xref: /openbmc/linux/arch/x86/kvm/ioapic.c (revision 842ed298)
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 <linux/nospec.h>
40 #include <asm/processor.h>
41 #include <asm/page.h>
42 #include <asm/current.h>
43 #include <trace/events/kvm.h>
44 
45 #include "ioapic.h"
46 #include "lapic.h"
47 #include "irq.h"
48 
49 static int ioapic_service(struct kvm_ioapic *vioapic, int irq,
50 		bool line_status);
51 
52 static void kvm_ioapic_update_eoi_one(struct kvm_vcpu *vcpu,
53 				      struct kvm_ioapic *ioapic,
54 				      int trigger_mode,
55 				      int pin);
56 
57 static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
58 					  unsigned long addr,
59 					  unsigned long length)
60 {
61 	unsigned long result = 0;
62 
63 	switch (ioapic->ioregsel) {
64 	case IOAPIC_REG_VERSION:
65 		result = ((((IOAPIC_NUM_PINS - 1) & 0xff) << 16)
66 			  | (IOAPIC_VERSION_ID & 0xff));
67 		break;
68 
69 	case IOAPIC_REG_APIC_ID:
70 	case IOAPIC_REG_ARB_ID:
71 		result = ((ioapic->id & 0xf) << 24);
72 		break;
73 
74 	default:
75 		{
76 			u32 redir_index = (ioapic->ioregsel - 0x10) >> 1;
77 			u64 redir_content = ~0ULL;
78 
79 			if (redir_index < IOAPIC_NUM_PINS) {
80 				u32 index = array_index_nospec(
81 					redir_index, IOAPIC_NUM_PINS);
82 
83 				redir_content = ioapic->redirtbl[index].bits;
84 			}
85 
86 			result = (ioapic->ioregsel & 0x1) ?
87 			    (redir_content >> 32) & 0xffffffff :
88 			    redir_content & 0xffffffff;
89 			break;
90 		}
91 	}
92 
93 	return result;
94 }
95 
96 static void rtc_irq_eoi_tracking_reset(struct kvm_ioapic *ioapic)
97 {
98 	ioapic->rtc_status.pending_eoi = 0;
99 	bitmap_zero(ioapic->rtc_status.dest_map.map, KVM_MAX_VCPU_ID);
100 }
101 
102 static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic);
103 
104 static void rtc_status_pending_eoi_check_valid(struct kvm_ioapic *ioapic)
105 {
106 	if (WARN_ON(ioapic->rtc_status.pending_eoi < 0))
107 		kvm_rtc_eoi_tracking_restore_all(ioapic);
108 }
109 
110 static void __rtc_irq_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
111 {
112 	bool new_val, old_val;
113 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
114 	struct dest_map *dest_map = &ioapic->rtc_status.dest_map;
115 	union kvm_ioapic_redirect_entry *e;
116 
117 	e = &ioapic->redirtbl[RTC_GSI];
118 	if (!kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
119 				 e->fields.dest_id,
120 				 kvm_lapic_irq_dest_mode(!!e->fields.dest_mode)))
121 		return;
122 
123 	new_val = kvm_apic_pending_eoi(vcpu, e->fields.vector);
124 	old_val = test_bit(vcpu->vcpu_id, dest_map->map);
125 
126 	if (new_val == old_val)
127 		return;
128 
129 	if (new_val) {
130 		__set_bit(vcpu->vcpu_id, dest_map->map);
131 		dest_map->vectors[vcpu->vcpu_id] = e->fields.vector;
132 		ioapic->rtc_status.pending_eoi++;
133 	} else {
134 		__clear_bit(vcpu->vcpu_id, dest_map->map);
135 		ioapic->rtc_status.pending_eoi--;
136 		rtc_status_pending_eoi_check_valid(ioapic);
137 	}
138 }
139 
140 void kvm_rtc_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
141 {
142 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
143 
144 	spin_lock(&ioapic->lock);
145 	__rtc_irq_eoi_tracking_restore_one(vcpu);
146 	spin_unlock(&ioapic->lock);
147 }
148 
149 static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic)
150 {
151 	struct kvm_vcpu *vcpu;
152 	int i;
153 
154 	if (RTC_GSI >= IOAPIC_NUM_PINS)
155 		return;
156 
157 	rtc_irq_eoi_tracking_reset(ioapic);
158 	kvm_for_each_vcpu(i, vcpu, ioapic->kvm)
159 	    __rtc_irq_eoi_tracking_restore_one(vcpu);
160 }
161 
162 static void rtc_irq_eoi(struct kvm_ioapic *ioapic, struct kvm_vcpu *vcpu,
163 			int vector)
164 {
165 	struct dest_map *dest_map = &ioapic->rtc_status.dest_map;
166 
167 	/* RTC special handling */
168 	if (test_bit(vcpu->vcpu_id, dest_map->map) &&
169 	    (vector == dest_map->vectors[vcpu->vcpu_id]) &&
170 	    (test_and_clear_bit(vcpu->vcpu_id,
171 				ioapic->rtc_status.dest_map.map))) {
172 		--ioapic->rtc_status.pending_eoi;
173 		rtc_status_pending_eoi_check_valid(ioapic);
174 	}
175 }
176 
177 static bool rtc_irq_check_coalesced(struct kvm_ioapic *ioapic)
178 {
179 	if (ioapic->rtc_status.pending_eoi > 0)
180 		return true; /* coalesced */
181 
182 	return false;
183 }
184 
185 static void ioapic_lazy_update_eoi(struct kvm_ioapic *ioapic, int irq)
186 {
187 	int i;
188 	struct kvm_vcpu *vcpu;
189 	union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
190 
191 	kvm_for_each_vcpu(i, vcpu, ioapic->kvm) {
192 		if (!kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
193 					 entry->fields.dest_id,
194 					 entry->fields.dest_mode) ||
195 		    kvm_apic_pending_eoi(vcpu, entry->fields.vector))
196 			continue;
197 
198 		/*
199 		 * If no longer has pending EOI in LAPICs, update
200 		 * EOI for this vector.
201 		 */
202 		rtc_irq_eoi(ioapic, vcpu, entry->fields.vector);
203 		break;
204 	}
205 }
206 
207 static int ioapic_set_irq(struct kvm_ioapic *ioapic, unsigned int irq,
208 		int irq_level, bool line_status)
209 {
210 	union kvm_ioapic_redirect_entry entry;
211 	u32 mask = 1 << irq;
212 	u32 old_irr;
213 	int edge, ret;
214 
215 	entry = ioapic->redirtbl[irq];
216 	edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
217 
218 	if (!irq_level) {
219 		ioapic->irr &= ~mask;
220 		ret = 1;
221 		goto out;
222 	}
223 
224 	/*
225 	 * AMD SVM AVIC accelerate EOI write iff the interrupt is edge
226 	 * triggered, in which case the in-kernel IOAPIC will not be able
227 	 * to receive the EOI.  In this case, we do a lazy update of the
228 	 * pending EOI when trying to set IOAPIC irq.
229 	 */
230 	if (edge && kvm_apicv_activated(ioapic->kvm))
231 		ioapic_lazy_update_eoi(ioapic, irq);
232 
233 	/*
234 	 * Return 0 for coalesced interrupts; for edge-triggered interrupts,
235 	 * this only happens if a previous edge has not been delivered due
236 	 * to masking.  For level interrupts, the remote_irr field tells
237 	 * us if the interrupt is waiting for an EOI.
238 	 *
239 	 * RTC is special: it is edge-triggered, but userspace likes to know
240 	 * if it has been already ack-ed via EOI because coalesced RTC
241 	 * interrupts lead to time drift in Windows guests.  So we track
242 	 * EOI manually for the RTC interrupt.
243 	 */
244 	if (irq == RTC_GSI && line_status &&
245 		rtc_irq_check_coalesced(ioapic)) {
246 		ret = 0;
247 		goto out;
248 	}
249 
250 	old_irr = ioapic->irr;
251 	ioapic->irr |= mask;
252 	if (edge) {
253 		ioapic->irr_delivered &= ~mask;
254 		if (old_irr == ioapic->irr) {
255 			ret = 0;
256 			goto out;
257 		}
258 	}
259 
260 	ret = ioapic_service(ioapic, irq, line_status);
261 
262 out:
263 	trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
264 	return ret;
265 }
266 
267 static void kvm_ioapic_inject_all(struct kvm_ioapic *ioapic, unsigned long irr)
268 {
269 	u32 idx;
270 
271 	rtc_irq_eoi_tracking_reset(ioapic);
272 	for_each_set_bit(idx, &irr, IOAPIC_NUM_PINS)
273 		ioapic_set_irq(ioapic, idx, 1, true);
274 
275 	kvm_rtc_eoi_tracking_restore_all(ioapic);
276 }
277 
278 
279 void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, ulong *ioapic_handled_vectors)
280 {
281 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
282 	struct dest_map *dest_map = &ioapic->rtc_status.dest_map;
283 	union kvm_ioapic_redirect_entry *e;
284 	int index;
285 
286 	spin_lock(&ioapic->lock);
287 
288 	/* Make sure we see any missing RTC EOI */
289 	if (test_bit(vcpu->vcpu_id, dest_map->map))
290 		__set_bit(dest_map->vectors[vcpu->vcpu_id],
291 			  ioapic_handled_vectors);
292 
293 	for (index = 0; index < IOAPIC_NUM_PINS; index++) {
294 		e = &ioapic->redirtbl[index];
295 		if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
296 		    kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index) ||
297 		    index == RTC_GSI) {
298 			u16 dm = kvm_lapic_irq_dest_mode(!!e->fields.dest_mode);
299 
300 			if (kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
301 						e->fields.dest_id, dm) ||
302 			    kvm_apic_pending_eoi(vcpu, e->fields.vector))
303 				__set_bit(e->fields.vector,
304 					  ioapic_handled_vectors);
305 		}
306 	}
307 	spin_unlock(&ioapic->lock);
308 }
309 
310 void kvm_arch_post_irq_ack_notifier_list_update(struct kvm *kvm)
311 {
312 	if (!ioapic_in_kernel(kvm))
313 		return;
314 	kvm_make_scan_ioapic_request(kvm);
315 }
316 
317 static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
318 {
319 	unsigned index;
320 	bool mask_before, mask_after;
321 	union kvm_ioapic_redirect_entry *e;
322 	unsigned long vcpu_bitmap;
323 	int old_remote_irr, old_delivery_status, old_dest_id, old_dest_mode;
324 
325 	switch (ioapic->ioregsel) {
326 	case IOAPIC_REG_VERSION:
327 		/* Writes are ignored. */
328 		break;
329 
330 	case IOAPIC_REG_APIC_ID:
331 		ioapic->id = (val >> 24) & 0xf;
332 		break;
333 
334 	case IOAPIC_REG_ARB_ID:
335 		break;
336 
337 	default:
338 		index = (ioapic->ioregsel - 0x10) >> 1;
339 
340 		if (index >= IOAPIC_NUM_PINS)
341 			return;
342 		index = array_index_nospec(index, IOAPIC_NUM_PINS);
343 		e = &ioapic->redirtbl[index];
344 		mask_before = e->fields.mask;
345 		/* Preserve read-only fields */
346 		old_remote_irr = e->fields.remote_irr;
347 		old_delivery_status = e->fields.delivery_status;
348 		old_dest_id = e->fields.dest_id;
349 		old_dest_mode = e->fields.dest_mode;
350 		if (ioapic->ioregsel & 1) {
351 			e->bits &= 0xffffffff;
352 			e->bits |= (u64) val << 32;
353 		} else {
354 			e->bits &= ~0xffffffffULL;
355 			e->bits |= (u32) val;
356 		}
357 		e->fields.remote_irr = old_remote_irr;
358 		e->fields.delivery_status = old_delivery_status;
359 
360 		/*
361 		 * Some OSes (Linux, Xen) assume that Remote IRR bit will
362 		 * be cleared by IOAPIC hardware when the entry is configured
363 		 * as edge-triggered. This behavior is used to simulate an
364 		 * explicit EOI on IOAPICs that don't have the EOI register.
365 		 */
366 		if (e->fields.trig_mode == IOAPIC_EDGE_TRIG)
367 			e->fields.remote_irr = 0;
368 
369 		mask_after = e->fields.mask;
370 		if (mask_before != mask_after)
371 			kvm_fire_mask_notifiers(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index, mask_after);
372 		if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG
373 		    && ioapic->irr & (1 << index))
374 			ioapic_service(ioapic, index, false);
375 		if (e->fields.delivery_mode == APIC_DM_FIXED) {
376 			struct kvm_lapic_irq irq;
377 
378 			irq.vector = e->fields.vector;
379 			irq.delivery_mode = e->fields.delivery_mode << 8;
380 			irq.dest_mode =
381 			    kvm_lapic_irq_dest_mode(!!e->fields.dest_mode);
382 			irq.level = false;
383 			irq.trig_mode = e->fields.trig_mode;
384 			irq.shorthand = APIC_DEST_NOSHORT;
385 			irq.dest_id = e->fields.dest_id;
386 			irq.msi_redir_hint = false;
387 			bitmap_zero(&vcpu_bitmap, 16);
388 			kvm_bitmap_or_dest_vcpus(ioapic->kvm, &irq,
389 						 &vcpu_bitmap);
390 			if (old_dest_mode != e->fields.dest_mode ||
391 			    old_dest_id != e->fields.dest_id) {
392 				/*
393 				 * Update vcpu_bitmap with vcpus specified in
394 				 * the previous request as well. This is done to
395 				 * keep ioapic_handled_vectors synchronized.
396 				 */
397 				irq.dest_id = old_dest_id;
398 				irq.dest_mode =
399 				    kvm_lapic_irq_dest_mode(
400 					!!e->fields.dest_mode);
401 				kvm_bitmap_or_dest_vcpus(ioapic->kvm, &irq,
402 							 &vcpu_bitmap);
403 			}
404 			kvm_make_scan_ioapic_request_mask(ioapic->kvm,
405 							  &vcpu_bitmap);
406 		} else {
407 			kvm_make_scan_ioapic_request(ioapic->kvm);
408 		}
409 		break;
410 	}
411 }
412 
413 static int ioapic_service(struct kvm_ioapic *ioapic, int irq, bool line_status)
414 {
415 	union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
416 	struct kvm_lapic_irq irqe;
417 	int ret;
418 
419 	if (entry->fields.mask ||
420 	    (entry->fields.trig_mode == IOAPIC_LEVEL_TRIG &&
421 	    entry->fields.remote_irr))
422 		return -1;
423 
424 	irqe.dest_id = entry->fields.dest_id;
425 	irqe.vector = entry->fields.vector;
426 	irqe.dest_mode = kvm_lapic_irq_dest_mode(!!entry->fields.dest_mode);
427 	irqe.trig_mode = entry->fields.trig_mode;
428 	irqe.delivery_mode = entry->fields.delivery_mode << 8;
429 	irqe.level = 1;
430 	irqe.shorthand = APIC_DEST_NOSHORT;
431 	irqe.msi_redir_hint = false;
432 
433 	if (irqe.trig_mode == IOAPIC_EDGE_TRIG)
434 		ioapic->irr_delivered |= 1 << irq;
435 
436 	if (irq == RTC_GSI && line_status) {
437 		/*
438 		 * pending_eoi cannot ever become negative (see
439 		 * rtc_status_pending_eoi_check_valid) and the caller
440 		 * ensures that it is only called if it is >= zero, namely
441 		 * if rtc_irq_check_coalesced returns false).
442 		 */
443 		BUG_ON(ioapic->rtc_status.pending_eoi != 0);
444 		ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe,
445 					       &ioapic->rtc_status.dest_map);
446 		ioapic->rtc_status.pending_eoi = (ret < 0 ? 0 : ret);
447 	} else
448 		ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, NULL);
449 
450 	if (ret && irqe.trig_mode == IOAPIC_LEVEL_TRIG)
451 		entry->fields.remote_irr = 1;
452 
453 	return ret;
454 }
455 
456 int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
457 		       int level, bool line_status)
458 {
459 	int ret, irq_level;
460 
461 	BUG_ON(irq < 0 || irq >= IOAPIC_NUM_PINS);
462 
463 	spin_lock(&ioapic->lock);
464 	irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
465 					 irq_source_id, level);
466 	ret = ioapic_set_irq(ioapic, irq, irq_level, line_status);
467 
468 	spin_unlock(&ioapic->lock);
469 
470 	return ret;
471 }
472 
473 void kvm_ioapic_clear_all(struct kvm_ioapic *ioapic, int irq_source_id)
474 {
475 	int i;
476 
477 	spin_lock(&ioapic->lock);
478 	for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
479 		__clear_bit(irq_source_id, &ioapic->irq_states[i]);
480 	spin_unlock(&ioapic->lock);
481 }
482 
483 static void kvm_ioapic_eoi_inject_work(struct work_struct *work)
484 {
485 	int i;
486 	struct kvm_ioapic *ioapic = container_of(work, struct kvm_ioapic,
487 						 eoi_inject.work);
488 	spin_lock(&ioapic->lock);
489 	for (i = 0; i < IOAPIC_NUM_PINS; i++) {
490 		union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
491 
492 		if (ent->fields.trig_mode != IOAPIC_LEVEL_TRIG)
493 			continue;
494 
495 		if (ioapic->irr & (1 << i) && !ent->fields.remote_irr)
496 			ioapic_service(ioapic, i, false);
497 	}
498 	spin_unlock(&ioapic->lock);
499 }
500 
501 #define IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT 10000
502 static void kvm_ioapic_update_eoi_one(struct kvm_vcpu *vcpu,
503 				      struct kvm_ioapic *ioapic,
504 				      int trigger_mode,
505 				      int pin)
506 {
507 	struct kvm_lapic *apic = vcpu->arch.apic;
508 	union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[pin];
509 
510 	/*
511 	 * We are dropping lock while calling ack notifiers because ack
512 	 * notifier callbacks for assigned devices call into IOAPIC
513 	 * recursively. Since remote_irr is cleared only after call
514 	 * to notifiers if the same vector will be delivered while lock
515 	 * is dropped it will be put into irr and will be delivered
516 	 * after ack notifier returns.
517 	 */
518 	spin_unlock(&ioapic->lock);
519 	kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, pin);
520 	spin_lock(&ioapic->lock);
521 
522 	if (trigger_mode != IOAPIC_LEVEL_TRIG ||
523 	    kvm_lapic_get_reg(apic, APIC_SPIV) & APIC_SPIV_DIRECTED_EOI)
524 		return;
525 
526 	ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
527 	ent->fields.remote_irr = 0;
528 	if (!ent->fields.mask && (ioapic->irr & (1 << pin))) {
529 		++ioapic->irq_eoi[pin];
530 		if (ioapic->irq_eoi[pin] == IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT) {
531 			/*
532 			 * Real hardware does not deliver the interrupt
533 			 * immediately during eoi broadcast, and this
534 			 * lets a buggy guest make slow progress
535 			 * even if it does not correctly handle a
536 			 * level-triggered interrupt.  Emulate this
537 			 * behavior if we detect an interrupt storm.
538 			 */
539 			schedule_delayed_work(&ioapic->eoi_inject, HZ / 100);
540 			ioapic->irq_eoi[pin] = 0;
541 			trace_kvm_ioapic_delayed_eoi_inj(ent->bits);
542 		} else {
543 			ioapic_service(ioapic, pin, false);
544 		}
545 	} else {
546 		ioapic->irq_eoi[pin] = 0;
547 	}
548 }
549 
550 void kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, int vector, int trigger_mode)
551 {
552 	int i;
553 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
554 
555 	spin_lock(&ioapic->lock);
556 	rtc_irq_eoi(ioapic, vcpu, vector);
557 	for (i = 0; i < IOAPIC_NUM_PINS; i++) {
558 		union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
559 
560 		if (ent->fields.vector != vector)
561 			continue;
562 		kvm_ioapic_update_eoi_one(vcpu, ioapic, trigger_mode, i);
563 	}
564 	spin_unlock(&ioapic->lock);
565 }
566 
567 static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
568 {
569 	return container_of(dev, struct kvm_ioapic, dev);
570 }
571 
572 static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
573 {
574 	return ((addr >= ioapic->base_address &&
575 		 (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
576 }
577 
578 static int ioapic_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *this,
579 				gpa_t addr, int len, void *val)
580 {
581 	struct kvm_ioapic *ioapic = to_ioapic(this);
582 	u32 result;
583 	if (!ioapic_in_range(ioapic, addr))
584 		return -EOPNOTSUPP;
585 
586 	ASSERT(!(addr & 0xf));	/* check alignment */
587 
588 	addr &= 0xff;
589 	spin_lock(&ioapic->lock);
590 	switch (addr) {
591 	case IOAPIC_REG_SELECT:
592 		result = ioapic->ioregsel;
593 		break;
594 
595 	case IOAPIC_REG_WINDOW:
596 		result = ioapic_read_indirect(ioapic, addr, len);
597 		break;
598 
599 	default:
600 		result = 0;
601 		break;
602 	}
603 	spin_unlock(&ioapic->lock);
604 
605 	switch (len) {
606 	case 8:
607 		*(u64 *) val = result;
608 		break;
609 	case 1:
610 	case 2:
611 	case 4:
612 		memcpy(val, (char *)&result, len);
613 		break;
614 	default:
615 		printk(KERN_WARNING "ioapic: wrong length %d\n", len);
616 	}
617 	return 0;
618 }
619 
620 static int ioapic_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *this,
621 				 gpa_t addr, int len, const void *val)
622 {
623 	struct kvm_ioapic *ioapic = to_ioapic(this);
624 	u32 data;
625 	if (!ioapic_in_range(ioapic, addr))
626 		return -EOPNOTSUPP;
627 
628 	ASSERT(!(addr & 0xf));	/* check alignment */
629 
630 	switch (len) {
631 	case 8:
632 	case 4:
633 		data = *(u32 *) val;
634 		break;
635 	case 2:
636 		data = *(u16 *) val;
637 		break;
638 	case 1:
639 		data = *(u8  *) val;
640 		break;
641 	default:
642 		printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
643 		return 0;
644 	}
645 
646 	addr &= 0xff;
647 	spin_lock(&ioapic->lock);
648 	switch (addr) {
649 	case IOAPIC_REG_SELECT:
650 		ioapic->ioregsel = data & 0xFF; /* 8-bit register */
651 		break;
652 
653 	case IOAPIC_REG_WINDOW:
654 		ioapic_write_indirect(ioapic, data);
655 		break;
656 
657 	default:
658 		break;
659 	}
660 	spin_unlock(&ioapic->lock);
661 	return 0;
662 }
663 
664 static void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
665 {
666 	int i;
667 
668 	cancel_delayed_work_sync(&ioapic->eoi_inject);
669 	for (i = 0; i < IOAPIC_NUM_PINS; i++)
670 		ioapic->redirtbl[i].fields.mask = 1;
671 	ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
672 	ioapic->ioregsel = 0;
673 	ioapic->irr = 0;
674 	ioapic->irr_delivered = 0;
675 	ioapic->id = 0;
676 	memset(ioapic->irq_eoi, 0x00, sizeof(ioapic->irq_eoi));
677 	rtc_irq_eoi_tracking_reset(ioapic);
678 }
679 
680 static const struct kvm_io_device_ops ioapic_mmio_ops = {
681 	.read     = ioapic_mmio_read,
682 	.write    = ioapic_mmio_write,
683 };
684 
685 int kvm_ioapic_init(struct kvm *kvm)
686 {
687 	struct kvm_ioapic *ioapic;
688 	int ret;
689 
690 	ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL_ACCOUNT);
691 	if (!ioapic)
692 		return -ENOMEM;
693 	spin_lock_init(&ioapic->lock);
694 	INIT_DELAYED_WORK(&ioapic->eoi_inject, kvm_ioapic_eoi_inject_work);
695 	kvm->arch.vioapic = ioapic;
696 	kvm_ioapic_reset(ioapic);
697 	kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
698 	ioapic->kvm = kvm;
699 	mutex_lock(&kvm->slots_lock);
700 	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, ioapic->base_address,
701 				      IOAPIC_MEM_LENGTH, &ioapic->dev);
702 	mutex_unlock(&kvm->slots_lock);
703 	if (ret < 0) {
704 		kvm->arch.vioapic = NULL;
705 		kfree(ioapic);
706 	}
707 
708 	return ret;
709 }
710 
711 void kvm_ioapic_destroy(struct kvm *kvm)
712 {
713 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
714 
715 	if (!ioapic)
716 		return;
717 
718 	cancel_delayed_work_sync(&ioapic->eoi_inject);
719 	mutex_lock(&kvm->slots_lock);
720 	kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
721 	mutex_unlock(&kvm->slots_lock);
722 	kvm->arch.vioapic = NULL;
723 	kfree(ioapic);
724 }
725 
726 void kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
727 {
728 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
729 
730 	spin_lock(&ioapic->lock);
731 	memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));
732 	state->irr &= ~ioapic->irr_delivered;
733 	spin_unlock(&ioapic->lock);
734 }
735 
736 void kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
737 {
738 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
739 
740 	spin_lock(&ioapic->lock);
741 	memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
742 	ioapic->irr = 0;
743 	ioapic->irr_delivered = 0;
744 	kvm_make_scan_ioapic_request(kvm);
745 	kvm_ioapic_inject_all(ioapic, state->irr);
746 	spin_unlock(&ioapic->lock);
747 }
748