xref: /openbmc/linux/arch/x86/kvm/ioapic.c (revision 1f9f6a78)
1 /*
2  *  Copyright (C) 2001  MandrakeSoft S.A.
3  *  Copyright 2010 Red Hat, Inc. and/or its affiliates.
4  *
5  *    MandrakeSoft S.A.
6  *    43, rue d'Aboukir
7  *    75002 Paris - France
8  *    http://www.linux-mandrake.com/
9  *    http://www.mandrakesoft.com/
10  *
11  *  This library is free software; you can redistribute it and/or
12  *  modify it under the terms of the GNU Lesser General Public
13  *  License as published by the Free Software Foundation; either
14  *  version 2 of the License, or (at your option) any later version.
15  *
16  *  This library is distributed in the hope that it will be useful,
17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  *  Lesser General Public License for more details.
20  *
21  *  You should have received a copy of the GNU Lesser General Public
22  *  License along with this library; if not, write to the Free Software
23  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
24  *
25  *  Yunhong Jiang <yunhong.jiang@intel.com>
26  *  Yaozu (Eddie) Dong <eddie.dong@intel.com>
27  *  Based on Xen 3.1 code.
28  */
29 
30 #include <linux/kvm_host.h>
31 #include <linux/kvm.h>
32 #include <linux/mm.h>
33 #include <linux/highmem.h>
34 #include <linux/smp.h>
35 #include <linux/hrtimer.h>
36 #include <linux/io.h>
37 #include <linux/slab.h>
38 #include <linux/export.h>
39 #include <asm/processor.h>
40 #include <asm/page.h>
41 #include <asm/current.h>
42 #include <trace/events/kvm.h>
43 
44 #include "ioapic.h"
45 #include "lapic.h"
46 #include "irq.h"
47 
48 #if 0
49 #define ioapic_debug(fmt,arg...) printk(KERN_WARNING fmt,##arg)
50 #else
51 #define ioapic_debug(fmt, arg...)
52 #endif
53 static int ioapic_service(struct kvm_ioapic *vioapic, int irq,
54 		bool line_status);
55 
56 static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
57 					  unsigned long addr,
58 					  unsigned long length)
59 {
60 	unsigned long result = 0;
61 
62 	switch (ioapic->ioregsel) {
63 	case IOAPIC_REG_VERSION:
64 		result = ((((IOAPIC_NUM_PINS - 1) & 0xff) << 16)
65 			  | (IOAPIC_VERSION_ID & 0xff));
66 		break;
67 
68 	case IOAPIC_REG_APIC_ID:
69 	case IOAPIC_REG_ARB_ID:
70 		result = ((ioapic->id & 0xf) << 24);
71 		break;
72 
73 	default:
74 		{
75 			u32 redir_index = (ioapic->ioregsel - 0x10) >> 1;
76 			u64 redir_content;
77 
78 			if (redir_index < IOAPIC_NUM_PINS)
79 				redir_content =
80 					ioapic->redirtbl[redir_index].bits;
81 			else
82 				redir_content = ~0ULL;
83 
84 			result = (ioapic->ioregsel & 0x1) ?
85 			    (redir_content >> 32) & 0xffffffff :
86 			    redir_content & 0xffffffff;
87 			break;
88 		}
89 	}
90 
91 	return result;
92 }
93 
94 static void rtc_irq_eoi_tracking_reset(struct kvm_ioapic *ioapic)
95 {
96 	ioapic->rtc_status.pending_eoi = 0;
97 	bitmap_zero(ioapic->rtc_status.dest_map, KVM_MAX_VCPUS);
98 }
99 
100 static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic);
101 
102 static void rtc_status_pending_eoi_check_valid(struct kvm_ioapic *ioapic)
103 {
104 	if (WARN_ON(ioapic->rtc_status.pending_eoi < 0))
105 		kvm_rtc_eoi_tracking_restore_all(ioapic);
106 }
107 
108 static void __rtc_irq_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
109 {
110 	bool new_val, old_val;
111 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
112 	union kvm_ioapic_redirect_entry *e;
113 
114 	e = &ioapic->redirtbl[RTC_GSI];
115 	if (!kvm_apic_match_dest(vcpu, NULL, 0,	e->fields.dest_id,
116 				e->fields.dest_mode))
117 		return;
118 
119 	new_val = kvm_apic_pending_eoi(vcpu, e->fields.vector);
120 	old_val = test_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
121 
122 	if (new_val == old_val)
123 		return;
124 
125 	if (new_val) {
126 		__set_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
127 		ioapic->rtc_status.pending_eoi++;
128 	} else {
129 		__clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
130 		ioapic->rtc_status.pending_eoi--;
131 		rtc_status_pending_eoi_check_valid(ioapic);
132 	}
133 }
134 
135 void kvm_rtc_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
136 {
137 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
138 
139 	spin_lock(&ioapic->lock);
140 	__rtc_irq_eoi_tracking_restore_one(vcpu);
141 	spin_unlock(&ioapic->lock);
142 }
143 
144 static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic)
145 {
146 	struct kvm_vcpu *vcpu;
147 	int i;
148 
149 	if (RTC_GSI >= IOAPIC_NUM_PINS)
150 		return;
151 
152 	rtc_irq_eoi_tracking_reset(ioapic);
153 	kvm_for_each_vcpu(i, vcpu, ioapic->kvm)
154 	    __rtc_irq_eoi_tracking_restore_one(vcpu);
155 }
156 
157 static void rtc_irq_eoi(struct kvm_ioapic *ioapic, struct kvm_vcpu *vcpu)
158 {
159 	if (test_and_clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map)) {
160 		--ioapic->rtc_status.pending_eoi;
161 		rtc_status_pending_eoi_check_valid(ioapic);
162 	}
163 }
164 
165 static bool rtc_irq_check_coalesced(struct kvm_ioapic *ioapic)
166 {
167 	if (ioapic->rtc_status.pending_eoi > 0)
168 		return true; /* coalesced */
169 
170 	return false;
171 }
172 
173 static int ioapic_set_irq(struct kvm_ioapic *ioapic, unsigned int irq,
174 		int irq_level, bool line_status)
175 {
176 	union kvm_ioapic_redirect_entry entry;
177 	u32 mask = 1 << irq;
178 	u32 old_irr;
179 	int edge, ret;
180 
181 	entry = ioapic->redirtbl[irq];
182 	edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
183 
184 	if (!irq_level) {
185 		ioapic->irr &= ~mask;
186 		ret = 1;
187 		goto out;
188 	}
189 
190 	/*
191 	 * Return 0 for coalesced interrupts; for edge-triggered interrupts,
192 	 * this only happens if a previous edge has not been delivered due
193 	 * do masking.  For level interrupts, the remote_irr field tells
194 	 * us if the interrupt is waiting for an EOI.
195 	 *
196 	 * RTC is special: it is edge-triggered, but userspace likes to know
197 	 * if it has been already ack-ed via EOI because coalesced RTC
198 	 * interrupts lead to time drift in Windows guests.  So we track
199 	 * EOI manually for the RTC interrupt.
200 	 */
201 	if (irq == RTC_GSI && line_status &&
202 		rtc_irq_check_coalesced(ioapic)) {
203 		ret = 0;
204 		goto out;
205 	}
206 
207 	old_irr = ioapic->irr;
208 	ioapic->irr |= mask;
209 	if ((edge && old_irr == ioapic->irr) ||
210 	    (!edge && entry.fields.remote_irr)) {
211 		ret = 0;
212 		goto out;
213 	}
214 
215 	ret = ioapic_service(ioapic, irq, line_status);
216 
217 out:
218 	trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
219 	return ret;
220 }
221 
222 static void kvm_ioapic_inject_all(struct kvm_ioapic *ioapic, unsigned long irr)
223 {
224 	u32 idx;
225 
226 	rtc_irq_eoi_tracking_reset(ioapic);
227 	for_each_set_bit(idx, &irr, IOAPIC_NUM_PINS)
228 		ioapic_set_irq(ioapic, idx, 1, true);
229 
230 	kvm_rtc_eoi_tracking_restore_all(ioapic);
231 }
232 
233 
234 static void update_handled_vectors(struct kvm_ioapic *ioapic)
235 {
236 	DECLARE_BITMAP(handled_vectors, 256);
237 	int i;
238 
239 	memset(handled_vectors, 0, sizeof(handled_vectors));
240 	for (i = 0; i < IOAPIC_NUM_PINS; ++i)
241 		__set_bit(ioapic->redirtbl[i].fields.vector, handled_vectors);
242 	memcpy(ioapic->handled_vectors, handled_vectors,
243 	       sizeof(handled_vectors));
244 	smp_wmb();
245 }
246 
247 void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
248 			u32 *tmr)
249 {
250 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
251 	union kvm_ioapic_redirect_entry *e;
252 	int index;
253 
254 	spin_lock(&ioapic->lock);
255 	for (index = 0; index < IOAPIC_NUM_PINS; index++) {
256 		e = &ioapic->redirtbl[index];
257 		if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
258 		    kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index) ||
259 		    index == RTC_GSI) {
260 			if (kvm_apic_match_dest(vcpu, NULL, 0,
261 				e->fields.dest_id, e->fields.dest_mode)) {
262 				__set_bit(e->fields.vector,
263 					(unsigned long *)eoi_exit_bitmap);
264 				if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG)
265 					__set_bit(e->fields.vector,
266 						(unsigned long *)tmr);
267 			}
268 		}
269 	}
270 	spin_unlock(&ioapic->lock);
271 }
272 
273 void kvm_vcpu_request_scan_ioapic(struct kvm *kvm)
274 {
275 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
276 
277 	if (!ioapic)
278 		return;
279 	kvm_make_scan_ioapic_request(kvm);
280 }
281 
282 static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
283 {
284 	unsigned index;
285 	bool mask_before, mask_after;
286 	union kvm_ioapic_redirect_entry *e;
287 
288 	switch (ioapic->ioregsel) {
289 	case IOAPIC_REG_VERSION:
290 		/* Writes are ignored. */
291 		break;
292 
293 	case IOAPIC_REG_APIC_ID:
294 		ioapic->id = (val >> 24) & 0xf;
295 		break;
296 
297 	case IOAPIC_REG_ARB_ID:
298 		break;
299 
300 	default:
301 		index = (ioapic->ioregsel - 0x10) >> 1;
302 
303 		ioapic_debug("change redir index %x val %x\n", index, val);
304 		if (index >= IOAPIC_NUM_PINS)
305 			return;
306 		e = &ioapic->redirtbl[index];
307 		mask_before = e->fields.mask;
308 		if (ioapic->ioregsel & 1) {
309 			e->bits &= 0xffffffff;
310 			e->bits |= (u64) val << 32;
311 		} else {
312 			e->bits &= ~0xffffffffULL;
313 			e->bits |= (u32) val;
314 			e->fields.remote_irr = 0;
315 		}
316 		update_handled_vectors(ioapic);
317 		mask_after = e->fields.mask;
318 		if (mask_before != mask_after)
319 			kvm_fire_mask_notifiers(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index, mask_after);
320 		if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG
321 		    && ioapic->irr & (1 << index))
322 			ioapic_service(ioapic, index, false);
323 		kvm_vcpu_request_scan_ioapic(ioapic->kvm);
324 		break;
325 	}
326 }
327 
328 static int ioapic_service(struct kvm_ioapic *ioapic, int irq, bool line_status)
329 {
330 	union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
331 	struct kvm_lapic_irq irqe;
332 	int ret;
333 
334 	if (entry->fields.mask)
335 		return -1;
336 
337 	ioapic_debug("dest=%x dest_mode=%x delivery_mode=%x "
338 		     "vector=%x trig_mode=%x\n",
339 		     entry->fields.dest_id, entry->fields.dest_mode,
340 		     entry->fields.delivery_mode, entry->fields.vector,
341 		     entry->fields.trig_mode);
342 
343 	irqe.dest_id = entry->fields.dest_id;
344 	irqe.vector = entry->fields.vector;
345 	irqe.dest_mode = entry->fields.dest_mode;
346 	irqe.trig_mode = entry->fields.trig_mode;
347 	irqe.delivery_mode = entry->fields.delivery_mode << 8;
348 	irqe.level = 1;
349 	irqe.shorthand = 0;
350 
351 	if (irqe.trig_mode == IOAPIC_EDGE_TRIG)
352 		ioapic->irr &= ~(1 << irq);
353 
354 	if (irq == RTC_GSI && line_status) {
355 		/*
356 		 * pending_eoi cannot ever become negative (see
357 		 * rtc_status_pending_eoi_check_valid) and the caller
358 		 * ensures that it is only called if it is >= zero, namely
359 		 * if rtc_irq_check_coalesced returns false).
360 		 */
361 		BUG_ON(ioapic->rtc_status.pending_eoi != 0);
362 		ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe,
363 				ioapic->rtc_status.dest_map);
364 		ioapic->rtc_status.pending_eoi = (ret < 0 ? 0 : ret);
365 	} else
366 		ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, NULL);
367 
368 	if (ret && irqe.trig_mode == IOAPIC_LEVEL_TRIG)
369 		entry->fields.remote_irr = 1;
370 
371 	return ret;
372 }
373 
374 int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
375 		       int level, bool line_status)
376 {
377 	int ret, irq_level;
378 
379 	BUG_ON(irq < 0 || irq >= IOAPIC_NUM_PINS);
380 
381 	spin_lock(&ioapic->lock);
382 	irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
383 					 irq_source_id, level);
384 	ret = ioapic_set_irq(ioapic, irq, irq_level, line_status);
385 
386 	spin_unlock(&ioapic->lock);
387 
388 	return ret;
389 }
390 
391 void kvm_ioapic_clear_all(struct kvm_ioapic *ioapic, int irq_source_id)
392 {
393 	int i;
394 
395 	spin_lock(&ioapic->lock);
396 	for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
397 		__clear_bit(irq_source_id, &ioapic->irq_states[i]);
398 	spin_unlock(&ioapic->lock);
399 }
400 
401 static void kvm_ioapic_eoi_inject_work(struct work_struct *work)
402 {
403 	int i;
404 	struct kvm_ioapic *ioapic = container_of(work, struct kvm_ioapic,
405 						 eoi_inject.work);
406 	spin_lock(&ioapic->lock);
407 	for (i = 0; i < IOAPIC_NUM_PINS; i++) {
408 		union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
409 
410 		if (ent->fields.trig_mode != IOAPIC_LEVEL_TRIG)
411 			continue;
412 
413 		if (ioapic->irr & (1 << i) && !ent->fields.remote_irr)
414 			ioapic_service(ioapic, i, false);
415 	}
416 	spin_unlock(&ioapic->lock);
417 }
418 
419 #define IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT 10000
420 
421 static void __kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu,
422 			struct kvm_ioapic *ioapic, int vector, int trigger_mode)
423 {
424 	int i;
425 
426 	for (i = 0; i < IOAPIC_NUM_PINS; i++) {
427 		union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
428 
429 		if (ent->fields.vector != vector)
430 			continue;
431 
432 		if (i == RTC_GSI)
433 			rtc_irq_eoi(ioapic, vcpu);
434 		/*
435 		 * We are dropping lock while calling ack notifiers because ack
436 		 * notifier callbacks for assigned devices call into IOAPIC
437 		 * recursively. Since remote_irr is cleared only after call
438 		 * to notifiers if the same vector will be delivered while lock
439 		 * is dropped it will be put into irr and will be delivered
440 		 * after ack notifier returns.
441 		 */
442 		spin_unlock(&ioapic->lock);
443 		kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);
444 		spin_lock(&ioapic->lock);
445 
446 		if (trigger_mode != IOAPIC_LEVEL_TRIG)
447 			continue;
448 
449 		ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
450 		ent->fields.remote_irr = 0;
451 		if (!ent->fields.mask && (ioapic->irr & (1 << i))) {
452 			++ioapic->irq_eoi[i];
453 			if (ioapic->irq_eoi[i] == IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT) {
454 				/*
455 				 * Real hardware does not deliver the interrupt
456 				 * immediately during eoi broadcast, and this
457 				 * lets a buggy guest make slow progress
458 				 * even if it does not correctly handle a
459 				 * level-triggered interrupt.  Emulate this
460 				 * behavior if we detect an interrupt storm.
461 				 */
462 				schedule_delayed_work(&ioapic->eoi_inject, HZ / 100);
463 				ioapic->irq_eoi[i] = 0;
464 				trace_kvm_ioapic_delayed_eoi_inj(ent->bits);
465 			} else {
466 				ioapic_service(ioapic, i, false);
467 			}
468 		} else {
469 			ioapic->irq_eoi[i] = 0;
470 		}
471 	}
472 }
473 
474 bool kvm_ioapic_handles_vector(struct kvm *kvm, int vector)
475 {
476 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
477 	smp_rmb();
478 	return test_bit(vector, ioapic->handled_vectors);
479 }
480 
481 void kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, int vector, int trigger_mode)
482 {
483 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
484 
485 	spin_lock(&ioapic->lock);
486 	__kvm_ioapic_update_eoi(vcpu, ioapic, vector, trigger_mode);
487 	spin_unlock(&ioapic->lock);
488 }
489 
490 static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
491 {
492 	return container_of(dev, struct kvm_ioapic, dev);
493 }
494 
495 static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
496 {
497 	return ((addr >= ioapic->base_address &&
498 		 (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
499 }
500 
501 static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
502 			    void *val)
503 {
504 	struct kvm_ioapic *ioapic = to_ioapic(this);
505 	u32 result;
506 	if (!ioapic_in_range(ioapic, addr))
507 		return -EOPNOTSUPP;
508 
509 	ioapic_debug("addr %lx\n", (unsigned long)addr);
510 	ASSERT(!(addr & 0xf));	/* check alignment */
511 
512 	addr &= 0xff;
513 	spin_lock(&ioapic->lock);
514 	switch (addr) {
515 	case IOAPIC_REG_SELECT:
516 		result = ioapic->ioregsel;
517 		break;
518 
519 	case IOAPIC_REG_WINDOW:
520 		result = ioapic_read_indirect(ioapic, addr, len);
521 		break;
522 
523 	default:
524 		result = 0;
525 		break;
526 	}
527 	spin_unlock(&ioapic->lock);
528 
529 	switch (len) {
530 	case 8:
531 		*(u64 *) val = result;
532 		break;
533 	case 1:
534 	case 2:
535 	case 4:
536 		memcpy(val, (char *)&result, len);
537 		break;
538 	default:
539 		printk(KERN_WARNING "ioapic: wrong length %d\n", len);
540 	}
541 	return 0;
542 }
543 
544 static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
545 			     const void *val)
546 {
547 	struct kvm_ioapic *ioapic = to_ioapic(this);
548 	u32 data;
549 	if (!ioapic_in_range(ioapic, addr))
550 		return -EOPNOTSUPP;
551 
552 	ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
553 		     (void*)addr, len, val);
554 	ASSERT(!(addr & 0xf));	/* check alignment */
555 
556 	switch (len) {
557 	case 8:
558 	case 4:
559 		data = *(u32 *) val;
560 		break;
561 	case 2:
562 		data = *(u16 *) val;
563 		break;
564 	case 1:
565 		data = *(u8  *) val;
566 		break;
567 	default:
568 		printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
569 		return 0;
570 	}
571 
572 	addr &= 0xff;
573 	spin_lock(&ioapic->lock);
574 	switch (addr) {
575 	case IOAPIC_REG_SELECT:
576 		ioapic->ioregsel = data & 0xFF; /* 8-bit register */
577 		break;
578 
579 	case IOAPIC_REG_WINDOW:
580 		ioapic_write_indirect(ioapic, data);
581 		break;
582 
583 	default:
584 		break;
585 	}
586 	spin_unlock(&ioapic->lock);
587 	return 0;
588 }
589 
590 static void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
591 {
592 	int i;
593 
594 	cancel_delayed_work_sync(&ioapic->eoi_inject);
595 	for (i = 0; i < IOAPIC_NUM_PINS; i++)
596 		ioapic->redirtbl[i].fields.mask = 1;
597 	ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
598 	ioapic->ioregsel = 0;
599 	ioapic->irr = 0;
600 	ioapic->id = 0;
601 	memset(ioapic->irq_eoi, 0x00, IOAPIC_NUM_PINS);
602 	rtc_irq_eoi_tracking_reset(ioapic);
603 	update_handled_vectors(ioapic);
604 }
605 
606 static const struct kvm_io_device_ops ioapic_mmio_ops = {
607 	.read     = ioapic_mmio_read,
608 	.write    = ioapic_mmio_write,
609 };
610 
611 int kvm_ioapic_init(struct kvm *kvm)
612 {
613 	struct kvm_ioapic *ioapic;
614 	int ret;
615 
616 	ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
617 	if (!ioapic)
618 		return -ENOMEM;
619 	spin_lock_init(&ioapic->lock);
620 	INIT_DELAYED_WORK(&ioapic->eoi_inject, kvm_ioapic_eoi_inject_work);
621 	kvm->arch.vioapic = ioapic;
622 	kvm_ioapic_reset(ioapic);
623 	kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
624 	ioapic->kvm = kvm;
625 	mutex_lock(&kvm->slots_lock);
626 	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, ioapic->base_address,
627 				      IOAPIC_MEM_LENGTH, &ioapic->dev);
628 	mutex_unlock(&kvm->slots_lock);
629 	if (ret < 0) {
630 		kvm->arch.vioapic = NULL;
631 		kfree(ioapic);
632 	}
633 
634 	return ret;
635 }
636 
637 void kvm_ioapic_destroy(struct kvm *kvm)
638 {
639 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
640 
641 	cancel_delayed_work_sync(&ioapic->eoi_inject);
642 	if (ioapic) {
643 		kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
644 		kvm->arch.vioapic = NULL;
645 		kfree(ioapic);
646 	}
647 }
648 
649 int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
650 {
651 	struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
652 	if (!ioapic)
653 		return -EINVAL;
654 
655 	spin_lock(&ioapic->lock);
656 	memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));
657 	spin_unlock(&ioapic->lock);
658 	return 0;
659 }
660 
661 int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
662 {
663 	struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
664 	if (!ioapic)
665 		return -EINVAL;
666 
667 	spin_lock(&ioapic->lock);
668 	memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
669 	ioapic->irr = 0;
670 	update_handled_vectors(ioapic);
671 	kvm_vcpu_request_scan_ioapic(kvm);
672 	kvm_ioapic_inject_all(ioapic, state->irr);
673 	spin_unlock(&ioapic->lock);
674 	return 0;
675 }
676