xref: /freebsd/sys/dev/virtio/pci/virtio_pci_legacy.c (revision 535af610) 
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2011, Bryan Venteicher <bryanv@FreeBSD.org>
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 unmodified, this list of conditions, and the following
12  *    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 THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /* Driver for the legacy VirtIO PCI interface. */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/bus.h>
37 #include <sys/lock.h>
38 #include <sys/kernel.h>
39 #include <sys/module.h>
40 #include <sys/endian.h>
41 
42 #include <machine/bus.h>
43 #include <machine/resource.h>
44 #include <sys/bus.h>
45 #include <sys/rman.h>
46 
47 #include <dev/pci/pcivar.h>
48 #include <dev/pci/pcireg.h>
49 
50 #include <dev/virtio/virtio.h>
51 #include <dev/virtio/virtqueue.h>
52 #include <dev/virtio/pci/virtio_pci.h>
53 #include <dev/virtio/pci/virtio_pci_legacy_var.h>
54 
55 #include "virtio_bus_if.h"
56 #include "virtio_pci_if.h"
57 #include "virtio_if.h"
58 
59 struct vtpci_legacy_softc {
60 	device_t			 vtpci_dev;
61 	struct vtpci_common		 vtpci_common;
62 	int				 vtpci_res_type;
63 	struct resource			*vtpci_res;
64 	struct resource			*vtpci_msix_table_res;
65 	struct resource			*vtpci_msix_pba_res;
66 };
67 
68 static int	vtpci_legacy_probe(device_t);
69 static int	vtpci_legacy_attach(device_t);
70 static int	vtpci_legacy_detach(device_t);
71 static int	vtpci_legacy_suspend(device_t);
72 static int	vtpci_legacy_resume(device_t);
73 static int	vtpci_legacy_shutdown(device_t);
74 
75 static void	vtpci_legacy_driver_added(device_t, driver_t *);
76 static void	vtpci_legacy_child_detached(device_t, device_t);
77 static int	vtpci_legacy_read_ivar(device_t, device_t, int, uintptr_t *);
78 static int	vtpci_legacy_write_ivar(device_t, device_t, int, uintptr_t);
79 
80 static uint8_t	vtpci_legacy_read_isr(device_t);
81 static uint16_t	vtpci_legacy_get_vq_size(device_t, int);
82 static bus_size_t vtpci_legacy_get_vq_notify_off(device_t, int);
83 static void	vtpci_legacy_set_vq(device_t, struct virtqueue *);
84 static void	vtpci_legacy_disable_vq(device_t, int);
85 static int	vtpci_legacy_register_cfg_msix(device_t,
86 		    struct vtpci_interrupt *);
87 static int	vtpci_legacy_register_vq_msix(device_t, int idx,
88 		    struct vtpci_interrupt *);
89 
90 static uint64_t	vtpci_legacy_negotiate_features(device_t, uint64_t);
91 static int	vtpci_legacy_with_feature(device_t, uint64_t);
92 static int	vtpci_legacy_alloc_virtqueues(device_t, int, int,
93 		    struct vq_alloc_info *);
94 static int	vtpci_legacy_setup_interrupts(device_t, enum intr_type);
95 static void	vtpci_legacy_stop(device_t);
96 static int	vtpci_legacy_reinit(device_t, uint64_t);
97 static void	vtpci_legacy_reinit_complete(device_t);
98 static void	vtpci_legacy_notify_vq(device_t, uint16_t, bus_size_t);
99 static void	vtpci_legacy_read_dev_config(device_t, bus_size_t, void *, int);
100 static void	vtpci_legacy_write_dev_config(device_t, bus_size_t, const void *, int);
101 
102 static bool	vtpci_legacy_setup_msix(struct vtpci_legacy_softc *sc);
103 static void	vtpci_legacy_teardown_msix(struct vtpci_legacy_softc *sc);
104 static int	vtpci_legacy_alloc_resources(struct vtpci_legacy_softc *);
105 static void	vtpci_legacy_free_resources(struct vtpci_legacy_softc *);
106 
107 static void	vtpci_legacy_probe_and_attach_child(struct vtpci_legacy_softc *);
108 
109 static uint8_t	vtpci_legacy_get_status(struct vtpci_legacy_softc *);
110 static void	vtpci_legacy_set_status(struct vtpci_legacy_softc *, uint8_t);
111 static void	vtpci_legacy_select_virtqueue(struct vtpci_legacy_softc *, int);
112 static void	vtpci_legacy_reset(struct vtpci_legacy_softc *);
113 
114 #define VIRTIO_PCI_LEGACY_CONFIG(_sc) \
115     VIRTIO_PCI_CONFIG_OFF(vtpci_is_msix_enabled(&(_sc)->vtpci_common))
116 
117 #define vtpci_legacy_read_config_1(sc, o) \
118     bus_read_1((sc)->vtpci_res, (o))
119 #define vtpci_legacy_write_config_1(sc, o, v) \
120     bus_write_1((sc)->vtpci_res, (o), (v))
121 /*
122  * VirtIO specifies that PCI Configuration area is guest endian. However,
123  * since PCI devices are inherently little-endian, on big-endian systems
124  * the bus layer transparently converts it to BE. For virtio-legacy, this
125  * conversion is undesired, so an extra byte swap is required to fix it.
126  */
127 #define vtpci_legacy_read_config_2(sc, o) \
128     le16toh(bus_read_2((sc)->vtpci_res, (o)))
129 #define vtpci_legacy_read_config_4(sc, o) \
130     le32toh(bus_read_4((sc)->vtpci_res, (o)))
131 #define vtpci_legacy_write_config_2(sc, o, v) \
132     bus_write_2((sc)->vtpci_res, (o), (htole16(v)))
133 #define vtpci_legacy_write_config_4(sc, o, v) \
134     bus_write_4((sc)->vtpci_res, (o), (htole32(v)))
135 /* PCI Header LE. On BE systems the bus layer takes care of byte swapping. */
136 #define vtpci_legacy_read_header_2(sc, o) \
137     bus_read_2((sc)->vtpci_res, (o))
138 #define vtpci_legacy_read_header_4(sc, o) \
139     bus_read_4((sc)->vtpci_res, (o))
140 #define vtpci_legacy_write_header_2(sc, o, v) \
141     bus_write_2((sc)->vtpci_res, (o), (v))
142 #define vtpci_legacy_write_header_4(sc, o, v) \
143     bus_write_4((sc)->vtpci_res, (o), (v))
144 
145 static device_method_t vtpci_legacy_methods[] = {
146 	/* Device interface. */
147 	DEVMETHOD(device_probe,			  vtpci_legacy_probe),
148 	DEVMETHOD(device_attach,		  vtpci_legacy_attach),
149 	DEVMETHOD(device_detach,		  vtpci_legacy_detach),
150 	DEVMETHOD(device_suspend,		  vtpci_legacy_suspend),
151 	DEVMETHOD(device_resume,		  vtpci_legacy_resume),
152 	DEVMETHOD(device_shutdown,		  vtpci_legacy_shutdown),
153 
154 	/* Bus interface. */
155 	DEVMETHOD(bus_driver_added,		  vtpci_legacy_driver_added),
156 	DEVMETHOD(bus_child_detached,		  vtpci_legacy_child_detached),
157 	DEVMETHOD(bus_child_pnpinfo,		  virtio_child_pnpinfo),
158 	DEVMETHOD(bus_read_ivar,		  vtpci_legacy_read_ivar),
159 	DEVMETHOD(bus_write_ivar,		  vtpci_legacy_write_ivar),
160 
161 	/* VirtIO PCI interface. */
162 	DEVMETHOD(virtio_pci_read_isr,		 vtpci_legacy_read_isr),
163 	DEVMETHOD(virtio_pci_get_vq_size,	 vtpci_legacy_get_vq_size),
164 	DEVMETHOD(virtio_pci_get_vq_notify_off,	 vtpci_legacy_get_vq_notify_off),
165 	DEVMETHOD(virtio_pci_set_vq,		 vtpci_legacy_set_vq),
166 	DEVMETHOD(virtio_pci_disable_vq,	 vtpci_legacy_disable_vq),
167 	DEVMETHOD(virtio_pci_register_cfg_msix,  vtpci_legacy_register_cfg_msix),
168 	DEVMETHOD(virtio_pci_register_vq_msix,	 vtpci_legacy_register_vq_msix),
169 
170 	/* VirtIO bus interface. */
171 	DEVMETHOD(virtio_bus_negotiate_features,  vtpci_legacy_negotiate_features),
172 	DEVMETHOD(virtio_bus_with_feature,	  vtpci_legacy_with_feature),
173 	DEVMETHOD(virtio_bus_alloc_virtqueues,	  vtpci_legacy_alloc_virtqueues),
174 	DEVMETHOD(virtio_bus_setup_intr,	  vtpci_legacy_setup_interrupts),
175 	DEVMETHOD(virtio_bus_stop,		  vtpci_legacy_stop),
176 	DEVMETHOD(virtio_bus_reinit,		  vtpci_legacy_reinit),
177 	DEVMETHOD(virtio_bus_reinit_complete,	  vtpci_legacy_reinit_complete),
178 	DEVMETHOD(virtio_bus_notify_vq,		  vtpci_legacy_notify_vq),
179 	DEVMETHOD(virtio_bus_read_device_config,  vtpci_legacy_read_dev_config),
180 	DEVMETHOD(virtio_bus_write_device_config, vtpci_legacy_write_dev_config),
181 
182 	DEVMETHOD_END
183 };
184 
185 static driver_t vtpci_legacy_driver = {
186 	.name = "virtio_pci",
187 	.methods = vtpci_legacy_methods,
188 	.size = sizeof(struct vtpci_legacy_softc)
189 };
190 
191 DRIVER_MODULE(virtio_pci_legacy, pci, vtpci_legacy_driver, 0, 0);
192 
193 static int
194 vtpci_legacy_probe(device_t dev)
195 {
196 	char desc[64];
197 	const char *name;
198 
199 	if (pci_get_vendor(dev) != VIRTIO_PCI_VENDORID)
200 		return (ENXIO);
201 
202 	if (pci_get_device(dev) < VIRTIO_PCI_DEVICEID_MIN ||
203 	    pci_get_device(dev) > VIRTIO_PCI_DEVICEID_LEGACY_MAX)
204 		return (ENXIO);
205 
206 	if (pci_get_revid(dev) != VIRTIO_PCI_ABI_VERSION)
207 		return (ENXIO);
208 
209 	name = virtio_device_name(pci_get_subdevice(dev));
210 	if (name == NULL)
211 		name = "Unknown";
212 
213 	snprintf(desc, sizeof(desc), "VirtIO PCI (legacy) %s adapter", name);
214 	device_set_desc_copy(dev, desc);
215 
216 	/* Prefer transitional modern VirtIO PCI. */
217 	return (BUS_PROBE_LOW_PRIORITY);
218 }
219 
220 static int
221 vtpci_legacy_attach(device_t dev)
222 {
223 	struct vtpci_legacy_softc *sc;
224 	int error;
225 
226 	sc = device_get_softc(dev);
227 	sc->vtpci_dev = dev;
228 	vtpci_init(&sc->vtpci_common, dev, false);
229 
230 	error = vtpci_legacy_alloc_resources(sc);
231 	if (error) {
232 		device_printf(dev, "cannot map I/O space nor memory space\n");
233 		return (error);
234 	}
235 
236 	if (vtpci_is_msix_available(&sc->vtpci_common) &&
237 	    !vtpci_legacy_setup_msix(sc)) {
238 		device_printf(dev, "cannot setup MSI-x resources\n");
239 		error = ENXIO;
240 		goto fail;
241 	}
242 
243 	vtpci_legacy_reset(sc);
244 
245 	/* Tell the host we've noticed this device. */
246 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_ACK);
247 
248 	error = vtpci_add_child(&sc->vtpci_common);
249 	if (error)
250 		goto fail;
251 
252 	vtpci_legacy_probe_and_attach_child(sc);
253 
254 	return (0);
255 
256 fail:
257 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_FAILED);
258 	vtpci_legacy_detach(dev);
259 
260 	return (error);
261 }
262 
263 static int
264 vtpci_legacy_detach(device_t dev)
265 {
266 	struct vtpci_legacy_softc *sc;
267 	int error;
268 
269 	sc = device_get_softc(dev);
270 
271 	error = vtpci_delete_child(&sc->vtpci_common);
272 	if (error)
273 		return (error);
274 
275 	vtpci_legacy_reset(sc);
276 	vtpci_legacy_teardown_msix(sc);
277 	vtpci_legacy_free_resources(sc);
278 
279 	return (0);
280 }
281 
282 static int
283 vtpci_legacy_suspend(device_t dev)
284 {
285 	return (bus_generic_suspend(dev));
286 }
287 
288 static int
289 vtpci_legacy_resume(device_t dev)
290 {
291 	return (bus_generic_resume(dev));
292 }
293 
294 static int
295 vtpci_legacy_shutdown(device_t dev)
296 {
297 	(void) bus_generic_shutdown(dev);
298 	/* Forcibly stop the host device. */
299 	vtpci_legacy_stop(dev);
300 
301 	return (0);
302 }
303 
304 static void
305 vtpci_legacy_driver_added(device_t dev, driver_t *driver)
306 {
307 	vtpci_legacy_probe_and_attach_child(device_get_softc(dev));
308 }
309 
310 static void
311 vtpci_legacy_child_detached(device_t dev, device_t child)
312 {
313 	struct vtpci_legacy_softc *sc;
314 
315 	sc = device_get_softc(dev);
316 
317 	vtpci_legacy_reset(sc);
318 	vtpci_child_detached(&sc->vtpci_common);
319 
320 	/* After the reset, retell the host we've noticed this device. */
321 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_ACK);
322 }
323 
324 static int
325 vtpci_legacy_read_ivar(device_t dev, device_t child, int index,
326     uintptr_t *result)
327 {
328 	struct vtpci_legacy_softc *sc;
329 	struct vtpci_common *cn;
330 
331 	sc = device_get_softc(dev);
332 	cn = &sc->vtpci_common;
333 
334 	if (vtpci_child_device(cn) != child)
335 		return (ENOENT);
336 
337 	switch (index) {
338 	case VIRTIO_IVAR_DEVTYPE:
339 		*result = pci_get_subdevice(dev);
340 		break;
341 	default:
342 		return (vtpci_read_ivar(cn, index, result));
343 	}
344 
345 	return (0);
346 }
347 
348 static int
349 vtpci_legacy_write_ivar(device_t dev, device_t child, int index, uintptr_t value)
350 {
351 	struct vtpci_legacy_softc *sc;
352 	struct vtpci_common *cn;
353 
354 	sc = device_get_softc(dev);
355 	cn = &sc->vtpci_common;
356 
357 	if (vtpci_child_device(cn) != child)
358 		return (ENOENT);
359 
360 	switch (index) {
361 	default:
362 		return (vtpci_write_ivar(cn, index, value));
363 	}
364 
365 	return (0);
366 }
367 
368 static uint64_t
369 vtpci_legacy_negotiate_features(device_t dev, uint64_t child_features)
370 {
371 	struct vtpci_legacy_softc *sc;
372 	uint64_t host_features, features;
373 
374 	sc = device_get_softc(dev);
375 	host_features = vtpci_legacy_read_header_4(sc, VIRTIO_PCI_HOST_FEATURES);
376 
377 	features = vtpci_negotiate_features(&sc->vtpci_common,
378 	    child_features, host_features);
379 	vtpci_legacy_write_header_4(sc, VIRTIO_PCI_GUEST_FEATURES, features);
380 
381 	return (features);
382 }
383 
384 static int
385 vtpci_legacy_with_feature(device_t dev, uint64_t feature)
386 {
387 	struct vtpci_legacy_softc *sc;
388 
389 	sc = device_get_softc(dev);
390 
391 	return (vtpci_with_feature(&sc->vtpci_common, feature));
392 }
393 
394 static int
395 vtpci_legacy_alloc_virtqueues(device_t dev, int flags, int nvqs,
396     struct vq_alloc_info *vq_info)
397 {
398 	struct vtpci_legacy_softc *sc;
399 	struct vtpci_common *cn;
400 
401 	sc = device_get_softc(dev);
402 	cn = &sc->vtpci_common;
403 
404 	return (vtpci_alloc_virtqueues(cn, flags, nvqs, vq_info));
405 }
406 
407 static int
408 vtpci_legacy_setup_interrupts(device_t dev, enum intr_type type)
409 {
410 	struct vtpci_legacy_softc *sc;
411 
412 	sc = device_get_softc(dev);
413 
414 	return (vtpci_setup_interrupts(&sc->vtpci_common, type));
415 }
416 
417 static void
418 vtpci_legacy_stop(device_t dev)
419 {
420 	vtpci_legacy_reset(device_get_softc(dev));
421 }
422 
423 static int
424 vtpci_legacy_reinit(device_t dev, uint64_t features)
425 {
426 	struct vtpci_legacy_softc *sc;
427 	struct vtpci_common *cn;
428 	int error;
429 
430 	sc = device_get_softc(dev);
431 	cn = &sc->vtpci_common;
432 
433 	/*
434 	 * Redrive the device initialization. This is a bit of an abuse of
435 	 * the specification, but VirtualBox, QEMU/KVM, and BHyVe seem to
436 	 * play nice.
437 	 *
438 	 * We do not allow the host device to change from what was originally
439 	 * negotiated beyond what the guest driver changed. MSIX state should
440 	 * not change, number of virtqueues and their size remain the same, etc.
441 	 * This will need to be rethought when we want to support migration.
442 	 */
443 
444 	if (vtpci_legacy_get_status(sc) != VIRTIO_CONFIG_STATUS_RESET)
445 		vtpci_legacy_stop(dev);
446 
447 	/*
448 	 * Quickly drive the status through ACK and DRIVER. The device does
449 	 * not become usable again until DRIVER_OK in reinit complete.
450 	 */
451 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_ACK);
452 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER);
453 
454 	vtpci_legacy_negotiate_features(dev, features);
455 
456 	error = vtpci_reinit(cn);
457 	if (error)
458 		return (error);
459 
460 	return (0);
461 }
462 
463 static void
464 vtpci_legacy_reinit_complete(device_t dev)
465 {
466 	struct vtpci_legacy_softc *sc;
467 
468 	sc = device_get_softc(dev);
469 
470 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER_OK);
471 }
472 
473 static void
474 vtpci_legacy_notify_vq(device_t dev, uint16_t queue, bus_size_t offset)
475 {
476 	struct vtpci_legacy_softc *sc;
477 
478 	sc = device_get_softc(dev);
479 	MPASS(offset == VIRTIO_PCI_QUEUE_NOTIFY);
480 
481 	vtpci_legacy_write_header_2(sc, offset, queue);
482 }
483 
484 static uint8_t
485 vtpci_legacy_get_status(struct vtpci_legacy_softc *sc)
486 {
487 	return (vtpci_legacy_read_config_1(sc, VIRTIO_PCI_STATUS));
488 }
489 
490 static void
491 vtpci_legacy_set_status(struct vtpci_legacy_softc *sc, uint8_t status)
492 {
493 	if (status != VIRTIO_CONFIG_STATUS_RESET)
494 		status |= vtpci_legacy_get_status(sc);
495 
496 	vtpci_legacy_write_config_1(sc, VIRTIO_PCI_STATUS, status);
497 }
498 
499 static void
500 vtpci_legacy_read_dev_config(device_t dev, bus_size_t offset,
501     void *dst, int length)
502 {
503 	struct vtpci_legacy_softc *sc;
504 	bus_size_t off;
505 	uint8_t *d;
506 	int i;
507 
508 	sc = device_get_softc(dev);
509 	off = VIRTIO_PCI_LEGACY_CONFIG(sc) + offset;
510 
511 	d = dst;
512 	for (i = 0; i < length; i++) {
513 		d[i] = vtpci_legacy_read_config_1(sc, off + i);
514 	}
515 }
516 
517 static void
518 vtpci_legacy_write_dev_config(device_t dev, bus_size_t offset,
519     const void *src, int length)
520 {
521 	struct vtpci_legacy_softc *sc;
522 	bus_size_t off;
523 	const uint8_t *s;
524 	int i;
525 
526 	sc = device_get_softc(dev);
527 	off = VIRTIO_PCI_LEGACY_CONFIG(sc) + offset;
528 
529 	s = src;
530 	for (i = 0; i < length; i++) {
531 		vtpci_legacy_write_config_1(sc, off + i, s[i]);
532 	}
533 }
534 
535 static bool
536 vtpci_legacy_setup_msix(struct vtpci_legacy_softc *sc)
537 {
538 	device_t dev;
539 	int rid, table_rid;
540 
541 	dev = sc->vtpci_dev;
542 
543 	rid = table_rid = pci_msix_table_bar(dev);
544 	if (rid != PCIR_BAR(0)) {
545 		sc->vtpci_msix_table_res = bus_alloc_resource_any(
546 		    dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
547 		if (sc->vtpci_msix_table_res == NULL)
548 			return (false);
549 	}
550 
551 	rid = pci_msix_pba_bar(dev);
552 	if (rid != table_rid && rid != PCIR_BAR(0)) {
553 		sc->vtpci_msix_pba_res = bus_alloc_resource_any(
554 		    dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
555 		if (sc->vtpci_msix_pba_res == NULL)
556 			return (false);
557 	}
558 
559 	return (true);
560 }
561 
562 static void
563 vtpci_legacy_teardown_msix(struct vtpci_legacy_softc *sc)
564 {
565 	device_t dev;
566 
567 	dev = sc->vtpci_dev;
568 
569 	if (sc->vtpci_msix_pba_res != NULL) {
570 		bus_release_resource(dev, SYS_RES_MEMORY,
571 		    rman_get_rid(sc->vtpci_msix_pba_res),
572 		    sc->vtpci_msix_pba_res);
573 		sc->vtpci_msix_pba_res = NULL;
574 	}
575 	if (sc->vtpci_msix_table_res != NULL) {
576 		bus_release_resource(dev, SYS_RES_MEMORY,
577 		    rman_get_rid(sc->vtpci_msix_table_res),
578 		    sc->vtpci_msix_table_res);
579 		sc->vtpci_msix_table_res = NULL;
580 	}
581 }
582 
583 static int
584 vtpci_legacy_alloc_resources(struct vtpci_legacy_softc *sc)
585 {
586 	const int res_types[] = { SYS_RES_IOPORT, SYS_RES_MEMORY };
587 	device_t dev;
588 	int rid, i;
589 
590 	dev = sc->vtpci_dev;
591 
592 	/*
593 	 * Most hypervisors export the common configuration structure in IO
594 	 * space, but some use memory space; try both.
595 	 */
596 	for (i = 0; nitems(res_types); i++) {
597 		rid = PCIR_BAR(0);
598 		sc->vtpci_res_type = res_types[i];
599 		sc->vtpci_res = bus_alloc_resource_any(dev, res_types[i], &rid,
600 		    RF_ACTIVE);
601 		if (sc->vtpci_res != NULL)
602 			break;
603 	}
604 	if (sc->vtpci_res == NULL)
605 		return (ENXIO);
606 
607 	return (0);
608 }
609 
610 static void
611 vtpci_legacy_free_resources(struct vtpci_legacy_softc *sc)
612 {
613 	device_t dev;
614 
615 	dev = sc->vtpci_dev;
616 
617 	if (sc->vtpci_res != NULL) {
618 		bus_release_resource(dev, sc->vtpci_res_type, PCIR_BAR(0),
619 		    sc->vtpci_res);
620 		sc->vtpci_res = NULL;
621 	}
622 }
623 
624 static void
625 vtpci_legacy_probe_and_attach_child(struct vtpci_legacy_softc *sc)
626 {
627 	device_t dev, child;
628 
629 	dev = sc->vtpci_dev;
630 	child = vtpci_child_device(&sc->vtpci_common);
631 
632 	if (child == NULL || device_get_state(child) != DS_NOTPRESENT)
633 		return;
634 
635 	if (device_probe(child) != 0)
636 		return;
637 
638 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER);
639 
640 	if (device_attach(child) != 0) {
641 		vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_FAILED);
642 		/* Reset status for future attempt. */
643 		vtpci_legacy_child_detached(dev, child);
644 	} else {
645 		vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER_OK);
646 		VIRTIO_ATTACH_COMPLETED(child);
647 	}
648 }
649 
650 static int
651 vtpci_legacy_register_msix(struct vtpci_legacy_softc *sc, int offset,
652     struct vtpci_interrupt *intr)
653 {
654 	uint16_t vector;
655 
656 	if (intr != NULL) {
657 		/* Map from guest rid to host vector. */
658 		vector = intr->vti_rid - 1;
659 	} else
660 		vector = VIRTIO_MSI_NO_VECTOR;
661 
662 	vtpci_legacy_write_header_2(sc, offset, vector);
663 	return (vtpci_legacy_read_header_2(sc, offset) == vector ? 0 : ENODEV);
664 }
665 
666 static int
667 vtpci_legacy_register_cfg_msix(device_t dev, struct vtpci_interrupt *intr)
668 {
669 	struct vtpci_legacy_softc *sc;
670 	int error;
671 
672 	sc = device_get_softc(dev);
673 
674 	error = vtpci_legacy_register_msix(sc, VIRTIO_MSI_CONFIG_VECTOR, intr);
675 	if (error) {
676 		device_printf(dev,
677 		    "unable to register config MSIX interrupt\n");
678 		return (error);
679 	}
680 
681 	return (0);
682 }
683 
684 static int
685 vtpci_legacy_register_vq_msix(device_t dev, int idx,
686     struct vtpci_interrupt *intr)
687 {
688 	struct vtpci_legacy_softc *sc;
689 	int error;
690 
691 	sc = device_get_softc(dev);
692 
693 	vtpci_legacy_select_virtqueue(sc, idx);
694 	error = vtpci_legacy_register_msix(sc, VIRTIO_MSI_QUEUE_VECTOR, intr);
695 	if (error) {
696 		device_printf(dev,
697 		    "unable to register virtqueue MSIX interrupt\n");
698 		return (error);
699 	}
700 
701 	return (0);
702 }
703 
704 static void
705 vtpci_legacy_reset(struct vtpci_legacy_softc *sc)
706 {
707 	/*
708 	 * Setting the status to RESET sets the host device to the
709 	 * original, uninitialized state.
710 	 */
711 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_RESET);
712 	(void) vtpci_legacy_get_status(sc);
713 }
714 
715 static void
716 vtpci_legacy_select_virtqueue(struct vtpci_legacy_softc *sc, int idx)
717 {
718 	vtpci_legacy_write_header_2(sc, VIRTIO_PCI_QUEUE_SEL, idx);
719 }
720 
721 static uint8_t
722 vtpci_legacy_read_isr(device_t dev)
723 {
724 	struct vtpci_legacy_softc *sc;
725 
726 	sc = device_get_softc(dev);
727 
728 	return (vtpci_legacy_read_config_1(sc, VIRTIO_PCI_ISR));
729 }
730 
731 static uint16_t
732 vtpci_legacy_get_vq_size(device_t dev, int idx)
733 {
734 	struct vtpci_legacy_softc *sc;
735 
736 	sc = device_get_softc(dev);
737 
738 	vtpci_legacy_select_virtqueue(sc, idx);
739 	return (vtpci_legacy_read_header_2(sc, VIRTIO_PCI_QUEUE_NUM));
740 }
741 
742 static bus_size_t
743 vtpci_legacy_get_vq_notify_off(device_t dev, int idx)
744 {
745 	return (VIRTIO_PCI_QUEUE_NOTIFY);
746 }
747 
748 static void
749 vtpci_legacy_set_vq(device_t dev, struct virtqueue *vq)
750 {
751 	struct vtpci_legacy_softc *sc;
752 
753 	sc = device_get_softc(dev);
754 
755 	vtpci_legacy_select_virtqueue(sc, virtqueue_index(vq));
756 	vtpci_legacy_write_header_4(sc, VIRTIO_PCI_QUEUE_PFN,
757 	    virtqueue_paddr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT);
758 }
759 
760 static void
761 vtpci_legacy_disable_vq(device_t dev, int idx)
762 {
763 	struct vtpci_legacy_softc *sc;
764 
765 	sc = device_get_softc(dev);
766 
767 	vtpci_legacy_select_virtqueue(sc, idx);
768 	vtpci_legacy_write_header_4(sc, VIRTIO_PCI_QUEUE_PFN, 0);
769 }
770