xref: /linux/virt/kvm/kvm_main.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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 affilates.
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/sysdev.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 
51 #include <asm/processor.h>
52 #include <asm/io.h>
53 #include <asm/uaccess.h>
54 #include <asm/pgtable.h>
55 #include <asm-generic/bitops/le.h>
56 
57 #include "coalesced_mmio.h"
58 
59 #define CREATE_TRACE_POINTS
60 #include <trace/events/kvm.h>
61 
62 MODULE_AUTHOR("Qumranet");
63 MODULE_LICENSE("GPL");
64 
65 /*
66  * Ordering of locks:
67  *
68  * 		kvm->lock --> kvm->slots_lock --> kvm->irq_lock
69  */
70 
71 DEFINE_SPINLOCK(kvm_lock);
72 LIST_HEAD(vm_list);
73 
74 static cpumask_var_t cpus_hardware_enabled;
75 static int kvm_usage_count = 0;
76 static atomic_t hardware_enable_failed;
77 
78 struct kmem_cache *kvm_vcpu_cache;
79 EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
80 
81 static __read_mostly struct preempt_ops kvm_preempt_ops;
82 
83 struct dentry *kvm_debugfs_dir;
84 
85 static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
86 			   unsigned long arg);
87 static int hardware_enable_all(void);
88 static void hardware_disable_all(void);
89 
90 static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
91 
92 static bool kvm_rebooting;
93 
94 static bool largepages_enabled = true;
95 
96 static struct page *hwpoison_page;
97 static pfn_t hwpoison_pfn;
98 
99 static struct page *fault_page;
100 static pfn_t fault_pfn;
101 
102 inline int kvm_is_mmio_pfn(pfn_t pfn)
103 {
104 	if (pfn_valid(pfn)) {
105 		struct page *page = compound_head(pfn_to_page(pfn));
106 		return PageReserved(page);
107 	}
108 
109 	return true;
110 }
111 
112 /*
113  * Switches to specified vcpu, until a matching vcpu_put()
114  */
115 void vcpu_load(struct kvm_vcpu *vcpu)
116 {
117 	int cpu;
118 
119 	mutex_lock(&vcpu->mutex);
120 	cpu = get_cpu();
121 	preempt_notifier_register(&vcpu->preempt_notifier);
122 	kvm_arch_vcpu_load(vcpu, cpu);
123 	put_cpu();
124 }
125 
126 void vcpu_put(struct kvm_vcpu *vcpu)
127 {
128 	preempt_disable();
129 	kvm_arch_vcpu_put(vcpu);
130 	preempt_notifier_unregister(&vcpu->preempt_notifier);
131 	preempt_enable();
132 	mutex_unlock(&vcpu->mutex);
133 }
134 
135 static void ack_flush(void *_completed)
136 {
137 }
138 
139 static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
140 {
141 	int i, cpu, me;
142 	cpumask_var_t cpus;
143 	bool called = true;
144 	struct kvm_vcpu *vcpu;
145 
146 	zalloc_cpumask_var(&cpus, GFP_ATOMIC);
147 
148 	raw_spin_lock(&kvm->requests_lock);
149 	me = smp_processor_id();
150 	kvm_for_each_vcpu(i, vcpu, kvm) {
151 		if (kvm_make_check_request(req, vcpu))
152 			continue;
153 		cpu = vcpu->cpu;
154 		if (cpus != NULL && cpu != -1 && cpu != me)
155 			cpumask_set_cpu(cpu, cpus);
156 	}
157 	if (unlikely(cpus == NULL))
158 		smp_call_function_many(cpu_online_mask, ack_flush, NULL, 1);
159 	else if (!cpumask_empty(cpus))
160 		smp_call_function_many(cpus, ack_flush, NULL, 1);
161 	else
162 		called = false;
163 	raw_spin_unlock(&kvm->requests_lock);
164 	free_cpumask_var(cpus);
165 	return called;
166 }
167 
168 void kvm_flush_remote_tlbs(struct kvm *kvm)
169 {
170 	if (make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
171 		++kvm->stat.remote_tlb_flush;
172 }
173 
174 void kvm_reload_remote_mmus(struct kvm *kvm)
175 {
176 	make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD);
177 }
178 
179 int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
180 {
181 	struct page *page;
182 	int r;
183 
184 	mutex_init(&vcpu->mutex);
185 	vcpu->cpu = -1;
186 	vcpu->kvm = kvm;
187 	vcpu->vcpu_id = id;
188 	init_waitqueue_head(&vcpu->wq);
189 
190 	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
191 	if (!page) {
192 		r = -ENOMEM;
193 		goto fail;
194 	}
195 	vcpu->run = page_address(page);
196 
197 	r = kvm_arch_vcpu_init(vcpu);
198 	if (r < 0)
199 		goto fail_free_run;
200 	return 0;
201 
202 fail_free_run:
203 	free_page((unsigned long)vcpu->run);
204 fail:
205 	return r;
206 }
207 EXPORT_SYMBOL_GPL(kvm_vcpu_init);
208 
209 void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
210 {
211 	kvm_arch_vcpu_uninit(vcpu);
212 	free_page((unsigned long)vcpu->run);
213 }
214 EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
215 
216 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
217 static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
218 {
219 	return container_of(mn, struct kvm, mmu_notifier);
220 }
221 
222 static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
223 					     struct mm_struct *mm,
224 					     unsigned long address)
225 {
226 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
227 	int need_tlb_flush, idx;
228 
229 	/*
230 	 * When ->invalidate_page runs, the linux pte has been zapped
231 	 * already but the page is still allocated until
232 	 * ->invalidate_page returns. So if we increase the sequence
233 	 * here the kvm page fault will notice if the spte can't be
234 	 * established because the page is going to be freed. If
235 	 * instead the kvm page fault establishes the spte before
236 	 * ->invalidate_page runs, kvm_unmap_hva will release it
237 	 * before returning.
238 	 *
239 	 * The sequence increase only need to be seen at spin_unlock
240 	 * time, and not at spin_lock time.
241 	 *
242 	 * Increasing the sequence after the spin_unlock would be
243 	 * unsafe because the kvm page fault could then establish the
244 	 * pte after kvm_unmap_hva returned, without noticing the page
245 	 * is going to be freed.
246 	 */
247 	idx = srcu_read_lock(&kvm->srcu);
248 	spin_lock(&kvm->mmu_lock);
249 	kvm->mmu_notifier_seq++;
250 	need_tlb_flush = kvm_unmap_hva(kvm, address);
251 	spin_unlock(&kvm->mmu_lock);
252 	srcu_read_unlock(&kvm->srcu, idx);
253 
254 	/* we've to flush the tlb before the pages can be freed */
255 	if (need_tlb_flush)
256 		kvm_flush_remote_tlbs(kvm);
257 
258 }
259 
260 static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
261 					struct mm_struct *mm,
262 					unsigned long address,
263 					pte_t pte)
264 {
265 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
266 	int idx;
267 
268 	idx = srcu_read_lock(&kvm->srcu);
269 	spin_lock(&kvm->mmu_lock);
270 	kvm->mmu_notifier_seq++;
271 	kvm_set_spte_hva(kvm, address, pte);
272 	spin_unlock(&kvm->mmu_lock);
273 	srcu_read_unlock(&kvm->srcu, idx);
274 }
275 
276 static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
277 						    struct mm_struct *mm,
278 						    unsigned long start,
279 						    unsigned long end)
280 {
281 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
282 	int need_tlb_flush = 0, idx;
283 
284 	idx = srcu_read_lock(&kvm->srcu);
285 	spin_lock(&kvm->mmu_lock);
286 	/*
287 	 * The count increase must become visible at unlock time as no
288 	 * spte can be established without taking the mmu_lock and
289 	 * count is also read inside the mmu_lock critical section.
290 	 */
291 	kvm->mmu_notifier_count++;
292 	for (; start < end; start += PAGE_SIZE)
293 		need_tlb_flush |= kvm_unmap_hva(kvm, start);
294 	spin_unlock(&kvm->mmu_lock);
295 	srcu_read_unlock(&kvm->srcu, idx);
296 
297 	/* we've to flush the tlb before the pages can be freed */
298 	if (need_tlb_flush)
299 		kvm_flush_remote_tlbs(kvm);
300 }
301 
302 static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
303 						  struct mm_struct *mm,
304 						  unsigned long start,
305 						  unsigned long end)
306 {
307 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
308 
309 	spin_lock(&kvm->mmu_lock);
310 	/*
311 	 * This sequence increase will notify the kvm page fault that
312 	 * the page that is going to be mapped in the spte could have
313 	 * been freed.
314 	 */
315 	kvm->mmu_notifier_seq++;
316 	/*
317 	 * The above sequence increase must be visible before the
318 	 * below count decrease but both values are read by the kvm
319 	 * page fault under mmu_lock spinlock so we don't need to add
320 	 * a smb_wmb() here in between the two.
321 	 */
322 	kvm->mmu_notifier_count--;
323 	spin_unlock(&kvm->mmu_lock);
324 
325 	BUG_ON(kvm->mmu_notifier_count < 0);
326 }
327 
328 static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
329 					      struct mm_struct *mm,
330 					      unsigned long address)
331 {
332 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
333 	int young, idx;
334 
335 	idx = srcu_read_lock(&kvm->srcu);
336 	spin_lock(&kvm->mmu_lock);
337 	young = kvm_age_hva(kvm, address);
338 	spin_unlock(&kvm->mmu_lock);
339 	srcu_read_unlock(&kvm->srcu, idx);
340 
341 	if (young)
342 		kvm_flush_remote_tlbs(kvm);
343 
344 	return young;
345 }
346 
347 static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
348 				     struct mm_struct *mm)
349 {
350 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
351 	int idx;
352 
353 	idx = srcu_read_lock(&kvm->srcu);
354 	kvm_arch_flush_shadow(kvm);
355 	srcu_read_unlock(&kvm->srcu, idx);
356 }
357 
358 static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
359 	.invalidate_page	= kvm_mmu_notifier_invalidate_page,
360 	.invalidate_range_start	= kvm_mmu_notifier_invalidate_range_start,
361 	.invalidate_range_end	= kvm_mmu_notifier_invalidate_range_end,
362 	.clear_flush_young	= kvm_mmu_notifier_clear_flush_young,
363 	.change_pte		= kvm_mmu_notifier_change_pte,
364 	.release		= kvm_mmu_notifier_release,
365 };
366 
367 static int kvm_init_mmu_notifier(struct kvm *kvm)
368 {
369 	kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
370 	return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
371 }
372 
373 #else  /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */
374 
375 static int kvm_init_mmu_notifier(struct kvm *kvm)
376 {
377 	return 0;
378 }
379 
380 #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
381 
382 static struct kvm *kvm_create_vm(void)
383 {
384 	int r = 0, i;
385 	struct kvm *kvm = kvm_arch_create_vm();
386 
387 	if (IS_ERR(kvm))
388 		goto out;
389 
390 	r = hardware_enable_all();
391 	if (r)
392 		goto out_err_nodisable;
393 
394 #ifdef CONFIG_HAVE_KVM_IRQCHIP
395 	INIT_HLIST_HEAD(&kvm->mask_notifier_list);
396 	INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
397 #endif
398 
399 	r = -ENOMEM;
400 	kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
401 	if (!kvm->memslots)
402 		goto out_err;
403 	if (init_srcu_struct(&kvm->srcu))
404 		goto out_err;
405 	for (i = 0; i < KVM_NR_BUSES; i++) {
406 		kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus),
407 					GFP_KERNEL);
408 		if (!kvm->buses[i]) {
409 			cleanup_srcu_struct(&kvm->srcu);
410 			goto out_err;
411 		}
412 	}
413 
414 	r = kvm_init_mmu_notifier(kvm);
415 	if (r) {
416 		cleanup_srcu_struct(&kvm->srcu);
417 		goto out_err;
418 	}
419 
420 	kvm->mm = current->mm;
421 	atomic_inc(&kvm->mm->mm_count);
422 	spin_lock_init(&kvm->mmu_lock);
423 	raw_spin_lock_init(&kvm->requests_lock);
424 	kvm_eventfd_init(kvm);
425 	mutex_init(&kvm->lock);
426 	mutex_init(&kvm->irq_lock);
427 	mutex_init(&kvm->slots_lock);
428 	atomic_set(&kvm->users_count, 1);
429 	spin_lock(&kvm_lock);
430 	list_add(&kvm->vm_list, &vm_list);
431 	spin_unlock(&kvm_lock);
432 out:
433 	return kvm;
434 
435 out_err:
436 	hardware_disable_all();
437 out_err_nodisable:
438 	for (i = 0; i < KVM_NR_BUSES; i++)
439 		kfree(kvm->buses[i]);
440 	kfree(kvm->memslots);
441 	kfree(kvm);
442 	return ERR_PTR(r);
443 }
444 
445 /*
446  * Free any memory in @free but not in @dont.
447  */
448 static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
449 				  struct kvm_memory_slot *dont)
450 {
451 	int i;
452 
453 	if (!dont || free->rmap != dont->rmap)
454 		vfree(free->rmap);
455 
456 	if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
457 		vfree(free->dirty_bitmap);
458 
459 
460 	for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
461 		if (!dont || free->lpage_info[i] != dont->lpage_info[i]) {
462 			vfree(free->lpage_info[i]);
463 			free->lpage_info[i] = NULL;
464 		}
465 	}
466 
467 	free->npages = 0;
468 	free->dirty_bitmap = NULL;
469 	free->rmap = NULL;
470 }
471 
472 void kvm_free_physmem(struct kvm *kvm)
473 {
474 	int i;
475 	struct kvm_memslots *slots = kvm->memslots;
476 
477 	for (i = 0; i < slots->nmemslots; ++i)
478 		kvm_free_physmem_slot(&slots->memslots[i], NULL);
479 
480 	kfree(kvm->memslots);
481 }
482 
483 static void kvm_destroy_vm(struct kvm *kvm)
484 {
485 	int i;
486 	struct mm_struct *mm = kvm->mm;
487 
488 	kvm_arch_sync_events(kvm);
489 	spin_lock(&kvm_lock);
490 	list_del(&kvm->vm_list);
491 	spin_unlock(&kvm_lock);
492 	kvm_free_irq_routing(kvm);
493 	for (i = 0; i < KVM_NR_BUSES; i++)
494 		kvm_io_bus_destroy(kvm->buses[i]);
495 	kvm_coalesced_mmio_free(kvm);
496 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
497 	mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
498 #else
499 	kvm_arch_flush_shadow(kvm);
500 #endif
501 	kvm_arch_destroy_vm(kvm);
502 	hardware_disable_all();
503 	mmdrop(mm);
504 }
505 
506 void kvm_get_kvm(struct kvm *kvm)
507 {
508 	atomic_inc(&kvm->users_count);
509 }
510 EXPORT_SYMBOL_GPL(kvm_get_kvm);
511 
512 void kvm_put_kvm(struct kvm *kvm)
513 {
514 	if (atomic_dec_and_test(&kvm->users_count))
515 		kvm_destroy_vm(kvm);
516 }
517 EXPORT_SYMBOL_GPL(kvm_put_kvm);
518 
519 
520 static int kvm_vm_release(struct inode *inode, struct file *filp)
521 {
522 	struct kvm *kvm = filp->private_data;
523 
524 	kvm_irqfd_release(kvm);
525 
526 	kvm_put_kvm(kvm);
527 	return 0;
528 }
529 
530 /*
531  * Allocate some memory and give it an address in the guest physical address
532  * space.
533  *
534  * Discontiguous memory is allowed, mostly for framebuffers.
535  *
536  * Must be called holding mmap_sem for write.
537  */
538 int __kvm_set_memory_region(struct kvm *kvm,
539 			    struct kvm_userspace_memory_region *mem,
540 			    int user_alloc)
541 {
542 	int r, flush_shadow = 0;
543 	gfn_t base_gfn;
544 	unsigned long npages;
545 	unsigned long i;
546 	struct kvm_memory_slot *memslot;
547 	struct kvm_memory_slot old, new;
548 	struct kvm_memslots *slots, *old_memslots;
549 
550 	r = -EINVAL;
551 	/* General sanity checks */
552 	if (mem->memory_size & (PAGE_SIZE - 1))
553 		goto out;
554 	if (mem->guest_phys_addr & (PAGE_SIZE - 1))
555 		goto out;
556 	if (user_alloc && (mem->userspace_addr & (PAGE_SIZE - 1)))
557 		goto out;
558 	if (mem->slot >= KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS)
559 		goto out;
560 	if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
561 		goto out;
562 
563 	memslot = &kvm->memslots->memslots[mem->slot];
564 	base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
565 	npages = mem->memory_size >> PAGE_SHIFT;
566 
567 	r = -EINVAL;
568 	if (npages > KVM_MEM_MAX_NR_PAGES)
569 		goto out;
570 
571 	if (!npages)
572 		mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
573 
574 	new = old = *memslot;
575 
576 	new.id = mem->slot;
577 	new.base_gfn = base_gfn;
578 	new.npages = npages;
579 	new.flags = mem->flags;
580 
581 	/* Disallow changing a memory slot's size. */
582 	r = -EINVAL;
583 	if (npages && old.npages && npages != old.npages)
584 		goto out_free;
585 
586 	/* Check for overlaps */
587 	r = -EEXIST;
588 	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
589 		struct kvm_memory_slot *s = &kvm->memslots->memslots[i];
590 
591 		if (s == memslot || !s->npages)
592 			continue;
593 		if (!((base_gfn + npages <= s->base_gfn) ||
594 		      (base_gfn >= s->base_gfn + s->npages)))
595 			goto out_free;
596 	}
597 
598 	/* Free page dirty bitmap if unneeded */
599 	if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
600 		new.dirty_bitmap = NULL;
601 
602 	r = -ENOMEM;
603 
604 	/* Allocate if a slot is being created */
605 #ifndef CONFIG_S390
606 	if (npages && !new.rmap) {
607 		new.rmap = vmalloc(npages * sizeof(*new.rmap));
608 
609 		if (!new.rmap)
610 			goto out_free;
611 
612 		memset(new.rmap, 0, npages * sizeof(*new.rmap));
613 
614 		new.user_alloc = user_alloc;
615 		new.userspace_addr = mem->userspace_addr;
616 	}
617 	if (!npages)
618 		goto skip_lpage;
619 
620 	for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
621 		unsigned long ugfn;
622 		unsigned long j;
623 		int lpages;
624 		int level = i + 2;
625 
626 		/* Avoid unused variable warning if no large pages */
627 		(void)level;
628 
629 		if (new.lpage_info[i])
630 			continue;
631 
632 		lpages = 1 + ((base_gfn + npages - 1)
633 			     >> KVM_HPAGE_GFN_SHIFT(level));
634 		lpages -= base_gfn >> KVM_HPAGE_GFN_SHIFT(level);
635 
636 		new.lpage_info[i] = vmalloc(lpages * sizeof(*new.lpage_info[i]));
637 
638 		if (!new.lpage_info[i])
639 			goto out_free;
640 
641 		memset(new.lpage_info[i], 0,
642 		       lpages * sizeof(*new.lpage_info[i]));
643 
644 		if (base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
645 			new.lpage_info[i][0].write_count = 1;
646 		if ((base_gfn+npages) & (KVM_PAGES_PER_HPAGE(level) - 1))
647 			new.lpage_info[i][lpages - 1].write_count = 1;
648 		ugfn = new.userspace_addr >> PAGE_SHIFT;
649 		/*
650 		 * If the gfn and userspace address are not aligned wrt each
651 		 * other, or if explicitly asked to, disable large page
652 		 * support for this slot
653 		 */
654 		if ((base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE(level) - 1) ||
655 		    !largepages_enabled)
656 			for (j = 0; j < lpages; ++j)
657 				new.lpage_info[i][j].write_count = 1;
658 	}
659 
660 skip_lpage:
661 
662 	/* Allocate page dirty bitmap if needed */
663 	if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
664 		unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(&new);
665 
666 		new.dirty_bitmap = vmalloc(dirty_bytes);
667 		if (!new.dirty_bitmap)
668 			goto out_free;
669 		memset(new.dirty_bitmap, 0, dirty_bytes);
670 		/* destroy any largepage mappings for dirty tracking */
671 		if (old.npages)
672 			flush_shadow = 1;
673 	}
674 #else  /* not defined CONFIG_S390 */
675 	new.user_alloc = user_alloc;
676 	if (user_alloc)
677 		new.userspace_addr = mem->userspace_addr;
678 #endif /* not defined CONFIG_S390 */
679 
680 	if (!npages) {
681 		r = -ENOMEM;
682 		slots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
683 		if (!slots)
684 			goto out_free;
685 		memcpy(slots, kvm->memslots, sizeof(struct kvm_memslots));
686 		if (mem->slot >= slots->nmemslots)
687 			slots->nmemslots = mem->slot + 1;
688 		slots->memslots[mem->slot].flags |= KVM_MEMSLOT_INVALID;
689 
690 		old_memslots = kvm->memslots;
691 		rcu_assign_pointer(kvm->memslots, slots);
692 		synchronize_srcu_expedited(&kvm->srcu);
693 		/* From this point no new shadow pages pointing to a deleted
694 		 * memslot will be created.
695 		 *
696 		 * validation of sp->gfn happens in:
697 		 * 	- gfn_to_hva (kvm_read_guest, gfn_to_pfn)
698 		 * 	- kvm_is_visible_gfn (mmu_check_roots)
699 		 */
700 		kvm_arch_flush_shadow(kvm);
701 		kfree(old_memslots);
702 	}
703 
704 	r = kvm_arch_prepare_memory_region(kvm, &new, old, mem, user_alloc);
705 	if (r)
706 		goto out_free;
707 
708 #ifdef CONFIG_DMAR
709 	/* map the pages in iommu page table */
710 	if (npages) {
711 		r = kvm_iommu_map_pages(kvm, &new);
712 		if (r)
713 			goto out_free;
714 	}
715 #endif
716 
717 	r = -ENOMEM;
718 	slots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
719 	if (!slots)
720 		goto out_free;
721 	memcpy(slots, kvm->memslots, sizeof(struct kvm_memslots));
722 	if (mem->slot >= slots->nmemslots)
723 		slots->nmemslots = mem->slot + 1;
724 
725 	/* actual memory is freed via old in kvm_free_physmem_slot below */
726 	if (!npages) {
727 		new.rmap = NULL;
728 		new.dirty_bitmap = NULL;
729 		for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i)
730 			new.lpage_info[i] = NULL;
731 	}
732 
733 	slots->memslots[mem->slot] = new;
734 	old_memslots = kvm->memslots;
735 	rcu_assign_pointer(kvm->memslots, slots);
736 	synchronize_srcu_expedited(&kvm->srcu);
737 
738 	kvm_arch_commit_memory_region(kvm, mem, old, user_alloc);
739 
740 	kvm_free_physmem_slot(&old, &new);
741 	kfree(old_memslots);
742 
743 	if (flush_shadow)
744 		kvm_arch_flush_shadow(kvm);
745 
746 	return 0;
747 
748 out_free:
749 	kvm_free_physmem_slot(&new, &old);
750 out:
751 	return r;
752 
753 }
754 EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
755 
756 int kvm_set_memory_region(struct kvm *kvm,
757 			  struct kvm_userspace_memory_region *mem,
758 			  int user_alloc)
759 {
760 	int r;
761 
762 	mutex_lock(&kvm->slots_lock);
763 	r = __kvm_set_memory_region(kvm, mem, user_alloc);
764 	mutex_unlock(&kvm->slots_lock);
765 	return r;
766 }
767 EXPORT_SYMBOL_GPL(kvm_set_memory_region);
768 
769 int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
770 				   struct
771 				   kvm_userspace_memory_region *mem,
772 				   int user_alloc)
773 {
774 	if (mem->slot >= KVM_MEMORY_SLOTS)
775 		return -EINVAL;
776 	return kvm_set_memory_region(kvm, mem, user_alloc);
777 }
778 
779 int kvm_get_dirty_log(struct kvm *kvm,
780 			struct kvm_dirty_log *log, int *is_dirty)
781 {
782 	struct kvm_memory_slot *memslot;
783 	int r, i;
784 	unsigned long n;
785 	unsigned long any = 0;
786 
787 	r = -EINVAL;
788 	if (log->slot >= KVM_MEMORY_SLOTS)
789 		goto out;
790 
791 	memslot = &kvm->memslots->memslots[log->slot];
792 	r = -ENOENT;
793 	if (!memslot->dirty_bitmap)
794 		goto out;
795 
796 	n = kvm_dirty_bitmap_bytes(memslot);
797 
798 	for (i = 0; !any && i < n/sizeof(long); ++i)
799 		any = memslot->dirty_bitmap[i];
800 
801 	r = -EFAULT;
802 	if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
803 		goto out;
804 
805 	if (any)
806 		*is_dirty = 1;
807 
808 	r = 0;
809 out:
810 	return r;
811 }
812 
813 void kvm_disable_largepages(void)
814 {
815 	largepages_enabled = false;
816 }
817 EXPORT_SYMBOL_GPL(kvm_disable_largepages);
818 
819 int is_error_page(struct page *page)
820 {
821 	return page == bad_page || page == hwpoison_page || page == fault_page;
822 }
823 EXPORT_SYMBOL_GPL(is_error_page);
824 
825 int is_error_pfn(pfn_t pfn)
826 {
827 	return pfn == bad_pfn || pfn == hwpoison_pfn || pfn == fault_pfn;
828 }
829 EXPORT_SYMBOL_GPL(is_error_pfn);
830 
831 int is_hwpoison_pfn(pfn_t pfn)
832 {
833 	return pfn == hwpoison_pfn;
834 }
835 EXPORT_SYMBOL_GPL(is_hwpoison_pfn);
836 
837 int is_fault_pfn(pfn_t pfn)
838 {
839 	return pfn == fault_pfn;
840 }
841 EXPORT_SYMBOL_GPL(is_fault_pfn);
842 
843 static inline unsigned long bad_hva(void)
844 {
845 	return PAGE_OFFSET;
846 }
847 
848 int kvm_is_error_hva(unsigned long addr)
849 {
850 	return addr == bad_hva();
851 }
852 EXPORT_SYMBOL_GPL(kvm_is_error_hva);
853 
854 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
855 {
856 	int i;
857 	struct kvm_memslots *slots = kvm_memslots(kvm);
858 
859 	for (i = 0; i < slots->nmemslots; ++i) {
860 		struct kvm_memory_slot *memslot = &slots->memslots[i];
861 
862 		if (gfn >= memslot->base_gfn
863 		    && gfn < memslot->base_gfn + memslot->npages)
864 			return memslot;
865 	}
866 	return NULL;
867 }
868 EXPORT_SYMBOL_GPL(gfn_to_memslot);
869 
870 int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
871 {
872 	int i;
873 	struct kvm_memslots *slots = kvm_memslots(kvm);
874 
875 	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
876 		struct kvm_memory_slot *memslot = &slots->memslots[i];
877 
878 		if (memslot->flags & KVM_MEMSLOT_INVALID)
879 			continue;
880 
881 		if (gfn >= memslot->base_gfn
882 		    && gfn < memslot->base_gfn + memslot->npages)
883 			return 1;
884 	}
885 	return 0;
886 }
887 EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
888 
889 unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn)
890 {
891 	struct vm_area_struct *vma;
892 	unsigned long addr, size;
893 
894 	size = PAGE_SIZE;
895 
896 	addr = gfn_to_hva(kvm, gfn);
897 	if (kvm_is_error_hva(addr))
898 		return PAGE_SIZE;
899 
900 	down_read(&current->mm->mmap_sem);
901 	vma = find_vma(current->mm, addr);
902 	if (!vma)
903 		goto out;
904 
905 	size = vma_kernel_pagesize(vma);
906 
907 out:
908 	up_read(&current->mm->mmap_sem);
909 
910 	return size;
911 }
912 
913 int memslot_id(struct kvm *kvm, gfn_t gfn)
914 {
915 	int i;
916 	struct kvm_memslots *slots = kvm_memslots(kvm);
917 	struct kvm_memory_slot *memslot = NULL;
918 
919 	for (i = 0; i < slots->nmemslots; ++i) {
920 		memslot = &slots->memslots[i];
921 
922 		if (gfn >= memslot->base_gfn
923 		    && gfn < memslot->base_gfn + memslot->npages)
924 			break;
925 	}
926 
927 	return memslot - slots->memslots;
928 }
929 
930 static unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
931 {
932 	return slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE;
933 }
934 
935 unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
936 {
937 	struct kvm_memory_slot *slot;
938 
939 	slot = gfn_to_memslot(kvm, gfn);
940 	if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
941 		return bad_hva();
942 	return gfn_to_hva_memslot(slot, gfn);
943 }
944 EXPORT_SYMBOL_GPL(gfn_to_hva);
945 
946 static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr)
947 {
948 	struct page *page[1];
949 	int npages;
950 	pfn_t pfn;
951 
952 	might_sleep();
953 
954 	npages = get_user_pages_fast(addr, 1, 1, page);
955 
956 	if (unlikely(npages != 1)) {
957 		struct vm_area_struct *vma;
958 
959 		down_read(&current->mm->mmap_sem);
960 		if (is_hwpoison_address(addr)) {
961 			up_read(&current->mm->mmap_sem);
962 			get_page(hwpoison_page);
963 			return page_to_pfn(hwpoison_page);
964 		}
965 
966 		vma = find_vma(current->mm, addr);
967 
968 		if (vma == NULL || addr < vma->vm_start ||
969 		    !(vma->vm_flags & VM_PFNMAP)) {
970 			up_read(&current->mm->mmap_sem);
971 			get_page(fault_page);
972 			return page_to_pfn(fault_page);
973 		}
974 
975 		pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
976 		up_read(&current->mm->mmap_sem);
977 		BUG_ON(!kvm_is_mmio_pfn(pfn));
978 	} else
979 		pfn = page_to_pfn(page[0]);
980 
981 	return pfn;
982 }
983 
984 pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
985 {
986 	unsigned long addr;
987 
988 	addr = gfn_to_hva(kvm, gfn);
989 	if (kvm_is_error_hva(addr)) {
990 		get_page(bad_page);
991 		return page_to_pfn(bad_page);
992 	}
993 
994 	return hva_to_pfn(kvm, addr);
995 }
996 EXPORT_SYMBOL_GPL(gfn_to_pfn);
997 
998 pfn_t gfn_to_pfn_memslot(struct kvm *kvm,
999 			 struct kvm_memory_slot *slot, gfn_t gfn)
1000 {
1001 	unsigned long addr = gfn_to_hva_memslot(slot, gfn);
1002 	return hva_to_pfn(kvm, addr);
1003 }
1004 
1005 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
1006 {
1007 	pfn_t pfn;
1008 
1009 	pfn = gfn_to_pfn(kvm, gfn);
1010 	if (!kvm_is_mmio_pfn(pfn))
1011 		return pfn_to_page(pfn);
1012 
1013 	WARN_ON(kvm_is_mmio_pfn(pfn));
1014 
1015 	get_page(bad_page);
1016 	return bad_page;
1017 }
1018 
1019 EXPORT_SYMBOL_GPL(gfn_to_page);
1020 
1021 void kvm_release_page_clean(struct page *page)
1022 {
1023 	kvm_release_pfn_clean(page_to_pfn(page));
1024 }
1025 EXPORT_SYMBOL_GPL(kvm_release_page_clean);
1026 
1027 void kvm_release_pfn_clean(pfn_t pfn)
1028 {
1029 	if (!kvm_is_mmio_pfn(pfn))
1030 		put_page(pfn_to_page(pfn));
1031 }
1032 EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
1033 
1034 void kvm_release_page_dirty(struct page *page)
1035 {
1036 	kvm_release_pfn_dirty(page_to_pfn(page));
1037 }
1038 EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
1039 
1040 void kvm_release_pfn_dirty(pfn_t pfn)
1041 {
1042 	kvm_set_pfn_dirty(pfn);
1043 	kvm_release_pfn_clean(pfn);
1044 }
1045 EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
1046 
1047 void kvm_set_page_dirty(struct page *page)
1048 {
1049 	kvm_set_pfn_dirty(page_to_pfn(page));
1050 }
1051 EXPORT_SYMBOL_GPL(kvm_set_page_dirty);
1052 
1053 void kvm_set_pfn_dirty(pfn_t pfn)
1054 {
1055 	if (!kvm_is_mmio_pfn(pfn)) {
1056 		struct page *page = pfn_to_page(pfn);
1057 		if (!PageReserved(page))
1058 			SetPageDirty(page);
1059 	}
1060 }
1061 EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
1062 
1063 void kvm_set_pfn_accessed(pfn_t pfn)
1064 {
1065 	if (!kvm_is_mmio_pfn(pfn))
1066 		mark_page_accessed(pfn_to_page(pfn));
1067 }
1068 EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
1069 
1070 void kvm_get_pfn(pfn_t pfn)
1071 {
1072 	if (!kvm_is_mmio_pfn(pfn))
1073 		get_page(pfn_to_page(pfn));
1074 }
1075 EXPORT_SYMBOL_GPL(kvm_get_pfn);
1076 
1077 static int next_segment(unsigned long len, int offset)
1078 {
1079 	if (len > PAGE_SIZE - offset)
1080 		return PAGE_SIZE - offset;
1081 	else
1082 		return len;
1083 }
1084 
1085 int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
1086 			int len)
1087 {
1088 	int r;
1089 	unsigned long addr;
1090 
1091 	addr = gfn_to_hva(kvm, gfn);
1092 	if (kvm_is_error_hva(addr))
1093 		return -EFAULT;
1094 	r = copy_from_user(data, (void __user *)addr + offset, len);
1095 	if (r)
1096 		return -EFAULT;
1097 	return 0;
1098 }
1099 EXPORT_SYMBOL_GPL(kvm_read_guest_page);
1100 
1101 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
1102 {
1103 	gfn_t gfn = gpa >> PAGE_SHIFT;
1104 	int seg;
1105 	int offset = offset_in_page(gpa);
1106 	int ret;
1107 
1108 	while ((seg = next_segment(len, offset)) != 0) {
1109 		ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
1110 		if (ret < 0)
1111 			return ret;
1112 		offset = 0;
1113 		len -= seg;
1114 		data += seg;
1115 		++gfn;
1116 	}
1117 	return 0;
1118 }
1119 EXPORT_SYMBOL_GPL(kvm_read_guest);
1120 
1121 int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
1122 			  unsigned long len)
1123 {
1124 	int r;
1125 	unsigned long addr;
1126 	gfn_t gfn = gpa >> PAGE_SHIFT;
1127 	int offset = offset_in_page(gpa);
1128 
1129 	addr = gfn_to_hva(kvm, gfn);
1130 	if (kvm_is_error_hva(addr))
1131 		return -EFAULT;
1132 	pagefault_disable();
1133 	r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
1134 	pagefault_enable();
1135 	if (r)
1136 		return -EFAULT;
1137 	return 0;
1138 }
1139 EXPORT_SYMBOL(kvm_read_guest_atomic);
1140 
1141 int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
1142 			 int offset, int len)
1143 {
1144 	int r;
1145 	unsigned long addr;
1146 
1147 	addr = gfn_to_hva(kvm, gfn);
1148 	if (kvm_is_error_hva(addr))
1149 		return -EFAULT;
1150 	r = copy_to_user((void __user *)addr + offset, data, len);
1151 	if (r)
1152 		return -EFAULT;
1153 	mark_page_dirty(kvm, gfn);
1154 	return 0;
1155 }
1156 EXPORT_SYMBOL_GPL(kvm_write_guest_page);
1157 
1158 int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
1159 		    unsigned long len)
1160 {
1161 	gfn_t gfn = gpa >> PAGE_SHIFT;
1162 	int seg;
1163 	int offset = offset_in_page(gpa);
1164 	int ret;
1165 
1166 	while ((seg = next_segment(len, offset)) != 0) {
1167 		ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
1168 		if (ret < 0)
1169 			return ret;
1170 		offset = 0;
1171 		len -= seg;
1172 		data += seg;
1173 		++gfn;
1174 	}
1175 	return 0;
1176 }
1177 
1178 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
1179 {
1180 	return kvm_write_guest_page(kvm, gfn, empty_zero_page, offset, len);
1181 }
1182 EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
1183 
1184 int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
1185 {
1186 	gfn_t gfn = gpa >> PAGE_SHIFT;
1187 	int seg;
1188 	int offset = offset_in_page(gpa);
1189 	int ret;
1190 
1191         while ((seg = next_segment(len, offset)) != 0) {
1192 		ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
1193 		if (ret < 0)
1194 			return ret;
1195 		offset = 0;
1196 		len -= seg;
1197 		++gfn;
1198 	}
1199 	return 0;
1200 }
1201 EXPORT_SYMBOL_GPL(kvm_clear_guest);
1202 
1203 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
1204 {
1205 	struct kvm_memory_slot *memslot;
1206 
1207 	memslot = gfn_to_memslot(kvm, gfn);
1208 	if (memslot && memslot->dirty_bitmap) {
1209 		unsigned long rel_gfn = gfn - memslot->base_gfn;
1210 
1211 		generic___set_le_bit(rel_gfn, memslot->dirty_bitmap);
1212 	}
1213 }
1214 
1215 /*
1216  * The vCPU has executed a HLT instruction with in-kernel mode enabled.
1217  */
1218 void kvm_vcpu_block(struct kvm_vcpu *vcpu)
1219 {
1220 	DEFINE_WAIT(wait);
1221 
1222 	for (;;) {
1223 		prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
1224 
1225 		if (kvm_arch_vcpu_runnable(vcpu)) {
1226 			kvm_make_request(KVM_REQ_UNHALT, vcpu);
1227 			break;
1228 		}
1229 		if (kvm_cpu_has_pending_timer(vcpu))
1230 			break;
1231 		if (signal_pending(current))
1232 			break;
1233 
1234 		schedule();
1235 	}
1236 
1237 	finish_wait(&vcpu->wq, &wait);
1238 }
1239 
1240 void kvm_resched(struct kvm_vcpu *vcpu)
1241 {
1242 	if (!need_resched())
1243 		return;
1244 	cond_resched();
1245 }
1246 EXPORT_SYMBOL_GPL(kvm_resched);
1247 
1248 void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu)
1249 {
1250 	ktime_t expires;
1251 	DEFINE_WAIT(wait);
1252 
1253 	prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
1254 
1255 	/* Sleep for 100 us, and hope lock-holder got scheduled */
1256 	expires = ktime_add_ns(ktime_get(), 100000UL);
1257 	schedule_hrtimeout(&expires, HRTIMER_MODE_ABS);
1258 
1259 	finish_wait(&vcpu->wq, &wait);
1260 }
1261 EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
1262 
1263 static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1264 {
1265 	struct kvm_vcpu *vcpu = vma->vm_file->private_data;
1266 	struct page *page;
1267 
1268 	if (vmf->pgoff == 0)
1269 		page = virt_to_page(vcpu->run);
1270 #ifdef CONFIG_X86
1271 	else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
1272 		page = virt_to_page(vcpu->arch.pio_data);
1273 #endif
1274 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1275 	else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
1276 		page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
1277 #endif
1278 	else
1279 		return VM_FAULT_SIGBUS;
1280 	get_page(page);
1281 	vmf->page = page;
1282 	return 0;
1283 }
1284 
1285 static const struct vm_operations_struct kvm_vcpu_vm_ops = {
1286 	.fault = kvm_vcpu_fault,
1287 };
1288 
1289 static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
1290 {
1291 	vma->vm_ops = &kvm_vcpu_vm_ops;
1292 	return 0;
1293 }
1294 
1295 static int kvm_vcpu_release(struct inode *inode, struct file *filp)
1296 {
1297 	struct kvm_vcpu *vcpu = filp->private_data;
1298 
1299 	kvm_put_kvm(vcpu->kvm);
1300 	return 0;
1301 }
1302 
1303 static struct file_operations kvm_vcpu_fops = {
1304 	.release        = kvm_vcpu_release,
1305 	.unlocked_ioctl = kvm_vcpu_ioctl,
1306 	.compat_ioctl   = kvm_vcpu_ioctl,
1307 	.mmap           = kvm_vcpu_mmap,
1308 };
1309 
1310 /*
1311  * Allocates an inode for the vcpu.
1312  */
1313 static int create_vcpu_fd(struct kvm_vcpu *vcpu)
1314 {
1315 	return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR);
1316 }
1317 
1318 /*
1319  * Creates some virtual cpus.  Good luck creating more than one.
1320  */
1321 static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
1322 {
1323 	int r;
1324 	struct kvm_vcpu *vcpu, *v;
1325 
1326 	vcpu = kvm_arch_vcpu_create(kvm, id);
1327 	if (IS_ERR(vcpu))
1328 		return PTR_ERR(vcpu);
1329 
1330 	preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
1331 
1332 	r = kvm_arch_vcpu_setup(vcpu);
1333 	if (r)
1334 		return r;
1335 
1336 	mutex_lock(&kvm->lock);
1337 	if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
1338 		r = -EINVAL;
1339 		goto vcpu_destroy;
1340 	}
1341 
1342 	kvm_for_each_vcpu(r, v, kvm)
1343 		if (v->vcpu_id == id) {
1344 			r = -EEXIST;
1345 			goto vcpu_destroy;
1346 		}
1347 
1348 	BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
1349 
1350 	/* Now it's all set up, let userspace reach it */
1351 	kvm_get_kvm(kvm);
1352 	r = create_vcpu_fd(vcpu);
1353 	if (r < 0) {
1354 		kvm_put_kvm(kvm);
1355 		goto vcpu_destroy;
1356 	}
1357 
1358 	kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
1359 	smp_wmb();
1360 	atomic_inc(&kvm->online_vcpus);
1361 
1362 #ifdef CONFIG_KVM_APIC_ARCHITECTURE
1363 	if (kvm->bsp_vcpu_id == id)
1364 		kvm->bsp_vcpu = vcpu;
1365 #endif
1366 	mutex_unlock(&kvm->lock);
1367 	return r;
1368 
1369 vcpu_destroy:
1370 	mutex_unlock(&kvm->lock);
1371 	kvm_arch_vcpu_destroy(vcpu);
1372 	return r;
1373 }
1374 
1375 static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
1376 {
1377 	if (sigset) {
1378 		sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
1379 		vcpu->sigset_active = 1;
1380 		vcpu->sigset = *sigset;
1381 	} else
1382 		vcpu->sigset_active = 0;
1383 	return 0;
1384 }
1385 
1386 static long kvm_vcpu_ioctl(struct file *filp,
1387 			   unsigned int ioctl, unsigned long arg)
1388 {
1389 	struct kvm_vcpu *vcpu = filp->private_data;
1390 	void __user *argp = (void __user *)arg;
1391 	int r;
1392 	struct kvm_fpu *fpu = NULL;
1393 	struct kvm_sregs *kvm_sregs = NULL;
1394 
1395 	if (vcpu->kvm->mm != current->mm)
1396 		return -EIO;
1397 
1398 #if defined(CONFIG_S390) || defined(CONFIG_PPC)
1399 	/*
1400 	 * Special cases: vcpu ioctls that are asynchronous to vcpu execution,
1401 	 * so vcpu_load() would break it.
1402 	 */
1403 	if (ioctl == KVM_S390_INTERRUPT || ioctl == KVM_INTERRUPT)
1404 		return kvm_arch_vcpu_ioctl(filp, ioctl, arg);
1405 #endif
1406 
1407 
1408 	vcpu_load(vcpu);
1409 	switch (ioctl) {
1410 	case KVM_RUN:
1411 		r = -EINVAL;
1412 		if (arg)
1413 			goto out;
1414 		r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
1415 		break;
1416 	case KVM_GET_REGS: {
1417 		struct kvm_regs *kvm_regs;
1418 
1419 		r = -ENOMEM;
1420 		kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
1421 		if (!kvm_regs)
1422 			goto out;
1423 		r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
1424 		if (r)
1425 			goto out_free1;
1426 		r = -EFAULT;
1427 		if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
1428 			goto out_free1;
1429 		r = 0;
1430 out_free1:
1431 		kfree(kvm_regs);
1432 		break;
1433 	}
1434 	case KVM_SET_REGS: {
1435 		struct kvm_regs *kvm_regs;
1436 
1437 		r = -ENOMEM;
1438 		kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
1439 		if (!kvm_regs)
1440 			goto out;
1441 		r = -EFAULT;
1442 		if (copy_from_user(kvm_regs, argp, sizeof(struct kvm_regs)))
1443 			goto out_free2;
1444 		r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
1445 		if (r)
1446 			goto out_free2;
1447 		r = 0;
1448 out_free2:
1449 		kfree(kvm_regs);
1450 		break;
1451 	}
1452 	case KVM_GET_SREGS: {
1453 		kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
1454 		r = -ENOMEM;
1455 		if (!kvm_sregs)
1456 			goto out;
1457 		r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs);
1458 		if (r)
1459 			goto out;
1460 		r = -EFAULT;
1461 		if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs)))
1462 			goto out;
1463 		r = 0;
1464 		break;
1465 	}
1466 	case KVM_SET_SREGS: {
1467 		kvm_sregs = kmalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
1468 		r = -ENOMEM;
1469 		if (!kvm_sregs)
1470 			goto out;
1471 		r = -EFAULT;
1472 		if (copy_from_user(kvm_sregs, argp, sizeof(struct kvm_sregs)))
1473 			goto out;
1474 		r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs);
1475 		if (r)
1476 			goto out;
1477 		r = 0;
1478 		break;
1479 	}
1480 	case KVM_GET_MP_STATE: {
1481 		struct kvm_mp_state mp_state;
1482 
1483 		r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
1484 		if (r)
1485 			goto out;
1486 		r = -EFAULT;
1487 		if (copy_to_user(argp, &mp_state, sizeof mp_state))
1488 			goto out;
1489 		r = 0;
1490 		break;
1491 	}
1492 	case KVM_SET_MP_STATE: {
1493 		struct kvm_mp_state mp_state;
1494 
1495 		r = -EFAULT;
1496 		if (copy_from_user(&mp_state, argp, sizeof mp_state))
1497 			goto out;
1498 		r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
1499 		if (r)
1500 			goto out;
1501 		r = 0;
1502 		break;
1503 	}
1504 	case KVM_TRANSLATE: {
1505 		struct kvm_translation tr;
1506 
1507 		r = -EFAULT;
1508 		if (copy_from_user(&tr, argp, sizeof tr))
1509 			goto out;
1510 		r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
1511 		if (r)
1512 			goto out;
1513 		r = -EFAULT;
1514 		if (copy_to_user(argp, &tr, sizeof tr))
1515 			goto out;
1516 		r = 0;
1517 		break;
1518 	}
1519 	case KVM_SET_GUEST_DEBUG: {
1520 		struct kvm_guest_debug dbg;
1521 
1522 		r = -EFAULT;
1523 		if (copy_from_user(&dbg, argp, sizeof dbg))
1524 			goto out;
1525 		r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg);
1526 		if (r)
1527 			goto out;
1528 		r = 0;
1529 		break;
1530 	}
1531 	case KVM_SET_SIGNAL_MASK: {
1532 		struct kvm_signal_mask __user *sigmask_arg = argp;
1533 		struct kvm_signal_mask kvm_sigmask;
1534 		sigset_t sigset, *p;
1535 
1536 		p = NULL;
1537 		if (argp) {
1538 			r = -EFAULT;
1539 			if (copy_from_user(&kvm_sigmask, argp,
1540 					   sizeof kvm_sigmask))
1541 				goto out;
1542 			r = -EINVAL;
1543 			if (kvm_sigmask.len != sizeof sigset)
1544 				goto out;
1545 			r = -EFAULT;
1546 			if (copy_from_user(&sigset, sigmask_arg->sigset,
1547 					   sizeof sigset))
1548 				goto out;
1549 			p = &sigset;
1550 		}
1551 		r = kvm_vcpu_ioctl_set_sigmask(vcpu, p);
1552 		break;
1553 	}
1554 	case KVM_GET_FPU: {
1555 		fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
1556 		r = -ENOMEM;
1557 		if (!fpu)
1558 			goto out;
1559 		r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
1560 		if (r)
1561 			goto out;
1562 		r = -EFAULT;
1563 		if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu)))
1564 			goto out;
1565 		r = 0;
1566 		break;
1567 	}
1568 	case KVM_SET_FPU: {
1569 		fpu = kmalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
1570 		r = -ENOMEM;
1571 		if (!fpu)
1572 			goto out;
1573 		r = -EFAULT;
1574 		if (copy_from_user(fpu, argp, sizeof(struct kvm_fpu)))
1575 			goto out;
1576 		r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
1577 		if (r)
1578 			goto out;
1579 		r = 0;
1580 		break;
1581 	}
1582 	default:
1583 		r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
1584 	}
1585 out:
1586 	vcpu_put(vcpu);
1587 	kfree(fpu);
1588 	kfree(kvm_sregs);
1589 	return r;
1590 }
1591 
1592 static long kvm_vm_ioctl(struct file *filp,
1593 			   unsigned int ioctl, unsigned long arg)
1594 {
1595 	struct kvm *kvm = filp->private_data;
1596 	void __user *argp = (void __user *)arg;
1597 	int r;
1598 
1599 	if (kvm->mm != current->mm)
1600 		return -EIO;
1601 	switch (ioctl) {
1602 	case KVM_CREATE_VCPU:
1603 		r = kvm_vm_ioctl_create_vcpu(kvm, arg);
1604 		if (r < 0)
1605 			goto out;
1606 		break;
1607 	case KVM_SET_USER_MEMORY_REGION: {
1608 		struct kvm_userspace_memory_region kvm_userspace_mem;
1609 
1610 		r = -EFAULT;
1611 		if (copy_from_user(&kvm_userspace_mem, argp,
1612 						sizeof kvm_userspace_mem))
1613 			goto out;
1614 
1615 		r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem, 1);
1616 		if (r)
1617 			goto out;
1618 		break;
1619 	}
1620 	case KVM_GET_DIRTY_LOG: {
1621 		struct kvm_dirty_log log;
1622 
1623 		r = -EFAULT;
1624 		if (copy_from_user(&log, argp, sizeof log))
1625 			goto out;
1626 		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
1627 		if (r)
1628 			goto out;
1629 		break;
1630 	}
1631 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1632 	case KVM_REGISTER_COALESCED_MMIO: {
1633 		struct kvm_coalesced_mmio_zone zone;
1634 		r = -EFAULT;
1635 		if (copy_from_user(&zone, argp, sizeof zone))
1636 			goto out;
1637 		r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
1638 		if (r)
1639 			goto out;
1640 		r = 0;
1641 		break;
1642 	}
1643 	case KVM_UNREGISTER_COALESCED_MMIO: {
1644 		struct kvm_coalesced_mmio_zone zone;
1645 		r = -EFAULT;
1646 		if (copy_from_user(&zone, argp, sizeof zone))
1647 			goto out;
1648 		r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
1649 		if (r)
1650 			goto out;
1651 		r = 0;
1652 		break;
1653 	}
1654 #endif
1655 	case KVM_IRQFD: {
1656 		struct kvm_irqfd data;
1657 
1658 		r = -EFAULT;
1659 		if (copy_from_user(&data, argp, sizeof data))
1660 			goto out;
1661 		r = kvm_irqfd(kvm, data.fd, data.gsi, data.flags);
1662 		break;
1663 	}
1664 	case KVM_IOEVENTFD: {
1665 		struct kvm_ioeventfd data;
1666 
1667 		r = -EFAULT;
1668 		if (copy_from_user(&data, argp, sizeof data))
1669 			goto out;
1670 		r = kvm_ioeventfd(kvm, &data);
1671 		break;
1672 	}
1673 #ifdef CONFIG_KVM_APIC_ARCHITECTURE
1674 	case KVM_SET_BOOT_CPU_ID:
1675 		r = 0;
1676 		mutex_lock(&kvm->lock);
1677 		if (atomic_read(&kvm->online_vcpus) != 0)
1678 			r = -EBUSY;
1679 		else
1680 			kvm->bsp_vcpu_id = arg;
1681 		mutex_unlock(&kvm->lock);
1682 		break;
1683 #endif
1684 	default:
1685 		r = kvm_arch_vm_ioctl(filp, ioctl, arg);
1686 		if (r == -ENOTTY)
1687 			r = kvm_vm_ioctl_assigned_device(kvm, ioctl, arg);
1688 	}
1689 out:
1690 	return r;
1691 }
1692 
1693 #ifdef CONFIG_COMPAT
1694 struct compat_kvm_dirty_log {
1695 	__u32 slot;
1696 	__u32 padding1;
1697 	union {
1698 		compat_uptr_t dirty_bitmap; /* one bit per page */
1699 		__u64 padding2;
1700 	};
1701 };
1702 
1703 static long kvm_vm_compat_ioctl(struct file *filp,
1704 			   unsigned int ioctl, unsigned long arg)
1705 {
1706 	struct kvm *kvm = filp->private_data;
1707 	int r;
1708 
1709 	if (kvm->mm != current->mm)
1710 		return -EIO;
1711 	switch (ioctl) {
1712 	case KVM_GET_DIRTY_LOG: {
1713 		struct compat_kvm_dirty_log compat_log;
1714 		struct kvm_dirty_log log;
1715 
1716 		r = -EFAULT;
1717 		if (copy_from_user(&compat_log, (void __user *)arg,
1718 				   sizeof(compat_log)))
1719 			goto out;
1720 		log.slot	 = compat_log.slot;
1721 		log.padding1	 = compat_log.padding1;
1722 		log.padding2	 = compat_log.padding2;
1723 		log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
1724 
1725 		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
1726 		if (r)
1727 			goto out;
1728 		break;
1729 	}
1730 	default:
1731 		r = kvm_vm_ioctl(filp, ioctl, arg);
1732 	}
1733 
1734 out:
1735 	return r;
1736 }
1737 #endif
1738 
1739 static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1740 {
1741 	struct page *page[1];
1742 	unsigned long addr;
1743 	int npages;
1744 	gfn_t gfn = vmf->pgoff;
1745 	struct kvm *kvm = vma->vm_file->private_data;
1746 
1747 	addr = gfn_to_hva(kvm, gfn);
1748 	if (kvm_is_error_hva(addr))
1749 		return VM_FAULT_SIGBUS;
1750 
1751 	npages = get_user_pages(current, current->mm, addr, 1, 1, 0, page,
1752 				NULL);
1753 	if (unlikely(npages != 1))
1754 		return VM_FAULT_SIGBUS;
1755 
1756 	vmf->page = page[0];
1757 	return 0;
1758 }
1759 
1760 static const struct vm_operations_struct kvm_vm_vm_ops = {
1761 	.fault = kvm_vm_fault,
1762 };
1763 
1764 static int kvm_vm_mmap(struct file *file, struct vm_area_struct *vma)
1765 {
1766 	vma->vm_ops = &kvm_vm_vm_ops;
1767 	return 0;
1768 }
1769 
1770 static struct file_operations kvm_vm_fops = {
1771 	.release        = kvm_vm_release,
1772 	.unlocked_ioctl = kvm_vm_ioctl,
1773 #ifdef CONFIG_COMPAT
1774 	.compat_ioctl   = kvm_vm_compat_ioctl,
1775 #endif
1776 	.mmap           = kvm_vm_mmap,
1777 };
1778 
1779 static int kvm_dev_ioctl_create_vm(void)
1780 {
1781 	int fd, r;
1782 	struct kvm *kvm;
1783 
1784 	kvm = kvm_create_vm();
1785 	if (IS_ERR(kvm))
1786 		return PTR_ERR(kvm);
1787 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1788 	r = kvm_coalesced_mmio_init(kvm);
1789 	if (r < 0) {
1790 		kvm_put_kvm(kvm);
1791 		return r;
1792 	}
1793 #endif
1794 	fd = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
1795 	if (fd < 0)
1796 		kvm_put_kvm(kvm);
1797 
1798 	return fd;
1799 }
1800 
1801 static long kvm_dev_ioctl_check_extension_generic(long arg)
1802 {
1803 	switch (arg) {
1804 	case KVM_CAP_USER_MEMORY:
1805 	case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
1806 	case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
1807 #ifdef CONFIG_KVM_APIC_ARCHITECTURE
1808 	case KVM_CAP_SET_BOOT_CPU_ID:
1809 #endif
1810 	case KVM_CAP_INTERNAL_ERROR_DATA:
1811 		return 1;
1812 #ifdef CONFIG_HAVE_KVM_IRQCHIP
1813 	case KVM_CAP_IRQ_ROUTING:
1814 		return KVM_MAX_IRQ_ROUTES;
1815 #endif
1816 	default:
1817 		break;
1818 	}
1819 	return kvm_dev_ioctl_check_extension(arg);
1820 }
1821 
1822 static long kvm_dev_ioctl(struct file *filp,
1823 			  unsigned int ioctl, unsigned long arg)
1824 {
1825 	long r = -EINVAL;
1826 
1827 	switch (ioctl) {
1828 	case KVM_GET_API_VERSION:
1829 		r = -EINVAL;
1830 		if (arg)
1831 			goto out;
1832 		r = KVM_API_VERSION;
1833 		break;
1834 	case KVM_CREATE_VM:
1835 		r = -EINVAL;
1836 		if (arg)
1837 			goto out;
1838 		r = kvm_dev_ioctl_create_vm();
1839 		break;
1840 	case KVM_CHECK_EXTENSION:
1841 		r = kvm_dev_ioctl_check_extension_generic(arg);
1842 		break;
1843 	case KVM_GET_VCPU_MMAP_SIZE:
1844 		r = -EINVAL;
1845 		if (arg)
1846 			goto out;
1847 		r = PAGE_SIZE;     /* struct kvm_run */
1848 #ifdef CONFIG_X86
1849 		r += PAGE_SIZE;    /* pio data page */
1850 #endif
1851 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1852 		r += PAGE_SIZE;    /* coalesced mmio ring page */
1853 #endif
1854 		break;
1855 	case KVM_TRACE_ENABLE:
1856 	case KVM_TRACE_PAUSE:
1857 	case KVM_TRACE_DISABLE:
1858 		r = -EOPNOTSUPP;
1859 		break;
1860 	default:
1861 		return kvm_arch_dev_ioctl(filp, ioctl, arg);
1862 	}
1863 out:
1864 	return r;
1865 }
1866 
1867 static struct file_operations kvm_chardev_ops = {
1868 	.unlocked_ioctl = kvm_dev_ioctl,
1869 	.compat_ioctl   = kvm_dev_ioctl,
1870 };
1871 
1872 static struct miscdevice kvm_dev = {
1873 	KVM_MINOR,
1874 	"kvm",
1875 	&kvm_chardev_ops,
1876 };
1877 
1878 static void hardware_enable(void *junk)
1879 {
1880 	int cpu = raw_smp_processor_id();
1881 	int r;
1882 
1883 	if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
1884 		return;
1885 
1886 	cpumask_set_cpu(cpu, cpus_hardware_enabled);
1887 
1888 	r = kvm_arch_hardware_enable(NULL);
1889 
1890 	if (r) {
1891 		cpumask_clear_cpu(cpu, cpus_hardware_enabled);
1892 		atomic_inc(&hardware_enable_failed);
1893 		printk(KERN_INFO "kvm: enabling virtualization on "
1894 				 "CPU%d failed\n", cpu);
1895 	}
1896 }
1897 
1898 static void hardware_disable(void *junk)
1899 {
1900 	int cpu = raw_smp_processor_id();
1901 
1902 	if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
1903 		return;
1904 	cpumask_clear_cpu(cpu, cpus_hardware_enabled);
1905 	kvm_arch_hardware_disable(NULL);
1906 }
1907 
1908 static void hardware_disable_all_nolock(void)
1909 {
1910 	BUG_ON(!kvm_usage_count);
1911 
1912 	kvm_usage_count--;
1913 	if (!kvm_usage_count)
1914 		on_each_cpu(hardware_disable, NULL, 1);
1915 }
1916 
1917 static void hardware_disable_all(void)
1918 {
1919 	spin_lock(&kvm_lock);
1920 	hardware_disable_all_nolock();
1921 	spin_unlock(&kvm_lock);
1922 }
1923 
1924 static int hardware_enable_all(void)
1925 {
1926 	int r = 0;
1927 
1928 	spin_lock(&kvm_lock);
1929 
1930 	kvm_usage_count++;
1931 	if (kvm_usage_count == 1) {
1932 		atomic_set(&hardware_enable_failed, 0);
1933 		on_each_cpu(hardware_enable, NULL, 1);
1934 
1935 		if (atomic_read(&hardware_enable_failed)) {
1936 			hardware_disable_all_nolock();
1937 			r = -EBUSY;
1938 		}
1939 	}
1940 
1941 	spin_unlock(&kvm_lock);
1942 
1943 	return r;
1944 }
1945 
1946 static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
1947 			   void *v)
1948 {
1949 	int cpu = (long)v;
1950 
1951 	if (!kvm_usage_count)
1952 		return NOTIFY_OK;
1953 
1954 	val &= ~CPU_TASKS_FROZEN;
1955 	switch (val) {
1956 	case CPU_DYING:
1957 		printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
1958 		       cpu);
1959 		hardware_disable(NULL);
1960 		break;
1961 	case CPU_ONLINE:
1962 		printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
1963 		       cpu);
1964 		smp_call_function_single(cpu, hardware_enable, NULL, 1);
1965 		break;
1966 	}
1967 	return NOTIFY_OK;
1968 }
1969 
1970 
1971 asmlinkage void kvm_handle_fault_on_reboot(void)
1972 {
1973 	if (kvm_rebooting)
1974 		/* spin while reset goes on */
1975 		while (true)
1976 			;
1977 	/* Fault while not rebooting.  We want the trace. */
1978 	BUG();
1979 }
1980 EXPORT_SYMBOL_GPL(kvm_handle_fault_on_reboot);
1981 
1982 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
1983 		      void *v)
1984 {
1985 	/*
1986 	 * Some (well, at least mine) BIOSes hang on reboot if
1987 	 * in vmx root mode.
1988 	 *
1989 	 * And Intel TXT required VMX off for all cpu when system shutdown.
1990 	 */
1991 	printk(KERN_INFO "kvm: exiting hardware virtualization\n");
1992 	kvm_rebooting = true;
1993 	on_each_cpu(hardware_disable, NULL, 1);
1994 	return NOTIFY_OK;
1995 }
1996 
1997 static struct notifier_block kvm_reboot_notifier = {
1998 	.notifier_call = kvm_reboot,
1999 	.priority = 0,
2000 };
2001 
2002 static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
2003 {
2004 	int i;
2005 
2006 	for (i = 0; i < bus->dev_count; i++) {
2007 		struct kvm_io_device *pos = bus->devs[i];
2008 
2009 		kvm_iodevice_destructor(pos);
2010 	}
2011 	kfree(bus);
2012 }
2013 
2014 /* kvm_io_bus_write - called under kvm->slots_lock */
2015 int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
2016 		     int len, const void *val)
2017 {
2018 	int i;
2019 	struct kvm_io_bus *bus;
2020 
2021 	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
2022 	for (i = 0; i < bus->dev_count; i++)
2023 		if (!kvm_iodevice_write(bus->devs[i], addr, len, val))
2024 			return 0;
2025 	return -EOPNOTSUPP;
2026 }
2027 
2028 /* kvm_io_bus_read - called under kvm->slots_lock */
2029 int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
2030 		    int len, void *val)
2031 {
2032 	int i;
2033 	struct kvm_io_bus *bus;
2034 
2035 	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
2036 	for (i = 0; i < bus->dev_count; i++)
2037 		if (!kvm_iodevice_read(bus->devs[i], addr, len, val))
2038 			return 0;
2039 	return -EOPNOTSUPP;
2040 }
2041 
2042 /* Caller must hold slots_lock. */
2043 int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx,
2044 			    struct kvm_io_device *dev)
2045 {
2046 	struct kvm_io_bus *new_bus, *bus;
2047 
2048 	bus = kvm->buses[bus_idx];
2049 	if (bus->dev_count > NR_IOBUS_DEVS-1)
2050 		return -ENOSPC;
2051 
2052 	new_bus = kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL);
2053 	if (!new_bus)
2054 		return -ENOMEM;
2055 	memcpy(new_bus, bus, sizeof(struct kvm_io_bus));
2056 	new_bus->devs[new_bus->dev_count++] = dev;
2057 	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
2058 	synchronize_srcu_expedited(&kvm->srcu);
2059 	kfree(bus);
2060 
2061 	return 0;
2062 }
2063 
2064 /* Caller must hold slots_lock. */
2065 int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
2066 			      struct kvm_io_device *dev)
2067 {
2068 	int i, r;
2069 	struct kvm_io_bus *new_bus, *bus;
2070 
2071 	new_bus = kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL);
2072 	if (!new_bus)
2073 		return -ENOMEM;
2074 
2075 	bus = kvm->buses[bus_idx];
2076 	memcpy(new_bus, bus, sizeof(struct kvm_io_bus));
2077 
2078 	r = -ENOENT;
2079 	for (i = 0; i < new_bus->dev_count; i++)
2080 		if (new_bus->devs[i] == dev) {
2081 			r = 0;
2082 			new_bus->devs[i] = new_bus->devs[--new_bus->dev_count];
2083 			break;
2084 		}
2085 
2086 	if (r) {
2087 		kfree(new_bus);
2088 		return r;
2089 	}
2090 
2091 	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
2092 	synchronize_srcu_expedited(&kvm->srcu);
2093 	kfree(bus);
2094 	return r;
2095 }
2096 
2097 static struct notifier_block kvm_cpu_notifier = {
2098 	.notifier_call = kvm_cpu_hotplug,
2099 	.priority = 20, /* must be > scheduler priority */
2100 };
2101 
2102 static int vm_stat_get(void *_offset, u64 *val)
2103 {
2104 	unsigned offset = (long)_offset;
2105 	struct kvm *kvm;
2106 
2107 	*val = 0;
2108 	spin_lock(&kvm_lock);
2109 	list_for_each_entry(kvm, &vm_list, vm_list)
2110 		*val += *(u32 *)((void *)kvm + offset);
2111 	spin_unlock(&kvm_lock);
2112 	return 0;
2113 }
2114 
2115 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
2116 
2117 static int vcpu_stat_get(void *_offset, u64 *val)
2118 {
2119 	unsigned offset = (long)_offset;
2120 	struct kvm *kvm;
2121 	struct kvm_vcpu *vcpu;
2122 	int i;
2123 
2124 	*val = 0;
2125 	spin_lock(&kvm_lock);
2126 	list_for_each_entry(kvm, &vm_list, vm_list)
2127 		kvm_for_each_vcpu(i, vcpu, kvm)
2128 			*val += *(u32 *)((void *)vcpu + offset);
2129 
2130 	spin_unlock(&kvm_lock);
2131 	return 0;
2132 }
2133 
2134 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
2135 
2136 static const struct file_operations *stat_fops[] = {
2137 	[KVM_STAT_VCPU] = &vcpu_stat_fops,
2138 	[KVM_STAT_VM]   = &vm_stat_fops,
2139 };
2140 
2141 static void kvm_init_debug(void)
2142 {
2143 	struct kvm_stats_debugfs_item *p;
2144 
2145 	kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
2146 	for (p = debugfs_entries; p->name; ++p)
2147 		p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
2148 						(void *)(long)p->offset,
2149 						stat_fops[p->kind]);
2150 }
2151 
2152 static void kvm_exit_debug(void)
2153 {
2154 	struct kvm_stats_debugfs_item *p;
2155 
2156 	for (p = debugfs_entries; p->name; ++p)
2157 		debugfs_remove(p->dentry);
2158 	debugfs_remove(kvm_debugfs_dir);
2159 }
2160 
2161 static int kvm_suspend(struct sys_device *dev, pm_message_t state)
2162 {
2163 	if (kvm_usage_count)
2164 		hardware_disable(NULL);
2165 	return 0;
2166 }
2167 
2168 static int kvm_resume(struct sys_device *dev)
2169 {
2170 	if (kvm_usage_count)
2171 		hardware_enable(NULL);
2172 	return 0;
2173 }
2174 
2175 static struct sysdev_class kvm_sysdev_class = {
2176 	.name = "kvm",
2177 	.suspend = kvm_suspend,
2178 	.resume = kvm_resume,
2179 };
2180 
2181 static struct sys_device kvm_sysdev = {
2182 	.id = 0,
2183 	.cls = &kvm_sysdev_class,
2184 };
2185 
2186 struct page *bad_page;
2187 pfn_t bad_pfn;
2188 
2189 static inline
2190 struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
2191 {
2192 	return container_of(pn, struct kvm_vcpu, preempt_notifier);
2193 }
2194 
2195 static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
2196 {
2197 	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
2198 
2199 	kvm_arch_vcpu_load(vcpu, cpu);
2200 }
2201 
2202 static void kvm_sched_out(struct preempt_notifier *pn,
2203 			  struct task_struct *next)
2204 {
2205 	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
2206 
2207 	kvm_arch_vcpu_put(vcpu);
2208 }
2209 
2210 int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
2211 		  struct module *module)
2212 {
2213 	int r;
2214 	int cpu;
2215 
2216 	r = kvm_arch_init(opaque);
2217 	if (r)
2218 		goto out_fail;
2219 
2220 	bad_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
2221 
2222 	if (bad_page == NULL) {
2223 		r = -ENOMEM;
2224 		goto out;
2225 	}
2226 
2227 	bad_pfn = page_to_pfn(bad_page);
2228 
2229 	hwpoison_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
2230 
2231 	if (hwpoison_page == NULL) {
2232 		r = -ENOMEM;
2233 		goto out_free_0;
2234 	}
2235 
2236 	hwpoison_pfn = page_to_pfn(hwpoison_page);
2237 
2238 	fault_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
2239 
2240 	if (fault_page == NULL) {
2241 		r = -ENOMEM;
2242 		goto out_free_0;
2243 	}
2244 
2245 	fault_pfn = page_to_pfn(fault_page);
2246 
2247 	if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
2248 		r = -ENOMEM;
2249 		goto out_free_0;
2250 	}
2251 
2252 	r = kvm_arch_hardware_setup();
2253 	if (r < 0)
2254 		goto out_free_0a;
2255 
2256 	for_each_online_cpu(cpu) {
2257 		smp_call_function_single(cpu,
2258 				kvm_arch_check_processor_compat,
2259 				&r, 1);
2260 		if (r < 0)
2261 			goto out_free_1;
2262 	}
2263 
2264 	r = register_cpu_notifier(&kvm_cpu_notifier);
2265 	if (r)
2266 		goto out_free_2;
2267 	register_reboot_notifier(&kvm_reboot_notifier);
2268 
2269 	r = sysdev_class_register(&kvm_sysdev_class);
2270 	if (r)
2271 		goto out_free_3;
2272 
2273 	r = sysdev_register(&kvm_sysdev);
2274 	if (r)
2275 		goto out_free_4;
2276 
2277 	/* A kmem cache lets us meet the alignment requirements of fx_save. */
2278 	if (!vcpu_align)
2279 		vcpu_align = __alignof__(struct kvm_vcpu);
2280 	kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size, vcpu_align,
2281 					   0, NULL);
2282 	if (!kvm_vcpu_cache) {
2283 		r = -ENOMEM;
2284 		goto out_free_5;
2285 	}
2286 
2287 	kvm_chardev_ops.owner = module;
2288 	kvm_vm_fops.owner = module;
2289 	kvm_vcpu_fops.owner = module;
2290 
2291 	r = misc_register(&kvm_dev);
2292 	if (r) {
2293 		printk(KERN_ERR "kvm: misc device register failed\n");
2294 		goto out_free;
2295 	}
2296 
2297 	kvm_preempt_ops.sched_in = kvm_sched_in;
2298 	kvm_preempt_ops.sched_out = kvm_sched_out;
2299 
2300 	kvm_init_debug();
2301 
2302 	return 0;
2303 
2304 out_free:
2305 	kmem_cache_destroy(kvm_vcpu_cache);
2306 out_free_5:
2307 	sysdev_unregister(&kvm_sysdev);
2308 out_free_4:
2309 	sysdev_class_unregister(&kvm_sysdev_class);
2310 out_free_3:
2311 	unregister_reboot_notifier(&kvm_reboot_notifier);
2312 	unregister_cpu_notifier(&kvm_cpu_notifier);
2313 out_free_2:
2314 out_free_1:
2315 	kvm_arch_hardware_unsetup();
2316 out_free_0a:
2317 	free_cpumask_var(cpus_hardware_enabled);
2318 out_free_0:
2319 	if (fault_page)
2320 		__free_page(fault_page);
2321 	if (hwpoison_page)
2322 		__free_page(hwpoison_page);
2323 	__free_page(bad_page);
2324 out:
2325 	kvm_arch_exit();
2326 out_fail:
2327 	return r;
2328 }
2329 EXPORT_SYMBOL_GPL(kvm_init);
2330 
2331 void kvm_exit(void)
2332 {
2333 	kvm_exit_debug();
2334 	misc_deregister(&kvm_dev);
2335 	kmem_cache_destroy(kvm_vcpu_cache);
2336 	sysdev_unregister(&kvm_sysdev);
2337 	sysdev_class_unregister(&kvm_sysdev_class);
2338 	unregister_reboot_notifier(&kvm_reboot_notifier);
2339 	unregister_cpu_notifier(&kvm_cpu_notifier);
2340 	on_each_cpu(hardware_disable, NULL, 1);
2341 	kvm_arch_hardware_unsetup();
2342 	kvm_arch_exit();
2343 	free_cpumask_var(cpus_hardware_enabled);
2344 	__free_page(hwpoison_page);
2345 	__free_page(bad_page);
2346 }
2347 EXPORT_SYMBOL_GPL(kvm_exit);
2348