xref: /freebsd/sys/amd64/vmm/io/vlapic.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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		(16)
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 
87 static __inline uint32_t
88 vlapic_get_id(struct vlapic *vlapic)
89 {
90 
91 	if (x2apic(vlapic))
92 		return (vlapic->vcpuid);
93 	else
94 		return (vlapic->vcpuid << 24);
95 }
96 
97 static uint32_t
98 x2apic_ldr(struct vlapic *vlapic)
99 {
100 	int apicid;
101 	uint32_t ldr;
102 
103 	apicid = vlapic_get_id(vlapic);
104 	ldr = 1 << (apicid & 0xf);
105 	ldr |= (apicid & 0xffff0) << 12;
106 	return (ldr);
107 }
108 
109 void
110 vlapic_dfr_write_handler(struct vlapic *vlapic)
111 {
112 	struct LAPIC *lapic;
113 
114 	lapic = vlapic->apic_page;
115 	if (x2apic(vlapic)) {
116 		VM_CTR1(vlapic->vm, "ignoring write to DFR in x2apic mode: %#x",
117 		    lapic->dfr);
118 		lapic->dfr = 0;
119 		return;
120 	}
121 
122 	lapic->dfr &= APIC_DFR_MODEL_MASK;
123 	lapic->dfr |= APIC_DFR_RESERVED;
124 
125 	if ((lapic->dfr & APIC_DFR_MODEL_MASK) == APIC_DFR_MODEL_FLAT)
126 		VLAPIC_CTR0(vlapic, "vlapic DFR in Flat Model");
127 	else if ((lapic->dfr & APIC_DFR_MODEL_MASK) == APIC_DFR_MODEL_CLUSTER)
128 		VLAPIC_CTR0(vlapic, "vlapic DFR in Cluster Model");
129 	else
130 		VLAPIC_CTR1(vlapic, "DFR in Unknown Model %#x", lapic->dfr);
131 }
132 
133 void
134 vlapic_ldr_write_handler(struct vlapic *vlapic)
135 {
136 	struct LAPIC *lapic;
137 
138 	lapic = vlapic->apic_page;
139 
140 	/* LDR is read-only in x2apic mode */
141 	if (x2apic(vlapic)) {
142 		VLAPIC_CTR1(vlapic, "ignoring write to LDR in x2apic mode: %#x",
143 		    lapic->ldr);
144 		lapic->ldr = x2apic_ldr(vlapic);
145 	} else {
146 		lapic->ldr &= ~APIC_LDR_RESERVED;
147 		VLAPIC_CTR1(vlapic, "vlapic LDR set to %#x", lapic->ldr);
148 	}
149 }
150 
151 void
152 vlapic_id_write_handler(struct vlapic *vlapic)
153 {
154 	struct LAPIC *lapic;
155 
156 	/*
157 	 * We don't allow the ID register to be modified so reset it back to
158 	 * its default value.
159 	 */
160 	lapic = vlapic->apic_page;
161 	lapic->id = vlapic_get_id(vlapic);
162 }
163 
164 static int
165 vlapic_timer_divisor(uint32_t dcr)
166 {
167 	switch (dcr & 0xB) {
168 	case APIC_TDCR_1:
169 		return (1);
170 	case APIC_TDCR_2:
171 		return (2);
172 	case APIC_TDCR_4:
173 		return (4);
174 	case APIC_TDCR_8:
175 		return (8);
176 	case APIC_TDCR_16:
177 		return (16);
178 	case APIC_TDCR_32:
179 		return (32);
180 	case APIC_TDCR_64:
181 		return (64);
182 	case APIC_TDCR_128:
183 		return (128);
184 	default:
185 		panic("vlapic_timer_divisor: invalid dcr 0x%08x", dcr);
186 	}
187 }
188 
189 #if 0
190 static inline void
191 vlapic_dump_lvt(uint32_t offset, uint32_t *lvt)
192 {
193 	printf("Offset %x: lvt %08x (V:%02x DS:%x M:%x)\n", offset,
194 	    *lvt, *lvt & APIC_LVTT_VECTOR, *lvt & APIC_LVTT_DS,
195 	    *lvt & APIC_LVTT_M);
196 }
197 #endif
198 
199 static uint32_t
200 vlapic_get_ccr(struct vlapic *vlapic)
201 {
202 	struct bintime bt_now, bt_rem;
203 	struct LAPIC *lapic;
204 	uint32_t ccr;
205 
206 	ccr = 0;
207 	lapic = vlapic->apic_page;
208 
209 	VLAPIC_TIMER_LOCK(vlapic);
210 	if (callout_active(&vlapic->callout)) {
211 		/*
212 		 * If the timer is scheduled to expire in the future then
213 		 * compute the value of 'ccr' based on the remaining time.
214 		 */
215 		binuptime(&bt_now);
216 		if (bintime_cmp(&vlapic->timer_fire_bt, &bt_now, >)) {
217 			bt_rem = vlapic->timer_fire_bt;
218 			bintime_sub(&bt_rem, &bt_now);
219 			ccr += bt_rem.sec * BT2FREQ(&vlapic->timer_freq_bt);
220 			ccr += bt_rem.frac / vlapic->timer_freq_bt.frac;
221 		}
222 	}
223 	KASSERT(ccr <= lapic->icr_timer, ("vlapic_get_ccr: invalid ccr %#x, "
224 	    "icr_timer is %#x", ccr, lapic->icr_timer));
225 	VLAPIC_CTR2(vlapic, "vlapic ccr_timer = %#x, icr_timer = %#x",
226 	    ccr, lapic->icr_timer);
227 	VLAPIC_TIMER_UNLOCK(vlapic);
228 	return (ccr);
229 }
230 
231 void
232 vlapic_dcr_write_handler(struct vlapic *vlapic)
233 {
234 	struct LAPIC *lapic;
235 	int divisor;
236 
237 	lapic = vlapic->apic_page;
238 	VLAPIC_TIMER_LOCK(vlapic);
239 
240 	divisor = vlapic_timer_divisor(lapic->dcr_timer);
241 	VLAPIC_CTR2(vlapic, "vlapic dcr_timer=%#x, divisor=%d",
242 	    lapic->dcr_timer, divisor);
243 
244 	/*
245 	 * Update the timer frequency and the timer period.
246 	 *
247 	 * XXX changes to the frequency divider will not take effect until
248 	 * the timer is reloaded.
249 	 */
250 	FREQ2BT(VLAPIC_BUS_FREQ / divisor, &vlapic->timer_freq_bt);
251 	vlapic->timer_period_bt = vlapic->timer_freq_bt;
252 	bintime_mul(&vlapic->timer_period_bt, lapic->icr_timer);
253 
254 	VLAPIC_TIMER_UNLOCK(vlapic);
255 }
256 
257 void
258 vlapic_esr_write_handler(struct vlapic *vlapic)
259 {
260 	struct LAPIC *lapic;
261 
262 	lapic = vlapic->apic_page;
263 	lapic->esr = vlapic->esr_pending;
264 	vlapic->esr_pending = 0;
265 }
266 
267 int
268 vlapic_set_intr_ready(struct vlapic *vlapic, int vector, bool level)
269 {
270 	struct LAPIC *lapic;
271 	uint32_t *irrptr, *tmrptr, mask;
272 	int idx;
273 
274 	KASSERT(vector >= 0 && vector < 256, ("invalid vector %d", vector));
275 
276 	lapic = vlapic->apic_page;
277 	if (!(lapic->svr & APIC_SVR_ENABLE)) {
278 		VLAPIC_CTR1(vlapic, "vlapic is software disabled, ignoring "
279 		    "interrupt %d", vector);
280 		return (0);
281 	}
282 
283 	if (vector < 16) {
284 		vlapic_set_error(vlapic, APIC_ESR_RECEIVE_ILLEGAL_VECTOR,
285 		    false);
286 		VLAPIC_CTR1(vlapic, "vlapic ignoring interrupt to vector %d",
287 		    vector);
288 		return (1);
289 	}
290 
291 	if (vlapic->ops.set_intr_ready)
292 		return ((*vlapic->ops.set_intr_ready)(vlapic, vector, level));
293 
294 	idx = (vector / 32) * 4;
295 	mask = 1 << (vector % 32);
296 
297 	irrptr = &lapic->irr0;
298 	atomic_set_int(&irrptr[idx], mask);
299 
300 	/*
301 	 * Verify that the trigger-mode of the interrupt matches with
302 	 * the vlapic TMR registers.
303 	 */
304 	tmrptr = &lapic->tmr0;
305 	if ((tmrptr[idx] & mask) != (level ? mask : 0)) {
306 		VLAPIC_CTR3(vlapic, "vlapic TMR[%d] is 0x%08x but "
307 		    "interrupt is %s-triggered", idx / 4, tmrptr[idx],
308 		    level ? "level" : "edge");
309 	}
310 
311 	VLAPIC_CTR_IRR(vlapic, "vlapic_set_intr_ready");
312 	return (1);
313 }
314 
315 static __inline uint32_t *
316 vlapic_get_lvtptr(struct vlapic *vlapic, uint32_t offset)
317 {
318 	struct LAPIC	*lapic = vlapic->apic_page;
319 	int 		 i;
320 
321 	switch (offset) {
322 	case APIC_OFFSET_CMCI_LVT:
323 		return (&lapic->lvt_cmci);
324 	case APIC_OFFSET_TIMER_LVT ... APIC_OFFSET_ERROR_LVT:
325 		i = (offset - APIC_OFFSET_TIMER_LVT) >> 2;
326 		return ((&lapic->lvt_timer) + i);
327 	default:
328 		panic("vlapic_get_lvt: invalid LVT\n");
329 	}
330 }
331 
332 static __inline int
333 lvt_off_to_idx(uint32_t offset)
334 {
335 	int index;
336 
337 	switch (offset) {
338 	case APIC_OFFSET_CMCI_LVT:
339 		index = APIC_LVT_CMCI;
340 		break;
341 	case APIC_OFFSET_TIMER_LVT:
342 		index = APIC_LVT_TIMER;
343 		break;
344 	case APIC_OFFSET_THERM_LVT:
345 		index = APIC_LVT_THERMAL;
346 		break;
347 	case APIC_OFFSET_PERF_LVT:
348 		index = APIC_LVT_PMC;
349 		break;
350 	case APIC_OFFSET_LINT0_LVT:
351 		index = APIC_LVT_LINT0;
352 		break;
353 	case APIC_OFFSET_LINT1_LVT:
354 		index = APIC_LVT_LINT1;
355 		break;
356 	case APIC_OFFSET_ERROR_LVT:
357 		index = APIC_LVT_ERROR;
358 		break;
359 	default:
360 		index = -1;
361 		break;
362 	}
363 	KASSERT(index >= 0 && index <= VLAPIC_MAXLVT_INDEX, ("lvt_off_to_idx: "
364 	    "invalid lvt index %d for offset %#x", index, offset));
365 
366 	return (index);
367 }
368 
369 static __inline uint32_t
370 vlapic_get_lvt(struct vlapic *vlapic, uint32_t offset)
371 {
372 	int idx;
373 	uint32_t val;
374 
375 	idx = lvt_off_to_idx(offset);
376 	val = atomic_load_acq_32(&vlapic->lvt_last[idx]);
377 	return (val);
378 }
379 
380 void
381 vlapic_lvt_write_handler(struct vlapic *vlapic, uint32_t offset)
382 {
383 	uint32_t *lvtptr, mask, val;
384 	struct LAPIC *lapic;
385 	int idx;
386 
387 	lapic = vlapic->apic_page;
388 	lvtptr = vlapic_get_lvtptr(vlapic, offset);
389 	val = *lvtptr;
390 	idx = lvt_off_to_idx(offset);
391 
392 	if (!(lapic->svr & APIC_SVR_ENABLE))
393 		val |= APIC_LVT_M;
394 	mask = APIC_LVT_M | APIC_LVT_DS | APIC_LVT_VECTOR;
395 	switch (offset) {
396 	case APIC_OFFSET_TIMER_LVT:
397 		mask |= APIC_LVTT_TM;
398 		break;
399 	case APIC_OFFSET_ERROR_LVT:
400 		break;
401 	case APIC_OFFSET_LINT0_LVT:
402 	case APIC_OFFSET_LINT1_LVT:
403 		mask |= APIC_LVT_TM | APIC_LVT_RIRR | APIC_LVT_IIPP;
404 		/* FALLTHROUGH */
405 	default:
406 		mask |= APIC_LVT_DM;
407 		break;
408 	}
409 	val &= mask;
410 	*lvtptr = val;
411 	atomic_store_rel_32(&vlapic->lvt_last[idx], val);
412 }
413 
414 static void
415 vlapic_mask_lvts(struct vlapic *vlapic)
416 {
417 	struct LAPIC *lapic = vlapic->apic_page;
418 
419 	lapic->lvt_cmci |= APIC_LVT_M;
420 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_CMCI_LVT);
421 
422 	lapic->lvt_timer |= APIC_LVT_M;
423 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_TIMER_LVT);
424 
425 	lapic->lvt_thermal |= APIC_LVT_M;
426 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_THERM_LVT);
427 
428 	lapic->lvt_pcint |= APIC_LVT_M;
429 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_PERF_LVT);
430 
431 	lapic->lvt_lint0 |= APIC_LVT_M;
432 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_LINT0_LVT);
433 
434 	lapic->lvt_lint1 |= APIC_LVT_M;
435 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_LINT1_LVT);
436 
437 	lapic->lvt_error |= APIC_LVT_M;
438 	vlapic_lvt_write_handler(vlapic, APIC_OFFSET_ERROR_LVT);
439 }
440 
441 static int
442 vlapic_fire_lvt(struct vlapic *vlapic, u_int lvt)
443 {
444 	uint32_t mode, reg, vec;
445 
446 	reg = atomic_load_acq_32(&vlapic->lvt_last[lvt]);
447 
448 	if (reg & APIC_LVT_M)
449 		return (0);
450 	vec = reg & APIC_LVT_VECTOR;
451 	mode = reg & APIC_LVT_DM;
452 
453 	switch (mode) {
454 	case APIC_LVT_DM_FIXED:
455 		if (vec < 16) {
456 			vlapic_set_error(vlapic, APIC_ESR_SEND_ILLEGAL_VECTOR,
457 			    lvt == APIC_LVT_ERROR);
458 			return (0);
459 		}
460 		if (vlapic_set_intr_ready(vlapic, vec, false))
461 			vcpu_notify_event(vlapic->vm, vlapic->vcpuid, true);
462 		break;
463 	case APIC_LVT_DM_NMI:
464 		vm_inject_nmi(vlapic->vm, vlapic->vcpuid);
465 		break;
466 	case APIC_LVT_DM_EXTINT:
467 		vm_inject_extint(vlapic->vm, vlapic->vcpuid);
468 		break;
469 	default:
470 		// Other modes ignored
471 		return (0);
472 	}
473 	return (1);
474 }
475 
476 #if 1
477 static void
478 dump_isrvec_stk(struct vlapic *vlapic)
479 {
480 	int i;
481 	uint32_t *isrptr;
482 
483 	isrptr = &vlapic->apic_page->isr0;
484 	for (i = 0; i < 8; i++)
485 		printf("ISR%d 0x%08x\n", i, isrptr[i * 4]);
486 
487 	for (i = 0; i <= vlapic->isrvec_stk_top; i++)
488 		printf("isrvec_stk[%d] = %d\n", i, vlapic->isrvec_stk[i]);
489 }
490 #endif
491 
492 /*
493  * Algorithm adopted from section "Interrupt, Task and Processor Priority"
494  * in Intel Architecture Manual Vol 3a.
495  */
496 static void
497 vlapic_update_ppr(struct vlapic *vlapic)
498 {
499 	int isrvec, tpr, ppr;
500 
501 	/*
502 	 * Note that the value on the stack at index 0 is always 0.
503 	 *
504 	 * This is a placeholder for the value of ISRV when none of the
505 	 * bits is set in the ISRx registers.
506 	 */
507 	isrvec = vlapic->isrvec_stk[vlapic->isrvec_stk_top];
508 	tpr = vlapic->apic_page->tpr;
509 
510 #if 1
511 	{
512 		int i, lastprio, curprio, vector, idx;
513 		uint32_t *isrptr;
514 
515 		if (vlapic->isrvec_stk_top == 0 && isrvec != 0)
516 			panic("isrvec_stk is corrupted: %d", isrvec);
517 
518 		/*
519 		 * Make sure that the priority of the nested interrupts is
520 		 * always increasing.
521 		 */
522 		lastprio = -1;
523 		for (i = 1; i <= vlapic->isrvec_stk_top; i++) {
524 			curprio = PRIO(vlapic->isrvec_stk[i]);
525 			if (curprio <= lastprio) {
526 				dump_isrvec_stk(vlapic);
527 				panic("isrvec_stk does not satisfy invariant");
528 			}
529 			lastprio = curprio;
530 		}
531 
532 		/*
533 		 * Make sure that each bit set in the ISRx registers has a
534 		 * corresponding entry on the isrvec stack.
535 		 */
536 		i = 1;
537 		isrptr = &vlapic->apic_page->isr0;
538 		for (vector = 0; vector < 256; vector++) {
539 			idx = (vector / 32) * 4;
540 			if (isrptr[idx] & (1 << (vector % 32))) {
541 				if (i > vlapic->isrvec_stk_top ||
542 				    vlapic->isrvec_stk[i] != vector) {
543 					dump_isrvec_stk(vlapic);
544 					panic("ISR and isrvec_stk out of sync");
545 				}
546 				i++;
547 			}
548 		}
549 	}
550 #endif
551 
552 	if (PRIO(tpr) >= PRIO(isrvec))
553 		ppr = tpr;
554 	else
555 		ppr = isrvec & 0xf0;
556 
557 	vlapic->apic_page->ppr = ppr;
558 	VLAPIC_CTR1(vlapic, "vlapic_update_ppr 0x%02x", ppr);
559 }
560 
561 void
562 vlapic_sync_tpr(struct vlapic *vlapic)
563 {
564 	vlapic_update_ppr(vlapic);
565 }
566 
567 static VMM_STAT(VLAPIC_GRATUITOUS_EOI, "EOI without any in-service interrupt");
568 
569 static void
570 vlapic_process_eoi(struct vlapic *vlapic)
571 {
572 	struct LAPIC	*lapic = vlapic->apic_page;
573 	uint32_t	*isrptr, *tmrptr;
574 	int		i, idx, bitpos, vector;
575 
576 	isrptr = &lapic->isr0;
577 	tmrptr = &lapic->tmr0;
578 
579 	for (i = 7; i >= 0; i--) {
580 		idx = i * 4;
581 		bitpos = fls(isrptr[idx]);
582 		if (bitpos-- != 0) {
583 			if (vlapic->isrvec_stk_top <= 0) {
584 				panic("invalid vlapic isrvec_stk_top %d",
585 				      vlapic->isrvec_stk_top);
586 			}
587 			isrptr[idx] &= ~(1 << bitpos);
588 			vector = i * 32 + bitpos;
589 			VCPU_CTR1(vlapic->vm, vlapic->vcpuid, "EOI vector %d",
590 			    vector);
591 			VLAPIC_CTR_ISR(vlapic, "vlapic_process_eoi");
592 			vlapic->isrvec_stk_top--;
593 			vlapic_update_ppr(vlapic);
594 			if ((tmrptr[idx] & (1 << bitpos)) != 0) {
595 				vioapic_process_eoi(vlapic->vm, vlapic->vcpuid,
596 				    vector);
597 			}
598 			return;
599 		}
600 	}
601 	VCPU_CTR0(vlapic->vm, vlapic->vcpuid, "Gratuitous EOI");
602 	vmm_stat_incr(vlapic->vm, vlapic->vcpuid, 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->vm, vlapic->vcpuid, 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->vm, vlapic->vcpuid, 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->vm, vlapic->vcpuid, 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->vm, vlapic->vcpuid);
684 				break;
685 			case APIC_LVT_LINT1:
686 				vm_inject_nmi(vlapic->vm, vlapic->vcpuid);
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->vm, vlapic->vcpuid,
704 			    LVTS_TRIGGERRED, vector, 1);
705 		}
706 		break;
707 	default:
708 		return (EINVAL);
709 	}
710 	return (0);
711 }
712 
713 static void
714 vlapic_callout_handler(void *arg)
715 {
716 	struct vlapic *vlapic;
717 	struct bintime bt, btnow;
718 	sbintime_t rem_sbt;
719 
720 	vlapic = arg;
721 
722 	VLAPIC_TIMER_LOCK(vlapic);
723 	if (callout_pending(&vlapic->callout))	/* callout was reset */
724 		goto done;
725 
726 	if (!callout_active(&vlapic->callout))	/* callout was stopped */
727 		goto done;
728 
729 	callout_deactivate(&vlapic->callout);
730 
731 	vlapic_fire_timer(vlapic);
732 
733 	if (vlapic_periodic_timer(vlapic)) {
734 		binuptime(&btnow);
735 		KASSERT(bintime_cmp(&btnow, &vlapic->timer_fire_bt, >=),
736 		    ("vlapic callout at %#lx.%#lx, expected at %#lx.#%lx",
737 		    btnow.sec, btnow.frac, vlapic->timer_fire_bt.sec,
738 		    vlapic->timer_fire_bt.frac));
739 
740 		/*
741 		 * Compute the delta between when the timer was supposed to
742 		 * fire and the present time.
743 		 */
744 		bt = btnow;
745 		bintime_sub(&bt, &vlapic->timer_fire_bt);
746 
747 		rem_sbt = bttosbt(vlapic->timer_period_bt);
748 		if (bintime_cmp(&bt, &vlapic->timer_period_bt, <)) {
749 			/*
750 			 * Adjust the time until the next countdown downward
751 			 * to account for the lost time.
752 			 */
753 			rem_sbt -= bttosbt(bt);
754 		} else {
755 			/*
756 			 * If the delta is greater than the timer period then
757 			 * just reset our time base instead of trying to catch
758 			 * up.
759 			 */
760 			vlapic->timer_fire_bt = btnow;
761 			VLAPIC_CTR2(vlapic, "vlapic timer lagging by %lu "
762 			    "usecs, period is %lu usecs - resetting time base",
763 			    bttosbt(bt) / SBT_1US,
764 			    bttosbt(vlapic->timer_period_bt) / SBT_1US);
765 		}
766 
767 		bintime_add(&vlapic->timer_fire_bt, &vlapic->timer_period_bt);
768 		callout_reset_sbt(&vlapic->callout, rem_sbt, 0,
769 		    vlapic_callout_handler, vlapic, 0);
770 	}
771 done:
772 	VLAPIC_TIMER_UNLOCK(vlapic);
773 }
774 
775 void
776 vlapic_icrtmr_write_handler(struct vlapic *vlapic)
777 {
778 	struct LAPIC *lapic;
779 	sbintime_t sbt;
780 	uint32_t icr_timer;
781 
782 	VLAPIC_TIMER_LOCK(vlapic);
783 
784 	lapic = vlapic->apic_page;
785 	icr_timer = lapic->icr_timer;
786 
787 	vlapic->timer_period_bt = vlapic->timer_freq_bt;
788 	bintime_mul(&vlapic->timer_period_bt, icr_timer);
789 
790 	if (icr_timer != 0) {
791 		binuptime(&vlapic->timer_fire_bt);
792 		bintime_add(&vlapic->timer_fire_bt, &vlapic->timer_period_bt);
793 
794 		sbt = bttosbt(vlapic->timer_period_bt);
795 		callout_reset_sbt(&vlapic->callout, sbt, 0,
796 		    vlapic_callout_handler, vlapic, 0);
797 	} else
798 		callout_stop(&vlapic->callout);
799 
800 	VLAPIC_TIMER_UNLOCK(vlapic);
801 }
802 
803 /*
804  * This function populates 'dmask' with the set of vcpus that match the
805  * addressing specified by the (dest, phys, lowprio) tuple.
806  *
807  * 'x2apic_dest' specifies whether 'dest' is interpreted as x2APIC (32-bit)
808  * or xAPIC (8-bit) destination field.
809  */
810 static void
811 vlapic_calcdest(struct vm *vm, cpuset_t *dmask, uint32_t dest, bool phys,
812     bool lowprio, bool x2apic_dest)
813 {
814 	struct vlapic *vlapic;
815 	uint32_t dfr, ldr, ldest, cluster;
816 	uint32_t mda_flat_ldest, mda_cluster_ldest, mda_ldest, mda_cluster_id;
817 	cpuset_t amask;
818 	int vcpuid;
819 
820 	if ((x2apic_dest && dest == 0xffffffff) ||
821 	    (!x2apic_dest && dest == 0xff)) {
822 		/*
823 		 * Broadcast in both logical and physical modes.
824 		 */
825 		*dmask = vm_active_cpus(vm);
826 		return;
827 	}
828 
829 	if (phys) {
830 		/*
831 		 * Physical mode: destination is APIC ID.
832 		 */
833 		CPU_ZERO(dmask);
834 		vcpuid = vm_apicid2vcpuid(vm, dest);
835 		amask = vm_active_cpus(vm);
836 		if (vcpuid < vm_get_maxcpus(vm) && CPU_ISSET(vcpuid, &amask))
837 			CPU_SET(vcpuid, dmask);
838 	} else {
839 		/*
840 		 * In the "Flat Model" the MDA is interpreted as an 8-bit wide
841 		 * bitmask. This model is only available in the xAPIC mode.
842 		 */
843 		mda_flat_ldest = dest & 0xff;
844 
845 		/*
846 		 * In the "Cluster Model" the MDA is used to identify a
847 		 * specific cluster and a set of APICs in that cluster.
848 		 */
849 		if (x2apic_dest) {
850 			mda_cluster_id = dest >> 16;
851 			mda_cluster_ldest = dest & 0xffff;
852 		} else {
853 			mda_cluster_id = (dest >> 4) & 0xf;
854 			mda_cluster_ldest = dest & 0xf;
855 		}
856 
857 		/*
858 		 * Logical mode: match each APIC that has a bit set
859 		 * in its LDR that matches a bit in the ldest.
860 		 */
861 		CPU_ZERO(dmask);
862 		amask = vm_active_cpus(vm);
863 		while ((vcpuid = CPU_FFS(&amask)) != 0) {
864 			vcpuid--;
865 			CPU_CLR(vcpuid, &amask);
866 
867 			vlapic = vm_lapic(vm, vcpuid);
868 			dfr = vlapic->apic_page->dfr;
869 			ldr = vlapic->apic_page->ldr;
870 
871 			if ((dfr & APIC_DFR_MODEL_MASK) ==
872 			    APIC_DFR_MODEL_FLAT) {
873 				ldest = ldr >> 24;
874 				mda_ldest = mda_flat_ldest;
875 			} else if ((dfr & APIC_DFR_MODEL_MASK) ==
876 			    APIC_DFR_MODEL_CLUSTER) {
877 				if (x2apic(vlapic)) {
878 					cluster = ldr >> 16;
879 					ldest = ldr & 0xffff;
880 				} else {
881 					cluster = ldr >> 28;
882 					ldest = (ldr >> 24) & 0xf;
883 				}
884 				if (cluster != mda_cluster_id)
885 					continue;
886 				mda_ldest = mda_cluster_ldest;
887 			} else {
888 				/*
889 				 * Guest has configured a bad logical
890 				 * model for this vcpu - skip it.
891 				 */
892 				VLAPIC_CTR1(vlapic, "vlapic has bad logical "
893 				    "model %x - cannot deliver interrupt", dfr);
894 				continue;
895 			}
896 
897 			if ((mda_ldest & ldest) != 0) {
898 				CPU_SET(vcpuid, dmask);
899 				if (lowprio)
900 					break;
901 			}
902 		}
903 	}
904 }
905 
906 static VMM_STAT_ARRAY(IPIS_SENT, VM_MAXCPU, "ipis sent to vcpu");
907 
908 static void
909 vlapic_set_tpr(struct vlapic *vlapic, uint8_t val)
910 {
911 	struct LAPIC *lapic = vlapic->apic_page;
912 
913 	if (lapic->tpr != val) {
914 		VCPU_CTR2(vlapic->vm, vlapic->vcpuid, "vlapic TPR changed "
915 		    "from %#x to %#x", lapic->tpr, val);
916 		lapic->tpr = val;
917 		vlapic_update_ppr(vlapic);
918 	}
919 }
920 
921 static uint8_t
922 vlapic_get_tpr(struct vlapic *vlapic)
923 {
924 	struct LAPIC *lapic = vlapic->apic_page;
925 
926 	return (lapic->tpr);
927 }
928 
929 void
930 vlapic_set_cr8(struct vlapic *vlapic, uint64_t val)
931 {
932 	uint8_t tpr;
933 
934 	if (val & ~0xf) {
935 		vm_inject_gp(vlapic->vm, vlapic->vcpuid);
936 		return;
937 	}
938 
939 	tpr = val << 4;
940 	vlapic_set_tpr(vlapic, tpr);
941 }
942 
943 uint64_t
944 vlapic_get_cr8(struct vlapic *vlapic)
945 {
946 	uint8_t tpr;
947 
948 	tpr = vlapic_get_tpr(vlapic);
949 	return (tpr >> 4);
950 }
951 
952 int
953 vlapic_icrlo_write_handler(struct vlapic *vlapic, bool *retu)
954 {
955 	int i;
956 	bool phys;
957 	cpuset_t dmask;
958 	uint64_t icrval;
959 	uint32_t dest, vec, mode;
960 	struct vlapic *vlapic2;
961 	struct vm_exit *vmexit;
962 	struct LAPIC *lapic;
963 	uint16_t maxcpus;
964 
965 	lapic = vlapic->apic_page;
966 	lapic->icr_lo &= ~APIC_DELSTAT_PEND;
967 	icrval = ((uint64_t)lapic->icr_hi << 32) | lapic->icr_lo;
968 
969 	if (x2apic(vlapic))
970 		dest = icrval >> 32;
971 	else
972 		dest = icrval >> (32 + 24);
973 	vec = icrval & APIC_VECTOR_MASK;
974 	mode = icrval & APIC_DELMODE_MASK;
975 
976 	if (mode == APIC_DELMODE_FIXED && vec < 16) {
977 		vlapic_set_error(vlapic, APIC_ESR_SEND_ILLEGAL_VECTOR, false);
978 		VLAPIC_CTR1(vlapic, "Ignoring invalid IPI %d", vec);
979 		return (0);
980 	}
981 
982 	VLAPIC_CTR2(vlapic, "icrlo 0x%016lx triggered ipi %d", icrval, vec);
983 
984 	if (mode == APIC_DELMODE_FIXED || mode == APIC_DELMODE_NMI) {
985 		switch (icrval & APIC_DEST_MASK) {
986 		case APIC_DEST_DESTFLD:
987 			phys = ((icrval & APIC_DESTMODE_LOG) == 0);
988 			vlapic_calcdest(vlapic->vm, &dmask, dest, phys, false,
989 			    x2apic(vlapic));
990 			break;
991 		case APIC_DEST_SELF:
992 			CPU_SETOF(vlapic->vcpuid, &dmask);
993 			break;
994 		case APIC_DEST_ALLISELF:
995 			dmask = vm_active_cpus(vlapic->vm);
996 			break;
997 		case APIC_DEST_ALLESELF:
998 			dmask = vm_active_cpus(vlapic->vm);
999 			CPU_CLR(vlapic->vcpuid, &dmask);
1000 			break;
1001 		default:
1002 			CPU_ZERO(&dmask);	/* satisfy gcc */
1003 			break;
1004 		}
1005 
1006 		while ((i = CPU_FFS(&dmask)) != 0) {
1007 			i--;
1008 			CPU_CLR(i, &dmask);
1009 			if (mode == APIC_DELMODE_FIXED) {
1010 				lapic_intr_edge(vlapic->vm, i, vec);
1011 				vmm_stat_array_incr(vlapic->vm, vlapic->vcpuid,
1012 						    IPIS_SENT, i, 1);
1013 				VLAPIC_CTR2(vlapic, "vlapic sending ipi %d "
1014 				    "to vcpuid %d", vec, i);
1015 			} else {
1016 				vm_inject_nmi(vlapic->vm, i);
1017 				VLAPIC_CTR1(vlapic, "vlapic sending ipi nmi "
1018 				    "to vcpuid %d", i);
1019 			}
1020 		}
1021 
1022 		return (0);	/* handled completely in the kernel */
1023 	}
1024 
1025 	maxcpus = vm_get_maxcpus(vlapic->vm);
1026 	if (mode == APIC_DELMODE_INIT) {
1027 		if ((icrval & APIC_LEVEL_MASK) == APIC_LEVEL_DEASSERT)
1028 			return (0);
1029 
1030 		if (vlapic->vcpuid == 0 && dest != 0 && dest < maxcpus) {
1031 			vlapic2 = vm_lapic(vlapic->vm, dest);
1032 
1033 			/* move from INIT to waiting-for-SIPI state */
1034 			if (vlapic2->boot_state == BS_INIT) {
1035 				vlapic2->boot_state = BS_SIPI;
1036 			}
1037 
1038 			return (0);
1039 		}
1040 	}
1041 
1042 	if (mode == APIC_DELMODE_STARTUP) {
1043 		if (vlapic->vcpuid == 0 && dest != 0 && dest < maxcpus) {
1044 			vlapic2 = vm_lapic(vlapic->vm, dest);
1045 
1046 			/*
1047 			 * Ignore SIPIs in any state other than wait-for-SIPI
1048 			 */
1049 			if (vlapic2->boot_state != BS_SIPI)
1050 				return (0);
1051 
1052 			vlapic2->boot_state = BS_RUNNING;
1053 
1054 			*retu = true;
1055 			vmexit = vm_exitinfo(vlapic->vm, vlapic->vcpuid);
1056 			vmexit->exitcode = VM_EXITCODE_SPINUP_AP;
1057 			vmexit->u.spinup_ap.vcpu = dest;
1058 			vmexit->u.spinup_ap.rip = vec << PAGE_SHIFT;
1059 
1060 			return (0);
1061 		}
1062 	}
1063 
1064 	/*
1065 	 * This will cause a return to userland.
1066 	 */
1067 	return (1);
1068 }
1069 
1070 void
1071 vlapic_self_ipi_handler(struct vlapic *vlapic, uint64_t val)
1072 {
1073 	int vec;
1074 
1075 	KASSERT(x2apic(vlapic), ("SELF_IPI does not exist in xAPIC mode"));
1076 
1077 	vec = val & 0xff;
1078 	lapic_intr_edge(vlapic->vm, vlapic->vcpuid, vec);
1079 	vmm_stat_array_incr(vlapic->vm, vlapic->vcpuid, IPIS_SENT,
1080 	    vlapic->vcpuid, 1);
1081 	VLAPIC_CTR1(vlapic, "vlapic self-ipi %d", vec);
1082 }
1083 
1084 int
1085 vlapic_pending_intr(struct vlapic *vlapic, int *vecptr)
1086 {
1087 	struct LAPIC	*lapic = vlapic->apic_page;
1088 	int	  	 idx, i, bitpos, vector;
1089 	uint32_t	*irrptr, val;
1090 
1091 	vlapic_update_ppr(vlapic);
1092 
1093 	if (vlapic->ops.pending_intr)
1094 		return ((*vlapic->ops.pending_intr)(vlapic, vecptr));
1095 
1096 	irrptr = &lapic->irr0;
1097 
1098 	for (i = 7; i >= 0; i--) {
1099 		idx = i * 4;
1100 		val = atomic_load_acq_int(&irrptr[idx]);
1101 		bitpos = fls(val);
1102 		if (bitpos != 0) {
1103 			vector = i * 32 + (bitpos - 1);
1104 			if (PRIO(vector) > PRIO(lapic->ppr)) {
1105 				VLAPIC_CTR1(vlapic, "pending intr %d", vector);
1106 				if (vecptr != NULL)
1107 					*vecptr = vector;
1108 				return (1);
1109 			} else
1110 				break;
1111 		}
1112 	}
1113 	return (0);
1114 }
1115 
1116 void
1117 vlapic_intr_accepted(struct vlapic *vlapic, int vector)
1118 {
1119 	struct LAPIC	*lapic = vlapic->apic_page;
1120 	uint32_t	*irrptr, *isrptr;
1121 	int		idx, stk_top;
1122 
1123 	if (vlapic->ops.intr_accepted)
1124 		return ((*vlapic->ops.intr_accepted)(vlapic, vector));
1125 
1126 	/*
1127 	 * clear the ready bit for vector being accepted in irr
1128 	 * and set the vector as in service in isr.
1129 	 */
1130 	idx = (vector / 32) * 4;
1131 
1132 	irrptr = &lapic->irr0;
1133 	atomic_clear_int(&irrptr[idx], 1 << (vector % 32));
1134 	VLAPIC_CTR_IRR(vlapic, "vlapic_intr_accepted");
1135 
1136 	isrptr = &lapic->isr0;
1137 	isrptr[idx] |= 1 << (vector % 32);
1138 	VLAPIC_CTR_ISR(vlapic, "vlapic_intr_accepted");
1139 
1140 	/*
1141 	 * Update the PPR
1142 	 */
1143 	vlapic->isrvec_stk_top++;
1144 
1145 	stk_top = vlapic->isrvec_stk_top;
1146 	if (stk_top >= ISRVEC_STK_SIZE)
1147 		panic("isrvec_stk_top overflow %d", stk_top);
1148 
1149 	vlapic->isrvec_stk[stk_top] = vector;
1150 }
1151 
1152 void
1153 vlapic_svr_write_handler(struct vlapic *vlapic)
1154 {
1155 	struct LAPIC *lapic;
1156 	uint32_t old, new, changed;
1157 
1158 	lapic = vlapic->apic_page;
1159 
1160 	new = lapic->svr;
1161 	old = vlapic->svr_last;
1162 	vlapic->svr_last = new;
1163 
1164 	changed = old ^ new;
1165 	if ((changed & APIC_SVR_ENABLE) != 0) {
1166 		if ((new & APIC_SVR_ENABLE) == 0) {
1167 			/*
1168 			 * The apic is now disabled so stop the apic timer
1169 			 * and mask all the LVT entries.
1170 			 */
1171 			VLAPIC_CTR0(vlapic, "vlapic is software-disabled");
1172 			VLAPIC_TIMER_LOCK(vlapic);
1173 			callout_stop(&vlapic->callout);
1174 			VLAPIC_TIMER_UNLOCK(vlapic);
1175 			vlapic_mask_lvts(vlapic);
1176 		} else {
1177 			/*
1178 			 * The apic is now enabled so restart the apic timer
1179 			 * if it is configured in periodic mode.
1180 			 */
1181 			VLAPIC_CTR0(vlapic, "vlapic is software-enabled");
1182 			if (vlapic_periodic_timer(vlapic))
1183 				vlapic_icrtmr_write_handler(vlapic);
1184 		}
1185 	}
1186 }
1187 
1188 int
1189 vlapic_read(struct vlapic *vlapic, int mmio_access, uint64_t offset,
1190     uint64_t *data, bool *retu)
1191 {
1192 	struct LAPIC	*lapic = vlapic->apic_page;
1193 	uint32_t	*reg;
1194 	int		 i;
1195 
1196 	/* Ignore MMIO accesses in x2APIC mode */
1197 	if (x2apic(vlapic) && mmio_access) {
1198 		VLAPIC_CTR1(vlapic, "MMIO read from offset %#lx in x2APIC mode",
1199 		    offset);
1200 		*data = 0;
1201 		goto done;
1202 	}
1203 
1204 	if (!x2apic(vlapic) && !mmio_access) {
1205 		/*
1206 		 * XXX Generate GP fault for MSR accesses in xAPIC mode
1207 		 */
1208 		VLAPIC_CTR1(vlapic, "x2APIC MSR read from offset %#lx in "
1209 		    "xAPIC mode", offset);
1210 		*data = 0;
1211 		goto done;
1212 	}
1213 
1214 	if (offset > sizeof(*lapic)) {
1215 		*data = 0;
1216 		goto done;
1217 	}
1218 
1219 	offset &= ~3;
1220 	switch(offset)
1221 	{
1222 		case APIC_OFFSET_ID:
1223 			*data = lapic->id;
1224 			break;
1225 		case APIC_OFFSET_VER:
1226 			*data = lapic->version;
1227 			break;
1228 		case APIC_OFFSET_TPR:
1229 			*data = vlapic_get_tpr(vlapic);
1230 			break;
1231 		case APIC_OFFSET_APR:
1232 			*data = lapic->apr;
1233 			break;
1234 		case APIC_OFFSET_PPR:
1235 			*data = lapic->ppr;
1236 			break;
1237 		case APIC_OFFSET_EOI:
1238 			*data = lapic->eoi;
1239 			break;
1240 		case APIC_OFFSET_LDR:
1241 			*data = lapic->ldr;
1242 			break;
1243 		case APIC_OFFSET_DFR:
1244 			*data = lapic->dfr;
1245 			break;
1246 		case APIC_OFFSET_SVR:
1247 			*data = lapic->svr;
1248 			break;
1249 		case APIC_OFFSET_ISR0 ... APIC_OFFSET_ISR7:
1250 			i = (offset - APIC_OFFSET_ISR0) >> 2;
1251 			reg = &lapic->isr0;
1252 			*data = *(reg + i);
1253 			break;
1254 		case APIC_OFFSET_TMR0 ... APIC_OFFSET_TMR7:
1255 			i = (offset - APIC_OFFSET_TMR0) >> 2;
1256 			reg = &lapic->tmr0;
1257 			*data = *(reg + i);
1258 			break;
1259 		case APIC_OFFSET_IRR0 ... APIC_OFFSET_IRR7:
1260 			i = (offset - APIC_OFFSET_IRR0) >> 2;
1261 			reg = &lapic->irr0;
1262 			*data = atomic_load_acq_int(reg + i);
1263 			break;
1264 		case APIC_OFFSET_ESR:
1265 			*data = lapic->esr;
1266 			break;
1267 		case APIC_OFFSET_ICR_LOW:
1268 			*data = lapic->icr_lo;
1269 			if (x2apic(vlapic))
1270 				*data |= (uint64_t)lapic->icr_hi << 32;
1271 			break;
1272 		case APIC_OFFSET_ICR_HI:
1273 			*data = lapic->icr_hi;
1274 			break;
1275 		case APIC_OFFSET_CMCI_LVT:
1276 		case APIC_OFFSET_TIMER_LVT ... APIC_OFFSET_ERROR_LVT:
1277 			*data = vlapic_get_lvt(vlapic, offset);
1278 #ifdef INVARIANTS
1279 			reg = vlapic_get_lvtptr(vlapic, offset);
1280 			KASSERT(*data == *reg, ("inconsistent lvt value at "
1281 			    "offset %#lx: %#lx/%#x", offset, *data, *reg));
1282 #endif
1283 			break;
1284 		case APIC_OFFSET_TIMER_ICR:
1285 			*data = lapic->icr_timer;
1286 			break;
1287 		case APIC_OFFSET_TIMER_CCR:
1288 			*data = vlapic_get_ccr(vlapic);
1289 			break;
1290 		case APIC_OFFSET_TIMER_DCR:
1291 			*data = lapic->dcr_timer;
1292 			break;
1293 		case APIC_OFFSET_SELF_IPI:
1294 			/*
1295 			 * XXX generate a GP fault if vlapic is in x2apic mode
1296 			 */
1297 			*data = 0;
1298 			break;
1299 		case APIC_OFFSET_RRR:
1300 		default:
1301 			*data = 0;
1302 			break;
1303 	}
1304 done:
1305 	VLAPIC_CTR2(vlapic, "vlapic read offset %#x, data %#lx", offset, *data);
1306 	return 0;
1307 }
1308 
1309 int
1310 vlapic_write(struct vlapic *vlapic, int mmio_access, uint64_t offset,
1311     uint64_t data, bool *retu)
1312 {
1313 	struct LAPIC	*lapic = vlapic->apic_page;
1314 	uint32_t	*regptr;
1315 	int		retval;
1316 
1317 	KASSERT((offset & 0xf) == 0 && offset < PAGE_SIZE,
1318 	    ("vlapic_write: invalid offset %#lx", offset));
1319 
1320 	VLAPIC_CTR2(vlapic, "vlapic write offset %#lx, data %#lx",
1321 	    offset, data);
1322 
1323 	if (offset > sizeof(*lapic))
1324 		return (0);
1325 
1326 	/* Ignore MMIO accesses in x2APIC mode */
1327 	if (x2apic(vlapic) && mmio_access) {
1328 		VLAPIC_CTR2(vlapic, "MMIO write of %#lx to offset %#lx "
1329 		    "in x2APIC mode", data, offset);
1330 		return (0);
1331 	}
1332 
1333 	/*
1334 	 * XXX Generate GP fault for MSR accesses in xAPIC mode
1335 	 */
1336 	if (!x2apic(vlapic) && !mmio_access) {
1337 		VLAPIC_CTR2(vlapic, "x2APIC MSR write of %#lx to offset %#lx "
1338 		    "in xAPIC mode", data, offset);
1339 		return (0);
1340 	}
1341 
1342 	retval = 0;
1343 	switch(offset)
1344 	{
1345 		case APIC_OFFSET_ID:
1346 			lapic->id = data;
1347 			vlapic_id_write_handler(vlapic);
1348 			break;
1349 		case APIC_OFFSET_TPR:
1350 			vlapic_set_tpr(vlapic, data & 0xff);
1351 			break;
1352 		case APIC_OFFSET_EOI:
1353 			vlapic_process_eoi(vlapic);
1354 			break;
1355 		case APIC_OFFSET_LDR:
1356 			lapic->ldr = data;
1357 			vlapic_ldr_write_handler(vlapic);
1358 			break;
1359 		case APIC_OFFSET_DFR:
1360 			lapic->dfr = data;
1361 			vlapic_dfr_write_handler(vlapic);
1362 			break;
1363 		case APIC_OFFSET_SVR:
1364 			lapic->svr = data;
1365 			vlapic_svr_write_handler(vlapic);
1366 			break;
1367 		case APIC_OFFSET_ICR_LOW:
1368 			lapic->icr_lo = data;
1369 			if (x2apic(vlapic))
1370 				lapic->icr_hi = data >> 32;
1371 			retval = vlapic_icrlo_write_handler(vlapic, retu);
1372 			break;
1373 		case APIC_OFFSET_ICR_HI:
1374 			lapic->icr_hi = data;
1375 			break;
1376 		case APIC_OFFSET_CMCI_LVT:
1377 		case APIC_OFFSET_TIMER_LVT ... APIC_OFFSET_ERROR_LVT:
1378 			regptr = vlapic_get_lvtptr(vlapic, offset);
1379 			*regptr = data;
1380 			vlapic_lvt_write_handler(vlapic, offset);
1381 			break;
1382 		case APIC_OFFSET_TIMER_ICR:
1383 			lapic->icr_timer = data;
1384 			vlapic_icrtmr_write_handler(vlapic);
1385 			break;
1386 
1387 		case APIC_OFFSET_TIMER_DCR:
1388 			lapic->dcr_timer = data;
1389 			vlapic_dcr_write_handler(vlapic);
1390 			break;
1391 
1392 		case APIC_OFFSET_ESR:
1393 			vlapic_esr_write_handler(vlapic);
1394 			break;
1395 
1396 		case APIC_OFFSET_SELF_IPI:
1397 			if (x2apic(vlapic))
1398 				vlapic_self_ipi_handler(vlapic, data);
1399 			break;
1400 
1401 		case APIC_OFFSET_VER:
1402 		case APIC_OFFSET_APR:
1403 		case APIC_OFFSET_PPR:
1404 		case APIC_OFFSET_RRR:
1405 		case APIC_OFFSET_ISR0 ... APIC_OFFSET_ISR7:
1406 		case APIC_OFFSET_TMR0 ... APIC_OFFSET_TMR7:
1407 		case APIC_OFFSET_IRR0 ... APIC_OFFSET_IRR7:
1408 		case APIC_OFFSET_TIMER_CCR:
1409 		default:
1410 			// Read only.
1411 			break;
1412 	}
1413 
1414 	return (retval);
1415 }
1416 
1417 static void
1418 vlapic_reset(struct vlapic *vlapic)
1419 {
1420 	struct LAPIC *lapic;
1421 
1422 	lapic = vlapic->apic_page;
1423 	bzero(lapic, sizeof(struct LAPIC));
1424 
1425 	lapic->id = vlapic_get_id(vlapic);
1426 	lapic->version = VLAPIC_VERSION;
1427 	lapic->version |= (VLAPIC_MAXLVT_INDEX << MAXLVTSHIFT);
1428 	lapic->dfr = 0xffffffff;
1429 	lapic->svr = APIC_SVR_VECTOR;
1430 	vlapic_mask_lvts(vlapic);
1431 	vlapic_reset_tmr(vlapic);
1432 
1433 	lapic->dcr_timer = 0;
1434 	vlapic_dcr_write_handler(vlapic);
1435 
1436 	if (vlapic->vcpuid == 0)
1437 		vlapic->boot_state = BS_RUNNING;	/* BSP */
1438 	else
1439 		vlapic->boot_state = BS_INIT;		/* AP */
1440 
1441 	vlapic->svr_last = lapic->svr;
1442 }
1443 
1444 void
1445 vlapic_init(struct vlapic *vlapic)
1446 {
1447 	KASSERT(vlapic->vm != NULL, ("vlapic_init: vm is not initialized"));
1448 	KASSERT(vlapic->vcpuid >= 0 &&
1449 	    vlapic->vcpuid < vm_get_maxcpus(vlapic->vm),
1450 	    ("vlapic_init: vcpuid is not initialized"));
1451 	KASSERT(vlapic->apic_page != NULL, ("vlapic_init: apic_page is not "
1452 	    "initialized"));
1453 
1454 	/*
1455 	 * If the vlapic is configured in x2apic mode then it will be
1456 	 * accessed in the critical section via the MSR emulation code.
1457 	 *
1458 	 * Therefore the timer mutex must be a spinlock because blockable
1459 	 * mutexes cannot be acquired in a critical section.
1460 	 */
1461 	mtx_init(&vlapic->timer_mtx, "vlapic timer mtx", NULL, MTX_SPIN);
1462 	callout_init(&vlapic->callout, 1);
1463 
1464 	vlapic->msr_apicbase = DEFAULT_APIC_BASE | APICBASE_ENABLED;
1465 
1466 	if (vlapic->vcpuid == 0)
1467 		vlapic->msr_apicbase |= APICBASE_BSP;
1468 
1469 	vlapic_reset(vlapic);
1470 }
1471 
1472 void
1473 vlapic_cleanup(struct vlapic *vlapic)
1474 {
1475 
1476 	callout_drain(&vlapic->callout);
1477 }
1478 
1479 uint64_t
1480 vlapic_get_apicbase(struct vlapic *vlapic)
1481 {
1482 
1483 	return (vlapic->msr_apicbase);
1484 }
1485 
1486 int
1487 vlapic_set_apicbase(struct vlapic *vlapic, uint64_t new)
1488 {
1489 
1490 	if (vlapic->msr_apicbase != new) {
1491 		VLAPIC_CTR2(vlapic, "Changing APIC_BASE MSR from %#lx to %#lx "
1492 		    "not supported", vlapic->msr_apicbase, new);
1493 		return (-1);
1494 	}
1495 
1496 	return (0);
1497 }
1498 
1499 void
1500 vlapic_set_x2apic_state(struct vm *vm, int vcpuid, enum x2apic_state state)
1501 {
1502 	struct vlapic *vlapic;
1503 	struct LAPIC *lapic;
1504 
1505 	vlapic = vm_lapic(vm, vcpuid);
1506 
1507 	if (state == X2APIC_DISABLED)
1508 		vlapic->msr_apicbase &= ~APICBASE_X2APIC;
1509 	else
1510 		vlapic->msr_apicbase |= APICBASE_X2APIC;
1511 
1512 	/*
1513 	 * Reset the local APIC registers whose values are mode-dependent.
1514 	 *
1515 	 * XXX this works because the APIC mode can be changed only at vcpu
1516 	 * initialization time.
1517 	 */
1518 	lapic = vlapic->apic_page;
1519 	lapic->id = vlapic_get_id(vlapic);
1520 	if (x2apic(vlapic)) {
1521 		lapic->ldr = x2apic_ldr(vlapic);
1522 		lapic->dfr = 0;
1523 	} else {
1524 		lapic->ldr = 0;
1525 		lapic->dfr = 0xffffffff;
1526 	}
1527 
1528 	if (state == X2APIC_ENABLED) {
1529 		if (vlapic->ops.enable_x2apic_mode)
1530 			(*vlapic->ops.enable_x2apic_mode)(vlapic);
1531 	}
1532 }
1533 
1534 void
1535 vlapic_deliver_intr(struct vm *vm, bool level, uint32_t dest, bool phys,
1536     int delmode, int vec)
1537 {
1538 	bool lowprio;
1539 	int vcpuid;
1540 	cpuset_t dmask;
1541 
1542 	if (delmode != IOART_DELFIXED &&
1543 	    delmode != IOART_DELLOPRI &&
1544 	    delmode != IOART_DELEXINT) {
1545 		VM_CTR1(vm, "vlapic intr invalid delmode %#x", delmode);
1546 		return;
1547 	}
1548 	lowprio = (delmode == IOART_DELLOPRI);
1549 
1550 	/*
1551 	 * We don't provide any virtual interrupt redirection hardware so
1552 	 * all interrupts originating from the ioapic or MSI specify the
1553 	 * 'dest' in the legacy xAPIC format.
1554 	 */
1555 	vlapic_calcdest(vm, &dmask, dest, phys, lowprio, false);
1556 
1557 	while ((vcpuid = CPU_FFS(&dmask)) != 0) {
1558 		vcpuid--;
1559 		CPU_CLR(vcpuid, &dmask);
1560 		if (delmode == IOART_DELEXINT) {
1561 			vm_inject_extint(vm, vcpuid);
1562 		} else {
1563 			lapic_set_intr(vm, vcpuid, vec, level);
1564 		}
1565 	}
1566 }
1567 
1568 void
1569 vlapic_post_intr(struct vlapic *vlapic, int hostcpu, int ipinum)
1570 {
1571 	/*
1572 	 * Post an interrupt to the vcpu currently running on 'hostcpu'.
1573 	 *
1574 	 * This is done by leveraging features like Posted Interrupts (Intel)
1575 	 * Doorbell MSR (AMD AVIC) that avoid a VM exit.
1576 	 *
1577 	 * If neither of these features are available then fallback to
1578 	 * sending an IPI to 'hostcpu'.
1579 	 */
1580 	if (vlapic->ops.post_intr)
1581 		(*vlapic->ops.post_intr)(vlapic, hostcpu);
1582 	else
1583 		ipi_cpu(hostcpu, ipinum);
1584 }
1585 
1586 bool
1587 vlapic_enabled(struct vlapic *vlapic)
1588 {
1589 	struct LAPIC *lapic = vlapic->apic_page;
1590 
1591 	if ((vlapic->msr_apicbase & APICBASE_ENABLED) != 0 &&
1592 	    (lapic->svr & APIC_SVR_ENABLE) != 0)
1593 		return (true);
1594 	else
1595 		return (false);
1596 }
1597 
1598 static void
1599 vlapic_set_tmr(struct vlapic *vlapic, int vector, bool level)
1600 {
1601 	struct LAPIC *lapic;
1602 	uint32_t *tmrptr, mask;
1603 	int idx;
1604 
1605 	lapic = vlapic->apic_page;
1606 	tmrptr = &lapic->tmr0;
1607 	idx = (vector / 32) * 4;
1608 	mask = 1 << (vector % 32);
1609 	if (level)
1610 		tmrptr[idx] |= mask;
1611 	else
1612 		tmrptr[idx] &= ~mask;
1613 
1614 	if (vlapic->ops.set_tmr != NULL)
1615 		(*vlapic->ops.set_tmr)(vlapic, vector, level);
1616 }
1617 
1618 void
1619 vlapic_reset_tmr(struct vlapic *vlapic)
1620 {
1621 	int vector;
1622 
1623 	VLAPIC_CTR0(vlapic, "vlapic resetting all vectors to edge-triggered");
1624 
1625 	for (vector = 0; vector <= 255; vector++)
1626 		vlapic_set_tmr(vlapic, vector, false);
1627 }
1628 
1629 void
1630 vlapic_set_tmr_level(struct vlapic *vlapic, uint32_t dest, bool phys,
1631     int delmode, int vector)
1632 {
1633 	cpuset_t dmask;
1634 	bool lowprio;
1635 
1636 	KASSERT(vector >= 0 && vector <= 255, ("invalid vector %d", vector));
1637 
1638 	/*
1639 	 * A level trigger is valid only for fixed and lowprio delivery modes.
1640 	 */
1641 	if (delmode != APIC_DELMODE_FIXED && delmode != APIC_DELMODE_LOWPRIO) {
1642 		VLAPIC_CTR1(vlapic, "Ignoring level trigger-mode for "
1643 		    "delivery-mode %d", delmode);
1644 		return;
1645 	}
1646 
1647 	lowprio = (delmode == APIC_DELMODE_LOWPRIO);
1648 	vlapic_calcdest(vlapic->vm, &dmask, dest, phys, lowprio, false);
1649 
1650 	if (!CPU_ISSET(vlapic->vcpuid, &dmask))
1651 		return;
1652 
1653 	VLAPIC_CTR1(vlapic, "vector %d set to level-triggered", vector);
1654 	vlapic_set_tmr(vlapic, vector, true);
1655 }
1656 
1657 #ifdef BHYVE_SNAPSHOT
1658 static void
1659 vlapic_reset_callout(struct vlapic *vlapic, uint32_t ccr)
1660 {
1661 	/* The implementation is similar to the one in the
1662 	 * `vlapic_icrtmr_write_handler` function
1663 	 */
1664 	sbintime_t sbt;
1665 	struct bintime bt;
1666 
1667 	VLAPIC_TIMER_LOCK(vlapic);
1668 
1669 	bt = vlapic->timer_freq_bt;
1670 	bintime_mul(&bt, ccr);
1671 
1672 	if (ccr != 0) {
1673 		binuptime(&vlapic->timer_fire_bt);
1674 		bintime_add(&vlapic->timer_fire_bt, &bt);
1675 
1676 		sbt = bttosbt(bt);
1677 		callout_reset_sbt(&vlapic->callout, sbt, 0,
1678 		    vlapic_callout_handler, vlapic, 0);
1679 	} else {
1680 		/* even if the CCR was 0, periodic timers should be reset */
1681 		if (vlapic_periodic_timer(vlapic)) {
1682 			binuptime(&vlapic->timer_fire_bt);
1683 			bintime_add(&vlapic->timer_fire_bt,
1684 				    &vlapic->timer_period_bt);
1685 			sbt = bttosbt(vlapic->timer_period_bt);
1686 
1687 			callout_stop(&vlapic->callout);
1688 			callout_reset_sbt(&vlapic->callout, sbt, 0,
1689 					  vlapic_callout_handler, vlapic, 0);
1690 		}
1691 	}
1692 
1693 	VLAPIC_TIMER_UNLOCK(vlapic);
1694 }
1695 
1696 int
1697 vlapic_snapshot(struct vm *vm, struct vm_snapshot_meta *meta)
1698 {
1699 	int i, ret;
1700 	struct vlapic *vlapic;
1701 	struct LAPIC *lapic;
1702 	uint32_t ccr;
1703 
1704 	KASSERT(vm != NULL, ("%s: arg was NULL", __func__));
1705 
1706 	ret = 0;
1707 
1708 	for (i = 0; i < VM_MAXCPU; i++) {
1709 		vlapic = vm_lapic(vm, i);
1710 
1711 		/* snapshot the page first; timer period depends on icr_timer */
1712 		lapic = vlapic->apic_page;
1713 		SNAPSHOT_BUF_OR_LEAVE(lapic, PAGE_SIZE, meta, ret, done);
1714 
1715 		SNAPSHOT_VAR_OR_LEAVE(vlapic->esr_pending, meta, ret, done);
1716 
1717 		SNAPSHOT_VAR_OR_LEAVE(vlapic->timer_freq_bt.sec,
1718 				      meta, ret, done);
1719 		SNAPSHOT_VAR_OR_LEAVE(vlapic->timer_freq_bt.frac,
1720 				      meta, ret, done);
1721 
1722 		/*
1723 		 * Timer period is equal to 'icr_timer' ticks at a frequency of
1724 		 * 'timer_freq_bt'.
1725 		 */
1726 		if (meta->op == VM_SNAPSHOT_RESTORE) {
1727 			vlapic->timer_period_bt = vlapic->timer_freq_bt;
1728 			bintime_mul(&vlapic->timer_period_bt, lapic->icr_timer);
1729 		}
1730 
1731 		SNAPSHOT_BUF_OR_LEAVE(vlapic->isrvec_stk,
1732 				      sizeof(vlapic->isrvec_stk),
1733 				      meta, ret, done);
1734 		SNAPSHOT_VAR_OR_LEAVE(vlapic->isrvec_stk_top, meta, ret, done);
1735 		SNAPSHOT_VAR_OR_LEAVE(vlapic->boot_state, meta, ret, done);
1736 
1737 		SNAPSHOT_BUF_OR_LEAVE(vlapic->lvt_last,
1738 				      sizeof(vlapic->lvt_last),
1739 				      meta, ret, done);
1740 
1741 		if (meta->op == VM_SNAPSHOT_SAVE)
1742 			ccr = vlapic_get_ccr(vlapic);
1743 
1744 		SNAPSHOT_VAR_OR_LEAVE(ccr, meta, ret, done);
1745 
1746 		if (meta->op == VM_SNAPSHOT_RESTORE) {
1747 			/* Reset the value of the 'timer_fire_bt' and the vlapic
1748 			 * callout based on the value of the current count
1749 			 * register saved when the VM snapshot was created
1750 			 */
1751 			vlapic_reset_callout(vlapic, ccr);
1752 		}
1753 	}
1754 
1755 done:
1756 	return (ret);
1757 }
1758 #endif
1759