xref: /freebsd/sys/amd64/vmm/io/vlapic.c (revision 7899f917b1c0ea178f1d2be0cfb452086d079d23)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
30 #include <sys/cdefs.h>
31 #include "opt_bhyve_snapshot.h"
32 
33 #include <sys/param.h>
34 #include <sys/lock.h>
35 #include <sys/kernel.h>
36 #include <sys/malloc.h>
37 #include <sys/mutex.h>
38 #include <sys/systm.h>
39 #include <sys/smp.h>
40 
41 #include <x86/specialreg.h>
42 #include <x86/apicreg.h>
43 
44 #include <machine/clock.h>
45 #include <machine/smp.h>
46 #include <machine/vmm.h>
47 #include <machine/vmm_snapshot.h>
48 
49 #include <dev/vmm/vmm_ktr.h>
50 
51 #include "vmm_lapic.h"
52 #include "vmm_stat.h"
53 
54 #include "vlapic.h"
55 #include "vlapic_priv.h"
56 #include "vioapic.h"
57 
58 #define	PRIO(x)			((x) >> 4)
59 
60 #define VLAPIC_VERSION		(0x14)
61 
62 #define	x2apic(vlapic)	(((vlapic)->msr_apicbase & APICBASE_X2APIC) ? 1 : 0)
63 
64 /*
65  * The 'vlapic->timer_mtx' is used to provide mutual exclusion between the
66  * vlapic_callout_handler() and vcpu accesses to:
67  * - timer_freq_bt, timer_period_bt, timer_fire_bt
68  * - timer LVT register
69  */
70 #define	VLAPIC_TIMER_LOCK(vlapic)	mtx_lock_spin(&((vlapic)->timer_mtx))
71 #define	VLAPIC_TIMER_UNLOCK(vlapic)	mtx_unlock_spin(&((vlapic)->timer_mtx))
72 #define	VLAPIC_TIMER_LOCKED(vlapic)	mtx_owned(&((vlapic)->timer_mtx))
73 
74 /*
75  * APIC timer frequency:
76  * - arbitrary but chosen to be in the ballpark of contemporary hardware.
77  * - power-of-two to avoid loss of precision when converted to a bintime.
78  */
79 #define VLAPIC_BUS_FREQ		(128 * 1024 * 1024)
80 
81 static void vlapic_set_error(struct vlapic *, uint32_t, bool);
82 static void vlapic_callout_handler(void *arg);
83 static void vlapic_reset(struct vlapic *vlapic);
84 
85 static __inline uint32_t
86 vlapic_get_id(struct vlapic *vlapic)
87 {
88 
89 	if (x2apic(vlapic))
90 		return (vlapic->vcpuid);
91 	else
92 		return (vlapic->vcpuid << 24);
93 }
94 
95 static uint32_t
96 x2apic_ldr(struct vlapic *vlapic)
97 {
98 	int apicid;
99 	uint32_t ldr;
100 
101 	apicid = vlapic_get_id(vlapic);
102 	ldr = 1 << (apicid & 0xf);
103 	ldr |= (apicid & 0xffff0) << 12;
104 	return (ldr);
105 }
106 
107 void
108 vlapic_dfr_write_handler(struct vlapic *vlapic)
109 {
110 	struct LAPIC *lapic;
111 
112 	lapic = vlapic->apic_page;
113 	if (x2apic(vlapic)) {
114 		VM_CTR1(vlapic->vm, "ignoring write to DFR in x2apic mode: %#x",
115 		    lapic->dfr);
116 		lapic->dfr = 0;
117 		return;
118 	}
119 
120 	lapic->dfr &= APIC_DFR_MODEL_MASK;
121 	lapic->dfr |= APIC_DFR_RESERVED;
122 
123 	if ((lapic->dfr & APIC_DFR_MODEL_MASK) == APIC_DFR_MODEL_FLAT)
124 		VLAPIC_CTR0(vlapic, "vlapic DFR in Flat Model");
125 	else if ((lapic->dfr & APIC_DFR_MODEL_MASK) == APIC_DFR_MODEL_CLUSTER)
126 		VLAPIC_CTR0(vlapic, "vlapic DFR in Cluster Model");
127 	else
128 		VLAPIC_CTR1(vlapic, "DFR in Unknown Model %#x", lapic->dfr);
129 }
130 
131 void
132 vlapic_ldr_write_handler(struct vlapic *vlapic)
133 {
134 	struct LAPIC *lapic;
135 
136 	lapic = vlapic->apic_page;
137 
138 	/* LDR is read-only in x2apic mode */
139 	if (x2apic(vlapic)) {
140 		VLAPIC_CTR1(vlapic, "ignoring write to LDR in x2apic mode: %#x",
141 		    lapic->ldr);
142 		lapic->ldr = x2apic_ldr(vlapic);
143 	} else {
144 		lapic->ldr &= ~APIC_LDR_RESERVED;
145 		VLAPIC_CTR1(vlapic, "vlapic LDR set to %#x", lapic->ldr);
146 	}
147 }
148 
149 void
150 vlapic_id_write_handler(struct vlapic *vlapic)
151 {
152 	struct LAPIC *lapic;
153 
154 	/*
155 	 * We don't allow the ID register to be modified so reset it back to
156 	 * its default value.
157 	 */
158 	lapic = vlapic->apic_page;
159 	lapic->id = vlapic_get_id(vlapic);
160 }
161 
162 static int
163 vlapic_timer_divisor(uint32_t dcr)
164 {
165 	switch (dcr & 0xB) {
166 	case APIC_TDCR_1:
167 		return (1);
168 	case APIC_TDCR_2:
169 		return (2);
170 	case APIC_TDCR_4:
171 		return (4);
172 	case APIC_TDCR_8:
173 		return (8);
174 	case APIC_TDCR_16:
175 		return (16);
176 	case APIC_TDCR_32:
177 		return (32);
178 	case APIC_TDCR_64:
179 		return (64);
180 	case APIC_TDCR_128:
181 		return (128);
182 	default:
183 		panic("vlapic_timer_divisor: invalid dcr 0x%08x", dcr);
184 	}
185 }
186 
187 #if 0
188 static inline void
189 vlapic_dump_lvt(uint32_t offset, uint32_t *lvt)
190 {
191 	printf("Offset %x: lvt %08x (V:%02x DS:%x M:%x)\n", offset,
192 	    *lvt, *lvt & APIC_LVTT_VECTOR, *lvt & APIC_LVTT_DS,
193 	    *lvt & APIC_LVTT_M);
194 }
195 #endif
196 
197 static uint32_t
198 vlapic_get_ccr(struct vlapic *vlapic)
199 {
200 	struct bintime bt_now, bt_rem;
201 	struct LAPIC *lapic __diagused;
202 	uint32_t ccr;
203 
204 	ccr = 0;
205 	lapic = vlapic->apic_page;
206 
207 	VLAPIC_TIMER_LOCK(vlapic);
208 	if (callout_active(&vlapic->callout)) {
209 		/*
210 		 * If the timer is scheduled to expire in the future then
211 		 * compute the value of 'ccr' based on the remaining time.
212 		 */
213 		binuptime(&bt_now);
214 		if (bintime_cmp(&vlapic->timer_fire_bt, &bt_now, >)) {
215 			bt_rem = vlapic->timer_fire_bt;
216 			bintime_sub(&bt_rem, &bt_now);
217 			ccr += bt_rem.sec * BT2FREQ(&vlapic->timer_freq_bt);
218 			ccr += bt_rem.frac / vlapic->timer_freq_bt.frac;
219 		}
220 	}
221 	KASSERT(ccr <= lapic->icr_timer, ("vlapic_get_ccr: invalid ccr %#x, "
222 	    "icr_timer is %#x", ccr, lapic->icr_timer));
223 	VLAPIC_CTR2(vlapic, "vlapic ccr_timer = %#x, icr_timer = %#x",
224 	    ccr, lapic->icr_timer);
225 	VLAPIC_TIMER_UNLOCK(vlapic);
226 	return (ccr);
227 }
228 
229 void
230 vlapic_dcr_write_handler(struct vlapic *vlapic)
231 {
232 	struct LAPIC *lapic;
233 	int divisor;
234 
235 	lapic = vlapic->apic_page;
236 	VLAPIC_TIMER_LOCK(vlapic);
237 
238 	divisor = vlapic_timer_divisor(lapic->dcr_timer);
239 	VLAPIC_CTR2(vlapic, "vlapic dcr_timer=%#x, divisor=%d",
240 	    lapic->dcr_timer, divisor);
241 
242 	/*
243 	 * Update the timer frequency and the timer period.
244 	 *
245 	 * XXX changes to the frequency divider will not take effect until
246 	 * the timer is reloaded.
247 	 */
248 	FREQ2BT(VLAPIC_BUS_FREQ / divisor, &vlapic->timer_freq_bt);
249 	vlapic->timer_period_bt = vlapic->timer_freq_bt;
250 	bintime_mul(&vlapic->timer_period_bt, lapic->icr_timer);
251 
252 	VLAPIC_TIMER_UNLOCK(vlapic);
253 }
254 
255 void
256 vlapic_esr_write_handler(struct vlapic *vlapic)
257 {
258 	struct LAPIC *lapic;
259 
260 	lapic = vlapic->apic_page;
261 	lapic->esr = vlapic->esr_pending;
262 	vlapic->esr_pending = 0;
263 }
264 
265 int
266 vlapic_set_intr_ready(struct vlapic *vlapic, int vector, bool level)
267 {
268 	struct LAPIC *lapic;
269 	uint32_t *irrptr, *tmrptr, mask;
270 	int idx;
271 
272 	KASSERT(vector >= 0 && vector < 256, ("invalid vector %d", vector));
273 
274 	lapic = vlapic->apic_page;
275 	if (!(lapic->svr & APIC_SVR_ENABLE)) {
276 		VLAPIC_CTR1(vlapic, "vlapic is software disabled, ignoring "
277 		    "interrupt %d", vector);
278 		return (0);
279 	}
280 
281 	if (vector < 16) {
282 		vlapic_set_error(vlapic, APIC_ESR_RECEIVE_ILLEGAL_VECTOR,
283 		    false);
284 		VLAPIC_CTR1(vlapic, "vlapic ignoring interrupt to vector %d",
285 		    vector);
286 		return (1);
287 	}
288 
289 	if (vlapic->ops.set_intr_ready)
290 		return ((*vlapic->ops.set_intr_ready)(vlapic, vector, level));
291 
292 	idx = (vector / 32) * 4;
293 	mask = 1 << (vector % 32);
294 
295 	irrptr = &lapic->irr0;
296 	atomic_set_int(&irrptr[idx], mask);
297 
298 	/*
299 	 * Verify that the trigger-mode of the interrupt matches with
300 	 * the vlapic TMR registers.
301 	 */
302 	tmrptr = &lapic->tmr0;
303 	if ((tmrptr[idx] & mask) != (level ? mask : 0)) {
304 		VLAPIC_CTR3(vlapic, "vlapic TMR[%d] is 0x%08x but "
305 		    "interrupt is %s-triggered", idx / 4, tmrptr[idx],
306 		    level ? "level" : "edge");
307 	}
308 
309 	VLAPIC_CTR_IRR(vlapic, "vlapic_set_intr_ready");
310 	return (1);
311 }
312 
313 static __inline uint32_t *
314 vlapic_get_lvtptr(struct vlapic *vlapic, uint32_t offset)
315 {
316 	struct LAPIC	*lapic = vlapic->apic_page;
317 	int 		 i;
318 
319 	switch (offset) {
320 	case APIC_OFFSET_CMCI_LVT:
321 		return (&lapic->lvt_cmci);
322 	case APIC_OFFSET_TIMER_LVT ... APIC_OFFSET_ERROR_LVT:
323 		i = (offset - APIC_OFFSET_TIMER_LVT) >> 2;
324 		return ((&lapic->lvt_timer) + i);
325 	default:
326 		panic("vlapic_get_lvt: invalid LVT\n");
327 	}
328 }
329 
330 static __inline int
331 lvt_off_to_idx(uint32_t offset)
332 {
333 	int index;
334 
335 	switch (offset) {
336 	case APIC_OFFSET_CMCI_LVT:
337 		index = APIC_LVT_CMCI;
338 		break;
339 	case APIC_OFFSET_TIMER_LVT:
340 		index = APIC_LVT_TIMER;
341 		break;
342 	case APIC_OFFSET_THERM_LVT:
343 		index = APIC_LVT_THERMAL;
344 		break;
345 	case APIC_OFFSET_PERF_LVT:
346 		index = APIC_LVT_PMC;
347 		break;
348 	case APIC_OFFSET_LINT0_LVT:
349 		index = APIC_LVT_LINT0;
350 		break;
351 	case APIC_OFFSET_LINT1_LVT:
352 		index = APIC_LVT_LINT1;
353 		break;
354 	case APIC_OFFSET_ERROR_LVT:
355 		index = APIC_LVT_ERROR;
356 		break;
357 	default:
358 		index = -1;
359 		break;
360 	}
361 	KASSERT(index >= 0 && index <= VLAPIC_MAXLVT_INDEX, ("lvt_off_to_idx: "
362 	    "invalid lvt index %d for offset %#x", index, offset));
363 
364 	return (index);
365 }
366 
367 static __inline uint32_t
368 vlapic_get_lvt(struct vlapic *vlapic, uint32_t offset)
369 {
370 	int idx;
371 	uint32_t val;
372 
373 	idx = lvt_off_to_idx(offset);
374 	val = atomic_load_acq_32(&vlapic->lvt_last[idx]);
375 	return (val);
376 }
377 
378 void
379 vlapic_lvt_write_handler(struct vlapic *vlapic, uint32_t offset)
380 {
381 	uint32_t *lvtptr, mask, val;
382 	struct LAPIC *lapic;
383 	int idx;
384 
385 	lapic = vlapic->apic_page;
386 	lvtptr = vlapic_get_lvtptr(vlapic, offset);
387 	val = *lvtptr;
388 	idx = lvt_off_to_idx(offset);
389 
390 	if (!(lapic->svr & APIC_SVR_ENABLE))
391 		val |= APIC_LVT_M;
392 	mask = APIC_LVT_M | APIC_LVT_DS | APIC_LVT_VECTOR;
393 	switch (offset) {
394 	case APIC_OFFSET_TIMER_LVT:
395 		mask |= APIC_LVTT_TM;
396 		break;
397 	case APIC_OFFSET_ERROR_LVT:
398 		break;
399 	case APIC_OFFSET_LINT0_LVT:
400 	case APIC_OFFSET_LINT1_LVT:
401 		mask |= APIC_LVT_TM | APIC_LVT_RIRR | APIC_LVT_IIPP;
402 		/* FALLTHROUGH */
403 	default:
404 		mask |= APIC_LVT_DM;
405 		break;
406 	}
407 	val &= mask;
408 	*lvtptr = val;
409 	atomic_store_rel_32(&vlapic->lvt_last[idx], val);
410 }
411 
412 static void
413 vlapic_mask_lvts(struct vlapic *vlapic)
414 {
415 	struct LAPIC *lapic = vlapic->apic_page;
416 
417 	lapic->lvt_cmci |= APIC_LVT_M;
418 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_CMCI_LVT);
419 
420 	lapic->lvt_timer |= APIC_LVT_M;
421 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_TIMER_LVT);
422 
423 	lapic->lvt_thermal |= APIC_LVT_M;
424 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_THERM_LVT);
425 
426 	lapic->lvt_pcint |= APIC_LVT_M;
427 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_PERF_LVT);
428 
429 	lapic->lvt_lint0 |= APIC_LVT_M;
430 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_LINT0_LVT);
431 
432 	lapic->lvt_lint1 |= APIC_LVT_M;
433 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_LINT1_LVT);
434 
435 	lapic->lvt_error |= APIC_LVT_M;
436 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_ERROR_LVT);
437 }
438 
439 static int
440 vlapic_fire_lvt(struct vlapic *vlapic, u_int lvt)
441 {
442 	uint32_t mode, reg, vec;
443 
444 	reg = atomic_load_acq_32(&vlapic->lvt_last[lvt]);
445 
446 	if (reg & APIC_LVT_M)
447 		return (0);
448 	vec = reg & APIC_LVT_VECTOR;
449 	mode = reg & APIC_LVT_DM;
450 
451 	switch (mode) {
452 	case APIC_LVT_DM_FIXED:
453 		if (vec < 16) {
454 			vlapic_set_error(vlapic, APIC_ESR_SEND_ILLEGAL_VECTOR,
455 			    lvt == APIC_LVT_ERROR);
456 			return (0);
457 		}
458 		if (vlapic_set_intr_ready(vlapic, vec, false))
459 			vcpu_notify_event(vlapic->vcpu, true);
460 		break;
461 	case APIC_LVT_DM_NMI:
462 		vm_inject_nmi(vlapic->vcpu);
463 		break;
464 	case APIC_LVT_DM_EXTINT:
465 		vm_inject_extint(vlapic->vcpu);
466 		break;
467 	default:
468 		// Other modes ignored
469 		return (0);
470 	}
471 	return (1);
472 }
473 
474 #if 1
475 static void
476 dump_isrvec_stk(struct vlapic *vlapic)
477 {
478 	int i;
479 	uint32_t *isrptr;
480 
481 	isrptr = &vlapic->apic_page->isr0;
482 	for (i = 0; i < 8; i++)
483 		printf("ISR%d 0x%08x\n", i, isrptr[i * 4]);
484 
485 	for (i = 0; i <= vlapic->isrvec_stk_top; i++)
486 		printf("isrvec_stk[%d] = %d\n", i, vlapic->isrvec_stk[i]);
487 }
488 #endif
489 
490 /*
491  * Algorithm adopted from section "Interrupt, Task and Processor Priority"
492  * in Intel Architecture Manual Vol 3a.
493  */
494 static void
495 vlapic_update_ppr(struct vlapic *vlapic)
496 {
497 	int isrvec, tpr, ppr;
498 
499 	/*
500 	 * Note that the value on the stack at index 0 is always 0.
501 	 *
502 	 * This is a placeholder for the value of ISRV when none of the
503 	 * bits is set in the ISRx registers.
504 	 */
505 	isrvec = vlapic->isrvec_stk[vlapic->isrvec_stk_top];
506 	tpr = vlapic->apic_page->tpr;
507 
508 #if 1
509 	{
510 		int i, lastprio, curprio, vector, idx;
511 		uint32_t *isrptr;
512 
513 		if (vlapic->isrvec_stk_top == 0 && isrvec != 0)
514 			panic("isrvec_stk is corrupted: %d", isrvec);
515 
516 		/*
517 		 * Make sure that the priority of the nested interrupts is
518 		 * always increasing.
519 		 */
520 		lastprio = -1;
521 		for (i = 1; i <= vlapic->isrvec_stk_top; i++) {
522 			curprio = PRIO(vlapic->isrvec_stk[i]);
523 			if (curprio <= lastprio) {
524 				dump_isrvec_stk(vlapic);
525 				panic("isrvec_stk does not satisfy invariant");
526 			}
527 			lastprio = curprio;
528 		}
529 
530 		/*
531 		 * Make sure that each bit set in the ISRx registers has a
532 		 * corresponding entry on the isrvec stack.
533 		 */
534 		i = 1;
535 		isrptr = &vlapic->apic_page->isr0;
536 		for (vector = 0; vector < 256; vector++) {
537 			idx = (vector / 32) * 4;
538 			if (isrptr[idx] & (1 << (vector % 32))) {
539 				if (i > vlapic->isrvec_stk_top ||
540 				    vlapic->isrvec_stk[i] != vector) {
541 					dump_isrvec_stk(vlapic);
542 					panic("ISR and isrvec_stk out of sync");
543 				}
544 				i++;
545 			}
546 		}
547 	}
548 #endif
549 
550 	if (PRIO(tpr) >= PRIO(isrvec))
551 		ppr = tpr;
552 	else
553 		ppr = isrvec & 0xf0;
554 
555 	vlapic->apic_page->ppr = ppr;
556 	VLAPIC_CTR1(vlapic, "vlapic_update_ppr 0x%02x", ppr);
557 }
558 
559 void
560 vlapic_sync_tpr(struct vlapic *vlapic)
561 {
562 	vlapic_update_ppr(vlapic);
563 }
564 
565 static VMM_STAT(VLAPIC_GRATUITOUS_EOI, "EOI without any in-service interrupt");
566 
567 static void
568 vlapic_process_eoi(struct vlapic *vlapic)
569 {
570 	struct LAPIC	*lapic = vlapic->apic_page;
571 	uint32_t	*isrptr, *tmrptr;
572 	int		i, idx, bitpos, vector;
573 
574 	isrptr = &lapic->isr0;
575 	tmrptr = &lapic->tmr0;
576 
577 	for (i = 7; i >= 0; i--) {
578 		idx = i * 4;
579 		bitpos = fls(isrptr[idx]);
580 		if (bitpos-- != 0) {
581 			if (vlapic->isrvec_stk_top <= 0) {
582 				panic("invalid vlapic isrvec_stk_top %d",
583 				      vlapic->isrvec_stk_top);
584 			}
585 			isrptr[idx] &= ~(1 << bitpos);
586 			vector = i * 32 + bitpos;
587 			VLAPIC_CTR1(vlapic, "EOI vector %d", vector);
588 			VLAPIC_CTR_ISR(vlapic, "vlapic_process_eoi");
589 			vlapic->isrvec_stk_top--;
590 			vlapic_update_ppr(vlapic);
591 			if ((tmrptr[idx] & (1 << bitpos)) != 0) {
592 				vioapic_process_eoi(vlapic->vm, vector);
593 			}
594 			return;
595 		}
596 	}
597 	VLAPIC_CTR0(vlapic, "Gratuitous EOI");
598 	vmm_stat_incr(vlapic->vcpu, VLAPIC_GRATUITOUS_EOI, 1);
599 }
600 
601 static __inline int
602 vlapic_get_lvt_field(uint32_t lvt, uint32_t mask)
603 {
604 
605 	return (lvt & mask);
606 }
607 
608 static __inline int
609 vlapic_periodic_timer(struct vlapic *vlapic)
610 {
611 	uint32_t lvt;
612 
613 	lvt = vlapic_get_lvt(vlapic, APIC_OFFSET_TIMER_LVT);
614 
615 	return (vlapic_get_lvt_field(lvt, APIC_LVTT_TM_PERIODIC));
616 }
617 
618 static VMM_STAT(VLAPIC_INTR_ERROR, "error interrupts generated by vlapic");
619 
620 static void
621 vlapic_set_error(struct vlapic *vlapic, uint32_t mask, bool lvt_error)
622 {
623 
624 	vlapic->esr_pending |= mask;
625 
626 	/*
627 	 * Avoid infinite recursion if the error LVT itself is configured with
628 	 * an illegal vector.
629 	 */
630 	if (lvt_error)
631 		return;
632 
633 	if (vlapic_fire_lvt(vlapic, APIC_LVT_ERROR)) {
634 		vmm_stat_incr(vlapic->vcpu, VLAPIC_INTR_ERROR, 1);
635 	}
636 }
637 
638 static VMM_STAT(VLAPIC_INTR_TIMER, "timer interrupts generated by vlapic");
639 
640 static void
641 vlapic_fire_timer(struct vlapic *vlapic)
642 {
643 
644 	KASSERT(VLAPIC_TIMER_LOCKED(vlapic), ("vlapic_fire_timer not locked"));
645 
646 	if (vlapic_fire_lvt(vlapic, APIC_LVT_TIMER)) {
647 		VLAPIC_CTR0(vlapic, "vlapic timer fired");
648 		vmm_stat_incr(vlapic->vcpu, VLAPIC_INTR_TIMER, 1);
649 	}
650 }
651 
652 static VMM_STAT(VLAPIC_INTR_CMC,
653     "corrected machine check interrupts generated by vlapic");
654 
655 void
656 vlapic_fire_cmci(struct vlapic *vlapic)
657 {
658 
659 	if (vlapic_fire_lvt(vlapic, APIC_LVT_CMCI)) {
660 		vmm_stat_incr(vlapic->vcpu, VLAPIC_INTR_CMC, 1);
661 	}
662 }
663 
664 static VMM_STAT_ARRAY(LVTS_TRIGGERRED, VLAPIC_MAXLVT_INDEX + 1,
665     "lvts triggered");
666 
667 int
668 vlapic_trigger_lvt(struct vlapic *vlapic, int vector)
669 {
670 
671 	if (vlapic_enabled(vlapic) == false) {
672 		/*
673 		 * When the local APIC is global/hardware disabled,
674 		 * LINT[1:0] pins are configured as INTR and NMI pins,
675 		 * respectively.
676 		*/
677 		switch (vector) {
678 			case APIC_LVT_LINT0:
679 				vm_inject_extint(vlapic->vcpu);
680 				break;
681 			case APIC_LVT_LINT1:
682 				vm_inject_nmi(vlapic->vcpu);
683 				break;
684 			default:
685 				break;
686 		}
687 		return (0);
688 	}
689 
690 	switch (vector) {
691 	case APIC_LVT_LINT0:
692 	case APIC_LVT_LINT1:
693 	case APIC_LVT_TIMER:
694 	case APIC_LVT_ERROR:
695 	case APIC_LVT_PMC:
696 	case APIC_LVT_THERMAL:
697 	case APIC_LVT_CMCI:
698 		if (vlapic_fire_lvt(vlapic, vector)) {
699 			vmm_stat_array_incr(vlapic->vcpu, LVTS_TRIGGERRED,
700 			    vector, 1);
701 		}
702 		break;
703 	default:
704 		return (EINVAL);
705 	}
706 	return (0);
707 }
708 
709 static void
710 vlapic_callout_reset(struct vlapic *vlapic, sbintime_t t)
711 {
712 	callout_reset_sbt_curcpu(&vlapic->callout, t, 0,
713 	    vlapic_callout_handler, vlapic, 0);
714 }
715 
716 static void
717 vlapic_callout_handler(void *arg)
718 {
719 	struct vlapic *vlapic;
720 	struct bintime bt, btnow;
721 	sbintime_t rem_sbt;
722 
723 	vlapic = arg;
724 
725 	VLAPIC_TIMER_LOCK(vlapic);
726 	if (callout_pending(&vlapic->callout))	/* callout was reset */
727 		goto done;
728 
729 	if (!callout_active(&vlapic->callout))	/* callout was stopped */
730 		goto done;
731 
732 	callout_deactivate(&vlapic->callout);
733 
734 	vlapic_fire_timer(vlapic);
735 
736 	if (vlapic_periodic_timer(vlapic)) {
737 		binuptime(&btnow);
738 		KASSERT(bintime_cmp(&btnow, &vlapic->timer_fire_bt, >=),
739 		    ("vlapic callout at %#lx.%#lx, expected at %#lx.#%lx",
740 		    btnow.sec, btnow.frac, vlapic->timer_fire_bt.sec,
741 		    vlapic->timer_fire_bt.frac));
742 
743 		/*
744 		 * Compute the delta between when the timer was supposed to
745 		 * fire and the present time.
746 		 */
747 		bt = btnow;
748 		bintime_sub(&bt, &vlapic->timer_fire_bt);
749 
750 		rem_sbt = bttosbt(vlapic->timer_period_bt);
751 		if (bintime_cmp(&bt, &vlapic->timer_period_bt, <)) {
752 			/*
753 			 * Adjust the time until the next countdown downward
754 			 * to account for the lost time.
755 			 */
756 			rem_sbt -= bttosbt(bt);
757 		} else {
758 			/*
759 			 * If the delta is greater than the timer period then
760 			 * just reset our time base instead of trying to catch
761 			 * up.
762 			 */
763 			vlapic->timer_fire_bt = btnow;
764 			VLAPIC_CTR2(vlapic, "vlapic timer lagging by %lu "
765 			    "usecs, period is %lu usecs - resetting time base",
766 			    bttosbt(bt) / SBT_1US,
767 			    bttosbt(vlapic->timer_period_bt) / SBT_1US);
768 		}
769 
770 		bintime_add(&vlapic->timer_fire_bt, &vlapic->timer_period_bt);
771 		vlapic_callout_reset(vlapic, rem_sbt);
772 	}
773 done:
774 	VLAPIC_TIMER_UNLOCK(vlapic);
775 }
776 
777 void
778 vlapic_icrtmr_write_handler(struct vlapic *vlapic)
779 {
780 	struct LAPIC *lapic;
781 	sbintime_t sbt;
782 	uint32_t icr_timer;
783 
784 	VLAPIC_TIMER_LOCK(vlapic);
785 
786 	lapic = vlapic->apic_page;
787 	icr_timer = lapic->icr_timer;
788 
789 	vlapic->timer_period_bt = vlapic->timer_freq_bt;
790 	bintime_mul(&vlapic->timer_period_bt, icr_timer);
791 
792 	if (icr_timer != 0) {
793 		binuptime(&vlapic->timer_fire_bt);
794 		bintime_add(&vlapic->timer_fire_bt, &vlapic->timer_period_bt);
795 
796 		sbt = bttosbt(vlapic->timer_period_bt);
797 		vlapic_callout_reset(vlapic, sbt);
798 	} else
799 		callout_stop(&vlapic->callout);
800 
801 	VLAPIC_TIMER_UNLOCK(vlapic);
802 }
803 
804 /*
805  * This function populates 'dmask' with the set of vcpus that match the
806  * addressing specified by the (dest, phys, lowprio) tuple.
807  *
808  * 'x2apic_dest' specifies whether 'dest' is interpreted as x2APIC (32-bit)
809  * or xAPIC (8-bit) destination field.
810  */
811 static void
812 vlapic_calcdest(struct vm *vm, cpuset_t *dmask, uint32_t dest, bool phys,
813     bool lowprio, bool x2apic_dest)
814 {
815 	struct vlapic *vlapic;
816 	uint32_t dfr, ldr, ldest, cluster;
817 	uint32_t mda_flat_ldest, mda_cluster_ldest, mda_ldest, mda_cluster_id;
818 	cpuset_t amask;
819 	int vcpuid;
820 
821 	if ((x2apic_dest && dest == 0xffffffff) ||
822 	    (!x2apic_dest && dest == 0xff)) {
823 		/*
824 		 * Broadcast in both logical and physical modes.
825 		 */
826 		*dmask = vm_active_cpus(vm);
827 		return;
828 	}
829 
830 	if (phys) {
831 		/*
832 		 * Physical mode: destination is APIC ID.
833 		 */
834 		CPU_ZERO(dmask);
835 		vcpuid = vm_apicid2vcpuid(vm, dest);
836 		amask = vm_active_cpus(vm);
837 		if (vcpuid < vm_get_maxcpus(vm) && CPU_ISSET(vcpuid, &amask))
838 			CPU_SET(vcpuid, dmask);
839 	} else {
840 		/*
841 		 * In the "Flat Model" the MDA is interpreted as an 8-bit wide
842 		 * bitmask. This model is only available in the xAPIC mode.
843 		 */
844 		mda_flat_ldest = dest & 0xff;
845 
846 		/*
847 		 * In the "Cluster Model" the MDA is used to identify a
848 		 * specific cluster and a set of APICs in that cluster.
849 		 */
850 		if (x2apic_dest) {
851 			mda_cluster_id = dest >> 16;
852 			mda_cluster_ldest = dest & 0xffff;
853 		} else {
854 			mda_cluster_id = (dest >> 4) & 0xf;
855 			mda_cluster_ldest = dest & 0xf;
856 		}
857 
858 		/*
859 		 * Logical mode: match each APIC that has a bit set
860 		 * in its LDR that matches a bit in the ldest.
861 		 */
862 		CPU_ZERO(dmask);
863 		amask = vm_active_cpus(vm);
864 		CPU_FOREACH_ISSET(vcpuid, &amask) {
865 			vlapic = vm_lapic(vm_vcpu(vm, vcpuid));
866 			dfr = vlapic->apic_page->dfr;
867 			ldr = vlapic->apic_page->ldr;
868 
869 			if ((dfr & APIC_DFR_MODEL_MASK) ==
870 			    APIC_DFR_MODEL_FLAT) {
871 				ldest = ldr >> 24;
872 				mda_ldest = mda_flat_ldest;
873 			} else if ((dfr & APIC_DFR_MODEL_MASK) ==
874 			    APIC_DFR_MODEL_CLUSTER) {
875 				if (x2apic(vlapic)) {
876 					cluster = ldr >> 16;
877 					ldest = ldr & 0xffff;
878 				} else {
879 					cluster = ldr >> 28;
880 					ldest = (ldr >> 24) & 0xf;
881 				}
882 				if (cluster != mda_cluster_id)
883 					continue;
884 				mda_ldest = mda_cluster_ldest;
885 			} else {
886 				/*
887 				 * Guest has configured a bad logical
888 				 * model for this vcpu - skip it.
889 				 */
890 				VLAPIC_CTR1(vlapic, "vlapic has bad logical "
891 				    "model %x - cannot deliver interrupt", dfr);
892 				continue;
893 			}
894 
895 			if ((mda_ldest & ldest) != 0) {
896 				CPU_SET(vcpuid, dmask);
897 				if (lowprio)
898 					break;
899 			}
900 		}
901 	}
902 }
903 
904 static VMM_STAT(VLAPIC_IPI_SEND, "ipis sent from vcpu");
905 static VMM_STAT(VLAPIC_IPI_RECV, "ipis received by vcpu");
906 
907 static void
908 vlapic_set_tpr(struct vlapic *vlapic, uint8_t val)
909 {
910 	struct LAPIC *lapic = vlapic->apic_page;
911 
912 	if (lapic->tpr != val) {
913 		VLAPIC_CTR2(vlapic, "vlapic TPR changed from %#x to %#x",
914 		    lapic->tpr, val);
915 		lapic->tpr = val;
916 		vlapic_update_ppr(vlapic);
917 	}
918 }
919 
920 static uint8_t
921 vlapic_get_tpr(struct vlapic *vlapic)
922 {
923 	struct LAPIC *lapic = vlapic->apic_page;
924 
925 	return (lapic->tpr);
926 }
927 
928 void
929 vlapic_set_cr8(struct vlapic *vlapic, uint64_t val)
930 {
931 	uint8_t tpr;
932 
933 	if (val & ~0xf) {
934 		vm_inject_gp(vlapic->vcpu);
935 		return;
936 	}
937 
938 	tpr = val << 4;
939 	vlapic_set_tpr(vlapic, tpr);
940 }
941 
942 uint64_t
943 vlapic_get_cr8(struct vlapic *vlapic)
944 {
945 	uint8_t tpr;
946 
947 	tpr = vlapic_get_tpr(vlapic);
948 	return (tpr >> 4);
949 }
950 
951 static bool
952 vlapic_is_icr_valid(uint64_t icrval)
953 {
954 	uint32_t mode = icrval & APIC_DELMODE_MASK;
955 	uint32_t level = icrval & APIC_LEVEL_MASK;
956 	uint32_t trigger = icrval & APIC_TRIGMOD_MASK;
957 	uint32_t shorthand = icrval & APIC_DEST_MASK;
958 
959 	switch (mode) {
960 	case APIC_DELMODE_FIXED:
961 		if (trigger == APIC_TRIGMOD_EDGE)
962 			return (true);
963 		/*
964 		 * AMD allows a level assert IPI and Intel converts a level
965 		 * assert IPI into an edge IPI.
966 		 */
967 		if (trigger == APIC_TRIGMOD_LEVEL && level == APIC_LEVEL_ASSERT)
968 			return (true);
969 		break;
970 	case APIC_DELMODE_LOWPRIO:
971 	case APIC_DELMODE_SMI:
972 	case APIC_DELMODE_NMI:
973 	case APIC_DELMODE_INIT:
974 		if (trigger == APIC_TRIGMOD_EDGE &&
975 		    (shorthand == APIC_DEST_DESTFLD ||
976 			shorthand == APIC_DEST_ALLESELF))
977 			return (true);
978 		/*
979 		 * AMD allows a level assert IPI and Intel converts a level
980 		 * assert IPI into an edge IPI.
981 		 */
982 		if (trigger == APIC_TRIGMOD_LEVEL &&
983 		    level == APIC_LEVEL_ASSERT &&
984 		    (shorthand == APIC_DEST_DESTFLD ||
985 			shorthand == APIC_DEST_ALLESELF))
986 			return (true);
987 		/*
988 		 * An level triggered deassert INIT is defined in the Intel
989 		 * Multiprocessor Specification and the Intel Software Developer
990 		 * Manual. Due to the MPS it's required to send a level assert
991 		 * INIT to a cpu and then a level deassert INIT. Some operating
992 		 * systems e.g. FreeBSD or Linux use that algorithm. According
993 		 * to the SDM a level deassert INIT is only supported by Pentium
994 		 * and P6 processors. It's always send to all cpus regardless of
995 		 * the destination or shorthand field. It resets the arbitration
996 		 * id register. This register is not software accessible and
997 		 * only required for the APIC bus arbitration. So, the level
998 		 * deassert INIT doesn't need any emulation and we should ignore
999 		 * it. The SDM also defines that newer processors don't support
1000 		 * the level deassert INIT and it's not valid any more. As it's
1001 		 * defined for older systems, it can't be invalid per se.
1002 		 * Otherwise, backward compatibility would be broken. However,
1003 		 * when returning false here, it'll be ignored which is the
1004 		 * desired behaviour.
1005 		 */
1006 		if (mode == APIC_DELMODE_INIT &&
1007 		    trigger == APIC_TRIGMOD_LEVEL &&
1008 		    level == APIC_LEVEL_DEASSERT)
1009 			return (false);
1010 		break;
1011 	case APIC_DELMODE_STARTUP:
1012 		if (shorthand == APIC_DEST_DESTFLD ||
1013 		    shorthand == APIC_DEST_ALLESELF)
1014 			return (true);
1015 		break;
1016 	case APIC_DELMODE_RR:
1017 		/* Only available on AMD! */
1018 		if (trigger == APIC_TRIGMOD_EDGE &&
1019 		    shorthand == APIC_DEST_DESTFLD)
1020 			return (true);
1021 		break;
1022 	case APIC_DELMODE_RESV:
1023 		return (false);
1024 	default:
1025 		__assert_unreachable();
1026 	}
1027 
1028 	return (false);
1029 }
1030 
1031 int
1032 vlapic_icrlo_write_handler(struct vlapic *vlapic, bool *retu)
1033 {
1034 	int i;
1035 	bool phys;
1036 	cpuset_t dmask, ipimask;
1037 	uint64_t icrval;
1038 	uint32_t dest, vec, mode, shorthand;
1039 	struct vcpu *vcpu;
1040 	struct vm_exit *vmexit;
1041 	struct LAPIC *lapic;
1042 
1043 	lapic = vlapic->apic_page;
1044 	lapic->icr_lo &= ~APIC_DELSTAT_PEND;
1045 	icrval = ((uint64_t)lapic->icr_hi << 32) | lapic->icr_lo;
1046 
1047 	if (x2apic(vlapic))
1048 		dest = icrval >> 32;
1049 	else
1050 		dest = icrval >> (32 + 24);
1051 	vec = icrval & APIC_VECTOR_MASK;
1052 	mode = icrval & APIC_DELMODE_MASK;
1053 	phys = (icrval & APIC_DESTMODE_LOG) == 0;
1054 	shorthand = icrval & APIC_DEST_MASK;
1055 
1056 	VLAPIC_CTR2(vlapic, "icrlo 0x%016lx triggered ipi %d", icrval, vec);
1057 
1058 	switch (shorthand) {
1059 	case APIC_DEST_DESTFLD:
1060 		vlapic_calcdest(vlapic->vm, &dmask, dest, phys, false, x2apic(vlapic));
1061 		break;
1062 	case APIC_DEST_SELF:
1063 		CPU_SETOF(vlapic->vcpuid, &dmask);
1064 		break;
1065 	case APIC_DEST_ALLISELF:
1066 		dmask = vm_active_cpus(vlapic->vm);
1067 		break;
1068 	case APIC_DEST_ALLESELF:
1069 		dmask = vm_active_cpus(vlapic->vm);
1070 		CPU_CLR(vlapic->vcpuid, &dmask);
1071 		break;
1072 	default:
1073 		__assert_unreachable();
1074 	}
1075 
1076 	/*
1077 	 * Ignore invalid combinations of the icr.
1078 	 */
1079 	if (!vlapic_is_icr_valid(icrval)) {
1080 		VLAPIC_CTR1(vlapic, "Ignoring invalid ICR %016lx", icrval);
1081 		return (0);
1082 	}
1083 
1084 	/*
1085 	 * ipimask is a set of vCPUs needing userland handling of the current
1086 	 * IPI.
1087 	 */
1088 	CPU_ZERO(&ipimask);
1089 
1090 	switch (mode) {
1091 	case APIC_DELMODE_FIXED:
1092 		if (vec < 16) {
1093 			vlapic_set_error(vlapic, APIC_ESR_SEND_ILLEGAL_VECTOR,
1094 			    false);
1095 			VLAPIC_CTR1(vlapic, "Ignoring invalid IPI %d", vec);
1096 			return (0);
1097 		}
1098 
1099 		CPU_FOREACH_ISSET(i, &dmask) {
1100 			vcpu = vm_vcpu(vlapic->vm, i);
1101 			lapic_intr_edge(vcpu, vec);
1102 			vmm_stat_incr(vlapic->vcpu, VLAPIC_IPI_SEND, 1);
1103 			vmm_stat_incr(vcpu, VLAPIC_IPI_RECV, 1);
1104 			VLAPIC_CTR2(vlapic,
1105 			    "vlapic sending ipi %d to vcpuid %d", vec, i);
1106 		}
1107 
1108 		break;
1109 	case APIC_DELMODE_NMI:
1110 		CPU_FOREACH_ISSET(i, &dmask) {
1111 			vcpu = vm_vcpu(vlapic->vm, i);
1112 			vm_inject_nmi(vcpu);
1113 			VLAPIC_CTR1(vlapic,
1114 			    "vlapic sending ipi nmi to vcpuid %d", i);
1115 		}
1116 
1117 		break;
1118 	case APIC_DELMODE_INIT:
1119 	case APIC_DELMODE_STARTUP:
1120 		if (!vlapic->ipi_exit) {
1121 			if (!phys)
1122 				break;
1123 
1124 			i = vm_apicid2vcpuid(vlapic->vm, dest);
1125 			if (i >= vm_get_maxcpus(vlapic->vm) ||
1126 			    i == vlapic->vcpuid)
1127 				break;
1128 
1129 			CPU_SETOF(i, &ipimask);
1130 
1131 			break;
1132 		}
1133 
1134 		CPU_COPY(&dmask, &ipimask);
1135 		break;
1136 	default:
1137 		return (1);
1138 	}
1139 
1140 	if (!CPU_EMPTY(&ipimask)) {
1141 		vmexit = vm_exitinfo(vlapic->vcpu);
1142 		vmexit->exitcode = VM_EXITCODE_IPI;
1143 		vmexit->u.ipi.mode = mode;
1144 		vmexit->u.ipi.vector = vec;
1145 		*vm_exitinfo_cpuset(vlapic->vcpu) = ipimask;
1146 
1147 		*retu = true;
1148 	}
1149 
1150 	return (0);
1151 }
1152 
1153 static void
1154 vlapic_handle_init(struct vcpu *vcpu, void *arg)
1155 {
1156 	struct vlapic *vlapic = vm_lapic(vcpu);
1157 
1158 	vlapic_reset(vlapic);
1159 }
1160 
1161 int
1162 vm_handle_ipi(struct vcpu *vcpu, struct vm_exit *vme, bool *retu)
1163 {
1164 	struct vlapic *vlapic = vm_lapic(vcpu);
1165 	cpuset_t *dmask = vm_exitinfo_cpuset(vcpu);
1166 	uint8_t vec = vme->u.ipi.vector;
1167 
1168 	*retu = true;
1169 	switch (vme->u.ipi.mode) {
1170 	case APIC_DELMODE_INIT: {
1171 		cpuset_t active, reinit;
1172 
1173 		active = vm_active_cpus(vcpu_vm(vcpu));
1174 		CPU_AND(&reinit, &active, dmask);
1175 		if (!CPU_EMPTY(&reinit)) {
1176 			vm_smp_rendezvous(vcpu, reinit, vlapic_handle_init,
1177 			    NULL);
1178 		}
1179 		vm_await_start(vcpu_vm(vcpu), dmask);
1180 
1181 		if (!vlapic->ipi_exit)
1182 			*retu = false;
1183 
1184 		break;
1185 	}
1186 	case APIC_DELMODE_STARTUP:
1187 		/*
1188 		 * Ignore SIPIs in any state other than wait-for-SIPI
1189 		 */
1190 		*dmask = vm_start_cpus(vcpu_vm(vcpu), dmask);
1191 
1192 		if (CPU_EMPTY(dmask)) {
1193 			*retu = false;
1194 			break;
1195 		}
1196 
1197 		/*
1198 		 * Old bhyve versions don't support the IPI
1199 		 * exit. Translate it into the old style.
1200 		 */
1201 		if (!vlapic->ipi_exit) {
1202 			vme->exitcode = VM_EXITCODE_SPINUP_AP;
1203 			vme->u.spinup_ap.vcpu = CPU_FFS(dmask) - 1;
1204 			vme->u.spinup_ap.rip = vec << PAGE_SHIFT;
1205 		}
1206 
1207 		break;
1208 	default:
1209 		__assert_unreachable();
1210 	}
1211 
1212 	return (0);
1213 }
1214 
1215 void
1216 vlapic_self_ipi_handler(struct vlapic *vlapic, uint64_t val)
1217 {
1218 	int vec;
1219 
1220 	KASSERT(x2apic(vlapic), ("SELF_IPI does not exist in xAPIC mode"));
1221 
1222 	vec = val & 0xff;
1223 	lapic_intr_edge(vlapic->vcpu, vec);
1224 	vmm_stat_incr(vlapic->vcpu, VLAPIC_IPI_SEND, 1);
1225 	vmm_stat_incr(vlapic->vcpu, VLAPIC_IPI_RECV, 1);
1226 	VLAPIC_CTR1(vlapic, "vlapic self-ipi %d", vec);
1227 }
1228 
1229 int
1230 vlapic_pending_intr(struct vlapic *vlapic, int *vecptr)
1231 {
1232 	struct LAPIC	*lapic = vlapic->apic_page;
1233 	int	  	 idx, i, bitpos, vector;
1234 	uint32_t	*irrptr, val;
1235 
1236 	vlapic_update_ppr(vlapic);
1237 
1238 	if (vlapic->ops.pending_intr)
1239 		return ((*vlapic->ops.pending_intr)(vlapic, vecptr));
1240 
1241 	irrptr = &lapic->irr0;
1242 
1243 	for (i = 7; i >= 0; i--) {
1244 		idx = i * 4;
1245 		val = atomic_load_acq_int(&irrptr[idx]);
1246 		bitpos = fls(val);
1247 		if (bitpos != 0) {
1248 			vector = i * 32 + (bitpos - 1);
1249 			if (PRIO(vector) > PRIO(lapic->ppr)) {
1250 				VLAPIC_CTR1(vlapic, "pending intr %d", vector);
1251 				if (vecptr != NULL)
1252 					*vecptr = vector;
1253 				return (1);
1254 			} else
1255 				break;
1256 		}
1257 	}
1258 	return (0);
1259 }
1260 
1261 void
1262 vlapic_intr_accepted(struct vlapic *vlapic, int vector)
1263 {
1264 	struct LAPIC	*lapic = vlapic->apic_page;
1265 	uint32_t	*irrptr, *isrptr;
1266 	int		idx, stk_top;
1267 
1268 	if (vlapic->ops.intr_accepted)
1269 		return ((*vlapic->ops.intr_accepted)(vlapic, vector));
1270 
1271 	/*
1272 	 * clear the ready bit for vector being accepted in irr
1273 	 * and set the vector as in service in isr.
1274 	 */
1275 	idx = (vector / 32) * 4;
1276 
1277 	irrptr = &lapic->irr0;
1278 	atomic_clear_int(&irrptr[idx], 1 << (vector % 32));
1279 	VLAPIC_CTR_IRR(vlapic, "vlapic_intr_accepted");
1280 
1281 	isrptr = &lapic->isr0;
1282 	isrptr[idx] |= 1 << (vector % 32);
1283 	VLAPIC_CTR_ISR(vlapic, "vlapic_intr_accepted");
1284 
1285 	/*
1286 	 * Update the PPR
1287 	 */
1288 	vlapic->isrvec_stk_top++;
1289 
1290 	stk_top = vlapic->isrvec_stk_top;
1291 	if (stk_top >= ISRVEC_STK_SIZE)
1292 		panic("isrvec_stk_top overflow %d", stk_top);
1293 
1294 	vlapic->isrvec_stk[stk_top] = vector;
1295 }
1296 
1297 void
1298 vlapic_svr_write_handler(struct vlapic *vlapic)
1299 {
1300 	struct LAPIC *lapic;
1301 	uint32_t old, new, changed;
1302 
1303 	lapic = vlapic->apic_page;
1304 
1305 	new = lapic->svr;
1306 	old = vlapic->svr_last;
1307 	vlapic->svr_last = new;
1308 
1309 	changed = old ^ new;
1310 	if ((changed & APIC_SVR_ENABLE) != 0) {
1311 		if ((new & APIC_SVR_ENABLE) == 0) {
1312 			/*
1313 			 * The apic is now disabled so stop the apic timer
1314 			 * and mask all the LVT entries.
1315 			 */
1316 			VLAPIC_CTR0(vlapic, "vlapic is software-disabled");
1317 			VLAPIC_TIMER_LOCK(vlapic);
1318 			callout_stop(&vlapic->callout);
1319 			VLAPIC_TIMER_UNLOCK(vlapic);
1320 			vlapic_mask_lvts(vlapic);
1321 		} else {
1322 			/*
1323 			 * The apic is now enabled so restart the apic timer
1324 			 * if it is configured in periodic mode.
1325 			 */
1326 			VLAPIC_CTR0(vlapic, "vlapic is software-enabled");
1327 			if (vlapic_periodic_timer(vlapic))
1328 				vlapic_icrtmr_write_handler(vlapic);
1329 		}
1330 	}
1331 }
1332 
1333 int
1334 vlapic_read(struct vlapic *vlapic, int mmio_access, uint64_t offset,
1335     uint64_t *data, bool *retu)
1336 {
1337 	struct LAPIC	*lapic = vlapic->apic_page;
1338 	uint32_t	*reg;
1339 	int		 i;
1340 
1341 	/* Ignore MMIO accesses in x2APIC mode */
1342 	if (x2apic(vlapic) && mmio_access) {
1343 		VLAPIC_CTR1(vlapic, "MMIO read from offset %#lx in x2APIC mode",
1344 		    offset);
1345 		*data = 0;
1346 		goto done;
1347 	}
1348 
1349 	if (!x2apic(vlapic) && !mmio_access) {
1350 		/*
1351 		 * XXX Generate GP fault for MSR accesses in xAPIC mode
1352 		 */
1353 		VLAPIC_CTR1(vlapic, "x2APIC MSR read from offset %#lx in "
1354 		    "xAPIC mode", offset);
1355 		*data = 0;
1356 		goto done;
1357 	}
1358 
1359 	if (offset > sizeof(*lapic)) {
1360 		*data = 0;
1361 		goto done;
1362 	}
1363 
1364 	offset &= ~3;
1365 	switch(offset)
1366 	{
1367 		case APIC_OFFSET_ID:
1368 			*data = lapic->id;
1369 			break;
1370 		case APIC_OFFSET_VER:
1371 			*data = lapic->version;
1372 			break;
1373 		case APIC_OFFSET_TPR:
1374 			*data = vlapic_get_tpr(vlapic);
1375 			break;
1376 		case APIC_OFFSET_APR:
1377 			*data = lapic->apr;
1378 			break;
1379 		case APIC_OFFSET_PPR:
1380 			*data = lapic->ppr;
1381 			break;
1382 		case APIC_OFFSET_EOI:
1383 			*data = lapic->eoi;
1384 			break;
1385 		case APIC_OFFSET_LDR:
1386 			*data = lapic->ldr;
1387 			break;
1388 		case APIC_OFFSET_DFR:
1389 			*data = lapic->dfr;
1390 			break;
1391 		case APIC_OFFSET_SVR:
1392 			*data = lapic->svr;
1393 			break;
1394 		case APIC_OFFSET_ISR0 ... APIC_OFFSET_ISR7:
1395 			i = (offset - APIC_OFFSET_ISR0) >> 2;
1396 			reg = &lapic->isr0;
1397 			*data = *(reg + i);
1398 			break;
1399 		case APIC_OFFSET_TMR0 ... APIC_OFFSET_TMR7:
1400 			i = (offset - APIC_OFFSET_TMR0) >> 2;
1401 			reg = &lapic->tmr0;
1402 			*data = *(reg + i);
1403 			break;
1404 		case APIC_OFFSET_IRR0 ... APIC_OFFSET_IRR7:
1405 			i = (offset - APIC_OFFSET_IRR0) >> 2;
1406 			reg = &lapic->irr0;
1407 			*data = atomic_load_acq_int(reg + i);
1408 			break;
1409 		case APIC_OFFSET_ESR:
1410 			*data = lapic->esr;
1411 			break;
1412 		case APIC_OFFSET_ICR_LOW:
1413 			*data = lapic->icr_lo;
1414 			if (x2apic(vlapic))
1415 				*data |= (uint64_t)lapic->icr_hi << 32;
1416 			break;
1417 		case APIC_OFFSET_ICR_HI:
1418 			*data = lapic->icr_hi;
1419 			break;
1420 		case APIC_OFFSET_CMCI_LVT:
1421 		case APIC_OFFSET_TIMER_LVT ... APIC_OFFSET_ERROR_LVT:
1422 			*data = vlapic_get_lvt(vlapic, offset);
1423 #ifdef INVARIANTS
1424 			reg = vlapic_get_lvtptr(vlapic, offset);
1425 			KASSERT(*data == *reg, ("inconsistent lvt value at "
1426 			    "offset %#lx: %#lx/%#x", offset, *data, *reg));
1427 #endif
1428 			break;
1429 		case APIC_OFFSET_TIMER_ICR:
1430 			*data = lapic->icr_timer;
1431 			break;
1432 		case APIC_OFFSET_TIMER_CCR:
1433 			*data = vlapic_get_ccr(vlapic);
1434 			break;
1435 		case APIC_OFFSET_TIMER_DCR:
1436 			*data = lapic->dcr_timer;
1437 			break;
1438 		case APIC_OFFSET_SELF_IPI:
1439 			/*
1440 			 * XXX generate a GP fault if vlapic is in x2apic mode
1441 			 */
1442 			*data = 0;
1443 			break;
1444 		case APIC_OFFSET_RRR:
1445 		default:
1446 			*data = 0;
1447 			break;
1448 	}
1449 done:
1450 	VLAPIC_CTR2(vlapic, "vlapic read offset %#x, data %#lx", offset, *data);
1451 	return 0;
1452 }
1453 
1454 int
1455 vlapic_write(struct vlapic *vlapic, int mmio_access, uint64_t offset,
1456     uint64_t data, bool *retu)
1457 {
1458 	struct LAPIC	*lapic = vlapic->apic_page;
1459 	uint32_t	*regptr;
1460 	int		retval;
1461 
1462 	KASSERT((offset & 0xf) == 0 && offset < PAGE_SIZE,
1463 	    ("vlapic_write: invalid offset %#lx", offset));
1464 
1465 	VLAPIC_CTR2(vlapic, "vlapic write offset %#lx, data %#lx",
1466 	    offset, data);
1467 
1468 	if (offset > sizeof(*lapic))
1469 		return (0);
1470 
1471 	/* Ignore MMIO accesses in x2APIC mode */
1472 	if (x2apic(vlapic) && mmio_access) {
1473 		VLAPIC_CTR2(vlapic, "MMIO write of %#lx to offset %#lx "
1474 		    "in x2APIC mode", data, offset);
1475 		return (0);
1476 	}
1477 
1478 	/*
1479 	 * XXX Generate GP fault for MSR accesses in xAPIC mode
1480 	 */
1481 	if (!x2apic(vlapic) && !mmio_access) {
1482 		VLAPIC_CTR2(vlapic, "x2APIC MSR write of %#lx to offset %#lx "
1483 		    "in xAPIC mode", data, offset);
1484 		return (0);
1485 	}
1486 
1487 	retval = 0;
1488 	switch(offset)
1489 	{
1490 		case APIC_OFFSET_ID:
1491 			lapic->id = data;
1492 			vlapic_id_write_handler(vlapic);
1493 			break;
1494 		case APIC_OFFSET_TPR:
1495 			vlapic_set_tpr(vlapic, data & 0xff);
1496 			break;
1497 		case APIC_OFFSET_EOI:
1498 			vlapic_process_eoi(vlapic);
1499 			break;
1500 		case APIC_OFFSET_LDR:
1501 			lapic->ldr = data;
1502 			vlapic_ldr_write_handler(vlapic);
1503 			break;
1504 		case APIC_OFFSET_DFR:
1505 			lapic->dfr = data;
1506 			vlapic_dfr_write_handler(vlapic);
1507 			break;
1508 		case APIC_OFFSET_SVR:
1509 			lapic->svr = data;
1510 			vlapic_svr_write_handler(vlapic);
1511 			break;
1512 		case APIC_OFFSET_ICR_LOW:
1513 			lapic->icr_lo = data;
1514 			if (x2apic(vlapic))
1515 				lapic->icr_hi = data >> 32;
1516 			retval = vlapic_icrlo_write_handler(vlapic, retu);
1517 			break;
1518 		case APIC_OFFSET_ICR_HI:
1519 			lapic->icr_hi = data;
1520 			break;
1521 		case APIC_OFFSET_CMCI_LVT:
1522 		case APIC_OFFSET_TIMER_LVT ... APIC_OFFSET_ERROR_LVT:
1523 			regptr = vlapic_get_lvtptr(vlapic, offset);
1524 			*regptr = data;
1525 			vlapic_lvt_write_handler(vlapic, offset);
1526 			break;
1527 		case APIC_OFFSET_TIMER_ICR:
1528 			lapic->icr_timer = data;
1529 			vlapic_icrtmr_write_handler(vlapic);
1530 			break;
1531 
1532 		case APIC_OFFSET_TIMER_DCR:
1533 			lapic->dcr_timer = data;
1534 			vlapic_dcr_write_handler(vlapic);
1535 			break;
1536 
1537 		case APIC_OFFSET_ESR:
1538 			vlapic_esr_write_handler(vlapic);
1539 			break;
1540 
1541 		case APIC_OFFSET_SELF_IPI:
1542 			if (x2apic(vlapic))
1543 				vlapic_self_ipi_handler(vlapic, data);
1544 			break;
1545 
1546 		case APIC_OFFSET_VER:
1547 		case APIC_OFFSET_APR:
1548 		case APIC_OFFSET_PPR:
1549 		case APIC_OFFSET_RRR:
1550 		case APIC_OFFSET_ISR0 ... APIC_OFFSET_ISR7:
1551 		case APIC_OFFSET_TMR0 ... APIC_OFFSET_TMR7:
1552 		case APIC_OFFSET_IRR0 ... APIC_OFFSET_IRR7:
1553 		case APIC_OFFSET_TIMER_CCR:
1554 		default:
1555 			// Read only.
1556 			break;
1557 	}
1558 
1559 	return (retval);
1560 }
1561 
1562 static void
1563 vlapic_reset(struct vlapic *vlapic)
1564 {
1565 	struct LAPIC *lapic;
1566 
1567 	lapic = vlapic->apic_page;
1568 	bzero(lapic, sizeof(struct LAPIC));
1569 
1570 	lapic->id = vlapic_get_id(vlapic);
1571 	lapic->version = VLAPIC_VERSION;
1572 	lapic->version |= (VLAPIC_MAXLVT_INDEX << MAXLVTSHIFT);
1573 	lapic->dfr = 0xffffffff;
1574 	lapic->svr = APIC_SVR_VECTOR;
1575 	vlapic_mask_lvts(vlapic);
1576 	vlapic_reset_tmr(vlapic);
1577 
1578 	lapic->dcr_timer = 0;
1579 	vlapic_dcr_write_handler(vlapic);
1580 
1581 	vlapic->svr_last = lapic->svr;
1582 }
1583 
1584 void
1585 vlapic_init(struct vlapic *vlapic)
1586 {
1587 	KASSERT(vlapic->vm != NULL, ("vlapic_init: vm is not initialized"));
1588 	KASSERT(vlapic->vcpuid >= 0 &&
1589 	    vlapic->vcpuid < vm_get_maxcpus(vlapic->vm),
1590 	    ("vlapic_init: vcpuid is not initialized"));
1591 	KASSERT(vlapic->apic_page != NULL, ("vlapic_init: apic_page is not "
1592 	    "initialized"));
1593 
1594 	/*
1595 	 * If the vlapic is configured in x2apic mode then it will be
1596 	 * accessed in the critical section via the MSR emulation code.
1597 	 *
1598 	 * Therefore the timer mutex must be a spinlock because blockable
1599 	 * mutexes cannot be acquired in a critical section.
1600 	 */
1601 	mtx_init(&vlapic->timer_mtx, "vlapic timer mtx", NULL, MTX_SPIN);
1602 	callout_init(&vlapic->callout, 1);
1603 
1604 	vlapic->msr_apicbase = DEFAULT_APIC_BASE | APICBASE_ENABLED;
1605 
1606 	if (vlapic->vcpuid == 0)
1607 		vlapic->msr_apicbase |= APICBASE_BSP;
1608 
1609 	vlapic->ipi_exit = false;
1610 
1611 	vlapic_reset(vlapic);
1612 }
1613 
1614 void
1615 vlapic_cleanup(struct vlapic *vlapic)
1616 {
1617 
1618 	callout_drain(&vlapic->callout);
1619 	mtx_destroy(&vlapic->timer_mtx);
1620 }
1621 
1622 uint64_t
1623 vlapic_get_apicbase(struct vlapic *vlapic)
1624 {
1625 
1626 	return (vlapic->msr_apicbase);
1627 }
1628 
1629 int
1630 vlapic_set_apicbase(struct vlapic *vlapic, uint64_t new)
1631 {
1632 
1633 	if (vlapic->msr_apicbase != new) {
1634 		VLAPIC_CTR2(vlapic, "Changing APIC_BASE MSR from %#lx to %#lx "
1635 		    "not supported", vlapic->msr_apicbase, new);
1636 		return (-1);
1637 	}
1638 
1639 	return (0);
1640 }
1641 
1642 void
1643 vlapic_set_x2apic_state(struct vcpu *vcpu, enum x2apic_state state)
1644 {
1645 	struct vlapic *vlapic;
1646 	struct LAPIC *lapic;
1647 
1648 	vlapic = vm_lapic(vcpu);
1649 
1650 	if (state == X2APIC_DISABLED)
1651 		vlapic->msr_apicbase &= ~APICBASE_X2APIC;
1652 	else
1653 		vlapic->msr_apicbase |= APICBASE_X2APIC;
1654 
1655 	/*
1656 	 * Reset the local APIC registers whose values are mode-dependent.
1657 	 *
1658 	 * XXX this works because the APIC mode can be changed only at vcpu
1659 	 * initialization time.
1660 	 */
1661 	lapic = vlapic->apic_page;
1662 	lapic->id = vlapic_get_id(vlapic);
1663 	if (x2apic(vlapic)) {
1664 		lapic->ldr = x2apic_ldr(vlapic);
1665 		lapic->dfr = 0;
1666 	} else {
1667 		lapic->ldr = 0;
1668 		lapic->dfr = 0xffffffff;
1669 	}
1670 
1671 	if (state == X2APIC_ENABLED) {
1672 		if (vlapic->ops.enable_x2apic_mode)
1673 			(*vlapic->ops.enable_x2apic_mode)(vlapic);
1674 	}
1675 }
1676 
1677 void
1678 vlapic_deliver_intr(struct vm *vm, bool level, uint32_t dest, bool phys,
1679     int delmode, int vec)
1680 {
1681 	struct vcpu *vcpu;
1682 	bool lowprio;
1683 	int vcpuid;
1684 	cpuset_t dmask;
1685 
1686 	if (delmode != IOART_DELFIXED &&
1687 	    delmode != IOART_DELLOPRI &&
1688 	    delmode != IOART_DELEXINT) {
1689 		VM_CTR1(vm, "vlapic intr invalid delmode %#x", delmode);
1690 		return;
1691 	}
1692 	lowprio = (delmode == IOART_DELLOPRI);
1693 
1694 	/*
1695 	 * We don't provide any virtual interrupt redirection hardware so
1696 	 * all interrupts originating from the ioapic or MSI specify the
1697 	 * 'dest' in the legacy xAPIC format.
1698 	 */
1699 	vlapic_calcdest(vm, &dmask, dest, phys, lowprio, false);
1700 
1701 	CPU_FOREACH_ISSET(vcpuid, &dmask) {
1702 		vcpu = vm_vcpu(vm, vcpuid);
1703 		if (delmode == IOART_DELEXINT) {
1704 			vm_inject_extint(vcpu);
1705 		} else {
1706 			lapic_set_intr(vcpu, vec, level);
1707 		}
1708 	}
1709 }
1710 
1711 void
1712 vlapic_post_intr(struct vlapic *vlapic, int hostcpu, int ipinum)
1713 {
1714 	/*
1715 	 * Post an interrupt to the vcpu currently running on 'hostcpu'.
1716 	 *
1717 	 * This is done by leveraging features like Posted Interrupts (Intel)
1718 	 * Doorbell MSR (AMD AVIC) that avoid a VM exit.
1719 	 *
1720 	 * If neither of these features are available then fallback to
1721 	 * sending an IPI to 'hostcpu'.
1722 	 */
1723 	if (vlapic->ops.post_intr)
1724 		(*vlapic->ops.post_intr)(vlapic, hostcpu);
1725 	else
1726 		ipi_cpu(hostcpu, ipinum);
1727 }
1728 
1729 bool
1730 vlapic_enabled(struct vlapic *vlapic)
1731 {
1732 	struct LAPIC *lapic = vlapic->apic_page;
1733 
1734 	if ((vlapic->msr_apicbase & APICBASE_ENABLED) != 0 &&
1735 	    (lapic->svr & APIC_SVR_ENABLE) != 0)
1736 		return (true);
1737 	else
1738 		return (false);
1739 }
1740 
1741 static void
1742 vlapic_set_tmr(struct vlapic *vlapic, int vector, bool level)
1743 {
1744 	struct LAPIC *lapic;
1745 	uint32_t *tmrptr, mask;
1746 	int idx;
1747 
1748 	lapic = vlapic->apic_page;
1749 	tmrptr = &lapic->tmr0;
1750 	idx = (vector / 32) * 4;
1751 	mask = 1 << (vector % 32);
1752 	if (level)
1753 		tmrptr[idx] |= mask;
1754 	else
1755 		tmrptr[idx] &= ~mask;
1756 
1757 	if (vlapic->ops.set_tmr != NULL)
1758 		(*vlapic->ops.set_tmr)(vlapic, vector, level);
1759 }
1760 
1761 void
1762 vlapic_reset_tmr(struct vlapic *vlapic)
1763 {
1764 	int vector;
1765 
1766 	VLAPIC_CTR0(vlapic, "vlapic resetting all vectors to edge-triggered");
1767 
1768 	for (vector = 0; vector <= 255; vector++)
1769 		vlapic_set_tmr(vlapic, vector, false);
1770 }
1771 
1772 void
1773 vlapic_set_tmr_level(struct vlapic *vlapic, uint32_t dest, bool phys,
1774     int delmode, int vector)
1775 {
1776 	cpuset_t dmask;
1777 	bool lowprio;
1778 
1779 	KASSERT(vector >= 0 && vector <= 255, ("invalid vector %d", vector));
1780 
1781 	/*
1782 	 * A level trigger is valid only for fixed and lowprio delivery modes.
1783 	 */
1784 	if (delmode != APIC_DELMODE_FIXED && delmode != APIC_DELMODE_LOWPRIO) {
1785 		VLAPIC_CTR1(vlapic, "Ignoring level trigger-mode for "
1786 		    "delivery-mode %d", delmode);
1787 		return;
1788 	}
1789 
1790 	lowprio = (delmode == APIC_DELMODE_LOWPRIO);
1791 	vlapic_calcdest(vlapic->vm, &dmask, dest, phys, lowprio, false);
1792 
1793 	if (!CPU_ISSET(vlapic->vcpuid, &dmask))
1794 		return;
1795 
1796 	VLAPIC_CTR1(vlapic, "vector %d set to level-triggered", vector);
1797 	vlapic_set_tmr(vlapic, vector, true);
1798 }
1799 
1800 #ifdef BHYVE_SNAPSHOT
1801 static void
1802 vlapic_reset_callout(struct vlapic *vlapic, uint32_t ccr)
1803 {
1804 	/* The implementation is similar to the one in the
1805 	 * `vlapic_icrtmr_write_handler` function
1806 	 */
1807 	sbintime_t sbt;
1808 	struct bintime bt;
1809 
1810 	VLAPIC_TIMER_LOCK(vlapic);
1811 
1812 	bt = vlapic->timer_freq_bt;
1813 	bintime_mul(&bt, ccr);
1814 
1815 	if (ccr != 0) {
1816 		binuptime(&vlapic->timer_fire_bt);
1817 		bintime_add(&vlapic->timer_fire_bt, &bt);
1818 
1819 		sbt = bttosbt(bt);
1820 		vlapic_callout_reset(vlapic, sbt);
1821 	} else {
1822 		/* even if the CCR was 0, periodic timers should be reset */
1823 		if (vlapic_periodic_timer(vlapic)) {
1824 			binuptime(&vlapic->timer_fire_bt);
1825 			bintime_add(&vlapic->timer_fire_bt,
1826 				    &vlapic->timer_period_bt);
1827 			sbt = bttosbt(vlapic->timer_period_bt);
1828 
1829 			callout_stop(&vlapic->callout);
1830 			vlapic_callout_reset(vlapic, sbt);
1831 		}
1832 	}
1833 
1834 	VLAPIC_TIMER_UNLOCK(vlapic);
1835 }
1836 
1837 int
1838 vlapic_snapshot(struct vm *vm, struct vm_snapshot_meta *meta)
1839 {
1840 	int ret;
1841 	struct vcpu *vcpu;
1842 	struct vlapic *vlapic;
1843 	struct LAPIC *lapic;
1844 	uint32_t ccr;
1845 	uint16_t i, maxcpus;
1846 
1847 	KASSERT(vm != NULL, ("%s: arg was NULL", __func__));
1848 
1849 	ret = 0;
1850 
1851 	maxcpus = vm_get_maxcpus(vm);
1852 	for (i = 0; i < maxcpus; i++) {
1853 		vcpu = vm_vcpu(vm, i);
1854 		if (vcpu == NULL)
1855 			continue;
1856 		vlapic = vm_lapic(vcpu);
1857 
1858 		/* snapshot the page first; timer period depends on icr_timer */
1859 		lapic = vlapic->apic_page;
1860 		SNAPSHOT_BUF_OR_LEAVE(lapic, PAGE_SIZE, meta, ret, done);
1861 
1862 		SNAPSHOT_VAR_OR_LEAVE(vlapic->esr_pending, meta, ret, done);
1863 
1864 		SNAPSHOT_VAR_OR_LEAVE(vlapic->timer_freq_bt.sec,
1865 				      meta, ret, done);
1866 		SNAPSHOT_VAR_OR_LEAVE(vlapic->timer_freq_bt.frac,
1867 				      meta, ret, done);
1868 
1869 		/*
1870 		 * Timer period is equal to 'icr_timer' ticks at a frequency of
1871 		 * 'timer_freq_bt'.
1872 		 */
1873 		if (meta->op == VM_SNAPSHOT_RESTORE) {
1874 			vlapic->timer_period_bt = vlapic->timer_freq_bt;
1875 			bintime_mul(&vlapic->timer_period_bt, lapic->icr_timer);
1876 		}
1877 
1878 		SNAPSHOT_BUF_OR_LEAVE(vlapic->isrvec_stk,
1879 				      sizeof(vlapic->isrvec_stk),
1880 				      meta, ret, done);
1881 		SNAPSHOT_VAR_OR_LEAVE(vlapic->isrvec_stk_top, meta, ret, done);
1882 
1883 		SNAPSHOT_BUF_OR_LEAVE(vlapic->lvt_last,
1884 				      sizeof(vlapic->lvt_last),
1885 				      meta, ret, done);
1886 
1887 		if (meta->op == VM_SNAPSHOT_SAVE)
1888 			ccr = vlapic_get_ccr(vlapic);
1889 
1890 		SNAPSHOT_VAR_OR_LEAVE(ccr, meta, ret, done);
1891 
1892 		if (meta->op == VM_SNAPSHOT_RESTORE &&
1893 		    vlapic_enabled(vlapic) && lapic->icr_timer != 0) {
1894 			/* Reset the value of the 'timer_fire_bt' and the vlapic
1895 			 * callout based on the value of the current count
1896 			 * register saved when the VM snapshot was created.
1897 			 * If initial count register is 0, timer is not used.
1898 			 * Look at "10.5.4 APIC Timer" in Software Developer Manual.
1899 			 */
1900 			vlapic_reset_callout(vlapic, ccr);
1901 		}
1902 	}
1903 
1904 done:
1905 	return (ret);
1906 }
1907 #endif
1908