xref: /freebsd/sys/amd64/vmm/io/vioapic.c (revision e17f5b1d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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  * $FreeBSD$
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/queue.h>
39 #include <sys/lock.h>
40 #include <sys/mutex.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/malloc.h>
44 
45 #include <x86/apicreg.h>
46 #include <machine/vmm.h>
47 #include <machine/vmm_snapshot.h>
48 
49 #include "vmm_ktr.h"
50 #include "vmm_lapic.h"
51 #include "vlapic.h"
52 #include "vioapic.h"
53 
54 #define	IOREGSEL	0x00
55 #define	IOWIN		0x10
56 
57 #define	REDIR_ENTRIES	32
58 #define	RTBL_RO_BITS	((uint64_t)(IOART_REM_IRR | IOART_DELIVS))
59 
60 struct vioapic {
61 	struct vm	*vm;
62 	struct mtx	mtx;
63 	uint32_t	id;
64 	uint32_t	ioregsel;
65 	struct {
66 		uint64_t reg;
67 		int	 acnt;	/* sum of pin asserts (+1) and deasserts (-1) */
68 	} rtbl[REDIR_ENTRIES];
69 };
70 
71 #define	VIOAPIC_LOCK(vioapic)		mtx_lock_spin(&((vioapic)->mtx))
72 #define	VIOAPIC_UNLOCK(vioapic)		mtx_unlock_spin(&((vioapic)->mtx))
73 #define	VIOAPIC_LOCKED(vioapic)		mtx_owned(&((vioapic)->mtx))
74 
75 static MALLOC_DEFINE(M_VIOAPIC, "vioapic", "bhyve virtual ioapic");
76 
77 #define	VIOAPIC_CTR1(vioapic, fmt, a1)					\
78 	VM_CTR1((vioapic)->vm, fmt, a1)
79 
80 #define	VIOAPIC_CTR2(vioapic, fmt, a1, a2)				\
81 	VM_CTR2((vioapic)->vm, fmt, a1, a2)
82 
83 #define	VIOAPIC_CTR3(vioapic, fmt, a1, a2, a3)				\
84 	VM_CTR3((vioapic)->vm, fmt, a1, a2, a3)
85 
86 #define	VIOAPIC_CTR4(vioapic, fmt, a1, a2, a3, a4)			\
87 	VM_CTR4((vioapic)->vm, fmt, a1, a2, a3, a4)
88 
89 #ifdef KTR
90 static const char *
91 pinstate_str(bool asserted)
92 {
93 
94 	if (asserted)
95 		return ("asserted");
96 	else
97 		return ("deasserted");
98 }
99 #endif
100 
101 static void
102 vioapic_send_intr(struct vioapic *vioapic, int pin)
103 {
104 	int vector, delmode;
105 	uint32_t low, high, dest;
106 	bool level, phys;
107 
108 	KASSERT(pin >= 0 && pin < REDIR_ENTRIES,
109 	    ("vioapic_set_pinstate: invalid pin number %d", pin));
110 
111 	KASSERT(VIOAPIC_LOCKED(vioapic),
112 	    ("vioapic_set_pinstate: vioapic is not locked"));
113 
114 	low = vioapic->rtbl[pin].reg;
115 	high = vioapic->rtbl[pin].reg >> 32;
116 
117 	if ((low & IOART_INTMASK) == IOART_INTMSET) {
118 		VIOAPIC_CTR1(vioapic, "ioapic pin%d: masked", pin);
119 		return;
120 	}
121 
122 	phys = ((low & IOART_DESTMOD) == IOART_DESTPHY);
123 	delmode = low & IOART_DELMOD;
124 	level = low & IOART_TRGRLVL ? true : false;
125 	if (level)
126 		vioapic->rtbl[pin].reg |= IOART_REM_IRR;
127 
128 	vector = low & IOART_INTVEC;
129 	dest = high >> APIC_ID_SHIFT;
130 	vlapic_deliver_intr(vioapic->vm, level, dest, phys, delmode, vector);
131 }
132 
133 static void
134 vioapic_set_pinstate(struct vioapic *vioapic, int pin, bool newstate)
135 {
136 	int oldcnt, newcnt;
137 	bool needintr;
138 
139 	KASSERT(pin >= 0 && pin < REDIR_ENTRIES,
140 	    ("vioapic_set_pinstate: invalid pin number %d", pin));
141 
142 	KASSERT(VIOAPIC_LOCKED(vioapic),
143 	    ("vioapic_set_pinstate: vioapic is not locked"));
144 
145 	oldcnt = vioapic->rtbl[pin].acnt;
146 	if (newstate)
147 		vioapic->rtbl[pin].acnt++;
148 	else
149 		vioapic->rtbl[pin].acnt--;
150 	newcnt = vioapic->rtbl[pin].acnt;
151 
152 	if (newcnt < 0) {
153 		VIOAPIC_CTR2(vioapic, "ioapic pin%d: bad acnt %d",
154 		    pin, newcnt);
155 	}
156 
157 	needintr = false;
158 	if (oldcnt == 0 && newcnt == 1) {
159 		needintr = true;
160 		VIOAPIC_CTR1(vioapic, "ioapic pin%d: asserted", pin);
161 	} else if (oldcnt == 1 && newcnt == 0) {
162 		VIOAPIC_CTR1(vioapic, "ioapic pin%d: deasserted", pin);
163 	} else {
164 		VIOAPIC_CTR3(vioapic, "ioapic pin%d: %s, ignored, acnt %d",
165 		    pin, pinstate_str(newstate), newcnt);
166 	}
167 
168 	if (needintr)
169 		vioapic_send_intr(vioapic, pin);
170 }
171 
172 enum irqstate {
173 	IRQSTATE_ASSERT,
174 	IRQSTATE_DEASSERT,
175 	IRQSTATE_PULSE
176 };
177 
178 static int
179 vioapic_set_irqstate(struct vm *vm, int irq, enum irqstate irqstate)
180 {
181 	struct vioapic *vioapic;
182 
183 	if (irq < 0 || irq >= REDIR_ENTRIES)
184 		return (EINVAL);
185 
186 	vioapic = vm_ioapic(vm);
187 
188 	VIOAPIC_LOCK(vioapic);
189 	switch (irqstate) {
190 	case IRQSTATE_ASSERT:
191 		vioapic_set_pinstate(vioapic, irq, true);
192 		break;
193 	case IRQSTATE_DEASSERT:
194 		vioapic_set_pinstate(vioapic, irq, false);
195 		break;
196 	case IRQSTATE_PULSE:
197 		vioapic_set_pinstate(vioapic, irq, true);
198 		vioapic_set_pinstate(vioapic, irq, false);
199 		break;
200 	default:
201 		panic("vioapic_set_irqstate: invalid irqstate %d", irqstate);
202 	}
203 	VIOAPIC_UNLOCK(vioapic);
204 
205 	return (0);
206 }
207 
208 int
209 vioapic_assert_irq(struct vm *vm, int irq)
210 {
211 
212 	return (vioapic_set_irqstate(vm, irq, IRQSTATE_ASSERT));
213 }
214 
215 int
216 vioapic_deassert_irq(struct vm *vm, int irq)
217 {
218 
219 	return (vioapic_set_irqstate(vm, irq, IRQSTATE_DEASSERT));
220 }
221 
222 int
223 vioapic_pulse_irq(struct vm *vm, int irq)
224 {
225 
226 	return (vioapic_set_irqstate(vm, irq, IRQSTATE_PULSE));
227 }
228 
229 /*
230  * Reset the vlapic's trigger-mode register to reflect the ioapic pin
231  * configuration.
232  */
233 static void
234 vioapic_update_tmr(struct vm *vm, int vcpuid, void *arg)
235 {
236 	struct vioapic *vioapic;
237 	struct vlapic *vlapic;
238 	uint32_t low, high, dest;
239 	int delmode, pin, vector;
240 	bool level, phys;
241 
242 	vlapic = vm_lapic(vm, vcpuid);
243 	vioapic = vm_ioapic(vm);
244 
245 	VIOAPIC_LOCK(vioapic);
246 	/*
247 	 * Reset all vectors to be edge-triggered.
248 	 */
249 	vlapic_reset_tmr(vlapic);
250 	for (pin = 0; pin < REDIR_ENTRIES; pin++) {
251 		low = vioapic->rtbl[pin].reg;
252 		high = vioapic->rtbl[pin].reg >> 32;
253 
254 		level = low & IOART_TRGRLVL ? true : false;
255 		if (!level)
256 			continue;
257 
258 		/*
259 		 * For a level-triggered 'pin' let the vlapic figure out if
260 		 * an assertion on this 'pin' would result in an interrupt
261 		 * being delivered to it. If yes, then it will modify the
262 		 * TMR bit associated with this vector to level-triggered.
263 		 */
264 		phys = ((low & IOART_DESTMOD) == IOART_DESTPHY);
265 		delmode = low & IOART_DELMOD;
266 		vector = low & IOART_INTVEC;
267 		dest = high >> APIC_ID_SHIFT;
268 		vlapic_set_tmr_level(vlapic, dest, phys, delmode, vector);
269 	}
270 	VIOAPIC_UNLOCK(vioapic);
271 }
272 
273 static uint32_t
274 vioapic_read(struct vioapic *vioapic, int vcpuid, uint32_t addr)
275 {
276 	int regnum, pin, rshift;
277 
278 	regnum = addr & 0xff;
279 	switch (regnum) {
280 	case IOAPIC_ID:
281 		return (vioapic->id);
282 		break;
283 	case IOAPIC_VER:
284 		return (((REDIR_ENTRIES - 1) << MAXREDIRSHIFT) | 0x11);
285 		break;
286 	case IOAPIC_ARB:
287 		return (vioapic->id);
288 		break;
289 	default:
290 		break;
291 	}
292 
293 	/* redirection table entries */
294 	if (regnum >= IOAPIC_REDTBL &&
295 	    regnum < IOAPIC_REDTBL + REDIR_ENTRIES * 2) {
296 		pin = (regnum - IOAPIC_REDTBL) / 2;
297 		if ((regnum - IOAPIC_REDTBL) % 2)
298 			rshift = 32;
299 		else
300 			rshift = 0;
301 
302 		return (vioapic->rtbl[pin].reg >> rshift);
303 	}
304 
305 	return (0);
306 }
307 
308 static void
309 vioapic_write(struct vioapic *vioapic, int vcpuid, uint32_t addr, uint32_t data)
310 {
311 	uint64_t data64, mask64;
312 	uint64_t last, changed;
313 	int regnum, pin, lshift;
314 	cpuset_t allvcpus;
315 
316 	regnum = addr & 0xff;
317 	switch (regnum) {
318 	case IOAPIC_ID:
319 		vioapic->id = data & APIC_ID_MASK;
320 		break;
321 	case IOAPIC_VER:
322 	case IOAPIC_ARB:
323 		/* readonly */
324 		break;
325 	default:
326 		break;
327 	}
328 
329 	/* redirection table entries */
330 	if (regnum >= IOAPIC_REDTBL &&
331 	    regnum < IOAPIC_REDTBL + REDIR_ENTRIES * 2) {
332 		pin = (regnum - IOAPIC_REDTBL) / 2;
333 		if ((regnum - IOAPIC_REDTBL) % 2)
334 			lshift = 32;
335 		else
336 			lshift = 0;
337 
338 		last = vioapic->rtbl[pin].reg;
339 
340 		data64 = (uint64_t)data << lshift;
341 		mask64 = (uint64_t)0xffffffff << lshift;
342 		vioapic->rtbl[pin].reg &= ~mask64 | RTBL_RO_BITS;
343 		vioapic->rtbl[pin].reg |= data64 & ~RTBL_RO_BITS;
344 
345 		VIOAPIC_CTR2(vioapic, "ioapic pin%d: redir table entry %#lx",
346 		    pin, vioapic->rtbl[pin].reg);
347 
348 		/*
349 		 * If any fields in the redirection table entry (except mask
350 		 * or polarity) have changed then rendezvous all the vcpus
351 		 * to update their vlapic trigger-mode registers.
352 		 */
353 		changed = last ^ vioapic->rtbl[pin].reg;
354 		if (changed & ~(IOART_INTMASK | IOART_INTPOL)) {
355 			VIOAPIC_CTR1(vioapic, "ioapic pin%d: recalculate "
356 			    "vlapic trigger-mode register", pin);
357 			VIOAPIC_UNLOCK(vioapic);
358 			allvcpus = vm_active_cpus(vioapic->vm);
359 			(void)vm_smp_rendezvous(vioapic->vm, vcpuid, allvcpus,
360 			    vioapic_update_tmr, NULL);
361 			VIOAPIC_LOCK(vioapic);
362 		}
363 
364 		/*
365 		 * Generate an interrupt if the following conditions are met:
366 		 * - pin is not masked
367 		 * - previous interrupt has been EOIed
368 		 * - pin level is asserted
369 		 */
370 		if ((vioapic->rtbl[pin].reg & IOART_INTMASK) == IOART_INTMCLR &&
371 		    (vioapic->rtbl[pin].reg & IOART_REM_IRR) == 0 &&
372 		    (vioapic->rtbl[pin].acnt > 0)) {
373 			VIOAPIC_CTR2(vioapic, "ioapic pin%d: asserted at rtbl "
374 			    "write, acnt %d", pin, vioapic->rtbl[pin].acnt);
375 			vioapic_send_intr(vioapic, pin);
376 		}
377 	}
378 }
379 
380 static int
381 vioapic_mmio_rw(struct vioapic *vioapic, int vcpuid, uint64_t gpa,
382     uint64_t *data, int size, bool doread)
383 {
384 	uint64_t offset;
385 
386 	offset = gpa - VIOAPIC_BASE;
387 
388 	/*
389 	 * The IOAPIC specification allows 32-bit wide accesses to the
390 	 * IOREGSEL (offset 0) and IOWIN (offset 16) registers.
391 	 */
392 	if (size != 4 || (offset != IOREGSEL && offset != IOWIN)) {
393 		if (doread)
394 			*data = 0;
395 		return (0);
396 	}
397 
398 	VIOAPIC_LOCK(vioapic);
399 	if (offset == IOREGSEL) {
400 		if (doread)
401 			*data = vioapic->ioregsel;
402 		else
403 			vioapic->ioregsel = *data;
404 	} else {
405 		if (doread) {
406 			*data = vioapic_read(vioapic, vcpuid,
407 			    vioapic->ioregsel);
408 		} else {
409 			vioapic_write(vioapic, vcpuid, vioapic->ioregsel,
410 			    *data);
411 		}
412 	}
413 	VIOAPIC_UNLOCK(vioapic);
414 
415 	return (0);
416 }
417 
418 int
419 vioapic_mmio_read(void *vm, int vcpuid, uint64_t gpa, uint64_t *rval,
420     int size, void *arg)
421 {
422 	int error;
423 	struct vioapic *vioapic;
424 
425 	vioapic = vm_ioapic(vm);
426 	error = vioapic_mmio_rw(vioapic, vcpuid, gpa, rval, size, true);
427 	return (error);
428 }
429 
430 int
431 vioapic_mmio_write(void *vm, int vcpuid, uint64_t gpa, uint64_t wval,
432     int size, void *arg)
433 {
434 	int error;
435 	struct vioapic *vioapic;
436 
437 	vioapic = vm_ioapic(vm);
438 	error = vioapic_mmio_rw(vioapic, vcpuid, gpa, &wval, size, false);
439 	return (error);
440 }
441 
442 void
443 vioapic_process_eoi(struct vm *vm, int vcpuid, int vector)
444 {
445 	struct vioapic *vioapic;
446 	int pin;
447 
448 	KASSERT(vector >= 0 && vector < 256,
449 	    ("vioapic_process_eoi: invalid vector %d", vector));
450 
451 	vioapic = vm_ioapic(vm);
452 	VIOAPIC_CTR1(vioapic, "ioapic processing eoi for vector %d", vector);
453 
454 	/*
455 	 * XXX keep track of the pins associated with this vector instead
456 	 * of iterating on every single pin each time.
457 	 */
458 	VIOAPIC_LOCK(vioapic);
459 	for (pin = 0; pin < REDIR_ENTRIES; pin++) {
460 		if ((vioapic->rtbl[pin].reg & IOART_REM_IRR) == 0)
461 			continue;
462 		if ((vioapic->rtbl[pin].reg & IOART_INTVEC) != vector)
463 			continue;
464 		vioapic->rtbl[pin].reg &= ~IOART_REM_IRR;
465 		if (vioapic->rtbl[pin].acnt > 0) {
466 			VIOAPIC_CTR2(vioapic, "ioapic pin%d: asserted at eoi, "
467 			    "acnt %d", pin, vioapic->rtbl[pin].acnt);
468 			vioapic_send_intr(vioapic, pin);
469 		}
470 	}
471 	VIOAPIC_UNLOCK(vioapic);
472 }
473 
474 struct vioapic *
475 vioapic_init(struct vm *vm)
476 {
477 	int i;
478 	struct vioapic *vioapic;
479 
480 	vioapic = malloc(sizeof(struct vioapic), M_VIOAPIC, M_WAITOK | M_ZERO);
481 
482 	vioapic->vm = vm;
483 	mtx_init(&vioapic->mtx, "vioapic lock", NULL, MTX_SPIN);
484 
485 	/* Initialize all redirection entries to mask all interrupts */
486 	for (i = 0; i < REDIR_ENTRIES; i++)
487 		vioapic->rtbl[i].reg = 0x0001000000010000UL;
488 
489 	return (vioapic);
490 }
491 
492 void
493 vioapic_cleanup(struct vioapic *vioapic)
494 {
495 
496 	free(vioapic, M_VIOAPIC);
497 }
498 
499 int
500 vioapic_pincount(struct vm *vm)
501 {
502 
503 	return (REDIR_ENTRIES);
504 }
505 
506 #ifdef BHYVE_SNAPSHOT
507 int
508 vioapic_snapshot(struct vioapic *vioapic, struct vm_snapshot_meta *meta)
509 {
510 	int ret;
511 	int i;
512 
513 	SNAPSHOT_VAR_OR_LEAVE(vioapic->ioregsel, meta, ret, done);
514 
515 	for (i = 0; i < nitems(vioapic->rtbl); i++) {
516 		SNAPSHOT_VAR_OR_LEAVE(vioapic->rtbl[i].reg, meta, ret, done);
517 		SNAPSHOT_VAR_OR_LEAVE(vioapic->rtbl[i].acnt, meta, ret, done);
518 	}
519 
520 done:
521 	return (ret);
522 }
523 #endif
524