1/*
2 * 8253/8254 interval timer emulation
3 *
4 * Copyright (c) 2003-2004 Fabrice Bellard
5 * Copyright (c) 2006 Intel Corporation
6 * Copyright (c) 2007 Keir Fraser, XenSource Inc
7 * Copyright (c) 2008 Intel Corporation
8 * Copyright 2009 Red Hat, Inc. and/or its affiliates.
9 *
10 * Permission is hereby granted, free of charge, to any person obtaining a copy
11 * of this software and associated documentation files (the "Software"), to deal
12 * in the Software without restriction, including without limitation the rights
13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14 * copies of the Software, and to permit persons to whom the Software is
15 * furnished to do so, subject to the following conditions:
16 *
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
26 * THE SOFTWARE.
27 *
28 * Authors:
29 *   Sheng Yang <sheng.yang@intel.com>
30 *   Based on QEMU and Xen.
31 */
32
33#define pr_fmt(fmt) "pit: " fmt
34
35#include <linux/kvm_host.h>
36#include <linux/slab.h>
37
38#include "irq.h"
39#include "i8254.h"
40#include "x86.h"
41
42#ifndef CONFIG_X86_64
43#define mod_64(x, y) ((x) - (y) * div64_u64(x, y))
44#else
45#define mod_64(x, y) ((x) % (y))
46#endif
47
48#define RW_STATE_LSB 1
49#define RW_STATE_MSB 2
50#define RW_STATE_WORD0 3
51#define RW_STATE_WORD1 4
52
53/* Compute with 96 bit intermediate result: (a*b)/c */
54static u64 muldiv64(u64 a, u32 b, u32 c)
55{
56	union {
57		u64 ll;
58		struct {
59			u32 low, high;
60		} l;
61	} u, res;
62	u64 rl, rh;
63
64	u.ll = a;
65	rl = (u64)u.l.low * (u64)b;
66	rh = (u64)u.l.high * (u64)b;
67	rh += (rl >> 32);
68	res.l.high = div64_u64(rh, c);
69	res.l.low = div64_u64(((mod_64(rh, c) << 32) + (rl & 0xffffffff)), c);
70	return res.ll;
71}
72
73static void pit_set_gate(struct kvm *kvm, int channel, u32 val)
74{
75	struct kvm_kpit_channel_state *c =
76		&kvm->arch.vpit->pit_state.channels[channel];
77
78	WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
79
80	switch (c->mode) {
81	default:
82	case 0:
83	case 4:
84		/* XXX: just disable/enable counting */
85		break;
86	case 1:
87	case 2:
88	case 3:
89	case 5:
90		/* Restart counting on rising edge. */
91		if (c->gate < val)
92			c->count_load_time = ktime_get();
93		break;
94	}
95
96	c->gate = val;
97}
98
99static int pit_get_gate(struct kvm *kvm, int channel)
100{
101	WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
102
103	return kvm->arch.vpit->pit_state.channels[channel].gate;
104}
105
106static s64 __kpit_elapsed(struct kvm *kvm)
107{
108	s64 elapsed;
109	ktime_t remaining;
110	struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
111
112	if (!ps->period)
113		return 0;
114
115	/*
116	 * The Counter does not stop when it reaches zero. In
117	 * Modes 0, 1, 4, and 5 the Counter ``wraps around'' to
118	 * the highest count, either FFFF hex for binary counting
119	 * or 9999 for BCD counting, and continues counting.
120	 * Modes 2 and 3 are periodic; the Counter reloads
121	 * itself with the initial count and continues counting
122	 * from there.
123	 */
124	remaining = hrtimer_get_remaining(&ps->timer);
125	elapsed = ps->period - ktime_to_ns(remaining);
126
127	return elapsed;
128}
129
130static s64 kpit_elapsed(struct kvm *kvm, struct kvm_kpit_channel_state *c,
131			int channel)
132{
133	if (channel == 0)
134		return __kpit_elapsed(kvm);
135
136	return ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time));
137}
138
139static int pit_get_count(struct kvm *kvm, int channel)
140{
141	struct kvm_kpit_channel_state *c =
142		&kvm->arch.vpit->pit_state.channels[channel];
143	s64 d, t;
144	int counter;
145
146	WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
147
148	t = kpit_elapsed(kvm, c, channel);
149	d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
150
151	switch (c->mode) {
152	case 0:
153	case 1:
154	case 4:
155	case 5:
156		counter = (c->count - d) & 0xffff;
157		break;
158	case 3:
159		/* XXX: may be incorrect for odd counts */
160		counter = c->count - (mod_64((2 * d), c->count));
161		break;
162	default:
163		counter = c->count - mod_64(d, c->count);
164		break;
165	}
166	return counter;
167}
168
169static int pit_get_out(struct kvm *kvm, int channel)
170{
171	struct kvm_kpit_channel_state *c =
172		&kvm->arch.vpit->pit_state.channels[channel];
173	s64 d, t;
174	int out;
175
176	WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
177
178	t = kpit_elapsed(kvm, c, channel);
179	d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
180
181	switch (c->mode) {
182	default:
183	case 0:
184		out = (d >= c->count);
185		break;
186	case 1:
187		out = (d < c->count);
188		break;
189	case 2:
190		out = ((mod_64(d, c->count) == 0) && (d != 0));
191		break;
192	case 3:
193		out = (mod_64(d, c->count) < ((c->count + 1) >> 1));
194		break;
195	case 4:
196	case 5:
197		out = (d == c->count);
198		break;
199	}
200
201	return out;
202}
203
204static void pit_latch_count(struct kvm *kvm, int channel)
205{
206	struct kvm_kpit_channel_state *c =
207		&kvm->arch.vpit->pit_state.channels[channel];
208
209	WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
210
211	if (!c->count_latched) {
212		c->latched_count = pit_get_count(kvm, channel);
213		c->count_latched = c->rw_mode;
214	}
215}
216
217static void pit_latch_status(struct kvm *kvm, int channel)
218{
219	struct kvm_kpit_channel_state *c =
220		&kvm->arch.vpit->pit_state.channels[channel];
221
222	WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
223
224	if (!c->status_latched) {
225		/* TODO: Return NULL COUNT (bit 6). */
226		c->status = ((pit_get_out(kvm, channel) << 7) |
227				(c->rw_mode << 4) |
228				(c->mode << 1) |
229				c->bcd);
230		c->status_latched = 1;
231	}
232}
233
234static void kvm_pit_ack_irq(struct kvm_irq_ack_notifier *kian)
235{
236	struct kvm_kpit_state *ps = container_of(kian, struct kvm_kpit_state,
237						 irq_ack_notifier);
238	int value;
239
240	spin_lock(&ps->inject_lock);
241	value = atomic_dec_return(&ps->pending);
242	if (value < 0)
243		/* spurious acks can be generated if, for example, the
244		 * PIC is being reset.  Handle it gracefully here
245		 */
246		atomic_inc(&ps->pending);
247	else if (value > 0 && ps->reinject)
248		/* in this case, we had multiple outstanding pit interrupts
249		 * that we needed to inject.  Reinject
250		 */
251		queue_kthread_work(&ps->pit->worker, &ps->pit->expired);
252	ps->irq_ack = 1;
253	spin_unlock(&ps->inject_lock);
254}
255
256void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu)
257{
258	struct kvm_pit *pit = vcpu->kvm->arch.vpit;
259	struct hrtimer *timer;
260
261	if (!kvm_vcpu_is_bsp(vcpu) || !pit)
262		return;
263
264	timer = &pit->pit_state.timer;
265	mutex_lock(&pit->pit_state.lock);
266	if (hrtimer_cancel(timer))
267		hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
268	mutex_unlock(&pit->pit_state.lock);
269}
270
271static void destroy_pit_timer(struct kvm_pit *pit)
272{
273	hrtimer_cancel(&pit->pit_state.timer);
274	flush_kthread_work(&pit->expired);
275}
276
277static void pit_do_work(struct kthread_work *work)
278{
279	struct kvm_pit *pit = container_of(work, struct kvm_pit, expired);
280	struct kvm *kvm = pit->kvm;
281	struct kvm_vcpu *vcpu;
282	int i;
283	struct kvm_kpit_state *ps = &pit->pit_state;
284	int inject = 0;
285
286	/* Try to inject pending interrupts when
287	 * last one has been acked.
288	 */
289	spin_lock(&ps->inject_lock);
290	if (!ps->reinject)
291		inject = 1;
292	else if (ps->irq_ack) {
293		ps->irq_ack = 0;
294		inject = 1;
295	}
296	spin_unlock(&ps->inject_lock);
297	if (inject) {
298		kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1, false);
299		kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0, false);
300
301		/*
302		 * Provides NMI watchdog support via Virtual Wire mode.
303		 * The route is: PIT -> PIC -> LVT0 in NMI mode.
304		 *
305		 * Note: Our Virtual Wire implementation is simplified, only
306		 * propagating PIT interrupts to all VCPUs when they have set
307		 * LVT0 to NMI delivery. Other PIC interrupts are just sent to
308		 * VCPU0, and only if its LVT0 is in EXTINT mode.
309		 */
310		if (atomic_read(&kvm->arch.vapics_in_nmi_mode) > 0)
311			kvm_for_each_vcpu(i, vcpu, kvm)
312				kvm_apic_nmi_wd_deliver(vcpu);
313	}
314}
315
316static enum hrtimer_restart pit_timer_fn(struct hrtimer *data)
317{
318	struct kvm_kpit_state *ps = container_of(data, struct kvm_kpit_state, timer);
319	struct kvm_pit *pt = ps->kvm->arch.vpit;
320
321	if (ps->reinject)
322		atomic_inc(&ps->pending);
323
324	queue_kthread_work(&pt->worker, &pt->expired);
325
326	if (ps->is_periodic) {
327		hrtimer_add_expires_ns(&ps->timer, ps->period);
328		return HRTIMER_RESTART;
329	} else
330		return HRTIMER_NORESTART;
331}
332
333static void create_pit_timer(struct kvm *kvm, u32 val, int is_period)
334{
335	struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
336	s64 interval;
337
338	if (!irqchip_in_kernel(kvm) || ps->flags & KVM_PIT_FLAGS_HPET_LEGACY)
339		return;
340
341	interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ);
342
343	pr_debug("create pit timer, interval is %llu nsec\n", interval);
344
345	/* TODO The new value only affected after the retriggered */
346	hrtimer_cancel(&ps->timer);
347	flush_kthread_work(&ps->pit->expired);
348	ps->period = interval;
349	ps->is_periodic = is_period;
350
351	ps->timer.function = pit_timer_fn;
352	ps->kvm = ps->pit->kvm;
353
354	atomic_set(&ps->pending, 0);
355	ps->irq_ack = 1;
356
357	/*
358	 * Do not allow the guest to program periodic timers with small
359	 * interval, since the hrtimers are not throttled by the host
360	 * scheduler.
361	 */
362	if (ps->is_periodic) {
363		s64 min_period = min_timer_period_us * 1000LL;
364
365		if (ps->period < min_period) {
366			pr_info_ratelimited(
367			    "kvm: requested %lld ns "
368			    "i8254 timer period limited to %lld ns\n",
369			    ps->period, min_period);
370			ps->period = min_period;
371		}
372	}
373
374	hrtimer_start(&ps->timer, ktime_add_ns(ktime_get(), interval),
375		      HRTIMER_MODE_ABS);
376}
377
378static void pit_load_count(struct kvm *kvm, int channel, u32 val)
379{
380	struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
381
382	WARN_ON(!mutex_is_locked(&ps->lock));
383
384	pr_debug("load_count val is %d, channel is %d\n", val, channel);
385
386	/*
387	 * The largest possible initial count is 0; this is equivalent
388	 * to 216 for binary counting and 104 for BCD counting.
389	 */
390	if (val == 0)
391		val = 0x10000;
392
393	ps->channels[channel].count = val;
394
395	if (channel != 0) {
396		ps->channels[channel].count_load_time = ktime_get();
397		return;
398	}
399
400	/* Two types of timer
401	 * mode 1 is one shot, mode 2 is period, otherwise del timer */
402	switch (ps->channels[0].mode) {
403	case 0:
404	case 1:
405        /* FIXME: enhance mode 4 precision */
406	case 4:
407		create_pit_timer(kvm, val, 0);
408		break;
409	case 2:
410	case 3:
411		create_pit_timer(kvm, val, 1);
412		break;
413	default:
414		destroy_pit_timer(kvm->arch.vpit);
415	}
416}
417
418void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val, int hpet_legacy_start)
419{
420	u8 saved_mode;
421	if (hpet_legacy_start) {
422		/* save existing mode for later reenablement */
423		saved_mode = kvm->arch.vpit->pit_state.channels[0].mode;
424		kvm->arch.vpit->pit_state.channels[0].mode = 0xff; /* disable timer */
425		pit_load_count(kvm, channel, val);
426		kvm->arch.vpit->pit_state.channels[0].mode = saved_mode;
427	} else {
428		pit_load_count(kvm, channel, val);
429	}
430}
431
432static inline struct kvm_pit *dev_to_pit(struct kvm_io_device *dev)
433{
434	return container_of(dev, struct kvm_pit, dev);
435}
436
437static inline struct kvm_pit *speaker_to_pit(struct kvm_io_device *dev)
438{
439	return container_of(dev, struct kvm_pit, speaker_dev);
440}
441
442static inline int pit_in_range(gpa_t addr)
443{
444	return ((addr >= KVM_PIT_BASE_ADDRESS) &&
445		(addr < KVM_PIT_BASE_ADDRESS + KVM_PIT_MEM_LENGTH));
446}
447
448static int pit_ioport_write(struct kvm_vcpu *vcpu,
449				struct kvm_io_device *this,
450			    gpa_t addr, int len, const void *data)
451{
452	struct kvm_pit *pit = dev_to_pit(this);
453	struct kvm_kpit_state *pit_state = &pit->pit_state;
454	struct kvm *kvm = pit->kvm;
455	int channel, access;
456	struct kvm_kpit_channel_state *s;
457	u32 val = *(u32 *) data;
458	if (!pit_in_range(addr))
459		return -EOPNOTSUPP;
460
461	val  &= 0xff;
462	addr &= KVM_PIT_CHANNEL_MASK;
463
464	mutex_lock(&pit_state->lock);
465
466	if (val != 0)
467		pr_debug("write addr is 0x%x, len is %d, val is 0x%x\n",
468			 (unsigned int)addr, len, val);
469
470	if (addr == 3) {
471		channel = val >> 6;
472		if (channel == 3) {
473			/* Read-Back Command. */
474			for (channel = 0; channel < 3; channel++) {
475				s = &pit_state->channels[channel];
476				if (val & (2 << channel)) {
477					if (!(val & 0x20))
478						pit_latch_count(kvm, channel);
479					if (!(val & 0x10))
480						pit_latch_status(kvm, channel);
481				}
482			}
483		} else {
484			/* Select Counter <channel>. */
485			s = &pit_state->channels[channel];
486			access = (val >> 4) & KVM_PIT_CHANNEL_MASK;
487			if (access == 0) {
488				pit_latch_count(kvm, channel);
489			} else {
490				s->rw_mode = access;
491				s->read_state = access;
492				s->write_state = access;
493				s->mode = (val >> 1) & 7;
494				if (s->mode > 5)
495					s->mode -= 4;
496				s->bcd = val & 1;
497			}
498		}
499	} else {
500		/* Write Count. */
501		s = &pit_state->channels[addr];
502		switch (s->write_state) {
503		default:
504		case RW_STATE_LSB:
505			pit_load_count(kvm, addr, val);
506			break;
507		case RW_STATE_MSB:
508			pit_load_count(kvm, addr, val << 8);
509			break;
510		case RW_STATE_WORD0:
511			s->write_latch = val;
512			s->write_state = RW_STATE_WORD1;
513			break;
514		case RW_STATE_WORD1:
515			pit_load_count(kvm, addr, s->write_latch | (val << 8));
516			s->write_state = RW_STATE_WORD0;
517			break;
518		}
519	}
520
521	mutex_unlock(&pit_state->lock);
522	return 0;
523}
524
525static int pit_ioport_read(struct kvm_vcpu *vcpu,
526			   struct kvm_io_device *this,
527			   gpa_t addr, int len, void *data)
528{
529	struct kvm_pit *pit = dev_to_pit(this);
530	struct kvm_kpit_state *pit_state = &pit->pit_state;
531	struct kvm *kvm = pit->kvm;
532	int ret, count;
533	struct kvm_kpit_channel_state *s;
534	if (!pit_in_range(addr))
535		return -EOPNOTSUPP;
536
537	addr &= KVM_PIT_CHANNEL_MASK;
538	if (addr == 3)
539		return 0;
540
541	s = &pit_state->channels[addr];
542
543	mutex_lock(&pit_state->lock);
544
545	if (s->status_latched) {
546		s->status_latched = 0;
547		ret = s->status;
548	} else if (s->count_latched) {
549		switch (s->count_latched) {
550		default:
551		case RW_STATE_LSB:
552			ret = s->latched_count & 0xff;
553			s->count_latched = 0;
554			break;
555		case RW_STATE_MSB:
556			ret = s->latched_count >> 8;
557			s->count_latched = 0;
558			break;
559		case RW_STATE_WORD0:
560			ret = s->latched_count & 0xff;
561			s->count_latched = RW_STATE_MSB;
562			break;
563		}
564	} else {
565		switch (s->read_state) {
566		default:
567		case RW_STATE_LSB:
568			count = pit_get_count(kvm, addr);
569			ret = count & 0xff;
570			break;
571		case RW_STATE_MSB:
572			count = pit_get_count(kvm, addr);
573			ret = (count >> 8) & 0xff;
574			break;
575		case RW_STATE_WORD0:
576			count = pit_get_count(kvm, addr);
577			ret = count & 0xff;
578			s->read_state = RW_STATE_WORD1;
579			break;
580		case RW_STATE_WORD1:
581			count = pit_get_count(kvm, addr);
582			ret = (count >> 8) & 0xff;
583			s->read_state = RW_STATE_WORD0;
584			break;
585		}
586	}
587
588	if (len > sizeof(ret))
589		len = sizeof(ret);
590	memcpy(data, (char *)&ret, len);
591
592	mutex_unlock(&pit_state->lock);
593	return 0;
594}
595
596static int speaker_ioport_write(struct kvm_vcpu *vcpu,
597				struct kvm_io_device *this,
598				gpa_t addr, int len, const void *data)
599{
600	struct kvm_pit *pit = speaker_to_pit(this);
601	struct kvm_kpit_state *pit_state = &pit->pit_state;
602	struct kvm *kvm = pit->kvm;
603	u32 val = *(u32 *) data;
604	if (addr != KVM_SPEAKER_BASE_ADDRESS)
605		return -EOPNOTSUPP;
606
607	mutex_lock(&pit_state->lock);
608	pit_state->speaker_data_on = (val >> 1) & 1;
609	pit_set_gate(kvm, 2, val & 1);
610	mutex_unlock(&pit_state->lock);
611	return 0;
612}
613
614static int speaker_ioport_read(struct kvm_vcpu *vcpu,
615				   struct kvm_io_device *this,
616				   gpa_t addr, int len, void *data)
617{
618	struct kvm_pit *pit = speaker_to_pit(this);
619	struct kvm_kpit_state *pit_state = &pit->pit_state;
620	struct kvm *kvm = pit->kvm;
621	unsigned int refresh_clock;
622	int ret;
623	if (addr != KVM_SPEAKER_BASE_ADDRESS)
624		return -EOPNOTSUPP;
625
626	/* Refresh clock toggles at about 15us. We approximate as 2^14ns. */
627	refresh_clock = ((unsigned int)ktime_to_ns(ktime_get()) >> 14) & 1;
628
629	mutex_lock(&pit_state->lock);
630	ret = ((pit_state->speaker_data_on << 1) | pit_get_gate(kvm, 2) |
631		(pit_get_out(kvm, 2) << 5) | (refresh_clock << 4));
632	if (len > sizeof(ret))
633		len = sizeof(ret);
634	memcpy(data, (char *)&ret, len);
635	mutex_unlock(&pit_state->lock);
636	return 0;
637}
638
639void kvm_pit_reset(struct kvm_pit *pit)
640{
641	int i;
642	struct kvm_kpit_channel_state *c;
643
644	mutex_lock(&pit->pit_state.lock);
645	pit->pit_state.flags = 0;
646	for (i = 0; i < 3; i++) {
647		c = &pit->pit_state.channels[i];
648		c->mode = 0xff;
649		c->gate = (i != 2);
650		pit_load_count(pit->kvm, i, 0);
651	}
652	mutex_unlock(&pit->pit_state.lock);
653
654	atomic_set(&pit->pit_state.pending, 0);
655	pit->pit_state.irq_ack = 1;
656}
657
658static void pit_mask_notifer(struct kvm_irq_mask_notifier *kimn, bool mask)
659{
660	struct kvm_pit *pit = container_of(kimn, struct kvm_pit, mask_notifier);
661
662	if (!mask) {
663		atomic_set(&pit->pit_state.pending, 0);
664		pit->pit_state.irq_ack = 1;
665	}
666}
667
668static const struct kvm_io_device_ops pit_dev_ops = {
669	.read     = pit_ioport_read,
670	.write    = pit_ioport_write,
671};
672
673static const struct kvm_io_device_ops speaker_dev_ops = {
674	.read     = speaker_ioport_read,
675	.write    = speaker_ioport_write,
676};
677
678/* Caller must hold slots_lock */
679struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags)
680{
681	struct kvm_pit *pit;
682	struct kvm_kpit_state *pit_state;
683	struct pid *pid;
684	pid_t pid_nr;
685	int ret;
686
687	pit = kzalloc(sizeof(struct kvm_pit), GFP_KERNEL);
688	if (!pit)
689		return NULL;
690
691	pit->irq_source_id = kvm_request_irq_source_id(kvm);
692	if (pit->irq_source_id < 0) {
693		kfree(pit);
694		return NULL;
695	}
696
697	mutex_init(&pit->pit_state.lock);
698	mutex_lock(&pit->pit_state.lock);
699	spin_lock_init(&pit->pit_state.inject_lock);
700
701	pid = get_pid(task_tgid(current));
702	pid_nr = pid_vnr(pid);
703	put_pid(pid);
704
705	init_kthread_worker(&pit->worker);
706	pit->worker_task = kthread_run(kthread_worker_fn, &pit->worker,
707				       "kvm-pit/%d", pid_nr);
708	if (IS_ERR(pit->worker_task)) {
709		mutex_unlock(&pit->pit_state.lock);
710		kvm_free_irq_source_id(kvm, pit->irq_source_id);
711		kfree(pit);
712		return NULL;
713	}
714	init_kthread_work(&pit->expired, pit_do_work);
715
716	kvm->arch.vpit = pit;
717	pit->kvm = kvm;
718
719	pit_state = &pit->pit_state;
720	pit_state->pit = pit;
721	hrtimer_init(&pit_state->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
722	pit_state->irq_ack_notifier.gsi = 0;
723	pit_state->irq_ack_notifier.irq_acked = kvm_pit_ack_irq;
724	kvm_register_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier);
725	pit_state->reinject = true;
726	mutex_unlock(&pit->pit_state.lock);
727
728	kvm_pit_reset(pit);
729
730	pit->mask_notifier.func = pit_mask_notifer;
731	kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier);
732
733	kvm_iodevice_init(&pit->dev, &pit_dev_ops);
734	ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, KVM_PIT_BASE_ADDRESS,
735				      KVM_PIT_MEM_LENGTH, &pit->dev);
736	if (ret < 0)
737		goto fail;
738
739	if (flags & KVM_PIT_SPEAKER_DUMMY) {
740		kvm_iodevice_init(&pit->speaker_dev, &speaker_dev_ops);
741		ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS,
742					      KVM_SPEAKER_BASE_ADDRESS, 4,
743					      &pit->speaker_dev);
744		if (ret < 0)
745			goto fail_unregister;
746	}
747
748	return pit;
749
750fail_unregister:
751	kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &pit->dev);
752
753fail:
754	kvm_unregister_irq_mask_notifier(kvm, 0, &pit->mask_notifier);
755	kvm_unregister_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier);
756	kvm_free_irq_source_id(kvm, pit->irq_source_id);
757	kthread_stop(pit->worker_task);
758	kfree(pit);
759	return NULL;
760}
761
762void kvm_free_pit(struct kvm *kvm)
763{
764	struct hrtimer *timer;
765
766	if (kvm->arch.vpit) {
767		kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &kvm->arch.vpit->dev);
768		kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS,
769					      &kvm->arch.vpit->speaker_dev);
770		kvm_unregister_irq_mask_notifier(kvm, 0,
771					       &kvm->arch.vpit->mask_notifier);
772		kvm_unregister_irq_ack_notifier(kvm,
773				&kvm->arch.vpit->pit_state.irq_ack_notifier);
774		mutex_lock(&kvm->arch.vpit->pit_state.lock);
775		timer = &kvm->arch.vpit->pit_state.timer;
776		hrtimer_cancel(timer);
777		flush_kthread_work(&kvm->arch.vpit->expired);
778		kthread_stop(kvm->arch.vpit->worker_task);
779		kvm_free_irq_source_id(kvm, kvm->arch.vpit->irq_source_id);
780		mutex_unlock(&kvm->arch.vpit->pit_state.lock);
781		kfree(kvm->arch.vpit);
782	}
783}
784