1 // SPDX-License-Identifier: GPL-2.0-only
3 * Kernel-based Virtual Machine driver for Linux
5 * This module enables machines with Intel VT-x extensions to run virtual
6 * machines without emulation or binary translation.
8 * Copyright (C) 2006 Qumranet, Inc.
9 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
12 * Avi Kivity <avi@qumranet.com>
13 * Yaniv Kamay <yaniv@qumranet.com>
16 #include <kvm/iodev.h>
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>
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>
52 #include <linux/lockdep.h>
53 #include <linux/kthread.h>
54 #include <linux/suspend.h>
56 #include <asm/processor.h>
57 #include <asm/ioctl.h>
58 #include <linux/uaccess.h>
60 #include "coalesced_mmio.h"
65 #include <trace/events/ipi.h>
67 #define CREATE_TRACE_POINTS
68 #include <trace/events/kvm.h>
70 #include <linux/kvm_dirty_ring.h>
73 /* Worst case buffer size needed for holding an integer. */
74 #define ITOA_MAX_LEN 12
76 MODULE_AUTHOR("Qumranet");
77 MODULE_LICENSE("GPL");
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
);
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
);
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
);
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
);
102 * kvm->lock --> kvm->slots_lock --> kvm->irq_lock
105 DEFINE_MUTEX(kvm_lock
);
108 static struct kmem_cache
*kvm_vcpu_cache
;
110 static __read_mostly
struct preempt_ops kvm_preempt_ops
;
111 static DEFINE_PER_CPU(struct kvm_vcpu
*, kvm_running_vcpu
);
113 struct dentry
*kvm_debugfs_dir
;
114 EXPORT_SYMBOL_GPL(kvm_debugfs_dir
);
116 static const struct file_operations stat_fops_per_vm
;
118 static struct file_operations kvm_chardev_ops
;
120 static long kvm_vcpu_ioctl(struct file
*file
, unsigned int ioctl
,
122 #ifdef CONFIG_KVM_COMPAT
123 static long kvm_vcpu_compat_ioctl(struct file
*file
, unsigned int ioctl
,
125 #define KVM_COMPAT(c) .compat_ioctl = (c)
128 * For architectures that don't implement a compat infrastructure,
129 * adopt a double line of defense:
130 * - Prevent a compat task from opening /dev/kvm
131 * - If the open has been done by a 64bit task, and the KVM fd
132 * passed to a compat task, let the ioctls fail.
134 static long kvm_no_compat_ioctl(struct file
*file
, unsigned int ioctl
,
135 unsigned long arg
) { return -EINVAL
; }
137 static int kvm_no_compat_open(struct inode
*inode
, struct file
*file
)
139 return is_compat_task() ? -ENODEV
: 0;
141 #define KVM_COMPAT(c) .compat_ioctl = kvm_no_compat_ioctl, \
142 .open = kvm_no_compat_open
144 static int hardware_enable_all(void);
145 static void hardware_disable_all(void);
147 static void kvm_io_bus_destroy(struct kvm_io_bus
*bus
);
149 #define KVM_EVENT_CREATE_VM 0
150 #define KVM_EVENT_DESTROY_VM 1
151 static void kvm_uevent_notify_change(unsigned int type
, struct kvm
*kvm
);
152 static unsigned long long kvm_createvm_count
;
153 static unsigned long long kvm_active_vms
;
155 static DEFINE_PER_CPU(cpumask_var_t
, cpu_kick_mask
);
157 __weak
void kvm_arch_guest_memory_reclaimed(struct kvm
*kvm
)
161 bool kvm_is_zone_device_page(struct page
*page
)
164 * The metadata used by is_zone_device_page() to determine whether or
165 * not a page is ZONE_DEVICE is guaranteed to be valid if and only if
166 * the device has been pinned, e.g. by get_user_pages(). WARN if the
167 * page_count() is zero to help detect bad usage of this helper.
169 if (WARN_ON_ONCE(!page_count(page
)))
172 return is_zone_device_page(page
);
176 * Returns a 'struct page' if the pfn is "valid" and backed by a refcounted
177 * page, NULL otherwise. Note, the list of refcounted PG_reserved page types
178 * is likely incomplete, it has been compiled purely through people wanting to
179 * back guest with a certain type of memory and encountering issues.
181 struct page
*kvm_pfn_to_refcounted_page(kvm_pfn_t pfn
)
188 page
= pfn_to_page(pfn
);
189 if (!PageReserved(page
))
192 /* The ZERO_PAGE(s) is marked PG_reserved, but is refcounted. */
193 if (is_zero_pfn(pfn
))
197 * ZONE_DEVICE pages currently set PG_reserved, but from a refcounting
198 * perspective they are "normal" pages, albeit with slightly different
201 if (kvm_is_zone_device_page(page
))
208 * Switches to specified vcpu, until a matching vcpu_put()
210 void vcpu_load(struct kvm_vcpu
*vcpu
)
214 __this_cpu_write(kvm_running_vcpu
, vcpu
);
215 preempt_notifier_register(&vcpu
->preempt_notifier
);
216 kvm_arch_vcpu_load(vcpu
, cpu
);
219 EXPORT_SYMBOL_GPL(vcpu_load
);
221 void vcpu_put(struct kvm_vcpu
*vcpu
)
224 kvm_arch_vcpu_put(vcpu
);
225 preempt_notifier_unregister(&vcpu
->preempt_notifier
);
226 __this_cpu_write(kvm_running_vcpu
, NULL
);
229 EXPORT_SYMBOL_GPL(vcpu_put
);
231 /* TODO: merge with kvm_arch_vcpu_should_kick */
232 static bool kvm_request_needs_ipi(struct kvm_vcpu
*vcpu
, unsigned req
)
234 int mode
= kvm_vcpu_exiting_guest_mode(vcpu
);
237 * We need to wait for the VCPU to reenable interrupts and get out of
238 * READING_SHADOW_PAGE_TABLES mode.
240 if (req
& KVM_REQUEST_WAIT
)
241 return mode
!= OUTSIDE_GUEST_MODE
;
244 * Need to kick a running VCPU, but otherwise there is nothing to do.
246 return mode
== IN_GUEST_MODE
;
249 static void ack_kick(void *_completed
)
253 static inline bool kvm_kick_many_cpus(struct cpumask
*cpus
, bool wait
)
255 if (cpumask_empty(cpus
))
258 smp_call_function_many(cpus
, ack_kick
, NULL
, wait
);
262 static void kvm_make_vcpu_request(struct kvm_vcpu
*vcpu
, unsigned int req
,
263 struct cpumask
*tmp
, int current_cpu
)
267 if (likely(!(req
& KVM_REQUEST_NO_ACTION
)))
268 __kvm_make_request(req
, vcpu
);
270 if (!(req
& KVM_REQUEST_NO_WAKEUP
) && kvm_vcpu_wake_up(vcpu
))
274 * Note, the vCPU could get migrated to a different pCPU at any point
275 * after kvm_request_needs_ipi(), which could result in sending an IPI
276 * to the previous pCPU. But, that's OK because the purpose of the IPI
277 * is to ensure the vCPU returns to OUTSIDE_GUEST_MODE, which is
278 * satisfied if the vCPU migrates. Entering READING_SHADOW_PAGE_TABLES
279 * after this point is also OK, as the requirement is only that KVM wait
280 * for vCPUs that were reading SPTEs _before_ any changes were
281 * finalized. See kvm_vcpu_kick() for more details on handling requests.
283 if (kvm_request_needs_ipi(vcpu
, req
)) {
284 cpu
= READ_ONCE(vcpu
->cpu
);
285 if (cpu
!= -1 && cpu
!= current_cpu
)
286 __cpumask_set_cpu(cpu
, tmp
);
290 bool kvm_make_vcpus_request_mask(struct kvm
*kvm
, unsigned int req
,
291 unsigned long *vcpu_bitmap
)
293 struct kvm_vcpu
*vcpu
;
294 struct cpumask
*cpus
;
300 cpus
= this_cpu_cpumask_var_ptr(cpu_kick_mask
);
303 for_each_set_bit(i
, vcpu_bitmap
, KVM_MAX_VCPUS
) {
304 vcpu
= kvm_get_vcpu(kvm
, i
);
307 kvm_make_vcpu_request(vcpu
, req
, cpus
, me
);
310 called
= kvm_kick_many_cpus(cpus
, !!(req
& KVM_REQUEST_WAIT
));
316 bool kvm_make_all_cpus_request_except(struct kvm
*kvm
, unsigned int req
,
317 struct kvm_vcpu
*except
)
319 struct kvm_vcpu
*vcpu
;
320 struct cpumask
*cpus
;
327 cpus
= this_cpu_cpumask_var_ptr(cpu_kick_mask
);
330 kvm_for_each_vcpu(i
, vcpu
, kvm
) {
333 kvm_make_vcpu_request(vcpu
, req
, cpus
, me
);
336 called
= kvm_kick_many_cpus(cpus
, !!(req
& KVM_REQUEST_WAIT
));
342 bool kvm_make_all_cpus_request(struct kvm
*kvm
, unsigned int req
)
344 return kvm_make_all_cpus_request_except(kvm
, req
, NULL
);
346 EXPORT_SYMBOL_GPL(kvm_make_all_cpus_request
);
348 void kvm_flush_remote_tlbs(struct kvm
*kvm
)
350 ++kvm
->stat
.generic
.remote_tlb_flush_requests
;
353 * We want to publish modifications to the page tables before reading
354 * mode. Pairs with a memory barrier in arch-specific code.
355 * - x86: smp_mb__after_srcu_read_unlock in vcpu_enter_guest
356 * and smp_mb in walk_shadow_page_lockless_begin/end.
357 * - powerpc: smp_mb in kvmppc_prepare_to_enter.
359 * There is already an smp_mb__after_atomic() before
360 * kvm_make_all_cpus_request() reads vcpu->mode. We reuse that
363 if (!kvm_arch_flush_remote_tlbs(kvm
)
364 || kvm_make_all_cpus_request(kvm
, KVM_REQ_TLB_FLUSH
))
365 ++kvm
->stat
.generic
.remote_tlb_flush
;
367 EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs
);
369 void kvm_flush_remote_tlbs_range(struct kvm
*kvm
, gfn_t gfn
, u64 nr_pages
)
371 if (!kvm_arch_flush_remote_tlbs_range(kvm
, gfn
, nr_pages
))
375 * Fall back to a flushing entire TLBs if the architecture range-based
376 * TLB invalidation is unsupported or can't be performed for whatever
379 kvm_flush_remote_tlbs(kvm
);
382 void kvm_flush_remote_tlbs_memslot(struct kvm
*kvm
,
383 const struct kvm_memory_slot
*memslot
)
386 * All current use cases for flushing the TLBs for a specific memslot
387 * are related to dirty logging, and many do the TLB flush out of
388 * mmu_lock. The interaction between the various operations on memslot
389 * must be serialized by slots_locks to ensure the TLB flush from one
390 * operation is observed by any other operation on the same memslot.
392 lockdep_assert_held(&kvm
->slots_lock
);
393 kvm_flush_remote_tlbs_range(kvm
, memslot
->base_gfn
, memslot
->npages
);
396 static void kvm_flush_shadow_all(struct kvm
*kvm
)
398 kvm_arch_flush_shadow_all(kvm
);
399 kvm_arch_guest_memory_reclaimed(kvm
);
402 #ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
403 static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache
*mc
,
406 gfp_flags
|= mc
->gfp_zero
;
409 return kmem_cache_alloc(mc
->kmem_cache
, gfp_flags
);
411 return (void *)__get_free_page(gfp_flags
);
414 int __kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*mc
, int capacity
, int min
)
416 gfp_t gfp
= mc
->gfp_custom
? mc
->gfp_custom
: GFP_KERNEL_ACCOUNT
;
419 if (mc
->nobjs
>= min
)
422 if (unlikely(!mc
->objects
)) {
423 if (WARN_ON_ONCE(!capacity
))
426 mc
->objects
= kvmalloc_array(sizeof(void *), capacity
, gfp
);
430 mc
->capacity
= capacity
;
433 /* It is illegal to request a different capacity across topups. */
434 if (WARN_ON_ONCE(mc
->capacity
!= capacity
))
437 while (mc
->nobjs
< mc
->capacity
) {
438 obj
= mmu_memory_cache_alloc_obj(mc
, gfp
);
440 return mc
->nobjs
>= min
? 0 : -ENOMEM
;
441 mc
->objects
[mc
->nobjs
++] = obj
;
446 int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*mc
, int min
)
448 return __kvm_mmu_topup_memory_cache(mc
, KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
, min
);
451 int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache
*mc
)
456 void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
)
460 kmem_cache_free(mc
->kmem_cache
, mc
->objects
[--mc
->nobjs
]);
462 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
471 void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
)
475 if (WARN_ON(!mc
->nobjs
))
476 p
= mmu_memory_cache_alloc_obj(mc
, GFP_ATOMIC
| __GFP_ACCOUNT
);
478 p
= mc
->objects
[--mc
->nobjs
];
484 static void kvm_vcpu_init(struct kvm_vcpu
*vcpu
, struct kvm
*kvm
, unsigned id
)
486 mutex_init(&vcpu
->mutex
);
491 #ifndef __KVM_HAVE_ARCH_WQP
492 rcuwait_init(&vcpu
->wait
);
494 kvm_async_pf_vcpu_init(vcpu
);
496 kvm_vcpu_set_in_spin_loop(vcpu
, false);
497 kvm_vcpu_set_dy_eligible(vcpu
, false);
498 vcpu
->preempted
= false;
500 preempt_notifier_init(&vcpu
->preempt_notifier
, &kvm_preempt_ops
);
501 vcpu
->last_used_slot
= NULL
;
503 /* Fill the stats id string for the vcpu */
504 snprintf(vcpu
->stats_id
, sizeof(vcpu
->stats_id
), "kvm-%d/vcpu-%d",
505 task_pid_nr(current
), id
);
508 static void kvm_vcpu_destroy(struct kvm_vcpu
*vcpu
)
510 kvm_arch_vcpu_destroy(vcpu
);
511 kvm_dirty_ring_free(&vcpu
->dirty_ring
);
514 * No need for rcu_read_lock as VCPU_RUN is the only place that changes
515 * the vcpu->pid pointer, and at destruction time all file descriptors
518 put_pid(rcu_dereference_protected(vcpu
->pid
, 1));
520 free_page((unsigned long)vcpu
->run
);
521 kmem_cache_free(kvm_vcpu_cache
, vcpu
);
524 void kvm_destroy_vcpus(struct kvm
*kvm
)
527 struct kvm_vcpu
*vcpu
;
529 kvm_for_each_vcpu(i
, vcpu
, kvm
) {
530 kvm_vcpu_destroy(vcpu
);
531 xa_erase(&kvm
->vcpu_array
, i
);
534 atomic_set(&kvm
->online_vcpus
, 0);
536 EXPORT_SYMBOL_GPL(kvm_destroy_vcpus
);
538 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
539 static inline struct kvm
*mmu_notifier_to_kvm(struct mmu_notifier
*mn
)
541 return container_of(mn
, struct kvm
, mmu_notifier
);
544 typedef bool (*hva_handler_t
)(struct kvm
*kvm
, struct kvm_gfn_range
*range
);
546 typedef void (*on_lock_fn_t
)(struct kvm
*kvm
, unsigned long start
,
549 typedef void (*on_unlock_fn_t
)(struct kvm
*kvm
);
551 struct kvm_hva_range
{
554 union kvm_mmu_notifier_arg arg
;
555 hva_handler_t handler
;
556 on_lock_fn_t on_lock
;
557 on_unlock_fn_t on_unlock
;
563 * Use a dedicated stub instead of NULL to indicate that there is no callback
564 * function/handler. The compiler technically can't guarantee that a real
565 * function will have a non-zero address, and so it will generate code to
566 * check for !NULL, whereas comparing against a stub will be elided at compile
567 * time (unless the compiler is getting long in the tooth, e.g. gcc 4.9).
569 static void kvm_null_fn(void)
573 #define IS_KVM_NULL_FN(fn) ((fn) == (void *)kvm_null_fn)
575 static const union kvm_mmu_notifier_arg KVM_MMU_NOTIFIER_NO_ARG
;
577 /* Iterate over each memslot intersecting [start, last] (inclusive) range */
578 #define kvm_for_each_memslot_in_hva_range(node, slots, start, last) \
579 for (node = interval_tree_iter_first(&slots->hva_tree, start, last); \
581 node = interval_tree_iter_next(node, start, last)) \
583 static __always_inline int __kvm_handle_hva_range(struct kvm *kvm,
584 const struct kvm_hva_range
*range
)
586 bool ret
= false, locked
= false;
587 struct kvm_gfn_range gfn_range
;
588 struct kvm_memory_slot
*slot
;
589 struct kvm_memslots
*slots
;
592 if (WARN_ON_ONCE(range
->end
<= range
->start
))
595 /* A null handler is allowed if and only if on_lock() is provided. */
596 if (WARN_ON_ONCE(IS_KVM_NULL_FN(range
->on_lock
) &&
597 IS_KVM_NULL_FN(range
->handler
)))
600 idx
= srcu_read_lock(&kvm
->srcu
);
602 for (i
= 0; i
< KVM_ADDRESS_SPACE_NUM
; i
++) {
603 struct interval_tree_node
*node
;
605 slots
= __kvm_memslots(kvm
, i
);
606 kvm_for_each_memslot_in_hva_range(node
, slots
,
607 range
->start
, range
->end
- 1) {
608 unsigned long hva_start
, hva_end
;
610 slot
= container_of(node
, struct kvm_memory_slot
, hva_node
[slots
->node_idx
]);
611 hva_start
= max(range
->start
, slot
->userspace_addr
);
612 hva_end
= min(range
->end
, slot
->userspace_addr
+
613 (slot
->npages
<< PAGE_SHIFT
));
616 * To optimize for the likely case where the address
617 * range is covered by zero or one memslots, don't
618 * bother making these conditional (to avoid writes on
619 * the second or later invocation of the handler).
621 gfn_range
.arg
= range
->arg
;
622 gfn_range
.may_block
= range
->may_block
;
625 * {gfn(page) | page intersects with [hva_start, hva_end)} =
626 * {gfn_start, gfn_start+1, ..., gfn_end-1}.
628 gfn_range
.start
= hva_to_gfn_memslot(hva_start
, slot
);
629 gfn_range
.end
= hva_to_gfn_memslot(hva_end
+ PAGE_SIZE
- 1, slot
);
630 gfn_range
.slot
= slot
;
635 if (!IS_KVM_NULL_FN(range
->on_lock
))
636 range
->on_lock(kvm
, range
->start
, range
->end
);
637 if (IS_KVM_NULL_FN(range
->handler
))
640 ret
|= range
->handler(kvm
, &gfn_range
);
644 if (range
->flush_on_ret
&& ret
)
645 kvm_flush_remote_tlbs(kvm
);
649 if (!IS_KVM_NULL_FN(range
->on_unlock
))
650 range
->on_unlock(kvm
);
653 srcu_read_unlock(&kvm
->srcu
, idx
);
655 /* The notifiers are averse to booleans. :-( */
659 static __always_inline
int kvm_handle_hva_range(struct mmu_notifier
*mn
,
662 union kvm_mmu_notifier_arg arg
,
663 hva_handler_t handler
)
665 struct kvm
*kvm
= mmu_notifier_to_kvm(mn
);
666 const struct kvm_hva_range range
= {
671 .on_lock
= (void *)kvm_null_fn
,
672 .on_unlock
= (void *)kvm_null_fn
,
673 .flush_on_ret
= true,
677 return __kvm_handle_hva_range(kvm
, &range
);
680 static __always_inline
int kvm_handle_hva_range_no_flush(struct mmu_notifier
*mn
,
683 hva_handler_t handler
)
685 struct kvm
*kvm
= mmu_notifier_to_kvm(mn
);
686 const struct kvm_hva_range range
= {
690 .on_lock
= (void *)kvm_null_fn
,
691 .on_unlock
= (void *)kvm_null_fn
,
692 .flush_on_ret
= false,
696 return __kvm_handle_hva_range(kvm
, &range
);
699 static bool kvm_change_spte_gfn(struct kvm
*kvm
, struct kvm_gfn_range
*range
)
702 * Skipping invalid memslots is correct if and only change_pte() is
703 * surrounded by invalidate_range_{start,end}(), which is currently
704 * guaranteed by the primary MMU. If that ever changes, KVM needs to
705 * unmap the memslot instead of skipping the memslot to ensure that KVM
706 * doesn't hold references to the old PFN.
708 WARN_ON_ONCE(!READ_ONCE(kvm
->mn_active_invalidate_count
));
710 if (range
->slot
->flags
& KVM_MEMSLOT_INVALID
)
713 return kvm_set_spte_gfn(kvm
, range
);
716 static void kvm_mmu_notifier_change_pte(struct mmu_notifier
*mn
,
717 struct mm_struct
*mm
,
718 unsigned long address
,
721 struct kvm
*kvm
= mmu_notifier_to_kvm(mn
);
722 const union kvm_mmu_notifier_arg arg
= { .pte
= pte
};
724 trace_kvm_set_spte_hva(address
);
727 * .change_pte() must be surrounded by .invalidate_range_{start,end}().
728 * If mmu_invalidate_in_progress is zero, then no in-progress
729 * invalidations, including this one, found a relevant memslot at
730 * start(); rechecking memslots here is unnecessary. Note, a false
731 * positive (count elevated by a different invalidation) is sub-optimal
732 * but functionally ok.
734 WARN_ON_ONCE(!READ_ONCE(kvm
->mn_active_invalidate_count
));
735 if (!READ_ONCE(kvm
->mmu_invalidate_in_progress
))
738 kvm_handle_hva_range(mn
, address
, address
+ 1, arg
, kvm_change_spte_gfn
);
741 void kvm_mmu_invalidate_begin(struct kvm
*kvm
, unsigned long start
,
745 * The count increase must become visible at unlock time as no
746 * spte can be established without taking the mmu_lock and
747 * count is also read inside the mmu_lock critical section.
749 kvm
->mmu_invalidate_in_progress
++;
750 if (likely(kvm
->mmu_invalidate_in_progress
== 1)) {
751 kvm
->mmu_invalidate_range_start
= start
;
752 kvm
->mmu_invalidate_range_end
= end
;
755 * Fully tracking multiple concurrent ranges has diminishing
756 * returns. Keep things simple and just find the minimal range
757 * which includes the current and new ranges. As there won't be
758 * enough information to subtract a range after its invalidate
759 * completes, any ranges invalidated concurrently will
760 * accumulate and persist until all outstanding invalidates
763 kvm
->mmu_invalidate_range_start
=
764 min(kvm
->mmu_invalidate_range_start
, start
);
765 kvm
->mmu_invalidate_range_end
=
766 max(kvm
->mmu_invalidate_range_end
, end
);
770 static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier
*mn
,
771 const struct mmu_notifier_range
*range
)
773 struct kvm
*kvm
= mmu_notifier_to_kvm(mn
);
774 const struct kvm_hva_range hva_range
= {
775 .start
= range
->start
,
777 .handler
= kvm_unmap_gfn_range
,
778 .on_lock
= kvm_mmu_invalidate_begin
,
779 .on_unlock
= kvm_arch_guest_memory_reclaimed
,
780 .flush_on_ret
= true,
781 .may_block
= mmu_notifier_range_blockable(range
),
784 trace_kvm_unmap_hva_range(range
->start
, range
->end
);
787 * Prevent memslot modification between range_start() and range_end()
788 * so that conditionally locking provides the same result in both
789 * functions. Without that guarantee, the mmu_invalidate_in_progress
790 * adjustments will be imbalanced.
792 * Pairs with the decrement in range_end().
794 spin_lock(&kvm
->mn_invalidate_lock
);
795 kvm
->mn_active_invalidate_count
++;
796 spin_unlock(&kvm
->mn_invalidate_lock
);
799 * Invalidate pfn caches _before_ invalidating the secondary MMUs, i.e.
800 * before acquiring mmu_lock, to avoid holding mmu_lock while acquiring
801 * each cache's lock. There are relatively few caches in existence at
802 * any given time, and the caches themselves can check for hva overlap,
803 * i.e. don't need to rely on memslot overlap checks for performance.
804 * Because this runs without holding mmu_lock, the pfn caches must use
805 * mn_active_invalidate_count (see above) instead of
806 * mmu_invalidate_in_progress.
808 gfn_to_pfn_cache_invalidate_start(kvm
, range
->start
, range
->end
,
809 hva_range
.may_block
);
811 __kvm_handle_hva_range(kvm
, &hva_range
);
816 void kvm_mmu_invalidate_end(struct kvm
*kvm
, unsigned long start
,
820 * This sequence increase will notify the kvm page fault that
821 * the page that is going to be mapped in the spte could have
824 kvm
->mmu_invalidate_seq
++;
827 * The above sequence increase must be visible before the
828 * below count decrease, which is ensured by the smp_wmb above
829 * in conjunction with the smp_rmb in mmu_invalidate_retry().
831 kvm
->mmu_invalidate_in_progress
--;
834 static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier
*mn
,
835 const struct mmu_notifier_range
*range
)
837 struct kvm
*kvm
= mmu_notifier_to_kvm(mn
);
838 const struct kvm_hva_range hva_range
= {
839 .start
= range
->start
,
841 .handler
= (void *)kvm_null_fn
,
842 .on_lock
= kvm_mmu_invalidate_end
,
843 .on_unlock
= (void *)kvm_null_fn
,
844 .flush_on_ret
= false,
845 .may_block
= mmu_notifier_range_blockable(range
),
849 __kvm_handle_hva_range(kvm
, &hva_range
);
851 /* Pairs with the increment in range_start(). */
852 spin_lock(&kvm
->mn_invalidate_lock
);
853 wake
= (--kvm
->mn_active_invalidate_count
== 0);
854 spin_unlock(&kvm
->mn_invalidate_lock
);
857 * There can only be one waiter, since the wait happens under
861 rcuwait_wake_up(&kvm
->mn_memslots_update_rcuwait
);
863 BUG_ON(kvm
->mmu_invalidate_in_progress
< 0);
866 static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier
*mn
,
867 struct mm_struct
*mm
,
871 trace_kvm_age_hva(start
, end
);
873 return kvm_handle_hva_range(mn
, start
, end
, KVM_MMU_NOTIFIER_NO_ARG
,
877 static int kvm_mmu_notifier_clear_young(struct mmu_notifier
*mn
,
878 struct mm_struct
*mm
,
882 trace_kvm_age_hva(start
, end
);
885 * Even though we do not flush TLB, this will still adversely
886 * affect performance on pre-Haswell Intel EPT, where there is
887 * no EPT Access Bit to clear so that we have to tear down EPT
888 * tables instead. If we find this unacceptable, we can always
889 * add a parameter to kvm_age_hva so that it effectively doesn't
890 * do anything on clear_young.
892 * Also note that currently we never issue secondary TLB flushes
893 * from clear_young, leaving this job up to the regular system
894 * cadence. If we find this inaccurate, we might come up with a
895 * more sophisticated heuristic later.
897 return kvm_handle_hva_range_no_flush(mn
, start
, end
, kvm_age_gfn
);
900 static int kvm_mmu_notifier_test_young(struct mmu_notifier
*mn
,
901 struct mm_struct
*mm
,
902 unsigned long address
)
904 trace_kvm_test_age_hva(address
);
906 return kvm_handle_hva_range_no_flush(mn
, address
, address
+ 1,
910 static void kvm_mmu_notifier_release(struct mmu_notifier
*mn
,
911 struct mm_struct
*mm
)
913 struct kvm
*kvm
= mmu_notifier_to_kvm(mn
);
916 idx
= srcu_read_lock(&kvm
->srcu
);
917 kvm_flush_shadow_all(kvm
);
918 srcu_read_unlock(&kvm
->srcu
, idx
);
921 static const struct mmu_notifier_ops kvm_mmu_notifier_ops
= {
922 .invalidate_range_start
= kvm_mmu_notifier_invalidate_range_start
,
923 .invalidate_range_end
= kvm_mmu_notifier_invalidate_range_end
,
924 .clear_flush_young
= kvm_mmu_notifier_clear_flush_young
,
925 .clear_young
= kvm_mmu_notifier_clear_young
,
926 .test_young
= kvm_mmu_notifier_test_young
,
927 .change_pte
= kvm_mmu_notifier_change_pte
,
928 .release
= kvm_mmu_notifier_release
,
931 static int kvm_init_mmu_notifier(struct kvm
*kvm
)
933 kvm
->mmu_notifier
.ops
= &kvm_mmu_notifier_ops
;
934 return mmu_notifier_register(&kvm
->mmu_notifier
, current
->mm
);
937 #else /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */
939 static int kvm_init_mmu_notifier(struct kvm
*kvm
)
944 #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
946 #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
947 static int kvm_pm_notifier_call(struct notifier_block
*bl
,
951 struct kvm
*kvm
= container_of(bl
, struct kvm
, pm_notifier
);
953 return kvm_arch_pm_notifier(kvm
, state
);
956 static void kvm_init_pm_notifier(struct kvm
*kvm
)
958 kvm
->pm_notifier
.notifier_call
= kvm_pm_notifier_call
;
959 /* Suspend KVM before we suspend ftrace, RCU, etc. */
960 kvm
->pm_notifier
.priority
= INT_MAX
;
961 register_pm_notifier(&kvm
->pm_notifier
);
964 static void kvm_destroy_pm_notifier(struct kvm
*kvm
)
966 unregister_pm_notifier(&kvm
->pm_notifier
);
968 #else /* !CONFIG_HAVE_KVM_PM_NOTIFIER */
969 static void kvm_init_pm_notifier(struct kvm
*kvm
)
973 static void kvm_destroy_pm_notifier(struct kvm
*kvm
)
976 #endif /* CONFIG_HAVE_KVM_PM_NOTIFIER */
978 static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot
*memslot
)
980 if (!memslot
->dirty_bitmap
)
983 kvfree(memslot
->dirty_bitmap
);
984 memslot
->dirty_bitmap
= NULL
;
987 /* This does not remove the slot from struct kvm_memslots data structures */
988 static void kvm_free_memslot(struct kvm
*kvm
, struct kvm_memory_slot
*slot
)
990 kvm_destroy_dirty_bitmap(slot
);
992 kvm_arch_free_memslot(kvm
, slot
);
997 static void kvm_free_memslots(struct kvm
*kvm
, struct kvm_memslots
*slots
)
999 struct hlist_node
*idnode
;
1000 struct kvm_memory_slot
*memslot
;
1004 * The same memslot objects live in both active and inactive sets,
1005 * arbitrarily free using index '1' so the second invocation of this
1006 * function isn't operating over a structure with dangling pointers
1007 * (even though this function isn't actually touching them).
1009 if (!slots
->node_idx
)
1012 hash_for_each_safe(slots
->id_hash
, bkt
, idnode
, memslot
, id_node
[1])
1013 kvm_free_memslot(kvm
, memslot
);
1016 static umode_t
kvm_stats_debugfs_mode(const struct _kvm_stats_desc
*pdesc
)
1018 switch (pdesc
->desc
.flags
& KVM_STATS_TYPE_MASK
) {
1019 case KVM_STATS_TYPE_INSTANT
:
1021 case KVM_STATS_TYPE_CUMULATIVE
:
1022 case KVM_STATS_TYPE_PEAK
:
1029 static void kvm_destroy_vm_debugfs(struct kvm
*kvm
)
1032 int kvm_debugfs_num_entries
= kvm_vm_stats_header
.num_desc
+
1033 kvm_vcpu_stats_header
.num_desc
;
1035 if (IS_ERR(kvm
->debugfs_dentry
))
1038 debugfs_remove_recursive(kvm
->debugfs_dentry
);
1040 if (kvm
->debugfs_stat_data
) {
1041 for (i
= 0; i
< kvm_debugfs_num_entries
; i
++)
1042 kfree(kvm
->debugfs_stat_data
[i
]);
1043 kfree(kvm
->debugfs_stat_data
);
1047 static int kvm_create_vm_debugfs(struct kvm
*kvm
, const char *fdname
)
1049 static DEFINE_MUTEX(kvm_debugfs_lock
);
1050 struct dentry
*dent
;
1051 char dir_name
[ITOA_MAX_LEN
* 2];
1052 struct kvm_stat_data
*stat_data
;
1053 const struct _kvm_stats_desc
*pdesc
;
1054 int i
, ret
= -ENOMEM
;
1055 int kvm_debugfs_num_entries
= kvm_vm_stats_header
.num_desc
+
1056 kvm_vcpu_stats_header
.num_desc
;
1058 if (!debugfs_initialized())
1061 snprintf(dir_name
, sizeof(dir_name
), "%d-%s", task_pid_nr(current
), fdname
);
1062 mutex_lock(&kvm_debugfs_lock
);
1063 dent
= debugfs_lookup(dir_name
, kvm_debugfs_dir
);
1065 pr_warn_ratelimited("KVM: debugfs: duplicate directory %s\n", dir_name
);
1067 mutex_unlock(&kvm_debugfs_lock
);
1070 dent
= debugfs_create_dir(dir_name
, kvm_debugfs_dir
);
1071 mutex_unlock(&kvm_debugfs_lock
);
1075 kvm
->debugfs_dentry
= dent
;
1076 kvm
->debugfs_stat_data
= kcalloc(kvm_debugfs_num_entries
,
1077 sizeof(*kvm
->debugfs_stat_data
),
1078 GFP_KERNEL_ACCOUNT
);
1079 if (!kvm
->debugfs_stat_data
)
1082 for (i
= 0; i
< kvm_vm_stats_header
.num_desc
; ++i
) {
1083 pdesc
= &kvm_vm_stats_desc
[i
];
1084 stat_data
= kzalloc(sizeof(*stat_data
), GFP_KERNEL_ACCOUNT
);
1088 stat_data
->kvm
= kvm
;
1089 stat_data
->desc
= pdesc
;
1090 stat_data
->kind
= KVM_STAT_VM
;
1091 kvm
->debugfs_stat_data
[i
] = stat_data
;
1092 debugfs_create_file(pdesc
->name
, kvm_stats_debugfs_mode(pdesc
),
1093 kvm
->debugfs_dentry
, stat_data
,
1097 for (i
= 0; i
< kvm_vcpu_stats_header
.num_desc
; ++i
) {
1098 pdesc
= &kvm_vcpu_stats_desc
[i
];
1099 stat_data
= kzalloc(sizeof(*stat_data
), GFP_KERNEL_ACCOUNT
);
1103 stat_data
->kvm
= kvm
;
1104 stat_data
->desc
= pdesc
;
1105 stat_data
->kind
= KVM_STAT_VCPU
;
1106 kvm
->debugfs_stat_data
[i
+ kvm_vm_stats_header
.num_desc
] = stat_data
;
1107 debugfs_create_file(pdesc
->name
, kvm_stats_debugfs_mode(pdesc
),
1108 kvm
->debugfs_dentry
, stat_data
,
1112 ret
= kvm_arch_create_vm_debugfs(kvm
);
1118 kvm_destroy_vm_debugfs(kvm
);
1123 * Called after the VM is otherwise initialized, but just before adding it to
1126 int __weak
kvm_arch_post_init_vm(struct kvm
*kvm
)
1132 * Called just after removing the VM from the vm_list, but before doing any
1133 * other destruction.
1135 void __weak
kvm_arch_pre_destroy_vm(struct kvm
*kvm
)
1140 * Called after per-vm debugfs created. When called kvm->debugfs_dentry should
1141 * be setup already, so we can create arch-specific debugfs entries under it.
1142 * Cleanup should be automatic done in kvm_destroy_vm_debugfs() recursively, so
1143 * a per-arch destroy interface is not needed.
1145 int __weak
kvm_arch_create_vm_debugfs(struct kvm
*kvm
)
1150 static struct kvm
*kvm_create_vm(unsigned long type
, const char *fdname
)
1152 struct kvm
*kvm
= kvm_arch_alloc_vm();
1153 struct kvm_memslots
*slots
;
1158 return ERR_PTR(-ENOMEM
);
1160 /* KVM is pinned via open("/dev/kvm"), the fd passed to this ioctl(). */
1161 __module_get(kvm_chardev_ops
.owner
);
1163 KVM_MMU_LOCK_INIT(kvm
);
1164 mmgrab(current
->mm
);
1165 kvm
->mm
= current
->mm
;
1166 kvm_eventfd_init(kvm
);
1167 mutex_init(&kvm
->lock
);
1168 mutex_init(&kvm
->irq_lock
);
1169 mutex_init(&kvm
->slots_lock
);
1170 mutex_init(&kvm
->slots_arch_lock
);
1171 spin_lock_init(&kvm
->mn_invalidate_lock
);
1172 rcuwait_init(&kvm
->mn_memslots_update_rcuwait
);
1173 xa_init(&kvm
->vcpu_array
);
1175 INIT_LIST_HEAD(&kvm
->gpc_list
);
1176 spin_lock_init(&kvm
->gpc_lock
);
1178 INIT_LIST_HEAD(&kvm
->devices
);
1179 kvm
->max_vcpus
= KVM_MAX_VCPUS
;
1181 BUILD_BUG_ON(KVM_MEM_SLOTS_NUM
> SHRT_MAX
);
1184 * Force subsequent debugfs file creations to fail if the VM directory
1185 * is not created (by kvm_create_vm_debugfs()).
1187 kvm
->debugfs_dentry
= ERR_PTR(-ENOENT
);
1189 snprintf(kvm
->stats_id
, sizeof(kvm
->stats_id
), "kvm-%d",
1190 task_pid_nr(current
));
1192 if (init_srcu_struct(&kvm
->srcu
))
1193 goto out_err_no_srcu
;
1194 if (init_srcu_struct(&kvm
->irq_srcu
))
1195 goto out_err_no_irq_srcu
;
1197 refcount_set(&kvm
->users_count
, 1);
1198 for (i
= 0; i
< KVM_ADDRESS_SPACE_NUM
; i
++) {
1199 for (j
= 0; j
< 2; j
++) {
1200 slots
= &kvm
->__memslots
[i
][j
];
1202 atomic_long_set(&slots
->last_used_slot
, (unsigned long)NULL
);
1203 slots
->hva_tree
= RB_ROOT_CACHED
;
1204 slots
->gfn_tree
= RB_ROOT
;
1205 hash_init(slots
->id_hash
);
1206 slots
->node_idx
= j
;
1208 /* Generations must be different for each address space. */
1209 slots
->generation
= i
;
1212 rcu_assign_pointer(kvm
->memslots
[i
], &kvm
->__memslots
[i
][0]);
1215 for (i
= 0; i
< KVM_NR_BUSES
; i
++) {
1216 rcu_assign_pointer(kvm
->buses
[i
],
1217 kzalloc(sizeof(struct kvm_io_bus
), GFP_KERNEL_ACCOUNT
));
1219 goto out_err_no_arch_destroy_vm
;
1222 r
= kvm_arch_init_vm(kvm
, type
);
1224 goto out_err_no_arch_destroy_vm
;
1226 r
= hardware_enable_all();
1228 goto out_err_no_disable
;
1230 #ifdef CONFIG_HAVE_KVM_IRQFD
1231 INIT_HLIST_HEAD(&kvm
->irq_ack_notifier_list
);
1234 r
= kvm_init_mmu_notifier(kvm
);
1236 goto out_err_no_mmu_notifier
;
1238 r
= kvm_coalesced_mmio_init(kvm
);
1240 goto out_no_coalesced_mmio
;
1242 r
= kvm_create_vm_debugfs(kvm
, fdname
);
1244 goto out_err_no_debugfs
;
1246 r
= kvm_arch_post_init_vm(kvm
);
1250 mutex_lock(&kvm_lock
);
1251 list_add(&kvm
->vm_list
, &vm_list
);
1252 mutex_unlock(&kvm_lock
);
1254 preempt_notifier_inc();
1255 kvm_init_pm_notifier(kvm
);
1260 kvm_destroy_vm_debugfs(kvm
);
1262 kvm_coalesced_mmio_free(kvm
);
1263 out_no_coalesced_mmio
:
1264 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
1265 if (kvm
->mmu_notifier
.ops
)
1266 mmu_notifier_unregister(&kvm
->mmu_notifier
, current
->mm
);
1268 out_err_no_mmu_notifier
:
1269 hardware_disable_all();
1271 kvm_arch_destroy_vm(kvm
);
1272 out_err_no_arch_destroy_vm
:
1273 WARN_ON_ONCE(!refcount_dec_and_test(&kvm
->users_count
));
1274 for (i
= 0; i
< KVM_NR_BUSES
; i
++)
1275 kfree(kvm_get_bus(kvm
, i
));
1276 cleanup_srcu_struct(&kvm
->irq_srcu
);
1277 out_err_no_irq_srcu
:
1278 cleanup_srcu_struct(&kvm
->srcu
);
1280 kvm_arch_free_vm(kvm
);
1281 mmdrop(current
->mm
);
1282 module_put(kvm_chardev_ops
.owner
);
1286 static void kvm_destroy_devices(struct kvm
*kvm
)
1288 struct kvm_device
*dev
, *tmp
;
1291 * We do not need to take the kvm->lock here, because nobody else
1292 * has a reference to the struct kvm at this point and therefore
1293 * cannot access the devices list anyhow.
1295 list_for_each_entry_safe(dev
, tmp
, &kvm
->devices
, vm_node
) {
1296 list_del(&dev
->vm_node
);
1297 dev
->ops
->destroy(dev
);
1301 static void kvm_destroy_vm(struct kvm
*kvm
)
1304 struct mm_struct
*mm
= kvm
->mm
;
1306 kvm_destroy_pm_notifier(kvm
);
1307 kvm_uevent_notify_change(KVM_EVENT_DESTROY_VM
, kvm
);
1308 kvm_destroy_vm_debugfs(kvm
);
1309 kvm_arch_sync_events(kvm
);
1310 mutex_lock(&kvm_lock
);
1311 list_del(&kvm
->vm_list
);
1312 mutex_unlock(&kvm_lock
);
1313 kvm_arch_pre_destroy_vm(kvm
);
1315 kvm_free_irq_routing(kvm
);
1316 for (i
= 0; i
< KVM_NR_BUSES
; i
++) {
1317 struct kvm_io_bus
*bus
= kvm_get_bus(kvm
, i
);
1320 kvm_io_bus_destroy(bus
);
1321 kvm
->buses
[i
] = NULL
;
1323 kvm_coalesced_mmio_free(kvm
);
1324 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
1325 mmu_notifier_unregister(&kvm
->mmu_notifier
, kvm
->mm
);
1327 * At this point, pending calls to invalidate_range_start()
1328 * have completed but no more MMU notifiers will run, so
1329 * mn_active_invalidate_count may remain unbalanced.
1330 * No threads can be waiting in kvm_swap_active_memslots() as the
1331 * last reference on KVM has been dropped, but freeing
1332 * memslots would deadlock without this manual intervention.
1334 WARN_ON(rcuwait_active(&kvm
->mn_memslots_update_rcuwait
));
1335 kvm
->mn_active_invalidate_count
= 0;
1337 kvm_flush_shadow_all(kvm
);
1339 kvm_arch_destroy_vm(kvm
);
1340 kvm_destroy_devices(kvm
);
1341 for (i
= 0; i
< KVM_ADDRESS_SPACE_NUM
; i
++) {
1342 kvm_free_memslots(kvm
, &kvm
->__memslots
[i
][0]);
1343 kvm_free_memslots(kvm
, &kvm
->__memslots
[i
][1]);
1345 cleanup_srcu_struct(&kvm
->irq_srcu
);
1346 cleanup_srcu_struct(&kvm
->srcu
);
1347 kvm_arch_free_vm(kvm
);
1348 preempt_notifier_dec();
1349 hardware_disable_all();
1351 module_put(kvm_chardev_ops
.owner
);
1354 void kvm_get_kvm(struct kvm
*kvm
)
1356 refcount_inc(&kvm
->users_count
);
1358 EXPORT_SYMBOL_GPL(kvm_get_kvm
);
1361 * Make sure the vm is not during destruction, which is a safe version of
1362 * kvm_get_kvm(). Return true if kvm referenced successfully, false otherwise.
1364 bool kvm_get_kvm_safe(struct kvm
*kvm
)
1366 return refcount_inc_not_zero(&kvm
->users_count
);
1368 EXPORT_SYMBOL_GPL(kvm_get_kvm_safe
);
1370 void kvm_put_kvm(struct kvm
*kvm
)
1372 if (refcount_dec_and_test(&kvm
->users_count
))
1373 kvm_destroy_vm(kvm
);
1375 EXPORT_SYMBOL_GPL(kvm_put_kvm
);
1378 * Used to put a reference that was taken on behalf of an object associated
1379 * with a user-visible file descriptor, e.g. a vcpu or device, if installation
1380 * of the new file descriptor fails and the reference cannot be transferred to
1381 * its final owner. In such cases, the caller is still actively using @kvm and
1382 * will fail miserably if the refcount unexpectedly hits zero.
1384 void kvm_put_kvm_no_destroy(struct kvm
*kvm
)
1386 WARN_ON(refcount_dec_and_test(&kvm
->users_count
));
1388 EXPORT_SYMBOL_GPL(kvm_put_kvm_no_destroy
);
1390 static int kvm_vm_release(struct inode
*inode
, struct file
*filp
)
1392 struct kvm
*kvm
= filp
->private_data
;
1394 kvm_irqfd_release(kvm
);
1401 * Allocation size is twice as large as the actual dirty bitmap size.
1402 * See kvm_vm_ioctl_get_dirty_log() why this is needed.
1404 static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot
*memslot
)
1406 unsigned long dirty_bytes
= kvm_dirty_bitmap_bytes(memslot
);
1408 memslot
->dirty_bitmap
= __vcalloc(2, dirty_bytes
, GFP_KERNEL_ACCOUNT
);
1409 if (!memslot
->dirty_bitmap
)
1415 static struct kvm_memslots
*kvm_get_inactive_memslots(struct kvm
*kvm
, int as_id
)
1417 struct kvm_memslots
*active
= __kvm_memslots(kvm
, as_id
);
1418 int node_idx_inactive
= active
->node_idx
^ 1;
1420 return &kvm
->__memslots
[as_id
][node_idx_inactive
];
1424 * Helper to get the address space ID when one of memslot pointers may be NULL.
1425 * This also serves as a sanity that at least one of the pointers is non-NULL,
1426 * and that their address space IDs don't diverge.
1428 static int kvm_memslots_get_as_id(struct kvm_memory_slot
*a
,
1429 struct kvm_memory_slot
*b
)
1431 if (WARN_ON_ONCE(!a
&& !b
))
1439 WARN_ON_ONCE(a
->as_id
!= b
->as_id
);
1443 static void kvm_insert_gfn_node(struct kvm_memslots
*slots
,
1444 struct kvm_memory_slot
*slot
)
1446 struct rb_root
*gfn_tree
= &slots
->gfn_tree
;
1447 struct rb_node
**node
, *parent
;
1448 int idx
= slots
->node_idx
;
1451 for (node
= &gfn_tree
->rb_node
; *node
; ) {
1452 struct kvm_memory_slot
*tmp
;
1454 tmp
= container_of(*node
, struct kvm_memory_slot
, gfn_node
[idx
]);
1456 if (slot
->base_gfn
< tmp
->base_gfn
)
1457 node
= &(*node
)->rb_left
;
1458 else if (slot
->base_gfn
> tmp
->base_gfn
)
1459 node
= &(*node
)->rb_right
;
1464 rb_link_node(&slot
->gfn_node
[idx
], parent
, node
);
1465 rb_insert_color(&slot
->gfn_node
[idx
], gfn_tree
);
1468 static void kvm_erase_gfn_node(struct kvm_memslots
*slots
,
1469 struct kvm_memory_slot
*slot
)
1471 rb_erase(&slot
->gfn_node
[slots
->node_idx
], &slots
->gfn_tree
);
1474 static void kvm_replace_gfn_node(struct kvm_memslots
*slots
,
1475 struct kvm_memory_slot
*old
,
1476 struct kvm_memory_slot
*new)
1478 int idx
= slots
->node_idx
;
1480 WARN_ON_ONCE(old
->base_gfn
!= new->base_gfn
);
1482 rb_replace_node(&old
->gfn_node
[idx
], &new->gfn_node
[idx
],
1487 * Replace @old with @new in the inactive memslots.
1489 * With NULL @old this simply adds @new.
1490 * With NULL @new this simply removes @old.
1492 * If @new is non-NULL its hva_node[slots_idx] range has to be set
1495 static void kvm_replace_memslot(struct kvm
*kvm
,
1496 struct kvm_memory_slot
*old
,
1497 struct kvm_memory_slot
*new)
1499 int as_id
= kvm_memslots_get_as_id(old
, new);
1500 struct kvm_memslots
*slots
= kvm_get_inactive_memslots(kvm
, as_id
);
1501 int idx
= slots
->node_idx
;
1504 hash_del(&old
->id_node
[idx
]);
1505 interval_tree_remove(&old
->hva_node
[idx
], &slots
->hva_tree
);
1507 if ((long)old
== atomic_long_read(&slots
->last_used_slot
))
1508 atomic_long_set(&slots
->last_used_slot
, (long)new);
1511 kvm_erase_gfn_node(slots
, old
);
1517 * Initialize @new's hva range. Do this even when replacing an @old
1518 * slot, kvm_copy_memslot() deliberately does not touch node data.
1520 new->hva_node
[idx
].start
= new->userspace_addr
;
1521 new->hva_node
[idx
].last
= new->userspace_addr
+
1522 (new->npages
<< PAGE_SHIFT
) - 1;
1525 * (Re)Add the new memslot. There is no O(1) interval_tree_replace(),
1526 * hva_node needs to be swapped with remove+insert even though hva can't
1527 * change when replacing an existing slot.
1529 hash_add(slots
->id_hash
, &new->id_node
[idx
], new->id
);
1530 interval_tree_insert(&new->hva_node
[idx
], &slots
->hva_tree
);
1533 * If the memslot gfn is unchanged, rb_replace_node() can be used to
1534 * switch the node in the gfn tree instead of removing the old and
1535 * inserting the new as two separate operations. Replacement is a
1536 * single O(1) operation versus two O(log(n)) operations for
1539 if (old
&& old
->base_gfn
== new->base_gfn
) {
1540 kvm_replace_gfn_node(slots
, old
, new);
1543 kvm_erase_gfn_node(slots
, old
);
1544 kvm_insert_gfn_node(slots
, new);
1548 static int check_memory_region_flags(const struct kvm_userspace_memory_region
*mem
)
1550 u32 valid_flags
= KVM_MEM_LOG_DIRTY_PAGES
;
1552 #ifdef __KVM_HAVE_READONLY_MEM
1553 valid_flags
|= KVM_MEM_READONLY
;
1556 if (mem
->flags
& ~valid_flags
)
1562 static void kvm_swap_active_memslots(struct kvm
*kvm
, int as_id
)
1564 struct kvm_memslots
*slots
= kvm_get_inactive_memslots(kvm
, as_id
);
1566 /* Grab the generation from the activate memslots. */
1567 u64 gen
= __kvm_memslots(kvm
, as_id
)->generation
;
1569 WARN_ON(gen
& KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS
);
1570 slots
->generation
= gen
| KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS
;
1573 * Do not store the new memslots while there are invalidations in
1574 * progress, otherwise the locking in invalidate_range_start and
1575 * invalidate_range_end will be unbalanced.
1577 spin_lock(&kvm
->mn_invalidate_lock
);
1578 prepare_to_rcuwait(&kvm
->mn_memslots_update_rcuwait
);
1579 while (kvm
->mn_active_invalidate_count
) {
1580 set_current_state(TASK_UNINTERRUPTIBLE
);
1581 spin_unlock(&kvm
->mn_invalidate_lock
);
1583 spin_lock(&kvm
->mn_invalidate_lock
);
1585 finish_rcuwait(&kvm
->mn_memslots_update_rcuwait
);
1586 rcu_assign_pointer(kvm
->memslots
[as_id
], slots
);
1587 spin_unlock(&kvm
->mn_invalidate_lock
);
1590 * Acquired in kvm_set_memslot. Must be released before synchronize
1591 * SRCU below in order to avoid deadlock with another thread
1592 * acquiring the slots_arch_lock in an srcu critical section.
1594 mutex_unlock(&kvm
->slots_arch_lock
);
1596 synchronize_srcu_expedited(&kvm
->srcu
);
1599 * Increment the new memslot generation a second time, dropping the
1600 * update in-progress flag and incrementing the generation based on
1601 * the number of address spaces. This provides a unique and easily
1602 * identifiable generation number while the memslots are in flux.
1604 gen
= slots
->generation
& ~KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS
;
1607 * Generations must be unique even across address spaces. We do not need
1608 * a global counter for that, instead the generation space is evenly split
1609 * across address spaces. For example, with two address spaces, address
1610 * space 0 will use generations 0, 2, 4, ... while address space 1 will
1611 * use generations 1, 3, 5, ...
1613 gen
+= KVM_ADDRESS_SPACE_NUM
;
1615 kvm_arch_memslots_updated(kvm
, gen
);
1617 slots
->generation
= gen
;
1620 static int kvm_prepare_memory_region(struct kvm
*kvm
,
1621 const struct kvm_memory_slot
*old
,
1622 struct kvm_memory_slot
*new,
1623 enum kvm_mr_change change
)
1628 * If dirty logging is disabled, nullify the bitmap; the old bitmap
1629 * will be freed on "commit". If logging is enabled in both old and
1630 * new, reuse the existing bitmap. If logging is enabled only in the
1631 * new and KVM isn't using a ring buffer, allocate and initialize a
1634 if (change
!= KVM_MR_DELETE
) {
1635 if (!(new->flags
& KVM_MEM_LOG_DIRTY_PAGES
))
1636 new->dirty_bitmap
= NULL
;
1637 else if (old
&& old
->dirty_bitmap
)
1638 new->dirty_bitmap
= old
->dirty_bitmap
;
1639 else if (kvm_use_dirty_bitmap(kvm
)) {
1640 r
= kvm_alloc_dirty_bitmap(new);
1644 if (kvm_dirty_log_manual_protect_and_init_set(kvm
))
1645 bitmap_set(new->dirty_bitmap
, 0, new->npages
);
1649 r
= kvm_arch_prepare_memory_region(kvm
, old
, new, change
);
1651 /* Free the bitmap on failure if it was allocated above. */
1652 if (r
&& new && new->dirty_bitmap
&& (!old
|| !old
->dirty_bitmap
))
1653 kvm_destroy_dirty_bitmap(new);
1658 static void kvm_commit_memory_region(struct kvm
*kvm
,
1659 struct kvm_memory_slot
*old
,
1660 const struct kvm_memory_slot
*new,
1661 enum kvm_mr_change change
)
1663 int old_flags
= old
? old
->flags
: 0;
1664 int new_flags
= new ? new->flags
: 0;
1666 * Update the total number of memslot pages before calling the arch
1667 * hook so that architectures can consume the result directly.
1669 if (change
== KVM_MR_DELETE
)
1670 kvm
->nr_memslot_pages
-= old
->npages
;
1671 else if (change
== KVM_MR_CREATE
)
1672 kvm
->nr_memslot_pages
+= new->npages
;
1674 if ((old_flags
^ new_flags
) & KVM_MEM_LOG_DIRTY_PAGES
) {
1675 int change
= (new_flags
& KVM_MEM_LOG_DIRTY_PAGES
) ? 1 : -1;
1676 atomic_set(&kvm
->nr_memslots_dirty_logging
,
1677 atomic_read(&kvm
->nr_memslots_dirty_logging
) + change
);
1680 kvm_arch_commit_memory_region(kvm
, old
, new, change
);
1684 /* Nothing more to do. */
1687 /* Free the old memslot and all its metadata. */
1688 kvm_free_memslot(kvm
, old
);
1691 case KVM_MR_FLAGS_ONLY
:
1693 * Free the dirty bitmap as needed; the below check encompasses
1694 * both the flags and whether a ring buffer is being used)
1696 if (old
->dirty_bitmap
&& !new->dirty_bitmap
)
1697 kvm_destroy_dirty_bitmap(old
);
1700 * The final quirk. Free the detached, old slot, but only its
1701 * memory, not any metadata. Metadata, including arch specific
1702 * data, may be reused by @new.
1712 * Activate @new, which must be installed in the inactive slots by the caller,
1713 * by swapping the active slots and then propagating @new to @old once @old is
1714 * unreachable and can be safely modified.
1716 * With NULL @old this simply adds @new to @active (while swapping the sets).
1717 * With NULL @new this simply removes @old from @active and frees it
1718 * (while also swapping the sets).
1720 static void kvm_activate_memslot(struct kvm
*kvm
,
1721 struct kvm_memory_slot
*old
,
1722 struct kvm_memory_slot
*new)
1724 int as_id
= kvm_memslots_get_as_id(old
, new);
1726 kvm_swap_active_memslots(kvm
, as_id
);
1728 /* Propagate the new memslot to the now inactive memslots. */
1729 kvm_replace_memslot(kvm
, old
, new);
1732 static void kvm_copy_memslot(struct kvm_memory_slot
*dest
,
1733 const struct kvm_memory_slot
*src
)
1735 dest
->base_gfn
= src
->base_gfn
;
1736 dest
->npages
= src
->npages
;
1737 dest
->dirty_bitmap
= src
->dirty_bitmap
;
1738 dest
->arch
= src
->arch
;
1739 dest
->userspace_addr
= src
->userspace_addr
;
1740 dest
->flags
= src
->flags
;
1742 dest
->as_id
= src
->as_id
;
1745 static void kvm_invalidate_memslot(struct kvm
*kvm
,
1746 struct kvm_memory_slot
*old
,
1747 struct kvm_memory_slot
*invalid_slot
)
1750 * Mark the current slot INVALID. As with all memslot modifications,
1751 * this must be done on an unreachable slot to avoid modifying the
1752 * current slot in the active tree.
1754 kvm_copy_memslot(invalid_slot
, old
);
1755 invalid_slot
->flags
|= KVM_MEMSLOT_INVALID
;
1756 kvm_replace_memslot(kvm
, old
, invalid_slot
);
1759 * Activate the slot that is now marked INVALID, but don't propagate
1760 * the slot to the now inactive slots. The slot is either going to be
1761 * deleted or recreated as a new slot.
1763 kvm_swap_active_memslots(kvm
, old
->as_id
);
1766 * From this point no new shadow pages pointing to a deleted, or moved,
1767 * memslot will be created. Validation of sp->gfn happens in:
1768 * - gfn_to_hva (kvm_read_guest, gfn_to_pfn)
1769 * - kvm_is_visible_gfn (mmu_check_root)
1771 kvm_arch_flush_shadow_memslot(kvm
, old
);
1772 kvm_arch_guest_memory_reclaimed(kvm
);
1774 /* Was released by kvm_swap_active_memslots(), reacquire. */
1775 mutex_lock(&kvm
->slots_arch_lock
);
1778 * Copy the arch-specific field of the newly-installed slot back to the
1779 * old slot as the arch data could have changed between releasing
1780 * slots_arch_lock in kvm_swap_active_memslots() and re-acquiring the lock
1781 * above. Writers are required to retrieve memslots *after* acquiring
1782 * slots_arch_lock, thus the active slot's data is guaranteed to be fresh.
1784 old
->arch
= invalid_slot
->arch
;
1787 static void kvm_create_memslot(struct kvm
*kvm
,
1788 struct kvm_memory_slot
*new)
1790 /* Add the new memslot to the inactive set and activate. */
1791 kvm_replace_memslot(kvm
, NULL
, new);
1792 kvm_activate_memslot(kvm
, NULL
, new);
1795 static void kvm_delete_memslot(struct kvm
*kvm
,
1796 struct kvm_memory_slot
*old
,
1797 struct kvm_memory_slot
*invalid_slot
)
1800 * Remove the old memslot (in the inactive memslots) by passing NULL as
1801 * the "new" slot, and for the invalid version in the active slots.
1803 kvm_replace_memslot(kvm
, old
, NULL
);
1804 kvm_activate_memslot(kvm
, invalid_slot
, NULL
);
1807 static void kvm_move_memslot(struct kvm
*kvm
,
1808 struct kvm_memory_slot
*old
,
1809 struct kvm_memory_slot
*new,
1810 struct kvm_memory_slot
*invalid_slot
)
1813 * Replace the old memslot in the inactive slots, and then swap slots
1814 * and replace the current INVALID with the new as well.
1816 kvm_replace_memslot(kvm
, old
, new);
1817 kvm_activate_memslot(kvm
, invalid_slot
, new);
1820 static void kvm_update_flags_memslot(struct kvm
*kvm
,
1821 struct kvm_memory_slot
*old
,
1822 struct kvm_memory_slot
*new)
1825 * Similar to the MOVE case, but the slot doesn't need to be zapped as
1826 * an intermediate step. Instead, the old memslot is simply replaced
1827 * with a new, updated copy in both memslot sets.
1829 kvm_replace_memslot(kvm
, old
, new);
1830 kvm_activate_memslot(kvm
, old
, new);
1833 static int kvm_set_memslot(struct kvm
*kvm
,
1834 struct kvm_memory_slot
*old
,
1835 struct kvm_memory_slot
*new,
1836 enum kvm_mr_change change
)
1838 struct kvm_memory_slot
*invalid_slot
;
1842 * Released in kvm_swap_active_memslots().
1844 * Must be held from before the current memslots are copied until after
1845 * the new memslots are installed with rcu_assign_pointer, then
1846 * released before the synchronize srcu in kvm_swap_active_memslots().
1848 * When modifying memslots outside of the slots_lock, must be held
1849 * before reading the pointer to the current memslots until after all
1850 * changes to those memslots are complete.
1852 * These rules ensure that installing new memslots does not lose
1853 * changes made to the previous memslots.
1855 mutex_lock(&kvm
->slots_arch_lock
);
1858 * Invalidate the old slot if it's being deleted or moved. This is
1859 * done prior to actually deleting/moving the memslot to allow vCPUs to
1860 * continue running by ensuring there are no mappings or shadow pages
1861 * for the memslot when it is deleted/moved. Without pre-invalidation
1862 * (and without a lock), a window would exist between effecting the
1863 * delete/move and committing the changes in arch code where KVM or a
1864 * guest could access a non-existent memslot.
1866 * Modifications are done on a temporary, unreachable slot. The old
1867 * slot needs to be preserved in case a later step fails and the
1868 * invalidation needs to be reverted.
1870 if (change
== KVM_MR_DELETE
|| change
== KVM_MR_MOVE
) {
1871 invalid_slot
= kzalloc(sizeof(*invalid_slot
), GFP_KERNEL_ACCOUNT
);
1872 if (!invalid_slot
) {
1873 mutex_unlock(&kvm
->slots_arch_lock
);
1876 kvm_invalidate_memslot(kvm
, old
, invalid_slot
);
1879 r
= kvm_prepare_memory_region(kvm
, old
, new, change
);
1882 * For DELETE/MOVE, revert the above INVALID change. No
1883 * modifications required since the original slot was preserved
1884 * in the inactive slots. Changing the active memslots also
1885 * release slots_arch_lock.
1887 if (change
== KVM_MR_DELETE
|| change
== KVM_MR_MOVE
) {
1888 kvm_activate_memslot(kvm
, invalid_slot
, old
);
1889 kfree(invalid_slot
);
1891 mutex_unlock(&kvm
->slots_arch_lock
);
1897 * For DELETE and MOVE, the working slot is now active as the INVALID
1898 * version of the old slot. MOVE is particularly special as it reuses
1899 * the old slot and returns a copy of the old slot (in working_slot).
1900 * For CREATE, there is no old slot. For DELETE and FLAGS_ONLY, the
1901 * old slot is detached but otherwise preserved.
1903 if (change
== KVM_MR_CREATE
)
1904 kvm_create_memslot(kvm
, new);
1905 else if (change
== KVM_MR_DELETE
)
1906 kvm_delete_memslot(kvm
, old
, invalid_slot
);
1907 else if (change
== KVM_MR_MOVE
)
1908 kvm_move_memslot(kvm
, old
, new, invalid_slot
);
1909 else if (change
== KVM_MR_FLAGS_ONLY
)
1910 kvm_update_flags_memslot(kvm
, old
, new);
1914 /* Free the temporary INVALID slot used for DELETE and MOVE. */
1915 if (change
== KVM_MR_DELETE
|| change
== KVM_MR_MOVE
)
1916 kfree(invalid_slot
);
1919 * No need to refresh new->arch, changes after dropping slots_arch_lock
1920 * will directly hit the final, active memslot. Architectures are
1921 * responsible for knowing that new->arch may be stale.
1923 kvm_commit_memory_region(kvm
, old
, new, change
);
1928 static bool kvm_check_memslot_overlap(struct kvm_memslots
*slots
, int id
,
1929 gfn_t start
, gfn_t end
)
1931 struct kvm_memslot_iter iter
;
1933 kvm_for_each_memslot_in_gfn_range(&iter
, slots
, start
, end
) {
1934 if (iter
.slot
->id
!= id
)
1942 * Allocate some memory and give it an address in the guest physical address
1945 * Discontiguous memory is allowed, mostly for framebuffers.
1947 * Must be called holding kvm->slots_lock for write.
1949 int __kvm_set_memory_region(struct kvm
*kvm
,
1950 const struct kvm_userspace_memory_region
*mem
)
1952 struct kvm_memory_slot
*old
, *new;
1953 struct kvm_memslots
*slots
;
1954 enum kvm_mr_change change
;
1955 unsigned long npages
;
1960 r
= check_memory_region_flags(mem
);
1964 as_id
= mem
->slot
>> 16;
1965 id
= (u16
)mem
->slot
;
1967 /* General sanity checks */
1968 if ((mem
->memory_size
& (PAGE_SIZE
- 1)) ||
1969 (mem
->memory_size
!= (unsigned long)mem
->memory_size
))
1971 if (mem
->guest_phys_addr
& (PAGE_SIZE
- 1))
1973 /* We can read the guest memory with __xxx_user() later on. */
1974 if ((mem
->userspace_addr
& (PAGE_SIZE
- 1)) ||
1975 (mem
->userspace_addr
!= untagged_addr(mem
->userspace_addr
)) ||
1976 !access_ok((void __user
*)(unsigned long)mem
->userspace_addr
,
1979 if (as_id
>= KVM_ADDRESS_SPACE_NUM
|| id
>= KVM_MEM_SLOTS_NUM
)
1981 if (mem
->guest_phys_addr
+ mem
->memory_size
< mem
->guest_phys_addr
)
1983 if ((mem
->memory_size
>> PAGE_SHIFT
) > KVM_MEM_MAX_NR_PAGES
)
1986 slots
= __kvm_memslots(kvm
, as_id
);
1989 * Note, the old memslot (and the pointer itself!) may be invalidated
1990 * and/or destroyed by kvm_set_memslot().
1992 old
= id_to_memslot(slots
, id
);
1994 if (!mem
->memory_size
) {
1995 if (!old
|| !old
->npages
)
1998 if (WARN_ON_ONCE(kvm
->nr_memslot_pages
< old
->npages
))
2001 return kvm_set_memslot(kvm
, old
, NULL
, KVM_MR_DELETE
);
2004 base_gfn
= (mem
->guest_phys_addr
>> PAGE_SHIFT
);
2005 npages
= (mem
->memory_size
>> PAGE_SHIFT
);
2007 if (!old
|| !old
->npages
) {
2008 change
= KVM_MR_CREATE
;
2011 * To simplify KVM internals, the total number of pages across
2012 * all memslots must fit in an unsigned long.
2014 if ((kvm
->nr_memslot_pages
+ npages
) < kvm
->nr_memslot_pages
)
2016 } else { /* Modify an existing slot. */
2017 if ((mem
->userspace_addr
!= old
->userspace_addr
) ||
2018 (npages
!= old
->npages
) ||
2019 ((mem
->flags
^ old
->flags
) & KVM_MEM_READONLY
))
2022 if (base_gfn
!= old
->base_gfn
)
2023 change
= KVM_MR_MOVE
;
2024 else if (mem
->flags
!= old
->flags
)
2025 change
= KVM_MR_FLAGS_ONLY
;
2026 else /* Nothing to change. */
2030 if ((change
== KVM_MR_CREATE
|| change
== KVM_MR_MOVE
) &&
2031 kvm_check_memslot_overlap(slots
, id
, base_gfn
, base_gfn
+ npages
))
2034 /* Allocate a slot that will persist in the memslot. */
2035 new = kzalloc(sizeof(*new), GFP_KERNEL_ACCOUNT
);
2041 new->base_gfn
= base_gfn
;
2042 new->npages
= npages
;
2043 new->flags
= mem
->flags
;
2044 new->userspace_addr
= mem
->userspace_addr
;
2046 r
= kvm_set_memslot(kvm
, old
, new, change
);
2051 EXPORT_SYMBOL_GPL(__kvm_set_memory_region
);
2053 int kvm_set_memory_region(struct kvm
*kvm
,
2054 const struct kvm_userspace_memory_region
*mem
)
2058 mutex_lock(&kvm
->slots_lock
);
2059 r
= __kvm_set_memory_region(kvm
, mem
);
2060 mutex_unlock(&kvm
->slots_lock
);
2063 EXPORT_SYMBOL_GPL(kvm_set_memory_region
);
2065 static int kvm_vm_ioctl_set_memory_region(struct kvm
*kvm
,
2066 struct kvm_userspace_memory_region
*mem
)
2068 if ((u16
)mem
->slot
>= KVM_USER_MEM_SLOTS
)
2071 return kvm_set_memory_region(kvm
, mem
);
2074 #ifndef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
2076 * kvm_get_dirty_log - get a snapshot of dirty pages
2077 * @kvm: pointer to kvm instance
2078 * @log: slot id and address to which we copy the log
2079 * @is_dirty: set to '1' if any dirty pages were found
2080 * @memslot: set to the associated memslot, always valid on success
2082 int kvm_get_dirty_log(struct kvm
*kvm
, struct kvm_dirty_log
*log
,
2083 int *is_dirty
, struct kvm_memory_slot
**memslot
)
2085 struct kvm_memslots
*slots
;
2088 unsigned long any
= 0;
2090 /* Dirty ring tracking may be exclusive to dirty log tracking */
2091 if (!kvm_use_dirty_bitmap(kvm
))
2097 as_id
= log
->slot
>> 16;
2098 id
= (u16
)log
->slot
;
2099 if (as_id
>= KVM_ADDRESS_SPACE_NUM
|| id
>= KVM_USER_MEM_SLOTS
)
2102 slots
= __kvm_memslots(kvm
, as_id
);
2103 *memslot
= id_to_memslot(slots
, id
);
2104 if (!(*memslot
) || !(*memslot
)->dirty_bitmap
)
2107 kvm_arch_sync_dirty_log(kvm
, *memslot
);
2109 n
= kvm_dirty_bitmap_bytes(*memslot
);
2111 for (i
= 0; !any
&& i
< n
/sizeof(long); ++i
)
2112 any
= (*memslot
)->dirty_bitmap
[i
];
2114 if (copy_to_user(log
->dirty_bitmap
, (*memslot
)->dirty_bitmap
, n
))
2121 EXPORT_SYMBOL_GPL(kvm_get_dirty_log
);
2123 #else /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */
2125 * kvm_get_dirty_log_protect - get a snapshot of dirty pages
2126 * and reenable dirty page tracking for the corresponding pages.
2127 * @kvm: pointer to kvm instance
2128 * @log: slot id and address to which we copy the log
2130 * We need to keep it in mind that VCPU threads can write to the bitmap
2131 * concurrently. So, to avoid losing track of dirty pages we keep the
2134 * 1. Take a snapshot of the bit and clear it if needed.
2135 * 2. Write protect the corresponding page.
2136 * 3. Copy the snapshot to the userspace.
2137 * 4. Upon return caller flushes TLB's if needed.
2139 * Between 2 and 4, the guest may write to the page using the remaining TLB
2140 * entry. This is not a problem because the page is reported dirty using
2141 * the snapshot taken before and step 4 ensures that writes done after
2142 * exiting to userspace will be logged for the next call.
2145 static int kvm_get_dirty_log_protect(struct kvm
*kvm
, struct kvm_dirty_log
*log
)
2147 struct kvm_memslots
*slots
;
2148 struct kvm_memory_slot
*memslot
;
2151 unsigned long *dirty_bitmap
;
2152 unsigned long *dirty_bitmap_buffer
;
2155 /* Dirty ring tracking may be exclusive to dirty log tracking */
2156 if (!kvm_use_dirty_bitmap(kvm
))
2159 as_id
= log
->slot
>> 16;
2160 id
= (u16
)log
->slot
;
2161 if (as_id
>= KVM_ADDRESS_SPACE_NUM
|| id
>= KVM_USER_MEM_SLOTS
)
2164 slots
= __kvm_memslots(kvm
, as_id
);
2165 memslot
= id_to_memslot(slots
, id
);
2166 if (!memslot
|| !memslot
->dirty_bitmap
)
2169 dirty_bitmap
= memslot
->dirty_bitmap
;
2171 kvm_arch_sync_dirty_log(kvm
, memslot
);
2173 n
= kvm_dirty_bitmap_bytes(memslot
);
2175 if (kvm
->manual_dirty_log_protect
) {
2177 * Unlike kvm_get_dirty_log, we always return false in *flush,
2178 * because no flush is needed until KVM_CLEAR_DIRTY_LOG. There
2179 * is some code duplication between this function and
2180 * kvm_get_dirty_log, but hopefully all architecture
2181 * transition to kvm_get_dirty_log_protect and kvm_get_dirty_log
2182 * can be eliminated.
2184 dirty_bitmap_buffer
= dirty_bitmap
;
2186 dirty_bitmap_buffer
= kvm_second_dirty_bitmap(memslot
);
2187 memset(dirty_bitmap_buffer
, 0, n
);
2190 for (i
= 0; i
< n
/ sizeof(long); i
++) {
2194 if (!dirty_bitmap
[i
])
2198 mask
= xchg(&dirty_bitmap
[i
], 0);
2199 dirty_bitmap_buffer
[i
] = mask
;
2201 offset
= i
* BITS_PER_LONG
;
2202 kvm_arch_mmu_enable_log_dirty_pt_masked(kvm
, memslot
,
2205 KVM_MMU_UNLOCK(kvm
);
2209 kvm_flush_remote_tlbs_memslot(kvm
, memslot
);
2211 if (copy_to_user(log
->dirty_bitmap
, dirty_bitmap_buffer
, n
))
2218 * kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot
2219 * @kvm: kvm instance
2220 * @log: slot id and address to which we copy the log
2222 * Steps 1-4 below provide general overview of dirty page logging. See
2223 * kvm_get_dirty_log_protect() function description for additional details.
2225 * We call kvm_get_dirty_log_protect() to handle steps 1-3, upon return we
2226 * always flush the TLB (step 4) even if previous step failed and the dirty
2227 * bitmap may be corrupt. Regardless of previous outcome the KVM logging API
2228 * does not preclude user space subsequent dirty log read. Flushing TLB ensures
2229 * writes will be marked dirty for next log read.
2231 * 1. Take a snapshot of the bit and clear it if needed.
2232 * 2. Write protect the corresponding page.
2233 * 3. Copy the snapshot to the userspace.
2234 * 4. Flush TLB's if needed.
2236 static int kvm_vm_ioctl_get_dirty_log(struct kvm
*kvm
,
2237 struct kvm_dirty_log
*log
)
2241 mutex_lock(&kvm
->slots_lock
);
2243 r
= kvm_get_dirty_log_protect(kvm
, log
);
2245 mutex_unlock(&kvm
->slots_lock
);
2250 * kvm_clear_dirty_log_protect - clear dirty bits in the bitmap
2251 * and reenable dirty page tracking for the corresponding pages.
2252 * @kvm: pointer to kvm instance
2253 * @log: slot id and address from which to fetch the bitmap of dirty pages
2255 static int kvm_clear_dirty_log_protect(struct kvm
*kvm
,
2256 struct kvm_clear_dirty_log
*log
)
2258 struct kvm_memslots
*slots
;
2259 struct kvm_memory_slot
*memslot
;
2263 unsigned long *dirty_bitmap
;
2264 unsigned long *dirty_bitmap_buffer
;
2267 /* Dirty ring tracking may be exclusive to dirty log tracking */
2268 if (!kvm_use_dirty_bitmap(kvm
))
2271 as_id
= log
->slot
>> 16;
2272 id
= (u16
)log
->slot
;
2273 if (as_id
>= KVM_ADDRESS_SPACE_NUM
|| id
>= KVM_USER_MEM_SLOTS
)
2276 if (log
->first_page
& 63)
2279 slots
= __kvm_memslots(kvm
, as_id
);
2280 memslot
= id_to_memslot(slots
, id
);
2281 if (!memslot
|| !memslot
->dirty_bitmap
)
2284 dirty_bitmap
= memslot
->dirty_bitmap
;
2286 n
= ALIGN(log
->num_pages
, BITS_PER_LONG
) / 8;
2288 if (log
->first_page
> memslot
->npages
||
2289 log
->num_pages
> memslot
->npages
- log
->first_page
||
2290 (log
->num_pages
< memslot
->npages
- log
->first_page
&& (log
->num_pages
& 63)))
2293 kvm_arch_sync_dirty_log(kvm
, memslot
);
2296 dirty_bitmap_buffer
= kvm_second_dirty_bitmap(memslot
);
2297 if (copy_from_user(dirty_bitmap_buffer
, log
->dirty_bitmap
, n
))
2301 for (offset
= log
->first_page
, i
= offset
/ BITS_PER_LONG
,
2302 n
= DIV_ROUND_UP(log
->num_pages
, BITS_PER_LONG
); n
--;
2303 i
++, offset
+= BITS_PER_LONG
) {
2304 unsigned long mask
= *dirty_bitmap_buffer
++;
2305 atomic_long_t
*p
= (atomic_long_t
*) &dirty_bitmap
[i
];
2309 mask
&= atomic_long_fetch_andnot(mask
, p
);
2312 * mask contains the bits that really have been cleared. This
2313 * never includes any bits beyond the length of the memslot (if
2314 * the length is not aligned to 64 pages), therefore it is not
2315 * a problem if userspace sets them in log->dirty_bitmap.
2319 kvm_arch_mmu_enable_log_dirty_pt_masked(kvm
, memslot
,
2323 KVM_MMU_UNLOCK(kvm
);
2326 kvm_flush_remote_tlbs_memslot(kvm
, memslot
);
2331 static int kvm_vm_ioctl_clear_dirty_log(struct kvm
*kvm
,
2332 struct kvm_clear_dirty_log
*log
)
2336 mutex_lock(&kvm
->slots_lock
);
2338 r
= kvm_clear_dirty_log_protect(kvm
, log
);
2340 mutex_unlock(&kvm
->slots_lock
);
2343 #endif /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */
2345 struct kvm_memory_slot
*gfn_to_memslot(struct kvm
*kvm
, gfn_t gfn
)
2347 return __gfn_to_memslot(kvm_memslots(kvm
), gfn
);
2349 EXPORT_SYMBOL_GPL(gfn_to_memslot
);
2351 struct kvm_memory_slot
*kvm_vcpu_gfn_to_memslot(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2353 struct kvm_memslots
*slots
= kvm_vcpu_memslots(vcpu
);
2354 u64 gen
= slots
->generation
;
2355 struct kvm_memory_slot
*slot
;
2358 * This also protects against using a memslot from a different address space,
2359 * since different address spaces have different generation numbers.
2361 if (unlikely(gen
!= vcpu
->last_used_slot_gen
)) {
2362 vcpu
->last_used_slot
= NULL
;
2363 vcpu
->last_used_slot_gen
= gen
;
2366 slot
= try_get_memslot(vcpu
->last_used_slot
, gfn
);
2371 * Fall back to searching all memslots. We purposely use
2372 * search_memslots() instead of __gfn_to_memslot() to avoid
2373 * thrashing the VM-wide last_used_slot in kvm_memslots.
2375 slot
= search_memslots(slots
, gfn
, false);
2377 vcpu
->last_used_slot
= slot
;
2384 bool kvm_is_visible_gfn(struct kvm
*kvm
, gfn_t gfn
)
2386 struct kvm_memory_slot
*memslot
= gfn_to_memslot(kvm
, gfn
);
2388 return kvm_is_visible_memslot(memslot
);
2390 EXPORT_SYMBOL_GPL(kvm_is_visible_gfn
);
2392 bool kvm_vcpu_is_visible_gfn(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2394 struct kvm_memory_slot
*memslot
= kvm_vcpu_gfn_to_memslot(vcpu
, gfn
);
2396 return kvm_is_visible_memslot(memslot
);
2398 EXPORT_SYMBOL_GPL(kvm_vcpu_is_visible_gfn
);
2400 unsigned long kvm_host_page_size(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2402 struct vm_area_struct
*vma
;
2403 unsigned long addr
, size
;
2407 addr
= kvm_vcpu_gfn_to_hva_prot(vcpu
, gfn
, NULL
);
2408 if (kvm_is_error_hva(addr
))
2411 mmap_read_lock(current
->mm
);
2412 vma
= find_vma(current
->mm
, addr
);
2416 size
= vma_kernel_pagesize(vma
);
2419 mmap_read_unlock(current
->mm
);
2424 static bool memslot_is_readonly(const struct kvm_memory_slot
*slot
)
2426 return slot
->flags
& KVM_MEM_READONLY
;
2429 static unsigned long __gfn_to_hva_many(const struct kvm_memory_slot
*slot
, gfn_t gfn
,
2430 gfn_t
*nr_pages
, bool write
)
2432 if (!slot
|| slot
->flags
& KVM_MEMSLOT_INVALID
)
2433 return KVM_HVA_ERR_BAD
;
2435 if (memslot_is_readonly(slot
) && write
)
2436 return KVM_HVA_ERR_RO_BAD
;
2439 *nr_pages
= slot
->npages
- (gfn
- slot
->base_gfn
);
2441 return __gfn_to_hva_memslot(slot
, gfn
);
2444 static unsigned long gfn_to_hva_many(struct kvm_memory_slot
*slot
, gfn_t gfn
,
2447 return __gfn_to_hva_many(slot
, gfn
, nr_pages
, true);
2450 unsigned long gfn_to_hva_memslot(struct kvm_memory_slot
*slot
,
2453 return gfn_to_hva_many(slot
, gfn
, NULL
);
2455 EXPORT_SYMBOL_GPL(gfn_to_hva_memslot
);
2457 unsigned long gfn_to_hva(struct kvm
*kvm
, gfn_t gfn
)
2459 return gfn_to_hva_many(gfn_to_memslot(kvm
, gfn
), gfn
, NULL
);
2461 EXPORT_SYMBOL_GPL(gfn_to_hva
);
2463 unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2465 return gfn_to_hva_many(kvm_vcpu_gfn_to_memslot(vcpu
, gfn
), gfn
, NULL
);
2467 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_hva
);
2470 * Return the hva of a @gfn and the R/W attribute if possible.
2472 * @slot: the kvm_memory_slot which contains @gfn
2473 * @gfn: the gfn to be translated
2474 * @writable: used to return the read/write attribute of the @slot if the hva
2475 * is valid and @writable is not NULL
2477 unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot
*slot
,
2478 gfn_t gfn
, bool *writable
)
2480 unsigned long hva
= __gfn_to_hva_many(slot
, gfn
, NULL
, false);
2482 if (!kvm_is_error_hva(hva
) && writable
)
2483 *writable
= !memslot_is_readonly(slot
);
2488 unsigned long gfn_to_hva_prot(struct kvm
*kvm
, gfn_t gfn
, bool *writable
)
2490 struct kvm_memory_slot
*slot
= gfn_to_memslot(kvm
, gfn
);
2492 return gfn_to_hva_memslot_prot(slot
, gfn
, writable
);
2495 unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu
*vcpu
, gfn_t gfn
, bool *writable
)
2497 struct kvm_memory_slot
*slot
= kvm_vcpu_gfn_to_memslot(vcpu
, gfn
);
2499 return gfn_to_hva_memslot_prot(slot
, gfn
, writable
);
2502 static inline int check_user_page_hwpoison(unsigned long addr
)
2504 int rc
, flags
= FOLL_HWPOISON
| FOLL_WRITE
;
2506 rc
= get_user_pages(addr
, 1, flags
, NULL
);
2507 return rc
== -EHWPOISON
;
2511 * The fast path to get the writable pfn which will be stored in @pfn,
2512 * true indicates success, otherwise false is returned. It's also the
2513 * only part that runs if we can in atomic context.
2515 static bool hva_to_pfn_fast(unsigned long addr
, bool write_fault
,
2516 bool *writable
, kvm_pfn_t
*pfn
)
2518 struct page
*page
[1];
2521 * Fast pin a writable pfn only if it is a write fault request
2522 * or the caller allows to map a writable pfn for a read fault
2525 if (!(write_fault
|| writable
))
2528 if (get_user_page_fast_only(addr
, FOLL_WRITE
, page
)) {
2529 *pfn
= page_to_pfn(page
[0]);
2540 * The slow path to get the pfn of the specified host virtual address,
2541 * 1 indicates success, -errno is returned if error is detected.
2543 static int hva_to_pfn_slow(unsigned long addr
, bool *async
, bool write_fault
,
2544 bool interruptible
, bool *writable
, kvm_pfn_t
*pfn
)
2547 * When a VCPU accesses a page that is not mapped into the secondary
2548 * MMU, we lookup the page using GUP to map it, so the guest VCPU can
2549 * make progress. We always want to honor NUMA hinting faults in that
2550 * case, because GUP usage corresponds to memory accesses from the VCPU.
2551 * Otherwise, we'd not trigger NUMA hinting faults once a page is
2552 * mapped into the secondary MMU and gets accessed by a VCPU.
2554 * Note that get_user_page_fast_only() and FOLL_WRITE for now
2555 * implicitly honor NUMA hinting faults and don't need this flag.
2557 unsigned int flags
= FOLL_HWPOISON
| FOLL_HONOR_NUMA_FAULT
;
2564 *writable
= write_fault
;
2567 flags
|= FOLL_WRITE
;
2569 flags
|= FOLL_NOWAIT
;
2571 flags
|= FOLL_INTERRUPTIBLE
;
2573 npages
= get_user_pages_unlocked(addr
, 1, &page
, flags
);
2577 /* map read fault as writable if possible */
2578 if (unlikely(!write_fault
) && writable
) {
2581 if (get_user_page_fast_only(addr
, FOLL_WRITE
, &wpage
)) {
2587 *pfn
= page_to_pfn(page
);
2591 static bool vma_is_valid(struct vm_area_struct
*vma
, bool write_fault
)
2593 if (unlikely(!(vma
->vm_flags
& VM_READ
)))
2596 if (write_fault
&& (unlikely(!(vma
->vm_flags
& VM_WRITE
))))
2602 static int kvm_try_get_pfn(kvm_pfn_t pfn
)
2604 struct page
*page
= kvm_pfn_to_refcounted_page(pfn
);
2609 return get_page_unless_zero(page
);
2612 static int hva_to_pfn_remapped(struct vm_area_struct
*vma
,
2613 unsigned long addr
, bool write_fault
,
2614 bool *writable
, kvm_pfn_t
*p_pfn
)
2622 r
= follow_pte(vma
->vm_mm
, addr
, &ptep
, &ptl
);
2625 * get_user_pages fails for VM_IO and VM_PFNMAP vmas and does
2626 * not call the fault handler, so do it here.
2628 bool unlocked
= false;
2629 r
= fixup_user_fault(current
->mm
, addr
,
2630 (write_fault
? FAULT_FLAG_WRITE
: 0),
2637 r
= follow_pte(vma
->vm_mm
, addr
, &ptep
, &ptl
);
2642 pte
= ptep_get(ptep
);
2644 if (write_fault
&& !pte_write(pte
)) {
2645 pfn
= KVM_PFN_ERR_RO_FAULT
;
2650 *writable
= pte_write(pte
);
2654 * Get a reference here because callers of *hva_to_pfn* and
2655 * *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the
2656 * returned pfn. This is only needed if the VMA has VM_MIXEDMAP
2657 * set, but the kvm_try_get_pfn/kvm_release_pfn_clean pair will
2658 * simply do nothing for reserved pfns.
2660 * Whoever called remap_pfn_range is also going to call e.g.
2661 * unmap_mapping_range before the underlying pages are freed,
2662 * causing a call to our MMU notifier.
2664 * Certain IO or PFNMAP mappings can be backed with valid
2665 * struct pages, but be allocated without refcounting e.g.,
2666 * tail pages of non-compound higher order allocations, which
2667 * would then underflow the refcount when the caller does the
2668 * required put_page. Don't allow those pages here.
2670 if (!kvm_try_get_pfn(pfn
))
2674 pte_unmap_unlock(ptep
, ptl
);
2681 * Pin guest page in memory and return its pfn.
2682 * @addr: host virtual address which maps memory to the guest
2683 * @atomic: whether this function can sleep
2684 * @interruptible: whether the process can be interrupted by non-fatal signals
2685 * @async: whether this function need to wait IO complete if the
2686 * host page is not in the memory
2687 * @write_fault: whether we should get a writable host page
2688 * @writable: whether it allows to map a writable host page for !@write_fault
2690 * The function will map a writable host page for these two cases:
2691 * 1): @write_fault = true
2692 * 2): @write_fault = false && @writable, @writable will tell the caller
2693 * whether the mapping is writable.
2695 kvm_pfn_t
hva_to_pfn(unsigned long addr
, bool atomic
, bool interruptible
,
2696 bool *async
, bool write_fault
, bool *writable
)
2698 struct vm_area_struct
*vma
;
2702 /* we can do it either atomically or asynchronously, not both */
2703 BUG_ON(atomic
&& async
);
2705 if (hva_to_pfn_fast(addr
, write_fault
, writable
, &pfn
))
2709 return KVM_PFN_ERR_FAULT
;
2711 npages
= hva_to_pfn_slow(addr
, async
, write_fault
, interruptible
,
2715 if (npages
== -EINTR
)
2716 return KVM_PFN_ERR_SIGPENDING
;
2718 mmap_read_lock(current
->mm
);
2719 if (npages
== -EHWPOISON
||
2720 (!async
&& check_user_page_hwpoison(addr
))) {
2721 pfn
= KVM_PFN_ERR_HWPOISON
;
2726 vma
= vma_lookup(current
->mm
, addr
);
2729 pfn
= KVM_PFN_ERR_FAULT
;
2730 else if (vma
->vm_flags
& (VM_IO
| VM_PFNMAP
)) {
2731 r
= hva_to_pfn_remapped(vma
, addr
, write_fault
, writable
, &pfn
);
2735 pfn
= KVM_PFN_ERR_FAULT
;
2737 if (async
&& vma_is_valid(vma
, write_fault
))
2739 pfn
= KVM_PFN_ERR_FAULT
;
2742 mmap_read_unlock(current
->mm
);
2746 kvm_pfn_t
__gfn_to_pfn_memslot(const struct kvm_memory_slot
*slot
, gfn_t gfn
,
2747 bool atomic
, bool interruptible
, bool *async
,
2748 bool write_fault
, bool *writable
, hva_t
*hva
)
2750 unsigned long addr
= __gfn_to_hva_many(slot
, gfn
, NULL
, write_fault
);
2755 if (addr
== KVM_HVA_ERR_RO_BAD
) {
2758 return KVM_PFN_ERR_RO_FAULT
;
2761 if (kvm_is_error_hva(addr
)) {
2764 return KVM_PFN_NOSLOT
;
2767 /* Do not map writable pfn in the readonly memslot. */
2768 if (writable
&& memslot_is_readonly(slot
)) {
2773 return hva_to_pfn(addr
, atomic
, interruptible
, async
, write_fault
,
2776 EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot
);
2778 kvm_pfn_t
gfn_to_pfn_prot(struct kvm
*kvm
, gfn_t gfn
, bool write_fault
,
2781 return __gfn_to_pfn_memslot(gfn_to_memslot(kvm
, gfn
), gfn
, false, false,
2782 NULL
, write_fault
, writable
, NULL
);
2784 EXPORT_SYMBOL_GPL(gfn_to_pfn_prot
);
2786 kvm_pfn_t
gfn_to_pfn_memslot(const struct kvm_memory_slot
*slot
, gfn_t gfn
)
2788 return __gfn_to_pfn_memslot(slot
, gfn
, false, false, NULL
, true,
2791 EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot
);
2793 kvm_pfn_t
gfn_to_pfn_memslot_atomic(const struct kvm_memory_slot
*slot
, gfn_t gfn
)
2795 return __gfn_to_pfn_memslot(slot
, gfn
, true, false, NULL
, true,
2798 EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic
);
2800 kvm_pfn_t
kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2802 return gfn_to_pfn_memslot_atomic(kvm_vcpu_gfn_to_memslot(vcpu
, gfn
), gfn
);
2804 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_atomic
);
2806 kvm_pfn_t
gfn_to_pfn(struct kvm
*kvm
, gfn_t gfn
)
2808 return gfn_to_pfn_memslot(gfn_to_memslot(kvm
, gfn
), gfn
);
2810 EXPORT_SYMBOL_GPL(gfn_to_pfn
);
2812 kvm_pfn_t
kvm_vcpu_gfn_to_pfn(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2814 return gfn_to_pfn_memslot(kvm_vcpu_gfn_to_memslot(vcpu
, gfn
), gfn
);
2816 EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn
);
2818 int gfn_to_page_many_atomic(struct kvm_memory_slot
*slot
, gfn_t gfn
,
2819 struct page
**pages
, int nr_pages
)
2824 addr
= gfn_to_hva_many(slot
, gfn
, &entry
);
2825 if (kvm_is_error_hva(addr
))
2828 if (entry
< nr_pages
)
2831 return get_user_pages_fast_only(addr
, nr_pages
, FOLL_WRITE
, pages
);
2833 EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic
);
2836 * Do not use this helper unless you are absolutely certain the gfn _must_ be
2837 * backed by 'struct page'. A valid example is if the backing memslot is
2838 * controlled by KVM. Note, if the returned page is valid, it's refcount has
2839 * been elevated by gfn_to_pfn().
2841 struct page
*gfn_to_page(struct kvm
*kvm
, gfn_t gfn
)
2846 pfn
= gfn_to_pfn(kvm
, gfn
);
2848 if (is_error_noslot_pfn(pfn
))
2849 return KVM_ERR_PTR_BAD_PAGE
;
2851 page
= kvm_pfn_to_refcounted_page(pfn
);
2853 return KVM_ERR_PTR_BAD_PAGE
;
2857 EXPORT_SYMBOL_GPL(gfn_to_page
);
2859 void kvm_release_pfn(kvm_pfn_t pfn
, bool dirty
)
2862 kvm_release_pfn_dirty(pfn
);
2864 kvm_release_pfn_clean(pfn
);
2867 int kvm_vcpu_map(struct kvm_vcpu
*vcpu
, gfn_t gfn
, struct kvm_host_map
*map
)
2871 struct page
*page
= KVM_UNMAPPED_PAGE
;
2876 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
2877 if (is_error_noslot_pfn(pfn
))
2880 if (pfn_valid(pfn
)) {
2881 page
= pfn_to_page(pfn
);
2883 #ifdef CONFIG_HAS_IOMEM
2885 hva
= memremap(pfn_to_hpa(pfn
), PAGE_SIZE
, MEMREMAP_WB
);
2899 EXPORT_SYMBOL_GPL(kvm_vcpu_map
);
2901 void kvm_vcpu_unmap(struct kvm_vcpu
*vcpu
, struct kvm_host_map
*map
, bool dirty
)
2909 if (map
->page
!= KVM_UNMAPPED_PAGE
)
2911 #ifdef CONFIG_HAS_IOMEM
2917 kvm_vcpu_mark_page_dirty(vcpu
, map
->gfn
);
2919 kvm_release_pfn(map
->pfn
, dirty
);
2924 EXPORT_SYMBOL_GPL(kvm_vcpu_unmap
);
2926 static bool kvm_is_ad_tracked_page(struct page
*page
)
2929 * Per page-flags.h, pages tagged PG_reserved "should in general not be
2930 * touched (e.g. set dirty) except by its owner".
2932 return !PageReserved(page
);
2935 static void kvm_set_page_dirty(struct page
*page
)
2937 if (kvm_is_ad_tracked_page(page
))
2941 static void kvm_set_page_accessed(struct page
*page
)
2943 if (kvm_is_ad_tracked_page(page
))
2944 mark_page_accessed(page
);
2947 void kvm_release_page_clean(struct page
*page
)
2949 WARN_ON(is_error_page(page
));
2951 kvm_set_page_accessed(page
);
2954 EXPORT_SYMBOL_GPL(kvm_release_page_clean
);
2956 void kvm_release_pfn_clean(kvm_pfn_t pfn
)
2960 if (is_error_noslot_pfn(pfn
))
2963 page
= kvm_pfn_to_refcounted_page(pfn
);
2967 kvm_release_page_clean(page
);
2969 EXPORT_SYMBOL_GPL(kvm_release_pfn_clean
);
2971 void kvm_release_page_dirty(struct page
*page
)
2973 WARN_ON(is_error_page(page
));
2975 kvm_set_page_dirty(page
);
2976 kvm_release_page_clean(page
);
2978 EXPORT_SYMBOL_GPL(kvm_release_page_dirty
);
2980 void kvm_release_pfn_dirty(kvm_pfn_t pfn
)
2984 if (is_error_noslot_pfn(pfn
))
2987 page
= kvm_pfn_to_refcounted_page(pfn
);
2991 kvm_release_page_dirty(page
);
2993 EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty
);
2996 * Note, checking for an error/noslot pfn is the caller's responsibility when
2997 * directly marking a page dirty/accessed. Unlike the "release" helpers, the
2998 * "set" helpers are not to be used when the pfn might point at garbage.
3000 void kvm_set_pfn_dirty(kvm_pfn_t pfn
)
3002 if (WARN_ON(is_error_noslot_pfn(pfn
)))
3006 kvm_set_page_dirty(pfn_to_page(pfn
));
3008 EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty
);
3010 void kvm_set_pfn_accessed(kvm_pfn_t pfn
)
3012 if (WARN_ON(is_error_noslot_pfn(pfn
)))
3016 kvm_set_page_accessed(pfn_to_page(pfn
));
3018 EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed
);
3020 static int next_segment(unsigned long len
, int offset
)
3022 if (len
> PAGE_SIZE
- offset
)
3023 return PAGE_SIZE
- offset
;
3028 static int __kvm_read_guest_page(struct kvm_memory_slot
*slot
, gfn_t gfn
,
3029 void *data
, int offset
, int len
)
3034 addr
= gfn_to_hva_memslot_prot(slot
, gfn
, NULL
);
3035 if (kvm_is_error_hva(addr
))
3037 r
= __copy_from_user(data
, (void __user
*)addr
+ offset
, len
);
3043 int kvm_read_guest_page(struct kvm
*kvm
, gfn_t gfn
, void *data
, int offset
,
3046 struct kvm_memory_slot
*slot
= gfn_to_memslot(kvm
, gfn
);
3048 return __kvm_read_guest_page(slot
, gfn
, data
, offset
, len
);
3050 EXPORT_SYMBOL_GPL(kvm_read_guest_page
);
3052 int kvm_vcpu_read_guest_page(struct kvm_vcpu
*vcpu
, gfn_t gfn
, void *data
,
3053 int offset
, int len
)
3055 struct kvm_memory_slot
*slot
= kvm_vcpu_gfn_to_memslot(vcpu
, gfn
);
3057 return __kvm_read_guest_page(slot
, gfn
, data
, offset
, len
);
3059 EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_page
);
3061 int kvm_read_guest(struct kvm
*kvm
, gpa_t gpa
, void *data
, unsigned long len
)
3063 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3065 int offset
= offset_in_page(gpa
);
3068 while ((seg
= next_segment(len
, offset
)) != 0) {
3069 ret
= kvm_read_guest_page(kvm
, gfn
, data
, offset
, seg
);
3079 EXPORT_SYMBOL_GPL(kvm_read_guest
);
3081 int kvm_vcpu_read_guest(struct kvm_vcpu
*vcpu
, gpa_t gpa
, void *data
, unsigned long len
)
3083 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3085 int offset
= offset_in_page(gpa
);
3088 while ((seg
= next_segment(len
, offset
)) != 0) {
3089 ret
= kvm_vcpu_read_guest_page(vcpu
, gfn
, data
, offset
, seg
);
3099 EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest
);
3101 static int __kvm_read_guest_atomic(struct kvm_memory_slot
*slot
, gfn_t gfn
,
3102 void *data
, int offset
, unsigned long len
)
3107 addr
= gfn_to_hva_memslot_prot(slot
, gfn
, NULL
);
3108 if (kvm_is_error_hva(addr
))
3110 pagefault_disable();
3111 r
= __copy_from_user_inatomic(data
, (void __user
*)addr
+ offset
, len
);
3118 int kvm_vcpu_read_guest_atomic(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
3119 void *data
, unsigned long len
)
3121 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3122 struct kvm_memory_slot
*slot
= kvm_vcpu_gfn_to_memslot(vcpu
, gfn
);
3123 int offset
= offset_in_page(gpa
);
3125 return __kvm_read_guest_atomic(slot
, gfn
, data
, offset
, len
);
3127 EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic
);
3129 static int __kvm_write_guest_page(struct kvm
*kvm
,
3130 struct kvm_memory_slot
*memslot
, gfn_t gfn
,
3131 const void *data
, int offset
, int len
)
3136 addr
= gfn_to_hva_memslot(memslot
, gfn
);
3137 if (kvm_is_error_hva(addr
))
3139 r
= __copy_to_user((void __user
*)addr
+ offset
, data
, len
);
3142 mark_page_dirty_in_slot(kvm
, memslot
, gfn
);
3146 int kvm_write_guest_page(struct kvm
*kvm
, gfn_t gfn
,
3147 const void *data
, int offset
, int len
)
3149 struct kvm_memory_slot
*slot
= gfn_to_memslot(kvm
, gfn
);
3151 return __kvm_write_guest_page(kvm
, slot
, gfn
, data
, offset
, len
);
3153 EXPORT_SYMBOL_GPL(kvm_write_guest_page
);
3155 int kvm_vcpu_write_guest_page(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
3156 const void *data
, int offset
, int len
)
3158 struct kvm_memory_slot
*slot
= kvm_vcpu_gfn_to_memslot(vcpu
, gfn
);
3160 return __kvm_write_guest_page(vcpu
->kvm
, slot
, gfn
, data
, offset
, len
);
3162 EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest_page
);
3164 int kvm_write_guest(struct kvm
*kvm
, gpa_t gpa
, const void *data
,
3167 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3169 int offset
= offset_in_page(gpa
);
3172 while ((seg
= next_segment(len
, offset
)) != 0) {
3173 ret
= kvm_write_guest_page(kvm
, gfn
, data
, offset
, seg
);
3183 EXPORT_SYMBOL_GPL(kvm_write_guest
);
3185 int kvm_vcpu_write_guest(struct kvm_vcpu
*vcpu
, gpa_t gpa
, const void *data
,
3188 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3190 int offset
= offset_in_page(gpa
);
3193 while ((seg
= next_segment(len
, offset
)) != 0) {
3194 ret
= kvm_vcpu_write_guest_page(vcpu
, gfn
, data
, offset
, seg
);
3204 EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest
);
3206 static int __kvm_gfn_to_hva_cache_init(struct kvm_memslots
*slots
,
3207 struct gfn_to_hva_cache
*ghc
,
3208 gpa_t gpa
, unsigned long len
)
3210 int offset
= offset_in_page(gpa
);
3211 gfn_t start_gfn
= gpa
>> PAGE_SHIFT
;
3212 gfn_t end_gfn
= (gpa
+ len
- 1) >> PAGE_SHIFT
;
3213 gfn_t nr_pages_needed
= end_gfn
- start_gfn
+ 1;
3214 gfn_t nr_pages_avail
;
3216 /* Update ghc->generation before performing any error checks. */
3217 ghc
->generation
= slots
->generation
;
3219 if (start_gfn
> end_gfn
) {
3220 ghc
->hva
= KVM_HVA_ERR_BAD
;
3225 * If the requested region crosses two memslots, we still
3226 * verify that the entire region is valid here.
3228 for ( ; start_gfn
<= end_gfn
; start_gfn
+= nr_pages_avail
) {
3229 ghc
->memslot
= __gfn_to_memslot(slots
, start_gfn
);
3230 ghc
->hva
= gfn_to_hva_many(ghc
->memslot
, start_gfn
,
3232 if (kvm_is_error_hva(ghc
->hva
))
3236 /* Use the slow path for cross page reads and writes. */
3237 if (nr_pages_needed
== 1)
3240 ghc
->memslot
= NULL
;
3247 int kvm_gfn_to_hva_cache_init(struct kvm
*kvm
, struct gfn_to_hva_cache
*ghc
,
3248 gpa_t gpa
, unsigned long len
)
3250 struct kvm_memslots
*slots
= kvm_memslots(kvm
);
3251 return __kvm_gfn_to_hva_cache_init(slots
, ghc
, gpa
, len
);
3253 EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init
);
3255 int kvm_write_guest_offset_cached(struct kvm
*kvm
, struct gfn_to_hva_cache
*ghc
,
3256 void *data
, unsigned int offset
,
3259 struct kvm_memslots
*slots
= kvm_memslots(kvm
);
3261 gpa_t gpa
= ghc
->gpa
+ offset
;
3263 if (WARN_ON_ONCE(len
+ offset
> ghc
->len
))
3266 if (slots
->generation
!= ghc
->generation
) {
3267 if (__kvm_gfn_to_hva_cache_init(slots
, ghc
, ghc
->gpa
, ghc
->len
))
3271 if (kvm_is_error_hva(ghc
->hva
))
3274 if (unlikely(!ghc
->memslot
))
3275 return kvm_write_guest(kvm
, gpa
, data
, len
);
3277 r
= __copy_to_user((void __user
*)ghc
->hva
+ offset
, data
, len
);
3280 mark_page_dirty_in_slot(kvm
, ghc
->memslot
, gpa
>> PAGE_SHIFT
);
3284 EXPORT_SYMBOL_GPL(kvm_write_guest_offset_cached
);
3286 int kvm_write_guest_cached(struct kvm
*kvm
, struct gfn_to_hva_cache
*ghc
,
3287 void *data
, unsigned long len
)
3289 return kvm_write_guest_offset_cached(kvm
, ghc
, data
, 0, len
);
3291 EXPORT_SYMBOL_GPL(kvm_write_guest_cached
);
3293 int kvm_read_guest_offset_cached(struct kvm
*kvm
, struct gfn_to_hva_cache
*ghc
,
3294 void *data
, unsigned int offset
,
3297 struct kvm_memslots
*slots
= kvm_memslots(kvm
);
3299 gpa_t gpa
= ghc
->gpa
+ offset
;
3301 if (WARN_ON_ONCE(len
+ offset
> ghc
->len
))
3304 if (slots
->generation
!= ghc
->generation
) {
3305 if (__kvm_gfn_to_hva_cache_init(slots
, ghc
, ghc
->gpa
, ghc
->len
))
3309 if (kvm_is_error_hva(ghc
->hva
))
3312 if (unlikely(!ghc
->memslot
))
3313 return kvm_read_guest(kvm
, gpa
, data
, len
);
3315 r
= __copy_from_user(data
, (void __user
*)ghc
->hva
+ offset
, len
);
3321 EXPORT_SYMBOL_GPL(kvm_read_guest_offset_cached
);
3323 int kvm_read_guest_cached(struct kvm
*kvm
, struct gfn_to_hva_cache
*ghc
,
3324 void *data
, unsigned long len
)
3326 return kvm_read_guest_offset_cached(kvm
, ghc
, data
, 0, len
);
3328 EXPORT_SYMBOL_GPL(kvm_read_guest_cached
);
3330 int kvm_clear_guest(struct kvm
*kvm
, gpa_t gpa
, unsigned long len
)
3332 const void *zero_page
= (const void *) __va(page_to_phys(ZERO_PAGE(0)));
3333 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3335 int offset
= offset_in_page(gpa
);
3338 while ((seg
= next_segment(len
, offset
)) != 0) {
3339 ret
= kvm_write_guest_page(kvm
, gfn
, zero_page
, offset
, len
);
3348 EXPORT_SYMBOL_GPL(kvm_clear_guest
);
3350 void mark_page_dirty_in_slot(struct kvm
*kvm
,
3351 const struct kvm_memory_slot
*memslot
,
3354 struct kvm_vcpu
*vcpu
= kvm_get_running_vcpu();
3356 #ifdef CONFIG_HAVE_KVM_DIRTY_RING
3357 if (WARN_ON_ONCE(vcpu
&& vcpu
->kvm
!= kvm
))
3360 WARN_ON_ONCE(!vcpu
&& !kvm_arch_allow_write_without_running_vcpu(kvm
));
3363 if (memslot
&& kvm_slot_dirty_track_enabled(memslot
)) {
3364 unsigned long rel_gfn
= gfn
- memslot
->base_gfn
;
3365 u32 slot
= (memslot
->as_id
<< 16) | memslot
->id
;
3367 if (kvm
->dirty_ring_size
&& vcpu
)
3368 kvm_dirty_ring_push(vcpu
, slot
, rel_gfn
);
3369 else if (memslot
->dirty_bitmap
)
3370 set_bit_le(rel_gfn
, memslot
->dirty_bitmap
);
3373 EXPORT_SYMBOL_GPL(mark_page_dirty_in_slot
);
3375 void mark_page_dirty(struct kvm
*kvm
, gfn_t gfn
)
3377 struct kvm_memory_slot
*memslot
;
3379 memslot
= gfn_to_memslot(kvm
, gfn
);
3380 mark_page_dirty_in_slot(kvm
, memslot
, gfn
);
3382 EXPORT_SYMBOL_GPL(mark_page_dirty
);
3384 void kvm_vcpu_mark_page_dirty(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
3386 struct kvm_memory_slot
*memslot
;
3388 memslot
= kvm_vcpu_gfn_to_memslot(vcpu
, gfn
);
3389 mark_page_dirty_in_slot(vcpu
->kvm
, memslot
, gfn
);
3391 EXPORT_SYMBOL_GPL(kvm_vcpu_mark_page_dirty
);
3393 void kvm_sigset_activate(struct kvm_vcpu
*vcpu
)
3395 if (!vcpu
->sigset_active
)
3399 * This does a lockless modification of ->real_blocked, which is fine
3400 * because, only current can change ->real_blocked and all readers of
3401 * ->real_blocked don't care as long ->real_blocked is always a subset
3404 sigprocmask(SIG_SETMASK
, &vcpu
->sigset
, ¤t
->real_blocked
);
3407 void kvm_sigset_deactivate(struct kvm_vcpu
*vcpu
)
3409 if (!vcpu
->sigset_active
)
3412 sigprocmask(SIG_SETMASK
, ¤t
->real_blocked
, NULL
);
3413 sigemptyset(¤t
->real_blocked
);
3416 static void grow_halt_poll_ns(struct kvm_vcpu
*vcpu
)
3418 unsigned int old
, val
, grow
, grow_start
;
3420 old
= val
= vcpu
->halt_poll_ns
;
3421 grow_start
= READ_ONCE(halt_poll_ns_grow_start
);
3422 grow
= READ_ONCE(halt_poll_ns_grow
);
3427 if (val
< grow_start
)
3430 vcpu
->halt_poll_ns
= val
;
3432 trace_kvm_halt_poll_ns_grow(vcpu
->vcpu_id
, val
, old
);
3435 static void shrink_halt_poll_ns(struct kvm_vcpu
*vcpu
)
3437 unsigned int old
, val
, shrink
, grow_start
;
3439 old
= val
= vcpu
->halt_poll_ns
;
3440 shrink
= READ_ONCE(halt_poll_ns_shrink
);
3441 grow_start
= READ_ONCE(halt_poll_ns_grow_start
);
3447 if (val
< grow_start
)
3450 vcpu
->halt_poll_ns
= val
;
3451 trace_kvm_halt_poll_ns_shrink(vcpu
->vcpu_id
, val
, old
);
3454 static int kvm_vcpu_check_block(struct kvm_vcpu
*vcpu
)
3457 int idx
= srcu_read_lock(&vcpu
->kvm
->srcu
);
3459 if (kvm_arch_vcpu_runnable(vcpu
))
3461 if (kvm_cpu_has_pending_timer(vcpu
))
3463 if (signal_pending(current
))
3465 if (kvm_check_request(KVM_REQ_UNBLOCK
, vcpu
))
3470 srcu_read_unlock(&vcpu
->kvm
->srcu
, idx
);
3475 * Block the vCPU until the vCPU is runnable, an event arrives, or a signal is
3476 * pending. This is mostly used when halting a vCPU, but may also be used
3477 * directly for other vCPU non-runnable states, e.g. x86's Wait-For-SIPI.
3479 bool kvm_vcpu_block(struct kvm_vcpu
*vcpu
)
3481 struct rcuwait
*wait
= kvm_arch_vcpu_get_wait(vcpu
);
3482 bool waited
= false;
3484 vcpu
->stat
.generic
.blocking
= 1;
3487 kvm_arch_vcpu_blocking(vcpu
);
3488 prepare_to_rcuwait(wait
);
3492 set_current_state(TASK_INTERRUPTIBLE
);
3494 if (kvm_vcpu_check_block(vcpu
) < 0)
3502 finish_rcuwait(wait
);
3503 kvm_arch_vcpu_unblocking(vcpu
);
3506 vcpu
->stat
.generic
.blocking
= 0;
3511 static inline void update_halt_poll_stats(struct kvm_vcpu
*vcpu
, ktime_t start
,
3512 ktime_t end
, bool success
)
3514 struct kvm_vcpu_stat_generic
*stats
= &vcpu
->stat
.generic
;
3515 u64 poll_ns
= ktime_to_ns(ktime_sub(end
, start
));
3517 ++vcpu
->stat
.generic
.halt_attempted_poll
;
3520 ++vcpu
->stat
.generic
.halt_successful_poll
;
3522 if (!vcpu_valid_wakeup(vcpu
))
3523 ++vcpu
->stat
.generic
.halt_poll_invalid
;
3525 stats
->halt_poll_success_ns
+= poll_ns
;
3526 KVM_STATS_LOG_HIST_UPDATE(stats
->halt_poll_success_hist
, poll_ns
);
3528 stats
->halt_poll_fail_ns
+= poll_ns
;
3529 KVM_STATS_LOG_HIST_UPDATE(stats
->halt_poll_fail_hist
, poll_ns
);
3533 static unsigned int kvm_vcpu_max_halt_poll_ns(struct kvm_vcpu
*vcpu
)
3535 struct kvm
*kvm
= vcpu
->kvm
;
3537 if (kvm
->override_halt_poll_ns
) {
3539 * Ensure kvm->max_halt_poll_ns is not read before
3540 * kvm->override_halt_poll_ns.
3542 * Pairs with the smp_wmb() when enabling KVM_CAP_HALT_POLL.
3545 return READ_ONCE(kvm
->max_halt_poll_ns
);
3548 return READ_ONCE(halt_poll_ns
);
3552 * Emulate a vCPU halt condition, e.g. HLT on x86, WFI on arm, etc... If halt
3553 * polling is enabled, busy wait for a short time before blocking to avoid the
3554 * expensive block+unblock sequence if a wake event arrives soon after the vCPU
3557 void kvm_vcpu_halt(struct kvm_vcpu
*vcpu
)
3559 unsigned int max_halt_poll_ns
= kvm_vcpu_max_halt_poll_ns(vcpu
);
3560 bool halt_poll_allowed
= !kvm_arch_no_poll(vcpu
);
3561 ktime_t start
, cur
, poll_end
;
3562 bool waited
= false;
3566 if (vcpu
->halt_poll_ns
> max_halt_poll_ns
)
3567 vcpu
->halt_poll_ns
= max_halt_poll_ns
;
3569 do_halt_poll
= halt_poll_allowed
&& vcpu
->halt_poll_ns
;
3571 start
= cur
= poll_end
= ktime_get();
3573 ktime_t stop
= ktime_add_ns(start
, vcpu
->halt_poll_ns
);
3576 if (kvm_vcpu_check_block(vcpu
) < 0)
3579 poll_end
= cur
= ktime_get();
3580 } while (kvm_vcpu_can_poll(cur
, stop
));
3583 waited
= kvm_vcpu_block(vcpu
);
3587 vcpu
->stat
.generic
.halt_wait_ns
+=
3588 ktime_to_ns(cur
) - ktime_to_ns(poll_end
);
3589 KVM_STATS_LOG_HIST_UPDATE(vcpu
->stat
.generic
.halt_wait_hist
,
3590 ktime_to_ns(cur
) - ktime_to_ns(poll_end
));
3593 /* The total time the vCPU was "halted", including polling time. */
3594 halt_ns
= ktime_to_ns(cur
) - ktime_to_ns(start
);
3597 * Note, halt-polling is considered successful so long as the vCPU was
3598 * never actually scheduled out, i.e. even if the wake event arrived
3599 * after of the halt-polling loop itself, but before the full wait.
3602 update_halt_poll_stats(vcpu
, start
, poll_end
, !waited
);
3604 if (halt_poll_allowed
) {
3605 /* Recompute the max halt poll time in case it changed. */
3606 max_halt_poll_ns
= kvm_vcpu_max_halt_poll_ns(vcpu
);
3608 if (!vcpu_valid_wakeup(vcpu
)) {
3609 shrink_halt_poll_ns(vcpu
);
3610 } else if (max_halt_poll_ns
) {
3611 if (halt_ns
<= vcpu
->halt_poll_ns
)
3613 /* we had a long block, shrink polling */
3614 else if (vcpu
->halt_poll_ns
&&
3615 halt_ns
> max_halt_poll_ns
)
3616 shrink_halt_poll_ns(vcpu
);
3617 /* we had a short halt and our poll time is too small */
3618 else if (vcpu
->halt_poll_ns
< max_halt_poll_ns
&&
3619 halt_ns
< max_halt_poll_ns
)
3620 grow_halt_poll_ns(vcpu
);
3622 vcpu
->halt_poll_ns
= 0;
3626 trace_kvm_vcpu_wakeup(halt_ns
, waited
, vcpu_valid_wakeup(vcpu
));
3628 EXPORT_SYMBOL_GPL(kvm_vcpu_halt
);
3630 bool kvm_vcpu_wake_up(struct kvm_vcpu
*vcpu
)
3632 if (__kvm_vcpu_wake_up(vcpu
)) {
3633 WRITE_ONCE(vcpu
->ready
, true);
3634 ++vcpu
->stat
.generic
.halt_wakeup
;
3640 EXPORT_SYMBOL_GPL(kvm_vcpu_wake_up
);
3644 * Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode.
3646 void kvm_vcpu_kick(struct kvm_vcpu
*vcpu
)
3650 if (kvm_vcpu_wake_up(vcpu
))
3655 * The only state change done outside the vcpu mutex is IN_GUEST_MODE
3656 * to EXITING_GUEST_MODE. Therefore the moderately expensive "should
3657 * kick" check does not need atomic operations if kvm_vcpu_kick is used
3658 * within the vCPU thread itself.
3660 if (vcpu
== __this_cpu_read(kvm_running_vcpu
)) {
3661 if (vcpu
->mode
== IN_GUEST_MODE
)
3662 WRITE_ONCE(vcpu
->mode
, EXITING_GUEST_MODE
);
3667 * Note, the vCPU could get migrated to a different pCPU at any point
3668 * after kvm_arch_vcpu_should_kick(), which could result in sending an
3669 * IPI to the previous pCPU. But, that's ok because the purpose of the
3670 * IPI is to force the vCPU to leave IN_GUEST_MODE, and migrating the
3671 * vCPU also requires it to leave IN_GUEST_MODE.
3673 if (kvm_arch_vcpu_should_kick(vcpu
)) {
3674 cpu
= READ_ONCE(vcpu
->cpu
);
3675 if (cpu
!= me
&& (unsigned)cpu
< nr_cpu_ids
&& cpu_online(cpu
))
3676 smp_send_reschedule(cpu
);
3681 EXPORT_SYMBOL_GPL(kvm_vcpu_kick
);
3682 #endif /* !CONFIG_S390 */
3684 int kvm_vcpu_yield_to(struct kvm_vcpu
*target
)
3687 struct task_struct
*task
= NULL
;
3691 pid
= rcu_dereference(target
->pid
);
3693 task
= get_pid_task(pid
, PIDTYPE_PID
);
3697 ret
= yield_to(task
, 1);
3698 put_task_struct(task
);
3702 EXPORT_SYMBOL_GPL(kvm_vcpu_yield_to
);
3705 * Helper that checks whether a VCPU is eligible for directed yield.
3706 * Most eligible candidate to yield is decided by following heuristics:
3708 * (a) VCPU which has not done pl-exit or cpu relax intercepted recently
3709 * (preempted lock holder), indicated by @in_spin_loop.
3710 * Set at the beginning and cleared at the end of interception/PLE handler.
3712 * (b) VCPU which has done pl-exit/ cpu relax intercepted but did not get
3713 * chance last time (mostly it has become eligible now since we have probably
3714 * yielded to lockholder in last iteration. This is done by toggling
3715 * @dy_eligible each time a VCPU checked for eligibility.)
3717 * Yielding to a recently pl-exited/cpu relax intercepted VCPU before yielding
3718 * to preempted lock-holder could result in wrong VCPU selection and CPU
3719 * burning. Giving priority for a potential lock-holder increases lock
3722 * Since algorithm is based on heuristics, accessing another VCPU data without
3723 * locking does not harm. It may result in trying to yield to same VCPU, fail
3724 * and continue with next VCPU and so on.
3726 static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu
*vcpu
)
3728 #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
3731 eligible
= !vcpu
->spin_loop
.in_spin_loop
||
3732 vcpu
->spin_loop
.dy_eligible
;
3734 if (vcpu
->spin_loop
.in_spin_loop
)
3735 kvm_vcpu_set_dy_eligible(vcpu
, !vcpu
->spin_loop
.dy_eligible
);
3744 * Unlike kvm_arch_vcpu_runnable, this function is called outside
3745 * a vcpu_load/vcpu_put pair. However, for most architectures
3746 * kvm_arch_vcpu_runnable does not require vcpu_load.
3748 bool __weak
kvm_arch_dy_runnable(struct kvm_vcpu
*vcpu
)
3750 return kvm_arch_vcpu_runnable(vcpu
);
3753 static bool vcpu_dy_runnable(struct kvm_vcpu
*vcpu
)
3755 if (kvm_arch_dy_runnable(vcpu
))
3758 #ifdef CONFIG_KVM_ASYNC_PF
3759 if (!list_empty_careful(&vcpu
->async_pf
.done
))
3766 bool __weak
kvm_arch_dy_has_pending_interrupt(struct kvm_vcpu
*vcpu
)
3771 void kvm_vcpu_on_spin(struct kvm_vcpu
*me
, bool yield_to_kernel_mode
)
3773 struct kvm
*kvm
= me
->kvm
;
3774 struct kvm_vcpu
*vcpu
;
3775 int last_boosted_vcpu
= me
->kvm
->last_boosted_vcpu
;
3781 kvm_vcpu_set_in_spin_loop(me
, true);
3783 * We boost the priority of a VCPU that is runnable but not
3784 * currently running, because it got preempted by something
3785 * else and called schedule in __vcpu_run. Hopefully that
3786 * VCPU is holding the lock that we need and will release it.
3787 * We approximate round-robin by starting at the last boosted VCPU.
3789 for (pass
= 0; pass
< 2 && !yielded
&& try; pass
++) {
3790 kvm_for_each_vcpu(i
, vcpu
, kvm
) {
3791 if (!pass
&& i
<= last_boosted_vcpu
) {
3792 i
= last_boosted_vcpu
;
3794 } else if (pass
&& i
> last_boosted_vcpu
)
3796 if (!READ_ONCE(vcpu
->ready
))
3800 if (kvm_vcpu_is_blocking(vcpu
) && !vcpu_dy_runnable(vcpu
))
3802 if (READ_ONCE(vcpu
->preempted
) && yield_to_kernel_mode
&&
3803 !kvm_arch_dy_has_pending_interrupt(vcpu
) &&
3804 !kvm_arch_vcpu_in_kernel(vcpu
))
3806 if (!kvm_vcpu_eligible_for_directed_yield(vcpu
))
3809 yielded
= kvm_vcpu_yield_to(vcpu
);
3811 kvm
->last_boosted_vcpu
= i
;
3813 } else if (yielded
< 0) {
3820 kvm_vcpu_set_in_spin_loop(me
, false);
3822 /* Ensure vcpu is not eligible during next spinloop */
3823 kvm_vcpu_set_dy_eligible(me
, false);
3825 EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin
);
3827 static bool kvm_page_in_dirty_ring(struct kvm
*kvm
, unsigned long pgoff
)
3829 #ifdef CONFIG_HAVE_KVM_DIRTY_RING
3830 return (pgoff
>= KVM_DIRTY_LOG_PAGE_OFFSET
) &&
3831 (pgoff
< KVM_DIRTY_LOG_PAGE_OFFSET
+
3832 kvm
->dirty_ring_size
/ PAGE_SIZE
);
3838 static vm_fault_t
kvm_vcpu_fault(struct vm_fault
*vmf
)
3840 struct kvm_vcpu
*vcpu
= vmf
->vma
->vm_file
->private_data
;
3843 if (vmf
->pgoff
== 0)
3844 page
= virt_to_page(vcpu
->run
);
3846 else if (vmf
->pgoff
== KVM_PIO_PAGE_OFFSET
)
3847 page
= virt_to_page(vcpu
->arch
.pio_data
);
3849 #ifdef CONFIG_KVM_MMIO
3850 else if (vmf
->pgoff
== KVM_COALESCED_MMIO_PAGE_OFFSET
)
3851 page
= virt_to_page(vcpu
->kvm
->coalesced_mmio_ring
);
3853 else if (kvm_page_in_dirty_ring(vcpu
->kvm
, vmf
->pgoff
))
3854 page
= kvm_dirty_ring_get_page(
3856 vmf
->pgoff
- KVM_DIRTY_LOG_PAGE_OFFSET
);
3858 return kvm_arch_vcpu_fault(vcpu
, vmf
);
3864 static const struct vm_operations_struct kvm_vcpu_vm_ops
= {
3865 .fault
= kvm_vcpu_fault
,
3868 static int kvm_vcpu_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3870 struct kvm_vcpu
*vcpu
= file
->private_data
;
3871 unsigned long pages
= vma_pages(vma
);
3873 if ((kvm_page_in_dirty_ring(vcpu
->kvm
, vma
->vm_pgoff
) ||
3874 kvm_page_in_dirty_ring(vcpu
->kvm
, vma
->vm_pgoff
+ pages
- 1)) &&
3875 ((vma
->vm_flags
& VM_EXEC
) || !(vma
->vm_flags
& VM_SHARED
)))
3878 vma
->vm_ops
= &kvm_vcpu_vm_ops
;
3882 static int kvm_vcpu_release(struct inode
*inode
, struct file
*filp
)
3884 struct kvm_vcpu
*vcpu
= filp
->private_data
;
3886 kvm_put_kvm(vcpu
->kvm
);
3890 static const struct file_operations kvm_vcpu_fops
= {
3891 .release
= kvm_vcpu_release
,
3892 .unlocked_ioctl
= kvm_vcpu_ioctl
,
3893 .mmap
= kvm_vcpu_mmap
,
3894 .llseek
= noop_llseek
,
3895 KVM_COMPAT(kvm_vcpu_compat_ioctl
),
3899 * Allocates an inode for the vcpu.
3901 static int create_vcpu_fd(struct kvm_vcpu
*vcpu
)
3903 char name
[8 + 1 + ITOA_MAX_LEN
+ 1];
3905 snprintf(name
, sizeof(name
), "kvm-vcpu:%d", vcpu
->vcpu_id
);
3906 return anon_inode_getfd(name
, &kvm_vcpu_fops
, vcpu
, O_RDWR
| O_CLOEXEC
);
3909 #ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
3910 static int vcpu_get_pid(void *data
, u64
*val
)
3912 struct kvm_vcpu
*vcpu
= data
;
3915 *val
= pid_nr(rcu_dereference(vcpu
->pid
));
3920 DEFINE_SIMPLE_ATTRIBUTE(vcpu_get_pid_fops
, vcpu_get_pid
, NULL
, "%llu\n");
3922 static void kvm_create_vcpu_debugfs(struct kvm_vcpu
*vcpu
)
3924 struct dentry
*debugfs_dentry
;
3925 char dir_name
[ITOA_MAX_LEN
* 2];
3927 if (!debugfs_initialized())
3930 snprintf(dir_name
, sizeof(dir_name
), "vcpu%d", vcpu
->vcpu_id
);
3931 debugfs_dentry
= debugfs_create_dir(dir_name
,
3932 vcpu
->kvm
->debugfs_dentry
);
3933 debugfs_create_file("pid", 0444, debugfs_dentry
, vcpu
,
3934 &vcpu_get_pid_fops
);
3936 kvm_arch_create_vcpu_debugfs(vcpu
, debugfs_dentry
);
3941 * Creates some virtual cpus. Good luck creating more than one.
3943 static int kvm_vm_ioctl_create_vcpu(struct kvm
*kvm
, u32 id
)
3946 struct kvm_vcpu
*vcpu
;
3949 if (id
>= KVM_MAX_VCPU_IDS
)
3952 mutex_lock(&kvm
->lock
);
3953 if (kvm
->created_vcpus
>= kvm
->max_vcpus
) {
3954 mutex_unlock(&kvm
->lock
);
3958 r
= kvm_arch_vcpu_precreate(kvm
, id
);
3960 mutex_unlock(&kvm
->lock
);
3964 kvm
->created_vcpus
++;
3965 mutex_unlock(&kvm
->lock
);
3967 vcpu
= kmem_cache_zalloc(kvm_vcpu_cache
, GFP_KERNEL_ACCOUNT
);
3970 goto vcpu_decrement
;
3973 BUILD_BUG_ON(sizeof(struct kvm_run
) > PAGE_SIZE
);
3974 page
= alloc_page(GFP_KERNEL_ACCOUNT
| __GFP_ZERO
);
3979 vcpu
->run
= page_address(page
);
3981 kvm_vcpu_init(vcpu
, kvm
, id
);
3983 r
= kvm_arch_vcpu_create(vcpu
);
3985 goto vcpu_free_run_page
;
3987 if (kvm
->dirty_ring_size
) {
3988 r
= kvm_dirty_ring_alloc(&vcpu
->dirty_ring
,
3989 id
, kvm
->dirty_ring_size
);
3991 goto arch_vcpu_destroy
;
3994 mutex_lock(&kvm
->lock
);
3996 #ifdef CONFIG_LOCKDEP
3997 /* Ensure that lockdep knows vcpu->mutex is taken *inside* kvm->lock */
3998 mutex_lock(&vcpu
->mutex
);
3999 mutex_unlock(&vcpu
->mutex
);
4002 if (kvm_get_vcpu_by_id(kvm
, id
)) {
4004 goto unlock_vcpu_destroy
;
4007 vcpu
->vcpu_idx
= atomic_read(&kvm
->online_vcpus
);
4008 r
= xa_reserve(&kvm
->vcpu_array
, vcpu
->vcpu_idx
, GFP_KERNEL_ACCOUNT
);
4010 goto unlock_vcpu_destroy
;
4012 /* Now it's all set up, let userspace reach it */
4014 r
= create_vcpu_fd(vcpu
);
4016 goto kvm_put_xa_release
;
4018 if (KVM_BUG_ON(xa_store(&kvm
->vcpu_array
, vcpu
->vcpu_idx
, vcpu
, 0), kvm
)) {
4020 goto kvm_put_xa_release
;
4024 * Pairs with smp_rmb() in kvm_get_vcpu. Store the vcpu
4025 * pointer before kvm->online_vcpu's incremented value.
4028 atomic_inc(&kvm
->online_vcpus
);
4030 mutex_unlock(&kvm
->lock
);
4031 kvm_arch_vcpu_postcreate(vcpu
);
4032 kvm_create_vcpu_debugfs(vcpu
);
4036 kvm_put_kvm_no_destroy(kvm
);
4037 xa_release(&kvm
->vcpu_array
, vcpu
->vcpu_idx
);
4038 unlock_vcpu_destroy
:
4039 mutex_unlock(&kvm
->lock
);
4040 kvm_dirty_ring_free(&vcpu
->dirty_ring
);
4042 kvm_arch_vcpu_destroy(vcpu
);
4044 free_page((unsigned long)vcpu
->run
);
4046 kmem_cache_free(kvm_vcpu_cache
, vcpu
);
4048 mutex_lock(&kvm
->lock
);
4049 kvm
->created_vcpus
--;
4050 mutex_unlock(&kvm
->lock
);
4054 static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu
*vcpu
, sigset_t
*sigset
)
4057 sigdelsetmask(sigset
, sigmask(SIGKILL
)|sigmask(SIGSTOP
));
4058 vcpu
->sigset_active
= 1;
4059 vcpu
->sigset
= *sigset
;
4061 vcpu
->sigset_active
= 0;
4065 static ssize_t
kvm_vcpu_stats_read(struct file
*file
, char __user
*user_buffer
,
4066 size_t size
, loff_t
*offset
)
4068 struct kvm_vcpu
*vcpu
= file
->private_data
;
4070 return kvm_stats_read(vcpu
->stats_id
, &kvm_vcpu_stats_header
,
4071 &kvm_vcpu_stats_desc
[0], &vcpu
->stat
,
4072 sizeof(vcpu
->stat
), user_buffer
, size
, offset
);
4075 static int kvm_vcpu_stats_release(struct inode
*inode
, struct file
*file
)
4077 struct kvm_vcpu
*vcpu
= file
->private_data
;
4079 kvm_put_kvm(vcpu
->kvm
);
4083 static const struct file_operations kvm_vcpu_stats_fops
= {
4084 .read
= kvm_vcpu_stats_read
,
4085 .release
= kvm_vcpu_stats_release
,
4086 .llseek
= noop_llseek
,
4089 static int kvm_vcpu_ioctl_get_stats_fd(struct kvm_vcpu
*vcpu
)
4093 char name
[15 + ITOA_MAX_LEN
+ 1];
4095 snprintf(name
, sizeof(name
), "kvm-vcpu-stats:%d", vcpu
->vcpu_id
);
4097 fd
= get_unused_fd_flags(O_CLOEXEC
);
4101 file
= anon_inode_getfile(name
, &kvm_vcpu_stats_fops
, vcpu
, O_RDONLY
);
4104 return PTR_ERR(file
);
4107 kvm_get_kvm(vcpu
->kvm
);
4109 file
->f_mode
|= FMODE_PREAD
;
4110 fd_install(fd
, file
);
4115 static long kvm_vcpu_ioctl(struct file
*filp
,
4116 unsigned int ioctl
, unsigned long arg
)
4118 struct kvm_vcpu
*vcpu
= filp
->private_data
;
4119 void __user
*argp
= (void __user
*)arg
;
4121 struct kvm_fpu
*fpu
= NULL
;
4122 struct kvm_sregs
*kvm_sregs
= NULL
;
4124 if (vcpu
->kvm
->mm
!= current
->mm
|| vcpu
->kvm
->vm_dead
)
4127 if (unlikely(_IOC_TYPE(ioctl
) != KVMIO
))
4131 * Some architectures have vcpu ioctls that are asynchronous to vcpu
4132 * execution; mutex_lock() would break them.
4134 r
= kvm_arch_vcpu_async_ioctl(filp
, ioctl
, arg
);
4135 if (r
!= -ENOIOCTLCMD
)
4138 if (mutex_lock_killable(&vcpu
->mutex
))
4146 oldpid
= rcu_access_pointer(vcpu
->pid
);
4147 if (unlikely(oldpid
!= task_pid(current
))) {
4148 /* The thread running this VCPU changed. */
4151 r
= kvm_arch_vcpu_run_pid_change(vcpu
);
4155 newpid
= get_task_pid(current
, PIDTYPE_PID
);
4156 rcu_assign_pointer(vcpu
->pid
, newpid
);
4161 r
= kvm_arch_vcpu_ioctl_run(vcpu
);
4162 trace_kvm_userspace_exit(vcpu
->run
->exit_reason
, r
);
4165 case KVM_GET_REGS
: {
4166 struct kvm_regs
*kvm_regs
;
4169 kvm_regs
= kzalloc(sizeof(struct kvm_regs
), GFP_KERNEL_ACCOUNT
);
4172 r
= kvm_arch_vcpu_ioctl_get_regs(vcpu
, kvm_regs
);
4176 if (copy_to_user(argp
, kvm_regs
, sizeof(struct kvm_regs
)))
4183 case KVM_SET_REGS
: {
4184 struct kvm_regs
*kvm_regs
;
4186 kvm_regs
= memdup_user(argp
, sizeof(*kvm_regs
));
4187 if (IS_ERR(kvm_regs
)) {
4188 r
= PTR_ERR(kvm_regs
);
4191 r
= kvm_arch_vcpu_ioctl_set_regs(vcpu
, kvm_regs
);
4195 case KVM_GET_SREGS
: {
4196 kvm_sregs
= kzalloc(sizeof(struct kvm_sregs
),
4197 GFP_KERNEL_ACCOUNT
);
4201 r
= kvm_arch_vcpu_ioctl_get_sregs(vcpu
, kvm_sregs
);
4205 if (copy_to_user(argp
, kvm_sregs
, sizeof(struct kvm_sregs
)))
4210 case KVM_SET_SREGS
: {
4211 kvm_sregs
= memdup_user(argp
, sizeof(*kvm_sregs
));
4212 if (IS_ERR(kvm_sregs
)) {
4213 r
= PTR_ERR(kvm_sregs
);
4217 r
= kvm_arch_vcpu_ioctl_set_sregs(vcpu
, kvm_sregs
);
4220 case KVM_GET_MP_STATE
: {
4221 struct kvm_mp_state mp_state
;
4223 r
= kvm_arch_vcpu_ioctl_get_mpstate(vcpu
, &mp_state
);
4227 if (copy_to_user(argp
, &mp_state
, sizeof(mp_state
)))
4232 case KVM_SET_MP_STATE
: {
4233 struct kvm_mp_state mp_state
;
4236 if (copy_from_user(&mp_state
, argp
, sizeof(mp_state
)))
4238 r
= kvm_arch_vcpu_ioctl_set_mpstate(vcpu
, &mp_state
);
4241 case KVM_TRANSLATE
: {
4242 struct kvm_translation tr
;
4245 if (copy_from_user(&tr
, argp
, sizeof(tr
)))
4247 r
= kvm_arch_vcpu_ioctl_translate(vcpu
, &tr
);
4251 if (copy_to_user(argp
, &tr
, sizeof(tr
)))
4256 case KVM_SET_GUEST_DEBUG
: {
4257 struct kvm_guest_debug dbg
;
4260 if (copy_from_user(&dbg
, argp
, sizeof(dbg
)))
4262 r
= kvm_arch_vcpu_ioctl_set_guest_debug(vcpu
, &dbg
);
4265 case KVM_SET_SIGNAL_MASK
: {
4266 struct kvm_signal_mask __user
*sigmask_arg
= argp
;
4267 struct kvm_signal_mask kvm_sigmask
;
4268 sigset_t sigset
, *p
;
4273 if (copy_from_user(&kvm_sigmask
, argp
,
4274 sizeof(kvm_sigmask
)))
4277 if (kvm_sigmask
.len
!= sizeof(sigset
))
4280 if (copy_from_user(&sigset
, sigmask_arg
->sigset
,
4285 r
= kvm_vcpu_ioctl_set_sigmask(vcpu
, p
);
4289 fpu
= kzalloc(sizeof(struct kvm_fpu
), GFP_KERNEL_ACCOUNT
);
4293 r
= kvm_arch_vcpu_ioctl_get_fpu(vcpu
, fpu
);
4297 if (copy_to_user(argp
, fpu
, sizeof(struct kvm_fpu
)))
4303 fpu
= memdup_user(argp
, sizeof(*fpu
));
4309 r
= kvm_arch_vcpu_ioctl_set_fpu(vcpu
, fpu
);
4312 case KVM_GET_STATS_FD
: {
4313 r
= kvm_vcpu_ioctl_get_stats_fd(vcpu
);
4317 r
= kvm_arch_vcpu_ioctl(filp
, ioctl
, arg
);
4320 mutex_unlock(&vcpu
->mutex
);
4326 #ifdef CONFIG_KVM_COMPAT
4327 static long kvm_vcpu_compat_ioctl(struct file
*filp
,
4328 unsigned int ioctl
, unsigned long arg
)
4330 struct kvm_vcpu
*vcpu
= filp
->private_data
;
4331 void __user
*argp
= compat_ptr(arg
);
4334 if (vcpu
->kvm
->mm
!= current
->mm
|| vcpu
->kvm
->vm_dead
)
4338 case KVM_SET_SIGNAL_MASK
: {
4339 struct kvm_signal_mask __user
*sigmask_arg
= argp
;
4340 struct kvm_signal_mask kvm_sigmask
;
4345 if (copy_from_user(&kvm_sigmask
, argp
,
4346 sizeof(kvm_sigmask
)))
4349 if (kvm_sigmask
.len
!= sizeof(compat_sigset_t
))
4352 if (get_compat_sigset(&sigset
,
4353 (compat_sigset_t __user
*)sigmask_arg
->sigset
))
4355 r
= kvm_vcpu_ioctl_set_sigmask(vcpu
, &sigset
);
4357 r
= kvm_vcpu_ioctl_set_sigmask(vcpu
, NULL
);
4361 r
= kvm_vcpu_ioctl(filp
, ioctl
, arg
);
4369 static int kvm_device_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
4371 struct kvm_device
*dev
= filp
->private_data
;
4374 return dev
->ops
->mmap(dev
, vma
);
4379 static int kvm_device_ioctl_attr(struct kvm_device
*dev
,
4380 int (*accessor
)(struct kvm_device
*dev
,
4381 struct kvm_device_attr
*attr
),
4384 struct kvm_device_attr attr
;
4389 if (copy_from_user(&attr
, (void __user
*)arg
, sizeof(attr
)))
4392 return accessor(dev
, &attr
);
4395 static long kvm_device_ioctl(struct file
*filp
, unsigned int ioctl
,
4398 struct kvm_device
*dev
= filp
->private_data
;
4400 if (dev
->kvm
->mm
!= current
->mm
|| dev
->kvm
->vm_dead
)
4404 case KVM_SET_DEVICE_ATTR
:
4405 return kvm_device_ioctl_attr(dev
, dev
->ops
->set_attr
, arg
);
4406 case KVM_GET_DEVICE_ATTR
:
4407 return kvm_device_ioctl_attr(dev
, dev
->ops
->get_attr
, arg
);
4408 case KVM_HAS_DEVICE_ATTR
:
4409 return kvm_device_ioctl_attr(dev
, dev
->ops
->has_attr
, arg
);
4411 if (dev
->ops
->ioctl
)
4412 return dev
->ops
->ioctl(dev
, ioctl
, arg
);
4418 static int kvm_device_release(struct inode
*inode
, struct file
*filp
)
4420 struct kvm_device
*dev
= filp
->private_data
;
4421 struct kvm
*kvm
= dev
->kvm
;
4423 if (dev
->ops
->release
) {
4424 mutex_lock(&kvm
->lock
);
4425 list_del(&dev
->vm_node
);
4426 dev
->ops
->release(dev
);
4427 mutex_unlock(&kvm
->lock
);
4434 static const struct file_operations kvm_device_fops
= {
4435 .unlocked_ioctl
= kvm_device_ioctl
,
4436 .release
= kvm_device_release
,
4437 KVM_COMPAT(kvm_device_ioctl
),
4438 .mmap
= kvm_device_mmap
,
4441 struct kvm_device
*kvm_device_from_filp(struct file
*filp
)
4443 if (filp
->f_op
!= &kvm_device_fops
)
4446 return filp
->private_data
;
4449 static const struct kvm_device_ops
*kvm_device_ops_table
[KVM_DEV_TYPE_MAX
] = {
4450 #ifdef CONFIG_KVM_MPIC
4451 [KVM_DEV_TYPE_FSL_MPIC_20
] = &kvm_mpic_ops
,
4452 [KVM_DEV_TYPE_FSL_MPIC_42
] = &kvm_mpic_ops
,
4456 int kvm_register_device_ops(const struct kvm_device_ops
*ops
, u32 type
)
4458 if (type
>= ARRAY_SIZE(kvm_device_ops_table
))
4461 if (kvm_device_ops_table
[type
] != NULL
)
4464 kvm_device_ops_table
[type
] = ops
;
4468 void kvm_unregister_device_ops(u32 type
)
4470 if (kvm_device_ops_table
[type
] != NULL
)
4471 kvm_device_ops_table
[type
] = NULL
;
4474 static int kvm_ioctl_create_device(struct kvm
*kvm
,
4475 struct kvm_create_device
*cd
)
4477 const struct kvm_device_ops
*ops
;
4478 struct kvm_device
*dev
;
4479 bool test
= cd
->flags
& KVM_CREATE_DEVICE_TEST
;
4483 if (cd
->type
>= ARRAY_SIZE(kvm_device_ops_table
))
4486 type
= array_index_nospec(cd
->type
, ARRAY_SIZE(kvm_device_ops_table
));
4487 ops
= kvm_device_ops_table
[type
];
4494 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL_ACCOUNT
);
4501 mutex_lock(&kvm
->lock
);
4502 ret
= ops
->create(dev
, type
);
4504 mutex_unlock(&kvm
->lock
);
4508 list_add(&dev
->vm_node
, &kvm
->devices
);
4509 mutex_unlock(&kvm
->lock
);
4515 ret
= anon_inode_getfd(ops
->name
, &kvm_device_fops
, dev
, O_RDWR
| O_CLOEXEC
);
4517 kvm_put_kvm_no_destroy(kvm
);
4518 mutex_lock(&kvm
->lock
);
4519 list_del(&dev
->vm_node
);
4522 mutex_unlock(&kvm
->lock
);
4532 static int kvm_vm_ioctl_check_extension_generic(struct kvm
*kvm
, long arg
)
4535 case KVM_CAP_USER_MEMORY
:
4536 case KVM_CAP_DESTROY_MEMORY_REGION_WORKS
:
4537 case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS
:
4538 case KVM_CAP_INTERNAL_ERROR_DATA
:
4539 #ifdef CONFIG_HAVE_KVM_MSI
4540 case KVM_CAP_SIGNAL_MSI
:
4542 #ifdef CONFIG_HAVE_KVM_IRQFD
4545 case KVM_CAP_IOEVENTFD_ANY_LENGTH
:
4546 case KVM_CAP_CHECK_EXTENSION_VM
:
4547 case KVM_CAP_ENABLE_CAP_VM
:
4548 case KVM_CAP_HALT_POLL
:
4550 #ifdef CONFIG_KVM_MMIO
4551 case KVM_CAP_COALESCED_MMIO
:
4552 return KVM_COALESCED_MMIO_PAGE_OFFSET
;
4553 case KVM_CAP_COALESCED_PIO
:
4556 #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
4557 case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
:
4558 return KVM_DIRTY_LOG_MANUAL_CAPS
;
4560 #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
4561 case KVM_CAP_IRQ_ROUTING
:
4562 return KVM_MAX_IRQ_ROUTES
;
4564 #if KVM_ADDRESS_SPACE_NUM > 1
4565 case KVM_CAP_MULTI_ADDRESS_SPACE
:
4566 return KVM_ADDRESS_SPACE_NUM
;
4568 case KVM_CAP_NR_MEMSLOTS
:
4569 return KVM_USER_MEM_SLOTS
;
4570 case KVM_CAP_DIRTY_LOG_RING
:
4571 #ifdef CONFIG_HAVE_KVM_DIRTY_RING_TSO
4572 return KVM_DIRTY_RING_MAX_ENTRIES
* sizeof(struct kvm_dirty_gfn
);
4576 case KVM_CAP_DIRTY_LOG_RING_ACQ_REL
:
4577 #ifdef CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL
4578 return KVM_DIRTY_RING_MAX_ENTRIES
* sizeof(struct kvm_dirty_gfn
);
4582 #ifdef CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP
4583 case KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP
:
4585 case KVM_CAP_BINARY_STATS_FD
:
4586 case KVM_CAP_SYSTEM_EVENT_DATA
:
4591 return kvm_vm_ioctl_check_extension(kvm
, arg
);
4594 static int kvm_vm_ioctl_enable_dirty_log_ring(struct kvm
*kvm
, u32 size
)
4598 if (!KVM_DIRTY_LOG_PAGE_OFFSET
)
4601 /* the size should be power of 2 */
4602 if (!size
|| (size
& (size
- 1)))
4605 /* Should be bigger to keep the reserved entries, or a page */
4606 if (size
< kvm_dirty_ring_get_rsvd_entries() *
4607 sizeof(struct kvm_dirty_gfn
) || size
< PAGE_SIZE
)
4610 if (size
> KVM_DIRTY_RING_MAX_ENTRIES
*
4611 sizeof(struct kvm_dirty_gfn
))
4614 /* We only allow it to set once */
4615 if (kvm
->dirty_ring_size
)
4618 mutex_lock(&kvm
->lock
);
4620 if (kvm
->created_vcpus
) {
4621 /* We don't allow to change this value after vcpu created */
4624 kvm
->dirty_ring_size
= size
;
4628 mutex_unlock(&kvm
->lock
);
4632 static int kvm_vm_ioctl_reset_dirty_pages(struct kvm
*kvm
)
4635 struct kvm_vcpu
*vcpu
;
4638 if (!kvm
->dirty_ring_size
)
4641 mutex_lock(&kvm
->slots_lock
);
4643 kvm_for_each_vcpu(i
, vcpu
, kvm
)
4644 cleared
+= kvm_dirty_ring_reset(vcpu
->kvm
, &vcpu
->dirty_ring
);
4646 mutex_unlock(&kvm
->slots_lock
);
4649 kvm_flush_remote_tlbs(kvm
);
4654 int __attribute__((weak
)) kvm_vm_ioctl_enable_cap(struct kvm
*kvm
,
4655 struct kvm_enable_cap
*cap
)
4660 bool kvm_are_all_memslots_empty(struct kvm
*kvm
)
4664 lockdep_assert_held(&kvm
->slots_lock
);
4666 for (i
= 0; i
< KVM_ADDRESS_SPACE_NUM
; i
++) {
4667 if (!kvm_memslots_empty(__kvm_memslots(kvm
, i
)))
4673 EXPORT_SYMBOL_GPL(kvm_are_all_memslots_empty
);
4675 static int kvm_vm_ioctl_enable_cap_generic(struct kvm
*kvm
,
4676 struct kvm_enable_cap
*cap
)
4679 #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
4680 case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
: {
4681 u64 allowed_options
= KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE
;
4683 if (cap
->args
[0] & KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE
)
4684 allowed_options
= KVM_DIRTY_LOG_MANUAL_CAPS
;
4686 if (cap
->flags
|| (cap
->args
[0] & ~allowed_options
))
4688 kvm
->manual_dirty_log_protect
= cap
->args
[0];
4692 case KVM_CAP_HALT_POLL
: {
4693 if (cap
->flags
|| cap
->args
[0] != (unsigned int)cap
->args
[0])
4696 kvm
->max_halt_poll_ns
= cap
->args
[0];
4699 * Ensure kvm->override_halt_poll_ns does not become visible
4700 * before kvm->max_halt_poll_ns.
4702 * Pairs with the smp_rmb() in kvm_vcpu_max_halt_poll_ns().
4705 kvm
->override_halt_poll_ns
= true;
4709 case KVM_CAP_DIRTY_LOG_RING
:
4710 case KVM_CAP_DIRTY_LOG_RING_ACQ_REL
:
4711 if (!kvm_vm_ioctl_check_extension_generic(kvm
, cap
->cap
))
4714 return kvm_vm_ioctl_enable_dirty_log_ring(kvm
, cap
->args
[0]);
4715 case KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP
: {
4718 if (!IS_ENABLED(CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP
) ||
4719 !kvm
->dirty_ring_size
|| cap
->flags
)
4722 mutex_lock(&kvm
->slots_lock
);
4725 * For simplicity, allow enabling ring+bitmap if and only if
4726 * there are no memslots, e.g. to ensure all memslots allocate
4727 * a bitmap after the capability is enabled.
4729 if (kvm_are_all_memslots_empty(kvm
)) {
4730 kvm
->dirty_ring_with_bitmap
= true;
4734 mutex_unlock(&kvm
->slots_lock
);
4739 return kvm_vm_ioctl_enable_cap(kvm
, cap
);
4743 static ssize_t
kvm_vm_stats_read(struct file
*file
, char __user
*user_buffer
,
4744 size_t size
, loff_t
*offset
)
4746 struct kvm
*kvm
= file
->private_data
;
4748 return kvm_stats_read(kvm
->stats_id
, &kvm_vm_stats_header
,
4749 &kvm_vm_stats_desc
[0], &kvm
->stat
,
4750 sizeof(kvm
->stat
), user_buffer
, size
, offset
);
4753 static int kvm_vm_stats_release(struct inode
*inode
, struct file
*file
)
4755 struct kvm
*kvm
= file
->private_data
;
4761 static const struct file_operations kvm_vm_stats_fops
= {
4762 .read
= kvm_vm_stats_read
,
4763 .release
= kvm_vm_stats_release
,
4764 .llseek
= noop_llseek
,
4767 static int kvm_vm_ioctl_get_stats_fd(struct kvm
*kvm
)
4772 fd
= get_unused_fd_flags(O_CLOEXEC
);
4776 file
= anon_inode_getfile("kvm-vm-stats",
4777 &kvm_vm_stats_fops
, kvm
, O_RDONLY
);
4780 return PTR_ERR(file
);
4785 file
->f_mode
|= FMODE_PREAD
;
4786 fd_install(fd
, file
);
4791 static long kvm_vm_ioctl(struct file
*filp
,
4792 unsigned int ioctl
, unsigned long arg
)
4794 struct kvm
*kvm
= filp
->private_data
;
4795 void __user
*argp
= (void __user
*)arg
;
4798 if (kvm
->mm
!= current
->mm
|| kvm
->vm_dead
)
4801 case KVM_CREATE_VCPU
:
4802 r
= kvm_vm_ioctl_create_vcpu(kvm
, arg
);
4804 case KVM_ENABLE_CAP
: {
4805 struct kvm_enable_cap cap
;
4808 if (copy_from_user(&cap
, argp
, sizeof(cap
)))
4810 r
= kvm_vm_ioctl_enable_cap_generic(kvm
, &cap
);
4813 case KVM_SET_USER_MEMORY_REGION
: {
4814 struct kvm_userspace_memory_region kvm_userspace_mem
;
4817 if (copy_from_user(&kvm_userspace_mem
, argp
,
4818 sizeof(kvm_userspace_mem
)))
4821 r
= kvm_vm_ioctl_set_memory_region(kvm
, &kvm_userspace_mem
);
4824 case KVM_GET_DIRTY_LOG
: {
4825 struct kvm_dirty_log log
;
4828 if (copy_from_user(&log
, argp
, sizeof(log
)))
4830 r
= kvm_vm_ioctl_get_dirty_log(kvm
, &log
);
4833 #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
4834 case KVM_CLEAR_DIRTY_LOG
: {
4835 struct kvm_clear_dirty_log log
;
4838 if (copy_from_user(&log
, argp
, sizeof(log
)))
4840 r
= kvm_vm_ioctl_clear_dirty_log(kvm
, &log
);
4844 #ifdef CONFIG_KVM_MMIO
4845 case KVM_REGISTER_COALESCED_MMIO
: {
4846 struct kvm_coalesced_mmio_zone zone
;
4849 if (copy_from_user(&zone
, argp
, sizeof(zone
)))
4851 r
= kvm_vm_ioctl_register_coalesced_mmio(kvm
, &zone
);
4854 case KVM_UNREGISTER_COALESCED_MMIO
: {
4855 struct kvm_coalesced_mmio_zone zone
;
4858 if (copy_from_user(&zone
, argp
, sizeof(zone
)))
4860 r
= kvm_vm_ioctl_unregister_coalesced_mmio(kvm
, &zone
);
4865 struct kvm_irqfd data
;
4868 if (copy_from_user(&data
, argp
, sizeof(data
)))
4870 r
= kvm_irqfd(kvm
, &data
);
4873 case KVM_IOEVENTFD
: {
4874 struct kvm_ioeventfd data
;
4877 if (copy_from_user(&data
, argp
, sizeof(data
)))
4879 r
= kvm_ioeventfd(kvm
, &data
);
4882 #ifdef CONFIG_HAVE_KVM_MSI
4883 case KVM_SIGNAL_MSI
: {
4887 if (copy_from_user(&msi
, argp
, sizeof(msi
)))
4889 r
= kvm_send_userspace_msi(kvm
, &msi
);
4893 #ifdef __KVM_HAVE_IRQ_LINE
4894 case KVM_IRQ_LINE_STATUS
:
4895 case KVM_IRQ_LINE
: {
4896 struct kvm_irq_level irq_event
;
4899 if (copy_from_user(&irq_event
, argp
, sizeof(irq_event
)))
4902 r
= kvm_vm_ioctl_irq_line(kvm
, &irq_event
,
4903 ioctl
== KVM_IRQ_LINE_STATUS
);
4908 if (ioctl
== KVM_IRQ_LINE_STATUS
) {
4909 if (copy_to_user(argp
, &irq_event
, sizeof(irq_event
)))
4917 #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
4918 case KVM_SET_GSI_ROUTING
: {
4919 struct kvm_irq_routing routing
;
4920 struct kvm_irq_routing __user
*urouting
;
4921 struct kvm_irq_routing_entry
*entries
= NULL
;
4924 if (copy_from_user(&routing
, argp
, sizeof(routing
)))
4927 if (!kvm_arch_can_set_irq_routing(kvm
))
4929 if (routing
.nr
> KVM_MAX_IRQ_ROUTES
)
4935 entries
= vmemdup_user(urouting
->entries
,
4936 array_size(sizeof(*entries
),
4938 if (IS_ERR(entries
)) {
4939 r
= PTR_ERR(entries
);
4943 r
= kvm_set_irq_routing(kvm
, entries
, routing
.nr
,
4948 #endif /* CONFIG_HAVE_KVM_IRQ_ROUTING */
4949 case KVM_CREATE_DEVICE
: {
4950 struct kvm_create_device cd
;
4953 if (copy_from_user(&cd
, argp
, sizeof(cd
)))
4956 r
= kvm_ioctl_create_device(kvm
, &cd
);
4961 if (copy_to_user(argp
, &cd
, sizeof(cd
)))
4967 case KVM_CHECK_EXTENSION
:
4968 r
= kvm_vm_ioctl_check_extension_generic(kvm
, arg
);
4970 case KVM_RESET_DIRTY_RINGS
:
4971 r
= kvm_vm_ioctl_reset_dirty_pages(kvm
);
4973 case KVM_GET_STATS_FD
:
4974 r
= kvm_vm_ioctl_get_stats_fd(kvm
);
4977 r
= kvm_arch_vm_ioctl(filp
, ioctl
, arg
);
4983 #ifdef CONFIG_KVM_COMPAT
4984 struct compat_kvm_dirty_log
{
4988 compat_uptr_t dirty_bitmap
; /* one bit per page */
4993 struct compat_kvm_clear_dirty_log
{
4998 compat_uptr_t dirty_bitmap
; /* one bit per page */
5003 long __weak
kvm_arch_vm_compat_ioctl(struct file
*filp
, unsigned int ioctl
,
5009 static long kvm_vm_compat_ioctl(struct file
*filp
,
5010 unsigned int ioctl
, unsigned long arg
)
5012 struct kvm
*kvm
= filp
->private_data
;
5015 if (kvm
->mm
!= current
->mm
|| kvm
->vm_dead
)
5018 r
= kvm_arch_vm_compat_ioctl(filp
, ioctl
, arg
);
5023 #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
5024 case KVM_CLEAR_DIRTY_LOG
: {
5025 struct compat_kvm_clear_dirty_log compat_log
;
5026 struct kvm_clear_dirty_log log
;
5028 if (copy_from_user(&compat_log
, (void __user
*)arg
,
5029 sizeof(compat_log
)))
5031 log
.slot
= compat_log
.slot
;
5032 log
.num_pages
= compat_log
.num_pages
;
5033 log
.first_page
= compat_log
.first_page
;
5034 log
.padding2
= compat_log
.padding2
;
5035 log
.dirty_bitmap
= compat_ptr(compat_log
.dirty_bitmap
);
5037 r
= kvm_vm_ioctl_clear_dirty_log(kvm
, &log
);
5041 case KVM_GET_DIRTY_LOG
: {
5042 struct compat_kvm_dirty_log compat_log
;
5043 struct kvm_dirty_log log
;
5045 if (copy_from_user(&compat_log
, (void __user
*)arg
,
5046 sizeof(compat_log
)))
5048 log
.slot
= compat_log
.slot
;
5049 log
.padding1
= compat_log
.padding1
;
5050 log
.padding2
= compat_log
.padding2
;
5051 log
.dirty_bitmap
= compat_ptr(compat_log
.dirty_bitmap
);
5053 r
= kvm_vm_ioctl_get_dirty_log(kvm
, &log
);
5057 r
= kvm_vm_ioctl(filp
, ioctl
, arg
);
5063 static const struct file_operations kvm_vm_fops
= {
5064 .release
= kvm_vm_release
,
5065 .unlocked_ioctl
= kvm_vm_ioctl
,
5066 .llseek
= noop_llseek
,
5067 KVM_COMPAT(kvm_vm_compat_ioctl
),
5070 bool file_is_kvm(struct file
*file
)
5072 return file
&& file
->f_op
== &kvm_vm_fops
;
5074 EXPORT_SYMBOL_GPL(file_is_kvm
);
5076 static int kvm_dev_ioctl_create_vm(unsigned long type
)
5078 char fdname
[ITOA_MAX_LEN
+ 1];
5083 fd
= get_unused_fd_flags(O_CLOEXEC
);
5087 snprintf(fdname
, sizeof(fdname
), "%d", fd
);
5089 kvm
= kvm_create_vm(type
, fdname
);
5095 file
= anon_inode_getfile("kvm-vm", &kvm_vm_fops
, kvm
, O_RDWR
);
5102 * Don't call kvm_put_kvm anymore at this point; file->f_op is
5103 * already set, with ->release() being kvm_vm_release(). In error
5104 * cases it will be called by the final fput(file) and will take
5105 * care of doing kvm_put_kvm(kvm).
5107 kvm_uevent_notify_change(KVM_EVENT_CREATE_VM
, kvm
);
5109 fd_install(fd
, file
);
5119 static long kvm_dev_ioctl(struct file
*filp
,
5120 unsigned int ioctl
, unsigned long arg
)
5125 case KVM_GET_API_VERSION
:
5128 r
= KVM_API_VERSION
;
5131 r
= kvm_dev_ioctl_create_vm(arg
);
5133 case KVM_CHECK_EXTENSION
:
5134 r
= kvm_vm_ioctl_check_extension_generic(NULL
, arg
);
5136 case KVM_GET_VCPU_MMAP_SIZE
:
5139 r
= PAGE_SIZE
; /* struct kvm_run */
5141 r
+= PAGE_SIZE
; /* pio data page */
5143 #ifdef CONFIG_KVM_MMIO
5144 r
+= PAGE_SIZE
; /* coalesced mmio ring page */
5147 case KVM_TRACE_ENABLE
:
5148 case KVM_TRACE_PAUSE
:
5149 case KVM_TRACE_DISABLE
:
5153 return kvm_arch_dev_ioctl(filp
, ioctl
, arg
);
5159 static struct file_operations kvm_chardev_ops
= {
5160 .unlocked_ioctl
= kvm_dev_ioctl
,
5161 .llseek
= noop_llseek
,
5162 KVM_COMPAT(kvm_dev_ioctl
),
5165 static struct miscdevice kvm_dev
= {
5171 #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
5172 __visible
bool kvm_rebooting
;
5173 EXPORT_SYMBOL_GPL(kvm_rebooting
);
5175 static DEFINE_PER_CPU(bool, hardware_enabled
);
5176 static int kvm_usage_count
;
5178 static int __hardware_enable_nolock(void)
5180 if (__this_cpu_read(hardware_enabled
))
5183 if (kvm_arch_hardware_enable()) {
5184 pr_info("kvm: enabling virtualization on CPU%d failed\n",
5185 raw_smp_processor_id());
5189 __this_cpu_write(hardware_enabled
, true);
5193 static void hardware_enable_nolock(void *failed
)
5195 if (__hardware_enable_nolock())
5199 static int kvm_online_cpu(unsigned int cpu
)
5204 * Abort the CPU online process if hardware virtualization cannot
5205 * be enabled. Otherwise running VMs would encounter unrecoverable
5206 * errors when scheduled to this CPU.
5208 mutex_lock(&kvm_lock
);
5209 if (kvm_usage_count
)
5210 ret
= __hardware_enable_nolock();
5211 mutex_unlock(&kvm_lock
);
5215 static void hardware_disable_nolock(void *junk
)
5218 * Note, hardware_disable_all_nolock() tells all online CPUs to disable
5219 * hardware, not just CPUs that successfully enabled hardware!
5221 if (!__this_cpu_read(hardware_enabled
))
5224 kvm_arch_hardware_disable();
5226 __this_cpu_write(hardware_enabled
, false);
5229 static int kvm_offline_cpu(unsigned int cpu
)
5231 mutex_lock(&kvm_lock
);
5232 if (kvm_usage_count
)
5233 hardware_disable_nolock(NULL
);
5234 mutex_unlock(&kvm_lock
);
5238 static void hardware_disable_all_nolock(void)
5240 BUG_ON(!kvm_usage_count
);
5243 if (!kvm_usage_count
)
5244 on_each_cpu(hardware_disable_nolock
, NULL
, 1);
5247 static void hardware_disable_all(void)
5250 mutex_lock(&kvm_lock
);
5251 hardware_disable_all_nolock();
5252 mutex_unlock(&kvm_lock
);
5256 static int hardware_enable_all(void)
5258 atomic_t failed
= ATOMIC_INIT(0);
5262 * Do not enable hardware virtualization if the system is going down.
5263 * If userspace initiated a forced reboot, e.g. reboot -f, then it's
5264 * possible for an in-flight KVM_CREATE_VM to trigger hardware enabling
5265 * after kvm_reboot() is called. Note, this relies on system_state
5266 * being set _before_ kvm_reboot(), which is why KVM uses a syscore ops
5267 * hook instead of registering a dedicated reboot notifier (the latter
5268 * runs before system_state is updated).
5270 if (system_state
== SYSTEM_HALT
|| system_state
== SYSTEM_POWER_OFF
||
5271 system_state
== SYSTEM_RESTART
)
5275 * When onlining a CPU, cpu_online_mask is set before kvm_online_cpu()
5276 * is called, and so on_each_cpu() between them includes the CPU that
5277 * is being onlined. As a result, hardware_enable_nolock() may get
5278 * invoked before kvm_online_cpu(), which also enables hardware if the
5279 * usage count is non-zero. Disable CPU hotplug to avoid attempting to
5280 * enable hardware multiple times.
5283 mutex_lock(&kvm_lock
);
5288 if (kvm_usage_count
== 1) {
5289 on_each_cpu(hardware_enable_nolock
, &failed
, 1);
5291 if (atomic_read(&failed
)) {
5292 hardware_disable_all_nolock();
5297 mutex_unlock(&kvm_lock
);
5303 static void kvm_shutdown(void)
5306 * Disable hardware virtualization and set kvm_rebooting to indicate
5307 * that KVM has asynchronously disabled hardware virtualization, i.e.
5308 * that relevant errors and exceptions aren't entirely unexpected.
5309 * Some flavors of hardware virtualization need to be disabled before
5310 * transferring control to firmware (to perform shutdown/reboot), e.g.
5311 * on x86, virtualization can block INIT interrupts, which are used by
5312 * firmware to pull APs back under firmware control. Note, this path
5313 * is used for both shutdown and reboot scenarios, i.e. neither name is
5314 * 100% comprehensive.
5316 pr_info("kvm: exiting hardware virtualization\n");
5317 kvm_rebooting
= true;
5318 on_each_cpu(hardware_disable_nolock
, NULL
, 1);
5321 static int kvm_suspend(void)
5324 * Secondary CPUs and CPU hotplug are disabled across the suspend/resume
5325 * callbacks, i.e. no need to acquire kvm_lock to ensure the usage count
5326 * is stable. Assert that kvm_lock is not held to ensure the system
5327 * isn't suspended while KVM is enabling hardware. Hardware enabling
5328 * can be preempted, but the task cannot be frozen until it has dropped
5329 * all locks (userspace tasks are frozen via a fake signal).
5331 lockdep_assert_not_held(&kvm_lock
);
5332 lockdep_assert_irqs_disabled();
5334 if (kvm_usage_count
)
5335 hardware_disable_nolock(NULL
);
5339 static void kvm_resume(void)
5341 lockdep_assert_not_held(&kvm_lock
);
5342 lockdep_assert_irqs_disabled();
5344 if (kvm_usage_count
)
5345 WARN_ON_ONCE(__hardware_enable_nolock());
5348 static struct syscore_ops kvm_syscore_ops
= {
5349 .suspend
= kvm_suspend
,
5350 .resume
= kvm_resume
,
5351 .shutdown
= kvm_shutdown
,
5353 #else /* CONFIG_KVM_GENERIC_HARDWARE_ENABLING */
5354 static int hardware_enable_all(void)
5359 static void hardware_disable_all(void)
5363 #endif /* CONFIG_KVM_GENERIC_HARDWARE_ENABLING */
5365 static void kvm_iodevice_destructor(struct kvm_io_device
*dev
)
5367 if (dev
->ops
->destructor
)
5368 dev
->ops
->destructor(dev
);
5371 static void kvm_io_bus_destroy(struct kvm_io_bus
*bus
)
5375 for (i
= 0; i
< bus
->dev_count
; i
++) {
5376 struct kvm_io_device
*pos
= bus
->range
[i
].dev
;
5378 kvm_iodevice_destructor(pos
);
5383 static inline int kvm_io_bus_cmp(const struct kvm_io_range
*r1
,
5384 const struct kvm_io_range
*r2
)
5386 gpa_t addr1
= r1
->addr
;
5387 gpa_t addr2
= r2
->addr
;
5392 /* If r2->len == 0, match the exact address. If r2->len != 0,
5393 * accept any overlapping write. Any order is acceptable for
5394 * overlapping ranges, because kvm_io_bus_get_first_dev ensures
5395 * we process all of them.
5408 static int kvm_io_bus_sort_cmp(const void *p1
, const void *p2
)
5410 return kvm_io_bus_cmp(p1
, p2
);
5413 static int kvm_io_bus_get_first_dev(struct kvm_io_bus
*bus
,
5414 gpa_t addr
, int len
)
5416 struct kvm_io_range
*range
, key
;
5419 key
= (struct kvm_io_range
) {
5424 range
= bsearch(&key
, bus
->range
, bus
->dev_count
,
5425 sizeof(struct kvm_io_range
), kvm_io_bus_sort_cmp
);
5429 off
= range
- bus
->range
;
5431 while (off
> 0 && kvm_io_bus_cmp(&key
, &bus
->range
[off
-1]) == 0)
5437 static int __kvm_io_bus_write(struct kvm_vcpu
*vcpu
, struct kvm_io_bus
*bus
,
5438 struct kvm_io_range
*range
, const void *val
)
5442 idx
= kvm_io_bus_get_first_dev(bus
, range
->addr
, range
->len
);
5446 while (idx
< bus
->dev_count
&&
5447 kvm_io_bus_cmp(range
, &bus
->range
[idx
]) == 0) {
5448 if (!kvm_iodevice_write(vcpu
, bus
->range
[idx
].dev
, range
->addr
,
5457 /* kvm_io_bus_write - called under kvm->slots_lock */
5458 int kvm_io_bus_write(struct kvm_vcpu
*vcpu
, enum kvm_bus bus_idx
, gpa_t addr
,
5459 int len
, const void *val
)
5461 struct kvm_io_bus
*bus
;
5462 struct kvm_io_range range
;
5465 range
= (struct kvm_io_range
) {
5470 bus
= srcu_dereference(vcpu
->kvm
->buses
[bus_idx
], &vcpu
->kvm
->srcu
);
5473 r
= __kvm_io_bus_write(vcpu
, bus
, &range
, val
);
5474 return r
< 0 ? r
: 0;
5476 EXPORT_SYMBOL_GPL(kvm_io_bus_write
);
5478 /* kvm_io_bus_write_cookie - called under kvm->slots_lock */
5479 int kvm_io_bus_write_cookie(struct kvm_vcpu
*vcpu
, enum kvm_bus bus_idx
,
5480 gpa_t addr
, int len
, const void *val
, long cookie
)
5482 struct kvm_io_bus
*bus
;
5483 struct kvm_io_range range
;
5485 range
= (struct kvm_io_range
) {
5490 bus
= srcu_dereference(vcpu
->kvm
->buses
[bus_idx
], &vcpu
->kvm
->srcu
);
5494 /* First try the device referenced by cookie. */
5495 if ((cookie
>= 0) && (cookie
< bus
->dev_count
) &&
5496 (kvm_io_bus_cmp(&range
, &bus
->range
[cookie
]) == 0))
5497 if (!kvm_iodevice_write(vcpu
, bus
->range
[cookie
].dev
, addr
, len
,
5502 * cookie contained garbage; fall back to search and return the
5503 * correct cookie value.
5505 return __kvm_io_bus_write(vcpu
, bus
, &range
, val
);
5508 static int __kvm_io_bus_read(struct kvm_vcpu
*vcpu
, struct kvm_io_bus
*bus
,
5509 struct kvm_io_range
*range
, void *val
)
5513 idx
= kvm_io_bus_get_first_dev(bus
, range
->addr
, range
->len
);
5517 while (idx
< bus
->dev_count
&&
5518 kvm_io_bus_cmp(range
, &bus
->range
[idx
]) == 0) {
5519 if (!kvm_iodevice_read(vcpu
, bus
->range
[idx
].dev
, range
->addr
,
5528 /* kvm_io_bus_read - called under kvm->slots_lock */
5529 int kvm_io_bus_read(struct kvm_vcpu
*vcpu
, enum kvm_bus bus_idx
, gpa_t addr
,
5532 struct kvm_io_bus
*bus
;
5533 struct kvm_io_range range
;
5536 range
= (struct kvm_io_range
) {
5541 bus
= srcu_dereference(vcpu
->kvm
->buses
[bus_idx
], &vcpu
->kvm
->srcu
);
5544 r
= __kvm_io_bus_read(vcpu
, bus
, &range
, val
);
5545 return r
< 0 ? r
: 0;
5548 /* Caller must hold slots_lock. */
5549 int kvm_io_bus_register_dev(struct kvm
*kvm
, enum kvm_bus bus_idx
, gpa_t addr
,
5550 int len
, struct kvm_io_device
*dev
)
5553 struct kvm_io_bus
*new_bus
, *bus
;
5554 struct kvm_io_range range
;
5556 bus
= kvm_get_bus(kvm
, bus_idx
);
5560 /* exclude ioeventfd which is limited by maximum fd */
5561 if (bus
->dev_count
- bus
->ioeventfd_count
> NR_IOBUS_DEVS
- 1)
5564 new_bus
= kmalloc(struct_size(bus
, range
, bus
->dev_count
+ 1),
5565 GFP_KERNEL_ACCOUNT
);
5569 range
= (struct kvm_io_range
) {
5575 for (i
= 0; i
< bus
->dev_count
; i
++)
5576 if (kvm_io_bus_cmp(&bus
->range
[i
], &range
) > 0)
5579 memcpy(new_bus
, bus
, sizeof(*bus
) + i
* sizeof(struct kvm_io_range
));
5580 new_bus
->dev_count
++;
5581 new_bus
->range
[i
] = range
;
5582 memcpy(new_bus
->range
+ i
+ 1, bus
->range
+ i
,
5583 (bus
->dev_count
- i
) * sizeof(struct kvm_io_range
));
5584 rcu_assign_pointer(kvm
->buses
[bus_idx
], new_bus
);
5585 synchronize_srcu_expedited(&kvm
->srcu
);
5591 int kvm_io_bus_unregister_dev(struct kvm
*kvm
, enum kvm_bus bus_idx
,
5592 struct kvm_io_device
*dev
)
5595 struct kvm_io_bus
*new_bus
, *bus
;
5597 lockdep_assert_held(&kvm
->slots_lock
);
5599 bus
= kvm_get_bus(kvm
, bus_idx
);
5603 for (i
= 0; i
< bus
->dev_count
; i
++) {
5604 if (bus
->range
[i
].dev
== dev
) {
5609 if (i
== bus
->dev_count
)
5612 new_bus
= kmalloc(struct_size(bus
, range
, bus
->dev_count
- 1),
5613 GFP_KERNEL_ACCOUNT
);
5615 memcpy(new_bus
, bus
, struct_size(bus
, range
, i
));
5616 new_bus
->dev_count
--;
5617 memcpy(new_bus
->range
+ i
, bus
->range
+ i
+ 1,
5618 flex_array_size(new_bus
, range
, new_bus
->dev_count
- i
));
5621 rcu_assign_pointer(kvm
->buses
[bus_idx
], new_bus
);
5622 synchronize_srcu_expedited(&kvm
->srcu
);
5625 * If NULL bus is installed, destroy the old bus, including all the
5626 * attached devices. Otherwise, destroy the caller's device only.
5629 pr_err("kvm: failed to shrink bus, removing it completely\n");
5630 kvm_io_bus_destroy(bus
);
5634 kvm_iodevice_destructor(dev
);
5639 struct kvm_io_device
*kvm_io_bus_get_dev(struct kvm
*kvm
, enum kvm_bus bus_idx
,
5642 struct kvm_io_bus
*bus
;
5643 int dev_idx
, srcu_idx
;
5644 struct kvm_io_device
*iodev
= NULL
;
5646 srcu_idx
= srcu_read_lock(&kvm
->srcu
);
5648 bus
= srcu_dereference(kvm
->buses
[bus_idx
], &kvm
->srcu
);
5652 dev_idx
= kvm_io_bus_get_first_dev(bus
, addr
, 1);
5656 iodev
= bus
->range
[dev_idx
].dev
;
5659 srcu_read_unlock(&kvm
->srcu
, srcu_idx
);
5663 EXPORT_SYMBOL_GPL(kvm_io_bus_get_dev
);
5665 static int kvm_debugfs_open(struct inode
*inode
, struct file
*file
,
5666 int (*get
)(void *, u64
*), int (*set
)(void *, u64
),
5670 struct kvm_stat_data
*stat_data
= inode
->i_private
;
5673 * The debugfs files are a reference to the kvm struct which
5674 * is still valid when kvm_destroy_vm is called. kvm_get_kvm_safe
5675 * avoids the race between open and the removal of the debugfs directory.
5677 if (!kvm_get_kvm_safe(stat_data
->kvm
))
5680 ret
= simple_attr_open(inode
, file
, get
,
5681 kvm_stats_debugfs_mode(stat_data
->desc
) & 0222
5684 kvm_put_kvm(stat_data
->kvm
);
5689 static int kvm_debugfs_release(struct inode
*inode
, struct file
*file
)
5691 struct kvm_stat_data
*stat_data
= inode
->i_private
;
5693 simple_attr_release(inode
, file
);
5694 kvm_put_kvm(stat_data
->kvm
);
5699 static int kvm_get_stat_per_vm(struct kvm
*kvm
, size_t offset
, u64
*val
)
5701 *val
= *(u64
*)((void *)(&kvm
->stat
) + offset
);
5706 static int kvm_clear_stat_per_vm(struct kvm
*kvm
, size_t offset
)
5708 *(u64
*)((void *)(&kvm
->stat
) + offset
) = 0;
5713 static int kvm_get_stat_per_vcpu(struct kvm
*kvm
, size_t offset
, u64
*val
)
5716 struct kvm_vcpu
*vcpu
;
5720 kvm_for_each_vcpu(i
, vcpu
, kvm
)
5721 *val
+= *(u64
*)((void *)(&vcpu
->stat
) + offset
);
5726 static int kvm_clear_stat_per_vcpu(struct kvm
*kvm
, size_t offset
)
5729 struct kvm_vcpu
*vcpu
;
5731 kvm_for_each_vcpu(i
, vcpu
, kvm
)
5732 *(u64
*)((void *)(&vcpu
->stat
) + offset
) = 0;
5737 static int kvm_stat_data_get(void *data
, u64
*val
)
5740 struct kvm_stat_data
*stat_data
= data
;
5742 switch (stat_data
->kind
) {
5744 r
= kvm_get_stat_per_vm(stat_data
->kvm
,
5745 stat_data
->desc
->desc
.offset
, val
);
5748 r
= kvm_get_stat_per_vcpu(stat_data
->kvm
,
5749 stat_data
->desc
->desc
.offset
, val
);
5756 static int kvm_stat_data_clear(void *data
, u64 val
)
5759 struct kvm_stat_data
*stat_data
= data
;
5764 switch (stat_data
->kind
) {
5766 r
= kvm_clear_stat_per_vm(stat_data
->kvm
,
5767 stat_data
->desc
->desc
.offset
);
5770 r
= kvm_clear_stat_per_vcpu(stat_data
->kvm
,
5771 stat_data
->desc
->desc
.offset
);
5778 static int kvm_stat_data_open(struct inode
*inode
, struct file
*file
)
5780 __simple_attr_check_format("%llu\n", 0ull);
5781 return kvm_debugfs_open(inode
, file
, kvm_stat_data_get
,
5782 kvm_stat_data_clear
, "%llu\n");
5785 static const struct file_operations stat_fops_per_vm
= {
5786 .owner
= THIS_MODULE
,
5787 .open
= kvm_stat_data_open
,
5788 .release
= kvm_debugfs_release
,
5789 .read
= simple_attr_read
,
5790 .write
= simple_attr_write
,
5791 .llseek
= no_llseek
,
5794 static int vm_stat_get(void *_offset
, u64
*val
)
5796 unsigned offset
= (long)_offset
;
5801 mutex_lock(&kvm_lock
);
5802 list_for_each_entry(kvm
, &vm_list
, vm_list
) {
5803 kvm_get_stat_per_vm(kvm
, offset
, &tmp_val
);
5806 mutex_unlock(&kvm_lock
);
5810 static int vm_stat_clear(void *_offset
, u64 val
)
5812 unsigned offset
= (long)_offset
;
5818 mutex_lock(&kvm_lock
);
5819 list_for_each_entry(kvm
, &vm_list
, vm_list
) {
5820 kvm_clear_stat_per_vm(kvm
, offset
);
5822 mutex_unlock(&kvm_lock
);
5827 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops
, vm_stat_get
, vm_stat_clear
, "%llu\n");
5828 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_readonly_fops
, vm_stat_get
, NULL
, "%llu\n");
5830 static int vcpu_stat_get(void *_offset
, u64
*val
)
5832 unsigned offset
= (long)_offset
;
5837 mutex_lock(&kvm_lock
);
5838 list_for_each_entry(kvm
, &vm_list
, vm_list
) {
5839 kvm_get_stat_per_vcpu(kvm
, offset
, &tmp_val
);
5842 mutex_unlock(&kvm_lock
);
5846 static int vcpu_stat_clear(void *_offset
, u64 val
)
5848 unsigned offset
= (long)_offset
;
5854 mutex_lock(&kvm_lock
);
5855 list_for_each_entry(kvm
, &vm_list
, vm_list
) {
5856 kvm_clear_stat_per_vcpu(kvm
, offset
);
5858 mutex_unlock(&kvm_lock
);
5863 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops
, vcpu_stat_get
, vcpu_stat_clear
,
5865 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_readonly_fops
, vcpu_stat_get
, NULL
, "%llu\n");
5867 static void kvm_uevent_notify_change(unsigned int type
, struct kvm
*kvm
)
5869 struct kobj_uevent_env
*env
;
5870 unsigned long long created
, active
;
5872 if (!kvm_dev
.this_device
|| !kvm
)
5875 mutex_lock(&kvm_lock
);
5876 if (type
== KVM_EVENT_CREATE_VM
) {
5877 kvm_createvm_count
++;
5879 } else if (type
== KVM_EVENT_DESTROY_VM
) {
5882 created
= kvm_createvm_count
;
5883 active
= kvm_active_vms
;
5884 mutex_unlock(&kvm_lock
);
5886 env
= kzalloc(sizeof(*env
), GFP_KERNEL_ACCOUNT
);
5890 add_uevent_var(env
, "CREATED=%llu", created
);
5891 add_uevent_var(env
, "COUNT=%llu", active
);
5893 if (type
== KVM_EVENT_CREATE_VM
) {
5894 add_uevent_var(env
, "EVENT=create");
5895 kvm
->userspace_pid
= task_pid_nr(current
);
5896 } else if (type
== KVM_EVENT_DESTROY_VM
) {
5897 add_uevent_var(env
, "EVENT=destroy");
5899 add_uevent_var(env
, "PID=%d", kvm
->userspace_pid
);
5901 if (!IS_ERR(kvm
->debugfs_dentry
)) {
5902 char *tmp
, *p
= kmalloc(PATH_MAX
, GFP_KERNEL_ACCOUNT
);
5905 tmp
= dentry_path_raw(kvm
->debugfs_dentry
, p
, PATH_MAX
);
5907 add_uevent_var(env
, "STATS_PATH=%s", tmp
);
5911 /* no need for checks, since we are adding at most only 5 keys */
5912 env
->envp
[env
->envp_idx
++] = NULL
;
5913 kobject_uevent_env(&kvm_dev
.this_device
->kobj
, KOBJ_CHANGE
, env
->envp
);
5917 static void kvm_init_debug(void)
5919 const struct file_operations
*fops
;
5920 const struct _kvm_stats_desc
*pdesc
;
5923 kvm_debugfs_dir
= debugfs_create_dir("kvm", NULL
);
5925 for (i
= 0; i
< kvm_vm_stats_header
.num_desc
; ++i
) {
5926 pdesc
= &kvm_vm_stats_desc
[i
];
5927 if (kvm_stats_debugfs_mode(pdesc
) & 0222)
5928 fops
= &vm_stat_fops
;
5930 fops
= &vm_stat_readonly_fops
;
5931 debugfs_create_file(pdesc
->name
, kvm_stats_debugfs_mode(pdesc
),
5933 (void *)(long)pdesc
->desc
.offset
, fops
);
5936 for (i
= 0; i
< kvm_vcpu_stats_header
.num_desc
; ++i
) {
5937 pdesc
= &kvm_vcpu_stats_desc
[i
];
5938 if (kvm_stats_debugfs_mode(pdesc
) & 0222)
5939 fops
= &vcpu_stat_fops
;
5941 fops
= &vcpu_stat_readonly_fops
;
5942 debugfs_create_file(pdesc
->name
, kvm_stats_debugfs_mode(pdesc
),
5944 (void *)(long)pdesc
->desc
.offset
, fops
);
5949 struct kvm_vcpu
*preempt_notifier_to_vcpu(struct preempt_notifier
*pn
)
5951 return container_of(pn
, struct kvm_vcpu
, preempt_notifier
);
5954 static void kvm_sched_in(struct preempt_notifier
*pn
, int cpu
)
5956 struct kvm_vcpu
*vcpu
= preempt_notifier_to_vcpu(pn
);
5958 WRITE_ONCE(vcpu
->preempted
, false);
5959 WRITE_ONCE(vcpu
->ready
, false);
5961 __this_cpu_write(kvm_running_vcpu
, vcpu
);
5962 kvm_arch_sched_in(vcpu
, cpu
);
5963 kvm_arch_vcpu_load(vcpu
, cpu
);
5966 static void kvm_sched_out(struct preempt_notifier
*pn
,
5967 struct task_struct
*next
)
5969 struct kvm_vcpu
*vcpu
= preempt_notifier_to_vcpu(pn
);
5971 if (current
->on_rq
) {
5972 WRITE_ONCE(vcpu
->preempted
, true);
5973 WRITE_ONCE(vcpu
->ready
, true);
5975 kvm_arch_vcpu_put(vcpu
);
5976 __this_cpu_write(kvm_running_vcpu
, NULL
);
5980 * kvm_get_running_vcpu - get the vcpu running on the current CPU.
5982 * We can disable preemption locally around accessing the per-CPU variable,
5983 * and use the resolved vcpu pointer after enabling preemption again,
5984 * because even if the current thread is migrated to another CPU, reading
5985 * the per-CPU value later will give us the same value as we update the
5986 * per-CPU variable in the preempt notifier handlers.
5988 struct kvm_vcpu
*kvm_get_running_vcpu(void)
5990 struct kvm_vcpu
*vcpu
;
5993 vcpu
= __this_cpu_read(kvm_running_vcpu
);
5998 EXPORT_SYMBOL_GPL(kvm_get_running_vcpu
);
6001 * kvm_get_running_vcpus - get the per-CPU array of currently running vcpus.
6003 struct kvm_vcpu
* __percpu
*kvm_get_running_vcpus(void)
6005 return &kvm_running_vcpu
;
6008 #ifdef CONFIG_GUEST_PERF_EVENTS
6009 static unsigned int kvm_guest_state(void)
6011 struct kvm_vcpu
*vcpu
= kvm_get_running_vcpu();
6014 if (!kvm_arch_pmi_in_guest(vcpu
))
6017 state
= PERF_GUEST_ACTIVE
;
6018 if (!kvm_arch_vcpu_in_kernel(vcpu
))
6019 state
|= PERF_GUEST_USER
;
6024 static unsigned long kvm_guest_get_ip(void)
6026 struct kvm_vcpu
*vcpu
= kvm_get_running_vcpu();
6028 /* Retrieving the IP must be guarded by a call to kvm_guest_state(). */
6029 if (WARN_ON_ONCE(!kvm_arch_pmi_in_guest(vcpu
)))
6032 return kvm_arch_vcpu_get_ip(vcpu
);
6035 static struct perf_guest_info_callbacks kvm_guest_cbs
= {
6036 .state
= kvm_guest_state
,
6037 .get_ip
= kvm_guest_get_ip
,
6038 .handle_intel_pt_intr
= NULL
,
6041 void kvm_register_perf_callbacks(unsigned int (*pt_intr_handler
)(void))
6043 kvm_guest_cbs
.handle_intel_pt_intr
= pt_intr_handler
;
6044 perf_register_guest_info_callbacks(&kvm_guest_cbs
);
6046 void kvm_unregister_perf_callbacks(void)
6048 perf_unregister_guest_info_callbacks(&kvm_guest_cbs
);
6052 int kvm_init(unsigned vcpu_size
, unsigned vcpu_align
, struct module
*module
)
6057 #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
6058 r
= cpuhp_setup_state_nocalls(CPUHP_AP_KVM_ONLINE
, "kvm/cpu:online",
6059 kvm_online_cpu
, kvm_offline_cpu
);
6063 register_syscore_ops(&kvm_syscore_ops
);
6066 /* A kmem cache lets us meet the alignment requirements of fx_save. */
6068 vcpu_align
= __alignof__(struct kvm_vcpu
);
6070 kmem_cache_create_usercopy("kvm_vcpu", vcpu_size
, vcpu_align
,
6072 offsetof(struct kvm_vcpu
, arch
),
6073 offsetofend(struct kvm_vcpu
, stats_id
)
6074 - offsetof(struct kvm_vcpu
, arch
),
6076 if (!kvm_vcpu_cache
) {
6078 goto err_vcpu_cache
;
6081 for_each_possible_cpu(cpu
) {
6082 if (!alloc_cpumask_var_node(&per_cpu(cpu_kick_mask
, cpu
),
6083 GFP_KERNEL
, cpu_to_node(cpu
))) {
6085 goto err_cpu_kick_mask
;
6089 r
= kvm_irqfd_init();
6093 r
= kvm_async_pf_init();
6097 kvm_chardev_ops
.owner
= module
;
6099 kvm_preempt_ops
.sched_in
= kvm_sched_in
;
6100 kvm_preempt_ops
.sched_out
= kvm_sched_out
;
6104 r
= kvm_vfio_ops_init();
6105 if (WARN_ON_ONCE(r
))
6109 * Registration _must_ be the very last thing done, as this exposes
6110 * /dev/kvm to userspace, i.e. all infrastructure must be setup!
6112 r
= misc_register(&kvm_dev
);
6114 pr_err("kvm: misc device register failed\n");
6121 kvm_vfio_ops_exit();
6123 kvm_async_pf_deinit();
6128 for_each_possible_cpu(cpu
)
6129 free_cpumask_var(per_cpu(cpu_kick_mask
, cpu
));
6130 kmem_cache_destroy(kvm_vcpu_cache
);
6132 #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
6133 unregister_syscore_ops(&kvm_syscore_ops
);
6134 cpuhp_remove_state_nocalls(CPUHP_AP_KVM_ONLINE
);
6138 EXPORT_SYMBOL_GPL(kvm_init
);
6145 * Note, unregistering /dev/kvm doesn't strictly need to come first,
6146 * fops_get(), a.k.a. try_module_get(), prevents acquiring references
6147 * to KVM while the module is being stopped.
6149 misc_deregister(&kvm_dev
);
6151 debugfs_remove_recursive(kvm_debugfs_dir
);
6152 for_each_possible_cpu(cpu
)
6153 free_cpumask_var(per_cpu(cpu_kick_mask
, cpu
));
6154 kmem_cache_destroy(kvm_vcpu_cache
);
6155 kvm_vfio_ops_exit();
6156 kvm_async_pf_deinit();
6157 #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
6158 unregister_syscore_ops(&kvm_syscore_ops
);
6159 cpuhp_remove_state_nocalls(CPUHP_AP_KVM_ONLINE
);
6163 EXPORT_SYMBOL_GPL(kvm_exit
);
6165 struct kvm_vm_worker_thread_context
{
6167 struct task_struct
*parent
;
6168 struct completion init_done
;
6169 kvm_vm_thread_fn_t thread_fn
;
6174 static int kvm_vm_worker_thread(void *context
)
6177 * The init_context is allocated on the stack of the parent thread, so
6178 * we have to locally copy anything that is needed beyond initialization
6180 struct kvm_vm_worker_thread_context
*init_context
= context
;
6181 struct task_struct
*parent
;
6182 struct kvm
*kvm
= init_context
->kvm
;
6183 kvm_vm_thread_fn_t thread_fn
= init_context
->thread_fn
;
6184 uintptr_t data
= init_context
->data
;
6187 err
= kthread_park(current
);
6188 /* kthread_park(current) is never supposed to return an error */
6193 err
= cgroup_attach_task_all(init_context
->parent
, current
);
6195 kvm_err("%s: cgroup_attach_task_all failed with err %d\n",
6200 set_user_nice(current
, task_nice(init_context
->parent
));
6203 init_context
->err
= err
;
6204 complete(&init_context
->init_done
);
6205 init_context
= NULL
;
6210 /* Wait to be woken up by the spawner before proceeding. */
6213 if (!kthread_should_stop())
6214 err
= thread_fn(kvm
, data
);
6218 * Move kthread back to its original cgroup to prevent it lingering in
6219 * the cgroup of the VM process, after the latter finishes its
6222 * kthread_stop() waits on the 'exited' completion condition which is
6223 * set in exit_mm(), via mm_release(), in do_exit(). However, the
6224 * kthread is removed from the cgroup in the cgroup_exit() which is
6225 * called after the exit_mm(). This causes the kthread_stop() to return
6226 * before the kthread actually quits the cgroup.
6229 parent
= rcu_dereference(current
->real_parent
);
6230 get_task_struct(parent
);
6232 cgroup_attach_task_all(parent
, current
);
6233 put_task_struct(parent
);
6238 int kvm_vm_create_worker_thread(struct kvm
*kvm
, kvm_vm_thread_fn_t thread_fn
,
6239 uintptr_t data
, const char *name
,
6240 struct task_struct
**thread_ptr
)
6242 struct kvm_vm_worker_thread_context init_context
= {};
6243 struct task_struct
*thread
;
6246 init_context
.kvm
= kvm
;
6247 init_context
.parent
= current
;
6248 init_context
.thread_fn
= thread_fn
;
6249 init_context
.data
= data
;
6250 init_completion(&init_context
.init_done
);
6252 thread
= kthread_run(kvm_vm_worker_thread
, &init_context
,
6253 "%s-%d", name
, task_pid_nr(current
));
6255 return PTR_ERR(thread
);
6257 /* kthread_run is never supposed to return NULL */
6258 WARN_ON(thread
== NULL
);
6260 wait_for_completion(&init_context
.init_done
);
6262 if (!init_context
.err
)
6263 *thread_ptr
= thread
;
6265 return init_context
.err
;