xref: /netbsd-src/sys/dev/pci/virtio_pci.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /* $NetBSD: virtio_pci.c,v 1.11 2020/05/27 11:24:31 yamaguchi Exp $ */
2 
3 /*
4  * Copyright (c) 2010 Minoura Makoto.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: virtio_pci.c,v 1.11 2020/05/27 11:24:31 yamaguchi Exp $");
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/kmem.h>
34 #include <sys/module.h>
35 #include <sys/interrupt.h>
36 
37 #include <sys/device.h>
38 
39 #include <dev/pci/pcidevs.h>
40 #include <dev/pci/pcireg.h>
41 #include <dev/pci/pcivar.h>
42 
43 #define VIRTIO_PRIVATE
44 
45 #include <dev/pci/virtioreg.h> /* XXX: move to non-pci */
46 #include <dev/pci/virtiovar.h> /* XXX: move to non-pci */
47 
48 static int	virtio_pci_match(device_t, cfdata_t, void *);
49 static void	virtio_pci_attach(device_t, device_t, void *);
50 static int	virtio_pci_rescan(device_t, const char *, const int *);
51 static int	virtio_pci_detach(device_t, int);
52 
53 struct virtio_pci_softc {
54 	struct virtio_softc	sc_sc;
55 	bus_space_tag_t		sc_iot;
56 	bus_space_handle_t	sc_ioh;
57 	bus_size_t		sc_iosize;
58 	struct pci_attach_args	sc_pa;
59 	pci_intr_handle_t	*sc_ihp;
60 	void			**sc_ihs;
61 	int			sc_ihs_num;
62 	int			sc_config_offset;
63 };
64 
65 static void	virtio_pci_kick(struct virtio_softc *, uint16_t);
66 static uint8_t	virtio_pci_read_device_config_1(struct virtio_softc *, int);
67 static uint16_t	virtio_pci_read_device_config_2(struct virtio_softc *, int);
68 static uint32_t	virtio_pci_read_device_config_4(struct virtio_softc *, int);
69 static uint64_t	virtio_pci_read_device_config_8(struct virtio_softc *, int);
70 static void 	virtio_pci_write_device_config_1(struct virtio_softc *, int, uint8_t);
71 static void	virtio_pci_write_device_config_2(struct virtio_softc *, int, uint16_t);
72 static void	virtio_pci_write_device_config_4(struct virtio_softc *, int, uint32_t);
73 static void	virtio_pci_write_device_config_8(struct virtio_softc *, int, uint64_t);
74 static uint16_t	virtio_pci_read_queue_size(struct virtio_softc *, uint16_t);
75 static void	virtio_pci_setup_queue(struct virtio_softc *, uint16_t, uint32_t);
76 static void	virtio_pci_set_status(struct virtio_softc *, int);
77 static uint32_t	virtio_pci_negotiate_features(struct virtio_softc *, uint32_t);
78 static int	virtio_pci_setup_interrupts(struct virtio_softc *);
79 static void	virtio_pci_free_interrupts(struct virtio_softc *);
80 
81 static int	virtio_pci_intr(void *arg);
82 static int	virtio_pci_msix_queue_intr(void *);
83 static int	virtio_pci_msix_config_intr(void *);
84 static int	virtio_pci_setup_msix_vectors(struct virtio_softc *);
85 static int	virtio_pci_setup_msix_interrupts(struct virtio_softc *,
86 		    struct pci_attach_args *);
87 static int	virtio_pci_setup_intx_interrupt(struct virtio_softc *,
88 		    struct pci_attach_args *);
89 
90 #define VIRTIO_MSIX_CONFIG_VECTOR_INDEX	0
91 #define VIRTIO_MSIX_QUEUE_VECTOR_INDEX	1
92 
93 /* we use the legacy virtio spec, so the PCI registers are host native
94  * byte order, not PCI (i.e. LE) byte order */
95 #if BYTE_ORDER == BIG_ENDIAN
96 #define REG_HI_OFF      0
97 #define REG_LO_OFF      4
98 #ifndef __BUS_SPACE_HAS_STREAM_METHODS
99 #define bus_space_read_stream_1 bus_space_read_1
100 #define bus_space_write_stream_1 bus_space_write_1
101 static inline uint16_t
102 bus_space_read_stream_2(bus_space_tag_t t, bus_space_handle_t h,
103     bus_size_t o)
104 {
105 	return le16toh(bus_space_read_2(t, h, o));
106 }
107 static inline void
108 bus_space_write_stream_2(bus_space_tag_t t, bus_space_handle_t h,
109     bus_size_t o, uint16_t v)
110 {
111 	bus_space_write_2(t, h, o, htole16(v));
112 }
113 static inline uint32_t
114 bus_space_read_stream_4(bus_space_tag_t t, bus_space_handle_t h,
115     bus_size_t o)
116 {
117 	return le32toh(bus_space_read_4(t, h, o));
118 }
119 static inline void
120 bus_space_write_stream_4(bus_space_tag_t t, bus_space_handle_t h,
121     bus_size_t o, uint32_t v)
122 {
123 	bus_space_write_4(t, h, o, htole32(v));
124 }
125 #endif
126 #else
127 #define REG_HI_OFF	4
128 #define REG_LO_OFF	0
129 #ifndef __BUS_SPACE_HAS_STREAM_METHODS
130 #define bus_space_read_stream_1 bus_space_read_1
131 #define bus_space_read_stream_2 bus_space_read_2
132 #define bus_space_read_stream_4 bus_space_read_4
133 #define bus_space_write_stream_1 bus_space_write_1
134 #define bus_space_write_stream_2 bus_space_write_2
135 #define bus_space_write_stream_4 bus_space_write_4
136 #endif
137 #endif
138 
139 
140 static const char *virtio_device_name[] = {
141 	"Unknown (0)",			/* 0 */
142 	"Network",			/* 1 */
143 	"Block",			/* 2 */
144 	"Console",			/* 3 */
145 	"Entropy",			/* 4 */
146 	"Memory Balloon",		/* 5 */
147 	"I/O Memory",			/* 6 */
148 	"Remote Processor Messaging",	/* 7 */
149 	"SCSI",				/* 8 */
150 	"9P Transport",			/* 9 */
151 	"mac80211 wlan",		/* 10 */
152 };
153 #define NDEVNAMES	__arraycount(virtio_device_name)
154 
155 CFATTACH_DECL3_NEW(virtio_pci, sizeof(struct virtio_pci_softc),
156     virtio_pci_match, virtio_pci_attach, virtio_pci_detach, NULL,
157     virtio_pci_rescan, NULL, DVF_DETACH_SHUTDOWN);
158 
159 static const struct virtio_ops virtio_pci_ops = {
160 	.kick = virtio_pci_kick,
161 	.read_dev_cfg_1 = virtio_pci_read_device_config_1,
162 	.read_dev_cfg_2 = virtio_pci_read_device_config_2,
163 	.read_dev_cfg_4 = virtio_pci_read_device_config_4,
164 	.read_dev_cfg_8 = virtio_pci_read_device_config_8,
165 	.write_dev_cfg_1 = virtio_pci_write_device_config_1,
166 	.write_dev_cfg_2 = virtio_pci_write_device_config_2,
167 	.write_dev_cfg_4 = virtio_pci_write_device_config_4,
168 	.write_dev_cfg_8 = virtio_pci_write_device_config_8,
169 	.read_queue_size = virtio_pci_read_queue_size,
170 	.setup_queue = virtio_pci_setup_queue,
171 	.set_status = virtio_pci_set_status,
172 	.neg_features = virtio_pci_negotiate_features,
173 	.setup_interrupts = virtio_pci_setup_interrupts,
174 	.free_interrupts = virtio_pci_free_interrupts,
175 };
176 
177 static int
178 virtio_pci_match(device_t parent, cfdata_t match, void *aux)
179 {
180 	struct pci_attach_args *pa;
181 
182 	pa = (struct pci_attach_args *)aux;
183 	switch (PCI_VENDOR(pa->pa_id)) {
184 	case PCI_VENDOR_QUMRANET:
185 		if ((PCI_PRODUCT_QUMRANET_VIRTIO_1000 <=
186 		     PCI_PRODUCT(pa->pa_id)) &&
187 		    (PCI_PRODUCT(pa->pa_id) <=
188 		     PCI_PRODUCT_QUMRANET_VIRTIO_103F))
189 			return 1;
190 		break;
191 	}
192 
193 	return 0;
194 }
195 
196 static void
197 virtio_pci_attach(device_t parent, device_t self, void *aux)
198 {
199 	struct virtio_pci_softc * const psc = device_private(self);
200 	struct virtio_softc * const sc = &psc->sc_sc;
201 	struct pci_attach_args *pa = (struct pci_attach_args *)aux;
202 	pci_chipset_tag_t pc = pa->pa_pc;
203 	pcitag_t tag = pa->pa_tag;
204 	int revision;
205 	pcireg_t id;
206 	pcireg_t csr;
207 
208 	revision = PCI_REVISION(pa->pa_class);
209 	if (revision != 0) {
210 		aprint_normal(": unknown revision 0x%02x; giving up\n",
211 			      revision);
212 		return;
213 	}
214 	aprint_normal("\n");
215 	aprint_naive("\n");
216 
217 	/* subsystem ID shows what I am */
218 	id = pci_conf_read(pc, tag, PCI_SUBSYS_ID_REG);
219 	aprint_normal_dev(self, "Virtio %s Device (rev. 0x%02x)\n",
220 			  (PCI_SUBSYS_ID(id) < NDEVNAMES?
221 			   virtio_device_name[PCI_SUBSYS_ID(id)] : "Unknown"),
222 			  revision);
223 
224 	csr = pci_conf_read(pc, tag, PCI_COMMAND_STATUS_REG);
225 	csr |= PCI_COMMAND_MASTER_ENABLE | PCI_COMMAND_IO_ENABLE;
226 	pci_conf_write(pc, tag, PCI_COMMAND_STATUS_REG, csr);
227 
228 	sc->sc_dev = self;
229 	sc->sc_ops = &virtio_pci_ops;
230 	psc->sc_pa = *pa;
231 	psc->sc_iot = pa->pa_iot;
232 	if (pci_dma64_available(pa))
233 		sc->sc_dmat = pa->pa_dmat64;
234 	else
235 		sc->sc_dmat = pa->pa_dmat;
236 	psc->sc_config_offset = VIRTIO_CONFIG_DEVICE_CONFIG_NOMSI;
237 
238 	if (pci_mapreg_map(pa, PCI_MAPREG_START, PCI_MAPREG_TYPE_IO, 0,
239 			   &psc->sc_iot, &psc->sc_ioh, NULL, &psc->sc_iosize)) {
240 		aprint_error_dev(self, "can't map i/o space\n");
241 		return;
242 	}
243 
244 	virtio_device_reset(sc);
245 	virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_ACK);
246 	virtio_set_status(sc, VIRTIO_CONFIG_DEVICE_STATUS_DRIVER);
247 
248 	sc->sc_childdevid = PCI_SUBSYS_ID(id);
249 	sc->sc_child = NULL;
250 	virtio_pci_rescan(self, "virtio", 0);
251 	return;
252 }
253 
254 /* ARGSUSED */
255 static int
256 virtio_pci_rescan(device_t self, const char *attr, const int *scan_flags)
257 {
258 	struct virtio_pci_softc * const psc = device_private(self);
259 	struct virtio_softc * const sc = &psc->sc_sc;
260 	struct virtio_attach_args va;
261 
262 	if (sc->sc_child)	/* Child already attached? */
263 		return 0;
264 
265 	memset(&va, 0, sizeof(va));
266 	va.sc_childdevid = sc->sc_childdevid;
267 
268 	config_found_ia(self, attr, &va, NULL);
269 
270 	if (sc->sc_child == NULL) {
271 		aprint_error_dev(self,
272 				 "no matching child driver; not configured\n");
273 		return 0;
274 	}
275 
276 	if (sc->sc_child == VIRTIO_CHILD_FAILED) {
277 		aprint_error_dev(self,
278 				 "virtio configuration failed\n");
279 		return 0;
280 	}
281 
282 	/*
283 	 * Make sure child drivers initialize interrupts via call
284 	 * to virtio_child_attach_finish().
285 	 */
286 	KASSERT(psc->sc_ihs_num != 0);
287 
288 	return 0;
289 }
290 
291 
292 static int
293 virtio_pci_detach(device_t self, int flags)
294 {
295 	struct virtio_pci_softc * const psc = device_private(self);
296 	struct virtio_softc * const sc = &psc->sc_sc;
297 	int r;
298 
299 	if (sc->sc_child != NULL) {
300 		r = config_detach(sc->sc_child, flags);
301 		if (r)
302 			return r;
303 	}
304 
305 	/* Check that child detached properly */
306 	KASSERT(sc->sc_child == NULL);
307 	KASSERT(sc->sc_vqs == NULL);
308 	KASSERT(psc->sc_ihs_num == 0);
309 
310 	if (psc->sc_iosize)
311 		bus_space_unmap(psc->sc_iot, psc->sc_ioh, psc->sc_iosize);
312 	psc->sc_iosize = 0;
313 
314 	return 0;
315 }
316 
317 static void
318 virtio_pci_kick(struct virtio_softc *sc, uint16_t idx)
319 {
320 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
321 
322 	bus_space_write_stream_2(psc->sc_iot, psc->sc_ioh,
323 	    VIRTIO_CONFIG_QUEUE_NOTIFY, idx);
324 }
325 
326 static uint8_t
327 virtio_pci_read_device_config_1(struct virtio_softc *sc, int index)
328 {
329 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
330 	return bus_space_read_stream_1(psc->sc_iot, psc->sc_ioh,
331 	    psc->sc_config_offset + index);
332 }
333 
334 static uint16_t
335 virtio_pci_read_device_config_2(struct virtio_softc *sc, int index)
336 {
337 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
338 	return bus_space_read_stream_2(psc->sc_iot, psc->sc_ioh,
339 	    psc->sc_config_offset + index);
340 }
341 
342 static uint32_t
343 virtio_pci_read_device_config_4(struct virtio_softc *sc, int index)
344 {
345 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
346 	return bus_space_read_stream_4(psc->sc_iot, psc->sc_ioh,
347 	    psc->sc_config_offset + index);
348 }
349 
350 static uint64_t
351 virtio_pci_read_device_config_8(struct virtio_softc *sc, int index)
352 {
353 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
354 	uint64_t r;
355 
356 	r = bus_space_read_stream_4(psc->sc_iot, psc->sc_ioh,
357 	    psc->sc_config_offset + index + REG_HI_OFF);
358 	r <<= 32;
359 	r |= bus_space_read_stream_4(psc->sc_iot, psc->sc_ioh,
360 	    psc->sc_config_offset + index + REG_LO_OFF);
361 
362 	return r;
363 }
364 
365 static void
366 virtio_pci_write_device_config_1(struct virtio_softc *sc, int index,
367     uint8_t value)
368 {
369 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
370 
371 	bus_space_write_stream_1(psc->sc_iot, psc->sc_ioh,
372 	    psc->sc_config_offset + index, value);
373 }
374 
375 static void
376 virtio_pci_write_device_config_2(struct virtio_softc *sc, int index,
377     uint16_t value)
378 {
379 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
380 
381 	bus_space_write_stream_2(psc->sc_iot, psc->sc_ioh,
382 	    psc->sc_config_offset + index, value);
383 }
384 
385 static void
386 virtio_pci_write_device_config_4(struct virtio_softc *sc, int index,
387     uint32_t value)
388 {
389 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
390 
391 	bus_space_write_stream_4(psc->sc_iot, psc->sc_ioh,
392 	    psc->sc_config_offset + index, value);
393 }
394 
395 static void
396 virtio_pci_write_device_config_8(struct virtio_softc *sc, int index,
397     uint64_t value)
398 {
399 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
400 
401 	bus_space_write_stream_4(psc->sc_iot, psc->sc_ioh,
402 	    psc->sc_config_offset + index + REG_LO_OFF,
403 	    value & 0xffffffff);
404 	bus_space_write_stream_4(psc->sc_iot, psc->sc_ioh,
405 	    psc->sc_config_offset + index + REG_HI_OFF,
406 	    value >> 32);
407 }
408 
409 static uint16_t
410 virtio_pci_read_queue_size(struct virtio_softc *sc, uint16_t idx)
411 {
412 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
413 
414 	bus_space_write_stream_2(psc->sc_iot, psc->sc_ioh,
415 	    VIRTIO_CONFIG_QUEUE_SELECT, idx);
416 	return bus_space_read_stream_2(psc->sc_iot, psc->sc_ioh,
417 	    VIRTIO_CONFIG_QUEUE_SIZE);
418 }
419 
420 static void
421 virtio_pci_setup_queue(struct virtio_softc *sc, uint16_t idx, uint32_t addr)
422 {
423 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
424 
425 	bus_space_write_stream_2(psc->sc_iot, psc->sc_ioh,
426 	    VIRTIO_CONFIG_QUEUE_SELECT, idx);
427 	bus_space_write_stream_4(psc->sc_iot, psc->sc_ioh,
428 	    VIRTIO_CONFIG_QUEUE_ADDRESS, addr);
429 
430 	if (psc->sc_ihs_num > 1) {
431 		int vec = VIRTIO_MSIX_QUEUE_VECTOR_INDEX;
432 		if (sc->sc_child_mq)
433 			vec += idx;
434 		bus_space_write_stream_2(psc->sc_iot, psc->sc_ioh,
435 		    VIRTIO_CONFIG_MSI_QUEUE_VECTOR, vec);
436 	}
437 }
438 
439 static void
440 virtio_pci_set_status(struct virtio_softc *sc, int status)
441 {
442 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
443 	int old = 0;
444 
445 	if (status != 0) {
446 	    old = bus_space_read_stream_1(psc->sc_iot, psc->sc_ioh,
447 		VIRTIO_CONFIG_DEVICE_STATUS);
448 	}
449 	bus_space_write_stream_1(psc->sc_iot, psc->sc_ioh,
450 	    VIRTIO_CONFIG_DEVICE_STATUS, status|old);
451 }
452 
453 static uint32_t
454 virtio_pci_negotiate_features(struct virtio_softc *sc, uint32_t guest_features)
455 {
456 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
457 	uint32_t r;
458 
459 	r = bus_space_read_stream_4(psc->sc_iot, psc->sc_ioh,
460 	    VIRTIO_CONFIG_DEVICE_FEATURES);
461 	r &= guest_features;
462 	bus_space_write_stream_4(psc->sc_iot, psc->sc_ioh,
463 	    VIRTIO_CONFIG_GUEST_FEATURES, r);
464 
465 	return r;
466 }
467 
468 
469 static int
470 virtio_pci_setup_msix_vectors(struct virtio_softc *sc)
471 {
472 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
473 	int offset, vector, ret, qid;
474 
475 	offset = VIRTIO_CONFIG_MSI_CONFIG_VECTOR;
476 	vector = VIRTIO_MSIX_CONFIG_VECTOR_INDEX;
477 
478 	bus_space_write_stream_2(psc->sc_iot, psc->sc_ioh, offset, vector);
479 	ret = bus_space_read_stream_2(psc->sc_iot, psc->sc_ioh, offset);
480 	aprint_debug_dev(sc->sc_dev, "expected=%d, actual=%d\n",
481 	    vector, ret);
482 	if (ret != vector)
483 		return -1;
484 
485 	for (qid = 0; qid < sc->sc_nvqs; qid++) {
486 		offset = VIRTIO_CONFIG_QUEUE_SELECT;
487 		bus_space_write_stream_2(psc->sc_iot, psc->sc_ioh, offset, qid);
488 
489 		offset = VIRTIO_CONFIG_MSI_QUEUE_VECTOR;
490 		vector = VIRTIO_MSIX_QUEUE_VECTOR_INDEX;
491 
492 		if (sc->sc_child_mq)
493 			vector += qid;
494 
495 		bus_space_write_stream_2(psc->sc_iot, psc->sc_ioh, offset, vector);
496 		ret = bus_space_read_stream_2(psc->sc_iot, psc->sc_ioh, offset);
497 		aprint_debug_dev(sc->sc_dev, "expected=%d, actual=%d\n",
498 		    vector, ret);
499 		if (ret != vector)
500 			return -1;
501 	}
502 
503 	return 0;
504 }
505 
506 static int
507 virtio_pci_setup_msix_interrupts(struct virtio_softc *sc,
508     struct pci_attach_args *pa)
509 {
510 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
511 	device_t self = sc->sc_dev;
512 	pci_chipset_tag_t pc = pa->pa_pc;
513 	struct virtqueue *vq;
514 	char intrbuf[PCI_INTRSTR_LEN];
515 	char intr_xname[INTRDEVNAMEBUF];
516 	char const *intrstr;
517 	int idx, qid, n;
518 
519 	idx = VIRTIO_MSIX_CONFIG_VECTOR_INDEX;
520 	if (sc->sc_flags & VIRTIO_F_PCI_INTR_MPSAFE)
521 		pci_intr_setattr(pc, &psc->sc_ihp[idx], PCI_INTR_MPSAFE, true);
522 
523 	snprintf(intr_xname, sizeof(intr_xname), "%s config",
524 	    device_xname(sc->sc_dev));
525 
526 	psc->sc_ihs[idx] = pci_intr_establish_xname(pc, psc->sc_ihp[idx],
527 	    sc->sc_ipl, virtio_pci_msix_config_intr, sc, intr_xname);
528 	if (psc->sc_ihs[idx] == NULL) {
529 		aprint_error_dev(self, "couldn't establish MSI-X for config\n");
530 		goto error;
531 	}
532 
533 	idx = VIRTIO_MSIX_QUEUE_VECTOR_INDEX;
534 	if (sc->sc_child_mq) {
535 		for (qid = 0; qid < sc->sc_nvqs; qid++) {
536 			n = idx + qid;
537 			vq = &sc->sc_vqs[qid];
538 
539 			snprintf(intr_xname, sizeof(intr_xname), "%s vq#%d",
540 			    device_xname(sc->sc_dev), qid);
541 
542 			if (sc->sc_flags & VIRTIO_F_PCI_INTR_MPSAFE) {
543 				pci_intr_setattr(pc, &psc->sc_ihp[n],
544 				    PCI_INTR_MPSAFE, true);
545 			}
546 
547 			psc->sc_ihs[n] = pci_intr_establish_xname(pc, psc->sc_ihp[n],
548 			    sc->sc_ipl, vq->vq_intrhand, vq->vq_intrhand_arg, intr_xname);
549 			if (psc->sc_ihs[n] == NULL) {
550 				aprint_error_dev(self, "couldn't establish MSI-X for a vq\n");
551 				goto error;
552 			}
553 		}
554 	} else {
555 		if (sc->sc_flags & VIRTIO_F_PCI_INTR_MPSAFE)
556 			pci_intr_setattr(pc, &psc->sc_ihp[idx], PCI_INTR_MPSAFE, true);
557 
558 		snprintf(intr_xname, sizeof(intr_xname), "%s queues",
559 		    device_xname(sc->sc_dev));
560 		psc->sc_ihs[idx] = pci_intr_establish_xname(pc, psc->sc_ihp[idx],
561 		    sc->sc_ipl, virtio_pci_msix_queue_intr, sc, intr_xname);
562 		if (psc->sc_ihs[idx] == NULL) {
563 			aprint_error_dev(self, "couldn't establish MSI-X for queues\n");
564 			goto error;
565 		}
566 	}
567 
568 	if (virtio_pci_setup_msix_vectors(sc) != 0) {
569 		aprint_error_dev(self, "couldn't setup MSI-X vectors\n");
570 		goto error;
571 	}
572 
573 	idx = VIRTIO_MSIX_CONFIG_VECTOR_INDEX;
574 	intrstr = pci_intr_string(pc, psc->sc_ihp[idx], intrbuf, sizeof(intrbuf));
575 	aprint_normal_dev(self, "config interrupting at %s\n", intrstr);
576 	idx = VIRTIO_MSIX_QUEUE_VECTOR_INDEX;
577 	if (sc->sc_child_mq) {
578 		kcpuset_t *affinity;
579 		int affinity_to, r;
580 
581 		kcpuset_create(&affinity, false);
582 
583 		for (qid = 0; qid < sc->sc_nvqs; qid++) {
584 			n = idx + qid;
585 			affinity_to = (qid / 2) % ncpu;
586 
587 			intrstr = pci_intr_string(pc, psc->sc_ihp[n],
588 			    intrbuf, sizeof(intrbuf));
589 
590 			kcpuset_zero(affinity);
591 			kcpuset_set(affinity, affinity_to);
592 			r = interrupt_distribute(psc->sc_ihs[n], affinity, NULL);
593 			if (r == 0) {
594 				aprint_normal_dev(self,
595 				    "for vq #%d interrupting at %s affinity to %u\n",
596 				    qid, intrstr, affinity_to);
597 			} else {
598 				aprint_normal_dev(self,
599 				    "for vq #%d interrupting at %s\n",
600 				    qid, intrstr);
601 			}
602 		}
603 
604 		kcpuset_destroy(affinity);
605 	} else {
606 		intrstr = pci_intr_string(pc, psc->sc_ihp[idx], intrbuf, sizeof(intrbuf));
607 		aprint_normal_dev(self, "queues interrupting at %s\n", intrstr);
608 	}
609 
610 	return 0;
611 
612 error:
613 	idx = VIRTIO_MSIX_CONFIG_VECTOR_INDEX;
614 	if (psc->sc_ihs[idx] != NULL)
615 		pci_intr_disestablish(psc->sc_pa.pa_pc, psc->sc_ihs[idx]);
616 	idx = VIRTIO_MSIX_QUEUE_VECTOR_INDEX;
617 	if (sc->sc_child_mq) {
618 		for (qid = 0; qid < sc->sc_nvqs; qid++) {
619 			n = idx + qid;
620 			if (psc->sc_ihs[n] == NULL)
621 				continue;
622 			pci_intr_disestablish(psc->sc_pa.pa_pc, psc->sc_ihs[n]);
623 		}
624 
625 	} else {
626 		if (psc->sc_ihs[idx] != NULL)
627 			pci_intr_disestablish(psc->sc_pa.pa_pc, psc->sc_ihs[idx]);
628 	}
629 
630 	return -1;
631 }
632 
633 static int
634 virtio_pci_setup_intx_interrupt(struct virtio_softc *sc,
635     struct pci_attach_args *pa)
636 {
637 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
638 	device_t self = sc->sc_dev;
639 	pci_chipset_tag_t pc = pa->pa_pc;
640 	char intrbuf[PCI_INTRSTR_LEN];
641 	char const *intrstr;
642 
643 	if (sc->sc_flags & VIRTIO_F_PCI_INTR_MPSAFE)
644 		pci_intr_setattr(pc, &psc->sc_ihp[0], PCI_INTR_MPSAFE, true);
645 
646 	psc->sc_ihs[0] = pci_intr_establish_xname(pc, psc->sc_ihp[0],
647 	    sc->sc_ipl, virtio_pci_intr, sc, device_xname(sc->sc_dev));
648 	if (psc->sc_ihs[0] == NULL) {
649 		aprint_error_dev(self, "couldn't establish INTx\n");
650 		return -1;
651 	}
652 
653 	intrstr = pci_intr_string(pc, psc->sc_ihp[0], intrbuf, sizeof(intrbuf));
654 	aprint_normal_dev(self, "interrupting at %s\n", intrstr);
655 
656 	return 0;
657 }
658 
659 static int
660 virtio_pci_setup_interrupts(struct virtio_softc *sc)
661 {
662 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
663 	device_t self = sc->sc_dev;
664 	pci_chipset_tag_t pc = psc->sc_pa.pa_pc;
665 	int error;
666 	int nmsix;
667 	int counts[PCI_INTR_TYPE_SIZE];
668 	pci_intr_type_t max_type;
669 
670 	nmsix = pci_msix_count(psc->sc_pa.pa_pc, psc->sc_pa.pa_tag);
671 	aprint_debug_dev(self, "pci_msix_count=%d\n", nmsix);
672 
673 	/* We need at least two: one for config and the other for queues */
674 	if ((sc->sc_flags & VIRTIO_F_PCI_INTR_MSIX) == 0 || nmsix < 2) {
675 		/* Try INTx only */
676 		max_type = PCI_INTR_TYPE_INTX;
677 		counts[PCI_INTR_TYPE_INTX] = 1;
678 	} else {
679 		/* Try MSI-X first and INTx second */
680 		if (sc->sc_nvqs + VIRTIO_MSIX_QUEUE_VECTOR_INDEX <= nmsix) {
681 			nmsix = sc->sc_nvqs + VIRTIO_MSIX_QUEUE_VECTOR_INDEX;
682 		} else {
683 			sc->sc_child_mq = false;
684 		}
685 
686 		if (sc->sc_child_mq == false) {
687 			nmsix = 2;
688 		}
689 
690 		max_type = PCI_INTR_TYPE_MSIX;
691 		counts[PCI_INTR_TYPE_MSIX] = nmsix;
692 		counts[PCI_INTR_TYPE_MSI] = 0;
693 		counts[PCI_INTR_TYPE_INTX] = 1;
694 	}
695 
696 retry:
697 	error = pci_intr_alloc(&psc->sc_pa, &psc->sc_ihp, counts, max_type);
698 	if (error != 0) {
699 		aprint_error_dev(self, "couldn't map interrupt\n");
700 		return -1;
701 	}
702 
703 	if (pci_intr_type(pc, psc->sc_ihp[0]) == PCI_INTR_TYPE_MSIX) {
704 		psc->sc_ihs = kmem_alloc(sizeof(*psc->sc_ihs) * nmsix,
705 		    KM_SLEEP);
706 
707 		error = virtio_pci_setup_msix_interrupts(sc, &psc->sc_pa);
708 		if (error != 0) {
709 			kmem_free(psc->sc_ihs, sizeof(*psc->sc_ihs) * nmsix);
710 			pci_intr_release(pc, psc->sc_ihp, nmsix);
711 
712 			/* Retry INTx */
713 			max_type = PCI_INTR_TYPE_INTX;
714 			counts[PCI_INTR_TYPE_INTX] = 1;
715 			goto retry;
716 		}
717 
718 		psc->sc_ihs_num = nmsix;
719 		psc->sc_config_offset = VIRTIO_CONFIG_DEVICE_CONFIG_MSI;
720 	} else if (pci_intr_type(pc, psc->sc_ihp[0]) == PCI_INTR_TYPE_INTX) {
721 		psc->sc_ihs = kmem_alloc(sizeof(*psc->sc_ihs) * 1,
722 		    KM_SLEEP);
723 
724 		error = virtio_pci_setup_intx_interrupt(sc, &psc->sc_pa);
725 		if (error != 0) {
726 			kmem_free(psc->sc_ihs, sizeof(*psc->sc_ihs) * 1);
727 			pci_intr_release(pc, psc->sc_ihp, 1);
728 			return -1;
729 		}
730 
731 		psc->sc_ihs_num = 1;
732 		psc->sc_config_offset = VIRTIO_CONFIG_DEVICE_CONFIG_NOMSI;
733 	}
734 
735 	return 0;
736 }
737 
738 static void
739 virtio_pci_free_interrupts(struct virtio_softc *sc)
740 {
741 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
742 
743 	for (int i = 0; i < psc->sc_ihs_num; i++) {
744 		if (psc->sc_ihs[i] == NULL)
745 			continue;
746 		pci_intr_disestablish(psc->sc_pa.pa_pc, psc->sc_ihs[i]);
747 		psc->sc_ihs[i] = NULL;
748 	}
749 
750 	if (psc->sc_ihs_num > 0)
751 		pci_intr_release(psc->sc_pa.pa_pc, psc->sc_ihp, psc->sc_ihs_num);
752 
753 	if (psc->sc_ihs != NULL) {
754 		kmem_free(psc->sc_ihs, sizeof(*psc->sc_ihs) * psc->sc_ihs_num);
755 		psc->sc_ihs = NULL;
756 	}
757 	psc->sc_ihs_num = 0;
758 }
759 
760 /*
761  * Interrupt handler.
762  */
763 static int
764 virtio_pci_intr(void *arg)
765 {
766 	struct virtio_softc *sc = arg;
767 	struct virtio_pci_softc * const psc = (struct virtio_pci_softc *)sc;
768 	int isr, r = 0;
769 
770 	/* check and ack the interrupt */
771 	isr = bus_space_read_stream_1(psc->sc_iot, psc->sc_ioh,
772 			       VIRTIO_CONFIG_ISR_STATUS);
773 	if (isr == 0)
774 		return 0;
775 	if ((isr & VIRTIO_CONFIG_ISR_CONFIG_CHANGE) &&
776 	    (sc->sc_config_change != NULL))
777 		r = (sc->sc_config_change)(sc);
778 	if (sc->sc_intrhand != NULL) {
779 		if (sc->sc_soft_ih != NULL)
780 			softint_schedule(sc->sc_soft_ih);
781 		else
782 			r |= (sc->sc_intrhand)(sc);
783 	}
784 
785 	return r;
786 }
787 
788 static int
789 virtio_pci_msix_queue_intr(void *arg)
790 {
791 	struct virtio_softc *sc = arg;
792 	int r = 0;
793 
794 	if (sc->sc_intrhand != NULL) {
795 		if (sc->sc_soft_ih != NULL)
796 			softint_schedule(sc->sc_soft_ih);
797 		else
798 			r |= (sc->sc_intrhand)(sc);
799 	}
800 
801 	return r;
802 }
803 
804 static int
805 virtio_pci_msix_config_intr(void *arg)
806 {
807 	struct virtio_softc *sc = arg;
808 	int r = 0;
809 
810 	if (sc->sc_config_change != NULL)
811 		r = (sc->sc_config_change)(sc);
812 	return r;
813 }
814 
815 MODULE(MODULE_CLASS_DRIVER, virtio_pci, "pci,virtio");
816 
817 #ifdef _MODULE
818 #include "ioconf.c"
819 #endif
820 
821 static int
822 virtio_pci_modcmd(modcmd_t cmd, void *opaque)
823 {
824 	int error = 0;
825 
826 #ifdef _MODULE
827 	switch (cmd) {
828 	case MODULE_CMD_INIT:
829 		error = config_init_component(cfdriver_ioconf_virtio_pci,
830 		    cfattach_ioconf_virtio_pci, cfdata_ioconf_virtio_pci);
831 		break;
832 	case MODULE_CMD_FINI:
833 		error = config_fini_component(cfdriver_ioconf_virtio_pci,
834 		    cfattach_ioconf_virtio_pci, cfdata_ioconf_virtio_pci);
835 		break;
836 	default:
837 		error = ENOTTY;
838 		break;
839 	}
840 #endif
841 
842 	return error;
843 }
844