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 /* halt polling only reduces halt latency by 5-7 us, 500us is enough */
  70 static unsigned int halt_poll_ns = 500000;
  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(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(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 void kvm_make_mclock_inprogress_request(struct kvm *kvm)
 210 {
 211         kvm_make_all_cpus_request(kvm, KVM_REQ_MCLOCK_INPROGRESS);
 212 }
 213
 214 void kvm_make_scan_ioapic_request(struct kvm *kvm)
 215 {
 216         kvm_make_all_cpus_request(kvm, KVM_REQ_SCAN_IOAPIC);
 217 }
 218
 219 int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
 220 {
 221         struct page *page;
 222         int r;
 223
 224         mutex_init(&vcpu->mutex);
 225         vcpu->cpu = -1;
 226         vcpu->kvm = kvm;
 227         vcpu->vcpu_id = id;
 228         vcpu->pid = NULL;
 229         vcpu->halt_poll_ns = 0;
 230         init_waitqueue_head(&vcpu->wq);
 231         kvm_async_pf_vcpu_init(vcpu);
 232
 233         page = alloc_page(GFP_KERNEL | __GFP_ZERO);
 234         if (!page) {
 235                 r = -ENOMEM;
 236                 goto fail;
 237         }
 238         vcpu->run = page_address(page);
 239
 240         kvm_vcpu_set_in_spin_loop(vcpu, false);
 241         kvm_vcpu_set_dy_eligible(vcpu, false);
 242         vcpu->preempted = false;
 243
 244         r = kvm_arch_vcpu_init(vcpu);
 245         if (r < 0)
 246                 goto fail_free_run;
 247         return 0;
 248
 249 fail_free_run:
 250         free_page((unsigned long)vcpu->run);
 251 fail:
 252         return r;
 253 }
 254 EXPORT_SYMBOL_GPL(kvm_vcpu_init);
 255
 256 void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
 257 {
 258         put_pid(vcpu->pid);
 259         kvm_arch_vcpu_uninit(vcpu);
 260         free_page((unsigned long)vcpu->run);
 261 }
 262 EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
 263
 264 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
 265 static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
 266 {
 267         return container_of(mn, struct kvm, mmu_notifier);
 268 }
 269
 270 static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
 271                                              struct mm_struct *mm,
 272                                              unsigned long address)
 273 {
 274         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 275         int need_tlb_flush, idx;
 276
 277         /*
 278          * When ->invalidate_page runs, the linux pte has been zapped
 279          * already but the page is still allocated until
 280          * ->invalidate_page returns. So if we increase the sequence
 281          * here the kvm page fault will notice if the spte can't be
 282          * established because the page is going to be freed. If
 283          * instead the kvm page fault establishes the spte before
 284          * ->invalidate_page runs, kvm_unmap_hva will release it
 285          * before returning.
 286          *
 287          * The sequence increase only need to be seen at spin_unlock
 288          * time, and not at spin_lock time.
 289          *
 290          * Increasing the sequence after the spin_unlock would be
 291          * unsafe because the kvm page fault could then establish the
 292          * pte after kvm_unmap_hva returned, without noticing the page
 293          * is going to be freed.
 294          */
 295         idx = srcu_read_lock(&kvm->srcu);
 296         spin_lock(&kvm->mmu_lock);
 297
 298         kvm->mmu_notifier_seq++;
 299         need_tlb_flush = kvm_unmap_hva(kvm, address) | kvm->tlbs_dirty;
 300         /* we've to flush the tlb before the pages can be freed */
 301         if (need_tlb_flush)
 302                 kvm_flush_remote_tlbs(kvm);
 303
 304         spin_unlock(&kvm->mmu_lock);
 305
 306         kvm_arch_mmu_notifier_invalidate_page(kvm, address);
 307
 308         srcu_read_unlock(&kvm->srcu, idx);
 309 }
 310
 311 static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
 312                                         struct mm_struct *mm,
 313                                         unsigned long address,
 314                                         pte_t pte)
 315 {
 316         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 317         int idx;
 318
 319         idx = srcu_read_lock(&kvm->srcu);
 320         spin_lock(&kvm->mmu_lock);
 321         kvm->mmu_notifier_seq++;
 322         kvm_set_spte_hva(kvm, address, pte);
 323         spin_unlock(&kvm->mmu_lock);
 324         srcu_read_unlock(&kvm->srcu, idx);
 325 }
 326
 327 static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
 328                                                     struct mm_struct *mm,
 329                                                     unsigned long start,
 330                                                     unsigned long end)
 331 {
 332         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 333         int need_tlb_flush = 0, idx;
 334
 335         idx = srcu_read_lock(&kvm->srcu);
 336         spin_lock(&kvm->mmu_lock);
 337         /*
 338          * The count increase must become visible at unlock time as no
 339          * spte can be established without taking the mmu_lock and
 340          * count is also read inside the mmu_lock critical section.
 341          */
 342         kvm->mmu_notifier_count++;
 343         need_tlb_flush = kvm_unmap_hva_range(kvm, start, end);
 344         need_tlb_flush |= kvm->tlbs_dirty;
 345         /* we've to flush the tlb before the pages can be freed */
 346         if (need_tlb_flush)
 347                 kvm_flush_remote_tlbs(kvm);
 348
 349         spin_unlock(&kvm->mmu_lock);
 350         srcu_read_unlock(&kvm->srcu, idx);
 351 }
 352
 353 static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
 354                                                   struct mm_struct *mm,
 355                                                   unsigned long start,
 356                                                   unsigned long end)
 357 {
 358         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 359
 360         spin_lock(&kvm->mmu_lock);
 361         /*
 362          * This sequence increase will notify the kvm page fault that
 363          * the page that is going to be mapped in the spte could have
 364          * been freed.
 365          */
 366         kvm->mmu_notifier_seq++;
 367         smp_wmb();
 368         /*
 369          * The above sequence increase must be visible before the
 370          * below count decrease, which is ensured by the smp_wmb above
 371          * in conjunction with the smp_rmb in mmu_notifier_retry().
 372          */
 373         kvm->mmu_notifier_count--;
 374         spin_unlock(&kvm->mmu_lock);
 375
 376         BUG_ON(kvm->mmu_notifier_count < 0);
 377 }
 378
 379 static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
 380                                               struct mm_struct *mm,
 381                                               unsigned long start,
 382                                               unsigned long end)
 383 {
 384         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 385         int young, idx;
 386
 387         idx = srcu_read_lock(&kvm->srcu);
 388         spin_lock(&kvm->mmu_lock);
 389
 390         young = kvm_age_hva(kvm, start, end);
 391         if (young)
 392                 kvm_flush_remote_tlbs(kvm);
 393
 394         spin_unlock(&kvm->mmu_lock);
 395         srcu_read_unlock(&kvm->srcu, idx);
 396
 397         return young;
 398 }
 399
 400 static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
 401                                         struct mm_struct *mm,
 402                                         unsigned long start,
 403                                         unsigned long end)
 404 {
 405         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 406         int young, idx;
 407
 408         idx = srcu_read_lock(&kvm->srcu);
 409         spin_lock(&kvm->mmu_lock);
 410         /*
 411          * Even though we do not flush TLB, this will still adversely
 412          * affect performance on pre-Haswell Intel EPT, where there is
 413          * no EPT Access Bit to clear so that we have to tear down EPT
 414          * tables instead. If we find this unacceptable, we can always
 415          * add a parameter to kvm_age_hva so that it effectively doesn't
 416          * do anything on clear_young.
 417          *
 418          * Also note that currently we never issue secondary TLB flushes
 419          * from clear_young, leaving this job up to the regular system
 420          * cadence. If we find this inaccurate, we might come up with a
 421          * more sophisticated heuristic later.
 422          */
 423         young = kvm_age_hva(kvm, start, end);
 424         spin_unlock(&kvm->mmu_lock);
 425         srcu_read_unlock(&kvm->srcu, idx);
 426
 427         return young;
 428 }
 429
 430 static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
 431                                        struct mm_struct *mm,
 432                                        unsigned long address)
 433 {
 434         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 435         int young, idx;
 436
 437         idx = srcu_read_lock(&kvm->srcu);
 438         spin_lock(&kvm->mmu_lock);
 439         young = kvm_test_age_hva(kvm, address);
 440         spin_unlock(&kvm->mmu_lock);
 441         srcu_read_unlock(&kvm->srcu, idx);
 442
 443         return young;
 444 }
 445
 446 static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
 447                                      struct mm_struct *mm)
 448 {
 449         struct kvm *kvm = mmu_notifier_to_kvm(mn);
 450         int idx;
 451
 452         idx = srcu_read_lock(&kvm->srcu);
 453         kvm_arch_flush_shadow_all(kvm);
 454         srcu_read_unlock(&kvm->srcu, idx);
 455 }
 456
 457 static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
 458         .invalidate_page        = kvm_mmu_notifier_invalidate_page,
 459         .invalidate_range_start = kvm_mmu_notifier_invalidate_range_start,
 460         .invalidate_range_end   = kvm_mmu_notifier_invalidate_range_end,
 461         .clear_flush_young      = kvm_mmu_notifier_clear_flush_young,
 462         .clear_young            = kvm_mmu_notifier_clear_young,
 463         .test_young             = kvm_mmu_notifier_test_young,
 464         .change_pte             = kvm_mmu_notifier_change_pte,
 465         .release                = kvm_mmu_notifier_release,
 466 };
 467
 468 static int kvm_init_mmu_notifier(struct kvm *kvm)
 469 {
 470         kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
 471         return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
 472 }
 473
 474 #else  /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */
 475
 476 static int kvm_init_mmu_notifier(struct kvm *kvm)
 477 {
 478         return 0;
 479 }
 480
 481 #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
 482
 483 static struct kvm_memslots *kvm_alloc_memslots(void)
 484 {
 485         int i;
 486         struct kvm_memslots *slots;
 487
 488         slots = kvm_kvzalloc(sizeof(struct kvm_memslots));
 489         if (!slots)
 490                 return NULL;
 491
 492         /*
 493          * Init kvm generation close to the maximum to easily test the
 494          * code of handling generation number wrap-around.
 495          */
 496         slots->generation = -150;
 497         for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
 498                 slots->id_to_index[i] = slots->memslots[i].id = i;
 499
 500         return slots;
 501 }
 502
 503 static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
 504 {
 505         if (!memslot->dirty_bitmap)
 506                 return;
 507
 508         kvfree(memslot->dirty_bitmap);
 509         memslot->dirty_bitmap = NULL;
 510 }
 511
 512 /*
 513  * Free any memory in @free but not in @dont.
 514  */
 515 static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
 516                               struct kvm_memory_slot *dont)
 517 {
 518         if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
 519                 kvm_destroy_dirty_bitmap(free);
 520
 521         kvm_arch_free_memslot(kvm, free, dont);
 522
 523         free->npages = 0;
 524 }
 525
 526 static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots)
 527 {
 528         struct kvm_memory_slot *memslot;
 529
 530         if (!slots)
 531                 return;
 532
 533         kvm_for_each_memslot(memslot, slots)
 534                 kvm_free_memslot(kvm, memslot, NULL);
 535
 536         kvfree(slots);
 537 }
 538
 539 static struct kvm *kvm_create_vm(unsigned long type)
 540 {
 541         int r, i;
 542         struct kvm *kvm = kvm_arch_alloc_vm();
 543
 544         if (!kvm)
 545                 return ERR_PTR(-ENOMEM);
 546
 547         r = kvm_arch_init_vm(kvm, type);
 548         if (r)
 549                 goto out_err_no_disable;
 550
 551         r = hardware_enable_all();
 552         if (r)
 553                 goto out_err_no_disable;
 554
 555 #ifdef CONFIG_HAVE_KVM_IRQFD
 556         INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
 557 #endif
 558
 559         BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX);
 560
 561         r = -ENOMEM;
 562         for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
 563                 kvm->memslots[i] = kvm_alloc_memslots();
 564                 if (!kvm->memslots[i])
 565                         goto out_err_no_srcu;
 566         }
 567
 568         if (init_srcu_struct(&kvm->srcu))
 569                 goto out_err_no_srcu;
 570         if (init_srcu_struct(&kvm->irq_srcu))
 571                 goto out_err_no_irq_srcu;
 572         for (i = 0; i < KVM_NR_BUSES; i++) {
 573                 kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus),
 574                                         GFP_KERNEL);
 575                 if (!kvm->buses[i])
 576                         goto out_err;
 577         }
 578
 579         spin_lock_init(&kvm->mmu_lock);
 580         kvm->mm = current->mm;
 581         atomic_inc(&kvm->mm->mm_count);
 582         kvm_eventfd_init(kvm);
 583         mutex_init(&kvm->lock);
 584         mutex_init(&kvm->irq_lock);
 585         mutex_init(&kvm->slots_lock);
 586         atomic_set(&kvm->users_count, 1);
 587         INIT_LIST_HEAD(&kvm->devices);
 588
 589         r = kvm_init_mmu_notifier(kvm);
 590         if (r)
 591                 goto out_err;
 592
 593         spin_lock(&kvm_lock);
 594         list_add(&kvm->vm_list, &vm_list);
 595         spin_unlock(&kvm_lock);
 596
 597         preempt_notifier_inc();
 598
 599         return kvm;
 600
 601 out_err:
 602         cleanup_srcu_struct(&kvm->irq_srcu);
 603 out_err_no_irq_srcu:
 604         cleanup_srcu_struct(&kvm->srcu);
 605 out_err_no_srcu:
 606         hardware_disable_all();
 607 out_err_no_disable:
 608         for (i = 0; i < KVM_NR_BUSES; i++)
 609                 kfree(kvm->buses[i]);
 610         for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
 611                 kvm_free_memslots(kvm, kvm->memslots[i]);
 612         kvm_arch_free_vm(kvm);
 613         return ERR_PTR(r);
 614 }
 615
 616 /*
 617  * Avoid using vmalloc for a small buffer.
 618  * Should not be used when the size is statically known.
 619  */
 620 void *kvm_kvzalloc(unsigned long size)
 621 {
 622         if (size > PAGE_SIZE)
 623                 return vzalloc(size);
 624         else
 625                 return kzalloc(size, GFP_KERNEL);
 626 }
 627
 628 static void kvm_destroy_devices(struct kvm *kvm)
 629 {
 630         struct list_head *node, *tmp;
 631
 632         list_for_each_safe(node, tmp, &kvm->devices) {
 633                 struct kvm_device *dev =
 634                         list_entry(node, struct kvm_device, vm_node);
 635
 636                 list_del(node);
 637                 dev->ops->destroy(dev);
 638         }
 639 }
 640
 641 static void kvm_destroy_vm(struct kvm *kvm)
 642 {
 643         int i;
 644         struct mm_struct *mm = kvm->mm;
 645
 646         kvm_arch_sync_events(kvm);
 647         spin_lock(&kvm_lock);
 648         list_del(&kvm->vm_list);
 649         spin_unlock(&kvm_lock);
 650         kvm_free_irq_routing(kvm);
 651         for (i = 0; i < KVM_NR_BUSES; i++)
 652                 kvm_io_bus_destroy(kvm->buses[i]);
 653         kvm_coalesced_mmio_free(kvm);
 654 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
 655         mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
 656 #else
 657         kvm_arch_flush_shadow_all(kvm);
 658 #endif
 659         kvm_arch_destroy_vm(kvm);
 660         kvm_destroy_devices(kvm);
 661         for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
 662                 kvm_free_memslots(kvm, kvm->memslots[i]);
 663         cleanup_srcu_struct(&kvm->irq_srcu);
 664         cleanup_srcu_struct(&kvm->srcu);
 665         kvm_arch_free_vm(kvm);
 666         preempt_notifier_dec();
 667         hardware_disable_all();
 668         mmdrop(mm);
 669 }
 670
 671 void kvm_get_kvm(struct kvm *kvm)
 672 {
 673         atomic_inc(&kvm->users_count);
 674 }
 675 EXPORT_SYMBOL_GPL(kvm_get_kvm);
 676
 677 void kvm_put_kvm(struct kvm *kvm)
 678 {
 679         if (atomic_dec_and_test(&kvm->users_count))
 680                 kvm_destroy_vm(kvm);
 681 }
 682 EXPORT_SYMBOL_GPL(kvm_put_kvm);
 683
 684
 685 static int kvm_vm_release(struct inode *inode, struct file *filp)
 686 {
 687         struct kvm *kvm = filp->private_data;
 688
 689         kvm_irqfd_release(kvm);
 690
 691         kvm_put_kvm(kvm);
 692         return 0;
 693 }
 694
 695 /*
 696  * Allocation size is twice as large as the actual dirty bitmap size.
 697  * See x86's kvm_vm_ioctl_get_dirty_log() why this is needed.
 698  */
 699 static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
 700 {
 701         unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
 702
 703         memslot->dirty_bitmap = kvm_kvzalloc(dirty_bytes);
 704         if (!memslot->dirty_bitmap)
 705                 return -ENOMEM;
 706
 707         return 0;
 708 }
 709
 710 /*
 711  * Insert memslot and re-sort memslots based on their GFN,
 712  * so binary search could be used to lookup GFN.
 713  * Sorting algorithm takes advantage of having initially
 714  * sorted array and known changed memslot position.
 715  */
 716 static void update_memslots(struct kvm_memslots *slots,
 717                             struct kvm_memory_slot *new)
 718 {
 719         int id = new->id;
 720         int i = slots->id_to_index[id];
 721         struct kvm_memory_slot *mslots = slots->memslots;
 722
 723         WARN_ON(mslots[i].id != id);
 724         if (!new->npages) {
 725                 WARN_ON(!mslots[i].npages);
 726                 if (mslots[i].npages)
 727                         slots->used_slots--;
 728         } else {
 729                 if (!mslots[i].npages)
 730                         slots->used_slots++;
 731         }
 732
 733         while (i < KVM_MEM_SLOTS_NUM - 1 &&
 734                new->base_gfn <= mslots[i + 1].base_gfn) {
 735                 if (!mslots[i + 1].npages)
 736                         break;
 737                 mslots[i] = mslots[i + 1];
 738                 slots->id_to_index[mslots[i].id] = i;
 739                 i++;
 740         }
 741
 742         /*
 743          * The ">=" is needed when creating a slot with base_gfn == 0,
 744          * so that it moves before all those with base_gfn == npages == 0.
 745          *
 746          * On the other hand, if new->npages is zero, the above loop has
 747          * already left i pointing to the beginning of the empty part of
 748          * mslots, and the ">=" would move the hole backwards in this
 749          * case---which is wrong.  So skip the loop when deleting a slot.
 750          */
 751         if (new->npages) {
 752                 while (i > 0 &&
 753                        new->base_gfn >= mslots[i - 1].base_gfn) {
 754                         mslots[i] = mslots[i - 1];
 755                         slots->id_to_index[mslots[i].id] = i;
 756                         i--;
 757                 }
 758         } else
 759                 WARN_ON_ONCE(i != slots->used_slots);
 760
 761         mslots[i] = *new;
 762         slots->id_to_index[mslots[i].id] = i;
 763 }
 764
 765 static int check_memory_region_flags(const struct kvm_userspace_memory_region *mem)
 766 {
 767         u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES;
 768
 769 #ifdef __KVM_HAVE_READONLY_MEM
 770         valid_flags |= KVM_MEM_READONLY;
 771 #endif
 772
 773         if (mem->flags & ~valid_flags)
 774                 return -EINVAL;
 775
 776         return 0;
 777 }
 778
 779 static struct kvm_memslots *install_new_memslots(struct kvm *kvm,
 780                 int as_id, struct kvm_memslots *slots)
 781 {
 782         struct kvm_memslots *old_memslots = __kvm_memslots(kvm, as_id);
 783
 784         /*
 785          * Set the low bit in the generation, which disables SPTE caching
 786          * until the end of synchronize_srcu_expedited.
 787          */
 788         WARN_ON(old_memslots->generation & 1);
 789         slots->generation = old_memslots->generation + 1;
 790
 791         rcu_assign_pointer(kvm->memslots[as_id], slots);
 792         synchronize_srcu_expedited(&kvm->srcu);
 793
 794         /*
 795          * Increment the new memslot generation a second time. This prevents
 796          * vm exits that race with memslot updates from caching a memslot
 797          * generation that will (potentially) be valid forever.
 798          */
 799         slots->generation++;
 800
 801         kvm_arch_memslots_updated(kvm, slots);
 802
 803         return old_memslots;
 804 }
 805
 806 /*
 807  * Allocate some memory and give it an address in the guest physical address
 808  * space.
 809  *
 810  * Discontiguous memory is allowed, mostly for framebuffers.
 811  *
 812  * Must be called holding kvm->slots_lock for write.
 813  */
 814 int __kvm_set_memory_region(struct kvm *kvm,
 815                             const struct kvm_userspace_memory_region *mem)
 816 {
 817         int r;
 818         gfn_t base_gfn;
 819         unsigned long npages;
 820         struct kvm_memory_slot *slot;
 821         struct kvm_memory_slot old, new;
 822         struct kvm_memslots *slots = NULL, *old_memslots;
 823         int as_id, id;
 824         enum kvm_mr_change change;
 825
 826         r = check_memory_region_flags(mem);
 827         if (r)
 828                 goto out;
 829
 830         r = -EINVAL;
 831         as_id = mem->slot >> 16;
 832         id = (u16)mem->slot;
 833
 834         /* General sanity checks */
 835         if (mem->memory_size & (PAGE_SIZE - 1))
 836                 goto out;
 837         if (mem->guest_phys_addr & (PAGE_SIZE - 1))
 838                 goto out;
 839         /* We can read the guest memory with __xxx_user() later on. */
 840         if ((id < KVM_USER_MEM_SLOTS) &&
 841             ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
 842              !access_ok(VERIFY_WRITE,
 843                         (void __user *)(unsigned long)mem->userspace_addr,
 844                         mem->memory_size)))
 845                 goto out;
 846         if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_MEM_SLOTS_NUM)
 847                 goto out;
 848         if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
 849                 goto out;
 850
 851         slot = id_to_memslot(__kvm_memslots(kvm, as_id), id);
 852         base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
 853         npages = mem->memory_size >> PAGE_SHIFT;
 854
 855         if (npages > KVM_MEM_MAX_NR_PAGES)
 856                 goto out;
 857
 858         new = old = *slot;
 859
 860         new.id = id;
 861         new.base_gfn = base_gfn;
 862         new.npages = npages;
 863         new.flags = mem->flags;
 864
 865         if (npages) {
 866                 if (!old.npages)
 867                         change = KVM_MR_CREATE;
 868                 else { /* Modify an existing slot. */
 869                         if ((mem->userspace_addr != old.userspace_addr) ||
 870                             (npages != old.npages) ||
 871                             ((new.flags ^ old.flags) & KVM_MEM_READONLY))
 872                                 goto out;
 873
 874                         if (base_gfn != old.base_gfn)
 875                                 change = KVM_MR_MOVE;
 876                         else if (new.flags != old.flags)
 877                                 change = KVM_MR_FLAGS_ONLY;
 878                         else { /* Nothing to change. */
 879                                 r = 0;
 880                                 goto out;
 881                         }
 882                 }
 883         } else {
 884                 if (!old.npages)
 885                         goto out;
 886
 887                 change = KVM_MR_DELETE;
 888                 new.base_gfn = 0;
 889                 new.flags = 0;
 890         }
 891
 892         if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) {
 893                 /* Check for overlaps */
 894                 r = -EEXIST;
 895                 kvm_for_each_memslot(slot, __kvm_memslots(kvm, as_id)) {
 896                         if ((slot->id >= KVM_USER_MEM_SLOTS) ||
 897                             (slot->id == id))
 898                                 continue;
 899                         if (!((base_gfn + npages <= slot->base_gfn) ||
 900                               (base_gfn >= slot->base_gfn + slot->npages)))
 901                                 goto out;
 902                 }
 903         }
 904
 905         /* Free page dirty bitmap if unneeded */
 906         if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
 907                 new.dirty_bitmap = NULL;
 908
 909         r = -ENOMEM;
 910         if (change == KVM_MR_CREATE) {
 911                 new.userspace_addr = mem->userspace_addr;
 912
 913                 if (kvm_arch_create_memslot(kvm, &new, npages))
 914                         goto out_free;
 915         }
 916
 917         /* Allocate page dirty bitmap if needed */
 918         if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
 919                 if (kvm_create_dirty_bitmap(&new) < 0)
 920                         goto out_free;
 921         }
 922
 923         slots = kvm_kvzalloc(sizeof(struct kvm_memslots));
 924         if (!slots)
 925                 goto out_free;
 926         memcpy(slots, __kvm_memslots(kvm, as_id), sizeof(struct kvm_memslots));
 927
 928         if ((change == KVM_MR_DELETE) || (change == KVM_MR_MOVE)) {
 929                 slot = id_to_memslot(slots, id);
 930                 slot->flags |= KVM_MEMSLOT_INVALID;
 931
 932                 old_memslots = install_new_memslots(kvm, as_id, slots);
 933
 934                 /* slot was deleted or moved, clear iommu mapping */
 935                 kvm_iommu_unmap_pages(kvm, &old);
 936                 /* From this point no new shadow pages pointing to a deleted,
 937                  * or moved, memslot will be created.
 938                  *
 939                  * validation of sp->gfn happens in:
 940                  *      - gfn_to_hva (kvm_read_guest, gfn_to_pfn)
 941                  *      - kvm_is_visible_gfn (mmu_check_roots)
 942                  */
 943                 kvm_arch_flush_shadow_memslot(kvm, slot);
 944
 945                 /*
 946                  * We can re-use the old_memslots from above, the only difference
 947                  * from the currently installed memslots is the invalid flag.  This
 948                  * will get overwritten by update_memslots anyway.
 949                  */
 950                 slots = old_memslots;
 951         }
 952
 953         r = kvm_arch_prepare_memory_region(kvm, &new, mem, change);
 954         if (r)
 955                 goto out_slots;
 956
 957         /* actual memory is freed via old in kvm_free_memslot below */
 958         if (change == KVM_MR_DELETE) {
 959                 new.dirty_bitmap = NULL;
 960                 memset(&new.arch, 0, sizeof(new.arch));
 961         }
 962
 963         update_memslots(slots, &new);
 964         old_memslots = install_new_memslots(kvm, as_id, slots);
 965
 966         kvm_arch_commit_memory_region(kvm, mem, &old, &new, change);
 967
 968         kvm_free_memslot(kvm, &old, &new);
 969         kvfree(old_memslots);
 970
 971         /*
 972          * IOMMU mapping:  New slots need to be mapped.  Old slots need to be
 973          * un-mapped and re-mapped if their base changes.  Since base change
 974          * unmapping is handled above with slot deletion, mapping alone is
 975          * needed here.  Anything else the iommu might care about for existing
 976          * slots (size changes, userspace addr changes and read-only flag
 977          * changes) is disallowed above, so any other attribute changes getting
 978          * here can be skipped.
 979          */
 980         if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) {
 981                 r = kvm_iommu_map_pages(kvm, &new);
 982                 return r;
 983         }
 984
 985         return 0;
 986
 987 out_slots:
 988         kvfree(slots);
 989 out_free:
 990         kvm_free_memslot(kvm, &new, &old);
 991 out:
 992         return r;
 993 }
 994 EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
 995
 996 int kvm_set_memory_region(struct kvm *kvm,
 997                           const struct kvm_userspace_memory_region *mem)
 998 {
 999         int r;
1000
1001         mutex_lock(&kvm->slots_lock);
1002         r = __kvm_set_memory_region(kvm, mem);
1003         mutex_unlock(&kvm->slots_lock);
1004         return r;
1005 }
1006 EXPORT_SYMBOL_GPL(kvm_set_memory_region);
1007
1008 static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
1009                                           struct kvm_userspace_memory_region *mem)
1010 {
1011         if ((u16)mem->slot >= KVM_USER_MEM_SLOTS)
1012                 return -EINVAL;
1013
1014         return kvm_set_memory_region(kvm, mem);
1015 }
1016
1017 int kvm_get_dirty_log(struct kvm *kvm,
1018                         struct kvm_dirty_log *log, int *is_dirty)
1019 {
1020         struct kvm_memslots *slots;
1021         struct kvm_memory_slot *memslot;
1022         int r, i, as_id, id;
1023         unsigned long n;
1024         unsigned long any = 0;
1025
1026         r = -EINVAL;
1027         as_id = log->slot >> 16;
1028         id = (u16)log->slot;
1029         if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
1030                 goto out;
1031
1032         slots = __kvm_memslots(kvm, as_id);
1033         memslot = id_to_memslot(slots, id);
1034         r = -ENOENT;
1035         if (!memslot->dirty_bitmap)
1036                 goto out;
1037
1038         n = kvm_dirty_bitmap_bytes(memslot);
1039
1040         for (i = 0; !any && i < n/sizeof(long); ++i)
1041                 any = memslot->dirty_bitmap[i];
1042
1043         r = -EFAULT;
1044         if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
1045                 goto out;
1046
1047         if (any)
1048                 *is_dirty = 1;
1049
1050         r = 0;
1051 out:
1052         return r;
1053 }
1054 EXPORT_SYMBOL_GPL(kvm_get_dirty_log);
1055
1056 #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
1057 /**
1058  * kvm_get_dirty_log_protect - get a snapshot of dirty pages, and if any pages
1059  *      are dirty write protect them for next write.
1060  * @kvm:        pointer to kvm instance
1061  * @log:        slot id and address to which we copy the log
1062  * @is_dirty:   flag set if any page is dirty
1063  *
1064  * We need to keep it in mind that VCPU threads can write to the bitmap
1065  * concurrently. So, to avoid losing track of dirty pages we keep the
1066  * following order:
1067  *
1068  *    1. Take a snapshot of the bit and clear it if needed.
1069  *    2. Write protect the corresponding page.
1070  *    3. Copy the snapshot to the userspace.
1071  *    4. Upon return caller flushes TLB's if needed.
1072  *
1073  * Between 2 and 4, the guest may write to the page using the remaining TLB
1074  * entry.  This is not a problem because the page is reported dirty using
1075  * the snapshot taken before and step 4 ensures that writes done after
1076  * exiting to userspace will be logged for the next call.
1077  *
1078  */
1079 int kvm_get_dirty_log_protect(struct kvm *kvm,
1080                         struct kvm_dirty_log *log, bool *is_dirty)
1081 {
1082         struct kvm_memslots *slots;
1083         struct kvm_memory_slot *memslot;
1084         int r, i, as_id, id;
1085         unsigned long n;
1086         unsigned long *dirty_bitmap;
1087         unsigned long *dirty_bitmap_buffer;
1088
1089         r = -EINVAL;
1090         as_id = log->slot >> 16;
1091         id = (u16)log->slot;
1092         if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
1093                 goto out;
1094
1095         slots = __kvm_memslots(kvm, as_id);
1096         memslot = id_to_memslot(slots, id);
1097
1098         dirty_bitmap = memslot->dirty_bitmap;
1099         r = -ENOENT;
1100         if (!dirty_bitmap)
1101                 goto out;
1102
1103         n = kvm_dirty_bitmap_bytes(memslot);
1104
1105         dirty_bitmap_buffer = dirty_bitmap + n / sizeof(long);
1106         memset(dirty_bitmap_buffer, 0, n);
1107
1108         spin_lock(&kvm->mmu_lock);
1109         *is_dirty = false;
1110         for (i = 0; i < n / sizeof(long); i++) {
1111                 unsigned long mask;
1112                 gfn_t offset;
1113
1114                 if (!dirty_bitmap[i])
1115                         continue;
1116
1117                 *is_dirty = true;
1118
1119                 mask = xchg(&dirty_bitmap[i], 0);
1120                 dirty_bitmap_buffer[i] = mask;
1121
1122                 if (mask) {
1123                         offset = i * BITS_PER_LONG;
1124                         kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot,
1125                                                                 offset, mask);
1126                 }
1127         }
1128
1129         spin_unlock(&kvm->mmu_lock);
1130
1131         r = -EFAULT;
1132         if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n))
1133                 goto out;
1134
1135         r = 0;
1136 out:
1137         return r;
1138 }
1139 EXPORT_SYMBOL_GPL(kvm_get_dirty_log_protect);
1140 #endif
1141
1142 bool kvm_largepages_enabled(void)
1143 {
1144         return largepages_enabled;
1145 }
1146
1147 void kvm_disable_largepages(void)
1148 {
1149         largepages_enabled = false;
1150 }
1151 EXPORT_SYMBOL_GPL(kvm_disable_largepages);
1152
1153 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
1154 {
1155         return __gfn_to_memslot(kvm_memslots(kvm), gfn);
1156 }
1157 EXPORT_SYMBOL_GPL(gfn_to_memslot);
1158
1159 struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn)
1160 {
1161         return __gfn_to_memslot(kvm_vcpu_memslots(vcpu), gfn);
1162 }
1163
1164 int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
1165 {
1166         struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn);
1167
1168         if (!memslot || memslot->id >= KVM_USER_MEM_SLOTS ||
1169               memslot->flags & KVM_MEMSLOT_INVALID)
1170                 return 0;
1171
1172         return 1;
1173 }
1174 EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
1175
1176 unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn)
1177 {
1178         struct vm_area_struct *vma;
1179         unsigned long addr, size;
1180
1181         size = PAGE_SIZE;
1182
1183         addr = gfn_to_hva(kvm, gfn);
1184         if (kvm_is_error_hva(addr))
1185                 return PAGE_SIZE;
1186
1187         down_read(&current->mm->mmap_sem);
1188         vma = find_vma(current->mm, addr);
1189         if (!vma)
1190                 goto out;
1191
1192         size = vma_kernel_pagesize(vma);
1193
1194 out:
1195         up_read(&current->mm->mmap_sem);
1196
1197         return size;
1198 }
1199
1200 static bool memslot_is_readonly(struct kvm_memory_slot *slot)
1201 {
1202         return slot->flags & KVM_MEM_READONLY;
1203 }
1204
1205 static unsigned long __gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
1206                                        gfn_t *nr_pages, bool write)
1207 {
1208         if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
1209                 return KVM_HVA_ERR_BAD;
1210
1211         if (memslot_is_readonly(slot) && write)
1212                 return KVM_HVA_ERR_RO_BAD;
1213
1214         if (nr_pages)
1215                 *nr_pages = slot->npages - (gfn - slot->base_gfn);
1216
1217         return __gfn_to_hva_memslot(slot, gfn);
1218 }
1219
1220 static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
1221                                      gfn_t *nr_pages)
1222 {
1223         return __gfn_to_hva_many(slot, gfn, nr_pages, true);
1224 }
1225
1226 unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot,
1227                                         gfn_t gfn)
1228 {
1229         return gfn_to_hva_many(slot, gfn, NULL);
1230 }
1231 EXPORT_SYMBOL_GPL(gfn_to_hva_memslot);
1232
1233 unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
1234 {
1235         return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL);
1236 }
1237 EXPORT_SYMBOL_GPL(gfn_to_hva);
1238
1239 unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn)
1240 {
1241         return gfn_to_hva_many(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn, NULL);
1242 }
1243 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_hva);
1244
1245 /*
1246  * If writable is set to false, the hva returned by this function is only
1247  * allowed to be read.
1248  */
1249 unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot,
1250                                       gfn_t gfn, bool *writable)
1251 {
1252         unsigned long hva = __gfn_to_hva_many(slot, gfn, NULL, false);
1253
1254         if (!kvm_is_error_hva(hva) && writable)
1255                 *writable = !memslot_is_readonly(slot);
1256
1257         return hva;
1258 }
1259
1260 unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable)
1261 {
1262         struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
1263
1264         return gfn_to_hva_memslot_prot(slot, gfn, writable);
1265 }
1266
1267 unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable)
1268 {
1269         struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1270
1271         return gfn_to_hva_memslot_prot(slot, gfn, writable);
1272 }
1273
1274 static int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm,
1275         unsigned long start, int write, struct page **page)
1276 {
1277         int flags = FOLL_TOUCH | FOLL_NOWAIT | FOLL_HWPOISON | FOLL_GET;
1278
1279         if (write)
1280                 flags |= FOLL_WRITE;
1281
1282         return __get_user_pages(tsk, mm, start, 1, flags, page, NULL, NULL);
1283 }
1284
1285 static inline int check_user_page_hwpoison(unsigned long addr)
1286 {
1287         int rc, flags = FOLL_TOUCH | FOLL_HWPOISON | FOLL_WRITE;
1288
1289         rc = __get_user_pages(current, current->mm, addr, 1,
1290                               flags, NULL, NULL, NULL);
1291         return rc == -EHWPOISON;
1292 }
1293
1294 /*
1295  * The atomic path to get the writable pfn which will be stored in @pfn,
1296  * true indicates success, otherwise false is returned.
1297  */
1298 static bool hva_to_pfn_fast(unsigned long addr, bool atomic, bool *async,
1299                             bool write_fault, bool *writable, pfn_t *pfn)
1300 {
1301         struct page *page[1];
1302         int npages;
1303
1304         if (!(async || atomic))
1305                 return false;
1306
1307         /*
1308          * Fast pin a writable pfn only if it is a write fault request
1309          * or the caller allows to map a writable pfn for a read fault
1310          * request.
1311          */
1312         if (!(write_fault || writable))
1313                 return false;
1314
1315         npages = __get_user_pages_fast(addr, 1, 1, page);
1316         if (npages == 1) {
1317                 *pfn = page_to_pfn(page[0]);
1318
1319                 if (writable)
1320                         *writable = true;
1321                 return true;
1322         }
1323
1324         return false;
1325 }
1326
1327 /*
1328  * The slow path to get the pfn of the specified host virtual address,
1329  * 1 indicates success, -errno is returned if error is detected.
1330  */
1331 static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault,
1332                            bool *writable, pfn_t *pfn)
1333 {
1334         struct page *page[1];
1335         int npages = 0;
1336
1337         might_sleep();
1338
1339         if (writable)
1340                 *writable = write_fault;
1341
1342         if (async) {
1343                 down_read(&current->mm->mmap_sem);
1344                 npages = get_user_page_nowait(current, current->mm,
1345                                               addr, write_fault, page);
1346                 up_read(&current->mm->mmap_sem);
1347         } else
1348                 npages = __get_user_pages_unlocked(current, current->mm, addr, 1,
1349                                                    write_fault, 0, page,
1350                                                    FOLL_TOUCH|FOLL_HWPOISON);
1351         if (npages != 1)
1352                 return npages;
1353
1354         /* map read fault as writable if possible */
1355         if (unlikely(!write_fault) && writable) {
1356                 struct page *wpage[1];
1357
1358                 npages = __get_user_pages_fast(addr, 1, 1, wpage);
1359                 if (npages == 1) {
1360                         *writable = true;
1361                         put_page(page[0]);
1362                         page[0] = wpage[0];
1363                 }
1364
1365                 npages = 1;
1366         }
1367         *pfn = page_to_pfn(page[0]);
1368         return npages;
1369 }
1370
1371 static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault)
1372 {
1373         if (unlikely(!(vma->vm_flags & VM_READ)))
1374                 return false;
1375
1376         if (write_fault && (unlikely(!(vma->vm_flags & VM_WRITE))))
1377                 return false;
1378
1379         return true;
1380 }
1381
1382 /*
1383  * Pin guest page in memory and return its pfn.
1384  * @addr: host virtual address which maps memory to the guest
1385  * @atomic: whether this function can sleep
1386  * @async: whether this function need to wait IO complete if the
1387  *         host page is not in the memory
1388  * @write_fault: whether we should get a writable host page
1389  * @writable: whether it allows to map a writable host page for !@write_fault
1390  *
1391  * The function will map a writable host page for these two cases:
1392  * 1): @write_fault = true
1393  * 2): @write_fault = false && @writable, @writable will tell the caller
1394  *     whether the mapping is writable.
1395  */
1396 static pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
1397                         bool write_fault, bool *writable)
1398 {
1399         struct vm_area_struct *vma;
1400         pfn_t pfn = 0;
1401         int npages;
1402
1403         /* we can do it either atomically or asynchronously, not both */
1404         BUG_ON(atomic && async);
1405
1406         if (hva_to_pfn_fast(addr, atomic, async, write_fault, writable, &pfn))
1407                 return pfn;
1408
1409         if (atomic)
1410                 return KVM_PFN_ERR_FAULT;
1411
1412         npages = hva_to_pfn_slow(addr, async, write_fault, writable, &pfn);
1413         if (npages == 1)
1414                 return pfn;
1415
1416         down_read(&current->mm->mmap_sem);
1417         if (npages == -EHWPOISON ||
1418               (!async && check_user_page_hwpoison(addr))) {
1419                 pfn = KVM_PFN_ERR_HWPOISON;
1420                 goto exit;
1421         }
1422
1423         vma = find_vma_intersection(current->mm, addr, addr + 1);
1424
1425         if (vma == NULL)
1426                 pfn = KVM_PFN_ERR_FAULT;
1427         else if ((vma->vm_flags & VM_PFNMAP)) {
1428                 pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) +
1429                         vma->vm_pgoff;
1430                 BUG_ON(!kvm_is_reserved_pfn(pfn));
1431         } else {
1432                 if (async && vma_is_valid(vma, write_fault))
1433                         *async = true;
1434                 pfn = KVM_PFN_ERR_FAULT;
1435         }
1436 exit:
1437         up_read(&current->mm->mmap_sem);
1438         return pfn;
1439 }
1440
1441 pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic,
1442                            bool *async, bool write_fault, bool *writable)
1443 {
1444         unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault);
1445
1446         if (addr == KVM_HVA_ERR_RO_BAD)
1447                 return KVM_PFN_ERR_RO_FAULT;
1448
1449         if (kvm_is_error_hva(addr))
1450                 return KVM_PFN_NOSLOT;
1451
1452         /* Do not map writable pfn in the readonly memslot. */
1453         if (writable && memslot_is_readonly(slot)) {
1454                 *writable = false;
1455                 writable = NULL;
1456         }
1457
1458         return hva_to_pfn(addr, atomic, async, write_fault,
1459                           writable);
1460 }
1461 EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot);
1462
1463 pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
1464                       bool *writable)
1465 {
1466         return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, NULL,
1467                                     write_fault, writable);
1468 }
1469 EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);
1470
1471 pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
1472 {
1473         return __gfn_to_pfn_memslot(slot, gfn, false, NULL, true, NULL);
1474 }
1475 EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot);
1476
1477 pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn)
1478 {
1479         return __gfn_to_pfn_memslot(slot, gfn, true, NULL, true, NULL);
1480 }
1481 EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic);
1482
1483 pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn)
1484 {
1485         return gfn_to_pfn_memslot_atomic(gfn_to_memslot(kvm, gfn), gfn);
1486 }
1487 EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic);
1488
1489 pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn)
1490 {
1491         return gfn_to_pfn_memslot_atomic(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
1492 }
1493 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_atomic);
1494
1495 pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
1496 {
1497         return gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn);
1498 }
1499 EXPORT_SYMBOL_GPL(gfn_to_pfn);
1500
1501 pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn)
1502 {
1503         return gfn_to_pfn_memslot(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
1504 }
1505 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn);
1506
1507 int gfn_to_page_many_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
1508                             struct page **pages, int nr_pages)
1509 {
1510         unsigned long addr;
1511         gfn_t entry;
1512
1513         addr = gfn_to_hva_many(slot, gfn, &entry);
1514         if (kvm_is_error_hva(addr))
1515                 return -1;
1516
1517         if (entry < nr_pages)
1518                 return 0;
1519
1520         return __get_user_pages_fast(addr, nr_pages, 1, pages);
1521 }
1522 EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
1523
1524 static struct page *kvm_pfn_to_page(pfn_t pfn)
1525 {
1526         if (is_error_noslot_pfn(pfn))
1527                 return KVM_ERR_PTR_BAD_PAGE;
1528
1529         if (kvm_is_reserved_pfn(pfn)) {
1530                 WARN_ON(1);
1531                 return KVM_ERR_PTR_BAD_PAGE;
1532         }
1533
1534         return pfn_to_page(pfn);
1535 }
1536
1537 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
1538 {
1539         pfn_t pfn;
1540
1541         pfn = gfn_to_pfn(kvm, gfn);
1542
1543         return kvm_pfn_to_page(pfn);
1544 }
1545 EXPORT_SYMBOL_GPL(gfn_to_page);
1546
1547 struct page *kvm_vcpu_gfn_to_page(struct kvm_vcpu *vcpu, gfn_t gfn)
1548 {
1549         pfn_t pfn;
1550
1551         pfn = kvm_vcpu_gfn_to_pfn(vcpu, gfn);
1552
1553         return kvm_pfn_to_page(pfn);
1554 }
1555 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_page);
1556
1557 void kvm_release_page_clean(struct page *page)
1558 {
1559         WARN_ON(is_error_page(page));
1560
1561         kvm_release_pfn_clean(page_to_pfn(page));
1562 }
1563 EXPORT_SYMBOL_GPL(kvm_release_page_clean);
1564
1565 void kvm_release_pfn_clean(pfn_t pfn)
1566 {
1567         if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn))
1568                 put_page(pfn_to_page(pfn));
1569 }
1570 EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
1571
1572 void kvm_release_page_dirty(struct page *page)
1573 {
1574         WARN_ON(is_error_page(page));
1575
1576         kvm_release_pfn_dirty(page_to_pfn(page));
1577 }
1578 EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
1579
1580 static void kvm_release_pfn_dirty(pfn_t pfn)
1581 {
1582         kvm_set_pfn_dirty(pfn);
1583         kvm_release_pfn_clean(pfn);
1584 }
1585
1586 void kvm_set_pfn_dirty(pfn_t pfn)
1587 {
1588         if (!kvm_is_reserved_pfn(pfn)) {
1589                 struct page *page = pfn_to_page(pfn);
1590
1591                 if (!PageReserved(page))
1592                         SetPageDirty(page);
1593         }
1594 }
1595 EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
1596
1597 void kvm_set_pfn_accessed(pfn_t pfn)
1598 {
1599         if (!kvm_is_reserved_pfn(pfn))
1600                 mark_page_accessed(pfn_to_page(pfn));
1601 }
1602 EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
1603
1604 void kvm_get_pfn(pfn_t pfn)
1605 {
1606         if (!kvm_is_reserved_pfn(pfn))
1607                 get_page(pfn_to_page(pfn));
1608 }
1609 EXPORT_SYMBOL_GPL(kvm_get_pfn);
1610
1611 static int next_segment(unsigned long len, int offset)
1612 {
1613         if (len > PAGE_SIZE - offset)
1614                 return PAGE_SIZE - offset;
1615         else
1616                 return len;
1617 }
1618
1619 static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn,
1620                                  void *data, int offset, int len)
1621 {
1622         int r;
1623         unsigned long addr;
1624
1625         addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
1626         if (kvm_is_error_hva(addr))
1627                 return -EFAULT;
1628         r = __copy_from_user(data, (void __user *)addr + offset, len);
1629         if (r)
1630                 return -EFAULT;
1631         return 0;
1632 }
1633
1634 int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
1635                         int len)
1636 {
1637         struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
1638
1639         return __kvm_read_guest_page(slot, gfn, data, offset, len);
1640 }
1641 EXPORT_SYMBOL_GPL(kvm_read_guest_page);
1642
1643 int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data,
1644                              int offset, int len)
1645 {
1646         struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1647
1648         return __kvm_read_guest_page(slot, gfn, data, offset, len);
1649 }
1650 EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_page);
1651
1652 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
1653 {
1654         gfn_t gfn = gpa >> PAGE_SHIFT;
1655         int seg;
1656         int offset = offset_in_page(gpa);
1657         int ret;
1658
1659         while ((seg = next_segment(len, offset)) != 0) {
1660                 ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
1661                 if (ret < 0)
1662                         return ret;
1663                 offset = 0;
1664                 len -= seg;
1665                 data += seg;
1666                 ++gfn;
1667         }
1668         return 0;
1669 }
1670 EXPORT_SYMBOL_GPL(kvm_read_guest);
1671
1672 int kvm_vcpu_read_guest(struct kvm_vcpu *vcpu, gpa_t gpa, void *data, unsigned long len)
1673 {
1674         gfn_t gfn = gpa >> PAGE_SHIFT;
1675         int seg;
1676         int offset = offset_in_page(gpa);
1677         int ret;
1678
1679         while ((seg = next_segment(len, offset)) != 0) {
1680                 ret = kvm_vcpu_read_guest_page(vcpu, gfn, data, offset, seg);
1681                 if (ret < 0)
1682                         return ret;
1683                 offset = 0;
1684                 len -= seg;
1685                 data += seg;
1686                 ++gfn;
1687         }
1688         return 0;
1689 }
1690 EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest);
1691
1692 static int __kvm_read_guest_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
1693                                    void *data, int offset, unsigned long len)
1694 {
1695         int r;
1696         unsigned long addr;
1697
1698         addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
1699         if (kvm_is_error_hva(addr))
1700                 return -EFAULT;
1701         pagefault_disable();
1702         r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
1703         pagefault_enable();
1704         if (r)
1705                 return -EFAULT;
1706         return 0;
1707 }
1708
1709 int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
1710                           unsigned long len)
1711 {
1712         gfn_t gfn = gpa >> PAGE_SHIFT;
1713         struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
1714         int offset = offset_in_page(gpa);
1715
1716         return __kvm_read_guest_atomic(slot, gfn, data, offset, len);
1717 }
1718 EXPORT_SYMBOL_GPL(kvm_read_guest_atomic);
1719
1720 int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa,
1721                                void *data, unsigned long len)
1722 {
1723         gfn_t gfn = gpa >> PAGE_SHIFT;
1724         struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1725         int offset = offset_in_page(gpa);
1726
1727         return __kvm_read_guest_atomic(slot, gfn, data, offset, len);
1728 }
1729 EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic);
1730
1731 static int __kvm_write_guest_page(struct kvm_memory_slot *memslot, gfn_t gfn,
1732                                   const void *data, int offset, int len)
1733 {
1734         int r;
1735         unsigned long addr;
1736
1737         addr = gfn_to_hva_memslot(memslot, gfn);
1738         if (kvm_is_error_hva(addr))
1739                 return -EFAULT;
1740         r = __copy_to_user((void __user *)addr + offset, data, len);
1741         if (r)
1742                 return -EFAULT;
1743         mark_page_dirty_in_slot(memslot, gfn);
1744         return 0;
1745 }
1746
1747 int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn,
1748                          const void *data, int offset, int len)
1749 {
1750         struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
1751
1752         return __kvm_write_guest_page(slot, gfn, data, offset, len);
1753 }
1754 EXPORT_SYMBOL_GPL(kvm_write_guest_page);
1755
1756 int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn,
1757                               const void *data, int offset, int len)
1758 {
1759         struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1760
1761         return __kvm_write_guest_page(slot, gfn, data, offset, len);
1762 }
1763 EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest_page);
1764
1765 int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
1766                     unsigned long len)
1767 {
1768         gfn_t gfn = gpa >> PAGE_SHIFT;
1769         int seg;
1770         int offset = offset_in_page(gpa);
1771         int ret;
1772
1773         while ((seg = next_segment(len, offset)) != 0) {
1774                 ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
1775                 if (ret < 0)
1776                         return ret;
1777                 offset = 0;
1778                 len -= seg;
1779                 data += seg;
1780                 ++gfn;
1781         }
1782         return 0;
1783 }
1784 EXPORT_SYMBOL_GPL(kvm_write_guest);
1785
1786 int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data,
1787                          unsigned long len)
1788 {
1789         gfn_t gfn = gpa >> PAGE_SHIFT;
1790         int seg;
1791         int offset = offset_in_page(gpa);
1792         int ret;
1793
1794         while ((seg = next_segment(len, offset)) != 0) {
1795                 ret = kvm_vcpu_write_guest_page(vcpu, gfn, data, offset, seg);
1796                 if (ret < 0)
1797                         return ret;
1798                 offset = 0;
1799                 len -= seg;
1800                 data += seg;
1801                 ++gfn;
1802         }
1803         return 0;
1804 }
1805 EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest);
1806
1807 int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1808                               gpa_t gpa, unsigned long len)
1809 {
1810         struct kvm_memslots *slots = kvm_memslots(kvm);
1811         int offset = offset_in_page(gpa);
1812         gfn_t start_gfn = gpa >> PAGE_SHIFT;
1813         gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT;
1814         gfn_t nr_pages_needed = end_gfn - start_gfn + 1;
1815         gfn_t nr_pages_avail;
1816
1817         ghc->gpa = gpa;
1818         ghc->generation = slots->generation;
1819         ghc->len = len;
1820         ghc->memslot = gfn_to_memslot(kvm, start_gfn);
1821         ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, NULL);
1822         if (!kvm_is_error_hva(ghc->hva) && nr_pages_needed <= 1) {
1823                 ghc->hva += offset;
1824         } else {
1825                 /*
1826                  * If the requested region crosses two memslots, we still
1827                  * verify that the entire region is valid here.
1828                  */
1829                 while (start_gfn <= end_gfn) {
1830                         ghc->memslot = gfn_to_memslot(kvm, start_gfn);
1831                         ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn,
1832                                                    &nr_pages_avail);
1833                         if (kvm_is_error_hva(ghc->hva))
1834                                 return -EFAULT;
1835                         start_gfn += nr_pages_avail;
1836                 }
1837                 /* Use the slow path for cross page reads and writes. */
1838                 ghc->memslot = NULL;
1839         }
1840         return 0;
1841 }
1842 EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
1843
1844 int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1845                            void *data, unsigned long len)
1846 {
1847         struct kvm_memslots *slots = kvm_memslots(kvm);
1848         int r;
1849
1850         BUG_ON(len > ghc->len);
1851
1852         if (slots->generation != ghc->generation)
1853                 kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa, ghc->len);
1854
1855         if (unlikely(!ghc->memslot))
1856                 return kvm_write_guest(kvm, ghc->gpa, data, len);
1857
1858         if (kvm_is_error_hva(ghc->hva))
1859                 return -EFAULT;
1860
1861         r = __copy_to_user((void __user *)ghc->hva, data, len);
1862         if (r)
1863                 return -EFAULT;
1864         mark_page_dirty_in_slot(ghc->memslot, ghc->gpa >> PAGE_SHIFT);
1865
1866         return 0;
1867 }
1868 EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
1869
1870 int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1871                            void *data, unsigned long len)
1872 {
1873         struct kvm_memslots *slots = kvm_memslots(kvm);
1874         int r;
1875
1876         BUG_ON(len > ghc->len);
1877
1878         if (slots->generation != ghc->generation)
1879                 kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa, ghc->len);
1880
1881         if (unlikely(!ghc->memslot))
1882                 return kvm_read_guest(kvm, ghc->gpa, data, len);
1883
1884         if (kvm_is_error_hva(ghc->hva))
1885                 return -EFAULT;
1886
1887         r = __copy_from_user(data, (void __user *)ghc->hva, len);
1888         if (r)
1889                 return -EFAULT;
1890
1891         return 0;
1892 }
1893 EXPORT_SYMBOL_GPL(kvm_read_guest_cached);
1894
1895 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
1896 {
1897         const void *zero_page = (const void *) __va(page_to_phys(ZERO_PAGE(0)));
1898
1899         return kvm_write_guest_page(kvm, gfn, zero_page, offset, len);
1900 }
1901 EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
1902
1903 int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
1904 {
1905         gfn_t gfn = gpa >> PAGE_SHIFT;
1906         int seg;
1907         int offset = offset_in_page(gpa);
1908         int ret;
1909
1910         while ((seg = next_segment(len, offset)) != 0) {
1911                 ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
1912                 if (ret < 0)
1913                         return ret;
1914                 offset = 0;
1915                 len -= seg;
1916                 ++gfn;
1917         }
1918         return 0;
1919 }
1920 EXPORT_SYMBOL_GPL(kvm_clear_guest);
1921
1922 static void mark_page_dirty_in_slot(struct kvm_memory_slot *memslot,
1923                                     gfn_t gfn)
1924 {
1925         if (memslot && memslot->dirty_bitmap) {
1926                 unsigned long rel_gfn = gfn - memslot->base_gfn;
1927
1928                 set_bit_le(rel_gfn, memslot->dirty_bitmap);
1929         }
1930 }
1931
1932 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
1933 {
1934         struct kvm_memory_slot *memslot;
1935
1936         memslot = gfn_to_memslot(kvm, gfn);
1937         mark_page_dirty_in_slot(memslot, gfn);
1938 }
1939 EXPORT_SYMBOL_GPL(mark_page_dirty);
1940
1941 void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn)
1942 {
1943         struct kvm_memory_slot *memslot;
1944
1945         memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1946         mark_page_dirty_in_slot(memslot, gfn);
1947 }
1948 EXPORT_SYMBOL_GPL(kvm_vcpu_mark_page_dirty);
1949
1950 static void grow_halt_poll_ns(struct kvm_vcpu *vcpu)
1951 {
1952         int old, val;
1953
1954         old = val = vcpu->halt_poll_ns;
1955         /* 10us base */
1956         if (val == 0 && halt_poll_ns_grow)
1957                 val = 10000;
1958         else
1959                 val *= halt_poll_ns_grow;
1960
1961         vcpu->halt_poll_ns = val;
1962         trace_kvm_halt_poll_ns_grow(vcpu->vcpu_id, val, old);
1963 }
1964
1965 static void shrink_halt_poll_ns(struct kvm_vcpu *vcpu)
1966 {
1967         int old, val;
1968
1969         old = val = vcpu->halt_poll_ns;
1970         if (halt_poll_ns_shrink == 0)
1971                 val = 0;
1972         else
1973                 val /= halt_poll_ns_shrink;
1974
1975         vcpu->halt_poll_ns = val;
1976         trace_kvm_halt_poll_ns_shrink(vcpu->vcpu_id, val, old);
1977 }
1978
1979 static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu)
1980 {
1981         if (kvm_arch_vcpu_runnable(vcpu)) {
1982                 kvm_make_request(KVM_REQ_UNHALT, vcpu);
1983                 return -EINTR;
1984         }
1985         if (kvm_cpu_has_pending_timer(vcpu))
1986                 return -EINTR;
1987         if (signal_pending(current))
1988                 return -EINTR;
1989
1990         return 0;
1991 }
1992
1993 /*
1994  * The vCPU has executed a HLT instruction with in-kernel mode enabled.
1995  */
1996 void kvm_vcpu_block(struct kvm_vcpu *vcpu)
1997 {
1998         ktime_t start, cur;
1999         DEFINE_WAIT(wait);
2000         bool waited = false;
2001         u64 block_ns;
2002
2003         start = cur = ktime_get();
2004         if (vcpu->halt_poll_ns) {
2005                 ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns);
2006
2007                 do {
2008                         /*
2009                          * This sets KVM_REQ_UNHALT if an interrupt
2010                          * arrives.
2011                          */
2012                         if (kvm_vcpu_check_block(vcpu) < 0) {
2013                                 ++vcpu->stat.halt_successful_poll;
2014                                 goto out;
2015                         }
2016                         cur = ktime_get();
2017                 } while (single_task_running() && ktime_before(cur, stop));
2018         }
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 out:
2034         block_ns = ktime_to_ns(cur) - ktime_to_ns(start);
2035
2036         if (halt_poll_ns) {
2037                 if (block_ns <= vcpu->halt_poll_ns)
2038                         ;
2039                 /* we had a long block, shrink polling */
2040                 else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns)
2041                         shrink_halt_poll_ns(vcpu);
2042                 /* we had a short halt and our poll time is too small */
2043                 else if (vcpu->halt_poll_ns < halt_poll_ns &&
2044                         block_ns < halt_poll_ns)
2045                         grow_halt_poll_ns(vcpu);
2046         }
2047
2048         trace_kvm_vcpu_wakeup(block_ns, waited);
2049 }
2050 EXPORT_SYMBOL_GPL(kvm_vcpu_block);
2051
2052 #ifndef CONFIG_S390
2053 /*
2054  * Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode.
2055  */
2056 void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
2057 {
2058         int me;
2059         int cpu = vcpu->cpu;
2060         wait_queue_head_t *wqp;
2061
2062         wqp = kvm_arch_vcpu_wq(vcpu);
2063         if (waitqueue_active(wqp)) {
2064                 wake_up_interruptible(wqp);
2065                 ++vcpu->stat.halt_wakeup;
2066         }
2067
2068         me = get_cpu();
2069         if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu))
2070                 if (kvm_arch_vcpu_should_kick(vcpu))
2071                         smp_send_reschedule(cpu);
2072         put_cpu();
2073 }
2074 EXPORT_SYMBOL_GPL(kvm_vcpu_kick);
2075 #endif /* !CONFIG_S390 */
2076
2077 int kvm_vcpu_yield_to(struct kvm_vcpu *target)
2078 {
2079         struct pid *pid;
2080         struct task_struct *task = NULL;
2081         int ret = 0;
2082
2083         rcu_read_lock();
2084         pid = rcu_dereference(target->pid);
2085         if (pid)
2086                 task = get_pid_task(pid, PIDTYPE_PID);
2087         rcu_read_unlock();
2088         if (!task)
2089                 return ret;
2090         ret = yield_to(task, 1);
2091         put_task_struct(task);
2092
2093         return ret;
2094 }
2095 EXPORT_SYMBOL_GPL(kvm_vcpu_yield_to);
2096
2097 /*
2098  * Helper that checks whether a VCPU is eligible for directed yield.
2099  * Most eligible candidate to yield is decided by following heuristics:
2100  *
2101  *  (a) VCPU which has not done pl-exit or cpu relax intercepted recently
2102  *  (preempted lock holder), indicated by @in_spin_loop.
2103  *  Set at the beiginning and cleared at the end of interception/PLE handler.
2104  *
2105  *  (b) VCPU which has done pl-exit/ cpu relax intercepted but did not get
2106  *  chance last time (mostly it has become eligible now since we have probably
2107  *  yielded to lockholder in last iteration. This is done by toggling
2108  *  @dy_eligible each time a VCPU checked for eligibility.)
2109  *
2110  *  Yielding to a recently pl-exited/cpu relax intercepted VCPU before yielding
2111  *  to preempted lock-holder could result in wrong VCPU selection and CPU
2112  *  burning. Giving priority for a potential lock-holder increases lock
2113  *  progress.
2114  *
2115  *  Since algorithm is based on heuristics, accessing another VCPU data without
2116  *  locking does not harm. It may result in trying to yield to  same VCPU, fail
2117  *  and continue with next VCPU and so on.
2118  */
2119 static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu)
2120 {
2121 #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
2122         bool eligible;
2123
2124         eligible = !vcpu->spin_loop.in_spin_loop ||
2125                     vcpu->spin_loop.dy_eligible;
2126
2127         if (vcpu->spin_loop.in_spin_loop)
2128                 kvm_vcpu_set_dy_eligible(vcpu, !vcpu->spin_loop.dy_eligible);
2129
2130         return eligible;
2131 #else
2132         return true;
2133 #endif
2134 }
2135
2136 void kvm_vcpu_on_spin(struct kvm_vcpu *me)
2137 {
2138         struct kvm *kvm = me->kvm;
2139         struct kvm_vcpu *vcpu;
2140         int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
2141         int yielded = 0;
2142         int try = 3;
2143         int pass;
2144         int i;
2145
2146         kvm_vcpu_set_in_spin_loop(me, true);
2147         /*
2148          * We boost the priority of a VCPU that is runnable but not
2149          * currently running, because it got preempted by something
2150          * else and called schedule in __vcpu_run.  Hopefully that
2151          * VCPU is holding the lock that we need and will release it.
2152          * We approximate round-robin by starting at the last boosted VCPU.
2153          */
2154         for (pass = 0; pass < 2 && !yielded && try; pass++) {
2155                 kvm_for_each_vcpu(i, vcpu, kvm) {
2156                         if (!pass && i <= last_boosted_vcpu) {
2157                                 i = last_boosted_vcpu;
2158                                 continue;
2159                         } else if (pass && i > last_boosted_vcpu)
2160                                 break;
2161                         if (!ACCESS_ONCE(vcpu->preempted))
2162                                 continue;
2163                         if (vcpu == me)
2164                                 continue;
2165                         if (waitqueue_active(&vcpu->wq) && !kvm_arch_vcpu_runnable(vcpu))
2166                                 continue;
2167                         if (!kvm_vcpu_eligible_for_directed_yield(vcpu))
2168                                 continue;
2169
2170                         yielded = kvm_vcpu_yield_to(vcpu);
2171                         if (yielded > 0) {
2172                                 kvm->last_boosted_vcpu = i;
2173                                 break;
2174                         } else if (yielded < 0) {
2175                                 try--;
2176                                 if (!try)
2177                                         break;
2178                         }
2179                 }
2180         }
2181         kvm_vcpu_set_in_spin_loop(me, false);
2182
2183         /* Ensure vcpu is not eligible during next spinloop */
2184         kvm_vcpu_set_dy_eligible(me, false);
2185 }
2186 EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
2187
2188 static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
2189 {
2190         struct kvm_vcpu *vcpu = vma->vm_file->private_data;
2191         struct page *page;
2192
2193         if (vmf->pgoff == 0)
2194                 page = virt_to_page(vcpu->run);
2195 #ifdef CONFIG_X86
2196         else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
2197                 page = virt_to_page(vcpu->arch.pio_data);
2198 #endif
2199 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2200         else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
2201                 page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
2202 #endif
2203         else
2204                 return kvm_arch_vcpu_fault(vcpu, vmf);
2205         get_page(page);
2206         vmf->page = page;
2207         return 0;
2208 }
2209
2210 static const struct vm_operations_struct kvm_vcpu_vm_ops = {
2211         .fault = kvm_vcpu_fault,
2212 };
2213
2214 static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
2215 {
2216         vma->vm_ops = &kvm_vcpu_vm_ops;
2217         return 0;
2218 }
2219
2220 static int kvm_vcpu_release(struct inode *inode, struct file *filp)
2221 {
2222         struct kvm_vcpu *vcpu = filp->private_data;
2223
2224         kvm_put_kvm(vcpu->kvm);
2225         return 0;
2226 }
2227
2228 static struct file_operations kvm_vcpu_fops = {
2229         .release        = kvm_vcpu_release,
2230         .unlocked_ioctl = kvm_vcpu_ioctl,
2231 #ifdef CONFIG_KVM_COMPAT
2232         .compat_ioctl   = kvm_vcpu_compat_ioctl,
2233 #endif
2234         .mmap           = kvm_vcpu_mmap,
2235         .llseek         = noop_llseek,
2236 };
2237
2238 /*
2239  * Allocates an inode for the vcpu.
2240  */
2241 static int create_vcpu_fd(struct kvm_vcpu *vcpu)
2242 {
2243         return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC);
2244 }
2245
2246 /*
2247  * Creates some virtual cpus.  Good luck creating more than one.
2248  */
2249 static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
2250 {
2251         int r;
2252         struct kvm_vcpu *vcpu, *v;
2253
2254         if (id >= KVM_MAX_VCPUS)
2255                 return -EINVAL;
2256
2257         vcpu = kvm_arch_vcpu_create(kvm, id);
2258         if (IS_ERR(vcpu))
2259                 return PTR_ERR(vcpu);
2260
2261         preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
2262
2263         r = kvm_arch_vcpu_setup(vcpu);
2264         if (r)
2265                 goto vcpu_destroy;
2266
2267         mutex_lock(&kvm->lock);
2268         if (!kvm_vcpu_compatible(vcpu)) {
2269                 r = -EINVAL;
2270                 goto unlock_vcpu_destroy;
2271         }
2272         if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
2273                 r = -EINVAL;
2274                 goto unlock_vcpu_destroy;
2275         }
2276
2277         kvm_for_each_vcpu(r, v, kvm)
2278                 if (v->vcpu_id == 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_CHECK_EXTENSION_VM:
2720                 return 1;
2721 #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
2722         case KVM_CAP_IRQ_ROUTING:
2723                 return KVM_MAX_IRQ_ROUTES;
2724 #endif
2725 #if KVM_ADDRESS_SPACE_NUM > 1
2726         case KVM_CAP_MULTI_ADDRESS_SPACE:
2727                 return KVM_ADDRESS_SPACE_NUM;
2728 #endif
2729         default:
2730                 break;
2731         }
2732         return kvm_vm_ioctl_check_extension(kvm, arg);
2733 }
2734
2735 static long kvm_vm_ioctl(struct file *filp,
2736                            unsigned int ioctl, unsigned long arg)
2737 {
2738         struct kvm *kvm = filp->private_data;
2739         void __user *argp = (void __user *)arg;
2740         int r;
2741
2742         if (kvm->mm != current->mm)
2743                 return -EIO;
2744         switch (ioctl) {
2745         case KVM_CREATE_VCPU:
2746                 r = kvm_vm_ioctl_create_vcpu(kvm, arg);
2747                 break;
2748         case KVM_SET_USER_MEMORY_REGION: {
2749                 struct kvm_userspace_memory_region kvm_userspace_mem;
2750
2751                 r = -EFAULT;
2752                 if (copy_from_user(&kvm_userspace_mem, argp,
2753                                                 sizeof(kvm_userspace_mem)))
2754                         goto out;
2755
2756                 r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem);
2757                 break;
2758         }
2759         case KVM_GET_DIRTY_LOG: {
2760                 struct kvm_dirty_log log;
2761
2762                 r = -EFAULT;
2763                 if (copy_from_user(&log, argp, sizeof(log)))
2764                         goto out;
2765                 r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
2766                 break;
2767         }
2768 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2769         case KVM_REGISTER_COALESCED_MMIO: {
2770                 struct kvm_coalesced_mmio_zone zone;
2771
2772                 r = -EFAULT;
2773                 if (copy_from_user(&zone, argp, sizeof(zone)))
2774                         goto out;
2775                 r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
2776                 break;
2777         }
2778         case KVM_UNREGISTER_COALESCED_MMIO: {
2779                 struct kvm_coalesced_mmio_zone zone;
2780
2781                 r = -EFAULT;
2782                 if (copy_from_user(&zone, argp, sizeof(zone)))
2783                         goto out;
2784                 r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
2785                 break;
2786         }
2787 #endif
2788         case KVM_IRQFD: {
2789                 struct kvm_irqfd data;
2790
2791                 r = -EFAULT;
2792                 if (copy_from_user(&data, argp, sizeof(data)))
2793                         goto out;
2794                 r = kvm_irqfd(kvm, &data);
2795                 break;
2796         }
2797         case KVM_IOEVENTFD: {
2798                 struct kvm_ioeventfd data;
2799
2800                 r = -EFAULT;
2801                 if (copy_from_user(&data, argp, sizeof(data)))
2802                         goto out;
2803                 r = kvm_ioeventfd(kvm, &data);
2804                 break;
2805         }
2806 #ifdef CONFIG_HAVE_KVM_MSI
2807         case KVM_SIGNAL_MSI: {
2808                 struct kvm_msi msi;
2809
2810                 r = -EFAULT;
2811                 if (copy_from_user(&msi, argp, sizeof(msi)))
2812                         goto out;
2813                 r = kvm_send_userspace_msi(kvm, &msi);
2814                 break;
2815         }
2816 #endif
2817 #ifdef __KVM_HAVE_IRQ_LINE
2818         case KVM_IRQ_LINE_STATUS:
2819         case KVM_IRQ_LINE: {
2820                 struct kvm_irq_level irq_event;
2821
2822                 r = -EFAULT;
2823                 if (copy_from_user(&irq_event, argp, sizeof(irq_event)))
2824                         goto out;
2825
2826                 r = kvm_vm_ioctl_irq_line(kvm, &irq_event,
2827                                         ioctl == KVM_IRQ_LINE_STATUS);
2828                 if (r)
2829                         goto out;
2830
2831                 r = -EFAULT;
2832                 if (ioctl == KVM_IRQ_LINE_STATUS) {
2833                         if (copy_to_user(argp, &irq_event, sizeof(irq_event)))
2834                                 goto out;
2835                 }
2836
2837                 r = 0;
2838                 break;
2839         }
2840 #endif
2841 #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
2842         case KVM_SET_GSI_ROUTING: {
2843                 struct kvm_irq_routing routing;
2844                 struct kvm_irq_routing __user *urouting;
2845                 struct kvm_irq_routing_entry *entries;
2846
2847                 r = -EFAULT;
2848                 if (copy_from_user(&routing, argp, sizeof(routing)))
2849                         goto out;
2850                 r = -EINVAL;
2851                 if (routing.nr >= KVM_MAX_IRQ_ROUTES)
2852                         goto out;
2853                 if (routing.flags)
2854                         goto out;
2855                 r = -ENOMEM;
2856                 entries = vmalloc(routing.nr * sizeof(*entries));
2857                 if (!entries)
2858                         goto out;
2859                 r = -EFAULT;
2860                 urouting = argp;
2861                 if (copy_from_user(entries, urouting->entries,
2862                                    routing.nr * sizeof(*entries)))
2863                         goto out_free_irq_routing;
2864                 r = kvm_set_irq_routing(kvm, entries, routing.nr,
2865                                         routing.flags);
2866 out_free_irq_routing:
2867                 vfree(entries);
2868                 break;
2869         }
2870 #endif /* CONFIG_HAVE_KVM_IRQ_ROUTING */
2871         case KVM_CREATE_DEVICE: {
2872                 struct kvm_create_device cd;
2873
2874                 r = -EFAULT;
2875                 if (copy_from_user(&cd, argp, sizeof(cd)))
2876                         goto out;
2877
2878                 r = kvm_ioctl_create_device(kvm, &cd);
2879                 if (r)
2880                         goto out;
2881
2882                 r = -EFAULT;
2883                 if (copy_to_user(argp, &cd, sizeof(cd)))
2884                         goto out;
2885
2886                 r = 0;
2887                 break;
2888         }
2889         case KVM_CHECK_EXTENSION:
2890                 r = kvm_vm_ioctl_check_extension_generic(kvm, arg);
2891                 break;
2892         default:
2893                 r = kvm_arch_vm_ioctl(filp, ioctl, arg);
2894         }
2895 out:
2896         return r;
2897 }
2898
2899 #ifdef CONFIG_KVM_COMPAT
2900 struct compat_kvm_dirty_log {
2901         __u32 slot;
2902         __u32 padding1;
2903         union {
2904                 compat_uptr_t dirty_bitmap; /* one bit per page */
2905                 __u64 padding2;
2906         };
2907 };
2908
2909 static long kvm_vm_compat_ioctl(struct file *filp,
2910                            unsigned int ioctl, unsigned long arg)
2911 {
2912         struct kvm *kvm = filp->private_data;
2913         int r;
2914
2915         if (kvm->mm != current->mm)
2916                 return -EIO;
2917         switch (ioctl) {
2918         case KVM_GET_DIRTY_LOG: {
2919                 struct compat_kvm_dirty_log compat_log;
2920                 struct kvm_dirty_log log;
2921
2922                 r = -EFAULT;
2923                 if (copy_from_user(&compat_log, (void __user *)arg,
2924                                    sizeof(compat_log)))
2925                         goto out;
2926                 log.slot         = compat_log.slot;
2927                 log.padding1     = compat_log.padding1;
2928                 log.padding2     = compat_log.padding2;
2929                 log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
2930
2931                 r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
2932                 break;
2933         }
2934         default:
2935                 r = kvm_vm_ioctl(filp, ioctl, arg);
2936         }
2937
2938 out:
2939         return r;
2940 }
2941 #endif
2942
2943 static struct file_operations kvm_vm_fops = {
2944         .release        = kvm_vm_release,
2945         .unlocked_ioctl = kvm_vm_ioctl,
2946 #ifdef CONFIG_KVM_COMPAT
2947         .compat_ioctl   = kvm_vm_compat_ioctl,
2948 #endif
2949         .llseek         = noop_llseek,
2950 };
2951
2952 static int kvm_dev_ioctl_create_vm(unsigned long type)
2953 {
2954         int r;
2955         struct kvm *kvm;
2956
2957         kvm = kvm_create_vm(type);
2958         if (IS_ERR(kvm))
2959                 return PTR_ERR(kvm);
2960 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2961         r = kvm_coalesced_mmio_init(kvm);
2962         if (r < 0) {
2963                 kvm_put_kvm(kvm);
2964                 return r;
2965         }
2966 #endif
2967         r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR | O_CLOEXEC);
2968         if (r < 0)
2969                 kvm_put_kvm(kvm);
2970
2971         return r;
2972 }
2973
2974 static long kvm_dev_ioctl(struct file *filp,
2975                           unsigned int ioctl, unsigned long arg)
2976 {
2977         long r = -EINVAL;
2978
2979         switch (ioctl) {
2980         case KVM_GET_API_VERSION:
2981                 if (arg)
2982                         goto out;
2983                 r = KVM_API_VERSION;
2984                 break;
2985         case KVM_CREATE_VM:
2986                 r = kvm_dev_ioctl_create_vm(arg);
2987                 break;
2988         case KVM_CHECK_EXTENSION:
2989                 r = kvm_vm_ioctl_check_extension_generic(NULL, arg);
2990                 break;
2991         case KVM_GET_VCPU_MMAP_SIZE:
2992                 if (arg)
2993                         goto out;
2994                 r = PAGE_SIZE;     /* struct kvm_run */
2995 #ifdef CONFIG_X86
2996                 r += PAGE_SIZE;    /* pio data page */
2997 #endif
2998 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2999                 r += PAGE_SIZE;    /* coalesced mmio ring page */
3000 #endif
3001                 break;
3002         case KVM_TRACE_ENABLE:
3003         case KVM_TRACE_PAUSE:
3004         case KVM_TRACE_DISABLE:
3005                 r = -EOPNOTSUPP;
3006                 break;
3007         default:
3008                 return kvm_arch_dev_ioctl(filp, ioctl, arg);
3009         }
3010 out:
3011         return r;
3012 }
3013
3014 static struct file_operations kvm_chardev_ops = {
3015         .unlocked_ioctl = kvm_dev_ioctl,
3016         .compat_ioctl   = kvm_dev_ioctl,
3017         .llseek         = noop_llseek,
3018 };
3019
3020 static struct miscdevice kvm_dev = {
3021         KVM_MINOR,
3022         "kvm",
3023         &kvm_chardev_ops,
3024 };
3025
3026 static void hardware_enable_nolock(void *junk)
3027 {
3028         int cpu = raw_smp_processor_id();
3029         int r;
3030
3031         if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
3032                 return;
3033
3034         cpumask_set_cpu(cpu, cpus_hardware_enabled);
3035
3036         r = kvm_arch_hardware_enable();
3037
3038         if (r) {
3039                 cpumask_clear_cpu(cpu, cpus_hardware_enabled);
3040                 atomic_inc(&hardware_enable_failed);
3041                 pr_info("kvm: enabling virtualization on CPU%d failed\n", cpu);
3042         }
3043 }
3044
3045 static void hardware_enable(void)
3046 {
3047         raw_spin_lock(&kvm_count_lock);
3048         if (kvm_usage_count)
3049                 hardware_enable_nolock(NULL);
3050         raw_spin_unlock(&kvm_count_lock);
3051 }
3052
3053 static void hardware_disable_nolock(void *junk)
3054 {
3055         int cpu = raw_smp_processor_id();
3056
3057         if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
3058                 return;
3059         cpumask_clear_cpu(cpu, cpus_hardware_enabled);
3060         kvm_arch_hardware_disable();
3061 }
3062
3063 static void hardware_disable(void)
3064 {
3065         raw_spin_lock(&kvm_count_lock);
3066         if (kvm_usage_count)
3067                 hardware_disable_nolock(NULL);
3068         raw_spin_unlock(&kvm_count_lock);
3069 }
3070
3071 static void hardware_disable_all_nolock(void)
3072 {
3073         BUG_ON(!kvm_usage_count);
3074
3075         kvm_usage_count--;
3076         if (!kvm_usage_count)
3077                 on_each_cpu(hardware_disable_nolock, NULL, 1);
3078 }
3079
3080 static void hardware_disable_all(void)
3081 {
3082         raw_spin_lock(&kvm_count_lock);
3083         hardware_disable_all_nolock();
3084         raw_spin_unlock(&kvm_count_lock);
3085 }
3086
3087 static int hardware_enable_all(void)
3088 {
3089         int r = 0;
3090
3091         raw_spin_lock(&kvm_count_lock);
3092
3093         kvm_usage_count++;
3094         if (kvm_usage_count == 1) {
3095                 atomic_set(&hardware_enable_failed, 0);
3096                 on_each_cpu(hardware_enable_nolock, NULL, 1);
3097
3098                 if (atomic_read(&hardware_enable_failed)) {
3099                         hardware_disable_all_nolock();
3100                         r = -EBUSY;
3101                 }
3102         }
3103
3104         raw_spin_unlock(&kvm_count_lock);
3105
3106         return r;
3107 }
3108
3109 static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
3110                            void *v)
3111 {
3112         val &= ~CPU_TASKS_FROZEN;
3113         switch (val) {
3114         case CPU_DYING:
3115                 hardware_disable();
3116                 break;
3117         case CPU_STARTING:
3118                 hardware_enable();
3119                 break;
3120         }
3121         return NOTIFY_OK;
3122 }
3123
3124 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
3125                       void *v)
3126 {
3127         /*
3128          * Some (well, at least mine) BIOSes hang on reboot if
3129          * in vmx root mode.
3130          *
3131          * And Intel TXT required VMX off for all cpu when system shutdown.
3132          */
3133         pr_info("kvm: exiting hardware virtualization\n");
3134         kvm_rebooting = true;
3135         on_each_cpu(hardware_disable_nolock, NULL, 1);
3136         return NOTIFY_OK;
3137 }
3138
3139 static struct notifier_block kvm_reboot_notifier = {
3140         .notifier_call = kvm_reboot,
3141         .priority = 0,
3142 };
3143
3144 static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
3145 {
3146         int i;
3147
3148         for (i = 0; i < bus->dev_count; i++) {
3149                 struct kvm_io_device *pos = bus->range[i].dev;
3150
3151                 kvm_iodevice_destructor(pos);
3152         }
3153         kfree(bus);
3154 }
3155
3156 static inline int kvm_io_bus_cmp(const struct kvm_io_range *r1,
3157                                  const struct kvm_io_range *r2)
3158 {
3159         if (r1->addr < r2->addr)
3160                 return -1;
3161         if (r1->addr + r1->len > r2->addr + r2->len)
3162                 return 1;
3163         return 0;
3164 }
3165
3166 static int kvm_io_bus_sort_cmp(const void *p1, const void *p2)
3167 {
3168         return kvm_io_bus_cmp(p1, p2);
3169 }
3170
3171 static int kvm_io_bus_insert_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev,
3172                           gpa_t addr, int len)
3173 {
3174         bus->range[bus->dev_count++] = (struct kvm_io_range) {
3175                 .addr = addr,
3176                 .len = len,
3177                 .dev = dev,
3178         };
3179
3180         sort(bus->range, bus->dev_count, sizeof(struct kvm_io_range),
3181                 kvm_io_bus_sort_cmp, NULL);
3182
3183         return 0;
3184 }
3185
3186 static int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus,
3187                              gpa_t addr, int len)
3188 {
3189         struct kvm_io_range *range, key;
3190         int off;
3191
3192         key = (struct kvm_io_range) {
3193                 .addr = addr,
3194                 .len = len,
3195         };
3196
3197         range = bsearch(&key, bus->range, bus->dev_count,
3198                         sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp);
3199         if (range == NULL)
3200                 return -ENOENT;
3201
3202         off = range - bus->range;
3203
3204         while (off > 0 && kvm_io_bus_cmp(&key, &bus->range[off-1]) == 0)
3205                 off--;
3206
3207         return off;
3208 }
3209
3210 static int __kvm_io_bus_write(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
3211                               struct kvm_io_range *range, const void *val)
3212 {
3213         int idx;
3214
3215         idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len);
3216         if (idx < 0)
3217                 return -EOPNOTSUPP;
3218
3219         while (idx < bus->dev_count &&
3220                 kvm_io_bus_cmp(range, &bus->range[idx]) == 0) {
3221                 if (!kvm_iodevice_write(vcpu, bus->range[idx].dev, range->addr,
3222                                         range->len, val))
3223                         return idx;
3224                 idx++;
3225         }
3226
3227         return -EOPNOTSUPP;
3228 }
3229
3230 /* kvm_io_bus_write - called under kvm->slots_lock */
3231 int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
3232                      int len, const void *val)
3233 {
3234         struct kvm_io_bus *bus;
3235         struct kvm_io_range range;
3236         int r;
3237
3238         range = (struct kvm_io_range) {
3239                 .addr = addr,
3240                 .len = len,
3241         };
3242
3243         bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
3244         r = __kvm_io_bus_write(vcpu, bus, &range, val);
3245         return r < 0 ? r : 0;
3246 }
3247
3248 /* kvm_io_bus_write_cookie - called under kvm->slots_lock */
3249 int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx,
3250                             gpa_t addr, int len, const void *val, long cookie)
3251 {
3252         struct kvm_io_bus *bus;
3253         struct kvm_io_range range;
3254
3255         range = (struct kvm_io_range) {
3256                 .addr = addr,
3257                 .len = len,
3258         };
3259
3260         bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
3261
3262         /* First try the device referenced by cookie. */
3263         if ((cookie >= 0) && (cookie < bus->dev_count) &&
3264             (kvm_io_bus_cmp(&range, &bus->range[cookie]) == 0))
3265                 if (!kvm_iodevice_write(vcpu, bus->range[cookie].dev, addr, len,
3266                                         val))
3267                         return cookie;
3268
3269         /*
3270          * cookie contained garbage; fall back to search and return the
3271          * correct cookie value.
3272          */
3273         return __kvm_io_bus_write(vcpu, bus, &range, val);
3274 }
3275
3276 static int __kvm_io_bus_read(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
3277                              struct kvm_io_range *range, void *val)
3278 {
3279         int idx;
3280
3281         idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len);
3282         if (idx < 0)
3283                 return -EOPNOTSUPP;
3284
3285         while (idx < bus->dev_count &&
3286                 kvm_io_bus_cmp(range, &bus->range[idx]) == 0) {
3287                 if (!kvm_iodevice_read(vcpu, bus->range[idx].dev, range->addr,
3288                                        range->len, val))
3289                         return idx;
3290                 idx++;
3291         }
3292
3293         return -EOPNOTSUPP;
3294 }
3295 EXPORT_SYMBOL_GPL(kvm_io_bus_write);
3296
3297 /* kvm_io_bus_read - called under kvm->slots_lock */
3298 int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
3299                     int len, void *val)
3300 {
3301         struct kvm_io_bus *bus;
3302         struct kvm_io_range range;
3303         int r;
3304
3305         range = (struct kvm_io_range) {
3306                 .addr = addr,
3307                 .len = len,
3308         };
3309
3310         bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
3311         r = __kvm_io_bus_read(vcpu, bus, &range, val);
3312         return r < 0 ? r : 0;
3313 }
3314
3315
3316 /* Caller must hold slots_lock. */
3317 int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
3318                             int len, struct kvm_io_device *dev)
3319 {
3320         struct kvm_io_bus *new_bus, *bus;
3321
3322         bus = kvm->buses[bus_idx];
3323         /* exclude ioeventfd which is limited by maximum fd */
3324         if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1)
3325                 return -ENOSPC;
3326
3327         new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count + 1) *
3328                           sizeof(struct kvm_io_range)), GFP_KERNEL);
3329         if (!new_bus)
3330                 return -ENOMEM;
3331         memcpy(new_bus, bus, sizeof(*bus) + (bus->dev_count *
3332                sizeof(struct kvm_io_range)));
3333         kvm_io_bus_insert_dev(new_bus, dev, addr, len);
3334         rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
3335         synchronize_srcu_expedited(&kvm->srcu);
3336         kfree(bus);
3337
3338         return 0;
3339 }
3340
3341 /* Caller must hold slots_lock. */
3342 int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
3343                               struct kvm_io_device *dev)
3344 {
3345         int i, r;
3346         struct kvm_io_bus *new_bus, *bus;
3347
3348         bus = kvm->buses[bus_idx];
3349         r = -ENOENT;
3350         for (i = 0; i < bus->dev_count; i++)
3351                 if (bus->range[i].dev == dev) {
3352                         r = 0;
3353                         break;
3354                 }
3355
3356         if (r)
3357                 return r;
3358
3359         new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count - 1) *
3360                           sizeof(struct kvm_io_range)), GFP_KERNEL);
3361         if (!new_bus)
3362                 return -ENOMEM;
3363
3364         memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range));
3365         new_bus->dev_count--;
3366         memcpy(new_bus->range + i, bus->range + i + 1,
3367                (new_bus->dev_count - i) * sizeof(struct kvm_io_range));
3368
3369         rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
3370         synchronize_srcu_expedited(&kvm->srcu);
3371         kfree(bus);
3372         return r;
3373 }
3374
3375 static struct notifier_block kvm_cpu_notifier = {
3376         .notifier_call = kvm_cpu_hotplug,
3377 };
3378
3379 static int vm_stat_get(void *_offset, u64 *val)
3380 {
3381         unsigned offset = (long)_offset;
3382         struct kvm *kvm;
3383
3384         *val = 0;
3385         spin_lock(&kvm_lock);
3386         list_for_each_entry(kvm, &vm_list, vm_list)
3387                 *val += *(u32 *)((void *)kvm + offset);
3388         spin_unlock(&kvm_lock);
3389         return 0;
3390 }
3391
3392 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
3393
3394 static int vcpu_stat_get(void *_offset, u64 *val)
3395 {
3396         unsigned offset = (long)_offset;
3397         struct kvm *kvm;
3398         struct kvm_vcpu *vcpu;
3399         int i;
3400
3401         *val = 0;
3402         spin_lock(&kvm_lock);
3403         list_for_each_entry(kvm, &vm_list, vm_list)
3404                 kvm_for_each_vcpu(i, vcpu, kvm)
3405                         *val += *(u32 *)((void *)vcpu + offset);
3406
3407         spin_unlock(&kvm_lock);
3408         return 0;
3409 }
3410
3411 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
3412
3413 static const struct file_operations *stat_fops[] = {
3414         [KVM_STAT_VCPU] = &vcpu_stat_fops,
3415         [KVM_STAT_VM]   = &vm_stat_fops,
3416 };
3417
3418 static int kvm_init_debug(void)
3419 {
3420         int r = -EEXIST;
3421         struct kvm_stats_debugfs_item *p;
3422
3423         kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
3424         if (kvm_debugfs_dir == NULL)
3425                 goto out;
3426
3427         for (p = debugfs_entries; p->name; ++p) {
3428                 p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
3429                                                 (void *)(long)p->offset,
3430                                                 stat_fops[p->kind]);
3431                 if (p->dentry == NULL)
3432                         goto out_dir;
3433         }
3434
3435         return 0;
3436
3437 out_dir:
3438         debugfs_remove_recursive(kvm_debugfs_dir);
3439 out:
3440         return r;
3441 }
3442
3443 static void kvm_exit_debug(void)
3444 {
3445         struct kvm_stats_debugfs_item *p;
3446
3447         for (p = debugfs_entries; p->name; ++p)
3448                 debugfs_remove(p->dentry);
3449         debugfs_remove(kvm_debugfs_dir);
3450 }
3451
3452 static int kvm_suspend(void)
3453 {
3454         if (kvm_usage_count)
3455                 hardware_disable_nolock(NULL);
3456         return 0;
3457 }
3458
3459 static void kvm_resume(void)
3460 {
3461         if (kvm_usage_count) {
3462                 WARN_ON(raw_spin_is_locked(&kvm_count_lock));
3463                 hardware_enable_nolock(NULL);
3464         }
3465 }
3466
3467 static struct syscore_ops kvm_syscore_ops = {
3468         .suspend = kvm_suspend,
3469         .resume = kvm_resume,
3470 };
3471
3472 static inline
3473 struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
3474 {
3475         return container_of(pn, struct kvm_vcpu, preempt_notifier);
3476 }
3477
3478 static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
3479 {
3480         struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
3481
3482         if (vcpu->preempted)
3483                 vcpu->preempted = false;
3484
3485         kvm_arch_sched_in(vcpu, cpu);
3486
3487         kvm_arch_vcpu_load(vcpu, cpu);
3488 }
3489
3490 static void kvm_sched_out(struct preempt_notifier *pn,
3491                           struct task_struct *next)
3492 {
3493         struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
3494
3495         if (current->state == TASK_RUNNING)
3496                 vcpu->preempted = true;
3497         kvm_arch_vcpu_put(vcpu);
3498 }
3499
3500 int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
3501                   struct module *module)
3502 {
3503         int r;
3504         int cpu;
3505
3506         r = kvm_arch_init(opaque);
3507         if (r)
3508                 goto out_fail;
3509
3510         /*
3511          * kvm_arch_init makes sure there's at most one caller
3512          * for architectures that support multiple implementations,
3513          * like intel and amd on x86.
3514          * kvm_arch_init must be called before kvm_irqfd_init to avoid creating
3515          * conflicts in case kvm is already setup for another implementation.
3516          */
3517         r = kvm_irqfd_init();
3518         if (r)
3519                 goto out_irqfd;
3520
3521         if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
3522                 r = -ENOMEM;
3523                 goto out_free_0;
3524         }
3525
3526         r = kvm_arch_hardware_setup();
3527         if (r < 0)
3528                 goto out_free_0a;
3529
3530         for_each_online_cpu(cpu) {
3531                 smp_call_function_single(cpu,
3532                                 kvm_arch_check_processor_compat,
3533                                 &r, 1);
3534                 if (r < 0)
3535                         goto out_free_1;
3536         }
3537
3538         r = register_cpu_notifier(&kvm_cpu_notifier);
3539         if (r)
3540                 goto out_free_2;
3541         register_reboot_notifier(&kvm_reboot_notifier);
3542
3543         /* A kmem cache lets us meet the alignment requirements of fx_save. */
3544         if (!vcpu_align)
3545                 vcpu_align = __alignof__(struct kvm_vcpu);
3546         kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size, vcpu_align,
3547                                            0, NULL);
3548         if (!kvm_vcpu_cache) {
3549                 r = -ENOMEM;
3550                 goto out_free_3;
3551         }
3552
3553         r = kvm_async_pf_init();
3554         if (r)
3555                 goto out_free;
3556
3557         kvm_chardev_ops.owner = module;
3558         kvm_vm_fops.owner = module;
3559         kvm_vcpu_fops.owner = module;
3560
3561         r = misc_register(&kvm_dev);
3562         if (r) {
3563                 pr_err("kvm: misc device register failed\n");
3564                 goto out_unreg;
3565         }
3566
3567         register_syscore_ops(&kvm_syscore_ops);
3568
3569         kvm_preempt_ops.sched_in = kvm_sched_in;
3570         kvm_preempt_ops.sched_out = kvm_sched_out;
3571
3572         r = kvm_init_debug();
3573         if (r) {
3574                 pr_err("kvm: create debugfs files failed\n");
3575                 goto out_undebugfs;
3576         }
3577
3578         r = kvm_vfio_ops_init();
3579         WARN_ON(r);
3580
3581         return 0;
3582
3583 out_undebugfs:
3584         unregister_syscore_ops(&kvm_syscore_ops);
3585         misc_deregister(&kvm_dev);
3586 out_unreg:
3587         kvm_async_pf_deinit();
3588 out_free:
3589         kmem_cache_destroy(kvm_vcpu_cache);
3590 out_free_3:
3591         unregister_reboot_notifier(&kvm_reboot_notifier);
3592         unregister_cpu_notifier(&kvm_cpu_notifier);
3593 out_free_2:
3594 out_free_1:
3595         kvm_arch_hardware_unsetup();
3596 out_free_0a:
3597         free_cpumask_var(cpus_hardware_enabled);
3598 out_free_0:
3599         kvm_irqfd_exit();
3600 out_irqfd:
3601         kvm_arch_exit();
3602 out_fail:
3603         return r;
3604 }
3605 EXPORT_SYMBOL_GPL(kvm_init);
3606
3607 void kvm_exit(void)
3608 {
3609         kvm_exit_debug();
3610         misc_deregister(&kvm_dev);
3611         kmem_cache_destroy(kvm_vcpu_cache);
3612         kvm_async_pf_deinit();
3613         unregister_syscore_ops(&kvm_syscore_ops);
3614         unregister_reboot_notifier(&kvm_reboot_notifier);
3615         unregister_cpu_notifier(&kvm_cpu_notifier);
3616         on_each_cpu(hardware_disable_nolock, NULL, 1);
3617         kvm_arch_hardware_unsetup();
3618         kvm_arch_exit();
3619         kvm_irqfd_exit();
3620         free_cpumask_var(cpus_hardware_enabled);
3621         kvm_vfio_ops_exit();
3622 }
3623 EXPORT_SYMBOL_GPL(kvm_exit);