xref: /linux/virt/kvm/kvm_main.c (revision fea88a0c02822fbb91a0b8301bf9af04377876a3)
1 /*
2  * Kernel-based Virtual Machine driver for Linux
3  *
4  * This module enables machines with Intel VT-x extensions to run virtual
5  * machines without emulation or binary translation.
6  *
7  * Copyright (C) 2006 Qumranet, Inc.
8  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
9  *
10  * Authors:
11  *   Avi Kivity   <avi@qumranet.com>
12  *   Yaniv Kamay  <yaniv@qumranet.com>
13  *
14  * This work is licensed under the terms of the GNU GPL, version 2.  See
15  * the COPYING file in the top-level directory.
16  *
17  */
18 
19 #include "iodev.h"
20 
21 #include <linux/kvm_host.h>
22 #include <linux/kvm.h>
23 #include <linux/module.h>
24 #include <linux/errno.h>
25 #include <linux/percpu.h>
26 #include <linux/mm.h>
27 #include <linux/miscdevice.h>
28 #include <linux/vmalloc.h>
29 #include <linux/reboot.h>
30 #include <linux/debugfs.h>
31 #include <linux/highmem.h>
32 #include <linux/file.h>
33 #include <linux/syscore_ops.h>
34 #include <linux/cpu.h>
35 #include <linux/sched.h>
36 #include <linux/cpumask.h>
37 #include <linux/smp.h>
38 #include <linux/anon_inodes.h>
39 #include <linux/profile.h>
40 #include <linux/kvm_para.h>
41 #include <linux/pagemap.h>
42 #include <linux/mman.h>
43 #include <linux/swap.h>
44 #include <linux/bitops.h>
45 #include <linux/spinlock.h>
46 #include <linux/compat.h>
47 #include <linux/srcu.h>
48 #include <linux/hugetlb.h>
49 #include <linux/slab.h>
50 #include <linux/sort.h>
51 #include <linux/bsearch.h>
52 
53 #include <asm/processor.h>
54 #include <asm/io.h>
55 #include <asm/uaccess.h>
56 #include <asm/pgtable.h>
57 
58 #include "coalesced_mmio.h"
59 #include "async_pf.h"
60 
61 #define CREATE_TRACE_POINTS
62 #include <trace/events/kvm.h>
63 
64 MODULE_AUTHOR("Qumranet");
65 MODULE_LICENSE("GPL");
66 
67 /*
68  * Ordering of locks:
69  *
70  * 		kvm->lock --> kvm->slots_lock --> kvm->irq_lock
71  */
72 
73 DEFINE_RAW_SPINLOCK(kvm_lock);
74 LIST_HEAD(vm_list);
75 
76 static cpumask_var_t cpus_hardware_enabled;
77 static int kvm_usage_count = 0;
78 static atomic_t hardware_enable_failed;
79 
80 struct kmem_cache *kvm_vcpu_cache;
81 EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
82 
83 static __read_mostly struct preempt_ops kvm_preempt_ops;
84 
85 struct dentry *kvm_debugfs_dir;
86 
87 static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
88 			   unsigned long arg);
89 #ifdef CONFIG_COMPAT
90 static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl,
91 				  unsigned long arg);
92 #endif
93 static int hardware_enable_all(void);
94 static void hardware_disable_all(void);
95 
96 static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
97 
98 bool kvm_rebooting;
99 EXPORT_SYMBOL_GPL(kvm_rebooting);
100 
101 static bool largepages_enabled = true;
102 
103 static struct page *hwpoison_page;
104 static pfn_t hwpoison_pfn;
105 
106 struct page *fault_page;
107 pfn_t fault_pfn;
108 
109 inline int kvm_is_mmio_pfn(pfn_t pfn)
110 {
111 	if (pfn_valid(pfn)) {
112 		int reserved;
113 		struct page *tail = pfn_to_page(pfn);
114 		struct page *head = compound_trans_head(tail);
115 		reserved = PageReserved(head);
116 		if (head != tail) {
117 			/*
118 			 * "head" is not a dangling pointer
119 			 * (compound_trans_head takes care of that)
120 			 * but the hugepage may have been splitted
121 			 * from under us (and we may not hold a
122 			 * reference count on the head page so it can
123 			 * be reused before we run PageReferenced), so
124 			 * we've to check PageTail before returning
125 			 * what we just read.
126 			 */
127 			smp_rmb();
128 			if (PageTail(tail))
129 				return reserved;
130 		}
131 		return PageReserved(tail);
132 	}
133 
134 	return true;
135 }
136 
137 /*
138  * Switches to specified vcpu, until a matching vcpu_put()
139  */
140 void vcpu_load(struct kvm_vcpu *vcpu)
141 {
142 	int cpu;
143 
144 	mutex_lock(&vcpu->mutex);
145 	if (unlikely(vcpu->pid != current->pids[PIDTYPE_PID].pid)) {
146 		/* The thread running this VCPU changed. */
147 		struct pid *oldpid = vcpu->pid;
148 		struct pid *newpid = get_task_pid(current, PIDTYPE_PID);
149 		rcu_assign_pointer(vcpu->pid, newpid);
150 		synchronize_rcu();
151 		put_pid(oldpid);
152 	}
153 	cpu = get_cpu();
154 	preempt_notifier_register(&vcpu->preempt_notifier);
155 	kvm_arch_vcpu_load(vcpu, cpu);
156 	put_cpu();
157 }
158 
159 void vcpu_put(struct kvm_vcpu *vcpu)
160 {
161 	preempt_disable();
162 	kvm_arch_vcpu_put(vcpu);
163 	preempt_notifier_unregister(&vcpu->preempt_notifier);
164 	preempt_enable();
165 	mutex_unlock(&vcpu->mutex);
166 }
167 
168 static void ack_flush(void *_completed)
169 {
170 }
171 
172 static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
173 {
174 	int i, cpu, me;
175 	cpumask_var_t cpus;
176 	bool called = true;
177 	struct kvm_vcpu *vcpu;
178 
179 	zalloc_cpumask_var(&cpus, GFP_ATOMIC);
180 
181 	me = get_cpu();
182 	kvm_for_each_vcpu(i, vcpu, kvm) {
183 		kvm_make_request(req, vcpu);
184 		cpu = vcpu->cpu;
185 
186 		/* Set ->requests bit before we read ->mode */
187 		smp_mb();
188 
189 		if (cpus != NULL && cpu != -1 && cpu != me &&
190 		      kvm_vcpu_exiting_guest_mode(vcpu) != OUTSIDE_GUEST_MODE)
191 			cpumask_set_cpu(cpu, cpus);
192 	}
193 	if (unlikely(cpus == NULL))
194 		smp_call_function_many(cpu_online_mask, ack_flush, NULL, 1);
195 	else if (!cpumask_empty(cpus))
196 		smp_call_function_many(cpus, ack_flush, NULL, 1);
197 	else
198 		called = false;
199 	put_cpu();
200 	free_cpumask_var(cpus);
201 	return called;
202 }
203 
204 void kvm_flush_remote_tlbs(struct kvm *kvm)
205 {
206 	long dirty_count = kvm->tlbs_dirty;
207 
208 	smp_mb();
209 	if (make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
210 		++kvm->stat.remote_tlb_flush;
211 	cmpxchg(&kvm->tlbs_dirty, dirty_count, 0);
212 }
213 
214 void kvm_reload_remote_mmus(struct kvm *kvm)
215 {
216 	make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD);
217 }
218 
219 int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
220 {
221 	struct page *page;
222 	int r;
223 
224 	mutex_init(&vcpu->mutex);
225 	vcpu->cpu = -1;
226 	vcpu->kvm = kvm;
227 	vcpu->vcpu_id = id;
228 	vcpu->pid = NULL;
229 	init_waitqueue_head(&vcpu->wq);
230 	kvm_async_pf_vcpu_init(vcpu);
231 
232 	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
233 	if (!page) {
234 		r = -ENOMEM;
235 		goto fail;
236 	}
237 	vcpu->run = page_address(page);
238 
239 	r = kvm_arch_vcpu_init(vcpu);
240 	if (r < 0)
241 		goto fail_free_run;
242 	return 0;
243 
244 fail_free_run:
245 	free_page((unsigned long)vcpu->run);
246 fail:
247 	return r;
248 }
249 EXPORT_SYMBOL_GPL(kvm_vcpu_init);
250 
251 void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
252 {
253 	put_pid(vcpu->pid);
254 	kvm_arch_vcpu_uninit(vcpu);
255 	free_page((unsigned long)vcpu->run);
256 }
257 EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
258 
259 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
260 static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
261 {
262 	return container_of(mn, struct kvm, mmu_notifier);
263 }
264 
265 static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
266 					     struct mm_struct *mm,
267 					     unsigned long address)
268 {
269 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
270 	int need_tlb_flush, idx;
271 
272 	/*
273 	 * When ->invalidate_page runs, the linux pte has been zapped
274 	 * already but the page is still allocated until
275 	 * ->invalidate_page returns. So if we increase the sequence
276 	 * here the kvm page fault will notice if the spte can't be
277 	 * established because the page is going to be freed. If
278 	 * instead the kvm page fault establishes the spte before
279 	 * ->invalidate_page runs, kvm_unmap_hva will release it
280 	 * before returning.
281 	 *
282 	 * The sequence increase only need to be seen at spin_unlock
283 	 * time, and not at spin_lock time.
284 	 *
285 	 * Increasing the sequence after the spin_unlock would be
286 	 * unsafe because the kvm page fault could then establish the
287 	 * pte after kvm_unmap_hva returned, without noticing the page
288 	 * is going to be freed.
289 	 */
290 	idx = srcu_read_lock(&kvm->srcu);
291 	spin_lock(&kvm->mmu_lock);
292 
293 	kvm->mmu_notifier_seq++;
294 	need_tlb_flush = kvm_unmap_hva(kvm, address) | kvm->tlbs_dirty;
295 	/* we've to flush the tlb before the pages can be freed */
296 	if (need_tlb_flush)
297 		kvm_flush_remote_tlbs(kvm);
298 
299 	spin_unlock(&kvm->mmu_lock);
300 	srcu_read_unlock(&kvm->srcu, idx);
301 }
302 
303 static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
304 					struct mm_struct *mm,
305 					unsigned long address,
306 					pte_t pte)
307 {
308 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
309 	int idx;
310 
311 	idx = srcu_read_lock(&kvm->srcu);
312 	spin_lock(&kvm->mmu_lock);
313 	kvm->mmu_notifier_seq++;
314 	kvm_set_spte_hva(kvm, address, pte);
315 	spin_unlock(&kvm->mmu_lock);
316 	srcu_read_unlock(&kvm->srcu, idx);
317 }
318 
319 static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
320 						    struct mm_struct *mm,
321 						    unsigned long start,
322 						    unsigned long end)
323 {
324 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
325 	int need_tlb_flush = 0, idx;
326 
327 	idx = srcu_read_lock(&kvm->srcu);
328 	spin_lock(&kvm->mmu_lock);
329 	/*
330 	 * The count increase must become visible at unlock time as no
331 	 * spte can be established without taking the mmu_lock and
332 	 * count is also read inside the mmu_lock critical section.
333 	 */
334 	kvm->mmu_notifier_count++;
335 	for (; start < end; start += PAGE_SIZE)
336 		need_tlb_flush |= kvm_unmap_hva(kvm, start);
337 	need_tlb_flush |= kvm->tlbs_dirty;
338 	/* we've to flush the tlb before the pages can be freed */
339 	if (need_tlb_flush)
340 		kvm_flush_remote_tlbs(kvm);
341 
342 	spin_unlock(&kvm->mmu_lock);
343 	srcu_read_unlock(&kvm->srcu, idx);
344 }
345 
346 static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
347 						  struct mm_struct *mm,
348 						  unsigned long start,
349 						  unsigned long end)
350 {
351 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
352 
353 	spin_lock(&kvm->mmu_lock);
354 	/*
355 	 * This sequence increase will notify the kvm page fault that
356 	 * the page that is going to be mapped in the spte could have
357 	 * been freed.
358 	 */
359 	kvm->mmu_notifier_seq++;
360 	smp_wmb();
361 	/*
362 	 * The above sequence increase must be visible before the
363 	 * below count decrease, which is ensured by the smp_wmb above
364 	 * in conjunction with the smp_rmb in mmu_notifier_retry().
365 	 */
366 	kvm->mmu_notifier_count--;
367 	spin_unlock(&kvm->mmu_lock);
368 
369 	BUG_ON(kvm->mmu_notifier_count < 0);
370 }
371 
372 static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
373 					      struct mm_struct *mm,
374 					      unsigned long address)
375 {
376 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
377 	int young, idx;
378 
379 	idx = srcu_read_lock(&kvm->srcu);
380 	spin_lock(&kvm->mmu_lock);
381 
382 	young = kvm_age_hva(kvm, address);
383 	if (young)
384 		kvm_flush_remote_tlbs(kvm);
385 
386 	spin_unlock(&kvm->mmu_lock);
387 	srcu_read_unlock(&kvm->srcu, idx);
388 
389 	return young;
390 }
391 
392 static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
393 				       struct mm_struct *mm,
394 				       unsigned long address)
395 {
396 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
397 	int young, idx;
398 
399 	idx = srcu_read_lock(&kvm->srcu);
400 	spin_lock(&kvm->mmu_lock);
401 	young = kvm_test_age_hva(kvm, address);
402 	spin_unlock(&kvm->mmu_lock);
403 	srcu_read_unlock(&kvm->srcu, idx);
404 
405 	return young;
406 }
407 
408 static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
409 				     struct mm_struct *mm)
410 {
411 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
412 	int idx;
413 
414 	idx = srcu_read_lock(&kvm->srcu);
415 	kvm_arch_flush_shadow(kvm);
416 	srcu_read_unlock(&kvm->srcu, idx);
417 }
418 
419 static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
420 	.invalidate_page	= kvm_mmu_notifier_invalidate_page,
421 	.invalidate_range_start	= kvm_mmu_notifier_invalidate_range_start,
422 	.invalidate_range_end	= kvm_mmu_notifier_invalidate_range_end,
423 	.clear_flush_young	= kvm_mmu_notifier_clear_flush_young,
424 	.test_young		= kvm_mmu_notifier_test_young,
425 	.change_pte		= kvm_mmu_notifier_change_pte,
426 	.release		= kvm_mmu_notifier_release,
427 };
428 
429 static int kvm_init_mmu_notifier(struct kvm *kvm)
430 {
431 	kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
432 	return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
433 }
434 
435 #else  /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */
436 
437 static int kvm_init_mmu_notifier(struct kvm *kvm)
438 {
439 	return 0;
440 }
441 
442 #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
443 
444 static void kvm_init_memslots_id(struct kvm *kvm)
445 {
446 	int i;
447 	struct kvm_memslots *slots = kvm->memslots;
448 
449 	for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
450 		slots->id_to_index[i] = slots->memslots[i].id = i;
451 }
452 
453 static struct kvm *kvm_create_vm(unsigned long type)
454 {
455 	int r, i;
456 	struct kvm *kvm = kvm_arch_alloc_vm();
457 
458 	if (!kvm)
459 		return ERR_PTR(-ENOMEM);
460 
461 	r = kvm_arch_init_vm(kvm, type);
462 	if (r)
463 		goto out_err_nodisable;
464 
465 	r = hardware_enable_all();
466 	if (r)
467 		goto out_err_nodisable;
468 
469 #ifdef CONFIG_HAVE_KVM_IRQCHIP
470 	INIT_HLIST_HEAD(&kvm->mask_notifier_list);
471 	INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
472 #endif
473 
474 	r = -ENOMEM;
475 	kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
476 	if (!kvm->memslots)
477 		goto out_err_nosrcu;
478 	kvm_init_memslots_id(kvm);
479 	if (init_srcu_struct(&kvm->srcu))
480 		goto out_err_nosrcu;
481 	for (i = 0; i < KVM_NR_BUSES; i++) {
482 		kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus),
483 					GFP_KERNEL);
484 		if (!kvm->buses[i])
485 			goto out_err;
486 	}
487 
488 	spin_lock_init(&kvm->mmu_lock);
489 	kvm->mm = current->mm;
490 	atomic_inc(&kvm->mm->mm_count);
491 	kvm_eventfd_init(kvm);
492 	mutex_init(&kvm->lock);
493 	mutex_init(&kvm->irq_lock);
494 	mutex_init(&kvm->slots_lock);
495 	atomic_set(&kvm->users_count, 1);
496 
497 	r = kvm_init_mmu_notifier(kvm);
498 	if (r)
499 		goto out_err;
500 
501 	raw_spin_lock(&kvm_lock);
502 	list_add(&kvm->vm_list, &vm_list);
503 	raw_spin_unlock(&kvm_lock);
504 
505 	return kvm;
506 
507 out_err:
508 	cleanup_srcu_struct(&kvm->srcu);
509 out_err_nosrcu:
510 	hardware_disable_all();
511 out_err_nodisable:
512 	for (i = 0; i < KVM_NR_BUSES; i++)
513 		kfree(kvm->buses[i]);
514 	kfree(kvm->memslots);
515 	kvm_arch_free_vm(kvm);
516 	return ERR_PTR(r);
517 }
518 
519 static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
520 {
521 	if (!memslot->dirty_bitmap)
522 		return;
523 
524 	if (2 * kvm_dirty_bitmap_bytes(memslot) > PAGE_SIZE)
525 		vfree(memslot->dirty_bitmap_head);
526 	else
527 		kfree(memslot->dirty_bitmap_head);
528 
529 	memslot->dirty_bitmap = NULL;
530 	memslot->dirty_bitmap_head = NULL;
531 }
532 
533 /*
534  * Free any memory in @free but not in @dont.
535  */
536 static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
537 				  struct kvm_memory_slot *dont)
538 {
539 	if (!dont || free->rmap != dont->rmap)
540 		vfree(free->rmap);
541 
542 	if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
543 		kvm_destroy_dirty_bitmap(free);
544 
545 	kvm_arch_free_memslot(free, dont);
546 
547 	free->npages = 0;
548 	free->rmap = NULL;
549 }
550 
551 void kvm_free_physmem(struct kvm *kvm)
552 {
553 	struct kvm_memslots *slots = kvm->memslots;
554 	struct kvm_memory_slot *memslot;
555 
556 	kvm_for_each_memslot(memslot, slots)
557 		kvm_free_physmem_slot(memslot, NULL);
558 
559 	kfree(kvm->memslots);
560 }
561 
562 static void kvm_destroy_vm(struct kvm *kvm)
563 {
564 	int i;
565 	struct mm_struct *mm = kvm->mm;
566 
567 	kvm_arch_sync_events(kvm);
568 	raw_spin_lock(&kvm_lock);
569 	list_del(&kvm->vm_list);
570 	raw_spin_unlock(&kvm_lock);
571 	kvm_free_irq_routing(kvm);
572 	for (i = 0; i < KVM_NR_BUSES; i++)
573 		kvm_io_bus_destroy(kvm->buses[i]);
574 	kvm_coalesced_mmio_free(kvm);
575 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
576 	mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
577 #else
578 	kvm_arch_flush_shadow(kvm);
579 #endif
580 	kvm_arch_destroy_vm(kvm);
581 	kvm_free_physmem(kvm);
582 	cleanup_srcu_struct(&kvm->srcu);
583 	kvm_arch_free_vm(kvm);
584 	hardware_disable_all();
585 	mmdrop(mm);
586 }
587 
588 void kvm_get_kvm(struct kvm *kvm)
589 {
590 	atomic_inc(&kvm->users_count);
591 }
592 EXPORT_SYMBOL_GPL(kvm_get_kvm);
593 
594 void kvm_put_kvm(struct kvm *kvm)
595 {
596 	if (atomic_dec_and_test(&kvm->users_count))
597 		kvm_destroy_vm(kvm);
598 }
599 EXPORT_SYMBOL_GPL(kvm_put_kvm);
600 
601 
602 static int kvm_vm_release(struct inode *inode, struct file *filp)
603 {
604 	struct kvm *kvm = filp->private_data;
605 
606 	kvm_irqfd_release(kvm);
607 
608 	kvm_put_kvm(kvm);
609 	return 0;
610 }
611 
612 /*
613  * Allocation size is twice as large as the actual dirty bitmap size.
614  * This makes it possible to do double buffering: see x86's
615  * kvm_vm_ioctl_get_dirty_log().
616  */
617 static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
618 {
619 #ifndef CONFIG_S390
620 	unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
621 
622 	if (dirty_bytes > PAGE_SIZE)
623 		memslot->dirty_bitmap = vzalloc(dirty_bytes);
624 	else
625 		memslot->dirty_bitmap = kzalloc(dirty_bytes, GFP_KERNEL);
626 
627 	if (!memslot->dirty_bitmap)
628 		return -ENOMEM;
629 
630 	memslot->dirty_bitmap_head = memslot->dirty_bitmap;
631 	memslot->nr_dirty_pages = 0;
632 #endif /* !CONFIG_S390 */
633 	return 0;
634 }
635 
636 static int cmp_memslot(const void *slot1, const void *slot2)
637 {
638 	struct kvm_memory_slot *s1, *s2;
639 
640 	s1 = (struct kvm_memory_slot *)slot1;
641 	s2 = (struct kvm_memory_slot *)slot2;
642 
643 	if (s1->npages < s2->npages)
644 		return 1;
645 	if (s1->npages > s2->npages)
646 		return -1;
647 
648 	return 0;
649 }
650 
651 /*
652  * Sort the memslots base on its size, so the larger slots
653  * will get better fit.
654  */
655 static void sort_memslots(struct kvm_memslots *slots)
656 {
657 	int i;
658 
659 	sort(slots->memslots, KVM_MEM_SLOTS_NUM,
660 	      sizeof(struct kvm_memory_slot), cmp_memslot, NULL);
661 
662 	for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
663 		slots->id_to_index[slots->memslots[i].id] = i;
664 }
665 
666 void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new)
667 {
668 	if (new) {
669 		int id = new->id;
670 		struct kvm_memory_slot *old = id_to_memslot(slots, id);
671 		unsigned long npages = old->npages;
672 
673 		*old = *new;
674 		if (new->npages != npages)
675 			sort_memslots(slots);
676 	}
677 
678 	slots->generation++;
679 }
680 
681 /*
682  * Allocate some memory and give it an address in the guest physical address
683  * space.
684  *
685  * Discontiguous memory is allowed, mostly for framebuffers.
686  *
687  * Must be called holding mmap_sem for write.
688  */
689 int __kvm_set_memory_region(struct kvm *kvm,
690 			    struct kvm_userspace_memory_region *mem,
691 			    int user_alloc)
692 {
693 	int r;
694 	gfn_t base_gfn;
695 	unsigned long npages;
696 	unsigned long i;
697 	struct kvm_memory_slot *memslot;
698 	struct kvm_memory_slot old, new;
699 	struct kvm_memslots *slots, *old_memslots;
700 
701 	r = -EINVAL;
702 	/* General sanity checks */
703 	if (mem->memory_size & (PAGE_SIZE - 1))
704 		goto out;
705 	if (mem->guest_phys_addr & (PAGE_SIZE - 1))
706 		goto out;
707 	/* We can read the guest memory with __xxx_user() later on. */
708 	if (user_alloc &&
709 	    ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
710 	     !access_ok(VERIFY_WRITE,
711 			(void __user *)(unsigned long)mem->userspace_addr,
712 			mem->memory_size)))
713 		goto out;
714 	if (mem->slot >= KVM_MEM_SLOTS_NUM)
715 		goto out;
716 	if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
717 		goto out;
718 
719 	memslot = id_to_memslot(kvm->memslots, mem->slot);
720 	base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
721 	npages = mem->memory_size >> PAGE_SHIFT;
722 
723 	r = -EINVAL;
724 	if (npages > KVM_MEM_MAX_NR_PAGES)
725 		goto out;
726 
727 	if (!npages)
728 		mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
729 
730 	new = old = *memslot;
731 
732 	new.id = mem->slot;
733 	new.base_gfn = base_gfn;
734 	new.npages = npages;
735 	new.flags = mem->flags;
736 
737 	/* Disallow changing a memory slot's size. */
738 	r = -EINVAL;
739 	if (npages && old.npages && npages != old.npages)
740 		goto out_free;
741 
742 	/* Check for overlaps */
743 	r = -EEXIST;
744 	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
745 		struct kvm_memory_slot *s = &kvm->memslots->memslots[i];
746 
747 		if (s == memslot || !s->npages)
748 			continue;
749 		if (!((base_gfn + npages <= s->base_gfn) ||
750 		      (base_gfn >= s->base_gfn + s->npages)))
751 			goto out_free;
752 	}
753 
754 	/* Free page dirty bitmap if unneeded */
755 	if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
756 		new.dirty_bitmap = NULL;
757 
758 	r = -ENOMEM;
759 
760 	/* Allocate if a slot is being created */
761 	if (npages && !old.npages) {
762 		new.user_alloc = user_alloc;
763 		new.userspace_addr = mem->userspace_addr;
764 #ifndef CONFIG_S390
765 		new.rmap = vzalloc(npages * sizeof(*new.rmap));
766 		if (!new.rmap)
767 			goto out_free;
768 #endif /* not defined CONFIG_S390 */
769 		if (kvm_arch_create_memslot(&new, npages))
770 			goto out_free;
771 	}
772 
773 	/* Allocate page dirty bitmap if needed */
774 	if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
775 		if (kvm_create_dirty_bitmap(&new) < 0)
776 			goto out_free;
777 		/* destroy any largepage mappings for dirty tracking */
778 	}
779 
780 	if (!npages) {
781 		struct kvm_memory_slot *slot;
782 
783 		r = -ENOMEM;
784 		slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
785 				GFP_KERNEL);
786 		if (!slots)
787 			goto out_free;
788 		slot = id_to_memslot(slots, mem->slot);
789 		slot->flags |= KVM_MEMSLOT_INVALID;
790 
791 		update_memslots(slots, NULL);
792 
793 		old_memslots = kvm->memslots;
794 		rcu_assign_pointer(kvm->memslots, slots);
795 		synchronize_srcu_expedited(&kvm->srcu);
796 		/* From this point no new shadow pages pointing to a deleted
797 		 * memslot will be created.
798 		 *
799 		 * validation of sp->gfn happens in:
800 		 * 	- gfn_to_hva (kvm_read_guest, gfn_to_pfn)
801 		 * 	- kvm_is_visible_gfn (mmu_check_roots)
802 		 */
803 		kvm_arch_flush_shadow(kvm);
804 		kfree(old_memslots);
805 	}
806 
807 	r = kvm_arch_prepare_memory_region(kvm, &new, old, mem, user_alloc);
808 	if (r)
809 		goto out_free;
810 
811 	/* map the pages in iommu page table */
812 	if (npages) {
813 		r = kvm_iommu_map_pages(kvm, &new);
814 		if (r)
815 			goto out_free;
816 	}
817 
818 	r = -ENOMEM;
819 	slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
820 			GFP_KERNEL);
821 	if (!slots)
822 		goto out_free;
823 
824 	/* actual memory is freed via old in kvm_free_physmem_slot below */
825 	if (!npages) {
826 		new.rmap = NULL;
827 		new.dirty_bitmap = NULL;
828 		memset(&new.arch, 0, sizeof(new.arch));
829 	}
830 
831 	update_memslots(slots, &new);
832 	old_memslots = kvm->memslots;
833 	rcu_assign_pointer(kvm->memslots, slots);
834 	synchronize_srcu_expedited(&kvm->srcu);
835 
836 	kvm_arch_commit_memory_region(kvm, mem, old, user_alloc);
837 
838 	/*
839 	 * If the new memory slot is created, we need to clear all
840 	 * mmio sptes.
841 	 */
842 	if (npages && old.base_gfn != mem->guest_phys_addr >> PAGE_SHIFT)
843 		kvm_arch_flush_shadow(kvm);
844 
845 	kvm_free_physmem_slot(&old, &new);
846 	kfree(old_memslots);
847 
848 	return 0;
849 
850 out_free:
851 	kvm_free_physmem_slot(&new, &old);
852 out:
853 	return r;
854 
855 }
856 EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
857 
858 int kvm_set_memory_region(struct kvm *kvm,
859 			  struct kvm_userspace_memory_region *mem,
860 			  int user_alloc)
861 {
862 	int r;
863 
864 	mutex_lock(&kvm->slots_lock);
865 	r = __kvm_set_memory_region(kvm, mem, user_alloc);
866 	mutex_unlock(&kvm->slots_lock);
867 	return r;
868 }
869 EXPORT_SYMBOL_GPL(kvm_set_memory_region);
870 
871 int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
872 				   struct
873 				   kvm_userspace_memory_region *mem,
874 				   int user_alloc)
875 {
876 	if (mem->slot >= KVM_MEMORY_SLOTS)
877 		return -EINVAL;
878 	return kvm_set_memory_region(kvm, mem, user_alloc);
879 }
880 
881 int kvm_get_dirty_log(struct kvm *kvm,
882 			struct kvm_dirty_log *log, int *is_dirty)
883 {
884 	struct kvm_memory_slot *memslot;
885 	int r, i;
886 	unsigned long n;
887 	unsigned long any = 0;
888 
889 	r = -EINVAL;
890 	if (log->slot >= KVM_MEMORY_SLOTS)
891 		goto out;
892 
893 	memslot = id_to_memslot(kvm->memslots, log->slot);
894 	r = -ENOENT;
895 	if (!memslot->dirty_bitmap)
896 		goto out;
897 
898 	n = kvm_dirty_bitmap_bytes(memslot);
899 
900 	for (i = 0; !any && i < n/sizeof(long); ++i)
901 		any = memslot->dirty_bitmap[i];
902 
903 	r = -EFAULT;
904 	if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
905 		goto out;
906 
907 	if (any)
908 		*is_dirty = 1;
909 
910 	r = 0;
911 out:
912 	return r;
913 }
914 
915 bool kvm_largepages_enabled(void)
916 {
917 	return largepages_enabled;
918 }
919 
920 void kvm_disable_largepages(void)
921 {
922 	largepages_enabled = false;
923 }
924 EXPORT_SYMBOL_GPL(kvm_disable_largepages);
925 
926 int is_error_page(struct page *page)
927 {
928 	return page == bad_page || page == hwpoison_page || page == fault_page;
929 }
930 EXPORT_SYMBOL_GPL(is_error_page);
931 
932 int is_error_pfn(pfn_t pfn)
933 {
934 	return pfn == bad_pfn || pfn == hwpoison_pfn || pfn == fault_pfn;
935 }
936 EXPORT_SYMBOL_GPL(is_error_pfn);
937 
938 int is_hwpoison_pfn(pfn_t pfn)
939 {
940 	return pfn == hwpoison_pfn;
941 }
942 EXPORT_SYMBOL_GPL(is_hwpoison_pfn);
943 
944 int is_fault_pfn(pfn_t pfn)
945 {
946 	return pfn == fault_pfn;
947 }
948 EXPORT_SYMBOL_GPL(is_fault_pfn);
949 
950 int is_noslot_pfn(pfn_t pfn)
951 {
952 	return pfn == bad_pfn;
953 }
954 EXPORT_SYMBOL_GPL(is_noslot_pfn);
955 
956 int is_invalid_pfn(pfn_t pfn)
957 {
958 	return pfn == hwpoison_pfn || pfn == fault_pfn;
959 }
960 EXPORT_SYMBOL_GPL(is_invalid_pfn);
961 
962 static inline unsigned long bad_hva(void)
963 {
964 	return PAGE_OFFSET;
965 }
966 
967 int kvm_is_error_hva(unsigned long addr)
968 {
969 	return addr == bad_hva();
970 }
971 EXPORT_SYMBOL_GPL(kvm_is_error_hva);
972 
973 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
974 {
975 	return __gfn_to_memslot(kvm_memslots(kvm), gfn);
976 }
977 EXPORT_SYMBOL_GPL(gfn_to_memslot);
978 
979 int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
980 {
981 	struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn);
982 
983 	if (!memslot || memslot->id >= KVM_MEMORY_SLOTS ||
984 	      memslot->flags & KVM_MEMSLOT_INVALID)
985 		return 0;
986 
987 	return 1;
988 }
989 EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
990 
991 unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn)
992 {
993 	struct vm_area_struct *vma;
994 	unsigned long addr, size;
995 
996 	size = PAGE_SIZE;
997 
998 	addr = gfn_to_hva(kvm, gfn);
999 	if (kvm_is_error_hva(addr))
1000 		return PAGE_SIZE;
1001 
1002 	down_read(&current->mm->mmap_sem);
1003 	vma = find_vma(current->mm, addr);
1004 	if (!vma)
1005 		goto out;
1006 
1007 	size = vma_kernel_pagesize(vma);
1008 
1009 out:
1010 	up_read(&current->mm->mmap_sem);
1011 
1012 	return size;
1013 }
1014 
1015 static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
1016 				     gfn_t *nr_pages)
1017 {
1018 	if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
1019 		return bad_hva();
1020 
1021 	if (nr_pages)
1022 		*nr_pages = slot->npages - (gfn - slot->base_gfn);
1023 
1024 	return gfn_to_hva_memslot(slot, gfn);
1025 }
1026 
1027 unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
1028 {
1029 	return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL);
1030 }
1031 EXPORT_SYMBOL_GPL(gfn_to_hva);
1032 
1033 static pfn_t get_fault_pfn(void)
1034 {
1035 	get_page(fault_page);
1036 	return fault_pfn;
1037 }
1038 
1039 int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm,
1040 	unsigned long start, int write, struct page **page)
1041 {
1042 	int flags = FOLL_TOUCH | FOLL_NOWAIT | FOLL_HWPOISON | FOLL_GET;
1043 
1044 	if (write)
1045 		flags |= FOLL_WRITE;
1046 
1047 	return __get_user_pages(tsk, mm, start, 1, flags, page, NULL, NULL);
1048 }
1049 
1050 static inline int check_user_page_hwpoison(unsigned long addr)
1051 {
1052 	int rc, flags = FOLL_TOUCH | FOLL_HWPOISON | FOLL_WRITE;
1053 
1054 	rc = __get_user_pages(current, current->mm, addr, 1,
1055 			      flags, NULL, NULL, NULL);
1056 	return rc == -EHWPOISON;
1057 }
1058 
1059 static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic,
1060 			bool *async, bool write_fault, bool *writable)
1061 {
1062 	struct page *page[1];
1063 	int npages = 0;
1064 	pfn_t pfn;
1065 
1066 	/* we can do it either atomically or asynchronously, not both */
1067 	BUG_ON(atomic && async);
1068 
1069 	BUG_ON(!write_fault && !writable);
1070 
1071 	if (writable)
1072 		*writable = true;
1073 
1074 	if (atomic || async)
1075 		npages = __get_user_pages_fast(addr, 1, 1, page);
1076 
1077 	if (unlikely(npages != 1) && !atomic) {
1078 		might_sleep();
1079 
1080 		if (writable)
1081 			*writable = write_fault;
1082 
1083 		if (async) {
1084 			down_read(&current->mm->mmap_sem);
1085 			npages = get_user_page_nowait(current, current->mm,
1086 						     addr, write_fault, page);
1087 			up_read(&current->mm->mmap_sem);
1088 		} else
1089 			npages = get_user_pages_fast(addr, 1, write_fault,
1090 						     page);
1091 
1092 		/* map read fault as writable if possible */
1093 		if (unlikely(!write_fault) && npages == 1) {
1094 			struct page *wpage[1];
1095 
1096 			npages = __get_user_pages_fast(addr, 1, 1, wpage);
1097 			if (npages == 1) {
1098 				*writable = true;
1099 				put_page(page[0]);
1100 				page[0] = wpage[0];
1101 			}
1102 			npages = 1;
1103 		}
1104 	}
1105 
1106 	if (unlikely(npages != 1)) {
1107 		struct vm_area_struct *vma;
1108 
1109 		if (atomic)
1110 			return get_fault_pfn();
1111 
1112 		down_read(&current->mm->mmap_sem);
1113 		if (npages == -EHWPOISON ||
1114 			(!async && check_user_page_hwpoison(addr))) {
1115 			up_read(&current->mm->mmap_sem);
1116 			get_page(hwpoison_page);
1117 			return page_to_pfn(hwpoison_page);
1118 		}
1119 
1120 		vma = find_vma_intersection(current->mm, addr, addr+1);
1121 
1122 		if (vma == NULL)
1123 			pfn = get_fault_pfn();
1124 		else if ((vma->vm_flags & VM_PFNMAP)) {
1125 			pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) +
1126 				vma->vm_pgoff;
1127 			BUG_ON(!kvm_is_mmio_pfn(pfn));
1128 		} else {
1129 			if (async && (vma->vm_flags & VM_WRITE))
1130 				*async = true;
1131 			pfn = get_fault_pfn();
1132 		}
1133 		up_read(&current->mm->mmap_sem);
1134 	} else
1135 		pfn = page_to_pfn(page[0]);
1136 
1137 	return pfn;
1138 }
1139 
1140 pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr)
1141 {
1142 	return hva_to_pfn(kvm, addr, true, NULL, true, NULL);
1143 }
1144 EXPORT_SYMBOL_GPL(hva_to_pfn_atomic);
1145 
1146 static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async,
1147 			  bool write_fault, bool *writable)
1148 {
1149 	unsigned long addr;
1150 
1151 	if (async)
1152 		*async = false;
1153 
1154 	addr = gfn_to_hva(kvm, gfn);
1155 	if (kvm_is_error_hva(addr)) {
1156 		get_page(bad_page);
1157 		return page_to_pfn(bad_page);
1158 	}
1159 
1160 	return hva_to_pfn(kvm, addr, atomic, async, write_fault, writable);
1161 }
1162 
1163 pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn)
1164 {
1165 	return __gfn_to_pfn(kvm, gfn, true, NULL, true, NULL);
1166 }
1167 EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic);
1168 
1169 pfn_t gfn_to_pfn_async(struct kvm *kvm, gfn_t gfn, bool *async,
1170 		       bool write_fault, bool *writable)
1171 {
1172 	return __gfn_to_pfn(kvm, gfn, false, async, write_fault, writable);
1173 }
1174 EXPORT_SYMBOL_GPL(gfn_to_pfn_async);
1175 
1176 pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
1177 {
1178 	return __gfn_to_pfn(kvm, gfn, false, NULL, true, NULL);
1179 }
1180 EXPORT_SYMBOL_GPL(gfn_to_pfn);
1181 
1182 pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
1183 		      bool *writable)
1184 {
1185 	return __gfn_to_pfn(kvm, gfn, false, NULL, write_fault, writable);
1186 }
1187 EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);
1188 
1189 pfn_t gfn_to_pfn_memslot(struct kvm *kvm,
1190 			 struct kvm_memory_slot *slot, gfn_t gfn)
1191 {
1192 	unsigned long addr = gfn_to_hva_memslot(slot, gfn);
1193 	return hva_to_pfn(kvm, addr, false, NULL, true, NULL);
1194 }
1195 
1196 int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages,
1197 								  int nr_pages)
1198 {
1199 	unsigned long addr;
1200 	gfn_t entry;
1201 
1202 	addr = gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, &entry);
1203 	if (kvm_is_error_hva(addr))
1204 		return -1;
1205 
1206 	if (entry < nr_pages)
1207 		return 0;
1208 
1209 	return __get_user_pages_fast(addr, nr_pages, 1, pages);
1210 }
1211 EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
1212 
1213 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
1214 {
1215 	pfn_t pfn;
1216 
1217 	pfn = gfn_to_pfn(kvm, gfn);
1218 	if (!kvm_is_mmio_pfn(pfn))
1219 		return pfn_to_page(pfn);
1220 
1221 	WARN_ON(kvm_is_mmio_pfn(pfn));
1222 
1223 	get_page(bad_page);
1224 	return bad_page;
1225 }
1226 
1227 EXPORT_SYMBOL_GPL(gfn_to_page);
1228 
1229 void kvm_release_page_clean(struct page *page)
1230 {
1231 	kvm_release_pfn_clean(page_to_pfn(page));
1232 }
1233 EXPORT_SYMBOL_GPL(kvm_release_page_clean);
1234 
1235 void kvm_release_pfn_clean(pfn_t pfn)
1236 {
1237 	if (!kvm_is_mmio_pfn(pfn))
1238 		put_page(pfn_to_page(pfn));
1239 }
1240 EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
1241 
1242 void kvm_release_page_dirty(struct page *page)
1243 {
1244 	kvm_release_pfn_dirty(page_to_pfn(page));
1245 }
1246 EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
1247 
1248 void kvm_release_pfn_dirty(pfn_t pfn)
1249 {
1250 	kvm_set_pfn_dirty(pfn);
1251 	kvm_release_pfn_clean(pfn);
1252 }
1253 EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
1254 
1255 void kvm_set_page_dirty(struct page *page)
1256 {
1257 	kvm_set_pfn_dirty(page_to_pfn(page));
1258 }
1259 EXPORT_SYMBOL_GPL(kvm_set_page_dirty);
1260 
1261 void kvm_set_pfn_dirty(pfn_t pfn)
1262 {
1263 	if (!kvm_is_mmio_pfn(pfn)) {
1264 		struct page *page = pfn_to_page(pfn);
1265 		if (!PageReserved(page))
1266 			SetPageDirty(page);
1267 	}
1268 }
1269 EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
1270 
1271 void kvm_set_pfn_accessed(pfn_t pfn)
1272 {
1273 	if (!kvm_is_mmio_pfn(pfn))
1274 		mark_page_accessed(pfn_to_page(pfn));
1275 }
1276 EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
1277 
1278 void kvm_get_pfn(pfn_t pfn)
1279 {
1280 	if (!kvm_is_mmio_pfn(pfn))
1281 		get_page(pfn_to_page(pfn));
1282 }
1283 EXPORT_SYMBOL_GPL(kvm_get_pfn);
1284 
1285 static int next_segment(unsigned long len, int offset)
1286 {
1287 	if (len > PAGE_SIZE - offset)
1288 		return PAGE_SIZE - offset;
1289 	else
1290 		return len;
1291 }
1292 
1293 int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
1294 			int len)
1295 {
1296 	int r;
1297 	unsigned long addr;
1298 
1299 	addr = gfn_to_hva(kvm, gfn);
1300 	if (kvm_is_error_hva(addr))
1301 		return -EFAULT;
1302 	r = __copy_from_user(data, (void __user *)addr + offset, len);
1303 	if (r)
1304 		return -EFAULT;
1305 	return 0;
1306 }
1307 EXPORT_SYMBOL_GPL(kvm_read_guest_page);
1308 
1309 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
1310 {
1311 	gfn_t gfn = gpa >> PAGE_SHIFT;
1312 	int seg;
1313 	int offset = offset_in_page(gpa);
1314 	int ret;
1315 
1316 	while ((seg = next_segment(len, offset)) != 0) {
1317 		ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
1318 		if (ret < 0)
1319 			return ret;
1320 		offset = 0;
1321 		len -= seg;
1322 		data += seg;
1323 		++gfn;
1324 	}
1325 	return 0;
1326 }
1327 EXPORT_SYMBOL_GPL(kvm_read_guest);
1328 
1329 int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
1330 			  unsigned long len)
1331 {
1332 	int r;
1333 	unsigned long addr;
1334 	gfn_t gfn = gpa >> PAGE_SHIFT;
1335 	int offset = offset_in_page(gpa);
1336 
1337 	addr = gfn_to_hva(kvm, gfn);
1338 	if (kvm_is_error_hva(addr))
1339 		return -EFAULT;
1340 	pagefault_disable();
1341 	r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
1342 	pagefault_enable();
1343 	if (r)
1344 		return -EFAULT;
1345 	return 0;
1346 }
1347 EXPORT_SYMBOL(kvm_read_guest_atomic);
1348 
1349 int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
1350 			 int offset, int len)
1351 {
1352 	int r;
1353 	unsigned long addr;
1354 
1355 	addr = gfn_to_hva(kvm, gfn);
1356 	if (kvm_is_error_hva(addr))
1357 		return -EFAULT;
1358 	r = __copy_to_user((void __user *)addr + offset, data, len);
1359 	if (r)
1360 		return -EFAULT;
1361 	mark_page_dirty(kvm, gfn);
1362 	return 0;
1363 }
1364 EXPORT_SYMBOL_GPL(kvm_write_guest_page);
1365 
1366 int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
1367 		    unsigned long len)
1368 {
1369 	gfn_t gfn = gpa >> PAGE_SHIFT;
1370 	int seg;
1371 	int offset = offset_in_page(gpa);
1372 	int ret;
1373 
1374 	while ((seg = next_segment(len, offset)) != 0) {
1375 		ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
1376 		if (ret < 0)
1377 			return ret;
1378 		offset = 0;
1379 		len -= seg;
1380 		data += seg;
1381 		++gfn;
1382 	}
1383 	return 0;
1384 }
1385 
1386 int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1387 			      gpa_t gpa)
1388 {
1389 	struct kvm_memslots *slots = kvm_memslots(kvm);
1390 	int offset = offset_in_page(gpa);
1391 	gfn_t gfn = gpa >> PAGE_SHIFT;
1392 
1393 	ghc->gpa = gpa;
1394 	ghc->generation = slots->generation;
1395 	ghc->memslot = gfn_to_memslot(kvm, gfn);
1396 	ghc->hva = gfn_to_hva_many(ghc->memslot, gfn, NULL);
1397 	if (!kvm_is_error_hva(ghc->hva))
1398 		ghc->hva += offset;
1399 	else
1400 		return -EFAULT;
1401 
1402 	return 0;
1403 }
1404 EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
1405 
1406 int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1407 			   void *data, unsigned long len)
1408 {
1409 	struct kvm_memslots *slots = kvm_memslots(kvm);
1410 	int r;
1411 
1412 	if (slots->generation != ghc->generation)
1413 		kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa);
1414 
1415 	if (kvm_is_error_hva(ghc->hva))
1416 		return -EFAULT;
1417 
1418 	r = __copy_to_user((void __user *)ghc->hva, data, len);
1419 	if (r)
1420 		return -EFAULT;
1421 	mark_page_dirty_in_slot(kvm, ghc->memslot, ghc->gpa >> PAGE_SHIFT);
1422 
1423 	return 0;
1424 }
1425 EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
1426 
1427 int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1428 			   void *data, unsigned long len)
1429 {
1430 	struct kvm_memslots *slots = kvm_memslots(kvm);
1431 	int r;
1432 
1433 	if (slots->generation != ghc->generation)
1434 		kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa);
1435 
1436 	if (kvm_is_error_hva(ghc->hva))
1437 		return -EFAULT;
1438 
1439 	r = __copy_from_user(data, (void __user *)ghc->hva, len);
1440 	if (r)
1441 		return -EFAULT;
1442 
1443 	return 0;
1444 }
1445 EXPORT_SYMBOL_GPL(kvm_read_guest_cached);
1446 
1447 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
1448 {
1449 	return kvm_write_guest_page(kvm, gfn, (const void *) empty_zero_page,
1450 				    offset, len);
1451 }
1452 EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
1453 
1454 int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
1455 {
1456 	gfn_t gfn = gpa >> PAGE_SHIFT;
1457 	int seg;
1458 	int offset = offset_in_page(gpa);
1459 	int ret;
1460 
1461         while ((seg = next_segment(len, offset)) != 0) {
1462 		ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
1463 		if (ret < 0)
1464 			return ret;
1465 		offset = 0;
1466 		len -= seg;
1467 		++gfn;
1468 	}
1469 	return 0;
1470 }
1471 EXPORT_SYMBOL_GPL(kvm_clear_guest);
1472 
1473 void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot,
1474 			     gfn_t gfn)
1475 {
1476 	if (memslot && memslot->dirty_bitmap) {
1477 		unsigned long rel_gfn = gfn - memslot->base_gfn;
1478 
1479 		if (!test_and_set_bit_le(rel_gfn, memslot->dirty_bitmap))
1480 			memslot->nr_dirty_pages++;
1481 	}
1482 }
1483 
1484 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
1485 {
1486 	struct kvm_memory_slot *memslot;
1487 
1488 	memslot = gfn_to_memslot(kvm, gfn);
1489 	mark_page_dirty_in_slot(kvm, memslot, gfn);
1490 }
1491 
1492 /*
1493  * The vCPU has executed a HLT instruction with in-kernel mode enabled.
1494  */
1495 void kvm_vcpu_block(struct kvm_vcpu *vcpu)
1496 {
1497 	DEFINE_WAIT(wait);
1498 
1499 	for (;;) {
1500 		prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
1501 
1502 		if (kvm_arch_vcpu_runnable(vcpu)) {
1503 			kvm_make_request(KVM_REQ_UNHALT, vcpu);
1504 			break;
1505 		}
1506 		if (kvm_cpu_has_pending_timer(vcpu))
1507 			break;
1508 		if (signal_pending(current))
1509 			break;
1510 
1511 		schedule();
1512 	}
1513 
1514 	finish_wait(&vcpu->wq, &wait);
1515 }
1516 
1517 void kvm_resched(struct kvm_vcpu *vcpu)
1518 {
1519 	if (!need_resched())
1520 		return;
1521 	cond_resched();
1522 }
1523 EXPORT_SYMBOL_GPL(kvm_resched);
1524 
1525 void kvm_vcpu_on_spin(struct kvm_vcpu *me)
1526 {
1527 	struct kvm *kvm = me->kvm;
1528 	struct kvm_vcpu *vcpu;
1529 	int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
1530 	int yielded = 0;
1531 	int pass;
1532 	int i;
1533 
1534 	/*
1535 	 * We boost the priority of a VCPU that is runnable but not
1536 	 * currently running, because it got preempted by something
1537 	 * else and called schedule in __vcpu_run.  Hopefully that
1538 	 * VCPU is holding the lock that we need and will release it.
1539 	 * We approximate round-robin by starting at the last boosted VCPU.
1540 	 */
1541 	for (pass = 0; pass < 2 && !yielded; pass++) {
1542 		kvm_for_each_vcpu(i, vcpu, kvm) {
1543 			struct task_struct *task = NULL;
1544 			struct pid *pid;
1545 			if (!pass && i < last_boosted_vcpu) {
1546 				i = last_boosted_vcpu;
1547 				continue;
1548 			} else if (pass && i > last_boosted_vcpu)
1549 				break;
1550 			if (vcpu == me)
1551 				continue;
1552 			if (waitqueue_active(&vcpu->wq))
1553 				continue;
1554 			rcu_read_lock();
1555 			pid = rcu_dereference(vcpu->pid);
1556 			if (pid)
1557 				task = get_pid_task(vcpu->pid, PIDTYPE_PID);
1558 			rcu_read_unlock();
1559 			if (!task)
1560 				continue;
1561 			if (task->flags & PF_VCPU) {
1562 				put_task_struct(task);
1563 				continue;
1564 			}
1565 			if (yield_to(task, 1)) {
1566 				put_task_struct(task);
1567 				kvm->last_boosted_vcpu = i;
1568 				yielded = 1;
1569 				break;
1570 			}
1571 			put_task_struct(task);
1572 		}
1573 	}
1574 }
1575 EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
1576 
1577 static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1578 {
1579 	struct kvm_vcpu *vcpu = vma->vm_file->private_data;
1580 	struct page *page;
1581 
1582 	if (vmf->pgoff == 0)
1583 		page = virt_to_page(vcpu->run);
1584 #ifdef CONFIG_X86
1585 	else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
1586 		page = virt_to_page(vcpu->arch.pio_data);
1587 #endif
1588 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1589 	else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
1590 		page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
1591 #endif
1592 	else
1593 		return kvm_arch_vcpu_fault(vcpu, vmf);
1594 	get_page(page);
1595 	vmf->page = page;
1596 	return 0;
1597 }
1598 
1599 static const struct vm_operations_struct kvm_vcpu_vm_ops = {
1600 	.fault = kvm_vcpu_fault,
1601 };
1602 
1603 static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
1604 {
1605 	vma->vm_ops = &kvm_vcpu_vm_ops;
1606 	return 0;
1607 }
1608 
1609 static int kvm_vcpu_release(struct inode *inode, struct file *filp)
1610 {
1611 	struct kvm_vcpu *vcpu = filp->private_data;
1612 
1613 	kvm_put_kvm(vcpu->kvm);
1614 	return 0;
1615 }
1616 
1617 static struct file_operations kvm_vcpu_fops = {
1618 	.release        = kvm_vcpu_release,
1619 	.unlocked_ioctl = kvm_vcpu_ioctl,
1620 #ifdef CONFIG_COMPAT
1621 	.compat_ioctl   = kvm_vcpu_compat_ioctl,
1622 #endif
1623 	.mmap           = kvm_vcpu_mmap,
1624 	.llseek		= noop_llseek,
1625 };
1626 
1627 /*
1628  * Allocates an inode for the vcpu.
1629  */
1630 static int create_vcpu_fd(struct kvm_vcpu *vcpu)
1631 {
1632 	return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR);
1633 }
1634 
1635 /*
1636  * Creates some virtual cpus.  Good luck creating more than one.
1637  */
1638 static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
1639 {
1640 	int r;
1641 	struct kvm_vcpu *vcpu, *v;
1642 
1643 	vcpu = kvm_arch_vcpu_create(kvm, id);
1644 	if (IS_ERR(vcpu))
1645 		return PTR_ERR(vcpu);
1646 
1647 	preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
1648 
1649 	r = kvm_arch_vcpu_setup(vcpu);
1650 	if (r)
1651 		goto vcpu_destroy;
1652 
1653 	mutex_lock(&kvm->lock);
1654 	if (!kvm_vcpu_compatible(vcpu)) {
1655 		r = -EINVAL;
1656 		goto unlock_vcpu_destroy;
1657 	}
1658 	if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
1659 		r = -EINVAL;
1660 		goto unlock_vcpu_destroy;
1661 	}
1662 
1663 	kvm_for_each_vcpu(r, v, kvm)
1664 		if (v->vcpu_id == id) {
1665 			r = -EEXIST;
1666 			goto unlock_vcpu_destroy;
1667 		}
1668 
1669 	BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
1670 
1671 	/* Now it's all set up, let userspace reach it */
1672 	kvm_get_kvm(kvm);
1673 	r = create_vcpu_fd(vcpu);
1674 	if (r < 0) {
1675 		kvm_put_kvm(kvm);
1676 		goto unlock_vcpu_destroy;
1677 	}
1678 
1679 	kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
1680 	smp_wmb();
1681 	atomic_inc(&kvm->online_vcpus);
1682 
1683 	mutex_unlock(&kvm->lock);
1684 	return r;
1685 
1686 unlock_vcpu_destroy:
1687 	mutex_unlock(&kvm->lock);
1688 vcpu_destroy:
1689 	kvm_arch_vcpu_destroy(vcpu);
1690 	return r;
1691 }
1692 
1693 static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
1694 {
1695 	if (sigset) {
1696 		sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
1697 		vcpu->sigset_active = 1;
1698 		vcpu->sigset = *sigset;
1699 	} else
1700 		vcpu->sigset_active = 0;
1701 	return 0;
1702 }
1703 
1704 static long kvm_vcpu_ioctl(struct file *filp,
1705 			   unsigned int ioctl, unsigned long arg)
1706 {
1707 	struct kvm_vcpu *vcpu = filp->private_data;
1708 	void __user *argp = (void __user *)arg;
1709 	int r;
1710 	struct kvm_fpu *fpu = NULL;
1711 	struct kvm_sregs *kvm_sregs = NULL;
1712 
1713 	if (vcpu->kvm->mm != current->mm)
1714 		return -EIO;
1715 
1716 #if defined(CONFIG_S390) || defined(CONFIG_PPC)
1717 	/*
1718 	 * Special cases: vcpu ioctls that are asynchronous to vcpu execution,
1719 	 * so vcpu_load() would break it.
1720 	 */
1721 	if (ioctl == KVM_S390_INTERRUPT || ioctl == KVM_INTERRUPT)
1722 		return kvm_arch_vcpu_ioctl(filp, ioctl, arg);
1723 #endif
1724 
1725 
1726 	vcpu_load(vcpu);
1727 	switch (ioctl) {
1728 	case KVM_RUN:
1729 		r = -EINVAL;
1730 		if (arg)
1731 			goto out;
1732 		r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
1733 		trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
1734 		break;
1735 	case KVM_GET_REGS: {
1736 		struct kvm_regs *kvm_regs;
1737 
1738 		r = -ENOMEM;
1739 		kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
1740 		if (!kvm_regs)
1741 			goto out;
1742 		r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
1743 		if (r)
1744 			goto out_free1;
1745 		r = -EFAULT;
1746 		if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
1747 			goto out_free1;
1748 		r = 0;
1749 out_free1:
1750 		kfree(kvm_regs);
1751 		break;
1752 	}
1753 	case KVM_SET_REGS: {
1754 		struct kvm_regs *kvm_regs;
1755 
1756 		r = -ENOMEM;
1757 		kvm_regs = memdup_user(argp, sizeof(*kvm_regs));
1758 		if (IS_ERR(kvm_regs)) {
1759 			r = PTR_ERR(kvm_regs);
1760 			goto out;
1761 		}
1762 		r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
1763 		if (r)
1764 			goto out_free2;
1765 		r = 0;
1766 out_free2:
1767 		kfree(kvm_regs);
1768 		break;
1769 	}
1770 	case KVM_GET_SREGS: {
1771 		kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
1772 		r = -ENOMEM;
1773 		if (!kvm_sregs)
1774 			goto out;
1775 		r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs);
1776 		if (r)
1777 			goto out;
1778 		r = -EFAULT;
1779 		if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs)))
1780 			goto out;
1781 		r = 0;
1782 		break;
1783 	}
1784 	case KVM_SET_SREGS: {
1785 		kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs));
1786 		if (IS_ERR(kvm_sregs)) {
1787 			r = PTR_ERR(kvm_sregs);
1788 			goto out;
1789 		}
1790 		r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs);
1791 		if (r)
1792 			goto out;
1793 		r = 0;
1794 		break;
1795 	}
1796 	case KVM_GET_MP_STATE: {
1797 		struct kvm_mp_state mp_state;
1798 
1799 		r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
1800 		if (r)
1801 			goto out;
1802 		r = -EFAULT;
1803 		if (copy_to_user(argp, &mp_state, sizeof mp_state))
1804 			goto out;
1805 		r = 0;
1806 		break;
1807 	}
1808 	case KVM_SET_MP_STATE: {
1809 		struct kvm_mp_state mp_state;
1810 
1811 		r = -EFAULT;
1812 		if (copy_from_user(&mp_state, argp, sizeof mp_state))
1813 			goto out;
1814 		r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
1815 		if (r)
1816 			goto out;
1817 		r = 0;
1818 		break;
1819 	}
1820 	case KVM_TRANSLATE: {
1821 		struct kvm_translation tr;
1822 
1823 		r = -EFAULT;
1824 		if (copy_from_user(&tr, argp, sizeof tr))
1825 			goto out;
1826 		r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
1827 		if (r)
1828 			goto out;
1829 		r = -EFAULT;
1830 		if (copy_to_user(argp, &tr, sizeof tr))
1831 			goto out;
1832 		r = 0;
1833 		break;
1834 	}
1835 	case KVM_SET_GUEST_DEBUG: {
1836 		struct kvm_guest_debug dbg;
1837 
1838 		r = -EFAULT;
1839 		if (copy_from_user(&dbg, argp, sizeof dbg))
1840 			goto out;
1841 		r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg);
1842 		if (r)
1843 			goto out;
1844 		r = 0;
1845 		break;
1846 	}
1847 	case KVM_SET_SIGNAL_MASK: {
1848 		struct kvm_signal_mask __user *sigmask_arg = argp;
1849 		struct kvm_signal_mask kvm_sigmask;
1850 		sigset_t sigset, *p;
1851 
1852 		p = NULL;
1853 		if (argp) {
1854 			r = -EFAULT;
1855 			if (copy_from_user(&kvm_sigmask, argp,
1856 					   sizeof kvm_sigmask))
1857 				goto out;
1858 			r = -EINVAL;
1859 			if (kvm_sigmask.len != sizeof sigset)
1860 				goto out;
1861 			r = -EFAULT;
1862 			if (copy_from_user(&sigset, sigmask_arg->sigset,
1863 					   sizeof sigset))
1864 				goto out;
1865 			p = &sigset;
1866 		}
1867 		r = kvm_vcpu_ioctl_set_sigmask(vcpu, p);
1868 		break;
1869 	}
1870 	case KVM_GET_FPU: {
1871 		fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
1872 		r = -ENOMEM;
1873 		if (!fpu)
1874 			goto out;
1875 		r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
1876 		if (r)
1877 			goto out;
1878 		r = -EFAULT;
1879 		if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu)))
1880 			goto out;
1881 		r = 0;
1882 		break;
1883 	}
1884 	case KVM_SET_FPU: {
1885 		fpu = memdup_user(argp, sizeof(*fpu));
1886 		if (IS_ERR(fpu)) {
1887 			r = PTR_ERR(fpu);
1888 			goto out;
1889 		}
1890 		r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
1891 		if (r)
1892 			goto out;
1893 		r = 0;
1894 		break;
1895 	}
1896 	default:
1897 		r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
1898 	}
1899 out:
1900 	vcpu_put(vcpu);
1901 	kfree(fpu);
1902 	kfree(kvm_sregs);
1903 	return r;
1904 }
1905 
1906 #ifdef CONFIG_COMPAT
1907 static long kvm_vcpu_compat_ioctl(struct file *filp,
1908 				  unsigned int ioctl, unsigned long arg)
1909 {
1910 	struct kvm_vcpu *vcpu = filp->private_data;
1911 	void __user *argp = compat_ptr(arg);
1912 	int r;
1913 
1914 	if (vcpu->kvm->mm != current->mm)
1915 		return -EIO;
1916 
1917 	switch (ioctl) {
1918 	case KVM_SET_SIGNAL_MASK: {
1919 		struct kvm_signal_mask __user *sigmask_arg = argp;
1920 		struct kvm_signal_mask kvm_sigmask;
1921 		compat_sigset_t csigset;
1922 		sigset_t sigset;
1923 
1924 		if (argp) {
1925 			r = -EFAULT;
1926 			if (copy_from_user(&kvm_sigmask, argp,
1927 					   sizeof kvm_sigmask))
1928 				goto out;
1929 			r = -EINVAL;
1930 			if (kvm_sigmask.len != sizeof csigset)
1931 				goto out;
1932 			r = -EFAULT;
1933 			if (copy_from_user(&csigset, sigmask_arg->sigset,
1934 					   sizeof csigset))
1935 				goto out;
1936 		}
1937 		sigset_from_compat(&sigset, &csigset);
1938 		r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
1939 		break;
1940 	}
1941 	default:
1942 		r = kvm_vcpu_ioctl(filp, ioctl, arg);
1943 	}
1944 
1945 out:
1946 	return r;
1947 }
1948 #endif
1949 
1950 static long kvm_vm_ioctl(struct file *filp,
1951 			   unsigned int ioctl, unsigned long arg)
1952 {
1953 	struct kvm *kvm = filp->private_data;
1954 	void __user *argp = (void __user *)arg;
1955 	int r;
1956 
1957 	if (kvm->mm != current->mm)
1958 		return -EIO;
1959 	switch (ioctl) {
1960 	case KVM_CREATE_VCPU:
1961 		r = kvm_vm_ioctl_create_vcpu(kvm, arg);
1962 		if (r < 0)
1963 			goto out;
1964 		break;
1965 	case KVM_SET_USER_MEMORY_REGION: {
1966 		struct kvm_userspace_memory_region kvm_userspace_mem;
1967 
1968 		r = -EFAULT;
1969 		if (copy_from_user(&kvm_userspace_mem, argp,
1970 						sizeof kvm_userspace_mem))
1971 			goto out;
1972 
1973 		r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem, 1);
1974 		if (r)
1975 			goto out;
1976 		break;
1977 	}
1978 	case KVM_GET_DIRTY_LOG: {
1979 		struct kvm_dirty_log log;
1980 
1981 		r = -EFAULT;
1982 		if (copy_from_user(&log, argp, sizeof log))
1983 			goto out;
1984 		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
1985 		if (r)
1986 			goto out;
1987 		break;
1988 	}
1989 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1990 	case KVM_REGISTER_COALESCED_MMIO: {
1991 		struct kvm_coalesced_mmio_zone zone;
1992 		r = -EFAULT;
1993 		if (copy_from_user(&zone, argp, sizeof zone))
1994 			goto out;
1995 		r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
1996 		if (r)
1997 			goto out;
1998 		r = 0;
1999 		break;
2000 	}
2001 	case KVM_UNREGISTER_COALESCED_MMIO: {
2002 		struct kvm_coalesced_mmio_zone zone;
2003 		r = -EFAULT;
2004 		if (copy_from_user(&zone, argp, sizeof zone))
2005 			goto out;
2006 		r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
2007 		if (r)
2008 			goto out;
2009 		r = 0;
2010 		break;
2011 	}
2012 #endif
2013 	case KVM_IRQFD: {
2014 		struct kvm_irqfd data;
2015 
2016 		r = -EFAULT;
2017 		if (copy_from_user(&data, argp, sizeof data))
2018 			goto out;
2019 		r = kvm_irqfd(kvm, data.fd, data.gsi, data.flags);
2020 		break;
2021 	}
2022 	case KVM_IOEVENTFD: {
2023 		struct kvm_ioeventfd data;
2024 
2025 		r = -EFAULT;
2026 		if (copy_from_user(&data, argp, sizeof data))
2027 			goto out;
2028 		r = kvm_ioeventfd(kvm, &data);
2029 		break;
2030 	}
2031 #ifdef CONFIG_KVM_APIC_ARCHITECTURE
2032 	case KVM_SET_BOOT_CPU_ID:
2033 		r = 0;
2034 		mutex_lock(&kvm->lock);
2035 		if (atomic_read(&kvm->online_vcpus) != 0)
2036 			r = -EBUSY;
2037 		else
2038 			kvm->bsp_vcpu_id = arg;
2039 		mutex_unlock(&kvm->lock);
2040 		break;
2041 #endif
2042 	default:
2043 		r = kvm_arch_vm_ioctl(filp, ioctl, arg);
2044 		if (r == -ENOTTY)
2045 			r = kvm_vm_ioctl_assigned_device(kvm, ioctl, arg);
2046 	}
2047 out:
2048 	return r;
2049 }
2050 
2051 #ifdef CONFIG_COMPAT
2052 struct compat_kvm_dirty_log {
2053 	__u32 slot;
2054 	__u32 padding1;
2055 	union {
2056 		compat_uptr_t dirty_bitmap; /* one bit per page */
2057 		__u64 padding2;
2058 	};
2059 };
2060 
2061 static long kvm_vm_compat_ioctl(struct file *filp,
2062 			   unsigned int ioctl, unsigned long arg)
2063 {
2064 	struct kvm *kvm = filp->private_data;
2065 	int r;
2066 
2067 	if (kvm->mm != current->mm)
2068 		return -EIO;
2069 	switch (ioctl) {
2070 	case KVM_GET_DIRTY_LOG: {
2071 		struct compat_kvm_dirty_log compat_log;
2072 		struct kvm_dirty_log log;
2073 
2074 		r = -EFAULT;
2075 		if (copy_from_user(&compat_log, (void __user *)arg,
2076 				   sizeof(compat_log)))
2077 			goto out;
2078 		log.slot	 = compat_log.slot;
2079 		log.padding1	 = compat_log.padding1;
2080 		log.padding2	 = compat_log.padding2;
2081 		log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
2082 
2083 		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
2084 		if (r)
2085 			goto out;
2086 		break;
2087 	}
2088 	default:
2089 		r = kvm_vm_ioctl(filp, ioctl, arg);
2090 	}
2091 
2092 out:
2093 	return r;
2094 }
2095 #endif
2096 
2097 static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
2098 {
2099 	struct page *page[1];
2100 	unsigned long addr;
2101 	int npages;
2102 	gfn_t gfn = vmf->pgoff;
2103 	struct kvm *kvm = vma->vm_file->private_data;
2104 
2105 	addr = gfn_to_hva(kvm, gfn);
2106 	if (kvm_is_error_hva(addr))
2107 		return VM_FAULT_SIGBUS;
2108 
2109 	npages = get_user_pages(current, current->mm, addr, 1, 1, 0, page,
2110 				NULL);
2111 	if (unlikely(npages != 1))
2112 		return VM_FAULT_SIGBUS;
2113 
2114 	vmf->page = page[0];
2115 	return 0;
2116 }
2117 
2118 static const struct vm_operations_struct kvm_vm_vm_ops = {
2119 	.fault = kvm_vm_fault,
2120 };
2121 
2122 static int kvm_vm_mmap(struct file *file, struct vm_area_struct *vma)
2123 {
2124 	vma->vm_ops = &kvm_vm_vm_ops;
2125 	return 0;
2126 }
2127 
2128 static struct file_operations kvm_vm_fops = {
2129 	.release        = kvm_vm_release,
2130 	.unlocked_ioctl = kvm_vm_ioctl,
2131 #ifdef CONFIG_COMPAT
2132 	.compat_ioctl   = kvm_vm_compat_ioctl,
2133 #endif
2134 	.mmap           = kvm_vm_mmap,
2135 	.llseek		= noop_llseek,
2136 };
2137 
2138 static int kvm_dev_ioctl_create_vm(unsigned long type)
2139 {
2140 	int r;
2141 	struct kvm *kvm;
2142 
2143 	kvm = kvm_create_vm(type);
2144 	if (IS_ERR(kvm))
2145 		return PTR_ERR(kvm);
2146 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2147 	r = kvm_coalesced_mmio_init(kvm);
2148 	if (r < 0) {
2149 		kvm_put_kvm(kvm);
2150 		return r;
2151 	}
2152 #endif
2153 	r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
2154 	if (r < 0)
2155 		kvm_put_kvm(kvm);
2156 
2157 	return r;
2158 }
2159 
2160 static long kvm_dev_ioctl_check_extension_generic(long arg)
2161 {
2162 	switch (arg) {
2163 	case KVM_CAP_USER_MEMORY:
2164 	case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
2165 	case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
2166 #ifdef CONFIG_KVM_APIC_ARCHITECTURE
2167 	case KVM_CAP_SET_BOOT_CPU_ID:
2168 #endif
2169 	case KVM_CAP_INTERNAL_ERROR_DATA:
2170 		return 1;
2171 #ifdef CONFIG_HAVE_KVM_IRQCHIP
2172 	case KVM_CAP_IRQ_ROUTING:
2173 		return KVM_MAX_IRQ_ROUTES;
2174 #endif
2175 	default:
2176 		break;
2177 	}
2178 	return kvm_dev_ioctl_check_extension(arg);
2179 }
2180 
2181 static long kvm_dev_ioctl(struct file *filp,
2182 			  unsigned int ioctl, unsigned long arg)
2183 {
2184 	long r = -EINVAL;
2185 
2186 	switch (ioctl) {
2187 	case KVM_GET_API_VERSION:
2188 		r = -EINVAL;
2189 		if (arg)
2190 			goto out;
2191 		r = KVM_API_VERSION;
2192 		break;
2193 	case KVM_CREATE_VM:
2194 		r = kvm_dev_ioctl_create_vm(arg);
2195 		break;
2196 	case KVM_CHECK_EXTENSION:
2197 		r = kvm_dev_ioctl_check_extension_generic(arg);
2198 		break;
2199 	case KVM_GET_VCPU_MMAP_SIZE:
2200 		r = -EINVAL;
2201 		if (arg)
2202 			goto out;
2203 		r = PAGE_SIZE;     /* struct kvm_run */
2204 #ifdef CONFIG_X86
2205 		r += PAGE_SIZE;    /* pio data page */
2206 #endif
2207 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2208 		r += PAGE_SIZE;    /* coalesced mmio ring page */
2209 #endif
2210 		break;
2211 	case KVM_TRACE_ENABLE:
2212 	case KVM_TRACE_PAUSE:
2213 	case KVM_TRACE_DISABLE:
2214 		r = -EOPNOTSUPP;
2215 		break;
2216 	default:
2217 		return kvm_arch_dev_ioctl(filp, ioctl, arg);
2218 	}
2219 out:
2220 	return r;
2221 }
2222 
2223 static struct file_operations kvm_chardev_ops = {
2224 	.unlocked_ioctl = kvm_dev_ioctl,
2225 	.compat_ioctl   = kvm_dev_ioctl,
2226 	.llseek		= noop_llseek,
2227 };
2228 
2229 static struct miscdevice kvm_dev = {
2230 	KVM_MINOR,
2231 	"kvm",
2232 	&kvm_chardev_ops,
2233 };
2234 
2235 static void hardware_enable_nolock(void *junk)
2236 {
2237 	int cpu = raw_smp_processor_id();
2238 	int r;
2239 
2240 	if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
2241 		return;
2242 
2243 	cpumask_set_cpu(cpu, cpus_hardware_enabled);
2244 
2245 	r = kvm_arch_hardware_enable(NULL);
2246 
2247 	if (r) {
2248 		cpumask_clear_cpu(cpu, cpus_hardware_enabled);
2249 		atomic_inc(&hardware_enable_failed);
2250 		printk(KERN_INFO "kvm: enabling virtualization on "
2251 				 "CPU%d failed\n", cpu);
2252 	}
2253 }
2254 
2255 static void hardware_enable(void *junk)
2256 {
2257 	raw_spin_lock(&kvm_lock);
2258 	hardware_enable_nolock(junk);
2259 	raw_spin_unlock(&kvm_lock);
2260 }
2261 
2262 static void hardware_disable_nolock(void *junk)
2263 {
2264 	int cpu = raw_smp_processor_id();
2265 
2266 	if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
2267 		return;
2268 	cpumask_clear_cpu(cpu, cpus_hardware_enabled);
2269 	kvm_arch_hardware_disable(NULL);
2270 }
2271 
2272 static void hardware_disable(void *junk)
2273 {
2274 	raw_spin_lock(&kvm_lock);
2275 	hardware_disable_nolock(junk);
2276 	raw_spin_unlock(&kvm_lock);
2277 }
2278 
2279 static void hardware_disable_all_nolock(void)
2280 {
2281 	BUG_ON(!kvm_usage_count);
2282 
2283 	kvm_usage_count--;
2284 	if (!kvm_usage_count)
2285 		on_each_cpu(hardware_disable_nolock, NULL, 1);
2286 }
2287 
2288 static void hardware_disable_all(void)
2289 {
2290 	raw_spin_lock(&kvm_lock);
2291 	hardware_disable_all_nolock();
2292 	raw_spin_unlock(&kvm_lock);
2293 }
2294 
2295 static int hardware_enable_all(void)
2296 {
2297 	int r = 0;
2298 
2299 	raw_spin_lock(&kvm_lock);
2300 
2301 	kvm_usage_count++;
2302 	if (kvm_usage_count == 1) {
2303 		atomic_set(&hardware_enable_failed, 0);
2304 		on_each_cpu(hardware_enable_nolock, NULL, 1);
2305 
2306 		if (atomic_read(&hardware_enable_failed)) {
2307 			hardware_disable_all_nolock();
2308 			r = -EBUSY;
2309 		}
2310 	}
2311 
2312 	raw_spin_unlock(&kvm_lock);
2313 
2314 	return r;
2315 }
2316 
2317 static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
2318 			   void *v)
2319 {
2320 	int cpu = (long)v;
2321 
2322 	if (!kvm_usage_count)
2323 		return NOTIFY_OK;
2324 
2325 	val &= ~CPU_TASKS_FROZEN;
2326 	switch (val) {
2327 	case CPU_DYING:
2328 		printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
2329 		       cpu);
2330 		hardware_disable(NULL);
2331 		break;
2332 	case CPU_STARTING:
2333 		printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
2334 		       cpu);
2335 		hardware_enable(NULL);
2336 		break;
2337 	}
2338 	return NOTIFY_OK;
2339 }
2340 
2341 
2342 asmlinkage void kvm_spurious_fault(void)
2343 {
2344 	/* Fault while not rebooting.  We want the trace. */
2345 	BUG();
2346 }
2347 EXPORT_SYMBOL_GPL(kvm_spurious_fault);
2348 
2349 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
2350 		      void *v)
2351 {
2352 	/*
2353 	 * Some (well, at least mine) BIOSes hang on reboot if
2354 	 * in vmx root mode.
2355 	 *
2356 	 * And Intel TXT required VMX off for all cpu when system shutdown.
2357 	 */
2358 	printk(KERN_INFO "kvm: exiting hardware virtualization\n");
2359 	kvm_rebooting = true;
2360 	on_each_cpu(hardware_disable_nolock, NULL, 1);
2361 	return NOTIFY_OK;
2362 }
2363 
2364 static struct notifier_block kvm_reboot_notifier = {
2365 	.notifier_call = kvm_reboot,
2366 	.priority = 0,
2367 };
2368 
2369 static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
2370 {
2371 	int i;
2372 
2373 	for (i = 0; i < bus->dev_count; i++) {
2374 		struct kvm_io_device *pos = bus->range[i].dev;
2375 
2376 		kvm_iodevice_destructor(pos);
2377 	}
2378 	kfree(bus);
2379 }
2380 
2381 int kvm_io_bus_sort_cmp(const void *p1, const void *p2)
2382 {
2383 	const struct kvm_io_range *r1 = p1;
2384 	const struct kvm_io_range *r2 = p2;
2385 
2386 	if (r1->addr < r2->addr)
2387 		return -1;
2388 	if (r1->addr + r1->len > r2->addr + r2->len)
2389 		return 1;
2390 	return 0;
2391 }
2392 
2393 int kvm_io_bus_insert_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev,
2394 			  gpa_t addr, int len)
2395 {
2396 	if (bus->dev_count == NR_IOBUS_DEVS)
2397 		return -ENOSPC;
2398 
2399 	bus->range[bus->dev_count++] = (struct kvm_io_range) {
2400 		.addr = addr,
2401 		.len = len,
2402 		.dev = dev,
2403 	};
2404 
2405 	sort(bus->range, bus->dev_count, sizeof(struct kvm_io_range),
2406 		kvm_io_bus_sort_cmp, NULL);
2407 
2408 	return 0;
2409 }
2410 
2411 int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus,
2412 			     gpa_t addr, int len)
2413 {
2414 	struct kvm_io_range *range, key;
2415 	int off;
2416 
2417 	key = (struct kvm_io_range) {
2418 		.addr = addr,
2419 		.len = len,
2420 	};
2421 
2422 	range = bsearch(&key, bus->range, bus->dev_count,
2423 			sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp);
2424 	if (range == NULL)
2425 		return -ENOENT;
2426 
2427 	off = range - bus->range;
2428 
2429 	while (off > 0 && kvm_io_bus_sort_cmp(&key, &bus->range[off-1]) == 0)
2430 		off--;
2431 
2432 	return off;
2433 }
2434 
2435 /* kvm_io_bus_write - called under kvm->slots_lock */
2436 int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
2437 		     int len, const void *val)
2438 {
2439 	int idx;
2440 	struct kvm_io_bus *bus;
2441 	struct kvm_io_range range;
2442 
2443 	range = (struct kvm_io_range) {
2444 		.addr = addr,
2445 		.len = len,
2446 	};
2447 
2448 	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
2449 	idx = kvm_io_bus_get_first_dev(bus, addr, len);
2450 	if (idx < 0)
2451 		return -EOPNOTSUPP;
2452 
2453 	while (idx < bus->dev_count &&
2454 		kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) {
2455 		if (!kvm_iodevice_write(bus->range[idx].dev, addr, len, val))
2456 			return 0;
2457 		idx++;
2458 	}
2459 
2460 	return -EOPNOTSUPP;
2461 }
2462 
2463 /* kvm_io_bus_read - called under kvm->slots_lock */
2464 int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
2465 		    int len, void *val)
2466 {
2467 	int idx;
2468 	struct kvm_io_bus *bus;
2469 	struct kvm_io_range range;
2470 
2471 	range = (struct kvm_io_range) {
2472 		.addr = addr,
2473 		.len = len,
2474 	};
2475 
2476 	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
2477 	idx = kvm_io_bus_get_first_dev(bus, addr, len);
2478 	if (idx < 0)
2479 		return -EOPNOTSUPP;
2480 
2481 	while (idx < bus->dev_count &&
2482 		kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) {
2483 		if (!kvm_iodevice_read(bus->range[idx].dev, addr, len, val))
2484 			return 0;
2485 		idx++;
2486 	}
2487 
2488 	return -EOPNOTSUPP;
2489 }
2490 
2491 /* Caller must hold slots_lock. */
2492 int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
2493 			    int len, struct kvm_io_device *dev)
2494 {
2495 	struct kvm_io_bus *new_bus, *bus;
2496 
2497 	bus = kvm->buses[bus_idx];
2498 	if (bus->dev_count > NR_IOBUS_DEVS-1)
2499 		return -ENOSPC;
2500 
2501 	new_bus = kmemdup(bus, sizeof(struct kvm_io_bus), GFP_KERNEL);
2502 	if (!new_bus)
2503 		return -ENOMEM;
2504 	kvm_io_bus_insert_dev(new_bus, dev, addr, len);
2505 	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
2506 	synchronize_srcu_expedited(&kvm->srcu);
2507 	kfree(bus);
2508 
2509 	return 0;
2510 }
2511 
2512 /* Caller must hold slots_lock. */
2513 int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
2514 			      struct kvm_io_device *dev)
2515 {
2516 	int i, r;
2517 	struct kvm_io_bus *new_bus, *bus;
2518 
2519 	bus = kvm->buses[bus_idx];
2520 
2521 	new_bus = kmemdup(bus, sizeof(*bus), GFP_KERNEL);
2522 	if (!new_bus)
2523 		return -ENOMEM;
2524 
2525 	r = -ENOENT;
2526 	for (i = 0; i < new_bus->dev_count; i++)
2527 		if (new_bus->range[i].dev == dev) {
2528 			r = 0;
2529 			new_bus->dev_count--;
2530 			new_bus->range[i] = new_bus->range[new_bus->dev_count];
2531 			sort(new_bus->range, new_bus->dev_count,
2532 			     sizeof(struct kvm_io_range),
2533 			     kvm_io_bus_sort_cmp, NULL);
2534 			break;
2535 		}
2536 
2537 	if (r) {
2538 		kfree(new_bus);
2539 		return r;
2540 	}
2541 
2542 	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
2543 	synchronize_srcu_expedited(&kvm->srcu);
2544 	kfree(bus);
2545 	return r;
2546 }
2547 
2548 static struct notifier_block kvm_cpu_notifier = {
2549 	.notifier_call = kvm_cpu_hotplug,
2550 };
2551 
2552 static int vm_stat_get(void *_offset, u64 *val)
2553 {
2554 	unsigned offset = (long)_offset;
2555 	struct kvm *kvm;
2556 
2557 	*val = 0;
2558 	raw_spin_lock(&kvm_lock);
2559 	list_for_each_entry(kvm, &vm_list, vm_list)
2560 		*val += *(u32 *)((void *)kvm + offset);
2561 	raw_spin_unlock(&kvm_lock);
2562 	return 0;
2563 }
2564 
2565 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
2566 
2567 static int vcpu_stat_get(void *_offset, u64 *val)
2568 {
2569 	unsigned offset = (long)_offset;
2570 	struct kvm *kvm;
2571 	struct kvm_vcpu *vcpu;
2572 	int i;
2573 
2574 	*val = 0;
2575 	raw_spin_lock(&kvm_lock);
2576 	list_for_each_entry(kvm, &vm_list, vm_list)
2577 		kvm_for_each_vcpu(i, vcpu, kvm)
2578 			*val += *(u32 *)((void *)vcpu + offset);
2579 
2580 	raw_spin_unlock(&kvm_lock);
2581 	return 0;
2582 }
2583 
2584 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
2585 
2586 static const struct file_operations *stat_fops[] = {
2587 	[KVM_STAT_VCPU] = &vcpu_stat_fops,
2588 	[KVM_STAT_VM]   = &vm_stat_fops,
2589 };
2590 
2591 static int kvm_init_debug(void)
2592 {
2593 	int r = -EFAULT;
2594 	struct kvm_stats_debugfs_item *p;
2595 
2596 	kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
2597 	if (kvm_debugfs_dir == NULL)
2598 		goto out;
2599 
2600 	for (p = debugfs_entries; p->name; ++p) {
2601 		p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
2602 						(void *)(long)p->offset,
2603 						stat_fops[p->kind]);
2604 		if (p->dentry == NULL)
2605 			goto out_dir;
2606 	}
2607 
2608 	return 0;
2609 
2610 out_dir:
2611 	debugfs_remove_recursive(kvm_debugfs_dir);
2612 out:
2613 	return r;
2614 }
2615 
2616 static void kvm_exit_debug(void)
2617 {
2618 	struct kvm_stats_debugfs_item *p;
2619 
2620 	for (p = debugfs_entries; p->name; ++p)
2621 		debugfs_remove(p->dentry);
2622 	debugfs_remove(kvm_debugfs_dir);
2623 }
2624 
2625 static int kvm_suspend(void)
2626 {
2627 	if (kvm_usage_count)
2628 		hardware_disable_nolock(NULL);
2629 	return 0;
2630 }
2631 
2632 static void kvm_resume(void)
2633 {
2634 	if (kvm_usage_count) {
2635 		WARN_ON(raw_spin_is_locked(&kvm_lock));
2636 		hardware_enable_nolock(NULL);
2637 	}
2638 }
2639 
2640 static struct syscore_ops kvm_syscore_ops = {
2641 	.suspend = kvm_suspend,
2642 	.resume = kvm_resume,
2643 };
2644 
2645 struct page *bad_page;
2646 pfn_t bad_pfn;
2647 
2648 static inline
2649 struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
2650 {
2651 	return container_of(pn, struct kvm_vcpu, preempt_notifier);
2652 }
2653 
2654 static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
2655 {
2656 	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
2657 
2658 	kvm_arch_vcpu_load(vcpu, cpu);
2659 }
2660 
2661 static void kvm_sched_out(struct preempt_notifier *pn,
2662 			  struct task_struct *next)
2663 {
2664 	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
2665 
2666 	kvm_arch_vcpu_put(vcpu);
2667 }
2668 
2669 int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
2670 		  struct module *module)
2671 {
2672 	int r;
2673 	int cpu;
2674 
2675 	r = kvm_arch_init(opaque);
2676 	if (r)
2677 		goto out_fail;
2678 
2679 	bad_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
2680 
2681 	if (bad_page == NULL) {
2682 		r = -ENOMEM;
2683 		goto out;
2684 	}
2685 
2686 	bad_pfn = page_to_pfn(bad_page);
2687 
2688 	hwpoison_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
2689 
2690 	if (hwpoison_page == NULL) {
2691 		r = -ENOMEM;
2692 		goto out_free_0;
2693 	}
2694 
2695 	hwpoison_pfn = page_to_pfn(hwpoison_page);
2696 
2697 	fault_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
2698 
2699 	if (fault_page == NULL) {
2700 		r = -ENOMEM;
2701 		goto out_free_0;
2702 	}
2703 
2704 	fault_pfn = page_to_pfn(fault_page);
2705 
2706 	if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
2707 		r = -ENOMEM;
2708 		goto out_free_0;
2709 	}
2710 
2711 	r = kvm_arch_hardware_setup();
2712 	if (r < 0)
2713 		goto out_free_0a;
2714 
2715 	for_each_online_cpu(cpu) {
2716 		smp_call_function_single(cpu,
2717 				kvm_arch_check_processor_compat,
2718 				&r, 1);
2719 		if (r < 0)
2720 			goto out_free_1;
2721 	}
2722 
2723 	r = register_cpu_notifier(&kvm_cpu_notifier);
2724 	if (r)
2725 		goto out_free_2;
2726 	register_reboot_notifier(&kvm_reboot_notifier);
2727 
2728 	/* A kmem cache lets us meet the alignment requirements of fx_save. */
2729 	if (!vcpu_align)
2730 		vcpu_align = __alignof__(struct kvm_vcpu);
2731 	kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size, vcpu_align,
2732 					   0, NULL);
2733 	if (!kvm_vcpu_cache) {
2734 		r = -ENOMEM;
2735 		goto out_free_3;
2736 	}
2737 
2738 	r = kvm_async_pf_init();
2739 	if (r)
2740 		goto out_free;
2741 
2742 	kvm_chardev_ops.owner = module;
2743 	kvm_vm_fops.owner = module;
2744 	kvm_vcpu_fops.owner = module;
2745 
2746 	r = misc_register(&kvm_dev);
2747 	if (r) {
2748 		printk(KERN_ERR "kvm: misc device register failed\n");
2749 		goto out_unreg;
2750 	}
2751 
2752 	register_syscore_ops(&kvm_syscore_ops);
2753 
2754 	kvm_preempt_ops.sched_in = kvm_sched_in;
2755 	kvm_preempt_ops.sched_out = kvm_sched_out;
2756 
2757 	r = kvm_init_debug();
2758 	if (r) {
2759 		printk(KERN_ERR "kvm: create debugfs files failed\n");
2760 		goto out_undebugfs;
2761 	}
2762 
2763 	return 0;
2764 
2765 out_undebugfs:
2766 	unregister_syscore_ops(&kvm_syscore_ops);
2767 out_unreg:
2768 	kvm_async_pf_deinit();
2769 out_free:
2770 	kmem_cache_destroy(kvm_vcpu_cache);
2771 out_free_3:
2772 	unregister_reboot_notifier(&kvm_reboot_notifier);
2773 	unregister_cpu_notifier(&kvm_cpu_notifier);
2774 out_free_2:
2775 out_free_1:
2776 	kvm_arch_hardware_unsetup();
2777 out_free_0a:
2778 	free_cpumask_var(cpus_hardware_enabled);
2779 out_free_0:
2780 	if (fault_page)
2781 		__free_page(fault_page);
2782 	if (hwpoison_page)
2783 		__free_page(hwpoison_page);
2784 	__free_page(bad_page);
2785 out:
2786 	kvm_arch_exit();
2787 out_fail:
2788 	return r;
2789 }
2790 EXPORT_SYMBOL_GPL(kvm_init);
2791 
2792 void kvm_exit(void)
2793 {
2794 	kvm_exit_debug();
2795 	misc_deregister(&kvm_dev);
2796 	kmem_cache_destroy(kvm_vcpu_cache);
2797 	kvm_async_pf_deinit();
2798 	unregister_syscore_ops(&kvm_syscore_ops);
2799 	unregister_reboot_notifier(&kvm_reboot_notifier);
2800 	unregister_cpu_notifier(&kvm_cpu_notifier);
2801 	on_each_cpu(hardware_disable_nolock, NULL, 1);
2802 	kvm_arch_hardware_unsetup();
2803 	kvm_arch_exit();
2804 	free_cpumask_var(cpus_hardware_enabled);
2805 	__free_page(hwpoison_page);
2806 	__free_page(bad_page);
2807 }
2808 EXPORT_SYMBOL_GPL(kvm_exit);
2809