xref: /linux/virt/kvm/kvm_main.c (revision c145211d1f9e2ef19e7b4c2b943f68366daa97af)
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  *
9  * Authors:
10  *   Avi Kivity   <avi@qumranet.com>
11  *   Yaniv Kamay  <yaniv@qumranet.com>
12  *
13  * This work is licensed under the terms of the GNU GPL, version 2.  See
14  * the COPYING file in the top-level directory.
15  *
16  */
17 
18 #include "iodev.h"
19 
20 #include <linux/kvm_host.h>
21 #include <linux/kvm.h>
22 #include <linux/module.h>
23 #include <linux/errno.h>
24 #include <linux/percpu.h>
25 #include <linux/mm.h>
26 #include <linux/miscdevice.h>
27 #include <linux/vmalloc.h>
28 #include <linux/reboot.h>
29 #include <linux/debugfs.h>
30 #include <linux/highmem.h>
31 #include <linux/file.h>
32 #include <linux/sysdev.h>
33 #include <linux/cpu.h>
34 #include <linux/sched.h>
35 #include <linux/cpumask.h>
36 #include <linux/smp.h>
37 #include <linux/anon_inodes.h>
38 #include <linux/profile.h>
39 #include <linux/kvm_para.h>
40 #include <linux/pagemap.h>
41 #include <linux/mman.h>
42 #include <linux/swap.h>
43 #include <linux/bitops.h>
44 #include <linux/spinlock.h>
45 #include <linux/compat.h>
46 #include <linux/srcu.h>
47 #include <linux/hugetlb.h>
48 #include <linux/slab.h>
49 
50 #include <asm/processor.h>
51 #include <asm/io.h>
52 #include <asm/uaccess.h>
53 #include <asm/pgtable.h>
54 #include <asm-generic/bitops/le.h>
55 
56 #include "coalesced_mmio.h"
57 
58 #define CREATE_TRACE_POINTS
59 #include <trace/events/kvm.h>
60 
61 MODULE_AUTHOR("Qumranet");
62 MODULE_LICENSE("GPL");
63 
64 /*
65  * Ordering of locks:
66  *
67  * 		kvm->lock --> kvm->slots_lock --> kvm->irq_lock
68  */
69 
70 DEFINE_SPINLOCK(kvm_lock);
71 LIST_HEAD(vm_list);
72 
73 static cpumask_var_t cpus_hardware_enabled;
74 static int kvm_usage_count = 0;
75 static atomic_t hardware_enable_failed;
76 
77 struct kmem_cache *kvm_vcpu_cache;
78 EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
79 
80 static __read_mostly struct preempt_ops kvm_preempt_ops;
81 
82 struct dentry *kvm_debugfs_dir;
83 
84 static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
85 			   unsigned long arg);
86 static int hardware_enable_all(void);
87 static void hardware_disable_all(void);
88 
89 static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
90 
91 static bool kvm_rebooting;
92 
93 static bool largepages_enabled = true;
94 
95 inline int kvm_is_mmio_pfn(pfn_t pfn)
96 {
97 	if (pfn_valid(pfn)) {
98 		struct page *page = compound_head(pfn_to_page(pfn));
99 		return PageReserved(page);
100 	}
101 
102 	return true;
103 }
104 
105 /*
106  * Switches to specified vcpu, until a matching vcpu_put()
107  */
108 void vcpu_load(struct kvm_vcpu *vcpu)
109 {
110 	int cpu;
111 
112 	mutex_lock(&vcpu->mutex);
113 	cpu = get_cpu();
114 	preempt_notifier_register(&vcpu->preempt_notifier);
115 	kvm_arch_vcpu_load(vcpu, cpu);
116 	put_cpu();
117 }
118 
119 void vcpu_put(struct kvm_vcpu *vcpu)
120 {
121 	preempt_disable();
122 	kvm_arch_vcpu_put(vcpu);
123 	preempt_notifier_unregister(&vcpu->preempt_notifier);
124 	preempt_enable();
125 	mutex_unlock(&vcpu->mutex);
126 }
127 
128 static void ack_flush(void *_completed)
129 {
130 }
131 
132 static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
133 {
134 	int i, cpu, me;
135 	cpumask_var_t cpus;
136 	bool called = true;
137 	struct kvm_vcpu *vcpu;
138 
139 	zalloc_cpumask_var(&cpus, GFP_ATOMIC);
140 
141 	raw_spin_lock(&kvm->requests_lock);
142 	me = smp_processor_id();
143 	kvm_for_each_vcpu(i, vcpu, kvm) {
144 		if (test_and_set_bit(req, &vcpu->requests))
145 			continue;
146 		cpu = vcpu->cpu;
147 		if (cpus != NULL && cpu != -1 && cpu != me)
148 			cpumask_set_cpu(cpu, cpus);
149 	}
150 	if (unlikely(cpus == NULL))
151 		smp_call_function_many(cpu_online_mask, ack_flush, NULL, 1);
152 	else if (!cpumask_empty(cpus))
153 		smp_call_function_many(cpus, ack_flush, NULL, 1);
154 	else
155 		called = false;
156 	raw_spin_unlock(&kvm->requests_lock);
157 	free_cpumask_var(cpus);
158 	return called;
159 }
160 
161 void kvm_flush_remote_tlbs(struct kvm *kvm)
162 {
163 	if (make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
164 		++kvm->stat.remote_tlb_flush;
165 }
166 
167 void kvm_reload_remote_mmus(struct kvm *kvm)
168 {
169 	make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD);
170 }
171 
172 int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
173 {
174 	struct page *page;
175 	int r;
176 
177 	mutex_init(&vcpu->mutex);
178 	vcpu->cpu = -1;
179 	vcpu->kvm = kvm;
180 	vcpu->vcpu_id = id;
181 	init_waitqueue_head(&vcpu->wq);
182 
183 	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
184 	if (!page) {
185 		r = -ENOMEM;
186 		goto fail;
187 	}
188 	vcpu->run = page_address(page);
189 
190 	r = kvm_arch_vcpu_init(vcpu);
191 	if (r < 0)
192 		goto fail_free_run;
193 	return 0;
194 
195 fail_free_run:
196 	free_page((unsigned long)vcpu->run);
197 fail:
198 	return r;
199 }
200 EXPORT_SYMBOL_GPL(kvm_vcpu_init);
201 
202 void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
203 {
204 	kvm_arch_vcpu_uninit(vcpu);
205 	free_page((unsigned long)vcpu->run);
206 }
207 EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
208 
209 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
210 static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
211 {
212 	return container_of(mn, struct kvm, mmu_notifier);
213 }
214 
215 static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
216 					     struct mm_struct *mm,
217 					     unsigned long address)
218 {
219 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
220 	int need_tlb_flush, idx;
221 
222 	/*
223 	 * When ->invalidate_page runs, the linux pte has been zapped
224 	 * already but the page is still allocated until
225 	 * ->invalidate_page returns. So if we increase the sequence
226 	 * here the kvm page fault will notice if the spte can't be
227 	 * established because the page is going to be freed. If
228 	 * instead the kvm page fault establishes the spte before
229 	 * ->invalidate_page runs, kvm_unmap_hva will release it
230 	 * before returning.
231 	 *
232 	 * The sequence increase only need to be seen at spin_unlock
233 	 * time, and not at spin_lock time.
234 	 *
235 	 * Increasing the sequence after the spin_unlock would be
236 	 * unsafe because the kvm page fault could then establish the
237 	 * pte after kvm_unmap_hva returned, without noticing the page
238 	 * is going to be freed.
239 	 */
240 	idx = srcu_read_lock(&kvm->srcu);
241 	spin_lock(&kvm->mmu_lock);
242 	kvm->mmu_notifier_seq++;
243 	need_tlb_flush = kvm_unmap_hva(kvm, address);
244 	spin_unlock(&kvm->mmu_lock);
245 	srcu_read_unlock(&kvm->srcu, idx);
246 
247 	/* we've to flush the tlb before the pages can be freed */
248 	if (need_tlb_flush)
249 		kvm_flush_remote_tlbs(kvm);
250 
251 }
252 
253 static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
254 					struct mm_struct *mm,
255 					unsigned long address,
256 					pte_t pte)
257 {
258 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
259 	int idx;
260 
261 	idx = srcu_read_lock(&kvm->srcu);
262 	spin_lock(&kvm->mmu_lock);
263 	kvm->mmu_notifier_seq++;
264 	kvm_set_spte_hva(kvm, address, pte);
265 	spin_unlock(&kvm->mmu_lock);
266 	srcu_read_unlock(&kvm->srcu, idx);
267 }
268 
269 static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
270 						    struct mm_struct *mm,
271 						    unsigned long start,
272 						    unsigned long end)
273 {
274 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
275 	int need_tlb_flush = 0, idx;
276 
277 	idx = srcu_read_lock(&kvm->srcu);
278 	spin_lock(&kvm->mmu_lock);
279 	/*
280 	 * The count increase must become visible at unlock time as no
281 	 * spte can be established without taking the mmu_lock and
282 	 * count is also read inside the mmu_lock critical section.
283 	 */
284 	kvm->mmu_notifier_count++;
285 	for (; start < end; start += PAGE_SIZE)
286 		need_tlb_flush |= kvm_unmap_hva(kvm, start);
287 	spin_unlock(&kvm->mmu_lock);
288 	srcu_read_unlock(&kvm->srcu, idx);
289 
290 	/* we've to flush the tlb before the pages can be freed */
291 	if (need_tlb_flush)
292 		kvm_flush_remote_tlbs(kvm);
293 }
294 
295 static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
296 						  struct mm_struct *mm,
297 						  unsigned long start,
298 						  unsigned long end)
299 {
300 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
301 
302 	spin_lock(&kvm->mmu_lock);
303 	/*
304 	 * This sequence increase will notify the kvm page fault that
305 	 * the page that is going to be mapped in the spte could have
306 	 * been freed.
307 	 */
308 	kvm->mmu_notifier_seq++;
309 	/*
310 	 * The above sequence increase must be visible before the
311 	 * below count decrease but both values are read by the kvm
312 	 * page fault under mmu_lock spinlock so we don't need to add
313 	 * a smb_wmb() here in between the two.
314 	 */
315 	kvm->mmu_notifier_count--;
316 	spin_unlock(&kvm->mmu_lock);
317 
318 	BUG_ON(kvm->mmu_notifier_count < 0);
319 }
320 
321 static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
322 					      struct mm_struct *mm,
323 					      unsigned long address)
324 {
325 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
326 	int young, idx;
327 
328 	idx = srcu_read_lock(&kvm->srcu);
329 	spin_lock(&kvm->mmu_lock);
330 	young = kvm_age_hva(kvm, address);
331 	spin_unlock(&kvm->mmu_lock);
332 	srcu_read_unlock(&kvm->srcu, idx);
333 
334 	if (young)
335 		kvm_flush_remote_tlbs(kvm);
336 
337 	return young;
338 }
339 
340 static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
341 				     struct mm_struct *mm)
342 {
343 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
344 	int idx;
345 
346 	idx = srcu_read_lock(&kvm->srcu);
347 	kvm_arch_flush_shadow(kvm);
348 	srcu_read_unlock(&kvm->srcu, idx);
349 }
350 
351 static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
352 	.invalidate_page	= kvm_mmu_notifier_invalidate_page,
353 	.invalidate_range_start	= kvm_mmu_notifier_invalidate_range_start,
354 	.invalidate_range_end	= kvm_mmu_notifier_invalidate_range_end,
355 	.clear_flush_young	= kvm_mmu_notifier_clear_flush_young,
356 	.change_pte		= kvm_mmu_notifier_change_pte,
357 	.release		= kvm_mmu_notifier_release,
358 };
359 
360 static int kvm_init_mmu_notifier(struct kvm *kvm)
361 {
362 	kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
363 	return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
364 }
365 
366 #else  /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */
367 
368 static int kvm_init_mmu_notifier(struct kvm *kvm)
369 {
370 	return 0;
371 }
372 
373 #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
374 
375 static struct kvm *kvm_create_vm(void)
376 {
377 	int r = 0, i;
378 	struct kvm *kvm = kvm_arch_create_vm();
379 
380 	if (IS_ERR(kvm))
381 		goto out;
382 
383 	r = hardware_enable_all();
384 	if (r)
385 		goto out_err_nodisable;
386 
387 #ifdef CONFIG_HAVE_KVM_IRQCHIP
388 	INIT_HLIST_HEAD(&kvm->mask_notifier_list);
389 	INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
390 #endif
391 
392 	r = -ENOMEM;
393 	kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
394 	if (!kvm->memslots)
395 		goto out_err;
396 	if (init_srcu_struct(&kvm->srcu))
397 		goto out_err;
398 	for (i = 0; i < KVM_NR_BUSES; i++) {
399 		kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus),
400 					GFP_KERNEL);
401 		if (!kvm->buses[i]) {
402 			cleanup_srcu_struct(&kvm->srcu);
403 			goto out_err;
404 		}
405 	}
406 
407 	r = kvm_init_mmu_notifier(kvm);
408 	if (r) {
409 		cleanup_srcu_struct(&kvm->srcu);
410 		goto out_err;
411 	}
412 
413 	kvm->mm = current->mm;
414 	atomic_inc(&kvm->mm->mm_count);
415 	spin_lock_init(&kvm->mmu_lock);
416 	raw_spin_lock_init(&kvm->requests_lock);
417 	kvm_eventfd_init(kvm);
418 	mutex_init(&kvm->lock);
419 	mutex_init(&kvm->irq_lock);
420 	mutex_init(&kvm->slots_lock);
421 	atomic_set(&kvm->users_count, 1);
422 	spin_lock(&kvm_lock);
423 	list_add(&kvm->vm_list, &vm_list);
424 	spin_unlock(&kvm_lock);
425 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
426 	kvm_coalesced_mmio_init(kvm);
427 #endif
428 out:
429 	return kvm;
430 
431 out_err:
432 	hardware_disable_all();
433 out_err_nodisable:
434 	for (i = 0; i < KVM_NR_BUSES; i++)
435 		kfree(kvm->buses[i]);
436 	kfree(kvm->memslots);
437 	kfree(kvm);
438 	return ERR_PTR(r);
439 }
440 
441 /*
442  * Free any memory in @free but not in @dont.
443  */
444 static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
445 				  struct kvm_memory_slot *dont)
446 {
447 	int i;
448 
449 	if (!dont || free->rmap != dont->rmap)
450 		vfree(free->rmap);
451 
452 	if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
453 		vfree(free->dirty_bitmap);
454 
455 
456 	for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
457 		if (!dont || free->lpage_info[i] != dont->lpage_info[i]) {
458 			vfree(free->lpage_info[i]);
459 			free->lpage_info[i] = NULL;
460 		}
461 	}
462 
463 	free->npages = 0;
464 	free->dirty_bitmap = NULL;
465 	free->rmap = NULL;
466 }
467 
468 void kvm_free_physmem(struct kvm *kvm)
469 {
470 	int i;
471 	struct kvm_memslots *slots = kvm->memslots;
472 
473 	for (i = 0; i < slots->nmemslots; ++i)
474 		kvm_free_physmem_slot(&slots->memslots[i], NULL);
475 
476 	kfree(kvm->memslots);
477 }
478 
479 static void kvm_destroy_vm(struct kvm *kvm)
480 {
481 	int i;
482 	struct mm_struct *mm = kvm->mm;
483 
484 	kvm_arch_sync_events(kvm);
485 	spin_lock(&kvm_lock);
486 	list_del(&kvm->vm_list);
487 	spin_unlock(&kvm_lock);
488 	kvm_free_irq_routing(kvm);
489 	for (i = 0; i < KVM_NR_BUSES; i++)
490 		kvm_io_bus_destroy(kvm->buses[i]);
491 	kvm_coalesced_mmio_free(kvm);
492 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
493 	mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
494 #else
495 	kvm_arch_flush_shadow(kvm);
496 #endif
497 	kvm_arch_destroy_vm(kvm);
498 	hardware_disable_all();
499 	mmdrop(mm);
500 }
501 
502 void kvm_get_kvm(struct kvm *kvm)
503 {
504 	atomic_inc(&kvm->users_count);
505 }
506 EXPORT_SYMBOL_GPL(kvm_get_kvm);
507 
508 void kvm_put_kvm(struct kvm *kvm)
509 {
510 	if (atomic_dec_and_test(&kvm->users_count))
511 		kvm_destroy_vm(kvm);
512 }
513 EXPORT_SYMBOL_GPL(kvm_put_kvm);
514 
515 
516 static int kvm_vm_release(struct inode *inode, struct file *filp)
517 {
518 	struct kvm *kvm = filp->private_data;
519 
520 	kvm_irqfd_release(kvm);
521 
522 	kvm_put_kvm(kvm);
523 	return 0;
524 }
525 
526 /*
527  * Allocate some memory and give it an address in the guest physical address
528  * space.
529  *
530  * Discontiguous memory is allowed, mostly for framebuffers.
531  *
532  * Must be called holding mmap_sem for write.
533  */
534 int __kvm_set_memory_region(struct kvm *kvm,
535 			    struct kvm_userspace_memory_region *mem,
536 			    int user_alloc)
537 {
538 	int r, flush_shadow = 0;
539 	gfn_t base_gfn;
540 	unsigned long npages;
541 	unsigned long i;
542 	struct kvm_memory_slot *memslot;
543 	struct kvm_memory_slot old, new;
544 	struct kvm_memslots *slots, *old_memslots;
545 
546 	r = -EINVAL;
547 	/* General sanity checks */
548 	if (mem->memory_size & (PAGE_SIZE - 1))
549 		goto out;
550 	if (mem->guest_phys_addr & (PAGE_SIZE - 1))
551 		goto out;
552 	if (user_alloc && (mem->userspace_addr & (PAGE_SIZE - 1)))
553 		goto out;
554 	if (mem->slot >= KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS)
555 		goto out;
556 	if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
557 		goto out;
558 
559 	memslot = &kvm->memslots->memslots[mem->slot];
560 	base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
561 	npages = mem->memory_size >> PAGE_SHIFT;
562 
563 	if (!npages)
564 		mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
565 
566 	new = old = *memslot;
567 
568 	new.base_gfn = base_gfn;
569 	new.npages = npages;
570 	new.flags = mem->flags;
571 
572 	/* Disallow changing a memory slot's size. */
573 	r = -EINVAL;
574 	if (npages && old.npages && npages != old.npages)
575 		goto out_free;
576 
577 	/* Check for overlaps */
578 	r = -EEXIST;
579 	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
580 		struct kvm_memory_slot *s = &kvm->memslots->memslots[i];
581 
582 		if (s == memslot || !s->npages)
583 			continue;
584 		if (!((base_gfn + npages <= s->base_gfn) ||
585 		      (base_gfn >= s->base_gfn + s->npages)))
586 			goto out_free;
587 	}
588 
589 	/* Free page dirty bitmap if unneeded */
590 	if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
591 		new.dirty_bitmap = NULL;
592 
593 	r = -ENOMEM;
594 
595 	/* Allocate if a slot is being created */
596 #ifndef CONFIG_S390
597 	if (npages && !new.rmap) {
598 		new.rmap = vmalloc(npages * sizeof(struct page *));
599 
600 		if (!new.rmap)
601 			goto out_free;
602 
603 		memset(new.rmap, 0, npages * sizeof(*new.rmap));
604 
605 		new.user_alloc = user_alloc;
606 		new.userspace_addr = mem->userspace_addr;
607 	}
608 	if (!npages)
609 		goto skip_lpage;
610 
611 	for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
612 		unsigned long ugfn;
613 		unsigned long j;
614 		int lpages;
615 		int level = i + 2;
616 
617 		/* Avoid unused variable warning if no large pages */
618 		(void)level;
619 
620 		if (new.lpage_info[i])
621 			continue;
622 
623 		lpages = 1 + (base_gfn + npages - 1) /
624 			     KVM_PAGES_PER_HPAGE(level);
625 		lpages -= base_gfn / KVM_PAGES_PER_HPAGE(level);
626 
627 		new.lpage_info[i] = vmalloc(lpages * sizeof(*new.lpage_info[i]));
628 
629 		if (!new.lpage_info[i])
630 			goto out_free;
631 
632 		memset(new.lpage_info[i], 0,
633 		       lpages * sizeof(*new.lpage_info[i]));
634 
635 		if (base_gfn % KVM_PAGES_PER_HPAGE(level))
636 			new.lpage_info[i][0].write_count = 1;
637 		if ((base_gfn+npages) % KVM_PAGES_PER_HPAGE(level))
638 			new.lpage_info[i][lpages - 1].write_count = 1;
639 		ugfn = new.userspace_addr >> PAGE_SHIFT;
640 		/*
641 		 * If the gfn and userspace address are not aligned wrt each
642 		 * other, or if explicitly asked to, disable large page
643 		 * support for this slot
644 		 */
645 		if ((base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE(level) - 1) ||
646 		    !largepages_enabled)
647 			for (j = 0; j < lpages; ++j)
648 				new.lpage_info[i][j].write_count = 1;
649 	}
650 
651 skip_lpage:
652 
653 	/* Allocate page dirty bitmap if needed */
654 	if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
655 		unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(&new);
656 
657 		new.dirty_bitmap = vmalloc(dirty_bytes);
658 		if (!new.dirty_bitmap)
659 			goto out_free;
660 		memset(new.dirty_bitmap, 0, dirty_bytes);
661 		/* destroy any largepage mappings for dirty tracking */
662 		if (old.npages)
663 			flush_shadow = 1;
664 	}
665 #else  /* not defined CONFIG_S390 */
666 	new.user_alloc = user_alloc;
667 	if (user_alloc)
668 		new.userspace_addr = mem->userspace_addr;
669 #endif /* not defined CONFIG_S390 */
670 
671 	if (!npages) {
672 		r = -ENOMEM;
673 		slots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
674 		if (!slots)
675 			goto out_free;
676 		memcpy(slots, kvm->memslots, sizeof(struct kvm_memslots));
677 		if (mem->slot >= slots->nmemslots)
678 			slots->nmemslots = mem->slot + 1;
679 		slots->memslots[mem->slot].flags |= KVM_MEMSLOT_INVALID;
680 
681 		old_memslots = kvm->memslots;
682 		rcu_assign_pointer(kvm->memslots, slots);
683 		synchronize_srcu_expedited(&kvm->srcu);
684 		/* From this point no new shadow pages pointing to a deleted
685 		 * memslot will be created.
686 		 *
687 		 * validation of sp->gfn happens in:
688 		 * 	- gfn_to_hva (kvm_read_guest, gfn_to_pfn)
689 		 * 	- kvm_is_visible_gfn (mmu_check_roots)
690 		 */
691 		kvm_arch_flush_shadow(kvm);
692 		kfree(old_memslots);
693 	}
694 
695 	r = kvm_arch_prepare_memory_region(kvm, &new, old, mem, user_alloc);
696 	if (r)
697 		goto out_free;
698 
699 #ifdef CONFIG_DMAR
700 	/* map the pages in iommu page table */
701 	if (npages) {
702 		r = kvm_iommu_map_pages(kvm, &new);
703 		if (r)
704 			goto out_free;
705 	}
706 #endif
707 
708 	r = -ENOMEM;
709 	slots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
710 	if (!slots)
711 		goto out_free;
712 	memcpy(slots, kvm->memslots, sizeof(struct kvm_memslots));
713 	if (mem->slot >= slots->nmemslots)
714 		slots->nmemslots = mem->slot + 1;
715 
716 	/* actual memory is freed via old in kvm_free_physmem_slot below */
717 	if (!npages) {
718 		new.rmap = NULL;
719 		new.dirty_bitmap = NULL;
720 		for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i)
721 			new.lpage_info[i] = NULL;
722 	}
723 
724 	slots->memslots[mem->slot] = new;
725 	old_memslots = kvm->memslots;
726 	rcu_assign_pointer(kvm->memslots, slots);
727 	synchronize_srcu_expedited(&kvm->srcu);
728 
729 	kvm_arch_commit_memory_region(kvm, mem, old, user_alloc);
730 
731 	kvm_free_physmem_slot(&old, &new);
732 	kfree(old_memslots);
733 
734 	if (flush_shadow)
735 		kvm_arch_flush_shadow(kvm);
736 
737 	return 0;
738 
739 out_free:
740 	kvm_free_physmem_slot(&new, &old);
741 out:
742 	return r;
743 
744 }
745 EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
746 
747 int kvm_set_memory_region(struct kvm *kvm,
748 			  struct kvm_userspace_memory_region *mem,
749 			  int user_alloc)
750 {
751 	int r;
752 
753 	mutex_lock(&kvm->slots_lock);
754 	r = __kvm_set_memory_region(kvm, mem, user_alloc);
755 	mutex_unlock(&kvm->slots_lock);
756 	return r;
757 }
758 EXPORT_SYMBOL_GPL(kvm_set_memory_region);
759 
760 int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
761 				   struct
762 				   kvm_userspace_memory_region *mem,
763 				   int user_alloc)
764 {
765 	if (mem->slot >= KVM_MEMORY_SLOTS)
766 		return -EINVAL;
767 	return kvm_set_memory_region(kvm, mem, user_alloc);
768 }
769 
770 int kvm_get_dirty_log(struct kvm *kvm,
771 			struct kvm_dirty_log *log, int *is_dirty)
772 {
773 	struct kvm_memory_slot *memslot;
774 	int r, i;
775 	unsigned long n;
776 	unsigned long any = 0;
777 
778 	r = -EINVAL;
779 	if (log->slot >= KVM_MEMORY_SLOTS)
780 		goto out;
781 
782 	memslot = &kvm->memslots->memslots[log->slot];
783 	r = -ENOENT;
784 	if (!memslot->dirty_bitmap)
785 		goto out;
786 
787 	n = kvm_dirty_bitmap_bytes(memslot);
788 
789 	for (i = 0; !any && i < n/sizeof(long); ++i)
790 		any = memslot->dirty_bitmap[i];
791 
792 	r = -EFAULT;
793 	if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
794 		goto out;
795 
796 	if (any)
797 		*is_dirty = 1;
798 
799 	r = 0;
800 out:
801 	return r;
802 }
803 
804 void kvm_disable_largepages(void)
805 {
806 	largepages_enabled = false;
807 }
808 EXPORT_SYMBOL_GPL(kvm_disable_largepages);
809 
810 int is_error_page(struct page *page)
811 {
812 	return page == bad_page;
813 }
814 EXPORT_SYMBOL_GPL(is_error_page);
815 
816 int is_error_pfn(pfn_t pfn)
817 {
818 	return pfn == bad_pfn;
819 }
820 EXPORT_SYMBOL_GPL(is_error_pfn);
821 
822 static inline unsigned long bad_hva(void)
823 {
824 	return PAGE_OFFSET;
825 }
826 
827 int kvm_is_error_hva(unsigned long addr)
828 {
829 	return addr == bad_hva();
830 }
831 EXPORT_SYMBOL_GPL(kvm_is_error_hva);
832 
833 struct kvm_memory_slot *gfn_to_memslot_unaliased(struct kvm *kvm, gfn_t gfn)
834 {
835 	int i;
836 	struct kvm_memslots *slots = rcu_dereference(kvm->memslots);
837 
838 	for (i = 0; i < slots->nmemslots; ++i) {
839 		struct kvm_memory_slot *memslot = &slots->memslots[i];
840 
841 		if (gfn >= memslot->base_gfn
842 		    && gfn < memslot->base_gfn + memslot->npages)
843 			return memslot;
844 	}
845 	return NULL;
846 }
847 EXPORT_SYMBOL_GPL(gfn_to_memslot_unaliased);
848 
849 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
850 {
851 	gfn = unalias_gfn(kvm, gfn);
852 	return gfn_to_memslot_unaliased(kvm, gfn);
853 }
854 
855 int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
856 {
857 	int i;
858 	struct kvm_memslots *slots = rcu_dereference(kvm->memslots);
859 
860 	gfn = unalias_gfn_instantiation(kvm, gfn);
861 	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
862 		struct kvm_memory_slot *memslot = &slots->memslots[i];
863 
864 		if (memslot->flags & KVM_MEMSLOT_INVALID)
865 			continue;
866 
867 		if (gfn >= memslot->base_gfn
868 		    && gfn < memslot->base_gfn + memslot->npages)
869 			return 1;
870 	}
871 	return 0;
872 }
873 EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
874 
875 unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn)
876 {
877 	struct vm_area_struct *vma;
878 	unsigned long addr, size;
879 
880 	size = PAGE_SIZE;
881 
882 	addr = gfn_to_hva(kvm, gfn);
883 	if (kvm_is_error_hva(addr))
884 		return PAGE_SIZE;
885 
886 	down_read(&current->mm->mmap_sem);
887 	vma = find_vma(current->mm, addr);
888 	if (!vma)
889 		goto out;
890 
891 	size = vma_kernel_pagesize(vma);
892 
893 out:
894 	up_read(&current->mm->mmap_sem);
895 
896 	return size;
897 }
898 
899 int memslot_id(struct kvm *kvm, gfn_t gfn)
900 {
901 	int i;
902 	struct kvm_memslots *slots = rcu_dereference(kvm->memslots);
903 	struct kvm_memory_slot *memslot = NULL;
904 
905 	gfn = unalias_gfn(kvm, gfn);
906 	for (i = 0; i < slots->nmemslots; ++i) {
907 		memslot = &slots->memslots[i];
908 
909 		if (gfn >= memslot->base_gfn
910 		    && gfn < memslot->base_gfn + memslot->npages)
911 			break;
912 	}
913 
914 	return memslot - slots->memslots;
915 }
916 
917 unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
918 {
919 	struct kvm_memory_slot *slot;
920 
921 	gfn = unalias_gfn_instantiation(kvm, gfn);
922 	slot = gfn_to_memslot_unaliased(kvm, gfn);
923 	if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
924 		return bad_hva();
925 	return (slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE);
926 }
927 EXPORT_SYMBOL_GPL(gfn_to_hva);
928 
929 static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr)
930 {
931 	struct page *page[1];
932 	int npages;
933 	pfn_t pfn;
934 
935 	might_sleep();
936 
937 	npages = get_user_pages_fast(addr, 1, 1, page);
938 
939 	if (unlikely(npages != 1)) {
940 		struct vm_area_struct *vma;
941 
942 		down_read(&current->mm->mmap_sem);
943 		vma = find_vma(current->mm, addr);
944 
945 		if (vma == NULL || addr < vma->vm_start ||
946 		    !(vma->vm_flags & VM_PFNMAP)) {
947 			up_read(&current->mm->mmap_sem);
948 			get_page(bad_page);
949 			return page_to_pfn(bad_page);
950 		}
951 
952 		pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
953 		up_read(&current->mm->mmap_sem);
954 		BUG_ON(!kvm_is_mmio_pfn(pfn));
955 	} else
956 		pfn = page_to_pfn(page[0]);
957 
958 	return pfn;
959 }
960 
961 pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
962 {
963 	unsigned long addr;
964 
965 	addr = gfn_to_hva(kvm, gfn);
966 	if (kvm_is_error_hva(addr)) {
967 		get_page(bad_page);
968 		return page_to_pfn(bad_page);
969 	}
970 
971 	return hva_to_pfn(kvm, addr);
972 }
973 EXPORT_SYMBOL_GPL(gfn_to_pfn);
974 
975 static unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
976 {
977 	return (slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE);
978 }
979 
980 pfn_t gfn_to_pfn_memslot(struct kvm *kvm,
981 			 struct kvm_memory_slot *slot, gfn_t gfn)
982 {
983 	unsigned long addr = gfn_to_hva_memslot(slot, gfn);
984 	return hva_to_pfn(kvm, addr);
985 }
986 
987 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
988 {
989 	pfn_t pfn;
990 
991 	pfn = gfn_to_pfn(kvm, gfn);
992 	if (!kvm_is_mmio_pfn(pfn))
993 		return pfn_to_page(pfn);
994 
995 	WARN_ON(kvm_is_mmio_pfn(pfn));
996 
997 	get_page(bad_page);
998 	return bad_page;
999 }
1000 
1001 EXPORT_SYMBOL_GPL(gfn_to_page);
1002 
1003 void kvm_release_page_clean(struct page *page)
1004 {
1005 	kvm_release_pfn_clean(page_to_pfn(page));
1006 }
1007 EXPORT_SYMBOL_GPL(kvm_release_page_clean);
1008 
1009 void kvm_release_pfn_clean(pfn_t pfn)
1010 {
1011 	if (!kvm_is_mmio_pfn(pfn))
1012 		put_page(pfn_to_page(pfn));
1013 }
1014 EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
1015 
1016 void kvm_release_page_dirty(struct page *page)
1017 {
1018 	kvm_release_pfn_dirty(page_to_pfn(page));
1019 }
1020 EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
1021 
1022 void kvm_release_pfn_dirty(pfn_t pfn)
1023 {
1024 	kvm_set_pfn_dirty(pfn);
1025 	kvm_release_pfn_clean(pfn);
1026 }
1027 EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
1028 
1029 void kvm_set_page_dirty(struct page *page)
1030 {
1031 	kvm_set_pfn_dirty(page_to_pfn(page));
1032 }
1033 EXPORT_SYMBOL_GPL(kvm_set_page_dirty);
1034 
1035 void kvm_set_pfn_dirty(pfn_t pfn)
1036 {
1037 	if (!kvm_is_mmio_pfn(pfn)) {
1038 		struct page *page = pfn_to_page(pfn);
1039 		if (!PageReserved(page))
1040 			SetPageDirty(page);
1041 	}
1042 }
1043 EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
1044 
1045 void kvm_set_pfn_accessed(pfn_t pfn)
1046 {
1047 	if (!kvm_is_mmio_pfn(pfn))
1048 		mark_page_accessed(pfn_to_page(pfn));
1049 }
1050 EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
1051 
1052 void kvm_get_pfn(pfn_t pfn)
1053 {
1054 	if (!kvm_is_mmio_pfn(pfn))
1055 		get_page(pfn_to_page(pfn));
1056 }
1057 EXPORT_SYMBOL_GPL(kvm_get_pfn);
1058 
1059 static int next_segment(unsigned long len, int offset)
1060 {
1061 	if (len > PAGE_SIZE - offset)
1062 		return PAGE_SIZE - offset;
1063 	else
1064 		return len;
1065 }
1066 
1067 int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
1068 			int len)
1069 {
1070 	int r;
1071 	unsigned long addr;
1072 
1073 	addr = gfn_to_hva(kvm, gfn);
1074 	if (kvm_is_error_hva(addr))
1075 		return -EFAULT;
1076 	r = copy_from_user(data, (void __user *)addr + offset, len);
1077 	if (r)
1078 		return -EFAULT;
1079 	return 0;
1080 }
1081 EXPORT_SYMBOL_GPL(kvm_read_guest_page);
1082 
1083 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
1084 {
1085 	gfn_t gfn = gpa >> PAGE_SHIFT;
1086 	int seg;
1087 	int offset = offset_in_page(gpa);
1088 	int ret;
1089 
1090 	while ((seg = next_segment(len, offset)) != 0) {
1091 		ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
1092 		if (ret < 0)
1093 			return ret;
1094 		offset = 0;
1095 		len -= seg;
1096 		data += seg;
1097 		++gfn;
1098 	}
1099 	return 0;
1100 }
1101 EXPORT_SYMBOL_GPL(kvm_read_guest);
1102 
1103 int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
1104 			  unsigned long len)
1105 {
1106 	int r;
1107 	unsigned long addr;
1108 	gfn_t gfn = gpa >> PAGE_SHIFT;
1109 	int offset = offset_in_page(gpa);
1110 
1111 	addr = gfn_to_hva(kvm, gfn);
1112 	if (kvm_is_error_hva(addr))
1113 		return -EFAULT;
1114 	pagefault_disable();
1115 	r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
1116 	pagefault_enable();
1117 	if (r)
1118 		return -EFAULT;
1119 	return 0;
1120 }
1121 EXPORT_SYMBOL(kvm_read_guest_atomic);
1122 
1123 int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
1124 			 int offset, int len)
1125 {
1126 	int r;
1127 	unsigned long addr;
1128 
1129 	addr = gfn_to_hva(kvm, gfn);
1130 	if (kvm_is_error_hva(addr))
1131 		return -EFAULT;
1132 	r = copy_to_user((void __user *)addr + offset, data, len);
1133 	if (r)
1134 		return -EFAULT;
1135 	mark_page_dirty(kvm, gfn);
1136 	return 0;
1137 }
1138 EXPORT_SYMBOL_GPL(kvm_write_guest_page);
1139 
1140 int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
1141 		    unsigned long len)
1142 {
1143 	gfn_t gfn = gpa >> PAGE_SHIFT;
1144 	int seg;
1145 	int offset = offset_in_page(gpa);
1146 	int ret;
1147 
1148 	while ((seg = next_segment(len, offset)) != 0) {
1149 		ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
1150 		if (ret < 0)
1151 			return ret;
1152 		offset = 0;
1153 		len -= seg;
1154 		data += seg;
1155 		++gfn;
1156 	}
1157 	return 0;
1158 }
1159 
1160 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
1161 {
1162 	return kvm_write_guest_page(kvm, gfn, empty_zero_page, offset, len);
1163 }
1164 EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
1165 
1166 int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
1167 {
1168 	gfn_t gfn = gpa >> PAGE_SHIFT;
1169 	int seg;
1170 	int offset = offset_in_page(gpa);
1171 	int ret;
1172 
1173         while ((seg = next_segment(len, offset)) != 0) {
1174 		ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
1175 		if (ret < 0)
1176 			return ret;
1177 		offset = 0;
1178 		len -= seg;
1179 		++gfn;
1180 	}
1181 	return 0;
1182 }
1183 EXPORT_SYMBOL_GPL(kvm_clear_guest);
1184 
1185 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
1186 {
1187 	struct kvm_memory_slot *memslot;
1188 
1189 	gfn = unalias_gfn(kvm, gfn);
1190 	memslot = gfn_to_memslot_unaliased(kvm, gfn);
1191 	if (memslot && memslot->dirty_bitmap) {
1192 		unsigned long rel_gfn = gfn - memslot->base_gfn;
1193 		unsigned long *p = memslot->dirty_bitmap +
1194 					rel_gfn / BITS_PER_LONG;
1195 		int offset = rel_gfn % BITS_PER_LONG;
1196 
1197 		/* avoid RMW */
1198 		if (!generic_test_le_bit(offset, p))
1199 			generic___set_le_bit(offset, p);
1200 	}
1201 }
1202 
1203 /*
1204  * The vCPU has executed a HLT instruction with in-kernel mode enabled.
1205  */
1206 void kvm_vcpu_block(struct kvm_vcpu *vcpu)
1207 {
1208 	DEFINE_WAIT(wait);
1209 
1210 	for (;;) {
1211 		prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
1212 
1213 		if (kvm_arch_vcpu_runnable(vcpu)) {
1214 			set_bit(KVM_REQ_UNHALT, &vcpu->requests);
1215 			break;
1216 		}
1217 		if (kvm_cpu_has_pending_timer(vcpu))
1218 			break;
1219 		if (signal_pending(current))
1220 			break;
1221 
1222 		schedule();
1223 	}
1224 
1225 	finish_wait(&vcpu->wq, &wait);
1226 }
1227 
1228 void kvm_resched(struct kvm_vcpu *vcpu)
1229 {
1230 	if (!need_resched())
1231 		return;
1232 	cond_resched();
1233 }
1234 EXPORT_SYMBOL_GPL(kvm_resched);
1235 
1236 void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu)
1237 {
1238 	ktime_t expires;
1239 	DEFINE_WAIT(wait);
1240 
1241 	prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
1242 
1243 	/* Sleep for 100 us, and hope lock-holder got scheduled */
1244 	expires = ktime_add_ns(ktime_get(), 100000UL);
1245 	schedule_hrtimeout(&expires, HRTIMER_MODE_ABS);
1246 
1247 	finish_wait(&vcpu->wq, &wait);
1248 }
1249 EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
1250 
1251 static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1252 {
1253 	struct kvm_vcpu *vcpu = vma->vm_file->private_data;
1254 	struct page *page;
1255 
1256 	if (vmf->pgoff == 0)
1257 		page = virt_to_page(vcpu->run);
1258 #ifdef CONFIG_X86
1259 	else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
1260 		page = virt_to_page(vcpu->arch.pio_data);
1261 #endif
1262 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1263 	else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
1264 		page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
1265 #endif
1266 	else
1267 		return VM_FAULT_SIGBUS;
1268 	get_page(page);
1269 	vmf->page = page;
1270 	return 0;
1271 }
1272 
1273 static const struct vm_operations_struct kvm_vcpu_vm_ops = {
1274 	.fault = kvm_vcpu_fault,
1275 };
1276 
1277 static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
1278 {
1279 	vma->vm_ops = &kvm_vcpu_vm_ops;
1280 	return 0;
1281 }
1282 
1283 static int kvm_vcpu_release(struct inode *inode, struct file *filp)
1284 {
1285 	struct kvm_vcpu *vcpu = filp->private_data;
1286 
1287 	kvm_put_kvm(vcpu->kvm);
1288 	return 0;
1289 }
1290 
1291 static struct file_operations kvm_vcpu_fops = {
1292 	.release        = kvm_vcpu_release,
1293 	.unlocked_ioctl = kvm_vcpu_ioctl,
1294 	.compat_ioctl   = kvm_vcpu_ioctl,
1295 	.mmap           = kvm_vcpu_mmap,
1296 };
1297 
1298 /*
1299  * Allocates an inode for the vcpu.
1300  */
1301 static int create_vcpu_fd(struct kvm_vcpu *vcpu)
1302 {
1303 	return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR);
1304 }
1305 
1306 /*
1307  * Creates some virtual cpus.  Good luck creating more than one.
1308  */
1309 static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
1310 {
1311 	int r;
1312 	struct kvm_vcpu *vcpu, *v;
1313 
1314 	vcpu = kvm_arch_vcpu_create(kvm, id);
1315 	if (IS_ERR(vcpu))
1316 		return PTR_ERR(vcpu);
1317 
1318 	preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
1319 
1320 	r = kvm_arch_vcpu_setup(vcpu);
1321 	if (r)
1322 		return r;
1323 
1324 	mutex_lock(&kvm->lock);
1325 	if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
1326 		r = -EINVAL;
1327 		goto vcpu_destroy;
1328 	}
1329 
1330 	kvm_for_each_vcpu(r, v, kvm)
1331 		if (v->vcpu_id == id) {
1332 			r = -EEXIST;
1333 			goto vcpu_destroy;
1334 		}
1335 
1336 	BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
1337 
1338 	/* Now it's all set up, let userspace reach it */
1339 	kvm_get_kvm(kvm);
1340 	r = create_vcpu_fd(vcpu);
1341 	if (r < 0) {
1342 		kvm_put_kvm(kvm);
1343 		goto vcpu_destroy;
1344 	}
1345 
1346 	kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
1347 	smp_wmb();
1348 	atomic_inc(&kvm->online_vcpus);
1349 
1350 #ifdef CONFIG_KVM_APIC_ARCHITECTURE
1351 	if (kvm->bsp_vcpu_id == id)
1352 		kvm->bsp_vcpu = vcpu;
1353 #endif
1354 	mutex_unlock(&kvm->lock);
1355 	return r;
1356 
1357 vcpu_destroy:
1358 	mutex_unlock(&kvm->lock);
1359 	kvm_arch_vcpu_destroy(vcpu);
1360 	return r;
1361 }
1362 
1363 static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
1364 {
1365 	if (sigset) {
1366 		sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
1367 		vcpu->sigset_active = 1;
1368 		vcpu->sigset = *sigset;
1369 	} else
1370 		vcpu->sigset_active = 0;
1371 	return 0;
1372 }
1373 
1374 static long kvm_vcpu_ioctl(struct file *filp,
1375 			   unsigned int ioctl, unsigned long arg)
1376 {
1377 	struct kvm_vcpu *vcpu = filp->private_data;
1378 	void __user *argp = (void __user *)arg;
1379 	int r;
1380 	struct kvm_fpu *fpu = NULL;
1381 	struct kvm_sregs *kvm_sregs = NULL;
1382 
1383 	if (vcpu->kvm->mm != current->mm)
1384 		return -EIO;
1385 	switch (ioctl) {
1386 	case KVM_RUN:
1387 		r = -EINVAL;
1388 		if (arg)
1389 			goto out;
1390 		r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
1391 		break;
1392 	case KVM_GET_REGS: {
1393 		struct kvm_regs *kvm_regs;
1394 
1395 		r = -ENOMEM;
1396 		kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
1397 		if (!kvm_regs)
1398 			goto out;
1399 		r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
1400 		if (r)
1401 			goto out_free1;
1402 		r = -EFAULT;
1403 		if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
1404 			goto out_free1;
1405 		r = 0;
1406 out_free1:
1407 		kfree(kvm_regs);
1408 		break;
1409 	}
1410 	case KVM_SET_REGS: {
1411 		struct kvm_regs *kvm_regs;
1412 
1413 		r = -ENOMEM;
1414 		kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
1415 		if (!kvm_regs)
1416 			goto out;
1417 		r = -EFAULT;
1418 		if (copy_from_user(kvm_regs, argp, sizeof(struct kvm_regs)))
1419 			goto out_free2;
1420 		r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
1421 		if (r)
1422 			goto out_free2;
1423 		r = 0;
1424 out_free2:
1425 		kfree(kvm_regs);
1426 		break;
1427 	}
1428 	case KVM_GET_SREGS: {
1429 		kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
1430 		r = -ENOMEM;
1431 		if (!kvm_sregs)
1432 			goto out;
1433 		r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs);
1434 		if (r)
1435 			goto out;
1436 		r = -EFAULT;
1437 		if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs)))
1438 			goto out;
1439 		r = 0;
1440 		break;
1441 	}
1442 	case KVM_SET_SREGS: {
1443 		kvm_sregs = kmalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
1444 		r = -ENOMEM;
1445 		if (!kvm_sregs)
1446 			goto out;
1447 		r = -EFAULT;
1448 		if (copy_from_user(kvm_sregs, argp, sizeof(struct kvm_sregs)))
1449 			goto out;
1450 		r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs);
1451 		if (r)
1452 			goto out;
1453 		r = 0;
1454 		break;
1455 	}
1456 	case KVM_GET_MP_STATE: {
1457 		struct kvm_mp_state mp_state;
1458 
1459 		r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
1460 		if (r)
1461 			goto out;
1462 		r = -EFAULT;
1463 		if (copy_to_user(argp, &mp_state, sizeof mp_state))
1464 			goto out;
1465 		r = 0;
1466 		break;
1467 	}
1468 	case KVM_SET_MP_STATE: {
1469 		struct kvm_mp_state mp_state;
1470 
1471 		r = -EFAULT;
1472 		if (copy_from_user(&mp_state, argp, sizeof mp_state))
1473 			goto out;
1474 		r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
1475 		if (r)
1476 			goto out;
1477 		r = 0;
1478 		break;
1479 	}
1480 	case KVM_TRANSLATE: {
1481 		struct kvm_translation tr;
1482 
1483 		r = -EFAULT;
1484 		if (copy_from_user(&tr, argp, sizeof tr))
1485 			goto out;
1486 		r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
1487 		if (r)
1488 			goto out;
1489 		r = -EFAULT;
1490 		if (copy_to_user(argp, &tr, sizeof tr))
1491 			goto out;
1492 		r = 0;
1493 		break;
1494 	}
1495 	case KVM_SET_GUEST_DEBUG: {
1496 		struct kvm_guest_debug dbg;
1497 
1498 		r = -EFAULT;
1499 		if (copy_from_user(&dbg, argp, sizeof dbg))
1500 			goto out;
1501 		r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg);
1502 		if (r)
1503 			goto out;
1504 		r = 0;
1505 		break;
1506 	}
1507 	case KVM_SET_SIGNAL_MASK: {
1508 		struct kvm_signal_mask __user *sigmask_arg = argp;
1509 		struct kvm_signal_mask kvm_sigmask;
1510 		sigset_t sigset, *p;
1511 
1512 		p = NULL;
1513 		if (argp) {
1514 			r = -EFAULT;
1515 			if (copy_from_user(&kvm_sigmask, argp,
1516 					   sizeof kvm_sigmask))
1517 				goto out;
1518 			r = -EINVAL;
1519 			if (kvm_sigmask.len != sizeof sigset)
1520 				goto out;
1521 			r = -EFAULT;
1522 			if (copy_from_user(&sigset, sigmask_arg->sigset,
1523 					   sizeof sigset))
1524 				goto out;
1525 			p = &sigset;
1526 		}
1527 		r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
1528 		break;
1529 	}
1530 	case KVM_GET_FPU: {
1531 		fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
1532 		r = -ENOMEM;
1533 		if (!fpu)
1534 			goto out;
1535 		r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
1536 		if (r)
1537 			goto out;
1538 		r = -EFAULT;
1539 		if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu)))
1540 			goto out;
1541 		r = 0;
1542 		break;
1543 	}
1544 	case KVM_SET_FPU: {
1545 		fpu = kmalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
1546 		r = -ENOMEM;
1547 		if (!fpu)
1548 			goto out;
1549 		r = -EFAULT;
1550 		if (copy_from_user(fpu, argp, sizeof(struct kvm_fpu)))
1551 			goto out;
1552 		r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
1553 		if (r)
1554 			goto out;
1555 		r = 0;
1556 		break;
1557 	}
1558 	default:
1559 		r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
1560 	}
1561 out:
1562 	kfree(fpu);
1563 	kfree(kvm_sregs);
1564 	return r;
1565 }
1566 
1567 static long kvm_vm_ioctl(struct file *filp,
1568 			   unsigned int ioctl, unsigned long arg)
1569 {
1570 	struct kvm *kvm = filp->private_data;
1571 	void __user *argp = (void __user *)arg;
1572 	int r;
1573 
1574 	if (kvm->mm != current->mm)
1575 		return -EIO;
1576 	switch (ioctl) {
1577 	case KVM_CREATE_VCPU:
1578 		r = kvm_vm_ioctl_create_vcpu(kvm, arg);
1579 		if (r < 0)
1580 			goto out;
1581 		break;
1582 	case KVM_SET_USER_MEMORY_REGION: {
1583 		struct kvm_userspace_memory_region kvm_userspace_mem;
1584 
1585 		r = -EFAULT;
1586 		if (copy_from_user(&kvm_userspace_mem, argp,
1587 						sizeof kvm_userspace_mem))
1588 			goto out;
1589 
1590 		r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem, 1);
1591 		if (r)
1592 			goto out;
1593 		break;
1594 	}
1595 	case KVM_GET_DIRTY_LOG: {
1596 		struct kvm_dirty_log log;
1597 
1598 		r = -EFAULT;
1599 		if (copy_from_user(&log, argp, sizeof log))
1600 			goto out;
1601 		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
1602 		if (r)
1603 			goto out;
1604 		break;
1605 	}
1606 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1607 	case KVM_REGISTER_COALESCED_MMIO: {
1608 		struct kvm_coalesced_mmio_zone zone;
1609 		r = -EFAULT;
1610 		if (copy_from_user(&zone, argp, sizeof zone))
1611 			goto out;
1612 		r = -ENXIO;
1613 		r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
1614 		if (r)
1615 			goto out;
1616 		r = 0;
1617 		break;
1618 	}
1619 	case KVM_UNREGISTER_COALESCED_MMIO: {
1620 		struct kvm_coalesced_mmio_zone zone;
1621 		r = -EFAULT;
1622 		if (copy_from_user(&zone, argp, sizeof zone))
1623 			goto out;
1624 		r = -ENXIO;
1625 		r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
1626 		if (r)
1627 			goto out;
1628 		r = 0;
1629 		break;
1630 	}
1631 #endif
1632 	case KVM_IRQFD: {
1633 		struct kvm_irqfd data;
1634 
1635 		r = -EFAULT;
1636 		if (copy_from_user(&data, argp, sizeof data))
1637 			goto out;
1638 		r = kvm_irqfd(kvm, data.fd, data.gsi, data.flags);
1639 		break;
1640 	}
1641 	case KVM_IOEVENTFD: {
1642 		struct kvm_ioeventfd data;
1643 
1644 		r = -EFAULT;
1645 		if (copy_from_user(&data, argp, sizeof data))
1646 			goto out;
1647 		r = kvm_ioeventfd(kvm, &data);
1648 		break;
1649 	}
1650 #ifdef CONFIG_KVM_APIC_ARCHITECTURE
1651 	case KVM_SET_BOOT_CPU_ID:
1652 		r = 0;
1653 		mutex_lock(&kvm->lock);
1654 		if (atomic_read(&kvm->online_vcpus) != 0)
1655 			r = -EBUSY;
1656 		else
1657 			kvm->bsp_vcpu_id = arg;
1658 		mutex_unlock(&kvm->lock);
1659 		break;
1660 #endif
1661 	default:
1662 		r = kvm_arch_vm_ioctl(filp, ioctl, arg);
1663 		if (r == -ENOTTY)
1664 			r = kvm_vm_ioctl_assigned_device(kvm, ioctl, arg);
1665 	}
1666 out:
1667 	return r;
1668 }
1669 
1670 #ifdef CONFIG_COMPAT
1671 struct compat_kvm_dirty_log {
1672 	__u32 slot;
1673 	__u32 padding1;
1674 	union {
1675 		compat_uptr_t dirty_bitmap; /* one bit per page */
1676 		__u64 padding2;
1677 	};
1678 };
1679 
1680 static long kvm_vm_compat_ioctl(struct file *filp,
1681 			   unsigned int ioctl, unsigned long arg)
1682 {
1683 	struct kvm *kvm = filp->private_data;
1684 	int r;
1685 
1686 	if (kvm->mm != current->mm)
1687 		return -EIO;
1688 	switch (ioctl) {
1689 	case KVM_GET_DIRTY_LOG: {
1690 		struct compat_kvm_dirty_log compat_log;
1691 		struct kvm_dirty_log log;
1692 
1693 		r = -EFAULT;
1694 		if (copy_from_user(&compat_log, (void __user *)arg,
1695 				   sizeof(compat_log)))
1696 			goto out;
1697 		log.slot	 = compat_log.slot;
1698 		log.padding1	 = compat_log.padding1;
1699 		log.padding2	 = compat_log.padding2;
1700 		log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
1701 
1702 		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
1703 		if (r)
1704 			goto out;
1705 		break;
1706 	}
1707 	default:
1708 		r = kvm_vm_ioctl(filp, ioctl, arg);
1709 	}
1710 
1711 out:
1712 	return r;
1713 }
1714 #endif
1715 
1716 static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1717 {
1718 	struct page *page[1];
1719 	unsigned long addr;
1720 	int npages;
1721 	gfn_t gfn = vmf->pgoff;
1722 	struct kvm *kvm = vma->vm_file->private_data;
1723 
1724 	addr = gfn_to_hva(kvm, gfn);
1725 	if (kvm_is_error_hva(addr))
1726 		return VM_FAULT_SIGBUS;
1727 
1728 	npages = get_user_pages(current, current->mm, addr, 1, 1, 0, page,
1729 				NULL);
1730 	if (unlikely(npages != 1))
1731 		return VM_FAULT_SIGBUS;
1732 
1733 	vmf->page = page[0];
1734 	return 0;
1735 }
1736 
1737 static const struct vm_operations_struct kvm_vm_vm_ops = {
1738 	.fault = kvm_vm_fault,
1739 };
1740 
1741 static int kvm_vm_mmap(struct file *file, struct vm_area_struct *vma)
1742 {
1743 	vma->vm_ops = &kvm_vm_vm_ops;
1744 	return 0;
1745 }
1746 
1747 static struct file_operations kvm_vm_fops = {
1748 	.release        = kvm_vm_release,
1749 	.unlocked_ioctl = kvm_vm_ioctl,
1750 #ifdef CONFIG_COMPAT
1751 	.compat_ioctl   = kvm_vm_compat_ioctl,
1752 #endif
1753 	.mmap           = kvm_vm_mmap,
1754 };
1755 
1756 static int kvm_dev_ioctl_create_vm(void)
1757 {
1758 	int fd;
1759 	struct kvm *kvm;
1760 
1761 	kvm = kvm_create_vm();
1762 	if (IS_ERR(kvm))
1763 		return PTR_ERR(kvm);
1764 	fd = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
1765 	if (fd < 0)
1766 		kvm_put_kvm(kvm);
1767 
1768 	return fd;
1769 }
1770 
1771 static long kvm_dev_ioctl_check_extension_generic(long arg)
1772 {
1773 	switch (arg) {
1774 	case KVM_CAP_USER_MEMORY:
1775 	case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
1776 	case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
1777 #ifdef CONFIG_KVM_APIC_ARCHITECTURE
1778 	case KVM_CAP_SET_BOOT_CPU_ID:
1779 #endif
1780 	case KVM_CAP_INTERNAL_ERROR_DATA:
1781 		return 1;
1782 #ifdef CONFIG_HAVE_KVM_IRQCHIP
1783 	case KVM_CAP_IRQ_ROUTING:
1784 		return KVM_MAX_IRQ_ROUTES;
1785 #endif
1786 	default:
1787 		break;
1788 	}
1789 	return kvm_dev_ioctl_check_extension(arg);
1790 }
1791 
1792 static long kvm_dev_ioctl(struct file *filp,
1793 			  unsigned int ioctl, unsigned long arg)
1794 {
1795 	long r = -EINVAL;
1796 
1797 	switch (ioctl) {
1798 	case KVM_GET_API_VERSION:
1799 		r = -EINVAL;
1800 		if (arg)
1801 			goto out;
1802 		r = KVM_API_VERSION;
1803 		break;
1804 	case KVM_CREATE_VM:
1805 		r = -EINVAL;
1806 		if (arg)
1807 			goto out;
1808 		r = kvm_dev_ioctl_create_vm();
1809 		break;
1810 	case KVM_CHECK_EXTENSION:
1811 		r = kvm_dev_ioctl_check_extension_generic(arg);
1812 		break;
1813 	case KVM_GET_VCPU_MMAP_SIZE:
1814 		r = -EINVAL;
1815 		if (arg)
1816 			goto out;
1817 		r = PAGE_SIZE;     /* struct kvm_run */
1818 #ifdef CONFIG_X86
1819 		r += PAGE_SIZE;    /* pio data page */
1820 #endif
1821 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1822 		r += PAGE_SIZE;    /* coalesced mmio ring page */
1823 #endif
1824 		break;
1825 	case KVM_TRACE_ENABLE:
1826 	case KVM_TRACE_PAUSE:
1827 	case KVM_TRACE_DISABLE:
1828 		r = -EOPNOTSUPP;
1829 		break;
1830 	default:
1831 		return kvm_arch_dev_ioctl(filp, ioctl, arg);
1832 	}
1833 out:
1834 	return r;
1835 }
1836 
1837 static struct file_operations kvm_chardev_ops = {
1838 	.unlocked_ioctl = kvm_dev_ioctl,
1839 	.compat_ioctl   = kvm_dev_ioctl,
1840 };
1841 
1842 static struct miscdevice kvm_dev = {
1843 	KVM_MINOR,
1844 	"kvm",
1845 	&kvm_chardev_ops,
1846 };
1847 
1848 static void hardware_enable(void *junk)
1849 {
1850 	int cpu = raw_smp_processor_id();
1851 	int r;
1852 
1853 	if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
1854 		return;
1855 
1856 	cpumask_set_cpu(cpu, cpus_hardware_enabled);
1857 
1858 	r = kvm_arch_hardware_enable(NULL);
1859 
1860 	if (r) {
1861 		cpumask_clear_cpu(cpu, cpus_hardware_enabled);
1862 		atomic_inc(&hardware_enable_failed);
1863 		printk(KERN_INFO "kvm: enabling virtualization on "
1864 				 "CPU%d failed\n", cpu);
1865 	}
1866 }
1867 
1868 static void hardware_disable(void *junk)
1869 {
1870 	int cpu = raw_smp_processor_id();
1871 
1872 	if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
1873 		return;
1874 	cpumask_clear_cpu(cpu, cpus_hardware_enabled);
1875 	kvm_arch_hardware_disable(NULL);
1876 }
1877 
1878 static void hardware_disable_all_nolock(void)
1879 {
1880 	BUG_ON(!kvm_usage_count);
1881 
1882 	kvm_usage_count--;
1883 	if (!kvm_usage_count)
1884 		on_each_cpu(hardware_disable, NULL, 1);
1885 }
1886 
1887 static void hardware_disable_all(void)
1888 {
1889 	spin_lock(&kvm_lock);
1890 	hardware_disable_all_nolock();
1891 	spin_unlock(&kvm_lock);
1892 }
1893 
1894 static int hardware_enable_all(void)
1895 {
1896 	int r = 0;
1897 
1898 	spin_lock(&kvm_lock);
1899 
1900 	kvm_usage_count++;
1901 	if (kvm_usage_count == 1) {
1902 		atomic_set(&hardware_enable_failed, 0);
1903 		on_each_cpu(hardware_enable, NULL, 1);
1904 
1905 		if (atomic_read(&hardware_enable_failed)) {
1906 			hardware_disable_all_nolock();
1907 			r = -EBUSY;
1908 		}
1909 	}
1910 
1911 	spin_unlock(&kvm_lock);
1912 
1913 	return r;
1914 }
1915 
1916 static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
1917 			   void *v)
1918 {
1919 	int cpu = (long)v;
1920 
1921 	if (!kvm_usage_count)
1922 		return NOTIFY_OK;
1923 
1924 	val &= ~CPU_TASKS_FROZEN;
1925 	switch (val) {
1926 	case CPU_DYING:
1927 		printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
1928 		       cpu);
1929 		hardware_disable(NULL);
1930 		break;
1931 	case CPU_UP_CANCELED:
1932 		printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
1933 		       cpu);
1934 		smp_call_function_single(cpu, hardware_disable, NULL, 1);
1935 		break;
1936 	case CPU_ONLINE:
1937 		printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
1938 		       cpu);
1939 		smp_call_function_single(cpu, hardware_enable, NULL, 1);
1940 		break;
1941 	}
1942 	return NOTIFY_OK;
1943 }
1944 
1945 
1946 asmlinkage void kvm_handle_fault_on_reboot(void)
1947 {
1948 	if (kvm_rebooting)
1949 		/* spin while reset goes on */
1950 		while (true)
1951 			;
1952 	/* Fault while not rebooting.  We want the trace. */
1953 	BUG();
1954 }
1955 EXPORT_SYMBOL_GPL(kvm_handle_fault_on_reboot);
1956 
1957 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
1958 		      void *v)
1959 {
1960 	/*
1961 	 * Some (well, at least mine) BIOSes hang on reboot if
1962 	 * in vmx root mode.
1963 	 *
1964 	 * And Intel TXT required VMX off for all cpu when system shutdown.
1965 	 */
1966 	printk(KERN_INFO "kvm: exiting hardware virtualization\n");
1967 	kvm_rebooting = true;
1968 	on_each_cpu(hardware_disable, NULL, 1);
1969 	return NOTIFY_OK;
1970 }
1971 
1972 static struct notifier_block kvm_reboot_notifier = {
1973 	.notifier_call = kvm_reboot,
1974 	.priority = 0,
1975 };
1976 
1977 static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
1978 {
1979 	int i;
1980 
1981 	for (i = 0; i < bus->dev_count; i++) {
1982 		struct kvm_io_device *pos = bus->devs[i];
1983 
1984 		kvm_iodevice_destructor(pos);
1985 	}
1986 	kfree(bus);
1987 }
1988 
1989 /* kvm_io_bus_write - called under kvm->slots_lock */
1990 int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
1991 		     int len, const void *val)
1992 {
1993 	int i;
1994 	struct kvm_io_bus *bus = rcu_dereference(kvm->buses[bus_idx]);
1995 	for (i = 0; i < bus->dev_count; i++)
1996 		if (!kvm_iodevice_write(bus->devs[i], addr, len, val))
1997 			return 0;
1998 	return -EOPNOTSUPP;
1999 }
2000 
2001 /* kvm_io_bus_read - called under kvm->slots_lock */
2002 int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
2003 		    int len, void *val)
2004 {
2005 	int i;
2006 	struct kvm_io_bus *bus = rcu_dereference(kvm->buses[bus_idx]);
2007 
2008 	for (i = 0; i < bus->dev_count; i++)
2009 		if (!kvm_iodevice_read(bus->devs[i], addr, len, val))
2010 			return 0;
2011 	return -EOPNOTSUPP;
2012 }
2013 
2014 /* Caller must hold slots_lock. */
2015 int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx,
2016 			    struct kvm_io_device *dev)
2017 {
2018 	struct kvm_io_bus *new_bus, *bus;
2019 
2020 	bus = kvm->buses[bus_idx];
2021 	if (bus->dev_count > NR_IOBUS_DEVS-1)
2022 		return -ENOSPC;
2023 
2024 	new_bus = kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL);
2025 	if (!new_bus)
2026 		return -ENOMEM;
2027 	memcpy(new_bus, bus, sizeof(struct kvm_io_bus));
2028 	new_bus->devs[new_bus->dev_count++] = dev;
2029 	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
2030 	synchronize_srcu_expedited(&kvm->srcu);
2031 	kfree(bus);
2032 
2033 	return 0;
2034 }
2035 
2036 /* Caller must hold slots_lock. */
2037 int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
2038 			      struct kvm_io_device *dev)
2039 {
2040 	int i, r;
2041 	struct kvm_io_bus *new_bus, *bus;
2042 
2043 	new_bus = kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL);
2044 	if (!new_bus)
2045 		return -ENOMEM;
2046 
2047 	bus = kvm->buses[bus_idx];
2048 	memcpy(new_bus, bus, sizeof(struct kvm_io_bus));
2049 
2050 	r = -ENOENT;
2051 	for (i = 0; i < new_bus->dev_count; i++)
2052 		if (new_bus->devs[i] == dev) {
2053 			r = 0;
2054 			new_bus->devs[i] = new_bus->devs[--new_bus->dev_count];
2055 			break;
2056 		}
2057 
2058 	if (r) {
2059 		kfree(new_bus);
2060 		return r;
2061 	}
2062 
2063 	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
2064 	synchronize_srcu_expedited(&kvm->srcu);
2065 	kfree(bus);
2066 	return r;
2067 }
2068 
2069 static struct notifier_block kvm_cpu_notifier = {
2070 	.notifier_call = kvm_cpu_hotplug,
2071 	.priority = 20, /* must be > scheduler priority */
2072 };
2073 
2074 static int vm_stat_get(void *_offset, u64 *val)
2075 {
2076 	unsigned offset = (long)_offset;
2077 	struct kvm *kvm;
2078 
2079 	*val = 0;
2080 	spin_lock(&kvm_lock);
2081 	list_for_each_entry(kvm, &vm_list, vm_list)
2082 		*val += *(u32 *)((void *)kvm + offset);
2083 	spin_unlock(&kvm_lock);
2084 	return 0;
2085 }
2086 
2087 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
2088 
2089 static int vcpu_stat_get(void *_offset, u64 *val)
2090 {
2091 	unsigned offset = (long)_offset;
2092 	struct kvm *kvm;
2093 	struct kvm_vcpu *vcpu;
2094 	int i;
2095 
2096 	*val = 0;
2097 	spin_lock(&kvm_lock);
2098 	list_for_each_entry(kvm, &vm_list, vm_list)
2099 		kvm_for_each_vcpu(i, vcpu, kvm)
2100 			*val += *(u32 *)((void *)vcpu + offset);
2101 
2102 	spin_unlock(&kvm_lock);
2103 	return 0;
2104 }
2105 
2106 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
2107 
2108 static const struct file_operations *stat_fops[] = {
2109 	[KVM_STAT_VCPU] = &vcpu_stat_fops,
2110 	[KVM_STAT_VM]   = &vm_stat_fops,
2111 };
2112 
2113 static void kvm_init_debug(void)
2114 {
2115 	struct kvm_stats_debugfs_item *p;
2116 
2117 	kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
2118 	for (p = debugfs_entries; p->name; ++p)
2119 		p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
2120 						(void *)(long)p->offset,
2121 						stat_fops[p->kind]);
2122 }
2123 
2124 static void kvm_exit_debug(void)
2125 {
2126 	struct kvm_stats_debugfs_item *p;
2127 
2128 	for (p = debugfs_entries; p->name; ++p)
2129 		debugfs_remove(p->dentry);
2130 	debugfs_remove(kvm_debugfs_dir);
2131 }
2132 
2133 static int kvm_suspend(struct sys_device *dev, pm_message_t state)
2134 {
2135 	if (kvm_usage_count)
2136 		hardware_disable(NULL);
2137 	return 0;
2138 }
2139 
2140 static int kvm_resume(struct sys_device *dev)
2141 {
2142 	if (kvm_usage_count)
2143 		hardware_enable(NULL);
2144 	return 0;
2145 }
2146 
2147 static struct sysdev_class kvm_sysdev_class = {
2148 	.name = "kvm",
2149 	.suspend = kvm_suspend,
2150 	.resume = kvm_resume,
2151 };
2152 
2153 static struct sys_device kvm_sysdev = {
2154 	.id = 0,
2155 	.cls = &kvm_sysdev_class,
2156 };
2157 
2158 struct page *bad_page;
2159 pfn_t bad_pfn;
2160 
2161 static inline
2162 struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
2163 {
2164 	return container_of(pn, struct kvm_vcpu, preempt_notifier);
2165 }
2166 
2167 static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
2168 {
2169 	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
2170 
2171 	kvm_arch_vcpu_load(vcpu, cpu);
2172 }
2173 
2174 static void kvm_sched_out(struct preempt_notifier *pn,
2175 			  struct task_struct *next)
2176 {
2177 	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
2178 
2179 	kvm_arch_vcpu_put(vcpu);
2180 }
2181 
2182 int kvm_init(void *opaque, unsigned int vcpu_size,
2183 		  struct module *module)
2184 {
2185 	int r;
2186 	int cpu;
2187 
2188 	r = kvm_arch_init(opaque);
2189 	if (r)
2190 		goto out_fail;
2191 
2192 	bad_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
2193 
2194 	if (bad_page == NULL) {
2195 		r = -ENOMEM;
2196 		goto out;
2197 	}
2198 
2199 	bad_pfn = page_to_pfn(bad_page);
2200 
2201 	if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
2202 		r = -ENOMEM;
2203 		goto out_free_0;
2204 	}
2205 
2206 	r = kvm_arch_hardware_setup();
2207 	if (r < 0)
2208 		goto out_free_0a;
2209 
2210 	for_each_online_cpu(cpu) {
2211 		smp_call_function_single(cpu,
2212 				kvm_arch_check_processor_compat,
2213 				&r, 1);
2214 		if (r < 0)
2215 			goto out_free_1;
2216 	}
2217 
2218 	r = register_cpu_notifier(&kvm_cpu_notifier);
2219 	if (r)
2220 		goto out_free_2;
2221 	register_reboot_notifier(&kvm_reboot_notifier);
2222 
2223 	r = sysdev_class_register(&kvm_sysdev_class);
2224 	if (r)
2225 		goto out_free_3;
2226 
2227 	r = sysdev_register(&kvm_sysdev);
2228 	if (r)
2229 		goto out_free_4;
2230 
2231 	/* A kmem cache lets us meet the alignment requirements of fx_save. */
2232 	kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size,
2233 					   __alignof__(struct kvm_vcpu),
2234 					   0, NULL);
2235 	if (!kvm_vcpu_cache) {
2236 		r = -ENOMEM;
2237 		goto out_free_5;
2238 	}
2239 
2240 	kvm_chardev_ops.owner = module;
2241 	kvm_vm_fops.owner = module;
2242 	kvm_vcpu_fops.owner = module;
2243 
2244 	r = misc_register(&kvm_dev);
2245 	if (r) {
2246 		printk(KERN_ERR "kvm: misc device register failed\n");
2247 		goto out_free;
2248 	}
2249 
2250 	kvm_preempt_ops.sched_in = kvm_sched_in;
2251 	kvm_preempt_ops.sched_out = kvm_sched_out;
2252 
2253 	kvm_init_debug();
2254 
2255 	return 0;
2256 
2257 out_free:
2258 	kmem_cache_destroy(kvm_vcpu_cache);
2259 out_free_5:
2260 	sysdev_unregister(&kvm_sysdev);
2261 out_free_4:
2262 	sysdev_class_unregister(&kvm_sysdev_class);
2263 out_free_3:
2264 	unregister_reboot_notifier(&kvm_reboot_notifier);
2265 	unregister_cpu_notifier(&kvm_cpu_notifier);
2266 out_free_2:
2267 out_free_1:
2268 	kvm_arch_hardware_unsetup();
2269 out_free_0a:
2270 	free_cpumask_var(cpus_hardware_enabled);
2271 out_free_0:
2272 	__free_page(bad_page);
2273 out:
2274 	kvm_arch_exit();
2275 out_fail:
2276 	return r;
2277 }
2278 EXPORT_SYMBOL_GPL(kvm_init);
2279 
2280 void kvm_exit(void)
2281 {
2282 	tracepoint_synchronize_unregister();
2283 	kvm_exit_debug();
2284 	misc_deregister(&kvm_dev);
2285 	kmem_cache_destroy(kvm_vcpu_cache);
2286 	sysdev_unregister(&kvm_sysdev);
2287 	sysdev_class_unregister(&kvm_sysdev_class);
2288 	unregister_reboot_notifier(&kvm_reboot_notifier);
2289 	unregister_cpu_notifier(&kvm_cpu_notifier);
2290 	on_each_cpu(hardware_disable, NULL, 1);
2291 	kvm_arch_hardware_unsetup();
2292 	kvm_arch_exit();
2293 	free_cpumask_var(cpus_hardware_enabled);
2294 	__free_page(bad_page);
2295 }
2296 EXPORT_SYMBOL_GPL(kvm_exit);
2297