xref: /freebsd/sys/amd64/vmm/io/vioapic.c (revision 7899f917b1c0ea178f1d2be0cfb452086d079d23)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2013 Tycho Nightingale <tycho.nightingale@pluribusnetworks.com>
5  * Copyright (c) 2013 Neel Natu <neel@freebsd.org>
6  * All rights reserved.
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/queue.h>
35 #include <sys/lock.h>
36 #include <sys/mutex.h>
37 #include <sys/systm.h>
38 #include <sys/kernel.h>
39 #include <sys/malloc.h>
40 
41 #include <x86/apicreg.h>
42 #include <machine/vmm.h>
43 #include <machine/vmm_snapshot.h>
44 
45 #include <dev/vmm/vmm_ktr.h>
46 
47 #include "vmm_lapic.h"
48 #include "vlapic.h"
49 #include "vioapic.h"
50 
51 #define	IOREGSEL	0x00
52 #define	IOWIN		0x10
53 
54 #define	REDIR_ENTRIES	32
55 #define	RTBL_RO_BITS	((uint64_t)(IOART_REM_IRR | IOART_DELIVS))
56 
57 struct vioapic {
58 	struct vm	*vm;
59 	struct mtx	mtx;
60 	uint32_t	id;
61 	uint32_t	ioregsel;
62 	struct {
63 		uint64_t reg;
64 		int	 acnt;	/* sum of pin asserts (+1) and deasserts (-1) */
65 	} rtbl[REDIR_ENTRIES];
66 };
67 
68 #define	VIOAPIC_LOCK(vioapic)		mtx_lock_spin(&((vioapic)->mtx))
69 #define	VIOAPIC_UNLOCK(vioapic)		mtx_unlock_spin(&((vioapic)->mtx))
70 #define	VIOAPIC_LOCKED(vioapic)		mtx_owned(&((vioapic)->mtx))
71 
72 static MALLOC_DEFINE(M_VIOAPIC, "vioapic", "bhyve virtual ioapic");
73 
74 #define	VIOAPIC_CTR1(vioapic, fmt, a1)					\
75 	VM_CTR1((vioapic)->vm, fmt, a1)
76 
77 #define	VIOAPIC_CTR2(vioapic, fmt, a1, a2)				\
78 	VM_CTR2((vioapic)->vm, fmt, a1, a2)
79 
80 #define	VIOAPIC_CTR3(vioapic, fmt, a1, a2, a3)				\
81 	VM_CTR3((vioapic)->vm, fmt, a1, a2, a3)
82 
83 #define	VIOAPIC_CTR4(vioapic, fmt, a1, a2, a3, a4)			\
84 	VM_CTR4((vioapic)->vm, fmt, a1, a2, a3, a4)
85 
86 #ifdef KTR
87 static const char *
88 pinstate_str(bool asserted)
89 {
90 
91 	if (asserted)
92 		return ("asserted");
93 	else
94 		return ("deasserted");
95 }
96 #endif
97 
98 static void
99 vioapic_send_intr(struct vioapic *vioapic, int pin)
100 {
101 	int vector, delmode;
102 	uint32_t low, high, dest;
103 	bool level, phys;
104 
105 	KASSERT(pin >= 0 && pin < REDIR_ENTRIES,
106 	    ("vioapic_set_pinstate: invalid pin number %d", pin));
107 
108 	KASSERT(VIOAPIC_LOCKED(vioapic),
109 	    ("vioapic_set_pinstate: vioapic is not locked"));
110 
111 	low = vioapic->rtbl[pin].reg;
112 	high = vioapic->rtbl[pin].reg >> 32;
113 
114 	if ((low & IOART_INTMASK) == IOART_INTMSET) {
115 		VIOAPIC_CTR1(vioapic, "ioapic pin%d: masked", pin);
116 		return;
117 	}
118 
119 	phys = ((low & IOART_DESTMOD) == IOART_DESTPHY);
120 	delmode = low & IOART_DELMOD;
121 	level = low & IOART_TRGRLVL ? true : false;
122 	if (level) {
123 		if ((low & IOART_REM_IRR) != 0) {
124 			VIOAPIC_CTR1(vioapic, "ioapic pin%d: irr pending",
125 			    pin);
126 			return;
127 		}
128 		vioapic->rtbl[pin].reg |= IOART_REM_IRR;
129 	}
130 
131 	vector = low & IOART_INTVEC;
132 	dest = high >> APIC_ID_SHIFT;
133 	vlapic_deliver_intr(vioapic->vm, level, dest, phys, delmode, vector);
134 }
135 
136 static void
137 vioapic_set_pinstate(struct vioapic *vioapic, int pin, bool newstate)
138 {
139 	int oldcnt, newcnt;
140 	bool needintr;
141 
142 	KASSERT(pin >= 0 && pin < REDIR_ENTRIES,
143 	    ("vioapic_set_pinstate: invalid pin number %d", pin));
144 
145 	KASSERT(VIOAPIC_LOCKED(vioapic),
146 	    ("vioapic_set_pinstate: vioapic is not locked"));
147 
148 	oldcnt = vioapic->rtbl[pin].acnt;
149 	if (newstate)
150 		vioapic->rtbl[pin].acnt++;
151 	else
152 		vioapic->rtbl[pin].acnt--;
153 	newcnt = vioapic->rtbl[pin].acnt;
154 
155 	if (newcnt < 0) {
156 		VIOAPIC_CTR2(vioapic, "ioapic pin%d: bad acnt %d",
157 		    pin, newcnt);
158 	}
159 
160 	needintr = false;
161 	if (oldcnt == 0 && newcnt == 1) {
162 		needintr = true;
163 		VIOAPIC_CTR1(vioapic, "ioapic pin%d: asserted", pin);
164 	} else if (oldcnt == 1 && newcnt == 0) {
165 		VIOAPIC_CTR1(vioapic, "ioapic pin%d: deasserted", pin);
166 	} else {
167 		VIOAPIC_CTR3(vioapic, "ioapic pin%d: %s, ignored, acnt %d",
168 		    pin, pinstate_str(newstate), newcnt);
169 	}
170 
171 	if (needintr)
172 		vioapic_send_intr(vioapic, pin);
173 }
174 
175 enum irqstate {
176 	IRQSTATE_ASSERT,
177 	IRQSTATE_DEASSERT,
178 	IRQSTATE_PULSE
179 };
180 
181 static int
182 vioapic_set_irqstate(struct vm *vm, int irq, enum irqstate irqstate)
183 {
184 	struct vioapic *vioapic;
185 
186 	if (irq < 0 || irq >= REDIR_ENTRIES)
187 		return (EINVAL);
188 
189 	vioapic = vm_ioapic(vm);
190 
191 	VIOAPIC_LOCK(vioapic);
192 	switch (irqstate) {
193 	case IRQSTATE_ASSERT:
194 		vioapic_set_pinstate(vioapic, irq, true);
195 		break;
196 	case IRQSTATE_DEASSERT:
197 		vioapic_set_pinstate(vioapic, irq, false);
198 		break;
199 	case IRQSTATE_PULSE:
200 		vioapic_set_pinstate(vioapic, irq, true);
201 		vioapic_set_pinstate(vioapic, irq, false);
202 		break;
203 	default:
204 		panic("vioapic_set_irqstate: invalid irqstate %d", irqstate);
205 	}
206 	VIOAPIC_UNLOCK(vioapic);
207 
208 	return (0);
209 }
210 
211 int
212 vioapic_assert_irq(struct vm *vm, int irq)
213 {
214 
215 	return (vioapic_set_irqstate(vm, irq, IRQSTATE_ASSERT));
216 }
217 
218 int
219 vioapic_deassert_irq(struct vm *vm, int irq)
220 {
221 
222 	return (vioapic_set_irqstate(vm, irq, IRQSTATE_DEASSERT));
223 }
224 
225 int
226 vioapic_pulse_irq(struct vm *vm, int irq)
227 {
228 
229 	return (vioapic_set_irqstate(vm, irq, IRQSTATE_PULSE));
230 }
231 
232 /*
233  * Reset the vlapic's trigger-mode register to reflect the ioapic pin
234  * configuration.
235  */
236 static void
237 vioapic_update_tmr(struct vcpu *vcpu, void *arg)
238 {
239 	struct vioapic *vioapic;
240 	struct vlapic *vlapic;
241 	uint32_t low, high, dest;
242 	int delmode, pin, vector;
243 	bool level, phys;
244 
245 	vlapic = vm_lapic(vcpu);
246 	vioapic = vm_ioapic(vcpu_vm(vcpu));
247 
248 	VIOAPIC_LOCK(vioapic);
249 	/*
250 	 * Reset all vectors to be edge-triggered.
251 	 */
252 	vlapic_reset_tmr(vlapic);
253 	for (pin = 0; pin < REDIR_ENTRIES; pin++) {
254 		low = vioapic->rtbl[pin].reg;
255 		high = vioapic->rtbl[pin].reg >> 32;
256 
257 		level = low & IOART_TRGRLVL ? true : false;
258 		if (!level)
259 			continue;
260 
261 		/*
262 		 * For a level-triggered 'pin' let the vlapic figure out if
263 		 * an assertion on this 'pin' would result in an interrupt
264 		 * being delivered to it. If yes, then it will modify the
265 		 * TMR bit associated with this vector to level-triggered.
266 		 */
267 		phys = ((low & IOART_DESTMOD) == IOART_DESTPHY);
268 		delmode = low & IOART_DELMOD;
269 		vector = low & IOART_INTVEC;
270 		dest = high >> APIC_ID_SHIFT;
271 		vlapic_set_tmr_level(vlapic, dest, phys, delmode, vector);
272 	}
273 	VIOAPIC_UNLOCK(vioapic);
274 }
275 
276 static uint32_t
277 vioapic_read(struct vioapic *vioapic, struct vcpu *vcpu, uint32_t addr)
278 {
279 	int regnum, pin, rshift;
280 
281 	regnum = addr & 0xff;
282 	switch (regnum) {
283 	case IOAPIC_ID:
284 		return (vioapic->id);
285 		break;
286 	case IOAPIC_VER:
287 		return (((REDIR_ENTRIES - 1) << MAXREDIRSHIFT) | 0x11);
288 		break;
289 	case IOAPIC_ARB:
290 		return (vioapic->id);
291 		break;
292 	default:
293 		break;
294 	}
295 
296 	/* redirection table entries */
297 	if (regnum >= IOAPIC_REDTBL &&
298 	    regnum < IOAPIC_REDTBL + REDIR_ENTRIES * 2) {
299 		pin = (regnum - IOAPIC_REDTBL) / 2;
300 		if ((regnum - IOAPIC_REDTBL) % 2)
301 			rshift = 32;
302 		else
303 			rshift = 0;
304 
305 		return (vioapic->rtbl[pin].reg >> rshift);
306 	}
307 
308 	return (0);
309 }
310 
311 static void
312 vioapic_write(struct vioapic *vioapic, struct vcpu *vcpu, uint32_t addr,
313     uint32_t data)
314 {
315 	uint64_t data64, mask64;
316 	uint64_t last, changed;
317 	int regnum, pin, lshift;
318 	cpuset_t allvcpus;
319 
320 	regnum = addr & 0xff;
321 	switch (regnum) {
322 	case IOAPIC_ID:
323 		vioapic->id = data & APIC_ID_MASK;
324 		break;
325 	case IOAPIC_VER:
326 	case IOAPIC_ARB:
327 		/* readonly */
328 		break;
329 	default:
330 		break;
331 	}
332 
333 	/* redirection table entries */
334 	if (regnum >= IOAPIC_REDTBL &&
335 	    regnum < IOAPIC_REDTBL + REDIR_ENTRIES * 2) {
336 		pin = (regnum - IOAPIC_REDTBL) / 2;
337 		if ((regnum - IOAPIC_REDTBL) % 2)
338 			lshift = 32;
339 		else
340 			lshift = 0;
341 
342 		last = vioapic->rtbl[pin].reg;
343 
344 		data64 = (uint64_t)data << lshift;
345 		mask64 = (uint64_t)0xffffffff << lshift;
346 		vioapic->rtbl[pin].reg &= ~mask64 | RTBL_RO_BITS;
347 		vioapic->rtbl[pin].reg |= data64 & ~RTBL_RO_BITS;
348 
349 		/*
350 		 * Switching from level to edge triggering will clear the IRR
351 		 * bit. This is what FreeBSD will do in order to EOI an
352 		 * interrupt when the IO-APIC doesn't support targeted EOI (see
353 		 * _ioapic_eoi_source).
354 		 */
355 		if ((vioapic->rtbl[pin].reg & IOART_TRGRMOD) == IOART_TRGREDG &&
356 		    (vioapic->rtbl[pin].reg & IOART_REM_IRR) != 0)
357 			vioapic->rtbl[pin].reg &= ~IOART_REM_IRR;
358 
359 		VIOAPIC_CTR2(vioapic, "ioapic pin%d: redir table entry %#lx",
360 		    pin, vioapic->rtbl[pin].reg);
361 
362 		/*
363 		 * If any fields in the redirection table entry (except mask
364 		 * or polarity) have changed then rendezvous all the vcpus
365 		 * to update their vlapic trigger-mode registers.
366 		 */
367 		changed = last ^ vioapic->rtbl[pin].reg;
368 		if (changed & ~(IOART_INTMASK | IOART_INTPOL)) {
369 			VIOAPIC_CTR1(vioapic, "ioapic pin%d: recalculate "
370 			    "vlapic trigger-mode register", pin);
371 			VIOAPIC_UNLOCK(vioapic);
372 			allvcpus = vm_active_cpus(vioapic->vm);
373 			(void)vm_smp_rendezvous(vcpu, allvcpus,
374 			    vioapic_update_tmr, NULL);
375 			VIOAPIC_LOCK(vioapic);
376 		}
377 
378 		/*
379 		 * Generate an interrupt if the following conditions are met:
380 		 * - pin trigger mode is level
381 		 * - pin level is asserted
382 		 */
383 		if ((vioapic->rtbl[pin].reg & IOART_TRGRMOD) == IOART_TRGRLVL &&
384 		    (vioapic->rtbl[pin].acnt > 0)) {
385 			VIOAPIC_CTR2(vioapic, "ioapic pin%d: asserted at rtbl "
386 			    "write, acnt %d", pin, vioapic->rtbl[pin].acnt);
387 			vioapic_send_intr(vioapic, pin);
388 		}
389 	}
390 }
391 
392 static int
393 vioapic_mmio_rw(struct vioapic *vioapic, struct vcpu *vcpu, uint64_t gpa,
394     uint64_t *data, int size, bool doread)
395 {
396 	uint64_t offset;
397 
398 	offset = gpa - VIOAPIC_BASE;
399 
400 	/*
401 	 * The IOAPIC specification allows 32-bit wide accesses to the
402 	 * IOREGSEL (offset 0) and IOWIN (offset 16) registers.
403 	 */
404 	if (size != 4 || (offset != IOREGSEL && offset != IOWIN)) {
405 		if (doread)
406 			*data = 0;
407 		return (0);
408 	}
409 
410 	VIOAPIC_LOCK(vioapic);
411 	if (offset == IOREGSEL) {
412 		if (doread)
413 			*data = vioapic->ioregsel;
414 		else
415 			vioapic->ioregsel = *data;
416 	} else {
417 		if (doread) {
418 			*data = vioapic_read(vioapic, vcpu,
419 			    vioapic->ioregsel);
420 		} else {
421 			vioapic_write(vioapic, vcpu, vioapic->ioregsel,
422 			    *data);
423 		}
424 	}
425 	VIOAPIC_UNLOCK(vioapic);
426 
427 	return (0);
428 }
429 
430 int
431 vioapic_mmio_read(struct vcpu *vcpu, uint64_t gpa, uint64_t *rval,
432     int size, void *arg)
433 {
434 	int error;
435 	struct vioapic *vioapic;
436 
437 	vioapic = vm_ioapic(vcpu_vm(vcpu));
438 	error = vioapic_mmio_rw(vioapic, vcpu, gpa, rval, size, true);
439 	return (error);
440 }
441 
442 int
443 vioapic_mmio_write(struct vcpu *vcpu, uint64_t gpa, uint64_t wval,
444     int size, void *arg)
445 {
446 	int error;
447 	struct vioapic *vioapic;
448 
449 	vioapic = vm_ioapic(vcpu_vm(vcpu));
450 	error = vioapic_mmio_rw(vioapic, vcpu, gpa, &wval, size, false);
451 	return (error);
452 }
453 
454 void
455 vioapic_process_eoi(struct vm *vm, int vector)
456 {
457 	struct vioapic *vioapic;
458 	int pin;
459 
460 	KASSERT(vector >= 0 && vector < 256,
461 	    ("vioapic_process_eoi: invalid vector %d", vector));
462 
463 	vioapic = vm_ioapic(vm);
464 	VIOAPIC_CTR1(vioapic, "ioapic processing eoi for vector %d", vector);
465 
466 	/*
467 	 * XXX keep track of the pins associated with this vector instead
468 	 * of iterating on every single pin each time.
469 	 */
470 	VIOAPIC_LOCK(vioapic);
471 	for (pin = 0; pin < REDIR_ENTRIES; pin++) {
472 		if ((vioapic->rtbl[pin].reg & IOART_REM_IRR) == 0)
473 			continue;
474 		if ((vioapic->rtbl[pin].reg & IOART_INTVEC) != vector)
475 			continue;
476 		vioapic->rtbl[pin].reg &= ~IOART_REM_IRR;
477 		if (vioapic->rtbl[pin].acnt > 0) {
478 			VIOAPIC_CTR2(vioapic, "ioapic pin%d: asserted at eoi, "
479 			    "acnt %d", pin, vioapic->rtbl[pin].acnt);
480 			vioapic_send_intr(vioapic, pin);
481 		}
482 	}
483 	VIOAPIC_UNLOCK(vioapic);
484 }
485 
486 struct vioapic *
487 vioapic_init(struct vm *vm)
488 {
489 	int i;
490 	struct vioapic *vioapic;
491 
492 	vioapic = malloc(sizeof(struct vioapic), M_VIOAPIC, M_WAITOK | M_ZERO);
493 
494 	vioapic->vm = vm;
495 	mtx_init(&vioapic->mtx, "vioapic lock", NULL, MTX_SPIN);
496 
497 	/* Initialize all redirection entries to mask all interrupts */
498 	for (i = 0; i < REDIR_ENTRIES; i++)
499 		vioapic->rtbl[i].reg = 0x0001000000010000UL;
500 
501 	return (vioapic);
502 }
503 
504 void
505 vioapic_cleanup(struct vioapic *vioapic)
506 {
507 
508 	mtx_destroy(&vioapic->mtx);
509 	free(vioapic, M_VIOAPIC);
510 }
511 
512 int
513 vioapic_pincount(struct vm *vm)
514 {
515 
516 	return (REDIR_ENTRIES);
517 }
518 
519 #ifdef BHYVE_SNAPSHOT
520 int
521 vioapic_snapshot(struct vioapic *vioapic, struct vm_snapshot_meta *meta)
522 {
523 	int ret;
524 	int i;
525 
526 	SNAPSHOT_VAR_OR_LEAVE(vioapic->ioregsel, meta, ret, done);
527 
528 	for (i = 0; i < nitems(vioapic->rtbl); i++) {
529 		SNAPSHOT_VAR_OR_LEAVE(vioapic->rtbl[i].reg, meta, ret, done);
530 		SNAPSHOT_VAR_OR_LEAVE(vioapic->rtbl[i].acnt, meta, ret, done);
531 	}
532 
533 done:
534 	return (ret);
535 }
536 #endif
537