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Linux/virt/kvm/kvm_main.c

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  1 /*
  2  * Kernel-based Virtual Machine driver for Linux
  3  *
  4  * This module enables machines with Intel VT-x extensions to run virtual
  5  * machines without emulation or binary translation.
  6  *
  7  * Copyright (C) 2006 Qumranet, Inc.
  8  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
  9  *
 10  * Authors:
 11  *   Avi Kivity   <avi@qumranet.com>
 12  *   Yaniv Kamay  <yaniv@qumranet.com>
 13  *
 14  * This work is licensed under the terms of the GNU GPL, version 2.  See
 15  * the COPYING file in the top-level directory.
 16  *
 17  */
 18 
 19 #include <kvm/iodev.h>
 20 
 21 #include <linux/kvm_host.h>
 22 #include <linux/kvm.h>
 23 #include <linux/module.h>
 24 #include <linux/errno.h>
 25 #include <linux/percpu.h>
 26 #include <linux/mm.h>
 27 #include <linux/miscdevice.h>
 28 #include <linux/vmalloc.h>
 29 #include <linux/reboot.h>
 30 #include <linux/debugfs.h>
 31 #include <linux/highmem.h>
 32 #include <linux/file.h>
 33 #include <linux/syscore_ops.h>
 34 #include <linux/cpu.h>
 35 #include <linux/sched.h>
 36 #include <linux/cpumask.h>
 37 #include <linux/smp.h>
 38 #include <linux/anon_inodes.h>
 39 #include <linux/profile.h>
 40 #include <linux/kvm_para.h>
 41 #include <linux/pagemap.h>
 42 #include <linux/mman.h>
 43 #include <linux/swap.h>
 44 #include <linux/bitops.h>
 45 #include <linux/spinlock.h>
 46 #include <linux/compat.h>
 47 #include <linux/srcu.h>
 48 #include <linux/hugetlb.h>
 49 #include <linux/slab.h>
 50 #include <linux/sort.h>
 51 #include <linux/bsearch.h>
 52 
 53 #include <asm/processor.h>
 54 #include <asm/io.h>
 55 #include <asm/ioctl.h>
 56 #include <asm/uaccess.h>
 57 #include <asm/pgtable.h>
 58 
 59 #include "coalesced_mmio.h"
 60 #include "async_pf.h"
 61 #include "vfio.h"
 62 
 63 #define CREATE_TRACE_POINTS
 64 #include <trace/events/kvm.h>
 65 
 66 MODULE_AUTHOR("Qumranet");
 67 MODULE_LICENSE("GPL");
 68 
 69 /* Architectures should define their poll value according to the halt latency */
 70 static unsigned int halt_poll_ns = KVM_HALT_POLL_NS_DEFAULT;
 71 module_param(halt_poll_ns, uint, S_IRUGO | S_IWUSR);
 72 
 73 /* Default doubles per-vcpu halt_poll_ns. */
 74 static unsigned int halt_poll_ns_grow = 2;
 75 module_param(halt_poll_ns_grow, uint, S_IRUGO | S_IWUSR);
 76 
 77 /* Default resets per-vcpu halt_poll_ns . */
 78 static unsigned int halt_poll_ns_shrink;
 79 module_param(halt_poll_ns_shrink, uint, S_IRUGO | S_IWUSR);
 80 
 81 /*
 82  * Ordering of locks:
 83  *
 84  *      kvm->lock --> kvm->slots_lock --> kvm->irq_lock
 85  */
 86 
 87 DEFINE_SPINLOCK(kvm_lock);
 88 static DEFINE_RAW_SPINLOCK(kvm_count_lock);
 89 LIST_HEAD(vm_list);
 90 
 91 static cpumask_var_t cpus_hardware_enabled;
 92 static int kvm_usage_count;
 93 static atomic_t hardware_enable_failed;
 94 
 95 struct kmem_cache *kvm_vcpu_cache;
 96 EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
 97 
 98 static __read_mostly struct preempt_ops kvm_preempt_ops;
 99 
100 struct dentry *kvm_debugfs_dir;
101 EXPORT_SYMBOL_GPL(kvm_debugfs_dir);
102 
103 static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
104                            unsigned long arg);
105 #ifdef CONFIG_KVM_COMPAT
106 static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl,
107                                   unsigned long arg);
108 #endif
109 static int hardware_enable_all(void);
110 static void hardware_disable_all(void);
111 
112 static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
113 
114 static void kvm_release_pfn_dirty(kvm_pfn_t pfn);
115 static void mark_page_dirty_in_slot(struct kvm_memory_slot *memslot, gfn_t gfn);
116 
117 __visible bool kvm_rebooting;
118 EXPORT_SYMBOL_GPL(kvm_rebooting);
119 
120 static bool largepages_enabled = true;
121 
122 bool kvm_is_reserved_pfn(kvm_pfn_t pfn)
123 {
124         if (pfn_valid(pfn))
125                 return PageReserved(pfn_to_page(pfn));
126 
127         return true;
128 }
129 
130 /*
131  * Switches to specified vcpu, until a matching vcpu_put()
132  */
133 int vcpu_load(struct kvm_vcpu *vcpu)
134 {
135         int cpu;
136 
137         if (mutex_lock_killable(&vcpu->mutex))
138                 return -EINTR;
139         cpu = get_cpu();
140         preempt_notifier_register(&vcpu->preempt_notifier);
141         kvm_arch_vcpu_load(vcpu, cpu);
142         put_cpu();
143         return 0;
144 }
145 
146 void vcpu_put(struct kvm_vcpu *vcpu)
147 {
148         preempt_disable();
149         kvm_arch_vcpu_put(vcpu);
150         preempt_notifier_unregister(&vcpu->preempt_notifier);
151         preempt_enable();
152         mutex_unlock(&vcpu->mutex);
153 }
154 
155 static void ack_flush(void *_completed)
156 {
157 }
158 
159 bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
160 {
161         int i, cpu, me;
162         cpumask_var_t cpus;
163         bool called = true;
164         struct kvm_vcpu *vcpu;
165 
166         zalloc_cpumask_var(&cpus, GFP_ATOMIC);
167 
168         me = get_cpu();
169         kvm_for_each_vcpu(i, vcpu, kvm) {
170                 kvm_make_request(req, vcpu);
171                 cpu = vcpu->cpu;
172 
173                 /* Set ->requests bit before we read ->mode. */
174                 smp_mb__after_atomic();
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         /*
195          * Read tlbs_dirty before setting KVM_REQ_TLB_FLUSH in
196          * kvm_make_all_cpus_request.
197          */
198         long dirty_count = smp_load_acquire(&kvm->tlbs_dirty);
199 
200         /*
201          * We want to publish modifications to the page tables before reading
202          * mode. Pairs with a memory barrier in arch-specific code.
203          * - x86: smp_mb__after_srcu_read_unlock in vcpu_enter_guest
204          * and smp_mb in walk_shadow_page_lockless_begin/end.
205          * - powerpc: smp_mb in kvmppc_prepare_to_enter.
206          *
207          * There is already an smp_mb__after_atomic() before
208          * kvm_make_all_cpus_request() reads vcpu->mode. We reuse that
209          * barrier here.
210          */
211         if (kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
212                 ++kvm->stat.remote_tlb_flush;
213         cmpxchg(&kvm->tlbs_dirty, dirty_count, 0);
214 }
215 EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs);
216 #endif
217 
218 void kvm_reload_remote_mmus(struct kvm *kvm)
219 {
220         kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD);
221 }
222 
223 int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
224 {
225         struct page *page;
226         int r;
227 
228         mutex_init(&vcpu->mutex);
229         vcpu->cpu = -1;
230         vcpu->kvm = kvm;
231         vcpu->vcpu_id = id;
232         vcpu->pid = NULL;
233         init_swait_queue_head(&vcpu->wq);
234         kvm_async_pf_vcpu_init(vcpu);
235 
236         vcpu->pre_pcpu = -1;
237         INIT_LIST_HEAD(&vcpu->blocked_vcpu_list);
238 
239         page = alloc_page(GFP_KERNEL | __GFP_ZERO);
240         if (!page) {
241                 r = -ENOMEM;
242                 goto fail;
243         }
244         vcpu->run = page_address(page);
245 
246         kvm_vcpu_set_in_spin_loop(vcpu, false);
247         kvm_vcpu_set_dy_eligible(vcpu, false);
248         vcpu->preempted = false;
249 
250         r = kvm_arch_vcpu_init(vcpu);
251         if (r < 0)
252                 goto fail_free_run;
253         return 0;
254 
255 fail_free_run:
256         free_page((unsigned long)vcpu->run);
257 fail:
258         return r;
259 }
260 EXPORT_SYMBOL_GPL(kvm_vcpu_init);
261 
262 void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
263 {
264         put_pid(vcpu->pid);
265         kvm_arch_vcpu_uninit(vcpu);
266         free_page((unsigned long)vcpu->run);
267 }
268 EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
269 
270 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
271 static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
272 {
273         return container_of(mn, struct kvm, mmu_notifier);
274 }
275 
276 static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
277                                              struct mm_struct *mm,
278                                              unsigned long address)
279 {
280         struct kvm *kvm = mmu_notifier_to_kvm(mn);
281         int need_tlb_flush, idx;
282 
283         /*
284          * When ->invalidate_page runs, the linux pte has been zapped
285          * already but the page is still allocated until
286          * ->invalidate_page returns. So if we increase the sequence
287          * here the kvm page fault will notice if the spte can't be
288          * established because the page is going to be freed. If
289          * instead the kvm page fault establishes the spte before
290          * ->invalidate_page runs, kvm_unmap_hva will release it
291          * before returning.
292          *
293          * The sequence increase only need to be seen at spin_unlock
294          * time, and not at spin_lock time.
295          *
296          * Increasing the sequence after the spin_unlock would be
297          * unsafe because the kvm page fault could then establish the
298          * pte after kvm_unmap_hva returned, without noticing the page
299          * is going to be freed.
300          */
301         idx = srcu_read_lock(&kvm->srcu);
302         spin_lock(&kvm->mmu_lock);
303 
304         kvm->mmu_notifier_seq++;
305         need_tlb_flush = kvm_unmap_hva(kvm, address) | kvm->tlbs_dirty;
306         /* we've to flush the tlb before the pages can be freed */
307         if (need_tlb_flush)
308                 kvm_flush_remote_tlbs(kvm);
309 
310         spin_unlock(&kvm->mmu_lock);
311 
312         kvm_arch_mmu_notifier_invalidate_page(kvm, address);
313 
314         srcu_read_unlock(&kvm->srcu, idx);
315 }
316 
317 static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
318                                         struct mm_struct *mm,
319                                         unsigned long address,
320                                         pte_t pte)
321 {
322         struct kvm *kvm = mmu_notifier_to_kvm(mn);
323         int idx;
324 
325         idx = srcu_read_lock(&kvm->srcu);
326         spin_lock(&kvm->mmu_lock);
327         kvm->mmu_notifier_seq++;
328         kvm_set_spte_hva(kvm, address, pte);
329         spin_unlock(&kvm->mmu_lock);
330         srcu_read_unlock(&kvm->srcu, idx);
331 }
332 
333 static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
334                                                     struct mm_struct *mm,
335                                                     unsigned long start,
336                                                     unsigned long end)
337 {
338         struct kvm *kvm = mmu_notifier_to_kvm(mn);
339         int need_tlb_flush = 0, idx;
340 
341         idx = srcu_read_lock(&kvm->srcu);
342         spin_lock(&kvm->mmu_lock);
343         /*
344          * The count increase must become visible at unlock time as no
345          * spte can be established without taking the mmu_lock and
346          * count is also read inside the mmu_lock critical section.
347          */
348         kvm->mmu_notifier_count++;
349         need_tlb_flush = kvm_unmap_hva_range(kvm, start, end);
350         need_tlb_flush |= kvm->tlbs_dirty;
351         /* we've to flush the tlb before the pages can be freed */
352         if (need_tlb_flush)
353                 kvm_flush_remote_tlbs(kvm);
354 
355         spin_unlock(&kvm->mmu_lock);
356         srcu_read_unlock(&kvm->srcu, idx);
357 }
358 
359 static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
360                                                   struct mm_struct *mm,
361                                                   unsigned long start,
362                                                   unsigned long end)
363 {
364         struct kvm *kvm = mmu_notifier_to_kvm(mn);
365 
366         spin_lock(&kvm->mmu_lock);
367         /*
368          * This sequence increase will notify the kvm page fault that
369          * the page that is going to be mapped in the spte could have
370          * been freed.
371          */
372         kvm->mmu_notifier_seq++;
373         smp_wmb();
374         /*
375          * The above sequence increase must be visible before the
376          * below count decrease, which is ensured by the smp_wmb above
377          * in conjunction with the smp_rmb in mmu_notifier_retry().
378          */
379         kvm->mmu_notifier_count--;
380         spin_unlock(&kvm->mmu_lock);
381 
382         BUG_ON(kvm->mmu_notifier_count < 0);
383 }
384 
385 static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
386                                               struct mm_struct *mm,
387                                               unsigned long start,
388                                               unsigned long end)
389 {
390         struct kvm *kvm = mmu_notifier_to_kvm(mn);
391         int young, idx;
392 
393         idx = srcu_read_lock(&kvm->srcu);
394         spin_lock(&kvm->mmu_lock);
395 
396         young = kvm_age_hva(kvm, start, end);
397         if (young)
398                 kvm_flush_remote_tlbs(kvm);
399 
400         spin_unlock(&kvm->mmu_lock);
401         srcu_read_unlock(&kvm->srcu, idx);
402 
403         return young;
404 }
405 
406 static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
407                                         struct mm_struct *mm,
408                                         unsigned long start,
409                                         unsigned long end)
410 {
411         struct kvm *kvm = mmu_notifier_to_kvm(mn);
412         int young, idx;
413 
414         idx = srcu_read_lock(&kvm->srcu);
415         spin_lock(&kvm->mmu_lock);
416         /*
417          * Even though we do not flush TLB, this will still adversely
418          * affect performance on pre-Haswell Intel EPT, where there is
419          * no EPT Access Bit to clear so that we have to tear down EPT
420          * tables instead. If we find this unacceptable, we can always
421          * add a parameter to kvm_age_hva so that it effectively doesn't
422          * do anything on clear_young.
423          *
424          * Also note that currently we never issue secondary TLB flushes
425          * from clear_young, leaving this job up to the regular system
426          * cadence. If we find this inaccurate, we might come up with a
427          * more sophisticated heuristic later.
428          */
429         young = kvm_age_hva(kvm, start, end);
430         spin_unlock(&kvm->mmu_lock);
431         srcu_read_unlock(&kvm->srcu, idx);
432 
433         return young;
434 }
435 
436 static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
437                                        struct mm_struct *mm,
438                                        unsigned long address)
439 {
440         struct kvm *kvm = mmu_notifier_to_kvm(mn);
441         int young, idx;
442 
443         idx = srcu_read_lock(&kvm->srcu);
444         spin_lock(&kvm->mmu_lock);
445         young = kvm_test_age_hva(kvm, address);
446         spin_unlock(&kvm->mmu_lock);
447         srcu_read_unlock(&kvm->srcu, idx);
448 
449         return young;
450 }
451 
452 static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
453                                      struct mm_struct *mm)
454 {
455         struct kvm *kvm = mmu_notifier_to_kvm(mn);
456         int idx;
457 
458         idx = srcu_read_lock(&kvm->srcu);
459         kvm_arch_flush_shadow_all(kvm);
460         srcu_read_unlock(&kvm->srcu, idx);
461 }
462 
463 static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
464         .invalidate_page        = kvm_mmu_notifier_invalidate_page,
465         .invalidate_range_start = kvm_mmu_notifier_invalidate_range_start,
466         .invalidate_range_end   = kvm_mmu_notifier_invalidate_range_end,
467         .clear_flush_young      = kvm_mmu_notifier_clear_flush_young,
468         .clear_young            = kvm_mmu_notifier_clear_young,
469         .test_young             = kvm_mmu_notifier_test_young,
470         .change_pte             = kvm_mmu_notifier_change_pte,
471         .release                = kvm_mmu_notifier_release,
472 };
473 
474 static int kvm_init_mmu_notifier(struct kvm *kvm)
475 {
476         kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
477         return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
478 }
479 
480 #else  /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */
481 
482 static int kvm_init_mmu_notifier(struct kvm *kvm)
483 {
484         return 0;
485 }
486 
487 #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
488 
489 static struct kvm_memslots *kvm_alloc_memslots(void)
490 {
491         int i;
492         struct kvm_memslots *slots;
493 
494         slots = kvm_kvzalloc(sizeof(struct kvm_memslots));
495         if (!slots)
496                 return NULL;
497 
498         /*
499          * Init kvm generation close to the maximum to easily test the
500          * code of handling generation number wrap-around.
501          */
502         slots->generation = -150;
503         for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
504                 slots->id_to_index[i] = slots->memslots[i].id = i;
505 
506         return slots;
507 }
508 
509 static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
510 {
511         if (!memslot->dirty_bitmap)
512                 return;
513 
514         kvfree(memslot->dirty_bitmap);
515         memslot->dirty_bitmap = NULL;
516 }
517 
518 /*
519  * Free any memory in @free but not in @dont.
520  */
521 static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
522                               struct kvm_memory_slot *dont)
523 {
524         if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
525                 kvm_destroy_dirty_bitmap(free);
526 
527         kvm_arch_free_memslot(kvm, free, dont);
528 
529         free->npages = 0;
530 }
531 
532 static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots)
533 {
534         struct kvm_memory_slot *memslot;
535 
536         if (!slots)
537                 return;
538 
539         kvm_for_each_memslot(memslot, slots)
540                 kvm_free_memslot(kvm, memslot, NULL);
541 
542         kvfree(slots);
543 }
544 
545 static struct kvm *kvm_create_vm(unsigned long type)
546 {
547         int r, i;
548         struct kvm *kvm = kvm_arch_alloc_vm();
549 
550         if (!kvm)
551                 return ERR_PTR(-ENOMEM);
552 
553         spin_lock_init(&kvm->mmu_lock);
554         atomic_inc(&current->mm->mm_count);
555         kvm->mm = current->mm;
556         kvm_eventfd_init(kvm);
557         mutex_init(&kvm->lock);
558         mutex_init(&kvm->irq_lock);
559         mutex_init(&kvm->slots_lock);
560         atomic_set(&kvm->users_count, 1);
561         INIT_LIST_HEAD(&kvm->devices);
562 
563         r = kvm_arch_init_vm(kvm, type);
564         if (r)
565                 goto out_err_no_disable;
566 
567         r = hardware_enable_all();
568         if (r)
569                 goto out_err_no_disable;
570 
571 #ifdef CONFIG_HAVE_KVM_IRQFD
572         INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
573 #endif
574 
575         BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX);
576 
577         r = -ENOMEM;
578         for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
579                 kvm->memslots[i] = kvm_alloc_memslots();
580                 if (!kvm->memslots[i])
581                         goto out_err_no_srcu;
582         }
583 
584         if (init_srcu_struct(&kvm->srcu))
585                 goto out_err_no_srcu;
586         if (init_srcu_struct(&kvm->irq_srcu))
587                 goto out_err_no_irq_srcu;
588         for (i = 0; i < KVM_NR_BUSES; i++) {
589                 kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus),
590                                         GFP_KERNEL);
591                 if (!kvm->buses[i])
592                         goto out_err;
593         }
594 
595         r = kvm_init_mmu_notifier(kvm);
596         if (r)
597                 goto out_err;
598 
599         spin_lock(&kvm_lock);
600         list_add(&kvm->vm_list, &vm_list);
601         spin_unlock(&kvm_lock);
602 
603         preempt_notifier_inc();
604 
605         return kvm;
606 
607 out_err:
608         cleanup_srcu_struct(&kvm->irq_srcu);
609 out_err_no_irq_srcu:
610         cleanup_srcu_struct(&kvm->srcu);
611 out_err_no_srcu:
612         hardware_disable_all();
613 out_err_no_disable:
614         for (i = 0; i < KVM_NR_BUSES; i++)
615                 kfree(kvm->buses[i]);
616         for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
617                 kvm_free_memslots(kvm, kvm->memslots[i]);
618         kvm_arch_free_vm(kvm);
619         mmdrop(current->mm);
620         return ERR_PTR(r);
621 }
622 
623 /*
624  * Avoid using vmalloc for a small buffer.
625  * Should not be used when the size is statically known.
626  */
627 void *kvm_kvzalloc(unsigned long size)
628 {
629         if (size > PAGE_SIZE)
630                 return vzalloc(size);
631         else
632                 return kzalloc(size, GFP_KERNEL);
633 }
634 
635 static void kvm_destroy_devices(struct kvm *kvm)
636 {
637         struct kvm_device *dev, *tmp;
638 
639         list_for_each_entry_safe(dev, tmp, &kvm->devices, vm_node) {
640                 list_del(&dev->vm_node);
641                 dev->ops->destroy(dev);
642         }
643 }
644 
645 static void kvm_destroy_vm(struct kvm *kvm)
646 {
647         int i;
648         struct mm_struct *mm = kvm->mm;
649 
650         kvm_arch_sync_events(kvm);
651         spin_lock(&kvm_lock);
652         list_del(&kvm->vm_list);
653         spin_unlock(&kvm_lock);
654         kvm_free_irq_routing(kvm);
655         for (i = 0; i < KVM_NR_BUSES; i++)
656                 kvm_io_bus_destroy(kvm->buses[i]);
657         kvm_coalesced_mmio_free(kvm);
658 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
659         mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
660 #else
661         kvm_arch_flush_shadow_all(kvm);
662 #endif
663         kvm_arch_destroy_vm(kvm);
664         kvm_destroy_devices(kvm);
665         for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
666                 kvm_free_memslots(kvm, kvm->memslots[i]);
667         cleanup_srcu_struct(&kvm->irq_srcu);
668         cleanup_srcu_struct(&kvm->srcu);
669         kvm_arch_free_vm(kvm);
670         preempt_notifier_dec();
671         hardware_disable_all();
672         mmdrop(mm);
673 }
674 
675 void kvm_get_kvm(struct kvm *kvm)
676 {
677         atomic_inc(&kvm->users_count);
678 }
679 EXPORT_SYMBOL_GPL(kvm_get_kvm);
680 
681 void kvm_put_kvm(struct kvm *kvm)
682 {
683         if (atomic_dec_and_test(&kvm->users_count))
684                 kvm_destroy_vm(kvm);
685 }
686 EXPORT_SYMBOL_GPL(kvm_put_kvm);
687 
688 
689 static int kvm_vm_release(struct inode *inode, struct file *filp)
690 {
691         struct kvm *kvm = filp->private_data;
692 
693         kvm_irqfd_release(kvm);
694 
695         kvm_put_kvm(kvm);
696         return 0;
697 }
698 
699 /*
700  * Allocation size is twice as large as the actual dirty bitmap size.
701  * See x86's kvm_vm_ioctl_get_dirty_log() why this is needed.
702  */
703 static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
704 {
705         unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
706 
707         memslot->dirty_bitmap = kvm_kvzalloc(dirty_bytes);
708         if (!memslot->dirty_bitmap)
709                 return -ENOMEM;
710 
711         return 0;
712 }
713 
714 /*
715  * Insert memslot and re-sort memslots based on their GFN,
716  * so binary search could be used to lookup GFN.
717  * Sorting algorithm takes advantage of having initially
718  * sorted array and known changed memslot position.
719  */
720 static void update_memslots(struct kvm_memslots *slots,
721                             struct kvm_memory_slot *new)
722 {
723         int id = new->id;
724         int i = slots->id_to_index[id];
725         struct kvm_memory_slot *mslots = slots->memslots;
726 
727         WARN_ON(mslots[i].id != id);
728         if (!new->npages) {
729                 WARN_ON(!mslots[i].npages);
730                 if (mslots[i].npages)
731                         slots->used_slots--;
732         } else {
733                 if (!mslots[i].npages)
734                         slots->used_slots++;
735         }
736 
737         while (i < KVM_MEM_SLOTS_NUM - 1 &&
738                new->base_gfn <= mslots[i + 1].base_gfn) {
739                 if (!mslots[i + 1].npages)
740                         break;
741                 mslots[i] = mslots[i + 1];
742                 slots->id_to_index[mslots[i].id] = i;
743                 i++;
744         }
745 
746         /*
747          * The ">=" is needed when creating a slot with base_gfn == 0,
748          * so that it moves before all those with base_gfn == npages == 0.
749          *
750          * On the other hand, if new->npages is zero, the above loop has
751          * already left i pointing to the beginning of the empty part of
752          * mslots, and the ">=" would move the hole backwards in this
753          * case---which is wrong.  So skip the loop when deleting a slot.
754          */
755         if (new->npages) {
756                 while (i > 0 &&
757                        new->base_gfn >= mslots[i - 1].base_gfn) {
758                         mslots[i] = mslots[i - 1];
759                         slots->id_to_index[mslots[i].id] = i;
760                         i--;
761                 }
762         } else
763                 WARN_ON_ONCE(i != slots->used_slots);
764 
765         mslots[i] = *new;
766         slots->id_to_index[mslots[i].id] = i;
767 }
768 
769 static int check_memory_region_flags(const struct kvm_userspace_memory_region *mem)
770 {
771         u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES;
772 
773 #ifdef __KVM_HAVE_READONLY_MEM
774         valid_flags |= KVM_MEM_READONLY;
775 #endif
776 
777         if (mem->flags & ~valid_flags)
778                 return -EINVAL;
779 
780         return 0;
781 }
782 
783 static struct kvm_memslots *install_new_memslots(struct kvm *kvm,
784                 int as_id, struct kvm_memslots *slots)
785 {
786         struct kvm_memslots *old_memslots = __kvm_memslots(kvm, as_id);
787 
788         /*
789          * Set the low bit in the generation, which disables SPTE caching
790          * until the end of synchronize_srcu_expedited.
791          */
792         WARN_ON(old_memslots->generation & 1);
793         slots->generation = old_memslots->generation + 1;
794 
795         rcu_assign_pointer(kvm->memslots[as_id], slots);
796         synchronize_srcu_expedited(&kvm->srcu);
797 
798         /*
799          * Increment the new memslot generation a second time. This prevents
800          * vm exits that race with memslot updates from caching a memslot
801          * generation that will (potentially) be valid forever.
802          */
803         slots->generation++;
804 
805         kvm_arch_memslots_updated(kvm, slots);
806 
807         return old_memslots;
808 }
809 
810 /*
811  * Allocate some memory and give it an address in the guest physical address
812  * space.
813  *
814  * Discontiguous memory is allowed, mostly for framebuffers.
815  *
816  * Must be called holding kvm->slots_lock for write.
817  */
818 int __kvm_set_memory_region(struct kvm *kvm,
819                             const struct kvm_userspace_memory_region *mem)
820 {
821         int r;
822         gfn_t base_gfn;
823         unsigned long npages;
824         struct kvm_memory_slot *slot;
825         struct kvm_memory_slot old, new;
826         struct kvm_memslots *slots = NULL, *old_memslots;
827         int as_id, id;
828         enum kvm_mr_change change;
829 
830         r = check_memory_region_flags(mem);
831         if (r)
832                 goto out;
833 
834         r = -EINVAL;
835         as_id = mem->slot >> 16;
836         id = (u16)mem->slot;
837 
838         /* General sanity checks */
839         if (mem->memory_size & (PAGE_SIZE - 1))
840                 goto out;
841         if (mem->guest_phys_addr & (PAGE_SIZE - 1))
842                 goto out;
843         /* We can read the guest memory with __xxx_user() later on. */
844         if ((id < KVM_USER_MEM_SLOTS) &&
845             ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
846              !access_ok(VERIFY_WRITE,
847                         (void __user *)(unsigned long)mem->userspace_addr,
848                         mem->memory_size)))
849                 goto out;
850         if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_MEM_SLOTS_NUM)
851                 goto out;
852         if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
853                 goto out;
854 
855         slot = id_to_memslot(__kvm_memslots(kvm, as_id), id);
856         base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
857         npages = mem->memory_size >> PAGE_SHIFT;
858 
859         if (npages > KVM_MEM_MAX_NR_PAGES)
860                 goto out;
861 
862         new = old = *slot;
863 
864         new.id = id;
865         new.base_gfn = base_gfn;
866         new.npages = npages;
867         new.flags = mem->flags;
868 
869         if (npages) {
870                 if (!old.npages)
871                         change = KVM_MR_CREATE;
872                 else { /* Modify an existing slot. */
873                         if ((mem->userspace_addr != old.userspace_addr) ||
874                             (npages != old.npages) ||
875                             ((new.flags ^ old.flags) & KVM_MEM_READONLY))
876                                 goto out;
877 
878                         if (base_gfn != old.base_gfn)
879                                 change = KVM_MR_MOVE;
880                         else if (new.flags != old.flags)
881                                 change = KVM_MR_FLAGS_ONLY;
882                         else { /* Nothing to change. */
883                                 r = 0;
884                                 goto out;
885                         }
886                 }
887         } else {
888                 if (!old.npages)
889                         goto out;
890 
891                 change = KVM_MR_DELETE;
892                 new.base_gfn = 0;
893                 new.flags = 0;
894         }
895 
896         if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) {
897                 /* Check for overlaps */
898                 r = -EEXIST;
899                 kvm_for_each_memslot(slot, __kvm_memslots(kvm, as_id)) {
900                         if ((slot->id >= KVM_USER_MEM_SLOTS) ||
901                             (slot->id == id))
902                                 continue;
903                         if (!((base_gfn + npages <= slot->base_gfn) ||
904                               (base_gfn >= slot->base_gfn + slot->npages)))
905                                 goto out;
906                 }
907         }
908 
909         /* Free page dirty bitmap if unneeded */
910         if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
911                 new.dirty_bitmap = NULL;
912 
913         r = -ENOMEM;
914         if (change == KVM_MR_CREATE) {
915                 new.userspace_addr = mem->userspace_addr;
916 
917                 if (kvm_arch_create_memslot(kvm, &new, npages))
918                         goto out_free;
919         }
920 
921         /* Allocate page dirty bitmap if needed */
922         if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
923                 if (kvm_create_dirty_bitmap(&new) < 0)
924                         goto out_free;
925         }
926 
927         slots = kvm_kvzalloc(sizeof(struct kvm_memslots));
928         if (!slots)
929                 goto out_free;
930         memcpy(slots, __kvm_memslots(kvm, as_id), sizeof(struct kvm_memslots));
931 
932         if ((change == KVM_MR_DELETE) || (change == KVM_MR_MOVE)) {
933                 slot = id_to_memslot(slots, id);
934                 slot->flags |= KVM_MEMSLOT_INVALID;
935 
936                 old_memslots = install_new_memslots(kvm, as_id, slots);
937 
938                 /* slot was deleted or moved, clear iommu mapping */
939                 kvm_iommu_unmap_pages(kvm, &old);
940                 /* From this point no new shadow pages pointing to a deleted,
941                  * or moved, memslot will be created.
942                  *
943                  * validation of sp->gfn happens in:
944                  *      - gfn_to_hva (kvm_read_guest, gfn_to_pfn)
945                  *      - kvm_is_visible_gfn (mmu_check_roots)
946                  */
947                 kvm_arch_flush_shadow_memslot(kvm, slot);
948 
949                 /*
950                  * We can re-use the old_memslots from above, the only difference
951                  * from the currently installed memslots is the invalid flag.  This
952                  * will get overwritten by update_memslots anyway.
953                  */
954                 slots = old_memslots;
955         }
956 
957         r = kvm_arch_prepare_memory_region(kvm, &new, mem, change);
958         if (r)
959                 goto out_slots;
960 
961         /* actual memory is freed via old in kvm_free_memslot below */
962         if (change == KVM_MR_DELETE) {
963                 new.dirty_bitmap = NULL;
964                 memset(&new.arch, 0, sizeof(new.arch));
965         }
966 
967         update_memslots(slots, &new);
968         old_memslots = install_new_memslots(kvm, as_id, slots);
969 
970         kvm_arch_commit_memory_region(kvm, mem, &old, &new, change);
971 
972         kvm_free_memslot(kvm, &old, &new);
973         kvfree(old_memslots);
974 
975         /*
976          * IOMMU mapping:  New slots need to be mapped.  Old slots need to be
977          * un-mapped and re-mapped if their base changes.  Since base change
978          * unmapping is handled above with slot deletion, mapping alone is
979          * needed here.  Anything else the iommu might care about for existing
980          * slots (size changes, userspace addr changes and read-only flag
981          * changes) is disallowed above, so any other attribute changes getting
982          * here can be skipped.
983          */
984         if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) {
985                 r = kvm_iommu_map_pages(kvm, &new);
986                 return r;
987         }
988 
989         return 0;
990 
991 out_slots:
992         kvfree(slots);
993 out_free:
994         kvm_free_memslot(kvm, &new, &old);
995 out:
996         return r;
997 }
998 EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
999 
1000 int kvm_set_memory_region(struct kvm *kvm,
1001                           const struct kvm_userspace_memory_region *mem)
1002 {
1003         int r;
1004 
1005         mutex_lock(&kvm->slots_lock);
1006         r = __kvm_set_memory_region(kvm, mem);
1007         mutex_unlock(&kvm->slots_lock);
1008         return r;
1009 }
1010 EXPORT_SYMBOL_GPL(kvm_set_memory_region);
1011 
1012 static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
1013                                           struct kvm_userspace_memory_region *mem)
1014 {
1015         if ((u16)mem->slot >= KVM_USER_MEM_SLOTS)
1016                 return -EINVAL;
1017 
1018         return kvm_set_memory_region(kvm, mem);
1019 }
1020 
1021 int kvm_get_dirty_log(struct kvm *kvm,
1022                         struct kvm_dirty_log *log, int *is_dirty)
1023 {
1024         struct kvm_memslots *slots;
1025         struct kvm_memory_slot *memslot;
1026         int r, i, as_id, id;
1027         unsigned long n;
1028         unsigned long any = 0;
1029 
1030         r = -EINVAL;
1031         as_id = log->slot >> 16;
1032         id = (u16)log->slot;
1033         if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
1034                 goto out;
1035 
1036         slots = __kvm_memslots(kvm, as_id);
1037         memslot = id_to_memslot(slots, id);
1038         r = -ENOENT;
1039         if (!memslot->dirty_bitmap)
1040                 goto out;
1041 
1042         n = kvm_dirty_bitmap_bytes(memslot);
1043 
1044         for (i = 0; !any && i < n/sizeof(long); ++i)
1045                 any = memslot->dirty_bitmap[i];
1046 
1047         r = -EFAULT;
1048         if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
1049                 goto out;
1050 
1051         if (any)
1052                 *is_dirty = 1;
1053 
1054         r = 0;
1055 out:
1056         return r;
1057 }
1058 EXPORT_SYMBOL_GPL(kvm_get_dirty_log);
1059 
1060 #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
1061 /**
1062  * kvm_get_dirty_log_protect - get a snapshot of dirty pages, and if any pages
1063  *      are dirty write protect them for next write.
1064  * @kvm:        pointer to kvm instance
1065  * @log:        slot id and address to which we copy the log
1066  * @is_dirty:   flag set if any page is dirty
1067  *
1068  * We need to keep it in mind that VCPU threads can write to the bitmap
1069  * concurrently. So, to avoid losing track of dirty pages we keep the
1070  * following order:
1071  *
1072  *    1. Take a snapshot of the bit and clear it if needed.
1073  *    2. Write protect the corresponding page.
1074  *    3. Copy the snapshot to the userspace.
1075  *    4. Upon return caller flushes TLB's if needed.
1076  *
1077  * Between 2 and 4, the guest may write to the page using the remaining TLB
1078  * entry.  This is not a problem because the page is reported dirty using
1079  * the snapshot taken before and step 4 ensures that writes done after
1080  * exiting to userspace will be logged for the next call.
1081  *
1082  */
1083 int kvm_get_dirty_log_protect(struct kvm *kvm,
1084                         struct kvm_dirty_log *log, bool *is_dirty)
1085 {
1086         struct kvm_memslots *slots;
1087         struct kvm_memory_slot *memslot;
1088         int r, i, as_id, id;
1089         unsigned long n;
1090         unsigned long *dirty_bitmap;
1091         unsigned long *dirty_bitmap_buffer;
1092 
1093         r = -EINVAL;
1094         as_id = log->slot >> 16;
1095         id = (u16)log->slot;
1096         if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
1097                 goto out;
1098 
1099         slots = __kvm_memslots(kvm, as_id);
1100         memslot = id_to_memslot(slots, id);
1101 
1102         dirty_bitmap = memslot->dirty_bitmap;
1103         r = -ENOENT;
1104         if (!dirty_bitmap)
1105                 goto out;
1106 
1107         n = kvm_dirty_bitmap_bytes(memslot);
1108 
1109         dirty_bitmap_buffer = dirty_bitmap + n / sizeof(long);
1110         memset(dirty_bitmap_buffer, 0, n);
1111 
1112         spin_lock(&kvm->mmu_lock);
1113         *is_dirty = false;
1114         for (i = 0; i < n / sizeof(long); i++) {
1115                 unsigned long mask;
1116                 gfn_t offset;
1117 
1118                 if (!dirty_bitmap[i])
1119                         continue;
1120 
1121                 *is_dirty = true;
1122 
1123                 mask = xchg(&dirty_bitmap[i], 0);
1124                 dirty_bitmap_buffer[i] = mask;
1125 
1126                 if (mask) {
1127                         offset = i * BITS_PER_LONG;
1128                         kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot,
1129                                                                 offset, mask);
1130                 }
1131         }
1132 
1133         spin_unlock(&kvm->mmu_lock);
1134 
1135         r = -EFAULT;
1136         if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n))
1137                 goto out;
1138 
1139         r = 0;
1140 out:
1141         return r;
1142 }
1143 EXPORT_SYMBOL_GPL(kvm_get_dirty_log_protect);
1144 #endif
1145 
1146 bool kvm_largepages_enabled(void)
1147 {
1148         return largepages_enabled;
1149 }
1150 
1151 void kvm_disable_largepages(void)
1152 {
1153         largepages_enabled = false;
1154 }
1155 EXPORT_SYMBOL_GPL(kvm_disable_largepages);
1156 
1157 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
1158 {
1159         return __gfn_to_memslot(kvm_memslots(kvm), gfn);
1160 }
1161 EXPORT_SYMBOL_GPL(gfn_to_memslot);
1162 
1163 struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn)
1164 {
1165         return __gfn_to_memslot(kvm_vcpu_memslots(vcpu), gfn);
1166 }
1167 
1168 bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
1169 {
1170         struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn);
1171 
1172         if (!memslot || memslot->id >= KVM_USER_MEM_SLOTS ||
1173               memslot->flags & KVM_MEMSLOT_INVALID)
1174                 return false;
1175 
1176         return true;
1177 }
1178 EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
1179 
1180 unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn)
1181 {
1182         struct vm_area_struct *vma;
1183         unsigned long addr, size;
1184 
1185         size = PAGE_SIZE;
1186 
1187         addr = gfn_to_hva(kvm, gfn);
1188         if (kvm_is_error_hva(addr))
1189                 return PAGE_SIZE;
1190 
1191         down_read(&current->mm->mmap_sem);
1192         vma = find_vma(current->mm, addr);
1193         if (!vma)
1194                 goto out;
1195 
1196         size = vma_kernel_pagesize(vma);
1197 
1198 out:
1199         up_read(&current->mm->mmap_sem);
1200 
1201         return size;
1202 }
1203 
1204 static bool memslot_is_readonly(struct kvm_memory_slot *slot)
1205 {
1206         return slot->flags & KVM_MEM_READONLY;
1207 }
1208 
1209 static unsigned long __gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
1210                                        gfn_t *nr_pages, bool write)
1211 {
1212         if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
1213                 return KVM_HVA_ERR_BAD;
1214 
1215         if (memslot_is_readonly(slot) && write)
1216                 return KVM_HVA_ERR_RO_BAD;
1217 
1218         if (nr_pages)
1219                 *nr_pages = slot->npages - (gfn - slot->base_gfn);
1220 
1221         return __gfn_to_hva_memslot(slot, gfn);
1222 }
1223 
1224 static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
1225                                      gfn_t *nr_pages)
1226 {
1227         return __gfn_to_hva_many(slot, gfn, nr_pages, true);
1228 }
1229 
1230 unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot,
1231                                         gfn_t gfn)
1232 {
1233         return gfn_to_hva_many(slot, gfn, NULL);
1234 }
1235 EXPORT_SYMBOL_GPL(gfn_to_hva_memslot);
1236 
1237 unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
1238 {
1239         return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL);
1240 }
1241 EXPORT_SYMBOL_GPL(gfn_to_hva);
1242 
1243 unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn)
1244 {
1245         return gfn_to_hva_many(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn, NULL);
1246 }
1247 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_hva);
1248 
1249 /*
1250  * If writable is set to false, the hva returned by this function is only
1251  * allowed to be read.
1252  */
1253 unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot,
1254                                       gfn_t gfn, bool *writable)
1255 {
1256         unsigned long hva = __gfn_to_hva_many(slot, gfn, NULL, false);
1257 
1258         if (!kvm_is_error_hva(hva) && writable)
1259                 *writable = !memslot_is_readonly(slot);
1260 
1261         return hva;
1262 }
1263 
1264 unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable)
1265 {
1266         struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
1267 
1268         return gfn_to_hva_memslot_prot(slot, gfn, writable);
1269 }
1270 
1271 unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable)
1272 {
1273         struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1274 
1275         return gfn_to_hva_memslot_prot(slot, gfn, writable);
1276 }
1277 
1278 static int get_user_page_nowait(unsigned long start, int write,
1279                 struct page **page)
1280 {
1281         int flags = FOLL_TOUCH | FOLL_NOWAIT | FOLL_HWPOISON | FOLL_GET;
1282 
1283         if (write)
1284                 flags |= FOLL_WRITE;
1285 
1286         return __get_user_pages(current, current->mm, start, 1, flags, page,
1287                         NULL, NULL);
1288 }
1289 
1290 static inline int check_user_page_hwpoison(unsigned long addr)
1291 {
1292         int rc, flags = FOLL_TOUCH | FOLL_HWPOISON | FOLL_WRITE;
1293 
1294         rc = __get_user_pages(current, current->mm, addr, 1,
1295                               flags, NULL, NULL, NULL);
1296         return rc == -EHWPOISON;
1297 }
1298 
1299 /*
1300  * The atomic path to get the writable pfn which will be stored in @pfn,
1301  * true indicates success, otherwise false is returned.
1302  */
1303 static bool hva_to_pfn_fast(unsigned long addr, bool atomic, bool *async,
1304                             bool write_fault, bool *writable, kvm_pfn_t *pfn)
1305 {
1306         struct page *page[1];
1307         int npages;
1308 
1309         if (!(async || atomic))
1310                 return false;
1311 
1312         /*
1313          * Fast pin a writable pfn only if it is a write fault request
1314          * or the caller allows to map a writable pfn for a read fault
1315          * request.
1316          */
1317         if (!(write_fault || writable))
1318                 return false;
1319 
1320         npages = __get_user_pages_fast(addr, 1, 1, page);
1321         if (npages == 1) {
1322                 *pfn = page_to_pfn(page[0]);
1323 
1324                 if (writable)
1325                         *writable = true;
1326                 return true;
1327         }
1328 
1329         return false;
1330 }
1331 
1332 /*
1333  * The slow path to get the pfn of the specified host virtual address,
1334  * 1 indicates success, -errno is returned if error is detected.
1335  */
1336 static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault,
1337                            bool *writable, kvm_pfn_t *pfn)
1338 {
1339         struct page *page[1];
1340         int npages = 0;
1341 
1342         might_sleep();
1343 
1344         if (writable)
1345                 *writable = write_fault;
1346 
1347         if (async) {
1348                 down_read(&current->mm->mmap_sem);
1349                 npages = get_user_page_nowait(addr, write_fault, page);
1350                 up_read(&current->mm->mmap_sem);
1351         } else
1352                 npages = __get_user_pages_unlocked(current, current->mm, addr, 1,
1353                                                    write_fault, 0, page,
1354                                                    FOLL_TOUCH|FOLL_HWPOISON);
1355         if (npages != 1)
1356                 return npages;
1357 
1358         /* map read fault as writable if possible */
1359         if (unlikely(!write_fault) && writable) {
1360                 struct page *wpage[1];
1361 
1362                 npages = __get_user_pages_fast(addr, 1, 1, wpage);
1363                 if (npages == 1) {
1364                         *writable = true;
1365                         put_page(page[0]);
1366                         page[0] = wpage[0];
1367                 }
1368 
1369                 npages = 1;
1370         }
1371         *pfn = page_to_pfn(page[0]);
1372         return npages;
1373 }
1374 
1375 static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault)
1376 {
1377         if (unlikely(!(vma->vm_flags & VM_READ)))
1378                 return false;
1379 
1380         if (write_fault && (unlikely(!(vma->vm_flags & VM_WRITE))))
1381                 return false;
1382 
1383         return true;
1384 }
1385 
1386 /*
1387  * Pin guest page in memory and return its pfn.
1388  * @addr: host virtual address which maps memory to the guest
1389  * @atomic: whether this function can sleep
1390  * @async: whether this function need to wait IO complete if the
1391  *         host page is not in the memory
1392  * @write_fault: whether we should get a writable host page
1393  * @writable: whether it allows to map a writable host page for !@write_fault
1394  *
1395  * The function will map a writable host page for these two cases:
1396  * 1): @write_fault = true
1397  * 2): @write_fault = false && @writable, @writable will tell the caller
1398  *     whether the mapping is writable.
1399  */
1400 static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
1401                         bool write_fault, bool *writable)
1402 {
1403         struct vm_area_struct *vma;
1404         kvm_pfn_t pfn = 0;
1405         int npages;
1406 
1407         /* we can do it either atomically or asynchronously, not both */
1408         BUG_ON(atomic && async);
1409 
1410         if (hva_to_pfn_fast(addr, atomic, async, write_fault, writable, &pfn))
1411                 return pfn;
1412 
1413         if (atomic)
1414                 return KVM_PFN_ERR_FAULT;
1415 
1416         npages = hva_to_pfn_slow(addr, async, write_fault, writable, &pfn);
1417         if (npages == 1)
1418                 return pfn;
1419 
1420         down_read(&current->mm->mmap_sem);
1421         if (npages == -EHWPOISON ||
1422               (!async && check_user_page_hwpoison(addr))) {
1423                 pfn = KVM_PFN_ERR_HWPOISON;
1424                 goto exit;
1425         }
1426 
1427         vma = find_vma_intersection(current->mm, addr, addr + 1);
1428 
1429         if (vma == NULL)
1430                 pfn = KVM_PFN_ERR_FAULT;
1431         else if ((vma->vm_flags & VM_PFNMAP)) {
1432                 pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) +
1433                         vma->vm_pgoff;
1434                 BUG_ON(!kvm_is_reserved_pfn(pfn));
1435         } else {
1436                 if (async && vma_is_valid(vma, write_fault))
1437                         *async = true;
1438                 pfn = KVM_PFN_ERR_FAULT;
1439         }
1440 exit:
1441         up_read(&current->mm->mmap_sem);
1442         return pfn;
1443 }
1444 
1445 kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn,
1446                                bool atomic, bool *async, bool write_fault,
1447                                bool *writable)
1448 {
1449         unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault);
1450 
1451         if (addr == KVM_HVA_ERR_RO_BAD) {
1452                 if (writable)
1453                         *writable = false;
1454                 return KVM_PFN_ERR_RO_FAULT;
1455         }
1456 
1457         if (kvm_is_error_hva(addr)) {
1458                 if (writable)
1459                         *writable = false;
1460                 return KVM_PFN_NOSLOT;
1461         }
1462 
1463         /* Do not map writable pfn in the readonly memslot. */
1464         if (writable && memslot_is_readonly(slot)) {
1465                 *writable = false;
1466                 writable = NULL;
1467         }
1468 
1469         return hva_to_pfn(addr, atomic, async, write_fault,
1470                           writable);
1471 }
1472 EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot);
1473 
1474 kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
1475                       bool *writable)
1476 {
1477         return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, NULL,
1478                                     write_fault, writable);
1479 }
1480 EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);
1481 
1482 kvm_pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
1483 {
1484         return __gfn_to_pfn_memslot(slot, gfn, false, NULL, true, NULL);
1485 }
1486 EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot);
1487 
1488 kvm_pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn)
1489 {
1490         return __gfn_to_pfn_memslot(slot, gfn, true, NULL, true, NULL);
1491 }
1492 EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic);
1493 
1494 kvm_pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn)
1495 {
1496         return gfn_to_pfn_memslot_atomic(gfn_to_memslot(kvm, gfn), gfn);
1497 }
1498 EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic);
1499 
1500 kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn)
1501 {
1502         return gfn_to_pfn_memslot_atomic(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
1503 }
1504 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_atomic);
1505 
1506 kvm_pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
1507 {
1508         return gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn);
1509 }
1510 EXPORT_SYMBOL_GPL(gfn_to_pfn);
1511 
1512 kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn)
1513 {
1514         return gfn_to_pfn_memslot(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
1515 }
1516 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn);
1517 
1518 int gfn_to_page_many_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
1519                             struct page **pages, int nr_pages)
1520 {
1521         unsigned long addr;
1522         gfn_t entry;
1523 
1524         addr = gfn_to_hva_many(slot, gfn, &entry);
1525         if (kvm_is_error_hva(addr))
1526                 return -1;
1527 
1528         if (entry < nr_pages)
1529                 return 0;
1530 
1531         return __get_user_pages_fast(addr, nr_pages, 1, pages);
1532 }
1533 EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
1534 
1535 static struct page *kvm_pfn_to_page(kvm_pfn_t pfn)
1536 {
1537         if (is_error_noslot_pfn(pfn))
1538                 return KVM_ERR_PTR_BAD_PAGE;
1539 
1540         if (kvm_is_reserved_pfn(pfn)) {
1541                 WARN_ON(1);
1542                 return KVM_ERR_PTR_BAD_PAGE;
1543         }
1544 
1545         return pfn_to_page(pfn);
1546 }
1547 
1548 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
1549 {
1550         kvm_pfn_t pfn;
1551 
1552         pfn = gfn_to_pfn(kvm, gfn);
1553 
1554         return kvm_pfn_to_page(pfn);
1555 }
1556 EXPORT_SYMBOL_GPL(gfn_to_page);
1557 
1558 struct page *kvm_vcpu_gfn_to_page(struct kvm_vcpu *vcpu, gfn_t gfn)
1559 {
1560         kvm_pfn_t pfn;
1561 
1562         pfn = kvm_vcpu_gfn_to_pfn(vcpu, gfn);
1563 
1564         return kvm_pfn_to_page(pfn);
1565 }
1566 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_page);
1567 
1568 void kvm_release_page_clean(struct page *page)
1569 {
1570         WARN_ON(is_error_page(page));
1571 
1572         kvm_release_pfn_clean(page_to_pfn(page));
1573 }
1574 EXPORT_SYMBOL_GPL(kvm_release_page_clean);
1575 
1576 void kvm_release_pfn_clean(kvm_pfn_t pfn)
1577 {
1578         if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn))
1579                 put_page(pfn_to_page(pfn));
1580 }
1581 EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
1582 
1583 void kvm_release_page_dirty(struct page *page)
1584 {
1585         WARN_ON(is_error_page(page));
1586 
1587         kvm_release_pfn_dirty(page_to_pfn(page));
1588 }
1589 EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
1590 
1591 static void kvm_release_pfn_dirty(kvm_pfn_t pfn)
1592 {
1593         kvm_set_pfn_dirty(pfn);
1594         kvm_release_pfn_clean(pfn);
1595 }
1596 
1597 void kvm_set_pfn_dirty(kvm_pfn_t pfn)
1598 {
1599         if (!kvm_is_reserved_pfn(pfn)) {
1600                 struct page *page = pfn_to_page(pfn);
1601 
1602                 if (!PageReserved(page))
1603                         SetPageDirty(page);
1604         }
1605 }
1606 EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
1607 
1608 void kvm_set_pfn_accessed(kvm_pfn_t pfn)
1609 {
1610         if (!kvm_is_reserved_pfn(pfn))
1611                 mark_page_accessed(pfn_to_page(pfn));
1612 }
1613 EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
1614 
1615 void kvm_get_pfn(kvm_pfn_t pfn)
1616 {
1617         if (!kvm_is_reserved_pfn(pfn))
1618                 get_page(pfn_to_page(pfn));
1619 }
1620 EXPORT_SYMBOL_GPL(kvm_get_pfn);
1621 
1622 static int next_segment(unsigned long len, int offset)
1623 {
1624         if (len > PAGE_SIZE - offset)
1625                 return PAGE_SIZE - offset;
1626         else
1627                 return len;
1628 }
1629 
1630 static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn,
1631                                  void *data, int offset, int len)
1632 {
1633         int r;
1634         unsigned long addr;
1635 
1636         addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
1637         if (kvm_is_error_hva(addr))
1638                 return -EFAULT;
1639         r = __copy_from_user(data, (void __user *)addr + offset, len);
1640         if (r)
1641                 return -EFAULT;
1642         return 0;
1643 }
1644 
1645 int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
1646                         int len)
1647 {
1648         struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
1649 
1650         return __kvm_read_guest_page(slot, gfn, data, offset, len);
1651 }
1652 EXPORT_SYMBOL_GPL(kvm_read_guest_page);
1653 
1654 int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data,
1655                              int offset, int len)
1656 {
1657         struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1658 
1659         return __kvm_read_guest_page(slot, gfn, data, offset, len);
1660 }
1661 EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_page);
1662 
1663 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
1664 {
1665         gfn_t gfn = gpa >> PAGE_SHIFT;
1666         int seg;
1667         int offset = offset_in_page(gpa);
1668         int ret;
1669 
1670         while ((seg = next_segment(len, offset)) != 0) {
1671                 ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
1672                 if (ret < 0)
1673                         return ret;
1674                 offset = 0;
1675                 len -= seg;
1676                 data += seg;
1677                 ++gfn;
1678         }
1679         return 0;
1680 }
1681 EXPORT_SYMBOL_GPL(kvm_read_guest);
1682 
1683 int kvm_vcpu_read_guest(struct kvm_vcpu *vcpu, gpa_t gpa, void *data, unsigned long len)
1684 {
1685         gfn_t gfn = gpa >> PAGE_SHIFT;
1686         int seg;
1687         int offset = offset_in_page(gpa);
1688         int ret;
1689 
1690         while ((seg = next_segment(len, offset)) != 0) {
1691                 ret = kvm_vcpu_read_guest_page(vcpu, gfn, data, offset, seg);
1692                 if (ret < 0)
1693                         return ret;
1694                 offset = 0;
1695                 len -= seg;
1696                 data += seg;
1697                 ++gfn;
1698         }
1699         return 0;
1700 }
1701 EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest);
1702 
1703 static int __kvm_read_guest_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
1704                                    void *data, int offset, unsigned long len)
1705 {
1706         int r;
1707         unsigned long addr;
1708 
1709         addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
1710         if (kvm_is_error_hva(addr))
1711                 return -EFAULT;
1712         pagefault_disable();
1713         r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
1714         pagefault_enable();
1715         if (r)
1716                 return -EFAULT;
1717         return 0;
1718 }
1719 
1720 int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
1721                           unsigned long len)
1722 {
1723         gfn_t gfn = gpa >> PAGE_SHIFT;
1724         struct kvm_memory_slot *slot = gfn_to_memslot(kvm, 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_read_guest_atomic);
1730 
1731 int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa,
1732                                void *data, unsigned long len)
1733 {
1734         gfn_t gfn = gpa >> PAGE_SHIFT;
1735         struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1736         int offset = offset_in_page(gpa);
1737 
1738         return __kvm_read_guest_atomic(slot, gfn, data, offset, len);
1739 }
1740 EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic);
1741 
1742 static int __kvm_write_guest_page(struct kvm_memory_slot *memslot, gfn_t gfn,
1743                                   const void *data, int offset, int len)
1744 {
1745         int r;
1746         unsigned long addr;
1747 
1748         addr = gfn_to_hva_memslot(memslot, gfn);
1749         if (kvm_is_error_hva(addr))
1750                 return -EFAULT;
1751         r = __copy_to_user((void __user *)addr + offset, data, len);
1752         if (r)
1753                 return -EFAULT;
1754         mark_page_dirty_in_slot(memslot, gfn);
1755         return 0;
1756 }
1757 
1758 int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn,
1759                          const void *data, int offset, int len)
1760 {
1761         struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
1762 
1763         return __kvm_write_guest_page(slot, gfn, data, offset, len);
1764 }
1765 EXPORT_SYMBOL_GPL(kvm_write_guest_page);
1766 
1767 int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn,
1768                               const void *data, int offset, int len)
1769 {
1770         struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1771 
1772         return __kvm_write_guest_page(slot, gfn, data, offset, len);
1773 }
1774 EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest_page);
1775 
1776 int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
1777                     unsigned long len)
1778 {
1779         gfn_t gfn = gpa >> PAGE_SHIFT;
1780         int seg;
1781         int offset = offset_in_page(gpa);
1782         int ret;
1783 
1784         while ((seg = next_segment(len, offset)) != 0) {
1785                 ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
1786                 if (ret < 0)
1787                         return ret;
1788                 offset = 0;
1789                 len -= seg;
1790                 data += seg;
1791                 ++gfn;
1792         }
1793         return 0;
1794 }
1795 EXPORT_SYMBOL_GPL(kvm_write_guest);
1796 
1797 int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data,
1798                          unsigned long len)
1799 {
1800         gfn_t gfn = gpa >> PAGE_SHIFT;
1801         int seg;
1802         int offset = offset_in_page(gpa);
1803         int ret;
1804 
1805         while ((seg = next_segment(len, offset)) != 0) {
1806                 ret = kvm_vcpu_write_guest_page(vcpu, gfn, data, offset, seg);
1807                 if (ret < 0)
1808                         return ret;
1809                 offset = 0;
1810                 len -= seg;
1811                 data += seg;
1812                 ++gfn;
1813         }
1814         return 0;
1815 }
1816 EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest);
1817 
1818 int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1819                               gpa_t gpa, unsigned long len)
1820 {
1821         struct kvm_memslots *slots = kvm_memslots(kvm);
1822         int offset = offset_in_page(gpa);
1823         gfn_t start_gfn = gpa >> PAGE_SHIFT;
1824         gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT;
1825         gfn_t nr_pages_needed = end_gfn - start_gfn + 1;
1826         gfn_t nr_pages_avail;
1827 
1828         ghc->gpa = gpa;
1829         ghc->generation = slots->generation;
1830         ghc->len = len;
1831         ghc->memslot = gfn_to_memslot(kvm, start_gfn);
1832         ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, NULL);
1833         if (!kvm_is_error_hva(ghc->hva) && nr_pages_needed <= 1) {
1834                 ghc->hva += offset;
1835         } else {
1836                 /*
1837                  * If the requested region crosses two memslots, we still
1838                  * verify that the entire region is valid here.
1839                  */
1840                 while (start_gfn <= end_gfn) {
1841                         ghc->memslot = gfn_to_memslot(kvm, start_gfn);
1842                         ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn,
1843                                                    &nr_pages_avail);
1844                         if (kvm_is_error_hva(ghc->hva))
1845                                 return -EFAULT;
1846                         start_gfn += nr_pages_avail;
1847                 }
1848                 /* Use the slow path for cross page reads and writes. */
1849                 ghc->memslot = NULL;
1850         }
1851         return 0;
1852 }
1853 EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
1854 
1855 int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1856                            void *data, unsigned long len)
1857 {
1858         struct kvm_memslots *slots = kvm_memslots(kvm);
1859         int r;
1860 
1861         BUG_ON(len > ghc->len);
1862 
1863         if (slots->generation != ghc->generation)
1864                 kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa, ghc->len);
1865 
1866         if (unlikely(!ghc->memslot))
1867                 return kvm_write_guest(kvm, ghc->gpa, data, len);
1868 
1869         if (kvm_is_error_hva(ghc->hva))
1870                 return -EFAULT;
1871 
1872         r = __copy_to_user((void __user *)ghc->hva, data, len);
1873         if (r)
1874                 return -EFAULT;
1875         mark_page_dirty_in_slot(ghc->memslot, ghc->gpa >> PAGE_SHIFT);
1876 
1877         return 0;
1878 }
1879 EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
1880 
1881 int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1882                            void *data, unsigned long len)
1883 {
1884         struct kvm_memslots *slots = kvm_memslots(kvm);
1885         int r;
1886 
1887         BUG_ON(len > ghc->len);
1888 
1889         if (slots->generation != ghc->generation)
1890                 kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa, ghc->len);
1891 
1892         if (unlikely(!ghc->memslot))
1893                 return kvm_read_guest(kvm, ghc->gpa, data, len);
1894 
1895         if (kvm_is_error_hva(ghc->hva))
1896                 return -EFAULT;
1897 
1898         r = __copy_from_user(data, (void __user *)ghc->hva, len);
1899         if (r)
1900                 return -EFAULT;
1901 
1902         return 0;
1903 }
1904 EXPORT_SYMBOL_GPL(kvm_read_guest_cached);
1905 
1906 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
1907 {
1908         const void *zero_page = (const void *) __va(page_to_phys(ZERO_PAGE(0)));
1909 
1910         return kvm_write_guest_page(kvm, gfn, zero_page, offset, len);
1911 }
1912 EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
1913 
1914 int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
1915 {
1916         gfn_t gfn = gpa >> PAGE_SHIFT;
1917         int seg;
1918         int offset = offset_in_page(gpa);
1919         int ret;
1920 
1921         while ((seg = next_segment(len, offset)) != 0) {
1922                 ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
1923                 if (ret < 0)
1924                         return ret;
1925                 offset = 0;
1926                 len -= seg;
1927                 ++gfn;
1928         }
1929         return 0;
1930 }
1931 EXPORT_SYMBOL_GPL(kvm_clear_guest);
1932 
1933 static void mark_page_dirty_in_slot(struct kvm_memory_slot *memslot,
1934                                     gfn_t gfn)
1935 {
1936         if (memslot && memslot->dirty_bitmap) {
1937                 unsigned long rel_gfn = gfn - memslot->base_gfn;
1938 
1939                 set_bit_le(rel_gfn, memslot->dirty_bitmap);
1940         }
1941 }
1942 
1943 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
1944 {
1945         struct kvm_memory_slot *memslot;
1946 
1947         memslot = gfn_to_memslot(kvm, gfn);
1948         mark_page_dirty_in_slot(memslot, gfn);
1949 }
1950 EXPORT_SYMBOL_GPL(mark_page_dirty);
1951 
1952 void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn)
1953 {
1954         struct kvm_memory_slot *memslot;
1955 
1956         memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
1957         mark_page_dirty_in_slot(memslot, gfn);
1958 }
1959 EXPORT_SYMBOL_GPL(kvm_vcpu_mark_page_dirty);
1960 
1961 static void grow_halt_poll_ns(struct kvm_vcpu *vcpu)
1962 {
1963         unsigned int old, val, grow;
1964 
1965         old = val = vcpu->halt_poll_ns;
1966         grow = READ_ONCE(halt_poll_ns_grow);
1967         /* 10us base */
1968         if (val == 0 && grow)
1969                 val = 10000;
1970         else
1971                 val *= grow;
1972 
1973         if (val > halt_poll_ns)
1974                 val = halt_poll_ns;
1975 
1976         vcpu->halt_poll_ns = val;
1977         trace_kvm_halt_poll_ns_grow(vcpu->vcpu_id, val, old);
1978 }
1979 
1980 static void shrink_halt_poll_ns(struct kvm_vcpu *vcpu)
1981 {
1982         unsigned int old, val, shrink;
1983 
1984         old = val = vcpu->halt_poll_ns;
1985         shrink = READ_ONCE(halt_poll_ns_shrink);
1986         if (shrink == 0)
1987                 val = 0;
1988         else
1989                 val /= shrink;
1990 
1991         vcpu->halt_poll_ns = val;
1992         trace_kvm_halt_poll_ns_shrink(vcpu->vcpu_id, val, old);
1993 }
1994 
1995 static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu)
1996 {
1997         if (kvm_arch_vcpu_runnable(vcpu)) {
1998                 kvm_make_request(KVM_REQ_UNHALT, vcpu);
1999                 return -EINTR;
2000         }
2001         if (kvm_cpu_has_pending_timer(vcpu))
2002                 return -EINTR;
2003         if (signal_pending(current))
2004                 return -EINTR;
2005 
2006         return 0;
2007 }
2008 
2009 /*
2010  * The vCPU has executed a HLT instruction with in-kernel mode enabled.
2011  */
2012 void kvm_vcpu_block(struct kvm_vcpu *vcpu)
2013 {
2014         ktime_t start, cur;
2015         DECLARE_SWAITQUEUE(wait);
2016         bool waited = false;
2017         u64 block_ns;
2018 
2019         start = cur = ktime_get();
2020         if (vcpu->halt_poll_ns) {
2021                 ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns);
2022 
2023                 ++vcpu->stat.halt_attempted_poll;
2024                 do {
2025                         /*
2026                          * This sets KVM_REQ_UNHALT if an interrupt
2027                          * arrives.
2028                          */
2029                         if (kvm_vcpu_check_block(vcpu) < 0) {
2030                                 ++vcpu->stat.halt_successful_poll;
2031                                 goto out;
2032                         }
2033                         cur = ktime_get();
2034                 } while (single_task_running() && ktime_before(cur, stop));
2035         }
2036 
2037         kvm_arch_vcpu_blocking(vcpu);
2038 
2039         for (;;) {
2040                 prepare_to_swait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
2041 
2042                 if (kvm_vcpu_check_block(vcpu) < 0)
2043                         break;
2044 
2045                 waited = true;
2046                 schedule();
2047         }
2048 
2049         finish_swait(&vcpu->wq, &wait);
2050         cur = ktime_get();
2051 
2052         kvm_arch_vcpu_unblocking(vcpu);
2053 out:
2054         block_ns = ktime_to_ns(cur) - ktime_to_ns(start);
2055 
2056         if (halt_poll_ns) {
2057                 if (block_ns <= vcpu->halt_poll_ns)
2058                         ;
2059                 /* we had a long block, shrink polling */
2060                 else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns)
2061                         shrink_halt_poll_ns(vcpu);
2062                 /* we had a short halt and our poll time is too small */
2063                 else if (vcpu->halt_poll_ns < halt_poll_ns &&
2064                         block_ns < halt_poll_ns)
2065                         grow_halt_poll_ns(vcpu);
2066         } else
2067                 vcpu->halt_poll_ns = 0;
2068 
2069         trace_kvm_vcpu_wakeup(block_ns, waited);
2070 }
2071 EXPORT_SYMBOL_GPL(kvm_vcpu_block);
2072 
2073 #ifndef CONFIG_S390
2074 /*
2075  * Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode.
2076  */
2077 void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
2078 {
2079         int me;
2080         int cpu = vcpu->cpu;
2081         struct swait_queue_head *wqp;
2082 
2083         wqp = kvm_arch_vcpu_wq(vcpu);
2084         if (swait_active(wqp)) {
2085                 swake_up(wqp);
2086                 ++vcpu->stat.halt_wakeup;
2087         }
2088 
2089         me = get_cpu();
2090         if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu))
2091                 if (kvm_arch_vcpu_should_kick(vcpu))
2092                         smp_send_reschedule(cpu);
2093         put_cpu();
2094 }
2095 EXPORT_SYMBOL_GPL(kvm_vcpu_kick);
2096 #endif /* !CONFIG_S390 */
2097 
2098 int kvm_vcpu_yield_to(struct kvm_vcpu *target)
2099 {
2100         struct pid *pid;
2101         struct task_struct *task = NULL;
2102         int ret = 0;
2103 
2104         rcu_read_lock();
2105         pid = rcu_dereference(target->pid);
2106         if (pid)
2107                 task = get_pid_task(pid, PIDTYPE_PID);
2108         rcu_read_unlock();
2109         if (!task)
2110                 return ret;
2111         ret = yield_to(task, 1);
2112         put_task_struct(task);
2113 
2114         return ret;
2115 }
2116 EXPORT_SYMBOL_GPL(kvm_vcpu_yield_to);
2117 
2118 /*
2119  * Helper that checks whether a VCPU is eligible for directed yield.
2120  * Most eligible candidate to yield is decided by following heuristics:
2121  *
2122  *  (a) VCPU which has not done pl-exit or cpu relax intercepted recently
2123  *  (preempted lock holder), indicated by @in_spin_loop.
2124  *  Set at the beiginning and cleared at the end of interception/PLE handler.
2125  *
2126  *  (b) VCPU which has done pl-exit/ cpu relax intercepted but did not get
2127  *  chance last time (mostly it has become eligible now since we have probably
2128  *  yielded to lockholder in last iteration. This is done by toggling
2129  *  @dy_eligible each time a VCPU checked for eligibility.)
2130  *
2131  *  Yielding to a recently pl-exited/cpu relax intercepted VCPU before yielding
2132  *  to preempted lock-holder could result in wrong VCPU selection and CPU
2133  *  burning. Giving priority for a potential lock-holder increases lock
2134  *  progress.
2135  *
2136  *  Since algorithm is based on heuristics, accessing another VCPU data without
2137  *  locking does not harm. It may result in trying to yield to  same VCPU, fail
2138  *  and continue with next VCPU and so on.
2139  */
2140 static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu)
2141 {
2142 #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
2143         bool eligible;
2144 
2145         eligible = !vcpu->spin_loop.in_spin_loop ||
2146                     vcpu->spin_loop.dy_eligible;
2147 
2148         if (vcpu->spin_loop.in_spin_loop)
2149                 kvm_vcpu_set_dy_eligible(vcpu, !vcpu->spin_loop.dy_eligible);
2150 
2151         return eligible;
2152 #else
2153         return true;
2154 #endif
2155 }
2156 
2157 void kvm_vcpu_on_spin(struct kvm_vcpu *me)
2158 {
2159         struct kvm *kvm = me->kvm;
2160         struct kvm_vcpu *vcpu;
2161         int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
2162         int yielded = 0;
2163         int try = 3;
2164         int pass;
2165         int i;
2166 
2167         kvm_vcpu_set_in_spin_loop(me, true);
2168         /*
2169          * We boost the priority of a VCPU that is runnable but not
2170          * currently running, because it got preempted by something
2171          * else and called schedule in __vcpu_run.  Hopefully that
2172          * VCPU is holding the lock that we need and will release it.
2173          * We approximate round-robin by starting at the last boosted VCPU.
2174          */
2175         for (pass = 0; pass < 2 && !yielded && try; pass++) {
2176                 kvm_for_each_vcpu(i, vcpu, kvm) {
2177                         if (!pass && i <= last_boosted_vcpu) {
2178                                 i = last_boosted_vcpu;
2179                                 continue;
2180                         } else if (pass && i > last_boosted_vcpu)
2181                                 break;
2182                         if (!ACCESS_ONCE(vcpu->preempted))
2183                                 continue;
2184                         if (vcpu == me)
2185                                 continue;
2186                         if (swait_active(&vcpu->wq) && !kvm_arch_vcpu_runnable(vcpu))
2187                                 continue;
2188                         if (!kvm_vcpu_eligible_for_directed_yield(vcpu))
2189                                 continue;
2190 
2191                         yielded = kvm_vcpu_yield_to(vcpu);
2192                         if (yielded > 0) {
2193                                 kvm->last_boosted_vcpu = i;
2194                                 break;
2195                         } else if (yielded < 0) {
2196                                 try--;
2197                                 if (!try)
2198                                         break;
2199                         }
2200                 }
2201         }
2202         kvm_vcpu_set_in_spin_loop(me, false);
2203 
2204         /* Ensure vcpu is not eligible during next spinloop */
2205         kvm_vcpu_set_dy_eligible(me, false);
2206 }
2207 EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
2208 
2209 static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
2210 {
2211         struct kvm_vcpu *vcpu = vma->vm_file->private_data;
2212         struct page *page;
2213 
2214         if (vmf->pgoff == 0)
2215                 page = virt_to_page(vcpu->run);
2216 #ifdef CONFIG_X86
2217         else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
2218                 page = virt_to_page(vcpu->arch.pio_data);
2219 #endif
2220 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2221         else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
2222                 page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
2223 #endif
2224         else
2225                 return kvm_arch_vcpu_fault(vcpu, vmf);
2226         get_page(page);
2227         vmf->page = page;
2228         return 0;
2229 }
2230 
2231 static const struct vm_operations_struct kvm_vcpu_vm_ops = {
2232         .fault = kvm_vcpu_fault,
2233 };
2234 
2235 static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
2236 {
2237         vma->vm_ops = &kvm_vcpu_vm_ops;
2238         return 0;
2239 }
2240 
2241 static int kvm_vcpu_release(struct inode *inode, struct file *filp)
2242 {
2243         struct kvm_vcpu *vcpu = filp->private_data;
2244 
2245         kvm_put_kvm(vcpu->kvm);
2246         return 0;
2247 }
2248 
2249 static struct file_operations kvm_vcpu_fops = {
2250         .release        = kvm_vcpu_release,
2251         .unlocked_ioctl = kvm_vcpu_ioctl,
2252 #ifdef CONFIG_KVM_COMPAT
2253         .compat_ioctl   = kvm_vcpu_compat_ioctl,
2254 #endif
2255         .mmap           = kvm_vcpu_mmap,
2256         .llseek         = noop_llseek,
2257 };
2258 
2259 /*
2260  * Allocates an inode for the vcpu.
2261  */
2262 static int create_vcpu_fd(struct kvm_vcpu *vcpu)
2263 {
2264         return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC);
2265 }
2266 
2267 /*
2268  * Creates some virtual cpus.  Good luck creating more than one.
2269  */
2270 static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
2271 {
2272         int r;
2273         struct kvm_vcpu *vcpu;
2274 
2275         if (id >= KVM_MAX_VCPUS)
2276                 return -EINVAL;
2277 
2278         vcpu = kvm_arch_vcpu_create(kvm, id);
2279         if (IS_ERR(vcpu))
2280                 return PTR_ERR(vcpu);
2281 
2282         preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
2283 
2284         r = kvm_arch_vcpu_setup(vcpu);
2285         if (r)
2286                 goto vcpu_destroy;
2287 
2288         mutex_lock(&kvm->lock);
2289         if (!kvm_vcpu_compatible(vcpu)) {
2290                 r = -EINVAL;
2291                 goto unlock_vcpu_destroy;
2292         }
2293         if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
2294                 r = -EINVAL;
2295                 goto unlock_vcpu_destroy;
2296         }
2297         if (kvm_get_vcpu_by_id(kvm, id)) {
2298                 r = -EEXIST;
2299                 goto unlock_vcpu_destroy;
2300         }
2301 
2302         BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
2303 
2304         /* Now it's all set up, let userspace reach it */
2305         kvm_get_kvm(kvm);
2306         r = create_vcpu_fd(vcpu);
2307         if (r < 0) {
2308                 kvm_put_kvm(kvm);
2309                 goto unlock_vcpu_destroy;
2310         }
2311 
2312         kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
2313 
2314         /*
2315          * Pairs with smp_rmb() in kvm_get_vcpu.  Write kvm->vcpus
2316          * before kvm->online_vcpu's incremented value.
2317          */
2318         smp_wmb();
2319         atomic_inc(&kvm->online_vcpus);
2320 
2321         mutex_unlock(&kvm->lock);
2322         kvm_arch_vcpu_postcreate(vcpu);
2323         return r;
2324 
2325 unlock_vcpu_destroy:
2326         mutex_unlock(&kvm->lock);
2327 vcpu_destroy:
2328         kvm_arch_vcpu_destroy(vcpu);
2329         return r;
2330 }
2331 
2332 static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
2333 {
2334         if (sigset) {
2335                 sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
2336                 vcpu->sigset_active = 1;
2337                 vcpu->sigset = *sigset;
2338         } else
2339                 vcpu->sigset_active = 0;
2340         return 0;
2341 }
2342 
2343 static long kvm_vcpu_ioctl(struct file *filp,
2344                            unsigned int ioctl, unsigned long arg)
2345 {
2346         struct kvm_vcpu *vcpu = filp->private_data;
2347         void __user *argp = (void __user *)arg;
2348         int r;
2349         struct kvm_fpu *fpu = NULL;
2350         struct kvm_sregs *kvm_sregs = NULL;
2351 
2352         if (vcpu->kvm->mm != current->mm)
2353                 return -EIO;
2354 
2355         if (unlikely(_IOC_TYPE(ioctl) != KVMIO))
2356                 return -EINVAL;
2357 
2358 #if defined(CONFIG_S390) || defined(CONFIG_PPC) || defined(CONFIG_MIPS)
2359         /*
2360          * Special cases: vcpu ioctls that are asynchronous to vcpu execution,
2361          * so vcpu_load() would break it.
2362          */
2363         if (ioctl == KVM_S390_INTERRUPT || ioctl == KVM_S390_IRQ || ioctl == KVM_INTERRUPT)
2364                 return kvm_arch_vcpu_ioctl(filp, ioctl, arg);
2365 #endif
2366 
2367 
2368         r = vcpu_load(vcpu);
2369         if (r)
2370                 return r;
2371         switch (ioctl) {
2372         case KVM_RUN:
2373                 r = -EINVAL;
2374                 if (arg)
2375                         goto out;
2376                 if (unlikely(vcpu->pid != current->pids[PIDTYPE_PID].pid)) {
2377                         /* The thread running this VCPU changed. */
2378                         struct pid *oldpid = vcpu->pid;
2379                         struct pid *newpid = get_task_pid(current, PIDTYPE_PID);
2380 
2381                         rcu_assign_pointer(vcpu->pid, newpid);
2382                         if (oldpid)
2383                                 synchronize_rcu();
2384                         put_pid(oldpid);
2385                 }
2386                 r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
2387                 trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
2388                 break;
2389         case KVM_GET_REGS: {
2390                 struct kvm_regs *kvm_regs;
2391 
2392                 r = -ENOMEM;
2393                 kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
2394                 if (!kvm_regs)
2395                         goto out;
2396                 r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
2397                 if (r)
2398                         goto out_free1;
2399                 r = -EFAULT;
2400                 if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
2401                         goto out_free1;
2402                 r = 0;
2403 out_free1:
2404                 kfree(kvm_regs);
2405                 break;
2406         }
2407         case KVM_SET_REGS: {
2408                 struct kvm_regs *kvm_regs;
2409 
2410                 r = -ENOMEM;
2411                 kvm_regs = memdup_user(argp, sizeof(*kvm_regs));
2412                 if (IS_ERR(kvm_regs)) {
2413                         r = PTR_ERR(kvm_regs);
2414                         goto out;
2415                 }
2416                 r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
2417                 kfree(kvm_regs);
2418                 break;
2419         }
2420         case KVM_GET_SREGS: {
2421                 kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
2422                 r = -ENOMEM;
2423                 if (!kvm_sregs)
2424                         goto out;
2425                 r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs);
2426                 if (r)
2427                         goto out;
2428                 r = -EFAULT;
2429                 if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs)))
2430                         goto out;
2431                 r = 0;
2432                 break;
2433         }
2434         case KVM_SET_SREGS: {
2435                 kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs));
2436                 if (IS_ERR(kvm_sregs)) {
2437                         r = PTR_ERR(kvm_sregs);
2438                         kvm_sregs = NULL;
2439                         goto out;
2440                 }
2441                 r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs);
2442                 break;
2443         }
2444         case KVM_GET_MP_STATE: {
2445                 struct kvm_mp_state mp_state;
2446 
2447                 r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
2448                 if (r)
2449                         goto out;
2450                 r = -EFAULT;
2451                 if (copy_to_user(argp, &mp_state, sizeof(mp_state)))
2452                         goto out;
2453                 r = 0;
2454                 break;
2455         }
2456         case KVM_SET_MP_STATE: {
2457                 struct kvm_mp_state mp_state;
2458 
2459                 r = -EFAULT;
2460                 if (copy_from_user(&mp_state, argp, sizeof(mp_state)))
2461                         goto out;
2462                 r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
2463                 break;
2464         }
2465         case KVM_TRANSLATE: {
2466                 struct kvm_translation tr;
2467 
2468                 r = -EFAULT;
2469                 if (copy_from_user(&tr, argp, sizeof(tr)))
2470                         goto out;
2471                 r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
2472                 if (r)
2473                         goto out;
2474                 r = -EFAULT;
2475                 if (copy_to_user(argp, &tr, sizeof(tr)))
2476                         goto out;
2477                 r = 0;
2478                 break;
2479         }
2480         case KVM_SET_GUEST_DEBUG: {
2481                 struct kvm_guest_debug dbg;
2482 
2483                 r = -EFAULT;
2484                 if (copy_from_user(&dbg, argp, sizeof(dbg)))
2485                         goto out;
2486                 r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg);
2487                 break;
2488         }
2489         case KVM_SET_SIGNAL_MASK: {
2490                 struct kvm_signal_mask __user *sigmask_arg = argp;
2491                 struct kvm_signal_mask kvm_sigmask;
2492                 sigset_t sigset, *p;
2493 
2494                 p = NULL;
2495                 if (argp) {
2496                         r = -EFAULT;
2497                         if (copy_from_user(&kvm_sigmask, argp,
2498                                            sizeof(kvm_sigmask)))
2499                                 goto out;
2500                         r = -EINVAL;
2501                         if (kvm_sigmask.len != sizeof(sigset))
2502                                 goto out;
2503                         r = -EFAULT;
2504                         if (copy_from_user(&sigset, sigmask_arg->sigset,
2505                                            sizeof(sigset)))
2506                                 goto out;
2507                         p = &sigset;
2508                 }
2509                 r = kvm_vcpu_ioctl_set_sigmask(vcpu, p);
2510                 break;
2511         }
2512         case KVM_GET_FPU: {
2513                 fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
2514                 r = -ENOMEM;
2515                 if (!fpu)
2516                         goto out;
2517                 r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
2518                 if (r)
2519                         goto out;
2520                 r = -EFAULT;
2521                 if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu)))
2522                         goto out;
2523                 r = 0;
2524                 break;
2525         }
2526         case KVM_SET_FPU: {
2527                 fpu = memdup_user(argp, sizeof(*fpu));
2528                 if (IS_ERR(fpu)) {
2529                         r = PTR_ERR(fpu);
2530                         fpu = NULL;
2531                         goto out;
2532                 }
2533                 r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
2534                 break;
2535         }
2536         default:
2537                 r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
2538         }
2539 out:
2540         vcpu_put(vcpu);
2541         kfree(fpu);
2542         kfree(kvm_sregs);
2543         return r;
2544 }
2545 
2546 #ifdef CONFIG_KVM_COMPAT
2547 static long kvm_vcpu_compat_ioctl(struct file *filp,
2548                                   unsigned int ioctl, unsigned long arg)
2549 {
2550         struct kvm_vcpu *vcpu = filp->private_data;
2551         void __user *argp = compat_ptr(arg);
2552         int r;
2553 
2554         if (vcpu->kvm->mm != current->mm)
2555                 return -EIO;
2556 
2557         switch (ioctl) {
2558         case KVM_SET_SIGNAL_MASK: {
2559                 struct kvm_signal_mask __user *sigmask_arg = argp;
2560                 struct kvm_signal_mask kvm_sigmask;
2561                 compat_sigset_t csigset;
2562                 sigset_t sigset;
2563 
2564                 if (argp) {
2565                         r = -EFAULT;
2566                         if (copy_from_user(&kvm_sigmask, argp,
2567                                            sizeof(kvm_sigmask)))
2568                                 goto out;
2569                         r = -EINVAL;
2570                         if (kvm_sigmask.len != sizeof(csigset))
2571                                 goto out;
2572                         r = -EFAULT;
2573                         if (copy_from_user(&csigset, sigmask_arg->sigset,
2574                                            sizeof(csigset)))
2575                                 goto out;
2576                         sigset_from_compat(&sigset, &csigset);
2577                         r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
2578                 } else
2579                         r = kvm_vcpu_ioctl_set_sigmask(vcpu, NULL);
2580                 break;
2581         }
2582         default:
2583                 r = kvm_vcpu_ioctl(filp, ioctl, arg);
2584         }
2585 
2586 out:
2587         return r;
2588 }
2589 #endif
2590 
2591 static int kvm_device_ioctl_attr(struct kvm_device *dev,
2592                                  int (*accessor)(struct kvm_device *dev,
2593                                                  struct kvm_device_attr *attr),
2594                                  unsigned long arg)
2595 {
2596         struct kvm_device_attr attr;
2597 
2598         if (!accessor)
2599                 return -EPERM;
2600 
2601         if (copy_from_user(&attr, (void __user *)arg, sizeof(attr)))
2602                 return -EFAULT;
2603 
2604         return accessor(dev, &attr);
2605 }
2606 
2607 static long kvm_device_ioctl(struct file *filp, unsigned int ioctl,
2608                              unsigned long arg)
2609 {
2610         struct kvm_device *dev = filp->private_data;
2611 
2612         switch (ioctl) {
2613         case KVM_SET_DEVICE_ATTR:
2614                 return kvm_device_ioctl_attr(dev, dev->ops->set_attr, arg);
2615         case KVM_GET_DEVICE_ATTR:
2616                 return kvm_device_ioctl_attr(dev, dev->ops->get_attr, arg);
2617         case KVM_HAS_DEVICE_ATTR:
2618                 return kvm_device_ioctl_attr(dev, dev->ops->has_attr, arg);
2619         default:
2620                 if (dev->ops->ioctl)
2621                         return dev->ops->ioctl(dev, ioctl, arg);
2622 
2623                 return -ENOTTY;
2624         }
2625 }
2626 
2627 static int kvm_device_release(struct inode *inode, struct file *filp)
2628 {
2629         struct kvm_device *dev = filp->private_data;
2630         struct kvm *kvm = dev->kvm;
2631 
2632         kvm_put_kvm(kvm);
2633         return 0;
2634 }
2635 
2636 static const struct file_operations kvm_device_fops = {
2637         .unlocked_ioctl = kvm_device_ioctl,
2638 #ifdef CONFIG_KVM_COMPAT
2639         .compat_ioctl = kvm_device_ioctl,
2640 #endif
2641         .release = kvm_device_release,
2642 };
2643 
2644 struct kvm_device *kvm_device_from_filp(struct file *filp)
2645 {
2646         if (filp->f_op != &kvm_device_fops)
2647                 return NULL;
2648 
2649         return filp->private_data;
2650 }
2651 
2652 static struct kvm_device_ops *kvm_device_ops_table[KVM_DEV_TYPE_MAX] = {
2653 #ifdef CONFIG_KVM_MPIC
2654         [KVM_DEV_TYPE_FSL_MPIC_20]      = &kvm_mpic_ops,
2655         [KVM_DEV_TYPE_FSL_MPIC_42]      = &kvm_mpic_ops,
2656 #endif
2657 
2658 #ifdef CONFIG_KVM_XICS
2659         [KVM_DEV_TYPE_XICS]             = &kvm_xics_ops,
2660 #endif
2661 };
2662 
2663 int kvm_register_device_ops(struct kvm_device_ops *ops, u32 type)
2664 {
2665         if (type >= ARRAY_SIZE(kvm_device_ops_table))
2666                 return -ENOSPC;
2667 
2668         if (kvm_device_ops_table[type] != NULL)
2669                 return -EEXIST;
2670 
2671         kvm_device_ops_table[type] = ops;
2672         return 0;
2673 }
2674 
2675 void kvm_unregister_device_ops(u32 type)
2676 {
2677         if (kvm_device_ops_table[type] != NULL)
2678                 kvm_device_ops_table[type] = NULL;
2679 }
2680 
2681 static int kvm_ioctl_create_device(struct kvm *kvm,
2682                                    struct kvm_create_device *cd)
2683 {
2684         struct kvm_device_ops *ops = NULL;
2685         struct kvm_device *dev;
2686         bool test = cd->flags & KVM_CREATE_DEVICE_TEST;
2687         int ret;
2688 
2689         if (cd->type >= ARRAY_SIZE(kvm_device_ops_table))
2690                 return -ENODEV;
2691 
2692         ops = kvm_device_ops_table[cd->type];
2693         if (ops == NULL)
2694                 return -ENODEV;
2695 
2696         if (test)
2697                 return 0;
2698 
2699         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
2700         if (!dev)
2701                 return -ENOMEM;
2702 
2703         dev->ops = ops;
2704         dev->kvm = kvm;
2705 
2706         ret = ops->create(dev, cd->type);
2707         if (ret < 0) {
2708                 kfree(dev);
2709                 return ret;
2710         }
2711 
2712         ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC);
2713         if (ret < 0) {
2714                 ops->destroy(dev);
2715                 return ret;
2716         }
2717 
2718         list_add(&dev->vm_node, &kvm->devices);
2719         kvm_get_kvm(kvm);
2720         cd->fd = ret;
2721         return 0;
2722 }
2723 
2724 static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
2725 {
2726         switch (arg) {
2727         case KVM_CAP_USER_MEMORY:
2728         case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
2729         case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
2730         case KVM_CAP_INTERNAL_ERROR_DATA:
2731 #ifdef CONFIG_HAVE_KVM_MSI
2732         case KVM_CAP_SIGNAL_MSI:
2733 #endif
2734 #ifdef CONFIG_HAVE_KVM_IRQFD
2735         case KVM_CAP_IRQFD:
2736         case KVM_CAP_IRQFD_RESAMPLE:
2737 #endif
2738         case KVM_CAP_IOEVENTFD_ANY_LENGTH:
2739         case KVM_CAP_CHECK_EXTENSION_VM:
2740                 return 1;
2741 #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
2742         case KVM_CAP_IRQ_ROUTING:
2743                 return KVM_MAX_IRQ_ROUTES;
2744 #endif
2745 #if KVM_ADDRESS_SPACE_NUM > 1
2746         case KVM_CAP_MULTI_ADDRESS_SPACE:
2747                 return KVM_ADDRESS_SPACE_NUM;
2748 #endif
2749         default:
2750                 break;
2751         }
2752         return kvm_vm_ioctl_check_extension(kvm, arg);
2753 }
2754 
2755 static long kvm_vm_ioctl(struct file *filp,
2756                            unsigned int ioctl, unsigned long arg)
2757 {
2758         struct kvm *kvm = filp->private_data;
2759         void __user *argp = (void __user *)arg;
2760         int r;
2761 
2762         if (kvm->mm != current->mm)
2763                 return -EIO;
2764         switch (ioctl) {
2765         case KVM_CREATE_VCPU:
2766                 r = kvm_vm_ioctl_create_vcpu(kvm, arg);
2767                 break;
2768         case KVM_SET_USER_MEMORY_REGION: {
2769                 struct kvm_userspace_memory_region kvm_userspace_mem;
2770 
2771                 r = -EFAULT;
2772                 if (copy_from_user(&kvm_userspace_mem, argp,
2773                                                 sizeof(kvm_userspace_mem)))
2774                         goto out;
2775 
2776                 r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem);
2777                 break;
2778         }
2779         case KVM_GET_DIRTY_LOG: {
2780                 struct kvm_dirty_log log;
2781 
2782                 r = -EFAULT;
2783                 if (copy_from_user(&log, argp, sizeof(log)))
2784                         goto out;
2785                 r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
2786                 break;
2787         }
2788 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2789         case KVM_REGISTER_COALESCED_MMIO: {
2790                 struct kvm_coalesced_mmio_zone zone;
2791 
2792                 r = -EFAULT;
2793                 if (copy_from_user(&zone, argp, sizeof(zone)))
2794                         goto out;
2795                 r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
2796                 break;
2797         }
2798         case KVM_UNREGISTER_COALESCED_MMIO: {
2799                 struct kvm_coalesced_mmio_zone zone;
2800 
2801                 r = -EFAULT;
2802                 if (copy_from_user(&zone, argp, sizeof(zone)))
2803                         goto out;
2804                 r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
2805                 break;
2806         }
2807 #endif
2808         case KVM_IRQFD: {
2809                 struct kvm_irqfd data;
2810 
2811                 r = -EFAULT;
2812                 if (copy_from_user(&data, argp, sizeof(data)))
2813                         goto out;
2814                 r = kvm_irqfd(kvm, &data);
2815                 break;
2816         }
2817         case KVM_IOEVENTFD: {
2818                 struct kvm_ioeventfd data;
2819 
2820                 r = -EFAULT;
2821                 if (copy_from_user(&data, argp, sizeof(data)))
2822                         goto out;
2823                 r = kvm_ioeventfd(kvm, &data);
2824                 break;
2825         }
2826 #ifdef CONFIG_HAVE_KVM_MSI
2827         case KVM_SIGNAL_MSI: {
2828                 struct kvm_msi msi;
2829 
2830                 r = -EFAULT;
2831                 if (copy_from_user(&msi, argp, sizeof(msi)))
2832                         goto out;
2833                 r = kvm_send_userspace_msi(kvm, &msi);
2834                 break;
2835         }
2836 #endif
2837 #ifdef __KVM_HAVE_IRQ_LINE
2838         case KVM_IRQ_LINE_STATUS:
2839         case KVM_IRQ_LINE: {
2840                 struct kvm_irq_level irq_event;
2841 
2842                 r = -EFAULT;
2843                 if (copy_from_user(&irq_event, argp, sizeof(irq_event)))
2844                         goto out;
2845 
2846                 r = kvm_vm_ioctl_irq_line(kvm, &irq_event,
2847                                         ioctl == KVM_IRQ_LINE_STATUS);
2848                 if (r)
2849                         goto out;
2850 
2851                 r = -EFAULT;
2852                 if (ioctl == KVM_IRQ_LINE_STATUS) {
2853                         if (copy_to_user(argp, &irq_event, sizeof(irq_event)))
2854                                 goto out;
2855                 }
2856 
2857                 r = 0;
2858                 break;
2859         }
2860 #endif
2861 #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
2862         case KVM_SET_GSI_ROUTING: {
2863                 struct kvm_irq_routing routing;
2864                 struct kvm_irq_routing __user *urouting;
2865                 struct kvm_irq_routing_entry *entries;
2866 
2867                 r = -EFAULT;
2868                 if (copy_from_user(&routing, argp, sizeof(routing)))
2869                         goto out;
2870                 r = -EINVAL;
2871                 if (routing.nr > KVM_MAX_IRQ_ROUTES)
2872                         goto out;
2873                 if (routing.flags)
2874                         goto out;
2875                 r = -ENOMEM;
2876                 entries = vmalloc(routing.nr * sizeof(*entries));
2877                 if (!entries)
2878                         goto out;
2879                 r = -EFAULT;
2880                 urouting = argp;
2881                 if (copy_from_user(entries, urouting->entries,
2882                                    routing.nr * sizeof(*entries)))
2883                         goto out_free_irq_routing;
2884                 r = kvm_set_irq_routing(kvm, entries, routing.nr,
2885                                         routing.flags);
2886 out_free_irq_routing:
2887                 vfree(entries);
2888                 break;
2889         }
2890 #endif /* CONFIG_HAVE_KVM_IRQ_ROUTING */
2891         case KVM_CREATE_DEVICE: {
2892                 struct kvm_create_device cd;
2893 
2894                 r = -EFAULT;
2895                 if (copy_from_user(&cd, argp, sizeof(cd)))
2896                         goto out;
2897 
2898                 r = kvm_ioctl_create_device(kvm, &cd);
2899                 if (r)
2900                         goto out;
2901 
2902                 r = -EFAULT;
2903                 if (copy_to_user(argp, &cd, sizeof(cd)))
2904                         goto out;
2905 
2906                 r = 0;
2907                 break;
2908         }
2909         case KVM_CHECK_EXTENSION:
2910                 r = kvm_vm_ioctl_check_extension_generic(kvm, arg);
2911                 break;
2912         default:
2913                 r = kvm_arch_vm_ioctl(filp, ioctl, arg);
2914         }
2915 out:
2916         return r;
2917 }
2918 
2919 #ifdef CONFIG_KVM_COMPAT
2920 struct compat_kvm_dirty_log {
2921         __u32 slot;
2922         __u32 padding1;
2923         union {
2924                 compat_uptr_t dirty_bitmap; /* one bit per page */
2925                 __u64 padding2;
2926         };
2927 };
2928 
2929 static long kvm_vm_compat_ioctl(struct file *filp,
2930                            unsigned int ioctl, unsigned long arg)
2931 {
2932         struct kvm *kvm = filp->private_data;
2933         int r;
2934 
2935         if (kvm->mm != current->mm)
2936                 return -EIO;
2937         switch (ioctl) {
2938         case KVM_GET_DIRTY_LOG: {
2939                 struct compat_kvm_dirty_log compat_log;
2940                 struct kvm_dirty_log log;
2941 
2942                 r = -EFAULT;
2943                 if (copy_from_user(&compat_log, (void __user *)arg,
2944                                    sizeof(compat_log)))
2945                         goto out;
2946                 log.slot         = compat_log.slot;
2947                 log.padding1     = compat_log.padding1;
2948                 log.padding2     = compat_log.padding2;
2949                 log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
2950 
2951                 r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
2952                 break;
2953         }
2954         default:
2955                 r = kvm_vm_ioctl(filp, ioctl, arg);
2956         }
2957 
2958 out:
2959         return r;
2960 }
2961 #endif
2962 
2963 static struct file_operations kvm_vm_fops = {
2964         .release        = kvm_vm_release,
2965         .unlocked_ioctl = kvm_vm_ioctl,
2966 #ifdef CONFIG_KVM_COMPAT
2967         .compat_ioctl   = kvm_vm_compat_ioctl,
2968 #endif
2969         .llseek         = noop_llseek,
2970 };
2971 
2972 static int kvm_dev_ioctl_create_vm(unsigned long type)
2973 {
2974         int r;
2975         struct kvm *kvm;
2976 
2977         kvm = kvm_create_vm(type);
2978         if (IS_ERR(kvm))
2979                 return PTR_ERR(kvm);
2980 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2981         r = kvm_coalesced_mmio_init(kvm);
2982         if (r < 0) {
2983                 kvm_put_kvm(kvm);
2984                 return r;
2985         }
2986 #endif
2987         r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR | O_CLOEXEC);
2988         if (r < 0)
2989                 kvm_put_kvm(kvm);
2990 
2991         return r;
2992 }
2993 
2994 static long kvm_dev_ioctl(struct file *filp,
2995                           unsigned int ioctl, unsigned long arg)
2996 {
2997         long r = -EINVAL;
2998 
2999         switch (ioctl) {
3000         case KVM_GET_API_VERSION:
3001                 if (arg)
3002                         goto out;
3003                 r = KVM_API_VERSION;
3004                 break;
3005         case KVM_CREATE_VM:
3006                 r = kvm_dev_ioctl_create_vm(arg);
3007                 break;
3008         case KVM_CHECK_EXTENSION:
3009                 r = kvm_vm_ioctl_check_extension_generic(NULL, arg);
3010                 break;
3011         case KVM_GET_VCPU_MMAP_SIZE:
3012                 if (arg)
3013                         goto out;
3014                 r = PAGE_SIZE;     /* struct kvm_run */
3015 #ifdef CONFIG_X86
3016                 r += PAGE_SIZE;    /* pio data page */
3017 #endif
3018 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
3019                 r += PAGE_SIZE;    /* coalesced mmio ring page */
3020 #endif
3021                 break;
3022         case KVM_TRACE_ENABLE:
3023         case KVM_TRACE_PAUSE:
3024         case KVM_TRACE_DISABLE:
3025                 r = -EOPNOTSUPP;
3026                 break;
3027         default:
3028                 return kvm_arch_dev_ioctl(filp, ioctl, arg);
3029         }
3030 out:
3031         return r;
3032 }
3033 
3034 static struct file_operations kvm_chardev_ops = {
3035         .unlocked_ioctl = kvm_dev_ioctl,
3036         .compat_ioctl   = kvm_dev_ioctl,
3037         .llseek         = noop_llseek,
3038 };
3039 
3040 static struct miscdevice kvm_dev = {
3041         KVM_MINOR,
3042         "kvm",
3043         &kvm_chardev_ops,
3044 };
3045 
3046 static void hardware_enable_nolock(void *junk)
3047 {
3048         int cpu = raw_smp_processor_id();
3049         int r;
3050 
3051         if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
3052                 return;
3053 
3054         cpumask_set_cpu(cpu, cpus_hardware_enabled);
3055 
3056         r = kvm_arch_hardware_enable();
3057 
3058         if (r) {
3059                 cpumask_clear_cpu(cpu, cpus_hardware_enabled);
3060                 atomic_inc(&hardware_enable_failed);
3061                 pr_info("kvm: enabling virtualization on CPU%d failed\n", cpu);
3062         }
3063 }
3064 
3065 static void hardware_enable(void)
3066 {
3067         raw_spin_lock(&kvm_count_lock);
3068         if (kvm_usage_count)
3069                 hardware_enable_nolock(NULL);
3070         raw_spin_unlock(&kvm_count_lock);
3071 }
3072 
3073 static void hardware_disable_nolock(void *junk)
3074 {
3075         int cpu = raw_smp_processor_id();
3076 
3077         if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
3078                 return;
3079         cpumask_clear_cpu(cpu, cpus_hardware_enabled);
3080         kvm_arch_hardware_disable();
3081 }
3082 
3083 static void hardware_disable(void)
3084 {
3085         raw_spin_lock(&kvm_count_lock);
3086         if (kvm_usage_count)
3087                 hardware_disable_nolock(NULL);
3088         raw_spin_unlock(&kvm_count_lock);
3089 }
3090 
3091 static void hardware_disable_all_nolock(void)
3092 {
3093         BUG_ON(!kvm_usage_count);
3094 
3095         kvm_usage_count--;
3096         if (!kvm_usage_count)
3097                 on_each_cpu(hardware_disable_nolock, NULL, 1);
3098 }
3099 
3100 static void hardware_disable_all(void)
3101 {
3102         raw_spin_lock(&kvm_count_lock);
3103         hardware_disable_all_nolock();
3104         raw_spin_unlock(&kvm_count_lock);
3105 }
3106 
3107 static int hardware_enable_all(void)
3108 {
3109         int r = 0;
3110 
3111         raw_spin_lock(&kvm_count_lock);
3112 
3113         kvm_usage_count++;
3114         if (kvm_usage_count == 1) {
3115                 atomic_set(&hardware_enable_failed, 0);
3116                 on_each_cpu(hardware_enable_nolock, NULL, 1);
3117 
3118                 if (atomic_read(&hardware_enable_failed)) {
3119                         hardware_disable_all_nolock();
3120                         r = -EBUSY;
3121                 }
3122         }
3123 
3124         raw_spin_unlock(&kvm_count_lock);
3125 
3126         return r;
3127 }
3128 
3129 static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
3130                            void *v)
3131 {
3132         val &= ~CPU_TASKS_FROZEN;
3133         switch (val) {
3134         case CPU_DYING:
3135                 hardware_disable();
3136                 break;
3137         case CPU_STARTING:
3138                 hardware_enable();
3139                 break;
3140         }
3141         return NOTIFY_OK;
3142 }
3143 
3144 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
3145                       void *v)
3146 {
3147         /*
3148          * Some (well, at least mine) BIOSes hang on reboot if
3149          * in vmx root mode.
3150          *
3151          * And Intel TXT required VMX off for all cpu when system shutdown.
3152          */
3153         pr_info("kvm: exiting hardware virtualization\n");
3154         kvm_rebooting = true;
3155         on_each_cpu(hardware_disable_nolock, NULL, 1);
3156         return NOTIFY_OK;
3157 }
3158 
3159 static struct notifier_block kvm_reboot_notifier = {
3160         .notifier_call = kvm_reboot,
3161         .priority = 0,
3162 };
3163 
3164 static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
3165 {
3166         int i;
3167 
3168         for (i = 0; i < bus->dev_count; i++) {
3169                 struct kvm_io_device *pos = bus->range[i].dev;
3170 
3171                 kvm_iodevice_destructor(pos);
3172         }
3173         kfree(bus);
3174 }
3175 
3176 static inline int kvm_io_bus_cmp(const struct kvm_io_range *r1,
3177                                  const struct kvm_io_range *r2)
3178 {
3179         gpa_t addr1 = r1->addr;
3180         gpa_t addr2 = r2->addr;
3181 
3182         if (addr1 < addr2)
3183                 return -1;
3184 
3185         /* If r2->len == 0, match the exact address.  If r2->len != 0,
3186          * accept any overlapping write.  Any order is acceptable for
3187          * overlapping ranges, because kvm_io_bus_get_first_dev ensures
3188          * we process all of them.
3189          */
3190         if (r2->len) {
3191                 addr1 += r1->len;
3192                 addr2 += r2->len;
3193         }
3194 
3195         if (addr1 > addr2)
3196                 return 1;
3197 
3198         return 0;
3199 }
3200 
3201 static int kvm_io_bus_sort_cmp(const void *p1, const void *p2)
3202 {
3203         return kvm_io_bus_cmp(p1, p2);
3204 }
3205 
3206 static int kvm_io_bus_insert_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev,
3207                           gpa_t addr, int len)
3208 {
3209         bus->range[bus->dev_count++] = (struct kvm_io_range) {
3210                 .addr = addr,
3211                 .len = len,
3212                 .dev = dev,
3213         };
3214 
3215         sort(bus->range, bus->dev_count, sizeof(struct kvm_io_range),
3216                 kvm_io_bus_sort_cmp, NULL);
3217 
3218         return 0;
3219 }
3220 
3221 static int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus,
3222                              gpa_t addr, int len)
3223 {
3224         struct kvm_io_range *range, key;
3225         int off;
3226 
3227         key = (struct kvm_io_range) {
3228                 .addr = addr,
3229                 .len = len,
3230         };
3231 
3232         range = bsearch(&key, bus->range, bus->dev_count,
3233                         sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp);
3234         if (range == NULL)
3235                 return -ENOENT;
3236 
3237         off = range - bus->range;
3238 
3239         while (off > 0 && kvm_io_bus_cmp(&key, &bus->range[off-1]) == 0)
3240                 off--;
3241 
3242         return off;
3243 }
3244 
3245 static int __kvm_io_bus_write(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
3246                               struct kvm_io_range *range, const void *val)
3247 {
3248         int idx;
3249 
3250         idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len);
3251         if (idx < 0)
3252                 return -EOPNOTSUPP;
3253 
3254         while (idx < bus->dev_count &&
3255                 kvm_io_bus_cmp(range, &bus->range[idx]) == 0) {
3256                 if (!kvm_iodevice_write(vcpu, bus->range[idx].dev, range->addr,
3257                                         range->len, val))
3258                         return idx;
3259                 idx++;
3260         }
3261 
3262         return -EOPNOTSUPP;
3263 }
3264 
3265 /* kvm_io_bus_write - called under kvm->slots_lock */
3266 int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
3267                      int len, const void *val)
3268 {
3269         struct kvm_io_bus *bus;
3270         struct kvm_io_range range;
3271         int r;
3272 
3273         range = (struct kvm_io_range) {
3274                 .addr = addr,
3275                 .len = len,
3276         };
3277 
3278         bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
3279         r = __kvm_io_bus_write(vcpu, bus, &range, val);
3280         return r < 0 ? r : 0;
3281 }
3282 
3283 /* kvm_io_bus_write_cookie - called under kvm->slots_lock */
3284 int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx,
3285                             gpa_t addr, int len, const void *val, long cookie)
3286 {
3287         struct kvm_io_bus *bus;
3288         struct kvm_io_range range;
3289 
3290         range = (struct kvm_io_range) {
3291                 .addr = addr,
3292                 .len = len,
3293         };
3294 
3295         bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
3296 
3297         /* First try the device referenced by cookie. */
3298         if ((cookie >= 0) && (cookie < bus->dev_count) &&
3299             (kvm_io_bus_cmp(&range, &bus->range[cookie]) == 0))
3300                 if (!kvm_iodevice_write(vcpu, bus->range[cookie].dev, addr, len,
3301                                         val))
3302                         return cookie;
3303 
3304         /*
3305          * cookie contained garbage; fall back to search and return the
3306          * correct cookie value.
3307          */
3308         return __kvm_io_bus_write(vcpu, bus, &range, val);
3309 }
3310 
3311 static int __kvm_io_bus_read(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
3312                              struct kvm_io_range *range, void *val)
3313 {
3314         int idx;
3315 
3316         idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len);
3317         if (idx < 0)
3318                 return -EOPNOTSUPP;
3319 
3320         while (idx < bus->dev_count &&
3321                 kvm_io_bus_cmp(range, &bus->range[idx]) == 0) {
3322                 if (!kvm_iodevice_read(vcpu, bus->range[idx].dev, range->addr,
3323                                        range->len, val))
3324                         return idx;
3325                 idx++;
3326         }
3327 
3328         return -EOPNOTSUPP;
3329 }
3330 EXPORT_SYMBOL_GPL(kvm_io_bus_write);
3331 
3332 /* kvm_io_bus_read - called under kvm->slots_lock */
3333 int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
3334                     int len, void *val)
3335 {
3336         struct kvm_io_bus *bus;
3337         struct kvm_io_range range;
3338         int r;
3339 
3340         range = (struct kvm_io_range) {
3341                 .addr = addr,
3342                 .len = len,
3343         };
3344 
3345         bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
3346         r = __kvm_io_bus_read(vcpu, bus, &range, val);
3347         return r < 0 ? r : 0;
3348 }
3349 
3350 
3351 /* Caller must hold slots_lock. */
3352 int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
3353                             int len, struct kvm_io_device *dev)
3354 {
3355         struct kvm_io_bus *new_bus, *bus;
3356 
3357         bus = kvm->buses[bus_idx];
3358         /* exclude ioeventfd which is limited by maximum fd */
3359         if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1)
3360                 return -ENOSPC;
3361 
3362         new_bus = kmalloc(sizeof(*bus) + ((bus->dev_count + 1) *
3363                           sizeof(struct kvm_io_range)), GFP_KERNEL);
3364         if (!new_bus)
3365                 return -ENOMEM;
3366         memcpy(new_bus, bus, sizeof(*bus) + (bus->dev_count *
3367                sizeof(struct kvm_io_range)));
3368         kvm_io_bus_insert_dev(new_bus, dev, addr, len);
3369         rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
3370         synchronize_srcu_expedited(&kvm->srcu);
3371         kfree(bus);
3372 
3373         return 0;
3374 }
3375 
3376 /* Caller must hold slots_lock. */
3377 int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
3378                               struct kvm_io_device *dev)
3379 {
3380         int i, r;
3381         struct kvm_io_bus *new_bus, *bus;
3382 
3383         bus = kvm->buses[bus_idx];
3384         r = -ENOENT;
3385         for (i = 0; i < bus->dev_count; i++)
3386                 if (bus->range[i].dev == dev) {
3387                         r = 0;
3388                         break;
3389                 }
3390 
3391         if (r)
3392                 return r;
3393 
3394         new_bus = kmalloc(sizeof(*bus) + ((bus->dev_count - 1) *
3395                           sizeof(struct kvm_io_range)), GFP_KERNEL);
3396         if (!new_bus)
3397                 return -ENOMEM;
3398 
3399         memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range));
3400         new_bus->dev_count--;
3401         memcpy(new_bus->range + i, bus->range + i + 1,
3402                (new_bus->dev_count - i) * sizeof(struct kvm_io_range));
3403 
3404         rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
3405         synchronize_srcu_expedited(&kvm->srcu);
3406         kfree(bus);
3407         return r;
3408 }
3409 
3410 static struct notifier_block kvm_cpu_notifier = {
3411         .notifier_call = kvm_cpu_hotplug,
3412 };
3413 
3414 static int vm_stat_get(void *_offset, u64 *val)
3415 {
3416         unsigned offset = (long)_offset;
3417         struct kvm *kvm;
3418 
3419         *val = 0;
3420         spin_lock(&kvm_lock);
3421         list_for_each_entry(kvm, &vm_list, vm_list)
3422                 *val += *(u32 *)((void *)kvm + offset);
3423         spin_unlock(&kvm_lock);
3424         return 0;
3425 }
3426 
3427 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
3428 
3429 static int vcpu_stat_get(void *_offset, u64 *val)
3430 {
3431         unsigned offset = (long)_offset;
3432         struct kvm *kvm;
3433         struct kvm_vcpu *vcpu;
3434         int i;
3435 
3436         *val = 0;
3437         spin_lock(&kvm_lock);
3438         list_for_each_entry(kvm, &vm_list, vm_list)
3439                 kvm_for_each_vcpu(i, vcpu, kvm)
3440                         *val += *(u32 *)((void *)vcpu + offset);
3441 
3442         spin_unlock(&kvm_lock);
3443         return 0;
3444 }
3445 
3446 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
3447 
3448 static const struct file_operations *stat_fops[] = {
3449         [KVM_STAT_VCPU] = &vcpu_stat_fops,
3450         [KVM_STAT_VM]   = &vm_stat_fops,
3451 };
3452 
3453 static int kvm_init_debug(void)
3454 {
3455         int r = -EEXIST;
3456         struct kvm_stats_debugfs_item *p;
3457 
3458         kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
3459         if (kvm_debugfs_dir == NULL)
3460                 goto out;
3461 
3462         for (p = debugfs_entries; p->name; ++p) {
3463                 if (!debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
3464                                          (void *)(long)p->offset,
3465                                          stat_fops[p->kind]))
3466                         goto out_dir;
3467         }
3468 
3469         return 0;
3470 
3471 out_dir:
3472         debugfs_remove_recursive(kvm_debugfs_dir);
3473 out:
3474         return r;
3475 }
3476 
3477 static int kvm_suspend(void)
3478 {
3479         if (kvm_usage_count)
3480                 hardware_disable_nolock(NULL);
3481         return 0;
3482 }
3483 
3484 static void kvm_resume(void)
3485 {
3486         if (kvm_usage_count) {
3487                 WARN_ON(raw_spin_is_locked(&kvm_count_lock));
3488                 hardware_enable_nolock(NULL);
3489         }
3490 }
3491 
3492 static struct syscore_ops kvm_syscore_ops = {
3493         .suspend = kvm_suspend,
3494         .resume = kvm_resume,
3495 };
3496 
3497 static inline
3498 struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
3499 {
3500         return container_of(pn, struct kvm_vcpu, preempt_notifier);
3501 }
3502 
3503 static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
3504 {
3505         struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
3506 
3507         if (vcpu->preempted)
3508                 vcpu->preempted = false;
3509 
3510         kvm_arch_sched_in(vcpu, cpu);
3511 
3512         kvm_arch_vcpu_load(vcpu, cpu);
3513 }
3514 
3515 static void kvm_sched_out(struct preempt_notifier *pn,
3516                           struct task_struct *next)
3517 {
3518         struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
3519 
3520         if (current->state == TASK_RUNNING)
3521                 vcpu->preempted = true;
3522         kvm_arch_vcpu_put(vcpu);
3523 }
3524 
3525 int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
3526                   struct module *module)
3527 {
3528         int r;
3529         int cpu;
3530 
3531         r = kvm_arch_init(opaque);
3532         if (r)
3533                 goto out_fail;
3534 
3535         /*
3536          * kvm_arch_init makes sure there's at most one caller
3537          * for architectures that support multiple implementations,
3538          * like intel and amd on x86.
3539          * kvm_arch_init must be called before kvm_irqfd_init to avoid creating
3540          * conflicts in case kvm is already setup for another implementation.
3541          */
3542         r = kvm_irqfd_init();
3543         if (r)
3544                 goto out_irqfd;
3545 
3546         if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
3547                 r = -ENOMEM;
3548                 goto out_free_0;
3549         }
3550 
3551         r = kvm_arch_hardware_setup();
3552         if (r < 0)
3553                 goto out_free_0a;
3554 
3555         for_each_online_cpu(cpu) {
3556                 smp_call_function_single(cpu,
3557                                 kvm_arch_check_processor_compat,
3558                                 &r, 1);
3559                 if (r < 0)
3560                         goto out_free_1;
3561         }
3562 
3563         r = register_cpu_notifier(&kvm_cpu_notifier);
3564         if (r)
3565                 goto out_free_2;
3566         register_reboot_notifier(&kvm_reboot_notifier);
3567 
3568         /* A kmem cache lets us meet the alignment requirements of fx_save. */
3569         if (!vcpu_align)
3570                 vcpu_align = __alignof__(struct kvm_vcpu);
3571         kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size, vcpu_align,
3572                                            0, NULL);
3573         if (!kvm_vcpu_cache) {
3574                 r = -ENOMEM;
3575                 goto out_free_3;
3576         }
3577 
3578         r = kvm_async_pf_init();
3579         if (r)
3580                 goto out_free;
3581 
3582         kvm_chardev_ops.owner = module;
3583         kvm_vm_fops.owner = module;
3584         kvm_vcpu_fops.owner = module;
3585 
3586         r = misc_register(&kvm_dev);
3587         if (r) {
3588                 pr_err("kvm: misc device register failed\n");
3589                 goto out_unreg;
3590         }
3591 
3592         register_syscore_ops(&kvm_syscore_ops);
3593 
3594         kvm_preempt_ops.sched_in = kvm_sched_in;
3595         kvm_preempt_ops.sched_out = kvm_sched_out;
3596 
3597         r = kvm_init_debug();
3598         if (r) {
3599                 pr_err("kvm: create debugfs files failed\n");
3600                 goto out_undebugfs;
3601         }
3602 
3603         r = kvm_vfio_ops_init();
3604         WARN_ON(r);
3605 
3606         return 0;
3607 
3608 out_undebugfs:
3609         unregister_syscore_ops(&kvm_syscore_ops);
3610         misc_deregister(&kvm_dev);
3611 out_unreg:
3612         kvm_async_pf_deinit();
3613 out_free:
3614         kmem_cache_destroy(kvm_vcpu_cache);
3615 out_free_3:
3616         unregister_reboot_notifier(&kvm_reboot_notifier);
3617         unregister_cpu_notifier(&kvm_cpu_notifier);
3618 out_free_2:
3619 out_free_1:
3620         kvm_arch_hardware_unsetup();
3621 out_free_0a:
3622         free_cpumask_var(cpus_hardware_enabled);
3623 out_free_0:
3624         kvm_irqfd_exit();
3625 out_irqfd:
3626         kvm_arch_exit();
3627 out_fail:
3628         return r;
3629 }
3630 EXPORT_SYMBOL_GPL(kvm_init);
3631 
3632 void kvm_exit(void)
3633 {
3634         debugfs_remove_recursive(kvm_debugfs_dir);
3635         misc_deregister(&kvm_dev);
3636         kmem_cache_destroy(kvm_vcpu_cache);
3637         kvm_async_pf_deinit();
3638         unregister_syscore_ops(&kvm_syscore_ops);
3639         unregister_reboot_notifier(&kvm_reboot_notifier);
3640         unregister_cpu_notifier(&kvm_cpu_notifier);
3641         on_each_cpu(hardware_disable_nolock, NULL, 1);
3642         kvm_arch_hardware_unsetup();
3643         kvm_arch_exit();
3644         kvm_irqfd_exit();
3645         free_cpumask_var(cpus_hardware_enabled);
3646         kvm_vfio_ops_exit();
3647 }
3648 EXPORT_SYMBOL_GPL(kvm_exit);
3649 

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