xref: /openbmc/linux/arch/x86/kvm/ioapic.c (revision 5f2fb52fac15a8a8e10ce020dd532504a8abfc4e)
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 unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
53 					  unsigned long addr,
54 					  unsigned long length)
55 {
56 	unsigned long result = 0;
57 
58 	switch (ioapic->ioregsel) {
59 	case IOAPIC_REG_VERSION:
60 		result = ((((IOAPIC_NUM_PINS - 1) & 0xff) << 16)
61 			  | (IOAPIC_VERSION_ID & 0xff));
62 		break;
63 
64 	case IOAPIC_REG_APIC_ID:
65 	case IOAPIC_REG_ARB_ID:
66 		result = ((ioapic->id & 0xf) << 24);
67 		break;
68 
69 	default:
70 		{
71 			u32 redir_index = (ioapic->ioregsel - 0x10) >> 1;
72 			u64 redir_content = ~0ULL;
73 
74 			if (redir_index < IOAPIC_NUM_PINS) {
75 				u32 index = array_index_nospec(
76 					redir_index, IOAPIC_NUM_PINS);
77 
78 				redir_content = ioapic->redirtbl[index].bits;
79 			}
80 
81 			result = (ioapic->ioregsel & 0x1) ?
82 			    (redir_content >> 32) & 0xffffffff :
83 			    redir_content & 0xffffffff;
84 			break;
85 		}
86 	}
87 
88 	return result;
89 }
90 
91 static void rtc_irq_eoi_tracking_reset(struct kvm_ioapic *ioapic)
92 {
93 	ioapic->rtc_status.pending_eoi = 0;
94 	bitmap_zero(ioapic->rtc_status.dest_map.map, KVM_MAX_VCPU_ID);
95 }
96 
97 static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic);
98 
99 static void rtc_status_pending_eoi_check_valid(struct kvm_ioapic *ioapic)
100 {
101 	if (WARN_ON(ioapic->rtc_status.pending_eoi < 0))
102 		kvm_rtc_eoi_tracking_restore_all(ioapic);
103 }
104 
105 static void __rtc_irq_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
106 {
107 	bool new_val, old_val;
108 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
109 	struct dest_map *dest_map = &ioapic->rtc_status.dest_map;
110 	union kvm_ioapic_redirect_entry *e;
111 
112 	e = &ioapic->redirtbl[RTC_GSI];
113 	if (!kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
114 				 e->fields.dest_id,
115 				 kvm_lapic_irq_dest_mode(!!e->fields.dest_mode)))
116 		return;
117 
118 	new_val = kvm_apic_pending_eoi(vcpu, e->fields.vector);
119 	old_val = test_bit(vcpu->vcpu_id, dest_map->map);
120 
121 	if (new_val == old_val)
122 		return;
123 
124 	if (new_val) {
125 		__set_bit(vcpu->vcpu_id, dest_map->map);
126 		dest_map->vectors[vcpu->vcpu_id] = e->fields.vector;
127 		ioapic->rtc_status.pending_eoi++;
128 	} else {
129 		__clear_bit(vcpu->vcpu_id, dest_map->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,
160 			       ioapic->rtc_status.dest_map.map)) {
161 		--ioapic->rtc_status.pending_eoi;
162 		rtc_status_pending_eoi_check_valid(ioapic);
163 	}
164 }
165 
166 static bool rtc_irq_check_coalesced(struct kvm_ioapic *ioapic)
167 {
168 	if (ioapic->rtc_status.pending_eoi > 0)
169 		return true; /* coalesced */
170 
171 	return false;
172 }
173 
174 static int ioapic_set_irq(struct kvm_ioapic *ioapic, unsigned int irq,
175 		int irq_level, bool line_status)
176 {
177 	union kvm_ioapic_redirect_entry entry;
178 	u32 mask = 1 << irq;
179 	u32 old_irr;
180 	int edge, ret;
181 
182 	entry = ioapic->redirtbl[irq];
183 	edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
184 
185 	if (!irq_level) {
186 		ioapic->irr &= ~mask;
187 		ret = 1;
188 		goto out;
189 	}
190 
191 	/*
192 	 * Return 0 for coalesced interrupts; for edge-triggered interrupts,
193 	 * this only happens if a previous edge has not been delivered due
194 	 * to masking.  For level interrupts, the remote_irr field tells
195 	 * us if the interrupt is waiting for an EOI.
196 	 *
197 	 * RTC is special: it is edge-triggered, but userspace likes to know
198 	 * if it has been already ack-ed via EOI because coalesced RTC
199 	 * interrupts lead to time drift in Windows guests.  So we track
200 	 * EOI manually for the RTC interrupt.
201 	 */
202 	if (irq == RTC_GSI && line_status &&
203 		rtc_irq_check_coalesced(ioapic)) {
204 		ret = 0;
205 		goto out;
206 	}
207 
208 	old_irr = ioapic->irr;
209 	ioapic->irr |= mask;
210 	if (edge) {
211 		ioapic->irr_delivered &= ~mask;
212 		if (old_irr == ioapic->irr) {
213 			ret = 0;
214 			goto out;
215 		}
216 	}
217 
218 	ret = ioapic_service(ioapic, irq, line_status);
219 
220 out:
221 	trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
222 	return ret;
223 }
224 
225 static void kvm_ioapic_inject_all(struct kvm_ioapic *ioapic, unsigned long irr)
226 {
227 	u32 idx;
228 
229 	rtc_irq_eoi_tracking_reset(ioapic);
230 	for_each_set_bit(idx, &irr, IOAPIC_NUM_PINS)
231 		ioapic_set_irq(ioapic, idx, 1, true);
232 
233 	kvm_rtc_eoi_tracking_restore_all(ioapic);
234 }
235 
236 
237 void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, ulong *ioapic_handled_vectors)
238 {
239 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
240 	struct dest_map *dest_map = &ioapic->rtc_status.dest_map;
241 	union kvm_ioapic_redirect_entry *e;
242 	int index;
243 
244 	spin_lock(&ioapic->lock);
245 
246 	/* Make sure we see any missing RTC EOI */
247 	if (test_bit(vcpu->vcpu_id, dest_map->map))
248 		__set_bit(dest_map->vectors[vcpu->vcpu_id],
249 			  ioapic_handled_vectors);
250 
251 	for (index = 0; index < IOAPIC_NUM_PINS; index++) {
252 		e = &ioapic->redirtbl[index];
253 		if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
254 		    kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index) ||
255 		    index == RTC_GSI) {
256 			u16 dm = kvm_lapic_irq_dest_mode(!!e->fields.dest_mode);
257 
258 			if (kvm_apic_match_dest(vcpu, NULL, APIC_DEST_NOSHORT,
259 						e->fields.dest_id, dm) ||
260 			    kvm_apic_pending_eoi(vcpu, e->fields.vector))
261 				__set_bit(e->fields.vector,
262 					  ioapic_handled_vectors);
263 		}
264 	}
265 	spin_unlock(&ioapic->lock);
266 }
267 
268 void kvm_arch_post_irq_ack_notifier_list_update(struct kvm *kvm)
269 {
270 	if (!ioapic_in_kernel(kvm))
271 		return;
272 	kvm_make_scan_ioapic_request(kvm);
273 }
274 
275 static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
276 {
277 	unsigned index;
278 	bool mask_before, mask_after;
279 	union kvm_ioapic_redirect_entry *e;
280 	unsigned long vcpu_bitmap;
281 	int old_remote_irr, old_delivery_status, old_dest_id, old_dest_mode;
282 
283 	switch (ioapic->ioregsel) {
284 	case IOAPIC_REG_VERSION:
285 		/* Writes are ignored. */
286 		break;
287 
288 	case IOAPIC_REG_APIC_ID:
289 		ioapic->id = (val >> 24) & 0xf;
290 		break;
291 
292 	case IOAPIC_REG_ARB_ID:
293 		break;
294 
295 	default:
296 		index = (ioapic->ioregsel - 0x10) >> 1;
297 
298 		if (index >= IOAPIC_NUM_PINS)
299 			return;
300 		index = array_index_nospec(index, IOAPIC_NUM_PINS);
301 		e = &ioapic->redirtbl[index];
302 		mask_before = e->fields.mask;
303 		/* Preserve read-only fields */
304 		old_remote_irr = e->fields.remote_irr;
305 		old_delivery_status = e->fields.delivery_status;
306 		old_dest_id = e->fields.dest_id;
307 		old_dest_mode = e->fields.dest_mode;
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 		}
315 		e->fields.remote_irr = old_remote_irr;
316 		e->fields.delivery_status = old_delivery_status;
317 
318 		/*
319 		 * Some OSes (Linux, Xen) assume that Remote IRR bit will
320 		 * be cleared by IOAPIC hardware when the entry is configured
321 		 * as edge-triggered. This behavior is used to simulate an
322 		 * explicit EOI on IOAPICs that don't have the EOI register.
323 		 */
324 		if (e->fields.trig_mode == IOAPIC_EDGE_TRIG)
325 			e->fields.remote_irr = 0;
326 
327 		mask_after = e->fields.mask;
328 		if (mask_before != mask_after)
329 			kvm_fire_mask_notifiers(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index, mask_after);
330 		if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG
331 		    && ioapic->irr & (1 << index))
332 			ioapic_service(ioapic, index, false);
333 		if (e->fields.delivery_mode == APIC_DM_FIXED) {
334 			struct kvm_lapic_irq irq;
335 
336 			irq.shorthand = APIC_DEST_NOSHORT;
337 			irq.vector = e->fields.vector;
338 			irq.delivery_mode = e->fields.delivery_mode << 8;
339 			irq.dest_id = e->fields.dest_id;
340 			irq.dest_mode =
341 			    kvm_lapic_irq_dest_mode(!!e->fields.dest_mode);
342 			bitmap_zero(&vcpu_bitmap, 16);
343 			kvm_bitmap_or_dest_vcpus(ioapic->kvm, &irq,
344 						 &vcpu_bitmap);
345 			if (old_dest_mode != e->fields.dest_mode ||
346 			    old_dest_id != e->fields.dest_id) {
347 				/*
348 				 * Update vcpu_bitmap with vcpus specified in
349 				 * the previous request as well. This is done to
350 				 * keep ioapic_handled_vectors synchronized.
351 				 */
352 				irq.dest_id = old_dest_id;
353 				irq.dest_mode =
354 				    kvm_lapic_irq_dest_mode(
355 					!!e->fields.dest_mode);
356 				kvm_bitmap_or_dest_vcpus(ioapic->kvm, &irq,
357 							 &vcpu_bitmap);
358 			}
359 			kvm_make_scan_ioapic_request_mask(ioapic->kvm,
360 							  &vcpu_bitmap);
361 		} else {
362 			kvm_make_scan_ioapic_request(ioapic->kvm);
363 		}
364 		break;
365 	}
366 }
367 
368 static int ioapic_service(struct kvm_ioapic *ioapic, int irq, bool line_status)
369 {
370 	union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
371 	struct kvm_lapic_irq irqe;
372 	int ret;
373 
374 	if (entry->fields.mask ||
375 	    (entry->fields.trig_mode == IOAPIC_LEVEL_TRIG &&
376 	    entry->fields.remote_irr))
377 		return -1;
378 
379 	irqe.dest_id = entry->fields.dest_id;
380 	irqe.vector = entry->fields.vector;
381 	irqe.dest_mode = kvm_lapic_irq_dest_mode(!!entry->fields.dest_mode);
382 	irqe.trig_mode = entry->fields.trig_mode;
383 	irqe.delivery_mode = entry->fields.delivery_mode << 8;
384 	irqe.level = 1;
385 	irqe.shorthand = APIC_DEST_NOSHORT;
386 	irqe.msi_redir_hint = false;
387 
388 	if (irqe.trig_mode == IOAPIC_EDGE_TRIG)
389 		ioapic->irr_delivered |= 1 << irq;
390 
391 	if (irq == RTC_GSI && line_status) {
392 		/*
393 		 * pending_eoi cannot ever become negative (see
394 		 * rtc_status_pending_eoi_check_valid) and the caller
395 		 * ensures that it is only called if it is >= zero, namely
396 		 * if rtc_irq_check_coalesced returns false).
397 		 */
398 		BUG_ON(ioapic->rtc_status.pending_eoi != 0);
399 		ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe,
400 					       &ioapic->rtc_status.dest_map);
401 		ioapic->rtc_status.pending_eoi = (ret < 0 ? 0 : ret);
402 	} else
403 		ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, NULL);
404 
405 	if (ret && irqe.trig_mode == IOAPIC_LEVEL_TRIG)
406 		entry->fields.remote_irr = 1;
407 
408 	return ret;
409 }
410 
411 int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
412 		       int level, bool line_status)
413 {
414 	int ret, irq_level;
415 
416 	BUG_ON(irq < 0 || irq >= IOAPIC_NUM_PINS);
417 
418 	spin_lock(&ioapic->lock);
419 	irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
420 					 irq_source_id, level);
421 	ret = ioapic_set_irq(ioapic, irq, irq_level, line_status);
422 
423 	spin_unlock(&ioapic->lock);
424 
425 	return ret;
426 }
427 
428 void kvm_ioapic_clear_all(struct kvm_ioapic *ioapic, int irq_source_id)
429 {
430 	int i;
431 
432 	spin_lock(&ioapic->lock);
433 	for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
434 		__clear_bit(irq_source_id, &ioapic->irq_states[i]);
435 	spin_unlock(&ioapic->lock);
436 }
437 
438 static void kvm_ioapic_eoi_inject_work(struct work_struct *work)
439 {
440 	int i;
441 	struct kvm_ioapic *ioapic = container_of(work, struct kvm_ioapic,
442 						 eoi_inject.work);
443 	spin_lock(&ioapic->lock);
444 	for (i = 0; i < IOAPIC_NUM_PINS; i++) {
445 		union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
446 
447 		if (ent->fields.trig_mode != IOAPIC_LEVEL_TRIG)
448 			continue;
449 
450 		if (ioapic->irr & (1 << i) && !ent->fields.remote_irr)
451 			ioapic_service(ioapic, i, false);
452 	}
453 	spin_unlock(&ioapic->lock);
454 }
455 
456 #define IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT 10000
457 
458 static void __kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu,
459 			struct kvm_ioapic *ioapic, int vector, int trigger_mode)
460 {
461 	struct dest_map *dest_map = &ioapic->rtc_status.dest_map;
462 	struct kvm_lapic *apic = vcpu->arch.apic;
463 	int i;
464 
465 	/* RTC special handling */
466 	if (test_bit(vcpu->vcpu_id, dest_map->map) &&
467 	    vector == dest_map->vectors[vcpu->vcpu_id])
468 		rtc_irq_eoi(ioapic, vcpu);
469 
470 	for (i = 0; i < IOAPIC_NUM_PINS; i++) {
471 		union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
472 
473 		if (ent->fields.vector != vector)
474 			continue;
475 
476 		/*
477 		 * We are dropping lock while calling ack notifiers because ack
478 		 * notifier callbacks for assigned devices call into IOAPIC
479 		 * recursively. Since remote_irr is cleared only after call
480 		 * to notifiers if the same vector will be delivered while lock
481 		 * is dropped it will be put into irr and will be delivered
482 		 * after ack notifier returns.
483 		 */
484 		spin_unlock(&ioapic->lock);
485 		kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);
486 		spin_lock(&ioapic->lock);
487 
488 		if (trigger_mode != IOAPIC_LEVEL_TRIG ||
489 		    kvm_lapic_get_reg(apic, APIC_SPIV) & APIC_SPIV_DIRECTED_EOI)
490 			continue;
491 
492 		ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
493 		ent->fields.remote_irr = 0;
494 		if (!ent->fields.mask && (ioapic->irr & (1 << i))) {
495 			++ioapic->irq_eoi[i];
496 			if (ioapic->irq_eoi[i] == IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT) {
497 				/*
498 				 * Real hardware does not deliver the interrupt
499 				 * immediately during eoi broadcast, and this
500 				 * lets a buggy guest make slow progress
501 				 * even if it does not correctly handle a
502 				 * level-triggered interrupt.  Emulate this
503 				 * behavior if we detect an interrupt storm.
504 				 */
505 				schedule_delayed_work(&ioapic->eoi_inject, HZ / 100);
506 				ioapic->irq_eoi[i] = 0;
507 				trace_kvm_ioapic_delayed_eoi_inj(ent->bits);
508 			} else {
509 				ioapic_service(ioapic, i, false);
510 			}
511 		} else {
512 			ioapic->irq_eoi[i] = 0;
513 		}
514 	}
515 }
516 
517 void kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, int vector, int trigger_mode)
518 {
519 	struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
520 
521 	spin_lock(&ioapic->lock);
522 	__kvm_ioapic_update_eoi(vcpu, ioapic, vector, trigger_mode);
523 	spin_unlock(&ioapic->lock);
524 }
525 
526 static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
527 {
528 	return container_of(dev, struct kvm_ioapic, dev);
529 }
530 
531 static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
532 {
533 	return ((addr >= ioapic->base_address &&
534 		 (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
535 }
536 
537 static int ioapic_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *this,
538 				gpa_t addr, int len, void *val)
539 {
540 	struct kvm_ioapic *ioapic = to_ioapic(this);
541 	u32 result;
542 	if (!ioapic_in_range(ioapic, addr))
543 		return -EOPNOTSUPP;
544 
545 	ASSERT(!(addr & 0xf));	/* check alignment */
546 
547 	addr &= 0xff;
548 	spin_lock(&ioapic->lock);
549 	switch (addr) {
550 	case IOAPIC_REG_SELECT:
551 		result = ioapic->ioregsel;
552 		break;
553 
554 	case IOAPIC_REG_WINDOW:
555 		result = ioapic_read_indirect(ioapic, addr, len);
556 		break;
557 
558 	default:
559 		result = 0;
560 		break;
561 	}
562 	spin_unlock(&ioapic->lock);
563 
564 	switch (len) {
565 	case 8:
566 		*(u64 *) val = result;
567 		break;
568 	case 1:
569 	case 2:
570 	case 4:
571 		memcpy(val, (char *)&result, len);
572 		break;
573 	default:
574 		printk(KERN_WARNING "ioapic: wrong length %d\n", len);
575 	}
576 	return 0;
577 }
578 
579 static int ioapic_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *this,
580 				 gpa_t addr, int len, const void *val)
581 {
582 	struct kvm_ioapic *ioapic = to_ioapic(this);
583 	u32 data;
584 	if (!ioapic_in_range(ioapic, addr))
585 		return -EOPNOTSUPP;
586 
587 	ASSERT(!(addr & 0xf));	/* check alignment */
588 
589 	switch (len) {
590 	case 8:
591 	case 4:
592 		data = *(u32 *) val;
593 		break;
594 	case 2:
595 		data = *(u16 *) val;
596 		break;
597 	case 1:
598 		data = *(u8  *) val;
599 		break;
600 	default:
601 		printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
602 		return 0;
603 	}
604 
605 	addr &= 0xff;
606 	spin_lock(&ioapic->lock);
607 	switch (addr) {
608 	case IOAPIC_REG_SELECT:
609 		ioapic->ioregsel = data & 0xFF; /* 8-bit register */
610 		break;
611 
612 	case IOAPIC_REG_WINDOW:
613 		ioapic_write_indirect(ioapic, data);
614 		break;
615 
616 	default:
617 		break;
618 	}
619 	spin_unlock(&ioapic->lock);
620 	return 0;
621 }
622 
623 static void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
624 {
625 	int i;
626 
627 	cancel_delayed_work_sync(&ioapic->eoi_inject);
628 	for (i = 0; i < IOAPIC_NUM_PINS; i++)
629 		ioapic->redirtbl[i].fields.mask = 1;
630 	ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
631 	ioapic->ioregsel = 0;
632 	ioapic->irr = 0;
633 	ioapic->irr_delivered = 0;
634 	ioapic->id = 0;
635 	memset(ioapic->irq_eoi, 0x00, sizeof(ioapic->irq_eoi));
636 	rtc_irq_eoi_tracking_reset(ioapic);
637 }
638 
639 static const struct kvm_io_device_ops ioapic_mmio_ops = {
640 	.read     = ioapic_mmio_read,
641 	.write    = ioapic_mmio_write,
642 };
643 
644 int kvm_ioapic_init(struct kvm *kvm)
645 {
646 	struct kvm_ioapic *ioapic;
647 	int ret;
648 
649 	ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL_ACCOUNT);
650 	if (!ioapic)
651 		return -ENOMEM;
652 	spin_lock_init(&ioapic->lock);
653 	INIT_DELAYED_WORK(&ioapic->eoi_inject, kvm_ioapic_eoi_inject_work);
654 	kvm->arch.vioapic = ioapic;
655 	kvm_ioapic_reset(ioapic);
656 	kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
657 	ioapic->kvm = kvm;
658 	mutex_lock(&kvm->slots_lock);
659 	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, ioapic->base_address,
660 				      IOAPIC_MEM_LENGTH, &ioapic->dev);
661 	mutex_unlock(&kvm->slots_lock);
662 	if (ret < 0) {
663 		kvm->arch.vioapic = NULL;
664 		kfree(ioapic);
665 	}
666 
667 	return ret;
668 }
669 
670 void kvm_ioapic_destroy(struct kvm *kvm)
671 {
672 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
673 
674 	if (!ioapic)
675 		return;
676 
677 	cancel_delayed_work_sync(&ioapic->eoi_inject);
678 	mutex_lock(&kvm->slots_lock);
679 	kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
680 	mutex_unlock(&kvm->slots_lock);
681 	kvm->arch.vioapic = NULL;
682 	kfree(ioapic);
683 }
684 
685 void kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
686 {
687 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
688 
689 	spin_lock(&ioapic->lock);
690 	memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));
691 	state->irr &= ~ioapic->irr_delivered;
692 	spin_unlock(&ioapic->lock);
693 }
694 
695 void kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
696 {
697 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
698 
699 	spin_lock(&ioapic->lock);
700 	memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
701 	ioapic->irr = 0;
702 	ioapic->irr_delivered = 0;
703 	kvm_make_scan_ioapic_request(kvm);
704 	kvm_ioapic_inject_all(ioapic, state->irr);
705 	spin_unlock(&ioapic->lock);
706 }
707