xref: /freebsd/sys/amd64/vmm/io/vlapic.c (revision 38a52bd3b5cac3da6f7f6eef3dd050e6aa08ebb3)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2011 NetApp, Inc.
5  * All rights reserved.
6  * Copyright (c) 2019 Joyent, Inc.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "opt_bhyve_snapshot.h"
36 
37 #include <sys/param.h>
38 #include <sys/lock.h>
39 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/mutex.h>
42 #include <sys/systm.h>
43 #include <sys/smp.h>
44 
45 #include <x86/specialreg.h>
46 #include <x86/apicreg.h>
47 
48 #include <machine/clock.h>
49 #include <machine/smp.h>
50 
51 #include <machine/vmm.h>
52 #include <machine/vmm_snapshot.h>
53 
54 #include "vmm_lapic.h"
55 #include "vmm_ktr.h"
56 #include "vmm_stat.h"
57 
58 #include "vlapic.h"
59 #include "vlapic_priv.h"
60 #include "vioapic.h"
61 
62 #define	PRIO(x)			((x) >> 4)
63 
64 #define VLAPIC_VERSION		(0x14)
65 
66 #define	x2apic(vlapic)	(((vlapic)->msr_apicbase & APICBASE_X2APIC) ? 1 : 0)
67 
68 /*
69  * The 'vlapic->timer_mtx' is used to provide mutual exclusion between the
70  * vlapic_callout_handler() and vcpu accesses to:
71  * - timer_freq_bt, timer_period_bt, timer_fire_bt
72  * - timer LVT register
73  */
74 #define	VLAPIC_TIMER_LOCK(vlapic)	mtx_lock_spin(&((vlapic)->timer_mtx))
75 #define	VLAPIC_TIMER_UNLOCK(vlapic)	mtx_unlock_spin(&((vlapic)->timer_mtx))
76 #define	VLAPIC_TIMER_LOCKED(vlapic)	mtx_owned(&((vlapic)->timer_mtx))
77 
78 /*
79  * APIC timer frequency:
80  * - arbitrary but chosen to be in the ballpark of contemporary hardware.
81  * - power-of-two to avoid loss of precision when converted to a bintime.
82  */
83 #define VLAPIC_BUS_FREQ		(128 * 1024 * 1024)
84 
85 static void vlapic_set_error(struct vlapic *, uint32_t, bool);
86 static void vlapic_callout_handler(void *arg);
87 static void vlapic_reset(struct vlapic *vlapic);
88 
89 static __inline uint32_t
90 vlapic_get_id(struct vlapic *vlapic)
91 {
92 
93 	if (x2apic(vlapic))
94 		return (vlapic->vcpuid);
95 	else
96 		return (vlapic->vcpuid << 24);
97 }
98 
99 static uint32_t
100 x2apic_ldr(struct vlapic *vlapic)
101 {
102 	int apicid;
103 	uint32_t ldr;
104 
105 	apicid = vlapic_get_id(vlapic);
106 	ldr = 1 << (apicid & 0xf);
107 	ldr |= (apicid & 0xffff0) << 12;
108 	return (ldr);
109 }
110 
111 void
112 vlapic_dfr_write_handler(struct vlapic *vlapic)
113 {
114 	struct LAPIC *lapic;
115 
116 	lapic = vlapic->apic_page;
117 	if (x2apic(vlapic)) {
118 		VM_CTR1(vlapic->vm, "ignoring write to DFR in x2apic mode: %#x",
119 		    lapic->dfr);
120 		lapic->dfr = 0;
121 		return;
122 	}
123 
124 	lapic->dfr &= APIC_DFR_MODEL_MASK;
125 	lapic->dfr |= APIC_DFR_RESERVED;
126 
127 	if ((lapic->dfr & APIC_DFR_MODEL_MASK) == APIC_DFR_MODEL_FLAT)
128 		VLAPIC_CTR0(vlapic, "vlapic DFR in Flat Model");
129 	else if ((lapic->dfr & APIC_DFR_MODEL_MASK) == APIC_DFR_MODEL_CLUSTER)
130 		VLAPIC_CTR0(vlapic, "vlapic DFR in Cluster Model");
131 	else
132 		VLAPIC_CTR1(vlapic, "DFR in Unknown Model %#x", lapic->dfr);
133 }
134 
135 void
136 vlapic_ldr_write_handler(struct vlapic *vlapic)
137 {
138 	struct LAPIC *lapic;
139 
140 	lapic = vlapic->apic_page;
141 
142 	/* LDR is read-only in x2apic mode */
143 	if (x2apic(vlapic)) {
144 		VLAPIC_CTR1(vlapic, "ignoring write to LDR in x2apic mode: %#x",
145 		    lapic->ldr);
146 		lapic->ldr = x2apic_ldr(vlapic);
147 	} else {
148 		lapic->ldr &= ~APIC_LDR_RESERVED;
149 		VLAPIC_CTR1(vlapic, "vlapic LDR set to %#x", lapic->ldr);
150 	}
151 }
152 
153 void
154 vlapic_id_write_handler(struct vlapic *vlapic)
155 {
156 	struct LAPIC *lapic;
157 
158 	/*
159 	 * We don't allow the ID register to be modified so reset it back to
160 	 * its default value.
161 	 */
162 	lapic = vlapic->apic_page;
163 	lapic->id = vlapic_get_id(vlapic);
164 }
165 
166 static int
167 vlapic_timer_divisor(uint32_t dcr)
168 {
169 	switch (dcr & 0xB) {
170 	case APIC_TDCR_1:
171 		return (1);
172 	case APIC_TDCR_2:
173 		return (2);
174 	case APIC_TDCR_4:
175 		return (4);
176 	case APIC_TDCR_8:
177 		return (8);
178 	case APIC_TDCR_16:
179 		return (16);
180 	case APIC_TDCR_32:
181 		return (32);
182 	case APIC_TDCR_64:
183 		return (64);
184 	case APIC_TDCR_128:
185 		return (128);
186 	default:
187 		panic("vlapic_timer_divisor: invalid dcr 0x%08x", dcr);
188 	}
189 }
190 
191 #if 0
192 static inline void
193 vlapic_dump_lvt(uint32_t offset, uint32_t *lvt)
194 {
195 	printf("Offset %x: lvt %08x (V:%02x DS:%x M:%x)\n", offset,
196 	    *lvt, *lvt & APIC_LVTT_VECTOR, *lvt & APIC_LVTT_DS,
197 	    *lvt & APIC_LVTT_M);
198 }
199 #endif
200 
201 static uint32_t
202 vlapic_get_ccr(struct vlapic *vlapic)
203 {
204 	struct bintime bt_now, bt_rem;
205 	struct LAPIC *lapic __diagused;
206 	uint32_t ccr;
207 
208 	ccr = 0;
209 	lapic = vlapic->apic_page;
210 
211 	VLAPIC_TIMER_LOCK(vlapic);
212 	if (callout_active(&vlapic->callout)) {
213 		/*
214 		 * If the timer is scheduled to expire in the future then
215 		 * compute the value of 'ccr' based on the remaining time.
216 		 */
217 		binuptime(&bt_now);
218 		if (bintime_cmp(&vlapic->timer_fire_bt, &bt_now, >)) {
219 			bt_rem = vlapic->timer_fire_bt;
220 			bintime_sub(&bt_rem, &bt_now);
221 			ccr += bt_rem.sec * BT2FREQ(&vlapic->timer_freq_bt);
222 			ccr += bt_rem.frac / vlapic->timer_freq_bt.frac;
223 		}
224 	}
225 	KASSERT(ccr <= lapic->icr_timer, ("vlapic_get_ccr: invalid ccr %#x, "
226 	    "icr_timer is %#x", ccr, lapic->icr_timer));
227 	VLAPIC_CTR2(vlapic, "vlapic ccr_timer = %#x, icr_timer = %#x",
228 	    ccr, lapic->icr_timer);
229 	VLAPIC_TIMER_UNLOCK(vlapic);
230 	return (ccr);
231 }
232 
233 void
234 vlapic_dcr_write_handler(struct vlapic *vlapic)
235 {
236 	struct LAPIC *lapic;
237 	int divisor;
238 
239 	lapic = vlapic->apic_page;
240 	VLAPIC_TIMER_LOCK(vlapic);
241 
242 	divisor = vlapic_timer_divisor(lapic->dcr_timer);
243 	VLAPIC_CTR2(vlapic, "vlapic dcr_timer=%#x, divisor=%d",
244 	    lapic->dcr_timer, divisor);
245 
246 	/*
247 	 * Update the timer frequency and the timer period.
248 	 *
249 	 * XXX changes to the frequency divider will not take effect until
250 	 * the timer is reloaded.
251 	 */
252 	FREQ2BT(VLAPIC_BUS_FREQ / divisor, &vlapic->timer_freq_bt);
253 	vlapic->timer_period_bt = vlapic->timer_freq_bt;
254 	bintime_mul(&vlapic->timer_period_bt, lapic->icr_timer);
255 
256 	VLAPIC_TIMER_UNLOCK(vlapic);
257 }
258 
259 void
260 vlapic_esr_write_handler(struct vlapic *vlapic)
261 {
262 	struct LAPIC *lapic;
263 
264 	lapic = vlapic->apic_page;
265 	lapic->esr = vlapic->esr_pending;
266 	vlapic->esr_pending = 0;
267 }
268 
269 int
270 vlapic_set_intr_ready(struct vlapic *vlapic, int vector, bool level)
271 {
272 	struct LAPIC *lapic;
273 	uint32_t *irrptr, *tmrptr, mask;
274 	int idx;
275 
276 	KASSERT(vector >= 0 && vector < 256, ("invalid vector %d", vector));
277 
278 	lapic = vlapic->apic_page;
279 	if (!(lapic->svr & APIC_SVR_ENABLE)) {
280 		VLAPIC_CTR1(vlapic, "vlapic is software disabled, ignoring "
281 		    "interrupt %d", vector);
282 		return (0);
283 	}
284 
285 	if (vector < 16) {
286 		vlapic_set_error(vlapic, APIC_ESR_RECEIVE_ILLEGAL_VECTOR,
287 		    false);
288 		VLAPIC_CTR1(vlapic, "vlapic ignoring interrupt to vector %d",
289 		    vector);
290 		return (1);
291 	}
292 
293 	if (vlapic->ops.set_intr_ready)
294 		return ((*vlapic->ops.set_intr_ready)(vlapic, vector, level));
295 
296 	idx = (vector / 32) * 4;
297 	mask = 1 << (vector % 32);
298 
299 	irrptr = &lapic->irr0;
300 	atomic_set_int(&irrptr[idx], mask);
301 
302 	/*
303 	 * Verify that the trigger-mode of the interrupt matches with
304 	 * the vlapic TMR registers.
305 	 */
306 	tmrptr = &lapic->tmr0;
307 	if ((tmrptr[idx] & mask) != (level ? mask : 0)) {
308 		VLAPIC_CTR3(vlapic, "vlapic TMR[%d] is 0x%08x but "
309 		    "interrupt is %s-triggered", idx / 4, tmrptr[idx],
310 		    level ? "level" : "edge");
311 	}
312 
313 	VLAPIC_CTR_IRR(vlapic, "vlapic_set_intr_ready");
314 	return (1);
315 }
316 
317 static __inline uint32_t *
318 vlapic_get_lvtptr(struct vlapic *vlapic, uint32_t offset)
319 {
320 	struct LAPIC	*lapic = vlapic->apic_page;
321 	int 		 i;
322 
323 	switch (offset) {
324 	case APIC_OFFSET_CMCI_LVT:
325 		return (&lapic->lvt_cmci);
326 	case APIC_OFFSET_TIMER_LVT ... APIC_OFFSET_ERROR_LVT:
327 		i = (offset - APIC_OFFSET_TIMER_LVT) >> 2;
328 		return ((&lapic->lvt_timer) + i);
329 	default:
330 		panic("vlapic_get_lvt: invalid LVT\n");
331 	}
332 }
333 
334 static __inline int
335 lvt_off_to_idx(uint32_t offset)
336 {
337 	int index;
338 
339 	switch (offset) {
340 	case APIC_OFFSET_CMCI_LVT:
341 		index = APIC_LVT_CMCI;
342 		break;
343 	case APIC_OFFSET_TIMER_LVT:
344 		index = APIC_LVT_TIMER;
345 		break;
346 	case APIC_OFFSET_THERM_LVT:
347 		index = APIC_LVT_THERMAL;
348 		break;
349 	case APIC_OFFSET_PERF_LVT:
350 		index = APIC_LVT_PMC;
351 		break;
352 	case APIC_OFFSET_LINT0_LVT:
353 		index = APIC_LVT_LINT0;
354 		break;
355 	case APIC_OFFSET_LINT1_LVT:
356 		index = APIC_LVT_LINT1;
357 		break;
358 	case APIC_OFFSET_ERROR_LVT:
359 		index = APIC_LVT_ERROR;
360 		break;
361 	default:
362 		index = -1;
363 		break;
364 	}
365 	KASSERT(index >= 0 && index <= VLAPIC_MAXLVT_INDEX, ("lvt_off_to_idx: "
366 	    "invalid lvt index %d for offset %#x", index, offset));
367 
368 	return (index);
369 }
370 
371 static __inline uint32_t
372 vlapic_get_lvt(struct vlapic *vlapic, uint32_t offset)
373 {
374 	int idx;
375 	uint32_t val;
376 
377 	idx = lvt_off_to_idx(offset);
378 	val = atomic_load_acq_32(&vlapic->lvt_last[idx]);
379 	return (val);
380 }
381 
382 void
383 vlapic_lvt_write_handler(struct vlapic *vlapic, uint32_t offset)
384 {
385 	uint32_t *lvtptr, mask, val;
386 	struct LAPIC *lapic;
387 	int idx;
388 
389 	lapic = vlapic->apic_page;
390 	lvtptr = vlapic_get_lvtptr(vlapic, offset);
391 	val = *lvtptr;
392 	idx = lvt_off_to_idx(offset);
393 
394 	if (!(lapic->svr & APIC_SVR_ENABLE))
395 		val |= APIC_LVT_M;
396 	mask = APIC_LVT_M | APIC_LVT_DS | APIC_LVT_VECTOR;
397 	switch (offset) {
398 	case APIC_OFFSET_TIMER_LVT:
399 		mask |= APIC_LVTT_TM;
400 		break;
401 	case APIC_OFFSET_ERROR_LVT:
402 		break;
403 	case APIC_OFFSET_LINT0_LVT:
404 	case APIC_OFFSET_LINT1_LVT:
405 		mask |= APIC_LVT_TM | APIC_LVT_RIRR | APIC_LVT_IIPP;
406 		/* FALLTHROUGH */
407 	default:
408 		mask |= APIC_LVT_DM;
409 		break;
410 	}
411 	val &= mask;
412 	*lvtptr = val;
413 	atomic_store_rel_32(&vlapic->lvt_last[idx], val);
414 }
415 
416 static void
417 vlapic_mask_lvts(struct vlapic *vlapic)
418 {
419 	struct LAPIC *lapic = vlapic->apic_page;
420 
421 	lapic->lvt_cmci |= APIC_LVT_M;
422 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_CMCI_LVT);
423 
424 	lapic->lvt_timer |= APIC_LVT_M;
425 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_TIMER_LVT);
426 
427 	lapic->lvt_thermal |= APIC_LVT_M;
428 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_THERM_LVT);
429 
430 	lapic->lvt_pcint |= APIC_LVT_M;
431 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_PERF_LVT);
432 
433 	lapic->lvt_lint0 |= APIC_LVT_M;
434 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_LINT0_LVT);
435 
436 	lapic->lvt_lint1 |= APIC_LVT_M;
437 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_LINT1_LVT);
438 
439 	lapic->lvt_error |= APIC_LVT_M;
440 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_ERROR_LVT);
441 }
442 
443 static int
444 vlapic_fire_lvt(struct vlapic *vlapic, u_int lvt)
445 {
446 	uint32_t mode, reg, vec;
447 
448 	reg = atomic_load_acq_32(&vlapic->lvt_last[lvt]);
449 
450 	if (reg & APIC_LVT_M)
451 		return (0);
452 	vec = reg & APIC_LVT_VECTOR;
453 	mode = reg & APIC_LVT_DM;
454 
455 	switch (mode) {
456 	case APIC_LVT_DM_FIXED:
457 		if (vec < 16) {
458 			vlapic_set_error(vlapic, APIC_ESR_SEND_ILLEGAL_VECTOR,
459 			    lvt == APIC_LVT_ERROR);
460 			return (0);
461 		}
462 		if (vlapic_set_intr_ready(vlapic, vec, false))
463 			vcpu_notify_event(vlapic->vm, vlapic->vcpuid, true);
464 		break;
465 	case APIC_LVT_DM_NMI:
466 		vm_inject_nmi(vlapic->vm, vlapic->vcpuid);
467 		break;
468 	case APIC_LVT_DM_EXTINT:
469 		vm_inject_extint(vlapic->vm, vlapic->vcpuid);
470 		break;
471 	default:
472 		// Other modes ignored
473 		return (0);
474 	}
475 	return (1);
476 }
477 
478 #if 1
479 static void
480 dump_isrvec_stk(struct vlapic *vlapic)
481 {
482 	int i;
483 	uint32_t *isrptr;
484 
485 	isrptr = &vlapic->apic_page->isr0;
486 	for (i = 0; i < 8; i++)
487 		printf("ISR%d 0x%08x\n", i, isrptr[i * 4]);
488 
489 	for (i = 0; i <= vlapic->isrvec_stk_top; i++)
490 		printf("isrvec_stk[%d] = %d\n", i, vlapic->isrvec_stk[i]);
491 }
492 #endif
493 
494 /*
495  * Algorithm adopted from section "Interrupt, Task and Processor Priority"
496  * in Intel Architecture Manual Vol 3a.
497  */
498 static void
499 vlapic_update_ppr(struct vlapic *vlapic)
500 {
501 	int isrvec, tpr, ppr;
502 
503 	/*
504 	 * Note that the value on the stack at index 0 is always 0.
505 	 *
506 	 * This is a placeholder for the value of ISRV when none of the
507 	 * bits is set in the ISRx registers.
508 	 */
509 	isrvec = vlapic->isrvec_stk[vlapic->isrvec_stk_top];
510 	tpr = vlapic->apic_page->tpr;
511 
512 #if 1
513 	{
514 		int i, lastprio, curprio, vector, idx;
515 		uint32_t *isrptr;
516 
517 		if (vlapic->isrvec_stk_top == 0 && isrvec != 0)
518 			panic("isrvec_stk is corrupted: %d", isrvec);
519 
520 		/*
521 		 * Make sure that the priority of the nested interrupts is
522 		 * always increasing.
523 		 */
524 		lastprio = -1;
525 		for (i = 1; i <= vlapic->isrvec_stk_top; i++) {
526 			curprio = PRIO(vlapic->isrvec_stk[i]);
527 			if (curprio <= lastprio) {
528 				dump_isrvec_stk(vlapic);
529 				panic("isrvec_stk does not satisfy invariant");
530 			}
531 			lastprio = curprio;
532 		}
533 
534 		/*
535 		 * Make sure that each bit set in the ISRx registers has a
536 		 * corresponding entry on the isrvec stack.
537 		 */
538 		i = 1;
539 		isrptr = &vlapic->apic_page->isr0;
540 		for (vector = 0; vector < 256; vector++) {
541 			idx = (vector / 32) * 4;
542 			if (isrptr[idx] & (1 << (vector % 32))) {
543 				if (i > vlapic->isrvec_stk_top ||
544 				    vlapic->isrvec_stk[i] != vector) {
545 					dump_isrvec_stk(vlapic);
546 					panic("ISR and isrvec_stk out of sync");
547 				}
548 				i++;
549 			}
550 		}
551 	}
552 #endif
553 
554 	if (PRIO(tpr) >= PRIO(isrvec))
555 		ppr = tpr;
556 	else
557 		ppr = isrvec & 0xf0;
558 
559 	vlapic->apic_page->ppr = ppr;
560 	VLAPIC_CTR1(vlapic, "vlapic_update_ppr 0x%02x", ppr);
561 }
562 
563 void
564 vlapic_sync_tpr(struct vlapic *vlapic)
565 {
566 	vlapic_update_ppr(vlapic);
567 }
568 
569 static VMM_STAT(VLAPIC_GRATUITOUS_EOI, "EOI without any in-service interrupt");
570 
571 static void
572 vlapic_process_eoi(struct vlapic *vlapic)
573 {
574 	struct LAPIC	*lapic = vlapic->apic_page;
575 	uint32_t	*isrptr, *tmrptr;
576 	int		i, idx, bitpos, vector;
577 
578 	isrptr = &lapic->isr0;
579 	tmrptr = &lapic->tmr0;
580 
581 	for (i = 7; i >= 0; i--) {
582 		idx = i * 4;
583 		bitpos = fls(isrptr[idx]);
584 		if (bitpos-- != 0) {
585 			if (vlapic->isrvec_stk_top <= 0) {
586 				panic("invalid vlapic isrvec_stk_top %d",
587 				      vlapic->isrvec_stk_top);
588 			}
589 			isrptr[idx] &= ~(1 << bitpos);
590 			vector = i * 32 + bitpos;
591 			VCPU_CTR1(vlapic->vm, vlapic->vcpuid, "EOI vector %d",
592 			    vector);
593 			VLAPIC_CTR_ISR(vlapic, "vlapic_process_eoi");
594 			vlapic->isrvec_stk_top--;
595 			vlapic_update_ppr(vlapic);
596 			if ((tmrptr[idx] & (1 << bitpos)) != 0) {
597 				vioapic_process_eoi(vlapic->vm, vlapic->vcpuid,
598 				    vector);
599 			}
600 			return;
601 		}
602 	}
603 	VCPU_CTR0(vlapic->vm, vlapic->vcpuid, "Gratuitous EOI");
604 	vmm_stat_incr(vlapic->vm, vlapic->vcpuid, VLAPIC_GRATUITOUS_EOI, 1);
605 }
606 
607 static __inline int
608 vlapic_get_lvt_field(uint32_t lvt, uint32_t mask)
609 {
610 
611 	return (lvt & mask);
612 }
613 
614 static __inline int
615 vlapic_periodic_timer(struct vlapic *vlapic)
616 {
617 	uint32_t lvt;
618 
619 	lvt = vlapic_get_lvt(vlapic, APIC_OFFSET_TIMER_LVT);
620 
621 	return (vlapic_get_lvt_field(lvt, APIC_LVTT_TM_PERIODIC));
622 }
623 
624 static VMM_STAT(VLAPIC_INTR_ERROR, "error interrupts generated by vlapic");
625 
626 static void
627 vlapic_set_error(struct vlapic *vlapic, uint32_t mask, bool lvt_error)
628 {
629 
630 	vlapic->esr_pending |= mask;
631 
632 	/*
633 	 * Avoid infinite recursion if the error LVT itself is configured with
634 	 * an illegal vector.
635 	 */
636 	if (lvt_error)
637 		return;
638 
639 	if (vlapic_fire_lvt(vlapic, APIC_LVT_ERROR)) {
640 		vmm_stat_incr(vlapic->vm, vlapic->vcpuid, VLAPIC_INTR_ERROR, 1);
641 	}
642 }
643 
644 static VMM_STAT(VLAPIC_INTR_TIMER, "timer interrupts generated by vlapic");
645 
646 static void
647 vlapic_fire_timer(struct vlapic *vlapic)
648 {
649 
650 	KASSERT(VLAPIC_TIMER_LOCKED(vlapic), ("vlapic_fire_timer not locked"));
651 
652 	if (vlapic_fire_lvt(vlapic, APIC_LVT_TIMER)) {
653 		VLAPIC_CTR0(vlapic, "vlapic timer fired");
654 		vmm_stat_incr(vlapic->vm, vlapic->vcpuid, VLAPIC_INTR_TIMER, 1);
655 	}
656 }
657 
658 static VMM_STAT(VLAPIC_INTR_CMC,
659     "corrected machine check interrupts generated by vlapic");
660 
661 void
662 vlapic_fire_cmci(struct vlapic *vlapic)
663 {
664 
665 	if (vlapic_fire_lvt(vlapic, APIC_LVT_CMCI)) {
666 		vmm_stat_incr(vlapic->vm, vlapic->vcpuid, VLAPIC_INTR_CMC, 1);
667 	}
668 }
669 
670 static VMM_STAT_ARRAY(LVTS_TRIGGERRED, VLAPIC_MAXLVT_INDEX + 1,
671     "lvts triggered");
672 
673 int
674 vlapic_trigger_lvt(struct vlapic *vlapic, int vector)
675 {
676 
677 	if (vlapic_enabled(vlapic) == false) {
678 		/*
679 		 * When the local APIC is global/hardware disabled,
680 		 * LINT[1:0] pins are configured as INTR and NMI pins,
681 		 * respectively.
682 		*/
683 		switch (vector) {
684 			case APIC_LVT_LINT0:
685 				vm_inject_extint(vlapic->vm, vlapic->vcpuid);
686 				break;
687 			case APIC_LVT_LINT1:
688 				vm_inject_nmi(vlapic->vm, vlapic->vcpuid);
689 				break;
690 			default:
691 				break;
692 		}
693 		return (0);
694 	}
695 
696 	switch (vector) {
697 	case APIC_LVT_LINT0:
698 	case APIC_LVT_LINT1:
699 	case APIC_LVT_TIMER:
700 	case APIC_LVT_ERROR:
701 	case APIC_LVT_PMC:
702 	case APIC_LVT_THERMAL:
703 	case APIC_LVT_CMCI:
704 		if (vlapic_fire_lvt(vlapic, vector)) {
705 			vmm_stat_array_incr(vlapic->vm, vlapic->vcpuid,
706 			    LVTS_TRIGGERRED, vector, 1);
707 		}
708 		break;
709 	default:
710 		return (EINVAL);
711 	}
712 	return (0);
713 }
714 
715 static void
716 vlapic_callout_reset(struct vlapic *vlapic, sbintime_t t)
717 {
718 	callout_reset_sbt_curcpu(&vlapic->callout, t, 0,
719 	    vlapic_callout_handler, vlapic, 0);
720 }
721 
722 static void
723 vlapic_callout_handler(void *arg)
724 {
725 	struct vlapic *vlapic;
726 	struct bintime bt, btnow;
727 	sbintime_t rem_sbt;
728 
729 	vlapic = arg;
730 
731 	VLAPIC_TIMER_LOCK(vlapic);
732 	if (callout_pending(&vlapic->callout))	/* callout was reset */
733 		goto done;
734 
735 	if (!callout_active(&vlapic->callout))	/* callout was stopped */
736 		goto done;
737 
738 	callout_deactivate(&vlapic->callout);
739 
740 	vlapic_fire_timer(vlapic);
741 
742 	if (vlapic_periodic_timer(vlapic)) {
743 		binuptime(&btnow);
744 		KASSERT(bintime_cmp(&btnow, &vlapic->timer_fire_bt, >=),
745 		    ("vlapic callout at %#lx.%#lx, expected at %#lx.#%lx",
746 		    btnow.sec, btnow.frac, vlapic->timer_fire_bt.sec,
747 		    vlapic->timer_fire_bt.frac));
748 
749 		/*
750 		 * Compute the delta between when the timer was supposed to
751 		 * fire and the present time.
752 		 */
753 		bt = btnow;
754 		bintime_sub(&bt, &vlapic->timer_fire_bt);
755 
756 		rem_sbt = bttosbt(vlapic->timer_period_bt);
757 		if (bintime_cmp(&bt, &vlapic->timer_period_bt, <)) {
758 			/*
759 			 * Adjust the time until the next countdown downward
760 			 * to account for the lost time.
761 			 */
762 			rem_sbt -= bttosbt(bt);
763 		} else {
764 			/*
765 			 * If the delta is greater than the timer period then
766 			 * just reset our time base instead of trying to catch
767 			 * up.
768 			 */
769 			vlapic->timer_fire_bt = btnow;
770 			VLAPIC_CTR2(vlapic, "vlapic timer lagging by %lu "
771 			    "usecs, period is %lu usecs - resetting time base",
772 			    bttosbt(bt) / SBT_1US,
773 			    bttosbt(vlapic->timer_period_bt) / SBT_1US);
774 		}
775 
776 		bintime_add(&vlapic->timer_fire_bt, &vlapic->timer_period_bt);
777 		vlapic_callout_reset(vlapic, rem_sbt);
778 	}
779 done:
780 	VLAPIC_TIMER_UNLOCK(vlapic);
781 }
782 
783 void
784 vlapic_icrtmr_write_handler(struct vlapic *vlapic)
785 {
786 	struct LAPIC *lapic;
787 	sbintime_t sbt;
788 	uint32_t icr_timer;
789 
790 	VLAPIC_TIMER_LOCK(vlapic);
791 
792 	lapic = vlapic->apic_page;
793 	icr_timer = lapic->icr_timer;
794 
795 	vlapic->timer_period_bt = vlapic->timer_freq_bt;
796 	bintime_mul(&vlapic->timer_period_bt, icr_timer);
797 
798 	if (icr_timer != 0) {
799 		binuptime(&vlapic->timer_fire_bt);
800 		bintime_add(&vlapic->timer_fire_bt, &vlapic->timer_period_bt);
801 
802 		sbt = bttosbt(vlapic->timer_period_bt);
803 		vlapic_callout_reset(vlapic, sbt);
804 	} else
805 		callout_stop(&vlapic->callout);
806 
807 	VLAPIC_TIMER_UNLOCK(vlapic);
808 }
809 
810 /*
811  * This function populates 'dmask' with the set of vcpus that match the
812  * addressing specified by the (dest, phys, lowprio) tuple.
813  *
814  * 'x2apic_dest' specifies whether 'dest' is interpreted as x2APIC (32-bit)
815  * or xAPIC (8-bit) destination field.
816  */
817 static void
818 vlapic_calcdest(struct vm *vm, cpuset_t *dmask, uint32_t dest, bool phys,
819     bool lowprio, bool x2apic_dest)
820 {
821 	struct vlapic *vlapic;
822 	uint32_t dfr, ldr, ldest, cluster;
823 	uint32_t mda_flat_ldest, mda_cluster_ldest, mda_ldest, mda_cluster_id;
824 	cpuset_t amask;
825 	int vcpuid;
826 
827 	if ((x2apic_dest && dest == 0xffffffff) ||
828 	    (!x2apic_dest && dest == 0xff)) {
829 		/*
830 		 * Broadcast in both logical and physical modes.
831 		 */
832 		*dmask = vm_active_cpus(vm);
833 		return;
834 	}
835 
836 	if (phys) {
837 		/*
838 		 * Physical mode: destination is APIC ID.
839 		 */
840 		CPU_ZERO(dmask);
841 		vcpuid = vm_apicid2vcpuid(vm, dest);
842 		amask = vm_active_cpus(vm);
843 		if (vcpuid < vm_get_maxcpus(vm) && CPU_ISSET(vcpuid, &amask))
844 			CPU_SET(vcpuid, dmask);
845 	} else {
846 		/*
847 		 * In the "Flat Model" the MDA is interpreted as an 8-bit wide
848 		 * bitmask. This model is only available in the xAPIC mode.
849 		 */
850 		mda_flat_ldest = dest & 0xff;
851 
852 		/*
853 		 * In the "Cluster Model" the MDA is used to identify a
854 		 * specific cluster and a set of APICs in that cluster.
855 		 */
856 		if (x2apic_dest) {
857 			mda_cluster_id = dest >> 16;
858 			mda_cluster_ldest = dest & 0xffff;
859 		} else {
860 			mda_cluster_id = (dest >> 4) & 0xf;
861 			mda_cluster_ldest = dest & 0xf;
862 		}
863 
864 		/*
865 		 * Logical mode: match each APIC that has a bit set
866 		 * in its LDR that matches a bit in the ldest.
867 		 */
868 		CPU_ZERO(dmask);
869 		amask = vm_active_cpus(vm);
870 		CPU_FOREACH_ISSET(vcpuid, &amask) {
871 			vlapic = vm_lapic(vm, vcpuid);
872 			dfr = vlapic->apic_page->dfr;
873 			ldr = vlapic->apic_page->ldr;
874 
875 			if ((dfr & APIC_DFR_MODEL_MASK) ==
876 			    APIC_DFR_MODEL_FLAT) {
877 				ldest = ldr >> 24;
878 				mda_ldest = mda_flat_ldest;
879 			} else if ((dfr & APIC_DFR_MODEL_MASK) ==
880 			    APIC_DFR_MODEL_CLUSTER) {
881 				if (x2apic(vlapic)) {
882 					cluster = ldr >> 16;
883 					ldest = ldr & 0xffff;
884 				} else {
885 					cluster = ldr >> 28;
886 					ldest = (ldr >> 24) & 0xf;
887 				}
888 				if (cluster != mda_cluster_id)
889 					continue;
890 				mda_ldest = mda_cluster_ldest;
891 			} else {
892 				/*
893 				 * Guest has configured a bad logical
894 				 * model for this vcpu - skip it.
895 				 */
896 				VLAPIC_CTR1(vlapic, "vlapic has bad logical "
897 				    "model %x - cannot deliver interrupt", dfr);
898 				continue;
899 			}
900 
901 			if ((mda_ldest & ldest) != 0) {
902 				CPU_SET(vcpuid, dmask);
903 				if (lowprio)
904 					break;
905 			}
906 		}
907 	}
908 }
909 
910 static VMM_STAT_ARRAY(IPIS_SENT, VM_MAXCPU, "ipis sent to vcpu");
911 
912 static void
913 vlapic_set_tpr(struct vlapic *vlapic, uint8_t val)
914 {
915 	struct LAPIC *lapic = vlapic->apic_page;
916 
917 	if (lapic->tpr != val) {
918 		VCPU_CTR2(vlapic->vm, vlapic->vcpuid, "vlapic TPR changed "
919 		    "from %#x to %#x", lapic->tpr, val);
920 		lapic->tpr = val;
921 		vlapic_update_ppr(vlapic);
922 	}
923 }
924 
925 static uint8_t
926 vlapic_get_tpr(struct vlapic *vlapic)
927 {
928 	struct LAPIC *lapic = vlapic->apic_page;
929 
930 	return (lapic->tpr);
931 }
932 
933 void
934 vlapic_set_cr8(struct vlapic *vlapic, uint64_t val)
935 {
936 	uint8_t tpr;
937 
938 	if (val & ~0xf) {
939 		vm_inject_gp(vlapic->vm, vlapic->vcpuid);
940 		return;
941 	}
942 
943 	tpr = val << 4;
944 	vlapic_set_tpr(vlapic, tpr);
945 }
946 
947 uint64_t
948 vlapic_get_cr8(struct vlapic *vlapic)
949 {
950 	uint8_t tpr;
951 
952 	tpr = vlapic_get_tpr(vlapic);
953 	return (tpr >> 4);
954 }
955 
956 static bool
957 vlapic_is_icr_valid(uint64_t icrval)
958 {
959 	uint32_t mode = icrval & APIC_DELMODE_MASK;
960 	uint32_t level = icrval & APIC_LEVEL_MASK;
961 	uint32_t trigger = icrval & APIC_TRIGMOD_MASK;
962 	uint32_t shorthand = icrval & APIC_DEST_MASK;
963 
964 	switch (mode) {
965 	case APIC_DELMODE_FIXED:
966 		if (trigger == APIC_TRIGMOD_EDGE)
967 			return (true);
968 		/*
969 		 * AMD allows a level assert IPI and Intel converts a level
970 		 * assert IPI into an edge IPI.
971 		 */
972 		if (trigger == APIC_TRIGMOD_LEVEL && level == APIC_LEVEL_ASSERT)
973 			return (true);
974 		break;
975 	case APIC_DELMODE_LOWPRIO:
976 	case APIC_DELMODE_SMI:
977 	case APIC_DELMODE_NMI:
978 	case APIC_DELMODE_INIT:
979 		if (trigger == APIC_TRIGMOD_EDGE &&
980 		    (shorthand == APIC_DEST_DESTFLD ||
981 			shorthand == APIC_DEST_ALLESELF))
982 			return (true);
983 		/*
984 		 * AMD allows a level assert IPI and Intel converts a level
985 		 * assert IPI into an edge IPI.
986 		 */
987 		if (trigger == APIC_TRIGMOD_LEVEL &&
988 		    level == APIC_LEVEL_ASSERT &&
989 		    (shorthand == APIC_DEST_DESTFLD ||
990 			shorthand == APIC_DEST_ALLESELF))
991 			return (true);
992 		/*
993 		 * An level triggered deassert INIT is defined in the Intel
994 		 * Multiprocessor Specification and the Intel Software Developer
995 		 * Manual. Due to the MPS it's required to send a level assert
996 		 * INIT to a cpu and then a level deassert INIT. Some operating
997 		 * systems e.g. FreeBSD or Linux use that algorithm. According
998 		 * to the SDM a level deassert INIT is only supported by Pentium
999 		 * and P6 processors. It's always send to all cpus regardless of
1000 		 * the destination or shorthand field. It resets the arbitration
1001 		 * id register. This register is not software accessible and
1002 		 * only required for the APIC bus arbitration. So, the level
1003 		 * deassert INIT doesn't need any emulation and we should ignore
1004 		 * it. The SDM also defines that newer processors don't support
1005 		 * the level deassert INIT and it's not valid any more. As it's
1006 		 * defined for older systems, it can't be invalid per se.
1007 		 * Otherwise, backward compatibility would be broken. However,
1008 		 * when returning false here, it'll be ignored which is the
1009 		 * desired behaviour.
1010 		 */
1011 		if (mode == APIC_DELMODE_INIT &&
1012 		    trigger == APIC_TRIGMOD_LEVEL &&
1013 		    level == APIC_LEVEL_DEASSERT)
1014 			return (false);
1015 		break;
1016 	case APIC_DELMODE_STARTUP:
1017 		if (shorthand == APIC_DEST_DESTFLD ||
1018 		    shorthand == APIC_DEST_ALLESELF)
1019 			return (true);
1020 		break;
1021 	case APIC_DELMODE_RR:
1022 		/* Only available on AMD! */
1023 		if (trigger == APIC_TRIGMOD_EDGE &&
1024 		    shorthand == APIC_DEST_DESTFLD)
1025 			return (true);
1026 		break;
1027 	case APIC_DELMODE_RESV:
1028 		return (false);
1029 	default:
1030 		__assert_unreachable();
1031 	}
1032 
1033 	return (false);
1034 }
1035 
1036 int
1037 vlapic_icrlo_write_handler(struct vlapic *vlapic, bool *retu)
1038 {
1039 	int i;
1040 	bool phys;
1041 	cpuset_t dmask, ipimask;
1042 	uint64_t icrval;
1043 	uint32_t dest, vec, mode, shorthand;
1044 	struct vlapic *vlapic2;
1045 	struct vm_exit *vmexit;
1046 	struct LAPIC *lapic;
1047 
1048 	lapic = vlapic->apic_page;
1049 	lapic->icr_lo &= ~APIC_DELSTAT_PEND;
1050 	icrval = ((uint64_t)lapic->icr_hi << 32) | lapic->icr_lo;
1051 
1052 	if (x2apic(vlapic))
1053 		dest = icrval >> 32;
1054 	else
1055 		dest = icrval >> (32 + 24);
1056 	vec = icrval & APIC_VECTOR_MASK;
1057 	mode = icrval & APIC_DELMODE_MASK;
1058 	phys = (icrval & APIC_DESTMODE_LOG) == 0;
1059 	shorthand = icrval & APIC_DEST_MASK;
1060 
1061 	VLAPIC_CTR2(vlapic, "icrlo 0x%016lx triggered ipi %d", icrval, vec);
1062 
1063 	switch (shorthand) {
1064 	case APIC_DEST_DESTFLD:
1065 		vlapic_calcdest(vlapic->vm, &dmask, dest, phys, false, x2apic(vlapic));
1066 		break;
1067 	case APIC_DEST_SELF:
1068 		CPU_SETOF(vlapic->vcpuid, &dmask);
1069 		break;
1070 	case APIC_DEST_ALLISELF:
1071 		dmask = vm_active_cpus(vlapic->vm);
1072 		break;
1073 	case APIC_DEST_ALLESELF:
1074 		dmask = vm_active_cpus(vlapic->vm);
1075 		CPU_CLR(vlapic->vcpuid, &dmask);
1076 		break;
1077 	default:
1078 		__assert_unreachable();
1079 	}
1080 
1081 	/*
1082 	 * Ignore invalid combinations of the icr.
1083 	 */
1084 	if (!vlapic_is_icr_valid(icrval)) {
1085 		VLAPIC_CTR1(vlapic, "Ignoring invalid ICR %016lx", icrval);
1086 		return (0);
1087 	}
1088 
1089 	/*
1090 	 * ipimask is a set of vCPUs needing userland handling of the current
1091 	 * IPI.
1092 	 */
1093 	CPU_ZERO(&ipimask);
1094 
1095 	switch (mode) {
1096 	case APIC_DELMODE_FIXED:
1097 		if (vec < 16) {
1098 			vlapic_set_error(vlapic, APIC_ESR_SEND_ILLEGAL_VECTOR,
1099 			    false);
1100 			VLAPIC_CTR1(vlapic, "Ignoring invalid IPI %d", vec);
1101 			return (0);
1102 		}
1103 
1104 		CPU_FOREACH_ISSET(i, &dmask) {
1105 			lapic_intr_edge(vlapic->vm, i, vec);
1106 			vmm_stat_array_incr(vlapic->vm, vlapic->vcpuid,
1107 			    IPIS_SENT, i, 1);
1108 			VLAPIC_CTR2(vlapic,
1109 			    "vlapic sending ipi %d to vcpuid %d", vec, i);
1110 		}
1111 
1112 		break;
1113 	case APIC_DELMODE_NMI:
1114 		CPU_FOREACH_ISSET(i, &dmask) {
1115 			vm_inject_nmi(vlapic->vm, i);
1116 			VLAPIC_CTR1(vlapic,
1117 			    "vlapic sending ipi nmi to vcpuid %d", i);
1118 		}
1119 
1120 		break;
1121 	case APIC_DELMODE_INIT:
1122 		CPU_FOREACH_ISSET(i, &dmask) {
1123 			/*
1124 			 * Userland which doesn't support the IPI exit requires
1125 			 * that the boot state is set to SIPI here.
1126 			 */
1127 			vlapic2 = vm_lapic(vlapic->vm, i);
1128 			vlapic2->boot_state = BS_SIPI;
1129 			CPU_SET(i, &ipimask);
1130 		}
1131 
1132 		break;
1133 	case APIC_DELMODE_STARTUP:
1134 		CPU_FOREACH_ISSET(i, &dmask) {
1135 			vlapic2 = vm_lapic(vlapic->vm, i);
1136 			/*
1137 			 * Ignore SIPIs in any state other than wait-for-SIPI
1138 			 */
1139 			if (vlapic2->boot_state != BS_SIPI)
1140 				continue;
1141 			vlapic2->boot_state = BS_RUNNING;
1142 			CPU_SET(i, &ipimask);
1143 		}
1144 
1145 		break;
1146 	default:
1147 		return (1);
1148 	}
1149 
1150 	if (!CPU_EMPTY(&ipimask)) {
1151 		vmexit = vm_exitinfo(vlapic->vm, vlapic->vcpuid);
1152 		vmexit->exitcode = VM_EXITCODE_IPI;
1153 		vmexit->u.ipi.mode = mode;
1154 		vmexit->u.ipi.vector = vec;
1155 		vmexit->u.ipi.dmask = dmask;
1156 
1157 		*retu = true;
1158 
1159 		/*
1160 		 * Old bhyve versions don't support the IPI exit. Translate it
1161 		 * into the old style.
1162 		 */
1163 		if (!vlapic->ipi_exit) {
1164 			if (mode == APIC_DELMODE_STARTUP) {
1165 				vmexit->exitcode = VM_EXITCODE_SPINUP_AP;
1166 				vmexit->u.spinup_ap.vcpu = CPU_FFS(&ipimask) - 1;
1167 				vmexit->u.spinup_ap.rip = vec << PAGE_SHIFT;
1168 			} else {
1169 				*retu = false;
1170 			}
1171 		}
1172 	}
1173 
1174 	return (0);
1175 }
1176 
1177 static void
1178 vlapic_handle_init(struct vm *vm, int vcpuid, void *arg)
1179 {
1180 	struct vlapic *vlapic = vm_lapic(vm, vcpuid);
1181 
1182 	vlapic_reset(vlapic);
1183 
1184 	/* vlapic_reset modifies the boot state. */
1185 	vlapic->boot_state = BS_SIPI;
1186 }
1187 
1188 int
1189 vm_handle_ipi(struct vm *vm, int vcpuid, struct vm_exit *vme, bool *retu)
1190 {
1191 	*retu = true;
1192 	switch (vme->u.ipi.mode) {
1193 	case APIC_DELMODE_INIT:
1194 		vm_smp_rendezvous(vm, vcpuid, vme->u.ipi.dmask,
1195 		    vlapic_handle_init, NULL);
1196 		break;
1197 	case APIC_DELMODE_STARTUP:
1198 		break;
1199 	default:
1200 		return (1);
1201 	}
1202 
1203 	return (0);
1204 }
1205 
1206 void
1207 vlapic_self_ipi_handler(struct vlapic *vlapic, uint64_t val)
1208 {
1209 	int vec;
1210 
1211 	KASSERT(x2apic(vlapic), ("SELF_IPI does not exist in xAPIC mode"));
1212 
1213 	vec = val & 0xff;
1214 	lapic_intr_edge(vlapic->vm, vlapic->vcpuid, vec);
1215 	vmm_stat_array_incr(vlapic->vm, vlapic->vcpuid, IPIS_SENT,
1216 	    vlapic->vcpuid, 1);
1217 	VLAPIC_CTR1(vlapic, "vlapic self-ipi %d", vec);
1218 }
1219 
1220 int
1221 vlapic_pending_intr(struct vlapic *vlapic, int *vecptr)
1222 {
1223 	struct LAPIC	*lapic = vlapic->apic_page;
1224 	int	  	 idx, i, bitpos, vector;
1225 	uint32_t	*irrptr, val;
1226 
1227 	vlapic_update_ppr(vlapic);
1228 
1229 	if (vlapic->ops.pending_intr)
1230 		return ((*vlapic->ops.pending_intr)(vlapic, vecptr));
1231 
1232 	irrptr = &lapic->irr0;
1233 
1234 	for (i = 7; i >= 0; i--) {
1235 		idx = i * 4;
1236 		val = atomic_load_acq_int(&irrptr[idx]);
1237 		bitpos = fls(val);
1238 		if (bitpos != 0) {
1239 			vector = i * 32 + (bitpos - 1);
1240 			if (PRIO(vector) > PRIO(lapic->ppr)) {
1241 				VLAPIC_CTR1(vlapic, "pending intr %d", vector);
1242 				if (vecptr != NULL)
1243 					*vecptr = vector;
1244 				return (1);
1245 			} else
1246 				break;
1247 		}
1248 	}
1249 	return (0);
1250 }
1251 
1252 void
1253 vlapic_intr_accepted(struct vlapic *vlapic, int vector)
1254 {
1255 	struct LAPIC	*lapic = vlapic->apic_page;
1256 	uint32_t	*irrptr, *isrptr;
1257 	int		idx, stk_top;
1258 
1259 	if (vlapic->ops.intr_accepted)
1260 		return ((*vlapic->ops.intr_accepted)(vlapic, vector));
1261 
1262 	/*
1263 	 * clear the ready bit for vector being accepted in irr
1264 	 * and set the vector as in service in isr.
1265 	 */
1266 	idx = (vector / 32) * 4;
1267 
1268 	irrptr = &lapic->irr0;
1269 	atomic_clear_int(&irrptr[idx], 1 << (vector % 32));
1270 	VLAPIC_CTR_IRR(vlapic, "vlapic_intr_accepted");
1271 
1272 	isrptr = &lapic->isr0;
1273 	isrptr[idx] |= 1 << (vector % 32);
1274 	VLAPIC_CTR_ISR(vlapic, "vlapic_intr_accepted");
1275 
1276 	/*
1277 	 * Update the PPR
1278 	 */
1279 	vlapic->isrvec_stk_top++;
1280 
1281 	stk_top = vlapic->isrvec_stk_top;
1282 	if (stk_top >= ISRVEC_STK_SIZE)
1283 		panic("isrvec_stk_top overflow %d", stk_top);
1284 
1285 	vlapic->isrvec_stk[stk_top] = vector;
1286 }
1287 
1288 void
1289 vlapic_svr_write_handler(struct vlapic *vlapic)
1290 {
1291 	struct LAPIC *lapic;
1292 	uint32_t old, new, changed;
1293 
1294 	lapic = vlapic->apic_page;
1295 
1296 	new = lapic->svr;
1297 	old = vlapic->svr_last;
1298 	vlapic->svr_last = new;
1299 
1300 	changed = old ^ new;
1301 	if ((changed & APIC_SVR_ENABLE) != 0) {
1302 		if ((new & APIC_SVR_ENABLE) == 0) {
1303 			/*
1304 			 * The apic is now disabled so stop the apic timer
1305 			 * and mask all the LVT entries.
1306 			 */
1307 			VLAPIC_CTR0(vlapic, "vlapic is software-disabled");
1308 			VLAPIC_TIMER_LOCK(vlapic);
1309 			callout_stop(&vlapic->callout);
1310 			VLAPIC_TIMER_UNLOCK(vlapic);
1311 			vlapic_mask_lvts(vlapic);
1312 		} else {
1313 			/*
1314 			 * The apic is now enabled so restart the apic timer
1315 			 * if it is configured in periodic mode.
1316 			 */
1317 			VLAPIC_CTR0(vlapic, "vlapic is software-enabled");
1318 			if (vlapic_periodic_timer(vlapic))
1319 				vlapic_icrtmr_write_handler(vlapic);
1320 		}
1321 	}
1322 }
1323 
1324 int
1325 vlapic_read(struct vlapic *vlapic, int mmio_access, uint64_t offset,
1326     uint64_t *data, bool *retu)
1327 {
1328 	struct LAPIC	*lapic = vlapic->apic_page;
1329 	uint32_t	*reg;
1330 	int		 i;
1331 
1332 	/* Ignore MMIO accesses in x2APIC mode */
1333 	if (x2apic(vlapic) && mmio_access) {
1334 		VLAPIC_CTR1(vlapic, "MMIO read from offset %#lx in x2APIC mode",
1335 		    offset);
1336 		*data = 0;
1337 		goto done;
1338 	}
1339 
1340 	if (!x2apic(vlapic) && !mmio_access) {
1341 		/*
1342 		 * XXX Generate GP fault for MSR accesses in xAPIC mode
1343 		 */
1344 		VLAPIC_CTR1(vlapic, "x2APIC MSR read from offset %#lx in "
1345 		    "xAPIC mode", offset);
1346 		*data = 0;
1347 		goto done;
1348 	}
1349 
1350 	if (offset > sizeof(*lapic)) {
1351 		*data = 0;
1352 		goto done;
1353 	}
1354 
1355 	offset &= ~3;
1356 	switch(offset)
1357 	{
1358 		case APIC_OFFSET_ID:
1359 			*data = lapic->id;
1360 			break;
1361 		case APIC_OFFSET_VER:
1362 			*data = lapic->version;
1363 			break;
1364 		case APIC_OFFSET_TPR:
1365 			*data = vlapic_get_tpr(vlapic);
1366 			break;
1367 		case APIC_OFFSET_APR:
1368 			*data = lapic->apr;
1369 			break;
1370 		case APIC_OFFSET_PPR:
1371 			*data = lapic->ppr;
1372 			break;
1373 		case APIC_OFFSET_EOI:
1374 			*data = lapic->eoi;
1375 			break;
1376 		case APIC_OFFSET_LDR:
1377 			*data = lapic->ldr;
1378 			break;
1379 		case APIC_OFFSET_DFR:
1380 			*data = lapic->dfr;
1381 			break;
1382 		case APIC_OFFSET_SVR:
1383 			*data = lapic->svr;
1384 			break;
1385 		case APIC_OFFSET_ISR0 ... APIC_OFFSET_ISR7:
1386 			i = (offset - APIC_OFFSET_ISR0) >> 2;
1387 			reg = &lapic->isr0;
1388 			*data = *(reg + i);
1389 			break;
1390 		case APIC_OFFSET_TMR0 ... APIC_OFFSET_TMR7:
1391 			i = (offset - APIC_OFFSET_TMR0) >> 2;
1392 			reg = &lapic->tmr0;
1393 			*data = *(reg + i);
1394 			break;
1395 		case APIC_OFFSET_IRR0 ... APIC_OFFSET_IRR7:
1396 			i = (offset - APIC_OFFSET_IRR0) >> 2;
1397 			reg = &lapic->irr0;
1398 			*data = atomic_load_acq_int(reg + i);
1399 			break;
1400 		case APIC_OFFSET_ESR:
1401 			*data = lapic->esr;
1402 			break;
1403 		case APIC_OFFSET_ICR_LOW:
1404 			*data = lapic->icr_lo;
1405 			if (x2apic(vlapic))
1406 				*data |= (uint64_t)lapic->icr_hi << 32;
1407 			break;
1408 		case APIC_OFFSET_ICR_HI:
1409 			*data = lapic->icr_hi;
1410 			break;
1411 		case APIC_OFFSET_CMCI_LVT:
1412 		case APIC_OFFSET_TIMER_LVT ... APIC_OFFSET_ERROR_LVT:
1413 			*data = vlapic_get_lvt(vlapic, offset);
1414 #ifdef INVARIANTS
1415 			reg = vlapic_get_lvtptr(vlapic, offset);
1416 			KASSERT(*data == *reg, ("inconsistent lvt value at "
1417 			    "offset %#lx: %#lx/%#x", offset, *data, *reg));
1418 #endif
1419 			break;
1420 		case APIC_OFFSET_TIMER_ICR:
1421 			*data = lapic->icr_timer;
1422 			break;
1423 		case APIC_OFFSET_TIMER_CCR:
1424 			*data = vlapic_get_ccr(vlapic);
1425 			break;
1426 		case APIC_OFFSET_TIMER_DCR:
1427 			*data = lapic->dcr_timer;
1428 			break;
1429 		case APIC_OFFSET_SELF_IPI:
1430 			/*
1431 			 * XXX generate a GP fault if vlapic is in x2apic mode
1432 			 */
1433 			*data = 0;
1434 			break;
1435 		case APIC_OFFSET_RRR:
1436 		default:
1437 			*data = 0;
1438 			break;
1439 	}
1440 done:
1441 	VLAPIC_CTR2(vlapic, "vlapic read offset %#x, data %#lx", offset, *data);
1442 	return 0;
1443 }
1444 
1445 int
1446 vlapic_write(struct vlapic *vlapic, int mmio_access, uint64_t offset,
1447     uint64_t data, bool *retu)
1448 {
1449 	struct LAPIC	*lapic = vlapic->apic_page;
1450 	uint32_t	*regptr;
1451 	int		retval;
1452 
1453 	KASSERT((offset & 0xf) == 0 && offset < PAGE_SIZE,
1454 	    ("vlapic_write: invalid offset %#lx", offset));
1455 
1456 	VLAPIC_CTR2(vlapic, "vlapic write offset %#lx, data %#lx",
1457 	    offset, data);
1458 
1459 	if (offset > sizeof(*lapic))
1460 		return (0);
1461 
1462 	/* Ignore MMIO accesses in x2APIC mode */
1463 	if (x2apic(vlapic) && mmio_access) {
1464 		VLAPIC_CTR2(vlapic, "MMIO write of %#lx to offset %#lx "
1465 		    "in x2APIC mode", data, offset);
1466 		return (0);
1467 	}
1468 
1469 	/*
1470 	 * XXX Generate GP fault for MSR accesses in xAPIC mode
1471 	 */
1472 	if (!x2apic(vlapic) && !mmio_access) {
1473 		VLAPIC_CTR2(vlapic, "x2APIC MSR write of %#lx to offset %#lx "
1474 		    "in xAPIC mode", data, offset);
1475 		return (0);
1476 	}
1477 
1478 	retval = 0;
1479 	switch(offset)
1480 	{
1481 		case APIC_OFFSET_ID:
1482 			lapic->id = data;
1483 			vlapic_id_write_handler(vlapic);
1484 			break;
1485 		case APIC_OFFSET_TPR:
1486 			vlapic_set_tpr(vlapic, data & 0xff);
1487 			break;
1488 		case APIC_OFFSET_EOI:
1489 			vlapic_process_eoi(vlapic);
1490 			break;
1491 		case APIC_OFFSET_LDR:
1492 			lapic->ldr = data;
1493 			vlapic_ldr_write_handler(vlapic);
1494 			break;
1495 		case APIC_OFFSET_DFR:
1496 			lapic->dfr = data;
1497 			vlapic_dfr_write_handler(vlapic);
1498 			break;
1499 		case APIC_OFFSET_SVR:
1500 			lapic->svr = data;
1501 			vlapic_svr_write_handler(vlapic);
1502 			break;
1503 		case APIC_OFFSET_ICR_LOW:
1504 			lapic->icr_lo = data;
1505 			if (x2apic(vlapic))
1506 				lapic->icr_hi = data >> 32;
1507 			retval = vlapic_icrlo_write_handler(vlapic, retu);
1508 			break;
1509 		case APIC_OFFSET_ICR_HI:
1510 			lapic->icr_hi = data;
1511 			break;
1512 		case APIC_OFFSET_CMCI_LVT:
1513 		case APIC_OFFSET_TIMER_LVT ... APIC_OFFSET_ERROR_LVT:
1514 			regptr = vlapic_get_lvtptr(vlapic, offset);
1515 			*regptr = data;
1516 			vlapic_lvt_write_handler(vlapic, offset);
1517 			break;
1518 		case APIC_OFFSET_TIMER_ICR:
1519 			lapic->icr_timer = data;
1520 			vlapic_icrtmr_write_handler(vlapic);
1521 			break;
1522 
1523 		case APIC_OFFSET_TIMER_DCR:
1524 			lapic->dcr_timer = data;
1525 			vlapic_dcr_write_handler(vlapic);
1526 			break;
1527 
1528 		case APIC_OFFSET_ESR:
1529 			vlapic_esr_write_handler(vlapic);
1530 			break;
1531 
1532 		case APIC_OFFSET_SELF_IPI:
1533 			if (x2apic(vlapic))
1534 				vlapic_self_ipi_handler(vlapic, data);
1535 			break;
1536 
1537 		case APIC_OFFSET_VER:
1538 		case APIC_OFFSET_APR:
1539 		case APIC_OFFSET_PPR:
1540 		case APIC_OFFSET_RRR:
1541 		case APIC_OFFSET_ISR0 ... APIC_OFFSET_ISR7:
1542 		case APIC_OFFSET_TMR0 ... APIC_OFFSET_TMR7:
1543 		case APIC_OFFSET_IRR0 ... APIC_OFFSET_IRR7:
1544 		case APIC_OFFSET_TIMER_CCR:
1545 		default:
1546 			// Read only.
1547 			break;
1548 	}
1549 
1550 	return (retval);
1551 }
1552 
1553 static void
1554 vlapic_reset(struct vlapic *vlapic)
1555 {
1556 	struct LAPIC *lapic;
1557 
1558 	lapic = vlapic->apic_page;
1559 	bzero(lapic, sizeof(struct LAPIC));
1560 
1561 	lapic->id = vlapic_get_id(vlapic);
1562 	lapic->version = VLAPIC_VERSION;
1563 	lapic->version |= (VLAPIC_MAXLVT_INDEX << MAXLVTSHIFT);
1564 	lapic->dfr = 0xffffffff;
1565 	lapic->svr = APIC_SVR_VECTOR;
1566 	vlapic_mask_lvts(vlapic);
1567 	vlapic_reset_tmr(vlapic);
1568 
1569 	lapic->dcr_timer = 0;
1570 	vlapic_dcr_write_handler(vlapic);
1571 
1572 	if (vlapic->vcpuid == 0)
1573 		vlapic->boot_state = BS_RUNNING;	/* BSP */
1574 	else
1575 		vlapic->boot_state = BS_INIT;		/* AP */
1576 
1577 	vlapic->svr_last = lapic->svr;
1578 }
1579 
1580 void
1581 vlapic_init(struct vlapic *vlapic)
1582 {
1583 	KASSERT(vlapic->vm != NULL, ("vlapic_init: vm is not initialized"));
1584 	KASSERT(vlapic->vcpuid >= 0 &&
1585 	    vlapic->vcpuid < vm_get_maxcpus(vlapic->vm),
1586 	    ("vlapic_init: vcpuid is not initialized"));
1587 	KASSERT(vlapic->apic_page != NULL, ("vlapic_init: apic_page is not "
1588 	    "initialized"));
1589 
1590 	/*
1591 	 * If the vlapic is configured in x2apic mode then it will be
1592 	 * accessed in the critical section via the MSR emulation code.
1593 	 *
1594 	 * Therefore the timer mutex must be a spinlock because blockable
1595 	 * mutexes cannot be acquired in a critical section.
1596 	 */
1597 	mtx_init(&vlapic->timer_mtx, "vlapic timer mtx", NULL, MTX_SPIN);
1598 	callout_init(&vlapic->callout, 1);
1599 
1600 	vlapic->msr_apicbase = DEFAULT_APIC_BASE | APICBASE_ENABLED;
1601 
1602 	if (vlapic->vcpuid == 0)
1603 		vlapic->msr_apicbase |= APICBASE_BSP;
1604 
1605 	vlapic->ipi_exit = false;
1606 
1607 	vlapic_reset(vlapic);
1608 }
1609 
1610 void
1611 vlapic_cleanup(struct vlapic *vlapic)
1612 {
1613 
1614 	callout_drain(&vlapic->callout);
1615 }
1616 
1617 uint64_t
1618 vlapic_get_apicbase(struct vlapic *vlapic)
1619 {
1620 
1621 	return (vlapic->msr_apicbase);
1622 }
1623 
1624 int
1625 vlapic_set_apicbase(struct vlapic *vlapic, uint64_t new)
1626 {
1627 
1628 	if (vlapic->msr_apicbase != new) {
1629 		VLAPIC_CTR2(vlapic, "Changing APIC_BASE MSR from %#lx to %#lx "
1630 		    "not supported", vlapic->msr_apicbase, new);
1631 		return (-1);
1632 	}
1633 
1634 	return (0);
1635 }
1636 
1637 void
1638 vlapic_set_x2apic_state(struct vm *vm, int vcpuid, enum x2apic_state state)
1639 {
1640 	struct vlapic *vlapic;
1641 	struct LAPIC *lapic;
1642 
1643 	vlapic = vm_lapic(vm, vcpuid);
1644 
1645 	if (state == X2APIC_DISABLED)
1646 		vlapic->msr_apicbase &= ~APICBASE_X2APIC;
1647 	else
1648 		vlapic->msr_apicbase |= APICBASE_X2APIC;
1649 
1650 	/*
1651 	 * Reset the local APIC registers whose values are mode-dependent.
1652 	 *
1653 	 * XXX this works because the APIC mode can be changed only at vcpu
1654 	 * initialization time.
1655 	 */
1656 	lapic = vlapic->apic_page;
1657 	lapic->id = vlapic_get_id(vlapic);
1658 	if (x2apic(vlapic)) {
1659 		lapic->ldr = x2apic_ldr(vlapic);
1660 		lapic->dfr = 0;
1661 	} else {
1662 		lapic->ldr = 0;
1663 		lapic->dfr = 0xffffffff;
1664 	}
1665 
1666 	if (state == X2APIC_ENABLED) {
1667 		if (vlapic->ops.enable_x2apic_mode)
1668 			(*vlapic->ops.enable_x2apic_mode)(vlapic);
1669 	}
1670 }
1671 
1672 void
1673 vlapic_deliver_intr(struct vm *vm, bool level, uint32_t dest, bool phys,
1674     int delmode, int vec)
1675 {
1676 	bool lowprio;
1677 	int vcpuid;
1678 	cpuset_t dmask;
1679 
1680 	if (delmode != IOART_DELFIXED &&
1681 	    delmode != IOART_DELLOPRI &&
1682 	    delmode != IOART_DELEXINT) {
1683 		VM_CTR1(vm, "vlapic intr invalid delmode %#x", delmode);
1684 		return;
1685 	}
1686 	lowprio = (delmode == IOART_DELLOPRI);
1687 
1688 	/*
1689 	 * We don't provide any virtual interrupt redirection hardware so
1690 	 * all interrupts originating from the ioapic or MSI specify the
1691 	 * 'dest' in the legacy xAPIC format.
1692 	 */
1693 	vlapic_calcdest(vm, &dmask, dest, phys, lowprio, false);
1694 
1695 	CPU_FOREACH_ISSET(vcpuid, &dmask) {
1696 		if (delmode == IOART_DELEXINT) {
1697 			vm_inject_extint(vm, vcpuid);
1698 		} else {
1699 			lapic_set_intr(vm, vcpuid, vec, level);
1700 		}
1701 	}
1702 }
1703 
1704 void
1705 vlapic_post_intr(struct vlapic *vlapic, int hostcpu, int ipinum)
1706 {
1707 	/*
1708 	 * Post an interrupt to the vcpu currently running on 'hostcpu'.
1709 	 *
1710 	 * This is done by leveraging features like Posted Interrupts (Intel)
1711 	 * Doorbell MSR (AMD AVIC) that avoid a VM exit.
1712 	 *
1713 	 * If neither of these features are available then fallback to
1714 	 * sending an IPI to 'hostcpu'.
1715 	 */
1716 	if (vlapic->ops.post_intr)
1717 		(*vlapic->ops.post_intr)(vlapic, hostcpu);
1718 	else
1719 		ipi_cpu(hostcpu, ipinum);
1720 }
1721 
1722 bool
1723 vlapic_enabled(struct vlapic *vlapic)
1724 {
1725 	struct LAPIC *lapic = vlapic->apic_page;
1726 
1727 	if ((vlapic->msr_apicbase & APICBASE_ENABLED) != 0 &&
1728 	    (lapic->svr & APIC_SVR_ENABLE) != 0)
1729 		return (true);
1730 	else
1731 		return (false);
1732 }
1733 
1734 static void
1735 vlapic_set_tmr(struct vlapic *vlapic, int vector, bool level)
1736 {
1737 	struct LAPIC *lapic;
1738 	uint32_t *tmrptr, mask;
1739 	int idx;
1740 
1741 	lapic = vlapic->apic_page;
1742 	tmrptr = &lapic->tmr0;
1743 	idx = (vector / 32) * 4;
1744 	mask = 1 << (vector % 32);
1745 	if (level)
1746 		tmrptr[idx] |= mask;
1747 	else
1748 		tmrptr[idx] &= ~mask;
1749 
1750 	if (vlapic->ops.set_tmr != NULL)
1751 		(*vlapic->ops.set_tmr)(vlapic, vector, level);
1752 }
1753 
1754 void
1755 vlapic_reset_tmr(struct vlapic *vlapic)
1756 {
1757 	int vector;
1758 
1759 	VLAPIC_CTR0(vlapic, "vlapic resetting all vectors to edge-triggered");
1760 
1761 	for (vector = 0; vector <= 255; vector++)
1762 		vlapic_set_tmr(vlapic, vector, false);
1763 }
1764 
1765 void
1766 vlapic_set_tmr_level(struct vlapic *vlapic, uint32_t dest, bool phys,
1767     int delmode, int vector)
1768 {
1769 	cpuset_t dmask;
1770 	bool lowprio;
1771 
1772 	KASSERT(vector >= 0 && vector <= 255, ("invalid vector %d", vector));
1773 
1774 	/*
1775 	 * A level trigger is valid only for fixed and lowprio delivery modes.
1776 	 */
1777 	if (delmode != APIC_DELMODE_FIXED && delmode != APIC_DELMODE_LOWPRIO) {
1778 		VLAPIC_CTR1(vlapic, "Ignoring level trigger-mode for "
1779 		    "delivery-mode %d", delmode);
1780 		return;
1781 	}
1782 
1783 	lowprio = (delmode == APIC_DELMODE_LOWPRIO);
1784 	vlapic_calcdest(vlapic->vm, &dmask, dest, phys, lowprio, false);
1785 
1786 	if (!CPU_ISSET(vlapic->vcpuid, &dmask))
1787 		return;
1788 
1789 	VLAPIC_CTR1(vlapic, "vector %d set to level-triggered", vector);
1790 	vlapic_set_tmr(vlapic, vector, true);
1791 }
1792 
1793 #ifdef BHYVE_SNAPSHOT
1794 static void
1795 vlapic_reset_callout(struct vlapic *vlapic, uint32_t ccr)
1796 {
1797 	/* The implementation is similar to the one in the
1798 	 * `vlapic_icrtmr_write_handler` function
1799 	 */
1800 	sbintime_t sbt;
1801 	struct bintime bt;
1802 
1803 	VLAPIC_TIMER_LOCK(vlapic);
1804 
1805 	bt = vlapic->timer_freq_bt;
1806 	bintime_mul(&bt, ccr);
1807 
1808 	if (ccr != 0) {
1809 		binuptime(&vlapic->timer_fire_bt);
1810 		bintime_add(&vlapic->timer_fire_bt, &bt);
1811 
1812 		sbt = bttosbt(bt);
1813 		vlapic_callout_reset(vlapic, sbt);
1814 	} else {
1815 		/* even if the CCR was 0, periodic timers should be reset */
1816 		if (vlapic_periodic_timer(vlapic)) {
1817 			binuptime(&vlapic->timer_fire_bt);
1818 			bintime_add(&vlapic->timer_fire_bt,
1819 				    &vlapic->timer_period_bt);
1820 			sbt = bttosbt(vlapic->timer_period_bt);
1821 
1822 			callout_stop(&vlapic->callout);
1823 			vlapic_callout_reset(vlapic, sbt);
1824 		}
1825 	}
1826 
1827 	VLAPIC_TIMER_UNLOCK(vlapic);
1828 }
1829 
1830 int
1831 vlapic_snapshot(struct vm *vm, struct vm_snapshot_meta *meta)
1832 {
1833 	int i, ret;
1834 	struct vlapic *vlapic;
1835 	struct LAPIC *lapic;
1836 	uint32_t ccr;
1837 
1838 	KASSERT(vm != NULL, ("%s: arg was NULL", __func__));
1839 
1840 	ret = 0;
1841 
1842 	for (i = 0; i < VM_MAXCPU; i++) {
1843 		vlapic = vm_lapic(vm, i);
1844 
1845 		/* snapshot the page first; timer period depends on icr_timer */
1846 		lapic = vlapic->apic_page;
1847 		SNAPSHOT_BUF_OR_LEAVE(lapic, PAGE_SIZE, meta, ret, done);
1848 
1849 		SNAPSHOT_VAR_OR_LEAVE(vlapic->esr_pending, meta, ret, done);
1850 
1851 		SNAPSHOT_VAR_OR_LEAVE(vlapic->timer_freq_bt.sec,
1852 				      meta, ret, done);
1853 		SNAPSHOT_VAR_OR_LEAVE(vlapic->timer_freq_bt.frac,
1854 				      meta, ret, done);
1855 
1856 		/*
1857 		 * Timer period is equal to 'icr_timer' ticks at a frequency of
1858 		 * 'timer_freq_bt'.
1859 		 */
1860 		if (meta->op == VM_SNAPSHOT_RESTORE) {
1861 			vlapic->timer_period_bt = vlapic->timer_freq_bt;
1862 			bintime_mul(&vlapic->timer_period_bt, lapic->icr_timer);
1863 		}
1864 
1865 		SNAPSHOT_BUF_OR_LEAVE(vlapic->isrvec_stk,
1866 				      sizeof(vlapic->isrvec_stk),
1867 				      meta, ret, done);
1868 		SNAPSHOT_VAR_OR_LEAVE(vlapic->isrvec_stk_top, meta, ret, done);
1869 		SNAPSHOT_VAR_OR_LEAVE(vlapic->boot_state, meta, ret, done);
1870 
1871 		SNAPSHOT_BUF_OR_LEAVE(vlapic->lvt_last,
1872 				      sizeof(vlapic->lvt_last),
1873 				      meta, ret, done);
1874 
1875 		if (meta->op == VM_SNAPSHOT_SAVE)
1876 			ccr = vlapic_get_ccr(vlapic);
1877 
1878 		SNAPSHOT_VAR_OR_LEAVE(ccr, meta, ret, done);
1879 
1880 		if (meta->op == VM_SNAPSHOT_RESTORE &&
1881 		    vlapic_enabled(vlapic) && lapic->icr_timer != 0) {
1882 			/* Reset the value of the 'timer_fire_bt' and the vlapic
1883 			 * callout based on the value of the current count
1884 			 * register saved when the VM snapshot was created.
1885 			 * If initial count register is 0, timer is not used.
1886 			 * Look at "10.5.4 APIC Timer" in Software Developer Manual.
1887 			 */
1888 			vlapic_reset_callout(vlapic, ccr);
1889 		}
1890 	}
1891 
1892 done:
1893 	return (ret);
1894 }
1895 #endif
1896