1	// SPDX-License-Identifier: GPL-2.0-only
2	/*
3	* Kernel-based Virtual Machine driver for Linux
4	*
5	* This module enables machines with Intel VT-x extensions to run virtual
6	* machines without emulation or binary translation.
7	*
8	* Copyright (C) 2006 Qumranet, Inc.
9	* Copyright 2010 Red Hat, Inc. and/or its affiliates.
10	*
11	* Authors:
12	* Avi Kivity <avi@qumranet.com>
13	* Yaniv Kamay <yaniv@qumranet.com>
14	*/
15
16	#include <kvm/iodev.h>
17
18	#include <linux/kvm_host.h>
19	#include <linux/kvm.h>
20	#include <linux/module.h>
21	#include <linux/errno.h>
22	#include <linux/percpu.h>
23	#include <linux/mm.h>
24	#include <linux/miscdevice.h>
25	#include <linux/vmalloc.h>
26	#include <linux/reboot.h>
27	#include <linux/debugfs.h>
28	#include <linux/highmem.h>
29	#include <linux/file.h>
30	#include <linux/syscore_ops.h>
31	#include <linux/cpu.h>
32	#include <linux/sched/signal.h>
33	#include <linux/sched/mm.h>
34	#include <linux/sched/stat.h>
35	#include <linux/cpumask.h>
36	#include <linux/smp.h>
37	#include <linux/anon_inodes.h>
38	#include <linux/profile.h>
39	#include <linux/kvm_para.h>
40	#include <linux/pagemap.h>
41	#include <linux/mman.h>
42	#include <linux/swap.h>
43	#include <linux/bitops.h>
44	#include <linux/spinlock.h>
45	#include <linux/compat.h>
46	#include <linux/srcu.h>
47	#include <linux/hugetlb.h>
48	#include <linux/slab.h>
49	#include <linux/sort.h>
50	#include <linux/bsearch.h>
51	#include <linux/io.h>
52	#include <linux/lockdep.h>
53	#include <linux/kthread.h>
54	#include <linux/suspend.h>
55
56	#include <asm/processor.h>
57	#include <asm/ioctl.h>
58	#include <linux/uaccess.h>
59
60	#include "coalesced_mmio.h"
61	#include "async_pf.h"
62	#include "kvm_mm.h"
63	#include "vfio.h"
64
65	#include <trace/events/ipi.h>
66
67	#define CREATE_TRACE_POINTS
68	#include <trace/events/kvm.h>
69
70	#include <linux/kvm_dirty_ring.h>
71
72
73	/* Worst case buffer size needed for holding an integer. */
74	#define ITOA_MAX_LEN 12
75
76	MODULE_AUTHOR("Qumranet");
77	MODULE_LICENSE("GPL");
78
79	/* Architectures should define their poll value according to the halt latency */
80	unsigned int halt_poll_ns = KVM_HALT_POLL_NS_DEFAULT;
81	module_param(halt_poll_ns, uint, 0644);
82	EXPORT_SYMBOL_GPL(halt_poll_ns);
83
84	/* Default doubles per-vcpu halt_poll_ns. */
85	unsigned int halt_poll_ns_grow = 2;
86	module_param(halt_poll_ns_grow, uint, 0644);
87	EXPORT_SYMBOL_GPL(halt_poll_ns_grow);
88
89	/* The start value to grow halt_poll_ns from */
90	unsigned int halt_poll_ns_grow_start = 10000; /* 10us */
91	module_param(halt_poll_ns_grow_start, uint, 0644);
92	EXPORT_SYMBOL_GPL(halt_poll_ns_grow_start);
93
94	/* Default resets per-vcpu halt_poll_ns . */
95	unsigned int halt_poll_ns_shrink;
96	module_param(halt_poll_ns_shrink, uint, 0644);
97	EXPORT_SYMBOL_GPL(halt_poll_ns_shrink);
98
99	/*
100	* Ordering of locks:
101	*
102	* kvm->lock --> kvm->slots_lock --> kvm->irq_lock
103	*/
104
105	DEFINE_MUTEX(kvm_lock);
106	LIST_HEAD(vm_list);
107
108	static struct kmem_cache *kvm_vcpu_cache;
109
110	static __read_mostly struct preempt_ops kvm_preempt_ops;
111	static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_running_vcpu);
112
113	struct dentry *kvm_debugfs_dir;
114	EXPORT_SYMBOL_GPL(kvm_debugfs_dir);
115
116	static const struct file_operations stat_fops_per_vm;
117
118	static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
119	unsigned long arg);
120	#ifdef CONFIG_KVM_COMPAT
121	static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl,
122	unsigned long arg);
123	#define KVM_COMPAT(c) .compat_ioctl = (c)
124	#else
125	/*
126	* For architectures that don't implement a compat infrastructure,
127	* adopt a double line of defense:
128	* - Prevent a compat task from opening /dev/kvm
129	* - If the open has been done by a 64bit task, and the KVM fd
130	* passed to a compat task, let the ioctls fail.
131	*/
132	static long kvm_no_compat_ioctl(struct file *file, unsigned int ioctl,
133	unsigned long arg) { return -EINVAL; }
134
135	static int kvm_no_compat_open(struct inode *inode, struct file *file)
136	{
137	return is_compat_task() ? -ENODEV : 0;
138	}
139	#define KVM_COMPAT(c) .compat_ioctl = kvm_no_compat_ioctl, \
140	.open = kvm_no_compat_open
141	#endif
142	static int hardware_enable_all(void);
143	static void hardware_disable_all(void);
144
145	static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
146
147	#define KVM_EVENT_CREATE_VM 0
148	#define KVM_EVENT_DESTROY_VM 1
149	static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm);
150	static unsigned long long kvm_createvm_count;
151	static unsigned long long kvm_active_vms;
152
153	static DEFINE_PER_CPU(cpumask_var_t, cpu_kick_mask);
154
155	__weak void kvm_arch_guest_memory_reclaimed(struct kvm *kvm)
156	{
157	}
158
159	bool kvm_is_zone_device_page(struct page *page)
160	{
161	/*
162	* The metadata used by is_zone_device_page() to determine whether or
163	* not a page is ZONE_DEVICE is guaranteed to be valid if and only if
164	* the device has been pinned, e.g. by get_user_pages(). WARN if the
165	* page_count() is zero to help detect bad usage of this helper.
166	*/
167	if (WARN_ON_ONCE(!page_count(page)))
168	return false;
169
170	return is_zone_device_page(page);
171	}
172
173	/*
174	* Returns a 'struct page' if the pfn is "valid" and backed by a refcounted
175	* page, NULL otherwise. Note, the list of refcounted PG_reserved page types
176	* is likely incomplete, it has been compiled purely through people wanting to
177	* back guest with a certain type of memory and encountering issues.
178	*/
179	struct page *kvm_pfn_to_refcounted_page(kvm_pfn_t pfn)
180	{
181	struct page *page;
182
183	if (!pfn_valid(pfn))
184	return NULL;
185
186	page = pfn_to_page(pfn);
187	if (!PageReserved(page))
188	return page;
189
190	/* The ZERO_PAGE(s) is marked PG_reserved, but is refcounted. */
191	if (is_zero_pfn(pfn))
192	return page;
193
194	/*
195	* ZONE_DEVICE pages currently set PG_reserved, but from a refcounting
196	* perspective they are "normal" pages, albeit with slightly different
197	* usage rules.
198	*/
199	if (kvm_is_zone_device_page(page))
200	return page;
201
202	return NULL;
203	}
204
205	/*
206	* Switches to specified vcpu, until a matching vcpu_put()
207	*/
208	void vcpu_load(struct kvm_vcpu *vcpu)
209	{
210	int cpu = get_cpu();
211
212	__this_cpu_write(kvm_running_vcpu, vcpu);
213	preempt_notifier_register(notifier: &vcpu->preempt_notifier);
214	kvm_arch_vcpu_load(vcpu, cpu);
215	put_cpu();
216	}
217	EXPORT_SYMBOL_GPL(vcpu_load);
218
219	void vcpu_put(struct kvm_vcpu *vcpu)
220	{
221	preempt_disable();
222	kvm_arch_vcpu_put(vcpu);
223	preempt_notifier_unregister(notifier: &vcpu->preempt_notifier);
224	__this_cpu_write(kvm_running_vcpu, NULL);
225	preempt_enable();
226	}
227	EXPORT_SYMBOL_GPL(vcpu_put);
228
229	/* TODO: merge with kvm_arch_vcpu_should_kick */
230	static bool kvm_request_needs_ipi(struct kvm_vcpu *vcpu, unsigned req)
231	{
232	int mode = kvm_vcpu_exiting_guest_mode(vcpu);
233
234	/*
235	* We need to wait for the VCPU to reenable interrupts and get out of
236	* READING_SHADOW_PAGE_TABLES mode.
237	*/
238	if (req & KVM_REQUEST_WAIT)
239	return mode != OUTSIDE_GUEST_MODE;
240
241	/*
242	* Need to kick a running VCPU, but otherwise there is nothing to do.
243	*/
244	return mode == IN_GUEST_MODE;
245	}
246
247	static void ack_kick(void *_completed)
248	{
249	}
250
251	static inline bool kvm_kick_many_cpus(struct cpumask *cpus, bool wait)
252	{
253	if (cpumask_empty(srcp: cpus))
254	return false;
255
256	smp_call_function_many(mask: cpus, func: ack_kick, NULL, wait);
257	return true;
258	}
259
260	static void kvm_make_vcpu_request(struct kvm_vcpu *vcpu, unsigned int req,
261	struct cpumask *tmp, int current_cpu)
262	{
263	int cpu;
264
265	if (likely(!(req & KVM_REQUEST_NO_ACTION)))
266	__kvm_make_request(req, vcpu);
267
268	if (!(req & KVM_REQUEST_NO_WAKEUP) && kvm_vcpu_wake_up(vcpu))
269	return;
270
271	/*
272	* Note, the vCPU could get migrated to a different pCPU at any point
273	* after kvm_request_needs_ipi(), which could result in sending an IPI
274	* to the previous pCPU. But, that's OK because the purpose of the IPI
275	* is to ensure the vCPU returns to OUTSIDE_GUEST_MODE, which is
276	* satisfied if the vCPU migrates. Entering READING_SHADOW_PAGE_TABLES
277	* after this point is also OK, as the requirement is only that KVM wait
278	* for vCPUs that were reading SPTEs _before_ any changes were
279	* finalized. See kvm_vcpu_kick() for more details on handling requests.
280	*/
281	if (kvm_request_needs_ipi(vcpu, req)) {
282	cpu = READ_ONCE(vcpu->cpu);
283	if (cpu != -1 && cpu != current_cpu)
284	__cpumask_set_cpu(cpu, dstp: tmp);
285	}
286	}
287
288	bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req,
289	unsigned long *vcpu_bitmap)
290	{
291	struct kvm_vcpu *vcpu;
292	struct cpumask *cpus;
293	int i, me;
294	bool called;
295
296	me = get_cpu();
297
298	cpus = this_cpu_cpumask_var_ptr(cpu_kick_mask);
299	cpumask_clear(dstp: cpus);
300
301	for_each_set_bit(i, vcpu_bitmap, KVM_MAX_VCPUS) {
302	vcpu = kvm_get_vcpu(kvm, i);
303	if (!vcpu)
304	continue;
305	kvm_make_vcpu_request(vcpu, req, tmp: cpus, current_cpu: me);
306	}
307
308	called = kvm_kick_many_cpus(cpus, wait: !!(req & KVM_REQUEST_WAIT));
309	put_cpu();
310
311	return called;
312	}
313
314	bool kvm_make_all_cpus_request_except(struct kvm *kvm, unsigned int req,
315	struct kvm_vcpu *except)
316	{
317	struct kvm_vcpu *vcpu;
318	struct cpumask *cpus;
319	unsigned long i;
320	bool called;
321	int me;
322
323	me = get_cpu();
324
325	cpus = this_cpu_cpumask_var_ptr(cpu_kick_mask);
326	cpumask_clear(dstp: cpus);
327
328	kvm_for_each_vcpu(i, vcpu, kvm) {
329	if (vcpu == except)
330	continue;
331	kvm_make_vcpu_request(vcpu, req, tmp: cpus, current_cpu: me);
332	}
333
334	called = kvm_kick_many_cpus(cpus, wait: !!(req & KVM_REQUEST_WAIT));
335	put_cpu();
336
337	return called;
338	}
339
340	bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
341	{
342	return kvm_make_all_cpus_request_except(kvm, req, NULL);
343	}
344	EXPORT_SYMBOL_GPL(kvm_make_all_cpus_request);
345
346	void kvm_flush_remote_tlbs(struct kvm *kvm)
347	{
348	++kvm->stat.generic.remote_tlb_flush_requests;
349
350	/*
351	* We want to publish modifications to the page tables before reading
352	* mode. Pairs with a memory barrier in arch-specific code.
353	* - x86: smp_mb__after_srcu_read_unlock in vcpu_enter_guest
354	* and smp_mb in walk_shadow_page_lockless_begin/end.
355	* - powerpc: smp_mb in kvmppc_prepare_to_enter.
356	*
357	* There is already an smp_mb__after_atomic() before
358	* kvm_make_all_cpus_request() reads vcpu->mode. We reuse that
359	* barrier here.
360	*/
361	if (!kvm_arch_flush_remote_tlbs(kvm)
362	|| kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
363	++kvm->stat.generic.remote_tlb_flush;
364	}
365	EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs);
366
367	void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, u64 nr_pages)
368	{
369	if (!kvm_arch_flush_remote_tlbs_range(kvm, gfn, nr_pages))
370	return;
371
372	/*
373	* Fall back to a flushing entire TLBs if the architecture range-based
374	* TLB invalidation is unsupported or can't be performed for whatever
375	* reason.
376	*/
377	kvm_flush_remote_tlbs(kvm);
378	}
379
380	void kvm_flush_remote_tlbs_memslot(struct kvm *kvm,
381	const struct kvm_memory_slot *memslot)
382	{
383	/*
384	* All current use cases for flushing the TLBs for a specific memslot
385	* are related to dirty logging, and many do the TLB flush out of
386	* mmu_lock. The interaction between the various operations on memslot
387	* must be serialized by slots_locks to ensure the TLB flush from one
388	* operation is observed by any other operation on the same memslot.
389	*/
390	lockdep_assert_held(&kvm->slots_lock);
391	kvm_flush_remote_tlbs_range(kvm, gfn: memslot->base_gfn, nr_pages: memslot->npages);
392	}
393
394	static void kvm_flush_shadow_all(struct kvm *kvm)
395	{
396	kvm_arch_flush_shadow_all(kvm);
397	kvm_arch_guest_memory_reclaimed(kvm);
398	}
399
400	#ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
401	static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache *mc,
402	gfp_t gfp_flags)
403	{
404	gfp_flags |= mc->gfp_zero;
405
406	if (mc->kmem_cache)
407	return kmem_cache_alloc(cachep: mc->kmem_cache, flags: gfp_flags);
408	else
409	return (void *)__get_free_page(gfp_flags);
410	}
411
412	int __kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int capacity, int min)
413	{
414	gfp_t gfp = mc->gfp_custom ? mc->gfp_custom : GFP_KERNEL_ACCOUNT;
415	void *obj;
416
417	if (mc->nobjs >= min)
418	return 0;
419
420	if (unlikely(!mc->objects)) {
421	if (WARN_ON_ONCE(!capacity))
422	return -EIO;
423
424	mc->objects = kvmalloc_array(n: capacity, size: sizeof(void *), flags: gfp);
425	if (!mc->objects)
426	return -ENOMEM;
427
428	mc->capacity = capacity;
429	}
430
431	/* It is illegal to request a different capacity across topups. */
432	if (WARN_ON_ONCE(mc->capacity != capacity))
433	return -EIO;
434
435	while (mc->nobjs < mc->capacity) {
436	obj = mmu_memory_cache_alloc_obj(mc, gfp_flags: gfp);
437	if (!obj)
438	return mc->nobjs >= min ? 0 : -ENOMEM;
439	mc->objects[mc->nobjs++] = obj;
440	}
441	return 0;
442	}
443
444	int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min)
445	{
446	return __kvm_mmu_topup_memory_cache(mc, KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE, min);
447	}
448
449	int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache *mc)
450	{
451	return mc->nobjs;
452	}
453
454	void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
455	{
456	while (mc->nobjs) {
457	if (mc->kmem_cache)
458	kmem_cache_free(s: mc->kmem_cache, objp: mc->objects[--mc->nobjs]);
459	else
460	free_page((unsigned long)mc->objects[--mc->nobjs]);
461	}
462
463	kvfree(addr: mc->objects);
464
465	mc->objects = NULL;
466	mc->capacity = 0;
467	}
468
469	void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
470	{
471	void *p;
472
473	if (WARN_ON(!mc->nobjs))
474	p = mmu_memory_cache_alloc_obj(mc, GFP_ATOMIC | __GFP_ACCOUNT);
475	else
476	p = mc->objects[--mc->nobjs];
477	BUG_ON(!p);
478	return p;
479	}
480	#endif
481
482	static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
483	{
484	mutex_init(&vcpu->mutex);
485	vcpu->cpu = -1;
486	vcpu->kvm = kvm;
487	vcpu->vcpu_id = id;
488	vcpu->pid = NULL;
489	#ifndef __KVM_HAVE_ARCH_WQP
490	rcuwait_init(w: &vcpu->wait);
491	#endif
492	kvm_async_pf_vcpu_init(vcpu);
493
494	kvm_vcpu_set_in_spin_loop(vcpu, val: false);
495	kvm_vcpu_set_dy_eligible(vcpu, val: false);
496	vcpu->preempted = false;
497	vcpu->ready = false;
498	preempt_notifier_init(notifier: &vcpu->preempt_notifier, ops: &kvm_preempt_ops);
499	vcpu->last_used_slot = NULL;
500
501	/* Fill the stats id string for the vcpu */
502	snprintf(buf: vcpu->stats_id, size: sizeof(vcpu->stats_id), fmt: "kvm-%d/vcpu-%d",
503	task_pid_nr(current), id);
504	}
505
506	static void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
507	{
508	kvm_arch_vcpu_destroy(vcpu);
509	kvm_dirty_ring_free(ring: &vcpu->dirty_ring);
510
511	/*
512	* No need for rcu_read_lock as VCPU_RUN is the only place that changes
513	* the vcpu->pid pointer, and at destruction time all file descriptors
514	* are already gone.
515	*/
516	put_pid(rcu_dereference_protected(vcpu->pid, 1));
517
518	free_page((unsigned long)vcpu->run);
519	kmem_cache_free(s: kvm_vcpu_cache, objp: vcpu);
520	}
521
522	void kvm_destroy_vcpus(struct kvm *kvm)
523	{
524	unsigned long i;
525	struct kvm_vcpu *vcpu;
526
527	kvm_for_each_vcpu(i, vcpu, kvm) {
528	kvm_vcpu_destroy(vcpu);
529	xa_erase(&kvm->vcpu_array, index: i);
530	}
531
532	atomic_set(v: &kvm->online_vcpus, i: 0);
533	}
534	EXPORT_SYMBOL_GPL(kvm_destroy_vcpus);
535
536	#ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER
537	static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
538	{
539	return container_of(mn, struct kvm, mmu_notifier);
540	}
541
542	typedef bool (*gfn_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range);
543
544	typedef void (*on_lock_fn_t)(struct kvm *kvm);
545
546	struct kvm_mmu_notifier_range {
547	/*
548	* 64-bit addresses, as KVM notifiers can operate on host virtual
549	* addresses (unsigned long) and guest physical addresses (64-bit).
550	*/
551	u64 start;
552	u64 end;
553	union kvm_mmu_notifier_arg arg;
554	gfn_handler_t handler;
555	on_lock_fn_t on_lock;
556	bool flush_on_ret;
557	bool may_block;
558	};
559
560	/*
561	* The inner-most helper returns a tuple containing the return value from the
562	* arch- and action-specific handler, plus a flag indicating whether or not at
563	* least one memslot was found, i.e. if the handler found guest memory.
564	*
565	* Note, most notifiers are averse to booleans, so even though KVM tracks the
566	* return from arch code as a bool, outer helpers will cast it to an int. :-(
567	*/
568	typedef struct kvm_mmu_notifier_return {
569	bool ret;
570	bool found_memslot;
571	} kvm_mn_ret_t;
572
573	/*
574	* Use a dedicated stub instead of NULL to indicate that there is no callback
575	* function/handler. The compiler technically can't guarantee that a real
576	* function will have a non-zero address, and so it will generate code to
577	* check for !NULL, whereas comparing against a stub will be elided at compile
578	* time (unless the compiler is getting long in the tooth, e.g. gcc 4.9).
579	*/
580	static void kvm_null_fn(void)
581	{
582
583	}
584	#define IS_KVM_NULL_FN(fn) ((fn) == (void *)kvm_null_fn)
585
586	static const union kvm_mmu_notifier_arg KVM_MMU_NOTIFIER_NO_ARG;
587
588	/* Iterate over each memslot intersecting [start, last] (inclusive) range */
589	#define kvm_for_each_memslot_in_hva_range(node, slots, start, last) \
590	for (node = interval_tree_iter_first(&slots->hva_tree, start, last); \
591	node; \
592	node = interval_tree_iter_next(node, start, last)) \
593
594	static __always_inline kvm_mn_ret_t __kvm_handle_hva_range(struct kvm *kvm,
595	const struct kvm_mmu_notifier_range *range)
596	{
597	struct kvm_mmu_notifier_return r = {
598	.ret = false,
599	.found_memslot = false,
600	};
601	struct kvm_gfn_range gfn_range;
602	struct kvm_memory_slot *slot;
603	struct kvm_memslots *slots;
604	int i, idx;
605
606	if (WARN_ON_ONCE(range->end <= range->start))
607	return r;
608
609	/* A null handler is allowed if and only if on_lock() is provided. */
610	if (WARN_ON_ONCE(IS_KVM_NULL_FN(range->on_lock) &&
611	IS_KVM_NULL_FN(range->handler)))
612	return r;
613
614	idx = srcu_read_lock(ssp: &kvm->srcu);
615
616	for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) {
617	struct interval_tree_node *node;
618
619	slots = __kvm_memslots(kvm, as_id: i);
620	kvm_for_each_memslot_in_hva_range(node, slots,
621	range->start, range->end - 1) {
622	unsigned long hva_start, hva_end;
623
624	slot = container_of(node, struct kvm_memory_slot, hva_node[slots->node_idx]);
625	hva_start = max_t(unsigned long, range->start, slot->userspace_addr);
626	hva_end = min_t(unsigned long, range->end,
627	slot->userspace_addr + (slot->npages << PAGE_SHIFT));
628
629	/*
630	* To optimize for the likely case where the address
631	* range is covered by zero or one memslots, don't
632	* bother making these conditional (to avoid writes on
633	* the second or later invocation of the handler).
634	*/
635	gfn_range.arg = range->arg;
636	gfn_range.may_block = range->may_block;
637
638	/*
639	* {gfn(page) | page intersects with [hva_start, hva_end)} =
640	* {gfn_start, gfn_start+1, ..., gfn_end-1}.
641	*/
642	gfn_range.start = hva_to_gfn_memslot(hva: hva_start, slot);
643	gfn_range.end = hva_to_gfn_memslot(hva: hva_end + PAGE_SIZE - 1, slot);
644	gfn_range.slot = slot;
645
646	if (!r.found_memslot) {
647	r.found_memslot = true;
648	KVM_MMU_LOCK(kvm);
649	if (!IS_KVM_NULL_FN(range->on_lock))
650	range->on_lock(kvm);
651
652	if (IS_KVM_NULL_FN(range->handler))
653	break;
654	}
655	r.ret |= range->handler(kvm, &gfn_range);
656	}
657	}
658
659	if (range->flush_on_ret && r.ret)
660	kvm_flush_remote_tlbs(kvm);
661
662	if (r.found_memslot)
663	KVM_MMU_UNLOCK(kvm);
664
665	srcu_read_unlock(ssp: &kvm->srcu, idx);
666
667	return r;
668	}
669
670	static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn,
671	unsigned long start,
672	unsigned long end,
673	union kvm_mmu_notifier_arg arg,
674	gfn_handler_t handler)
675	{
676	struct kvm *kvm = mmu_notifier_to_kvm(mn);
677	const struct kvm_mmu_notifier_range range = {
678	.start = start,
679	.end = end,
680	.arg = arg,
681	.handler = handler,
682	.on_lock = (void *)kvm_null_fn,
683	.flush_on_ret = true,
684	.may_block = false,
685	};
686
687	return __kvm_handle_hva_range(kvm, range: &range).ret;
688	}
689
690	static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn,
691	unsigned long start,
692	unsigned long end,
693	gfn_handler_t handler)
694	{
695	struct kvm *kvm = mmu_notifier_to_kvm(mn);
696	const struct kvm_mmu_notifier_range range = {
697	.start = start,
698	.end = end,
699	.handler = handler,
700	.on_lock = (void *)kvm_null_fn,
701	.flush_on_ret = false,
702	.may_block = false,
703	};
704
705	return __kvm_handle_hva_range(kvm, range: &range).ret;
706	}
707
708	static bool kvm_change_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
709	{
710	/*
711	* Skipping invalid memslots is correct if and only change_pte() is
712	* surrounded by invalidate_range_{start,end}(), which is currently
713	* guaranteed by the primary MMU. If that ever changes, KVM needs to
714	* unmap the memslot instead of skipping the memslot to ensure that KVM
715	* doesn't hold references to the old PFN.
716	*/
717	WARN_ON_ONCE(!READ_ONCE(kvm->mn_active_invalidate_count));
718
719	if (range->slot->flags & KVM_MEMSLOT_INVALID)
720	return false;
721
722	return kvm_set_spte_gfn(kvm, range);
723	}
724
725	static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
726	struct mm_struct *mm,
727	unsigned long address,
728	pte_t pte)
729	{
730	struct kvm *kvm = mmu_notifier_to_kvm(mn);
731	const union kvm_mmu_notifier_arg arg = { .pte = pte };
732
733	trace_kvm_set_spte_hva(hva: address);
734
735	/*
736	* .change_pte() must be surrounded by .invalidate_range_{start,end}().
737	* If mmu_invalidate_in_progress is zero, then no in-progress
738	* invalidations, including this one, found a relevant memslot at
739	* start(); rechecking memslots here is unnecessary. Note, a false
740	* positive (count elevated by a different invalidation) is sub-optimal
741	* but functionally ok.
742	*/
743	WARN_ON_ONCE(!READ_ONCE(kvm->mn_active_invalidate_count));
744	if (!READ_ONCE(kvm->mmu_invalidate_in_progress))
745	return;
746
747	kvm_handle_hva_range(mn, start: address, end: address + 1, arg, handler: kvm_change_spte_gfn);
748	}
749
750	void kvm_mmu_invalidate_begin(struct kvm *kvm)
751	{
752	lockdep_assert_held_write(&kvm->mmu_lock);
753	/*
754	* The count increase must become visible at unlock time as no
755	* spte can be established without taking the mmu_lock and
756	* count is also read inside the mmu_lock critical section.
757	*/
758	kvm->mmu_invalidate_in_progress++;
759
760	if (likely(kvm->mmu_invalidate_in_progress == 1)) {
761	kvm->mmu_invalidate_range_start = INVALID_GPA;
762	kvm->mmu_invalidate_range_end = INVALID_GPA;
763	}
764	}
765
766	void kvm_mmu_invalidate_range_add(struct kvm *kvm, gfn_t start, gfn_t end)
767	{
768	lockdep_assert_held_write(&kvm->mmu_lock);
769
770	WARN_ON_ONCE(!kvm->mmu_invalidate_in_progress);
771
772	if (likely(kvm->mmu_invalidate_range_start == INVALID_GPA)) {
773	kvm->mmu_invalidate_range_start = start;
774	kvm->mmu_invalidate_range_end = end;
775	} else {
776	/*
777	* Fully tracking multiple concurrent ranges has diminishing
778	* returns. Keep things simple and just find the minimal range
779	* which includes the current and new ranges. As there won't be
780	* enough information to subtract a range after its invalidate
781	* completes, any ranges invalidated concurrently will
782	* accumulate and persist until all outstanding invalidates
783	* complete.
784	*/
785	kvm->mmu_invalidate_range_start =
786	min(kvm->mmu_invalidate_range_start, start);
787	kvm->mmu_invalidate_range_end =
788	max(kvm->mmu_invalidate_range_end, end);
789	}
790	}
791
792	bool kvm_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
793	{
794	kvm_mmu_invalidate_range_add(kvm, start: range->start, end: range->end);
795	return kvm_unmap_gfn_range(kvm, range);
796	}
797
798	static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
799	const struct mmu_notifier_range *range)
800	{
801	struct kvm *kvm = mmu_notifier_to_kvm(mn);
802	const struct kvm_mmu_notifier_range hva_range = {
803	.start = range->start,
804	.end = range->end,
805	.handler = kvm_mmu_unmap_gfn_range,
806	.on_lock = kvm_mmu_invalidate_begin,
807	.flush_on_ret = true,
808	.may_block = mmu_notifier_range_blockable(range),
809	};
810
811	trace_kvm_unmap_hva_range(start: range->start, end: range->end);
812
813	/*
814	* Prevent memslot modification between range_start() and range_end()
815	* so that conditionally locking provides the same result in both
816	* functions. Without that guarantee, the mmu_invalidate_in_progress
817	* adjustments will be imbalanced.
818	*
819	* Pairs with the decrement in range_end().
820	*/
821	spin_lock(lock: &kvm->mn_invalidate_lock);
822	kvm->mn_active_invalidate_count++;
823	spin_unlock(lock: &kvm->mn_invalidate_lock);
824
825	/*
826	* Invalidate pfn caches _before_ invalidating the secondary MMUs, i.e.
827	* before acquiring mmu_lock, to avoid holding mmu_lock while acquiring
828	* each cache's lock. There are relatively few caches in existence at
829	* any given time, and the caches themselves can check for hva overlap,
830	* i.e. don't need to rely on memslot overlap checks for performance.
831	* Because this runs without holding mmu_lock, the pfn caches must use
832	* mn_active_invalidate_count (see above) instead of
833	* mmu_invalidate_in_progress.
834	*/
835	gfn_to_pfn_cache_invalidate_start(kvm, start: range->start, end: range->end);
836
837	/*
838	* If one or more memslots were found and thus zapped, notify arch code
839	* that guest memory has been reclaimed. This needs to be done *after*
840	* dropping mmu_lock, as x86's reclaim path is slooooow.
841	*/
842	if (__kvm_handle_hva_range(kvm, range: &hva_range).found_memslot)
843	kvm_arch_guest_memory_reclaimed(kvm);
844
845	return 0;
846	}
847
848	void kvm_mmu_invalidate_end(struct kvm *kvm)
849	{
850	lockdep_assert_held_write(&kvm->mmu_lock);
851
852	/*
853	* This sequence increase will notify the kvm page fault that
854	* the page that is going to be mapped in the spte could have
855	* been freed.
856	*/
857	kvm->mmu_invalidate_seq++;
858	smp_wmb();
859	/*
860	* The above sequence increase must be visible before the
861	* below count decrease, which is ensured by the smp_wmb above
862	* in conjunction with the smp_rmb in mmu_invalidate_retry().
863	*/
864	kvm->mmu_invalidate_in_progress--;
865	KVM_BUG_ON(kvm->mmu_invalidate_in_progress < 0, kvm);
866
867	/*
868	* Assert that at least one range was added between start() and end().
869	* Not adding a range isn't fatal, but it is a KVM bug.
870	*/
871	WARN_ON_ONCE(kvm->mmu_invalidate_range_start == INVALID_GPA);
872	}
873
874	static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
875	const struct mmu_notifier_range *range)
876	{
877	struct kvm *kvm = mmu_notifier_to_kvm(mn);
878	const struct kvm_mmu_notifier_range hva_range = {
879	.start = range->start,
880	.end = range->end,
881	.handler = (void *)kvm_null_fn,
882	.on_lock = kvm_mmu_invalidate_end,
883	.flush_on_ret = false,
884	.may_block = mmu_notifier_range_blockable(range),
885	};
886	bool wake;
887
888	__kvm_handle_hva_range(kvm, range: &hva_range);
889
890	/* Pairs with the increment in range_start(). */
891	spin_lock(lock: &kvm->mn_invalidate_lock);
892	if (!WARN_ON_ONCE(!kvm->mn_active_invalidate_count))
893	--kvm->mn_active_invalidate_count;
894	wake = !kvm->mn_active_invalidate_count;
895	spin_unlock(lock: &kvm->mn_invalidate_lock);
896
897	/*
898	* There can only be one waiter, since the wait happens under
899	* slots_lock.
900	*/
901	if (wake)
902	rcuwait_wake_up(w: &kvm->mn_memslots_update_rcuwait);
903	}
904
905	static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
906	struct mm_struct *mm,
907	unsigned long start,
908	unsigned long end)
909	{
910	trace_kvm_age_hva(start, end);
911
912	return kvm_handle_hva_range(mn, start, end, arg: KVM_MMU_NOTIFIER_NO_ARG,
913	handler: kvm_age_gfn);
914	}
915
916	static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
917	struct mm_struct *mm,
918	unsigned long start,
919	unsigned long end)
920	{
921	trace_kvm_age_hva(start, end);
922
923	/*
924	* Even though we do not flush TLB, this will still adversely
925	* affect performance on pre-Haswell Intel EPT, where there is
926	* no EPT Access Bit to clear so that we have to tear down EPT
927	* tables instead. If we find this unacceptable, we can always
928	* add a parameter to kvm_age_hva so that it effectively doesn't
929	* do anything on clear_young.
930	*
931	* Also note that currently we never issue secondary TLB flushes
932	* from clear_young, leaving this job up to the regular system
933	* cadence. If we find this inaccurate, we might come up with a
934	* more sophisticated heuristic later.
935	*/
936	return kvm_handle_hva_range_no_flush(mn, start, end, handler: kvm_age_gfn);
937	}
938
939	static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
940	struct mm_struct *mm,
941	unsigned long address)
942	{
943	trace_kvm_test_age_hva(hva: address);
944
945	return kvm_handle_hva_range_no_flush(mn, start: address, end: address + 1,
946	handler: kvm_test_age_gfn);
947	}
948
949	static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
950	struct mm_struct *mm)
951	{
952	struct kvm *kvm = mmu_notifier_to_kvm(mn);
953	int idx;
954
955	idx = srcu_read_lock(ssp: &kvm->srcu);
956	kvm_flush_shadow_all(kvm);
957	srcu_read_unlock(ssp: &kvm->srcu, idx);
958	}
959
960	static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
961	.invalidate_range_start = kvm_mmu_notifier_invalidate_range_start,
962	.invalidate_range_end = kvm_mmu_notifier_invalidate_range_end,
963	.clear_flush_young = kvm_mmu_notifier_clear_flush_young,
964	.clear_young = kvm_mmu_notifier_clear_young,
965	.test_young = kvm_mmu_notifier_test_young,
966	.change_pte = kvm_mmu_notifier_change_pte,
967	.release = kvm_mmu_notifier_release,
968	};
969
970	static int kvm_init_mmu_notifier(struct kvm *kvm)
971	{
972	kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
973	return mmu_notifier_register(subscription: &kvm->mmu_notifier, current->mm);
974	}
975
976	#else /* !CONFIG_KVM_GENERIC_MMU_NOTIFIER */
977
978	static int kvm_init_mmu_notifier(struct kvm *kvm)
979	{
980	return 0;
981	}
982
983	#endif /* CONFIG_KVM_GENERIC_MMU_NOTIFIER */
984
985	#ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
986	static int kvm_pm_notifier_call(struct notifier_block *bl,
987	unsigned long state,
988	void *unused)
989	{
990	struct kvm *kvm = container_of(bl, struct kvm, pm_notifier);
991
992	return kvm_arch_pm_notifier(kvm, state);
993	}
994
995	static void kvm_init_pm_notifier(struct kvm *kvm)
996	{
997	kvm->pm_notifier.notifier_call = kvm_pm_notifier_call;
998	/* Suspend KVM before we suspend ftrace, RCU, etc. */
999	kvm->pm_notifier.priority = INT_MAX;
1000	register_pm_notifier(nb: &kvm->pm_notifier);
1001	}
1002
1003	static void kvm_destroy_pm_notifier(struct kvm *kvm)
1004	{
1005	unregister_pm_notifier(nb: &kvm->pm_notifier);
1006	}
1007	#else /* !CONFIG_HAVE_KVM_PM_NOTIFIER */
1008	static void kvm_init_pm_notifier(struct kvm *kvm)
1009	{
1010	}
1011
1012	static void kvm_destroy_pm_notifier(struct kvm *kvm)
1013	{
1014	}
1015	#endif /* CONFIG_HAVE_KVM_PM_NOTIFIER */
1016
1017	static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
1018	{
1019	if (!memslot->dirty_bitmap)
1020	return;
1021
1022	kvfree(addr: memslot->dirty_bitmap);
1023	memslot->dirty_bitmap = NULL;
1024	}
1025
1026	/* This does not remove the slot from struct kvm_memslots data structures */
1027	static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
1028	{
1029	if (slot->flags & KVM_MEM_GUEST_MEMFD)
1030	kvm_gmem_unbind(slot);
1031
1032	kvm_destroy_dirty_bitmap(memslot: slot);
1033
1034	kvm_arch_free_memslot(kvm, slot);
1035
1036	kfree(objp: slot);
1037	}
1038
1039	static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots)
1040	{
1041	struct hlist_node *idnode;
1042	struct kvm_memory_slot *memslot;
1043	int bkt;
1044
1045	/*
1046	* The same memslot objects live in both active and inactive sets,
1047	* arbitrarily free using index '1' so the second invocation of this
1048	* function isn't operating over a structure with dangling pointers
1049	* (even though this function isn't actually touching them).
1050	*/
1051	if (!slots->node_idx)
1052	return;
1053
1054	hash_for_each_safe(slots->id_hash, bkt, idnode, memslot, id_node[1])
1055	kvm_free_memslot(kvm, slot: memslot);
1056	}
1057
1058	static umode_t kvm_stats_debugfs_mode(const struct _kvm_stats_desc *pdesc)
1059	{
1060	switch (pdesc->desc.flags & KVM_STATS_TYPE_MASK) {
1061	case KVM_STATS_TYPE_INSTANT:
1062	return 0444;
1063	case KVM_STATS_TYPE_CUMULATIVE:
1064	case KVM_STATS_TYPE_PEAK:
1065	default:
1066	return 0644;
1067	}
1068	}
1069
1070
1071	static void kvm_destroy_vm_debugfs(struct kvm *kvm)
1072	{
1073	int i;
1074	int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc +
1075	kvm_vcpu_stats_header.num_desc;
1076
1077	if (IS_ERR(ptr: kvm->debugfs_dentry))
1078	return;
1079
1080	debugfs_remove_recursive(dentry: kvm->debugfs_dentry);
1081
1082	if (kvm->debugfs_stat_data) {
1083	for (i = 0; i < kvm_debugfs_num_entries; i++)
1084	kfree(objp: kvm->debugfs_stat_data[i]);
1085	kfree(objp: kvm->debugfs_stat_data);
1086	}
1087	}
1088
1089	static int kvm_create_vm_debugfs(struct kvm *kvm, const char *fdname)
1090	{
1091	static DEFINE_MUTEX(kvm_debugfs_lock);
1092	struct dentry *dent;
1093	char dir_name[ITOA_MAX_LEN * 2];
1094	struct kvm_stat_data *stat_data;
1095	const struct _kvm_stats_desc *pdesc;
1096	int i, ret = -ENOMEM;
1097	int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc +
1098	kvm_vcpu_stats_header.num_desc;
1099
1100	if (!debugfs_initialized())
1101	return 0;
1102
1103	snprintf(buf: dir_name, size: sizeof(dir_name), fmt: "%d-%s", task_pid_nr(current), fdname);
1104	mutex_lock(&kvm_debugfs_lock);
1105	dent = debugfs_lookup(name: dir_name, parent: kvm_debugfs_dir);
1106	if (dent) {
1107	pr_warn_ratelimited("KVM: debugfs: duplicate directory %s\n", dir_name);
1108	dput(dent);
1109	mutex_unlock(lock: &kvm_debugfs_lock);
1110	return 0;
1111	}
1112	dent = debugfs_create_dir(name: dir_name, parent: kvm_debugfs_dir);
1113	mutex_unlock(lock: &kvm_debugfs_lock);
1114	if (IS_ERR(ptr: dent))
1115	return 0;
1116
1117	kvm->debugfs_dentry = dent;
1118	kvm->debugfs_stat_data = kcalloc(n: kvm_debugfs_num_entries,
1119	size: sizeof(*kvm->debugfs_stat_data),
1120	GFP_KERNEL_ACCOUNT);
1121	if (!kvm->debugfs_stat_data)
1122	goto out_err;
1123
1124	for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) {
1125	pdesc = &kvm_vm_stats_desc[i];
1126	stat_data = kzalloc(size: sizeof(*stat_data), GFP_KERNEL_ACCOUNT);
1127	if (!stat_data)
1128	goto out_err;
1129
1130	stat_data->kvm = kvm;
1131	stat_data->desc = pdesc;
1132	stat_data->kind = KVM_STAT_VM;
1133	kvm->debugfs_stat_data[i] = stat_data;
1134	debugfs_create_file(name: pdesc->name, mode: kvm_stats_debugfs_mode(pdesc),
1135	parent: kvm->debugfs_dentry, data: stat_data,
1136	fops: &stat_fops_per_vm);
1137	}
1138
1139	for (i = 0; i < kvm_vcpu_stats_header.num_desc; ++i) {
1140	pdesc = &kvm_vcpu_stats_desc[i];
1141	stat_data = kzalloc(size: sizeof(*stat_data), GFP_KERNEL_ACCOUNT);
1142	if (!stat_data)
1143	goto out_err;
1144
1145	stat_data->kvm = kvm;
1146	stat_data->desc = pdesc;
1147	stat_data->kind = KVM_STAT_VCPU;
1148	kvm->debugfs_stat_data[i + kvm_vm_stats_header.num_desc] = stat_data;
1149	debugfs_create_file(name: pdesc->name, mode: kvm_stats_debugfs_mode(pdesc),
1150	parent: kvm->debugfs_dentry, data: stat_data,
1151	fops: &stat_fops_per_vm);
1152	}
1153
1154	kvm_arch_create_vm_debugfs(kvm);
1155	return 0;
1156	out_err:
1157	kvm_destroy_vm_debugfs(kvm);
1158	return ret;
1159	}
1160
1161	/*
1162	* Called after the VM is otherwise initialized, but just before adding it to
1163	* the vm_list.
1164	*/
1165	int __weak kvm_arch_post_init_vm(struct kvm *kvm)
1166	{
1167	return 0;
1168	}
1169
1170	/*
1171	* Called just after removing the VM from the vm_list, but before doing any
1172	* other destruction.
1173	*/
1174	void __weak kvm_arch_pre_destroy_vm(struct kvm *kvm)
1175	{
1176	}
1177
1178	/*
1179	* Called after per-vm debugfs created. When called kvm->debugfs_dentry should
1180	* be setup already, so we can create arch-specific debugfs entries under it.
1181	* Cleanup should be automatic done in kvm_destroy_vm_debugfs() recursively, so
1182	* a per-arch destroy interface is not needed.
1183	*/
1184	void __weak kvm_arch_create_vm_debugfs(struct kvm *kvm)
1185	{
1186	}
1187
1188	static struct kvm *kvm_create_vm(unsigned long type, const char *fdname)
1189	{
1190	struct kvm *kvm = kvm_arch_alloc_vm();
1191	struct kvm_memslots *slots;
1192	int r = -ENOMEM;
1193	int i, j;
1194
1195	if (!kvm)
1196	return ERR_PTR(error: -ENOMEM);
1197
1198	KVM_MMU_LOCK_INIT(kvm);
1199	mmgrab(current->mm);
1200	kvm->mm = current->mm;
1201	kvm_eventfd_init(kvm);
1202	mutex_init(&kvm->lock);
1203	mutex_init(&kvm->irq_lock);
1204	mutex_init(&kvm->slots_lock);
1205	mutex_init(&kvm->slots_arch_lock);
1206	spin_lock_init(&kvm->mn_invalidate_lock);
1207	rcuwait_init(w: &kvm->mn_memslots_update_rcuwait);
1208	xa_init(xa: &kvm->vcpu_array);
1209	#ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES
1210	xa_init(xa: &kvm->mem_attr_array);
1211	#endif
1212
1213	INIT_LIST_HEAD(list: &kvm->gpc_list);
1214	spin_lock_init(&kvm->gpc_lock);
1215
1216	INIT_LIST_HEAD(list: &kvm->devices);
1217	kvm->max_vcpus = KVM_MAX_VCPUS;
1218
1219	BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX);
1220
1221	/*
1222	* Force subsequent debugfs file creations to fail if the VM directory
1223	* is not created (by kvm_create_vm_debugfs()).
1224	*/
1225	kvm->debugfs_dentry = ERR_PTR(error: -ENOENT);
1226
1227	snprintf(buf: kvm->stats_id, size: sizeof(kvm->stats_id), fmt: "kvm-%d",
1228	task_pid_nr(current));
1229
1230	if (init_srcu_struct(&kvm->srcu))
1231	goto out_err_no_srcu;
1232	if (init_srcu_struct(&kvm->irq_srcu))
1233	goto out_err_no_irq_srcu;
1234
1235	refcount_set(r: &kvm->users_count, n: 1);
1236	for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) {
1237	for (j = 0; j < 2; j++) {
1238	slots = &kvm->__memslots[i][j];
1239
1240	atomic_long_set(v: &slots->last_used_slot, i: (unsigned long)NULL);
1241	slots->hva_tree = RB_ROOT_CACHED;
1242	slots->gfn_tree = RB_ROOT;
1243	hash_init(slots->id_hash);
1244	slots->node_idx = j;
1245
1246	/* Generations must be different for each address space. */
1247	slots->generation = i;
1248	}
1249
1250	rcu_assign_pointer(kvm->memslots[i], &kvm->__memslots[i][0]);
1251	}
1252
1253	for (i = 0; i < KVM_NR_BUSES; i++) {
1254	rcu_assign_pointer(kvm->buses[i],
1255	kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT));
1256	if (!kvm->buses[i])
1257	goto out_err_no_arch_destroy_vm;
1258	}
1259
1260	r = kvm_arch_init_vm(kvm, type);
1261	if (r)
1262	goto out_err_no_arch_destroy_vm;
1263
1264	r = hardware_enable_all();
1265	if (r)
1266	goto out_err_no_disable;
1267
1268	#ifdef CONFIG_HAVE_KVM_IRQCHIP
1269	INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
1270	#endif
1271
1272	r = kvm_init_mmu_notifier(kvm);
1273	if (r)
1274	goto out_err_no_mmu_notifier;
1275
1276	r = kvm_coalesced_mmio_init(kvm);
1277	if (r < 0)
1278	goto out_no_coalesced_mmio;
1279
1280	r = kvm_create_vm_debugfs(kvm, fdname);
1281	if (r)
1282	goto out_err_no_debugfs;
1283
1284	r = kvm_arch_post_init_vm(kvm);
1285	if (r)
1286	goto out_err;
1287
1288	mutex_lock(&kvm_lock);
1289	list_add(new: &kvm->vm_list, head: &vm_list);
1290	mutex_unlock(lock: &kvm_lock);
1291
1292	preempt_notifier_inc();
1293	kvm_init_pm_notifier(kvm);
1294
1295	return kvm;
1296
1297	out_err:
1298	kvm_destroy_vm_debugfs(kvm);
1299	out_err_no_debugfs:
1300	kvm_coalesced_mmio_free(kvm);
1301	out_no_coalesced_mmio:
1302	#ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER
1303	if (kvm->mmu_notifier.ops)
1304	mmu_notifier_unregister(subscription: &kvm->mmu_notifier, current->mm);
1305	#endif
1306	out_err_no_mmu_notifier:
1307	hardware_disable_all();
1308	out_err_no_disable:
1309	kvm_arch_destroy_vm(kvm);
1310	out_err_no_arch_destroy_vm:
1311	WARN_ON_ONCE(!refcount_dec_and_test(&kvm->users_count));
1312	for (i = 0; i < KVM_NR_BUSES; i++)
1313	kfree(objp: kvm_get_bus(kvm, idx: i));
1314	cleanup_srcu_struct(ssp: &kvm->irq_srcu);
1315	out_err_no_irq_srcu:
1316	cleanup_srcu_struct(ssp: &kvm->srcu);
1317	out_err_no_srcu:
1318	kvm_arch_free_vm(kvm);
1319	mmdrop(current->mm);
1320	return ERR_PTR(error: r);
1321	}
1322
1323	static void kvm_destroy_devices(struct kvm *kvm)
1324	{
1325	struct kvm_device *dev, *tmp;
1326
1327	/*
1328	* We do not need to take the kvm->lock here, because nobody else
1329	* has a reference to the struct kvm at this point and therefore
1330	* cannot access the devices list anyhow.
1331	*/
1332	list_for_each_entry_safe(dev, tmp, &kvm->devices, vm_node) {
1333	list_del(entry: &dev->vm_node);
1334	dev->ops->destroy(dev);
1335	}
1336	}
1337
1338	static void kvm_destroy_vm(struct kvm *kvm)
1339	{
1340	int i;
1341	struct mm_struct *mm = kvm->mm;
1342
1343	kvm_destroy_pm_notifier(kvm);
1344	kvm_uevent_notify_change(KVM_EVENT_DESTROY_VM, kvm);
1345	kvm_destroy_vm_debugfs(kvm);
1346	kvm_arch_sync_events(kvm);
1347	mutex_lock(&kvm_lock);
1348	list_del(entry: &kvm->vm_list);
1349	mutex_unlock(lock: &kvm_lock);
1350	kvm_arch_pre_destroy_vm(kvm);
1351
1352	kvm_free_irq_routing(kvm);
1353	for (i = 0; i < KVM_NR_BUSES; i++) {
1354	struct kvm_io_bus *bus = kvm_get_bus(kvm, idx: i);
1355
1356	if (bus)
1357	kvm_io_bus_destroy(bus);
1358	kvm->buses[i] = NULL;
1359	}
1360	kvm_coalesced_mmio_free(kvm);
1361	#ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER
1362	mmu_notifier_unregister(subscription: &kvm->mmu_notifier, mm: kvm->mm);
1363	/*
1364	* At this point, pending calls to invalidate_range_start()
1365	* have completed but no more MMU notifiers will run, so
1366	* mn_active_invalidate_count may remain unbalanced.
1367	* No threads can be waiting in kvm_swap_active_memslots() as the
1368	* last reference on KVM has been dropped, but freeing
1369	* memslots would deadlock without this manual intervention.
1370	*
1371	* If the count isn't unbalanced, i.e. KVM did NOT unregister its MMU
1372	* notifier between a start() and end(), then there shouldn't be any
1373	* in-progress invalidations.
1374	*/
1375	WARN_ON(rcuwait_active(&kvm->mn_memslots_update_rcuwait));
1376	if (kvm->mn_active_invalidate_count)
1377	kvm->mn_active_invalidate_count = 0;
1378	else
1379	WARN_ON(kvm->mmu_invalidate_in_progress);
1380	#else
1381	kvm_flush_shadow_all(kvm);
1382	#endif
1383	kvm_arch_destroy_vm(kvm);
1384	kvm_destroy_devices(kvm);
1385	for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) {
1386	kvm_free_memslots(kvm, slots: &kvm->__memslots[i][0]);
1387	kvm_free_memslots(kvm, slots: &kvm->__memslots[i][1]);
1388	}
1389	cleanup_srcu_struct(ssp: &kvm->irq_srcu);
1390	cleanup_srcu_struct(ssp: &kvm->srcu);
1391	#ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES
1392	xa_destroy(&kvm->mem_attr_array);
1393	#endif
1394	kvm_arch_free_vm(kvm);
1395	preempt_notifier_dec();
1396	hardware_disable_all();
1397	mmdrop(mm);
1398	}
1399
1400	void kvm_get_kvm(struct kvm *kvm)
1401	{
1402	refcount_inc(r: &kvm->users_count);
1403	}
1404	EXPORT_SYMBOL_GPL(kvm_get_kvm);
1405
1406	/*
1407	* Make sure the vm is not during destruction, which is a safe version of
1408	* kvm_get_kvm(). Return true if kvm referenced successfully, false otherwise.
1409	*/
1410	bool kvm_get_kvm_safe(struct kvm *kvm)
1411	{
1412	return refcount_inc_not_zero(r: &kvm->users_count);
1413	}
1414	EXPORT_SYMBOL_GPL(kvm_get_kvm_safe);
1415
1416	void kvm_put_kvm(struct kvm *kvm)
1417	{
1418	if (refcount_dec_and_test(r: &kvm->users_count))
1419	kvm_destroy_vm(kvm);
1420	}
1421	EXPORT_SYMBOL_GPL(kvm_put_kvm);
1422
1423	/*
1424	* Used to put a reference that was taken on behalf of an object associated
1425	* with a user-visible file descriptor, e.g. a vcpu or device, if installation
1426	* of the new file descriptor fails and the reference cannot be transferred to
1427	* its final owner. In such cases, the caller is still actively using @kvm and
1428	* will fail miserably if the refcount unexpectedly hits zero.
1429	*/
1430	void kvm_put_kvm_no_destroy(struct kvm *kvm)
1431	{
1432	WARN_ON(refcount_dec_and_test(&kvm->users_count));
1433	}
1434	EXPORT_SYMBOL_GPL(kvm_put_kvm_no_destroy);
1435
1436	static int kvm_vm_release(struct inode *inode, struct file *filp)
1437	{
1438	struct kvm *kvm = filp->private_data;
1439
1440	kvm_irqfd_release(kvm);
1441
1442	kvm_put_kvm(kvm);
1443	return 0;
1444	}
1445
1446	/*
1447	* Allocation size is twice as large as the actual dirty bitmap size.
1448	* See kvm_vm_ioctl_get_dirty_log() why this is needed.
1449	*/
1450	static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot *memslot)
1451	{
1452	unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(memslot);
1453
1454	memslot->dirty_bitmap = __vcalloc(n: 2, size: dirty_bytes, GFP_KERNEL_ACCOUNT);
1455	if (!memslot->dirty_bitmap)
1456	return -ENOMEM;
1457
1458	return 0;
1459	}
1460
1461	static struct kvm_memslots *kvm_get_inactive_memslots(struct kvm *kvm, int as_id)
1462	{
1463	struct kvm_memslots *active = __kvm_memslots(kvm, as_id);
1464	int node_idx_inactive = active->node_idx ^ 1;
1465
1466	return &kvm->__memslots[as_id][node_idx_inactive];
1467	}
1468
1469	/*
1470	* Helper to get the address space ID when one of memslot pointers may be NULL.
1471	* This also serves as a sanity that at least one of the pointers is non-NULL,
1472	* and that their address space IDs don't diverge.
1473	*/
1474	static int kvm_memslots_get_as_id(struct kvm_memory_slot *a,
1475	struct kvm_memory_slot *b)
1476	{
1477	if (WARN_ON_ONCE(!a && !b))
1478	return 0;
1479
1480	if (!a)
1481	return b->as_id;
1482	if (!b)
1483	return a->as_id;
1484
1485	WARN_ON_ONCE(a->as_id != b->as_id);
1486	return a->as_id;
1487	}
1488
1489	static void kvm_insert_gfn_node(struct kvm_memslots *slots,
1490	struct kvm_memory_slot *slot)
1491	{
1492	struct rb_root *gfn_tree = &slots->gfn_tree;
1493	struct rb_node **node, *parent;
1494	int idx = slots->node_idx;
1495
1496	parent = NULL;
1497	for (node = &gfn_tree->rb_node; *node; ) {
1498	struct kvm_memory_slot *tmp;
1499
1500	tmp = container_of(*node, struct kvm_memory_slot, gfn_node[idx]);
1501	parent = *node;
1502	if (slot->base_gfn < tmp->base_gfn)
1503	node = &(*node)->rb_left;
1504	else if (slot->base_gfn > tmp->base_gfn)
1505	node = &(*node)->rb_right;
1506	else
1507	BUG();
1508	}
1509
1510	rb_link_node(node: &slot->gfn_node[idx], parent, rb_link: node);
1511	rb_insert_color(&slot->gfn_node[idx], gfn_tree);
1512	}
1513
1514	static void kvm_erase_gfn_node(struct kvm_memslots *slots,
1515	struct kvm_memory_slot *slot)
1516	{
1517	rb_erase(&slot->gfn_node[slots->node_idx], &slots->gfn_tree);
1518	}
1519
1520	static void kvm_replace_gfn_node(struct kvm_memslots *slots,
1521	struct kvm_memory_slot *old,
1522	struct kvm_memory_slot *new)
1523	{
1524	int idx = slots->node_idx;
1525
1526	WARN_ON_ONCE(old->base_gfn != new->base_gfn);
1527
1528	rb_replace_node(victim: &old->gfn_node[idx], new: &new->gfn_node[idx],
1529	root: &slots->gfn_tree);
1530	}
1531
1532	/*
1533	* Replace @old with @new in the inactive memslots.
1534	*
1535	* With NULL @old this simply adds @new.
1536	* With NULL @new this simply removes @old.
1537	*
1538	* If @new is non-NULL its hva_node[slots_idx] range has to be set
1539	* appropriately.
1540	*/
1541	static void kvm_replace_memslot(struct kvm *kvm,
1542	struct kvm_memory_slot *old,
1543	struct kvm_memory_slot *new)
1544	{
1545	int as_id = kvm_memslots_get_as_id(a: old, b: new);
1546	struct kvm_memslots *slots = kvm_get_inactive_memslots(kvm, as_id);
1547	int idx = slots->node_idx;
1548
1549	if (old) {
1550	hash_del(node: &old->id_node[idx]);
1551	interval_tree_remove(node: &old->hva_node[idx], root: &slots->hva_tree);
1552
1553	if ((long)old == atomic_long_read(v: &slots->last_used_slot))
1554	atomic_long_set(v: &slots->last_used_slot, i: (long)new);
1555
1556	if (!new) {
1557	kvm_erase_gfn_node(slots, slot: old);
1558	return;
1559	}
1560	}
1561
1562	/*
1563	* Initialize @new's hva range. Do this even when replacing an @old
1564	* slot, kvm_copy_memslot() deliberately does not touch node data.
1565	*/
1566	new->hva_node[idx].start = new->userspace_addr;
1567	new->hva_node[idx].last = new->userspace_addr +
1568	(new->npages << PAGE_SHIFT) - 1;
1569
1570	/*
1571	* (Re)Add the new memslot. There is no O(1) interval_tree_replace(),
1572	* hva_node needs to be swapped with remove+insert even though hva can't
1573	* change when replacing an existing slot.
1574	*/
1575	hash_add(slots->id_hash, &new->id_node[idx], new->id);
1576	interval_tree_insert(node: &new->hva_node[idx], root: &slots->hva_tree);
1577
1578	/*
1579	* If the memslot gfn is unchanged, rb_replace_node() can be used to
1580	* switch the node in the gfn tree instead of removing the old and
1581	* inserting the new as two separate operations. Replacement is a
1582	* single O(1) operation versus two O(log(n)) operations for
1583	* remove+insert.
1584	*/
1585	if (old && old->base_gfn == new->base_gfn) {
1586	kvm_replace_gfn_node(slots, old, new);
1587	} else {
1588	if (old)
1589	kvm_erase_gfn_node(slots, slot: old);
1590	kvm_insert_gfn_node(slots, slot: new);
1591	}
1592	}
1593
1594	/*
1595	* Flags that do not access any of the extra space of struct
1596	* kvm_userspace_memory_region2. KVM_SET_USER_MEMORY_REGION_V1_FLAGS
1597	* only allows these.
1598	*/
1599	#define KVM_SET_USER_MEMORY_REGION_V1_FLAGS \
1600	(KVM_MEM_LOG_DIRTY_PAGES | KVM_MEM_READONLY)
1601
1602	static int check_memory_region_flags(struct kvm *kvm,
1603	const struct kvm_userspace_memory_region2 *mem)
1604	{
1605	u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES;
1606
1607	if (kvm_arch_has_private_mem(kvm))
1608	valid_flags |= KVM_MEM_GUEST_MEMFD;
1609
1610	/* Dirty logging private memory is not currently supported. */
1611	if (mem->flags & KVM_MEM_GUEST_MEMFD)
1612	valid_flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
1613
1614	#ifdef CONFIG_HAVE_KVM_READONLY_MEM
1615	/*
1616	* GUEST_MEMFD is incompatible with read-only memslots, as writes to
1617	* read-only memslots have emulated MMIO, not page fault, semantics,
1618	* and KVM doesn't allow emulated MMIO for private memory.
1619	*/
1620	if (!(mem->flags & KVM_MEM_GUEST_MEMFD))
1621	valid_flags |= KVM_MEM_READONLY;
1622	#endif
1623
1624	if (mem->flags & ~valid_flags)
1625	return -EINVAL;
1626
1627	return 0;
1628	}
1629
1630	static void kvm_swap_active_memslots(struct kvm *kvm, int as_id)
1631	{
1632	struct kvm_memslots *slots = kvm_get_inactive_memslots(kvm, as_id);
1633
1634	/* Grab the generation from the activate memslots. */
1635	u64 gen = __kvm_memslots(kvm, as_id)->generation;
1636
1637	WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS);
1638	slots->generation = gen | KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS;
1639
1640	/*
1641	* Do not store the new memslots while there are invalidations in
1642	* progress, otherwise the locking in invalidate_range_start and
1643	* invalidate_range_end will be unbalanced.
1644	*/
1645	spin_lock(lock: &kvm->mn_invalidate_lock);
1646	prepare_to_rcuwait(w: &kvm->mn_memslots_update_rcuwait);
1647	while (kvm->mn_active_invalidate_count) {
1648	set_current_state(TASK_UNINTERRUPTIBLE);
1649	spin_unlock(lock: &kvm->mn_invalidate_lock);
1650	schedule();
1651	spin_lock(lock: &kvm->mn_invalidate_lock);
1652	}
1653	finish_rcuwait(w: &kvm->mn_memslots_update_rcuwait);
1654	rcu_assign_pointer(kvm->memslots[as_id], slots);
1655	spin_unlock(lock: &kvm->mn_invalidate_lock);
1656
1657	/*
1658	* Acquired in kvm_set_memslot. Must be released before synchronize
1659	* SRCU below in order to avoid deadlock with another thread
1660	* acquiring the slots_arch_lock in an srcu critical section.
1661	*/
1662	mutex_unlock(lock: &kvm->slots_arch_lock);
1663
1664	synchronize_srcu_expedited(ssp: &kvm->srcu);
1665
1666	/*
1667	* Increment the new memslot generation a second time, dropping the
1668	* update in-progress flag and incrementing the generation based on
1669	* the number of address spaces. This provides a unique and easily
1670	* identifiable generation number while the memslots are in flux.
1671	*/
1672	gen = slots->generation & ~KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS;
1673
1674	/*
1675	* Generations must be unique even across address spaces. We do not need
1676	* a global counter for that, instead the generation space is evenly split
1677	* across address spaces. For example, with two address spaces, address
1678	* space 0 will use generations 0, 2, 4, ... while address space 1 will
1679	* use generations 1, 3, 5, ...
1680	*/
1681	gen += kvm_arch_nr_memslot_as_ids(kvm);
1682
1683	kvm_arch_memslots_updated(kvm, gen);
1684
1685	slots->generation = gen;
1686	}
1687
1688	static int kvm_prepare_memory_region(struct kvm *kvm,
1689	const struct kvm_memory_slot *old,
1690	struct kvm_memory_slot *new,
1691	enum kvm_mr_change change)
1692	{
1693	int r;
1694
1695	/*
1696	* If dirty logging is disabled, nullify the bitmap; the old bitmap
1697	* will be freed on "commit". If logging is enabled in both old and
1698	* new, reuse the existing bitmap. If logging is enabled only in the
1699	* new and KVM isn't using a ring buffer, allocate and initialize a
1700	* new bitmap.
1701	*/
1702	if (change != KVM_MR_DELETE) {
1703	if (!(new->flags & KVM_MEM_LOG_DIRTY_PAGES))
1704	new->dirty_bitmap = NULL;
1705	else if (old && old->dirty_bitmap)
1706	new->dirty_bitmap = old->dirty_bitmap;
1707	else if (kvm_use_dirty_bitmap(kvm)) {
1708	r = kvm_alloc_dirty_bitmap(memslot: new);
1709	if (r)
1710	return r;
1711
1712	if (kvm_dirty_log_manual_protect_and_init_set(kvm))
1713	bitmap_set(map: new->dirty_bitmap, start: 0, nbits: new->npages);
1714	}
1715	}
1716
1717	r = kvm_arch_prepare_memory_region(kvm, old, new, change);
1718
1719	/* Free the bitmap on failure if it was allocated above. */
1720	if (r && new && new->dirty_bitmap && (!old || !old->dirty_bitmap))
1721	kvm_destroy_dirty_bitmap(memslot: new);
1722
1723	return r;
1724	}
1725
1726	static void kvm_commit_memory_region(struct kvm *kvm,
1727	struct kvm_memory_slot *old,
1728	const struct kvm_memory_slot *new,
1729	enum kvm_mr_change change)
1730	{
1731	int old_flags = old ? old->flags : 0;
1732	int new_flags = new ? new->flags : 0;
1733	/*
1734	* Update the total number of memslot pages before calling the arch
1735	* hook so that architectures can consume the result directly.
1736	*/
1737	if (change == KVM_MR_DELETE)
1738	kvm->nr_memslot_pages -= old->npages;
1739	else if (change == KVM_MR_CREATE)
1740	kvm->nr_memslot_pages += new->npages;
1741
1742	if ((old_flags ^ new_flags) & KVM_MEM_LOG_DIRTY_PAGES) {
1743	int change = (new_flags & KVM_MEM_LOG_DIRTY_PAGES) ? 1 : -1;
1744	atomic_set(v: &kvm->nr_memslots_dirty_logging,
1745	i: atomic_read(v: &kvm->nr_memslots_dirty_logging) + change);
1746	}
1747
1748	kvm_arch_commit_memory_region(kvm, old, new, change);
1749
1750	switch (change) {
1751	case KVM_MR_CREATE:
1752	/* Nothing more to do. */
1753	break;
1754	case KVM_MR_DELETE:
1755	/* Free the old memslot and all its metadata. */
1756	kvm_free_memslot(kvm, slot: old);
1757	break;
1758	case KVM_MR_MOVE:
1759	case KVM_MR_FLAGS_ONLY:
1760	/*
1761	* Free the dirty bitmap as needed; the below check encompasses
1762	* both the flags and whether a ring buffer is being used)
1763	*/
1764	if (old->dirty_bitmap && !new->dirty_bitmap)
1765	kvm_destroy_dirty_bitmap(memslot: old);
1766
1767	/*
1768	* The final quirk. Free the detached, old slot, but only its
1769	* memory, not any metadata. Metadata, including arch specific
1770	* data, may be reused by @new.
1771	*/
1772	kfree(objp: old);
1773	break;
1774	default:
1775	BUG();
1776	}
1777	}
1778
1779	/*
1780	* Activate @new, which must be installed in the inactive slots by the caller,
1781	* by swapping the active slots and then propagating @new to @old once @old is
1782	* unreachable and can be safely modified.
1783	*
1784	* With NULL @old this simply adds @new to @active (while swapping the sets).
1785	* With NULL @new this simply removes @old from @active and frees it
1786	* (while also swapping the sets).
1787	*/
1788	static void kvm_activate_memslot(struct kvm *kvm,
1789	struct kvm_memory_slot *old,
1790	struct kvm_memory_slot *new)
1791	{
1792	int as_id = kvm_memslots_get_as_id(a: old, b: new);
1793
1794	kvm_swap_active_memslots(kvm, as_id);
1795
1796	/* Propagate the new memslot to the now inactive memslots. */
1797	kvm_replace_memslot(kvm, old, new);
1798	}
1799
1800	static void kvm_copy_memslot(struct kvm_memory_slot *dest,
1801	const struct kvm_memory_slot *src)
1802	{
1803	dest->base_gfn = src->base_gfn;
1804	dest->npages = src->npages;
1805	dest->dirty_bitmap = src->dirty_bitmap;
1806	dest->arch = src->arch;
1807	dest->userspace_addr = src->userspace_addr;
1808	dest->flags = src->flags;
1809	dest->id = src->id;
1810	dest->as_id = src->as_id;
1811	}
1812
1813	static void kvm_invalidate_memslot(struct kvm *kvm,
1814	struct kvm_memory_slot *old,
1815	struct kvm_memory_slot *invalid_slot)
1816	{
1817	/*
1818	* Mark the current slot INVALID. As with all memslot modifications,
1819	* this must be done on an unreachable slot to avoid modifying the
1820	* current slot in the active tree.
1821	*/
1822	kvm_copy_memslot(dest: invalid_slot, src: old);
1823	invalid_slot->flags |= KVM_MEMSLOT_INVALID;
1824	kvm_replace_memslot(kvm, old, new: invalid_slot);
1825
1826	/*
1827	* Activate the slot that is now marked INVALID, but don't propagate
1828	* the slot to the now inactive slots. The slot is either going to be
1829	* deleted or recreated as a new slot.
1830	*/
1831	kvm_swap_active_memslots(kvm, as_id: old->as_id);
1832
1833	/*
1834	* From this point no new shadow pages pointing to a deleted, or moved,
1835	* memslot will be created. Validation of sp->gfn happens in:
1836	* - gfn_to_hva (kvm_read_guest, gfn_to_pfn)
1837	* - kvm_is_visible_gfn (mmu_check_root)
1838	*/
1839	kvm_arch_flush_shadow_memslot(kvm, slot: old);
1840	kvm_arch_guest_memory_reclaimed(kvm);
1841
1842	/* Was released by kvm_swap_active_memslots(), reacquire. */
1843	mutex_lock(&kvm->slots_arch_lock);
1844
1845	/*
1846	* Copy the arch-specific field of the newly-installed slot back to the
1847	* old slot as the arch data could have changed between releasing
1848	* slots_arch_lock in kvm_swap_active_memslots() and re-acquiring the lock
1849	* above. Writers are required to retrieve memslots *after* acquiring
1850	* slots_arch_lock, thus the active slot's data is guaranteed to be fresh.
1851	*/
1852	old->arch = invalid_slot->arch;
1853	}
1854
1855	static void kvm_create_memslot(struct kvm *kvm,
1856	struct kvm_memory_slot *new)
1857	{
1858	/* Add the new memslot to the inactive set and activate. */
1859	kvm_replace_memslot(kvm, NULL, new);
1860	kvm_activate_memslot(kvm, NULL, new);
1861	}
1862
1863	static void kvm_delete_memslot(struct kvm *kvm,
1864	struct kvm_memory_slot *old,
1865	struct kvm_memory_slot *invalid_slot)
1866	{
1867	/*
1868	* Remove the old memslot (in the inactive memslots) by passing NULL as
1869	* the "new" slot, and for the invalid version in the active slots.
1870	*/
1871	kvm_replace_memslot(kvm, old, NULL);
1872	kvm_activate_memslot(kvm, old: invalid_slot, NULL);
1873	}
1874
1875	static void kvm_move_memslot(struct kvm *kvm,
1876	struct kvm_memory_slot *old,
1877	struct kvm_memory_slot *new,
1878	struct kvm_memory_slot *invalid_slot)
1879	{
1880	/*
1881	* Replace the old memslot in the inactive slots, and then swap slots
1882	* and replace the current INVALID with the new as well.
1883	*/
1884	kvm_replace_memslot(kvm, old, new);
1885	kvm_activate_memslot(kvm, old: invalid_slot, new);
1886	}
1887
1888	static void kvm_update_flags_memslot(struct kvm *kvm,
1889	struct kvm_memory_slot *old,
1890	struct kvm_memory_slot *new)
1891	{
1892	/*
1893	* Similar to the MOVE case, but the slot doesn't need to be zapped as
1894	* an intermediate step. Instead, the old memslot is simply replaced
1895	* with a new, updated copy in both memslot sets.
1896	*/
1897	kvm_replace_memslot(kvm, old, new);
1898	kvm_activate_memslot(kvm, old, new);
1899	}
1900
1901	static int kvm_set_memslot(struct kvm *kvm,
1902	struct kvm_memory_slot *old,
1903	struct kvm_memory_slot *new,
1904	enum kvm_mr_change change)
1905	{
1906	struct kvm_memory_slot *invalid_slot;
1907	int r;
1908
1909	/*
1910	* Released in kvm_swap_active_memslots().
1911	*
1912	* Must be held from before the current memslots are copied until after
1913	* the new memslots are installed with rcu_assign_pointer, then
1914	* released before the synchronize srcu in kvm_swap_active_memslots().
1915	*
1916	* When modifying memslots outside of the slots_lock, must be held
1917	* before reading the pointer to the current memslots until after all
1918	* changes to those memslots are complete.
1919	*
1920	* These rules ensure that installing new memslots does not lose
1921	* changes made to the previous memslots.
1922	*/
1923	mutex_lock(&kvm->slots_arch_lock);
1924
1925	/*
1926	* Invalidate the old slot if it's being deleted or moved. This is
1927	* done prior to actually deleting/moving the memslot to allow vCPUs to
1928	* continue running by ensuring there are no mappings or shadow pages
1929	* for the memslot when it is deleted/moved. Without pre-invalidation
1930	* (and without a lock), a window would exist between effecting the
1931	* delete/move and committing the changes in arch code where KVM or a
1932	* guest could access a non-existent memslot.
1933	*
1934	* Modifications are done on a temporary, unreachable slot. The old
1935	* slot needs to be preserved in case a later step fails and the
1936	* invalidation needs to be reverted.
1937	*/
1938	if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) {
1939	invalid_slot = kzalloc(size: sizeof(*invalid_slot), GFP_KERNEL_ACCOUNT);
1940	if (!invalid_slot) {
1941	mutex_unlock(lock: &kvm->slots_arch_lock);
1942	return -ENOMEM;
1943	}
1944	kvm_invalidate_memslot(kvm, old, invalid_slot);
1945	}
1946
1947	r = kvm_prepare_memory_region(kvm, old, new, change);
1948	if (r) {
1949	/*
1950	* For DELETE/MOVE, revert the above INVALID change. No
1951	* modifications required since the original slot was preserved
1952	* in the inactive slots. Changing the active memslots also
1953	* release slots_arch_lock.
1954	*/
1955	if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) {
1956	kvm_activate_memslot(kvm, old: invalid_slot, new: old);
1957	kfree(objp: invalid_slot);
1958	} else {
1959	mutex_unlock(lock: &kvm->slots_arch_lock);
1960	}
1961	return r;
1962	}
1963
1964	/*
1965	* For DELETE and MOVE, the working slot is now active as the INVALID
1966	* version of the old slot. MOVE is particularly special as it reuses
1967	* the old slot and returns a copy of the old slot (in working_slot).
1968	* For CREATE, there is no old slot. For DELETE and FLAGS_ONLY, the
1969	* old slot is detached but otherwise preserved.
1970	*/
1971	if (change == KVM_MR_CREATE)
1972	kvm_create_memslot(kvm, new);
1973	else if (change == KVM_MR_DELETE)
1974	kvm_delete_memslot(kvm, old, invalid_slot);
1975	else if (change == KVM_MR_MOVE)
1976	kvm_move_memslot(kvm, old, new, invalid_slot);
1977	else if (change == KVM_MR_FLAGS_ONLY)
1978	kvm_update_flags_memslot(kvm, old, new);
1979	else
1980	BUG();
1981
1982	/* Free the temporary INVALID slot used for DELETE and MOVE. */
1983	if (change == KVM_MR_DELETE || change == KVM_MR_MOVE)
1984	kfree(objp: invalid_slot);
1985
1986	/*
1987	* No need to refresh new->arch, changes after dropping slots_arch_lock
1988	* will directly hit the final, active memslot. Architectures are
1989	* responsible for knowing that new->arch may be stale.
1990	*/
1991	kvm_commit_memory_region(kvm, old, new, change);
1992
1993	return 0;
1994	}
1995
1996	static bool kvm_check_memslot_overlap(struct kvm_memslots *slots, int id,
1997	gfn_t start, gfn_t end)
1998	{
1999	struct kvm_memslot_iter iter;
2000
2001	kvm_for_each_memslot_in_gfn_range(&iter, slots, start, end) {
2002	if (iter.slot->id != id)
2003	return true;
2004	}
2005
2006	return false;
2007	}
2008
2009	/*
2010	* Allocate some memory and give it an address in the guest physical address
2011	* space.
2012	*
2013	* Discontiguous memory is allowed, mostly for framebuffers.
2014	*
2015	* Must be called holding kvm->slots_lock for write.
2016	*/
2017	int __kvm_set_memory_region(struct kvm *kvm,
2018	const struct kvm_userspace_memory_region2 *mem)
2019	{
2020	struct kvm_memory_slot *old, *new;
2021	struct kvm_memslots *slots;
2022	enum kvm_mr_change change;
2023	unsigned long npages;
2024	gfn_t base_gfn;
2025	int as_id, id;
2026	int r;
2027
2028	r = check_memory_region_flags(kvm, mem);
2029	if (r)
2030	return r;
2031
2032	as_id = mem->slot >> 16;
2033	id = (u16)mem->slot;
2034
2035	/* General sanity checks */
2036	if ((mem->memory_size & (PAGE_SIZE - 1)) ||
2037	(mem->memory_size != (unsigned long)mem->memory_size))
2038	return -EINVAL;
2039	if (mem->guest_phys_addr & (PAGE_SIZE - 1))
2040	return -EINVAL;
2041	/* We can read the guest memory with __xxx_user() later on. */
2042	if ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
2043	(mem->userspace_addr != untagged_addr(mem->userspace_addr)) ||
2044	!access_ok((void __user *)(unsigned long)mem->userspace_addr,
2045	mem->memory_size))
2046	return -EINVAL;
2047	if (mem->flags & KVM_MEM_GUEST_MEMFD &&
2048	(mem->guest_memfd_offset & (PAGE_SIZE - 1) ||
2049	mem->guest_memfd_offset + mem->memory_size < mem->guest_memfd_offset))
2050	return -EINVAL;
2051	if (as_id >= kvm_arch_nr_memslot_as_ids(kvm) || id >= KVM_MEM_SLOTS_NUM)
2052	return -EINVAL;
2053	if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
2054	return -EINVAL;
2055	if ((mem->memory_size >> PAGE_SHIFT) > KVM_MEM_MAX_NR_PAGES)
2056	return -EINVAL;
2057
2058	slots = __kvm_memslots(kvm, as_id);
2059
2060	/*
2061	* Note, the old memslot (and the pointer itself!) may be invalidated
2062	* and/or destroyed by kvm_set_memslot().
2063	*/
2064	old = id_to_memslot(slots, id);
2065
2066	if (!mem->memory_size) {
2067	if (!old || !old->npages)
2068	return -EINVAL;
2069
2070	if (WARN_ON_ONCE(kvm->nr_memslot_pages < old->npages))
2071	return -EIO;
2072
2073	return kvm_set_memslot(kvm, old, NULL, change: KVM_MR_DELETE);
2074	}
2075
2076	base_gfn = (mem->guest_phys_addr >> PAGE_SHIFT);
2077	npages = (mem->memory_size >> PAGE_SHIFT);
2078
2079	if (!old || !old->npages) {
2080	change = KVM_MR_CREATE;
2081
2082	/*
2083	* To simplify KVM internals, the total number of pages across
2084	* all memslots must fit in an unsigned long.
2085	*/
2086	if ((kvm->nr_memslot_pages + npages) < kvm->nr_memslot_pages)
2087	return -EINVAL;
2088	} else { /* Modify an existing slot. */
2089	/* Private memslots are immutable, they can only be deleted. */
2090	if (mem->flags & KVM_MEM_GUEST_MEMFD)
2091	return -EINVAL;
2092	if ((mem->userspace_addr != old->userspace_addr) ||
2093	(npages != old->npages) ||
2094	((mem->flags ^ old->flags) & KVM_MEM_READONLY))
2095	return -EINVAL;
2096
2097	if (base_gfn != old->base_gfn)
2098	change = KVM_MR_MOVE;
2099	else if (mem->flags != old->flags)
2100	change = KVM_MR_FLAGS_ONLY;
2101	else /* Nothing to change. */
2102	return 0;
2103	}
2104
2105	if ((change == KVM_MR_CREATE || change == KVM_MR_MOVE) &&
2106	kvm_check_memslot_overlap(slots, id, start: base_gfn, end: base_gfn + npages))
2107	return -EEXIST;
2108
2109	/* Allocate a slot that will persist in the memslot. */
2110	new = kzalloc(size: sizeof(*new), GFP_KERNEL_ACCOUNT);
2111	if (!new)
2112	return -ENOMEM;
2113
2114	new->as_id = as_id;
2115	new->id = id;
2116	new->base_gfn = base_gfn;
2117	new->npages = npages;
2118	new->flags = mem->flags;
2119	new->userspace_addr = mem->userspace_addr;
2120	if (mem->flags & KVM_MEM_GUEST_MEMFD) {
2121	r = kvm_gmem_bind(kvm, slot: new, fd: mem->guest_memfd, offset: mem->guest_memfd_offset);
2122	if (r)
2123	goto out;
2124	}
2125
2126	r = kvm_set_memslot(kvm, old, new, change);
2127	if (r)
2128	goto out_unbind;
2129
2130	return 0;
2131
2132	out_unbind:
2133	if (mem->flags & KVM_MEM_GUEST_MEMFD)
2134	kvm_gmem_unbind(slot: new);
2135	out:
2136	kfree(objp: new);
2137	return r;
2138	}
2139	EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
2140
2141	int kvm_set_memory_region(struct kvm *kvm,
2142	const struct kvm_userspace_memory_region2 *mem)
2143	{
2144	int r;
2145
2146	mutex_lock(&kvm->slots_lock);
2147	r = __kvm_set_memory_region(kvm, mem);
2148	mutex_unlock(lock: &kvm->slots_lock);
2149	return r;
2150	}
2151	EXPORT_SYMBOL_GPL(kvm_set_memory_region);
2152
2153	static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
2154	struct kvm_userspace_memory_region2 *mem)
2155	{
2156	if ((u16)mem->slot >= KVM_USER_MEM_SLOTS)
2157	return -EINVAL;
2158
2159	return kvm_set_memory_region(kvm, mem);
2160	}
2161
2162	#ifndef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
2163	/**
2164	* kvm_get_dirty_log - get a snapshot of dirty pages
2165	* @kvm: pointer to kvm instance
2166	* @log: slot id and address to which we copy the log
2167	* @is_dirty: set to '1' if any dirty pages were found
2168	* @memslot: set to the associated memslot, always valid on success
2169	*/
2170	int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log,
2171	int *is_dirty, struct kvm_memory_slot **memslot)
2172	{
2173	struct kvm_memslots *slots;
2174	int i, as_id, id;
2175	unsigned long n;
2176	unsigned long any = 0;
2177
2178	/* Dirty ring tracking may be exclusive to dirty log tracking */
2179	if (!kvm_use_dirty_bitmap(kvm))
2180	return -ENXIO;
2181
2182	*memslot = NULL;
2183	*is_dirty = 0;
2184
2185	as_id = log->slot >> 16;
2186	id = (u16)log->slot;
2187	if (as_id >= kvm_arch_nr_memslot_as_ids(kvm) || id >= KVM_USER_MEM_SLOTS)
2188	return -EINVAL;
2189
2190	slots = __kvm_memslots(kvm, as_id);
2191	*memslot = id_to_memslot(slots, id);
2192	if (!(*memslot) || !(*memslot)->dirty_bitmap)
2193	return -ENOENT;
2194
2195	kvm_arch_sync_dirty_log(kvm, *memslot);
2196
2197	n = kvm_dirty_bitmap_bytes(*memslot);
2198
2199	for (i = 0; !any && i < n/sizeof(long); ++i)
2200	any = (*memslot)->dirty_bitmap[i];
2201
2202	if (copy_to_user(log->dirty_bitmap, (*memslot)->dirty_bitmap, n))
2203	return -EFAULT;
2204
2205	if (any)
2206	*is_dirty = 1;
2207	return 0;
2208	}
2209	EXPORT_SYMBOL_GPL(kvm_get_dirty_log);
2210
2211	#else /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */
2212	/**
2213	* kvm_get_dirty_log_protect - get a snapshot of dirty pages
2214	* and reenable dirty page tracking for the corresponding pages.
2215	* @kvm: pointer to kvm instance
2216	* @log: slot id and address to which we copy the log
2217	*
2218	* We need to keep it in mind that VCPU threads can write to the bitmap
2219	* concurrently. So, to avoid losing track of dirty pages we keep the
2220	* following order:
2221	*
2222	* 1. Take a snapshot of the bit and clear it if needed.
2223	* 2. Write protect the corresponding page.
2224	* 3. Copy the snapshot to the userspace.
2225	* 4. Upon return caller flushes TLB's if needed.
2226	*
2227	* Between 2 and 4, the guest may write to the page using the remaining TLB
2228	* entry. This is not a problem because the page is reported dirty using
2229	* the snapshot taken before and step 4 ensures that writes done after
2230	* exiting to userspace will be logged for the next call.
2231	*
2232	*/
2233	static int kvm_get_dirty_log_protect(struct kvm *kvm, struct kvm_dirty_log *log)
2234	{
2235	struct kvm_memslots *slots;
2236	struct kvm_memory_slot *memslot;
2237	int i, as_id, id;
2238	unsigned long n;
2239	unsigned long *dirty_bitmap;
2240	unsigned long *dirty_bitmap_buffer;
2241	bool flush;
2242
2243	/* Dirty ring tracking may be exclusive to dirty log tracking */
2244	if (!kvm_use_dirty_bitmap(kvm))
2245	return -ENXIO;
2246
2247	as_id = log->slot >> 16;
2248	id = (u16)log->slot;
2249	if (as_id >= kvm_arch_nr_memslot_as_ids(kvm) || id >= KVM_USER_MEM_SLOTS)
2250	return -EINVAL;
2251
2252	slots = __kvm_memslots(kvm, as_id);
2253	memslot = id_to_memslot(slots, id);
2254	if (!memslot || !memslot->dirty_bitmap)
2255	return -ENOENT;
2256
2257	dirty_bitmap = memslot->dirty_bitmap;
2258
2259	kvm_arch_sync_dirty_log(kvm, memslot);
2260
2261	n = kvm_dirty_bitmap_bytes(memslot);
2262	flush = false;
2263	if (kvm->manual_dirty_log_protect) {
2264	/*
2265	* Unlike kvm_get_dirty_log, we always return false in *flush,
2266	* because no flush is needed until KVM_CLEAR_DIRTY_LOG. There
2267	* is some code duplication between this function and
2268	* kvm_get_dirty_log, but hopefully all architecture
2269	* transition to kvm_get_dirty_log_protect and kvm_get_dirty_log
2270	* can be eliminated.
2271	*/
2272	dirty_bitmap_buffer = dirty_bitmap;
2273	} else {
2274	dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot);
2275	memset(dirty_bitmap_buffer, 0, n);
2276
2277	KVM_MMU_LOCK(kvm);
2278	for (i = 0; i < n / sizeof(long); i++) {
2279	unsigned long mask;
2280	gfn_t offset;
2281
2282	if (!dirty_bitmap[i])
2283	continue;
2284
2285	flush = true;
2286	mask = xchg(&dirty_bitmap[i], 0);
2287	dirty_bitmap_buffer[i] = mask;
2288
2289	offset = i * BITS_PER_LONG;
2290	kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, slot: memslot,
2291	gfn_offset: offset, mask);
2292	}
2293	KVM_MMU_UNLOCK(kvm);
2294	}
2295
2296	if (flush)
2297	kvm_flush_remote_tlbs_memslot(kvm, memslot);
2298
2299	if (copy_to_user(to: log->dirty_bitmap, from: dirty_bitmap_buffer, n))
2300	return -EFAULT;
2301	return 0;
2302	}
2303
2304
2305	/**
2306	* kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot
2307	* @kvm: kvm instance
2308	* @log: slot id and address to which we copy the log
2309	*
2310	* Steps 1-4 below provide general overview of dirty page logging. See
2311	* kvm_get_dirty_log_protect() function description for additional details.
2312	*
2313	* We call kvm_get_dirty_log_protect() to handle steps 1-3, upon return we
2314	* always flush the TLB (step 4) even if previous step failed and the dirty
2315	* bitmap may be corrupt. Regardless of previous outcome the KVM logging API
2316	* does not preclude user space subsequent dirty log read. Flushing TLB ensures
2317	* writes will be marked dirty for next log read.
2318	*
2319	* 1. Take a snapshot of the bit and clear it if needed.
2320	* 2. Write protect the corresponding page.
2321	* 3. Copy the snapshot to the userspace.
2322	* 4. Flush TLB's if needed.
2323	*/
2324	static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
2325	struct kvm_dirty_log *log)
2326	{
2327	int r;
2328
2329	mutex_lock(&kvm->slots_lock);
2330
2331	r = kvm_get_dirty_log_protect(kvm, log);
2332
2333	mutex_unlock(lock: &kvm->slots_lock);
2334	return r;
2335	}
2336
2337	/**
2338	* kvm_clear_dirty_log_protect - clear dirty bits in the bitmap
2339	* and reenable dirty page tracking for the corresponding pages.
2340	* @kvm: pointer to kvm instance
2341	* @log: slot id and address from which to fetch the bitmap of dirty pages
2342	*/
2343	static int kvm_clear_dirty_log_protect(struct kvm *kvm,
2344	struct kvm_clear_dirty_log *log)
2345	{
2346	struct kvm_memslots *slots;
2347	struct kvm_memory_slot *memslot;
2348	int as_id, id;
2349	gfn_t offset;
2350	unsigned long i, n;
2351	unsigned long *dirty_bitmap;
2352	unsigned long *dirty_bitmap_buffer;
2353	bool flush;
2354
2355	/* Dirty ring tracking may be exclusive to dirty log tracking */
2356	if (!kvm_use_dirty_bitmap(kvm))
2357	return -ENXIO;
2358
2359	as_id = log->slot >> 16;
2360	id = (u16)log->slot;
2361	if (as_id >= kvm_arch_nr_memslot_as_ids(kvm) || id >= KVM_USER_MEM_SLOTS)
2362	return -EINVAL;
2363
2364	if (log->first_page & 63)
2365	return -EINVAL;
2366
2367	slots = __kvm_memslots(kvm, as_id);
2368	memslot = id_to_memslot(slots, id);
2369	if (!memslot || !memslot->dirty_bitmap)
2370	return -ENOENT;
2371
2372	dirty_bitmap = memslot->dirty_bitmap;
2373
2374	n = ALIGN(log->num_pages, BITS_PER_LONG) / 8;
2375
2376	if (log->first_page > memslot->npages ||
2377	log->num_pages > memslot->npages - log->first_page ||
2378	(log->num_pages < memslot->npages - log->first_page && (log->num_pages & 63)))
2379	return -EINVAL;
2380
2381	kvm_arch_sync_dirty_log(kvm, memslot);
2382
2383	flush = false;
2384	dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot);
2385	if (copy_from_user(to: dirty_bitmap_buffer, from: log->dirty_bitmap, n))
2386	return -EFAULT;
2387
2388	KVM_MMU_LOCK(kvm);
2389	for (offset = log->first_page, i = offset / BITS_PER_LONG,
2390	n = DIV_ROUND_UP(log->num_pages, BITS_PER_LONG); n--;
2391	i++, offset += BITS_PER_LONG) {
2392	unsigned long mask = *dirty_bitmap_buffer++;
2393	atomic_long_t *p = (atomic_long_t *) &dirty_bitmap[i];
2394	if (!mask)
2395	continue;
2396
2397	mask &= atomic_long_fetch_andnot(i: mask, v: p);
2398
2399	/*
2400	* mask contains the bits that really have been cleared. This
2401	* never includes any bits beyond the length of the memslot (if
2402	* the length is not aligned to 64 pages), therefore it is not
2403	* a problem if userspace sets them in log->dirty_bitmap.
2404	*/
2405	if (mask) {
2406	flush = true;
2407	kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, slot: memslot,
2408	gfn_offset: offset, mask);
2409	}
2410	}
2411	KVM_MMU_UNLOCK(kvm);
2412
2413	if (flush)
2414	kvm_flush_remote_tlbs_memslot(kvm, memslot);
2415
2416	return 0;
2417	}
2418
2419	static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm,
2420	struct kvm_clear_dirty_log *log)
2421	{
2422	int r;
2423
2424	mutex_lock(&kvm->slots_lock);
2425
2426	r = kvm_clear_dirty_log_protect(kvm, log);
2427
2428	mutex_unlock(lock: &kvm->slots_lock);
2429	return r;
2430	}
2431	#endif /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */
2432
2433	#ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES
2434	/*
2435	* Returns true if _all_ gfns in the range [@start, @end) have attributes
2436	* matching @attrs.
2437	*/
2438	bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end,
2439	unsigned long attrs)
2440	{
2441	XA_STATE(xas, &kvm->mem_attr_array, start);
2442	unsigned long index;
2443	bool has_attrs;
2444	void *entry;
2445
2446	rcu_read_lock();
2447
2448	if (!attrs) {
2449	has_attrs = !xas_find(&xas, max: end - 1);
2450	goto out;
2451	}
2452
2453	has_attrs = true;
2454	for (index = start; index < end; index++) {
2455	do {
2456	entry = xas_next(xas: &xas);
2457	} while (xas_retry(xas: &xas, entry));
2458
2459	if (xas.xa_index != index || xa_to_value(entry) != attrs) {
2460	has_attrs = false;
2461	break;
2462	}
2463	}
2464
2465	out:
2466	rcu_read_unlock();
2467	return has_attrs;
2468	}
2469
2470	static u64 kvm_supported_mem_attributes(struct kvm *kvm)
2471	{
2472	if (!kvm || kvm_arch_has_private_mem(kvm))
2473	return KVM_MEMORY_ATTRIBUTE_PRIVATE;
2474
2475	return 0;
2476	}
2477
2478	static __always_inline void kvm_handle_gfn_range(struct kvm *kvm,
2479	struct kvm_mmu_notifier_range *range)
2480	{
2481	struct kvm_gfn_range gfn_range;
2482	struct kvm_memory_slot *slot;
2483	struct kvm_memslots *slots;
2484	struct kvm_memslot_iter iter;
2485	bool found_memslot = false;
2486	bool ret = false;
2487	int i;
2488
2489	gfn_range.arg = range->arg;
2490	gfn_range.may_block = range->may_block;
2491
2492	for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) {
2493	slots = __kvm_memslots(kvm, as_id: i);
2494
2495	kvm_for_each_memslot_in_gfn_range(&iter, slots, range->start, range->end) {
2496	slot = iter.slot;
2497	gfn_range.slot = slot;
2498
2499	gfn_range.start = max(range->start, slot->base_gfn);
2500	gfn_range.end = min(range->end, slot->base_gfn + slot->npages);
2501	if (gfn_range.start >= gfn_range.end)
2502	continue;
2503
2504	if (!found_memslot) {
2505	found_memslot = true;
2506	KVM_MMU_LOCK(kvm);
2507	if (!IS_KVM_NULL_FN(range->on_lock))
2508	range->on_lock(kvm);
2509	}
2510
2511	ret |= range->handler(kvm, &gfn_range);
2512	}
2513	}
2514
2515	if (range->flush_on_ret && ret)
2516	kvm_flush_remote_tlbs(kvm);
2517
2518	if (found_memslot)
2519	KVM_MMU_UNLOCK(kvm);
2520	}
2521
2522	static bool kvm_pre_set_memory_attributes(struct kvm *kvm,
2523	struct kvm_gfn_range *range)
2524	{
2525	/*
2526	* Unconditionally add the range to the invalidation set, regardless of
2527	* whether or not the arch callback actually needs to zap SPTEs. E.g.
2528	* if KVM supports RWX attributes in the future and the attributes are
2529	* going from R=>RW, zapping isn't strictly necessary. Unconditionally
2530	* adding the range allows KVM to require that MMU invalidations add at
2531	* least one range between begin() and end(), e.g. allows KVM to detect
2532	* bugs where the add() is missed. Relaxing the rule *might* be safe,
2533	* but it's not obvious that allowing new mappings while the attributes
2534	* are in flux is desirable or worth the complexity.
2535	*/
2536	kvm_mmu_invalidate_range_add(kvm, start: range->start, end: range->end);
2537
2538	return kvm_arch_pre_set_memory_attributes(kvm, range);
2539	}
2540
2541	/* Set @attributes for the gfn range [@start, @end). */
2542	static int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end,
2543	unsigned long attributes)
2544	{
2545	struct kvm_mmu_notifier_range pre_set_range = {
2546	.start = start,
2547	.end = end,
2548	.handler = kvm_pre_set_memory_attributes,
2549	.on_lock = kvm_mmu_invalidate_begin,
2550	.flush_on_ret = true,
2551	.may_block = true,
2552	};
2553	struct kvm_mmu_notifier_range post_set_range = {
2554	.start = start,
2555	.end = end,
2556	.arg.attributes = attributes,
2557	.handler = kvm_arch_post_set_memory_attributes,
2558	.on_lock = kvm_mmu_invalidate_end,
2559	.may_block = true,
2560	};
2561	unsigned long i;
2562	void *entry;
2563	int r = 0;
2564
2565	entry = attributes ? xa_mk_value(v: attributes) : NULL;
2566
2567	mutex_lock(&kvm->slots_lock);
2568
2569	/* Nothing to do if the entire range as the desired attributes. */
2570	if (kvm_range_has_memory_attributes(kvm, start, end, attrs: attributes))
2571	goto out_unlock;
2572
2573	/*
2574	* Reserve memory ahead of time to avoid having to deal with failures
2575	* partway through setting the new attributes.
2576	*/
2577	for (i = start; i < end; i++) {
2578	r = xa_reserve(xa: &kvm->mem_attr_array, index: i, GFP_KERNEL_ACCOUNT);
2579	if (r)
2580	goto out_unlock;
2581	}
2582
2583	kvm_handle_gfn_range(kvm, range: &pre_set_range);
2584
2585	for (i = start; i < end; i++) {
2586	r = xa_err(entry: xa_store(&kvm->mem_attr_array, index: i, entry,
2587	GFP_KERNEL_ACCOUNT));
2588	KVM_BUG_ON(r, kvm);
2589	}
2590
2591	kvm_handle_gfn_range(kvm, range: &post_set_range);
2592
2593	out_unlock:
2594	mutex_unlock(lock: &kvm->slots_lock);
2595
2596	return r;
2597	}
2598	static int kvm_vm_ioctl_set_mem_attributes(struct kvm *kvm,
2599	struct kvm_memory_attributes *attrs)
2600	{
2601	gfn_t start, end;
2602
2603	/* flags is currently not used. */
2604	if (attrs->flags)
2605	return -EINVAL;
2606	if (attrs->attributes & ~kvm_supported_mem_attributes(kvm))
2607	return -EINVAL;
2608	if (attrs->size == 0 || attrs->address + attrs->size < attrs->address)
2609	return -EINVAL;
2610	if (!PAGE_ALIGNED(attrs->address) || !PAGE_ALIGNED(attrs->size))
2611	return -EINVAL;
2612
2613	start = attrs->address >> PAGE_SHIFT;
2614	end = (attrs->address + attrs->size) >> PAGE_SHIFT;
2615
2616	/*
2617	* xarray tracks data using "unsigned long", and as a result so does
2618	* KVM. For simplicity, supports generic attributes only on 64-bit
2619	* architectures.
2620	*/
2621	BUILD_BUG_ON(sizeof(attrs->attributes) != sizeof(unsigned long));
2622
2623	return kvm_vm_set_mem_attributes(kvm, start, end, attributes: attrs->attributes);
2624	}
2625	#endif /* CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES */
2626
2627	struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
2628	{
2629	return __gfn_to_memslot(slots: kvm_memslots(kvm), gfn);
2630	}
2631	EXPORT_SYMBOL_GPL(gfn_to_memslot);
2632
2633	struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn)
2634	{
2635	struct kvm_memslots *slots = kvm_vcpu_memslots(vcpu);
2636	u64 gen = slots->generation;
2637	struct kvm_memory_slot *slot;
2638
2639	/*
2640	* This also protects against using a memslot from a different address space,
2641	* since different address spaces have different generation numbers.
2642	*/
2643	if (unlikely(gen != vcpu->last_used_slot_gen)) {
2644	vcpu->last_used_slot = NULL;
2645	vcpu->last_used_slot_gen = gen;
2646	}
2647
2648	slot = try_get_memslot(slot: vcpu->last_used_slot, gfn);
2649	if (slot)
2650	return slot;
2651
2652	/*
2653	* Fall back to searching all memslots. We purposely use
2654	* search_memslots() instead of __gfn_to_memslot() to avoid
2655	* thrashing the VM-wide last_used_slot in kvm_memslots.
2656	*/
2657	slot = search_memslots(slots, gfn, approx: false);
2658	if (slot) {
2659	vcpu->last_used_slot = slot;
2660	return slot;
2661	}
2662
2663	return NULL;
2664	}
2665
2666	bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
2667	{
2668	struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn);
2669
2670	return kvm_is_visible_memslot(memslot);
2671	}
2672	EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
2673
2674	bool kvm_vcpu_is_visible_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
2675	{
2676	struct kvm_memory_slot *memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
2677
2678	return kvm_is_visible_memslot(memslot);
2679	}
2680	EXPORT_SYMBOL_GPL(kvm_vcpu_is_visible_gfn);
2681
2682	unsigned long kvm_host_page_size(struct kvm_vcpu *vcpu, gfn_t gfn)
2683	{
2684	struct vm_area_struct *vma;
2685	unsigned long addr, size;
2686
2687	size = PAGE_SIZE;
2688
2689	addr = kvm_vcpu_gfn_to_hva_prot(vcpu, gfn, NULL);
2690	if (kvm_is_error_hva(addr))
2691	return PAGE_SIZE;
2692
2693	mmap_read_lock(current->mm);
2694	vma = find_vma(current->mm, addr);
2695	if (!vma)
2696	goto out;
2697
2698	size = vma_kernel_pagesize(vma);
2699
2700	out:
2701	mmap_read_unlock(current->mm);
2702
2703	return size;
2704	}
2705
2706	static bool memslot_is_readonly(const struct kvm_memory_slot *slot)
2707	{
2708	return slot->flags & KVM_MEM_READONLY;
2709	}
2710
2711	static unsigned long __gfn_to_hva_many(const struct kvm_memory_slot *slot, gfn_t gfn,
2712	gfn_t *nr_pages, bool write)
2713	{
2714	if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
2715	return KVM_HVA_ERR_BAD;
2716
2717	if (memslot_is_readonly(slot) && write)
2718	return KVM_HVA_ERR_RO_BAD;
2719
2720	if (nr_pages)
2721	*nr_pages = slot->npages - (gfn - slot->base_gfn);
2722
2723	return __gfn_to_hva_memslot(slot, gfn);
2724	}
2725
2726	static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
2727	gfn_t *nr_pages)
2728	{
2729	return __gfn_to_hva_many(slot, gfn, nr_pages, write: true);
2730	}
2731
2732	unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot,
2733	gfn_t gfn)
2734	{
2735	return gfn_to_hva_many(slot, gfn, NULL);
2736	}
2737	EXPORT_SYMBOL_GPL(gfn_to_hva_memslot);
2738
2739	unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
2740	{
2741	return gfn_to_hva_many(slot: gfn_to_memslot(kvm, gfn), gfn, NULL);
2742	}
2743	EXPORT_SYMBOL_GPL(gfn_to_hva);
2744
2745	unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn)
2746	{
2747	return gfn_to_hva_many(slot: kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn, NULL);
2748	}
2749	EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_hva);
2750
2751	/*
2752	* Return the hva of a @gfn and the R/W attribute if possible.
2753	*
2754	* @slot: the kvm_memory_slot which contains @gfn
2755	* @gfn: the gfn to be translated
2756	* @writable: used to return the read/write attribute of the @slot if the hva
2757	* is valid and @writable is not NULL
2758	*/
2759	unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot,
2760	gfn_t gfn, bool *writable)
2761	{
2762	unsigned long hva = __gfn_to_hva_many(slot, gfn, NULL, write: false);
2763
2764	if (!kvm_is_error_hva(addr: hva) && writable)
2765	*writable = !memslot_is_readonly(slot);
2766
2767	return hva;
2768	}
2769
2770	unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable)
2771	{
2772	struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
2773
2774	return gfn_to_hva_memslot_prot(slot, gfn, writable);
2775	}
2776
2777	unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable)
2778	{
2779	struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
2780
2781	return gfn_to_hva_memslot_prot(slot, gfn, writable);
2782	}
2783
2784	static inline int check_user_page_hwpoison(unsigned long addr)
2785	{
2786	int rc, flags = FOLL_HWPOISON | FOLL_WRITE;
2787
2788	rc = get_user_pages(start: addr, nr_pages: 1, gup_flags: flags, NULL);
2789	return rc == -EHWPOISON;
2790	}
2791
2792	/*
2793	* The fast path to get the writable pfn which will be stored in @pfn,
2794	* true indicates success, otherwise false is returned. It's also the
2795	* only part that runs if we can in atomic context.
2796	*/
2797	static bool hva_to_pfn_fast(unsigned long addr, bool write_fault,
2798	bool *writable, kvm_pfn_t *pfn)
2799	{
2800	struct page *page[1];
2801
2802	/*
2803	* Fast pin a writable pfn only if it is a write fault request
2804	* or the caller allows to map a writable pfn for a read fault
2805	* request.
2806	*/
2807	if (!(write_fault || writable))
2808	return false;
2809
2810	if (get_user_page_fast_only(addr, gup_flags: FOLL_WRITE, pagep: page)) {
2811	*pfn = page_to_pfn(page[0]);
2812
2813	if (writable)
2814	*writable = true;
2815	return true;
2816	}
2817
2818	return false;
2819	}
2820
2821	/*
2822	* The slow path to get the pfn of the specified host virtual address,
2823	* 1 indicates success, -errno is returned if error is detected.
2824	*/
2825	static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault,
2826	bool interruptible, bool *writable, kvm_pfn_t *pfn)
2827	{
2828	/*
2829	* When a VCPU accesses a page that is not mapped into the secondary
2830	* MMU, we lookup the page using GUP to map it, so the guest VCPU can
2831	* make progress. We always want to honor NUMA hinting faults in that
2832	* case, because GUP usage corresponds to memory accesses from the VCPU.
2833	* Otherwise, we'd not trigger NUMA hinting faults once a page is
2834	* mapped into the secondary MMU and gets accessed by a VCPU.
2835	*
2836	* Note that get_user_page_fast_only() and FOLL_WRITE for now
2837	* implicitly honor NUMA hinting faults and don't need this flag.
2838	*/
2839	unsigned int flags = FOLL_HWPOISON | FOLL_HONOR_NUMA_FAULT;
2840	struct page *page;
2841	int npages;
2842
2843	might_sleep();
2844
2845	if (writable)
2846	*writable = write_fault;
2847
2848	if (write_fault)
2849	flags |= FOLL_WRITE;
2850	if (async)
2851	flags |= FOLL_NOWAIT;
2852	if (interruptible)
2853	flags |= FOLL_INTERRUPTIBLE;
2854
2855	npages = get_user_pages_unlocked(start: addr, nr_pages: 1, pages: &page, gup_flags: flags);
2856	if (npages != 1)
2857	return npages;
2858
2859	/* map read fault as writable if possible */
2860	if (unlikely(!write_fault) && writable) {
2861	struct page *wpage;
2862
2863	if (get_user_page_fast_only(addr, gup_flags: FOLL_WRITE, pagep: &wpage)) {
2864	*writable = true;
2865	put_page(page);
2866	page = wpage;
2867	}
2868	}
2869	*pfn = page_to_pfn(page);
2870	return npages;
2871	}
2872
2873	static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault)
2874	{
2875	if (unlikely(!(vma->vm_flags & VM_READ)))
2876	return false;
2877
2878	if (write_fault && (unlikely(!(vma->vm_flags & VM_WRITE))))
2879	return false;
2880
2881	return true;
2882	}
2883
2884	static int kvm_try_get_pfn(kvm_pfn_t pfn)
2885	{
2886	struct page *page = kvm_pfn_to_refcounted_page(pfn);
2887
2888	if (!page)
2889	return 1;
2890
2891	return get_page_unless_zero(page);
2892	}
2893
2894	static int hva_to_pfn_remapped(struct vm_area_struct *vma,
2895	unsigned long addr, bool write_fault,
2896	bool *writable, kvm_pfn_t *p_pfn)
2897	{
2898	kvm_pfn_t pfn;
2899	pte_t *ptep;
2900	pte_t pte;
2901	spinlock_t *ptl;
2902	int r;
2903
2904	r = follow_pte(mm: vma->vm_mm, address: addr, ptepp: &ptep, ptlp: &ptl);
2905	if (r) {
2906	/*
2907	* get_user_pages fails for VM_IO and VM_PFNMAP vmas and does
2908	* not call the fault handler, so do it here.
2909	*/
2910	bool unlocked = false;
2911	r = fixup_user_fault(current->mm, address: addr,
2912	fault_flags: (write_fault ? FAULT_FLAG_WRITE : 0),
2913	unlocked: &unlocked);
2914	if (unlocked)
2915	return -EAGAIN;
2916	if (r)
2917	return r;
2918
2919	r = follow_pte(mm: vma->vm_mm, address: addr, ptepp: &ptep, ptlp: &ptl);
2920	if (r)
2921	return r;
2922	}
2923
2924	pte = ptep_get(ptep);
2925
2926	if (write_fault && !pte_write(pte)) {
2927	pfn = KVM_PFN_ERR_RO_FAULT;
2928	goto out;
2929	}
2930
2931	if (writable)
2932	*writable = pte_write(pte);
2933	pfn = pte_pfn(pte);
2934
2935	/*
2936	* Get a reference here because callers of *hva_to_pfn* and
2937	* *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the
2938	* returned pfn. This is only needed if the VMA has VM_MIXEDMAP
2939	* set, but the kvm_try_get_pfn/kvm_release_pfn_clean pair will
2940	* simply do nothing for reserved pfns.
2941	*
2942	* Whoever called remap_pfn_range is also going to call e.g.
2943	* unmap_mapping_range before the underlying pages are freed,
2944	* causing a call to our MMU notifier.
2945	*
2946	* Certain IO or PFNMAP mappings can be backed with valid
2947	* struct pages, but be allocated without refcounting e.g.,
2948	* tail pages of non-compound higher order allocations, which
2949	* would then underflow the refcount when the caller does the
2950	* required put_page. Don't allow those pages here.
2951	*/
2952	if (!kvm_try_get_pfn(pfn))
2953	r = -EFAULT;
2954
2955	out:
2956	pte_unmap_unlock(ptep, ptl);
2957	*p_pfn = pfn;
2958
2959	return r;
2960	}
2961
2962	/*
2963	* Pin guest page in memory and return its pfn.
2964	* @addr: host virtual address which maps memory to the guest
2965	* @atomic: whether this function can sleep
2966	* @interruptible: whether the process can be interrupted by non-fatal signals
2967	* @async: whether this function need to wait IO complete if the
2968	* host page is not in the memory
2969	* @write_fault: whether we should get a writable host page
2970	* @writable: whether it allows to map a writable host page for !@write_fault
2971	*
2972	* The function will map a writable host page for these two cases:
2973	* 1): @write_fault = true
2974	* 2): @write_fault = false && @writable, @writable will tell the caller
2975	* whether the mapping is writable.
2976	*/
2977	kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool interruptible,
2978	bool *async, bool write_fault, bool *writable)
2979	{
2980	struct vm_area_struct *vma;
2981	kvm_pfn_t pfn;
2982	int npages, r;
2983
2984	/* we can do it either atomically or asynchronously, not both */
2985	BUG_ON(atomic && async);
2986
2987	if (hva_to_pfn_fast(addr, write_fault, writable, pfn: &pfn))
2988	return pfn;
2989
2990	if (atomic)
2991	return KVM_PFN_ERR_FAULT;
2992
2993	npages = hva_to_pfn_slow(addr, async, write_fault, interruptible,
2994	writable, pfn: &pfn);
2995	if (npages == 1)
2996	return pfn;
2997	if (npages == -EINTR)
2998	return KVM_PFN_ERR_SIGPENDING;
2999
3000	mmap_read_lock(current->mm);
3001	if (npages == -EHWPOISON ||
3002	(!async && check_user_page_hwpoison(addr))) {
3003	pfn = KVM_PFN_ERR_HWPOISON;
3004	goto exit;
3005	}
3006
3007	retry:
3008	vma = vma_lookup(current->mm, addr);
3009
3010	if (vma == NULL)
3011	pfn = KVM_PFN_ERR_FAULT;
3012	else if (vma->vm_flags & (VM_IO | VM_PFNMAP)) {
3013	r = hva_to_pfn_remapped(vma, addr, write_fault, writable, p_pfn: &pfn);
3014	if (r == -EAGAIN)
3015	goto retry;
3016	if (r < 0)
3017	pfn = KVM_PFN_ERR_FAULT;
3018	} else {
3019	if (async && vma_is_valid(vma, write_fault))
3020	*async = true;
3021	pfn = KVM_PFN_ERR_FAULT;
3022	}
3023	exit:
3024	mmap_read_unlock(current->mm);
3025	return pfn;
3026	}
3027
3028	kvm_pfn_t __gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn,
3029	bool atomic, bool interruptible, bool *async,
3030	bool write_fault, bool *writable, hva_t *hva)
3031	{
3032	unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write: write_fault);
3033
3034	if (hva)
3035	*hva = addr;
3036
3037	if (addr == KVM_HVA_ERR_RO_BAD) {
3038	if (writable)
3039	*writable = false;
3040	return KVM_PFN_ERR_RO_FAULT;
3041	}
3042
3043	if (kvm_is_error_hva(addr)) {
3044	if (writable)
3045	*writable = false;
3046	return KVM_PFN_NOSLOT;
3047	}
3048
3049	/* Do not map writable pfn in the readonly memslot. */
3050	if (writable && memslot_is_readonly(slot)) {
3051	*writable = false;
3052	writable = NULL;
3053	}
3054
3055	return hva_to_pfn(addr, atomic, interruptible, async, write_fault,
3056	writable);
3057	}
3058	EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot);
3059
3060	kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
3061	bool *writable)
3062	{
3063	return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, false,
3064	NULL, write_fault, writable, NULL);
3065	}
3066	EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);
3067
3068	kvm_pfn_t gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn)
3069	{
3070	return __gfn_to_pfn_memslot(slot, gfn, false, false, NULL, true,
3071	NULL, NULL);
3072	}
3073	EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot);
3074
3075	kvm_pfn_t gfn_to_pfn_memslot_atomic(const struct kvm_memory_slot *slot, gfn_t gfn)
3076	{
3077	return __gfn_to_pfn_memslot(slot, gfn, true, false, NULL, true,
3078	NULL, NULL);
3079	}
3080	EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic);
3081
3082	kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn)
3083	{
3084	return gfn_to_pfn_memslot_atomic(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
3085	}
3086	EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_atomic);
3087
3088	kvm_pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
3089	{
3090	return gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn);
3091	}
3092	EXPORT_SYMBOL_GPL(gfn_to_pfn);
3093
3094	kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn)
3095	{
3096	return gfn_to_pfn_memslot(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
3097	}
3098	EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn);
3099
3100	int gfn_to_page_many_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
3101	struct page **pages, int nr_pages)
3102	{
3103	unsigned long addr;
3104	gfn_t entry = 0;
3105
3106	addr = gfn_to_hva_many(slot, gfn, nr_pages: &entry);
3107	if (kvm_is_error_hva(addr))
3108	return -1;
3109
3110	if (entry < nr_pages)
3111	return 0;
3112
3113	return get_user_pages_fast_only(start: addr, nr_pages, gup_flags: FOLL_WRITE, pages);
3114	}
3115	EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
3116
3117	/*
3118	* Do not use this helper unless you are absolutely certain the gfn _must_ be
3119	* backed by 'struct page'. A valid example is if the backing memslot is
3120	* controlled by KVM. Note, if the returned page is valid, it's refcount has
3121	* been elevated by gfn_to_pfn().
3122	*/
3123	struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
3124	{
3125	struct page *page;
3126	kvm_pfn_t pfn;
3127
3128	pfn = gfn_to_pfn(kvm, gfn);
3129
3130	if (is_error_noslot_pfn(pfn))
3131	return KVM_ERR_PTR_BAD_PAGE;
3132
3133	page = kvm_pfn_to_refcounted_page(pfn);
3134	if (!page)
3135	return KVM_ERR_PTR_BAD_PAGE;
3136
3137	return page;
3138	}
3139	EXPORT_SYMBOL_GPL(gfn_to_page);
3140
3141	void kvm_release_pfn(kvm_pfn_t pfn, bool dirty)
3142	{
3143	if (dirty)
3144	kvm_release_pfn_dirty(pfn);
3145	else
3146	kvm_release_pfn_clean(pfn);
3147	}
3148
3149	int kvm_vcpu_map(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map)
3150	{
3151	kvm_pfn_t pfn;
3152	void *hva = NULL;
3153	struct page *page = KVM_UNMAPPED_PAGE;
3154
3155	if (!map)
3156	return -EINVAL;
3157
3158	pfn = gfn_to_pfn(vcpu->kvm, gfn);
3159	if (is_error_noslot_pfn(pfn))
3160	return -EINVAL;
3161
3162	if (pfn_valid(pfn)) {
3163	page = pfn_to_page(pfn);
3164	hva = kmap(page);
3165	#ifdef CONFIG_HAS_IOMEM
3166	} else {
3167	hva = memremap(offset: pfn_to_hpa(pfn), PAGE_SIZE, flags: MEMREMAP_WB);
3168	#endif
3169	}
3170
3171	if (!hva)
3172	return -EFAULT;
3173
3174	map->page = page;
3175	map->hva = hva;
3176	map->pfn = pfn;
3177	map->gfn = gfn;
3178
3179	return 0;
3180	}
3181	EXPORT_SYMBOL_GPL(kvm_vcpu_map);
3182
3183	void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty)
3184	{
3185	if (!map)
3186	return;
3187
3188	if (!map->hva)
3189	return;
3190
3191	if (map->page != KVM_UNMAPPED_PAGE)
3192	kunmap(page: map->page);
3193	#ifdef CONFIG_HAS_IOMEM
3194	else
3195	memunmap(addr: map->hva);
3196	#endif
3197
3198	if (dirty)
3199	kvm_vcpu_mark_page_dirty(vcpu, gfn: map->gfn);
3200
3201	kvm_release_pfn(pfn: map->pfn, dirty);
3202
3203	map->hva = NULL;
3204	map->page = NULL;
3205	}
3206	EXPORT_SYMBOL_GPL(kvm_vcpu_unmap);
3207
3208	static bool kvm_is_ad_tracked_page(struct page *page)
3209	{
3210	/*
3211	* Per page-flags.h, pages tagged PG_reserved "should in general not be
3212	* touched (e.g. set dirty) except by its owner".
3213	*/
3214	return !PageReserved(page);
3215	}
3216
3217	static void kvm_set_page_dirty(struct page *page)
3218	{
3219	if (kvm_is_ad_tracked_page(page))
3220	SetPageDirty(page);
3221	}
3222
3223	static void kvm_set_page_accessed(struct page *page)
3224	{
3225	if (kvm_is_ad_tracked_page(page))
3226	mark_page_accessed(page);
3227	}
3228
3229	void kvm_release_page_clean(struct page *page)
3230	{
3231	WARN_ON(is_error_page(page));
3232
3233	kvm_set_page_accessed(page);
3234	put_page(page);
3235	}
3236	EXPORT_SYMBOL_GPL(kvm_release_page_clean);
3237
3238	void kvm_release_pfn_clean(kvm_pfn_t pfn)
3239	{
3240	struct page *page;
3241
3242	if (is_error_noslot_pfn(pfn))
3243	return;
3244
3245	page = kvm_pfn_to_refcounted_page(pfn);
3246	if (!page)
3247	return;
3248
3249	kvm_release_page_clean(page);
3250	}
3251	EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
3252
3253	void kvm_release_page_dirty(struct page *page)
3254	{
3255	WARN_ON(is_error_page(page));
3256
3257	kvm_set_page_dirty(page);
3258	kvm_release_page_clean(page);
3259	}
3260	EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
3261
3262	void kvm_release_pfn_dirty(kvm_pfn_t pfn)
3263	{
3264	struct page *page;
3265
3266	if (is_error_noslot_pfn(pfn))
3267	return;
3268
3269	page = kvm_pfn_to_refcounted_page(pfn);
3270	if (!page)
3271	return;
3272
3273	kvm_release_page_dirty(page);
3274	}
3275	EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
3276
3277	/*
3278	* Note, checking for an error/noslot pfn is the caller's responsibility when
3279	* directly marking a page dirty/accessed. Unlike the "release" helpers, the
3280	* "set" helpers are not to be used when the pfn might point at garbage.
3281	*/
3282	void kvm_set_pfn_dirty(kvm_pfn_t pfn)
3283	{
3284	if (WARN_ON(is_error_noslot_pfn(pfn)))
3285	return;
3286
3287	if (pfn_valid(pfn))
3288	kvm_set_page_dirty(pfn_to_page(pfn));
3289	}
3290	EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
3291
3292	void kvm_set_pfn_accessed(kvm_pfn_t pfn)
3293	{
3294	if (WARN_ON(is_error_noslot_pfn(pfn)))
3295	return;
3296
3297	if (pfn_valid(pfn))
3298	kvm_set_page_accessed(pfn_to_page(pfn));
3299	}
3300	EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
3301
3302	static int next_segment(unsigned long len, int offset)
3303	{
3304	if (len > PAGE_SIZE - offset)
3305	return PAGE_SIZE - offset;
3306	else
3307	return len;
3308	}
3309
3310	static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn,
3311	void *data, int offset, int len)
3312	{
3313	int r;
3314	unsigned long addr;
3315
3316	addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
3317	if (kvm_is_error_hva(addr))
3318	return -EFAULT;
3319	r = __copy_from_user(to: data, from: (void __user *)addr + offset, n: len);
3320	if (r)
3321	return -EFAULT;
3322	return 0;
3323	}
3324
3325	int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
3326	int len)
3327	{
3328	struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
3329
3330	return __kvm_read_guest_page(slot, gfn, data, offset, len);
3331	}
3332	EXPORT_SYMBOL_GPL(kvm_read_guest_page);
3333
3334	int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data,
3335	int offset, int len)
3336	{
3337	struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
3338
3339	return __kvm_read_guest_page(slot, gfn, data, offset, len);
3340	}
3341	EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_page);
3342
3343	int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
3344	{
3345	gfn_t gfn = gpa >> PAGE_SHIFT;
3346	int seg;
3347	int offset = offset_in_page(gpa);
3348	int ret;
3349
3350	while ((seg = next_segment(len, offset)) != 0) {
3351	ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
3352	if (ret < 0)
3353	return ret;
3354	offset = 0;
3355	len -= seg;
3356	data += seg;
3357	++gfn;
3358	}
3359	return 0;
3360	}
3361	EXPORT_SYMBOL_GPL(kvm_read_guest);
3362
3363	int kvm_vcpu_read_guest(struct kvm_vcpu *vcpu, gpa_t gpa, void *data, unsigned long len)
3364	{
3365	gfn_t gfn = gpa >> PAGE_SHIFT;
3366	int seg;
3367	int offset = offset_in_page(gpa);
3368	int ret;
3369
3370	while ((seg = next_segment(len, offset)) != 0) {
3371	ret = kvm_vcpu_read_guest_page(vcpu, gfn, data, offset, seg);
3372	if (ret < 0)
3373	return ret;
3374	offset = 0;
3375	len -= seg;
3376	data += seg;
3377	++gfn;
3378	}
3379	return 0;
3380	}
3381	EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest);
3382
3383	static int __kvm_read_guest_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
3384	void *data, int offset, unsigned long len)
3385	{
3386	int r;
3387	unsigned long addr;
3388
3389	addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
3390	if (kvm_is_error_hva(addr))
3391	return -EFAULT;
3392	pagefault_disable();
3393	r = __copy_from_user_inatomic(to: data, from: (void __user *)addr + offset, n: len);
3394	pagefault_enable();
3395	if (r)
3396	return -EFAULT;
3397	return 0;
3398	}
3399
3400	int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa,
3401	void *data, unsigned long len)
3402	{
3403	gfn_t gfn = gpa >> PAGE_SHIFT;
3404	struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
3405	int offset = offset_in_page(gpa);
3406
3407	return __kvm_read_guest_atomic(slot, gfn, data, offset, len);
3408	}
3409	EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic);
3410
3411	static int __kvm_write_guest_page(struct kvm *kvm,
3412	struct kvm_memory_slot *memslot, gfn_t gfn,
3413	const void *data, int offset, int len)
3414	{
3415	int r;
3416	unsigned long addr;
3417
3418	addr = gfn_to_hva_memslot(memslot, gfn);
3419	if (kvm_is_error_hva(addr))
3420	return -EFAULT;
3421	r = __copy_to_user(to: (void __user *)addr + offset, from: data, n: len);
3422	if (r)
3423	return -EFAULT;
3424	mark_page_dirty_in_slot(kvm, memslot, gfn);
3425	return 0;
3426	}
3427
3428	int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn,
3429	const void *data, int offset, int len)
3430	{
3431	struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
3432
3433	return __kvm_write_guest_page(kvm, memslot: slot, gfn, data, offset, len);
3434	}
3435	EXPORT_SYMBOL_GPL(kvm_write_guest_page);
3436
3437	int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn,
3438	const void *data, int offset, int len)
3439	{
3440	struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
3441
3442	return __kvm_write_guest_page(kvm: vcpu->kvm, memslot: slot, gfn, data, offset, len);
3443	}
3444	EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest_page);
3445
3446	int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
3447	unsigned long len)
3448	{
3449	gfn_t gfn = gpa >> PAGE_SHIFT;
3450	int seg;
3451	int offset = offset_in_page(gpa);
3452	int ret;
3453
3454	while ((seg = next_segment(len, offset)) != 0) {
3455	ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
3456	if (ret < 0)
3457	return ret;
3458	offset = 0;
3459	len -= seg;
3460	data += seg;
3461	++gfn;
3462	}
3463	return 0;
3464	}
3465	EXPORT_SYMBOL_GPL(kvm_write_guest);
3466
3467	int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data,
3468	unsigned long len)
3469	{
3470	gfn_t gfn = gpa >> PAGE_SHIFT;
3471	int seg;
3472	int offset = offset_in_page(gpa);
3473	int ret;
3474
3475	while ((seg = next_segment(len, offset)) != 0) {
3476	ret = kvm_vcpu_write_guest_page(vcpu, gfn, data, offset, seg);
3477	if (ret < 0)
3478	return ret;
3479	offset = 0;
3480	len -= seg;
3481	data += seg;
3482	++gfn;
3483	}
3484	return 0;
3485	}
3486	EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest);
3487
3488	static int __kvm_gfn_to_hva_cache_init(struct kvm_memslots *slots,
3489	struct gfn_to_hva_cache *ghc,
3490	gpa_t gpa, unsigned long len)
3491	{
3492	int offset = offset_in_page(gpa);
3493	gfn_t start_gfn = gpa >> PAGE_SHIFT;
3494	gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT;
3495	gfn_t nr_pages_needed = end_gfn - start_gfn + 1;
3496	gfn_t nr_pages_avail;
3497
3498	/* Update ghc->generation before performing any error checks. */
3499	ghc->generation = slots->generation;
3500
3501	if (start_gfn > end_gfn) {
3502	ghc->hva = KVM_HVA_ERR_BAD;
3503	return -EINVAL;
3504	}
3505
3506	/*
3507	* If the requested region crosses two memslots, we still
3508	* verify that the entire region is valid here.
3509	*/
3510	for ( ; start_gfn <= end_gfn; start_gfn += nr_pages_avail) {
3511	ghc->memslot = __gfn_to_memslot(slots, gfn: start_gfn);
3512	ghc->hva = gfn_to_hva_many(slot: ghc->memslot, gfn: start_gfn,
3513	nr_pages: &nr_pages_avail);
3514	if (kvm_is_error_hva(addr: ghc->hva))
3515	return -EFAULT;
3516	}
3517
3518	/* Use the slow path for cross page reads and writes. */
3519	if (nr_pages_needed == 1)
3520	ghc->hva += offset;
3521	else
3522	ghc->memslot = NULL;
3523
3524	ghc->gpa = gpa;
3525	ghc->len = len;
3526	return 0;
3527	}
3528
3529	int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
3530	gpa_t gpa, unsigned long len)
3531	{
3532	struct kvm_memslots *slots = kvm_memslots(kvm);
3533	return __kvm_gfn_to_hva_cache_init(slots, ghc, gpa, len);
3534	}
3535	EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
3536
3537	int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
3538	void *data, unsigned int offset,
3539	unsigned long len)
3540	{
3541	struct kvm_memslots *slots = kvm_memslots(kvm);
3542	int r;
3543	gpa_t gpa = ghc->gpa + offset;
3544
3545	if (WARN_ON_ONCE(len + offset > ghc->len))
3546	return -EINVAL;
3547
3548	if (slots->generation != ghc->generation) {
3549	if (__kvm_gfn_to_hva_cache_init(slots, ghc, gpa: ghc->gpa, len: ghc->len))
3550	return -EFAULT;
3551	}
3552
3553	if (kvm_is_error_hva(addr: ghc->hva))
3554	return -EFAULT;
3555
3556	if (unlikely(!ghc->memslot))
3557	return kvm_write_guest(kvm, gpa, data, len);
3558
3559	r = __copy_to_user(to: (void __user *)ghc->hva + offset, from: data, n: len);
3560	if (r)
3561	return -EFAULT;
3562	mark_page_dirty_in_slot(kvm, memslot: ghc->memslot, gfn: gpa >> PAGE_SHIFT);
3563
3564	return 0;
3565	}
3566	EXPORT_SYMBOL_GPL(kvm_write_guest_offset_cached);
3567
3568	int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
3569	void *data, unsigned long len)
3570	{
3571	return kvm_write_guest_offset_cached(kvm, ghc, data, 0, len);
3572	}
3573	EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
3574
3575	int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
3576	void *data, unsigned int offset,
3577	unsigned long len)
3578	{
3579	struct kvm_memslots *slots = kvm_memslots(kvm);
3580	int r;
3581	gpa_t gpa = ghc->gpa + offset;
3582
3583	if (WARN_ON_ONCE(len + offset > ghc->len))
3584	return -EINVAL;
3585
3586	if (slots->generation != ghc->generation) {
3587	if (__kvm_gfn_to_hva_cache_init(slots, ghc, gpa: ghc->gpa, len: ghc->len))
3588	return -EFAULT;
3589	}
3590
3591	if (kvm_is_error_hva(addr: ghc->hva))
3592	return -EFAULT;
3593
3594	if (unlikely(!ghc->memslot))
3595	return kvm_read_guest(kvm, gpa, data, len);
3596
3597	r = __copy_from_user(to: data, from: (void __user *)ghc->hva + offset, n: len);
3598	if (r)
3599	return -EFAULT;
3600
3601	return 0;
3602	}
3603	EXPORT_SYMBOL_GPL(kvm_read_guest_offset_cached);
3604
3605	int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
3606	void *data, unsigned long len)
3607	{
3608	return kvm_read_guest_offset_cached(kvm, ghc, data, 0, len);
3609	}
3610	EXPORT_SYMBOL_GPL(kvm_read_guest_cached);
3611
3612	int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
3613	{
3614	const void *zero_page = (const void *) __va(page_to_phys(ZERO_PAGE(0)));
3615	gfn_t gfn = gpa >> PAGE_SHIFT;
3616	int seg;
3617	int offset = offset_in_page(gpa);
3618	int ret;
3619
3620	while ((seg = next_segment(len, offset)) != 0) {
3621	ret = kvm_write_guest_page(kvm, gfn, zero_page, offset, len);
3622	if (ret < 0)
3623	return ret;
3624	offset = 0;
3625	len -= seg;
3626	++gfn;
3627	}
3628	return 0;
3629	}
3630	EXPORT_SYMBOL_GPL(kvm_clear_guest);
3631
3632	void mark_page_dirty_in_slot(struct kvm *kvm,
3633	const struct kvm_memory_slot *memslot,
3634	gfn_t gfn)
3635	{
3636	struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
3637
3638	#ifdef CONFIG_HAVE_KVM_DIRTY_RING
3639	if (WARN_ON_ONCE(vcpu && vcpu->kvm != kvm))
3640	return;
3641
3642	WARN_ON_ONCE(!vcpu && !kvm_arch_allow_write_without_running_vcpu(kvm));
3643	#endif
3644
3645	if (memslot && kvm_slot_dirty_track_enabled(slot: memslot)) {
3646	unsigned long rel_gfn = gfn - memslot->base_gfn;
3647	u32 slot = (memslot->as_id << 16) | memslot->id;
3648
3649	if (kvm->dirty_ring_size && vcpu)
3650	kvm_dirty_ring_push(vcpu, slot, offset: rel_gfn);
3651	else if (memslot->dirty_bitmap)
3652	set_bit_le(nr: rel_gfn, addr: memslot->dirty_bitmap);
3653	}
3654	}
3655	EXPORT_SYMBOL_GPL(mark_page_dirty_in_slot);
3656
3657	void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
3658	{
3659	struct kvm_memory_slot *memslot;
3660
3661	memslot = gfn_to_memslot(kvm, gfn);
3662	mark_page_dirty_in_slot(kvm, memslot, gfn);
3663	}
3664	EXPORT_SYMBOL_GPL(mark_page_dirty);
3665
3666	void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn)
3667	{
3668	struct kvm_memory_slot *memslot;
3669
3670	memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
3671	mark_page_dirty_in_slot(vcpu->kvm, memslot, gfn);
3672	}
3673	EXPORT_SYMBOL_GPL(kvm_vcpu_mark_page_dirty);
3674
3675	void kvm_sigset_activate(struct kvm_vcpu *vcpu)
3676	{
3677	if (!vcpu->sigset_active)
3678	return;
3679
3680	/*
3681	* This does a lockless modification of ->real_blocked, which is fine
3682	* because, only current can change ->real_blocked and all readers of
3683	* ->real_blocked don't care as long ->real_blocked is always a subset
3684	* of ->blocked.
3685	*/
3686	sigprocmask(SIG_SETMASK, &vcpu->sigset, &current->real_blocked);
3687	}
3688
3689	void kvm_sigset_deactivate(struct kvm_vcpu *vcpu)
3690	{
3691	if (!vcpu->sigset_active)
3692	return;
3693
3694	sigprocmask(SIG_SETMASK, &current->real_blocked, NULL);
3695	sigemptyset(set: &current->real_blocked);
3696	}
3697
3698	static void grow_halt_poll_ns(struct kvm_vcpu *vcpu)
3699	{
3700	unsigned int old, val, grow, grow_start;
3701
3702	old = val = vcpu->halt_poll_ns;
3703	grow_start = READ_ONCE(halt_poll_ns_grow_start);
3704	grow = READ_ONCE(halt_poll_ns_grow);
3705	if (!grow)
3706	goto out;
3707
3708	val *= grow;
3709	if (val < grow_start)
3710	val = grow_start;
3711
3712	vcpu->halt_poll_ns = val;
3713	out:
3714	trace_kvm_halt_poll_ns_grow(vcpu->vcpu_id, val, old);
3715	}
3716
3717	static void shrink_halt_poll_ns(struct kvm_vcpu *vcpu)
3718	{
3719	unsigned int old, val, shrink, grow_start;
3720
3721	old = val = vcpu->halt_poll_ns;
3722	shrink = READ_ONCE(halt_poll_ns_shrink);
3723	grow_start = READ_ONCE(halt_poll_ns_grow_start);
3724	if (shrink == 0)
3725	val = 0;
3726	else
3727	val /= shrink;
3728
3729	if (val < grow_start)
3730	val = 0;
3731
3732	vcpu->halt_poll_ns = val;
3733	trace_kvm_halt_poll_ns_shrink(vcpu->vcpu_id, val, old);
3734	}
3735
3736	static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu)
3737	{
3738	int ret = -EINTR;
3739	int idx = srcu_read_lock(ssp: &vcpu->kvm->srcu);
3740
3741	if (kvm_arch_vcpu_runnable(vcpu))
3742	goto out;
3743	if (kvm_cpu_has_pending_timer(vcpu))
3744	goto out;
3745	if (signal_pending(current))
3746	goto out;
3747	if (kvm_check_request(KVM_REQ_UNBLOCK, vcpu))
3748	goto out;
3749
3750	ret = 0;
3751	out:
3752	srcu_read_unlock(ssp: &vcpu->kvm->srcu, idx);
3753	return ret;
3754	}
3755
3756	/*
3757	* Block the vCPU until the vCPU is runnable, an event arrives, or a signal is
3758	* pending. This is mostly used when halting a vCPU, but may also be used
3759	* directly for other vCPU non-runnable states, e.g. x86's Wait-For-SIPI.
3760	*/
3761	bool kvm_vcpu_block(struct kvm_vcpu *vcpu)
3762	{
3763	struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu);
3764	bool waited = false;
3765
3766	vcpu->stat.generic.blocking = 1;
3767
3768	preempt_disable();
3769	kvm_arch_vcpu_blocking(vcpu);
3770	prepare_to_rcuwait(w: wait);
3771	preempt_enable();
3772
3773	for (;;) {
3774	set_current_state(TASK_INTERRUPTIBLE);
3775
3776	if (kvm_vcpu_check_block(vcpu) < 0)
3777	break;
3778
3779	waited = true;
3780	schedule();
3781	}
3782
3783	preempt_disable();
3784	finish_rcuwait(w: wait);
3785	kvm_arch_vcpu_unblocking(vcpu);
3786	preempt_enable();
3787
3788	vcpu->stat.generic.blocking = 0;
3789
3790	return waited;
3791	}
3792
3793	static inline void update_halt_poll_stats(struct kvm_vcpu *vcpu, ktime_t start,
3794	ktime_t end, bool success)
3795	{
3796	struct kvm_vcpu_stat_generic *stats = &vcpu->stat.generic;
3797	u64 poll_ns = ktime_to_ns(ktime_sub(end, start));
3798
3799	++vcpu->stat.generic.halt_attempted_poll;
3800
3801	if (success) {
3802	++vcpu->stat.generic.halt_successful_poll;
3803
3804	if (!vcpu_valid_wakeup(vcpu))
3805	++vcpu->stat.generic.halt_poll_invalid;
3806
3807	stats->halt_poll_success_ns += poll_ns;
3808	KVM_STATS_LOG_HIST_UPDATE(stats->halt_poll_success_hist, poll_ns);
3809	} else {
3810	stats->halt_poll_fail_ns += poll_ns;
3811	KVM_STATS_LOG_HIST_UPDATE(stats->halt_poll_fail_hist, poll_ns);
3812	}
3813	}
3814
3815	static unsigned int kvm_vcpu_max_halt_poll_ns(struct kvm_vcpu *vcpu)
3816	{
3817	struct kvm *kvm = vcpu->kvm;
3818
3819	if (kvm->override_halt_poll_ns) {
3820	/*
3821	* Ensure kvm->max_halt_poll_ns is not read before
3822	* kvm->override_halt_poll_ns.
3823	*
3824	* Pairs with the smp_wmb() when enabling KVM_CAP_HALT_POLL.
3825	*/
3826	smp_rmb();
3827	return READ_ONCE(kvm->max_halt_poll_ns);
3828	}
3829
3830	return READ_ONCE(halt_poll_ns);
3831	}
3832
3833	/*
3834	* Emulate a vCPU halt condition, e.g. HLT on x86, WFI on arm, etc... If halt
3835	* polling is enabled, busy wait for a short time before blocking to avoid the
3836	* expensive block+unblock sequence if a wake event arrives soon after the vCPU
3837	* is halted.
3838	*/
3839	void kvm_vcpu_halt(struct kvm_vcpu *vcpu)
3840	{
3841	unsigned int max_halt_poll_ns = kvm_vcpu_max_halt_poll_ns(vcpu);
3842	bool halt_poll_allowed = !kvm_arch_no_poll(vcpu);
3843	ktime_t start, cur, poll_end;
3844	bool waited = false;
3845	bool do_halt_poll;
3846	u64 halt_ns;
3847
3848	if (vcpu->halt_poll_ns > max_halt_poll_ns)
3849	vcpu->halt_poll_ns = max_halt_poll_ns;
3850
3851	do_halt_poll = halt_poll_allowed && vcpu->halt_poll_ns;
3852
3853	start = cur = poll_end = ktime_get();
3854	if (do_halt_poll) {
3855	ktime_t stop = ktime_add_ns(start, vcpu->halt_poll_ns);
3856
3857	do {
3858	if (kvm_vcpu_check_block(vcpu) < 0)
3859	goto out;
3860	cpu_relax();
3861	poll_end = cur = ktime_get();
3862	} while (kvm_vcpu_can_poll(cur, stop));
3863	}
3864
3865	waited = kvm_vcpu_block(vcpu);
3866
3867	cur = ktime_get();
3868	if (waited) {
3869	vcpu->stat.generic.halt_wait_ns +=
3870	ktime_to_ns(kt: cur) - ktime_to_ns(kt: poll_end);
3871	KVM_STATS_LOG_HIST_UPDATE(vcpu->stat.generic.halt_wait_hist,
3872	ktime_to_ns(cur) - ktime_to_ns(poll_end));
3873	}
3874	out:
3875	/* The total time the vCPU was "halted", including polling time. */
3876	halt_ns = ktime_to_ns(kt: cur) - ktime_to_ns(kt: start);
3877
3878	/*
3879	* Note, halt-polling is considered successful so long as the vCPU was
3880	* never actually scheduled out, i.e. even if the wake event arrived
3881	* after of the halt-polling loop itself, but before the full wait.
3882	*/
3883	if (do_halt_poll)
3884	update_halt_poll_stats(vcpu, start, end: poll_end, success: !waited);
3885
3886	if (halt_poll_allowed) {
3887	/* Recompute the max halt poll time in case it changed. */
3888	max_halt_poll_ns = kvm_vcpu_max_halt_poll_ns(vcpu);
3889
3890	if (!vcpu_valid_wakeup(vcpu)) {
3891	shrink_halt_poll_ns(vcpu);
3892	} else if (max_halt_poll_ns) {
3893	if (halt_ns <= vcpu->halt_poll_ns)
3894	;
3895	/* we had a long block, shrink polling */
3896	else if (vcpu->halt_poll_ns &&
3897	halt_ns > max_halt_poll_ns)
3898	shrink_halt_poll_ns(vcpu);
3899	/* we had a short halt and our poll time is too small */
3900	else if (vcpu->halt_poll_ns < max_halt_poll_ns &&
3901	halt_ns < max_halt_poll_ns)
3902	grow_halt_poll_ns(vcpu);
3903	} else {
3904	vcpu->halt_poll_ns = 0;
3905	}
3906	}
3907
3908	trace_kvm_vcpu_wakeup(ns: halt_ns, waited, valid: vcpu_valid_wakeup(vcpu));
3909	}
3910	EXPORT_SYMBOL_GPL(kvm_vcpu_halt);
3911
3912	bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu)
3913	{
3914	if (__kvm_vcpu_wake_up(vcpu)) {
3915	WRITE_ONCE(vcpu->ready, true);
3916	++vcpu->stat.generic.halt_wakeup;
3917	return true;
3918	}
3919
3920	return false;
3921	}
3922	EXPORT_SYMBOL_GPL(kvm_vcpu_wake_up);
3923
3924	#ifndef CONFIG_S390
3925	/*
3926	* Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode.
3927	*/
3928	void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
3929	{
3930	int me, cpu;
3931
3932	if (kvm_vcpu_wake_up(vcpu))
3933	return;
3934
3935	me = get_cpu();
3936	/*
3937	* The only state change done outside the vcpu mutex is IN_GUEST_MODE
3938	* to EXITING_GUEST_MODE. Therefore the moderately expensive "should
3939	* kick" check does not need atomic operations if kvm_vcpu_kick is used
3940	* within the vCPU thread itself.
3941	*/
3942	if (vcpu == __this_cpu_read(kvm_running_vcpu)) {
3943	if (vcpu->mode == IN_GUEST_MODE)
3944	WRITE_ONCE(vcpu->mode, EXITING_GUEST_MODE);
3945	goto out;
3946	}
3947
3948	/*
3949	* Note, the vCPU could get migrated to a different pCPU at any point
3950	* after kvm_arch_vcpu_should_kick(), which could result in sending an
3951	* IPI to the previous pCPU. But, that's ok because the purpose of the
3952	* IPI is to force the vCPU to leave IN_GUEST_MODE, and migrating the
3953	* vCPU also requires it to leave IN_GUEST_MODE.
3954	*/
3955	if (kvm_arch_vcpu_should_kick(vcpu)) {
3956	cpu = READ_ONCE(vcpu->cpu);
3957	if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu))
3958	smp_send_reschedule(cpu);
3959	}
3960	out:
3961	put_cpu();
3962	}
3963	EXPORT_SYMBOL_GPL(kvm_vcpu_kick);
3964	#endif /* !CONFIG_S390 */
3965
3966	int kvm_vcpu_yield_to(struct kvm_vcpu *target)
3967	{
3968	struct pid *pid;
3969	struct task_struct *task = NULL;
3970	int ret = 0;
3971
3972	rcu_read_lock();
3973	pid = rcu_dereference(target->pid);
3974	if (pid)
3975	task = get_pid_task(pid, PIDTYPE_PID);
3976	rcu_read_unlock();
3977	if (!task)
3978	return ret;
3979	ret = yield_to(p: task, preempt: 1);
3980	put_task_struct(t: task);
3981
3982	return ret;
3983	}
3984	EXPORT_SYMBOL_GPL(kvm_vcpu_yield_to);
3985
3986	/*
3987	* Helper that checks whether a VCPU is eligible for directed yield.
3988	* Most eligible candidate to yield is decided by following heuristics:
3989	*
3990	* (a) VCPU which has not done pl-exit or cpu relax intercepted recently
3991	* (preempted lock holder), indicated by @in_spin_loop.
3992	* Set at the beginning and cleared at the end of interception/PLE handler.
3993	*
3994	* (b) VCPU which has done pl-exit/ cpu relax intercepted but did not get
3995	* chance last time (mostly it has become eligible now since we have probably
3996	* yielded to lockholder in last iteration. This is done by toggling
3997	* @dy_eligible each time a VCPU checked for eligibility.)
3998	*
3999	* Yielding to a recently pl-exited/cpu relax intercepted VCPU before yielding
4000	* to preempted lock-holder could result in wrong VCPU selection and CPU
4001	* burning. Giving priority for a potential lock-holder increases lock
4002	* progress.
4003	*
4004	* Since algorithm is based on heuristics, accessing another VCPU data without
4005	* locking does not harm. It may result in trying to yield to same VCPU, fail
4006	* and continue with next VCPU and so on.
4007	*/
4008	static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu)
4009	{
4010	#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
4011	bool eligible;
4012
4013	eligible = !vcpu->spin_loop.in_spin_loop ||
4014	vcpu->spin_loop.dy_eligible;
4015
4016	if (vcpu->spin_loop.in_spin_loop)
4017	kvm_vcpu_set_dy_eligible(vcpu, val: !vcpu->spin_loop.dy_eligible);
4018
4019	return eligible;
4020	#else
4021	return true;
4022	#endif
4023	}
4024
4025	/*
4026	* Unlike kvm_arch_vcpu_runnable, this function is called outside
4027	* a vcpu_load/vcpu_put pair. However, for most architectures
4028	* kvm_arch_vcpu_runnable does not require vcpu_load.
4029	*/
4030	bool __weak kvm_arch_dy_runnable(struct kvm_vcpu *vcpu)
4031	{
4032	return kvm_arch_vcpu_runnable(vcpu);
4033	}
4034
4035	static bool vcpu_dy_runnable(struct kvm_vcpu *vcpu)
4036	{
4037	if (kvm_arch_dy_runnable(vcpu))
4038	return true;
4039
4040	#ifdef CONFIG_KVM_ASYNC_PF
4041	if (!list_empty_careful(head: &vcpu->async_pf.done))
4042	return true;
4043	#endif
4044
4045	return false;
4046	}
4047
4048	/*
4049	* By default, simply query the target vCPU's current mode when checking if a
4050	* vCPU was preempted in kernel mode. All architectures except x86 (or more
4051	* specifical, except VMX) allow querying whether or not a vCPU is in kernel
4052	* mode even if the vCPU is NOT loaded, i.e. using kvm_arch_vcpu_in_kernel()
4053	* directly for cross-vCPU checks is functionally correct and accurate.
4054	*/
4055	bool __weak kvm_arch_vcpu_preempted_in_kernel(struct kvm_vcpu *vcpu)
4056	{
4057	return kvm_arch_vcpu_in_kernel(vcpu);
4058	}
4059
4060	bool __weak kvm_arch_dy_has_pending_interrupt(struct kvm_vcpu *vcpu)
4061	{
4062	return false;
4063	}
4064
4065	void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode)
4066	{
4067	struct kvm *kvm = me->kvm;
4068	struct kvm_vcpu *vcpu;
4069	int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
4070	unsigned long i;
4071	int yielded = 0;
4072	int try = 3;
4073	int pass;
4074
4075	kvm_vcpu_set_in_spin_loop(vcpu: me, val: true);
4076	/*
4077	* We boost the priority of a VCPU that is runnable but not
4078	* currently running, because it got preempted by something
4079	* else and called schedule in __vcpu_run. Hopefully that
4080	* VCPU is holding the lock that we need and will release it.
4081	* We approximate round-robin by starting at the last boosted VCPU.
4082	*/
4083	for (pass = 0; pass < 2 && !yielded && try; pass++) {
4084	kvm_for_each_vcpu(i, vcpu, kvm) {
4085	if (!pass && i <= last_boosted_vcpu) {
4086	i = last_boosted_vcpu;
4087	continue;
4088	} else if (pass && i > last_boosted_vcpu)
4089	break;
4090	if (!READ_ONCE(vcpu->ready))
4091	continue;
4092	if (vcpu == me)
4093	continue;
4094	if (kvm_vcpu_is_blocking(vcpu) && !vcpu_dy_runnable(vcpu))
4095	continue;
4096
4097	/*
4098	* Treat the target vCPU as being in-kernel if it has a
4099	* pending interrupt, as the vCPU trying to yield may
4100	* be spinning waiting on IPI delivery, i.e. the target
4101	* vCPU is in-kernel for the purposes of directed yield.
4102	*/
4103	if (READ_ONCE(vcpu->preempted) && yield_to_kernel_mode &&
4104	!kvm_arch_dy_has_pending_interrupt(vcpu) &&
4105	!kvm_arch_vcpu_preempted_in_kernel(vcpu))
4106	continue;
4107	if (!kvm_vcpu_eligible_for_directed_yield(vcpu))
4108	continue;
4109
4110	yielded = kvm_vcpu_yield_to(vcpu);
4111	if (yielded > 0) {
4112	kvm->last_boosted_vcpu = i;
4113	break;
4114	} else if (yielded < 0) {
4115	try--;
4116	if (!try)
4117	break;
4118	}
4119	}
4120	}
4121	kvm_vcpu_set_in_spin_loop(vcpu: me, val: false);
4122
4123	/* Ensure vcpu is not eligible during next spinloop */
4124	kvm_vcpu_set_dy_eligible(vcpu: me, val: false);
4125	}
4126	EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
4127
4128	static bool kvm_page_in_dirty_ring(struct kvm *kvm, unsigned long pgoff)
4129	{
4130	#ifdef CONFIG_HAVE_KVM_DIRTY_RING
4131	return (pgoff >= KVM_DIRTY_LOG_PAGE_OFFSET) &&
4132	(pgoff < KVM_DIRTY_LOG_PAGE_OFFSET +
4133	kvm->dirty_ring_size / PAGE_SIZE);
4134	#else
4135	return false;
4136	#endif
4137	}
4138
4139	static vm_fault_t kvm_vcpu_fault(struct vm_fault *vmf)
4140	{
4141	struct kvm_vcpu *vcpu = vmf->vma->vm_file->private_data;
4142	struct page *page;
4143
4144	if (vmf->pgoff == 0)
4145	page = virt_to_page(vcpu->run);
4146	#ifdef CONFIG_X86
4147	else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
4148	page = virt_to_page(vcpu->arch.pio_data);
4149	#endif
4150	#ifdef CONFIG_KVM_MMIO
4151	else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
4152	page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
4153	#endif
4154	else if (kvm_page_in_dirty_ring(kvm: vcpu->kvm, pgoff: vmf->pgoff))
4155	page = kvm_dirty_ring_get_page(
4156	ring: &vcpu->dirty_ring,
4157	offset: vmf->pgoff - KVM_DIRTY_LOG_PAGE_OFFSET);
4158	else
4159	return kvm_arch_vcpu_fault(vcpu, vmf);
4160	get_page(page);
4161	vmf->page = page;
4162	return 0;
4163	}
4164
4165	static const struct vm_operations_struct kvm_vcpu_vm_ops = {
4166	.fault = kvm_vcpu_fault,
4167	};
4168
4169	static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
4170	{
4171	struct kvm_vcpu *vcpu = file->private_data;
4172	unsigned long pages = vma_pages(vma);
4173
4174	if ((kvm_page_in_dirty_ring(kvm: vcpu->kvm, pgoff: vma->vm_pgoff) ||
4175	kvm_page_in_dirty_ring(kvm: vcpu->kvm, pgoff: vma->vm_pgoff + pages - 1)) &&
4176	((vma->vm_flags & VM_EXEC) || !(vma->vm_flags & VM_SHARED)))
4177	return -EINVAL;
4178
4179	vma->vm_ops = &kvm_vcpu_vm_ops;
4180	return 0;
4181	}
4182
4183	static int kvm_vcpu_release(struct inode *inode, struct file *filp)
4184	{
4185	struct kvm_vcpu *vcpu = filp->private_data;
4186
4187	kvm_put_kvm(vcpu->kvm);
4188	return 0;
4189	}
4190
4191	static struct file_operations kvm_vcpu_fops = {
4192	.release = kvm_vcpu_release,
4193	.unlocked_ioctl = kvm_vcpu_ioctl,
4194	.mmap = kvm_vcpu_mmap,
4195	.llseek = noop_llseek,
4196	KVM_COMPAT(kvm_vcpu_compat_ioctl),
4197	};
4198
4199	/*
4200	* Allocates an inode for the vcpu.
4201	*/
4202	static int create_vcpu_fd(struct kvm_vcpu *vcpu)
4203	{
4204	char name[8 + 1 + ITOA_MAX_LEN + 1];
4205
4206	snprintf(buf: name, size: sizeof(name), fmt: "kvm-vcpu:%d", vcpu->vcpu_id);
4207	return anon_inode_getfd(name, fops: &kvm_vcpu_fops, priv: vcpu, O_RDWR | O_CLOEXEC);
4208	}
4209
4210	#ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
4211	static int vcpu_get_pid(void *data, u64 *val)
4212	{
4213	struct kvm_vcpu *vcpu = data;
4214
4215	rcu_read_lock();
4216	*val = pid_nr(rcu_dereference(vcpu->pid));
4217	rcu_read_unlock();
4218	return 0;
4219	}
4220
4221	DEFINE_SIMPLE_ATTRIBUTE(vcpu_get_pid_fops, vcpu_get_pid, NULL, "%llu\n");
4222
4223	static void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
4224	{
4225	struct dentry *debugfs_dentry;
4226	char dir_name[ITOA_MAX_LEN * 2];
4227
4228	if (!debugfs_initialized())
4229	return;
4230
4231	snprintf(buf: dir_name, size: sizeof(dir_name), fmt: "vcpu%d", vcpu->vcpu_id);
4232	debugfs_dentry = debugfs_create_dir(name: dir_name,
4233	parent: vcpu->kvm->debugfs_dentry);
4234	debugfs_create_file(name: "pid", mode: 0444, parent: debugfs_dentry, data: vcpu,
4235	fops: &vcpu_get_pid_fops);
4236
4237	kvm_arch_create_vcpu_debugfs(vcpu, debugfs_dentry);
4238	}
4239	#endif
4240
4241	/*
4242	* Creates some virtual cpus. Good luck creating more than one.
4243	*/
4244	static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
4245	{
4246	int r;
4247	struct kvm_vcpu *vcpu;
4248	struct page *page;
4249
4250	if (id >= KVM_MAX_VCPU_IDS)
4251	return -EINVAL;
4252
4253	mutex_lock(&kvm->lock);
4254	if (kvm->created_vcpus >= kvm->max_vcpus) {
4255	mutex_unlock(lock: &kvm->lock);
4256	return -EINVAL;
4257	}
4258
4259	r = kvm_arch_vcpu_precreate(kvm, id);
4260	if (r) {
4261	mutex_unlock(lock: &kvm->lock);
4262	return r;
4263	}
4264
4265	kvm->created_vcpus++;
4266	mutex_unlock(lock: &kvm->lock);
4267
4268	vcpu = kmem_cache_zalloc(k: kvm_vcpu_cache, GFP_KERNEL_ACCOUNT);
4269	if (!vcpu) {
4270	r = -ENOMEM;
4271	goto vcpu_decrement;
4272	}
4273
4274	BUILD_BUG_ON(sizeof(struct kvm_run) > PAGE_SIZE);
4275	page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
4276	if (!page) {
4277	r = -ENOMEM;
4278	goto vcpu_free;
4279	}
4280	vcpu->run = page_address(page);
4281
4282	kvm_vcpu_init(vcpu, kvm, id);
4283
4284	r = kvm_arch_vcpu_create(vcpu);
4285	if (r)
4286	goto vcpu_free_run_page;
4287
4288	if (kvm->dirty_ring_size) {
4289	r = kvm_dirty_ring_alloc(ring: &vcpu->dirty_ring,
4290	index: id, size: kvm->dirty_ring_size);
4291	if (r)
4292	goto arch_vcpu_destroy;
4293	}
4294
4295	mutex_lock(&kvm->lock);
4296
4297	#ifdef CONFIG_LOCKDEP
4298	/* Ensure that lockdep knows vcpu->mutex is taken *inside* kvm->lock */
4299	mutex_lock(&vcpu->mutex);
4300	mutex_unlock(lock: &vcpu->mutex);
4301	#endif
4302
4303	if (kvm_get_vcpu_by_id(kvm, id)) {
4304	r = -EEXIST;
4305	goto unlock_vcpu_destroy;
4306	}
4307
4308	vcpu->vcpu_idx = atomic_read(v: &kvm->online_vcpus);
4309	r = xa_reserve(xa: &kvm->vcpu_array, index: vcpu->vcpu_idx, GFP_KERNEL_ACCOUNT);
4310	if (r)
4311	goto unlock_vcpu_destroy;
4312
4313	/* Now it's all set up, let userspace reach it */
4314	kvm_get_kvm(kvm);
4315	r = create_vcpu_fd(vcpu);
4316	if (r < 0)
4317	goto kvm_put_xa_release;
4318
4319	if (KVM_BUG_ON(xa_store(&kvm->vcpu_array, vcpu->vcpu_idx, vcpu, 0), kvm)) {
4320	r = -EINVAL;
4321	goto kvm_put_xa_release;
4322	}
4323
4324	/*
4325	* Pairs with smp_rmb() in kvm_get_vcpu. Store the vcpu
4326	* pointer before kvm->online_vcpu's incremented value.
4327	*/
4328	smp_wmb();
4329	atomic_inc(v: &kvm->online_vcpus);
4330
4331	mutex_unlock(lock: &kvm->lock);
4332	kvm_arch_vcpu_postcreate(vcpu);
4333	kvm_create_vcpu_debugfs(vcpu);
4334	return r;
4335
4336	kvm_put_xa_release:
4337	kvm_put_kvm_no_destroy(kvm);
4338	xa_release(xa: &kvm->vcpu_array, index: vcpu->vcpu_idx);
4339	unlock_vcpu_destroy:
4340	mutex_unlock(lock: &kvm->lock);
4341	kvm_dirty_ring_free(ring: &vcpu->dirty_ring);
4342	arch_vcpu_destroy:
4343	kvm_arch_vcpu_destroy(vcpu);
4344	vcpu_free_run_page:
4345	free_page((unsigned long)vcpu->run);
4346	vcpu_free:
4347	kmem_cache_free(s: kvm_vcpu_cache, objp: vcpu);
4348	vcpu_decrement:
4349	mutex_lock(&kvm->lock);
4350	kvm->created_vcpus--;
4351	mutex_unlock(lock: &kvm->lock);
4352	return r;
4353	}
4354
4355	static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
4356	{
4357	if (sigset) {
4358	sigdelsetmask(set: sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
4359	vcpu->sigset_active = 1;
4360	vcpu->sigset = *sigset;
4361	} else
4362	vcpu->sigset_active = 0;
4363	return 0;
4364	}
4365
4366	static ssize_t kvm_vcpu_stats_read(struct file *file, char __user *user_buffer,
4367	size_t size, loff_t *offset)
4368	{
4369	struct kvm_vcpu *vcpu = file->private_data;
4370
4371	return kvm_stats_read(id: vcpu->stats_id, header: &kvm_vcpu_stats_header,
4372	desc: &kvm_vcpu_stats_desc[0], stats: &vcpu->stat,
4373	size_stats: sizeof(vcpu->stat), user_buffer, size, offset);
4374	}
4375
4376	static int kvm_vcpu_stats_release(struct inode *inode, struct file *file)
4377	{
4378	struct kvm_vcpu *vcpu = file->private_data;
4379
4380	kvm_put_kvm(vcpu->kvm);
4381	return 0;
4382	}
4383
4384	static const struct file_operations kvm_vcpu_stats_fops = {
4385	.owner = THIS_MODULE,
4386	.read = kvm_vcpu_stats_read,
4387	.release = kvm_vcpu_stats_release,
4388	.llseek = noop_llseek,
4389	};
4390
4391	static int kvm_vcpu_ioctl_get_stats_fd(struct kvm_vcpu *vcpu)
4392	{
4393	int fd;
4394	struct file *file;
4395	char name[15 + ITOA_MAX_LEN + 1];
4396
4397	snprintf(buf: name, size: sizeof(name), fmt: "kvm-vcpu-stats:%d", vcpu->vcpu_id);
4398
4399	fd = get_unused_fd_flags(O_CLOEXEC);
4400	if (fd < 0)
4401	return fd;
4402
4403	file = anon_inode_getfile(name, fops: &kvm_vcpu_stats_fops, priv: vcpu, O_RDONLY);
4404	if (IS_ERR(ptr: file)) {
4405	put_unused_fd(fd);
4406	return PTR_ERR(ptr: file);
4407	}
4408
4409	kvm_get_kvm(vcpu->kvm);
4410
4411	file->f_mode |= FMODE_PREAD;
4412	fd_install(fd, file);
4413
4414	return fd;
4415	}
4416
4417	static long kvm_vcpu_ioctl(struct file *filp,
4418	unsigned int ioctl, unsigned long arg)
4419	{
4420	struct kvm_vcpu *vcpu = filp->private_data;
4421	void __user *argp = (void __user *)arg;
4422	int r;
4423	struct kvm_fpu *fpu = NULL;
4424	struct kvm_sregs *kvm_sregs = NULL;
4425
4426	if (vcpu->kvm->mm != current->mm || vcpu->kvm->vm_dead)
4427	return -EIO;
4428
4429	if (unlikely(_IOC_TYPE(ioctl) != KVMIO))
4430	return -EINVAL;
4431
4432	/*
4433	* Some architectures have vcpu ioctls that are asynchronous to vcpu
4434	* execution; mutex_lock() would break them.
4435	*/
4436	r = kvm_arch_vcpu_async_ioctl(filp, ioctl, arg);
4437	if (r != -ENOIOCTLCMD)
4438	return r;
4439
4440	if (mutex_lock_killable(&vcpu->mutex))
4441	return -EINTR;
4442	switch (ioctl) {
4443	case KVM_RUN: {
4444	struct pid *oldpid;
4445	r = -EINVAL;
4446	if (arg)
4447	goto out;
4448	oldpid = rcu_access_pointer(vcpu->pid);
4449	if (unlikely(oldpid != task_pid(current))) {
4450	/* The thread running this VCPU changed. */
4451	struct pid *newpid;
4452
4453	r = kvm_arch_vcpu_run_pid_change(vcpu);
4454	if (r)
4455	break;
4456
4457	newpid = get_task_pid(current, type: PIDTYPE_PID);
4458	rcu_assign_pointer(vcpu->pid, newpid);
4459	if (oldpid)
4460	synchronize_rcu();
4461	put_pid(pid: oldpid);
4462	}
4463	r = kvm_arch_vcpu_ioctl_run(vcpu);
4464	trace_kvm_userspace_exit(reason: vcpu->run->exit_reason, errno: r);
4465	break;
4466	}
4467	case KVM_GET_REGS: {
4468	struct kvm_regs *kvm_regs;
4469
4470	r = -ENOMEM;
4471	kvm_regs = kzalloc(size: sizeof(struct kvm_regs), GFP_KERNEL_ACCOUNT);
4472	if (!kvm_regs)
4473	goto out;
4474	r = kvm_arch_vcpu_ioctl_get_regs(vcpu, regs: kvm_regs);
4475	if (r)
4476	goto out_free1;
4477	r = -EFAULT;
4478	if (copy_to_user(to: argp, from: kvm_regs, n: sizeof(struct kvm_regs)))
4479	goto out_free1;
4480	r = 0;
4481	out_free1:
4482	kfree(objp: kvm_regs);
4483	break;
4484	}
4485	case KVM_SET_REGS: {
4486	struct kvm_regs *kvm_regs;
4487
4488	kvm_regs = memdup_user(argp, sizeof(*kvm_regs));
4489	if (IS_ERR(ptr: kvm_regs)) {
4490	r = PTR_ERR(ptr: kvm_regs);
4491	goto out;
4492	}
4493	r = kvm_arch_vcpu_ioctl_set_regs(vcpu, regs: kvm_regs);
4494	kfree(objp: kvm_regs);
4495	break;
4496	}
4497	case KVM_GET_SREGS: {
4498	kvm_sregs = kzalloc(size: sizeof(struct kvm_sregs),
4499	GFP_KERNEL_ACCOUNT);
4500	r = -ENOMEM;
4501	if (!kvm_sregs)
4502	goto out;
4503	r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, sregs: kvm_sregs);
4504	if (r)
4505	goto out;
4506	r = -EFAULT;
4507	if (copy_to_user(to: argp, from: kvm_sregs, n: sizeof(struct kvm_sregs)))
4508	goto out;
4509	r = 0;
4510	break;
4511	}
4512	case KVM_SET_SREGS: {
4513	kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs));
4514	if (IS_ERR(ptr: kvm_sregs)) {
4515	r = PTR_ERR(ptr: kvm_sregs);
4516	kvm_sregs = NULL;
4517	goto out;
4518	}
4519	r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, sregs: kvm_sregs);
4520	break;
4521	}
4522	case KVM_GET_MP_STATE: {
4523	struct kvm_mp_state mp_state;
4524
4525	r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, mp_state: &mp_state);
4526	if (r)
4527	goto out;
4528	r = -EFAULT;
4529	if (copy_to_user(to: argp, from: &mp_state, n: sizeof(mp_state)))
4530	goto out;
4531	r = 0;
4532	break;
4533	}
4534	case KVM_SET_MP_STATE: {
4535	struct kvm_mp_state mp_state;
4536
4537	r = -EFAULT;
4538	if (copy_from_user(to: &mp_state, from: argp, n: sizeof(mp_state)))
4539	goto out;
4540	r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, mp_state: &mp_state);
4541	break;
4542	}
4543	case KVM_TRANSLATE: {
4544	struct kvm_translation tr;
4545
4546	r = -EFAULT;
4547	if (copy_from_user(to: &tr, from: argp, n: sizeof(tr)))
4548	goto out;
4549	r = kvm_arch_vcpu_ioctl_translate(vcpu, tr: &tr);
4550	if (r)
4551	goto out;
4552	r = -EFAULT;
4553	if (copy_to_user(to: argp, from: &tr, n: sizeof(tr)))
4554	goto out;
4555	r = 0;
4556	break;
4557	}
4558	case KVM_SET_GUEST_DEBUG: {
4559	struct kvm_guest_debug dbg;
4560
4561	r = -EFAULT;
4562	if (copy_from_user(to: &dbg, from: argp, n: sizeof(dbg)))
4563	goto out;
4564	r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, dbg: &dbg);
4565	break;
4566	}
4567	case KVM_SET_SIGNAL_MASK: {
4568	struct kvm_signal_mask __user *sigmask_arg = argp;
4569	struct kvm_signal_mask kvm_sigmask;
4570	sigset_t sigset, *p;
4571
4572	p = NULL;
4573	if (argp) {
4574	r = -EFAULT;
4575	if (copy_from_user(to: &kvm_sigmask, from: argp,
4576	n: sizeof(kvm_sigmask)))
4577	goto out;
4578	r = -EINVAL;
4579	if (kvm_sigmask.len != sizeof(sigset))
4580	goto out;
4581	r = -EFAULT;
4582	if (copy_from_user(to: &sigset, from: sigmask_arg->sigset,
4583	n: sizeof(sigset)))
4584	goto out;
4585	p = &sigset;
4586	}
4587	r = kvm_vcpu_ioctl_set_sigmask(vcpu, sigset: p);
4588	break;
4589	}
4590	case KVM_GET_FPU: {
4591	fpu = kzalloc(size: sizeof(struct kvm_fpu), GFP_KERNEL_ACCOUNT);
4592	r = -ENOMEM;
4593	if (!fpu)
4594	goto out;
4595	r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
4596	if (r)
4597	goto out;
4598	r = -EFAULT;
4599	if (copy_to_user(to: argp, from: fpu, n: sizeof(struct kvm_fpu)))
4600	goto out;
4601	r = 0;
4602	break;
4603	}
4604	case KVM_SET_FPU: {
4605	fpu = memdup_user(argp, sizeof(*fpu));
4606	if (IS_ERR(ptr: fpu)) {
4607	r = PTR_ERR(ptr: fpu);
4608	fpu = NULL;
4609	goto out;
4610	}
4611	r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
4612	break;
4613	}
4614	case KVM_GET_STATS_FD: {
4615	r = kvm_vcpu_ioctl_get_stats_fd(vcpu);
4616	break;
4617	}
4618	default:
4619	r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
4620	}
4621	out:
4622	mutex_unlock(lock: &vcpu->mutex);
4623	kfree(objp: fpu);
4624	kfree(objp: kvm_sregs);
4625	return r;
4626	}
4627
4628	#ifdef CONFIG_KVM_COMPAT
4629	static long kvm_vcpu_compat_ioctl(struct file *filp,
4630	unsigned int ioctl, unsigned long arg)
4631	{
4632	struct kvm_vcpu *vcpu = filp->private_data;
4633	void __user *argp = compat_ptr(uptr: arg);
4634	int r;
4635
4636	if (vcpu->kvm->mm != current->mm || vcpu->kvm->vm_dead)
4637	return -EIO;
4638
4639	switch (ioctl) {
4640	case KVM_SET_SIGNAL_MASK: {
4641	struct kvm_signal_mask __user *sigmask_arg = argp;
4642	struct kvm_signal_mask kvm_sigmask;
4643	sigset_t sigset;
4644
4645	if (argp) {
4646	r = -EFAULT;
4647	if (copy_from_user(to: &kvm_sigmask, from: argp,
4648	n: sizeof(kvm_sigmask)))
4649	goto out;
4650	r = -EINVAL;
4651	if (kvm_sigmask.len != sizeof(compat_sigset_t))
4652	goto out;
4653	r = -EFAULT;
4654	if (get_compat_sigset(set: &sigset,
4655	compat: (compat_sigset_t __user *)sigmask_arg->sigset))
4656	goto out;
4657	r = kvm_vcpu_ioctl_set_sigmask(vcpu, sigset: &sigset);
4658	} else
4659	r = kvm_vcpu_ioctl_set_sigmask(vcpu, NULL);
4660	break;
4661	}
4662	default:
4663	r = kvm_vcpu_ioctl(filp, ioctl, arg);
4664	}
4665
4666	out:
4667	return r;
4668	}
4669	#endif
4670
4671	static int kvm_device_mmap(struct file *filp, struct vm_area_struct *vma)
4672	{
4673	struct kvm_device *dev = filp->private_data;
4674
4675	if (dev->ops->mmap)
4676	return dev->ops->mmap(dev, vma);
4677
4678	return -ENODEV;
4679	}
4680
4681	static int kvm_device_ioctl_attr(struct kvm_device *dev,
4682	int (*accessor)(struct kvm_device *dev,
4683	struct kvm_device_attr *attr),
4684	unsigned long arg)
4685	{
4686	struct kvm_device_attr attr;
4687
4688	if (!accessor)
4689	return -EPERM;
4690
4691	if (copy_from_user(to: &attr, from: (void __user *)arg, n: sizeof(attr)))
4692	return -EFAULT;
4693
4694	return accessor(dev, &attr);
4695	}
4696
4697	static long kvm_device_ioctl(struct file *filp, unsigned int ioctl,
4698	unsigned long arg)
4699	{
4700	struct kvm_device *dev = filp->private_data;
4701
4702	if (dev->kvm->mm != current->mm || dev->kvm->vm_dead)
4703	return -EIO;
4704
4705	switch (ioctl) {
4706	case KVM_SET_DEVICE_ATTR:
4707	return kvm_device_ioctl_attr(dev, accessor: dev->ops->set_attr, arg);
4708	case KVM_GET_DEVICE_ATTR:
4709	return kvm_device_ioctl_attr(dev, accessor: dev->ops->get_attr, arg);
4710	case KVM_HAS_DEVICE_ATTR:
4711	return kvm_device_ioctl_attr(dev, accessor: dev->ops->has_attr, arg);
4712	default:
4713	if (dev->ops->ioctl)
4714	return dev->ops->ioctl(dev, ioctl, arg);
4715
4716	return -ENOTTY;
4717	}
4718	}
4719
4720	static int kvm_device_release(struct inode *inode, struct file *filp)
4721	{
4722	struct kvm_device *dev = filp->private_data;
4723	struct kvm *kvm = dev->kvm;
4724
4725	if (dev->ops->release) {
4726	mutex_lock(&kvm->lock);
4727	list_del(entry: &dev->vm_node);
4728	dev->ops->release(dev);
4729	mutex_unlock(lock: &kvm->lock);
4730	}
4731
4732	kvm_put_kvm(kvm);
4733	return 0;
4734	}
4735
4736	static struct file_operations kvm_device_fops = {
4737	.unlocked_ioctl = kvm_device_ioctl,
4738	.release = kvm_device_release,
4739	KVM_COMPAT(kvm_device_ioctl),
4740	.mmap = kvm_device_mmap,
4741	};
4742
4743	struct kvm_device *kvm_device_from_filp(struct file *filp)
4744	{
4745	if (filp->f_op != &kvm_device_fops)
4746	return NULL;
4747
4748	return filp->private_data;
4749	}
4750
4751	static const struct kvm_device_ops *kvm_device_ops_table[KVM_DEV_TYPE_MAX] = {
4752	#ifdef CONFIG_KVM_MPIC
4753	[KVM_DEV_TYPE_FSL_MPIC_20] = &kvm_mpic_ops,
4754	[KVM_DEV_TYPE_FSL_MPIC_42] = &kvm_mpic_ops,
4755	#endif
4756	};
4757
4758	int kvm_register_device_ops(const struct kvm_device_ops *ops, u32 type)
4759	{
4760	if (type >= ARRAY_SIZE(kvm_device_ops_table))
4761	return -ENOSPC;
4762
4763	if (kvm_device_ops_table[type] != NULL)
4764	return -EEXIST;
4765
4766	kvm_device_ops_table[type] = ops;
4767	return 0;
4768	}
4769
4770	void kvm_unregister_device_ops(u32 type)
4771	{
4772	if (kvm_device_ops_table[type] != NULL)
4773	kvm_device_ops_table[type] = NULL;
4774	}
4775
4776	static int kvm_ioctl_create_device(struct kvm *kvm,
4777	struct kvm_create_device *cd)
4778	{
4779	const struct kvm_device_ops *ops;
4780	struct kvm_device *dev;
4781	bool test = cd->flags & KVM_CREATE_DEVICE_TEST;
4782	int type;
4783	int ret;
4784
4785	if (cd->type >= ARRAY_SIZE(kvm_device_ops_table))
4786	return -ENODEV;
4787
4788	type = array_index_nospec(cd->type, ARRAY_SIZE(kvm_device_ops_table));
4789	ops = kvm_device_ops_table[type];
4790	if (ops == NULL)
4791	return -ENODEV;
4792
4793	if (test)
4794	return 0;
4795
4796	dev = kzalloc(size: sizeof(*dev), GFP_KERNEL_ACCOUNT);
4797	if (!dev)
4798	return -ENOMEM;
4799
4800	dev->ops = ops;
4801	dev->kvm = kvm;
4802
4803	mutex_lock(&kvm->lock);
4804	ret = ops->create(dev, type);
4805	if (ret < 0) {
4806	mutex_unlock(lock: &kvm->lock);
4807	kfree(objp: dev);
4808	return ret;
4809	}
4810	list_add(new: &dev->vm_node, head: &kvm->devices);
4811	mutex_unlock(lock: &kvm->lock);
4812
4813	if (ops->init)
4814	ops->init(dev);
4815
4816	kvm_get_kvm(kvm);
4817	ret = anon_inode_getfd(name: ops->name, fops: &kvm_device_fops, priv: dev, O_RDWR | O_CLOEXEC);
4818	if (ret < 0) {
4819	kvm_put_kvm_no_destroy(kvm);
4820	mutex_lock(&kvm->lock);
4821	list_del(entry: &dev->vm_node);
4822	if (ops->release)
4823	ops->release(dev);
4824	mutex_unlock(lock: &kvm->lock);
4825	if (ops->destroy)
4826	ops->destroy(dev);
4827	return ret;
4828	}
4829
4830	cd->fd = ret;
4831	return 0;
4832	}
4833
4834	static int kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
4835	{
4836	switch (arg) {
4837	case KVM_CAP_USER_MEMORY:
4838	case KVM_CAP_USER_MEMORY2:
4839	case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
4840	case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
4841	case KVM_CAP_INTERNAL_ERROR_DATA:
4842	#ifdef CONFIG_HAVE_KVM_MSI
4843	case KVM_CAP_SIGNAL_MSI:
4844	#endif
4845	#ifdef CONFIG_HAVE_KVM_IRQCHIP
4846	case KVM_CAP_IRQFD:
4847	#endif
4848	case KVM_CAP_IOEVENTFD_ANY_LENGTH:
4849	case KVM_CAP_CHECK_EXTENSION_VM:
4850	case KVM_CAP_ENABLE_CAP_VM:
4851	case KVM_CAP_HALT_POLL:
4852	return 1;
4853	#ifdef CONFIG_KVM_MMIO
4854	case KVM_CAP_COALESCED_MMIO:
4855	return KVM_COALESCED_MMIO_PAGE_OFFSET;
4856	case KVM_CAP_COALESCED_PIO:
4857	return 1;
4858	#endif
4859	#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
4860	case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2:
4861	return KVM_DIRTY_LOG_MANUAL_CAPS;
4862	#endif
4863	#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
4864	case KVM_CAP_IRQ_ROUTING:
4865	return KVM_MAX_IRQ_ROUTES;
4866	#endif
4867	#if KVM_MAX_NR_ADDRESS_SPACES > 1
4868	case KVM_CAP_MULTI_ADDRESS_SPACE:
4869	if (kvm)
4870	return kvm_arch_nr_memslot_as_ids(kvm);
4871	return KVM_MAX_NR_ADDRESS_SPACES;
4872	#endif
4873	case KVM_CAP_NR_MEMSLOTS:
4874	return KVM_USER_MEM_SLOTS;
4875	case KVM_CAP_DIRTY_LOG_RING:
4876	#ifdef CONFIG_HAVE_KVM_DIRTY_RING_TSO
4877	return KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn);
4878	#else
4879	return 0;
4880	#endif
4881	case KVM_CAP_DIRTY_LOG_RING_ACQ_REL:
4882	#ifdef CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL
4883	return KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn);
4884	#else
4885	return 0;
4886	#endif
4887	#ifdef CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP
4888	case KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP:
4889	#endif
4890	case KVM_CAP_BINARY_STATS_FD:
4891	case KVM_CAP_SYSTEM_EVENT_DATA:
4892	case KVM_CAP_DEVICE_CTRL:
4893	return 1;
4894	#ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES
4895	case KVM_CAP_MEMORY_ATTRIBUTES:
4896	return kvm_supported_mem_attributes(kvm);
4897	#endif
4898	#ifdef CONFIG_KVM_PRIVATE_MEM
4899	case KVM_CAP_GUEST_MEMFD:
4900	return !kvm || kvm_arch_has_private_mem(kvm);
4901	#endif
4902	default:
4903	break;
4904	}
4905	return kvm_vm_ioctl_check_extension(kvm, ext: arg);
4906	}
4907
4908	static int kvm_vm_ioctl_enable_dirty_log_ring(struct kvm *kvm, u32 size)
4909	{
4910	int r;
4911
4912	if (!KVM_DIRTY_LOG_PAGE_OFFSET)
4913	return -EINVAL;
4914
4915	/* the size should be power of 2 */
4916	if (!size || (size & (size - 1)))
4917	return -EINVAL;
4918
4919	/* Should be bigger to keep the reserved entries, or a page */
4920	if (size < kvm_dirty_ring_get_rsvd_entries() *
4921	sizeof(struct kvm_dirty_gfn) || size < PAGE_SIZE)
4922	return -EINVAL;
4923
4924	if (size > KVM_DIRTY_RING_MAX_ENTRIES *
4925	sizeof(struct kvm_dirty_gfn))
4926	return -E2BIG;
4927
4928	/* We only allow it to set once */
4929	if (kvm->dirty_ring_size)
4930	return -EINVAL;
4931
4932	mutex_lock(&kvm->lock);
4933
4934	if (kvm->created_vcpus) {
4935	/* We don't allow to change this value after vcpu created */
4936	r = -EINVAL;
4937	} else {
4938	kvm->dirty_ring_size = size;
4939	r = 0;
4940	}
4941
4942	mutex_unlock(lock: &kvm->lock);
4943	return r;
4944	}
4945
4946	static int kvm_vm_ioctl_reset_dirty_pages(struct kvm *kvm)
4947	{
4948	unsigned long i;
4949	struct kvm_vcpu *vcpu;
4950	int cleared = 0;
4951
4952	if (!kvm->dirty_ring_size)
4953	return -EINVAL;
4954
4955	mutex_lock(&kvm->slots_lock);
4956
4957	kvm_for_each_vcpu(i, vcpu, kvm)
4958	cleared += kvm_dirty_ring_reset(kvm: vcpu->kvm, ring: &vcpu->dirty_ring);
4959
4960	mutex_unlock(lock: &kvm->slots_lock);
4961
4962	if (cleared)
4963	kvm_flush_remote_tlbs(kvm);
4964
4965	return cleared;
4966	}
4967
4968	int __attribute__((weak)) kvm_vm_ioctl_enable_cap(struct kvm *kvm,
4969	struct kvm_enable_cap *cap)
4970	{
4971	return -EINVAL;
4972	}
4973
4974	bool kvm_are_all_memslots_empty(struct kvm *kvm)
4975	{
4976	int i;
4977
4978	lockdep_assert_held(&kvm->slots_lock);
4979
4980	for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) {
4981	if (!kvm_memslots_empty(slots: __kvm_memslots(kvm, as_id: i)))
4982	return false;
4983	}
4984
4985	return true;
4986	}
4987	EXPORT_SYMBOL_GPL(kvm_are_all_memslots_empty);
4988
4989	static int kvm_vm_ioctl_enable_cap_generic(struct kvm *kvm,
4990	struct kvm_enable_cap *cap)
4991	{
4992	switch (cap->cap) {
4993	#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
4994	case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2: {
4995	u64 allowed_options = KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE;
4996
4997	if (cap->args[0] & KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE)
4998	allowed_options = KVM_DIRTY_LOG_MANUAL_CAPS;
4999
5000	if (cap->flags || (cap->args[0] & ~allowed_options))
5001	return -EINVAL;
5002	kvm->manual_dirty_log_protect = cap->args[0];
5003	return 0;
5004	}
5005	#endif
5006	case KVM_CAP_HALT_POLL: {
5007	if (cap->flags || cap->args[0] != (unsigned int)cap->args[0])
5008	return -EINVAL;
5009
5010	kvm->max_halt_poll_ns = cap->args[0];
5011
5012	/*
5013	* Ensure kvm->override_halt_poll_ns does not become visible
5014	* before kvm->max_halt_poll_ns.
5015	*
5016	* Pairs with the smp_rmb() in kvm_vcpu_max_halt_poll_ns().
5017	*/
5018	smp_wmb();
5019	kvm->override_halt_poll_ns = true;
5020
5021	return 0;
5022	}
5023	case KVM_CAP_DIRTY_LOG_RING:
5024	case KVM_CAP_DIRTY_LOG_RING_ACQ_REL:
5025	if (!kvm_vm_ioctl_check_extension_generic(kvm, arg: cap->cap))
5026	return -EINVAL;
5027
5028	return kvm_vm_ioctl_enable_dirty_log_ring(kvm, size: cap->args[0]);
5029	case KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP: {
5030	int r = -EINVAL;
5031
5032	if (!IS_ENABLED(CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP) ||
5033	!kvm->dirty_ring_size || cap->flags)
5034	return r;
5035
5036	mutex_lock(&kvm->slots_lock);
5037
5038	/*
5039	* For simplicity, allow enabling ring+bitmap if and only if
5040	* there are no memslots, e.g. to ensure all memslots allocate
5041	* a bitmap after the capability is enabled.
5042	*/
5043	if (kvm_are_all_memslots_empty(kvm)) {
5044	kvm->dirty_ring_with_bitmap = true;
5045	r = 0;
5046	}
5047
5048	mutex_unlock(lock: &kvm->slots_lock);
5049
5050	return r;
5051	}
5052	default:
5053	return kvm_vm_ioctl_enable_cap(kvm, cap);
5054	}
5055	}
5056
5057	static ssize_t kvm_vm_stats_read(struct file *file, char __user *user_buffer,
5058	size_t size, loff_t *offset)
5059	{
5060	struct kvm *kvm = file->private_data;
5061
5062	return kvm_stats_read(id: kvm->stats_id, header: &kvm_vm_stats_header,
5063	desc: &kvm_vm_stats_desc[0], stats: &kvm->stat,
5064	size_stats: sizeof(kvm->stat), user_buffer, size, offset);
5065	}
5066
5067	static int kvm_vm_stats_release(struct inode *inode, struct file *file)
5068	{
5069	struct kvm *kvm = file->private_data;
5070
5071	kvm_put_kvm(kvm);
5072	return 0;
5073	}
5074
5075	static const struct file_operations kvm_vm_stats_fops = {
5076	.owner = THIS_MODULE,
5077	.read = kvm_vm_stats_read,
5078	.release = kvm_vm_stats_release,
5079	.llseek = noop_llseek,
5080	};
5081
5082	static int kvm_vm_ioctl_get_stats_fd(struct kvm *kvm)
5083	{
5084	int fd;
5085	struct file *file;
5086
5087	fd = get_unused_fd_flags(O_CLOEXEC);
5088	if (fd < 0)
5089	return fd;
5090
5091	file = anon_inode_getfile(name: "kvm-vm-stats",
5092	fops: &kvm_vm_stats_fops, priv: kvm, O_RDONLY);
5093	if (IS_ERR(ptr: file)) {
5094	put_unused_fd(fd);
5095	return PTR_ERR(ptr: file);
5096	}
5097
5098	kvm_get_kvm(kvm);
5099
5100	file->f_mode |= FMODE_PREAD;
5101	fd_install(fd, file);
5102
5103	return fd;
5104	}
5105
5106	#define SANITY_CHECK_MEM_REGION_FIELD(field) \
5107	do { \
5108	BUILD_BUG_ON(offsetof(struct kvm_userspace_memory_region, field) != \
5109	offsetof(struct kvm_userspace_memory_region2, field)); \
5110	BUILD_BUG_ON(sizeof_field(struct kvm_userspace_memory_region, field) != \
5111	sizeof_field(struct kvm_userspace_memory_region2, field)); \
5112	} while (0)
5113
5114	static long kvm_vm_ioctl(struct file *filp,
5115	unsigned int ioctl, unsigned long arg)
5116	{
5117	struct kvm *kvm = filp->private_data;
5118	void __user *argp = (void __user *)arg;
5119	int r;
5120
5121	if (kvm->mm != current->mm || kvm->vm_dead)
5122	return -EIO;
5123	switch (ioctl) {
5124	case KVM_CREATE_VCPU:
5125	r = kvm_vm_ioctl_create_vcpu(kvm, id: arg);
5126	break;
5127	case KVM_ENABLE_CAP: {
5128	struct kvm_enable_cap cap;
5129
5130	r = -EFAULT;
5131	if (copy_from_user(to: &cap, from: argp, n: sizeof(cap)))
5132	goto out;
5133	r = kvm_vm_ioctl_enable_cap_generic(kvm, cap: &cap);
5134	break;
5135	}
5136	case KVM_SET_USER_MEMORY_REGION2:
5137	case KVM_SET_USER_MEMORY_REGION: {
5138	struct kvm_userspace_memory_region2 mem;
5139	unsigned long size;
5140
5141	if (ioctl == KVM_SET_USER_MEMORY_REGION) {
5142	/*
5143	* Fields beyond struct kvm_userspace_memory_region shouldn't be
5144	* accessed, but avoid leaking kernel memory in case of a bug.
5145	*/
5146	memset(&mem, 0, sizeof(mem));
5147	size = sizeof(struct kvm_userspace_memory_region);
5148	} else {
5149	size = sizeof(struct kvm_userspace_memory_region2);
5150	}
5151
5152	/* Ensure the common parts of the two structs are identical. */
5153	SANITY_CHECK_MEM_REGION_FIELD(slot);
5154	SANITY_CHECK_MEM_REGION_FIELD(flags);
5155	SANITY_CHECK_MEM_REGION_FIELD(guest_phys_addr);
5156	SANITY_CHECK_MEM_REGION_FIELD(memory_size);
5157	SANITY_CHECK_MEM_REGION_FIELD(userspace_addr);
5158
5159	r = -EFAULT;
5160	if (copy_from_user(to: &mem, from: argp, n: size))
5161	goto out;
5162
5163	r = -EINVAL;
5164	if (ioctl == KVM_SET_USER_MEMORY_REGION &&
5165	(mem.flags & ~KVM_SET_USER_MEMORY_REGION_V1_FLAGS))
5166	goto out;
5167
5168	r = kvm_vm_ioctl_set_memory_region(kvm, mem: &mem);
5169	break;
5170	}
5171	case KVM_GET_DIRTY_LOG: {
5172	struct kvm_dirty_log log;
5173
5174	r = -EFAULT;
5175	if (copy_from_user(to: &log, from: argp, n: sizeof(log)))
5176	goto out;
5177	r = kvm_vm_ioctl_get_dirty_log(kvm, log: &log);
5178	break;
5179	}
5180	#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
5181	case KVM_CLEAR_DIRTY_LOG: {
5182	struct kvm_clear_dirty_log log;
5183
5184	r = -EFAULT;
5185	if (copy_from_user(to: &log, from: argp, n: sizeof(log)))
5186	goto out;
5187	r = kvm_vm_ioctl_clear_dirty_log(kvm, log: &log);
5188	break;
5189	}
5190	#endif
5191	#ifdef CONFIG_KVM_MMIO
5192	case KVM_REGISTER_COALESCED_MMIO: {
5193	struct kvm_coalesced_mmio_zone zone;
5194
5195	r = -EFAULT;
5196	if (copy_from_user(to: &zone, from: argp, n: sizeof(zone)))
5197	goto out;
5198	r = kvm_vm_ioctl_register_coalesced_mmio(kvm, zone: &zone);
5199	break;
5200	}
5201	case KVM_UNREGISTER_COALESCED_MMIO: {
5202	struct kvm_coalesced_mmio_zone zone;
5203
5204	r = -EFAULT;
5205	if (copy_from_user(to: &zone, from: argp, n: sizeof(zone)))
5206	goto out;
5207	r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, zone: &zone);
5208	break;
5209	}
5210	#endif
5211	case KVM_IRQFD: {
5212	struct kvm_irqfd data;
5213
5214	r = -EFAULT;
5215	if (copy_from_user(to: &data, from: argp, n: sizeof(data)))
5216	goto out;
5217	r = kvm_irqfd(kvm, args: &data);
5218	break;
5219	}
5220	case KVM_IOEVENTFD: {
5221	struct kvm_ioeventfd data;
5222
5223	r = -EFAULT;
5224	if (copy_from_user(to: &data, from: argp, n: sizeof(data)))
5225	goto out;
5226	r = kvm_ioeventfd(kvm, args: &data);
5227	break;
5228	}
5229	#ifdef CONFIG_HAVE_KVM_MSI
5230	case KVM_SIGNAL_MSI: {
5231	struct kvm_msi msi;
5232
5233	r = -EFAULT;
5234	if (copy_from_user(to: &msi, from: argp, n: sizeof(msi)))
5235	goto out;
5236	r = kvm_send_userspace_msi(kvm, msi: &msi);
5237	break;
5238	}
5239	#endif
5240	#ifdef __KVM_HAVE_IRQ_LINE
5241	case KVM_IRQ_LINE_STATUS:
5242	case KVM_IRQ_LINE: {
5243	struct kvm_irq_level irq_event;
5244
5245	r = -EFAULT;
5246	if (copy_from_user(to: &irq_event, from: argp, n: sizeof(irq_event)))
5247	goto out;
5248
5249	r = kvm_vm_ioctl_irq_line(kvm, irq_level: &irq_event,
5250	line_status: ioctl == KVM_IRQ_LINE_STATUS);
5251	if (r)
5252	goto out;
5253
5254	r = -EFAULT;
5255	if (ioctl == KVM_IRQ_LINE_STATUS) {
5256	if (copy_to_user(to: argp, from: &irq_event, n: sizeof(irq_event)))
5257	goto out;
5258	}
5259
5260	r = 0;
5261	break;
5262	}
5263	#endif
5264	#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
5265	case KVM_SET_GSI_ROUTING: {
5266	struct kvm_irq_routing routing;
5267	struct kvm_irq_routing __user *urouting;
5268	struct kvm_irq_routing_entry *entries = NULL;
5269
5270	r = -EFAULT;
5271	if (copy_from_user(to: &routing, from: argp, n: sizeof(routing)))
5272	goto out;
5273	r = -EINVAL;
5274	if (!kvm_arch_can_set_irq_routing(kvm))
5275	goto out;
5276	if (routing.nr > KVM_MAX_IRQ_ROUTES)
5277	goto out;
5278	if (routing.flags)
5279	goto out;
5280	if (routing.nr) {
5281	urouting = argp;
5282	entries = vmemdup_array_user(src: urouting->entries,
5283	n: routing.nr, size: sizeof(*entries));
5284	if (IS_ERR(ptr: entries)) {
5285	r = PTR_ERR(ptr: entries);
5286	goto out;
5287	}
5288	}
5289	r = kvm_set_irq_routing(kvm, entries, nr: routing.nr,
5290	flags: routing.flags);
5291	kvfree(addr: entries);
5292	break;
5293	}
5294	#endif /* CONFIG_HAVE_KVM_IRQ_ROUTING */
5295	#ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES
5296	case KVM_SET_MEMORY_ATTRIBUTES: {
5297	struct kvm_memory_attributes attrs;
5298
5299	r = -EFAULT;
5300	if (copy_from_user(to: &attrs, from: argp, n: sizeof(attrs)))
5301	goto out;
5302
5303	r = kvm_vm_ioctl_set_mem_attributes(kvm, attrs: &attrs);
5304	break;
5305	}
5306	#endif /* CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES */
5307	case KVM_CREATE_DEVICE: {
5308	struct kvm_create_device cd;
5309
5310	r = -EFAULT;
5311	if (copy_from_user(to: &cd, from: argp, n: sizeof(cd)))
5312	goto out;
5313
5314	r = kvm_ioctl_create_device(kvm, cd: &cd);
5315	if (r)
5316	goto out;
5317
5318	r = -EFAULT;
5319	if (copy_to_user(to: argp, from: &cd, n: sizeof(cd)))
5320	goto out;
5321
5322	r = 0;
5323	break;
5324	}
5325	case KVM_CHECK_EXTENSION:
5326	r = kvm_vm_ioctl_check_extension_generic(kvm, arg);
5327	break;
5328	case KVM_RESET_DIRTY_RINGS:
5329	r = kvm_vm_ioctl_reset_dirty_pages(kvm);
5330	break;
5331	case KVM_GET_STATS_FD:
5332	r = kvm_vm_ioctl_get_stats_fd(kvm);
5333	break;
5334	#ifdef CONFIG_KVM_PRIVATE_MEM
5335	case KVM_CREATE_GUEST_MEMFD: {
5336	struct kvm_create_guest_memfd guest_memfd;
5337
5338	r = -EFAULT;
5339	if (copy_from_user(to: &guest_memfd, from: argp, n: sizeof(guest_memfd)))
5340	goto out;
5341
5342	r = kvm_gmem_create(kvm, args: &guest_memfd);
5343	break;
5344	}
5345	#endif
5346	default:
5347	r = kvm_arch_vm_ioctl(filp, ioctl, arg);
5348	}
5349	out:
5350	return r;
5351	}
5352
5353	#ifdef CONFIG_KVM_COMPAT
5354	struct compat_kvm_dirty_log {
5355	__u32 slot;
5356	__u32 padding1;
5357	union {
5358	compat_uptr_t dirty_bitmap; /* one bit per page */
5359	__u64 padding2;
5360	};
5361	};
5362
5363	struct compat_kvm_clear_dirty_log {
5364	__u32 slot;
5365	__u32 num_pages;
5366	__u64 first_page;
5367	union {
5368	compat_uptr_t dirty_bitmap; /* one bit per page */
5369	__u64 padding2;
5370	};
5371	};
5372
5373	long __weak kvm_arch_vm_compat_ioctl(struct file *filp, unsigned int ioctl,
5374	unsigned long arg)
5375	{
5376	return -ENOTTY;
5377	}
5378
5379	static long kvm_vm_compat_ioctl(struct file *filp,
5380	unsigned int ioctl, unsigned long arg)
5381	{
5382	struct kvm *kvm = filp->private_data;
5383	int r;
5384
5385	if (kvm->mm != current->mm || kvm->vm_dead)
5386	return -EIO;
5387
5388	r = kvm_arch_vm_compat_ioctl(filp, ioctl, arg);
5389	if (r != -ENOTTY)
5390	return r;
5391
5392	switch (ioctl) {
5393	#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
5394	case KVM_CLEAR_DIRTY_LOG: {
5395	struct compat_kvm_clear_dirty_log compat_log;
5396	struct kvm_clear_dirty_log log;
5397
5398	if (copy_from_user(to: &compat_log, from: (void __user *)arg,
5399	n: sizeof(compat_log)))
5400	return -EFAULT;
5401	log.slot = compat_log.slot;
5402	log.num_pages = compat_log.num_pages;
5403	log.first_page = compat_log.first_page;
5404	log.padding2 = compat_log.padding2;
5405	log.dirty_bitmap = compat_ptr(uptr: compat_log.dirty_bitmap);
5406
5407	r = kvm_vm_ioctl_clear_dirty_log(kvm, log: &log);
5408	break;
5409	}
5410	#endif
5411	case KVM_GET_DIRTY_LOG: {
5412	struct compat_kvm_dirty_log compat_log;
5413	struct kvm_dirty_log log;
5414
5415	if (copy_from_user(to: &compat_log, from: (void __user *)arg,
5416	n: sizeof(compat_log)))
5417	return -EFAULT;
5418	log.slot = compat_log.slot;
5419	log.padding1 = compat_log.padding1;
5420	log.padding2 = compat_log.padding2;
5421	log.dirty_bitmap = compat_ptr(uptr: compat_log.dirty_bitmap);
5422
5423	r = kvm_vm_ioctl_get_dirty_log(kvm, log: &log);
5424	break;
5425	}
5426	default:
5427	r = kvm_vm_ioctl(filp, ioctl, arg);
5428	}
5429	return r;
5430	}
5431	#endif
5432
5433	static struct file_operations kvm_vm_fops = {
5434	.release = kvm_vm_release,
5435	.unlocked_ioctl = kvm_vm_ioctl,
5436	.llseek = noop_llseek,
5437	KVM_COMPAT(kvm_vm_compat_ioctl),
5438	};
5439
5440	bool file_is_kvm(struct file *file)
5441	{
5442	return file && file->f_op == &kvm_vm_fops;
5443	}
5444	EXPORT_SYMBOL_GPL(file_is_kvm);
5445
5446	static int kvm_dev_ioctl_create_vm(unsigned long type)
5447	{
5448	char fdname[ITOA_MAX_LEN + 1];
5449	int r, fd;
5450	struct kvm *kvm;
5451	struct file *file;
5452
5453	fd = get_unused_fd_flags(O_CLOEXEC);
5454	if (fd < 0)
5455	return fd;
5456
5457	snprintf(buf: fdname, size: sizeof(fdname), fmt: "%d", fd);
5458
5459	kvm = kvm_create_vm(type, fdname);
5460	if (IS_ERR(ptr: kvm)) {
5461	r = PTR_ERR(ptr: kvm);
5462	goto put_fd;
5463	}
5464
5465	file = anon_inode_getfile(name: "kvm-vm", fops: &kvm_vm_fops, priv: kvm, O_RDWR);
5466	if (IS_ERR(ptr: file)) {
5467	r = PTR_ERR(ptr: file);
5468	goto put_kvm;
5469	}
5470
5471	/*
5472	* Don't call kvm_put_kvm anymore at this point; file->f_op is
5473	* already set, with ->release() being kvm_vm_release(). In error
5474	* cases it will be called by the final fput(file) and will take
5475	* care of doing kvm_put_kvm(kvm).
5476	*/
5477	kvm_uevent_notify_change(KVM_EVENT_CREATE_VM, kvm);
5478
5479	fd_install(fd, file);
5480	return fd;
5481
5482	put_kvm:
5483	kvm_put_kvm(kvm);
5484	put_fd:
5485	put_unused_fd(fd);
5486	return r;
5487	}
5488
5489	static long kvm_dev_ioctl(struct file *filp,
5490	unsigned int ioctl, unsigned long arg)
5491	{
5492	int r = -EINVAL;
5493
5494	switch (ioctl) {
5495	case KVM_GET_API_VERSION:
5496	if (arg)
5497	goto out;
5498	r = KVM_API_VERSION;
5499	break;
5500	case KVM_CREATE_VM:
5501	r = kvm_dev_ioctl_create_vm(type: arg);
5502	break;
5503	case KVM_CHECK_EXTENSION:
5504	r = kvm_vm_ioctl_check_extension_generic(NULL, arg);
5505	break;
5506	case KVM_GET_VCPU_MMAP_SIZE:
5507	if (arg)
5508	goto out;
5509	r = PAGE_SIZE; /* struct kvm_run */
5510	#ifdef CONFIG_X86
5511	r += PAGE_SIZE; /* pio data page */
5512	#endif
5513	#ifdef CONFIG_KVM_MMIO
5514	r += PAGE_SIZE; /* coalesced mmio ring page */
5515	#endif
5516	break;
5517	default:
5518	return kvm_arch_dev_ioctl(filp, ioctl, arg);
5519	}
5520	out:
5521	return r;
5522	}
5523
5524	static struct file_operations kvm_chardev_ops = {
5525	.unlocked_ioctl = kvm_dev_ioctl,
5526	.llseek = noop_llseek,
5527	KVM_COMPAT(kvm_dev_ioctl),
5528	};
5529
5530	static struct miscdevice kvm_dev = {
5531	KVM_MINOR,
5532	"kvm",
5533	&kvm_chardev_ops,
5534	};
5535
5536	#ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
5537	__visible bool kvm_rebooting;
5538	EXPORT_SYMBOL_GPL(kvm_rebooting);
5539
5540	static DEFINE_PER_CPU(bool, hardware_enabled);
5541	static int kvm_usage_count;
5542
5543	static int __hardware_enable_nolock(void)
5544	{
5545	if (__this_cpu_read(hardware_enabled))
5546	return 0;
5547
5548	if (kvm_arch_hardware_enable()) {
5549	pr_info("kvm: enabling virtualization on CPU%d failed\n",
5550	raw_smp_processor_id());
5551	return -EIO;
5552	}
5553
5554	__this_cpu_write(hardware_enabled, true);
5555	return 0;
5556	}
5557
5558	static void hardware_enable_nolock(void *failed)
5559	{
5560	if (__hardware_enable_nolock())
5561	atomic_inc(v: failed);
5562	}
5563
5564	static int kvm_online_cpu(unsigned int cpu)
5565	{
5566	int ret = 0;
5567
5568	/*
5569	* Abort the CPU online process if hardware virtualization cannot
5570	* be enabled. Otherwise running VMs would encounter unrecoverable
5571	* errors when scheduled to this CPU.
5572	*/
5573	mutex_lock(&kvm_lock);
5574	if (kvm_usage_count)
5575	ret = __hardware_enable_nolock();
5576	mutex_unlock(lock: &kvm_lock);
5577	return ret;
5578	}
5579
5580	static void hardware_disable_nolock(void *junk)
5581	{
5582	/*
5583	* Note, hardware_disable_all_nolock() tells all online CPUs to disable
5584	* hardware, not just CPUs that successfully enabled hardware!
5585	*/
5586	if (!__this_cpu_read(hardware_enabled))
5587	return;
5588
5589	kvm_arch_hardware_disable();
5590
5591	__this_cpu_write(hardware_enabled, false);
5592	}
5593
5594	static int kvm_offline_cpu(unsigned int cpu)
5595	{
5596	mutex_lock(&kvm_lock);
5597	if (kvm_usage_count)
5598	hardware_disable_nolock(NULL);
5599	mutex_unlock(lock: &kvm_lock);
5600	return 0;
5601	}
5602
5603	static void hardware_disable_all_nolock(void)
5604	{
5605	BUG_ON(!kvm_usage_count);
5606
5607	kvm_usage_count--;
5608	if (!kvm_usage_count)
5609	on_each_cpu(func: hardware_disable_nolock, NULL, wait: 1);
5610	}
5611
5612	static void hardware_disable_all(void)
5613	{
5614	cpus_read_lock();
5615	mutex_lock(&kvm_lock);
5616	hardware_disable_all_nolock();
5617	mutex_unlock(lock: &kvm_lock);
5618	cpus_read_unlock();
5619	}
5620
5621	static int hardware_enable_all(void)
5622	{
5623	atomic_t failed = ATOMIC_INIT(0);
5624	int r;
5625
5626	/*
5627	* Do not enable hardware virtualization if the system is going down.
5628	* If userspace initiated a forced reboot, e.g. reboot -f, then it's
5629	* possible for an in-flight KVM_CREATE_VM to trigger hardware enabling
5630	* after kvm_reboot() is called. Note, this relies on system_state
5631	* being set _before_ kvm_reboot(), which is why KVM uses a syscore ops
5632	* hook instead of registering a dedicated reboot notifier (the latter
5633	* runs before system_state is updated).
5634	*/
5635	if (system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF ||
5636	system_state == SYSTEM_RESTART)
5637	return -EBUSY;
5638
5639	/*
5640	* When onlining a CPU, cpu_online_mask is set before kvm_online_cpu()
5641	* is called, and so on_each_cpu() between them includes the CPU that
5642	* is being onlined. As a result, hardware_enable_nolock() may get
5643	* invoked before kvm_online_cpu(), which also enables hardware if the
5644	* usage count is non-zero. Disable CPU hotplug to avoid attempting to
5645	* enable hardware multiple times.
5646	*/
5647	cpus_read_lock();
5648	mutex_lock(&kvm_lock);
5649
5650	r = 0;
5651
5652	kvm_usage_count++;
5653	if (kvm_usage_count == 1) {
5654	on_each_cpu(func: hardware_enable_nolock, info: &failed, wait: 1);
5655
5656	if (atomic_read(v: &failed)) {
5657	hardware_disable_all_nolock();
5658	r = -EBUSY;
5659	}
5660	}
5661
5662	mutex_unlock(lock: &kvm_lock);
5663	cpus_read_unlock();
5664
5665	return r;
5666	}
5667
5668	static void kvm_shutdown(void)
5669	{
5670	/*
5671	* Disable hardware virtualization and set kvm_rebooting to indicate
5672	* that KVM has asynchronously disabled hardware virtualization, i.e.
5673	* that relevant errors and exceptions aren't entirely unexpected.
5674	* Some flavors of hardware virtualization need to be disabled before
5675	* transferring control to firmware (to perform shutdown/reboot), e.g.
5676	* on x86, virtualization can block INIT interrupts, which are used by
5677	* firmware to pull APs back under firmware control. Note, this path
5678	* is used for both shutdown and reboot scenarios, i.e. neither name is
5679	* 100% comprehensive.
5680	*/
5681	pr_info("kvm: exiting hardware virtualization\n");
5682	kvm_rebooting = true;
5683	on_each_cpu(func: hardware_disable_nolock, NULL, wait: 1);
5684	}
5685
5686	static int kvm_suspend(void)
5687	{
5688	/*
5689	* Secondary CPUs and CPU hotplug are disabled across the suspend/resume
5690	* callbacks, i.e. no need to acquire kvm_lock to ensure the usage count
5691	* is stable. Assert that kvm_lock is not held to ensure the system
5692	* isn't suspended while KVM is enabling hardware. Hardware enabling
5693	* can be preempted, but the task cannot be frozen until it has dropped
5694	* all locks (userspace tasks are frozen via a fake signal).
5695	*/
5696	lockdep_assert_not_held(&kvm_lock);
5697	lockdep_assert_irqs_disabled();
5698
5699	if (kvm_usage_count)
5700	hardware_disable_nolock(NULL);
5701	return 0;
5702	}
5703
5704	static void kvm_resume(void)
5705	{
5706	lockdep_assert_not_held(&kvm_lock);
5707	lockdep_assert_irqs_disabled();
5708
5709	if (kvm_usage_count)
5710	WARN_ON_ONCE(__hardware_enable_nolock());
5711	}
5712
5713	static struct syscore_ops kvm_syscore_ops = {
5714	.suspend = kvm_suspend,
5715	.resume = kvm_resume,
5716	.shutdown = kvm_shutdown,
5717	};
5718	#else /* CONFIG_KVM_GENERIC_HARDWARE_ENABLING */
5719	static int hardware_enable_all(void)
5720	{
5721	return 0;
5722	}
5723
5724	static void hardware_disable_all(void)
5725	{
5726
5727	}
5728	#endif /* CONFIG_KVM_GENERIC_HARDWARE_ENABLING */
5729
5730	static void kvm_iodevice_destructor(struct kvm_io_device *dev)
5731	{
5732	if (dev->ops->destructor)
5733	dev->ops->destructor(dev);
5734	}
5735
5736	static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
5737	{
5738	int i;
5739
5740	for (i = 0; i < bus->dev_count; i++) {
5741	struct kvm_io_device *pos = bus->range[i].dev;
5742
5743	kvm_iodevice_destructor(dev: pos);
5744	}
5745	kfree(objp: bus);
5746	}
5747
5748	static inline int kvm_io_bus_cmp(const struct kvm_io_range *r1,
5749	const struct kvm_io_range *r2)
5750	{
5751	gpa_t addr1 = r1->addr;
5752	gpa_t addr2 = r2->addr;
5753
5754	if (addr1 < addr2)
5755	return -1;
5756
5757	/* If r2->len == 0, match the exact address. If r2->len != 0,
5758	* accept any overlapping write. Any order is acceptable for
5759	* overlapping ranges, because kvm_io_bus_get_first_dev ensures
5760	* we process all of them.
5761	*/
5762	if (r2->len) {
5763	addr1 += r1->len;
5764	addr2 += r2->len;
5765	}
5766
5767	if (addr1 > addr2)
5768	return 1;
5769
5770	return 0;
5771	}
5772
5773	static int kvm_io_bus_sort_cmp(const void *p1, const void *p2)
5774	{
5775	return kvm_io_bus_cmp(r1: p1, r2: p2);
5776	}
5777
5778	static int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus,
5779	gpa_t addr, int len)
5780	{
5781	struct kvm_io_range *range, key;
5782	int off;
5783
5784	key = (struct kvm_io_range) {
5785	.addr = addr,
5786	.len = len,
5787	};
5788
5789	range = bsearch(key: &key, base: bus->range, num: bus->dev_count,
5790	size: sizeof(struct kvm_io_range), cmp: kvm_io_bus_sort_cmp);
5791	if (range == NULL)
5792	return -ENOENT;
5793
5794	off = range - bus->range;
5795
5796	while (off > 0 && kvm_io_bus_cmp(r1: &key, r2: &bus->range[off-1]) == 0)
5797	off--;
5798
5799	return off;
5800	}
5801
5802	static int __kvm_io_bus_write(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
5803	struct kvm_io_range *range, const void *val)
5804	{
5805	int idx;
5806
5807	idx = kvm_io_bus_get_first_dev(bus, addr: range->addr, len: range->len);
5808	if (idx < 0)
5809	return -EOPNOTSUPP;
5810
5811	while (idx < bus->dev_count &&
5812	kvm_io_bus_cmp(r1: range, r2: &bus->range[idx]) == 0) {
5813	if (!kvm_iodevice_write(vcpu, dev: bus->range[idx].dev, addr: range->addr,
5814	l: range->len, v: val))
5815	return idx;
5816	idx++;
5817	}
5818
5819	return -EOPNOTSUPP;
5820	}
5821
5822	/* kvm_io_bus_write - called under kvm->slots_lock */
5823	int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
5824	int len, const void *val)
5825	{
5826	struct kvm_io_bus *bus;
5827	struct kvm_io_range range;
5828	int r;
5829
5830	range = (struct kvm_io_range) {
5831	.addr = addr,
5832	.len = len,
5833	};
5834
5835	bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
5836	if (!bus)
5837	return -ENOMEM;
5838	r = __kvm_io_bus_write(vcpu, bus, range: &range, val);
5839	return r < 0 ? r : 0;
5840	}
5841	EXPORT_SYMBOL_GPL(kvm_io_bus_write);
5842
5843	/* kvm_io_bus_write_cookie - called under kvm->slots_lock */
5844	int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx,
5845	gpa_t addr, int len, const void *val, long cookie)
5846	{
5847	struct kvm_io_bus *bus;
5848	struct kvm_io_range range;
5849
5850	range = (struct kvm_io_range) {
5851	.addr = addr,
5852	.len = len,
5853	};
5854
5855	bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
5856	if (!bus)
5857	return -ENOMEM;
5858
5859	/* First try the device referenced by cookie. */
5860	if ((cookie >= 0) && (cookie < bus->dev_count) &&
5861	(kvm_io_bus_cmp(r1: &range, r2: &bus->range[cookie]) == 0))
5862	if (!kvm_iodevice_write(vcpu, dev: bus->range[cookie].dev, addr, l: len,
5863	v: val))
5864	return cookie;
5865
5866	/*
5867	* cookie contained garbage; fall back to search and return the
5868	* correct cookie value.
5869	*/
5870	return __kvm_io_bus_write(vcpu, bus, range: &range, val);
5871	}
5872
5873	static int __kvm_io_bus_read(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
5874	struct kvm_io_range *range, void *val)
5875	{
5876	int idx;
5877
5878	idx = kvm_io_bus_get_first_dev(bus, addr: range->addr, len: range->len);
5879	if (idx < 0)
5880	return -EOPNOTSUPP;
5881
5882	while (idx < bus->dev_count &&
5883	kvm_io_bus_cmp(r1: range, r2: &bus->range[idx]) == 0) {
5884	if (!kvm_iodevice_read(vcpu, dev: bus->range[idx].dev, addr: range->addr,
5885	l: range->len, v: val))
5886	return idx;
5887	idx++;
5888	}
5889
5890	return -EOPNOTSUPP;
5891	}
5892
5893	/* kvm_io_bus_read - called under kvm->slots_lock */
5894	int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
5895	int len, void *val)
5896	{
5897	struct kvm_io_bus *bus;
5898	struct kvm_io_range range;
5899	int r;
5900
5901	range = (struct kvm_io_range) {
5902	.addr = addr,
5903	.len = len,
5904	};
5905
5906	bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
5907	if (!bus)
5908	return -ENOMEM;
5909	r = __kvm_io_bus_read(vcpu, bus, range: &range, val);
5910	return r < 0 ? r : 0;
5911	}
5912
5913	int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
5914	int len, struct kvm_io_device *dev)
5915	{
5916	int i;
5917	struct kvm_io_bus *new_bus, *bus;
5918	struct kvm_io_range range;
5919
5920	lockdep_assert_held(&kvm->slots_lock);
5921
5922	bus = kvm_get_bus(kvm, idx: bus_idx);
5923	if (!bus)
5924	return -ENOMEM;
5925
5926	/* exclude ioeventfd which is limited by maximum fd */
5927	if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1)
5928	return -ENOSPC;
5929
5930	new_bus = kmalloc(struct_size(bus, range, bus->dev_count + 1),
5931	GFP_KERNEL_ACCOUNT);
5932	if (!new_bus)
5933	return -ENOMEM;
5934
5935	range = (struct kvm_io_range) {
5936	.addr = addr,
5937	.len = len,
5938	.dev = dev,
5939	};
5940
5941	for (i = 0; i < bus->dev_count; i++)
5942	if (kvm_io_bus_cmp(r1: &bus->range[i], r2: &range) > 0)
5943	break;
5944
5945	memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range));
5946	new_bus->dev_count++;
5947	new_bus->range[i] = range;
5948	memcpy(new_bus->range + i + 1, bus->range + i,
5949	(bus->dev_count - i) * sizeof(struct kvm_io_range));
5950	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
5951	synchronize_srcu_expedited(ssp: &kvm->srcu);
5952	kfree(objp: bus);
5953
5954	return 0;
5955	}
5956
5957	int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
5958	struct kvm_io_device *dev)
5959	{
5960	int i;
5961	struct kvm_io_bus *new_bus, *bus;
5962
5963	lockdep_assert_held(&kvm->slots_lock);
5964
5965	bus = kvm_get_bus(kvm, idx: bus_idx);
5966	if (!bus)
5967	return 0;
5968
5969	for (i = 0; i < bus->dev_count; i++) {
5970	if (bus->range[i].dev == dev) {
5971	break;
5972	}
5973	}
5974
5975	if (i == bus->dev_count)
5976	return 0;
5977
5978	new_bus = kmalloc(struct_size(bus, range, bus->dev_count - 1),
5979	GFP_KERNEL_ACCOUNT);
5980	if (new_bus) {
5981	memcpy(new_bus, bus, struct_size(bus, range, i));
5982	new_bus->dev_count--;
5983	memcpy(new_bus->range + i, bus->range + i + 1,
5984	flex_array_size(new_bus, range, new_bus->dev_count - i));
5985	}
5986
5987	rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
5988	synchronize_srcu_expedited(ssp: &kvm->srcu);
5989
5990	/*
5991	* If NULL bus is installed, destroy the old bus, including all the
5992	* attached devices. Otherwise, destroy the caller's device only.
5993	*/
5994	if (!new_bus) {
5995	pr_err("kvm: failed to shrink bus, removing it completely\n");
5996	kvm_io_bus_destroy(bus);
5997	return -ENOMEM;
5998	}
5999
6000	kvm_iodevice_destructor(dev);
6001	kfree(objp: bus);
6002	return 0;
6003	}
6004
6005	struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,
6006	gpa_t addr)
6007	{
6008	struct kvm_io_bus *bus;
6009	int dev_idx, srcu_idx;
6010	struct kvm_io_device *iodev = NULL;
6011
6012	srcu_idx = srcu_read_lock(ssp: &kvm->srcu);
6013
6014	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
6015	if (!bus)
6016	goto out_unlock;
6017
6018	dev_idx = kvm_io_bus_get_first_dev(bus, addr, len: 1);
6019	if (dev_idx < 0)
6020	goto out_unlock;
6021
6022	iodev = bus->range[dev_idx].dev;
6023
6024	out_unlock:
6025	srcu_read_unlock(ssp: &kvm->srcu, idx: srcu_idx);
6026
6027	return iodev;
6028	}
6029	EXPORT_SYMBOL_GPL(kvm_io_bus_get_dev);
6030
6031	static int kvm_debugfs_open(struct inode *inode, struct file *file,
6032	int (*get)(void *, u64 *), int (*set)(void *, u64),
6033	const char *fmt)
6034	{
6035	int ret;
6036	struct kvm_stat_data *stat_data = inode->i_private;
6037
6038	/*
6039	* The debugfs files are a reference to the kvm struct which
6040	* is still valid when kvm_destroy_vm is called. kvm_get_kvm_safe
6041	* avoids the race between open and the removal of the debugfs directory.
6042	*/
6043	if (!kvm_get_kvm_safe(stat_data->kvm))
6044	return -ENOENT;
6045
6046	ret = simple_attr_open(inode, file, get,
6047	set: kvm_stats_debugfs_mode(pdesc: stat_data->desc) & 0222
6048	? set : NULL, fmt);
6049	if (ret)
6050	kvm_put_kvm(stat_data->kvm);
6051
6052	return ret;
6053	}
6054
6055	static int kvm_debugfs_release(struct inode *inode, struct file *file)
6056	{
6057	struct kvm_stat_data *stat_data = inode->i_private;
6058
6059	simple_attr_release(inode, file);
6060	kvm_put_kvm(stat_data->kvm);
6061
6062	return 0;
6063	}
6064
6065	static int kvm_get_stat_per_vm(struct kvm *kvm, size_t offset, u64 *val)
6066	{
6067	*val = *(u64 *)((void *)(&kvm->stat) + offset);
6068
6069	return 0;
6070	}
6071
6072	static int kvm_clear_stat_per_vm(struct kvm *kvm, size_t offset)
6073	{
6074	*(u64 *)((void *)(&kvm->stat) + offset) = 0;
6075
6076	return 0;
6077	}
6078
6079	static int kvm_get_stat_per_vcpu(struct kvm *kvm, size_t offset, u64 *val)
6080	{
6081	unsigned long i;
6082	struct kvm_vcpu *vcpu;
6083
6084	*val = 0;
6085
6086	kvm_for_each_vcpu(i, vcpu, kvm)
6087	*val += *(u64 *)((void *)(&vcpu->stat) + offset);
6088
6089	return 0;
6090	}
6091
6092	static int kvm_clear_stat_per_vcpu(struct kvm *kvm, size_t offset)
6093	{
6094	unsigned long i;
6095	struct kvm_vcpu *vcpu;
6096
6097	kvm_for_each_vcpu(i, vcpu, kvm)
6098	*(u64 *)((void *)(&vcpu->stat) + offset) = 0;
6099
6100	return 0;
6101	}
6102
6103	static int kvm_stat_data_get(void *data, u64 *val)
6104	{
6105	int r = -EFAULT;
6106	struct kvm_stat_data *stat_data = data;
6107
6108	switch (stat_data->kind) {
6109	case KVM_STAT_VM:
6110	r = kvm_get_stat_per_vm(kvm: stat_data->kvm,
6111	offset: stat_data->desc->desc.offset, val);
6112	break;
6113	case KVM_STAT_VCPU:
6114	r = kvm_get_stat_per_vcpu(kvm: stat_data->kvm,
6115	offset: stat_data->desc->desc.offset, val);
6116	break;
6117	}
6118
6119	return r;
6120	}
6121
6122	static int kvm_stat_data_clear(void *data, u64 val)
6123	{
6124	int r = -EFAULT;
6125	struct kvm_stat_data *stat_data = data;
6126
6127	if (val)
6128	return -EINVAL;
6129
6130	switch (stat_data->kind) {
6131	case KVM_STAT_VM:
6132	r = kvm_clear_stat_per_vm(kvm: stat_data->kvm,
6133	offset: stat_data->desc->desc.offset);
6134	break;
6135	case KVM_STAT_VCPU:
6136	r = kvm_clear_stat_per_vcpu(kvm: stat_data->kvm,
6137	offset: stat_data->desc->desc.offset);
6138	break;
6139	}
6140
6141	return r;
6142	}
6143
6144	static int kvm_stat_data_open(struct inode *inode, struct file *file)
6145	{
6146	__simple_attr_check_format(fmt: "%llu\n", 0ull);
6147	return kvm_debugfs_open(inode, file, get: kvm_stat_data_get,
6148	set: kvm_stat_data_clear, fmt: "%llu\n");
6149	}
6150
6151	static const struct file_operations stat_fops_per_vm = {
6152	.owner = THIS_MODULE,
6153	.open = kvm_stat_data_open,
6154	.release = kvm_debugfs_release,
6155	.read = simple_attr_read,
6156	.write = simple_attr_write,
6157	.llseek = no_llseek,
6158	};
6159
6160	static int vm_stat_get(void *_offset, u64 *val)
6161	{
6162	unsigned offset = (long)_offset;
6163	struct kvm *kvm;
6164	u64 tmp_val;
6165
6166	*val = 0;
6167	mutex_lock(&kvm_lock);
6168	list_for_each_entry(kvm, &vm_list, vm_list) {
6169	kvm_get_stat_per_vm(kvm, offset, val: &tmp_val);
6170	*val += tmp_val;
6171	}
6172	mutex_unlock(lock: &kvm_lock);
6173	return 0;
6174	}
6175
6176	static int vm_stat_clear(void *_offset, u64 val)
6177	{
6178	unsigned offset = (long)_offset;
6179	struct kvm *kvm;
6180
6181	if (val)
6182	return -EINVAL;
6183
6184	mutex_lock(&kvm_lock);
6185	list_for_each_entry(kvm, &vm_list, vm_list) {
6186	kvm_clear_stat_per_vm(kvm, offset);
6187	}
6188	mutex_unlock(lock: &kvm_lock);
6189
6190	return 0;
6191	}
6192
6193	DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, vm_stat_clear, "%llu\n");
6194	DEFINE_SIMPLE_ATTRIBUTE(vm_stat_readonly_fops, vm_stat_get, NULL, "%llu\n");
6195
6196	static int vcpu_stat_get(void *_offset, u64 *val)
6197	{
6198	unsigned offset = (long)_offset;
6199	struct kvm *kvm;
6200	u64 tmp_val;
6201
6202	*val = 0;
6203	mutex_lock(&kvm_lock);
6204	list_for_each_entry(kvm, &vm_list, vm_list) {
6205	kvm_get_stat_per_vcpu(kvm, offset, val: &tmp_val);
6206	*val += tmp_val;
6207	}
6208	mutex_unlock(lock: &kvm_lock);
6209	return 0;
6210	}
6211
6212	static int vcpu_stat_clear(void *_offset, u64 val)
6213	{
6214	unsigned offset = (long)_offset;
6215	struct kvm *kvm;
6216
6217	if (val)
6218	return -EINVAL;
6219
6220	mutex_lock(&kvm_lock);
6221	list_for_each_entry(kvm, &vm_list, vm_list) {
6222	kvm_clear_stat_per_vcpu(kvm, offset);
6223	}
6224	mutex_unlock(lock: &kvm_lock);
6225
6226	return 0;
6227	}
6228
6229	DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, vcpu_stat_clear,
6230	"%llu\n");
6231	DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_readonly_fops, vcpu_stat_get, NULL, "%llu\n");
6232
6233	static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
6234	{
6235	struct kobj_uevent_env *env;
6236	unsigned long long created, active;
6237
6238	if (!kvm_dev.this_device || !kvm)
6239	return;
6240
6241	mutex_lock(&kvm_lock);
6242	if (type == KVM_EVENT_CREATE_VM) {
6243	kvm_createvm_count++;
6244	kvm_active_vms++;
6245	} else if (type == KVM_EVENT_DESTROY_VM) {
6246	kvm_active_vms--;
6247	}
6248	created = kvm_createvm_count;
6249	active = kvm_active_vms;
6250	mutex_unlock(lock: &kvm_lock);
6251
6252	env = kzalloc(size: sizeof(*env), GFP_KERNEL_ACCOUNT);
6253	if (!env)
6254	return;
6255
6256	add_uevent_var(env, format: "CREATED=%llu", created);
6257	add_uevent_var(env, format: "COUNT=%llu", active);
6258
6259	if (type == KVM_EVENT_CREATE_VM) {
6260	add_uevent_var(env, format: "EVENT=create");
6261	kvm->userspace_pid = task_pid_nr(current);
6262	} else if (type == KVM_EVENT_DESTROY_VM) {
6263	add_uevent_var(env, format: "EVENT=destroy");
6264	}
6265	add_uevent_var(env, format: "PID=%d", kvm->userspace_pid);
6266
6267	if (!IS_ERR(ptr: kvm->debugfs_dentry)) {
6268	char *tmp, *p = kmalloc(PATH_MAX, GFP_KERNEL_ACCOUNT);
6269
6270	if (p) {
6271	tmp = dentry_path_raw(kvm->debugfs_dentry, p, PATH_MAX);
6272	if (!IS_ERR(ptr: tmp))
6273	add_uevent_var(env, format: "STATS_PATH=%s", tmp);
6274	kfree(objp: p);
6275	}
6276	}
6277	/* no need for checks, since we are adding at most only 5 keys */
6278	env->envp[env->envp_idx++] = NULL;
6279	kobject_uevent_env(kobj: &kvm_dev.this_device->kobj, action: KOBJ_CHANGE, envp: env->envp);
6280	kfree(objp: env);
6281	}
6282
6283	static void kvm_init_debug(void)
6284	{
6285	const struct file_operations *fops;
6286	const struct _kvm_stats_desc *pdesc;
6287	int i;
6288
6289	kvm_debugfs_dir = debugfs_create_dir(name: "kvm", NULL);
6290
6291	for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) {
6292	pdesc = &kvm_vm_stats_desc[i];
6293	if (kvm_stats_debugfs_mode(pdesc) & 0222)
6294	fops = &vm_stat_fops;
6295	else
6296	fops = &vm_stat_readonly_fops;
6297	debugfs_create_file(name: pdesc->name, mode: kvm_stats_debugfs_mode(pdesc),
6298	parent: kvm_debugfs_dir,
6299	data: (void *)(long)pdesc->desc.offset, fops);
6300	}
6301
6302	for (i = 0; i < kvm_vcpu_stats_header.num_desc; ++i) {
6303	pdesc = &kvm_vcpu_stats_desc[i];
6304	if (kvm_stats_debugfs_mode(pdesc) & 0222)
6305	fops = &vcpu_stat_fops;
6306	else
6307	fops = &vcpu_stat_readonly_fops;
6308	debugfs_create_file(name: pdesc->name, mode: kvm_stats_debugfs_mode(pdesc),
6309	parent: kvm_debugfs_dir,
6310	data: (void *)(long)pdesc->desc.offset, fops);
6311	}
6312	}
6313
6314	static inline
6315	struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
6316	{
6317	return container_of(pn, struct kvm_vcpu, preempt_notifier);
6318	}
6319
6320	static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
6321	{
6322	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
6323
6324	WRITE_ONCE(vcpu->preempted, false);
6325	WRITE_ONCE(vcpu->ready, false);
6326
6327	__this_cpu_write(kvm_running_vcpu, vcpu);
6328	kvm_arch_sched_in(vcpu, cpu);
6329	kvm_arch_vcpu_load(vcpu, cpu);
6330	}
6331
6332	static void kvm_sched_out(struct preempt_notifier *pn,
6333	struct task_struct *next)
6334	{
6335	struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
6336
6337	if (current->on_rq) {
6338	WRITE_ONCE(vcpu->preempted, true);
6339	WRITE_ONCE(vcpu->ready, true);
6340	}
6341	kvm_arch_vcpu_put(vcpu);
6342	__this_cpu_write(kvm_running_vcpu, NULL);
6343	}
6344
6345	/**
6346	* kvm_get_running_vcpu - get the vcpu running on the current CPU.
6347	*
6348	* We can disable preemption locally around accessing the per-CPU variable,
6349	* and use the resolved vcpu pointer after enabling preemption again,
6350	* because even if the current thread is migrated to another CPU, reading
6351	* the per-CPU value later will give us the same value as we update the
6352	* per-CPU variable in the preempt notifier handlers.
6353	*/
6354	struct kvm_vcpu *kvm_get_running_vcpu(void)
6355	{
6356	struct kvm_vcpu *vcpu;
6357
6358	preempt_disable();
6359	vcpu = __this_cpu_read(kvm_running_vcpu);
6360	preempt_enable();
6361
6362	return vcpu;
6363	}
6364	EXPORT_SYMBOL_GPL(kvm_get_running_vcpu);
6365
6366	/**
6367	* kvm_get_running_vcpus - get the per-CPU array of currently running vcpus.
6368	*/
6369	struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void)
6370	{
6371	return &kvm_running_vcpu;
6372	}
6373
6374	#ifdef CONFIG_GUEST_PERF_EVENTS
6375	static unsigned int kvm_guest_state(void)
6376	{
6377	struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
6378	unsigned int state;
6379
6380	if (!kvm_arch_pmi_in_guest(vcpu))
6381	return 0;
6382
6383	state = PERF_GUEST_ACTIVE;
6384	if (!kvm_arch_vcpu_in_kernel(vcpu))
6385	state |= PERF_GUEST_USER;
6386
6387	return state;
6388	}
6389
6390	static unsigned long kvm_guest_get_ip(void)
6391	{
6392	struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
6393
6394	/* Retrieving the IP must be guarded by a call to kvm_guest_state(). */
6395	if (WARN_ON_ONCE(!kvm_arch_pmi_in_guest(vcpu)))
6396	return 0;
6397
6398	return kvm_arch_vcpu_get_ip(vcpu);
6399	}
6400
6401	static struct perf_guest_info_callbacks kvm_guest_cbs = {
6402	.state = kvm_guest_state,
6403	.get_ip = kvm_guest_get_ip,
6404	.handle_intel_pt_intr = NULL,
6405	};
6406
6407	void kvm_register_perf_callbacks(unsigned int (*pt_intr_handler)(void))
6408	{
6409	kvm_guest_cbs.handle_intel_pt_intr = pt_intr_handler;
6410	perf_register_guest_info_callbacks(cbs: &kvm_guest_cbs);
6411	}
6412	void kvm_unregister_perf_callbacks(void)
6413	{
6414	perf_unregister_guest_info_callbacks(cbs: &kvm_guest_cbs);
6415	}
6416	#endif
6417
6418	int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module)
6419	{
6420	int r;
6421	int cpu;
6422
6423	#ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
6424	r = cpuhp_setup_state_nocalls(state: CPUHP_AP_KVM_ONLINE, name: "kvm/cpu:online",
6425	startup: kvm_online_cpu, teardown: kvm_offline_cpu);
6426	if (r)
6427	return r;
6428
6429	register_syscore_ops(ops: &kvm_syscore_ops);
6430	#endif
6431
6432	/* A kmem cache lets us meet the alignment requirements of fx_save. */
6433	if (!vcpu_align)
6434	vcpu_align = __alignof__(struct kvm_vcpu);
6435	kvm_vcpu_cache =
6436	kmem_cache_create_usercopy(name: "kvm_vcpu", size: vcpu_size, align: vcpu_align,
6437	SLAB_ACCOUNT,
6438	offsetof(struct kvm_vcpu, arch),
6439	offsetofend(struct kvm_vcpu, stats_id)
6440	- offsetof(struct kvm_vcpu, arch),
6441	NULL);
6442	if (!kvm_vcpu_cache) {
6443	r = -ENOMEM;
6444	goto err_vcpu_cache;
6445	}
6446
6447	for_each_possible_cpu(cpu) {
6448	if (!alloc_cpumask_var_node(mask: &per_cpu(cpu_kick_mask, cpu),
6449	GFP_KERNEL, cpu_to_node(cpu))) {
6450	r = -ENOMEM;
6451	goto err_cpu_kick_mask;
6452	}
6453	}
6454
6455	r = kvm_irqfd_init();
6456	if (r)
6457	goto err_irqfd;
6458
6459	r = kvm_async_pf_init();
6460	if (r)
6461	goto err_async_pf;
6462
6463	kvm_chardev_ops.owner = module;
6464	kvm_vm_fops.owner = module;
6465	kvm_vcpu_fops.owner = module;
6466	kvm_device_fops.owner = module;
6467
6468	kvm_preempt_ops.sched_in = kvm_sched_in;
6469	kvm_preempt_ops.sched_out = kvm_sched_out;
6470
6471	kvm_init_debug();
6472
6473	r = kvm_vfio_ops_init();
6474	if (WARN_ON_ONCE(r))
6475	goto err_vfio;
6476
6477	kvm_gmem_init(module);
6478
6479	/*
6480	* Registration _must_ be the very last thing done, as this exposes
6481	* /dev/kvm to userspace, i.e. all infrastructure must be setup!
6482	*/
6483	r = misc_register(misc: &kvm_dev);
6484	if (r) {
6485	pr_err("kvm: misc device register failed\n");
6486	goto err_register;
6487	}
6488
6489	return 0;
6490
6491	err_register:
6492	kvm_vfio_ops_exit();
6493	err_vfio:
6494	kvm_async_pf_deinit();
6495	err_async_pf:
6496	kvm_irqfd_exit();
6497	err_irqfd:
6498	err_cpu_kick_mask:
6499	for_each_possible_cpu(cpu)
6500	free_cpumask_var(per_cpu(cpu_kick_mask, cpu));
6501	kmem_cache_destroy(s: kvm_vcpu_cache);
6502	err_vcpu_cache:
6503	#ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
6504	unregister_syscore_ops(ops: &kvm_syscore_ops);
6505	cpuhp_remove_state_nocalls(state: CPUHP_AP_KVM_ONLINE);
6506	#endif
6507	return r;
6508	}
6509	EXPORT_SYMBOL_GPL(kvm_init);
6510
6511	void kvm_exit(void)
6512	{
6513	int cpu;
6514
6515	/*
6516	* Note, unregistering /dev/kvm doesn't strictly need to come first,
6517	* fops_get(), a.k.a. try_module_get(), prevents acquiring references
6518	* to KVM while the module is being stopped.
6519	*/
6520	misc_deregister(misc: &kvm_dev);
6521
6522	debugfs_remove_recursive(dentry: kvm_debugfs_dir);
6523	for_each_possible_cpu(cpu)
6524	free_cpumask_var(per_cpu(cpu_kick_mask, cpu));
6525	kmem_cache_destroy(s: kvm_vcpu_cache);
6526	kvm_vfio_ops_exit();
6527	kvm_async_pf_deinit();
6528	#ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
6529	unregister_syscore_ops(ops: &kvm_syscore_ops);
6530	cpuhp_remove_state_nocalls(state: CPUHP_AP_KVM_ONLINE);
6531	#endif
6532	kvm_irqfd_exit();
6533	}
6534	EXPORT_SYMBOL_GPL(kvm_exit);
6535
6536	struct kvm_vm_worker_thread_context {
6537	struct kvm *kvm;
6538	struct task_struct *parent;
6539	struct completion init_done;
6540	kvm_vm_thread_fn_t thread_fn;
6541	uintptr_t data;
6542	int err;
6543	};
6544
6545	static int kvm_vm_worker_thread(void *context)
6546	{
6547	/*
6548	* The init_context is allocated on the stack of the parent thread, so
6549	* we have to locally copy anything that is needed beyond initialization
6550	*/
6551	struct kvm_vm_worker_thread_context *init_context = context;
6552	struct task_struct *parent;
6553	struct kvm *kvm = init_context->kvm;
6554	kvm_vm_thread_fn_t thread_fn = init_context->thread_fn;
6555	uintptr_t data = init_context->data;
6556	int err;
6557
6558	err = kthread_park(current);
6559	/* kthread_park(current) is never supposed to return an error */
6560	WARN_ON(err != 0);
6561	if (err)
6562	goto init_complete;
6563
6564	err = cgroup_attach_task_all(from: init_context->parent, current);
6565	if (err) {
6566	kvm_err("%s: cgroup_attach_task_all failed with err %d\n",
6567	__func__, err);
6568	goto init_complete;
6569	}
6570
6571	set_user_nice(current, nice: task_nice(p: init_context->parent));
6572
6573	init_complete:
6574	init_context->err = err;
6575	complete(&init_context->init_done);
6576	init_context = NULL;
6577
6578	if (err)
6579	goto out;
6580
6581	/* Wait to be woken up by the spawner before proceeding. */
6582	kthread_parkme();
6583
6584	if (!kthread_should_stop())
6585	err = thread_fn(kvm, data);
6586
6587	out:
6588	/*
6589	* Move kthread back to its original cgroup to prevent it lingering in
6590	* the cgroup of the VM process, after the latter finishes its
6591	* execution.
6592	*
6593	* kthread_stop() waits on the 'exited' completion condition which is
6594	* set in exit_mm(), via mm_release(), in do_exit(). However, the
6595	* kthread is removed from the cgroup in the cgroup_exit() which is
6596	* called after the exit_mm(). This causes the kthread_stop() to return
6597	* before the kthread actually quits the cgroup.
6598	*/
6599	rcu_read_lock();
6600	parent = rcu_dereference(current->real_parent);
6601	get_task_struct(t: parent);
6602	rcu_read_unlock();
6603	cgroup_attach_task_all(from: parent, current);
6604	put_task_struct(t: parent);
6605
6606	return err;
6607	}
6608
6609	int kvm_vm_create_worker_thread(struct kvm *kvm, kvm_vm_thread_fn_t thread_fn,
6610	uintptr_t data, const char *name,
6611	struct task_struct **thread_ptr)
6612	{
6613	struct kvm_vm_worker_thread_context init_context = {};
6614	struct task_struct *thread;
6615
6616	*thread_ptr = NULL;
6617	init_context.kvm = kvm;
6618	init_context.parent = current;
6619	init_context.thread_fn = thread_fn;
6620	init_context.data = data;
6621	init_completion(x: &init_context.init_done);
6622
6623	thread = kthread_run(kvm_vm_worker_thread, &init_context,
6624	"%s-%d", name, task_pid_nr(current));
6625	if (IS_ERR(ptr: thread))
6626	return PTR_ERR(ptr: thread);
6627
6628	/* kthread_run is never supposed to return NULL */
6629	WARN_ON(thread == NULL);
6630
6631	wait_for_completion(&init_context.init_done);
6632
6633	if (!init_context.err)
6634	*thread_ptr = thread;
6635
6636	return init_context.err;
6637	}
6638