xref: /openbmc/linux/virt/kvm/kvm_main.c (revision 82ced6fd)
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 #ifdef KVM_CAP_DEVICE_ASSIGNMENT
55 #include <linux/pci.h>
56 #include <linux/interrupt.h>
57 #include "irq.h"
58 #endif
59 
60 MODULE_AUTHOR("Qumranet");
61 MODULE_LICENSE("GPL");
62 
63 static int msi2intx = 1;
64 module_param(msi2intx, bool, 0);
65 
66 DEFINE_SPINLOCK(kvm_lock);
67 LIST_HEAD(vm_list);
68 
69 static cpumask_var_t cpus_hardware_enabled;
70 
71 struct kmem_cache *kvm_vcpu_cache;
72 EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
73 
74 static __read_mostly struct preempt_ops kvm_preempt_ops;
75 
76 struct dentry *kvm_debugfs_dir;
77 
78 static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
79 			   unsigned long arg);
80 
81 static bool kvm_rebooting;
82 
83 #ifdef KVM_CAP_DEVICE_ASSIGNMENT
84 static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head,
85 						      int assigned_dev_id)
86 {
87 	struct list_head *ptr;
88 	struct kvm_assigned_dev_kernel *match;
89 
90 	list_for_each(ptr, head) {
91 		match = list_entry(ptr, struct kvm_assigned_dev_kernel, list);
92 		if (match->assigned_dev_id == assigned_dev_id)
93 			return match;
94 	}
95 	return NULL;
96 }
97 
98 static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
99 {
100 	struct kvm_assigned_dev_kernel *assigned_dev;
101 
102 	assigned_dev = container_of(work, struct kvm_assigned_dev_kernel,
103 				    interrupt_work);
104 
105 	/* This is taken to safely inject irq inside the guest. When
106 	 * the interrupt injection (or the ioapic code) uses a
107 	 * finer-grained lock, update this
108 	 */
109 	mutex_lock(&assigned_dev->kvm->lock);
110 	kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
111 		    assigned_dev->guest_irq, 1);
112 
113 	if (assigned_dev->irq_requested_type & KVM_ASSIGNED_DEV_GUEST_MSI) {
114 		enable_irq(assigned_dev->host_irq);
115 		assigned_dev->host_irq_disabled = false;
116 	}
117 	mutex_unlock(&assigned_dev->kvm->lock);
118 }
119 
120 static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
121 {
122 	struct kvm_assigned_dev_kernel *assigned_dev =
123 		(struct kvm_assigned_dev_kernel *) dev_id;
124 
125 	schedule_work(&assigned_dev->interrupt_work);
126 
127 	disable_irq_nosync(irq);
128 	assigned_dev->host_irq_disabled = true;
129 
130 	return IRQ_HANDLED;
131 }
132 
133 /* Ack the irq line for an assigned device */
134 static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
135 {
136 	struct kvm_assigned_dev_kernel *dev;
137 
138 	if (kian->gsi == -1)
139 		return;
140 
141 	dev = container_of(kian, struct kvm_assigned_dev_kernel,
142 			   ack_notifier);
143 
144 	kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0);
145 
146 	/* The guest irq may be shared so this ack may be
147 	 * from another device.
148 	 */
149 	if (dev->host_irq_disabled) {
150 		enable_irq(dev->host_irq);
151 		dev->host_irq_disabled = false;
152 	}
153 }
154 
155 /* The function implicit hold kvm->lock mutex due to cancel_work_sync() */
156 static void kvm_free_assigned_irq(struct kvm *kvm,
157 				  struct kvm_assigned_dev_kernel *assigned_dev)
158 {
159 	if (!irqchip_in_kernel(kvm))
160 		return;
161 
162 	kvm_unregister_irq_ack_notifier(&assigned_dev->ack_notifier);
163 
164 	if (assigned_dev->irq_source_id != -1)
165 		kvm_free_irq_source_id(kvm, assigned_dev->irq_source_id);
166 	assigned_dev->irq_source_id = -1;
167 
168 	if (!assigned_dev->irq_requested_type)
169 		return;
170 
171 	/*
172 	 * In kvm_free_device_irq, cancel_work_sync return true if:
173 	 * 1. work is scheduled, and then cancelled.
174 	 * 2. work callback is executed.
175 	 *
176 	 * The first one ensured that the irq is disabled and no more events
177 	 * would happen. But for the second one, the irq may be enabled (e.g.
178 	 * for MSI). So we disable irq here to prevent further events.
179 	 *
180 	 * Notice this maybe result in nested disable if the interrupt type is
181 	 * INTx, but it's OK for we are going to free it.
182 	 *
183 	 * If this function is a part of VM destroy, please ensure that till
184 	 * now, the kvm state is still legal for probably we also have to wait
185 	 * interrupt_work done.
186 	 */
187 	disable_irq_nosync(assigned_dev->host_irq);
188 	cancel_work_sync(&assigned_dev->interrupt_work);
189 
190 	free_irq(assigned_dev->host_irq, (void *)assigned_dev);
191 
192 	if (assigned_dev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI)
193 		pci_disable_msi(assigned_dev->dev);
194 
195 	assigned_dev->irq_requested_type = 0;
196 }
197 
198 
199 static void kvm_free_assigned_device(struct kvm *kvm,
200 				     struct kvm_assigned_dev_kernel
201 				     *assigned_dev)
202 {
203 	kvm_free_assigned_irq(kvm, assigned_dev);
204 
205 	pci_reset_function(assigned_dev->dev);
206 
207 	pci_release_regions(assigned_dev->dev);
208 	pci_disable_device(assigned_dev->dev);
209 	pci_dev_put(assigned_dev->dev);
210 
211 	list_del(&assigned_dev->list);
212 	kfree(assigned_dev);
213 }
214 
215 void kvm_free_all_assigned_devices(struct kvm *kvm)
216 {
217 	struct list_head *ptr, *ptr2;
218 	struct kvm_assigned_dev_kernel *assigned_dev;
219 
220 	list_for_each_safe(ptr, ptr2, &kvm->arch.assigned_dev_head) {
221 		assigned_dev = list_entry(ptr,
222 					  struct kvm_assigned_dev_kernel,
223 					  list);
224 
225 		kvm_free_assigned_device(kvm, assigned_dev);
226 	}
227 }
228 
229 static int assigned_device_update_intx(struct kvm *kvm,
230 			struct kvm_assigned_dev_kernel *adev,
231 			struct kvm_assigned_irq *airq)
232 {
233 	adev->guest_irq = airq->guest_irq;
234 	adev->ack_notifier.gsi = airq->guest_irq;
235 
236 	if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_INTX)
237 		return 0;
238 
239 	if (irqchip_in_kernel(kvm)) {
240 		if (!msi2intx &&
241 		    (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI)) {
242 			free_irq(adev->host_irq, (void *)adev);
243 			pci_disable_msi(adev->dev);
244 		}
245 
246 		if (!capable(CAP_SYS_RAWIO))
247 			return -EPERM;
248 
249 		if (airq->host_irq)
250 			adev->host_irq = airq->host_irq;
251 		else
252 			adev->host_irq = adev->dev->irq;
253 
254 		/* Even though this is PCI, we don't want to use shared
255 		 * interrupts. Sharing host devices with guest-assigned devices
256 		 * on the same interrupt line is not a happy situation: there
257 		 * are going to be long delays in accepting, acking, etc.
258 		 */
259 		if (request_irq(adev->host_irq, kvm_assigned_dev_intr,
260 				0, "kvm_assigned_intx_device", (void *)adev))
261 			return -EIO;
262 	}
263 
264 	adev->irq_requested_type = KVM_ASSIGNED_DEV_GUEST_INTX |
265 				   KVM_ASSIGNED_DEV_HOST_INTX;
266 	return 0;
267 }
268 
269 #ifdef CONFIG_X86
270 static int assigned_device_update_msi(struct kvm *kvm,
271 			struct kvm_assigned_dev_kernel *adev,
272 			struct kvm_assigned_irq *airq)
273 {
274 	int r;
275 
276 	adev->guest_irq = airq->guest_irq;
277 	if (airq->flags & KVM_DEV_IRQ_ASSIGN_ENABLE_MSI) {
278 		/* x86 don't care upper address of guest msi message addr */
279 		adev->irq_requested_type |= KVM_ASSIGNED_DEV_GUEST_MSI;
280 		adev->irq_requested_type &= ~KVM_ASSIGNED_DEV_GUEST_INTX;
281 		adev->ack_notifier.gsi = -1;
282 	} else if (msi2intx) {
283 		adev->irq_requested_type |= KVM_ASSIGNED_DEV_GUEST_INTX;
284 		adev->irq_requested_type &= ~KVM_ASSIGNED_DEV_GUEST_MSI;
285 		adev->ack_notifier.gsi = airq->guest_irq;
286 	} else {
287 		/*
288 		 * Guest require to disable device MSI, we disable MSI and
289 		 * re-enable INTx by default again. Notice it's only for
290 		 * non-msi2intx.
291 		 */
292 		assigned_device_update_intx(kvm, adev, airq);
293 		return 0;
294 	}
295 
296 	if (adev->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI)
297 		return 0;
298 
299 	if (irqchip_in_kernel(kvm)) {
300 		if (!msi2intx) {
301 			if (adev->irq_requested_type &
302 					KVM_ASSIGNED_DEV_HOST_INTX)
303 				free_irq(adev->host_irq, (void *)adev);
304 
305 			r = pci_enable_msi(adev->dev);
306 			if (r)
307 				return r;
308 		}
309 
310 		adev->host_irq = adev->dev->irq;
311 		if (request_irq(adev->host_irq, kvm_assigned_dev_intr, 0,
312 				"kvm_assigned_msi_device", (void *)adev))
313 			return -EIO;
314 	}
315 
316 	if (!msi2intx)
317 		adev->irq_requested_type = KVM_ASSIGNED_DEV_GUEST_MSI;
318 
319 	adev->irq_requested_type |= KVM_ASSIGNED_DEV_HOST_MSI;
320 	return 0;
321 }
322 #endif
323 
324 static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
325 				   struct kvm_assigned_irq
326 				   *assigned_irq)
327 {
328 	int r = 0;
329 	struct kvm_assigned_dev_kernel *match;
330 	u32 current_flags = 0, changed_flags;
331 
332 	mutex_lock(&kvm->lock);
333 
334 	match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
335 				      assigned_irq->assigned_dev_id);
336 	if (!match) {
337 		mutex_unlock(&kvm->lock);
338 		return -EINVAL;
339 	}
340 
341 	if (!match->irq_requested_type) {
342 		INIT_WORK(&match->interrupt_work,
343 				kvm_assigned_dev_interrupt_work_handler);
344 		if (irqchip_in_kernel(kvm)) {
345 			/* Register ack nofitier */
346 			match->ack_notifier.gsi = -1;
347 			match->ack_notifier.irq_acked =
348 					kvm_assigned_dev_ack_irq;
349 			kvm_register_irq_ack_notifier(kvm,
350 					&match->ack_notifier);
351 
352 			/* Request IRQ source ID */
353 			r = kvm_request_irq_source_id(kvm);
354 			if (r < 0)
355 				goto out_release;
356 			else
357 				match->irq_source_id = r;
358 
359 #ifdef CONFIG_X86
360 			/* Determine host device irq type, we can know the
361 			 * result from dev->msi_enabled */
362 			if (msi2intx)
363 				pci_enable_msi(match->dev);
364 #endif
365 		}
366 	}
367 
368 	if ((match->irq_requested_type & KVM_ASSIGNED_DEV_HOST_MSI) &&
369 		 (match->irq_requested_type & KVM_ASSIGNED_DEV_GUEST_MSI))
370 		current_flags |= KVM_DEV_IRQ_ASSIGN_ENABLE_MSI;
371 
372 	changed_flags = assigned_irq->flags ^ current_flags;
373 
374 	if ((changed_flags & KVM_DEV_IRQ_ASSIGN_MSI_ACTION) ||
375 	    (msi2intx && match->dev->msi_enabled)) {
376 #ifdef CONFIG_X86
377 		r = assigned_device_update_msi(kvm, match, assigned_irq);
378 		if (r) {
379 			printk(KERN_WARNING "kvm: failed to enable "
380 					"MSI device!\n");
381 			goto out_release;
382 		}
383 #else
384 		r = -ENOTTY;
385 #endif
386 	} else if (assigned_irq->host_irq == 0 && match->dev->irq == 0) {
387 		/* Host device IRQ 0 means don't support INTx */
388 		if (!msi2intx) {
389 			printk(KERN_WARNING
390 			       "kvm: wait device to enable MSI!\n");
391 			r = 0;
392 		} else {
393 			printk(KERN_WARNING
394 			       "kvm: failed to enable MSI device!\n");
395 			r = -ENOTTY;
396 			goto out_release;
397 		}
398 	} else {
399 		/* Non-sharing INTx mode */
400 		r = assigned_device_update_intx(kvm, match, assigned_irq);
401 		if (r) {
402 			printk(KERN_WARNING "kvm: failed to enable "
403 					"INTx device!\n");
404 			goto out_release;
405 		}
406 	}
407 
408 	mutex_unlock(&kvm->lock);
409 	return r;
410 out_release:
411 	mutex_unlock(&kvm->lock);
412 	kvm_free_assigned_device(kvm, match);
413 	return r;
414 }
415 
416 static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
417 				      struct kvm_assigned_pci_dev *assigned_dev)
418 {
419 	int r = 0;
420 	struct kvm_assigned_dev_kernel *match;
421 	struct pci_dev *dev;
422 
423 	down_read(&kvm->slots_lock);
424 	mutex_lock(&kvm->lock);
425 
426 	match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
427 				      assigned_dev->assigned_dev_id);
428 	if (match) {
429 		/* device already assigned */
430 		r = -EINVAL;
431 		goto out;
432 	}
433 
434 	match = kzalloc(sizeof(struct kvm_assigned_dev_kernel), GFP_KERNEL);
435 	if (match == NULL) {
436 		printk(KERN_INFO "%s: Couldn't allocate memory\n",
437 		       __func__);
438 		r = -ENOMEM;
439 		goto out;
440 	}
441 	dev = pci_get_bus_and_slot(assigned_dev->busnr,
442 				   assigned_dev->devfn);
443 	if (!dev) {
444 		printk(KERN_INFO "%s: host device not found\n", __func__);
445 		r = -EINVAL;
446 		goto out_free;
447 	}
448 	if (pci_enable_device(dev)) {
449 		printk(KERN_INFO "%s: Could not enable PCI device\n", __func__);
450 		r = -EBUSY;
451 		goto out_put;
452 	}
453 	r = pci_request_regions(dev, "kvm_assigned_device");
454 	if (r) {
455 		printk(KERN_INFO "%s: Could not get access to device regions\n",
456 		       __func__);
457 		goto out_disable;
458 	}
459 
460 	pci_reset_function(dev);
461 
462 	match->assigned_dev_id = assigned_dev->assigned_dev_id;
463 	match->host_busnr = assigned_dev->busnr;
464 	match->host_devfn = assigned_dev->devfn;
465 	match->flags = assigned_dev->flags;
466 	match->dev = dev;
467 	match->irq_source_id = -1;
468 	match->kvm = kvm;
469 
470 	list_add(&match->list, &kvm->arch.assigned_dev_head);
471 
472 	if (assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU) {
473 		if (!kvm->arch.iommu_domain) {
474 			r = kvm_iommu_map_guest(kvm);
475 			if (r)
476 				goto out_list_del;
477 		}
478 		r = kvm_assign_device(kvm, match);
479 		if (r)
480 			goto out_list_del;
481 	}
482 
483 out:
484 	mutex_unlock(&kvm->lock);
485 	up_read(&kvm->slots_lock);
486 	return r;
487 out_list_del:
488 	list_del(&match->list);
489 	pci_release_regions(dev);
490 out_disable:
491 	pci_disable_device(dev);
492 out_put:
493 	pci_dev_put(dev);
494 out_free:
495 	kfree(match);
496 	mutex_unlock(&kvm->lock);
497 	up_read(&kvm->slots_lock);
498 	return r;
499 }
500 #endif
501 
502 #ifdef KVM_CAP_DEVICE_DEASSIGNMENT
503 static int kvm_vm_ioctl_deassign_device(struct kvm *kvm,
504 		struct kvm_assigned_pci_dev *assigned_dev)
505 {
506 	int r = 0;
507 	struct kvm_assigned_dev_kernel *match;
508 
509 	mutex_lock(&kvm->lock);
510 
511 	match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
512 				      assigned_dev->assigned_dev_id);
513 	if (!match) {
514 		printk(KERN_INFO "%s: device hasn't been assigned before, "
515 		  "so cannot be deassigned\n", __func__);
516 		r = -EINVAL;
517 		goto out;
518 	}
519 
520 	if (match->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU)
521 		kvm_deassign_device(kvm, match);
522 
523 	kvm_free_assigned_device(kvm, match);
524 
525 out:
526 	mutex_unlock(&kvm->lock);
527 	return r;
528 }
529 #endif
530 
531 static inline int valid_vcpu(int n)
532 {
533 	return likely(n >= 0 && n < KVM_MAX_VCPUS);
534 }
535 
536 inline int kvm_is_mmio_pfn(pfn_t pfn)
537 {
538 	if (pfn_valid(pfn)) {
539 		struct page *page = compound_head(pfn_to_page(pfn));
540 		return PageReserved(page);
541 	}
542 
543 	return true;
544 }
545 
546 /*
547  * Switches to specified vcpu, until a matching vcpu_put()
548  */
549 void vcpu_load(struct kvm_vcpu *vcpu)
550 {
551 	int cpu;
552 
553 	mutex_lock(&vcpu->mutex);
554 	cpu = get_cpu();
555 	preempt_notifier_register(&vcpu->preempt_notifier);
556 	kvm_arch_vcpu_load(vcpu, cpu);
557 	put_cpu();
558 }
559 
560 void vcpu_put(struct kvm_vcpu *vcpu)
561 {
562 	preempt_disable();
563 	kvm_arch_vcpu_put(vcpu);
564 	preempt_notifier_unregister(&vcpu->preempt_notifier);
565 	preempt_enable();
566 	mutex_unlock(&vcpu->mutex);
567 }
568 
569 static void ack_flush(void *_completed)
570 {
571 }
572 
573 static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
574 {
575 	int i, cpu, me;
576 	cpumask_var_t cpus;
577 	bool called = true;
578 	struct kvm_vcpu *vcpu;
579 
580 	if (alloc_cpumask_var(&cpus, GFP_ATOMIC))
581 		cpumask_clear(cpus);
582 
583 	me = get_cpu();
584 	for (i = 0; i < KVM_MAX_VCPUS; ++i) {
585 		vcpu = kvm->vcpus[i];
586 		if (!vcpu)
587 			continue;
588 		if (test_and_set_bit(req, &vcpu->requests))
589 			continue;
590 		cpu = vcpu->cpu;
591 		if (cpus != NULL && cpu != -1 && cpu != me)
592 			cpumask_set_cpu(cpu, cpus);
593 	}
594 	if (unlikely(cpus == NULL))
595 		smp_call_function_many(cpu_online_mask, ack_flush, NULL, 1);
596 	else if (!cpumask_empty(cpus))
597 		smp_call_function_many(cpus, ack_flush, NULL, 1);
598 	else
599 		called = false;
600 	put_cpu();
601 	free_cpumask_var(cpus);
602 	return called;
603 }
604 
605 void kvm_flush_remote_tlbs(struct kvm *kvm)
606 {
607 	if (make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
608 		++kvm->stat.remote_tlb_flush;
609 }
610 
611 void kvm_reload_remote_mmus(struct kvm *kvm)
612 {
613 	make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD);
614 }
615 
616 int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
617 {
618 	struct page *page;
619 	int r;
620 
621 	mutex_init(&vcpu->mutex);
622 	vcpu->cpu = -1;
623 	vcpu->kvm = kvm;
624 	vcpu->vcpu_id = id;
625 	init_waitqueue_head(&vcpu->wq);
626 
627 	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
628 	if (!page) {
629 		r = -ENOMEM;
630 		goto fail;
631 	}
632 	vcpu->run = page_address(page);
633 
634 	r = kvm_arch_vcpu_init(vcpu);
635 	if (r < 0)
636 		goto fail_free_run;
637 	return 0;
638 
639 fail_free_run:
640 	free_page((unsigned long)vcpu->run);
641 fail:
642 	return r;
643 }
644 EXPORT_SYMBOL_GPL(kvm_vcpu_init);
645 
646 void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
647 {
648 	kvm_arch_vcpu_uninit(vcpu);
649 	free_page((unsigned long)vcpu->run);
650 }
651 EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
652 
653 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
654 static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
655 {
656 	return container_of(mn, struct kvm, mmu_notifier);
657 }
658 
659 static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
660 					     struct mm_struct *mm,
661 					     unsigned long address)
662 {
663 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
664 	int need_tlb_flush;
665 
666 	/*
667 	 * When ->invalidate_page runs, the linux pte has been zapped
668 	 * already but the page is still allocated until
669 	 * ->invalidate_page returns. So if we increase the sequence
670 	 * here the kvm page fault will notice if the spte can't be
671 	 * established because the page is going to be freed. If
672 	 * instead the kvm page fault establishes the spte before
673 	 * ->invalidate_page runs, kvm_unmap_hva will release it
674 	 * before returning.
675 	 *
676 	 * The sequence increase only need to be seen at spin_unlock
677 	 * time, and not at spin_lock time.
678 	 *
679 	 * Increasing the sequence after the spin_unlock would be
680 	 * unsafe because the kvm page fault could then establish the
681 	 * pte after kvm_unmap_hva returned, without noticing the page
682 	 * is going to be freed.
683 	 */
684 	spin_lock(&kvm->mmu_lock);
685 	kvm->mmu_notifier_seq++;
686 	need_tlb_flush = kvm_unmap_hva(kvm, address);
687 	spin_unlock(&kvm->mmu_lock);
688 
689 	/* we've to flush the tlb before the pages can be freed */
690 	if (need_tlb_flush)
691 		kvm_flush_remote_tlbs(kvm);
692 
693 }
694 
695 static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
696 						    struct mm_struct *mm,
697 						    unsigned long start,
698 						    unsigned long end)
699 {
700 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
701 	int need_tlb_flush = 0;
702 
703 	spin_lock(&kvm->mmu_lock);
704 	/*
705 	 * The count increase must become visible at unlock time as no
706 	 * spte can be established without taking the mmu_lock and
707 	 * count is also read inside the mmu_lock critical section.
708 	 */
709 	kvm->mmu_notifier_count++;
710 	for (; start < end; start += PAGE_SIZE)
711 		need_tlb_flush |= kvm_unmap_hva(kvm, start);
712 	spin_unlock(&kvm->mmu_lock);
713 
714 	/* we've to flush the tlb before the pages can be freed */
715 	if (need_tlb_flush)
716 		kvm_flush_remote_tlbs(kvm);
717 }
718 
719 static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
720 						  struct mm_struct *mm,
721 						  unsigned long start,
722 						  unsigned long end)
723 {
724 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
725 
726 	spin_lock(&kvm->mmu_lock);
727 	/*
728 	 * This sequence increase will notify the kvm page fault that
729 	 * the page that is going to be mapped in the spte could have
730 	 * been freed.
731 	 */
732 	kvm->mmu_notifier_seq++;
733 	/*
734 	 * The above sequence increase must be visible before the
735 	 * below count decrease but both values are read by the kvm
736 	 * page fault under mmu_lock spinlock so we don't need to add
737 	 * a smb_wmb() here in between the two.
738 	 */
739 	kvm->mmu_notifier_count--;
740 	spin_unlock(&kvm->mmu_lock);
741 
742 	BUG_ON(kvm->mmu_notifier_count < 0);
743 }
744 
745 static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
746 					      struct mm_struct *mm,
747 					      unsigned long address)
748 {
749 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
750 	int young;
751 
752 	spin_lock(&kvm->mmu_lock);
753 	young = kvm_age_hva(kvm, address);
754 	spin_unlock(&kvm->mmu_lock);
755 
756 	if (young)
757 		kvm_flush_remote_tlbs(kvm);
758 
759 	return young;
760 }
761 
762 static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
763 				     struct mm_struct *mm)
764 {
765 	struct kvm *kvm = mmu_notifier_to_kvm(mn);
766 	kvm_arch_flush_shadow(kvm);
767 }
768 
769 static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
770 	.invalidate_page	= kvm_mmu_notifier_invalidate_page,
771 	.invalidate_range_start	= kvm_mmu_notifier_invalidate_range_start,
772 	.invalidate_range_end	= kvm_mmu_notifier_invalidate_range_end,
773 	.clear_flush_young	= kvm_mmu_notifier_clear_flush_young,
774 	.release		= kvm_mmu_notifier_release,
775 };
776 #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
777 
778 static struct kvm *kvm_create_vm(void)
779 {
780 	struct kvm *kvm = kvm_arch_create_vm();
781 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
782 	struct page *page;
783 #endif
784 
785 	if (IS_ERR(kvm))
786 		goto out;
787 #ifdef CONFIG_HAVE_KVM_IRQCHIP
788 	INIT_LIST_HEAD(&kvm->irq_routing);
789 	INIT_HLIST_HEAD(&kvm->mask_notifier_list);
790 #endif
791 
792 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
793 	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
794 	if (!page) {
795 		kfree(kvm);
796 		return ERR_PTR(-ENOMEM);
797 	}
798 	kvm->coalesced_mmio_ring =
799 			(struct kvm_coalesced_mmio_ring *)page_address(page);
800 #endif
801 
802 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
803 	{
804 		int err;
805 		kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
806 		err = mmu_notifier_register(&kvm->mmu_notifier, current->mm);
807 		if (err) {
808 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
809 			put_page(page);
810 #endif
811 			kfree(kvm);
812 			return ERR_PTR(err);
813 		}
814 	}
815 #endif
816 
817 	kvm->mm = current->mm;
818 	atomic_inc(&kvm->mm->mm_count);
819 	spin_lock_init(&kvm->mmu_lock);
820 	kvm_io_bus_init(&kvm->pio_bus);
821 	mutex_init(&kvm->lock);
822 	kvm_io_bus_init(&kvm->mmio_bus);
823 	init_rwsem(&kvm->slots_lock);
824 	atomic_set(&kvm->users_count, 1);
825 	spin_lock(&kvm_lock);
826 	list_add(&kvm->vm_list, &vm_list);
827 	spin_unlock(&kvm_lock);
828 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
829 	kvm_coalesced_mmio_init(kvm);
830 #endif
831 out:
832 	return kvm;
833 }
834 
835 /*
836  * Free any memory in @free but not in @dont.
837  */
838 static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
839 				  struct kvm_memory_slot *dont)
840 {
841 	if (!dont || free->rmap != dont->rmap)
842 		vfree(free->rmap);
843 
844 	if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
845 		vfree(free->dirty_bitmap);
846 
847 	if (!dont || free->lpage_info != dont->lpage_info)
848 		vfree(free->lpage_info);
849 
850 	free->npages = 0;
851 	free->dirty_bitmap = NULL;
852 	free->rmap = NULL;
853 	free->lpage_info = NULL;
854 }
855 
856 void kvm_free_physmem(struct kvm *kvm)
857 {
858 	int i;
859 
860 	for (i = 0; i < kvm->nmemslots; ++i)
861 		kvm_free_physmem_slot(&kvm->memslots[i], NULL);
862 }
863 
864 static void kvm_destroy_vm(struct kvm *kvm)
865 {
866 	struct mm_struct *mm = kvm->mm;
867 
868 	kvm_arch_sync_events(kvm);
869 	spin_lock(&kvm_lock);
870 	list_del(&kvm->vm_list);
871 	spin_unlock(&kvm_lock);
872 	kvm_free_irq_routing(kvm);
873 	kvm_io_bus_destroy(&kvm->pio_bus);
874 	kvm_io_bus_destroy(&kvm->mmio_bus);
875 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
876 	if (kvm->coalesced_mmio_ring != NULL)
877 		free_page((unsigned long)kvm->coalesced_mmio_ring);
878 #endif
879 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
880 	mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
881 #endif
882 	kvm_arch_destroy_vm(kvm);
883 	mmdrop(mm);
884 }
885 
886 void kvm_get_kvm(struct kvm *kvm)
887 {
888 	atomic_inc(&kvm->users_count);
889 }
890 EXPORT_SYMBOL_GPL(kvm_get_kvm);
891 
892 void kvm_put_kvm(struct kvm *kvm)
893 {
894 	if (atomic_dec_and_test(&kvm->users_count))
895 		kvm_destroy_vm(kvm);
896 }
897 EXPORT_SYMBOL_GPL(kvm_put_kvm);
898 
899 
900 static int kvm_vm_release(struct inode *inode, struct file *filp)
901 {
902 	struct kvm *kvm = filp->private_data;
903 
904 	kvm_put_kvm(kvm);
905 	return 0;
906 }
907 
908 /*
909  * Allocate some memory and give it an address in the guest physical address
910  * space.
911  *
912  * Discontiguous memory is allowed, mostly for framebuffers.
913  *
914  * Must be called holding mmap_sem for write.
915  */
916 int __kvm_set_memory_region(struct kvm *kvm,
917 			    struct kvm_userspace_memory_region *mem,
918 			    int user_alloc)
919 {
920 	int r;
921 	gfn_t base_gfn;
922 	unsigned long npages;
923 	int largepages;
924 	unsigned long i;
925 	struct kvm_memory_slot *memslot;
926 	struct kvm_memory_slot old, new;
927 
928 	r = -EINVAL;
929 	/* General sanity checks */
930 	if (mem->memory_size & (PAGE_SIZE - 1))
931 		goto out;
932 	if (mem->guest_phys_addr & (PAGE_SIZE - 1))
933 		goto out;
934 	if (user_alloc && (mem->userspace_addr & (PAGE_SIZE - 1)))
935 		goto out;
936 	if (mem->slot >= KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS)
937 		goto out;
938 	if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
939 		goto out;
940 
941 	memslot = &kvm->memslots[mem->slot];
942 	base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
943 	npages = mem->memory_size >> PAGE_SHIFT;
944 
945 	if (!npages)
946 		mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
947 
948 	new = old = *memslot;
949 
950 	new.base_gfn = base_gfn;
951 	new.npages = npages;
952 	new.flags = mem->flags;
953 
954 	/* Disallow changing a memory slot's size. */
955 	r = -EINVAL;
956 	if (npages && old.npages && npages != old.npages)
957 		goto out_free;
958 
959 	/* Check for overlaps */
960 	r = -EEXIST;
961 	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
962 		struct kvm_memory_slot *s = &kvm->memslots[i];
963 
964 		if (s == memslot || !s->npages)
965 			continue;
966 		if (!((base_gfn + npages <= s->base_gfn) ||
967 		      (base_gfn >= s->base_gfn + s->npages)))
968 			goto out_free;
969 	}
970 
971 	/* Free page dirty bitmap if unneeded */
972 	if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
973 		new.dirty_bitmap = NULL;
974 
975 	r = -ENOMEM;
976 
977 	/* Allocate if a slot is being created */
978 #ifndef CONFIG_S390
979 	if (npages && !new.rmap) {
980 		new.rmap = vmalloc(npages * sizeof(struct page *));
981 
982 		if (!new.rmap)
983 			goto out_free;
984 
985 		memset(new.rmap, 0, npages * sizeof(*new.rmap));
986 
987 		new.user_alloc = user_alloc;
988 		/*
989 		 * hva_to_rmmap() serialzies with the mmu_lock and to be
990 		 * safe it has to ignore memslots with !user_alloc &&
991 		 * !userspace_addr.
992 		 */
993 		if (user_alloc)
994 			new.userspace_addr = mem->userspace_addr;
995 		else
996 			new.userspace_addr = 0;
997 	}
998 	if (npages && !new.lpage_info) {
999 		largepages = 1 + (base_gfn + npages - 1) / KVM_PAGES_PER_HPAGE;
1000 		largepages -= base_gfn / KVM_PAGES_PER_HPAGE;
1001 
1002 		new.lpage_info = vmalloc(largepages * sizeof(*new.lpage_info));
1003 
1004 		if (!new.lpage_info)
1005 			goto out_free;
1006 
1007 		memset(new.lpage_info, 0, largepages * sizeof(*new.lpage_info));
1008 
1009 		if (base_gfn % KVM_PAGES_PER_HPAGE)
1010 			new.lpage_info[0].write_count = 1;
1011 		if ((base_gfn+npages) % KVM_PAGES_PER_HPAGE)
1012 			new.lpage_info[largepages-1].write_count = 1;
1013 	}
1014 
1015 	/* Allocate page dirty bitmap if needed */
1016 	if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
1017 		unsigned dirty_bytes = ALIGN(npages, BITS_PER_LONG) / 8;
1018 
1019 		new.dirty_bitmap = vmalloc(dirty_bytes);
1020 		if (!new.dirty_bitmap)
1021 			goto out_free;
1022 		memset(new.dirty_bitmap, 0, dirty_bytes);
1023 	}
1024 #endif /* not defined CONFIG_S390 */
1025 
1026 	if (!npages)
1027 		kvm_arch_flush_shadow(kvm);
1028 
1029 	spin_lock(&kvm->mmu_lock);
1030 	if (mem->slot >= kvm->nmemslots)
1031 		kvm->nmemslots = mem->slot + 1;
1032 
1033 	*memslot = new;
1034 	spin_unlock(&kvm->mmu_lock);
1035 
1036 	r = kvm_arch_set_memory_region(kvm, mem, old, user_alloc);
1037 	if (r) {
1038 		spin_lock(&kvm->mmu_lock);
1039 		*memslot = old;
1040 		spin_unlock(&kvm->mmu_lock);
1041 		goto out_free;
1042 	}
1043 
1044 	kvm_free_physmem_slot(&old, npages ? &new : NULL);
1045 	/* Slot deletion case: we have to update the current slot */
1046 	if (!npages)
1047 		*memslot = old;
1048 #ifdef CONFIG_DMAR
1049 	/* map the pages in iommu page table */
1050 	r = kvm_iommu_map_pages(kvm, base_gfn, npages);
1051 	if (r)
1052 		goto out;
1053 #endif
1054 	return 0;
1055 
1056 out_free:
1057 	kvm_free_physmem_slot(&new, &old);
1058 out:
1059 	return r;
1060 
1061 }
1062 EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
1063 
1064 int kvm_set_memory_region(struct kvm *kvm,
1065 			  struct kvm_userspace_memory_region *mem,
1066 			  int user_alloc)
1067 {
1068 	int r;
1069 
1070 	down_write(&kvm->slots_lock);
1071 	r = __kvm_set_memory_region(kvm, mem, user_alloc);
1072 	up_write(&kvm->slots_lock);
1073 	return r;
1074 }
1075 EXPORT_SYMBOL_GPL(kvm_set_memory_region);
1076 
1077 int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
1078 				   struct
1079 				   kvm_userspace_memory_region *mem,
1080 				   int user_alloc)
1081 {
1082 	if (mem->slot >= KVM_MEMORY_SLOTS)
1083 		return -EINVAL;
1084 	return kvm_set_memory_region(kvm, mem, user_alloc);
1085 }
1086 
1087 int kvm_get_dirty_log(struct kvm *kvm,
1088 			struct kvm_dirty_log *log, int *is_dirty)
1089 {
1090 	struct kvm_memory_slot *memslot;
1091 	int r, i;
1092 	int n;
1093 	unsigned long any = 0;
1094 
1095 	r = -EINVAL;
1096 	if (log->slot >= KVM_MEMORY_SLOTS)
1097 		goto out;
1098 
1099 	memslot = &kvm->memslots[log->slot];
1100 	r = -ENOENT;
1101 	if (!memslot->dirty_bitmap)
1102 		goto out;
1103 
1104 	n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
1105 
1106 	for (i = 0; !any && i < n/sizeof(long); ++i)
1107 		any = memslot->dirty_bitmap[i];
1108 
1109 	r = -EFAULT;
1110 	if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
1111 		goto out;
1112 
1113 	if (any)
1114 		*is_dirty = 1;
1115 
1116 	r = 0;
1117 out:
1118 	return r;
1119 }
1120 
1121 int is_error_page(struct page *page)
1122 {
1123 	return page == bad_page;
1124 }
1125 EXPORT_SYMBOL_GPL(is_error_page);
1126 
1127 int is_error_pfn(pfn_t pfn)
1128 {
1129 	return pfn == bad_pfn;
1130 }
1131 EXPORT_SYMBOL_GPL(is_error_pfn);
1132 
1133 static inline unsigned long bad_hva(void)
1134 {
1135 	return PAGE_OFFSET;
1136 }
1137 
1138 int kvm_is_error_hva(unsigned long addr)
1139 {
1140 	return addr == bad_hva();
1141 }
1142 EXPORT_SYMBOL_GPL(kvm_is_error_hva);
1143 
1144 struct kvm_memory_slot *gfn_to_memslot_unaliased(struct kvm *kvm, gfn_t gfn)
1145 {
1146 	int i;
1147 
1148 	for (i = 0; i < kvm->nmemslots; ++i) {
1149 		struct kvm_memory_slot *memslot = &kvm->memslots[i];
1150 
1151 		if (gfn >= memslot->base_gfn
1152 		    && gfn < memslot->base_gfn + memslot->npages)
1153 			return memslot;
1154 	}
1155 	return NULL;
1156 }
1157 EXPORT_SYMBOL_GPL(gfn_to_memslot_unaliased);
1158 
1159 struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
1160 {
1161 	gfn = unalias_gfn(kvm, gfn);
1162 	return gfn_to_memslot_unaliased(kvm, gfn);
1163 }
1164 
1165 int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
1166 {
1167 	int i;
1168 
1169 	gfn = unalias_gfn(kvm, gfn);
1170 	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
1171 		struct kvm_memory_slot *memslot = &kvm->memslots[i];
1172 
1173 		if (gfn >= memslot->base_gfn
1174 		    && gfn < memslot->base_gfn + memslot->npages)
1175 			return 1;
1176 	}
1177 	return 0;
1178 }
1179 EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
1180 
1181 unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
1182 {
1183 	struct kvm_memory_slot *slot;
1184 
1185 	gfn = unalias_gfn(kvm, gfn);
1186 	slot = gfn_to_memslot_unaliased(kvm, gfn);
1187 	if (!slot)
1188 		return bad_hva();
1189 	return (slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE);
1190 }
1191 EXPORT_SYMBOL_GPL(gfn_to_hva);
1192 
1193 pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
1194 {
1195 	struct page *page[1];
1196 	unsigned long addr;
1197 	int npages;
1198 	pfn_t pfn;
1199 
1200 	might_sleep();
1201 
1202 	addr = gfn_to_hva(kvm, gfn);
1203 	if (kvm_is_error_hva(addr)) {
1204 		get_page(bad_page);
1205 		return page_to_pfn(bad_page);
1206 	}
1207 
1208 	npages = get_user_pages_fast(addr, 1, 1, page);
1209 
1210 	if (unlikely(npages != 1)) {
1211 		struct vm_area_struct *vma;
1212 
1213 		down_read(&current->mm->mmap_sem);
1214 		vma = find_vma(current->mm, addr);
1215 
1216 		if (vma == NULL || addr < vma->vm_start ||
1217 		    !(vma->vm_flags & VM_PFNMAP)) {
1218 			up_read(&current->mm->mmap_sem);
1219 			get_page(bad_page);
1220 			return page_to_pfn(bad_page);
1221 		}
1222 
1223 		pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
1224 		up_read(&current->mm->mmap_sem);
1225 		BUG_ON(!kvm_is_mmio_pfn(pfn));
1226 	} else
1227 		pfn = page_to_pfn(page[0]);
1228 
1229 	return pfn;
1230 }
1231 
1232 EXPORT_SYMBOL_GPL(gfn_to_pfn);
1233 
1234 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
1235 {
1236 	pfn_t pfn;
1237 
1238 	pfn = gfn_to_pfn(kvm, gfn);
1239 	if (!kvm_is_mmio_pfn(pfn))
1240 		return pfn_to_page(pfn);
1241 
1242 	WARN_ON(kvm_is_mmio_pfn(pfn));
1243 
1244 	get_page(bad_page);
1245 	return bad_page;
1246 }
1247 
1248 EXPORT_SYMBOL_GPL(gfn_to_page);
1249 
1250 void kvm_release_page_clean(struct page *page)
1251 {
1252 	kvm_release_pfn_clean(page_to_pfn(page));
1253 }
1254 EXPORT_SYMBOL_GPL(kvm_release_page_clean);
1255 
1256 void kvm_release_pfn_clean(pfn_t pfn)
1257 {
1258 	if (!kvm_is_mmio_pfn(pfn))
1259 		put_page(pfn_to_page(pfn));
1260 }
1261 EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
1262 
1263 void kvm_release_page_dirty(struct page *page)
1264 {
1265 	kvm_release_pfn_dirty(page_to_pfn(page));
1266 }
1267 EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
1268 
1269 void kvm_release_pfn_dirty(pfn_t pfn)
1270 {
1271 	kvm_set_pfn_dirty(pfn);
1272 	kvm_release_pfn_clean(pfn);
1273 }
1274 EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
1275 
1276 void kvm_set_page_dirty(struct page *page)
1277 {
1278 	kvm_set_pfn_dirty(page_to_pfn(page));
1279 }
1280 EXPORT_SYMBOL_GPL(kvm_set_page_dirty);
1281 
1282 void kvm_set_pfn_dirty(pfn_t pfn)
1283 {
1284 	if (!kvm_is_mmio_pfn(pfn)) {
1285 		struct page *page = pfn_to_page(pfn);
1286 		if (!PageReserved(page))
1287 			SetPageDirty(page);
1288 	}
1289 }
1290 EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
1291 
1292 void kvm_set_pfn_accessed(pfn_t pfn)
1293 {
1294 	if (!kvm_is_mmio_pfn(pfn))
1295 		mark_page_accessed(pfn_to_page(pfn));
1296 }
1297 EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
1298 
1299 void kvm_get_pfn(pfn_t pfn)
1300 {
1301 	if (!kvm_is_mmio_pfn(pfn))
1302 		get_page(pfn_to_page(pfn));
1303 }
1304 EXPORT_SYMBOL_GPL(kvm_get_pfn);
1305 
1306 static int next_segment(unsigned long len, int offset)
1307 {
1308 	if (len > PAGE_SIZE - offset)
1309 		return PAGE_SIZE - offset;
1310 	else
1311 		return len;
1312 }
1313 
1314 int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
1315 			int len)
1316 {
1317 	int r;
1318 	unsigned long addr;
1319 
1320 	addr = gfn_to_hva(kvm, gfn);
1321 	if (kvm_is_error_hva(addr))
1322 		return -EFAULT;
1323 	r = copy_from_user(data, (void __user *)addr + offset, len);
1324 	if (r)
1325 		return -EFAULT;
1326 	return 0;
1327 }
1328 EXPORT_SYMBOL_GPL(kvm_read_guest_page);
1329 
1330 int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
1331 {
1332 	gfn_t gfn = gpa >> PAGE_SHIFT;
1333 	int seg;
1334 	int offset = offset_in_page(gpa);
1335 	int ret;
1336 
1337 	while ((seg = next_segment(len, offset)) != 0) {
1338 		ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
1339 		if (ret < 0)
1340 			return ret;
1341 		offset = 0;
1342 		len -= seg;
1343 		data += seg;
1344 		++gfn;
1345 	}
1346 	return 0;
1347 }
1348 EXPORT_SYMBOL_GPL(kvm_read_guest);
1349 
1350 int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
1351 			  unsigned long len)
1352 {
1353 	int r;
1354 	unsigned long addr;
1355 	gfn_t gfn = gpa >> PAGE_SHIFT;
1356 	int offset = offset_in_page(gpa);
1357 
1358 	addr = gfn_to_hva(kvm, gfn);
1359 	if (kvm_is_error_hva(addr))
1360 		return -EFAULT;
1361 	pagefault_disable();
1362 	r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
1363 	pagefault_enable();
1364 	if (r)
1365 		return -EFAULT;
1366 	return 0;
1367 }
1368 EXPORT_SYMBOL(kvm_read_guest_atomic);
1369 
1370 int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
1371 			 int offset, int len)
1372 {
1373 	int r;
1374 	unsigned long addr;
1375 
1376 	addr = gfn_to_hva(kvm, gfn);
1377 	if (kvm_is_error_hva(addr))
1378 		return -EFAULT;
1379 	r = copy_to_user((void __user *)addr + offset, data, len);
1380 	if (r)
1381 		return -EFAULT;
1382 	mark_page_dirty(kvm, gfn);
1383 	return 0;
1384 }
1385 EXPORT_SYMBOL_GPL(kvm_write_guest_page);
1386 
1387 int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
1388 		    unsigned long len)
1389 {
1390 	gfn_t gfn = gpa >> PAGE_SHIFT;
1391 	int seg;
1392 	int offset = offset_in_page(gpa);
1393 	int ret;
1394 
1395 	while ((seg = next_segment(len, offset)) != 0) {
1396 		ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
1397 		if (ret < 0)
1398 			return ret;
1399 		offset = 0;
1400 		len -= seg;
1401 		data += seg;
1402 		++gfn;
1403 	}
1404 	return 0;
1405 }
1406 
1407 int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
1408 {
1409 	return kvm_write_guest_page(kvm, gfn, empty_zero_page, offset, len);
1410 }
1411 EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
1412 
1413 int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
1414 {
1415 	gfn_t gfn = gpa >> PAGE_SHIFT;
1416 	int seg;
1417 	int offset = offset_in_page(gpa);
1418 	int ret;
1419 
1420         while ((seg = next_segment(len, offset)) != 0) {
1421 		ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
1422 		if (ret < 0)
1423 			return ret;
1424 		offset = 0;
1425 		len -= seg;
1426 		++gfn;
1427 	}
1428 	return 0;
1429 }
1430 EXPORT_SYMBOL_GPL(kvm_clear_guest);
1431 
1432 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
1433 {
1434 	struct kvm_memory_slot *memslot;
1435 
1436 	gfn = unalias_gfn(kvm, gfn);
1437 	memslot = gfn_to_memslot_unaliased(kvm, gfn);
1438 	if (memslot && memslot->dirty_bitmap) {
1439 		unsigned long rel_gfn = gfn - memslot->base_gfn;
1440 
1441 		/* avoid RMW */
1442 		if (!test_bit(rel_gfn, memslot->dirty_bitmap))
1443 			set_bit(rel_gfn, memslot->dirty_bitmap);
1444 	}
1445 }
1446 
1447 /*
1448  * The vCPU has executed a HLT instruction with in-kernel mode enabled.
1449  */
1450 void kvm_vcpu_block(struct kvm_vcpu *vcpu)
1451 {
1452 	DEFINE_WAIT(wait);
1453 
1454 	for (;;) {
1455 		prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
1456 
1457 		if (kvm_cpu_has_interrupt(vcpu) ||
1458 		    kvm_cpu_has_pending_timer(vcpu) ||
1459 		    kvm_arch_vcpu_runnable(vcpu)) {
1460 			set_bit(KVM_REQ_UNHALT, &vcpu->requests);
1461 			break;
1462 		}
1463 		if (signal_pending(current))
1464 			break;
1465 
1466 		vcpu_put(vcpu);
1467 		schedule();
1468 		vcpu_load(vcpu);
1469 	}
1470 
1471 	finish_wait(&vcpu->wq, &wait);
1472 }
1473 
1474 void kvm_resched(struct kvm_vcpu *vcpu)
1475 {
1476 	if (!need_resched())
1477 		return;
1478 	cond_resched();
1479 }
1480 EXPORT_SYMBOL_GPL(kvm_resched);
1481 
1482 static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1483 {
1484 	struct kvm_vcpu *vcpu = vma->vm_file->private_data;
1485 	struct page *page;
1486 
1487 	if (vmf->pgoff == 0)
1488 		page = virt_to_page(vcpu->run);
1489 #ifdef CONFIG_X86
1490 	else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
1491 		page = virt_to_page(vcpu->arch.pio_data);
1492 #endif
1493 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1494 	else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
1495 		page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
1496 #endif
1497 	else
1498 		return VM_FAULT_SIGBUS;
1499 	get_page(page);
1500 	vmf->page = page;
1501 	return 0;
1502 }
1503 
1504 static struct vm_operations_struct kvm_vcpu_vm_ops = {
1505 	.fault = kvm_vcpu_fault,
1506 };
1507 
1508 static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
1509 {
1510 	vma->vm_ops = &kvm_vcpu_vm_ops;
1511 	return 0;
1512 }
1513 
1514 static int kvm_vcpu_release(struct inode *inode, struct file *filp)
1515 {
1516 	struct kvm_vcpu *vcpu = filp->private_data;
1517 
1518 	kvm_put_kvm(vcpu->kvm);
1519 	return 0;
1520 }
1521 
1522 static struct file_operations kvm_vcpu_fops = {
1523 	.release        = kvm_vcpu_release,
1524 	.unlocked_ioctl = kvm_vcpu_ioctl,
1525 	.compat_ioctl   = kvm_vcpu_ioctl,
1526 	.mmap           = kvm_vcpu_mmap,
1527 };
1528 
1529 /*
1530  * Allocates an inode for the vcpu.
1531  */
1532 static int create_vcpu_fd(struct kvm_vcpu *vcpu)
1533 {
1534 	int fd = anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, 0);
1535 	if (fd < 0)
1536 		kvm_put_kvm(vcpu->kvm);
1537 	return fd;
1538 }
1539 
1540 /*
1541  * Creates some virtual cpus.  Good luck creating more than one.
1542  */
1543 static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
1544 {
1545 	int r;
1546 	struct kvm_vcpu *vcpu;
1547 
1548 	if (!valid_vcpu(n))
1549 		return -EINVAL;
1550 
1551 	vcpu = kvm_arch_vcpu_create(kvm, n);
1552 	if (IS_ERR(vcpu))
1553 		return PTR_ERR(vcpu);
1554 
1555 	preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
1556 
1557 	r = kvm_arch_vcpu_setup(vcpu);
1558 	if (r)
1559 		return r;
1560 
1561 	mutex_lock(&kvm->lock);
1562 	if (kvm->vcpus[n]) {
1563 		r = -EEXIST;
1564 		goto vcpu_destroy;
1565 	}
1566 	kvm->vcpus[n] = vcpu;
1567 	mutex_unlock(&kvm->lock);
1568 
1569 	/* Now it's all set up, let userspace reach it */
1570 	kvm_get_kvm(kvm);
1571 	r = create_vcpu_fd(vcpu);
1572 	if (r < 0)
1573 		goto unlink;
1574 	return r;
1575 
1576 unlink:
1577 	mutex_lock(&kvm->lock);
1578 	kvm->vcpus[n] = NULL;
1579 vcpu_destroy:
1580 	mutex_unlock(&kvm->lock);
1581 	kvm_arch_vcpu_destroy(vcpu);
1582 	return r;
1583 }
1584 
1585 static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
1586 {
1587 	if (sigset) {
1588 		sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
1589 		vcpu->sigset_active = 1;
1590 		vcpu->sigset = *sigset;
1591 	} else
1592 		vcpu->sigset_active = 0;
1593 	return 0;
1594 }
1595 
1596 static long kvm_vcpu_ioctl(struct file *filp,
1597 			   unsigned int ioctl, unsigned long arg)
1598 {
1599 	struct kvm_vcpu *vcpu = filp->private_data;
1600 	void __user *argp = (void __user *)arg;
1601 	int r;
1602 	struct kvm_fpu *fpu = NULL;
1603 	struct kvm_sregs *kvm_sregs = NULL;
1604 
1605 	if (vcpu->kvm->mm != current->mm)
1606 		return -EIO;
1607 	switch (ioctl) {
1608 	case KVM_RUN:
1609 		r = -EINVAL;
1610 		if (arg)
1611 			goto out;
1612 		r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
1613 		break;
1614 	case KVM_GET_REGS: {
1615 		struct kvm_regs *kvm_regs;
1616 
1617 		r = -ENOMEM;
1618 		kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
1619 		if (!kvm_regs)
1620 			goto out;
1621 		r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
1622 		if (r)
1623 			goto out_free1;
1624 		r = -EFAULT;
1625 		if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
1626 			goto out_free1;
1627 		r = 0;
1628 out_free1:
1629 		kfree(kvm_regs);
1630 		break;
1631 	}
1632 	case KVM_SET_REGS: {
1633 		struct kvm_regs *kvm_regs;
1634 
1635 		r = -ENOMEM;
1636 		kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
1637 		if (!kvm_regs)
1638 			goto out;
1639 		r = -EFAULT;
1640 		if (copy_from_user(kvm_regs, argp, sizeof(struct kvm_regs)))
1641 			goto out_free2;
1642 		r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
1643 		if (r)
1644 			goto out_free2;
1645 		r = 0;
1646 out_free2:
1647 		kfree(kvm_regs);
1648 		break;
1649 	}
1650 	case KVM_GET_SREGS: {
1651 		kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
1652 		r = -ENOMEM;
1653 		if (!kvm_sregs)
1654 			goto out;
1655 		r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs);
1656 		if (r)
1657 			goto out;
1658 		r = -EFAULT;
1659 		if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs)))
1660 			goto out;
1661 		r = 0;
1662 		break;
1663 	}
1664 	case KVM_SET_SREGS: {
1665 		kvm_sregs = kmalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
1666 		r = -ENOMEM;
1667 		if (!kvm_sregs)
1668 			goto out;
1669 		r = -EFAULT;
1670 		if (copy_from_user(kvm_sregs, argp, sizeof(struct kvm_sregs)))
1671 			goto out;
1672 		r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs);
1673 		if (r)
1674 			goto out;
1675 		r = 0;
1676 		break;
1677 	}
1678 	case KVM_GET_MP_STATE: {
1679 		struct kvm_mp_state mp_state;
1680 
1681 		r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
1682 		if (r)
1683 			goto out;
1684 		r = -EFAULT;
1685 		if (copy_to_user(argp, &mp_state, sizeof mp_state))
1686 			goto out;
1687 		r = 0;
1688 		break;
1689 	}
1690 	case KVM_SET_MP_STATE: {
1691 		struct kvm_mp_state mp_state;
1692 
1693 		r = -EFAULT;
1694 		if (copy_from_user(&mp_state, argp, sizeof mp_state))
1695 			goto out;
1696 		r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
1697 		if (r)
1698 			goto out;
1699 		r = 0;
1700 		break;
1701 	}
1702 	case KVM_TRANSLATE: {
1703 		struct kvm_translation tr;
1704 
1705 		r = -EFAULT;
1706 		if (copy_from_user(&tr, argp, sizeof tr))
1707 			goto out;
1708 		r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
1709 		if (r)
1710 			goto out;
1711 		r = -EFAULT;
1712 		if (copy_to_user(argp, &tr, sizeof tr))
1713 			goto out;
1714 		r = 0;
1715 		break;
1716 	}
1717 	case KVM_SET_GUEST_DEBUG: {
1718 		struct kvm_guest_debug dbg;
1719 
1720 		r = -EFAULT;
1721 		if (copy_from_user(&dbg, argp, sizeof dbg))
1722 			goto out;
1723 		r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg);
1724 		if (r)
1725 			goto out;
1726 		r = 0;
1727 		break;
1728 	}
1729 	case KVM_SET_SIGNAL_MASK: {
1730 		struct kvm_signal_mask __user *sigmask_arg = argp;
1731 		struct kvm_signal_mask kvm_sigmask;
1732 		sigset_t sigset, *p;
1733 
1734 		p = NULL;
1735 		if (argp) {
1736 			r = -EFAULT;
1737 			if (copy_from_user(&kvm_sigmask, argp,
1738 					   sizeof kvm_sigmask))
1739 				goto out;
1740 			r = -EINVAL;
1741 			if (kvm_sigmask.len != sizeof sigset)
1742 				goto out;
1743 			r = -EFAULT;
1744 			if (copy_from_user(&sigset, sigmask_arg->sigset,
1745 					   sizeof sigset))
1746 				goto out;
1747 			p = &sigset;
1748 		}
1749 		r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
1750 		break;
1751 	}
1752 	case KVM_GET_FPU: {
1753 		fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
1754 		r = -ENOMEM;
1755 		if (!fpu)
1756 			goto out;
1757 		r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
1758 		if (r)
1759 			goto out;
1760 		r = -EFAULT;
1761 		if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu)))
1762 			goto out;
1763 		r = 0;
1764 		break;
1765 	}
1766 	case KVM_SET_FPU: {
1767 		fpu = kmalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
1768 		r = -ENOMEM;
1769 		if (!fpu)
1770 			goto out;
1771 		r = -EFAULT;
1772 		if (copy_from_user(fpu, argp, sizeof(struct kvm_fpu)))
1773 			goto out;
1774 		r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
1775 		if (r)
1776 			goto out;
1777 		r = 0;
1778 		break;
1779 	}
1780 	default:
1781 		r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
1782 	}
1783 out:
1784 	kfree(fpu);
1785 	kfree(kvm_sregs);
1786 	return r;
1787 }
1788 
1789 static long kvm_vm_ioctl(struct file *filp,
1790 			   unsigned int ioctl, unsigned long arg)
1791 {
1792 	struct kvm *kvm = filp->private_data;
1793 	void __user *argp = (void __user *)arg;
1794 	int r;
1795 
1796 	if (kvm->mm != current->mm)
1797 		return -EIO;
1798 	switch (ioctl) {
1799 	case KVM_CREATE_VCPU:
1800 		r = kvm_vm_ioctl_create_vcpu(kvm, arg);
1801 		if (r < 0)
1802 			goto out;
1803 		break;
1804 	case KVM_SET_USER_MEMORY_REGION: {
1805 		struct kvm_userspace_memory_region kvm_userspace_mem;
1806 
1807 		r = -EFAULT;
1808 		if (copy_from_user(&kvm_userspace_mem, argp,
1809 						sizeof kvm_userspace_mem))
1810 			goto out;
1811 
1812 		r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem, 1);
1813 		if (r)
1814 			goto out;
1815 		break;
1816 	}
1817 	case KVM_GET_DIRTY_LOG: {
1818 		struct kvm_dirty_log log;
1819 
1820 		r = -EFAULT;
1821 		if (copy_from_user(&log, argp, sizeof log))
1822 			goto out;
1823 		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
1824 		if (r)
1825 			goto out;
1826 		break;
1827 	}
1828 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1829 	case KVM_REGISTER_COALESCED_MMIO: {
1830 		struct kvm_coalesced_mmio_zone zone;
1831 		r = -EFAULT;
1832 		if (copy_from_user(&zone, argp, sizeof zone))
1833 			goto out;
1834 		r = -ENXIO;
1835 		r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
1836 		if (r)
1837 			goto out;
1838 		r = 0;
1839 		break;
1840 	}
1841 	case KVM_UNREGISTER_COALESCED_MMIO: {
1842 		struct kvm_coalesced_mmio_zone zone;
1843 		r = -EFAULT;
1844 		if (copy_from_user(&zone, argp, sizeof zone))
1845 			goto out;
1846 		r = -ENXIO;
1847 		r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
1848 		if (r)
1849 			goto out;
1850 		r = 0;
1851 		break;
1852 	}
1853 #endif
1854 #ifdef KVM_CAP_DEVICE_ASSIGNMENT
1855 	case KVM_ASSIGN_PCI_DEVICE: {
1856 		struct kvm_assigned_pci_dev assigned_dev;
1857 
1858 		r = -EFAULT;
1859 		if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
1860 			goto out;
1861 		r = kvm_vm_ioctl_assign_device(kvm, &assigned_dev);
1862 		if (r)
1863 			goto out;
1864 		break;
1865 	}
1866 	case KVM_ASSIGN_IRQ: {
1867 		struct kvm_assigned_irq assigned_irq;
1868 
1869 		r = -EFAULT;
1870 		if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq))
1871 			goto out;
1872 		r = kvm_vm_ioctl_assign_irq(kvm, &assigned_irq);
1873 		if (r)
1874 			goto out;
1875 		break;
1876 	}
1877 #endif
1878 #ifdef KVM_CAP_DEVICE_DEASSIGNMENT
1879 	case KVM_DEASSIGN_PCI_DEVICE: {
1880 		struct kvm_assigned_pci_dev assigned_dev;
1881 
1882 		r = -EFAULT;
1883 		if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
1884 			goto out;
1885 		r = kvm_vm_ioctl_deassign_device(kvm, &assigned_dev);
1886 		if (r)
1887 			goto out;
1888 		break;
1889 	}
1890 #endif
1891 #ifdef KVM_CAP_IRQ_ROUTING
1892 	case KVM_SET_GSI_ROUTING: {
1893 		struct kvm_irq_routing routing;
1894 		struct kvm_irq_routing __user *urouting;
1895 		struct kvm_irq_routing_entry *entries;
1896 
1897 		r = -EFAULT;
1898 		if (copy_from_user(&routing, argp, sizeof(routing)))
1899 			goto out;
1900 		r = -EINVAL;
1901 		if (routing.nr >= KVM_MAX_IRQ_ROUTES)
1902 			goto out;
1903 		if (routing.flags)
1904 			goto out;
1905 		r = -ENOMEM;
1906 		entries = vmalloc(routing.nr * sizeof(*entries));
1907 		if (!entries)
1908 			goto out;
1909 		r = -EFAULT;
1910 		urouting = argp;
1911 		if (copy_from_user(entries, urouting->entries,
1912 				   routing.nr * sizeof(*entries)))
1913 			goto out_free_irq_routing;
1914 		r = kvm_set_irq_routing(kvm, entries, routing.nr,
1915 					routing.flags);
1916 	out_free_irq_routing:
1917 		vfree(entries);
1918 		break;
1919 	}
1920 #endif
1921 	default:
1922 		r = kvm_arch_vm_ioctl(filp, ioctl, arg);
1923 	}
1924 out:
1925 	return r;
1926 }
1927 
1928 static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1929 {
1930 	struct page *page[1];
1931 	unsigned long addr;
1932 	int npages;
1933 	gfn_t gfn = vmf->pgoff;
1934 	struct kvm *kvm = vma->vm_file->private_data;
1935 
1936 	addr = gfn_to_hva(kvm, gfn);
1937 	if (kvm_is_error_hva(addr))
1938 		return VM_FAULT_SIGBUS;
1939 
1940 	npages = get_user_pages(current, current->mm, addr, 1, 1, 0, page,
1941 				NULL);
1942 	if (unlikely(npages != 1))
1943 		return VM_FAULT_SIGBUS;
1944 
1945 	vmf->page = page[0];
1946 	return 0;
1947 }
1948 
1949 static struct vm_operations_struct kvm_vm_vm_ops = {
1950 	.fault = kvm_vm_fault,
1951 };
1952 
1953 static int kvm_vm_mmap(struct file *file, struct vm_area_struct *vma)
1954 {
1955 	vma->vm_ops = &kvm_vm_vm_ops;
1956 	return 0;
1957 }
1958 
1959 static struct file_operations kvm_vm_fops = {
1960 	.release        = kvm_vm_release,
1961 	.unlocked_ioctl = kvm_vm_ioctl,
1962 	.compat_ioctl   = kvm_vm_ioctl,
1963 	.mmap           = kvm_vm_mmap,
1964 };
1965 
1966 static int kvm_dev_ioctl_create_vm(void)
1967 {
1968 	int fd;
1969 	struct kvm *kvm;
1970 
1971 	kvm = kvm_create_vm();
1972 	if (IS_ERR(kvm))
1973 		return PTR_ERR(kvm);
1974 	fd = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, 0);
1975 	if (fd < 0)
1976 		kvm_put_kvm(kvm);
1977 
1978 	return fd;
1979 }
1980 
1981 static long kvm_dev_ioctl_check_extension_generic(long arg)
1982 {
1983 	switch (arg) {
1984 	case KVM_CAP_USER_MEMORY:
1985 	case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
1986 	case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
1987 		return 1;
1988 #ifdef CONFIG_HAVE_KVM_IRQCHIP
1989 	case KVM_CAP_IRQ_ROUTING:
1990 		return KVM_MAX_IRQ_ROUTES;
1991 #endif
1992 	default:
1993 		break;
1994 	}
1995 	return kvm_dev_ioctl_check_extension(arg);
1996 }
1997 
1998 static long kvm_dev_ioctl(struct file *filp,
1999 			  unsigned int ioctl, unsigned long arg)
2000 {
2001 	long r = -EINVAL;
2002 
2003 	switch (ioctl) {
2004 	case KVM_GET_API_VERSION:
2005 		r = -EINVAL;
2006 		if (arg)
2007 			goto out;
2008 		r = KVM_API_VERSION;
2009 		break;
2010 	case KVM_CREATE_VM:
2011 		r = -EINVAL;
2012 		if (arg)
2013 			goto out;
2014 		r = kvm_dev_ioctl_create_vm();
2015 		break;
2016 	case KVM_CHECK_EXTENSION:
2017 		r = kvm_dev_ioctl_check_extension_generic(arg);
2018 		break;
2019 	case KVM_GET_VCPU_MMAP_SIZE:
2020 		r = -EINVAL;
2021 		if (arg)
2022 			goto out;
2023 		r = PAGE_SIZE;     /* struct kvm_run */
2024 #ifdef CONFIG_X86
2025 		r += PAGE_SIZE;    /* pio data page */
2026 #endif
2027 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2028 		r += PAGE_SIZE;    /* coalesced mmio ring page */
2029 #endif
2030 		break;
2031 	case KVM_TRACE_ENABLE:
2032 	case KVM_TRACE_PAUSE:
2033 	case KVM_TRACE_DISABLE:
2034 		r = kvm_trace_ioctl(ioctl, arg);
2035 		break;
2036 	default:
2037 		return kvm_arch_dev_ioctl(filp, ioctl, arg);
2038 	}
2039 out:
2040 	return r;
2041 }
2042 
2043 static struct file_operations kvm_chardev_ops = {
2044 	.unlocked_ioctl = kvm_dev_ioctl,
2045 	.compat_ioctl   = kvm_dev_ioctl,
2046 };
2047 
2048 static struct miscdevice kvm_dev = {
2049 	KVM_MINOR,
2050 	"kvm",
2051 	&kvm_chardev_ops,
2052 };
2053 
2054 static void hardware_enable(void *junk)
2055 {
2056 	int cpu = raw_smp_processor_id();
2057 
2058 	if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
2059 		return;
2060 	cpumask_set_cpu(cpu, cpus_hardware_enabled);
2061 	kvm_arch_hardware_enable(NULL);
2062 }
2063 
2064 static void hardware_disable(void *junk)
2065 {
2066 	int cpu = raw_smp_processor_id();
2067 
2068 	if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
2069 		return;
2070 	cpumask_clear_cpu(cpu, cpus_hardware_enabled);
2071 	kvm_arch_hardware_disable(NULL);
2072 }
2073 
2074 static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
2075 			   void *v)
2076 {
2077 	int cpu = (long)v;
2078 
2079 	val &= ~CPU_TASKS_FROZEN;
2080 	switch (val) {
2081 	case CPU_DYING:
2082 		printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
2083 		       cpu);
2084 		hardware_disable(NULL);
2085 		break;
2086 	case CPU_UP_CANCELED:
2087 		printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
2088 		       cpu);
2089 		smp_call_function_single(cpu, hardware_disable, NULL, 1);
2090 		break;
2091 	case CPU_ONLINE:
2092 		printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
2093 		       cpu);
2094 		smp_call_function_single(cpu, hardware_enable, NULL, 1);
2095 		break;
2096 	}
2097 	return NOTIFY_OK;
2098 }
2099 
2100 
2101 asmlinkage void kvm_handle_fault_on_reboot(void)
2102 {
2103 	if (kvm_rebooting)
2104 		/* spin while reset goes on */
2105 		while (true)
2106 			;
2107 	/* Fault while not rebooting.  We want the trace. */
2108 	BUG();
2109 }
2110 EXPORT_SYMBOL_GPL(kvm_handle_fault_on_reboot);
2111 
2112 static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
2113 		      void *v)
2114 {
2115 	if (val == SYS_RESTART) {
2116 		/*
2117 		 * Some (well, at least mine) BIOSes hang on reboot if
2118 		 * in vmx root mode.
2119 		 */
2120 		printk(KERN_INFO "kvm: exiting hardware virtualization\n");
2121 		kvm_rebooting = true;
2122 		on_each_cpu(hardware_disable, NULL, 1);
2123 	}
2124 	return NOTIFY_OK;
2125 }
2126 
2127 static struct notifier_block kvm_reboot_notifier = {
2128 	.notifier_call = kvm_reboot,
2129 	.priority = 0,
2130 };
2131 
2132 void kvm_io_bus_init(struct kvm_io_bus *bus)
2133 {
2134 	memset(bus, 0, sizeof(*bus));
2135 }
2136 
2137 void kvm_io_bus_destroy(struct kvm_io_bus *bus)
2138 {
2139 	int i;
2140 
2141 	for (i = 0; i < bus->dev_count; i++) {
2142 		struct kvm_io_device *pos = bus->devs[i];
2143 
2144 		kvm_iodevice_destructor(pos);
2145 	}
2146 }
2147 
2148 struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus,
2149 					  gpa_t addr, int len, int is_write)
2150 {
2151 	int i;
2152 
2153 	for (i = 0; i < bus->dev_count; i++) {
2154 		struct kvm_io_device *pos = bus->devs[i];
2155 
2156 		if (pos->in_range(pos, addr, len, is_write))
2157 			return pos;
2158 	}
2159 
2160 	return NULL;
2161 }
2162 
2163 void kvm_io_bus_register_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev)
2164 {
2165 	BUG_ON(bus->dev_count > (NR_IOBUS_DEVS-1));
2166 
2167 	bus->devs[bus->dev_count++] = dev;
2168 }
2169 
2170 static struct notifier_block kvm_cpu_notifier = {
2171 	.notifier_call = kvm_cpu_hotplug,
2172 	.priority = 20, /* must be > scheduler priority */
2173 };
2174 
2175 static int vm_stat_get(void *_offset, u64 *val)
2176 {
2177 	unsigned offset = (long)_offset;
2178 	struct kvm *kvm;
2179 
2180 	*val = 0;
2181 	spin_lock(&kvm_lock);
2182 	list_for_each_entry(kvm, &vm_list, vm_list)
2183 		*val += *(u32 *)((void *)kvm + offset);
2184 	spin_unlock(&kvm_lock);
2185 	return 0;
2186 }
2187 
2188 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
2189 
2190 static int vcpu_stat_get(void *_offset, u64 *val)
2191 {
2192 	unsigned offset = (long)_offset;
2193 	struct kvm *kvm;
2194 	struct kvm_vcpu *vcpu;
2195 	int i;
2196 
2197 	*val = 0;
2198 	spin_lock(&kvm_lock);
2199 	list_for_each_entry(kvm, &vm_list, vm_list)
2200 		for (i = 0; i < KVM_MAX_VCPUS; ++i) {
2201 			vcpu = kvm->vcpus[i];
2202 			if (vcpu)
2203 				*val += *(u32 *)((void *)vcpu + offset);
2204 		}
2205 	spin_unlock(&kvm_lock);
2206 	return 0;
2207 }
2208 
2209 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
2210 
2211 static struct file_operations *stat_fops[] = {
2212 	[KVM_STAT_VCPU] = &vcpu_stat_fops,
2213 	[KVM_STAT_VM]   = &vm_stat_fops,
2214 };
2215 
2216 static void kvm_init_debug(void)
2217 {
2218 	struct kvm_stats_debugfs_item *p;
2219 
2220 	kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
2221 	for (p = debugfs_entries; p->name; ++p)
2222 		p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
2223 						(void *)(long)p->offset,
2224 						stat_fops[p->kind]);
2225 }
2226 
2227 static void kvm_exit_debug(void)
2228 {
2229 	struct kvm_stats_debugfs_item *p;
2230 
2231 	for (p = debugfs_entries; p->name; ++p)
2232 		debugfs_remove(p->dentry);
2233 	debugfs_remove(kvm_debugfs_dir);
2234 }
2235 
2236 static int kvm_suspend(struct sys_device *dev, pm_message_t state)
2237 {
2238 	hardware_disable(NULL);
2239 	return 0;
2240 }
2241 
2242 static int kvm_resume(struct sys_device *dev)
2243 {
2244 	hardware_enable(NULL);
2245 	return 0;
2246 }
2247 
2248 static struct sysdev_class kvm_sysdev_class = {
2249 	.name = "kvm",
2250 	.suspend = kvm_suspend,
2251 	.resume = kvm_resume,
2252 };
2253 
2254 static struct sys_device kvm_sysdev = {
2255 	.id = 0,
2256 	.cls = &kvm_sysdev_class,
2257 };
2258 
2259 struct page *bad_page;
2260 pfn_t bad_pfn;
2261 
2262 static inline
2263 struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
2264 {
2265 	return container_of(pn, struct kvm_vcpu, preempt_notifier);
2266 }
2267 
2268 static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
2269 {
2270 	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
2271 
2272 	kvm_arch_vcpu_load(vcpu, cpu);
2273 }
2274 
2275 static void kvm_sched_out(struct preempt_notifier *pn,
2276 			  struct task_struct *next)
2277 {
2278 	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
2279 
2280 	kvm_arch_vcpu_put(vcpu);
2281 }
2282 
2283 int kvm_init(void *opaque, unsigned int vcpu_size,
2284 		  struct module *module)
2285 {
2286 	int r;
2287 	int cpu;
2288 
2289 	kvm_init_debug();
2290 
2291 	r = kvm_arch_init(opaque);
2292 	if (r)
2293 		goto out_fail;
2294 
2295 	bad_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
2296 
2297 	if (bad_page == NULL) {
2298 		r = -ENOMEM;
2299 		goto out;
2300 	}
2301 
2302 	bad_pfn = page_to_pfn(bad_page);
2303 
2304 	if (!alloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
2305 		r = -ENOMEM;
2306 		goto out_free_0;
2307 	}
2308 
2309 	r = kvm_arch_hardware_setup();
2310 	if (r < 0)
2311 		goto out_free_0a;
2312 
2313 	for_each_online_cpu(cpu) {
2314 		smp_call_function_single(cpu,
2315 				kvm_arch_check_processor_compat,
2316 				&r, 1);
2317 		if (r < 0)
2318 			goto out_free_1;
2319 	}
2320 
2321 	on_each_cpu(hardware_enable, NULL, 1);
2322 	r = register_cpu_notifier(&kvm_cpu_notifier);
2323 	if (r)
2324 		goto out_free_2;
2325 	register_reboot_notifier(&kvm_reboot_notifier);
2326 
2327 	r = sysdev_class_register(&kvm_sysdev_class);
2328 	if (r)
2329 		goto out_free_3;
2330 
2331 	r = sysdev_register(&kvm_sysdev);
2332 	if (r)
2333 		goto out_free_4;
2334 
2335 	/* A kmem cache lets us meet the alignment requirements of fx_save. */
2336 	kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size,
2337 					   __alignof__(struct kvm_vcpu),
2338 					   0, NULL);
2339 	if (!kvm_vcpu_cache) {
2340 		r = -ENOMEM;
2341 		goto out_free_5;
2342 	}
2343 
2344 	kvm_chardev_ops.owner = module;
2345 	kvm_vm_fops.owner = module;
2346 	kvm_vcpu_fops.owner = module;
2347 
2348 	r = misc_register(&kvm_dev);
2349 	if (r) {
2350 		printk(KERN_ERR "kvm: misc device register failed\n");
2351 		goto out_free;
2352 	}
2353 
2354 	kvm_preempt_ops.sched_in = kvm_sched_in;
2355 	kvm_preempt_ops.sched_out = kvm_sched_out;
2356 #ifndef CONFIG_X86
2357 	msi2intx = 0;
2358 #endif
2359 
2360 	return 0;
2361 
2362 out_free:
2363 	kmem_cache_destroy(kvm_vcpu_cache);
2364 out_free_5:
2365 	sysdev_unregister(&kvm_sysdev);
2366 out_free_4:
2367 	sysdev_class_unregister(&kvm_sysdev_class);
2368 out_free_3:
2369 	unregister_reboot_notifier(&kvm_reboot_notifier);
2370 	unregister_cpu_notifier(&kvm_cpu_notifier);
2371 out_free_2:
2372 	on_each_cpu(hardware_disable, NULL, 1);
2373 out_free_1:
2374 	kvm_arch_hardware_unsetup();
2375 out_free_0a:
2376 	free_cpumask_var(cpus_hardware_enabled);
2377 out_free_0:
2378 	__free_page(bad_page);
2379 out:
2380 	kvm_arch_exit();
2381 	kvm_exit_debug();
2382 out_fail:
2383 	return r;
2384 }
2385 EXPORT_SYMBOL_GPL(kvm_init);
2386 
2387 void kvm_exit(void)
2388 {
2389 	kvm_trace_cleanup();
2390 	misc_deregister(&kvm_dev);
2391 	kmem_cache_destroy(kvm_vcpu_cache);
2392 	sysdev_unregister(&kvm_sysdev);
2393 	sysdev_class_unregister(&kvm_sysdev_class);
2394 	unregister_reboot_notifier(&kvm_reboot_notifier);
2395 	unregister_cpu_notifier(&kvm_cpu_notifier);
2396 	on_each_cpu(hardware_disable, NULL, 1);
2397 	kvm_arch_hardware_unsetup();
2398 	kvm_arch_exit();
2399 	kvm_exit_debug();
2400 	free_cpumask_var(cpus_hardware_enabled);
2401 	__free_page(bad_page);
2402 }
2403 EXPORT_SYMBOL_GPL(kvm_exit);
2404