2 * kvm eventfd support - use eventfd objects to signal various KVM events
4 * Copyright 2009 Novell. All Rights Reserved.
5 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
8 * Gregory Haskins <ghaskins@novell.com>
10 * This file is free software; you can redistribute it and/or modify
11 * it under the terms of version 2 of the GNU General Public License
12 * as published by the Free Software Foundation.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
24 #include <linux/kvm_host.h>
25 #include <linux/kvm.h>
26 #include <linux/workqueue.h>
27 #include <linux/syscalls.h>
28 #include <linux/wait.h>
29 #include <linux/poll.h>
30 #include <linux/file.h>
31 #include <linux/list.h>
32 #include <linux/eventfd.h>
33 #include <linux/kernel.h>
34 #include <linux/srcu.h>
35 #include <linux/slab.h>
36 #include <linux/seqlock.h>
37 #include <trace/events/kvm.h>
42 #ifdef CONFIG_HAVE_KVM_IRQFD
44 * --------------------------------------------------------------------
45 * irqfd: Allows an fd to be used to inject an interrupt to the guest
47 * Credit goes to Avi Kivity for the original idea.
48 * --------------------------------------------------------------------
52 * Resampling irqfds are a special variety of irqfds used to emulate
53 * level triggered interrupts. The interrupt is asserted on eventfd
54 * trigger. On acknowledgement through the irq ack notifier, the
55 * interrupt is de-asserted and userspace is notified through the
56 * resamplefd. All resamplers on the same gsi are de-asserted
57 * together, so we don't need to track the state of each individual
58 * user. We can also therefore share the same irq source ID.
60 struct _irqfd_resampler {
63 * List of resampling struct _irqfd objects sharing this gsi.
64 * RCU list modified under kvm->irqfds.resampler_lock
66 struct list_head list;
67 struct kvm_irq_ack_notifier notifier;
69 * Entry in list of kvm->irqfd.resampler_list. Use for sharing
70 * resamplers among irqfds on the same gsi.
71 * Accessed and modified under kvm->irqfds.resampler_lock
73 struct list_head link;
77 /* Used for MSI fast-path */
80 /* Update side is protected by irqfds.lock */
81 struct kvm_kernel_irq_routing_entry irq_entry;
82 seqcount_t irq_entry_sc;
83 /* Used for level IRQ fast-path */
85 struct work_struct inject;
86 /* The resampler used by this irqfd (resampler-only) */
87 struct _irqfd_resampler *resampler;
88 /* Eventfd notified on resample (resampler-only) */
89 struct eventfd_ctx *resamplefd;
90 /* Entry in list of irqfds for a resampler (resampler-only) */
91 struct list_head resampler_link;
92 /* Used for setup/shutdown */
93 struct eventfd_ctx *eventfd;
94 struct list_head list;
96 struct work_struct shutdown;
99 static struct workqueue_struct *irqfd_cleanup_wq;
102 irqfd_inject(struct work_struct *work)
104 struct _irqfd *irqfd = container_of(work, struct _irqfd, inject);
105 struct kvm *kvm = irqfd->kvm;
107 if (!irqfd->resampler) {
108 kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, irqfd->gsi, 1,
110 kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, irqfd->gsi, 0,
113 kvm_set_irq(kvm, KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID,
114 irqfd->gsi, 1, false);
118 * Since resampler irqfds share an IRQ source ID, we de-assert once
119 * then notify all of the resampler irqfds using this GSI. We can't
120 * do multiple de-asserts or we risk racing with incoming re-asserts.
123 irqfd_resampler_ack(struct kvm_irq_ack_notifier *kian)
125 struct _irqfd_resampler *resampler;
127 struct _irqfd *irqfd;
130 resampler = container_of(kian, struct _irqfd_resampler, notifier);
131 kvm = resampler->kvm;
133 kvm_set_irq(kvm, KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID,
134 resampler->notifier.gsi, 0, false);
136 idx = srcu_read_lock(&kvm->irq_srcu);
138 list_for_each_entry_rcu(irqfd, &resampler->list, resampler_link)
139 eventfd_signal(irqfd->resamplefd, 1);
141 srcu_read_unlock(&kvm->irq_srcu, idx);
145 irqfd_resampler_shutdown(struct _irqfd *irqfd)
147 struct _irqfd_resampler *resampler = irqfd->resampler;
148 struct kvm *kvm = resampler->kvm;
150 mutex_lock(&kvm->irqfds.resampler_lock);
152 list_del_rcu(&irqfd->resampler_link);
153 synchronize_srcu(&kvm->irq_srcu);
155 if (list_empty(&resampler->list)) {
156 list_del(&resampler->link);
157 kvm_unregister_irq_ack_notifier(kvm, &resampler->notifier);
158 kvm_set_irq(kvm, KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID,
159 resampler->notifier.gsi, 0, false);
163 mutex_unlock(&kvm->irqfds.resampler_lock);
167 * Race-free decouple logic (ordering is critical)
170 irqfd_shutdown(struct work_struct *work)
172 struct _irqfd *irqfd = container_of(work, struct _irqfd, shutdown);
176 * Synchronize with the wait-queue and unhook ourselves to prevent
179 eventfd_ctx_remove_wait_queue(irqfd->eventfd, &irqfd->wait, &cnt);
182 * We know no new events will be scheduled at this point, so block
183 * until all previously outstanding events have completed
185 flush_work(&irqfd->inject);
187 if (irqfd->resampler) {
188 irqfd_resampler_shutdown(irqfd);
189 eventfd_ctx_put(irqfd->resamplefd);
193 * It is now safe to release the object's resources
195 eventfd_ctx_put(irqfd->eventfd);
200 /* assumes kvm->irqfds.lock is held */
202 irqfd_is_active(struct _irqfd *irqfd)
204 return list_empty(&irqfd->list) ? false : true;
208 * Mark the irqfd as inactive and schedule it for removal
210 * assumes kvm->irqfds.lock is held
213 irqfd_deactivate(struct _irqfd *irqfd)
215 BUG_ON(!irqfd_is_active(irqfd));
217 list_del_init(&irqfd->list);
219 queue_work(irqfd_cleanup_wq, &irqfd->shutdown);
223 * Called with wqh->lock held and interrupts disabled
226 irqfd_wakeup(wait_queue_t *wait, unsigned mode, int sync, void *key)
228 struct _irqfd *irqfd = container_of(wait, struct _irqfd, wait);
229 unsigned long flags = (unsigned long)key;
230 struct kvm_kernel_irq_routing_entry irq;
231 struct kvm *kvm = irqfd->kvm;
235 if (flags & POLLIN) {
236 idx = srcu_read_lock(&kvm->irq_srcu);
238 seq = read_seqcount_begin(&irqfd->irq_entry_sc);
239 irq = irqfd->irq_entry;
240 } while (read_seqcount_retry(&irqfd->irq_entry_sc, seq));
241 /* An event has been signaled, inject an interrupt */
242 if (irq.type == KVM_IRQ_ROUTING_MSI)
243 kvm_set_msi(&irq, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1,
246 schedule_work(&irqfd->inject);
247 srcu_read_unlock(&kvm->irq_srcu, idx);
250 if (flags & POLLHUP) {
251 /* The eventfd is closing, detach from KVM */
254 spin_lock_irqsave(&kvm->irqfds.lock, flags);
257 * We must check if someone deactivated the irqfd before
258 * we could acquire the irqfds.lock since the item is
259 * deactivated from the KVM side before it is unhooked from
260 * the wait-queue. If it is already deactivated, we can
261 * simply return knowing the other side will cleanup for us.
262 * We cannot race against the irqfd going away since the
263 * other side is required to acquire wqh->lock, which we hold
265 if (irqfd_is_active(irqfd))
266 irqfd_deactivate(irqfd);
268 spin_unlock_irqrestore(&kvm->irqfds.lock, flags);
275 irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh,
278 struct _irqfd *irqfd = container_of(pt, struct _irqfd, pt);
279 add_wait_queue(wqh, &irqfd->wait);
282 /* Must be called under irqfds.lock */
283 static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd)
285 struct kvm_kernel_irq_routing_entry *e;
286 struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS];
289 n_entries = kvm_irq_map_gsi(kvm, entries, irqfd->gsi);
291 write_seqcount_begin(&irqfd->irq_entry_sc);
293 irqfd->irq_entry.type = 0;
296 for (i = 0; i < n_entries; ++i, ++e) {
297 /* Only fast-path MSI. */
298 if (e->type == KVM_IRQ_ROUTING_MSI)
299 irqfd->irq_entry = *e;
302 write_seqcount_end(&irqfd->irq_entry_sc);
306 kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
308 struct _irqfd *irqfd, *tmp;
310 struct eventfd_ctx *eventfd = NULL, *resamplefd = NULL;
315 irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL);
320 irqfd->gsi = args->gsi;
321 INIT_LIST_HEAD(&irqfd->list);
322 INIT_WORK(&irqfd->inject, irqfd_inject);
323 INIT_WORK(&irqfd->shutdown, irqfd_shutdown);
324 seqcount_init(&irqfd->irq_entry_sc);
332 eventfd = eventfd_ctx_fileget(f.file);
333 if (IS_ERR(eventfd)) {
334 ret = PTR_ERR(eventfd);
338 irqfd->eventfd = eventfd;
340 if (args->flags & KVM_IRQFD_FLAG_RESAMPLE) {
341 struct _irqfd_resampler *resampler;
343 resamplefd = eventfd_ctx_fdget(args->resamplefd);
344 if (IS_ERR(resamplefd)) {
345 ret = PTR_ERR(resamplefd);
349 irqfd->resamplefd = resamplefd;
350 INIT_LIST_HEAD(&irqfd->resampler_link);
352 mutex_lock(&kvm->irqfds.resampler_lock);
354 list_for_each_entry(resampler,
355 &kvm->irqfds.resampler_list, link) {
356 if (resampler->notifier.gsi == irqfd->gsi) {
357 irqfd->resampler = resampler;
362 if (!irqfd->resampler) {
363 resampler = kzalloc(sizeof(*resampler), GFP_KERNEL);
366 mutex_unlock(&kvm->irqfds.resampler_lock);
370 resampler->kvm = kvm;
371 INIT_LIST_HEAD(&resampler->list);
372 resampler->notifier.gsi = irqfd->gsi;
373 resampler->notifier.irq_acked = irqfd_resampler_ack;
374 INIT_LIST_HEAD(&resampler->link);
376 list_add(&resampler->link, &kvm->irqfds.resampler_list);
377 kvm_register_irq_ack_notifier(kvm,
378 &resampler->notifier);
379 irqfd->resampler = resampler;
382 list_add_rcu(&irqfd->resampler_link, &irqfd->resampler->list);
383 synchronize_srcu(&kvm->irq_srcu);
385 mutex_unlock(&kvm->irqfds.resampler_lock);
389 * Install our own custom wake-up handling so we are notified via
390 * a callback whenever someone signals the underlying eventfd
392 init_waitqueue_func_entry(&irqfd->wait, irqfd_wakeup);
393 init_poll_funcptr(&irqfd->pt, irqfd_ptable_queue_proc);
395 spin_lock_irq(&kvm->irqfds.lock);
398 list_for_each_entry(tmp, &kvm->irqfds.items, list) {
399 if (irqfd->eventfd != tmp->eventfd)
401 /* This fd is used for another irq already. */
403 spin_unlock_irq(&kvm->irqfds.lock);
407 idx = srcu_read_lock(&kvm->irq_srcu);
408 irqfd_update(kvm, irqfd);
409 srcu_read_unlock(&kvm->irq_srcu, idx);
411 list_add_tail(&irqfd->list, &kvm->irqfds.items);
413 spin_unlock_irq(&kvm->irqfds.lock);
416 * Check if there was an event already pending on the eventfd
417 * before we registered, and trigger it as if we didn't miss it.
419 events = f.file->f_op->poll(f.file, &irqfd->pt);
422 schedule_work(&irqfd->inject);
425 * do not drop the file until the irqfd is fully initialized, otherwise
426 * we might race against the POLLHUP
433 if (irqfd->resampler)
434 irqfd_resampler_shutdown(irqfd);
436 if (resamplefd && !IS_ERR(resamplefd))
437 eventfd_ctx_put(resamplefd);
439 if (eventfd && !IS_ERR(eventfd))
440 eventfd_ctx_put(eventfd);
451 kvm_eventfd_init(struct kvm *kvm)
453 #ifdef CONFIG_HAVE_KVM_IRQFD
454 spin_lock_init(&kvm->irqfds.lock);
455 INIT_LIST_HEAD(&kvm->irqfds.items);
456 INIT_LIST_HEAD(&kvm->irqfds.resampler_list);
457 mutex_init(&kvm->irqfds.resampler_lock);
459 INIT_LIST_HEAD(&kvm->ioeventfds);
462 #ifdef CONFIG_HAVE_KVM_IRQFD
464 * shutdown any irqfd's that match fd+gsi
467 kvm_irqfd_deassign(struct kvm *kvm, struct kvm_irqfd *args)
469 struct _irqfd *irqfd, *tmp;
470 struct eventfd_ctx *eventfd;
472 eventfd = eventfd_ctx_fdget(args->fd);
474 return PTR_ERR(eventfd);
476 spin_lock_irq(&kvm->irqfds.lock);
478 list_for_each_entry_safe(irqfd, tmp, &kvm->irqfds.items, list) {
479 if (irqfd->eventfd == eventfd && irqfd->gsi == args->gsi) {
481 * This clearing of irq_entry.type is needed for when
482 * another thread calls kvm_irq_routing_update before
483 * we flush workqueue below (we synchronize with
484 * kvm_irq_routing_update using irqfds.lock).
486 write_seqcount_begin(&irqfd->irq_entry_sc);
487 irqfd->irq_entry.type = 0;
488 write_seqcount_end(&irqfd->irq_entry_sc);
489 irqfd_deactivate(irqfd);
493 spin_unlock_irq(&kvm->irqfds.lock);
494 eventfd_ctx_put(eventfd);
497 * Block until we know all outstanding shutdown jobs have completed
498 * so that we guarantee there will not be any more interrupts on this
499 * gsi once this deassign function returns.
501 flush_workqueue(irqfd_cleanup_wq);
507 kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args)
509 if (args->flags & ~(KVM_IRQFD_FLAG_DEASSIGN | KVM_IRQFD_FLAG_RESAMPLE))
512 if (args->flags & KVM_IRQFD_FLAG_DEASSIGN)
513 return kvm_irqfd_deassign(kvm, args);
515 return kvm_irqfd_assign(kvm, args);
519 * This function is called as the kvm VM fd is being released. Shutdown all
520 * irqfds that still remain open
523 kvm_irqfd_release(struct kvm *kvm)
525 struct _irqfd *irqfd, *tmp;
527 spin_lock_irq(&kvm->irqfds.lock);
529 list_for_each_entry_safe(irqfd, tmp, &kvm->irqfds.items, list)
530 irqfd_deactivate(irqfd);
532 spin_unlock_irq(&kvm->irqfds.lock);
535 * Block until we know all outstanding shutdown jobs have completed
536 * since we do not take a kvm* reference.
538 flush_workqueue(irqfd_cleanup_wq);
543 * Take note of a change in irq routing.
544 * Caller must invoke synchronize_srcu(&kvm->irq_srcu) afterwards.
546 void kvm_irq_routing_update(struct kvm *kvm)
548 struct _irqfd *irqfd;
550 spin_lock_irq(&kvm->irqfds.lock);
552 list_for_each_entry(irqfd, &kvm->irqfds.items, list)
553 irqfd_update(kvm, irqfd);
555 spin_unlock_irq(&kvm->irqfds.lock);
559 * create a host-wide workqueue for issuing deferred shutdown requests
560 * aggregated from all vm* instances. We need our own isolated single-thread
561 * queue to prevent deadlock against flushing the normal work-queue.
563 int kvm_irqfd_init(void)
565 irqfd_cleanup_wq = create_singlethread_workqueue("kvm-irqfd-cleanup");
566 if (!irqfd_cleanup_wq)
572 void kvm_irqfd_exit(void)
574 destroy_workqueue(irqfd_cleanup_wq);
579 * --------------------------------------------------------------------
580 * ioeventfd: translate a PIO/MMIO memory write to an eventfd signal.
582 * userspace can register a PIO/MMIO address with an eventfd for receiving
583 * notification when the memory has been touched.
584 * --------------------------------------------------------------------
588 struct list_head list;
591 struct eventfd_ctx *eventfd;
593 struct kvm_io_device dev;
598 static inline struct _ioeventfd *
599 to_ioeventfd(struct kvm_io_device *dev)
601 return container_of(dev, struct _ioeventfd, dev);
605 ioeventfd_release(struct _ioeventfd *p)
607 eventfd_ctx_put(p->eventfd);
613 ioeventfd_in_range(struct _ioeventfd *p, gpa_t addr, int len, const void *val)
618 /* address must be precise for a hit */
622 /* length = 0 means only look at the address, so always a hit */
625 if (len != p->length)
626 /* address-range must be precise for a hit */
630 /* all else equal, wildcard is always a hit */
633 /* otherwise, we have to actually compare the data */
635 BUG_ON(!IS_ALIGNED((unsigned long)val, len));
654 return _val == p->datamatch ? true : false;
657 /* MMIO/PIO writes trigger an event if the addr/val match */
659 ioeventfd_write(struct kvm_io_device *this, gpa_t addr, int len,
662 struct _ioeventfd *p = to_ioeventfd(this);
664 if (!ioeventfd_in_range(p, addr, len, val))
667 eventfd_signal(p->eventfd, 1);
672 * This function is called as KVM is completely shutting down. We do not
673 * need to worry about locking just nuke anything we have as quickly as possible
676 ioeventfd_destructor(struct kvm_io_device *this)
678 struct _ioeventfd *p = to_ioeventfd(this);
680 ioeventfd_release(p);
683 static const struct kvm_io_device_ops ioeventfd_ops = {
684 .write = ioeventfd_write,
685 .destructor = ioeventfd_destructor,
688 /* assumes kvm->slots_lock held */
690 ioeventfd_check_collision(struct kvm *kvm, struct _ioeventfd *p)
692 struct _ioeventfd *_p;
694 list_for_each_entry(_p, &kvm->ioeventfds, list)
695 if (_p->bus_idx == p->bus_idx &&
696 _p->addr == p->addr &&
697 (!_p->length || !p->length ||
698 (_p->length == p->length &&
699 (_p->wildcard || p->wildcard ||
700 _p->datamatch == p->datamatch))))
706 static enum kvm_bus ioeventfd_bus_from_flags(__u32 flags)
708 if (flags & KVM_IOEVENTFD_FLAG_PIO)
710 if (flags & KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY)
711 return KVM_VIRTIO_CCW_NOTIFY_BUS;
716 kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
718 enum kvm_bus bus_idx;
719 struct _ioeventfd *p;
720 struct eventfd_ctx *eventfd;
723 bus_idx = ioeventfd_bus_from_flags(args->flags);
724 /* must be natural-word sized, or 0 to ignore length */
736 /* check for range overflow */
737 if (args->addr + args->len < args->addr)
740 /* check for extra flags that we don't understand */
741 if (args->flags & ~KVM_IOEVENTFD_VALID_FLAG_MASK)
744 /* ioeventfd with no length can't be combined with DATAMATCH */
746 args->flags & (KVM_IOEVENTFD_FLAG_PIO |
747 KVM_IOEVENTFD_FLAG_DATAMATCH))
750 eventfd = eventfd_ctx_fdget(args->fd);
752 return PTR_ERR(eventfd);
754 p = kzalloc(sizeof(*p), GFP_KERNEL);
760 INIT_LIST_HEAD(&p->list);
761 p->addr = args->addr;
762 p->bus_idx = bus_idx;
763 p->length = args->len;
764 p->eventfd = eventfd;
766 /* The datamatch feature is optional, otherwise this is a wildcard */
767 if (args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH)
768 p->datamatch = args->datamatch;
772 mutex_lock(&kvm->slots_lock);
774 /* Verify that there isn't a match already */
775 if (ioeventfd_check_collision(kvm, p)) {
780 kvm_iodevice_init(&p->dev, &ioeventfd_ops);
782 ret = kvm_io_bus_register_dev(kvm, bus_idx, p->addr, p->length,
787 /* When length is ignored, MMIO is also put on a separate bus, for
790 if (!args->len && !(args->flags & KVM_IOEVENTFD_FLAG_PIO)) {
791 ret = kvm_io_bus_register_dev(kvm, KVM_FAST_MMIO_BUS,
792 p->addr, 0, &p->dev);
797 kvm->buses[bus_idx]->ioeventfd_count++;
798 list_add_tail(&p->list, &kvm->ioeventfds);
800 mutex_unlock(&kvm->slots_lock);
805 kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev);
807 mutex_unlock(&kvm->slots_lock);
811 eventfd_ctx_put(eventfd);
817 kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
819 enum kvm_bus bus_idx;
820 struct _ioeventfd *p, *tmp;
821 struct eventfd_ctx *eventfd;
824 bus_idx = ioeventfd_bus_from_flags(args->flags);
825 eventfd = eventfd_ctx_fdget(args->fd);
827 return PTR_ERR(eventfd);
829 mutex_lock(&kvm->slots_lock);
831 list_for_each_entry_safe(p, tmp, &kvm->ioeventfds, list) {
832 bool wildcard = !(args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH);
834 if (p->bus_idx != bus_idx ||
835 p->eventfd != eventfd ||
836 p->addr != args->addr ||
837 p->length != args->len ||
838 p->wildcard != wildcard)
841 if (!p->wildcard && p->datamatch != args->datamatch)
844 kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev);
846 kvm_io_bus_unregister_dev(kvm, KVM_FAST_MMIO_BUS,
849 kvm->buses[bus_idx]->ioeventfd_count--;
850 ioeventfd_release(p);
855 mutex_unlock(&kvm->slots_lock);
857 eventfd_ctx_put(eventfd);
863 kvm_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
865 if (args->flags & KVM_IOEVENTFD_FLAG_DEASSIGN)
866 return kvm_deassign_ioeventfd(kvm, args);
868 return kvm_assign_ioeventfd(kvm, args);
871 bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin)
873 struct kvm_irq_ack_notifier *kian;
876 idx = srcu_read_lock(&kvm->irq_srcu);
877 gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
879 hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,
881 if (kian->gsi == gsi) {
882 srcu_read_unlock(&kvm->irq_srcu, idx);
886 srcu_read_unlock(&kvm->irq_srcu, idx);
890 EXPORT_SYMBOL_GPL(kvm_irq_has_notifier);
892 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
894 struct kvm_irq_ack_notifier *kian;
897 trace_kvm_ack_irq(irqchip, pin);
899 idx = srcu_read_lock(&kvm->irq_srcu);
900 gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
902 hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,
904 if (kian->gsi == gsi)
905 kian->irq_acked(kian);
906 srcu_read_unlock(&kvm->irq_srcu, idx);
909 void kvm_register_irq_ack_notifier(struct kvm *kvm,
910 struct kvm_irq_ack_notifier *kian)
912 mutex_lock(&kvm->irq_lock);
913 hlist_add_head_rcu(&kian->link, &kvm->irq_ack_notifier_list);
914 mutex_unlock(&kvm->irq_lock);
915 #ifdef __KVM_HAVE_IOAPIC
916 kvm_vcpu_request_scan_ioapic(kvm);
920 void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
921 struct kvm_irq_ack_notifier *kian)
923 mutex_lock(&kvm->irq_lock);
924 hlist_del_init_rcu(&kian->link);
925 mutex_unlock(&kvm->irq_lock);
926 synchronize_srcu(&kvm->irq_srcu);
927 #ifdef __KVM_HAVE_IOAPIC
928 kvm_vcpu_request_scan_ioapic(kvm);