xref: /linux/virt/kvm/kvm_main.c (revision 1795cf48b322b4d19230a40dbe7181acedd34a94)
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/gfp.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 
45 #include <asm/processor.h>
46 #include <asm/io.h>
47 #include <asm/uaccess.h>
48 #include <asm/pgtable.h>
49 
50 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
51 #include "coalesced_mmio.h"
52 #endif
53 
54 MODULE_AUTHOR("Qumranet");
55 MODULE_LICENSE("GPL");
56 
57 DEFINE_SPINLOCK(kvm_lock);
58 LIST_HEAD(vm_list);
59 
60 static cpumask_t cpus_hardware_enabled;
61 
62 struct kmem_cache *kvm_vcpu_cache;
63 EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
64 
65 static __read_mostly struct preempt_ops kvm_preempt_ops;
66 
67 struct dentry *kvm_debugfs_dir;
68 
69 static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
70 			   unsigned long arg);
71 
72 bool kvm_rebooting;
73 
74 static inline int valid_vcpu(int n)
75 {
76 	return likely(n >= 0 && n < KVM_MAX_VCPUS);
77 }
78 
79 /*
80  * Switches to specified vcpu, until a matching vcpu_put()
81  */
82 void vcpu_load(struct kvm_vcpu *vcpu)
83 {
84 	int cpu;
85 
86 	mutex_lock(&vcpu->mutex);
87 	cpu = get_cpu();
88 	preempt_notifier_register(&vcpu->preempt_notifier);
89 	kvm_arch_vcpu_load(vcpu, cpu);
90 	put_cpu();
91 }
92 
93 void vcpu_put(struct kvm_vcpu *vcpu)
94 {
95 	preempt_disable();
96 	kvm_arch_vcpu_put(vcpu);
97 	preempt_notifier_unregister(&vcpu->preempt_notifier);
98 	preempt_enable();
99 	mutex_unlock(&vcpu->mutex);
100 }
101 
102 static void ack_flush(void *_completed)
103 {
104 }
105 
106 void kvm_flush_remote_tlbs(struct kvm *kvm)
107 {
108 	int i, cpu, me;
109 	cpumask_t cpus;
110 	struct kvm_vcpu *vcpu;
111 
112 	me = get_cpu();
113 	cpus_clear(cpus);
114 	for (i = 0; i < KVM_MAX_VCPUS; ++i) {
115 		vcpu = kvm->vcpus[i];
116 		if (!vcpu)
117 			continue;
118 		if (test_and_set_bit(KVM_REQ_TLB_FLUSH, &vcpu->requests))
119 			continue;
120 		cpu = vcpu->cpu;
121 		if (cpu != -1 && cpu != me)
122 			cpu_set(cpu, cpus);
123 	}
124 	if (cpus_empty(cpus))
125 		goto out;
126 	++kvm->stat.remote_tlb_flush;
127 	smp_call_function_mask(cpus, ack_flush, NULL, 1);
128 out:
129 	put_cpu();
130 }
131 
132 void kvm_reload_remote_mmus(struct kvm *kvm)
133 {
134 	int i, cpu, me;
135 	cpumask_t cpus;
136 	struct kvm_vcpu *vcpu;
137 
138 	me = get_cpu();
139 	cpus_clear(cpus);
140 	for (i = 0; i < KVM_MAX_VCPUS; ++i) {
141 		vcpu = kvm->vcpus[i];
142 		if (!vcpu)
143 			continue;
144 		if (test_and_set_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests))
145 			continue;
146 		cpu = vcpu->cpu;
147 		if (cpu != -1 && cpu != me)
148 			cpu_set(cpu, cpus);
149 	}
150 	if (cpus_empty(cpus))
151 		goto out;
152 	smp_call_function_mask(cpus, ack_flush, NULL, 1);
153 out:
154 	put_cpu();
155 }
156 
157 
158 int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
159 {
160 	struct page *page;
161 	int r;
162 
163 	mutex_init(&vcpu->mutex);
164 	vcpu->cpu = -1;
165 	vcpu->kvm = kvm;
166 	vcpu->vcpu_id = id;
167 	init_waitqueue_head(&vcpu->wq);
168 
169 	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
170 	if (!page) {
171 		r = -ENOMEM;
172 		goto fail;
173 	}
174 	vcpu->run = page_address(page);
175 
176 	r = kvm_arch_vcpu_init(vcpu);
177 	if (r < 0)
178 		goto fail_free_run;
179 	return 0;
180 
181 fail_free_run:
182 	free_page((unsigned long)vcpu->run);
183 fail:
184 	return r;
185 }
186 EXPORT_SYMBOL_GPL(kvm_vcpu_init);
187 
188 void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
189 {
190 	kvm_arch_vcpu_uninit(vcpu);
191 	free_page((unsigned long)vcpu->run);
192 }
193 EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
194 
195 static struct kvm *kvm_create_vm(void)
196 {
197 	struct kvm *kvm = kvm_arch_create_vm();
198 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
199 	struct page *page;
200 #endif
201 
202 	if (IS_ERR(kvm))
203 		goto out;
204 
205 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
206 	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
207 	if (!page) {
208 		kfree(kvm);
209 		return ERR_PTR(-ENOMEM);
210 	}
211 	kvm->coalesced_mmio_ring =
212 			(struct kvm_coalesced_mmio_ring *)page_address(page);
213 #endif
214 
215 	kvm->mm = current->mm;
216 	atomic_inc(&kvm->mm->mm_count);
217 	spin_lock_init(&kvm->mmu_lock);
218 	kvm_io_bus_init(&kvm->pio_bus);
219 	mutex_init(&kvm->lock);
220 	kvm_io_bus_init(&kvm->mmio_bus);
221 	init_rwsem(&kvm->slots_lock);
222 	atomic_set(&kvm->users_count, 1);
223 	spin_lock(&kvm_lock);
224 	list_add(&kvm->vm_list, &vm_list);
225 	spin_unlock(&kvm_lock);
226 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
227 	kvm_coalesced_mmio_init(kvm);
228 #endif
229 out:
230 	return kvm;
231 }
232 
233 /*
234  * Free any memory in @free but not in @dont.
235  */
236 static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
237 				  struct kvm_memory_slot *dont)
238 {
239 	if (!dont || free->rmap != dont->rmap)
240 		vfree(free->rmap);
241 
242 	if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
243 		vfree(free->dirty_bitmap);
244 
245 	if (!dont || free->lpage_info != dont->lpage_info)
246 		vfree(free->lpage_info);
247 
248 	free->npages = 0;
249 	free->dirty_bitmap = NULL;
250 	free->rmap = NULL;
251 	free->lpage_info = NULL;
252 }
253 
254 void kvm_free_physmem(struct kvm *kvm)
255 {
256 	int i;
257 
258 	for (i = 0; i < kvm->nmemslots; ++i)
259 		kvm_free_physmem_slot(&kvm->memslots[i], NULL);
260 }
261 
262 static void kvm_destroy_vm(struct kvm *kvm)
263 {
264 	struct mm_struct *mm = kvm->mm;
265 
266 	spin_lock(&kvm_lock);
267 	list_del(&kvm->vm_list);
268 	spin_unlock(&kvm_lock);
269 	kvm_io_bus_destroy(&kvm->pio_bus);
270 	kvm_io_bus_destroy(&kvm->mmio_bus);
271 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
272 	if (kvm->coalesced_mmio_ring != NULL)
273 		free_page((unsigned long)kvm->coalesced_mmio_ring);
274 #endif
275 	kvm_arch_destroy_vm(kvm);
276 	mmdrop(mm);
277 }
278 
279 void kvm_get_kvm(struct kvm *kvm)
280 {
281 	atomic_inc(&kvm->users_count);
282 }
283 EXPORT_SYMBOL_GPL(kvm_get_kvm);
284 
285 void kvm_put_kvm(struct kvm *kvm)
286 {
287 	if (atomic_dec_and_test(&kvm->users_count))
288 		kvm_destroy_vm(kvm);
289 }
290 EXPORT_SYMBOL_GPL(kvm_put_kvm);
291 
292 
293 static int kvm_vm_release(struct inode *inode, struct file *filp)
294 {
295 	struct kvm *kvm = filp->private_data;
296 
297 	kvm_put_kvm(kvm);
298 	return 0;
299 }
300 
301 /*
302  * Allocate some memory and give it an address in the guest physical address
303  * space.
304  *
305  * Discontiguous memory is allowed, mostly for framebuffers.
306  *
307  * Must be called holding mmap_sem for write.
308  */
309 int __kvm_set_memory_region(struct kvm *kvm,
310 			    struct kvm_userspace_memory_region *mem,
311 			    int user_alloc)
312 {
313 	int r;
314 	gfn_t base_gfn;
315 	unsigned long npages;
316 	unsigned long i;
317 	struct kvm_memory_slot *memslot;
318 	struct kvm_memory_slot old, new;
319 
320 	r = -EINVAL;
321 	/* General sanity checks */
322 	if (mem->memory_size & (PAGE_SIZE - 1))
323 		goto out;
324 	if (mem->guest_phys_addr & (PAGE_SIZE - 1))
325 		goto out;
326 	if (mem->slot >= KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS)
327 		goto out;
328 	if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
329 		goto out;
330 
331 	memslot = &kvm->memslots[mem->slot];
332 	base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
333 	npages = mem->memory_size >> PAGE_SHIFT;
334 
335 	if (!npages)
336 		mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
337 
338 	new = old = *memslot;
339 
340 	new.base_gfn = base_gfn;
341 	new.npages = npages;
342 	new.flags = mem->flags;
343 
344 	/* Disallow changing a memory slot's size. */
345 	r = -EINVAL;
346 	if (npages && old.npages && npages != old.npages)
347 		goto out_free;
348 
349 	/* Check for overlaps */
350 	r = -EEXIST;
351 	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
352 		struct kvm_memory_slot *s = &kvm->memslots[i];
353 
354 		if (s == memslot)
355 			continue;
356 		if (!((base_gfn + npages <= s->base_gfn) ||
357 		      (base_gfn >= s->base_gfn + s->npages)))
358 			goto out_free;
359 	}
360 
361 	/* Free page dirty bitmap if unneeded */
362 	if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
363 		new.dirty_bitmap = NULL;
364 
365 	r = -ENOMEM;
366 
367 	/* Allocate if a slot is being created */
368 #ifndef CONFIG_S390
369 	if (npages && !new.rmap) {
370 		new.rmap = vmalloc(npages * sizeof(struct page *));
371 
372 		if (!new.rmap)
373 			goto out_free;
374 
375 		memset(new.rmap, 0, npages * sizeof(*new.rmap));
376 
377 		new.user_alloc = user_alloc;
378 		new.userspace_addr = mem->userspace_addr;
379 	}
380 	if (npages && !new.lpage_info) {
381 		int largepages = npages / KVM_PAGES_PER_HPAGE;
382 		if (npages % KVM_PAGES_PER_HPAGE)
383 			largepages++;
384 		if (base_gfn % KVM_PAGES_PER_HPAGE)
385 			largepages++;
386 
387 		new.lpage_info = vmalloc(largepages * sizeof(*new.lpage_info));
388 
389 		if (!new.lpage_info)
390 			goto out_free;
391 
392 		memset(new.lpage_info, 0, largepages * sizeof(*new.lpage_info));
393 
394 		if (base_gfn % KVM_PAGES_PER_HPAGE)
395 			new.lpage_info[0].write_count = 1;
396 		if ((base_gfn+npages) % KVM_PAGES_PER_HPAGE)
397 			new.lpage_info[largepages-1].write_count = 1;
398 	}
399 
400 	/* Allocate page dirty bitmap if needed */
401 	if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
402 		unsigned dirty_bytes = ALIGN(npages, BITS_PER_LONG) / 8;
403 
404 		new.dirty_bitmap = vmalloc(dirty_bytes);
405 		if (!new.dirty_bitmap)
406 			goto out_free;
407 		memset(new.dirty_bitmap, 0, dirty_bytes);
408 	}
409 #endif /* not defined CONFIG_S390 */
410 
411 	if (mem->slot >= kvm->nmemslots)
412 		kvm->nmemslots = mem->slot + 1;
413 
414 	if (!npages)
415 		kvm_arch_flush_shadow(kvm);
416 
417 	*memslot = new;
418 
419 	r = kvm_arch_set_memory_region(kvm, mem, old, user_alloc);
420 	if (r) {
421 		*memslot = old;
422 		goto out_free;
423 	}
424 
425 	kvm_free_physmem_slot(&old, &new);
426 	return 0;
427 
428 out_free:
429 	kvm_free_physmem_slot(&new, &old);
430 out:
431 	return r;
432 
433 }
434 EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
435 
436 int kvm_set_memory_region(struct kvm *kvm,
437 			  struct kvm_userspace_memory_region *mem,
438 			  int user_alloc)
439 {
440 	int r;
441 
442 	down_write(&kvm->slots_lock);
443 	r = __kvm_set_memory_region(kvm, mem, user_alloc);
444 	up_write(&kvm->slots_lock);
445 	return r;
446 }
447 EXPORT_SYMBOL_GPL(kvm_set_memory_region);
448 
449 int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
450 				   struct
451 				   kvm_userspace_memory_region *mem,
452 				   int user_alloc)
453 {
454 	if (mem->slot >= KVM_MEMORY_SLOTS)
455 		return -EINVAL;
456 	return kvm_set_memory_region(kvm, mem, user_alloc);
457 }
458 
459 int kvm_get_dirty_log(struct kvm *kvm,
460 			struct kvm_dirty_log *log, int *is_dirty)
461 {
462 	struct kvm_memory_slot *memslot;
463 	int r, i;
464 	int n;
465 	unsigned long any = 0;
466 
467 	r = -EINVAL;
468 	if (log->slot >= KVM_MEMORY_SLOTS)
469 		goto out;
470 
471 	memslot = &kvm->memslots[log->slot];
472 	r = -ENOENT;
473 	if (!memslot->dirty_bitmap)
474 		goto out;
475 
476 	n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
477 
478 	for (i = 0; !any && i < n/sizeof(long); ++i)
479 		any = memslot->dirty_bitmap[i];
480 
481 	r = -EFAULT;
482 	if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
483 		goto out;
484 
485 	if (any)
486 		*is_dirty = 1;
487 
488 	r = 0;
489 out:
490 	return r;
491 }
492 
493 int is_error_page(struct page *page)
494 {
495 	return page == bad_page;
496 }
497 EXPORT_SYMBOL_GPL(is_error_page);
498 
499 int is_error_pfn(pfn_t pfn)
500 {
501 	return pfn == bad_pfn;
502 }
503 EXPORT_SYMBOL_GPL(is_error_pfn);
504 
505 static inline unsigned long bad_hva(void)
506 {
507 	return PAGE_OFFSET;
508 }
509 
510 int kvm_is_error_hva(unsigned long addr)
511 {
512 	return addr == bad_hva();
513 }
514 EXPORT_SYMBOL_GPL(kvm_is_error_hva);
515 
516 static struct kvm_memory_slot *__gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
517 {
518 	int i;
519 
520 	for (i = 0; i < kvm->nmemslots; ++i) {
521 		struct kvm_memory_slot *memslot = &kvm->memslots[i];
522 
523 		if (gfn >= memslot->base_gfn
524 		    && gfn < memslot->base_gfn + memslot->npages)
525 			return memslot;
526 	}
527 	return NULL;
528 }
529 
530 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
531 {
532 	gfn = unalias_gfn(kvm, gfn);
533 	return __gfn_to_memslot(kvm, gfn);
534 }
535 
536 int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
537 {
538 	int i;
539 
540 	gfn = unalias_gfn(kvm, gfn);
541 	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
542 		struct kvm_memory_slot *memslot = &kvm->memslots[i];
543 
544 		if (gfn >= memslot->base_gfn
545 		    && gfn < memslot->base_gfn + memslot->npages)
546 			return 1;
547 	}
548 	return 0;
549 }
550 EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
551 
552 unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
553 {
554 	struct kvm_memory_slot *slot;
555 
556 	gfn = unalias_gfn(kvm, gfn);
557 	slot = __gfn_to_memslot(kvm, gfn);
558 	if (!slot)
559 		return bad_hva();
560 	return (slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE);
561 }
562 EXPORT_SYMBOL_GPL(gfn_to_hva);
563 
564 /*
565  * Requires current->mm->mmap_sem to be held
566  */
567 pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
568 {
569 	struct page *page[1];
570 	unsigned long addr;
571 	int npages;
572 	pfn_t pfn;
573 
574 	might_sleep();
575 
576 	addr = gfn_to_hva(kvm, gfn);
577 	if (kvm_is_error_hva(addr)) {
578 		get_page(bad_page);
579 		return page_to_pfn(bad_page);
580 	}
581 
582 	npages = get_user_pages(current, current->mm, addr, 1, 1, 1, page,
583 				NULL);
584 
585 	if (unlikely(npages != 1)) {
586 		struct vm_area_struct *vma;
587 
588 		vma = find_vma(current->mm, addr);
589 		if (vma == NULL || addr < vma->vm_start ||
590 		    !(vma->vm_flags & VM_PFNMAP)) {
591 			get_page(bad_page);
592 			return page_to_pfn(bad_page);
593 		}
594 
595 		pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
596 		BUG_ON(pfn_valid(pfn));
597 	} else
598 		pfn = page_to_pfn(page[0]);
599 
600 	return pfn;
601 }
602 
603 EXPORT_SYMBOL_GPL(gfn_to_pfn);
604 
605 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
606 {
607 	pfn_t pfn;
608 
609 	pfn = gfn_to_pfn(kvm, gfn);
610 	if (pfn_valid(pfn))
611 		return pfn_to_page(pfn);
612 
613 	WARN_ON(!pfn_valid(pfn));
614 
615 	get_page(bad_page);
616 	return bad_page;
617 }
618 
619 EXPORT_SYMBOL_GPL(gfn_to_page);
620 
621 void kvm_release_page_clean(struct page *page)
622 {
623 	kvm_release_pfn_clean(page_to_pfn(page));
624 }
625 EXPORT_SYMBOL_GPL(kvm_release_page_clean);
626 
627 void kvm_release_pfn_clean(pfn_t pfn)
628 {
629 	if (pfn_valid(pfn))
630 		put_page(pfn_to_page(pfn));
631 }
632 EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
633 
634 void kvm_release_page_dirty(struct page *page)
635 {
636 	kvm_release_pfn_dirty(page_to_pfn(page));
637 }
638 EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
639 
640 void kvm_release_pfn_dirty(pfn_t pfn)
641 {
642 	kvm_set_pfn_dirty(pfn);
643 	kvm_release_pfn_clean(pfn);
644 }
645 EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
646 
647 void kvm_set_page_dirty(struct page *page)
648 {
649 	kvm_set_pfn_dirty(page_to_pfn(page));
650 }
651 EXPORT_SYMBOL_GPL(kvm_set_page_dirty);
652 
653 void kvm_set_pfn_dirty(pfn_t pfn)
654 {
655 	if (pfn_valid(pfn)) {
656 		struct page *page = pfn_to_page(pfn);
657 		if (!PageReserved(page))
658 			SetPageDirty(page);
659 	}
660 }
661 EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
662 
663 void kvm_set_pfn_accessed(pfn_t pfn)
664 {
665 	if (pfn_valid(pfn))
666 		mark_page_accessed(pfn_to_page(pfn));
667 }
668 EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
669 
670 void kvm_get_pfn(pfn_t pfn)
671 {
672 	if (pfn_valid(pfn))
673 		get_page(pfn_to_page(pfn));
674 }
675 EXPORT_SYMBOL_GPL(kvm_get_pfn);
676 
677 static int next_segment(unsigned long len, int offset)
678 {
679 	if (len > PAGE_SIZE - offset)
680 		return PAGE_SIZE - offset;
681 	else
682 		return len;
683 }
684 
685 int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
686 			int len)
687 {
688 	int r;
689 	unsigned long addr;
690 
691 	addr = gfn_to_hva(kvm, gfn);
692 	if (kvm_is_error_hva(addr))
693 		return -EFAULT;
694 	r = copy_from_user(data, (void __user *)addr + offset, len);
695 	if (r)
696 		return -EFAULT;
697 	return 0;
698 }
699 EXPORT_SYMBOL_GPL(kvm_read_guest_page);
700 
701 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
702 {
703 	gfn_t gfn = gpa >> PAGE_SHIFT;
704 	int seg;
705 	int offset = offset_in_page(gpa);
706 	int ret;
707 
708 	while ((seg = next_segment(len, offset)) != 0) {
709 		ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
710 		if (ret < 0)
711 			return ret;
712 		offset = 0;
713 		len -= seg;
714 		data += seg;
715 		++gfn;
716 	}
717 	return 0;
718 }
719 EXPORT_SYMBOL_GPL(kvm_read_guest);
720 
721 int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
722 			  unsigned long len)
723 {
724 	int r;
725 	unsigned long addr;
726 	gfn_t gfn = gpa >> PAGE_SHIFT;
727 	int offset = offset_in_page(gpa);
728 
729 	addr = gfn_to_hva(kvm, gfn);
730 	if (kvm_is_error_hva(addr))
731 		return -EFAULT;
732 	pagefault_disable();
733 	r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
734 	pagefault_enable();
735 	if (r)
736 		return -EFAULT;
737 	return 0;
738 }
739 EXPORT_SYMBOL(kvm_read_guest_atomic);
740 
741 int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
742 			 int offset, int len)
743 {
744 	int r;
745 	unsigned long addr;
746 
747 	addr = gfn_to_hva(kvm, gfn);
748 	if (kvm_is_error_hva(addr))
749 		return -EFAULT;
750 	r = copy_to_user((void __user *)addr + offset, data, len);
751 	if (r)
752 		return -EFAULT;
753 	mark_page_dirty(kvm, gfn);
754 	return 0;
755 }
756 EXPORT_SYMBOL_GPL(kvm_write_guest_page);
757 
758 int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
759 		    unsigned long len)
760 {
761 	gfn_t gfn = gpa >> PAGE_SHIFT;
762 	int seg;
763 	int offset = offset_in_page(gpa);
764 	int ret;
765 
766 	while ((seg = next_segment(len, offset)) != 0) {
767 		ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
768 		if (ret < 0)
769 			return ret;
770 		offset = 0;
771 		len -= seg;
772 		data += seg;
773 		++gfn;
774 	}
775 	return 0;
776 }
777 
778 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
779 {
780 	return kvm_write_guest_page(kvm, gfn, empty_zero_page, offset, len);
781 }
782 EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
783 
784 int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
785 {
786 	gfn_t gfn = gpa >> PAGE_SHIFT;
787 	int seg;
788 	int offset = offset_in_page(gpa);
789 	int ret;
790 
791         while ((seg = next_segment(len, offset)) != 0) {
792 		ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
793 		if (ret < 0)
794 			return ret;
795 		offset = 0;
796 		len -= seg;
797 		++gfn;
798 	}
799 	return 0;
800 }
801 EXPORT_SYMBOL_GPL(kvm_clear_guest);
802 
803 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
804 {
805 	struct kvm_memory_slot *memslot;
806 
807 	gfn = unalias_gfn(kvm, gfn);
808 	memslot = __gfn_to_memslot(kvm, gfn);
809 	if (memslot && memslot->dirty_bitmap) {
810 		unsigned long rel_gfn = gfn - memslot->base_gfn;
811 
812 		/* avoid RMW */
813 		if (!test_bit(rel_gfn, memslot->dirty_bitmap))
814 			set_bit(rel_gfn, memslot->dirty_bitmap);
815 	}
816 }
817 
818 /*
819  * The vCPU has executed a HLT instruction with in-kernel mode enabled.
820  */
821 void kvm_vcpu_block(struct kvm_vcpu *vcpu)
822 {
823 	DEFINE_WAIT(wait);
824 
825 	for (;;) {
826 		prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
827 
828 		if (kvm_cpu_has_interrupt(vcpu))
829 			break;
830 		if (kvm_cpu_has_pending_timer(vcpu))
831 			break;
832 		if (kvm_arch_vcpu_runnable(vcpu))
833 			break;
834 		if (signal_pending(current))
835 			break;
836 
837 		vcpu_put(vcpu);
838 		schedule();
839 		vcpu_load(vcpu);
840 	}
841 
842 	finish_wait(&vcpu->wq, &wait);
843 }
844 
845 void kvm_resched(struct kvm_vcpu *vcpu)
846 {
847 	if (!need_resched())
848 		return;
849 	cond_resched();
850 }
851 EXPORT_SYMBOL_GPL(kvm_resched);
852 
853 static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
854 {
855 	struct kvm_vcpu *vcpu = vma->vm_file->private_data;
856 	struct page *page;
857 
858 	if (vmf->pgoff == 0)
859 		page = virt_to_page(vcpu->run);
860 #ifdef CONFIG_X86
861 	else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
862 		page = virt_to_page(vcpu->arch.pio_data);
863 #endif
864 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
865 	else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
866 		page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
867 #endif
868 	else
869 		return VM_FAULT_SIGBUS;
870 	get_page(page);
871 	vmf->page = page;
872 	return 0;
873 }
874 
875 static struct vm_operations_struct kvm_vcpu_vm_ops = {
876 	.fault = kvm_vcpu_fault,
877 };
878 
879 static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
880 {
881 	vma->vm_ops = &kvm_vcpu_vm_ops;
882 	return 0;
883 }
884 
885 static int kvm_vcpu_release(struct inode *inode, struct file *filp)
886 {
887 	struct kvm_vcpu *vcpu = filp->private_data;
888 
889 	kvm_put_kvm(vcpu->kvm);
890 	return 0;
891 }
892 
893 static const struct file_operations kvm_vcpu_fops = {
894 	.release        = kvm_vcpu_release,
895 	.unlocked_ioctl = kvm_vcpu_ioctl,
896 	.compat_ioctl   = kvm_vcpu_ioctl,
897 	.mmap           = kvm_vcpu_mmap,
898 };
899 
900 /*
901  * Allocates an inode for the vcpu.
902  */
903 static int create_vcpu_fd(struct kvm_vcpu *vcpu)
904 {
905 	int fd = anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, 0);
906 	if (fd < 0)
907 		kvm_put_kvm(vcpu->kvm);
908 	return fd;
909 }
910 
911 /*
912  * Creates some virtual cpus.  Good luck creating more than one.
913  */
914 static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
915 {
916 	int r;
917 	struct kvm_vcpu *vcpu;
918 
919 	if (!valid_vcpu(n))
920 		return -EINVAL;
921 
922 	vcpu = kvm_arch_vcpu_create(kvm, n);
923 	if (IS_ERR(vcpu))
924 		return PTR_ERR(vcpu);
925 
926 	preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
927 
928 	r = kvm_arch_vcpu_setup(vcpu);
929 	if (r)
930 		goto vcpu_destroy;
931 
932 	mutex_lock(&kvm->lock);
933 	if (kvm->vcpus[n]) {
934 		r = -EEXIST;
935 		mutex_unlock(&kvm->lock);
936 		goto vcpu_destroy;
937 	}
938 	kvm->vcpus[n] = vcpu;
939 	mutex_unlock(&kvm->lock);
940 
941 	/* Now it's all set up, let userspace reach it */
942 	kvm_get_kvm(kvm);
943 	r = create_vcpu_fd(vcpu);
944 	if (r < 0)
945 		goto unlink;
946 	return r;
947 
948 unlink:
949 	mutex_lock(&kvm->lock);
950 	kvm->vcpus[n] = NULL;
951 	mutex_unlock(&kvm->lock);
952 vcpu_destroy:
953 	kvm_arch_vcpu_destroy(vcpu);
954 	return r;
955 }
956 
957 static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
958 {
959 	if (sigset) {
960 		sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
961 		vcpu->sigset_active = 1;
962 		vcpu->sigset = *sigset;
963 	} else
964 		vcpu->sigset_active = 0;
965 	return 0;
966 }
967 
968 static long kvm_vcpu_ioctl(struct file *filp,
969 			   unsigned int ioctl, unsigned long arg)
970 {
971 	struct kvm_vcpu *vcpu = filp->private_data;
972 	void __user *argp = (void __user *)arg;
973 	int r;
974 
975 	if (vcpu->kvm->mm != current->mm)
976 		return -EIO;
977 	switch (ioctl) {
978 	case KVM_RUN:
979 		r = -EINVAL;
980 		if (arg)
981 			goto out;
982 		r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
983 		break;
984 	case KVM_GET_REGS: {
985 		struct kvm_regs *kvm_regs;
986 
987 		r = -ENOMEM;
988 		kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
989 		if (!kvm_regs)
990 			goto out;
991 		r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
992 		if (r)
993 			goto out_free1;
994 		r = -EFAULT;
995 		if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
996 			goto out_free1;
997 		r = 0;
998 out_free1:
999 		kfree(kvm_regs);
1000 		break;
1001 	}
1002 	case KVM_SET_REGS: {
1003 		struct kvm_regs *kvm_regs;
1004 
1005 		r = -ENOMEM;
1006 		kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
1007 		if (!kvm_regs)
1008 			goto out;
1009 		r = -EFAULT;
1010 		if (copy_from_user(kvm_regs, argp, sizeof(struct kvm_regs)))
1011 			goto out_free2;
1012 		r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
1013 		if (r)
1014 			goto out_free2;
1015 		r = 0;
1016 out_free2:
1017 		kfree(kvm_regs);
1018 		break;
1019 	}
1020 	case KVM_GET_SREGS: {
1021 		struct kvm_sregs kvm_sregs;
1022 
1023 		memset(&kvm_sregs, 0, sizeof kvm_sregs);
1024 		r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, &kvm_sregs);
1025 		if (r)
1026 			goto out;
1027 		r = -EFAULT;
1028 		if (copy_to_user(argp, &kvm_sregs, sizeof kvm_sregs))
1029 			goto out;
1030 		r = 0;
1031 		break;
1032 	}
1033 	case KVM_SET_SREGS: {
1034 		struct kvm_sregs kvm_sregs;
1035 
1036 		r = -EFAULT;
1037 		if (copy_from_user(&kvm_sregs, argp, sizeof kvm_sregs))
1038 			goto out;
1039 		r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, &kvm_sregs);
1040 		if (r)
1041 			goto out;
1042 		r = 0;
1043 		break;
1044 	}
1045 	case KVM_GET_MP_STATE: {
1046 		struct kvm_mp_state mp_state;
1047 
1048 		r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
1049 		if (r)
1050 			goto out;
1051 		r = -EFAULT;
1052 		if (copy_to_user(argp, &mp_state, sizeof mp_state))
1053 			goto out;
1054 		r = 0;
1055 		break;
1056 	}
1057 	case KVM_SET_MP_STATE: {
1058 		struct kvm_mp_state mp_state;
1059 
1060 		r = -EFAULT;
1061 		if (copy_from_user(&mp_state, argp, sizeof mp_state))
1062 			goto out;
1063 		r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
1064 		if (r)
1065 			goto out;
1066 		r = 0;
1067 		break;
1068 	}
1069 	case KVM_TRANSLATE: {
1070 		struct kvm_translation tr;
1071 
1072 		r = -EFAULT;
1073 		if (copy_from_user(&tr, argp, sizeof tr))
1074 			goto out;
1075 		r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
1076 		if (r)
1077 			goto out;
1078 		r = -EFAULT;
1079 		if (copy_to_user(argp, &tr, sizeof tr))
1080 			goto out;
1081 		r = 0;
1082 		break;
1083 	}
1084 	case KVM_DEBUG_GUEST: {
1085 		struct kvm_debug_guest dbg;
1086 
1087 		r = -EFAULT;
1088 		if (copy_from_user(&dbg, argp, sizeof dbg))
1089 			goto out;
1090 		r = kvm_arch_vcpu_ioctl_debug_guest(vcpu, &dbg);
1091 		if (r)
1092 			goto out;
1093 		r = 0;
1094 		break;
1095 	}
1096 	case KVM_SET_SIGNAL_MASK: {
1097 		struct kvm_signal_mask __user *sigmask_arg = argp;
1098 		struct kvm_signal_mask kvm_sigmask;
1099 		sigset_t sigset, *p;
1100 
1101 		p = NULL;
1102 		if (argp) {
1103 			r = -EFAULT;
1104 			if (copy_from_user(&kvm_sigmask, argp,
1105 					   sizeof kvm_sigmask))
1106 				goto out;
1107 			r = -EINVAL;
1108 			if (kvm_sigmask.len != sizeof sigset)
1109 				goto out;
1110 			r = -EFAULT;
1111 			if (copy_from_user(&sigset, sigmask_arg->sigset,
1112 					   sizeof sigset))
1113 				goto out;
1114 			p = &sigset;
1115 		}
1116 		r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
1117 		break;
1118 	}
1119 	case KVM_GET_FPU: {
1120 		struct kvm_fpu fpu;
1121 
1122 		memset(&fpu, 0, sizeof fpu);
1123 		r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, &fpu);
1124 		if (r)
1125 			goto out;
1126 		r = -EFAULT;
1127 		if (copy_to_user(argp, &fpu, sizeof fpu))
1128 			goto out;
1129 		r = 0;
1130 		break;
1131 	}
1132 	case KVM_SET_FPU: {
1133 		struct kvm_fpu fpu;
1134 
1135 		r = -EFAULT;
1136 		if (copy_from_user(&fpu, argp, sizeof fpu))
1137 			goto out;
1138 		r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, &fpu);
1139 		if (r)
1140 			goto out;
1141 		r = 0;
1142 		break;
1143 	}
1144 	default:
1145 		r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
1146 	}
1147 out:
1148 	return r;
1149 }
1150 
1151 static long kvm_vm_ioctl(struct file *filp,
1152 			   unsigned int ioctl, unsigned long arg)
1153 {
1154 	struct kvm *kvm = filp->private_data;
1155 	void __user *argp = (void __user *)arg;
1156 	int r;
1157 
1158 	if (kvm->mm != current->mm)
1159 		return -EIO;
1160 	switch (ioctl) {
1161 	case KVM_CREATE_VCPU:
1162 		r = kvm_vm_ioctl_create_vcpu(kvm, arg);
1163 		if (r < 0)
1164 			goto out;
1165 		break;
1166 	case KVM_SET_USER_MEMORY_REGION: {
1167 		struct kvm_userspace_memory_region kvm_userspace_mem;
1168 
1169 		r = -EFAULT;
1170 		if (copy_from_user(&kvm_userspace_mem, argp,
1171 						sizeof kvm_userspace_mem))
1172 			goto out;
1173 
1174 		r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem, 1);
1175 		if (r)
1176 			goto out;
1177 		break;
1178 	}
1179 	case KVM_GET_DIRTY_LOG: {
1180 		struct kvm_dirty_log log;
1181 
1182 		r = -EFAULT;
1183 		if (copy_from_user(&log, argp, sizeof log))
1184 			goto out;
1185 		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
1186 		if (r)
1187 			goto out;
1188 		break;
1189 	}
1190 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1191 	case KVM_REGISTER_COALESCED_MMIO: {
1192 		struct kvm_coalesced_mmio_zone zone;
1193 		r = -EFAULT;
1194 		if (copy_from_user(&zone, argp, sizeof zone))
1195 			goto out;
1196 		r = -ENXIO;
1197 		r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
1198 		if (r)
1199 			goto out;
1200 		r = 0;
1201 		break;
1202 	}
1203 	case KVM_UNREGISTER_COALESCED_MMIO: {
1204 		struct kvm_coalesced_mmio_zone zone;
1205 		r = -EFAULT;
1206 		if (copy_from_user(&zone, argp, sizeof zone))
1207 			goto out;
1208 		r = -ENXIO;
1209 		r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
1210 		if (r)
1211 			goto out;
1212 		r = 0;
1213 		break;
1214 	}
1215 #endif
1216 	default:
1217 		r = kvm_arch_vm_ioctl(filp, ioctl, arg);
1218 	}
1219 out:
1220 	return r;
1221 }
1222 
1223 static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1224 {
1225 	struct kvm *kvm = vma->vm_file->private_data;
1226 	struct page *page;
1227 
1228 	if (!kvm_is_visible_gfn(kvm, vmf->pgoff))
1229 		return VM_FAULT_SIGBUS;
1230 	page = gfn_to_page(kvm, vmf->pgoff);
1231 	if (is_error_page(page)) {
1232 		kvm_release_page_clean(page);
1233 		return VM_FAULT_SIGBUS;
1234 	}
1235 	vmf->page = page;
1236 	return 0;
1237 }
1238 
1239 static struct vm_operations_struct kvm_vm_vm_ops = {
1240 	.fault = kvm_vm_fault,
1241 };
1242 
1243 static int kvm_vm_mmap(struct file *file, struct vm_area_struct *vma)
1244 {
1245 	vma->vm_ops = &kvm_vm_vm_ops;
1246 	return 0;
1247 }
1248 
1249 static const struct file_operations kvm_vm_fops = {
1250 	.release        = kvm_vm_release,
1251 	.unlocked_ioctl = kvm_vm_ioctl,
1252 	.compat_ioctl   = kvm_vm_ioctl,
1253 	.mmap           = kvm_vm_mmap,
1254 };
1255 
1256 static int kvm_dev_ioctl_create_vm(void)
1257 {
1258 	int fd;
1259 	struct kvm *kvm;
1260 
1261 	kvm = kvm_create_vm();
1262 	if (IS_ERR(kvm))
1263 		return PTR_ERR(kvm);
1264 	fd = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, 0);
1265 	if (fd < 0)
1266 		kvm_put_kvm(kvm);
1267 
1268 	return fd;
1269 }
1270 
1271 static long kvm_dev_ioctl(struct file *filp,
1272 			  unsigned int ioctl, unsigned long arg)
1273 {
1274 	long r = -EINVAL;
1275 
1276 	switch (ioctl) {
1277 	case KVM_GET_API_VERSION:
1278 		r = -EINVAL;
1279 		if (arg)
1280 			goto out;
1281 		r = KVM_API_VERSION;
1282 		break;
1283 	case KVM_CREATE_VM:
1284 		r = -EINVAL;
1285 		if (arg)
1286 			goto out;
1287 		r = kvm_dev_ioctl_create_vm();
1288 		break;
1289 	case KVM_CHECK_EXTENSION:
1290 		r = kvm_dev_ioctl_check_extension(arg);
1291 		break;
1292 	case KVM_GET_VCPU_MMAP_SIZE:
1293 		r = -EINVAL;
1294 		if (arg)
1295 			goto out;
1296 		r = PAGE_SIZE;     /* struct kvm_run */
1297 #ifdef CONFIG_X86
1298 		r += PAGE_SIZE;    /* pio data page */
1299 #endif
1300 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1301 		r += PAGE_SIZE;    /* coalesced mmio ring page */
1302 #endif
1303 		break;
1304 	case KVM_TRACE_ENABLE:
1305 	case KVM_TRACE_PAUSE:
1306 	case KVM_TRACE_DISABLE:
1307 		r = kvm_trace_ioctl(ioctl, arg);
1308 		break;
1309 	default:
1310 		return kvm_arch_dev_ioctl(filp, ioctl, arg);
1311 	}
1312 out:
1313 	return r;
1314 }
1315 
1316 static struct file_operations kvm_chardev_ops = {
1317 	.unlocked_ioctl = kvm_dev_ioctl,
1318 	.compat_ioctl   = kvm_dev_ioctl,
1319 };
1320 
1321 static struct miscdevice kvm_dev = {
1322 	KVM_MINOR,
1323 	"kvm",
1324 	&kvm_chardev_ops,
1325 };
1326 
1327 static void hardware_enable(void *junk)
1328 {
1329 	int cpu = raw_smp_processor_id();
1330 
1331 	if (cpu_isset(cpu, cpus_hardware_enabled))
1332 		return;
1333 	cpu_set(cpu, cpus_hardware_enabled);
1334 	kvm_arch_hardware_enable(NULL);
1335 }
1336 
1337 static void hardware_disable(void *junk)
1338 {
1339 	int cpu = raw_smp_processor_id();
1340 
1341 	if (!cpu_isset(cpu, cpus_hardware_enabled))
1342 		return;
1343 	cpu_clear(cpu, cpus_hardware_enabled);
1344 	kvm_arch_hardware_disable(NULL);
1345 }
1346 
1347 static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
1348 			   void *v)
1349 {
1350 	int cpu = (long)v;
1351 
1352 	val &= ~CPU_TASKS_FROZEN;
1353 	switch (val) {
1354 	case CPU_DYING:
1355 		printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
1356 		       cpu);
1357 		hardware_disable(NULL);
1358 		break;
1359 	case CPU_UP_CANCELED:
1360 		printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
1361 		       cpu);
1362 		smp_call_function_single(cpu, hardware_disable, NULL, 1);
1363 		break;
1364 	case CPU_ONLINE:
1365 		printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
1366 		       cpu);
1367 		smp_call_function_single(cpu, hardware_enable, NULL, 1);
1368 		break;
1369 	}
1370 	return NOTIFY_OK;
1371 }
1372 
1373 
1374 asmlinkage void kvm_handle_fault_on_reboot(void)
1375 {
1376 	if (kvm_rebooting)
1377 		/* spin while reset goes on */
1378 		while (true)
1379 			;
1380 	/* Fault while not rebooting.  We want the trace. */
1381 	BUG();
1382 }
1383 EXPORT_SYMBOL_GPL(kvm_handle_fault_on_reboot);
1384 
1385 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
1386 		      void *v)
1387 {
1388 	if (val == SYS_RESTART) {
1389 		/*
1390 		 * Some (well, at least mine) BIOSes hang on reboot if
1391 		 * in vmx root mode.
1392 		 */
1393 		printk(KERN_INFO "kvm: exiting hardware virtualization\n");
1394 		kvm_rebooting = true;
1395 		on_each_cpu(hardware_disable, NULL, 1);
1396 	}
1397 	return NOTIFY_OK;
1398 }
1399 
1400 static struct notifier_block kvm_reboot_notifier = {
1401 	.notifier_call = kvm_reboot,
1402 	.priority = 0,
1403 };
1404 
1405 void kvm_io_bus_init(struct kvm_io_bus *bus)
1406 {
1407 	memset(bus, 0, sizeof(*bus));
1408 }
1409 
1410 void kvm_io_bus_destroy(struct kvm_io_bus *bus)
1411 {
1412 	int i;
1413 
1414 	for (i = 0; i < bus->dev_count; i++) {
1415 		struct kvm_io_device *pos = bus->devs[i];
1416 
1417 		kvm_iodevice_destructor(pos);
1418 	}
1419 }
1420 
1421 struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus,
1422 					  gpa_t addr, int len, int is_write)
1423 {
1424 	int i;
1425 
1426 	for (i = 0; i < bus->dev_count; i++) {
1427 		struct kvm_io_device *pos = bus->devs[i];
1428 
1429 		if (pos->in_range(pos, addr, len, is_write))
1430 			return pos;
1431 	}
1432 
1433 	return NULL;
1434 }
1435 
1436 void kvm_io_bus_register_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev)
1437 {
1438 	BUG_ON(bus->dev_count > (NR_IOBUS_DEVS-1));
1439 
1440 	bus->devs[bus->dev_count++] = dev;
1441 }
1442 
1443 static struct notifier_block kvm_cpu_notifier = {
1444 	.notifier_call = kvm_cpu_hotplug,
1445 	.priority = 20, /* must be > scheduler priority */
1446 };
1447 
1448 static int vm_stat_get(void *_offset, u64 *val)
1449 {
1450 	unsigned offset = (long)_offset;
1451 	struct kvm *kvm;
1452 
1453 	*val = 0;
1454 	spin_lock(&kvm_lock);
1455 	list_for_each_entry(kvm, &vm_list, vm_list)
1456 		*val += *(u32 *)((void *)kvm + offset);
1457 	spin_unlock(&kvm_lock);
1458 	return 0;
1459 }
1460 
1461 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
1462 
1463 static int vcpu_stat_get(void *_offset, u64 *val)
1464 {
1465 	unsigned offset = (long)_offset;
1466 	struct kvm *kvm;
1467 	struct kvm_vcpu *vcpu;
1468 	int i;
1469 
1470 	*val = 0;
1471 	spin_lock(&kvm_lock);
1472 	list_for_each_entry(kvm, &vm_list, vm_list)
1473 		for (i = 0; i < KVM_MAX_VCPUS; ++i) {
1474 			vcpu = kvm->vcpus[i];
1475 			if (vcpu)
1476 				*val += *(u32 *)((void *)vcpu + offset);
1477 		}
1478 	spin_unlock(&kvm_lock);
1479 	return 0;
1480 }
1481 
1482 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
1483 
1484 static struct file_operations *stat_fops[] = {
1485 	[KVM_STAT_VCPU] = &vcpu_stat_fops,
1486 	[KVM_STAT_VM]   = &vm_stat_fops,
1487 };
1488 
1489 static void kvm_init_debug(void)
1490 {
1491 	struct kvm_stats_debugfs_item *p;
1492 
1493 	kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
1494 	for (p = debugfs_entries; p->name; ++p)
1495 		p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
1496 						(void *)(long)p->offset,
1497 						stat_fops[p->kind]);
1498 }
1499 
1500 static void kvm_exit_debug(void)
1501 {
1502 	struct kvm_stats_debugfs_item *p;
1503 
1504 	for (p = debugfs_entries; p->name; ++p)
1505 		debugfs_remove(p->dentry);
1506 	debugfs_remove(kvm_debugfs_dir);
1507 }
1508 
1509 static int kvm_suspend(struct sys_device *dev, pm_message_t state)
1510 {
1511 	hardware_disable(NULL);
1512 	return 0;
1513 }
1514 
1515 static int kvm_resume(struct sys_device *dev)
1516 {
1517 	hardware_enable(NULL);
1518 	return 0;
1519 }
1520 
1521 static struct sysdev_class kvm_sysdev_class = {
1522 	.name = "kvm",
1523 	.suspend = kvm_suspend,
1524 	.resume = kvm_resume,
1525 };
1526 
1527 static struct sys_device kvm_sysdev = {
1528 	.id = 0,
1529 	.cls = &kvm_sysdev_class,
1530 };
1531 
1532 struct page *bad_page;
1533 pfn_t bad_pfn;
1534 
1535 static inline
1536 struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
1537 {
1538 	return container_of(pn, struct kvm_vcpu, preempt_notifier);
1539 }
1540 
1541 static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
1542 {
1543 	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
1544 
1545 	kvm_arch_vcpu_load(vcpu, cpu);
1546 }
1547 
1548 static void kvm_sched_out(struct preempt_notifier *pn,
1549 			  struct task_struct *next)
1550 {
1551 	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
1552 
1553 	kvm_arch_vcpu_put(vcpu);
1554 }
1555 
1556 int kvm_init(void *opaque, unsigned int vcpu_size,
1557 		  struct module *module)
1558 {
1559 	int r;
1560 	int cpu;
1561 
1562 	kvm_init_debug();
1563 
1564 	r = kvm_arch_init(opaque);
1565 	if (r)
1566 		goto out_fail;
1567 
1568 	bad_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
1569 
1570 	if (bad_page == NULL) {
1571 		r = -ENOMEM;
1572 		goto out;
1573 	}
1574 
1575 	bad_pfn = page_to_pfn(bad_page);
1576 
1577 	r = kvm_arch_hardware_setup();
1578 	if (r < 0)
1579 		goto out_free_0;
1580 
1581 	for_each_online_cpu(cpu) {
1582 		smp_call_function_single(cpu,
1583 				kvm_arch_check_processor_compat,
1584 				&r, 1);
1585 		if (r < 0)
1586 			goto out_free_1;
1587 	}
1588 
1589 	on_each_cpu(hardware_enable, NULL, 1);
1590 	r = register_cpu_notifier(&kvm_cpu_notifier);
1591 	if (r)
1592 		goto out_free_2;
1593 	register_reboot_notifier(&kvm_reboot_notifier);
1594 
1595 	r = sysdev_class_register(&kvm_sysdev_class);
1596 	if (r)
1597 		goto out_free_3;
1598 
1599 	r = sysdev_register(&kvm_sysdev);
1600 	if (r)
1601 		goto out_free_4;
1602 
1603 	/* A kmem cache lets us meet the alignment requirements of fx_save. */
1604 	kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size,
1605 					   __alignof__(struct kvm_vcpu),
1606 					   0, NULL);
1607 	if (!kvm_vcpu_cache) {
1608 		r = -ENOMEM;
1609 		goto out_free_5;
1610 	}
1611 
1612 	kvm_chardev_ops.owner = module;
1613 
1614 	r = misc_register(&kvm_dev);
1615 	if (r) {
1616 		printk(KERN_ERR "kvm: misc device register failed\n");
1617 		goto out_free;
1618 	}
1619 
1620 	kvm_preempt_ops.sched_in = kvm_sched_in;
1621 	kvm_preempt_ops.sched_out = kvm_sched_out;
1622 
1623 	return 0;
1624 
1625 out_free:
1626 	kmem_cache_destroy(kvm_vcpu_cache);
1627 out_free_5:
1628 	sysdev_unregister(&kvm_sysdev);
1629 out_free_4:
1630 	sysdev_class_unregister(&kvm_sysdev_class);
1631 out_free_3:
1632 	unregister_reboot_notifier(&kvm_reboot_notifier);
1633 	unregister_cpu_notifier(&kvm_cpu_notifier);
1634 out_free_2:
1635 	on_each_cpu(hardware_disable, NULL, 1);
1636 out_free_1:
1637 	kvm_arch_hardware_unsetup();
1638 out_free_0:
1639 	__free_page(bad_page);
1640 out:
1641 	kvm_arch_exit();
1642 	kvm_exit_debug();
1643 out_fail:
1644 	return r;
1645 }
1646 EXPORT_SYMBOL_GPL(kvm_init);
1647 
1648 void kvm_exit(void)
1649 {
1650 	kvm_trace_cleanup();
1651 	misc_deregister(&kvm_dev);
1652 	kmem_cache_destroy(kvm_vcpu_cache);
1653 	sysdev_unregister(&kvm_sysdev);
1654 	sysdev_class_unregister(&kvm_sysdev_class);
1655 	unregister_reboot_notifier(&kvm_reboot_notifier);
1656 	unregister_cpu_notifier(&kvm_cpu_notifier);
1657 	on_each_cpu(hardware_disable, NULL, 1);
1658 	kvm_arch_hardware_unsetup();
1659 	kvm_arch_exit();
1660 	kvm_exit_debug();
1661 	__free_page(bad_page);
1662 }
1663 EXPORT_SYMBOL_GPL(kvm_exit);
1664