xref: /linux/arch/x86/kvm/ioapic.c (revision e78f70bad29c5ae1e1076698b690b15794e9b81e)
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
30 
31 #include <linux/kvm_host.h>
32 #include <linux/kvm.h>
33 #include <linux/mm.h>
34 #include <linux/highmem.h>
35 #include <linux/smp.h>
36 #include <linux/hrtimer.h>
37 #include <linux/io.h>
38 #include <linux/slab.h>
39 #include <linux/export.h>
40 #include <linux/nospec.h>
41 #include <asm/processor.h>
42 #include <asm/page.h>
43 #include <asm/current.h>
44 #include <trace/events/kvm.h>
45 
46 #include "ioapic.h"
47 #include "lapic.h"
48 #include "irq.h"
49 
50 static int ioapic_service(struct kvm_ioapic *vioapic, int irq,
51 		bool line_status);
52 
53 static void kvm_ioapic_update_eoi_one(struct kvm_vcpu *vcpu,
54 				      struct kvm_ioapic *ioapic,
55 				      int trigger_mode,
56 				      int pin);
57 
58 static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic)
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 = ~0ULL;
77 
78 			if (redir_index < IOAPIC_NUM_PINS) {
79 				u32 index = array_index_nospec(
80 					redir_index, IOAPIC_NUM_PINS);
81 
82 				redir_content = ioapic->redirtbl[index].bits;
83 			}
84 
85 			result = (ioapic->ioregsel & 0x1) ?
86 			    (redir_content >> 32) & 0xffffffff :
87 			    redir_content & 0xffffffff;
88 			break;
89 		}
90 	}
91 
92 	return result;
93 }
94 
95 static void rtc_irq_eoi_tracking_reset(struct kvm_ioapic *ioapic)
96 {
97 	ioapic->rtc_status.pending_eoi = 0;
98 	bitmap_zero(ioapic->rtc_status.dest_map.map, KVM_MAX_VCPU_IDS);
99 }
100 
101 static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic);
102 
103 static void rtc_status_pending_eoi_check_valid(struct kvm_ioapic *ioapic)
104 {
105 	if (WARN_ON(ioapic->rtc_status.pending_eoi < 0))
106 		kvm_rtc_eoi_tracking_restore_all(ioapic);
107 }
108 
109 static void __rtc_irq_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
110 {
111 	bool new_val, old_val;
112 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
113 	struct dest_map *dest_map = &ioapic->rtc_status.dest_map;
114 	union kvm_ioapic_redirect_entry *e;
115 
116 	e = &ioapic->redirtbl[RTC_GSI];
117 	if (!kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
118 				 e->fields.dest_id,
119 				 kvm_lapic_irq_dest_mode(!!e->fields.dest_mode)))
120 		return;
121 
122 	new_val = kvm_apic_pending_eoi(vcpu, e->fields.vector);
123 	old_val = test_bit(vcpu->vcpu_id, dest_map->map);
124 
125 	if (new_val == old_val)
126 		return;
127 
128 	if (new_val) {
129 		__set_bit(vcpu->vcpu_id, dest_map->map);
130 		dest_map->vectors[vcpu->vcpu_id] = e->fields.vector;
131 		ioapic->rtc_status.pending_eoi++;
132 	} else {
133 		__clear_bit(vcpu->vcpu_id, dest_map->map);
134 		ioapic->rtc_status.pending_eoi--;
135 		rtc_status_pending_eoi_check_valid(ioapic);
136 	}
137 }
138 
139 void kvm_rtc_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
140 {
141 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
142 
143 	spin_lock(&ioapic->lock);
144 	__rtc_irq_eoi_tracking_restore_one(vcpu);
145 	spin_unlock(&ioapic->lock);
146 }
147 
148 static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic)
149 {
150 	struct kvm_vcpu *vcpu;
151 	unsigned long i;
152 
153 	if (RTC_GSI >= IOAPIC_NUM_PINS)
154 		return;
155 
156 	rtc_irq_eoi_tracking_reset(ioapic);
157 	kvm_for_each_vcpu(i, vcpu, ioapic->kvm)
158 	    __rtc_irq_eoi_tracking_restore_one(vcpu);
159 }
160 
161 static void rtc_irq_eoi(struct kvm_ioapic *ioapic, struct kvm_vcpu *vcpu,
162 			int vector)
163 {
164 	struct dest_map *dest_map = &ioapic->rtc_status.dest_map;
165 
166 	/* RTC special handling */
167 	if (test_bit(vcpu->vcpu_id, dest_map->map) &&
168 	    (vector == dest_map->vectors[vcpu->vcpu_id]) &&
169 	    (test_and_clear_bit(vcpu->vcpu_id,
170 				ioapic->rtc_status.dest_map.map))) {
171 		--ioapic->rtc_status.pending_eoi;
172 		rtc_status_pending_eoi_check_valid(ioapic);
173 	}
174 }
175 
176 static bool rtc_irq_check_coalesced(struct kvm_ioapic *ioapic)
177 {
178 	if (ioapic->rtc_status.pending_eoi > 0)
179 		return true; /* coalesced */
180 
181 	return false;
182 }
183 
184 static void ioapic_lazy_update_eoi(struct kvm_ioapic *ioapic, int irq)
185 {
186 	unsigned long i;
187 	struct kvm_vcpu *vcpu;
188 	union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
189 
190 	kvm_for_each_vcpu(i, vcpu, ioapic->kvm) {
191 		if (!kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
192 					 entry->fields.dest_id,
193 					 entry->fields.dest_mode) ||
194 		    kvm_apic_pending_eoi(vcpu, entry->fields.vector))
195 			continue;
196 
197 		/*
198 		 * If no longer has pending EOI in LAPICs, update
199 		 * EOI for this vector.
200 		 */
201 		rtc_irq_eoi(ioapic, vcpu, entry->fields.vector);
202 		break;
203 	}
204 }
205 
206 static int ioapic_set_irq(struct kvm_ioapic *ioapic, unsigned int irq,
207 		int irq_level, bool line_status)
208 {
209 	union kvm_ioapic_redirect_entry entry;
210 	u32 mask = 1 << irq;
211 	u32 old_irr;
212 	int edge, ret;
213 
214 	entry = ioapic->redirtbl[irq];
215 	edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
216 
217 	if (!irq_level) {
218 		ioapic->irr &= ~mask;
219 		ret = 1;
220 		goto out;
221 	}
222 
223 	/*
224 	 * AMD SVM AVIC accelerate EOI write iff the interrupt is edge
225 	 * triggered, in which case the in-kernel IOAPIC will not be able
226 	 * to receive the EOI.  In this case, we do a lazy update of the
227 	 * pending EOI when trying to set IOAPIC irq.
228 	 */
229 	if (edge && kvm_apicv_activated(ioapic->kvm))
230 		ioapic_lazy_update_eoi(ioapic, irq);
231 
232 	/*
233 	 * Return 0 for coalesced interrupts; for edge-triggered interrupts,
234 	 * this only happens if a previous edge has not been delivered due
235 	 * to masking.  For level interrupts, the remote_irr field tells
236 	 * us if the interrupt is waiting for an EOI.
237 	 *
238 	 * RTC is special: it is edge-triggered, but userspace likes to know
239 	 * if it has been already ack-ed via EOI because coalesced RTC
240 	 * interrupts lead to time drift in Windows guests.  So we track
241 	 * EOI manually for the RTC interrupt.
242 	 */
243 	if (irq == RTC_GSI && line_status &&
244 		rtc_irq_check_coalesced(ioapic)) {
245 		ret = 0;
246 		goto out;
247 	}
248 
249 	old_irr = ioapic->irr;
250 	ioapic->irr |= mask;
251 	if (edge) {
252 		ioapic->irr_delivered &= ~mask;
253 		if (old_irr == ioapic->irr) {
254 			ret = 0;
255 			goto out;
256 		}
257 	}
258 
259 	ret = ioapic_service(ioapic, irq, line_status);
260 
261 out:
262 	trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
263 	return ret;
264 }
265 
266 static void kvm_ioapic_inject_all(struct kvm_ioapic *ioapic, unsigned long irr)
267 {
268 	u32 idx;
269 
270 	rtc_irq_eoi_tracking_reset(ioapic);
271 	for_each_set_bit(idx, &irr, IOAPIC_NUM_PINS)
272 		ioapic_set_irq(ioapic, idx, 1, true);
273 
274 	kvm_rtc_eoi_tracking_restore_all(ioapic);
275 }
276 
277 
278 void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, ulong *ioapic_handled_vectors)
279 {
280 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
281 	struct dest_map *dest_map = &ioapic->rtc_status.dest_map;
282 	union kvm_ioapic_redirect_entry *e;
283 	int index;
284 
285 	spin_lock(&ioapic->lock);
286 
287 	/* Make sure we see any missing RTC EOI */
288 	if (test_bit(vcpu->vcpu_id, dest_map->map))
289 		__set_bit(dest_map->vectors[vcpu->vcpu_id],
290 			  ioapic_handled_vectors);
291 
292 	for (index = 0; index < IOAPIC_NUM_PINS; index++) {
293 		e = &ioapic->redirtbl[index];
294 		if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
295 		    kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index) ||
296 		    index == RTC_GSI) {
297 			u16 dm = kvm_lapic_irq_dest_mode(!!e->fields.dest_mode);
298 
299 			kvm_scan_ioapic_irq(vcpu, e->fields.dest_id, dm,
300 					    e->fields.vector, ioapic_handled_vectors);
301 		}
302 	}
303 	spin_unlock(&ioapic->lock);
304 }
305 
306 void kvm_arch_post_irq_ack_notifier_list_update(struct kvm *kvm)
307 {
308 	if (!ioapic_in_kernel(kvm))
309 		return;
310 	kvm_make_scan_ioapic_request(kvm);
311 }
312 
313 static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
314 {
315 	unsigned index;
316 	bool mask_before, mask_after;
317 	union kvm_ioapic_redirect_entry *e;
318 	int old_remote_irr, old_delivery_status, old_dest_id, old_dest_mode;
319 	DECLARE_BITMAP(vcpu_bitmap, KVM_MAX_VCPUS);
320 
321 	switch (ioapic->ioregsel) {
322 	case IOAPIC_REG_VERSION:
323 		/* Writes are ignored. */
324 		break;
325 
326 	case IOAPIC_REG_APIC_ID:
327 		ioapic->id = (val >> 24) & 0xf;
328 		break;
329 
330 	case IOAPIC_REG_ARB_ID:
331 		break;
332 
333 	default:
334 		index = (ioapic->ioregsel - 0x10) >> 1;
335 
336 		if (index >= IOAPIC_NUM_PINS)
337 			return;
338 		index = array_index_nospec(index, IOAPIC_NUM_PINS);
339 		e = &ioapic->redirtbl[index];
340 		mask_before = e->fields.mask;
341 		/* Preserve read-only fields */
342 		old_remote_irr = e->fields.remote_irr;
343 		old_delivery_status = e->fields.delivery_status;
344 		old_dest_id = e->fields.dest_id;
345 		old_dest_mode = e->fields.dest_mode;
346 		if (ioapic->ioregsel & 1) {
347 			e->bits &= 0xffffffff;
348 			e->bits |= (u64) val << 32;
349 		} else {
350 			e->bits &= ~0xffffffffULL;
351 			e->bits |= (u32) val;
352 		}
353 		e->fields.remote_irr = old_remote_irr;
354 		e->fields.delivery_status = old_delivery_status;
355 
356 		/*
357 		 * Some OSes (Linux, Xen) assume that Remote IRR bit will
358 		 * be cleared by IOAPIC hardware when the entry is configured
359 		 * as edge-triggered. This behavior is used to simulate an
360 		 * explicit EOI on IOAPICs that don't have the EOI register.
361 		 */
362 		if (e->fields.trig_mode == IOAPIC_EDGE_TRIG)
363 			e->fields.remote_irr = 0;
364 
365 		mask_after = e->fields.mask;
366 		if (mask_before != mask_after)
367 			kvm_fire_mask_notifiers(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index, mask_after);
368 		if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG &&
369 		    ioapic->irr & (1 << index) && !e->fields.mask && !e->fields.remote_irr) {
370 			/*
371 			 * Pending status in irr may be outdated: the IRQ line may have
372 			 * already been deasserted by a device while the IRQ was masked.
373 			 * This occurs, for instance, if the interrupt is handled in a
374 			 * Linux guest as a oneshot interrupt (IRQF_ONESHOT). In this
375 			 * case the guest acknowledges the interrupt to the device in
376 			 * its threaded irq handler, i.e. after the EOI but before
377 			 * unmasking, so at the time of unmasking the IRQ line is
378 			 * already down but our pending irr bit is still set. In such
379 			 * cases, injecting this pending interrupt to the guest is
380 			 * buggy: the guest will receive an extra unwanted interrupt.
381 			 *
382 			 * So we need to check here if the IRQ is actually still pending.
383 			 * As we are generally not able to probe the IRQ line status
384 			 * directly, we do it through irqfd resampler. Namely, we clear
385 			 * the pending status and notify the resampler that this interrupt
386 			 * is done, without actually injecting it into the guest. If the
387 			 * IRQ line is actually already deasserted, we are done. If it is
388 			 * still asserted, a new interrupt will be shortly triggered
389 			 * through irqfd and injected into the guest.
390 			 *
391 			 * If, however, it's not possible to resample (no irqfd resampler
392 			 * registered for this irq), then unconditionally inject this
393 			 * pending interrupt into the guest, so the guest will not miss
394 			 * an interrupt, although may get an extra unwanted interrupt.
395 			 */
396 			if (kvm_notify_irqfd_resampler(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index))
397 				ioapic->irr &= ~(1 << index);
398 			else
399 				ioapic_service(ioapic, index, false);
400 		}
401 		if (e->fields.delivery_mode == APIC_DM_FIXED) {
402 			struct kvm_lapic_irq irq;
403 
404 			irq.vector = e->fields.vector;
405 			irq.delivery_mode = e->fields.delivery_mode << 8;
406 			irq.dest_mode =
407 			    kvm_lapic_irq_dest_mode(!!e->fields.dest_mode);
408 			irq.level = false;
409 			irq.trig_mode = e->fields.trig_mode;
410 			irq.shorthand = APIC_DEST_NOSHORT;
411 			irq.dest_id = e->fields.dest_id;
412 			irq.msi_redir_hint = false;
413 			bitmap_zero(vcpu_bitmap, KVM_MAX_VCPUS);
414 			kvm_bitmap_or_dest_vcpus(ioapic->kvm, &irq,
415 						 vcpu_bitmap);
416 			if (old_dest_mode != e->fields.dest_mode ||
417 			    old_dest_id != e->fields.dest_id) {
418 				/*
419 				 * Update vcpu_bitmap with vcpus specified in
420 				 * the previous request as well. This is done to
421 				 * keep ioapic_handled_vectors synchronized.
422 				 */
423 				irq.dest_id = old_dest_id;
424 				irq.dest_mode =
425 				    kvm_lapic_irq_dest_mode(
426 					!!e->fields.dest_mode);
427 				kvm_bitmap_or_dest_vcpus(ioapic->kvm, &irq,
428 							 vcpu_bitmap);
429 			}
430 			kvm_make_scan_ioapic_request_mask(ioapic->kvm,
431 							  vcpu_bitmap);
432 		} else {
433 			kvm_make_scan_ioapic_request(ioapic->kvm);
434 		}
435 		break;
436 	}
437 }
438 
439 static int ioapic_service(struct kvm_ioapic *ioapic, int irq, bool line_status)
440 {
441 	union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
442 	struct kvm_lapic_irq irqe;
443 	int ret;
444 
445 	if (entry->fields.mask ||
446 	    (entry->fields.trig_mode == IOAPIC_LEVEL_TRIG &&
447 	    entry->fields.remote_irr))
448 		return -1;
449 
450 	irqe.dest_id = entry->fields.dest_id;
451 	irqe.vector = entry->fields.vector;
452 	irqe.dest_mode = kvm_lapic_irq_dest_mode(!!entry->fields.dest_mode);
453 	irqe.trig_mode = entry->fields.trig_mode;
454 	irqe.delivery_mode = entry->fields.delivery_mode << 8;
455 	irqe.level = 1;
456 	irqe.shorthand = APIC_DEST_NOSHORT;
457 	irqe.msi_redir_hint = false;
458 
459 	if (irqe.trig_mode == IOAPIC_EDGE_TRIG)
460 		ioapic->irr_delivered |= 1 << irq;
461 
462 	if (irq == RTC_GSI && line_status) {
463 		/*
464 		 * pending_eoi cannot ever become negative (see
465 		 * rtc_status_pending_eoi_check_valid) and the caller
466 		 * ensures that it is only called if it is >= zero, namely
467 		 * if rtc_irq_check_coalesced returns false).
468 		 */
469 		BUG_ON(ioapic->rtc_status.pending_eoi != 0);
470 		ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe,
471 					       &ioapic->rtc_status.dest_map);
472 		ioapic->rtc_status.pending_eoi = (ret < 0 ? 0 : ret);
473 	} else
474 		ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, NULL);
475 
476 	if (ret && irqe.trig_mode == IOAPIC_LEVEL_TRIG)
477 		entry->fields.remote_irr = 1;
478 
479 	return ret;
480 }
481 
482 int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
483 		       int level, bool line_status)
484 {
485 	int ret, irq_level;
486 
487 	BUG_ON(irq < 0 || irq >= IOAPIC_NUM_PINS);
488 
489 	spin_lock(&ioapic->lock);
490 	irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
491 					 irq_source_id, level);
492 	ret = ioapic_set_irq(ioapic, irq, irq_level, line_status);
493 
494 	spin_unlock(&ioapic->lock);
495 
496 	return ret;
497 }
498 
499 void kvm_ioapic_clear_all(struct kvm_ioapic *ioapic, int irq_source_id)
500 {
501 	int i;
502 
503 	spin_lock(&ioapic->lock);
504 	for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
505 		__clear_bit(irq_source_id, &ioapic->irq_states[i]);
506 	spin_unlock(&ioapic->lock);
507 }
508 
509 static void kvm_ioapic_eoi_inject_work(struct work_struct *work)
510 {
511 	int i;
512 	struct kvm_ioapic *ioapic = container_of(work, struct kvm_ioapic,
513 						 eoi_inject.work);
514 	spin_lock(&ioapic->lock);
515 	for (i = 0; i < IOAPIC_NUM_PINS; i++) {
516 		union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
517 
518 		if (ent->fields.trig_mode != IOAPIC_LEVEL_TRIG)
519 			continue;
520 
521 		if (ioapic->irr & (1 << i) && !ent->fields.remote_irr)
522 			ioapic_service(ioapic, i, false);
523 	}
524 	spin_unlock(&ioapic->lock);
525 }
526 
527 #define IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT 10000
528 static void kvm_ioapic_update_eoi_one(struct kvm_vcpu *vcpu,
529 				      struct kvm_ioapic *ioapic,
530 				      int trigger_mode,
531 				      int pin)
532 {
533 	struct kvm_lapic *apic = vcpu->arch.apic;
534 	union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[pin];
535 
536 	/*
537 	 * We are dropping lock while calling ack notifiers because ack
538 	 * notifier callbacks for assigned devices call into IOAPIC
539 	 * recursively. Since remote_irr is cleared only after call
540 	 * to notifiers if the same vector will be delivered while lock
541 	 * is dropped it will be put into irr and will be delivered
542 	 * after ack notifier returns.
543 	 */
544 	spin_unlock(&ioapic->lock);
545 	kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, pin);
546 	spin_lock(&ioapic->lock);
547 
548 	if (trigger_mode != IOAPIC_LEVEL_TRIG ||
549 	    kvm_lapic_get_reg(apic, APIC_SPIV) & APIC_SPIV_DIRECTED_EOI)
550 		return;
551 
552 	ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
553 	ent->fields.remote_irr = 0;
554 	if (!ent->fields.mask && (ioapic->irr & (1 << pin))) {
555 		++ioapic->irq_eoi[pin];
556 		if (ioapic->irq_eoi[pin] == IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT) {
557 			/*
558 			 * Real hardware does not deliver the interrupt
559 			 * immediately during eoi broadcast, and this
560 			 * lets a buggy guest make slow progress
561 			 * even if it does not correctly handle a
562 			 * level-triggered interrupt.  Emulate this
563 			 * behavior if we detect an interrupt storm.
564 			 */
565 			schedule_delayed_work(&ioapic->eoi_inject, HZ / 100);
566 			ioapic->irq_eoi[pin] = 0;
567 			trace_kvm_ioapic_delayed_eoi_inj(ent->bits);
568 		} else {
569 			ioapic_service(ioapic, pin, false);
570 		}
571 	} else {
572 		ioapic->irq_eoi[pin] = 0;
573 	}
574 }
575 
576 void kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, int vector, int trigger_mode)
577 {
578 	int i;
579 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
580 
581 	spin_lock(&ioapic->lock);
582 	rtc_irq_eoi(ioapic, vcpu, vector);
583 	for (i = 0; i < IOAPIC_NUM_PINS; i++) {
584 		union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
585 
586 		if (ent->fields.vector != vector)
587 			continue;
588 		kvm_ioapic_update_eoi_one(vcpu, ioapic, trigger_mode, i);
589 	}
590 	spin_unlock(&ioapic->lock);
591 }
592 
593 static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
594 {
595 	return container_of(dev, struct kvm_ioapic, dev);
596 }
597 
598 static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
599 {
600 	return ((addr >= ioapic->base_address &&
601 		 (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
602 }
603 
604 static int ioapic_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *this,
605 				gpa_t addr, int len, void *val)
606 {
607 	struct kvm_ioapic *ioapic = to_ioapic(this);
608 	u32 result;
609 	if (!ioapic_in_range(ioapic, addr))
610 		return -EOPNOTSUPP;
611 
612 	ASSERT(!(addr & 0xf));	/* check alignment */
613 
614 	addr &= 0xff;
615 	spin_lock(&ioapic->lock);
616 	switch (addr) {
617 	case IOAPIC_REG_SELECT:
618 		result = ioapic->ioregsel;
619 		break;
620 
621 	case IOAPIC_REG_WINDOW:
622 		result = ioapic_read_indirect(ioapic);
623 		break;
624 
625 	default:
626 		result = 0;
627 		break;
628 	}
629 	spin_unlock(&ioapic->lock);
630 
631 	switch (len) {
632 	case 8:
633 		*(u64 *) val = result;
634 		break;
635 	case 1:
636 	case 2:
637 	case 4:
638 		memcpy(val, (char *)&result, len);
639 		break;
640 	default:
641 		printk(KERN_WARNING "ioapic: wrong length %d\n", len);
642 	}
643 	return 0;
644 }
645 
646 static int ioapic_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *this,
647 				 gpa_t addr, int len, const void *val)
648 {
649 	struct kvm_ioapic *ioapic = to_ioapic(this);
650 	u32 data;
651 	if (!ioapic_in_range(ioapic, addr))
652 		return -EOPNOTSUPP;
653 
654 	ASSERT(!(addr & 0xf));	/* check alignment */
655 
656 	switch (len) {
657 	case 8:
658 	case 4:
659 		data = *(u32 *) val;
660 		break;
661 	case 2:
662 		data = *(u16 *) val;
663 		break;
664 	case 1:
665 		data = *(u8  *) val;
666 		break;
667 	default:
668 		printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
669 		return 0;
670 	}
671 
672 	addr &= 0xff;
673 	spin_lock(&ioapic->lock);
674 	switch (addr) {
675 	case IOAPIC_REG_SELECT:
676 		ioapic->ioregsel = data & 0xFF; /* 8-bit register */
677 		break;
678 
679 	case IOAPIC_REG_WINDOW:
680 		ioapic_write_indirect(ioapic, data);
681 		break;
682 
683 	default:
684 		break;
685 	}
686 	spin_unlock(&ioapic->lock);
687 	return 0;
688 }
689 
690 static void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
691 {
692 	int i;
693 
694 	cancel_delayed_work_sync(&ioapic->eoi_inject);
695 	for (i = 0; i < IOAPIC_NUM_PINS; i++)
696 		ioapic->redirtbl[i].fields.mask = 1;
697 	ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
698 	ioapic->ioregsel = 0;
699 	ioapic->irr = 0;
700 	ioapic->irr_delivered = 0;
701 	ioapic->id = 0;
702 	memset(ioapic->irq_eoi, 0x00, sizeof(ioapic->irq_eoi));
703 	rtc_irq_eoi_tracking_reset(ioapic);
704 }
705 
706 static const struct kvm_io_device_ops ioapic_mmio_ops = {
707 	.read     = ioapic_mmio_read,
708 	.write    = ioapic_mmio_write,
709 };
710 
711 int kvm_ioapic_init(struct kvm *kvm)
712 {
713 	struct kvm_ioapic *ioapic;
714 	int ret;
715 
716 	ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL_ACCOUNT);
717 	if (!ioapic)
718 		return -ENOMEM;
719 	spin_lock_init(&ioapic->lock);
720 	INIT_DELAYED_WORK(&ioapic->eoi_inject, kvm_ioapic_eoi_inject_work);
721 	kvm->arch.vioapic = ioapic;
722 	kvm_ioapic_reset(ioapic);
723 	kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
724 	ioapic->kvm = kvm;
725 	mutex_lock(&kvm->slots_lock);
726 	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, ioapic->base_address,
727 				      IOAPIC_MEM_LENGTH, &ioapic->dev);
728 	mutex_unlock(&kvm->slots_lock);
729 	if (ret < 0) {
730 		kvm->arch.vioapic = NULL;
731 		kfree(ioapic);
732 	}
733 
734 	return ret;
735 }
736 
737 void kvm_ioapic_destroy(struct kvm *kvm)
738 {
739 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
740 
741 	if (!ioapic)
742 		return;
743 
744 	cancel_delayed_work_sync(&ioapic->eoi_inject);
745 	mutex_lock(&kvm->slots_lock);
746 	kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
747 	mutex_unlock(&kvm->slots_lock);
748 	kvm->arch.vioapic = NULL;
749 	kfree(ioapic);
750 }
751 
752 void kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
753 {
754 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
755 
756 	spin_lock(&ioapic->lock);
757 	memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));
758 	state->irr &= ~ioapic->irr_delivered;
759 	spin_unlock(&ioapic->lock);
760 }
761 
762 void kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
763 {
764 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
765 
766 	spin_lock(&ioapic->lock);
767 	memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
768 	ioapic->irr = 0;
769 	ioapic->irr_delivered = 0;
770 	kvm_make_scan_ioapic_request(kvm);
771 	kvm_ioapic_inject_all(ioapic, state->irr);
772 	spin_unlock(&ioapic->lock);
773 }
774