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 <kvm/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/ioctl.h>
  56 #include <asm/uaccess.h>
  57 #include <asm/pgtable.h>
  58
  59 #include "coalesced_mmio.h"
  60 #include "async_pf.h"
  61 #include "vfio.h"
  62
  63 #define CREATE_TRACE_POINTS
  64 #include <trace/events/kvm.h>
  65
  66 MODULE_AUTHOR("Qumranet");
  67 MODULE_LICENSE("GPL");
  68
  69 /* Architectures should define their poll value according to the halt latency */
  70 static unsigned int halt_poll_ns = KVM_HALT_POLL_NS_DEFAULT;
  71 module_param(halt_poll_ns, uint, S_IRUGO | S_IWUSR);
  72
  73 /* Default doubles per-vcpu halt_poll_ns. */
  74 static unsigned int halt_poll_ns_grow = 2;
  75 module_param(halt_poll_ns_grow, int, S_IRUGO);
  76
  77 /* Default resets per-vcpu halt_poll_ns . */
  78 static unsigned int halt_poll_ns_shrink;
  79 module_param(halt_poll_ns_shrink, int, S_IRUGO);
  80
  81 /*
  82  * Ordering of locks:
  83  *
  84  *      kvm->lock --> kvm->slots_lock --> kvm->irq_lock
  85  */
  86
  87 DEFINE_SPINLOCK(kvm_lock);
  88 static DEFINE_RAW_SPINLOCK(kvm_count_lock);
  89 LIST_HEAD(vm_list);
  90
  91 static cpumask_var_t cpus_hardware_enabled;
  92 static int kvm_usage_count;
  93 static atomic_t hardware_enable_failed;
  94
  95 struct kmem_cache *kvm_vcpu_cache;
  96 EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
  97
  98 static __read_mostly struct preempt_ops kvm_preempt_ops;
  99
 100 struct dentry *kvm_debugfs_dir;
 101 EXPORT_SYMBOL_GPL(kvm_debugfs_dir);
 102
 103 static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
 104                            unsigned long arg);
 105 #ifdef CONFIG_KVM_COMPAT
 106 static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl,
 107                                   unsigned long arg);
 108 #endif
 109 static int hardware_enable_all(void);
 110 static void hardware_disable_all(void);
 111
 112 static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
 113
 114 static void kvm_release_pfn_dirty(kvm_pfn_t pfn);
 115 static void mark_page_dirty_in_slot(struct kvm_memory_slot *memslot, gfn_t gfn);
 116
 117 __visible bool kvm_rebooting;
 118 EXPORT_SYMBOL_GPL(kvm_rebooting);
 119
 120 static bool largepages_enabled = true;
 121
 122 bool kvm_is_reserved_pfn(kvm_pfn_t pfn)
 123 {
 124         if (pfn_valid(pfn))
 125                 return PageReserved(pfn_to_page(pfn));
 126
 127         return true;
 128 }
 129
 130 /*
 131  * Switches to specified vcpu, until a matching vcpu_put()
 132  */
 133 int vcpu_load(struct kvm_vcpu *vcpu)
 134 {
 135         int cpu;
 136
 137         if (mutex_lock_killable(&vcpu->mutex))
 138                 return -EINTR;
 139         cpu = get_cpu();
 140         preempt_notifier_register(&vcpu->preempt_notifier);
 141         kvm_arch_vcpu_load(vcpu, cpu);
 142         put_cpu();
 143         return 0;
 144 }
 145
 146 void vcpu_put(struct kvm_vcpu *vcpu)
 147 {
 148         preempt_disable();
 149         kvm_arch_vcpu_put(vcpu);
 150         preempt_notifier_unregister(&vcpu->preempt_notifier);
 151         preempt_enable();
 152         mutex_unlock(&vcpu->mutex);
 153 }
 154
 155 static void ack_flush(void *_completed)
 156 {
 157 }
 158
 159 bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
 160 {
 161         int i, cpu, me;
 162         cpumask_var_t cpus;
 163         bool called = true;
 164         struct kvm_vcpu *vcpu;
 165
 166         zalloc_cpumask_var(&cpus, GFP_ATOMIC);
 167
 168         me = get_cpu();
 169         kvm_for_each_vcpu(i, vcpu, kvm) {
 170                 kvm_make_request(req, vcpu);
 171                 cpu = vcpu->cpu;
 172
 173                 /* Set ->requests bit before we read ->mode */
 174                 smp_mb();
 175
 176                 if (cpus != NULL && cpu != -1 && cpu != me &&
 177                       kvm_vcpu_exiting_guest_mode(vcpu) != OUTSIDE_GUEST_MODE)
 178                         cpumask_set_cpu(cpu, cpus);
 179         }
 180         if (unlikely(cpus == NULL))
 181                 smp_call_function_many(cpu_online_mask, ack_flush, NULL, 1);
 182         else if (!cpumask_empty(cpus))
 183                 smp_call_function_many(cpus, ack_flush, NULL, 1);
 184         else
 185                 called = false;
 186         put_cpu();
 187         free_cpumask_var(cpus);
 188         return called;
 189 }
 190
 191 #ifndef CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL
 192 void kvm_flush_remote_tlbs(struct kvm *kvm)
 193 {
 194         long dirty_count = kvm->tlbs_dirty;
 195
 196         smp_mb();
 197         if (kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
 198                 ++kvm->stat.remote_tlb_flush;
 199         cmpxchg(&kvm->tlbs_dirty, dirty_count, 0);
 200 }
 201 EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs);
 202 #endif
 203
 204 void kvm_reload_remote_mmus(struct kvm *kvm)
 205 {
 206         kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD);
 207 }
 208
 209 int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
 210 {
 211         struct page *page;
 212         int r;
 213
 214         mutex_init(&vcpu->mutex);
 215         vcpu->cpu = -1;
 216         vcpu->kvm = kvm;
 217         vcpu->vcpu_id = id;
 218         vcpu->pid = NULL;
 219         vcpu->halt_poll_ns = 0;
 220         init_waitqueue_head(&vcpu->wq);
 221         kvm_async_pf_vcpu_init(vcpu);
 222
 223         vcpu->pre_pcpu = -1;
 224         INIT_LIST_HEAD(&vcpu->blocked_vcpu_list);
 225
 226         page = alloc_page(GFP_KERNEL | __GFP_ZERO);
 227         if (!page) {
 228                 r = -ENOMEM;
 229                 goto fail;
 230         }
 231         vcpu->run = page_address(page);
 232
 233         kvm_vcpu_set_in_spin_loop(vcpu, false);
 234         kvm_vcpu_set_dy_eligible(vcpu, false);
 235         vcpu->preempted = false;
 236
 237         r = kvm_arch_vcpu_init(vcpu);
 238         if (r < 0)
 239                 goto fail_free_run;
 240         return 0;
 241
 242 fail_free_run:
 243         free_page((unsigned long)vcpu->run);
 244 fail:
 245         return r;
 246 }
 247 EXPORT_SYMBOL_GPL(kvm_vcpu_init);
 248
 249 void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
 250 {
 251         put_pid(vcpu->pid);
 252         kvm_arch_vcpu_uninit(vcpu);
 253         free_page((unsigned long)vcpu->run);
 254 }
 255 EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
 256
 257 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
 258 static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
 259 {
 260         return container_of(mn, struct kvm, mmu_notifier);
 261 }
 262
 263 static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
 264                                              struct mm_struct *mm,
 265                                              unsigned long address)
 266 {
 267         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 268         int need_tlb_flush, idx;
 269
 270         /*
 271          * When ->invalidate_page runs, the linux pte has been zapped
 272          * already but the page is still allocated until
 273          * ->invalidate_page returns. So if we increase the sequence
 274          * here the kvm page fault will notice if the spte can't be
 275          * established because the page is going to be freed. If
 276          * instead the kvm page fault establishes the spte before
 277          * ->invalidate_page runs, kvm_unmap_hva will release it
 278          * before returning.
 279          *
 280          * The sequence increase only need to be seen at spin_unlock
 281          * time, and not at spin_lock time.
 282          *
 283          * Increasing the sequence after the spin_unlock would be
 284          * unsafe because the kvm page fault could then establish the
 285          * pte after kvm_unmap_hva returned, without noticing the page
 286          * is going to be freed.
 287          */
 288         idx = srcu_read_lock(&kvm->srcu);
 289         spin_lock(&kvm->mmu_lock);
 290
 291         kvm->mmu_notifier_seq++;
 292         need_tlb_flush = kvm_unmap_hva(kvm, address) | kvm->tlbs_dirty;
 293         /* we've to flush the tlb before the pages can be freed */
 294         if (need_tlb_flush)
 295                 kvm_flush_remote_tlbs(kvm);
 296
 297         spin_unlock(&kvm->mmu_lock);
 298
 299         kvm_arch_mmu_notifier_invalidate_page(kvm, address);
 300
 301         srcu_read_unlock(&kvm->srcu, idx);
 302 }
 303
 304 static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
 305                                         struct mm_struct *mm,
 306                                         unsigned long address,
 307                                         pte_t pte)
 308 {
 309         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 310         int idx;
 311
 312         idx = srcu_read_lock(&kvm->srcu);
 313         spin_lock(&kvm->mmu_lock);
 314         kvm->mmu_notifier_seq++;
 315         kvm_set_spte_hva(kvm, address, pte);
 316         spin_unlock(&kvm->mmu_lock);
 317         srcu_read_unlock(&kvm->srcu, idx);
 318 }
 319
 320 static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
 321                                                     struct mm_struct *mm,
 322                                                     unsigned long start,
 323                                                     unsigned long end)
 324 {
 325         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 326         int need_tlb_flush = 0, idx;
 327
 328         idx = srcu_read_lock(&kvm->srcu);
 329         spin_lock(&kvm->mmu_lock);
 330         /*
 331          * The count increase must become visible at unlock time as no
 332          * spte can be established without taking the mmu_lock and
 333          * count is also read inside the mmu_lock critical section.
 334          */
 335         kvm->mmu_notifier_count++;
 336         need_tlb_flush = kvm_unmap_hva_range(kvm, start, end);
 337         need_tlb_flush |= kvm->tlbs_dirty;
 338         /* we've to flush the tlb before the pages can be freed */
 339         if (need_tlb_flush)
 340                 kvm_flush_remote_tlbs(kvm);
 341
 342         spin_unlock(&kvm->mmu_lock);
 343         srcu_read_unlock(&kvm->srcu, idx);
 344 }
 345
 346 static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
 347                                                   struct mm_struct *mm,
 348                                                   unsigned long start,
 349                                                   unsigned long end)
 350 {
 351         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 352
 353         spin_lock(&kvm->mmu_lock);
 354         /*
 355          * This sequence increase will notify the kvm page fault that
 356          * the page that is going to be mapped in the spte could have
 357          * been freed.
 358          */
 359         kvm->mmu_notifier_seq++;
 360         smp_wmb();
 361         /*
 362          * The above sequence increase must be visible before the
 363          * below count decrease, which is ensured by the smp_wmb above
 364          * in conjunction with the smp_rmb in mmu_notifier_retry().
 365          */
 366         kvm->mmu_notifier_count--;
 367         spin_unlock(&kvm->mmu_lock);
 368
 369         BUG_ON(kvm->mmu_notifier_count < 0);
 370 }
 371
 372 static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
 373                                               struct mm_struct *mm,
 374                                               unsigned long start,
 375                                               unsigned long end)
 376 {
 377         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 378         int young, idx;
 379
 380         idx = srcu_read_lock(&kvm->srcu);
 381         spin_lock(&kvm->mmu_lock);
 382
 383         young = kvm_age_hva(kvm, start, end);
 384         if (young)
 385                 kvm_flush_remote_tlbs(kvm);
 386
 387         spin_unlock(&kvm->mmu_lock);
 388         srcu_read_unlock(&kvm->srcu, idx);
 389
 390         return young;
 391 }
 392
 393 static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
 394                                         struct mm_struct *mm,
 395                                         unsigned long start,
 396                                         unsigned long end)
 397 {
 398         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 399         int young, idx;
 400
 401         idx = srcu_read_lock(&kvm->srcu);
 402         spin_lock(&kvm->mmu_lock);
 403         /*
 404          * Even though we do not flush TLB, this will still adversely
 405          * affect performance on pre-Haswell Intel EPT, where there is
 406          * no EPT Access Bit to clear so that we have to tear down EPT
 407          * tables instead. If we find this unacceptable, we can always
 408          * add a parameter to kvm_age_hva so that it effectively doesn't
 409          * do anything on clear_young.
 410          *
 411          * Also note that currently we never issue secondary TLB flushes
 412          * from clear_young, leaving this job up to the regular system
 413          * cadence. If we find this inaccurate, we might come up with a
 414          * more sophisticated heuristic later.
 415          */
 416         young = kvm_age_hva(kvm, start, end);
 417         spin_unlock(&kvm->mmu_lock);
 418         srcu_read_unlock(&kvm->srcu, idx);
 419
 420         return young;
 421 }
 422
 423 static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
 424                                        struct mm_struct *mm,
 425                                        unsigned long address)
 426 {
 427         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 428         int young, idx;
 429
 430         idx = srcu_read_lock(&kvm->srcu);
 431         spin_lock(&kvm->mmu_lock);
 432         young = kvm_test_age_hva(kvm, address);
 433         spin_unlock(&kvm->mmu_lock);
 434         srcu_read_unlock(&kvm->srcu, idx);
 435
 436         return young;
 437 }
 438
 439 static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
 440                                      struct mm_struct *mm)
 441 {
 442         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 443         int idx;
 444
 445         idx = srcu_read_lock(&kvm->srcu);
 446         kvm_arch_flush_shadow_all(kvm);
 447         srcu_read_unlock(&kvm->srcu, idx);
 448 }
 449
 450 static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
 451         .invalidate_page        = kvm_mmu_notifier_invalidate_page,
 452         .invalidate_range_start = kvm_mmu_notifier_invalidate_range_start,
 453         .invalidate_range_end   = kvm_mmu_notifier_invalidate_range_end,
 454         .clear_flush_young      = kvm_mmu_notifier_clear_flush_young,
 455         .clear_young            = kvm_mmu_notifier_clear_young,
 456         .test_young             = kvm_mmu_notifier_test_young,
 457         .change_pte             = kvm_mmu_notifier_change_pte,
 458         .release                = kvm_mmu_notifier_release,
 459 };
 460
 461 static int kvm_init_mmu_notifier(struct kvm *kvm)
 462 {
 463         kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
 464         return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
 465 }
 466
 467 #else  /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */
 468
 469 static int kvm_init_mmu_notifier(struct kvm *kvm)
 470 {
 471         return 0;
 472 }
 473
 474 #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
 475
 476 static struct kvm_memslots *kvm_alloc_memslots(void)
 477 {
 478         int i;
 479         struct kvm_memslots *slots;
 480
 481         slots = kvm_kvzalloc(sizeof(struct kvm_memslots));
 482         if (!slots)
 483                 return NULL;
 484
 485         /*
 486          * Init kvm generation close to the maximum to easily test the
 487          * code of handling generation number wrap-around.
 488          */
 489         slots->generation = -150;
 490         for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
 491                 slots->id_to_index[i] = slots->memslots[i].id = i;
 492
 493         return slots;
 494 }
 495
 496 static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
 497 {
 498         if (!memslot->dirty_bitmap)
 499                 return;
 500
 501         kvfree(memslot->dirty_bitmap);
 502         memslot->dirty_bitmap = NULL;
 503 }
 504
 505 /*
 506  * Free any memory in @free but not in @dont.
 507  */
 508 static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
 509                               struct kvm_memory_slot *dont)
 510 {
 511         if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
 512                 kvm_destroy_dirty_bitmap(free);
 513
 514         kvm_arch_free_memslot(kvm, free, dont);
 515
 516         free->npages = 0;
 517 }
 518
 519 static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots)
 520 {
 521         struct kvm_memory_slot *memslot;
 522
 523         if (!slots)
 524                 return;
 525
 526         kvm_for_each_memslot(memslot, slots)
 527                 kvm_free_memslot(kvm, memslot, NULL);
 528
 529         kvfree(slots);
 530 }
 531
 532 static struct kvm *kvm_create_vm(unsigned long type)
 533 {
 534         int r, i;
 535         struct kvm *kvm = kvm_arch_alloc_vm();
 536
 537         if (!kvm)
 538                 return ERR_PTR(-ENOMEM);
 539
 540         r = kvm_arch_init_vm(kvm, type);
 541         if (r)
 542                 goto out_err_no_disable;
 543
 544         r = hardware_enable_all();
 545         if (r)
 546                 goto out_err_no_disable;
 547
 548 #ifdef CONFIG_HAVE_KVM_IRQFD
 549         INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
 550 #endif
 551
 552         BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX);
 553
 554         r = -ENOMEM;
 555         for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
 556                 kvm->memslots[i] = kvm_alloc_memslots();
 557                 if (!kvm->memslots[i])
 558                         goto out_err_no_srcu;
 559         }
 560
 561         if (init_srcu_struct(&kvm->srcu))
 562                 goto out_err_no_srcu;
 563         if (init_srcu_struct(&kvm->irq_srcu))
 564                 goto out_err_no_irq_srcu;
 565         for (i = 0; i < KVM_NR_BUSES; i++) {
 566                 kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus),
 567                                         GFP_KERNEL);
 568                 if (!kvm->buses[i])
 569                         goto out_err;
 570         }
 571
 572         spin_lock_init(&kvm->mmu_lock);
 573         kvm->mm = current->mm;
 574         atomic_inc(&kvm->mm->mm_count);
 575         kvm_eventfd_init(kvm);
 576         mutex_init(&kvm->lock);
 577         mutex_init(&kvm->irq_lock);
 578         mutex_init(&kvm->slots_lock);
 579         atomic_set(&kvm->users_count, 1);
 580         INIT_LIST_HEAD(&kvm->devices);
 581
 582         r = kvm_init_mmu_notifier(kvm);
 583         if (r)
 584                 goto out_err;
 585
 586         spin_lock(&kvm_lock);
 587         list_add(&kvm->vm_list, &vm_list);
 588         spin_unlock(&kvm_lock);
 589
 590         preempt_notifier_inc();
 591
 592         return kvm;
 593
 594 out_err:
 595         cleanup_srcu_struct(&kvm->irq_srcu);
 596 out_err_no_irq_srcu:
 597         cleanup_srcu_struct(&kvm->srcu);
 598 out_err_no_srcu:
 599         hardware_disable_all();
 600 out_err_no_disable:
 601         for (i = 0; i < KVM_NR_BUSES; i++)
 602                 kfree(kvm->buses[i]);
 603         for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
 604                 kvm_free_memslots(kvm, kvm->memslots[i]);
 605         kvm_arch_free_vm(kvm);
 606         return ERR_PTR(r);
 607 }
 608
 609 /*
 610  * Avoid using vmalloc for a small buffer.
 611  * Should not be used when the size is statically known.
 612  */
 613 void *kvm_kvzalloc(unsigned long size)
 614 {
 615         if (size > PAGE_SIZE)
 616                 return vzalloc(size);
 617         else
 618                 return kzalloc(size, GFP_KERNEL);
 619 }
 620
 621 static void kvm_destroy_devices(struct kvm *kvm)
 622 {
 623         struct list_head *node, *tmp;
 624
 625         list_for_each_safe(node, tmp, &kvm->devices) {
 626                 struct kvm_device *dev =
 627                         list_entry(node, struct kvm_device, vm_node);
 628
 629                 list_del(node);
 630                 dev->ops->destroy(dev);
 631         }
 632 }
 633
 634 static void kvm_destroy_vm(struct kvm *kvm)
 635 {
 636         int i;
 637         struct mm_struct *mm = kvm->mm;
 638
 639         kvm_arch_sync_events(kvm);
 640         spin_lock(&kvm_lock);
 641         list_del(&kvm->vm_list);
 642         spin_unlock(&kvm_lock);
 643         kvm_free_irq_routing(kvm);
 644         for (i = 0; i < KVM_NR_BUSES; i++)
 645                 kvm_io_bus_destroy(kvm->buses[i]);
 646         kvm_coalesced_mmio_free(kvm);
 647 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
 648         mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
 649 #else
 650         kvm_arch_flush_shadow_all(kvm);
 651 #endif
 652         kvm_arch_destroy_vm(kvm);
 653         kvm_destroy_devices(kvm);
 654         for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
 655                 kvm_free_memslots(kvm, kvm->memslots[i]);
 656         cleanup_srcu_struct(&kvm->irq_srcu);
 657         cleanup_srcu_struct(&kvm->srcu);
 658         kvm_arch_free_vm(kvm);
 659         preempt_notifier_dec();
 660         hardware_disable_all();
 661         mmdrop(mm);
 662 }
 663
 664 void kvm_get_kvm(struct kvm *kvm)
 665 {
 666         atomic_inc(&kvm->users_count);
 667 }
 668 EXPORT_SYMBOL_GPL(kvm_get_kvm);
 669
 670 void kvm_put_kvm(struct kvm *kvm)
 671 {
 672         if (atomic_dec_and_test(&kvm->users_count))
 673                 kvm_destroy_vm(kvm);
 674 }
 675 EXPORT_SYMBOL_GPL(kvm_put_kvm);
 676
 677
 678 static int kvm_vm_release(struct inode *inode, struct file *filp)
 679 {
 680         struct kvm *kvm = filp->private_data;
 681
 682         kvm_irqfd_release(kvm);
 683
 684         kvm_put_kvm(kvm);
 685         return 0;
 686 }
 687
 688 /*
 689  * Allocation size is twice as large as the actual dirty bitmap size.
 690  * See x86's kvm_vm_ioctl_get_dirty_log() why this is needed.
 691  */
 692 static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
 693 {
 694         unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
 695
 696         memslot->dirty_bitmap = kvm_kvzalloc(dirty_bytes);
 697         if (!memslot->dirty_bitmap)
 698                 return -ENOMEM;
 699
 700         return 0;
 701 }
 702
 703 /*
 704  * Insert memslot and re-sort memslots based on their GFN,
 705  * so binary search could be used to lookup GFN.
 706  * Sorting algorithm takes advantage of having initially
 707  * sorted array and known changed memslot position.
 708  */
 709 static void update_memslots(struct kvm_memslots *slots,
 710                             struct kvm_memory_slot *new)
 711 {
 712         int id = new->id;
 713         int i = slots->id_to_index[id];
 714         struct kvm_memory_slot *mslots = slots->memslots;
 715
 716         WARN_ON(mslots[i].id != id);
 717         if (!new->npages) {
 718                 WARN_ON(!mslots[i].npages);
 719                 if (mslots[i].npages)
 720                         slots->used_slots--;
 721         } else {
 722                 if (!mslots[i].npages)
 723                         slots->used_slots++;
 724         }
 725
 726         while (i < KVM_MEM_SLOTS_NUM - 1 &&
 727                new->base_gfn <= mslots[i + 1].base_gfn) {
 728                 if (!mslots[i + 1].npages)
 729                         break;
 730                 mslots[i] = mslots[i + 1];
 731                 slots->id_to_index[mslots[i].id] = i;
 732                 i++;
 733         }
 734
 735         /*
 736          * The ">=" is needed when creating a slot with base_gfn == 0,
 737          * so that it moves before all those with base_gfn == npages == 0.
 738          *
 739          * On the other hand, if new->npages is zero, the above loop has
 740          * already left i pointing to the beginning of the empty part of
 741          * mslots, and the ">=" would move the hole backwards in this
 742          * case---which is wrong.  So skip the loop when deleting a slot.
 743          */
 744         if (new->npages) {
 745                 while (i > 0 &&
 746                        new->base_gfn >= mslots[i - 1].base_gfn) {
 747                         mslots[i] = mslots[i - 1];
 748                         slots->id_to_index[mslots[i].id] = i;
 749                         i--;
 750                 }
 751         } else
 752                 WARN_ON_ONCE(i != slots->used_slots);
 753
 754         mslots[i] = *new;
 755         slots->id_to_index[mslots[i].id] = i;
 756 }
 757
 758 static int check_memory_region_flags(const struct kvm_userspace_memory_region *mem)
 759 {
 760         u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES;
 761
 762 #ifdef __KVM_HAVE_READONLY_MEM
 763         valid_flags |= KVM_MEM_READONLY;
 764 #endif
 765
 766         if (mem->flags & ~valid_flags)
 767                 return -EINVAL;
 768
 769         return 0;
 770 }
 771
 772 static struct kvm_memslots *install_new_memslots(struct kvm *kvm,
 773                 int as_id, struct kvm_memslots *slots)
 774 {
 775         struct kvm_memslots *old_memslots = __kvm_memslots(kvm, as_id);
 776
 777         /*
 778          * Set the low bit in the generation, which disables SPTE caching
 779          * until the end of synchronize_srcu_expedited.
 780          */
 781         WARN_ON(old_memslots->generation & 1);
 782         slots->generation = old_memslots->generation + 1;
 783
 784         rcu_assign_pointer(kvm->memslots[as_id], slots);
 785         synchronize_srcu_expedited(&kvm->srcu);
 786
 787         /*
 788          * Increment the new memslot generation a second time. This prevents
 789          * vm exits that race with memslot updates from caching a memslot
 790          * generation that will (potentially) be valid forever.
 791          */
 792         slots->generation++;
 793
 794         kvm_arch_memslots_updated(kvm, slots);
 795
 796         return old_memslots;
 797 }
 798
 799 /*
 800  * Allocate some memory and give it an address in the guest physical address
 801  * space.
 802  *
 803  * Discontiguous memory is allowed, mostly for framebuffers.
 804  *
 805  * Must be called holding kvm->slots_lock for write.
 806  */
 807 int __kvm_set_memory_region(struct kvm *kvm,
 808                             const struct kvm_userspace_memory_region *mem)
 809 {
 810         int r;
 811         gfn_t base_gfn;
 812         unsigned long npages;
 813         struct kvm_memory_slot *slot;
 814         struct kvm_memory_slot old, new;
 815         struct kvm_memslots *slots = NULL, *old_memslots;
 816         int as_id, id;
 817         enum kvm_mr_change change;
 818
 819         r = check_memory_region_flags(mem);
 820         if (r)
 821                 goto out;
 822
 823         r = -EINVAL;
 824         as_id = mem->slot >> 16;
 825         id = (u16)mem->slot;
 826
 827         /* General sanity checks */
 828         if (mem->memory_size & (PAGE_SIZE - 1))
 829                 goto out;
 830         if (mem->guest_phys_addr & (PAGE_SIZE - 1))
 831                 goto out;
 832         /* We can read the guest memory with __xxx_user() later on. */
 833         if ((id < KVM_USER_MEM_SLOTS) &&
 834             ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
 835              !access_ok(VERIFY_WRITE,
 836                         (void __user *)(unsigned long)mem->userspace_addr,
 837                         mem->memory_size)))
 838                 goto out;
 839         if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_MEM_SLOTS_NUM)
 840                 goto out;
 841         if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
 842                 goto out;
 843
 844         slot = id_to_memslot(__kvm_memslots(kvm, as_id), id);
 845         base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
 846         npages = mem->memory_size >> PAGE_SHIFT;
 847
 848         if (npages > KVM_MEM_MAX_NR_PAGES)
 849                 goto out;
 850
 851         new = old = *slot;
 852
 853         new.id = id;
 854         new.base_gfn = base_gfn;
 855         new.npages = npages;
 856         new.flags = mem->flags;
 857
 858         if (npages) {
 859                 if (!old.npages)
 860                         change = KVM_MR_CREATE;
 861                 else { /* Modify an existing slot. */
 862                         if ((mem->userspace_addr != old.userspace_addr) ||
 863                             (npages != old.npages) ||
 864                             ((new.flags ^ old.flags) & KVM_MEM_READONLY))
 865                                 goto out;
 866
 867                         if (base_gfn != old.base_gfn)
 868                                 change = KVM_MR_MOVE;
 869                         else if (new.flags != old.flags)
 870                                 change = KVM_MR_FLAGS_ONLY;
 871                         else { /* Nothing to change. */
 872                                 r = 0;
 873                                 goto out;
 874                         }
 875                 }
 876         } else {
 877                 if (!old.npages)
 878                         goto out;
 879
 880                 change = KVM_MR_DELETE;
 881                 new.base_gfn = 0;
 882                 new.flags = 0;
 883         }
 884
 885         if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) {
 886                 /* Check for overlaps */
 887                 r = -EEXIST;
 888                 kvm_for_each_memslot(slot, __kvm_memslots(kvm, as_id)) {
 889                         if ((slot->id >= KVM_USER_MEM_SLOTS) ||
 890                             (slot->id == id))
 891                                 continue;
 892                         if (!((base_gfn + npages <= slot->base_gfn) ||
 893                               (base_gfn >= slot->base_gfn + slot->npages)))
 894                                 goto out;
 895                 }
 896         }
 897
 898         /* Free page dirty bitmap if unneeded */
 899         if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
 900                 new.dirty_bitmap = NULL;
 901
 902         r = -ENOMEM;
 903         if (change == KVM_MR_CREATE) {
 904                 new.userspace_addr = mem->userspace_addr;
 905
 906                 if (kvm_arch_create_memslot(kvm, &new, npages))
 907                         goto out_free;
 908         }
 909
 910         /* Allocate page dirty bitmap if needed */
 911         if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
 912                 if (kvm_create_dirty_bitmap(&new) < 0)
 913                         goto out_free;
 914         }
 915
 916         slots = kvm_kvzalloc(sizeof(struct kvm_memslots));
 917         if (!slots)
 918                 goto out_free;
 919         memcpy(slots, __kvm_memslots(kvm, as_id), sizeof(struct kvm_memslots));
 920
 921         if ((change == KVM_MR_DELETE) || (change == KVM_MR_MOVE)) {
 922                 slot = id_to_memslot(slots, id);
 923                 slot->flags |= KVM_MEMSLOT_INVALID;
 924
 925                 old_memslots = install_new_memslots(kvm, as_id, slots);
 926
 927                 /* slot was deleted or moved, clear iommu mapping */
 928                 kvm_iommu_unmap_pages(kvm, &old);
 929                 /* From this point no new shadow pages pointing to a deleted,
 930                  * or moved, memslot will be created.
 931                  *
 932                  * validation of sp->gfn happens in:
 933                  *      - gfn_to_hva (kvm_read_guest, gfn_to_pfn)
 934                  *      - kvm_is_visible_gfn (mmu_check_roots)
 935                  */
 936                 kvm_arch_flush_shadow_memslot(kvm, slot);
 937
 938                 /*
 939                  * We can re-use the old_memslots from above, the only difference
 940                  * from the currently installed memslots is the invalid flag.  This
 941                  * will get overwritten by update_memslots anyway.
 942                  */
 943                 slots = old_memslots;
 944         }
 945
 946         r = kvm_arch_prepare_memory_region(kvm, &new, mem, change);
 947         if (r)
 948                 goto out_slots;
 949
 950         /* actual memory is freed via old in kvm_free_memslot below */
 951         if (change == KVM_MR_DELETE) {
 952                 new.dirty_bitmap = NULL;
 953                 memset(&new.arch, 0, sizeof(new.arch));
 954         }
 955
 956         update_memslots(slots, &new);
 957         old_memslots = install_new_memslots(kvm, as_id, slots);
 958
 959         kvm_arch_commit_memory_region(kvm, mem, &old, &new, change);
 960
 961         kvm_free_memslot(kvm, &old, &new);
 962         kvfree(old_memslots);
 963
 964         /*
 965          * IOMMU mapping:  New slots need to be mapped.  Old slots need to be
 966          * un-mapped and re-mapped if their base changes.  Since base change
 967          * unmapping is handled above with slot deletion, mapping alone is
 968          * needed here.  Anything else the iommu might care about for existing
 969          * slots (size changes, userspace addr changes and read-only flag
 970          * changes) is disallowed above, so any other attribute changes getting
 971          * here can be skipped.
 972          */
 973         if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) {
 974                 r = kvm_iommu_map_pages(kvm, &new);
 975                 return r;
 976         }
 977
 978         return 0;
 979
 980 out_slots:
 981         kvfree(slots);
 982 out_free:
 983         kvm_free_memslot(kvm, &new, &old);
 984 out:
 985         return r;
 986 }
 987 EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
 988
 989 int kvm_set_memory_region(struct kvm *kvm,
 990                           const struct kvm_userspace_memory_region *mem)
 991 {
 992         int r;
 993
 994         mutex_lock(&kvm->slots_lock);
 995         r = __kvm_set_memory_region(kvm, mem);
 996         mutex_unlock(&kvm->slots_lock);
 997         return r;
 998 }
 999 EXPORT_SYMBOL_GPL(kvm_set_memory_region);
1000
1001 static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
1002                                           struct kvm_userspace_memory_region *mem)
1003 {
1004         if ((u16)mem->slot >= KVM_USER_MEM_SLOTS)
1005                 return -EINVAL;
1006
1007         return kvm_set_memory_region(kvm, mem);
1008 }
1009
1010 int kvm_get_dirty_log(struct kvm *kvm,
1011                         struct kvm_dirty_log *log, int *is_dirty)
1012 {
1013         struct kvm_memslots *slots;
1014         struct kvm_memory_slot *memslot;
1015         int r, i, as_id, id;
1016         unsigned long n;
1017         unsigned long any = 0;
1018
1019         r = -EINVAL;
1020         as_id = log->slot >> 16;
1021         id = (u16)log->slot;
1022         if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
1023                 goto out;
1024
1025         slots = __kvm_memslots(kvm, as_id);
1026         memslot = id_to_memslot(slots, id);
1027         r = -ENOENT;
1028         if (!memslot->dirty_bitmap)
1029                 goto out;
1030
1031         n = kvm_dirty_bitmap_bytes(memslot);
1032
1033         for (i = 0; !any && i < n/sizeof(long); ++i)
1034                 any = memslot->dirty_bitmap[i];
1035
1036         r = -EFAULT;
1037         if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
1038                 goto out;
1039
1040         if (any)
1041                 *is_dirty = 1;
1042
1043         r = 0;
1044 out:
1045         return r;
1046 }
1047 EXPORT_SYMBOL_GPL(kvm_get_dirty_log);
1048
1049 #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
1050 /**
1051  * kvm_get_dirty_log_protect - get a snapshot of dirty pages, and if any pages
1052  *      are dirty write protect them for next write.
1053  * @kvm:        pointer to kvm instance
1054  * @log:        slot id and address to which we copy the log
1055  * @is_dirty:   flag set if any page is dirty
1056  *
1057  * We need to keep it in mind that VCPU threads can write to the bitmap
1058  * concurrently. So, to avoid losing track of dirty pages we keep the
1059  * following order:
1060  *
1061  *    1. Take a snapshot of the bit and clear it if needed.
1062  *    2. Write protect the corresponding page.
1063  *    3. Copy the snapshot to the userspace.
1064  *    4. Upon return caller flushes TLB's if needed.
1065  *
1066  * Between 2 and 4, the guest may write to the page using the remaining TLB
1067  * entry.  This is not a problem because the page is reported dirty using
1068  * the snapshot taken before and step 4 ensures that writes done after
1069  * exiting to userspace will be logged for the next call.
1070  *
1071  */
1072 int kvm_get_dirty_log_protect(struct kvm *kvm,
1073                         struct kvm_dirty_log *log, bool *is_dirty)
1074 {
1075         struct kvm_memslots *slots;
1076         struct kvm_memory_slot *memslot;
1077         int r, i, as_id, id;
1078         unsigned long n;
1079         unsigned long *dirty_bitmap;
1080         unsigned long *dirty_bitmap_buffer;
1081
1082         r = -EINVAL;
1083         as_id = log->slot >> 16;
1084         id = (u16)log->slot;
1085         if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
1086                 goto out;
1087
1088         slots = __kvm_memslots(kvm, as_id);
1089         memslot = id_to_memslot(slots, id);
1090
1091         dirty_bitmap = memslot->dirty_bitmap;
1092         r = -ENOENT;
1093         if (!dirty_bitmap)
1094                 goto out;
1095
1096         n = kvm_dirty_bitmap_bytes(memslot);
1097
1098         dirty_bitmap_buffer = dirty_bitmap + n / sizeof(long);
1099         memset(dirty_bitmap_buffer, 0, n);
1100
1101         spin_lock(&kvm->mmu_lock);
1102         *is_dirty = false;
1103         for (i = 0; i < n / sizeof(long); i++) {
1104                 unsigned long mask;
1105                 gfn_t offset;
1106
1107                 if (!dirty_bitmap[i])
1108                         continue;
1109
1110                 *is_dirty = true;
1111
1112                 mask = xchg(&dirty_bitmap[i], 0);
1113                 dirty_bitmap_buffer[i] = mask;
1114
1115                 if (mask) {
1116                         offset = i * BITS_PER_LONG;
1117                         kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot,
1118                                                                 offset, mask);
1119                 }
1120         }
1121
1122         spin_unlock(&kvm->mmu_lock);
1123
1124         r = -EFAULT;
1125         if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n))
1126                 goto out;
1127
1128         r = 0;
1129 out:
1130         return r;
1131 }
1132 EXPORT_SYMBOL_GPL(kvm_get_dirty_log_protect);
1133 #endif
1134
1135 bool kvm_largepages_enabled(void)
1136 {
1137         return largepages_enabled;
1138 }
1139
1140 void kvm_disable_largepages(void)
1141 {
1142         largepages_enabled = false;
1143 }
1144 EXPORT_SYMBOL_GPL(kvm_disable_largepages);
1145
1146 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
1147 {
1148         return __gfn_to_memslot(kvm_memslots(kvm), gfn);
1149 }
1150 EXPORT_SYMBOL_GPL(gfn_to_memslot);
1151
1152 struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn)
1153 {
1154         return __gfn_to_memslot(kvm_vcpu_memslots(vcpu), gfn);
1155 }
1156
1157 bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
1158 {
1159         struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn);
1160
1161         if (!memslot || memslot->id >= KVM_USER_MEM_SLOTS ||
1162               memslot->flags & KVM_MEMSLOT_INVALID)
1163                 return false;
1164
1165         return true;
1166 }
1167 EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
1168
1169 unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn)
1170 {
1171         struct vm_area_struct *vma;
1172         unsigned long addr, size;
1173
1174         size = PAGE_SIZE;
1175
1176         addr = gfn_to_hva(kvm, gfn);
1177         if (kvm_is_error_hva(addr))
1178                 return PAGE_SIZE;
1179
1180         down_read(&current->mm->mmap_sem);
1181         vma = find_vma(current->mm, addr);
1182         if (!vma)
1183                 goto out;
1184
1185         size = vma_kernel_pagesize(vma);
1186
1187 out:
1188         up_read(&current->mm->mmap_sem);
1189
1190         return size;
1191 }
1192
1193 static bool memslot_is_readonly(struct kvm_memory_slot *slot)
1194 {
1195         return slot->flags & KVM_MEM_READONLY;
1196 }
1197
1198 static unsigned long __gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
1199                                        gfn_t *nr_pages, bool write)
1200 {
1201         if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
1202                 return KVM_HVA_ERR_BAD;
1203
1204         if (memslot_is_readonly(slot) && write)
1205                 return KVM_HVA_ERR_RO_BAD;
1206
1207         if (nr_pages)
1208                 *nr_pages = slot->npages - (gfn - slot->base_gfn);
1209
1210         return __gfn_to_hva_memslot(slot, gfn);
1211 }
1212
1213 static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
1214                                      gfn_t *nr_pages)
1215 {
1216         return __gfn_to_hva_many(slot, gfn, nr_pages, true);
1217 }
1218
1219 unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot,
1220                                         gfn_t gfn)
1221 {
1222         return gfn_to_hva_many(slot, gfn, NULL);
1223 }
1224 EXPORT_SYMBOL_GPL(gfn_to_hva_memslot);
1225
1226 unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
1227 {
1228         return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL);
1229 }
1230 EXPORT_SYMBOL_GPL(gfn_to_hva);
1231
1232 unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn)
1233 {
1234         return gfn_to_hva_many(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn, NULL);
1235 }
1236 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_hva);
1237
1238 /*
1239  * If writable is set to false, the hva returned by this function is only
1240  * allowed to be read.
1241  */
1242 unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot,
1243                                       gfn_t gfn, bool *writable)
1244 {
1245         unsigned long hva = __gfn_to_hva_many(slot, gfn, NULL, false);
1246
1247         if (!kvm_is_error_hva(hva) && writable)
1248                 *writable = !memslot_is_readonly(slot);
1249
1250         return hva;
1251 }
1252
1253 unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable)
1254 {
1255         struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
1256
1257         return gfn_to_hva_memslot_prot(slot, gfn, writable);
1258 }
1259
1260 unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable)
1261 {
1262         struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1263
1264         return gfn_to_hva_memslot_prot(slot, gfn, writable);
1265 }
1266
1267 static int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm,
1268         unsigned long start, int write, struct page **page)
1269 {
1270         int flags = FOLL_TOUCH | FOLL_NOWAIT | FOLL_HWPOISON | FOLL_GET;
1271
1272         if (write)
1273                 flags |= FOLL_WRITE;
1274
1275         return __get_user_pages(tsk, mm, start, 1, flags, page, NULL, NULL);
1276 }
1277
1278 static inline int check_user_page_hwpoison(unsigned long addr)
1279 {
1280         int rc, flags = FOLL_TOUCH | FOLL_HWPOISON | FOLL_WRITE;
1281
1282         rc = __get_user_pages(current, current->mm, addr, 1,
1283                               flags, NULL, NULL, NULL);
1284         return rc == -EHWPOISON;
1285 }
1286
1287 /*
1288  * The atomic path to get the writable pfn which will be stored in @pfn,
1289  * true indicates success, otherwise false is returned.
1290  */
1291 static bool hva_to_pfn_fast(unsigned long addr, bool atomic, bool *async,
1292                             bool write_fault, bool *writable, kvm_pfn_t *pfn)
1293 {
1294         struct page *page[1];
1295         int npages;
1296
1297         if (!(async || atomic))
1298                 return false;
1299
1300         /*
1301          * Fast pin a writable pfn only if it is a write fault request
1302          * or the caller allows to map a writable pfn for a read fault
1303          * request.
1304          */
1305         if (!(write_fault || writable))
1306                 return false;
1307
1308         npages = __get_user_pages_fast(addr, 1, 1, page);
1309         if (npages == 1) {
1310                 *pfn = page_to_pfn(page[0]);
1311
1312                 if (writable)
1313                         *writable = true;
1314                 return true;
1315         }
1316
1317         return false;
1318 }
1319
1320 /*
1321  * The slow path to get the pfn of the specified host virtual address,
1322  * 1 indicates success, -errno is returned if error is detected.
1323  */
1324 static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault,
1325                            bool *writable, kvm_pfn_t *pfn)
1326 {
1327         struct page *page[1];
1328         int npages = 0;
1329
1330         might_sleep();
1331
1332         if (writable)
1333                 *writable = write_fault;
1334
1335         if (async) {
1336                 down_read(&current->mm->mmap_sem);
1337                 npages = get_user_page_nowait(current, current->mm,
1338                                               addr, write_fault, page);
1339                 up_read(&current->mm->mmap_sem);
1340         } else
1341                 npages = __get_user_pages_unlocked(current, current->mm, addr, 1,
1342                                                    write_fault, 0, page,
1343                                                    FOLL_TOUCH|FOLL_HWPOISON);
1344         if (npages != 1)
1345                 return npages;
1346
1347         /* map read fault as writable if possible */
1348         if (unlikely(!write_fault) && writable) {
1349                 struct page *wpage[1];
1350
1351                 npages = __get_user_pages_fast(addr, 1, 1, wpage);
1352                 if (npages == 1) {
1353                         *writable = true;
1354                         put_page(page[0]);
1355                         page[0] = wpage[0];
1356                 }
1357
1358                 npages = 1;
1359         }
1360         *pfn = page_to_pfn(page[0]);
1361         return npages;
1362 }
1363
1364 static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault)
1365 {
1366         if (unlikely(!(vma->vm_flags & VM_READ)))
1367                 return false;
1368
1369         if (write_fault && (unlikely(!(vma->vm_flags & VM_WRITE))))
1370                 return false;
1371
1372         return true;
1373 }
1374
1375 /*
1376  * Pin guest page in memory and return its pfn.
1377  * @addr: host virtual address which maps memory to the guest
1378  * @atomic: whether this function can sleep
1379  * @async: whether this function need to wait IO complete if the
1380  *         host page is not in the memory
1381  * @write_fault: whether we should get a writable host page
1382  * @writable: whether it allows to map a writable host page for !@write_fault
1383  *
1384  * The function will map a writable host page for these two cases:
1385  * 1): @write_fault = true
1386  * 2): @write_fault = false && @writable, @writable will tell the caller
1387  *     whether the mapping is writable.
1388  */
1389 static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
1390                         bool write_fault, bool *writable)
1391 {
1392         struct vm_area_struct *vma;
1393         kvm_pfn_t pfn = 0;
1394         int npages;
1395
1396         /* we can do it either atomically or asynchronously, not both */
1397         BUG_ON(atomic && async);
1398
1399         if (hva_to_pfn_fast(addr, atomic, async, write_fault, writable, &pfn))
1400                 return pfn;
1401
1402         if (atomic)
1403                 return KVM_PFN_ERR_FAULT;
1404
1405         npages = hva_to_pfn_slow(addr, async, write_fault, writable, &pfn);
1406         if (npages == 1)
1407                 return pfn;
1408
1409         down_read(&current->mm->mmap_sem);
1410         if (npages == -EHWPOISON ||
1411               (!async && check_user_page_hwpoison(addr))) {
1412                 pfn = KVM_PFN_ERR_HWPOISON;
1413                 goto exit;
1414         }
1415
1416         vma = find_vma_intersection(current->mm, addr, addr + 1);
1417
1418         if (vma == NULL)
1419                 pfn = KVM_PFN_ERR_FAULT;
1420         else if ((vma->vm_flags & VM_PFNMAP)) {
1421                 pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) +
1422                         vma->vm_pgoff;
1423                 BUG_ON(!kvm_is_reserved_pfn(pfn));
1424         } else {
1425                 if (async && vma_is_valid(vma, write_fault))
1426                         *async = true;
1427                 pfn = KVM_PFN_ERR_FAULT;
1428         }
1429 exit:
1430         up_read(&current->mm->mmap_sem);
1431         return pfn;
1432 }
1433
1434 kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn,
1435                                bool atomic, bool *async, bool write_fault,
1436                                bool *writable)
1437 {
1438         unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault);
1439
1440         if (addr == KVM_HVA_ERR_RO_BAD)
1441                 return KVM_PFN_ERR_RO_FAULT;
1442
1443         if (kvm_is_error_hva(addr))
1444                 return KVM_PFN_NOSLOT;
1445
1446         /* Do not map writable pfn in the readonly memslot. */
1447         if (writable && memslot_is_readonly(slot)) {
1448                 *writable = false;
1449                 writable = NULL;
1450         }
1451
1452         return hva_to_pfn(addr, atomic, async, write_fault,
1453                           writable);
1454 }
1455 EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot);
1456
1457 kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
1458                       bool *writable)
1459 {
1460         return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, NULL,
1461                                     write_fault, writable);
1462 }
1463 EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);
1464
1465 kvm_pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
1466 {
1467         return __gfn_to_pfn_memslot(slot, gfn, false, NULL, true, NULL);
1468 }
1469 EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot);
1470
1471 kvm_pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn)
1472 {
1473         return __gfn_to_pfn_memslot(slot, gfn, true, NULL, true, NULL);
1474 }
1475 EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic);
1476
1477 kvm_pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn)
1478 {
1479         return gfn_to_pfn_memslot_atomic(gfn_to_memslot(kvm, gfn), gfn);
1480 }
1481 EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic);
1482
1483 kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn)
1484 {
1485         return gfn_to_pfn_memslot_atomic(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
1486 }
1487 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_atomic);
1488
1489 kvm_pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
1490 {
1491         return gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn);
1492 }
1493 EXPORT_SYMBOL_GPL(gfn_to_pfn);
1494
1495 kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn)
1496 {
1497         return gfn_to_pfn_memslot(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
1498 }
1499 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn);
1500
1501 int gfn_to_page_many_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
1502                             struct page **pages, int nr_pages)
1503 {
1504         unsigned long addr;
1505         gfn_t entry;
1506
1507         addr = gfn_to_hva_many(slot, gfn, &entry);
1508         if (kvm_is_error_hva(addr))
1509                 return -1;
1510
1511         if (entry < nr_pages)
1512                 return 0;
1513
1514         return __get_user_pages_fast(addr, nr_pages, 1, pages);
1515 }
1516 EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
1517
1518 static struct page *kvm_pfn_to_page(kvm_pfn_t pfn)
1519 {
1520         if (is_error_noslot_pfn(pfn))
1521                 return KVM_ERR_PTR_BAD_PAGE;
1522
1523         if (kvm_is_reserved_pfn(pfn)) {
1524                 WARN_ON(1);
1525                 return KVM_ERR_PTR_BAD_PAGE;
1526         }
1527
1528         return pfn_to_page(pfn);
1529 }
1530
1531 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
1532 {
1533         kvm_pfn_t pfn;
1534
1535         pfn = gfn_to_pfn(kvm, gfn);
1536
1537         return kvm_pfn_to_page(pfn);
1538 }
1539 EXPORT_SYMBOL_GPL(gfn_to_page);
1540
1541 struct page *kvm_vcpu_gfn_to_page(struct kvm_vcpu *vcpu, gfn_t gfn)
1542 {
1543         kvm_pfn_t pfn;
1544
1545         pfn = kvm_vcpu_gfn_to_pfn(vcpu, gfn);
1546
1547         return kvm_pfn_to_page(pfn);
1548 }
1549 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_page);
1550
1551 void kvm_release_page_clean(struct page *page)
1552 {
1553         WARN_ON(is_error_page(page));
1554
1555         kvm_release_pfn_clean(page_to_pfn(page));
1556 }
1557 EXPORT_SYMBOL_GPL(kvm_release_page_clean);
1558
1559 void kvm_release_pfn_clean(kvm_pfn_t pfn)
1560 {
1561         if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn))
1562                 put_page(pfn_to_page(pfn));
1563 }
1564 EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
1565
1566 void kvm_release_page_dirty(struct page *page)
1567 {
1568         WARN_ON(is_error_page(page));
1569
1570         kvm_release_pfn_dirty(page_to_pfn(page));
1571 }
1572 EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
1573
1574 static void kvm_release_pfn_dirty(kvm_pfn_t pfn)
1575 {
1576         kvm_set_pfn_dirty(pfn);
1577         kvm_release_pfn_clean(pfn);
1578 }
1579
1580 void kvm_set_pfn_dirty(kvm_pfn_t pfn)
1581 {
1582         if (!kvm_is_reserved_pfn(pfn)) {
1583                 struct page *page = pfn_to_page(pfn);
1584
1585                 if (!PageReserved(page))
1586                         SetPageDirty(page);
1587         }
1588 }
1589 EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
1590
1591 void kvm_set_pfn_accessed(kvm_pfn_t pfn)
1592 {
1593         if (!kvm_is_reserved_pfn(pfn))
1594                 mark_page_accessed(pfn_to_page(pfn));
1595 }
1596 EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
1597
1598 void kvm_get_pfn(kvm_pfn_t pfn)
1599 {
1600         if (!kvm_is_reserved_pfn(pfn))
1601                 get_page(pfn_to_page(pfn));
1602 }
1603 EXPORT_SYMBOL_GPL(kvm_get_pfn);
1604
1605 static int next_segment(unsigned long len, int offset)
1606 {
1607         if (len > PAGE_SIZE - offset)
1608                 return PAGE_SIZE - offset;
1609         else
1610                 return len;
1611 }
1612
1613 static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn,
1614                                  void *data, int offset, int len)
1615 {
1616         int r;
1617         unsigned long addr;
1618
1619         addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
1620         if (kvm_is_error_hva(addr))
1621                 return -EFAULT;
1622         r = __copy_from_user(data, (void __user *)addr + offset, len);
1623         if (r)
1624                 return -EFAULT;
1625         return 0;
1626 }
1627
1628 int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
1629                         int len)
1630 {
1631         struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
1632
1633         return __kvm_read_guest_page(slot, gfn, data, offset, len);
1634 }
1635 EXPORT_SYMBOL_GPL(kvm_read_guest_page);
1636
1637 int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data,
1638                              int offset, int len)
1639 {
1640         struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1641
1642         return __kvm_read_guest_page(slot, gfn, data, offset, len);
1643 }
1644 EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_page);
1645
1646 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
1647 {
1648         gfn_t gfn = gpa >> PAGE_SHIFT;
1649         int seg;
1650         int offset = offset_in_page(gpa);
1651         int ret;
1652
1653         while ((seg = next_segment(len, offset)) != 0) {
1654                 ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
1655                 if (ret < 0)
1656                         return ret;
1657                 offset = 0;
1658                 len -= seg;
1659                 data += seg;
1660                 ++gfn;
1661         }
1662         return 0;
1663 }
1664 EXPORT_SYMBOL_GPL(kvm_read_guest);
1665
1666 int kvm_vcpu_read_guest(struct kvm_vcpu *vcpu, gpa_t gpa, void *data, unsigned long len)
1667 {
1668         gfn_t gfn = gpa >> PAGE_SHIFT;
1669         int seg;
1670         int offset = offset_in_page(gpa);
1671         int ret;
1672
1673         while ((seg = next_segment(len, offset)) != 0) {
1674                 ret = kvm_vcpu_read_guest_page(vcpu, gfn, data, offset, seg);
1675                 if (ret < 0)
1676                         return ret;
1677                 offset = 0;
1678                 len -= seg;
1679                 data += seg;
1680                 ++gfn;
1681         }
1682         return 0;
1683 }
1684 EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest);
1685
1686 static int __kvm_read_guest_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
1687                                    void *data, int offset, unsigned long len)
1688 {
1689         int r;
1690         unsigned long addr;
1691
1692         addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
1693         if (kvm_is_error_hva(addr))
1694                 return -EFAULT;
1695         pagefault_disable();
1696         r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
1697         pagefault_enable();
1698         if (r)
1699                 return -EFAULT;
1700         return 0;
1701 }
1702
1703 int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
1704                           unsigned long len)
1705 {
1706         gfn_t gfn = gpa >> PAGE_SHIFT;
1707         struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
1708         int offset = offset_in_page(gpa);
1709
1710         return __kvm_read_guest_atomic(slot, gfn, data, offset, len);
1711 }
1712 EXPORT_SYMBOL_GPL(kvm_read_guest_atomic);
1713
1714 int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa,
1715                                void *data, unsigned long len)
1716 {
1717         gfn_t gfn = gpa >> PAGE_SHIFT;
1718         struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1719         int offset = offset_in_page(gpa);
1720
1721         return __kvm_read_guest_atomic(slot, gfn, data, offset, len);
1722 }
1723 EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic);
1724
1725 static int __kvm_write_guest_page(struct kvm_memory_slot *memslot, gfn_t gfn,
1726                                   const void *data, int offset, int len)
1727 {
1728         int r;
1729         unsigned long addr;
1730
1731         addr = gfn_to_hva_memslot(memslot, gfn);
1732         if (kvm_is_error_hva(addr))
1733                 return -EFAULT;
1734         r = __copy_to_user((void __user *)addr + offset, data, len);
1735         if (r)
1736                 return -EFAULT;
1737         mark_page_dirty_in_slot(memslot, gfn);
1738         return 0;
1739 }
1740
1741 int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn,
1742                          const void *data, int offset, int len)
1743 {
1744         struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
1745
1746         return __kvm_write_guest_page(slot, gfn, data, offset, len);
1747 }
1748 EXPORT_SYMBOL_GPL(kvm_write_guest_page);
1749
1750 int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn,
1751                               const void *data, int offset, int len)
1752 {
1753         struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1754
1755         return __kvm_write_guest_page(slot, gfn, data, offset, len);
1756 }
1757 EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest_page);
1758
1759 int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
1760                     unsigned long len)
1761 {
1762         gfn_t gfn = gpa >> PAGE_SHIFT;
1763         int seg;
1764         int offset = offset_in_page(gpa);
1765         int ret;
1766
1767         while ((seg = next_segment(len, offset)) != 0) {
1768                 ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
1769                 if (ret < 0)
1770                         return ret;
1771                 offset = 0;
1772                 len -= seg;
1773                 data += seg;
1774                 ++gfn;
1775         }
1776         return 0;
1777 }
1778 EXPORT_SYMBOL_GPL(kvm_write_guest);
1779
1780 int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data,
1781                          unsigned long len)
1782 {
1783         gfn_t gfn = gpa >> PAGE_SHIFT;
1784         int seg;
1785         int offset = offset_in_page(gpa);
1786         int ret;
1787
1788         while ((seg = next_segment(len, offset)) != 0) {
1789                 ret = kvm_vcpu_write_guest_page(vcpu, gfn, data, offset, seg);
1790                 if (ret < 0)
1791                         return ret;
1792                 offset = 0;
1793                 len -= seg;
1794                 data += seg;
1795                 ++gfn;
1796         }
1797         return 0;
1798 }
1799 EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest);
1800
1801 int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1802                               gpa_t gpa, unsigned long len)
1803 {
1804         struct kvm_memslots *slots = kvm_memslots(kvm);
1805         int offset = offset_in_page(gpa);
1806         gfn_t start_gfn = gpa >> PAGE_SHIFT;
1807         gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT;
1808         gfn_t nr_pages_needed = end_gfn - start_gfn + 1;
1809         gfn_t nr_pages_avail;
1810
1811         ghc->gpa = gpa;
1812         ghc->generation = slots->generation;
1813         ghc->len = len;
1814         ghc->memslot = gfn_to_memslot(kvm, start_gfn);
1815         ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, NULL);
1816         if (!kvm_is_error_hva(ghc->hva) && nr_pages_needed <= 1) {
1817                 ghc->hva += offset;
1818         } else {
1819                 /*
1820                  * If the requested region crosses two memslots, we still
1821                  * verify that the entire region is valid here.
1822                  */
1823                 while (start_gfn <= end_gfn) {
1824                         ghc->memslot = gfn_to_memslot(kvm, start_gfn);
1825                         ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn,
1826                                                    &nr_pages_avail);
1827                         if (kvm_is_error_hva(ghc->hva))
1828                                 return -EFAULT;
1829                         start_gfn += nr_pages_avail;
1830                 }
1831                 /* Use the slow path for cross page reads and writes. */
1832                 ghc->memslot = NULL;
1833         }
1834         return 0;
1835 }
1836 EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
1837
1838 int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1839                            void *data, unsigned long len)
1840 {
1841         struct kvm_memslots *slots = kvm_memslots(kvm);
1842         int r;
1843
1844         BUG_ON(len > ghc->len);
1845
1846         if (slots->generation != ghc->generation)
1847                 kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa, ghc->len);
1848
1849         if (unlikely(!ghc->memslot))
1850                 return kvm_write_guest(kvm, ghc->gpa, data, len);
1851
1852         if (kvm_is_error_hva(ghc->hva))
1853                 return -EFAULT;
1854
1855         r = __copy_to_user((void __user *)ghc->hva, data, len);
1856         if (r)
1857                 return -EFAULT;
1858         mark_page_dirty_in_slot(ghc->memslot, ghc->gpa >> PAGE_SHIFT);
1859
1860         return 0;
1861 }
1862 EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
1863
1864 int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1865                            void *data, unsigned long len)
1866 {
1867         struct kvm_memslots *slots = kvm_memslots(kvm);
1868         int r;
1869
1870         BUG_ON(len > ghc->len);
1871
1872         if (slots->generation != ghc->generation)
1873                 kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa, ghc->len);
1874
1875         if (unlikely(!ghc->memslot))
1876                 return kvm_read_guest(kvm, ghc->gpa, data, len);
1877
1878         if (kvm_is_error_hva(ghc->hva))
1879                 return -EFAULT;
1880
1881         r = __copy_from_user(data, (void __user *)ghc->hva, len);
1882         if (r)
1883                 return -EFAULT;
1884
1885         return 0;
1886 }
1887 EXPORT_SYMBOL_GPL(kvm_read_guest_cached);
1888
1889 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
1890 {
1891         const void *zero_page = (const void *) __va(page_to_phys(ZERO_PAGE(0)));
1892
1893         return kvm_write_guest_page(kvm, gfn, zero_page, offset, len);
1894 }
1895 EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
1896
1897 int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
1898 {
1899         gfn_t gfn = gpa >> PAGE_SHIFT;
1900         int seg;
1901         int offset = offset_in_page(gpa);
1902         int ret;
1903
1904         while ((seg = next_segment(len, offset)) != 0) {
1905                 ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
1906                 if (ret < 0)
1907                         return ret;
1908                 offset = 0;
1909                 len -= seg;
1910                 ++gfn;
1911         }
1912         return 0;
1913 }
1914 EXPORT_SYMBOL_GPL(kvm_clear_guest);
1915
1916 static void mark_page_dirty_in_slot(struct kvm_memory_slot *memslot,
1917                                     gfn_t gfn)
1918 {
1919         if (memslot && memslot->dirty_bitmap) {
1920                 unsigned long rel_gfn = gfn - memslot->base_gfn;
1921
1922                 set_bit_le(rel_gfn, memslot->dirty_bitmap);
1923         }
1924 }
1925
1926 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
1927 {
1928         struct kvm_memory_slot *memslot;
1929
1930         memslot = gfn_to_memslot(kvm, gfn);
1931         mark_page_dirty_in_slot(memslot, gfn);
1932 }
1933 EXPORT_SYMBOL_GPL(mark_page_dirty);
1934
1935 void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn)
1936 {
1937         struct kvm_memory_slot *memslot;
1938
1939         memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1940         mark_page_dirty_in_slot(memslot, gfn);
1941 }
1942 EXPORT_SYMBOL_GPL(kvm_vcpu_mark_page_dirty);
1943
1944 static void grow_halt_poll_ns(struct kvm_vcpu *vcpu)
1945 {
1946         int old, val;
1947
1948         old = val = vcpu->halt_poll_ns;
1949         /* 10us base */
1950         if (val == 0 && halt_poll_ns_grow)
1951                 val = 10000;
1952         else
1953                 val *= halt_poll_ns_grow;
1954
1955         if (val > halt_poll_ns)
1956                 val = halt_poll_ns;
1957
1958         vcpu->halt_poll_ns = val;
1959         trace_kvm_halt_poll_ns_grow(vcpu->vcpu_id, val, old);
1960 }
1961
1962 static void shrink_halt_poll_ns(struct kvm_vcpu *vcpu)
1963 {
1964         int old, val;
1965
1966         old = val = vcpu->halt_poll_ns;
1967         if (halt_poll_ns_shrink == 0)
1968                 val = 0;
1969         else
1970                 val /= halt_poll_ns_shrink;
1971
1972         vcpu->halt_poll_ns = val;
1973         trace_kvm_halt_poll_ns_shrink(vcpu->vcpu_id, val, old);
1974 }
1975
1976 static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu)
1977 {
1978         if (kvm_arch_vcpu_runnable(vcpu)) {
1979                 kvm_make_request(KVM_REQ_UNHALT, vcpu);
1980                 return -EINTR;
1981         }
1982         if (kvm_cpu_has_pending_timer(vcpu))
1983                 return -EINTR;
1984         if (signal_pending(current))
1985                 return -EINTR;
1986
1987         return 0;
1988 }
1989
1990 /*
1991  * The vCPU has executed a HLT instruction with in-kernel mode enabled.
1992  */
1993 void kvm_vcpu_block(struct kvm_vcpu *vcpu)
1994 {
1995         ktime_t start, cur;
1996         DEFINE_WAIT(wait);
1997         bool waited = false;
1998         u64 block_ns;
1999
2000         start = cur = ktime_get();
2001         if (vcpu->halt_poll_ns) {
2002                 ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns);
2003
2004                 ++vcpu->stat.halt_attempted_poll;
2005                 do {
2006                         /*
2007                          * This sets KVM_REQ_UNHALT if an interrupt
2008                          * arrives.
2009                          */
2010                         if (kvm_vcpu_check_block(vcpu) < 0) {
2011                                 ++vcpu->stat.halt_successful_poll;
2012                                 goto out;
2013                         }
2014                         cur = ktime_get();
2015                 } while (single_task_running() && ktime_before(cur, stop));
2016         }
2017
2018         kvm_arch_vcpu_blocking(vcpu);
2019
2020         for (;;) {
2021                 prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
2022
2023                 if (kvm_vcpu_check_block(vcpu) < 0)
2024                         break;
2025
2026                 waited = true;
2027                 schedule();
2028         }
2029
2030         finish_wait(&vcpu->wq, &wait);
2031         cur = ktime_get();
2032
2033         kvm_arch_vcpu_unblocking(vcpu);
2034 out:
2035         block_ns = ktime_to_ns(cur) - ktime_to_ns(start);
2036
2037         if (halt_poll_ns) {
2038                 if (block_ns <= vcpu->halt_poll_ns)
2039                         ;
2040                 /* we had a long block, shrink polling */
2041                 else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns)
2042                         shrink_halt_poll_ns(vcpu);
2043                 /* we had a short halt and our poll time is too small */
2044                 else if (vcpu->halt_poll_ns < halt_poll_ns &&
2045                         block_ns < halt_poll_ns)
2046                         grow_halt_poll_ns(vcpu);
2047         } else
2048                 vcpu->halt_poll_ns = 0;
2049
2050         trace_kvm_vcpu_wakeup(block_ns, waited);
2051 }
2052 EXPORT_SYMBOL_GPL(kvm_vcpu_block);
2053
2054 #ifndef CONFIG_S390
2055 /*
2056  * Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode.
2057  */
2058 void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
2059 {
2060         int me;
2061         int cpu = vcpu->cpu;
2062         wait_queue_head_t *wqp;
2063
2064         wqp = kvm_arch_vcpu_wq(vcpu);
2065         if (waitqueue_active(wqp)) {
2066                 wake_up_interruptible(wqp);
2067                 ++vcpu->stat.halt_wakeup;
2068         }
2069
2070         me = get_cpu();
2071         if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu))
2072                 if (kvm_arch_vcpu_should_kick(vcpu))
2073                         smp_send_reschedule(cpu);
2074         put_cpu();
2075 }
2076 EXPORT_SYMBOL_GPL(kvm_vcpu_kick);
2077 #endif /* !CONFIG_S390 */
2078
2079 int kvm_vcpu_yield_to(struct kvm_vcpu *target)
2080 {
2081         struct pid *pid;
2082         struct task_struct *task = NULL;
2083         int ret = 0;
2084
2085         rcu_read_lock();
2086         pid = rcu_dereference(target->pid);
2087         if (pid)
2088                 task = get_pid_task(pid, PIDTYPE_PID);
2089         rcu_read_unlock();
2090         if (!task)
2091                 return ret;
2092         ret = yield_to(task, 1);
2093         put_task_struct(task);
2094
2095         return ret;
2096 }
2097 EXPORT_SYMBOL_GPL(kvm_vcpu_yield_to);
2098
2099 /*
2100  * Helper that checks whether a VCPU is eligible for directed yield.
2101  * Most eligible candidate to yield is decided by following heuristics:
2102  *
2103  *  (a) VCPU which has not done pl-exit or cpu relax intercepted recently
2104  *  (preempted lock holder), indicated by @in_spin_loop.
2105  *  Set at the beiginning and cleared at the end of interception/PLE handler.
2106  *
2107  *  (b) VCPU which has done pl-exit/ cpu relax intercepted but did not get
2108  *  chance last time (mostly it has become eligible now since we have probably
2109  *  yielded to lockholder in last iteration. This is done by toggling
2110  *  @dy_eligible each time a VCPU checked for eligibility.)
2111  *
2112  *  Yielding to a recently pl-exited/cpu relax intercepted VCPU before yielding
2113  *  to preempted lock-holder could result in wrong VCPU selection and CPU
2114  *  burning. Giving priority for a potential lock-holder increases lock
2115  *  progress.
2116  *
2117  *  Since algorithm is based on heuristics, accessing another VCPU data without
2118  *  locking does not harm. It may result in trying to yield to  same VCPU, fail
2119  *  and continue with next VCPU and so on.
2120  */
2121 static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu)
2122 {
2123 #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
2124         bool eligible;
2125
2126         eligible = !vcpu->spin_loop.in_spin_loop ||
2127                     vcpu->spin_loop.dy_eligible;
2128
2129         if (vcpu->spin_loop.in_spin_loop)
2130                 kvm_vcpu_set_dy_eligible(vcpu, !vcpu->spin_loop.dy_eligible);
2131
2132         return eligible;
2133 #else
2134         return true;
2135 #endif
2136 }
2137
2138 void kvm_vcpu_on_spin(struct kvm_vcpu *me)
2139 {
2140         struct kvm *kvm = me->kvm;
2141         struct kvm_vcpu *vcpu;
2142         int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
2143         int yielded = 0;
2144         int try = 3;
2145         int pass;
2146         int i;
2147
2148         kvm_vcpu_set_in_spin_loop(me, true);
2149         /*
2150          * We boost the priority of a VCPU that is runnable but not
2151          * currently running, because it got preempted by something
2152          * else and called schedule in __vcpu_run.  Hopefully that
2153          * VCPU is holding the lock that we need and will release it.
2154          * We approximate round-robin by starting at the last boosted VCPU.
2155          */
2156         for (pass = 0; pass < 2 && !yielded && try; pass++) {
2157                 kvm_for_each_vcpu(i, vcpu, kvm) {
2158                         if (!pass && i <= last_boosted_vcpu) {
2159                                 i = last_boosted_vcpu;
2160                                 continue;
2161                         } else if (pass && i > last_boosted_vcpu)
2162                                 break;
2163                         if (!ACCESS_ONCE(vcpu->preempted))
2164                                 continue;
2165                         if (vcpu == me)
2166                                 continue;
2167                         if (waitqueue_active(&vcpu->wq) && !kvm_arch_vcpu_runnable(vcpu))
2168                                 continue;
2169                         if (!kvm_vcpu_eligible_for_directed_yield(vcpu))
2170                                 continue;
2171
2172                         yielded = kvm_vcpu_yield_to(vcpu);
2173                         if (yielded > 0) {
2174                                 kvm->last_boosted_vcpu = i;
2175                                 break;
2176                         } else if (yielded < 0) {
2177                                 try--;
2178                                 if (!try)
2179                                         break;
2180                         }
2181                 }
2182         }
2183         kvm_vcpu_set_in_spin_loop(me, false);
2184
2185         /* Ensure vcpu is not eligible during next spinloop */
2186         kvm_vcpu_set_dy_eligible(me, false);
2187 }
2188 EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
2189
2190 static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
2191 {
2192         struct kvm_vcpu *vcpu = vma->vm_file->private_data;
2193         struct page *page;
2194
2195         if (vmf->pgoff == 0)
2196                 page = virt_to_page(vcpu->run);
2197 #ifdef CONFIG_X86
2198         else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
2199                 page = virt_to_page(vcpu->arch.pio_data);
2200 #endif
2201 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2202         else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
2203                 page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
2204 #endif
2205         else
2206                 return kvm_arch_vcpu_fault(vcpu, vmf);
2207         get_page(page);
2208         vmf->page = page;
2209         return 0;
2210 }
2211
2212 static const struct vm_operations_struct kvm_vcpu_vm_ops = {
2213         .fault = kvm_vcpu_fault,
2214 };
2215
2216 static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
2217 {
2218         vma->vm_ops = &kvm_vcpu_vm_ops;
2219         return 0;
2220 }
2221
2222 static int kvm_vcpu_release(struct inode *inode, struct file *filp)
2223 {
2224         struct kvm_vcpu *vcpu = filp->private_data;
2225
2226         kvm_put_kvm(vcpu->kvm);
2227         return 0;
2228 }
2229
2230 static struct file_operations kvm_vcpu_fops = {
2231         .release        = kvm_vcpu_release,
2232         .unlocked_ioctl = kvm_vcpu_ioctl,
2233 #ifdef CONFIG_KVM_COMPAT
2234         .compat_ioctl   = kvm_vcpu_compat_ioctl,
2235 #endif
2236         .mmap           = kvm_vcpu_mmap,
2237         .llseek         = noop_llseek,
2238 };
2239
2240 /*
2241  * Allocates an inode for the vcpu.
2242  */
2243 static int create_vcpu_fd(struct kvm_vcpu *vcpu)
2244 {
2245         return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC);
2246 }
2247
2248 /*
2249  * Creates some virtual cpus.  Good luck creating more than one.
2250  */
2251 static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
2252 {
2253         int r;
2254         struct kvm_vcpu *vcpu;
2255
2256         if (id >= KVM_MAX_VCPUS)
2257                 return -EINVAL;
2258
2259         vcpu = kvm_arch_vcpu_create(kvm, id);
2260         if (IS_ERR(vcpu))
2261                 return PTR_ERR(vcpu);
2262
2263         preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
2264
2265         r = kvm_arch_vcpu_setup(vcpu);
2266         if (r)
2267                 goto vcpu_destroy;
2268
2269         mutex_lock(&kvm->lock);
2270         if (!kvm_vcpu_compatible(vcpu)) {
2271                 r = -EINVAL;
2272                 goto unlock_vcpu_destroy;
2273         }
2274         if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
2275                 r = -EINVAL;
2276                 goto unlock_vcpu_destroy;
2277         }
2278         if (kvm_get_vcpu_by_id(kvm, id)) {
2279                 r = -EEXIST;
2280                 goto unlock_vcpu_destroy;
2281         }
2282
2283         BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
2284
2285         /* Now it's all set up, let userspace reach it */
2286         kvm_get_kvm(kvm);
2287         r = create_vcpu_fd(vcpu);
2288         if (r < 0) {
2289                 kvm_put_kvm(kvm);
2290                 goto unlock_vcpu_destroy;
2291         }
2292
2293         kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
2294
2295         /*
2296          * Pairs with smp_rmb() in kvm_get_vcpu.  Write kvm->vcpus
2297          * before kvm->online_vcpu's incremented value.
2298          */
2299         smp_wmb();
2300         atomic_inc(&kvm->online_vcpus);
2301
2302         mutex_unlock(&kvm->lock);
2303         kvm_arch_vcpu_postcreate(vcpu);
2304         return r;
2305
2306 unlock_vcpu_destroy:
2307         mutex_unlock(&kvm->lock);
2308 vcpu_destroy:
2309         kvm_arch_vcpu_destroy(vcpu);
2310         return r;
2311 }
2312
2313 static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
2314 {
2315         if (sigset) {
2316                 sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
2317                 vcpu->sigset_active = 1;
2318                 vcpu->sigset = *sigset;
2319         } else
2320                 vcpu->sigset_active = 0;
2321         return 0;
2322 }
2323
2324 static long kvm_vcpu_ioctl(struct file *filp,
2325                            unsigned int ioctl, unsigned long arg)
2326 {
2327         struct kvm_vcpu *vcpu = filp->private_data;
2328         void __user *argp = (void __user *)arg;
2329         int r;
2330         struct kvm_fpu *fpu = NULL;
2331         struct kvm_sregs *kvm_sregs = NULL;
2332
2333         if (vcpu->kvm->mm != current->mm)
2334                 return -EIO;
2335
2336         if (unlikely(_IOC_TYPE(ioctl) != KVMIO))
2337                 return -EINVAL;
2338
2339 #if defined(CONFIG_S390) || defined(CONFIG_PPC) || defined(CONFIG_MIPS)
2340         /*
2341          * Special cases: vcpu ioctls that are asynchronous to vcpu execution,
2342          * so vcpu_load() would break it.
2343          */
2344         if (ioctl == KVM_S390_INTERRUPT || ioctl == KVM_S390_IRQ || ioctl == KVM_INTERRUPT)
2345                 return kvm_arch_vcpu_ioctl(filp, ioctl, arg);
2346 #endif
2347
2348
2349         r = vcpu_load(vcpu);
2350         if (r)
2351                 return r;
2352         switch (ioctl) {
2353         case KVM_RUN:
2354                 r = -EINVAL;
2355                 if (arg)
2356                         goto out;
2357                 if (unlikely(vcpu->pid != current->pids[PIDTYPE_PID].pid)) {
2358                         /* The thread running this VCPU changed. */
2359                         struct pid *oldpid = vcpu->pid;
2360                         struct pid *newpid = get_task_pid(current, PIDTYPE_PID);
2361
2362                         rcu_assign_pointer(vcpu->pid, newpid);
2363                         if (oldpid)
2364                                 synchronize_rcu();
2365                         put_pid(oldpid);
2366                 }
2367                 r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
2368                 trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
2369                 break;
2370         case KVM_GET_REGS: {
2371                 struct kvm_regs *kvm_regs;
2372
2373                 r = -ENOMEM;
2374                 kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
2375                 if (!kvm_regs)
2376                         goto out;
2377                 r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
2378                 if (r)
2379                         goto out_free1;
2380                 r = -EFAULT;
2381                 if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
2382                         goto out_free1;
2383                 r = 0;
2384 out_free1:
2385                 kfree(kvm_regs);
2386                 break;
2387         }
2388         case KVM_SET_REGS: {
2389                 struct kvm_regs *kvm_regs;
2390
2391                 r = -ENOMEM;
2392                 kvm_regs = memdup_user(argp, sizeof(*kvm_regs));
2393                 if (IS_ERR(kvm_regs)) {
2394                         r = PTR_ERR(kvm_regs);
2395                         goto out;
2396                 }
2397                 r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
2398                 kfree(kvm_regs);
2399                 break;
2400         }
2401         case KVM_GET_SREGS: {
2402                 kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
2403                 r = -ENOMEM;
2404                 if (!kvm_sregs)
2405                         goto out;
2406                 r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs);
2407                 if (r)
2408                         goto out;
2409                 r = -EFAULT;
2410                 if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs)))
2411                         goto out;
2412                 r = 0;
2413                 break;
2414         }
2415         case KVM_SET_SREGS: {
2416                 kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs));
2417                 if (IS_ERR(kvm_sregs)) {
2418                         r = PTR_ERR(kvm_sregs);
2419                         kvm_sregs = NULL;
2420                         goto out;
2421                 }
2422                 r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs);
2423                 break;
2424         }
2425         case KVM_GET_MP_STATE: {
2426                 struct kvm_mp_state mp_state;
2427
2428                 r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
2429                 if (r)
2430                         goto out;
2431                 r = -EFAULT;
2432                 if (copy_to_user(argp, &mp_state, sizeof(mp_state)))
2433                         goto out;
2434                 r = 0;
2435                 break;
2436         }
2437         case KVM_SET_MP_STATE: {
2438                 struct kvm_mp_state mp_state;
2439
2440                 r = -EFAULT;
2441                 if (copy_from_user(&mp_state, argp, sizeof(mp_state)))
2442                         goto out;
2443                 r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
2444                 break;
2445         }
2446         case KVM_TRANSLATE: {
2447                 struct kvm_translation tr;
2448
2449                 r = -EFAULT;
2450                 if (copy_from_user(&tr, argp, sizeof(tr)))
2451                         goto out;
2452                 r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
2453                 if (r)
2454                         goto out;
2455                 r = -EFAULT;
2456                 if (copy_to_user(argp, &tr, sizeof(tr)))
2457                         goto out;
2458                 r = 0;
2459                 break;
2460         }
2461         case KVM_SET_GUEST_DEBUG: {
2462                 struct kvm_guest_debug dbg;
2463
2464                 r = -EFAULT;
2465                 if (copy_from_user(&dbg, argp, sizeof(dbg)))
2466                         goto out;
2467                 r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg);
2468                 break;
2469         }
2470         case KVM_SET_SIGNAL_MASK: {
2471                 struct kvm_signal_mask __user *sigmask_arg = argp;
2472                 struct kvm_signal_mask kvm_sigmask;
2473                 sigset_t sigset, *p;
2474
2475                 p = NULL;
2476                 if (argp) {
2477                         r = -EFAULT;
2478                         if (copy_from_user(&kvm_sigmask, argp,
2479                                            sizeof(kvm_sigmask)))
2480                                 goto out;
2481                         r = -EINVAL;
2482                         if (kvm_sigmask.len != sizeof(sigset))
2483                                 goto out;
2484                         r = -EFAULT;
2485                         if (copy_from_user(&sigset, sigmask_arg->sigset,
2486                                            sizeof(sigset)))
2487                                 goto out;
2488                         p = &sigset;
2489                 }
2490                 r = kvm_vcpu_ioctl_set_sigmask(vcpu, p);
2491                 break;
2492         }
2493         case KVM_GET_FPU: {
2494                 fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
2495                 r = -ENOMEM;
2496                 if (!fpu)
2497                         goto out;
2498                 r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
2499                 if (r)
2500                         goto out;
2501                 r = -EFAULT;
2502                 if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu)))
2503                         goto out;
2504                 r = 0;
2505                 break;
2506         }
2507         case KVM_SET_FPU: {
2508                 fpu = memdup_user(argp, sizeof(*fpu));
2509                 if (IS_ERR(fpu)) {
2510                         r = PTR_ERR(fpu);
2511                         fpu = NULL;
2512                         goto out;
2513                 }
2514                 r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
2515                 break;
2516         }
2517         default:
2518                 r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
2519         }
2520 out:
2521         vcpu_put(vcpu);
2522         kfree(fpu);
2523         kfree(kvm_sregs);
2524         return r;
2525 }
2526
2527 #ifdef CONFIG_KVM_COMPAT
2528 static long kvm_vcpu_compat_ioctl(struct file *filp,
2529                                   unsigned int ioctl, unsigned long arg)
2530 {
2531         struct kvm_vcpu *vcpu = filp->private_data;
2532         void __user *argp = compat_ptr(arg);
2533         int r;
2534
2535         if (vcpu->kvm->mm != current->mm)
2536                 return -EIO;
2537
2538         switch (ioctl) {
2539         case KVM_SET_SIGNAL_MASK: {
2540                 struct kvm_signal_mask __user *sigmask_arg = argp;
2541                 struct kvm_signal_mask kvm_sigmask;
2542                 compat_sigset_t csigset;
2543                 sigset_t sigset;
2544
2545                 if (argp) {
2546                         r = -EFAULT;
2547                         if (copy_from_user(&kvm_sigmask, argp,
2548                                            sizeof(kvm_sigmask)))
2549                                 goto out;
2550                         r = -EINVAL;
2551                         if (kvm_sigmask.len != sizeof(csigset))
2552                                 goto out;
2553                         r = -EFAULT;
2554                         if (copy_from_user(&csigset, sigmask_arg->sigset,
2555                                            sizeof(csigset)))
2556                                 goto out;
2557                         sigset_from_compat(&sigset, &csigset);
2558                         r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
2559                 } else
2560                         r = kvm_vcpu_ioctl_set_sigmask(vcpu, NULL);
2561                 break;
2562         }
2563         default:
2564                 r = kvm_vcpu_ioctl(filp, ioctl, arg);
2565         }
2566
2567 out:
2568         return r;
2569 }
2570 #endif
2571
2572 static int kvm_device_ioctl_attr(struct kvm_device *dev,
2573                                  int (*accessor)(struct kvm_device *dev,
2574                                                  struct kvm_device_attr *attr),
2575                                  unsigned long arg)
2576 {
2577         struct kvm_device_attr attr;
2578
2579         if (!accessor)
2580                 return -EPERM;
2581
2582         if (copy_from_user(&attr, (void __user *)arg, sizeof(attr)))
2583                 return -EFAULT;
2584
2585         return accessor(dev, &attr);
2586 }
2587
2588 static long kvm_device_ioctl(struct file *filp, unsigned int ioctl,
2589                              unsigned long arg)
2590 {
2591         struct kvm_device *dev = filp->private_data;
2592
2593         switch (ioctl) {
2594         case KVM_SET_DEVICE_ATTR:
2595                 return kvm_device_ioctl_attr(dev, dev->ops->set_attr, arg);
2596         case KVM_GET_DEVICE_ATTR:
2597                 return kvm_device_ioctl_attr(dev, dev->ops->get_attr, arg);
2598         case KVM_HAS_DEVICE_ATTR:
2599                 return kvm_device_ioctl_attr(dev, dev->ops->has_attr, arg);
2600         default:
2601                 if (dev->ops->ioctl)
2602                         return dev->ops->ioctl(dev, ioctl, arg);
2603
2604                 return -ENOTTY;
2605         }
2606 }
2607
2608 static int kvm_device_release(struct inode *inode, struct file *filp)
2609 {
2610         struct kvm_device *dev = filp->private_data;
2611         struct kvm *kvm = dev->kvm;
2612
2613         kvm_put_kvm(kvm);
2614         return 0;
2615 }
2616
2617 static const struct file_operations kvm_device_fops = {
2618         .unlocked_ioctl = kvm_device_ioctl,
2619 #ifdef CONFIG_KVM_COMPAT
2620         .compat_ioctl = kvm_device_ioctl,
2621 #endif
2622         .release = kvm_device_release,
2623 };
2624
2625 struct kvm_device *kvm_device_from_filp(struct file *filp)
2626 {
2627         if (filp->f_op != &kvm_device_fops)
2628                 return NULL;
2629
2630         return filp->private_data;
2631 }
2632
2633 static struct kvm_device_ops *kvm_device_ops_table[KVM_DEV_TYPE_MAX] = {
2634 #ifdef CONFIG_KVM_MPIC
2635         [KVM_DEV_TYPE_FSL_MPIC_20]      = &kvm_mpic_ops,
2636         [KVM_DEV_TYPE_FSL_MPIC_42]      = &kvm_mpic_ops,
2637 #endif
2638
2639 #ifdef CONFIG_KVM_XICS
2640         [KVM_DEV_TYPE_XICS]             = &kvm_xics_ops,
2641 #endif
2642 };
2643
2644 int kvm_register_device_ops(struct kvm_device_ops *ops, u32 type)
2645 {
2646         if (type >= ARRAY_SIZE(kvm_device_ops_table))
2647                 return -ENOSPC;
2648
2649         if (kvm_device_ops_table[type] != NULL)
2650                 return -EEXIST;
2651
2652         kvm_device_ops_table[type] = ops;
2653         return 0;
2654 }
2655
2656 void kvm_unregister_device_ops(u32 type)
2657 {
2658         if (kvm_device_ops_table[type] != NULL)
2659                 kvm_device_ops_table[type] = NULL;
2660 }
2661
2662 static int kvm_ioctl_create_device(struct kvm *kvm,
2663                                    struct kvm_create_device *cd)
2664 {
2665         struct kvm_device_ops *ops = NULL;
2666         struct kvm_device *dev;
2667         bool test = cd->flags & KVM_CREATE_DEVICE_TEST;
2668         int ret;
2669
2670         if (cd->type >= ARRAY_SIZE(kvm_device_ops_table))
2671                 return -ENODEV;
2672
2673         ops = kvm_device_ops_table[cd->type];
2674         if (ops == NULL)
2675                 return -ENODEV;
2676
2677         if (test)
2678                 return 0;
2679
2680         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
2681         if (!dev)
2682                 return -ENOMEM;
2683
2684         dev->ops = ops;
2685         dev->kvm = kvm;
2686
2687         ret = ops->create(dev, cd->type);
2688         if (ret < 0) {
2689                 kfree(dev);
2690                 return ret;
2691         }
2692
2693         ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC);
2694         if (ret < 0) {
2695                 ops->destroy(dev);
2696                 return ret;
2697         }
2698
2699         list_add(&dev->vm_node, &kvm->devices);
2700         kvm_get_kvm(kvm);
2701         cd->fd = ret;
2702         return 0;
2703 }
2704
2705 static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
2706 {
2707         switch (arg) {
2708         case KVM_CAP_USER_MEMORY:
2709         case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
2710         case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
2711         case KVM_CAP_INTERNAL_ERROR_DATA:
2712 #ifdef CONFIG_HAVE_KVM_MSI
2713         case KVM_CAP_SIGNAL_MSI:
2714 #endif
2715 #ifdef CONFIG_HAVE_KVM_IRQFD
2716         case KVM_CAP_IRQFD:
2717         case KVM_CAP_IRQFD_RESAMPLE:
2718 #endif
2719         case KVM_CAP_IOEVENTFD_ANY_LENGTH:
2720         case KVM_CAP_CHECK_EXTENSION_VM:
2721                 return 1;
2722 #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
2723         case KVM_CAP_IRQ_ROUTING:
2724                 return KVM_MAX_IRQ_ROUTES;
2725 #endif
2726 #if KVM_ADDRESS_SPACE_NUM > 1
2727         case KVM_CAP_MULTI_ADDRESS_SPACE:
2728                 return KVM_ADDRESS_SPACE_NUM;
2729 #endif
2730         default:
2731                 break;
2732         }
2733         return kvm_vm_ioctl_check_extension(kvm, arg);
2734 }
2735
2736 static long kvm_vm_ioctl(struct file *filp,
2737                            unsigned int ioctl, unsigned long arg)
2738 {
2739         struct kvm *kvm = filp->private_data;
2740         void __user *argp = (void __user *)arg;
2741         int r;
2742
2743         if (kvm->mm != current->mm)
2744                 return -EIO;
2745         switch (ioctl) {
2746         case KVM_CREATE_VCPU:
2747                 r = kvm_vm_ioctl_create_vcpu(kvm, arg);
2748                 break;
2749         case KVM_SET_USER_MEMORY_REGION: {
2750                 struct kvm_userspace_memory_region kvm_userspace_mem;
2751
2752                 r = -EFAULT;
2753                 if (copy_from_user(&kvm_userspace_mem, argp,
2754                                                 sizeof(kvm_userspace_mem)))
2755                         goto out;
2756
2757                 r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem);
2758                 break;
2759         }
2760         case KVM_GET_DIRTY_LOG: {
2761                 struct kvm_dirty_log log;
2762
2763                 r = -EFAULT;
2764                 if (copy_from_user(&log, argp, sizeof(log)))
2765                         goto out;
2766                 r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
2767                 break;
2768         }
2769 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2770         case KVM_REGISTER_COALESCED_MMIO: {
2771                 struct kvm_coalesced_mmio_zone zone;
2772
2773                 r = -EFAULT;
2774                 if (copy_from_user(&zone, argp, sizeof(zone)))
2775                         goto out;
2776                 r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
2777                 break;
2778         }
2779         case KVM_UNREGISTER_COALESCED_MMIO: {
2780                 struct kvm_coalesced_mmio_zone zone;
2781
2782                 r = -EFAULT;
2783                 if (copy_from_user(&zone, argp, sizeof(zone)))
2784                         goto out;
2785                 r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
2786                 break;
2787         }
2788 #endif
2789         case KVM_IRQFD: {
2790                 struct kvm_irqfd data;
2791
2792                 r = -EFAULT;
2793                 if (copy_from_user(&data, argp, sizeof(data)))
2794                         goto out;
2795                 r = kvm_irqfd(kvm, &data);
2796                 break;
2797         }
2798         case KVM_IOEVENTFD: {
2799                 struct kvm_ioeventfd data;
2800
2801                 r = -EFAULT;
2802                 if (copy_from_user(&data, argp, sizeof(data)))
2803                         goto out;
2804                 r = kvm_ioeventfd(kvm, &data);
2805                 break;
2806         }
2807 #ifdef CONFIG_HAVE_KVM_MSI
2808         case KVM_SIGNAL_MSI: {
2809                 struct kvm_msi msi;
2810
2811                 r = -EFAULT;
2812                 if (copy_from_user(&msi, argp, sizeof(msi)))
2813                         goto out;
2814                 r = kvm_send_userspace_msi(kvm, &msi);
2815                 break;
2816         }
2817 #endif
2818 #ifdef __KVM_HAVE_IRQ_LINE
2819         case KVM_IRQ_LINE_STATUS:
2820         case KVM_IRQ_LINE: {
2821                 struct kvm_irq_level irq_event;
2822
2823                 r = -EFAULT;
2824                 if (copy_from_user(&irq_event, argp, sizeof(irq_event)))
2825                         goto out;
2826
2827                 r = kvm_vm_ioctl_irq_line(kvm, &irq_event,
2828                                         ioctl == KVM_IRQ_LINE_STATUS);
2829                 if (r)
2830                         goto out;
2831
2832                 r = -EFAULT;
2833                 if (ioctl == KVM_IRQ_LINE_STATUS) {
2834                         if (copy_to_user(argp, &irq_event, sizeof(irq_event)))
2835                                 goto out;
2836                 }
2837
2838                 r = 0;
2839                 break;
2840         }
2841 #endif
2842 #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
2843         case KVM_SET_GSI_ROUTING: {
2844                 struct kvm_irq_routing routing;
2845                 struct kvm_irq_routing __user *urouting;
2846                 struct kvm_irq_routing_entry *entries;
2847
2848                 r = -EFAULT;
2849                 if (copy_from_user(&routing, argp, sizeof(routing)))
2850                         goto out;
2851                 r = -EINVAL;
2852                 if (routing.nr >= KVM_MAX_IRQ_ROUTES)
2853                         goto out;
2854                 if (routing.flags)
2855                         goto out;
2856                 r = -ENOMEM;
2857                 entries = vmalloc(routing.nr * sizeof(*entries));
2858                 if (!entries)
2859                         goto out;
2860                 r = -EFAULT;
2861                 urouting = argp;
2862                 if (copy_from_user(entries, urouting->entries,
2863                                    routing.nr * sizeof(*entries)))
2864                         goto out_free_irq_routing;
2865                 r = kvm_set_irq_routing(kvm, entries, routing.nr,
2866                                         routing.flags);
2867 out_free_irq_routing:
2868                 vfree(entries);
2869                 break;
2870         }
2871 #endif /* CONFIG_HAVE_KVM_IRQ_ROUTING */
2872         case KVM_CREATE_DEVICE: {
2873                 struct kvm_create_device cd;
2874
2875                 r = -EFAULT;
2876                 if (copy_from_user(&cd, argp, sizeof(cd)))
2877                         goto out;
2878
2879                 r = kvm_ioctl_create_device(kvm, &cd);
2880                 if (r)
2881                         goto out;
2882
2883                 r = -EFAULT;
2884                 if (copy_to_user(argp, &cd, sizeof(cd)))
2885                         goto out;
2886
2887                 r = 0;
2888                 break;
2889         }
2890         case KVM_CHECK_EXTENSION:
2891                 r = kvm_vm_ioctl_check_extension_generic(kvm, arg);
2892                 break;
2893         default:
2894                 r = kvm_arch_vm_ioctl(filp, ioctl, arg);
2895         }
2896 out:
2897         return r;
2898 }
2899
2900 #ifdef CONFIG_KVM_COMPAT
2901 struct compat_kvm_dirty_log {
2902         __u32 slot;
2903         __u32 padding1;
2904         union {
2905                 compat_uptr_t dirty_bitmap; /* one bit per page */
2906                 __u64 padding2;
2907         };
2908 };
2909
2910 static long kvm_vm_compat_ioctl(struct file *filp,
2911                            unsigned int ioctl, unsigned long arg)
2912 {
2913         struct kvm *kvm = filp->private_data;
2914         int r;
2915
2916         if (kvm->mm != current->mm)
2917                 return -EIO;
2918         switch (ioctl) {
2919         case KVM_GET_DIRTY_LOG: {
2920                 struct compat_kvm_dirty_log compat_log;
2921                 struct kvm_dirty_log log;
2922
2923                 r = -EFAULT;
2924                 if (copy_from_user(&compat_log, (void __user *)arg,
2925                                    sizeof(compat_log)))
2926                         goto out;
2927                 log.slot         = compat_log.slot;
2928                 log.padding1     = compat_log.padding1;
2929                 log.padding2     = compat_log.padding2;
2930                 log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
2931
2932                 r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
2933                 break;
2934         }
2935         default:
2936                 r = kvm_vm_ioctl(filp, ioctl, arg);
2937         }
2938
2939 out:
2940         return r;
2941 }
2942 #endif
2943
2944 static struct file_operations kvm_vm_fops = {
2945         .release        = kvm_vm_release,
2946         .unlocked_ioctl = kvm_vm_ioctl,
2947 #ifdef CONFIG_KVM_COMPAT
2948         .compat_ioctl   = kvm_vm_compat_ioctl,
2949 #endif
2950         .llseek         = noop_llseek,
2951 };
2952
2953 static int kvm_dev_ioctl_create_vm(unsigned long type)
2954 {
2955         int r;
2956         struct kvm *kvm;
2957
2958         kvm = kvm_create_vm(type);
2959         if (IS_ERR(kvm))
2960                 return PTR_ERR(kvm);
2961 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2962         r = kvm_coalesced_mmio_init(kvm);
2963         if (r < 0) {
2964                 kvm_put_kvm(kvm);
2965                 return r;
2966         }
2967 #endif
2968         r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR | O_CLOEXEC);
2969         if (r < 0)
2970                 kvm_put_kvm(kvm);
2971
2972         return r;
2973 }
2974
2975 static long kvm_dev_ioctl(struct file *filp,
2976                           unsigned int ioctl, unsigned long arg)
2977 {
2978         long r = -EINVAL;
2979
2980         switch (ioctl) {
2981         case KVM_GET_API_VERSION:
2982                 if (arg)
2983                         goto out;
2984                 r = KVM_API_VERSION;
2985                 break;
2986         case KVM_CREATE_VM:
2987                 r = kvm_dev_ioctl_create_vm(arg);
2988                 break;
2989         case KVM_CHECK_EXTENSION:
2990                 r = kvm_vm_ioctl_check_extension_generic(NULL, arg);
2991                 break;
2992         case KVM_GET_VCPU_MMAP_SIZE:
2993                 if (arg)
2994                         goto out;
2995                 r = PAGE_SIZE;     /* struct kvm_run */
2996 #ifdef CONFIG_X86
2997                 r += PAGE_SIZE;    /* pio data page */
2998 #endif
2999 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
3000                 r += PAGE_SIZE;    /* coalesced mmio ring page */
3001 #endif
3002                 break;
3003         case KVM_TRACE_ENABLE:
3004         case KVM_TRACE_PAUSE:
3005         case KVM_TRACE_DISABLE:
3006                 r = -EOPNOTSUPP;
3007                 break;
3008         default:
3009                 return kvm_arch_dev_ioctl(filp, ioctl, arg);
3010         }
3011 out:
3012         return r;
3013 }
3014
3015 static struct file_operations kvm_chardev_ops = {
3016         .unlocked_ioctl = kvm_dev_ioctl,
3017         .compat_ioctl   = kvm_dev_ioctl,
3018         .llseek         = noop_llseek,
3019 };
3020
3021 static struct miscdevice kvm_dev = {
3022         KVM_MINOR,
3023         "kvm",
3024         &kvm_chardev_ops,
3025 };
3026
3027 static void hardware_enable_nolock(void *junk)
3028 {
3029         int cpu = raw_smp_processor_id();
3030         int r;
3031
3032         if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
3033                 return;
3034
3035         cpumask_set_cpu(cpu, cpus_hardware_enabled);
3036
3037         r = kvm_arch_hardware_enable();
3038
3039         if (r) {
3040                 cpumask_clear_cpu(cpu, cpus_hardware_enabled);
3041                 atomic_inc(&hardware_enable_failed);
3042                 pr_info("kvm: enabling virtualization on CPU%d failed\n", cpu);
3043         }
3044 }
3045
3046 static void hardware_enable(void)
3047 {
3048         raw_spin_lock(&kvm_count_lock);
3049         if (kvm_usage_count)
3050                 hardware_enable_nolock(NULL);
3051         raw_spin_unlock(&kvm_count_lock);
3052 }
3053
3054 static void hardware_disable_nolock(void *junk)
3055 {
3056         int cpu = raw_smp_processor_id();
3057
3058         if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
3059                 return;
3060         cpumask_clear_cpu(cpu, cpus_hardware_enabled);
3061         kvm_arch_hardware_disable();
3062 }
3063
3064 static void hardware_disable(void)
3065 {
3066         raw_spin_lock(&kvm_count_lock);
3067         if (kvm_usage_count)
3068                 hardware_disable_nolock(NULL);
3069         raw_spin_unlock(&kvm_count_lock);
3070 }
3071
3072 static void hardware_disable_all_nolock(void)
3073 {
3074         BUG_ON(!kvm_usage_count);
3075
3076         kvm_usage_count--;
3077         if (!kvm_usage_count)
3078                 on_each_cpu(hardware_disable_nolock, NULL, 1);
3079 }
3080
3081 static void hardware_disable_all(void)
3082 {
3083         raw_spin_lock(&kvm_count_lock);
3084         hardware_disable_all_nolock();
3085         raw_spin_unlock(&kvm_count_lock);
3086 }
3087
3088 static int hardware_enable_all(void)
3089 {
3090         int r = 0;
3091
3092         raw_spin_lock(&kvm_count_lock);
3093
3094         kvm_usage_count++;
3095         if (kvm_usage_count == 1) {
3096                 atomic_set(&hardware_enable_failed, 0);
3097                 on_each_cpu(hardware_enable_nolock, NULL, 1);
3098
3099                 if (atomic_read(&hardware_enable_failed)) {
3100                         hardware_disable_all_nolock();
3101                         r = -EBUSY;
3102                 }
3103         }
3104
3105         raw_spin_unlock(&kvm_count_lock);
3106
3107         return r;
3108 }
3109
3110 static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
3111                            void *v)
3112 {
3113         val &= ~CPU_TASKS_FROZEN;
3114         switch (val) {
3115         case CPU_DYING:
3116                 hardware_disable();
3117                 break;
3118         case CPU_STARTING:
3119                 hardware_enable();
3120                 break;
3121         }
3122         return NOTIFY_OK;
3123 }
3124
3125 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
3126                       void *v)
3127 {
3128         /*
3129          * Some (well, at least mine) BIOSes hang on reboot if
3130          * in vmx root mode.
3131          *
3132          * And Intel TXT required VMX off for all cpu when system shutdown.
3133          */
3134         pr_info("kvm: exiting hardware virtualization\n");
3135         kvm_rebooting = true;
3136         on_each_cpu(hardware_disable_nolock, NULL, 1);
3137         return NOTIFY_OK;
3138 }
3139
3140 static struct notifier_block kvm_reboot_notifier = {
3141         .notifier_call = kvm_reboot,
3142         .priority = 0,
3143 };
3144
3145 static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
3146 {
3147         int i;
3148
3149         for (i = 0; i < bus->dev_count; i++) {
3150                 struct kvm_io_device *pos = bus->range[i].dev;
3151
3152                 kvm_iodevice_destructor(pos);
3153         }
3154         kfree(bus);
3155 }
3156
3157 static inline int kvm_io_bus_cmp(const struct kvm_io_range *r1,
3158                                  const struct kvm_io_range *r2)
3159 {
3160         gpa_t addr1 = r1->addr;
3161         gpa_t addr2 = r2->addr;
3162
3163         if (addr1 < addr2)
3164                 return -1;
3165
3166         /* If r2->len == 0, match the exact address.  If r2->len != 0,
3167          * accept any overlapping write.  Any order is acceptable for
3168          * overlapping ranges, because kvm_io_bus_get_first_dev ensures
3169          * we process all of them.
3170          */
3171         if (r2->len) {
3172                 addr1 += r1->len;
3173                 addr2 += r2->len;
3174         }
3175
3176         if (addr1 > addr2)
3177                 return 1;
3178
3179         return 0;
3180 }
3181
3182 static int kvm_io_bus_sort_cmp(const void *p1, const void *p2)
3183 {
3184         return kvm_io_bus_cmp(p1, p2);
3185 }
3186
3187 static int kvm_io_bus_insert_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev,
3188                           gpa_t addr, int len)
3189 {
3190         bus->range[bus->dev_count++] = (struct kvm_io_range) {
3191                 .addr = addr,
3192                 .len = len,
3193                 .dev = dev,
3194         };
3195
3196         sort(bus->range, bus->dev_count, sizeof(struct kvm_io_range),
3197                 kvm_io_bus_sort_cmp, NULL);
3198
3199         return 0;
3200 }
3201
3202 static int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus,
3203                              gpa_t addr, int len)
3204 {
3205         struct kvm_io_range *range, key;
3206         int off;
3207
3208         key = (struct kvm_io_range) {
3209                 .addr = addr,
3210                 .len = len,
3211         };
3212
3213         range = bsearch(&key, bus->range, bus->dev_count,
3214                         sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp);
3215         if (range == NULL)
3216                 return -ENOENT;
3217
3218         off = range - bus->range;
3219
3220         while (off > 0 && kvm_io_bus_cmp(&key, &bus->range[off-1]) == 0)
3221                 off--;
3222
3223         return off;
3224 }
3225
3226 static int __kvm_io_bus_write(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
3227                               struct kvm_io_range *range, const void *val)
3228 {
3229         int idx;
3230
3231         idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len);
3232         if (idx < 0)
3233                 return -EOPNOTSUPP;
3234
3235         while (idx < bus->dev_count &&
3236                 kvm_io_bus_cmp(range, &bus->range[idx]) == 0) {
3237                 if (!kvm_iodevice_write(vcpu, bus->range[idx].dev, range->addr,
3238                                         range->len, val))
3239                         return idx;
3240                 idx++;
3241         }
3242
3243         return -EOPNOTSUPP;
3244 }
3245
3246 /* kvm_io_bus_write - called under kvm->slots_lock */
3247 int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
3248                      int len, const void *val)
3249 {
3250         struct kvm_io_bus *bus;
3251         struct kvm_io_range range;
3252         int r;
3253
3254         range = (struct kvm_io_range) {
3255                 .addr = addr,
3256                 .len = len,
3257         };
3258
3259         bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
3260         r = __kvm_io_bus_write(vcpu, bus, &range, val);
3261         return r < 0 ? r : 0;
3262 }
3263
3264 /* kvm_io_bus_write_cookie - called under kvm->slots_lock */
3265 int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx,
3266                             gpa_t addr, int len, const void *val, long cookie)
3267 {
3268         struct kvm_io_bus *bus;
3269         struct kvm_io_range range;
3270
3271         range = (struct kvm_io_range) {
3272                 .addr = addr,
3273                 .len = len,
3274         };
3275
3276         bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
3277
3278         /* First try the device referenced by cookie. */
3279         if ((cookie >= 0) && (cookie < bus->dev_count) &&
3280             (kvm_io_bus_cmp(&range, &bus->range[cookie]) == 0))
3281                 if (!kvm_iodevice_write(vcpu, bus->range[cookie].dev, addr, len,
3282                                         val))
3283                         return cookie;
3284
3285         /*
3286          * cookie contained garbage; fall back to search and return the
3287          * correct cookie value.
3288          */
3289         return __kvm_io_bus_write(vcpu, bus, &range, val);
3290 }
3291
3292 static int __kvm_io_bus_read(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
3293                              struct kvm_io_range *range, void *val)
3294 {
3295         int idx;
3296
3297         idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len);
3298         if (idx < 0)
3299                 return -EOPNOTSUPP;
3300
3301         while (idx < bus->dev_count &&
3302                 kvm_io_bus_cmp(range, &bus->range[idx]) == 0) {
3303                 if (!kvm_iodevice_read(vcpu, bus->range[idx].dev, range->addr,
3304                                        range->len, val))
3305                         return idx;
3306                 idx++;
3307         }
3308
3309         return -EOPNOTSUPP;
3310 }
3311 EXPORT_SYMBOL_GPL(kvm_io_bus_write);
3312
3313 /* kvm_io_bus_read - called under kvm->slots_lock */
3314 int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
3315                     int len, void *val)
3316 {
3317         struct kvm_io_bus *bus;
3318         struct kvm_io_range range;
3319         int r;
3320
3321         range = (struct kvm_io_range) {
3322                 .addr = addr,
3323                 .len = len,
3324         };
3325
3326         bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
3327         r = __kvm_io_bus_read(vcpu, bus, &range, val);
3328         return r < 0 ? r : 0;
3329 }
3330
3331
3332 /* Caller must hold slots_lock. */
3333 int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
3334                             int len, struct kvm_io_device *dev)
3335 {
3336         struct kvm_io_bus *new_bus, *bus;
3337
3338         bus = kvm->buses[bus_idx];
3339         /* exclude ioeventfd which is limited by maximum fd */
3340         if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1)
3341                 return -ENOSPC;
3342
3343         new_bus = kmalloc(sizeof(*bus) + ((bus->dev_count + 1) *
3344                           sizeof(struct kvm_io_range)), GFP_KERNEL);
3345         if (!new_bus)
3346                 return -ENOMEM;
3347         memcpy(new_bus, bus, sizeof(*bus) + (bus->dev_count *
3348                sizeof(struct kvm_io_range)));
3349         kvm_io_bus_insert_dev(new_bus, dev, addr, len);
3350         rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
3351         synchronize_srcu_expedited(&kvm->srcu);
3352         kfree(bus);
3353
3354         return 0;
3355 }
3356
3357 /* Caller must hold slots_lock. */
3358 int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
3359                               struct kvm_io_device *dev)
3360 {
3361         int i, r;
3362         struct kvm_io_bus *new_bus, *bus;
3363
3364         bus = kvm->buses[bus_idx];
3365         r = -ENOENT;
3366         for (i = 0; i < bus->dev_count; i++)
3367                 if (bus->range[i].dev == dev) {
3368                         r = 0;
3369                         break;
3370                 }
3371
3372         if (r)
3373                 return r;
3374
3375         new_bus = kmalloc(sizeof(*bus) + ((bus->dev_count - 1) *
3376                           sizeof(struct kvm_io_range)), GFP_KERNEL);
3377         if (!new_bus)
3378                 return -ENOMEM;
3379
3380         memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range));
3381         new_bus->dev_count--;
3382         memcpy(new_bus->range + i, bus->range + i + 1,
3383                (new_bus->dev_count - i) * sizeof(struct kvm_io_range));
3384
3385         rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
3386         synchronize_srcu_expedited(&kvm->srcu);
3387         kfree(bus);
3388         return r;
3389 }
3390
3391 static struct notifier_block kvm_cpu_notifier = {
3392         .notifier_call = kvm_cpu_hotplug,
3393 };
3394
3395 static int vm_stat_get(void *_offset, u64 *val)
3396 {
3397         unsigned offset = (long)_offset;
3398         struct kvm *kvm;
3399
3400         *val = 0;
3401         spin_lock(&kvm_lock);
3402         list_for_each_entry(kvm, &vm_list, vm_list)
3403                 *val += *(u32 *)((void *)kvm + offset);
3404         spin_unlock(&kvm_lock);
3405         return 0;
3406 }
3407
3408 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
3409
3410 static int vcpu_stat_get(void *_offset, u64 *val)
3411 {
3412         unsigned offset = (long)_offset;
3413         struct kvm *kvm;
3414         struct kvm_vcpu *vcpu;
3415         int i;
3416
3417         *val = 0;
3418         spin_lock(&kvm_lock);
3419         list_for_each_entry(kvm, &vm_list, vm_list)
3420                 kvm_for_each_vcpu(i, vcpu, kvm)
3421                         *val += *(u32 *)((void *)vcpu + offset);
3422
3423         spin_unlock(&kvm_lock);
3424         return 0;
3425 }
3426
3427 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
3428
3429 static const struct file_operations *stat_fops[] = {
3430         [KVM_STAT_VCPU] = &vcpu_stat_fops,
3431         [KVM_STAT_VM]   = &vm_stat_fops,
3432 };
3433
3434 static int kvm_init_debug(void)
3435 {
3436         int r = -EEXIST;
3437         struct kvm_stats_debugfs_item *p;
3438
3439         kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
3440         if (kvm_debugfs_dir == NULL)
3441                 goto out;
3442
3443         for (p = debugfs_entries; p->name; ++p) {
3444                 if (!debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
3445                                          (void *)(long)p->offset,
3446                                          stat_fops[p->kind]))
3447                         goto out_dir;
3448         }
3449
3450         return 0;
3451
3452 out_dir:
3453         debugfs_remove_recursive(kvm_debugfs_dir);
3454 out:
3455         return r;
3456 }
3457
3458 static int kvm_suspend(void)
3459 {
3460         if (kvm_usage_count)
3461                 hardware_disable_nolock(NULL);
3462         return 0;
3463 }
3464
3465 static void kvm_resume(void)
3466 {
3467         if (kvm_usage_count) {
3468                 WARN_ON(raw_spin_is_locked(&kvm_count_lock));
3469                 hardware_enable_nolock(NULL);
3470         }
3471 }
3472
3473 static struct syscore_ops kvm_syscore_ops = {
3474         .suspend = kvm_suspend,
3475         .resume = kvm_resume,
3476 };
3477
3478 static inline
3479 struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
3480 {
3481         return container_of(pn, struct kvm_vcpu, preempt_notifier);
3482 }
3483
3484 static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
3485 {
3486         struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
3487
3488         if (vcpu->preempted)
3489                 vcpu->preempted = false;
3490
3491         kvm_arch_sched_in(vcpu, cpu);
3492
3493         kvm_arch_vcpu_load(vcpu, cpu);
3494 }
3495
3496 static void kvm_sched_out(struct preempt_notifier *pn,
3497                           struct task_struct *next)
3498 {
3499         struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
3500
3501         if (current->state == TASK_RUNNING)
3502                 vcpu->preempted = true;
3503         kvm_arch_vcpu_put(vcpu);
3504 }
3505
3506 int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
3507                   struct module *module)
3508 {
3509         int r;
3510         int cpu;
3511
3512         r = kvm_arch_init(opaque);
3513         if (r)
3514                 goto out_fail;
3515
3516         /*
3517          * kvm_arch_init makes sure there's at most one caller
3518          * for architectures that support multiple implementations,
3519          * like intel and amd on x86.
3520          * kvm_arch_init must be called before kvm_irqfd_init to avoid creating
3521          * conflicts in case kvm is already setup for another implementation.
3522          */
3523         r = kvm_irqfd_init();
3524         if (r)
3525                 goto out_irqfd;
3526
3527         if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
3528                 r = -ENOMEM;
3529                 goto out_free_0;
3530         }
3531
3532         r = kvm_arch_hardware_setup();
3533         if (r < 0)
3534                 goto out_free_0a;
3535
3536         for_each_online_cpu(cpu) {
3537                 smp_call_function_single(cpu,
3538                                 kvm_arch_check_processor_compat,
3539                                 &r, 1);
3540                 if (r < 0)
3541                         goto out_free_1;
3542         }
3543
3544         r = register_cpu_notifier(&kvm_cpu_notifier);
3545         if (r)
3546                 goto out_free_2;
3547         register_reboot_notifier(&kvm_reboot_notifier);
3548
3549         /* A kmem cache lets us meet the alignment requirements of fx_save. */
3550         if (!vcpu_align)
3551                 vcpu_align = __alignof__(struct kvm_vcpu);
3552         kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size, vcpu_align,
3553                                            0, NULL);
3554         if (!kvm_vcpu_cache) {
3555                 r = -ENOMEM;
3556                 goto out_free_3;
3557         }
3558
3559         r = kvm_async_pf_init();
3560         if (r)
3561                 goto out_free;
3562
3563         kvm_chardev_ops.owner = module;
3564         kvm_vm_fops.owner = module;
3565         kvm_vcpu_fops.owner = module;
3566
3567         r = misc_register(&kvm_dev);
3568         if (r) {
3569                 pr_err("kvm: misc device register failed\n");
3570                 goto out_unreg;
3571         }
3572
3573         register_syscore_ops(&kvm_syscore_ops);
3574
3575         kvm_preempt_ops.sched_in = kvm_sched_in;
3576         kvm_preempt_ops.sched_out = kvm_sched_out;
3577
3578         r = kvm_init_debug();
3579         if (r) {
3580                 pr_err("kvm: create debugfs files failed\n");
3581                 goto out_undebugfs;
3582         }
3583
3584         r = kvm_vfio_ops_init();
3585         WARN_ON(r);
3586
3587         return 0;
3588
3589 out_undebugfs:
3590         unregister_syscore_ops(&kvm_syscore_ops);
3591         misc_deregister(&kvm_dev);
3592 out_unreg:
3593         kvm_async_pf_deinit();
3594 out_free:
3595         kmem_cache_destroy(kvm_vcpu_cache);
3596 out_free_3:
3597         unregister_reboot_notifier(&kvm_reboot_notifier);
3598         unregister_cpu_notifier(&kvm_cpu_notifier);
3599 out_free_2:
3600 out_free_1:
3601         kvm_arch_hardware_unsetup();
3602 out_free_0a:
3603         free_cpumask_var(cpus_hardware_enabled);
3604 out_free_0:
3605         kvm_irqfd_exit();
3606 out_irqfd:
3607         kvm_arch_exit();
3608 out_fail:
3609         return r;
3610 }
3611 EXPORT_SYMBOL_GPL(kvm_init);
3612
3613 void kvm_exit(void)
3614 {
3615         debugfs_remove_recursive(kvm_debugfs_dir);
3616         misc_deregister(&kvm_dev);
3617         kmem_cache_destroy(kvm_vcpu_cache);
3618         kvm_async_pf_deinit();
3619         unregister_syscore_ops(&kvm_syscore_ops);
3620         unregister_reboot_notifier(&kvm_reboot_notifier);
3621         unregister_cpu_notifier(&kvm_cpu_notifier);
3622         on_each_cpu(hardware_disable_nolock, NULL, 1);
3623         kvm_arch_hardware_unsetup();
3624         kvm_arch_exit();
3625         kvm_irqfd_exit();
3626         free_cpumask_var(cpus_hardware_enabled);
3627         kvm_vfio_ops_exit();
3628 }
3629 EXPORT_SYMBOL_GPL(kvm_exit);