aboutsummaryrefslogtreecommitdiff
path: root/virt/kvm/ioapic.c
blob: e8ce34c9db32cd0d2aa15016ea5c847cae6af2b6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
/*
 *  Copyright (C) 2001  MandrakeSoft S.A.
 *  Copyright 2010 Red Hat, Inc. and/or its affiliates.
 *
 *    MandrakeSoft S.A.
 *    43, rue d'Aboukir
 *    75002 Paris - France
 *    http://www.linux-mandrake.com/
 *    http://www.mandrakesoft.com/
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 *  Yunhong Jiang <yunhong.jiang@intel.com>
 *  Yaozu (Eddie) Dong <eddie.dong@intel.com>
 *  Based on Xen 3.1 code.
 */

#include <linux/kvm_host.h>
#include <linux/kvm.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/smp.h>
#include <linux/hrtimer.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/current.h>
#include <trace/events/kvm.h>

#include "ioapic.h"
#include "lapic.h"
#include "irq.h"

#if 0
#define ioapic_debug(fmt,arg...) printk(KERN_WARNING fmt,##arg)
#else
#define ioapic_debug(fmt, arg...)
#endif
static int ioapic_service(struct kvm_ioapic *vioapic, int irq,
		bool line_status);

static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
					  unsigned long addr,
					  unsigned long length)
{
	unsigned long result = 0;

	switch (ioapic->ioregsel) {
	case IOAPIC_REG_VERSION:
		result = ((((IOAPIC_NUM_PINS - 1) & 0xff) << 16)
			  | (IOAPIC_VERSION_ID & 0xff));
		break;

	case IOAPIC_REG_APIC_ID:
	case IOAPIC_REG_ARB_ID:
		result = ((ioapic->id & 0xf) << 24);
		break;

	default:
		{
			u32 redir_index = (ioapic->ioregsel - 0x10) >> 1;
			u64 redir_content;

			if (redir_index < IOAPIC_NUM_PINS)
				redir_content =
					ioapic->redirtbl[redir_index].bits;
			else
				redir_content = ~0ULL;

			result = (ioapic->ioregsel & 0x1) ?
			    (redir_content >> 32) & 0xffffffff :
			    redir_content & 0xffffffff;
			break;
		}
	}

	return result;
}

static void rtc_irq_eoi_tracking_reset(struct kvm_ioapic *ioapic)
{
	ioapic->rtc_status.pending_eoi = 0;
	bitmap_zero(ioapic->rtc_status.dest_map, KVM_MAX_VCPUS);
}

static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic);

static void rtc_status_pending_eoi_check_valid(struct kvm_ioapic *ioapic)
{
	if (WARN_ON(ioapic->rtc_status.pending_eoi < 0))
		kvm_rtc_eoi_tracking_restore_all(ioapic);
}

static void __rtc_irq_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
{
	bool new_val, old_val;
	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
	union kvm_ioapic_redirect_entry *e;

	e = &ioapic->redirtbl[RTC_GSI];
	if (!kvm_apic_match_dest(vcpu, NULL, 0,	e->fields.dest_id,
				e->fields.dest_mode))
		return;

	new_val = kvm_apic_pending_eoi(vcpu, e->fields.vector);
	old_val = test_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);

	if (new_val == old_val)
		return;

	if (new_val) {
		__set_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
		ioapic->rtc_status.pending_eoi++;
	} else {
		__clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
		ioapic->rtc_status.pending_eoi--;
		rtc_status_pending_eoi_check_valid(ioapic);
	}
}

void kvm_rtc_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
{
	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;

	spin_lock(&ioapic->lock);
	__rtc_irq_eoi_tracking_restore_one(vcpu);
	spin_unlock(&ioapic->lock);
}

static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic)
{
	struct kvm_vcpu *vcpu;
	int i;

	if (RTC_GSI >= IOAPIC_NUM_PINS)
		return;

	rtc_irq_eoi_tracking_reset(ioapic);
	kvm_for_each_vcpu(i, vcpu, ioapic->kvm)
	    __rtc_irq_eoi_tracking_restore_one(vcpu);
}

static void rtc_irq_eoi(struct kvm_ioapic *ioapic, struct kvm_vcpu *vcpu)
{
	if (test_and_clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map)) {
		--ioapic->rtc_status.pending_eoi;
		rtc_status_pending_eoi_check_valid(ioapic);
	}
}

static bool rtc_irq_check_coalesced(struct kvm_ioapic *ioapic)
{
	if (ioapic->rtc_status.pending_eoi > 0)
		return true; /* coalesced */

	return false;
}

static int ioapic_set_irq(struct kvm_ioapic *ioapic, unsigned int irq,
		int irq_level, bool line_status)
{
	union kvm_ioapic_redirect_entry entry;
	u32 mask = 1 << irq;
	u32 old_irr;
	int edge, ret;

	entry = ioapic->redirtbl[irq];
	edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);

	if (!irq_level) {
		ioapic->irr &= ~mask;
		ret = 1;
		goto out;
	}

	/*
	 * Return 0 for coalesced interrupts; for edge-triggered interrupts,
	 * this only happens if a previous edge has not been delivered due
	 * do masking.  For level interrupts, the remote_irr field tells
	 * us if the interrupt is waiting for an EOI.
	 *
	 * RTC is special: it is edge-triggered, but userspace likes to know
	 * if it has been already ack-ed via EOI because coalesced RTC
	 * interrupts lead to time drift in Windows guests.  So we track
	 * EOI manually for the RTC interrupt.
	 */
	if (irq == RTC_GSI && line_status &&
		rtc_irq_check_coalesced(ioapic)) {
		ret = 0;
		goto out;
	}

	old_irr = ioapic->irr;
	ioapic->irr |= mask;
	if ((edge && old_irr == ioapic->irr) ||
	    (!edge && entry.fields.remote_irr)) {
		ret = 0;
		goto out;
	}

	ret = ioapic_service(ioapic, irq, line_status);

out:
	trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
	return ret;
}

static void kvm_ioapic_inject_all(struct kvm_ioapic *ioapic, unsigned long irr)
{
	u32 idx;

	rtc_irq_eoi_tracking_reset(ioapic);
	for_each_set_bit(idx, &irr, IOAPIC_NUM_PINS)
		ioapic_set_irq(ioapic, idx, 1, true);

	kvm_rtc_eoi_tracking_restore_all(ioapic);
}


static void update_handled_vectors(struct kvm_ioapic *ioapic)
{
	DECLARE_BITMAP(handled_vectors, 256);
	int i;

	memset(handled_vectors, 0, sizeof(handled_vectors));
	for (i = 0; i < IOAPIC_NUM_PINS; ++i)
		__set_bit(ioapic->redirtbl[i].fields.vector, handled_vectors);
	memcpy(ioapic->handled_vectors, handled_vectors,
	       sizeof(handled_vectors));
	smp_wmb();
}

void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
			u32 *tmr)
{
	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
	union kvm_ioapic_redirect_entry *e;
	int index;

	spin_lock(&ioapic->lock);
	for (index = 0; index < IOAPIC_NUM_PINS; index++) {
		e = &ioapic->redirtbl[index];
		if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
		    kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index) ||
		    index == RTC_GSI) {
			if (kvm_apic_match_dest(vcpu, NULL, 0,
				e->fields.dest_id, e->fields.dest_mode)) {
				__set_bit(e->fields.vector,
					(unsigned long *)eoi_exit_bitmap);
				if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG)
					__set_bit(e->fields.vector,
						(unsigned long *)tmr);
			}
		}
	}
	spin_unlock(&ioapic->lock);
}

#ifdef CONFIG_X86
void kvm_vcpu_request_scan_ioapic(struct kvm *kvm)
{
	struct kvm_ioapic *ioapic = kvm->arch.vioapic;

	if (!ioapic)
		return;
	kvm_make_scan_ioapic_request(kvm);
}
#else
void kvm_vcpu_request_scan_ioapic(struct kvm *kvm)
{
	return;
}
#endif

static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
{
	unsigned index;
	bool mask_before, mask_after;
	union kvm_ioapic_redirect_entry *e;

	switch (ioapic->ioregsel) {
	case IOAPIC_REG_VERSION:
		/* Writes are ignored. */
		break;

	case IOAPIC_REG_APIC_ID:
		ioapic->id = (val >> 24) & 0xf;
		break;

	case IOAPIC_REG_ARB_ID:
		break;

	default:
		index = (ioapic->ioregsel - 0x10) >> 1;

		ioapic_debug("change redir index %x val %x\n", index, val);
		if (index >= IOAPIC_NUM_PINS)
			return;
		e = &ioapic->redirtbl[index];
		mask_before = e->fields.mask;
		if (ioapic->ioregsel & 1) {
			e->bits &= 0xffffffff;
			e->bits |= (u64) val << 32;
		} else {
			e->bits &= ~0xffffffffULL;
			e->bits |= (u32) val;
			e->fields.remote_irr = 0;
		}
		update_handled_vectors(ioapic);
		mask_after = e->fields.mask;
		if (mask_before != mask_after)
			kvm_fire_mask_notifiers(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index, mask_after);
		if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG
		    && ioapic->irr & (1 << index))
			ioapic_service(ioapic, index, false);
		kvm_vcpu_request_scan_ioapic(ioapic->kvm);
		break;
	}
}

static int ioapic_service(struct kvm_ioapic *ioapic, int irq, bool line_status)
{
	union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
	struct kvm_lapic_irq irqe;
	int ret;

	if (entry->fields.mask)
		return -1;

	ioapic_debug("dest=%x dest_mode=%x delivery_mode=%x "
		     "vector=%x trig_mode=%x\n",
		     entry->fields.dest_id, entry->fields.dest_mode,
		     entry->fields.delivery_mode, entry->fields.vector,
		     entry->fields.trig_mode);

	irqe.dest_id = entry->fields.dest_id;
	irqe.vector = entry->fields.vector;
	irqe.dest_mode = entry->fields.dest_mode;
	irqe.trig_mode = entry->fields.trig_mode;
	irqe.delivery_mode = entry->fields.delivery_mode << 8;
	irqe.level = 1;
	irqe.shorthand = 0;

	if (irqe.trig_mode == IOAPIC_EDGE_TRIG)
		ioapic->irr &= ~(1 << irq);

	if (irq == RTC_GSI && line_status) {
		/*
		 * pending_eoi cannot ever become negative (see
		 * rtc_status_pending_eoi_check_valid) and the caller
		 * ensures that it is only called if it is >= zero, namely
		 * if rtc_irq_check_coalesced returns false).
		 */
		BUG_ON(ioapic->rtc_status.pending_eoi != 0);
		ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe,
				ioapic->rtc_status.dest_map);
		ioapic->rtc_status.pending_eoi = (ret < 0 ? 0 : ret);
	} else
		ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, NULL);

	if (ret && irqe.trig_mode == IOAPIC_LEVEL_TRIG)
		entry->fields.remote_irr = 1;

	return ret;
}

int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
		       int level, bool line_status)
{
	int ret, irq_level;

	BUG_ON(irq < 0 || irq >= IOAPIC_NUM_PINS);

	spin_lock(&ioapic->lock);
	irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
					 irq_source_id, level);
	ret = ioapic_set_irq(ioapic, irq, irq_level, line_status);

	spin_unlock(&ioapic->lock);

	return ret;
}

void kvm_ioapic_clear_all(struct kvm_ioapic *ioapic, int irq_source_id)
{
	int i;

	spin_lock(&ioapic->lock);
	for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
		__clear_bit(irq_source_id, &ioapic->irq_states[i]);
	spin_unlock(&ioapic->lock);
}

static void __kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu,
			struct kvm_ioapic *ioapic, int vector, int trigger_mode)
{
	int i;

	for (i = 0; i < IOAPIC_NUM_PINS; i++) {
		union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];

		if (ent->fields.vector != vector)
			continue;

		if (i == RTC_GSI)
			rtc_irq_eoi(ioapic, vcpu);
		/*
		 * We are dropping lock while calling ack notifiers because ack
		 * notifier callbacks for assigned devices call into IOAPIC
		 * recursively. Since remote_irr is cleared only after call
		 * to notifiers if the same vector will be delivered while lock
		 * is dropped it will be put into irr and will be delivered
		 * after ack notifier returns.
		 */
		spin_unlock(&ioapic->lock);
		kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);
		spin_lock(&ioapic->lock);

		if (trigger_mode != IOAPIC_LEVEL_TRIG)
			continue;

		ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
		ent->fields.remote_irr = 0;
		if (ioapic->irr & (1 << i))
			ioapic_service(ioapic, i, false);
	}
}

bool kvm_ioapic_handles_vector(struct kvm *kvm, int vector)
{
	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
	smp_rmb();
	return test_bit(vector, ioapic->handled_vectors);
}

void kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, int vector, int trigger_mode)
{
	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;

	spin_lock(&ioapic->lock);
	__kvm_ioapic_update_eoi(vcpu, ioapic, vector, trigger_mode);
	spin_unlock(&ioapic->lock);
}

static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
{
	return container_of(dev, struct kvm_ioapic, dev);
}

static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
{
	return ((addr >= ioapic->base_address &&
		 (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
}

static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
			    void *val)
{
	struct kvm_ioapic *ioapic = to_ioapic(this);
	u32 result;
	if (!ioapic_in_range(ioapic, addr))
		return -EOPNOTSUPP;

	ioapic_debug("addr %lx\n", (unsigned long)addr);
	ASSERT(!(addr & 0xf));	/* check alignment */

	addr &= 0xff;
	spin_lock(&ioapic->lock);
	switch (addr) {
	case IOAPIC_REG_SELECT:
		result = ioapic->ioregsel;
		break;

	case IOAPIC_REG_WINDOW:
		result = ioapic_read_indirect(ioapic, addr, len);
		break;

	default:
		result = 0;
		break;
	}
	spin_unlock(&ioapic->lock);

	switch (len) {
	case 8:
		*(u64 *) val = result;
		break;
	case 1:
	case 2:
	case 4:
		memcpy(val, (char *)&result, len);
		break;
	default:
		printk(KERN_WARNING "ioapic: wrong length %d\n", len);
	}
	return 0;
}

static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
			     const void *val)
{
	struct kvm_ioapic *ioapic = to_ioapic(this);
	u32 data;
	if (!ioapic_in_range(ioapic, addr))
		return -EOPNOTSUPP;

	ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
		     (void*)addr, len, val);
	ASSERT(!(addr & 0xf));	/* check alignment */

	switch (len) {
	case 8:
	case 4:
		data = *(u32 *) val;
		break;
	case 2:
		data = *(u16 *) val;
		break;
	case 1:
		data = *(u8  *) val;
		break;
	default:
		printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
		return 0;
	}

	addr &= 0xff;
	spin_lock(&ioapic->lock);
	switch (addr) {
	case IOAPIC_REG_SELECT:
		ioapic->ioregsel = data & 0xFF; /* 8-bit register */
		break;

	case IOAPIC_REG_WINDOW:
		ioapic_write_indirect(ioapic, data);
		break;
#ifdef	CONFIG_IA64
	case IOAPIC_REG_EOI:
		__kvm_ioapic_update_eoi(NULL, ioapic, data, IOAPIC_LEVEL_TRIG);
		break;
#endif

	default:
		break;
	}
	spin_unlock(&ioapic->lock);
	return 0;
}

static void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
{
	int i;

	for (i = 0; i < IOAPIC_NUM_PINS; i++)
		ioapic->redirtbl[i].fields.mask = 1;
	ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
	ioapic->ioregsel = 0;
	ioapic->irr = 0;
	ioapic->id = 0;
	rtc_irq_eoi_tracking_reset(ioapic);
	update_handled_vectors(ioapic);
}

static const struct kvm_io_device_ops ioapic_mmio_ops = {
	.read     = ioapic_mmio_read,
	.write    = ioapic_mmio_write,
};

int kvm_ioapic_init(struct kvm *kvm)
{
	struct kvm_ioapic *ioapic;
	int ret;

	ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
	if (!ioapic)
		return -ENOMEM;
	spin_lock_init(&ioapic->lock);
	kvm->arch.vioapic = ioapic;
	kvm_ioapic_reset(ioapic);
	kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
	ioapic->kvm = kvm;
	mutex_lock(&kvm->slots_lock);
	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, ioapic->base_address,
				      IOAPIC_MEM_LENGTH, &ioapic->dev);
	mutex_unlock(&kvm->slots_lock);
	if (ret < 0) {
		kvm->arch.vioapic = NULL;
		kfree(ioapic);
	}

	return ret;
}

void kvm_ioapic_destroy(struct kvm *kvm)
{
	struct kvm_ioapic *ioapic = kvm->arch.vioapic;

	if (ioapic) {
		kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
		kvm->arch.vioapic = NULL;
		kfree(ioapic);
	}
}

int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
{
	struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
	if (!ioapic)
		return -EINVAL;

	spin_lock(&ioapic->lock);
	memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));
	spin_unlock(&ioapic->lock);
	return 0;
}

int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
{
	struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
	if (!ioapic)
		return -EINVAL;

	spin_lock(&ioapic->lock);
	memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
	ioapic->irr = 0;
	update_handled_vectors(ioapic);
	kvm_vcpu_request_scan_ioapic(kvm);
	kvm_ioapic_inject_all(ioapic, state->irr);
	spin_unlock(&ioapic->lock);
	return 0;
}