xref: /openbmc/linux/virt/kvm/kvm_main.c (revision 5b1f6d81e4c63ae30d92678cc35081001add7674)
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);
526 	else
527 		kfree(memslot->dirty_bitmap);
528 
529 	memslot->dirty_bitmap = NULL;
530 }
531 
532 /*
533  * Free any memory in @free but not in @dont.
534  */
535 static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
536 				  struct kvm_memory_slot *dont)
537 {
538 	if (!dont || free->rmap != dont->rmap)
539 		vfree(free->rmap);
540 
541 	if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
542 		kvm_destroy_dirty_bitmap(free);
543 
544 	kvm_arch_free_memslot(free, dont);
545 
546 	free->npages = 0;
547 	free->rmap = NULL;
548 }
549 
550 void kvm_free_physmem(struct kvm *kvm)
551 {
552 	struct kvm_memslots *slots = kvm->memslots;
553 	struct kvm_memory_slot *memslot;
554 
555 	kvm_for_each_memslot(memslot, slots)
556 		kvm_free_physmem_slot(memslot, NULL);
557 
558 	kfree(kvm->memslots);
559 }
560 
561 static void kvm_destroy_vm(struct kvm *kvm)
562 {
563 	int i;
564 	struct mm_struct *mm = kvm->mm;
565 
566 	kvm_arch_sync_events(kvm);
567 	raw_spin_lock(&kvm_lock);
568 	list_del(&kvm->vm_list);
569 	raw_spin_unlock(&kvm_lock);
570 	kvm_free_irq_routing(kvm);
571 	for (i = 0; i < KVM_NR_BUSES; i++)
572 		kvm_io_bus_destroy(kvm->buses[i]);
573 	kvm_coalesced_mmio_free(kvm);
574 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
575 	mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
576 #else
577 	kvm_arch_flush_shadow(kvm);
578 #endif
579 	kvm_arch_destroy_vm(kvm);
580 	kvm_free_physmem(kvm);
581 	cleanup_srcu_struct(&kvm->srcu);
582 	kvm_arch_free_vm(kvm);
583 	hardware_disable_all();
584 	mmdrop(mm);
585 }
586 
587 void kvm_get_kvm(struct kvm *kvm)
588 {
589 	atomic_inc(&kvm->users_count);
590 }
591 EXPORT_SYMBOL_GPL(kvm_get_kvm);
592 
593 void kvm_put_kvm(struct kvm *kvm)
594 {
595 	if (atomic_dec_and_test(&kvm->users_count))
596 		kvm_destroy_vm(kvm);
597 }
598 EXPORT_SYMBOL_GPL(kvm_put_kvm);
599 
600 
601 static int kvm_vm_release(struct inode *inode, struct file *filp)
602 {
603 	struct kvm *kvm = filp->private_data;
604 
605 	kvm_irqfd_release(kvm);
606 
607 	kvm_put_kvm(kvm);
608 	return 0;
609 }
610 
611 /*
612  * Allocation size is twice as large as the actual dirty bitmap size.
613  * See x86's kvm_vm_ioctl_get_dirty_log() why this is needed.
614  */
615 static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
616 {
617 #ifndef CONFIG_S390
618 	unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
619 
620 	if (dirty_bytes > PAGE_SIZE)
621 		memslot->dirty_bitmap = vzalloc(dirty_bytes);
622 	else
623 		memslot->dirty_bitmap = kzalloc(dirty_bytes, GFP_KERNEL);
624 
625 	if (!memslot->dirty_bitmap)
626 		return -ENOMEM;
627 
628 #endif /* !CONFIG_S390 */
629 	return 0;
630 }
631 
632 static int cmp_memslot(const void *slot1, const void *slot2)
633 {
634 	struct kvm_memory_slot *s1, *s2;
635 
636 	s1 = (struct kvm_memory_slot *)slot1;
637 	s2 = (struct kvm_memory_slot *)slot2;
638 
639 	if (s1->npages < s2->npages)
640 		return 1;
641 	if (s1->npages > s2->npages)
642 		return -1;
643 
644 	return 0;
645 }
646 
647 /*
648  * Sort the memslots base on its size, so the larger slots
649  * will get better fit.
650  */
651 static void sort_memslots(struct kvm_memslots *slots)
652 {
653 	int i;
654 
655 	sort(slots->memslots, KVM_MEM_SLOTS_NUM,
656 	      sizeof(struct kvm_memory_slot), cmp_memslot, NULL);
657 
658 	for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
659 		slots->id_to_index[slots->memslots[i].id] = i;
660 }
661 
662 void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new)
663 {
664 	if (new) {
665 		int id = new->id;
666 		struct kvm_memory_slot *old = id_to_memslot(slots, id);
667 		unsigned long npages = old->npages;
668 
669 		*old = *new;
670 		if (new->npages != npages)
671 			sort_memslots(slots);
672 	}
673 
674 	slots->generation++;
675 }
676 
677 /*
678  * Allocate some memory and give it an address in the guest physical address
679  * space.
680  *
681  * Discontiguous memory is allowed, mostly for framebuffers.
682  *
683  * Must be called holding mmap_sem for write.
684  */
685 int __kvm_set_memory_region(struct kvm *kvm,
686 			    struct kvm_userspace_memory_region *mem,
687 			    int user_alloc)
688 {
689 	int r;
690 	gfn_t base_gfn;
691 	unsigned long npages;
692 	unsigned long i;
693 	struct kvm_memory_slot *memslot;
694 	struct kvm_memory_slot old, new;
695 	struct kvm_memslots *slots, *old_memslots;
696 
697 	r = -EINVAL;
698 	/* General sanity checks */
699 	if (mem->memory_size & (PAGE_SIZE - 1))
700 		goto out;
701 	if (mem->guest_phys_addr & (PAGE_SIZE - 1))
702 		goto out;
703 	/* We can read the guest memory with __xxx_user() later on. */
704 	if (user_alloc &&
705 	    ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
706 	     !access_ok(VERIFY_WRITE,
707 			(void __user *)(unsigned long)mem->userspace_addr,
708 			mem->memory_size)))
709 		goto out;
710 	if (mem->slot >= KVM_MEM_SLOTS_NUM)
711 		goto out;
712 	if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
713 		goto out;
714 
715 	memslot = id_to_memslot(kvm->memslots, mem->slot);
716 	base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
717 	npages = mem->memory_size >> PAGE_SHIFT;
718 
719 	r = -EINVAL;
720 	if (npages > KVM_MEM_MAX_NR_PAGES)
721 		goto out;
722 
723 	if (!npages)
724 		mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
725 
726 	new = old = *memslot;
727 
728 	new.id = mem->slot;
729 	new.base_gfn = base_gfn;
730 	new.npages = npages;
731 	new.flags = mem->flags;
732 
733 	/* Disallow changing a memory slot's size. */
734 	r = -EINVAL;
735 	if (npages && old.npages && npages != old.npages)
736 		goto out_free;
737 
738 	/* Check for overlaps */
739 	r = -EEXIST;
740 	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
741 		struct kvm_memory_slot *s = &kvm->memslots->memslots[i];
742 
743 		if (s == memslot || !s->npages)
744 			continue;
745 		if (!((base_gfn + npages <= s->base_gfn) ||
746 		      (base_gfn >= s->base_gfn + s->npages)))
747 			goto out_free;
748 	}
749 
750 	/* Free page dirty bitmap if unneeded */
751 	if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
752 		new.dirty_bitmap = NULL;
753 
754 	r = -ENOMEM;
755 
756 	/* Allocate if a slot is being created */
757 	if (npages && !old.npages) {
758 		new.user_alloc = user_alloc;
759 		new.userspace_addr = mem->userspace_addr;
760 #ifndef CONFIG_S390
761 		new.rmap = vzalloc(npages * sizeof(*new.rmap));
762 		if (!new.rmap)
763 			goto out_free;
764 #endif /* not defined CONFIG_S390 */
765 		if (kvm_arch_create_memslot(&new, npages))
766 			goto out_free;
767 	}
768 
769 	/* Allocate page dirty bitmap if needed */
770 	if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
771 		if (kvm_create_dirty_bitmap(&new) < 0)
772 			goto out_free;
773 		/* destroy any largepage mappings for dirty tracking */
774 	}
775 
776 	if (!npages) {
777 		struct kvm_memory_slot *slot;
778 
779 		r = -ENOMEM;
780 		slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
781 				GFP_KERNEL);
782 		if (!slots)
783 			goto out_free;
784 		slot = id_to_memslot(slots, mem->slot);
785 		slot->flags |= KVM_MEMSLOT_INVALID;
786 
787 		update_memslots(slots, NULL);
788 
789 		old_memslots = kvm->memslots;
790 		rcu_assign_pointer(kvm->memslots, slots);
791 		synchronize_srcu_expedited(&kvm->srcu);
792 		/* From this point no new shadow pages pointing to a deleted
793 		 * memslot will be created.
794 		 *
795 		 * validation of sp->gfn happens in:
796 		 * 	- gfn_to_hva (kvm_read_guest, gfn_to_pfn)
797 		 * 	- kvm_is_visible_gfn (mmu_check_roots)
798 		 */
799 		kvm_arch_flush_shadow(kvm);
800 		kfree(old_memslots);
801 	}
802 
803 	r = kvm_arch_prepare_memory_region(kvm, &new, old, mem, user_alloc);
804 	if (r)
805 		goto out_free;
806 
807 	/* map/unmap the pages in iommu page table */
808 	if (npages) {
809 		r = kvm_iommu_map_pages(kvm, &new);
810 		if (r)
811 			goto out_free;
812 	} else
813 		kvm_iommu_unmap_pages(kvm, &old);
814 
815 	r = -ENOMEM;
816 	slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
817 			GFP_KERNEL);
818 	if (!slots)
819 		goto out_free;
820 
821 	/* actual memory is freed via old in kvm_free_physmem_slot below */
822 	if (!npages) {
823 		new.rmap = NULL;
824 		new.dirty_bitmap = NULL;
825 		memset(&new.arch, 0, sizeof(new.arch));
826 	}
827 
828 	update_memslots(slots, &new);
829 	old_memslots = kvm->memslots;
830 	rcu_assign_pointer(kvm->memslots, slots);
831 	synchronize_srcu_expedited(&kvm->srcu);
832 
833 	kvm_arch_commit_memory_region(kvm, mem, old, user_alloc);
834 
835 	/*
836 	 * If the new memory slot is created, we need to clear all
837 	 * mmio sptes.
838 	 */
839 	if (npages && old.base_gfn != mem->guest_phys_addr >> PAGE_SHIFT)
840 		kvm_arch_flush_shadow(kvm);
841 
842 	kvm_free_physmem_slot(&old, &new);
843 	kfree(old_memslots);
844 
845 	return 0;
846 
847 out_free:
848 	kvm_free_physmem_slot(&new, &old);
849 out:
850 	return r;
851 
852 }
853 EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
854 
855 int kvm_set_memory_region(struct kvm *kvm,
856 			  struct kvm_userspace_memory_region *mem,
857 			  int user_alloc)
858 {
859 	int r;
860 
861 	mutex_lock(&kvm->slots_lock);
862 	r = __kvm_set_memory_region(kvm, mem, user_alloc);
863 	mutex_unlock(&kvm->slots_lock);
864 	return r;
865 }
866 EXPORT_SYMBOL_GPL(kvm_set_memory_region);
867 
868 int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
869 				   struct
870 				   kvm_userspace_memory_region *mem,
871 				   int user_alloc)
872 {
873 	if (mem->slot >= KVM_MEMORY_SLOTS)
874 		return -EINVAL;
875 	return kvm_set_memory_region(kvm, mem, user_alloc);
876 }
877 
878 int kvm_get_dirty_log(struct kvm *kvm,
879 			struct kvm_dirty_log *log, int *is_dirty)
880 {
881 	struct kvm_memory_slot *memslot;
882 	int r, i;
883 	unsigned long n;
884 	unsigned long any = 0;
885 
886 	r = -EINVAL;
887 	if (log->slot >= KVM_MEMORY_SLOTS)
888 		goto out;
889 
890 	memslot = id_to_memslot(kvm->memslots, log->slot);
891 	r = -ENOENT;
892 	if (!memslot->dirty_bitmap)
893 		goto out;
894 
895 	n = kvm_dirty_bitmap_bytes(memslot);
896 
897 	for (i = 0; !any && i < n/sizeof(long); ++i)
898 		any = memslot->dirty_bitmap[i];
899 
900 	r = -EFAULT;
901 	if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
902 		goto out;
903 
904 	if (any)
905 		*is_dirty = 1;
906 
907 	r = 0;
908 out:
909 	return r;
910 }
911 
912 bool kvm_largepages_enabled(void)
913 {
914 	return largepages_enabled;
915 }
916 
917 void kvm_disable_largepages(void)
918 {
919 	largepages_enabled = false;
920 }
921 EXPORT_SYMBOL_GPL(kvm_disable_largepages);
922 
923 int is_error_page(struct page *page)
924 {
925 	return page == bad_page || page == hwpoison_page || page == fault_page;
926 }
927 EXPORT_SYMBOL_GPL(is_error_page);
928 
929 int is_error_pfn(pfn_t pfn)
930 {
931 	return pfn == bad_pfn || pfn == hwpoison_pfn || pfn == fault_pfn;
932 }
933 EXPORT_SYMBOL_GPL(is_error_pfn);
934 
935 int is_hwpoison_pfn(pfn_t pfn)
936 {
937 	return pfn == hwpoison_pfn;
938 }
939 EXPORT_SYMBOL_GPL(is_hwpoison_pfn);
940 
941 int is_fault_pfn(pfn_t pfn)
942 {
943 	return pfn == fault_pfn;
944 }
945 EXPORT_SYMBOL_GPL(is_fault_pfn);
946 
947 int is_noslot_pfn(pfn_t pfn)
948 {
949 	return pfn == bad_pfn;
950 }
951 EXPORT_SYMBOL_GPL(is_noslot_pfn);
952 
953 int is_invalid_pfn(pfn_t pfn)
954 {
955 	return pfn == hwpoison_pfn || pfn == fault_pfn;
956 }
957 EXPORT_SYMBOL_GPL(is_invalid_pfn);
958 
959 static inline unsigned long bad_hva(void)
960 {
961 	return PAGE_OFFSET;
962 }
963 
964 int kvm_is_error_hva(unsigned long addr)
965 {
966 	return addr == bad_hva();
967 }
968 EXPORT_SYMBOL_GPL(kvm_is_error_hva);
969 
970 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
971 {
972 	return __gfn_to_memslot(kvm_memslots(kvm), gfn);
973 }
974 EXPORT_SYMBOL_GPL(gfn_to_memslot);
975 
976 int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
977 {
978 	struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn);
979 
980 	if (!memslot || memslot->id >= KVM_MEMORY_SLOTS ||
981 	      memslot->flags & KVM_MEMSLOT_INVALID)
982 		return 0;
983 
984 	return 1;
985 }
986 EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
987 
988 unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn)
989 {
990 	struct vm_area_struct *vma;
991 	unsigned long addr, size;
992 
993 	size = PAGE_SIZE;
994 
995 	addr = gfn_to_hva(kvm, gfn);
996 	if (kvm_is_error_hva(addr))
997 		return PAGE_SIZE;
998 
999 	down_read(&current->mm->mmap_sem);
1000 	vma = find_vma(current->mm, addr);
1001 	if (!vma)
1002 		goto out;
1003 
1004 	size = vma_kernel_pagesize(vma);
1005 
1006 out:
1007 	up_read(&current->mm->mmap_sem);
1008 
1009 	return size;
1010 }
1011 
1012 static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
1013 				     gfn_t *nr_pages)
1014 {
1015 	if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
1016 		return bad_hva();
1017 
1018 	if (nr_pages)
1019 		*nr_pages = slot->npages - (gfn - slot->base_gfn);
1020 
1021 	return gfn_to_hva_memslot(slot, gfn);
1022 }
1023 
1024 unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
1025 {
1026 	return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL);
1027 }
1028 EXPORT_SYMBOL_GPL(gfn_to_hva);
1029 
1030 static pfn_t get_fault_pfn(void)
1031 {
1032 	get_page(fault_page);
1033 	return fault_pfn;
1034 }
1035 
1036 int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm,
1037 	unsigned long start, int write, struct page **page)
1038 {
1039 	int flags = FOLL_TOUCH | FOLL_NOWAIT | FOLL_HWPOISON | FOLL_GET;
1040 
1041 	if (write)
1042 		flags |= FOLL_WRITE;
1043 
1044 	return __get_user_pages(tsk, mm, start, 1, flags, page, NULL, NULL);
1045 }
1046 
1047 static inline int check_user_page_hwpoison(unsigned long addr)
1048 {
1049 	int rc, flags = FOLL_TOUCH | FOLL_HWPOISON | FOLL_WRITE;
1050 
1051 	rc = __get_user_pages(current, current->mm, addr, 1,
1052 			      flags, NULL, NULL, NULL);
1053 	return rc == -EHWPOISON;
1054 }
1055 
1056 static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic,
1057 			bool *async, bool write_fault, bool *writable)
1058 {
1059 	struct page *page[1];
1060 	int npages = 0;
1061 	pfn_t pfn;
1062 
1063 	/* we can do it either atomically or asynchronously, not both */
1064 	BUG_ON(atomic && async);
1065 
1066 	BUG_ON(!write_fault && !writable);
1067 
1068 	if (writable)
1069 		*writable = true;
1070 
1071 	if (atomic || async)
1072 		npages = __get_user_pages_fast(addr, 1, 1, page);
1073 
1074 	if (unlikely(npages != 1) && !atomic) {
1075 		might_sleep();
1076 
1077 		if (writable)
1078 			*writable = write_fault;
1079 
1080 		if (async) {
1081 			down_read(&current->mm->mmap_sem);
1082 			npages = get_user_page_nowait(current, current->mm,
1083 						     addr, write_fault, page);
1084 			up_read(&current->mm->mmap_sem);
1085 		} else
1086 			npages = get_user_pages_fast(addr, 1, write_fault,
1087 						     page);
1088 
1089 		/* map read fault as writable if possible */
1090 		if (unlikely(!write_fault) && npages == 1) {
1091 			struct page *wpage[1];
1092 
1093 			npages = __get_user_pages_fast(addr, 1, 1, wpage);
1094 			if (npages == 1) {
1095 				*writable = true;
1096 				put_page(page[0]);
1097 				page[0] = wpage[0];
1098 			}
1099 			npages = 1;
1100 		}
1101 	}
1102 
1103 	if (unlikely(npages != 1)) {
1104 		struct vm_area_struct *vma;
1105 
1106 		if (atomic)
1107 			return get_fault_pfn();
1108 
1109 		down_read(&current->mm->mmap_sem);
1110 		if (npages == -EHWPOISON ||
1111 			(!async && check_user_page_hwpoison(addr))) {
1112 			up_read(&current->mm->mmap_sem);
1113 			get_page(hwpoison_page);
1114 			return page_to_pfn(hwpoison_page);
1115 		}
1116 
1117 		vma = find_vma_intersection(current->mm, addr, addr+1);
1118 
1119 		if (vma == NULL)
1120 			pfn = get_fault_pfn();
1121 		else if ((vma->vm_flags & VM_PFNMAP)) {
1122 			pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) +
1123 				vma->vm_pgoff;
1124 			BUG_ON(!kvm_is_mmio_pfn(pfn));
1125 		} else {
1126 			if (async && (vma->vm_flags & VM_WRITE))
1127 				*async = true;
1128 			pfn = get_fault_pfn();
1129 		}
1130 		up_read(&current->mm->mmap_sem);
1131 	} else
1132 		pfn = page_to_pfn(page[0]);
1133 
1134 	return pfn;
1135 }
1136 
1137 pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr)
1138 {
1139 	return hva_to_pfn(kvm, addr, true, NULL, true, NULL);
1140 }
1141 EXPORT_SYMBOL_GPL(hva_to_pfn_atomic);
1142 
1143 static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async,
1144 			  bool write_fault, bool *writable)
1145 {
1146 	unsigned long addr;
1147 
1148 	if (async)
1149 		*async = false;
1150 
1151 	addr = gfn_to_hva(kvm, gfn);
1152 	if (kvm_is_error_hva(addr)) {
1153 		get_page(bad_page);
1154 		return page_to_pfn(bad_page);
1155 	}
1156 
1157 	return hva_to_pfn(kvm, addr, atomic, async, write_fault, writable);
1158 }
1159 
1160 pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn)
1161 {
1162 	return __gfn_to_pfn(kvm, gfn, true, NULL, true, NULL);
1163 }
1164 EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic);
1165 
1166 pfn_t gfn_to_pfn_async(struct kvm *kvm, gfn_t gfn, bool *async,
1167 		       bool write_fault, bool *writable)
1168 {
1169 	return __gfn_to_pfn(kvm, gfn, false, async, write_fault, writable);
1170 }
1171 EXPORT_SYMBOL_GPL(gfn_to_pfn_async);
1172 
1173 pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
1174 {
1175 	return __gfn_to_pfn(kvm, gfn, false, NULL, true, NULL);
1176 }
1177 EXPORT_SYMBOL_GPL(gfn_to_pfn);
1178 
1179 pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
1180 		      bool *writable)
1181 {
1182 	return __gfn_to_pfn(kvm, gfn, false, NULL, write_fault, writable);
1183 }
1184 EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);
1185 
1186 pfn_t gfn_to_pfn_memslot(struct kvm *kvm,
1187 			 struct kvm_memory_slot *slot, gfn_t gfn)
1188 {
1189 	unsigned long addr = gfn_to_hva_memslot(slot, gfn);
1190 	return hva_to_pfn(kvm, addr, false, NULL, true, NULL);
1191 }
1192 
1193 int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages,
1194 								  int nr_pages)
1195 {
1196 	unsigned long addr;
1197 	gfn_t entry;
1198 
1199 	addr = gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, &entry);
1200 	if (kvm_is_error_hva(addr))
1201 		return -1;
1202 
1203 	if (entry < nr_pages)
1204 		return 0;
1205 
1206 	return __get_user_pages_fast(addr, nr_pages, 1, pages);
1207 }
1208 EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
1209 
1210 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
1211 {
1212 	pfn_t pfn;
1213 
1214 	pfn = gfn_to_pfn(kvm, gfn);
1215 	if (!kvm_is_mmio_pfn(pfn))
1216 		return pfn_to_page(pfn);
1217 
1218 	WARN_ON(kvm_is_mmio_pfn(pfn));
1219 
1220 	get_page(bad_page);
1221 	return bad_page;
1222 }
1223 
1224 EXPORT_SYMBOL_GPL(gfn_to_page);
1225 
1226 void kvm_release_page_clean(struct page *page)
1227 {
1228 	kvm_release_pfn_clean(page_to_pfn(page));
1229 }
1230 EXPORT_SYMBOL_GPL(kvm_release_page_clean);
1231 
1232 void kvm_release_pfn_clean(pfn_t pfn)
1233 {
1234 	if (!kvm_is_mmio_pfn(pfn))
1235 		put_page(pfn_to_page(pfn));
1236 }
1237 EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
1238 
1239 void kvm_release_page_dirty(struct page *page)
1240 {
1241 	kvm_release_pfn_dirty(page_to_pfn(page));
1242 }
1243 EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
1244 
1245 void kvm_release_pfn_dirty(pfn_t pfn)
1246 {
1247 	kvm_set_pfn_dirty(pfn);
1248 	kvm_release_pfn_clean(pfn);
1249 }
1250 EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
1251 
1252 void kvm_set_page_dirty(struct page *page)
1253 {
1254 	kvm_set_pfn_dirty(page_to_pfn(page));
1255 }
1256 EXPORT_SYMBOL_GPL(kvm_set_page_dirty);
1257 
1258 void kvm_set_pfn_dirty(pfn_t pfn)
1259 {
1260 	if (!kvm_is_mmio_pfn(pfn)) {
1261 		struct page *page = pfn_to_page(pfn);
1262 		if (!PageReserved(page))
1263 			SetPageDirty(page);
1264 	}
1265 }
1266 EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
1267 
1268 void kvm_set_pfn_accessed(pfn_t pfn)
1269 {
1270 	if (!kvm_is_mmio_pfn(pfn))
1271 		mark_page_accessed(pfn_to_page(pfn));
1272 }
1273 EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
1274 
1275 void kvm_get_pfn(pfn_t pfn)
1276 {
1277 	if (!kvm_is_mmio_pfn(pfn))
1278 		get_page(pfn_to_page(pfn));
1279 }
1280 EXPORT_SYMBOL_GPL(kvm_get_pfn);
1281 
1282 static int next_segment(unsigned long len, int offset)
1283 {
1284 	if (len > PAGE_SIZE - offset)
1285 		return PAGE_SIZE - offset;
1286 	else
1287 		return len;
1288 }
1289 
1290 int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
1291 			int len)
1292 {
1293 	int r;
1294 	unsigned long addr;
1295 
1296 	addr = gfn_to_hva(kvm, gfn);
1297 	if (kvm_is_error_hva(addr))
1298 		return -EFAULT;
1299 	r = __copy_from_user(data, (void __user *)addr + offset, len);
1300 	if (r)
1301 		return -EFAULT;
1302 	return 0;
1303 }
1304 EXPORT_SYMBOL_GPL(kvm_read_guest_page);
1305 
1306 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
1307 {
1308 	gfn_t gfn = gpa >> PAGE_SHIFT;
1309 	int seg;
1310 	int offset = offset_in_page(gpa);
1311 	int ret;
1312 
1313 	while ((seg = next_segment(len, offset)) != 0) {
1314 		ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
1315 		if (ret < 0)
1316 			return ret;
1317 		offset = 0;
1318 		len -= seg;
1319 		data += seg;
1320 		++gfn;
1321 	}
1322 	return 0;
1323 }
1324 EXPORT_SYMBOL_GPL(kvm_read_guest);
1325 
1326 int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
1327 			  unsigned long len)
1328 {
1329 	int r;
1330 	unsigned long addr;
1331 	gfn_t gfn = gpa >> PAGE_SHIFT;
1332 	int offset = offset_in_page(gpa);
1333 
1334 	addr = gfn_to_hva(kvm, gfn);
1335 	if (kvm_is_error_hva(addr))
1336 		return -EFAULT;
1337 	pagefault_disable();
1338 	r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
1339 	pagefault_enable();
1340 	if (r)
1341 		return -EFAULT;
1342 	return 0;
1343 }
1344 EXPORT_SYMBOL(kvm_read_guest_atomic);
1345 
1346 int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
1347 			 int offset, int len)
1348 {
1349 	int r;
1350 	unsigned long addr;
1351 
1352 	addr = gfn_to_hva(kvm, gfn);
1353 	if (kvm_is_error_hva(addr))
1354 		return -EFAULT;
1355 	r = __copy_to_user((void __user *)addr + offset, data, len);
1356 	if (r)
1357 		return -EFAULT;
1358 	mark_page_dirty(kvm, gfn);
1359 	return 0;
1360 }
1361 EXPORT_SYMBOL_GPL(kvm_write_guest_page);
1362 
1363 int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
1364 		    unsigned long len)
1365 {
1366 	gfn_t gfn = gpa >> PAGE_SHIFT;
1367 	int seg;
1368 	int offset = offset_in_page(gpa);
1369 	int ret;
1370 
1371 	while ((seg = next_segment(len, offset)) != 0) {
1372 		ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
1373 		if (ret < 0)
1374 			return ret;
1375 		offset = 0;
1376 		len -= seg;
1377 		data += seg;
1378 		++gfn;
1379 	}
1380 	return 0;
1381 }
1382 
1383 int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1384 			      gpa_t gpa)
1385 {
1386 	struct kvm_memslots *slots = kvm_memslots(kvm);
1387 	int offset = offset_in_page(gpa);
1388 	gfn_t gfn = gpa >> PAGE_SHIFT;
1389 
1390 	ghc->gpa = gpa;
1391 	ghc->generation = slots->generation;
1392 	ghc->memslot = gfn_to_memslot(kvm, gfn);
1393 	ghc->hva = gfn_to_hva_many(ghc->memslot, gfn, NULL);
1394 	if (!kvm_is_error_hva(ghc->hva))
1395 		ghc->hva += offset;
1396 	else
1397 		return -EFAULT;
1398 
1399 	return 0;
1400 }
1401 EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
1402 
1403 int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1404 			   void *data, unsigned long len)
1405 {
1406 	struct kvm_memslots *slots = kvm_memslots(kvm);
1407 	int r;
1408 
1409 	if (slots->generation != ghc->generation)
1410 		kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa);
1411 
1412 	if (kvm_is_error_hva(ghc->hva))
1413 		return -EFAULT;
1414 
1415 	r = __copy_to_user((void __user *)ghc->hva, data, len);
1416 	if (r)
1417 		return -EFAULT;
1418 	mark_page_dirty_in_slot(kvm, ghc->memslot, ghc->gpa >> PAGE_SHIFT);
1419 
1420 	return 0;
1421 }
1422 EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
1423 
1424 int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1425 			   void *data, unsigned long len)
1426 {
1427 	struct kvm_memslots *slots = kvm_memslots(kvm);
1428 	int r;
1429 
1430 	if (slots->generation != ghc->generation)
1431 		kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa);
1432 
1433 	if (kvm_is_error_hva(ghc->hva))
1434 		return -EFAULT;
1435 
1436 	r = __copy_from_user(data, (void __user *)ghc->hva, len);
1437 	if (r)
1438 		return -EFAULT;
1439 
1440 	return 0;
1441 }
1442 EXPORT_SYMBOL_GPL(kvm_read_guest_cached);
1443 
1444 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
1445 {
1446 	return kvm_write_guest_page(kvm, gfn, (const void *) empty_zero_page,
1447 				    offset, len);
1448 }
1449 EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
1450 
1451 int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
1452 {
1453 	gfn_t gfn = gpa >> PAGE_SHIFT;
1454 	int seg;
1455 	int offset = offset_in_page(gpa);
1456 	int ret;
1457 
1458         while ((seg = next_segment(len, offset)) != 0) {
1459 		ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
1460 		if (ret < 0)
1461 			return ret;
1462 		offset = 0;
1463 		len -= seg;
1464 		++gfn;
1465 	}
1466 	return 0;
1467 }
1468 EXPORT_SYMBOL_GPL(kvm_clear_guest);
1469 
1470 void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot,
1471 			     gfn_t gfn)
1472 {
1473 	if (memslot && memslot->dirty_bitmap) {
1474 		unsigned long rel_gfn = gfn - memslot->base_gfn;
1475 
1476 		/* TODO: introduce set_bit_le() and use it */
1477 		test_and_set_bit_le(rel_gfn, memslot->dirty_bitmap);
1478 	}
1479 }
1480 
1481 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
1482 {
1483 	struct kvm_memory_slot *memslot;
1484 
1485 	memslot = gfn_to_memslot(kvm, gfn);
1486 	mark_page_dirty_in_slot(kvm, memslot, gfn);
1487 }
1488 
1489 /*
1490  * The vCPU has executed a HLT instruction with in-kernel mode enabled.
1491  */
1492 void kvm_vcpu_block(struct kvm_vcpu *vcpu)
1493 {
1494 	DEFINE_WAIT(wait);
1495 
1496 	for (;;) {
1497 		prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
1498 
1499 		if (kvm_arch_vcpu_runnable(vcpu)) {
1500 			kvm_make_request(KVM_REQ_UNHALT, vcpu);
1501 			break;
1502 		}
1503 		if (kvm_cpu_has_pending_timer(vcpu))
1504 			break;
1505 		if (signal_pending(current))
1506 			break;
1507 
1508 		schedule();
1509 	}
1510 
1511 	finish_wait(&vcpu->wq, &wait);
1512 }
1513 
1514 #ifndef CONFIG_S390
1515 /*
1516  * Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode.
1517  */
1518 void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
1519 {
1520 	int me;
1521 	int cpu = vcpu->cpu;
1522 	wait_queue_head_t *wqp;
1523 
1524 	wqp = kvm_arch_vcpu_wq(vcpu);
1525 	if (waitqueue_active(wqp)) {
1526 		wake_up_interruptible(wqp);
1527 		++vcpu->stat.halt_wakeup;
1528 	}
1529 
1530 	me = get_cpu();
1531 	if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu))
1532 		if (kvm_arch_vcpu_should_kick(vcpu))
1533 			smp_send_reschedule(cpu);
1534 	put_cpu();
1535 }
1536 #endif /* !CONFIG_S390 */
1537 
1538 void kvm_resched(struct kvm_vcpu *vcpu)
1539 {
1540 	if (!need_resched())
1541 		return;
1542 	cond_resched();
1543 }
1544 EXPORT_SYMBOL_GPL(kvm_resched);
1545 
1546 bool kvm_vcpu_yield_to(struct kvm_vcpu *target)
1547 {
1548 	struct pid *pid;
1549 	struct task_struct *task = NULL;
1550 
1551 	rcu_read_lock();
1552 	pid = rcu_dereference(target->pid);
1553 	if (pid)
1554 		task = get_pid_task(target->pid, PIDTYPE_PID);
1555 	rcu_read_unlock();
1556 	if (!task)
1557 		return false;
1558 	if (task->flags & PF_VCPU) {
1559 		put_task_struct(task);
1560 		return false;
1561 	}
1562 	if (yield_to(task, 1)) {
1563 		put_task_struct(task);
1564 		return true;
1565 	}
1566 	put_task_struct(task);
1567 	return false;
1568 }
1569 EXPORT_SYMBOL_GPL(kvm_vcpu_yield_to);
1570 
1571 void kvm_vcpu_on_spin(struct kvm_vcpu *me)
1572 {
1573 	struct kvm *kvm = me->kvm;
1574 	struct kvm_vcpu *vcpu;
1575 	int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
1576 	int yielded = 0;
1577 	int pass;
1578 	int i;
1579 
1580 	/*
1581 	 * We boost the priority of a VCPU that is runnable but not
1582 	 * currently running, because it got preempted by something
1583 	 * else and called schedule in __vcpu_run.  Hopefully that
1584 	 * VCPU is holding the lock that we need and will release it.
1585 	 * We approximate round-robin by starting at the last boosted VCPU.
1586 	 */
1587 	for (pass = 0; pass < 2 && !yielded; pass++) {
1588 		kvm_for_each_vcpu(i, vcpu, kvm) {
1589 			if (!pass && i < last_boosted_vcpu) {
1590 				i = last_boosted_vcpu;
1591 				continue;
1592 			} else if (pass && i > last_boosted_vcpu)
1593 				break;
1594 			if (vcpu == me)
1595 				continue;
1596 			if (waitqueue_active(&vcpu->wq))
1597 				continue;
1598 			if (kvm_vcpu_yield_to(vcpu)) {
1599 				kvm->last_boosted_vcpu = i;
1600 				yielded = 1;
1601 				break;
1602 			}
1603 		}
1604 	}
1605 }
1606 EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
1607 
1608 static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1609 {
1610 	struct kvm_vcpu *vcpu = vma->vm_file->private_data;
1611 	struct page *page;
1612 
1613 	if (vmf->pgoff == 0)
1614 		page = virt_to_page(vcpu->run);
1615 #ifdef CONFIG_X86
1616 	else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
1617 		page = virt_to_page(vcpu->arch.pio_data);
1618 #endif
1619 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1620 	else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
1621 		page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
1622 #endif
1623 	else
1624 		return kvm_arch_vcpu_fault(vcpu, vmf);
1625 	get_page(page);
1626 	vmf->page = page;
1627 	return 0;
1628 }
1629 
1630 static const struct vm_operations_struct kvm_vcpu_vm_ops = {
1631 	.fault = kvm_vcpu_fault,
1632 };
1633 
1634 static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
1635 {
1636 	vma->vm_ops = &kvm_vcpu_vm_ops;
1637 	return 0;
1638 }
1639 
1640 static int kvm_vcpu_release(struct inode *inode, struct file *filp)
1641 {
1642 	struct kvm_vcpu *vcpu = filp->private_data;
1643 
1644 	kvm_put_kvm(vcpu->kvm);
1645 	return 0;
1646 }
1647 
1648 static struct file_operations kvm_vcpu_fops = {
1649 	.release        = kvm_vcpu_release,
1650 	.unlocked_ioctl = kvm_vcpu_ioctl,
1651 #ifdef CONFIG_COMPAT
1652 	.compat_ioctl   = kvm_vcpu_compat_ioctl,
1653 #endif
1654 	.mmap           = kvm_vcpu_mmap,
1655 	.llseek		= noop_llseek,
1656 };
1657 
1658 /*
1659  * Allocates an inode for the vcpu.
1660  */
1661 static int create_vcpu_fd(struct kvm_vcpu *vcpu)
1662 {
1663 	return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR);
1664 }
1665 
1666 /*
1667  * Creates some virtual cpus.  Good luck creating more than one.
1668  */
1669 static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
1670 {
1671 	int r;
1672 	struct kvm_vcpu *vcpu, *v;
1673 
1674 	vcpu = kvm_arch_vcpu_create(kvm, id);
1675 	if (IS_ERR(vcpu))
1676 		return PTR_ERR(vcpu);
1677 
1678 	preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
1679 
1680 	r = kvm_arch_vcpu_setup(vcpu);
1681 	if (r)
1682 		goto vcpu_destroy;
1683 
1684 	mutex_lock(&kvm->lock);
1685 	if (!kvm_vcpu_compatible(vcpu)) {
1686 		r = -EINVAL;
1687 		goto unlock_vcpu_destroy;
1688 	}
1689 	if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
1690 		r = -EINVAL;
1691 		goto unlock_vcpu_destroy;
1692 	}
1693 
1694 	kvm_for_each_vcpu(r, v, kvm)
1695 		if (v->vcpu_id == id) {
1696 			r = -EEXIST;
1697 			goto unlock_vcpu_destroy;
1698 		}
1699 
1700 	BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
1701 
1702 	/* Now it's all set up, let userspace reach it */
1703 	kvm_get_kvm(kvm);
1704 	r = create_vcpu_fd(vcpu);
1705 	if (r < 0) {
1706 		kvm_put_kvm(kvm);
1707 		goto unlock_vcpu_destroy;
1708 	}
1709 
1710 	kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
1711 	smp_wmb();
1712 	atomic_inc(&kvm->online_vcpus);
1713 
1714 	mutex_unlock(&kvm->lock);
1715 	return r;
1716 
1717 unlock_vcpu_destroy:
1718 	mutex_unlock(&kvm->lock);
1719 vcpu_destroy:
1720 	kvm_arch_vcpu_destroy(vcpu);
1721 	return r;
1722 }
1723 
1724 static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
1725 {
1726 	if (sigset) {
1727 		sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
1728 		vcpu->sigset_active = 1;
1729 		vcpu->sigset = *sigset;
1730 	} else
1731 		vcpu->sigset_active = 0;
1732 	return 0;
1733 }
1734 
1735 static long kvm_vcpu_ioctl(struct file *filp,
1736 			   unsigned int ioctl, unsigned long arg)
1737 {
1738 	struct kvm_vcpu *vcpu = filp->private_data;
1739 	void __user *argp = (void __user *)arg;
1740 	int r;
1741 	struct kvm_fpu *fpu = NULL;
1742 	struct kvm_sregs *kvm_sregs = NULL;
1743 
1744 	if (vcpu->kvm->mm != current->mm)
1745 		return -EIO;
1746 
1747 #if defined(CONFIG_S390) || defined(CONFIG_PPC)
1748 	/*
1749 	 * Special cases: vcpu ioctls that are asynchronous to vcpu execution,
1750 	 * so vcpu_load() would break it.
1751 	 */
1752 	if (ioctl == KVM_S390_INTERRUPT || ioctl == KVM_INTERRUPT)
1753 		return kvm_arch_vcpu_ioctl(filp, ioctl, arg);
1754 #endif
1755 
1756 
1757 	vcpu_load(vcpu);
1758 	switch (ioctl) {
1759 	case KVM_RUN:
1760 		r = -EINVAL;
1761 		if (arg)
1762 			goto out;
1763 		r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
1764 		trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
1765 		break;
1766 	case KVM_GET_REGS: {
1767 		struct kvm_regs *kvm_regs;
1768 
1769 		r = -ENOMEM;
1770 		kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
1771 		if (!kvm_regs)
1772 			goto out;
1773 		r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
1774 		if (r)
1775 			goto out_free1;
1776 		r = -EFAULT;
1777 		if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
1778 			goto out_free1;
1779 		r = 0;
1780 out_free1:
1781 		kfree(kvm_regs);
1782 		break;
1783 	}
1784 	case KVM_SET_REGS: {
1785 		struct kvm_regs *kvm_regs;
1786 
1787 		r = -ENOMEM;
1788 		kvm_regs = memdup_user(argp, sizeof(*kvm_regs));
1789 		if (IS_ERR(kvm_regs)) {
1790 			r = PTR_ERR(kvm_regs);
1791 			goto out;
1792 		}
1793 		r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
1794 		if (r)
1795 			goto out_free2;
1796 		r = 0;
1797 out_free2:
1798 		kfree(kvm_regs);
1799 		break;
1800 	}
1801 	case KVM_GET_SREGS: {
1802 		kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
1803 		r = -ENOMEM;
1804 		if (!kvm_sregs)
1805 			goto out;
1806 		r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs);
1807 		if (r)
1808 			goto out;
1809 		r = -EFAULT;
1810 		if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs)))
1811 			goto out;
1812 		r = 0;
1813 		break;
1814 	}
1815 	case KVM_SET_SREGS: {
1816 		kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs));
1817 		if (IS_ERR(kvm_sregs)) {
1818 			r = PTR_ERR(kvm_sregs);
1819 			goto out;
1820 		}
1821 		r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs);
1822 		if (r)
1823 			goto out;
1824 		r = 0;
1825 		break;
1826 	}
1827 	case KVM_GET_MP_STATE: {
1828 		struct kvm_mp_state mp_state;
1829 
1830 		r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
1831 		if (r)
1832 			goto out;
1833 		r = -EFAULT;
1834 		if (copy_to_user(argp, &mp_state, sizeof mp_state))
1835 			goto out;
1836 		r = 0;
1837 		break;
1838 	}
1839 	case KVM_SET_MP_STATE: {
1840 		struct kvm_mp_state mp_state;
1841 
1842 		r = -EFAULT;
1843 		if (copy_from_user(&mp_state, argp, sizeof mp_state))
1844 			goto out;
1845 		r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
1846 		if (r)
1847 			goto out;
1848 		r = 0;
1849 		break;
1850 	}
1851 	case KVM_TRANSLATE: {
1852 		struct kvm_translation tr;
1853 
1854 		r = -EFAULT;
1855 		if (copy_from_user(&tr, argp, sizeof tr))
1856 			goto out;
1857 		r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
1858 		if (r)
1859 			goto out;
1860 		r = -EFAULT;
1861 		if (copy_to_user(argp, &tr, sizeof tr))
1862 			goto out;
1863 		r = 0;
1864 		break;
1865 	}
1866 	case KVM_SET_GUEST_DEBUG: {
1867 		struct kvm_guest_debug dbg;
1868 
1869 		r = -EFAULT;
1870 		if (copy_from_user(&dbg, argp, sizeof dbg))
1871 			goto out;
1872 		r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg);
1873 		if (r)
1874 			goto out;
1875 		r = 0;
1876 		break;
1877 	}
1878 	case KVM_SET_SIGNAL_MASK: {
1879 		struct kvm_signal_mask __user *sigmask_arg = argp;
1880 		struct kvm_signal_mask kvm_sigmask;
1881 		sigset_t sigset, *p;
1882 
1883 		p = NULL;
1884 		if (argp) {
1885 			r = -EFAULT;
1886 			if (copy_from_user(&kvm_sigmask, argp,
1887 					   sizeof kvm_sigmask))
1888 				goto out;
1889 			r = -EINVAL;
1890 			if (kvm_sigmask.len != sizeof sigset)
1891 				goto out;
1892 			r = -EFAULT;
1893 			if (copy_from_user(&sigset, sigmask_arg->sigset,
1894 					   sizeof sigset))
1895 				goto out;
1896 			p = &sigset;
1897 		}
1898 		r = kvm_vcpu_ioctl_set_sigmask(vcpu, p);
1899 		break;
1900 	}
1901 	case KVM_GET_FPU: {
1902 		fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
1903 		r = -ENOMEM;
1904 		if (!fpu)
1905 			goto out;
1906 		r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
1907 		if (r)
1908 			goto out;
1909 		r = -EFAULT;
1910 		if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu)))
1911 			goto out;
1912 		r = 0;
1913 		break;
1914 	}
1915 	case KVM_SET_FPU: {
1916 		fpu = memdup_user(argp, sizeof(*fpu));
1917 		if (IS_ERR(fpu)) {
1918 			r = PTR_ERR(fpu);
1919 			goto out;
1920 		}
1921 		r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
1922 		if (r)
1923 			goto out;
1924 		r = 0;
1925 		break;
1926 	}
1927 	default:
1928 		r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
1929 	}
1930 out:
1931 	vcpu_put(vcpu);
1932 	kfree(fpu);
1933 	kfree(kvm_sregs);
1934 	return r;
1935 }
1936 
1937 #ifdef CONFIG_COMPAT
1938 static long kvm_vcpu_compat_ioctl(struct file *filp,
1939 				  unsigned int ioctl, unsigned long arg)
1940 {
1941 	struct kvm_vcpu *vcpu = filp->private_data;
1942 	void __user *argp = compat_ptr(arg);
1943 	int r;
1944 
1945 	if (vcpu->kvm->mm != current->mm)
1946 		return -EIO;
1947 
1948 	switch (ioctl) {
1949 	case KVM_SET_SIGNAL_MASK: {
1950 		struct kvm_signal_mask __user *sigmask_arg = argp;
1951 		struct kvm_signal_mask kvm_sigmask;
1952 		compat_sigset_t csigset;
1953 		sigset_t sigset;
1954 
1955 		if (argp) {
1956 			r = -EFAULT;
1957 			if (copy_from_user(&kvm_sigmask, argp,
1958 					   sizeof kvm_sigmask))
1959 				goto out;
1960 			r = -EINVAL;
1961 			if (kvm_sigmask.len != sizeof csigset)
1962 				goto out;
1963 			r = -EFAULT;
1964 			if (copy_from_user(&csigset, sigmask_arg->sigset,
1965 					   sizeof csigset))
1966 				goto out;
1967 		}
1968 		sigset_from_compat(&sigset, &csigset);
1969 		r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
1970 		break;
1971 	}
1972 	default:
1973 		r = kvm_vcpu_ioctl(filp, ioctl, arg);
1974 	}
1975 
1976 out:
1977 	return r;
1978 }
1979 #endif
1980 
1981 static long kvm_vm_ioctl(struct file *filp,
1982 			   unsigned int ioctl, unsigned long arg)
1983 {
1984 	struct kvm *kvm = filp->private_data;
1985 	void __user *argp = (void __user *)arg;
1986 	int r;
1987 
1988 	if (kvm->mm != current->mm)
1989 		return -EIO;
1990 	switch (ioctl) {
1991 	case KVM_CREATE_VCPU:
1992 		r = kvm_vm_ioctl_create_vcpu(kvm, arg);
1993 		if (r < 0)
1994 			goto out;
1995 		break;
1996 	case KVM_SET_USER_MEMORY_REGION: {
1997 		struct kvm_userspace_memory_region kvm_userspace_mem;
1998 
1999 		r = -EFAULT;
2000 		if (copy_from_user(&kvm_userspace_mem, argp,
2001 						sizeof kvm_userspace_mem))
2002 			goto out;
2003 
2004 		r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem, 1);
2005 		if (r)
2006 			goto out;
2007 		break;
2008 	}
2009 	case KVM_GET_DIRTY_LOG: {
2010 		struct kvm_dirty_log log;
2011 
2012 		r = -EFAULT;
2013 		if (copy_from_user(&log, argp, sizeof log))
2014 			goto out;
2015 		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
2016 		if (r)
2017 			goto out;
2018 		break;
2019 	}
2020 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2021 	case KVM_REGISTER_COALESCED_MMIO: {
2022 		struct kvm_coalesced_mmio_zone zone;
2023 		r = -EFAULT;
2024 		if (copy_from_user(&zone, argp, sizeof zone))
2025 			goto out;
2026 		r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
2027 		if (r)
2028 			goto out;
2029 		r = 0;
2030 		break;
2031 	}
2032 	case KVM_UNREGISTER_COALESCED_MMIO: {
2033 		struct kvm_coalesced_mmio_zone zone;
2034 		r = -EFAULT;
2035 		if (copy_from_user(&zone, argp, sizeof zone))
2036 			goto out;
2037 		r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
2038 		if (r)
2039 			goto out;
2040 		r = 0;
2041 		break;
2042 	}
2043 #endif
2044 	case KVM_IRQFD: {
2045 		struct kvm_irqfd data;
2046 
2047 		r = -EFAULT;
2048 		if (copy_from_user(&data, argp, sizeof data))
2049 			goto out;
2050 		r = kvm_irqfd(kvm, &data);
2051 		break;
2052 	}
2053 	case KVM_IOEVENTFD: {
2054 		struct kvm_ioeventfd data;
2055 
2056 		r = -EFAULT;
2057 		if (copy_from_user(&data, argp, sizeof data))
2058 			goto out;
2059 		r = kvm_ioeventfd(kvm, &data);
2060 		break;
2061 	}
2062 #ifdef CONFIG_KVM_APIC_ARCHITECTURE
2063 	case KVM_SET_BOOT_CPU_ID:
2064 		r = 0;
2065 		mutex_lock(&kvm->lock);
2066 		if (atomic_read(&kvm->online_vcpus) != 0)
2067 			r = -EBUSY;
2068 		else
2069 			kvm->bsp_vcpu_id = arg;
2070 		mutex_unlock(&kvm->lock);
2071 		break;
2072 #endif
2073 #ifdef CONFIG_HAVE_KVM_MSI
2074 	case KVM_SIGNAL_MSI: {
2075 		struct kvm_msi msi;
2076 
2077 		r = -EFAULT;
2078 		if (copy_from_user(&msi, argp, sizeof msi))
2079 			goto out;
2080 		r = kvm_send_userspace_msi(kvm, &msi);
2081 		break;
2082 	}
2083 #endif
2084 	default:
2085 		r = kvm_arch_vm_ioctl(filp, ioctl, arg);
2086 		if (r == -ENOTTY)
2087 			r = kvm_vm_ioctl_assigned_device(kvm, ioctl, arg);
2088 	}
2089 out:
2090 	return r;
2091 }
2092 
2093 #ifdef CONFIG_COMPAT
2094 struct compat_kvm_dirty_log {
2095 	__u32 slot;
2096 	__u32 padding1;
2097 	union {
2098 		compat_uptr_t dirty_bitmap; /* one bit per page */
2099 		__u64 padding2;
2100 	};
2101 };
2102 
2103 static long kvm_vm_compat_ioctl(struct file *filp,
2104 			   unsigned int ioctl, unsigned long arg)
2105 {
2106 	struct kvm *kvm = filp->private_data;
2107 	int r;
2108 
2109 	if (kvm->mm != current->mm)
2110 		return -EIO;
2111 	switch (ioctl) {
2112 	case KVM_GET_DIRTY_LOG: {
2113 		struct compat_kvm_dirty_log compat_log;
2114 		struct kvm_dirty_log log;
2115 
2116 		r = -EFAULT;
2117 		if (copy_from_user(&compat_log, (void __user *)arg,
2118 				   sizeof(compat_log)))
2119 			goto out;
2120 		log.slot	 = compat_log.slot;
2121 		log.padding1	 = compat_log.padding1;
2122 		log.padding2	 = compat_log.padding2;
2123 		log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
2124 
2125 		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
2126 		if (r)
2127 			goto out;
2128 		break;
2129 	}
2130 	default:
2131 		r = kvm_vm_ioctl(filp, ioctl, arg);
2132 	}
2133 
2134 out:
2135 	return r;
2136 }
2137 #endif
2138 
2139 static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
2140 {
2141 	struct page *page[1];
2142 	unsigned long addr;
2143 	int npages;
2144 	gfn_t gfn = vmf->pgoff;
2145 	struct kvm *kvm = vma->vm_file->private_data;
2146 
2147 	addr = gfn_to_hva(kvm, gfn);
2148 	if (kvm_is_error_hva(addr))
2149 		return VM_FAULT_SIGBUS;
2150 
2151 	npages = get_user_pages(current, current->mm, addr, 1, 1, 0, page,
2152 				NULL);
2153 	if (unlikely(npages != 1))
2154 		return VM_FAULT_SIGBUS;
2155 
2156 	vmf->page = page[0];
2157 	return 0;
2158 }
2159 
2160 static const struct vm_operations_struct kvm_vm_vm_ops = {
2161 	.fault = kvm_vm_fault,
2162 };
2163 
2164 static int kvm_vm_mmap(struct file *file, struct vm_area_struct *vma)
2165 {
2166 	vma->vm_ops = &kvm_vm_vm_ops;
2167 	return 0;
2168 }
2169 
2170 static struct file_operations kvm_vm_fops = {
2171 	.release        = kvm_vm_release,
2172 	.unlocked_ioctl = kvm_vm_ioctl,
2173 #ifdef CONFIG_COMPAT
2174 	.compat_ioctl   = kvm_vm_compat_ioctl,
2175 #endif
2176 	.mmap           = kvm_vm_mmap,
2177 	.llseek		= noop_llseek,
2178 };
2179 
2180 static int kvm_dev_ioctl_create_vm(unsigned long type)
2181 {
2182 	int r;
2183 	struct kvm *kvm;
2184 
2185 	kvm = kvm_create_vm(type);
2186 	if (IS_ERR(kvm))
2187 		return PTR_ERR(kvm);
2188 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2189 	r = kvm_coalesced_mmio_init(kvm);
2190 	if (r < 0) {
2191 		kvm_put_kvm(kvm);
2192 		return r;
2193 	}
2194 #endif
2195 	r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
2196 	if (r < 0)
2197 		kvm_put_kvm(kvm);
2198 
2199 	return r;
2200 }
2201 
2202 static long kvm_dev_ioctl_check_extension_generic(long arg)
2203 {
2204 	switch (arg) {
2205 	case KVM_CAP_USER_MEMORY:
2206 	case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
2207 	case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
2208 #ifdef CONFIG_KVM_APIC_ARCHITECTURE
2209 	case KVM_CAP_SET_BOOT_CPU_ID:
2210 #endif
2211 	case KVM_CAP_INTERNAL_ERROR_DATA:
2212 #ifdef CONFIG_HAVE_KVM_MSI
2213 	case KVM_CAP_SIGNAL_MSI:
2214 #endif
2215 		return 1;
2216 #ifdef CONFIG_HAVE_KVM_IRQCHIP
2217 	case KVM_CAP_IRQ_ROUTING:
2218 		return KVM_MAX_IRQ_ROUTES;
2219 #endif
2220 	default:
2221 		break;
2222 	}
2223 	return kvm_dev_ioctl_check_extension(arg);
2224 }
2225 
2226 static long kvm_dev_ioctl(struct file *filp,
2227 			  unsigned int ioctl, unsigned long arg)
2228 {
2229 	long r = -EINVAL;
2230 
2231 	switch (ioctl) {
2232 	case KVM_GET_API_VERSION:
2233 		r = -EINVAL;
2234 		if (arg)
2235 			goto out;
2236 		r = KVM_API_VERSION;
2237 		break;
2238 	case KVM_CREATE_VM:
2239 		r = kvm_dev_ioctl_create_vm(arg);
2240 		break;
2241 	case KVM_CHECK_EXTENSION:
2242 		r = kvm_dev_ioctl_check_extension_generic(arg);
2243 		break;
2244 	case KVM_GET_VCPU_MMAP_SIZE:
2245 		r = -EINVAL;
2246 		if (arg)
2247 			goto out;
2248 		r = PAGE_SIZE;     /* struct kvm_run */
2249 #ifdef CONFIG_X86
2250 		r += PAGE_SIZE;    /* pio data page */
2251 #endif
2252 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2253 		r += PAGE_SIZE;    /* coalesced mmio ring page */
2254 #endif
2255 		break;
2256 	case KVM_TRACE_ENABLE:
2257 	case KVM_TRACE_PAUSE:
2258 	case KVM_TRACE_DISABLE:
2259 		r = -EOPNOTSUPP;
2260 		break;
2261 	default:
2262 		return kvm_arch_dev_ioctl(filp, ioctl, arg);
2263 	}
2264 out:
2265 	return r;
2266 }
2267 
2268 static struct file_operations kvm_chardev_ops = {
2269 	.unlocked_ioctl = kvm_dev_ioctl,
2270 	.compat_ioctl   = kvm_dev_ioctl,
2271 	.llseek		= noop_llseek,
2272 };
2273 
2274 static struct miscdevice kvm_dev = {
2275 	KVM_MINOR,
2276 	"kvm",
2277 	&kvm_chardev_ops,
2278 };
2279 
2280 static void hardware_enable_nolock(void *junk)
2281 {
2282 	int cpu = raw_smp_processor_id();
2283 	int r;
2284 
2285 	if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
2286 		return;
2287 
2288 	cpumask_set_cpu(cpu, cpus_hardware_enabled);
2289 
2290 	r = kvm_arch_hardware_enable(NULL);
2291 
2292 	if (r) {
2293 		cpumask_clear_cpu(cpu, cpus_hardware_enabled);
2294 		atomic_inc(&hardware_enable_failed);
2295 		printk(KERN_INFO "kvm: enabling virtualization on "
2296 				 "CPU%d failed\n", cpu);
2297 	}
2298 }
2299 
2300 static void hardware_enable(void *junk)
2301 {
2302 	raw_spin_lock(&kvm_lock);
2303 	hardware_enable_nolock(junk);
2304 	raw_spin_unlock(&kvm_lock);
2305 }
2306 
2307 static void hardware_disable_nolock(void *junk)
2308 {
2309 	int cpu = raw_smp_processor_id();
2310 
2311 	if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
2312 		return;
2313 	cpumask_clear_cpu(cpu, cpus_hardware_enabled);
2314 	kvm_arch_hardware_disable(NULL);
2315 }
2316 
2317 static void hardware_disable(void *junk)
2318 {
2319 	raw_spin_lock(&kvm_lock);
2320 	hardware_disable_nolock(junk);
2321 	raw_spin_unlock(&kvm_lock);
2322 }
2323 
2324 static void hardware_disable_all_nolock(void)
2325 {
2326 	BUG_ON(!kvm_usage_count);
2327 
2328 	kvm_usage_count--;
2329 	if (!kvm_usage_count)
2330 		on_each_cpu(hardware_disable_nolock, NULL, 1);
2331 }
2332 
2333 static void hardware_disable_all(void)
2334 {
2335 	raw_spin_lock(&kvm_lock);
2336 	hardware_disable_all_nolock();
2337 	raw_spin_unlock(&kvm_lock);
2338 }
2339 
2340 static int hardware_enable_all(void)
2341 {
2342 	int r = 0;
2343 
2344 	raw_spin_lock(&kvm_lock);
2345 
2346 	kvm_usage_count++;
2347 	if (kvm_usage_count == 1) {
2348 		atomic_set(&hardware_enable_failed, 0);
2349 		on_each_cpu(hardware_enable_nolock, NULL, 1);
2350 
2351 		if (atomic_read(&hardware_enable_failed)) {
2352 			hardware_disable_all_nolock();
2353 			r = -EBUSY;
2354 		}
2355 	}
2356 
2357 	raw_spin_unlock(&kvm_lock);
2358 
2359 	return r;
2360 }
2361 
2362 static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
2363 			   void *v)
2364 {
2365 	int cpu = (long)v;
2366 
2367 	if (!kvm_usage_count)
2368 		return NOTIFY_OK;
2369 
2370 	val &= ~CPU_TASKS_FROZEN;
2371 	switch (val) {
2372 	case CPU_DYING:
2373 		printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
2374 		       cpu);
2375 		hardware_disable(NULL);
2376 		break;
2377 	case CPU_STARTING:
2378 		printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
2379 		       cpu);
2380 		hardware_enable(NULL);
2381 		break;
2382 	}
2383 	return NOTIFY_OK;
2384 }
2385 
2386 
2387 asmlinkage void kvm_spurious_fault(void)
2388 {
2389 	/* Fault while not rebooting.  We want the trace. */
2390 	BUG();
2391 }
2392 EXPORT_SYMBOL_GPL(kvm_spurious_fault);
2393 
2394 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
2395 		      void *v)
2396 {
2397 	/*
2398 	 * Some (well, at least mine) BIOSes hang on reboot if
2399 	 * in vmx root mode.
2400 	 *
2401 	 * And Intel TXT required VMX off for all cpu when system shutdown.
2402 	 */
2403 	printk(KERN_INFO "kvm: exiting hardware virtualization\n");
2404 	kvm_rebooting = true;
2405 	on_each_cpu(hardware_disable_nolock, NULL, 1);
2406 	return NOTIFY_OK;
2407 }
2408 
2409 static struct notifier_block kvm_reboot_notifier = {
2410 	.notifier_call = kvm_reboot,
2411 	.priority = 0,
2412 };
2413 
2414 static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
2415 {
2416 	int i;
2417 
2418 	for (i = 0; i < bus->dev_count; i++) {
2419 		struct kvm_io_device *pos = bus->range[i].dev;
2420 
2421 		kvm_iodevice_destructor(pos);
2422 	}
2423 	kfree(bus);
2424 }
2425 
2426 int kvm_io_bus_sort_cmp(const void *p1, const void *p2)
2427 {
2428 	const struct kvm_io_range *r1 = p1;
2429 	const struct kvm_io_range *r2 = p2;
2430 
2431 	if (r1->addr < r2->addr)
2432 		return -1;
2433 	if (r1->addr + r1->len > r2->addr + r2->len)
2434 		return 1;
2435 	return 0;
2436 }
2437 
2438 int kvm_io_bus_insert_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev,
2439 			  gpa_t addr, int len)
2440 {
2441 	bus->range[bus->dev_count++] = (struct kvm_io_range) {
2442 		.addr = addr,
2443 		.len = len,
2444 		.dev = dev,
2445 	};
2446 
2447 	sort(bus->range, bus->dev_count, sizeof(struct kvm_io_range),
2448 		kvm_io_bus_sort_cmp, NULL);
2449 
2450 	return 0;
2451 }
2452 
2453 int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus,
2454 			     gpa_t addr, int len)
2455 {
2456 	struct kvm_io_range *range, key;
2457 	int off;
2458 
2459 	key = (struct kvm_io_range) {
2460 		.addr = addr,
2461 		.len = len,
2462 	};
2463 
2464 	range = bsearch(&key, bus->range, bus->dev_count,
2465 			sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp);
2466 	if (range == NULL)
2467 		return -ENOENT;
2468 
2469 	off = range - bus->range;
2470 
2471 	while (off > 0 && kvm_io_bus_sort_cmp(&key, &bus->range[off-1]) == 0)
2472 		off--;
2473 
2474 	return off;
2475 }
2476 
2477 /* kvm_io_bus_write - called under kvm->slots_lock */
2478 int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
2479 		     int len, const void *val)
2480 {
2481 	int idx;
2482 	struct kvm_io_bus *bus;
2483 	struct kvm_io_range range;
2484 
2485 	range = (struct kvm_io_range) {
2486 		.addr = addr,
2487 		.len = len,
2488 	};
2489 
2490 	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
2491 	idx = kvm_io_bus_get_first_dev(bus, addr, len);
2492 	if (idx < 0)
2493 		return -EOPNOTSUPP;
2494 
2495 	while (idx < bus->dev_count &&
2496 		kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) {
2497 		if (!kvm_iodevice_write(bus->range[idx].dev, addr, len, val))
2498 			return 0;
2499 		idx++;
2500 	}
2501 
2502 	return -EOPNOTSUPP;
2503 }
2504 
2505 /* kvm_io_bus_read - called under kvm->slots_lock */
2506 int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
2507 		    int len, void *val)
2508 {
2509 	int idx;
2510 	struct kvm_io_bus *bus;
2511 	struct kvm_io_range range;
2512 
2513 	range = (struct kvm_io_range) {
2514 		.addr = addr,
2515 		.len = len,
2516 	};
2517 
2518 	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
2519 	idx = kvm_io_bus_get_first_dev(bus, addr, len);
2520 	if (idx < 0)
2521 		return -EOPNOTSUPP;
2522 
2523 	while (idx < bus->dev_count &&
2524 		kvm_io_bus_sort_cmp(&range, &bus->range[idx]) == 0) {
2525 		if (!kvm_iodevice_read(bus->range[idx].dev, addr, len, val))
2526 			return 0;
2527 		idx++;
2528 	}
2529 
2530 	return -EOPNOTSUPP;
2531 }
2532 
2533 /* Caller must hold slots_lock. */
2534 int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
2535 			    int len, struct kvm_io_device *dev)
2536 {
2537 	struct kvm_io_bus *new_bus, *bus;
2538 
2539 	bus = kvm->buses[bus_idx];
2540 	if (bus->dev_count > NR_IOBUS_DEVS - 1)
2541 		return -ENOSPC;
2542 
2543 	new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count + 1) *
2544 			  sizeof(struct kvm_io_range)), GFP_KERNEL);
2545 	if (!new_bus)
2546 		return -ENOMEM;
2547 	memcpy(new_bus, bus, sizeof(*bus) + (bus->dev_count *
2548 	       sizeof(struct kvm_io_range)));
2549 	kvm_io_bus_insert_dev(new_bus, dev, addr, len);
2550 	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
2551 	synchronize_srcu_expedited(&kvm->srcu);
2552 	kfree(bus);
2553 
2554 	return 0;
2555 }
2556 
2557 /* Caller must hold slots_lock. */
2558 int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
2559 			      struct kvm_io_device *dev)
2560 {
2561 	int i, r;
2562 	struct kvm_io_bus *new_bus, *bus;
2563 
2564 	bus = kvm->buses[bus_idx];
2565 	r = -ENOENT;
2566 	for (i = 0; i < bus->dev_count; i++)
2567 		if (bus->range[i].dev == dev) {
2568 			r = 0;
2569 			break;
2570 		}
2571 
2572 	if (r)
2573 		return r;
2574 
2575 	new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count - 1) *
2576 			  sizeof(struct kvm_io_range)), GFP_KERNEL);
2577 	if (!new_bus)
2578 		return -ENOMEM;
2579 
2580 	memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range));
2581 	new_bus->dev_count--;
2582 	memcpy(new_bus->range + i, bus->range + i + 1,
2583 	       (new_bus->dev_count - i) * sizeof(struct kvm_io_range));
2584 
2585 	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
2586 	synchronize_srcu_expedited(&kvm->srcu);
2587 	kfree(bus);
2588 	return r;
2589 }
2590 
2591 static struct notifier_block kvm_cpu_notifier = {
2592 	.notifier_call = kvm_cpu_hotplug,
2593 };
2594 
2595 static int vm_stat_get(void *_offset, u64 *val)
2596 {
2597 	unsigned offset = (long)_offset;
2598 	struct kvm *kvm;
2599 
2600 	*val = 0;
2601 	raw_spin_lock(&kvm_lock);
2602 	list_for_each_entry(kvm, &vm_list, vm_list)
2603 		*val += *(u32 *)((void *)kvm + offset);
2604 	raw_spin_unlock(&kvm_lock);
2605 	return 0;
2606 }
2607 
2608 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
2609 
2610 static int vcpu_stat_get(void *_offset, u64 *val)
2611 {
2612 	unsigned offset = (long)_offset;
2613 	struct kvm *kvm;
2614 	struct kvm_vcpu *vcpu;
2615 	int i;
2616 
2617 	*val = 0;
2618 	raw_spin_lock(&kvm_lock);
2619 	list_for_each_entry(kvm, &vm_list, vm_list)
2620 		kvm_for_each_vcpu(i, vcpu, kvm)
2621 			*val += *(u32 *)((void *)vcpu + offset);
2622 
2623 	raw_spin_unlock(&kvm_lock);
2624 	return 0;
2625 }
2626 
2627 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
2628 
2629 static const struct file_operations *stat_fops[] = {
2630 	[KVM_STAT_VCPU] = &vcpu_stat_fops,
2631 	[KVM_STAT_VM]   = &vm_stat_fops,
2632 };
2633 
2634 static int kvm_init_debug(void)
2635 {
2636 	int r = -EFAULT;
2637 	struct kvm_stats_debugfs_item *p;
2638 
2639 	kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
2640 	if (kvm_debugfs_dir == NULL)
2641 		goto out;
2642 
2643 	for (p = debugfs_entries; p->name; ++p) {
2644 		p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
2645 						(void *)(long)p->offset,
2646 						stat_fops[p->kind]);
2647 		if (p->dentry == NULL)
2648 			goto out_dir;
2649 	}
2650 
2651 	return 0;
2652 
2653 out_dir:
2654 	debugfs_remove_recursive(kvm_debugfs_dir);
2655 out:
2656 	return r;
2657 }
2658 
2659 static void kvm_exit_debug(void)
2660 {
2661 	struct kvm_stats_debugfs_item *p;
2662 
2663 	for (p = debugfs_entries; p->name; ++p)
2664 		debugfs_remove(p->dentry);
2665 	debugfs_remove(kvm_debugfs_dir);
2666 }
2667 
2668 static int kvm_suspend(void)
2669 {
2670 	if (kvm_usage_count)
2671 		hardware_disable_nolock(NULL);
2672 	return 0;
2673 }
2674 
2675 static void kvm_resume(void)
2676 {
2677 	if (kvm_usage_count) {
2678 		WARN_ON(raw_spin_is_locked(&kvm_lock));
2679 		hardware_enable_nolock(NULL);
2680 	}
2681 }
2682 
2683 static struct syscore_ops kvm_syscore_ops = {
2684 	.suspend = kvm_suspend,
2685 	.resume = kvm_resume,
2686 };
2687 
2688 struct page *bad_page;
2689 pfn_t bad_pfn;
2690 
2691 static inline
2692 struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
2693 {
2694 	return container_of(pn, struct kvm_vcpu, preempt_notifier);
2695 }
2696 
2697 static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
2698 {
2699 	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
2700 
2701 	kvm_arch_vcpu_load(vcpu, cpu);
2702 }
2703 
2704 static void kvm_sched_out(struct preempt_notifier *pn,
2705 			  struct task_struct *next)
2706 {
2707 	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
2708 
2709 	kvm_arch_vcpu_put(vcpu);
2710 }
2711 
2712 int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
2713 		  struct module *module)
2714 {
2715 	int r;
2716 	int cpu;
2717 
2718 	r = kvm_arch_init(opaque);
2719 	if (r)
2720 		goto out_fail;
2721 
2722 	bad_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
2723 
2724 	if (bad_page == NULL) {
2725 		r = -ENOMEM;
2726 		goto out;
2727 	}
2728 
2729 	bad_pfn = page_to_pfn(bad_page);
2730 
2731 	hwpoison_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
2732 
2733 	if (hwpoison_page == NULL) {
2734 		r = -ENOMEM;
2735 		goto out_free_0;
2736 	}
2737 
2738 	hwpoison_pfn = page_to_pfn(hwpoison_page);
2739 
2740 	fault_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
2741 
2742 	if (fault_page == NULL) {
2743 		r = -ENOMEM;
2744 		goto out_free_0;
2745 	}
2746 
2747 	fault_pfn = page_to_pfn(fault_page);
2748 
2749 	if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
2750 		r = -ENOMEM;
2751 		goto out_free_0;
2752 	}
2753 
2754 	r = kvm_arch_hardware_setup();
2755 	if (r < 0)
2756 		goto out_free_0a;
2757 
2758 	for_each_online_cpu(cpu) {
2759 		smp_call_function_single(cpu,
2760 				kvm_arch_check_processor_compat,
2761 				&r, 1);
2762 		if (r < 0)
2763 			goto out_free_1;
2764 	}
2765 
2766 	r = register_cpu_notifier(&kvm_cpu_notifier);
2767 	if (r)
2768 		goto out_free_2;
2769 	register_reboot_notifier(&kvm_reboot_notifier);
2770 
2771 	/* A kmem cache lets us meet the alignment requirements of fx_save. */
2772 	if (!vcpu_align)
2773 		vcpu_align = __alignof__(struct kvm_vcpu);
2774 	kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size, vcpu_align,
2775 					   0, NULL);
2776 	if (!kvm_vcpu_cache) {
2777 		r = -ENOMEM;
2778 		goto out_free_3;
2779 	}
2780 
2781 	r = kvm_async_pf_init();
2782 	if (r)
2783 		goto out_free;
2784 
2785 	kvm_chardev_ops.owner = module;
2786 	kvm_vm_fops.owner = module;
2787 	kvm_vcpu_fops.owner = module;
2788 
2789 	r = misc_register(&kvm_dev);
2790 	if (r) {
2791 		printk(KERN_ERR "kvm: misc device register failed\n");
2792 		goto out_unreg;
2793 	}
2794 
2795 	register_syscore_ops(&kvm_syscore_ops);
2796 
2797 	kvm_preempt_ops.sched_in = kvm_sched_in;
2798 	kvm_preempt_ops.sched_out = kvm_sched_out;
2799 
2800 	r = kvm_init_debug();
2801 	if (r) {
2802 		printk(KERN_ERR "kvm: create debugfs files failed\n");
2803 		goto out_undebugfs;
2804 	}
2805 
2806 	return 0;
2807 
2808 out_undebugfs:
2809 	unregister_syscore_ops(&kvm_syscore_ops);
2810 out_unreg:
2811 	kvm_async_pf_deinit();
2812 out_free:
2813 	kmem_cache_destroy(kvm_vcpu_cache);
2814 out_free_3:
2815 	unregister_reboot_notifier(&kvm_reboot_notifier);
2816 	unregister_cpu_notifier(&kvm_cpu_notifier);
2817 out_free_2:
2818 out_free_1:
2819 	kvm_arch_hardware_unsetup();
2820 out_free_0a:
2821 	free_cpumask_var(cpus_hardware_enabled);
2822 out_free_0:
2823 	if (fault_page)
2824 		__free_page(fault_page);
2825 	if (hwpoison_page)
2826 		__free_page(hwpoison_page);
2827 	__free_page(bad_page);
2828 out:
2829 	kvm_arch_exit();
2830 out_fail:
2831 	return r;
2832 }
2833 EXPORT_SYMBOL_GPL(kvm_init);
2834 
2835 void kvm_exit(void)
2836 {
2837 	kvm_exit_debug();
2838 	misc_deregister(&kvm_dev);
2839 	kmem_cache_destroy(kvm_vcpu_cache);
2840 	kvm_async_pf_deinit();
2841 	unregister_syscore_ops(&kvm_syscore_ops);
2842 	unregister_reboot_notifier(&kvm_reboot_notifier);
2843 	unregister_cpu_notifier(&kvm_cpu_notifier);
2844 	on_each_cpu(hardware_disable_nolock, NULL, 1);
2845 	kvm_arch_hardware_unsetup();
2846 	kvm_arch_exit();
2847 	free_cpumask_var(cpus_hardware_enabled);
2848 	__free_page(fault_page);
2849 	__free_page(hwpoison_page);
2850 	__free_page(bad_page);
2851 }
2852 EXPORT_SYMBOL_GPL(kvm_exit);
2853