xref: /freebsd/sys/amd64/vmm/io/vlapic.c (revision 8c784bb8cf36911b828652f0bf7e88f443abec50)
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->vcpu, true);
464 		break;
465 	case APIC_LVT_DM_NMI:
466 		vm_inject_nmi(vlapic->vcpu);
467 		break;
468 	case APIC_LVT_DM_EXTINT:
469 		vm_inject_extint(vlapic->vcpu);
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 			VLAPIC_CTR1(vlapic, "EOI vector %d", vector);
592 			VLAPIC_CTR_ISR(vlapic, "vlapic_process_eoi");
593 			vlapic->isrvec_stk_top--;
594 			vlapic_update_ppr(vlapic);
595 			if ((tmrptr[idx] & (1 << bitpos)) != 0) {
596 				vioapic_process_eoi(vlapic->vm, vector);
597 			}
598 			return;
599 		}
600 	}
601 	VLAPIC_CTR0(vlapic, "Gratuitous EOI");
602 	vmm_stat_incr(vlapic->vcpu, VLAPIC_GRATUITOUS_EOI, 1);
603 }
604 
605 static __inline int
606 vlapic_get_lvt_field(uint32_t lvt, uint32_t mask)
607 {
608 
609 	return (lvt & mask);
610 }
611 
612 static __inline int
613 vlapic_periodic_timer(struct vlapic *vlapic)
614 {
615 	uint32_t lvt;
616 
617 	lvt = vlapic_get_lvt(vlapic, APIC_OFFSET_TIMER_LVT);
618 
619 	return (vlapic_get_lvt_field(lvt, APIC_LVTT_TM_PERIODIC));
620 }
621 
622 static VMM_STAT(VLAPIC_INTR_ERROR, "error interrupts generated by vlapic");
623 
624 static void
625 vlapic_set_error(struct vlapic *vlapic, uint32_t mask, bool lvt_error)
626 {
627 
628 	vlapic->esr_pending |= mask;
629 
630 	/*
631 	 * Avoid infinite recursion if the error LVT itself is configured with
632 	 * an illegal vector.
633 	 */
634 	if (lvt_error)
635 		return;
636 
637 	if (vlapic_fire_lvt(vlapic, APIC_LVT_ERROR)) {
638 		vmm_stat_incr(vlapic->vcpu, VLAPIC_INTR_ERROR, 1);
639 	}
640 }
641 
642 static VMM_STAT(VLAPIC_INTR_TIMER, "timer interrupts generated by vlapic");
643 
644 static void
645 vlapic_fire_timer(struct vlapic *vlapic)
646 {
647 
648 	KASSERT(VLAPIC_TIMER_LOCKED(vlapic), ("vlapic_fire_timer not locked"));
649 
650 	if (vlapic_fire_lvt(vlapic, APIC_LVT_TIMER)) {
651 		VLAPIC_CTR0(vlapic, "vlapic timer fired");
652 		vmm_stat_incr(vlapic->vcpu, VLAPIC_INTR_TIMER, 1);
653 	}
654 }
655 
656 static VMM_STAT(VLAPIC_INTR_CMC,
657     "corrected machine check interrupts generated by vlapic");
658 
659 void
660 vlapic_fire_cmci(struct vlapic *vlapic)
661 {
662 
663 	if (vlapic_fire_lvt(vlapic, APIC_LVT_CMCI)) {
664 		vmm_stat_incr(vlapic->vcpu, VLAPIC_INTR_CMC, 1);
665 	}
666 }
667 
668 static VMM_STAT_ARRAY(LVTS_TRIGGERRED, VLAPIC_MAXLVT_INDEX + 1,
669     "lvts triggered");
670 
671 int
672 vlapic_trigger_lvt(struct vlapic *vlapic, int vector)
673 {
674 
675 	if (vlapic_enabled(vlapic) == false) {
676 		/*
677 		 * When the local APIC is global/hardware disabled,
678 		 * LINT[1:0] pins are configured as INTR and NMI pins,
679 		 * respectively.
680 		*/
681 		switch (vector) {
682 			case APIC_LVT_LINT0:
683 				vm_inject_extint(vlapic->vcpu);
684 				break;
685 			case APIC_LVT_LINT1:
686 				vm_inject_nmi(vlapic->vcpu);
687 				break;
688 			default:
689 				break;
690 		}
691 		return (0);
692 	}
693 
694 	switch (vector) {
695 	case APIC_LVT_LINT0:
696 	case APIC_LVT_LINT1:
697 	case APIC_LVT_TIMER:
698 	case APIC_LVT_ERROR:
699 	case APIC_LVT_PMC:
700 	case APIC_LVT_THERMAL:
701 	case APIC_LVT_CMCI:
702 		if (vlapic_fire_lvt(vlapic, vector)) {
703 			vmm_stat_array_incr(vlapic->vcpu, LVTS_TRIGGERRED,
704 			    vector, 1);
705 		}
706 		break;
707 	default:
708 		return (EINVAL);
709 	}
710 	return (0);
711 }
712 
713 static void
714 vlapic_callout_reset(struct vlapic *vlapic, sbintime_t t)
715 {
716 	callout_reset_sbt_curcpu(&vlapic->callout, t, 0,
717 	    vlapic_callout_handler, vlapic, 0);
718 }
719 
720 static void
721 vlapic_callout_handler(void *arg)
722 {
723 	struct vlapic *vlapic;
724 	struct bintime bt, btnow;
725 	sbintime_t rem_sbt;
726 
727 	vlapic = arg;
728 
729 	VLAPIC_TIMER_LOCK(vlapic);
730 	if (callout_pending(&vlapic->callout))	/* callout was reset */
731 		goto done;
732 
733 	if (!callout_active(&vlapic->callout))	/* callout was stopped */
734 		goto done;
735 
736 	callout_deactivate(&vlapic->callout);
737 
738 	vlapic_fire_timer(vlapic);
739 
740 	if (vlapic_periodic_timer(vlapic)) {
741 		binuptime(&btnow);
742 		KASSERT(bintime_cmp(&btnow, &vlapic->timer_fire_bt, >=),
743 		    ("vlapic callout at %#lx.%#lx, expected at %#lx.#%lx",
744 		    btnow.sec, btnow.frac, vlapic->timer_fire_bt.sec,
745 		    vlapic->timer_fire_bt.frac));
746 
747 		/*
748 		 * Compute the delta between when the timer was supposed to
749 		 * fire and the present time.
750 		 */
751 		bt = btnow;
752 		bintime_sub(&bt, &vlapic->timer_fire_bt);
753 
754 		rem_sbt = bttosbt(vlapic->timer_period_bt);
755 		if (bintime_cmp(&bt, &vlapic->timer_period_bt, <)) {
756 			/*
757 			 * Adjust the time until the next countdown downward
758 			 * to account for the lost time.
759 			 */
760 			rem_sbt -= bttosbt(bt);
761 		} else {
762 			/*
763 			 * If the delta is greater than the timer period then
764 			 * just reset our time base instead of trying to catch
765 			 * up.
766 			 */
767 			vlapic->timer_fire_bt = btnow;
768 			VLAPIC_CTR2(vlapic, "vlapic timer lagging by %lu "
769 			    "usecs, period is %lu usecs - resetting time base",
770 			    bttosbt(bt) / SBT_1US,
771 			    bttosbt(vlapic->timer_period_bt) / SBT_1US);
772 		}
773 
774 		bintime_add(&vlapic->timer_fire_bt, &vlapic->timer_period_bt);
775 		vlapic_callout_reset(vlapic, rem_sbt);
776 	}
777 done:
778 	VLAPIC_TIMER_UNLOCK(vlapic);
779 }
780 
781 void
782 vlapic_icrtmr_write_handler(struct vlapic *vlapic)
783 {
784 	struct LAPIC *lapic;
785 	sbintime_t sbt;
786 	uint32_t icr_timer;
787 
788 	VLAPIC_TIMER_LOCK(vlapic);
789 
790 	lapic = vlapic->apic_page;
791 	icr_timer = lapic->icr_timer;
792 
793 	vlapic->timer_period_bt = vlapic->timer_freq_bt;
794 	bintime_mul(&vlapic->timer_period_bt, icr_timer);
795 
796 	if (icr_timer != 0) {
797 		binuptime(&vlapic->timer_fire_bt);
798 		bintime_add(&vlapic->timer_fire_bt, &vlapic->timer_period_bt);
799 
800 		sbt = bttosbt(vlapic->timer_period_bt);
801 		vlapic_callout_reset(vlapic, sbt);
802 	} else
803 		callout_stop(&vlapic->callout);
804 
805 	VLAPIC_TIMER_UNLOCK(vlapic);
806 }
807 
808 /*
809  * This function populates 'dmask' with the set of vcpus that match the
810  * addressing specified by the (dest, phys, lowprio) tuple.
811  *
812  * 'x2apic_dest' specifies whether 'dest' is interpreted as x2APIC (32-bit)
813  * or xAPIC (8-bit) destination field.
814  */
815 static void
816 vlapic_calcdest(struct vm *vm, cpuset_t *dmask, uint32_t dest, bool phys,
817     bool lowprio, bool x2apic_dest)
818 {
819 	struct vlapic *vlapic;
820 	uint32_t dfr, ldr, ldest, cluster;
821 	uint32_t mda_flat_ldest, mda_cluster_ldest, mda_ldest, mda_cluster_id;
822 	cpuset_t amask;
823 	int vcpuid;
824 
825 	if ((x2apic_dest && dest == 0xffffffff) ||
826 	    (!x2apic_dest && dest == 0xff)) {
827 		/*
828 		 * Broadcast in both logical and physical modes.
829 		 */
830 		*dmask = vm_active_cpus(vm);
831 		return;
832 	}
833 
834 	if (phys) {
835 		/*
836 		 * Physical mode: destination is APIC ID.
837 		 */
838 		CPU_ZERO(dmask);
839 		vcpuid = vm_apicid2vcpuid(vm, dest);
840 		amask = vm_active_cpus(vm);
841 		if (vcpuid < vm_get_maxcpus(vm) && CPU_ISSET(vcpuid, &amask))
842 			CPU_SET(vcpuid, dmask);
843 	} else {
844 		/*
845 		 * In the "Flat Model" the MDA is interpreted as an 8-bit wide
846 		 * bitmask. This model is only available in the xAPIC mode.
847 		 */
848 		mda_flat_ldest = dest & 0xff;
849 
850 		/*
851 		 * In the "Cluster Model" the MDA is used to identify a
852 		 * specific cluster and a set of APICs in that cluster.
853 		 */
854 		if (x2apic_dest) {
855 			mda_cluster_id = dest >> 16;
856 			mda_cluster_ldest = dest & 0xffff;
857 		} else {
858 			mda_cluster_id = (dest >> 4) & 0xf;
859 			mda_cluster_ldest = dest & 0xf;
860 		}
861 
862 		/*
863 		 * Logical mode: match each APIC that has a bit set
864 		 * in its LDR that matches a bit in the ldest.
865 		 */
866 		CPU_ZERO(dmask);
867 		amask = vm_active_cpus(vm);
868 		CPU_FOREACH_ISSET(vcpuid, &amask) {
869 			vlapic = vm_lapic(vm_vcpu(vm, vcpuid));
870 			dfr = vlapic->apic_page->dfr;
871 			ldr = vlapic->apic_page->ldr;
872 
873 			if ((dfr & APIC_DFR_MODEL_MASK) ==
874 			    APIC_DFR_MODEL_FLAT) {
875 				ldest = ldr >> 24;
876 				mda_ldest = mda_flat_ldest;
877 			} else if ((dfr & APIC_DFR_MODEL_MASK) ==
878 			    APIC_DFR_MODEL_CLUSTER) {
879 				if (x2apic(vlapic)) {
880 					cluster = ldr >> 16;
881 					ldest = ldr & 0xffff;
882 				} else {
883 					cluster = ldr >> 28;
884 					ldest = (ldr >> 24) & 0xf;
885 				}
886 				if (cluster != mda_cluster_id)
887 					continue;
888 				mda_ldest = mda_cluster_ldest;
889 			} else {
890 				/*
891 				 * Guest has configured a bad logical
892 				 * model for this vcpu - skip it.
893 				 */
894 				VLAPIC_CTR1(vlapic, "vlapic has bad logical "
895 				    "model %x - cannot deliver interrupt", dfr);
896 				continue;
897 			}
898 
899 			if ((mda_ldest & ldest) != 0) {
900 				CPU_SET(vcpuid, dmask);
901 				if (lowprio)
902 					break;
903 			}
904 		}
905 	}
906 }
907 
908 static VMM_STAT_ARRAY(IPIS_SENT, VMM_STAT_NELEMS_VCPU, "ipis sent to vcpu");
909 
910 static void
911 vlapic_set_tpr(struct vlapic *vlapic, uint8_t val)
912 {
913 	struct LAPIC *lapic = vlapic->apic_page;
914 
915 	if (lapic->tpr != val) {
916 		VLAPIC_CTR2(vlapic, "vlapic TPR changed from %#x to %#x",
917 		    lapic->tpr, val);
918 		lapic->tpr = val;
919 		vlapic_update_ppr(vlapic);
920 	}
921 }
922 
923 static uint8_t
924 vlapic_get_tpr(struct vlapic *vlapic)
925 {
926 	struct LAPIC *lapic = vlapic->apic_page;
927 
928 	return (lapic->tpr);
929 }
930 
931 void
932 vlapic_set_cr8(struct vlapic *vlapic, uint64_t val)
933 {
934 	uint8_t tpr;
935 
936 	if (val & ~0xf) {
937 		vm_inject_gp(vlapic->vcpu);
938 		return;
939 	}
940 
941 	tpr = val << 4;
942 	vlapic_set_tpr(vlapic, tpr);
943 }
944 
945 uint64_t
946 vlapic_get_cr8(struct vlapic *vlapic)
947 {
948 	uint8_t tpr;
949 
950 	tpr = vlapic_get_tpr(vlapic);
951 	return (tpr >> 4);
952 }
953 
954 static bool
955 vlapic_is_icr_valid(uint64_t icrval)
956 {
957 	uint32_t mode = icrval & APIC_DELMODE_MASK;
958 	uint32_t level = icrval & APIC_LEVEL_MASK;
959 	uint32_t trigger = icrval & APIC_TRIGMOD_MASK;
960 	uint32_t shorthand = icrval & APIC_DEST_MASK;
961 
962 	switch (mode) {
963 	case APIC_DELMODE_FIXED:
964 		if (trigger == APIC_TRIGMOD_EDGE)
965 			return (true);
966 		/*
967 		 * AMD allows a level assert IPI and Intel converts a level
968 		 * assert IPI into an edge IPI.
969 		 */
970 		if (trigger == APIC_TRIGMOD_LEVEL && level == APIC_LEVEL_ASSERT)
971 			return (true);
972 		break;
973 	case APIC_DELMODE_LOWPRIO:
974 	case APIC_DELMODE_SMI:
975 	case APIC_DELMODE_NMI:
976 	case APIC_DELMODE_INIT:
977 		if (trigger == APIC_TRIGMOD_EDGE &&
978 		    (shorthand == APIC_DEST_DESTFLD ||
979 			shorthand == APIC_DEST_ALLESELF))
980 			return (true);
981 		/*
982 		 * AMD allows a level assert IPI and Intel converts a level
983 		 * assert IPI into an edge IPI.
984 		 */
985 		if (trigger == APIC_TRIGMOD_LEVEL &&
986 		    level == APIC_LEVEL_ASSERT &&
987 		    (shorthand == APIC_DEST_DESTFLD ||
988 			shorthand == APIC_DEST_ALLESELF))
989 			return (true);
990 		/*
991 		 * An level triggered deassert INIT is defined in the Intel
992 		 * Multiprocessor Specification and the Intel Software Developer
993 		 * Manual. Due to the MPS it's required to send a level assert
994 		 * INIT to a cpu and then a level deassert INIT. Some operating
995 		 * systems e.g. FreeBSD or Linux use that algorithm. According
996 		 * to the SDM a level deassert INIT is only supported by Pentium
997 		 * and P6 processors. It's always send to all cpus regardless of
998 		 * the destination or shorthand field. It resets the arbitration
999 		 * id register. This register is not software accessible and
1000 		 * only required for the APIC bus arbitration. So, the level
1001 		 * deassert INIT doesn't need any emulation and we should ignore
1002 		 * it. The SDM also defines that newer processors don't support
1003 		 * the level deassert INIT and it's not valid any more. As it's
1004 		 * defined for older systems, it can't be invalid per se.
1005 		 * Otherwise, backward compatibility would be broken. However,
1006 		 * when returning false here, it'll be ignored which is the
1007 		 * desired behaviour.
1008 		 */
1009 		if (mode == APIC_DELMODE_INIT &&
1010 		    trigger == APIC_TRIGMOD_LEVEL &&
1011 		    level == APIC_LEVEL_DEASSERT)
1012 			return (false);
1013 		break;
1014 	case APIC_DELMODE_STARTUP:
1015 		if (shorthand == APIC_DEST_DESTFLD ||
1016 		    shorthand == APIC_DEST_ALLESELF)
1017 			return (true);
1018 		break;
1019 	case APIC_DELMODE_RR:
1020 		/* Only available on AMD! */
1021 		if (trigger == APIC_TRIGMOD_EDGE &&
1022 		    shorthand == APIC_DEST_DESTFLD)
1023 			return (true);
1024 		break;
1025 	case APIC_DELMODE_RESV:
1026 		return (false);
1027 	default:
1028 		__assert_unreachable();
1029 	}
1030 
1031 	return (false);
1032 }
1033 
1034 int
1035 vlapic_icrlo_write_handler(struct vlapic *vlapic, bool *retu)
1036 {
1037 	int i;
1038 	bool phys;
1039 	cpuset_t dmask, ipimask;
1040 	uint64_t icrval;
1041 	uint32_t dest, vec, mode, shorthand;
1042 	struct vcpu *vcpu;
1043 	struct vm_exit *vmexit;
1044 	struct LAPIC *lapic;
1045 
1046 	lapic = vlapic->apic_page;
1047 	lapic->icr_lo &= ~APIC_DELSTAT_PEND;
1048 	icrval = ((uint64_t)lapic->icr_hi << 32) | lapic->icr_lo;
1049 
1050 	if (x2apic(vlapic))
1051 		dest = icrval >> 32;
1052 	else
1053 		dest = icrval >> (32 + 24);
1054 	vec = icrval & APIC_VECTOR_MASK;
1055 	mode = icrval & APIC_DELMODE_MASK;
1056 	phys = (icrval & APIC_DESTMODE_LOG) == 0;
1057 	shorthand = icrval & APIC_DEST_MASK;
1058 
1059 	VLAPIC_CTR2(vlapic, "icrlo 0x%016lx triggered ipi %d", icrval, vec);
1060 
1061 	switch (shorthand) {
1062 	case APIC_DEST_DESTFLD:
1063 		vlapic_calcdest(vlapic->vm, &dmask, dest, phys, false, x2apic(vlapic));
1064 		break;
1065 	case APIC_DEST_SELF:
1066 		CPU_SETOF(vlapic->vcpuid, &dmask);
1067 		break;
1068 	case APIC_DEST_ALLISELF:
1069 		dmask = vm_active_cpus(vlapic->vm);
1070 		break;
1071 	case APIC_DEST_ALLESELF:
1072 		dmask = vm_active_cpus(vlapic->vm);
1073 		CPU_CLR(vlapic->vcpuid, &dmask);
1074 		break;
1075 	default:
1076 		__assert_unreachable();
1077 	}
1078 
1079 	/*
1080 	 * Ignore invalid combinations of the icr.
1081 	 */
1082 	if (!vlapic_is_icr_valid(icrval)) {
1083 		VLAPIC_CTR1(vlapic, "Ignoring invalid ICR %016lx", icrval);
1084 		return (0);
1085 	}
1086 
1087 	/*
1088 	 * ipimask is a set of vCPUs needing userland handling of the current
1089 	 * IPI.
1090 	 */
1091 	CPU_ZERO(&ipimask);
1092 
1093 	switch (mode) {
1094 	case APIC_DELMODE_FIXED:
1095 		if (vec < 16) {
1096 			vlapic_set_error(vlapic, APIC_ESR_SEND_ILLEGAL_VECTOR,
1097 			    false);
1098 			VLAPIC_CTR1(vlapic, "Ignoring invalid IPI %d", vec);
1099 			return (0);
1100 		}
1101 
1102 		CPU_FOREACH_ISSET(i, &dmask) {
1103 			vcpu = vm_vcpu(vlapic->vm, i);
1104 			lapic_intr_edge(vcpu, vec);
1105 			vmm_stat_array_incr(vlapic->vcpu, IPIS_SENT, i, 1);
1106 			VLAPIC_CTR2(vlapic,
1107 			    "vlapic sending ipi %d to vcpuid %d", vec, i);
1108 		}
1109 
1110 		break;
1111 	case APIC_DELMODE_NMI:
1112 		CPU_FOREACH_ISSET(i, &dmask) {
1113 			vcpu = vm_vcpu(vlapic->vm, i);
1114 			vm_inject_nmi(vcpu);
1115 			VLAPIC_CTR1(vlapic,
1116 			    "vlapic sending ipi nmi to vcpuid %d", i);
1117 		}
1118 
1119 		break;
1120 	case APIC_DELMODE_INIT:
1121 		if (!vlapic->ipi_exit) {
1122 			if (!phys)
1123 				break;
1124 
1125 			i = vm_apicid2vcpuid(vlapic->vm, dest);
1126 			if (i >= vm_get_maxcpus(vlapic->vm) ||
1127 			    i == vlapic->vcpuid)
1128 				break;
1129 
1130 			CPU_SETOF(i, &ipimask);
1131 
1132 			break;
1133 		}
1134 
1135 		CPU_COPY(&dmask, &ipimask);
1136 		break;
1137 	case APIC_DELMODE_STARTUP:
1138 		if (!vlapic->ipi_exit) {
1139 			if (!phys)
1140 				break;
1141 
1142 			i = vm_apicid2vcpuid(vlapic->vm, dest);
1143 			if (i >= vm_get_maxcpus(vlapic->vm) ||
1144 			    i == vlapic->vcpuid)
1145 				break;
1146 
1147 			CPU_SETOF(i, &ipimask);
1148 
1149 			break;
1150 		}
1151 
1152 		CPU_COPY(&dmask, &ipimask);
1153 		break;
1154 	default:
1155 		return (1);
1156 	}
1157 
1158 	if (!CPU_EMPTY(&ipimask)) {
1159 		vmexit = vm_exitinfo(vlapic->vcpu);
1160 		vmexit->exitcode = VM_EXITCODE_IPI;
1161 		vmexit->u.ipi.mode = mode;
1162 		vmexit->u.ipi.vector = vec;
1163 		vmexit->u.ipi.dmask = dmask;
1164 
1165 		*retu = true;
1166 	}
1167 
1168 	return (0);
1169 }
1170 
1171 static void
1172 vlapic_handle_init(struct vcpu *vcpu, void *arg)
1173 {
1174 	struct vlapic *vlapic = vm_lapic(vcpu);
1175 
1176 	vlapic_reset(vlapic);
1177 }
1178 
1179 int
1180 vm_handle_ipi(struct vcpu *vcpu, struct vm_exit *vme, bool *retu)
1181 {
1182 	struct vlapic *vlapic = vm_lapic(vcpu);
1183 	cpuset_t *dmask = &vme->u.ipi.dmask;
1184 	uint8_t vec = vme->u.ipi.vector;
1185 
1186 	*retu = true;
1187 	switch (vme->u.ipi.mode) {
1188 	case APIC_DELMODE_INIT:
1189 		vm_smp_rendezvous(vcpu, *dmask, vlapic_handle_init,
1190 		    NULL);
1191 		vm_await_start(vcpu_vm(vcpu), dmask);
1192 
1193 		if (!vlapic->ipi_exit) {
1194 			*retu = false;
1195 		}
1196 
1197 		break;
1198 	case APIC_DELMODE_STARTUP:
1199 		/*
1200 		 * Ignore SIPIs in any state other than wait-for-SIPI
1201 		 */
1202 		*dmask = vm_start_cpus(vcpu_vm(vcpu), dmask);
1203 
1204 		if (CPU_EMPTY(dmask)) {
1205 			*retu = false;
1206 			break;
1207 		}
1208 
1209 		/*
1210 		 * Old bhyve versions don't support the IPI
1211 		 * exit. Translate it into the old style.
1212 		 */
1213 		if (!vlapic->ipi_exit) {
1214 			vme->exitcode = VM_EXITCODE_SPINUP_AP;
1215 			vme->u.spinup_ap.vcpu = CPU_FFS(dmask);
1216 			vme->u.spinup_ap.rip = vec << PAGE_SHIFT;
1217 		}
1218 
1219 		break;
1220 	default:
1221 		return (1);
1222 	}
1223 
1224 	return (0);
1225 }
1226 
1227 void
1228 vlapic_self_ipi_handler(struct vlapic *vlapic, uint64_t val)
1229 {
1230 	int vec;
1231 
1232 	KASSERT(x2apic(vlapic), ("SELF_IPI does not exist in xAPIC mode"));
1233 
1234 	vec = val & 0xff;
1235 	lapic_intr_edge(vlapic->vcpu, vec);
1236 	vmm_stat_array_incr(vlapic->vcpu, IPIS_SENT, vlapic->vcpuid, 1);
1237 	VLAPIC_CTR1(vlapic, "vlapic self-ipi %d", vec);
1238 }
1239 
1240 int
1241 vlapic_pending_intr(struct vlapic *vlapic, int *vecptr)
1242 {
1243 	struct LAPIC	*lapic = vlapic->apic_page;
1244 	int	  	 idx, i, bitpos, vector;
1245 	uint32_t	*irrptr, val;
1246 
1247 	vlapic_update_ppr(vlapic);
1248 
1249 	if (vlapic->ops.pending_intr)
1250 		return ((*vlapic->ops.pending_intr)(vlapic, vecptr));
1251 
1252 	irrptr = &lapic->irr0;
1253 
1254 	for (i = 7; i >= 0; i--) {
1255 		idx = i * 4;
1256 		val = atomic_load_acq_int(&irrptr[idx]);
1257 		bitpos = fls(val);
1258 		if (bitpos != 0) {
1259 			vector = i * 32 + (bitpos - 1);
1260 			if (PRIO(vector) > PRIO(lapic->ppr)) {
1261 				VLAPIC_CTR1(vlapic, "pending intr %d", vector);
1262 				if (vecptr != NULL)
1263 					*vecptr = vector;
1264 				return (1);
1265 			} else
1266 				break;
1267 		}
1268 	}
1269 	return (0);
1270 }
1271 
1272 void
1273 vlapic_intr_accepted(struct vlapic *vlapic, int vector)
1274 {
1275 	struct LAPIC	*lapic = vlapic->apic_page;
1276 	uint32_t	*irrptr, *isrptr;
1277 	int		idx, stk_top;
1278 
1279 	if (vlapic->ops.intr_accepted)
1280 		return ((*vlapic->ops.intr_accepted)(vlapic, vector));
1281 
1282 	/*
1283 	 * clear the ready bit for vector being accepted in irr
1284 	 * and set the vector as in service in isr.
1285 	 */
1286 	idx = (vector / 32) * 4;
1287 
1288 	irrptr = &lapic->irr0;
1289 	atomic_clear_int(&irrptr[idx], 1 << (vector % 32));
1290 	VLAPIC_CTR_IRR(vlapic, "vlapic_intr_accepted");
1291 
1292 	isrptr = &lapic->isr0;
1293 	isrptr[idx] |= 1 << (vector % 32);
1294 	VLAPIC_CTR_ISR(vlapic, "vlapic_intr_accepted");
1295 
1296 	/*
1297 	 * Update the PPR
1298 	 */
1299 	vlapic->isrvec_stk_top++;
1300 
1301 	stk_top = vlapic->isrvec_stk_top;
1302 	if (stk_top >= ISRVEC_STK_SIZE)
1303 		panic("isrvec_stk_top overflow %d", stk_top);
1304 
1305 	vlapic->isrvec_stk[stk_top] = vector;
1306 }
1307 
1308 void
1309 vlapic_svr_write_handler(struct vlapic *vlapic)
1310 {
1311 	struct LAPIC *lapic;
1312 	uint32_t old, new, changed;
1313 
1314 	lapic = vlapic->apic_page;
1315 
1316 	new = lapic->svr;
1317 	old = vlapic->svr_last;
1318 	vlapic->svr_last = new;
1319 
1320 	changed = old ^ new;
1321 	if ((changed & APIC_SVR_ENABLE) != 0) {
1322 		if ((new & APIC_SVR_ENABLE) == 0) {
1323 			/*
1324 			 * The apic is now disabled so stop the apic timer
1325 			 * and mask all the LVT entries.
1326 			 */
1327 			VLAPIC_CTR0(vlapic, "vlapic is software-disabled");
1328 			VLAPIC_TIMER_LOCK(vlapic);
1329 			callout_stop(&vlapic->callout);
1330 			VLAPIC_TIMER_UNLOCK(vlapic);
1331 			vlapic_mask_lvts(vlapic);
1332 		} else {
1333 			/*
1334 			 * The apic is now enabled so restart the apic timer
1335 			 * if it is configured in periodic mode.
1336 			 */
1337 			VLAPIC_CTR0(vlapic, "vlapic is software-enabled");
1338 			if (vlapic_periodic_timer(vlapic))
1339 				vlapic_icrtmr_write_handler(vlapic);
1340 		}
1341 	}
1342 }
1343 
1344 int
1345 vlapic_read(struct vlapic *vlapic, int mmio_access, uint64_t offset,
1346     uint64_t *data, bool *retu)
1347 {
1348 	struct LAPIC	*lapic = vlapic->apic_page;
1349 	uint32_t	*reg;
1350 	int		 i;
1351 
1352 	/* Ignore MMIO accesses in x2APIC mode */
1353 	if (x2apic(vlapic) && mmio_access) {
1354 		VLAPIC_CTR1(vlapic, "MMIO read from offset %#lx in x2APIC mode",
1355 		    offset);
1356 		*data = 0;
1357 		goto done;
1358 	}
1359 
1360 	if (!x2apic(vlapic) && !mmio_access) {
1361 		/*
1362 		 * XXX Generate GP fault for MSR accesses in xAPIC mode
1363 		 */
1364 		VLAPIC_CTR1(vlapic, "x2APIC MSR read from offset %#lx in "
1365 		    "xAPIC mode", offset);
1366 		*data = 0;
1367 		goto done;
1368 	}
1369 
1370 	if (offset > sizeof(*lapic)) {
1371 		*data = 0;
1372 		goto done;
1373 	}
1374 
1375 	offset &= ~3;
1376 	switch(offset)
1377 	{
1378 		case APIC_OFFSET_ID:
1379 			*data = lapic->id;
1380 			break;
1381 		case APIC_OFFSET_VER:
1382 			*data = lapic->version;
1383 			break;
1384 		case APIC_OFFSET_TPR:
1385 			*data = vlapic_get_tpr(vlapic);
1386 			break;
1387 		case APIC_OFFSET_APR:
1388 			*data = lapic->apr;
1389 			break;
1390 		case APIC_OFFSET_PPR:
1391 			*data = lapic->ppr;
1392 			break;
1393 		case APIC_OFFSET_EOI:
1394 			*data = lapic->eoi;
1395 			break;
1396 		case APIC_OFFSET_LDR:
1397 			*data = lapic->ldr;
1398 			break;
1399 		case APIC_OFFSET_DFR:
1400 			*data = lapic->dfr;
1401 			break;
1402 		case APIC_OFFSET_SVR:
1403 			*data = lapic->svr;
1404 			break;
1405 		case APIC_OFFSET_ISR0 ... APIC_OFFSET_ISR7:
1406 			i = (offset - APIC_OFFSET_ISR0) >> 2;
1407 			reg = &lapic->isr0;
1408 			*data = *(reg + i);
1409 			break;
1410 		case APIC_OFFSET_TMR0 ... APIC_OFFSET_TMR7:
1411 			i = (offset - APIC_OFFSET_TMR0) >> 2;
1412 			reg = &lapic->tmr0;
1413 			*data = *(reg + i);
1414 			break;
1415 		case APIC_OFFSET_IRR0 ... APIC_OFFSET_IRR7:
1416 			i = (offset - APIC_OFFSET_IRR0) >> 2;
1417 			reg = &lapic->irr0;
1418 			*data = atomic_load_acq_int(reg + i);
1419 			break;
1420 		case APIC_OFFSET_ESR:
1421 			*data = lapic->esr;
1422 			break;
1423 		case APIC_OFFSET_ICR_LOW:
1424 			*data = lapic->icr_lo;
1425 			if (x2apic(vlapic))
1426 				*data |= (uint64_t)lapic->icr_hi << 32;
1427 			break;
1428 		case APIC_OFFSET_ICR_HI:
1429 			*data = lapic->icr_hi;
1430 			break;
1431 		case APIC_OFFSET_CMCI_LVT:
1432 		case APIC_OFFSET_TIMER_LVT ... APIC_OFFSET_ERROR_LVT:
1433 			*data = vlapic_get_lvt(vlapic, offset);
1434 #ifdef INVARIANTS
1435 			reg = vlapic_get_lvtptr(vlapic, offset);
1436 			KASSERT(*data == *reg, ("inconsistent lvt value at "
1437 			    "offset %#lx: %#lx/%#x", offset, *data, *reg));
1438 #endif
1439 			break;
1440 		case APIC_OFFSET_TIMER_ICR:
1441 			*data = lapic->icr_timer;
1442 			break;
1443 		case APIC_OFFSET_TIMER_CCR:
1444 			*data = vlapic_get_ccr(vlapic);
1445 			break;
1446 		case APIC_OFFSET_TIMER_DCR:
1447 			*data = lapic->dcr_timer;
1448 			break;
1449 		case APIC_OFFSET_SELF_IPI:
1450 			/*
1451 			 * XXX generate a GP fault if vlapic is in x2apic mode
1452 			 */
1453 			*data = 0;
1454 			break;
1455 		case APIC_OFFSET_RRR:
1456 		default:
1457 			*data = 0;
1458 			break;
1459 	}
1460 done:
1461 	VLAPIC_CTR2(vlapic, "vlapic read offset %#x, data %#lx", offset, *data);
1462 	return 0;
1463 }
1464 
1465 int
1466 vlapic_write(struct vlapic *vlapic, int mmio_access, uint64_t offset,
1467     uint64_t data, bool *retu)
1468 {
1469 	struct LAPIC	*lapic = vlapic->apic_page;
1470 	uint32_t	*regptr;
1471 	int		retval;
1472 
1473 	KASSERT((offset & 0xf) == 0 && offset < PAGE_SIZE,
1474 	    ("vlapic_write: invalid offset %#lx", offset));
1475 
1476 	VLAPIC_CTR2(vlapic, "vlapic write offset %#lx, data %#lx",
1477 	    offset, data);
1478 
1479 	if (offset > sizeof(*lapic))
1480 		return (0);
1481 
1482 	/* Ignore MMIO accesses in x2APIC mode */
1483 	if (x2apic(vlapic) && mmio_access) {
1484 		VLAPIC_CTR2(vlapic, "MMIO write of %#lx to offset %#lx "
1485 		    "in x2APIC mode", data, offset);
1486 		return (0);
1487 	}
1488 
1489 	/*
1490 	 * XXX Generate GP fault for MSR accesses in xAPIC mode
1491 	 */
1492 	if (!x2apic(vlapic) && !mmio_access) {
1493 		VLAPIC_CTR2(vlapic, "x2APIC MSR write of %#lx to offset %#lx "
1494 		    "in xAPIC mode", data, offset);
1495 		return (0);
1496 	}
1497 
1498 	retval = 0;
1499 	switch(offset)
1500 	{
1501 		case APIC_OFFSET_ID:
1502 			lapic->id = data;
1503 			vlapic_id_write_handler(vlapic);
1504 			break;
1505 		case APIC_OFFSET_TPR:
1506 			vlapic_set_tpr(vlapic, data & 0xff);
1507 			break;
1508 		case APIC_OFFSET_EOI:
1509 			vlapic_process_eoi(vlapic);
1510 			break;
1511 		case APIC_OFFSET_LDR:
1512 			lapic->ldr = data;
1513 			vlapic_ldr_write_handler(vlapic);
1514 			break;
1515 		case APIC_OFFSET_DFR:
1516 			lapic->dfr = data;
1517 			vlapic_dfr_write_handler(vlapic);
1518 			break;
1519 		case APIC_OFFSET_SVR:
1520 			lapic->svr = data;
1521 			vlapic_svr_write_handler(vlapic);
1522 			break;
1523 		case APIC_OFFSET_ICR_LOW:
1524 			lapic->icr_lo = data;
1525 			if (x2apic(vlapic))
1526 				lapic->icr_hi = data >> 32;
1527 			retval = vlapic_icrlo_write_handler(vlapic, retu);
1528 			break;
1529 		case APIC_OFFSET_ICR_HI:
1530 			lapic->icr_hi = data;
1531 			break;
1532 		case APIC_OFFSET_CMCI_LVT:
1533 		case APIC_OFFSET_TIMER_LVT ... APIC_OFFSET_ERROR_LVT:
1534 			regptr = vlapic_get_lvtptr(vlapic, offset);
1535 			*regptr = data;
1536 			vlapic_lvt_write_handler(vlapic, offset);
1537 			break;
1538 		case APIC_OFFSET_TIMER_ICR:
1539 			lapic->icr_timer = data;
1540 			vlapic_icrtmr_write_handler(vlapic);
1541 			break;
1542 
1543 		case APIC_OFFSET_TIMER_DCR:
1544 			lapic->dcr_timer = data;
1545 			vlapic_dcr_write_handler(vlapic);
1546 			break;
1547 
1548 		case APIC_OFFSET_ESR:
1549 			vlapic_esr_write_handler(vlapic);
1550 			break;
1551 
1552 		case APIC_OFFSET_SELF_IPI:
1553 			if (x2apic(vlapic))
1554 				vlapic_self_ipi_handler(vlapic, data);
1555 			break;
1556 
1557 		case APIC_OFFSET_VER:
1558 		case APIC_OFFSET_APR:
1559 		case APIC_OFFSET_PPR:
1560 		case APIC_OFFSET_RRR:
1561 		case APIC_OFFSET_ISR0 ... APIC_OFFSET_ISR7:
1562 		case APIC_OFFSET_TMR0 ... APIC_OFFSET_TMR7:
1563 		case APIC_OFFSET_IRR0 ... APIC_OFFSET_IRR7:
1564 		case APIC_OFFSET_TIMER_CCR:
1565 		default:
1566 			// Read only.
1567 			break;
1568 	}
1569 
1570 	return (retval);
1571 }
1572 
1573 static void
1574 vlapic_reset(struct vlapic *vlapic)
1575 {
1576 	struct LAPIC *lapic;
1577 
1578 	lapic = vlapic->apic_page;
1579 	bzero(lapic, sizeof(struct LAPIC));
1580 
1581 	lapic->id = vlapic_get_id(vlapic);
1582 	lapic->version = VLAPIC_VERSION;
1583 	lapic->version |= (VLAPIC_MAXLVT_INDEX << MAXLVTSHIFT);
1584 	lapic->dfr = 0xffffffff;
1585 	lapic->svr = APIC_SVR_VECTOR;
1586 	vlapic_mask_lvts(vlapic);
1587 	vlapic_reset_tmr(vlapic);
1588 
1589 	lapic->dcr_timer = 0;
1590 	vlapic_dcr_write_handler(vlapic);
1591 
1592 	vlapic->svr_last = lapic->svr;
1593 }
1594 
1595 void
1596 vlapic_init(struct vlapic *vlapic)
1597 {
1598 	KASSERT(vlapic->vm != NULL, ("vlapic_init: vm is not initialized"));
1599 	KASSERT(vlapic->vcpuid >= 0 &&
1600 	    vlapic->vcpuid < vm_get_maxcpus(vlapic->vm),
1601 	    ("vlapic_init: vcpuid is not initialized"));
1602 	KASSERT(vlapic->apic_page != NULL, ("vlapic_init: apic_page is not "
1603 	    "initialized"));
1604 
1605 	/*
1606 	 * If the vlapic is configured in x2apic mode then it will be
1607 	 * accessed in the critical section via the MSR emulation code.
1608 	 *
1609 	 * Therefore the timer mutex must be a spinlock because blockable
1610 	 * mutexes cannot be acquired in a critical section.
1611 	 */
1612 	mtx_init(&vlapic->timer_mtx, "vlapic timer mtx", NULL, MTX_SPIN);
1613 	callout_init(&vlapic->callout, 1);
1614 
1615 	vlapic->msr_apicbase = DEFAULT_APIC_BASE | APICBASE_ENABLED;
1616 
1617 	if (vlapic->vcpuid == 0)
1618 		vlapic->msr_apicbase |= APICBASE_BSP;
1619 
1620 	vlapic->ipi_exit = false;
1621 
1622 	vlapic_reset(vlapic);
1623 }
1624 
1625 void
1626 vlapic_cleanup(struct vlapic *vlapic)
1627 {
1628 
1629 	callout_drain(&vlapic->callout);
1630 	mtx_destroy(&vlapic->timer_mtx);
1631 }
1632 
1633 uint64_t
1634 vlapic_get_apicbase(struct vlapic *vlapic)
1635 {
1636 
1637 	return (vlapic->msr_apicbase);
1638 }
1639 
1640 int
1641 vlapic_set_apicbase(struct vlapic *vlapic, uint64_t new)
1642 {
1643 
1644 	if (vlapic->msr_apicbase != new) {
1645 		VLAPIC_CTR2(vlapic, "Changing APIC_BASE MSR from %#lx to %#lx "
1646 		    "not supported", vlapic->msr_apicbase, new);
1647 		return (-1);
1648 	}
1649 
1650 	return (0);
1651 }
1652 
1653 void
1654 vlapic_set_x2apic_state(struct vcpu *vcpu, enum x2apic_state state)
1655 {
1656 	struct vlapic *vlapic;
1657 	struct LAPIC *lapic;
1658 
1659 	vlapic = vm_lapic(vcpu);
1660 
1661 	if (state == X2APIC_DISABLED)
1662 		vlapic->msr_apicbase &= ~APICBASE_X2APIC;
1663 	else
1664 		vlapic->msr_apicbase |= APICBASE_X2APIC;
1665 
1666 	/*
1667 	 * Reset the local APIC registers whose values are mode-dependent.
1668 	 *
1669 	 * XXX this works because the APIC mode can be changed only at vcpu
1670 	 * initialization time.
1671 	 */
1672 	lapic = vlapic->apic_page;
1673 	lapic->id = vlapic_get_id(vlapic);
1674 	if (x2apic(vlapic)) {
1675 		lapic->ldr = x2apic_ldr(vlapic);
1676 		lapic->dfr = 0;
1677 	} else {
1678 		lapic->ldr = 0;
1679 		lapic->dfr = 0xffffffff;
1680 	}
1681 
1682 	if (state == X2APIC_ENABLED) {
1683 		if (vlapic->ops.enable_x2apic_mode)
1684 			(*vlapic->ops.enable_x2apic_mode)(vlapic);
1685 	}
1686 }
1687 
1688 void
1689 vlapic_deliver_intr(struct vm *vm, bool level, uint32_t dest, bool phys,
1690     int delmode, int vec)
1691 {
1692 	struct vcpu *vcpu;
1693 	bool lowprio;
1694 	int vcpuid;
1695 	cpuset_t dmask;
1696 
1697 	if (delmode != IOART_DELFIXED &&
1698 	    delmode != IOART_DELLOPRI &&
1699 	    delmode != IOART_DELEXINT) {
1700 		VM_CTR1(vm, "vlapic intr invalid delmode %#x", delmode);
1701 		return;
1702 	}
1703 	lowprio = (delmode == IOART_DELLOPRI);
1704 
1705 	/*
1706 	 * We don't provide any virtual interrupt redirection hardware so
1707 	 * all interrupts originating from the ioapic or MSI specify the
1708 	 * 'dest' in the legacy xAPIC format.
1709 	 */
1710 	vlapic_calcdest(vm, &dmask, dest, phys, lowprio, false);
1711 
1712 	CPU_FOREACH_ISSET(vcpuid, &dmask) {
1713 		vcpu = vm_vcpu(vm, vcpuid);
1714 		if (delmode == IOART_DELEXINT) {
1715 			vm_inject_extint(vcpu);
1716 		} else {
1717 			lapic_set_intr(vcpu, vec, level);
1718 		}
1719 	}
1720 }
1721 
1722 void
1723 vlapic_post_intr(struct vlapic *vlapic, int hostcpu, int ipinum)
1724 {
1725 	/*
1726 	 * Post an interrupt to the vcpu currently running on 'hostcpu'.
1727 	 *
1728 	 * This is done by leveraging features like Posted Interrupts (Intel)
1729 	 * Doorbell MSR (AMD AVIC) that avoid a VM exit.
1730 	 *
1731 	 * If neither of these features are available then fallback to
1732 	 * sending an IPI to 'hostcpu'.
1733 	 */
1734 	if (vlapic->ops.post_intr)
1735 		(*vlapic->ops.post_intr)(vlapic, hostcpu);
1736 	else
1737 		ipi_cpu(hostcpu, ipinum);
1738 }
1739 
1740 bool
1741 vlapic_enabled(struct vlapic *vlapic)
1742 {
1743 	struct LAPIC *lapic = vlapic->apic_page;
1744 
1745 	if ((vlapic->msr_apicbase & APICBASE_ENABLED) != 0 &&
1746 	    (lapic->svr & APIC_SVR_ENABLE) != 0)
1747 		return (true);
1748 	else
1749 		return (false);
1750 }
1751 
1752 static void
1753 vlapic_set_tmr(struct vlapic *vlapic, int vector, bool level)
1754 {
1755 	struct LAPIC *lapic;
1756 	uint32_t *tmrptr, mask;
1757 	int idx;
1758 
1759 	lapic = vlapic->apic_page;
1760 	tmrptr = &lapic->tmr0;
1761 	idx = (vector / 32) * 4;
1762 	mask = 1 << (vector % 32);
1763 	if (level)
1764 		tmrptr[idx] |= mask;
1765 	else
1766 		tmrptr[idx] &= ~mask;
1767 
1768 	if (vlapic->ops.set_tmr != NULL)
1769 		(*vlapic->ops.set_tmr)(vlapic, vector, level);
1770 }
1771 
1772 void
1773 vlapic_reset_tmr(struct vlapic *vlapic)
1774 {
1775 	int vector;
1776 
1777 	VLAPIC_CTR0(vlapic, "vlapic resetting all vectors to edge-triggered");
1778 
1779 	for (vector = 0; vector <= 255; vector++)
1780 		vlapic_set_tmr(vlapic, vector, false);
1781 }
1782 
1783 void
1784 vlapic_set_tmr_level(struct vlapic *vlapic, uint32_t dest, bool phys,
1785     int delmode, int vector)
1786 {
1787 	cpuset_t dmask;
1788 	bool lowprio;
1789 
1790 	KASSERT(vector >= 0 && vector <= 255, ("invalid vector %d", vector));
1791 
1792 	/*
1793 	 * A level trigger is valid only for fixed and lowprio delivery modes.
1794 	 */
1795 	if (delmode != APIC_DELMODE_FIXED && delmode != APIC_DELMODE_LOWPRIO) {
1796 		VLAPIC_CTR1(vlapic, "Ignoring level trigger-mode for "
1797 		    "delivery-mode %d", delmode);
1798 		return;
1799 	}
1800 
1801 	lowprio = (delmode == APIC_DELMODE_LOWPRIO);
1802 	vlapic_calcdest(vlapic->vm, &dmask, dest, phys, lowprio, false);
1803 
1804 	if (!CPU_ISSET(vlapic->vcpuid, &dmask))
1805 		return;
1806 
1807 	VLAPIC_CTR1(vlapic, "vector %d set to level-triggered", vector);
1808 	vlapic_set_tmr(vlapic, vector, true);
1809 }
1810 
1811 #ifdef BHYVE_SNAPSHOT
1812 static void
1813 vlapic_reset_callout(struct vlapic *vlapic, uint32_t ccr)
1814 {
1815 	/* The implementation is similar to the one in the
1816 	 * `vlapic_icrtmr_write_handler` function
1817 	 */
1818 	sbintime_t sbt;
1819 	struct bintime bt;
1820 
1821 	VLAPIC_TIMER_LOCK(vlapic);
1822 
1823 	bt = vlapic->timer_freq_bt;
1824 	bintime_mul(&bt, ccr);
1825 
1826 	if (ccr != 0) {
1827 		binuptime(&vlapic->timer_fire_bt);
1828 		bintime_add(&vlapic->timer_fire_bt, &bt);
1829 
1830 		sbt = bttosbt(bt);
1831 		vlapic_callout_reset(vlapic, sbt);
1832 	} else {
1833 		/* even if the CCR was 0, periodic timers should be reset */
1834 		if (vlapic_periodic_timer(vlapic)) {
1835 			binuptime(&vlapic->timer_fire_bt);
1836 			bintime_add(&vlapic->timer_fire_bt,
1837 				    &vlapic->timer_period_bt);
1838 			sbt = bttosbt(vlapic->timer_period_bt);
1839 
1840 			callout_stop(&vlapic->callout);
1841 			vlapic_callout_reset(vlapic, sbt);
1842 		}
1843 	}
1844 
1845 	VLAPIC_TIMER_UNLOCK(vlapic);
1846 }
1847 
1848 int
1849 vlapic_snapshot(struct vm *vm, struct vm_snapshot_meta *meta)
1850 {
1851 	int ret;
1852 	struct vcpu *vcpu;
1853 	struct vlapic *vlapic;
1854 	struct LAPIC *lapic;
1855 	uint32_t ccr;
1856 	uint16_t i, maxcpus;
1857 
1858 	KASSERT(vm != NULL, ("%s: arg was NULL", __func__));
1859 
1860 	ret = 0;
1861 
1862 	maxcpus = vm_get_maxcpus(vm);
1863 	for (i = 0; i < maxcpus; i++) {
1864 		vcpu = vm_vcpu(vm, i);
1865 		if (vcpu == NULL)
1866 			continue;
1867 		vlapic = vm_lapic(vcpu);
1868 
1869 		/* snapshot the page first; timer period depends on icr_timer */
1870 		lapic = vlapic->apic_page;
1871 		SNAPSHOT_BUF_OR_LEAVE(lapic, PAGE_SIZE, meta, ret, done);
1872 
1873 		SNAPSHOT_VAR_OR_LEAVE(vlapic->esr_pending, meta, ret, done);
1874 
1875 		SNAPSHOT_VAR_OR_LEAVE(vlapic->timer_freq_bt.sec,
1876 				      meta, ret, done);
1877 		SNAPSHOT_VAR_OR_LEAVE(vlapic->timer_freq_bt.frac,
1878 				      meta, ret, done);
1879 
1880 		/*
1881 		 * Timer period is equal to 'icr_timer' ticks at a frequency of
1882 		 * 'timer_freq_bt'.
1883 		 */
1884 		if (meta->op == VM_SNAPSHOT_RESTORE) {
1885 			vlapic->timer_period_bt = vlapic->timer_freq_bt;
1886 			bintime_mul(&vlapic->timer_period_bt, lapic->icr_timer);
1887 		}
1888 
1889 		SNAPSHOT_BUF_OR_LEAVE(vlapic->isrvec_stk,
1890 				      sizeof(vlapic->isrvec_stk),
1891 				      meta, ret, done);
1892 		SNAPSHOT_VAR_OR_LEAVE(vlapic->isrvec_stk_top, meta, ret, done);
1893 
1894 		SNAPSHOT_BUF_OR_LEAVE(vlapic->lvt_last,
1895 				      sizeof(vlapic->lvt_last),
1896 				      meta, ret, done);
1897 
1898 		if (meta->op == VM_SNAPSHOT_SAVE)
1899 			ccr = vlapic_get_ccr(vlapic);
1900 
1901 		SNAPSHOT_VAR_OR_LEAVE(ccr, meta, ret, done);
1902 
1903 		if (meta->op == VM_SNAPSHOT_RESTORE &&
1904 		    vlapic_enabled(vlapic) && lapic->icr_timer != 0) {
1905 			/* Reset the value of the 'timer_fire_bt' and the vlapic
1906 			 * callout based on the value of the current count
1907 			 * register saved when the VM snapshot was created.
1908 			 * If initial count register is 0, timer is not used.
1909 			 * Look at "10.5.4 APIC Timer" in Software Developer Manual.
1910 			 */
1911 			vlapic_reset_callout(vlapic, ccr);
1912 		}
1913 	}
1914 
1915 done:
1916 	return (ret);
1917 }
1918 #endif
1919