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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>
38
39#include <kvm/iodev.h>
40
41#ifdef CONFIG_HAVE_KVM_IRQFD
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59struct _irqfd_resampler {
60 struct kvm *kvm;
61
62
63
64
65 struct list_head list;
66 struct kvm_irq_ack_notifier notifier;
67
68
69
70
71
72 struct list_head link;
73};
74
75struct _irqfd {
76
77 struct kvm *kvm;
78 wait_queue_t wait;
79
80 struct kvm_kernel_irq_routing_entry irq_entry;
81 seqcount_t irq_entry_sc;
82
83 int gsi;
84 struct work_struct inject;
85
86 struct _irqfd_resampler *resampler;
87
88 struct eventfd_ctx *resamplefd;
89
90 struct list_head resampler_link;
91
92 struct eventfd_ctx *eventfd;
93 struct list_head list;
94 poll_table pt;
95 struct work_struct shutdown;
96};
97
98static struct workqueue_struct *irqfd_cleanup_wq;
99
100static void
101irqfd_inject(struct work_struct *work)
102{
103 struct _irqfd *irqfd = container_of(work, struct _irqfd, inject);
104 struct kvm *kvm = irqfd->kvm;
105
106 if (!irqfd->resampler) {
107 kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, irqfd->gsi, 1,
108 false);
109 kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, irqfd->gsi, 0,
110 false);
111 } else
112 kvm_set_irq(kvm, KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID,
113 irqfd->gsi, 1, false);
114}
115
116
117
118
119
120
121static void
122irqfd_resampler_ack(struct kvm_irq_ack_notifier *kian)
123{
124 struct _irqfd_resampler *resampler;
125 struct kvm *kvm;
126 struct _irqfd *irqfd;
127 int idx;
128
129 resampler = container_of(kian, struct _irqfd_resampler, notifier);
130 kvm = resampler->kvm;
131
132 kvm_set_irq(kvm, KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID,
133 resampler->notifier.gsi, 0, false);
134
135 idx = srcu_read_lock(&kvm->irq_srcu);
136
137 list_for_each_entry_rcu(irqfd, &resampler->list, resampler_link)
138 eventfd_signal(irqfd->resamplefd, 1);
139
140 srcu_read_unlock(&kvm->irq_srcu, idx);
141}
142
143static void
144irqfd_resampler_shutdown(struct _irqfd *irqfd)
145{
146 struct _irqfd_resampler *resampler = irqfd->resampler;
147 struct kvm *kvm = resampler->kvm;
148
149 mutex_lock(&kvm->irqfds.resampler_lock);
150
151 list_del_rcu(&irqfd->resampler_link);
152 synchronize_srcu(&kvm->irq_srcu);
153
154 if (list_empty(&resampler->list)) {
155 list_del(&resampler->link);
156 kvm_unregister_irq_ack_notifier(kvm, &resampler->notifier);
157 kvm_set_irq(kvm, KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID,
158 resampler->notifier.gsi, 0, false);
159 kfree(resampler);
160 }
161
162 mutex_unlock(&kvm->irqfds.resampler_lock);
163}
164
165
166
167
168static void
169irqfd_shutdown(struct work_struct *work)
170{
171 struct _irqfd *irqfd = container_of(work, struct _irqfd, shutdown);
172 u64 cnt;
173
174
175
176
177
178 eventfd_ctx_remove_wait_queue(irqfd->eventfd, &irqfd->wait, &cnt);
179
180
181
182
183
184 flush_work(&irqfd->inject);
185
186 if (irqfd->resampler) {
187 irqfd_resampler_shutdown(irqfd);
188 eventfd_ctx_put(irqfd->resamplefd);
189 }
190
191
192
193
194 eventfd_ctx_put(irqfd->eventfd);
195 kfree(irqfd);
196}
197
198
199
200static bool
201irqfd_is_active(struct _irqfd *irqfd)
202{
203 return list_empty(&irqfd->list) ? false : true;
204}
205
206
207
208
209
210
211static void
212irqfd_deactivate(struct _irqfd *irqfd)
213{
214 BUG_ON(!irqfd_is_active(irqfd));
215
216 list_del_init(&irqfd->list);
217
218 queue_work(irqfd_cleanup_wq, &irqfd->shutdown);
219}
220
221
222
223
224static int
225irqfd_wakeup(wait_queue_t *wait, unsigned mode, int sync, void *key)
226{
227 struct _irqfd *irqfd = container_of(wait, struct _irqfd, wait);
228 unsigned long flags = (unsigned long)key;
229 struct kvm_kernel_irq_routing_entry irq;
230 struct kvm *kvm = irqfd->kvm;
231 unsigned seq;
232 int idx;
233
234 if (flags & POLLIN) {
235 idx = srcu_read_lock(&kvm->irq_srcu);
236 do {
237 seq = read_seqcount_begin(&irqfd->irq_entry_sc);
238 irq = irqfd->irq_entry;
239 } while (read_seqcount_retry(&irqfd->irq_entry_sc, seq));
240
241 if (irq.type == KVM_IRQ_ROUTING_MSI)
242 kvm_set_msi(&irq, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1,
243 false);
244 else
245 schedule_work(&irqfd->inject);
246 srcu_read_unlock(&kvm->irq_srcu, idx);
247 }
248
249 if (flags & POLLHUP) {
250
251 unsigned long flags;
252
253 spin_lock_irqsave(&kvm->irqfds.lock, flags);
254
255
256
257
258
259
260
261
262
263
264 if (irqfd_is_active(irqfd))
265 irqfd_deactivate(irqfd);
266
267 spin_unlock_irqrestore(&kvm->irqfds.lock, flags);
268 }
269
270 return 0;
271}
272
273static void
274irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh,
275 poll_table *pt)
276{
277 struct _irqfd *irqfd = container_of(pt, struct _irqfd, pt);
278 add_wait_queue(wqh, &irqfd->wait);
279}
280
281
282static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd)
283{
284 struct kvm_kernel_irq_routing_entry *e;
285 struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS];
286 int i, n_entries;
287
288 n_entries = kvm_irq_map_gsi(kvm, entries, irqfd->gsi);
289
290 write_seqcount_begin(&irqfd->irq_entry_sc);
291
292 irqfd->irq_entry.type = 0;
293
294 e = entries;
295 for (i = 0; i < n_entries; ++i, ++e) {
296
297 if (e->type == KVM_IRQ_ROUTING_MSI)
298 irqfd->irq_entry = *e;
299 }
300
301 write_seqcount_end(&irqfd->irq_entry_sc);
302}
303
304static int
305kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
306{
307 struct _irqfd *irqfd, *tmp;
308 struct fd f;
309 struct eventfd_ctx *eventfd = NULL, *resamplefd = NULL;
310 int ret;
311 unsigned int events;
312 int idx;
313
314 if (!kvm_arch_intc_initialized(kvm))
315 return -EAGAIN;
316
317 irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL);
318 if (!irqfd)
319 return -ENOMEM;
320
321 irqfd->kvm = kvm;
322 irqfd->gsi = args->gsi;
323 INIT_LIST_HEAD(&irqfd->list);
324 INIT_WORK(&irqfd->inject, irqfd_inject);
325 INIT_WORK(&irqfd->shutdown, irqfd_shutdown);
326 seqcount_init(&irqfd->irq_entry_sc);
327
328 f = fdget(args->fd);
329 if (!f.file) {
330 ret = -EBADF;
331 goto out;
332 }
333
334 eventfd = eventfd_ctx_fileget(f.file);
335 if (IS_ERR(eventfd)) {
336 ret = PTR_ERR(eventfd);
337 goto fail;
338 }
339
340 irqfd->eventfd = eventfd;
341
342 if (args->flags & KVM_IRQFD_FLAG_RESAMPLE) {
343 struct _irqfd_resampler *resampler;
344
345 resamplefd = eventfd_ctx_fdget(args->resamplefd);
346 if (IS_ERR(resamplefd)) {
347 ret = PTR_ERR(resamplefd);
348 goto fail;
349 }
350
351 irqfd->resamplefd = resamplefd;
352 INIT_LIST_HEAD(&irqfd->resampler_link);
353
354 mutex_lock(&kvm->irqfds.resampler_lock);
355
356 list_for_each_entry(resampler,
357 &kvm->irqfds.resampler_list, link) {
358 if (resampler->notifier.gsi == irqfd->gsi) {
359 irqfd->resampler = resampler;
360 break;
361 }
362 }
363
364 if (!irqfd->resampler) {
365 resampler = kzalloc(sizeof(*resampler), GFP_KERNEL);
366 if (!resampler) {
367 ret = -ENOMEM;
368 mutex_unlock(&kvm->irqfds.resampler_lock);
369 goto fail;
370 }
371
372 resampler->kvm = kvm;
373 INIT_LIST_HEAD(&resampler->list);
374 resampler->notifier.gsi = irqfd->gsi;
375 resampler->notifier.irq_acked = irqfd_resampler_ack;
376 INIT_LIST_HEAD(&resampler->link);
377
378 list_add(&resampler->link, &kvm->irqfds.resampler_list);
379 kvm_register_irq_ack_notifier(kvm,
380 &resampler->notifier);
381 irqfd->resampler = resampler;
382 }
383
384 list_add_rcu(&irqfd->resampler_link, &irqfd->resampler->list);
385 synchronize_srcu(&kvm->irq_srcu);
386
387 mutex_unlock(&kvm->irqfds.resampler_lock);
388 }
389
390
391
392
393
394 init_waitqueue_func_entry(&irqfd->wait, irqfd_wakeup);
395 init_poll_funcptr(&irqfd->pt, irqfd_ptable_queue_proc);
396
397 spin_lock_irq(&kvm->irqfds.lock);
398
399 ret = 0;
400 list_for_each_entry(tmp, &kvm->irqfds.items, list) {
401 if (irqfd->eventfd != tmp->eventfd)
402 continue;
403
404 ret = -EBUSY;
405 spin_unlock_irq(&kvm->irqfds.lock);
406 goto fail;
407 }
408
409 idx = srcu_read_lock(&kvm->irq_srcu);
410 irqfd_update(kvm, irqfd);
411 srcu_read_unlock(&kvm->irq_srcu, idx);
412
413 list_add_tail(&irqfd->list, &kvm->irqfds.items);
414
415 spin_unlock_irq(&kvm->irqfds.lock);
416
417
418
419
420
421 events = f.file->f_op->poll(f.file, &irqfd->pt);
422
423 if (events & POLLIN)
424 schedule_work(&irqfd->inject);
425
426
427
428
429
430 fdput(f);
431
432 return 0;
433
434fail:
435 if (irqfd->resampler)
436 irqfd_resampler_shutdown(irqfd);
437
438 if (resamplefd && !IS_ERR(resamplefd))
439 eventfd_ctx_put(resamplefd);
440
441 if (eventfd && !IS_ERR(eventfd))
442 eventfd_ctx_put(eventfd);
443
444 fdput(f);
445
446out:
447 kfree(irqfd);
448 return ret;
449}
450
451bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin)
452{
453 struct kvm_irq_ack_notifier *kian;
454 int gsi, idx;
455
456 idx = srcu_read_lock(&kvm->irq_srcu);
457 gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
458 if (gsi != -1)
459 hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,
460 link)
461 if (kian->gsi == gsi) {
462 srcu_read_unlock(&kvm->irq_srcu, idx);
463 return true;
464 }
465
466 srcu_read_unlock(&kvm->irq_srcu, idx);
467
468 return false;
469}
470EXPORT_SYMBOL_GPL(kvm_irq_has_notifier);
471
472void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
473{
474 struct kvm_irq_ack_notifier *kian;
475 int gsi, idx;
476
477 trace_kvm_ack_irq(irqchip, pin);
478
479 idx = srcu_read_lock(&kvm->irq_srcu);
480 gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
481 if (gsi != -1)
482 hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,
483 link)
484 if (kian->gsi == gsi)
485 kian->irq_acked(kian);
486 srcu_read_unlock(&kvm->irq_srcu, idx);
487}
488
489void kvm_register_irq_ack_notifier(struct kvm *kvm,
490 struct kvm_irq_ack_notifier *kian)
491{
492 mutex_lock(&kvm->irq_lock);
493 hlist_add_head_rcu(&kian->link, &kvm->irq_ack_notifier_list);
494 mutex_unlock(&kvm->irq_lock);
495 kvm_vcpu_request_scan_ioapic(kvm);
496}
497
498void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
499 struct kvm_irq_ack_notifier *kian)
500{
501 mutex_lock(&kvm->irq_lock);
502 hlist_del_init_rcu(&kian->link);
503 mutex_unlock(&kvm->irq_lock);
504 synchronize_srcu(&kvm->irq_srcu);
505 kvm_vcpu_request_scan_ioapic(kvm);
506}
507#endif
508
509void
510kvm_eventfd_init(struct kvm *kvm)
511{
512#ifdef CONFIG_HAVE_KVM_IRQFD
513 spin_lock_init(&kvm->irqfds.lock);
514 INIT_LIST_HEAD(&kvm->irqfds.items);
515 INIT_LIST_HEAD(&kvm->irqfds.resampler_list);
516 mutex_init(&kvm->irqfds.resampler_lock);
517#endif
518 INIT_LIST_HEAD(&kvm->ioeventfds);
519}
520
521#ifdef CONFIG_HAVE_KVM_IRQFD
522
523
524
525static int
526kvm_irqfd_deassign(struct kvm *kvm, struct kvm_irqfd *args)
527{
528 struct _irqfd *irqfd, *tmp;
529 struct eventfd_ctx *eventfd;
530
531 eventfd = eventfd_ctx_fdget(args->fd);
532 if (IS_ERR(eventfd))
533 return PTR_ERR(eventfd);
534
535 spin_lock_irq(&kvm->irqfds.lock);
536
537 list_for_each_entry_safe(irqfd, tmp, &kvm->irqfds.items, list) {
538 if (irqfd->eventfd == eventfd && irqfd->gsi == args->gsi) {
539
540
541
542
543
544
545 write_seqcount_begin(&irqfd->irq_entry_sc);
546 irqfd->irq_entry.type = 0;
547 write_seqcount_end(&irqfd->irq_entry_sc);
548 irqfd_deactivate(irqfd);
549 }
550 }
551
552 spin_unlock_irq(&kvm->irqfds.lock);
553 eventfd_ctx_put(eventfd);
554
555
556
557
558
559
560 flush_workqueue(irqfd_cleanup_wq);
561
562 return 0;
563}
564
565int
566kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args)
567{
568 if (args->flags & ~(KVM_IRQFD_FLAG_DEASSIGN | KVM_IRQFD_FLAG_RESAMPLE))
569 return -EINVAL;
570
571 if (args->flags & KVM_IRQFD_FLAG_DEASSIGN)
572 return kvm_irqfd_deassign(kvm, args);
573
574 return kvm_irqfd_assign(kvm, args);
575}
576
577
578
579
580
581void
582kvm_irqfd_release(struct kvm *kvm)
583{
584 struct _irqfd *irqfd, *tmp;
585
586 spin_lock_irq(&kvm->irqfds.lock);
587
588 list_for_each_entry_safe(irqfd, tmp, &kvm->irqfds.items, list)
589 irqfd_deactivate(irqfd);
590
591 spin_unlock_irq(&kvm->irqfds.lock);
592
593
594
595
596
597 flush_workqueue(irqfd_cleanup_wq);
598
599}
600
601
602
603
604
605void kvm_irq_routing_update(struct kvm *kvm)
606{
607 struct _irqfd *irqfd;
608
609 spin_lock_irq(&kvm->irqfds.lock);
610
611 list_for_each_entry(irqfd, &kvm->irqfds.items, list)
612 irqfd_update(kvm, irqfd);
613
614 spin_unlock_irq(&kvm->irqfds.lock);
615}
616
617
618
619
620
621
622int kvm_irqfd_init(void)
623{
624 irqfd_cleanup_wq = create_singlethread_workqueue("kvm-irqfd-cleanup");
625 if (!irqfd_cleanup_wq)
626 return -ENOMEM;
627
628 return 0;
629}
630
631void kvm_irqfd_exit(void)
632{
633 destroy_workqueue(irqfd_cleanup_wq);
634}
635#endif
636
637
638
639
640
641
642
643
644
645
646struct _ioeventfd {
647 struct list_head list;
648 u64 addr;
649 int length;
650 struct eventfd_ctx *eventfd;
651 u64 datamatch;
652 struct kvm_io_device dev;
653 u8 bus_idx;
654 bool wildcard;
655};
656
657static inline struct _ioeventfd *
658to_ioeventfd(struct kvm_io_device *dev)
659{
660 return container_of(dev, struct _ioeventfd, dev);
661}
662
663static void
664ioeventfd_release(struct _ioeventfd *p)
665{
666 eventfd_ctx_put(p->eventfd);
667 list_del(&p->list);
668 kfree(p);
669}
670
671static bool
672ioeventfd_in_range(struct _ioeventfd *p, gpa_t addr, int len, const void *val)
673{
674 u64 _val;
675
676 if (addr != p->addr)
677
678 return false;
679
680 if (!p->length)
681
682 return true;
683
684 if (len != p->length)
685
686 return false;
687
688 if (p->wildcard)
689
690 return true;
691
692
693
694 BUG_ON(!IS_ALIGNED((unsigned long)val, len));
695
696 switch (len) {
697 case 1:
698 _val = *(u8 *)val;
699 break;
700 case 2:
701 _val = *(u16 *)val;
702 break;
703 case 4:
704 _val = *(u32 *)val;
705 break;
706 case 8:
707 _val = *(u64 *)val;
708 break;
709 default:
710 return false;
711 }
712
713 return _val == p->datamatch ? true : false;
714}
715
716
717static int
718ioeventfd_write(struct kvm_vcpu *vcpu, struct kvm_io_device *this, gpa_t addr,
719 int len, const void *val)
720{
721 struct _ioeventfd *p = to_ioeventfd(this);
722
723 if (!ioeventfd_in_range(p, addr, len, val))
724 return -EOPNOTSUPP;
725
726 eventfd_signal(p->eventfd, 1);
727 return 0;
728}
729
730
731
732
733
734static void
735ioeventfd_destructor(struct kvm_io_device *this)
736{
737 struct _ioeventfd *p = to_ioeventfd(this);
738
739 ioeventfd_release(p);
740}
741
742static const struct kvm_io_device_ops ioeventfd_ops = {
743 .write = ioeventfd_write,
744 .destructor = ioeventfd_destructor,
745};
746
747
748static bool
749ioeventfd_check_collision(struct kvm *kvm, struct _ioeventfd *p)
750{
751 struct _ioeventfd *_p;
752
753 list_for_each_entry(_p, &kvm->ioeventfds, list)
754 if (_p->bus_idx == p->bus_idx &&
755 _p->addr == p->addr &&
756 (!_p->length || !p->length ||
757 (_p->length == p->length &&
758 (_p->wildcard || p->wildcard ||
759 _p->datamatch == p->datamatch))))
760 return true;
761
762 return false;
763}
764
765static enum kvm_bus ioeventfd_bus_from_flags(__u32 flags)
766{
767 if (flags & KVM_IOEVENTFD_FLAG_PIO)
768 return KVM_PIO_BUS;
769 if (flags & KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY)
770 return KVM_VIRTIO_CCW_NOTIFY_BUS;
771 return KVM_MMIO_BUS;
772}
773
774static int kvm_assign_ioeventfd_idx(struct kvm *kvm,
775 enum kvm_bus bus_idx,
776 struct kvm_ioeventfd *args)
777{
778
779 struct eventfd_ctx *eventfd;
780 struct _ioeventfd *p;
781 int ret;
782
783 eventfd = eventfd_ctx_fdget(args->fd);
784 if (IS_ERR(eventfd))
785 return PTR_ERR(eventfd);
786
787 p = kzalloc(sizeof(*p), GFP_KERNEL);
788 if (!p) {
789 ret = -ENOMEM;
790 goto fail;
791 }
792
793 INIT_LIST_HEAD(&p->list);
794 p->addr = args->addr;
795 p->bus_idx = bus_idx;
796 p->length = args->len;
797 p->eventfd = eventfd;
798
799
800 if (args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH)
801 p->datamatch = args->datamatch;
802 else
803 p->wildcard = true;
804
805 mutex_lock(&kvm->slots_lock);
806
807
808 if (ioeventfd_check_collision(kvm, p)) {
809 ret = -EEXIST;
810 goto unlock_fail;
811 }
812
813 kvm_iodevice_init(&p->dev, &ioeventfd_ops);
814
815 ret = kvm_io_bus_register_dev(kvm, bus_idx, p->addr, p->length,
816 &p->dev);
817 if (ret < 0)
818 goto unlock_fail;
819
820 kvm->buses[bus_idx]->ioeventfd_count++;
821 list_add_tail(&p->list, &kvm->ioeventfds);
822
823 mutex_unlock(&kvm->slots_lock);
824
825 return 0;
826
827unlock_fail:
828 mutex_unlock(&kvm->slots_lock);
829
830fail:
831 kfree(p);
832 eventfd_ctx_put(eventfd);
833
834 return ret;
835}
836
837static int
838kvm_deassign_ioeventfd_idx(struct kvm *kvm, enum kvm_bus bus_idx,
839 struct kvm_ioeventfd *args)
840{
841 struct _ioeventfd *p, *tmp;
842 struct eventfd_ctx *eventfd;
843 int ret = -ENOENT;
844
845 eventfd = eventfd_ctx_fdget(args->fd);
846 if (IS_ERR(eventfd))
847 return PTR_ERR(eventfd);
848
849 mutex_lock(&kvm->slots_lock);
850
851 list_for_each_entry_safe(p, tmp, &kvm->ioeventfds, list) {
852 bool wildcard = !(args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH);
853
854 if (p->bus_idx != bus_idx ||
855 p->eventfd != eventfd ||
856 p->addr != args->addr ||
857 p->length != args->len ||
858 p->wildcard != wildcard)
859 continue;
860
861 if (!p->wildcard && p->datamatch != args->datamatch)
862 continue;
863
864 kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev);
865 kvm->buses[bus_idx]->ioeventfd_count--;
866 ioeventfd_release(p);
867 ret = 0;
868 break;
869 }
870
871 mutex_unlock(&kvm->slots_lock);
872
873 eventfd_ctx_put(eventfd);
874
875 return ret;
876}
877
878static int kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
879{
880 enum kvm_bus bus_idx = ioeventfd_bus_from_flags(args->flags);
881 int ret = kvm_deassign_ioeventfd_idx(kvm, bus_idx, args);
882
883 if (!args->len && bus_idx == KVM_MMIO_BUS)
884 kvm_deassign_ioeventfd_idx(kvm, KVM_FAST_MMIO_BUS, args);
885
886 return ret;
887}
888
889static int
890kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
891{
892 enum kvm_bus bus_idx;
893 int ret;
894
895 bus_idx = ioeventfd_bus_from_flags(args->flags);
896
897 switch (args->len) {
898 case 0:
899 case 1:
900 case 2:
901 case 4:
902 case 8:
903 break;
904 default:
905 return -EINVAL;
906 }
907
908
909 if (args->addr + args->len < args->addr)
910 return -EINVAL;
911
912
913 if (args->flags & ~KVM_IOEVENTFD_VALID_FLAG_MASK)
914 return -EINVAL;
915
916
917 if (!args->len &&
918 args->flags & (KVM_IOEVENTFD_FLAG_PIO |
919 KVM_IOEVENTFD_FLAG_DATAMATCH))
920 return -EINVAL;
921
922 ret = kvm_assign_ioeventfd_idx(kvm, bus_idx, args);
923 if (ret)
924 goto fail;
925
926
927
928
929 if (!args->len && bus_idx == KVM_MMIO_BUS) {
930 ret = kvm_assign_ioeventfd_idx(kvm, KVM_FAST_MMIO_BUS, args);
931 if (ret < 0)
932 goto fast_fail;
933 }
934
935 return 0;
936
937fast_fail:
938 kvm_deassign_ioeventfd_idx(kvm, bus_idx, args);
939fail:
940 return ret;
941}
942
943int
944kvm_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
945{
946 if (args->flags & KVM_IOEVENTFD_FLAG_DEASSIGN)
947 return kvm_deassign_ioeventfd(kvm, args);
948
949 return kvm_assign_ioeventfd(kvm, args);
950}
951