: {
2232                 struct kvm_dirty_log log;
2233
2234                 r = -EFAULT;
2235                 if (copy_from_user(&log, argp, sizeof log))
2236                         goto out;
2237                 r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
2238                 break;
2239         }
2240 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2241         case KVM_REGISTER_COALESCED_MMIO: {
2242                 struct kvm_coalesced_mmio_zone zone;
2243                 r = -EFAULT;
2244                 if (copy_from_user(&zone, argp, sizeof zone))
2245                         goto out;
2246                 r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
2247                 break;
2248         }
2249         case KVM_UNREGISTER_COALESCED_MMIO: {
2250                 struct kvm_coalesced_mmio_zone zone;
2251                 r = -EFAULT;
2252                 if (copy_from_user(&zone, argp, sizeof zone))
2253                         goto out;
2254                 r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
2255                 break;
2256         }
2257 #endif
2258         case KVM_IRQFD: {
2259                 struct kvm_irqfd data;
2260
2261                 r = -EFAULT;
2262                 if (copy_from_user(&data, argp, sizeof data))
2263                         goto out;
2264                 r = kvm_irqfd(kvm, &data);
2265                 break;
2266         }
2267         case KVM_IOEVENTFD: {
2268                 struct kvm_ioeventfd data;
2269
2270                 r = -EFAULT;
2271                 if (copy_from_user(&data, argp, sizeof data))
2272                         goto out;
2273                 r = kvm_ioeventfd(kvm, &data);
2274                 break;
2275         }
2276 #ifdef CONFIG_KVM_APIC_ARCHITECTURE
2277         case KVM_SET_BOOT_CPU_ID:
2278                 r = 0;
2279                 mutex_lock(&kvm->lock);
2280                 if (atomic_read(&kvm->online_vcpus) != 0)
2281                         r = -EBUSY;
2282                 else
2283                         kvm->bsp_vcpu_id = arg;
2284                 mutex_unlock(&kvm->lock);
2285                 break;
2286 #endif
2287 #ifdef CONFIG_HAVE_KVM_MSI
2288         case KVM_SIGNAL_MSI: {
2289                 struct kvm_msi msi;
2290
2291                 r = -EFAULT;
2292                 if (copy_from_user(&msi, argp, sizeof msi))
2293                         goto out;
2294                 r = kvm_send_userspace_msi(kvm, &msi);
2295                 break;
2296         }
2297 #endif
2298 #ifdef __KVM_HAVE_IRQ_LINE
2299         case KVM_IRQ_LINE_STATUS:
2300         case KVM_IRQ_LINE: {
2301                 struct kvm_irq_level irq_event;
2302
2303                 r = -EFAULT;
2304                 if (copy_from_user(&irq_event, argp, sizeof irq_event))
2305                         goto out;
2306
2307                 r = kvm_vm_ioctl_irq_line(kvm, &irq_event);
2308                 if (r)
2309                         goto out;
2310
2311                 r = -EFAULT;
2312                 if (ioctl == KVM_IRQ_LINE_STATUS) {
2313                         if (copy_to_user(argp, &irq_event, sizeof irq_event))
2314                                 goto out;
2315                 }
2316
2317                 r = 0;
2318                 break;
2319         }
2320 #endif
2321         default:
2322                 r = kvm_arch_vm_ioctl(filp, ioctl, arg);
2323                 if (r == -ENOTTY)
2324                         r = kvm_vm_ioctl_assigned_device(kvm, ioctl, arg);
2325         }
2326 out:
2327         return r;
2328 }
2329
2330 #ifdef CONFIG_COMPAT
2331 struct compat_kvm_dirty_log {
2332         __u32 slot;
2333         __u32 padding1;
2334         union {
2335                 compat_uptr_t dirty_bitmap; /* one bit per page */
2336                 __u64 padding2;
2337         };
2338 };
2339
2340 static long kvm_vm_compat_ioctl(struct file *filp,
2341                            unsigned int ioctl, unsigned long arg)
2342 {
2343         struct kvm *kvm = filp->private_data;
2344         int r;
2345
2346         if (kvm->mm != current->mm)
2347                 return -EIO;
2348         switch (ioctl) {
2349         case KVM_GET_DIRTY_LOG: {
2350                 struct compat_kvm_dirty_log compat_log;
2351                 struct kvm_dirty_log log;
2352
2353                 r = -EFAULT;
2354                 if (copy_from_user(&compat_log, (void __user *)arg,
2355                                    sizeof(compat_log)))
2356                         goto out;
2357                 log.slot         = compat_log.slot;
2358                 log.padding1     = compat_log.padding1;
2359                 log.padding2     = compat_log.padding2;
2360                 log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
2361
2362                 r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
2363                 break;
2364         }
2365         default:
2366                 r = kvm_vm_ioctl(filp, ioctl, arg);
2367         }
2368
2369 out:
2370         return r;
2371 }
2372 #endif
2373
2374 static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
2375 {
2376         struct page *page[1];
2377         unsigned long addr;
2378         int npages;
2379         gfn_t gfn = vmf->pgoff;
2380         struct kvm *kvm = vma->vm_file->private_data;
2381
2382         addr = gfn_to_hva(kvm, gfn);
2383         if (kvm_is_error_hva(addr))
2384                 return VM_FAULT_SIGBUS;
2385
2386         npages = get_user_pages(current, current->mm, addr, 1, 1, 0, page,
2387                                 NULL);
2388         if (unlikely(npages != 1))
2389                 return VM_FAULT_SIGBUS;
2390
2391         vmf->page = page[0];
2392         return 0;
2393 }
2394
2395 static const struct vm_operations_struct kvm_vm_vm_ops = {
2396         .fault = kvm_vm_fault,
2397 };
2398
2399 static int kvm_vm_mmap(struct file *file, struct vm_area_struct *vma)
2400 {
2401         vma->vm_ops = &kvm_vm_vm_ops;
2402         return 0;
2403 }
2404
2405 static struct file_operations kvm_vm_fops = {
2406         .release        = kvm_vm_release,
2407         .unlocked_ioctl = kvm_vm_ioctl,
2408 #ifdef CONFIG_COMPAT
2409         .compat_ioctl   = kvm_vm_compat_ioctl,
2410 #endif
2411         .mmap           = kvm_vm_mmap,
2412         .llseek         = noop_llseek,
2413 };
2414
2415 static int kvm_dev_ioctl_create_vm(unsigned long type)
2416 {
2417         int r;
2418         struct kvm *kvm;
2419
2420         kvm = kvm_create_vm(type);
2421         if (IS_ERR(kvm))
2422                 return PTR_ERR(kvm);
2423 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2424         r = kvm_coalesced_mmio_init(kvm);
2425         if (r < 0) {
2426                 kvm_put_kvm(kvm);
2427                 return r;
2428         }
2429 #endif
2430         r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
2431         if (r < 0)
2432                 kvm_put_kvm(kvm);
2433
2434         return r;
2435 }
2436
2437 static long kvm_dev_ioctl_check_extension_generic(long arg)
2438 {
2439         switch (arg) {
2440         case KVM_CAP_USER_MEMORY:
2441         case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
2442         case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
2443 #ifdef CONFIG_KVM_APIC_ARCHITECTURE
2444         case KVM_CAP_SET_BOOT_CPU_ID:
2445 #endif
2446         case KVM_CAP_INTERNAL_ERROR_DATA:
2447 #ifdef CONFIG_HAVE_KVM_MSI
2448         case KVM_CAP_SIGNAL_MSI:
2449 #endif
2450                 return 1;
2451 #ifdef KVM_CAP_IRQ_ROUTING
2452         case KVM_CAP_IRQ_ROUTING:
2453                 return KVM_MAX_IRQ_ROUTES;
2454 #endif
2455         default:
2456                 break;
2457         }
2458         return kvm_dev_ioctl_check_extension(arg);
2459 }
2460
2461 static long kvm_dev_ioctl(struct file *filp,
2462                           unsigned int ioctl, unsigned long arg)
2463 {
2464         long r = -EINVAL;
2465
2466         switch (ioctl) {
2467         case KVM_GET_API_VERSION:
2468                 r = -EINVAL;
2469                 if (arg)
2470                         goto out;
2471                 r = KVM_API_VERSION;
2472                 break;
2473         case KVM_CREATE_VM:
2474                 r = kvm_dev_ioctl_create_vm(arg);
2475                 break;
2476         case KVM_CHECK_EXTENSION:
2477                 r = kvm_dev_ioctl_check_extension_generic(arg);
2478                 break;
2479         case KVM_GET_VCPU_MMAP_SIZE:
2480                 r = -EINVAL;
2481                 if (arg)
2482                         goto out;
2483                 r = PAGE_SIZE;     /* struct kvm_run */
2484 #ifdef CONFIG_X86
2485                 r += PAGE_SIZE;    /* pio data page */
2486 #endif
2487 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2488                 r += PAGE_SIZE;    /* coalesced mmio ring page */
2489 #endif
2490                 break;
2491         case KVM_TRACE_ENABLE:
2492         case KVM_TRACE_PAUSE:
2493         case KVM_TRACE_DISABLE:
2494                 r = -EOPNOTSUPP;
2495                 break;
2496         default:
2497                 return kvm_arch_dev_ioctl(filp, ioctl, arg);
2498         }
2499 out:
2500         return r;
2501 }
2502
2503 static struct file_operations kvm_chardev_ops = {
2504         .unlocked_ioctl = kvm_dev_ioctl,
2505         .compat_ioctl   = kvm_dev_ioctl,
2506         .llseek         = noop_llseek,
2507 };
2508
2509 static struct miscdevice kvm_dev = {
2510         KVM_MINOR,
2511         "kvm",
2512         &kvm_chardev_ops,
2513 };
2514
2515 static void hardware_enable_nolock(void *junk)
2516 {
2517         int cpu = raw_smp_processor_id();
2518         int r;
2519
2520         if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
2521                 return;
2522
2523         cpumask_set_cpu(cpu, cpus_hardware_enabled);
2524
2525         r = kvm_arch_hardware_enable(NULL);
2526
2527         if (r) {
2528                 cpumask_clear_cpu(cpu, cpus_hardware_enabled);
2529                 atomic_inc(&hardware_enable_failed);
2530                 printk(KERN_INFO "kvm: enabling virtualization on "
2531                                  "CPU%d failed\n", cpu);
2532         }
2533 }
2534
2535 static void hardware_enable(void *junk)
2536 {
2537         raw_spin_lock(&kvm_lock);
2538         hardware_enable_nolock(junk);
2539         raw_spin_unlock(&kvm_lock);
2540 }
2541
2542 static void hardware_disable_nolock(void *junk)
2543 {
2544         int cpu = raw_smp_processor_id();
2545
2546         if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
2547                 return;
2548         cpumask_clear_cpu(cpu, cpus_hardware_enabled);
2549         kvm_arch_hardware_disable(NULL);
2550 }
2551
2552 static void hardware_disable(void *junk)
2553 {
2554         raw_spin_lock(&kvm_lock);
2555         hardware_disable_nolock(junk);
2556         raw_spin_unlock(&kvm_lock);
2557 }
2558
2559 static void hardware_disable_all_nolock(void)
2560 {
2561         BUG_ON(!kvm_usage_count);
2562
2563         kvm_usage_count--;
2564         if (!kvm_usage_count)
2565                 on_each_cpu(hardware_disable_nolock, NULL, 1);
2566 }
2567
2568 static void hardware_disable_all(void)
2569 {
2570         raw_spin_lock(&kvm_lock);
2571         hardware_disable_all_nolock();
2572         raw_spin_unlock(&kvm_lock);
2573 }
2574
2575 static int hardware_enable_all(void)
2576 {
2577         int r = 0;
2578
2579         raw_spin_lock(&kvm_lock);
2580
2581         kvm_usage_count++;
2582         if (kvm_usage_count == 1) {
2583                 atomic_set(&hardware_enable_failed, 0);
2584                 on_each_cpu(hardware_enable_nolock, NULL, 1);
2585
2586                 if (atomic_read(&hardware_enable_failed)) {
2587                         hardware_disable_all_nolock();
2588                         r = -EBUSY;
2589                 }
2590         }
2591
2592         raw_spin_unlock(&kvm_lock);
2593
2594         return r;
2595 }
2596
2597 static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
2598                            void *v)
2599 {
2600         int cpu = (long)v;
2601
2602         if (!kvm_usage_count)
2603                 return NOTIFY_OK;
2604
2605         val &= ~CPU_TASKS_FROZEN;
2606         switch (val) {
2607         case CPU_DYING:
2608                 printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
2609                        cpu);
2610                 hardware_disable(NULL);
2611                 break;
2612         case CPU_STARTING:
2613                 printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
2614                        cpu);
2615                 hardware_enable(NULL);
2616                 break;
2617         }
2618         return NOTIFY_OK;
2619 }
2620
2621
2622 asmlinkage void kvm_spurious_fault(void)
2623 {
2624         /* Fault while not rebooting.  We want the trace. */
2625         BUG();
2626 }
2627 EXPORT_SYMBOL_GPL(kvm_spurious_fault);
2628
2629 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
2630                       void *v)
2631 {
2632         /*
2633          * Some (well, at least mine) BIOSes hang on reboot if
2634          * in vmx root mode.
2635          *
2636          * And Intel TXT required VMX off for all cpu when system shutdown.
2637          */
2638         printk(KERN_INFO "kvm: exiting hardware virtualization\n");
2639         kvm_rebooting = true;
2640         on_each_cpu(hardware_disable_nolock, NULL, 1);
2641         return NOTIFY_OK;
2642 }
2643
2644 static struct notifier_block kvm_reboot_notifier = {
2645         .notifier_call = kvm_reboot,
2646         .priority = 0,
2647 };
2648
2649 static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
2650 {
2651         int i;
2652
2653         for (i = 0; i < bus->dev_count; i++) {
2654                 struct kvm_io_device *pos = bus->range[i].dev;
2655
2656                 kvm_iodevice_destructor(pos);
2657         }
2658         kfree(bus);
2659 }
2660
2661 int kvm_io_bus_sort_cmp(const void *p1, const void *p2)
2662 {
2663         const struct kvm_io_range *r1 = p1;
2664         const struct kvm_io_range *r2 = p2;
2665
2666         if (r1->addr < r2->addr)
2667                 return -1;
2668         if (r1->addr + r1->len > r2->addr + r2->len)
2669                 return 1;
2670         return 0;
2671 }
2672
2673 int kvm_io_bus_insert_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev,
2674                           gpa_t addr, int len)
2675 {
2676         bus->range[bus->dev_count++] = (struct kvm_io_range) {
2677                 .addr = addr,
2678                 .len = len,
2679                 .dev = dev,
2680         };
2681
2682         sort(bus->range, bus->dev_count, sizeof(struct kvm_io_range),
2683                 kvm_io_bus_sort_cmp, NULL);
2684
2685         return 0;
2686 }
2687
2688 int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus,
2689                              gpa_t addr, int len)
2690 {
2691         struct kvm_io_range *range, key;
2692         int off;
2693
2694         key = (struct kvm_io_range) {
2695                 .addr = addr,
2696                 .len = len,
2697         };
2698
2699         range = bsearch(&key, bus->range, bus->dev_count,
2700                         sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp);
2701         if (range == NULL)
2702                 return -ENOENT;
2703
2704         off = range - bus->range;
2705
2706         while (off > 0 && kvm_io_bus_sort_cmp(&key, &bus->range[off-1]) == 0)
2707                 off--;
2708
2709         return off;
2710 }
2711
2712 /* kvm_io_bus_write - called under kvm->slots_lock */
2713 int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
2714                      int len, const void *val)
2715 {
2716         int idx;
2717         struct kvm_io_bus *bus;
2718         struct kvm_io_range range;
2719
2720         range = (struct kvm_io_range) {
2721                 .addr = addr,
2722                 .len = len,
2723         };
2724
2725         bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
2726         idx = kvm_io_bus_get_first_dev(bus, addr, len);
2727         if (idx < 0)
2728                 return -EOPNOTSUPP;
2729
2730         while (idx < bus->dev_count &&
2731                 kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) {
2732                 if (!kvm_iodevice_write(bus->range[idx].dev, addr, len, val))
2733                         return 0;
2734                 idx++;
2735         }
2736
2737         return -EOPNOTSUPP;
2738 }
2739
2740 /* kvm_io_bus_read - called under kvm->slots_lock */
2741 int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
2742                     int len, void *val)
2743 {
2744         int idx;
2745         struct kvm_io_bus *bus;
2746         struct kvm_io_range range;
2747
2748         range = (struct kvm_io_range) {
2749                 .addr = addr,
2750                 .len = len,
2751         };
2752
2753         bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
2754         idx = kvm_io_bus_get_first_dev(bus, addr, len);
2755         if (idx < 0)
2756                 return -EOPNOTSUPP;
2757
2758         while (idx < bus->dev_count &&
2759                 kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) {
2760                 if (!kvm_iodevice_read(bus->range[idx].dev, addr, len, val))
2761                         return 0;
2762                 idx++;
2763         }
2764
2765         return -EOPNOTSUPP;
2766 }
2767
2768 /* Caller must hold slots_lock. */
2769 int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
2770                             int len, struct kvm_io_device *dev)
2771 {
2772         struct kvm_io_bus *new_bus, *bus;
2773
2774         bus = kvm->buses[bus_idx];
2775         if (bus->dev_count > NR_IOBUS_DEVS - 1)
2776                 return -ENOSPC;
2777
2778         new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count + 1) *
2779                           sizeof(struct kvm_io_range)), GFP_KERNEL);
2780         if (!new_bus)
2781                 return -ENOMEM;
2782         memcpy(new_bus, bus, sizeof(*bus) + (bus->dev_count *
2783                sizeof(struct kvm_io_range)));
2784         kvm_io_bus_insert_dev(new_bus, dev, addr, len);
2785         rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
2786         synchronize_srcu_expedited(&kvm->srcu);
2787         kfree(bus);
2788
2789         return 0;
2790 }
2791
2792 /* Caller must hold slots_lock. */
2793 int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
2794                               struct kvm_io_device *dev)
2795 {
2796         int i, r;
2797         struct kvm_io_bus *new_bus, *bus;
2798
2799         bus = kvm->buses[bus_idx];
2800         r = -ENOENT;
2801         for (i = 0; i < bus->dev_count; i++)
2802                 if (bus->range[i].dev == dev) {
2803                         r = 0;
2804                         break;
2805                 }
2806
2807         if (r)
2808                 return r;
2809
2810         new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count - 1) *
2811                           sizeof(struct kvm_io_range)), GFP_KERNEL);
2812         if (!new_bus)
2813                 return -ENOMEM;
2814
2815         memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range));
2816         new_bus->dev_count--;
2817         memcpy(new_bus->range + i, bus->range + i + 1,
2818                (new_bus->dev_count - i) * sizeof(struct kvm_io_range));
2819
2820         rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
2821         synchronize_srcu_expedited(&kvm->srcu);
2822         kfree(bus);
2823         return r;
2824 }
2825
2826 static struct notifier_block kvm_cpu_notifier = {
2827         .notifier_call = kvm_cpu_hotplug,
2828 };
2829
2830 static int vm_stat_get(void *_offset, u64 *val)
2831 {
2832         unsigned offset = (long)_offset;
2833         struct kvm *kvm;
2834
2835         *val = 0;
2836         raw_spin_lock(&kvm_lock);
2837         list_for_each_entry(kvm, &vm_list, vm_list)
2838                 *val += *(u32 *)((void *)kvm + offset);
2839         raw_spin_unlock(&kvm_lock);
2840         return 0;
2841 }
2842
2843 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
2844
2845 static int vcpu_stat_get(void *_offset, u64 *val)
2846 {
2847         unsigned offset = (long)_offset;
2848         struct kvm *kvm;
2849         struct kvm_vcpu *vcpu;
2850         int i;
2851
2852         *val = 0;
2853         raw_spin_lock(&kvm_lock);
2854         list_for_each_entry(kvm, &vm_list, vm_list)
2855                 kvm_for_each_vcpu(i, vcpu, kvm)
2856                         *val += *(u32 *)((void *)vcpu + offset);
2857
2858         raw_spin_unlock(&kvm_lock);
2859         return 0;
2860 }
2861
2862 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
2863
2864 static const struct file_operations *stat_fops[] = {
2865         [KVM_STAT_VCPU] = &vcpu_stat_fops,
2866         [KVM_STAT_VM]   = &vm_stat_fops,
2867 };
2868
2869 static int kvm_init_debug(void)
2870 {
2871         int r = -EFAULT;
2872         struct kvm_stats_debugfs_item *p;
2873
2874         kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
2875         if (kvm_debugfs_dir == NULL)
2876                 goto out;
2877
2878         for (p = debugfs_entries; p->name; ++p) {
2879                 p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
2880                                                 (void *)(long)p->offset,
2881                                                 stat_fops[p->kind]);
2882                 if (p->dentry == NULL)
2883                         goto out_dir;
2884         }
2885
2886         return 0;
2887
2888 out_dir:
2889         debugfs_remove_recursive(kvm_debugfs_dir);
2890 out:
2891         return r;
2892 }
2893
2894 static void kvm_exit_debug(void)
2895 {
2896         struct kvm_stats_debugfs_item *p;
2897
2898         for (p = debugfs_entries; p->name; ++p)
2899                 debugfs_remove(p->dentry);
2900         debugfs_remove(kvm_debugfs_dir);
2901 }
2902
2903 static int kvm_suspend(void)
2904 {
2905         if (kvm_usage_count)
2906                 hardware_disable_nolock(NULL);
2907         return 0;
2908 }
2909
2910 static void kvm_resume(void)
2911 {
2912         if (kvm_usage_count) {
2913                 WARN_ON(raw_spin_is_locked(&kvm_lock));
2914                 hardware_enable_nolock(NULL);
2915         }
2916 }
2917
2918 static struct syscore_ops kvm_syscore_ops = {
2919         .suspend = kvm_suspend,
2920         .resume = kvm_resume,
2921 };
2922
2923 static inline
2924 struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
2925 {
2926         return container_of(pn, struct kvm_vcpu, preempt_notifier);
2927 }
2928
2929 static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
2930 {
2931         struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
2932
2933         kvm_arch_vcpu_load(vcpu, cpu);
2934 }
2935
2936 static void kvm_sched_out(struct preempt_notifier *pn,
2937                           struct task_struct *next)
2938 {
2939         struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
2940
2941         kvm_arch_vcpu_put(vcpu);
2942 }
2943
2944 int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
2945                   struct module *module)
2946 {
2947         int r;
2948         int cpu;
2949
2950         r = kvm_arch_init(opaque);
2951         if (r)
2952                 goto out_fail;
2953
2954         if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
2955                 r = -ENOMEM;
2956                 goto out_free_0;
2957         }
2958
2959         r = kvm_arch_hardware_setup();
2960         if (r < 0)
2961                 goto out_free_0a;
2962
2963         for_each_online_cpu(cpu) {
2964                 smp_call_function_single(cpu,
2965                                 kvm_arch_check_processor_compat,
2966                                 &r, 1);
2967                 if (r < 0)
2968                         goto out_free_1;
2969         }
2970
2971         r = register_cpu_notifier(&kvm_cpu_notifier);
2972         if (r)
2973                 goto out_free_2;
2974         register_reboot_notifier(&kvm_reboot_notifier);
2975
2976         /* A kmem cache lets us meet the alignment requirements of fx_save. */
2977         if (!vcpu_align)
2978                 vcpu_align = __alignof__(struct kvm_vcpu);
2979         kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size, vcpu_align,
2980                                            0, NULL);
2981         if (!kvm_vcpu_cache) {
2982                 r = -ENOMEM;
2983                 goto out_free_3;
2984         }
2985
2986         r = kvm_async_pf_init();
2987         if (r)
2988                 goto out_free;
2989
2990         kvm_chardev_ops.owner = module;
2991         kvm_vm_fops.owner = module;
2992         kvm_vcpu_fops.owner = module;
2993
2994         r = misc_register(&kvm_dev);
2995         if (r) {
2996                 printk(KERN_ERR "kvm: misc device register failed\n");
2997                 goto out_unreg;
2998         }
2999
3000         register_syscore_ops(&kvm_syscore_ops);
3001
3002         kvm_preempt_ops.sched_in = kvm_sched_in;
3003         kvm_preempt_ops.sched_out = kvm_sched_out;
3004
3005         r = kvm_init_debug();
3006         if (r) {
3007                 printk(KERN_ERR "kvm: create debugfs files failed\n");
3008                 goto out_undebugfs;
3009         }
3010
3011         return 0;
3012
3013 out_undebugfs:
3014         unregister_syscore_ops(&kvm_syscore_ops);
3015 out_unreg:
3016         kvm_async_pf_deinit();
3017 out_free:
3018         kmem_cache_destroy(kvm_vcpu_cache);
3019 out_free_3:
3020         unregister_reboot_notifier(&kvm_reboot_notifier);
3021         unregister_cpu_notifier(&kvm_cpu_notifier);
3022 out_free_2:
3023 out_free_1:
3024         kvm_arch_hardware_unsetup();
3025 out_free_0a:
3026         free_cpumask_var(cpus_hardware_enabled);
3027 out_free_0:
3028         kvm_arch_exit();
3029 out_fail:
3030         return r;
3031 }
3032 EXPORT_SYMBOL_GPL(kvm_init);
3033
3034 void kvm_exit(void)
3035 {
3036         kvm_exit_debug();
3037         misc_deregister(&kvm_dev);
3038         kmem_cache_destroy(kvm_vcpu_cache);
3039         kvm_async_pf_deinit();
3040         unregister_syscore_ops(&kvm_syscore_ops);
3041         unregister_reboot_notifier(&kvm_reboot_notifier);
3042         unregister_cpu_notifier(&kvm_cpu_notifier);
3043         on_each_cpu(hardware_disable_nolock, NULL, 1);
3044         kvm_arch_hardware_unsetup();
3045         kvm_arch_exit();
3046         free_cpumask_var(cpus_hardware_enabled);
3047 }
3048 EXPORT_SYMBOL_GPL(kvm_exit);