xref: /freebsd-13-stable/sys/dev/virtio/pci/virtio_pci_legacy.c (revision 3bc80996974a61a4223eae4c1ccd47b6ee32a48a)
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 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/lock.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38 #include <sys/endian.h>
39 
40 #include <machine/bus.h>
41 #include <machine/resource.h>
42 #include <sys/bus.h>
43 #include <sys/rman.h>
44 
45 #include <dev/pci/pcivar.h>
46 #include <dev/pci/pcireg.h>
47 
48 #include <dev/virtio/virtio.h>
49 #include <dev/virtio/virtqueue.h>
50 #include <dev/virtio/pci/virtio_pci.h>
51 #include <dev/virtio/pci/virtio_pci_legacy_var.h>
52 
53 #include "virtio_bus_if.h"
54 #include "virtio_pci_if.h"
55 #include "virtio_if.h"
56 
57 struct vtpci_legacy_softc {
58 	device_t			 vtpci_dev;
59 	struct vtpci_common		 vtpci_common;
60 	int				 vtpci_res_type;
61 	struct resource			*vtpci_res;
62 	struct resource			*vtpci_msix_table_res;
63 	struct resource			*vtpci_msix_pba_res;
64 };
65 
66 static int	vtpci_legacy_probe(device_t);
67 static int	vtpci_legacy_attach(device_t);
68 static int	vtpci_legacy_detach(device_t);
69 static int	vtpci_legacy_suspend(device_t);
70 static int	vtpci_legacy_resume(device_t);
71 static int	vtpci_legacy_shutdown(device_t);
72 
73 static void	vtpci_legacy_driver_added(device_t, driver_t *);
74 static void	vtpci_legacy_child_detached(device_t, device_t);
75 static int	vtpci_legacy_read_ivar(device_t, device_t, int, uintptr_t *);
76 static int	vtpci_legacy_write_ivar(device_t, device_t, int, uintptr_t);
77 
78 static uint8_t	vtpci_legacy_read_isr(device_t);
79 static uint16_t	vtpci_legacy_get_vq_size(device_t, int);
80 static bus_size_t vtpci_legacy_get_vq_notify_off(device_t, int);
81 static void	vtpci_legacy_set_vq(device_t, struct virtqueue *);
82 static void	vtpci_legacy_disable_vq(device_t, int);
83 static int	vtpci_legacy_register_cfg_msix(device_t,
84 		    struct vtpci_interrupt *);
85 static int	vtpci_legacy_register_vq_msix(device_t, int idx,
86 		    struct vtpci_interrupt *);
87 
88 static uint64_t	vtpci_legacy_negotiate_features(device_t, uint64_t);
89 static int	vtpci_legacy_with_feature(device_t, uint64_t);
90 static int	vtpci_legacy_alloc_virtqueues(device_t, int, int,
91 		    struct vq_alloc_info *);
92 static int	vtpci_legacy_setup_interrupts(device_t, enum intr_type);
93 static void	vtpci_legacy_stop(device_t);
94 static int	vtpci_legacy_reinit(device_t, uint64_t);
95 static void	vtpci_legacy_reinit_complete(device_t);
96 static void	vtpci_legacy_notify_vq(device_t, uint16_t, bus_size_t);
97 static void	vtpci_legacy_read_dev_config(device_t, bus_size_t, void *, int);
98 static void	vtpci_legacy_write_dev_config(device_t, bus_size_t, const void *, int);
99 
100 static bool	vtpci_legacy_setup_msix(struct vtpci_legacy_softc *sc);
101 static void	vtpci_legacy_teardown_msix(struct vtpci_legacy_softc *sc);
102 static int	vtpci_legacy_alloc_resources(struct vtpci_legacy_softc *);
103 static void	vtpci_legacy_free_resources(struct vtpci_legacy_softc *);
104 
105 static void	vtpci_legacy_probe_and_attach_child(struct vtpci_legacy_softc *);
106 
107 static uint8_t	vtpci_legacy_get_status(struct vtpci_legacy_softc *);
108 static void	vtpci_legacy_set_status(struct vtpci_legacy_softc *, uint8_t);
109 static void	vtpci_legacy_select_virtqueue(struct vtpci_legacy_softc *, int);
110 static void	vtpci_legacy_reset(struct vtpci_legacy_softc *);
111 
112 #define VIRTIO_PCI_LEGACY_CONFIG(_sc) \
113     VIRTIO_PCI_CONFIG_OFF(vtpci_is_msix_enabled(&(_sc)->vtpci_common))
114 
115 #define vtpci_legacy_read_config_1(sc, o) \
116     bus_read_1((sc)->vtpci_res, (o))
117 #define vtpci_legacy_write_config_1(sc, o, v) \
118     bus_write_1((sc)->vtpci_res, (o), (v))
119 /*
120  * VirtIO specifies that PCI Configuration area is guest endian. However,
121  * since PCI devices are inherently little-endian, on big-endian systems
122  * the bus layer transparently converts it to BE. For virtio-legacy, this
123  * conversion is undesired, so an extra byte swap is required to fix it.
124  */
125 #define vtpci_legacy_read_config_2(sc, o) \
126     le16toh(bus_read_2((sc)->vtpci_res, (o)))
127 #define vtpci_legacy_read_config_4(sc, o) \
128     le32toh(bus_read_4((sc)->vtpci_res, (o)))
129 #define vtpci_legacy_write_config_2(sc, o, v) \
130     bus_write_2((sc)->vtpci_res, (o), (htole16(v)))
131 #define vtpci_legacy_write_config_4(sc, o, v) \
132     bus_write_4((sc)->vtpci_res, (o), (htole32(v)))
133 /* PCI Header LE. On BE systems the bus layer takes care of byte swapping. */
134 #define vtpci_legacy_read_header_2(sc, o) \
135     bus_read_2((sc)->vtpci_res, (o))
136 #define vtpci_legacy_read_header_4(sc, o) \
137     bus_read_4((sc)->vtpci_res, (o))
138 #define vtpci_legacy_write_header_2(sc, o, v) \
139     bus_write_2((sc)->vtpci_res, (o), (v))
140 #define vtpci_legacy_write_header_4(sc, o, v) \
141     bus_write_4((sc)->vtpci_res, (o), (v))
142 
143 static device_method_t vtpci_legacy_methods[] = {
144 	/* Device interface. */
145 	DEVMETHOD(device_probe,			  vtpci_legacy_probe),
146 	DEVMETHOD(device_attach,		  vtpci_legacy_attach),
147 	DEVMETHOD(device_detach,		  vtpci_legacy_detach),
148 	DEVMETHOD(device_suspend,		  vtpci_legacy_suspend),
149 	DEVMETHOD(device_resume,		  vtpci_legacy_resume),
150 	DEVMETHOD(device_shutdown,		  vtpci_legacy_shutdown),
151 
152 	/* Bus interface. */
153 	DEVMETHOD(bus_driver_added,		  vtpci_legacy_driver_added),
154 	DEVMETHOD(bus_child_detached,		  vtpci_legacy_child_detached),
155 	DEVMETHOD(bus_child_pnpinfo_str,	  virtio_child_pnpinfo_str),
156 	DEVMETHOD(bus_read_ivar,		  vtpci_legacy_read_ivar),
157 	DEVMETHOD(bus_write_ivar,		  vtpci_legacy_write_ivar),
158 
159 	/* VirtIO PCI interface. */
160 	DEVMETHOD(virtio_pci_read_isr,		 vtpci_legacy_read_isr),
161 	DEVMETHOD(virtio_pci_get_vq_size,	 vtpci_legacy_get_vq_size),
162 	DEVMETHOD(virtio_pci_get_vq_notify_off,	 vtpci_legacy_get_vq_notify_off),
163 	DEVMETHOD(virtio_pci_set_vq,		 vtpci_legacy_set_vq),
164 	DEVMETHOD(virtio_pci_disable_vq,	 vtpci_legacy_disable_vq),
165 	DEVMETHOD(virtio_pci_register_cfg_msix,  vtpci_legacy_register_cfg_msix),
166 	DEVMETHOD(virtio_pci_register_vq_msix,	 vtpci_legacy_register_vq_msix),
167 
168 	/* VirtIO bus interface. */
169 	DEVMETHOD(virtio_bus_negotiate_features,  vtpci_legacy_negotiate_features),
170 	DEVMETHOD(virtio_bus_with_feature,	  vtpci_legacy_with_feature),
171 	DEVMETHOD(virtio_bus_alloc_virtqueues,	  vtpci_legacy_alloc_virtqueues),
172 	DEVMETHOD(virtio_bus_setup_intr,	  vtpci_legacy_setup_interrupts),
173 	DEVMETHOD(virtio_bus_stop,		  vtpci_legacy_stop),
174 	DEVMETHOD(virtio_bus_reinit,		  vtpci_legacy_reinit),
175 	DEVMETHOD(virtio_bus_reinit_complete,	  vtpci_legacy_reinit_complete),
176 	DEVMETHOD(virtio_bus_notify_vq,		  vtpci_legacy_notify_vq),
177 	DEVMETHOD(virtio_bus_read_device_config,  vtpci_legacy_read_dev_config),
178 	DEVMETHOD(virtio_bus_write_device_config, vtpci_legacy_write_dev_config),
179 
180 	DEVMETHOD_END
181 };
182 
183 static driver_t vtpci_legacy_driver = {
184 	.name = "virtio_pci",
185 	.methods = vtpci_legacy_methods,
186 	.size = sizeof(struct vtpci_legacy_softc)
187 };
188 
189 devclass_t vtpci_legacy_devclass;
190 
191 DRIVER_MODULE(virtio_pci_legacy, pci, vtpci_legacy_driver,
192     vtpci_legacy_devclass, 0, 0);
193 
194 static int
vtpci_legacy_probe(device_t dev)195 vtpci_legacy_probe(device_t dev)
196 {
197 	char desc[64];
198 	const char *name;
199 
200 	if (pci_get_vendor(dev) != VIRTIO_PCI_VENDORID)
201 		return (ENXIO);
202 
203 	if (pci_get_device(dev) < VIRTIO_PCI_DEVICEID_MIN ||
204 	    pci_get_device(dev) > VIRTIO_PCI_DEVICEID_LEGACY_MAX)
205 		return (ENXIO);
206 
207 	if (pci_get_revid(dev) != VIRTIO_PCI_ABI_VERSION)
208 		return (ENXIO);
209 
210 	name = virtio_device_name(pci_get_subdevice(dev));
211 	if (name == NULL)
212 		name = "Unknown";
213 
214 	snprintf(desc, sizeof(desc), "VirtIO PCI (legacy) %s adapter", name);
215 	device_set_desc_copy(dev, desc);
216 
217 	/* Prefer transitional modern VirtIO PCI. */
218 	return (BUS_PROBE_LOW_PRIORITY);
219 }
220 
221 static int
vtpci_legacy_attach(device_t dev)222 vtpci_legacy_attach(device_t dev)
223 {
224 	struct vtpci_legacy_softc *sc;
225 	int error;
226 
227 	sc = device_get_softc(dev);
228 	sc->vtpci_dev = dev;
229 	vtpci_init(&sc->vtpci_common, dev, false);
230 
231 	error = vtpci_legacy_alloc_resources(sc);
232 	if (error) {
233 		device_printf(dev, "cannot map I/O space nor memory space\n");
234 		return (error);
235 	}
236 
237 	if (vtpci_is_msix_available(&sc->vtpci_common) &&
238 	    !vtpci_legacy_setup_msix(sc)) {
239 		device_printf(dev, "cannot setup MSI-x resources\n");
240 		error = ENXIO;
241 		goto fail;
242 	}
243 
244 	vtpci_legacy_reset(sc);
245 
246 	/* Tell the host we've noticed this device. */
247 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_ACK);
248 
249 	error = vtpci_add_child(&sc->vtpci_common);
250 	if (error)
251 		goto fail;
252 
253 	vtpci_legacy_probe_and_attach_child(sc);
254 
255 	return (0);
256 
257 fail:
258 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_FAILED);
259 	vtpci_legacy_detach(dev);
260 
261 	return (error);
262 }
263 
264 static int
vtpci_legacy_detach(device_t dev)265 vtpci_legacy_detach(device_t dev)
266 {
267 	struct vtpci_legacy_softc *sc;
268 	int error;
269 
270 	sc = device_get_softc(dev);
271 
272 	error = vtpci_delete_child(&sc->vtpci_common);
273 	if (error)
274 		return (error);
275 
276 	vtpci_legacy_reset(sc);
277 	vtpci_legacy_teardown_msix(sc);
278 	vtpci_legacy_free_resources(sc);
279 
280 	return (0);
281 }
282 
283 static int
vtpci_legacy_suspend(device_t dev)284 vtpci_legacy_suspend(device_t dev)
285 {
286 	return (bus_generic_suspend(dev));
287 }
288 
289 static int
vtpci_legacy_resume(device_t dev)290 vtpci_legacy_resume(device_t dev)
291 {
292 	return (bus_generic_resume(dev));
293 }
294 
295 static int
vtpci_legacy_shutdown(device_t dev)296 vtpci_legacy_shutdown(device_t dev)
297 {
298 	(void) bus_generic_shutdown(dev);
299 	/* Forcibly stop the host device. */
300 	vtpci_legacy_stop(dev);
301 
302 	return (0);
303 }
304 
305 static void
vtpci_legacy_driver_added(device_t dev,driver_t * driver)306 vtpci_legacy_driver_added(device_t dev, driver_t *driver)
307 {
308 	vtpci_legacy_probe_and_attach_child(device_get_softc(dev));
309 }
310 
311 static void
vtpci_legacy_child_detached(device_t dev,device_t child)312 vtpci_legacy_child_detached(device_t dev, device_t child)
313 {
314 	struct vtpci_legacy_softc *sc;
315 
316 	sc = device_get_softc(dev);
317 
318 	vtpci_legacy_reset(sc);
319 	vtpci_child_detached(&sc->vtpci_common);
320 
321 	/* After the reset, retell the host we've noticed this device. */
322 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_ACK);
323 }
324 
325 static int
vtpci_legacy_read_ivar(device_t dev,device_t child,int index,uintptr_t * result)326 vtpci_legacy_read_ivar(device_t dev, device_t child, int index,
327     uintptr_t *result)
328 {
329 	struct vtpci_legacy_softc *sc;
330 	struct vtpci_common *cn;
331 
332 	sc = device_get_softc(dev);
333 	cn = &sc->vtpci_common;
334 
335 	if (vtpci_child_device(cn) != child)
336 		return (ENOENT);
337 
338 	switch (index) {
339 	case VIRTIO_IVAR_DEVTYPE:
340 		*result = pci_get_subdevice(dev);
341 		break;
342 	default:
343 		return (vtpci_read_ivar(cn, index, result));
344 	}
345 
346 	return (0);
347 }
348 
349 static int
vtpci_legacy_write_ivar(device_t dev,device_t child,int index,uintptr_t value)350 vtpci_legacy_write_ivar(device_t dev, device_t child, int index, uintptr_t value)
351 {
352 	struct vtpci_legacy_softc *sc;
353 	struct vtpci_common *cn;
354 
355 	sc = device_get_softc(dev);
356 	cn = &sc->vtpci_common;
357 
358 	if (vtpci_child_device(cn) != child)
359 		return (ENOENT);
360 
361 	switch (index) {
362 	default:
363 		return (vtpci_write_ivar(cn, index, value));
364 	}
365 
366 	return (0);
367 }
368 
369 static uint64_t
vtpci_legacy_negotiate_features(device_t dev,uint64_t child_features)370 vtpci_legacy_negotiate_features(device_t dev, uint64_t child_features)
371 {
372 	struct vtpci_legacy_softc *sc;
373 	uint64_t host_features, features;
374 
375 	sc = device_get_softc(dev);
376 	host_features = vtpci_legacy_read_header_4(sc, VIRTIO_PCI_HOST_FEATURES);
377 
378 	features = vtpci_negotiate_features(&sc->vtpci_common,
379 	    child_features, host_features);
380 	vtpci_legacy_write_header_4(sc, VIRTIO_PCI_GUEST_FEATURES, features);
381 
382 	return (features);
383 }
384 
385 static int
vtpci_legacy_with_feature(device_t dev,uint64_t feature)386 vtpci_legacy_with_feature(device_t dev, uint64_t feature)
387 {
388 	struct vtpci_legacy_softc *sc;
389 
390 	sc = device_get_softc(dev);
391 
392 	return (vtpci_with_feature(&sc->vtpci_common, feature));
393 }
394 
395 static int
vtpci_legacy_alloc_virtqueues(device_t dev,int flags,int nvqs,struct vq_alloc_info * vq_info)396 vtpci_legacy_alloc_virtqueues(device_t dev, int flags, int nvqs,
397     struct vq_alloc_info *vq_info)
398 {
399 	struct vtpci_legacy_softc *sc;
400 	struct vtpci_common *cn;
401 
402 	sc = device_get_softc(dev);
403 	cn = &sc->vtpci_common;
404 
405 	return (vtpci_alloc_virtqueues(cn, flags, nvqs, vq_info));
406 }
407 
408 static int
vtpci_legacy_setup_interrupts(device_t dev,enum intr_type type)409 vtpci_legacy_setup_interrupts(device_t dev, enum intr_type type)
410 {
411 	struct vtpci_legacy_softc *sc;
412 
413 	sc = device_get_softc(dev);
414 
415 	return (vtpci_setup_interrupts(&sc->vtpci_common, type));
416 }
417 
418 static void
vtpci_legacy_stop(device_t dev)419 vtpci_legacy_stop(device_t dev)
420 {
421 	vtpci_legacy_reset(device_get_softc(dev));
422 }
423 
424 static int
vtpci_legacy_reinit(device_t dev,uint64_t features)425 vtpci_legacy_reinit(device_t dev, uint64_t features)
426 {
427 	struct vtpci_legacy_softc *sc;
428 	struct vtpci_common *cn;
429 	int error;
430 
431 	sc = device_get_softc(dev);
432 	cn = &sc->vtpci_common;
433 
434 	/*
435 	 * Redrive the device initialization. This is a bit of an abuse of
436 	 * the specification, but VirtualBox, QEMU/KVM, and BHyVe seem to
437 	 * play nice.
438 	 *
439 	 * We do not allow the host device to change from what was originally
440 	 * negotiated beyond what the guest driver changed. MSIX state should
441 	 * not change, number of virtqueues and their size remain the same, etc.
442 	 * This will need to be rethought when we want to support migration.
443 	 */
444 
445 	if (vtpci_legacy_get_status(sc) != VIRTIO_CONFIG_STATUS_RESET)
446 		vtpci_legacy_stop(dev);
447 
448 	/*
449 	 * Quickly drive the status through ACK and DRIVER. The device does
450 	 * not become usable again until DRIVER_OK in reinit complete.
451 	 */
452 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_ACK);
453 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER);
454 
455 	vtpci_legacy_negotiate_features(dev, features);
456 
457 	error = vtpci_reinit(cn);
458 	if (error)
459 		return (error);
460 
461 	return (0);
462 }
463 
464 static void
vtpci_legacy_reinit_complete(device_t dev)465 vtpci_legacy_reinit_complete(device_t dev)
466 {
467 	struct vtpci_legacy_softc *sc;
468 
469 	sc = device_get_softc(dev);
470 
471 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER_OK);
472 }
473 
474 static void
vtpci_legacy_notify_vq(device_t dev,uint16_t queue,bus_size_t offset)475 vtpci_legacy_notify_vq(device_t dev, uint16_t queue, bus_size_t offset)
476 {
477 	struct vtpci_legacy_softc *sc;
478 
479 	sc = device_get_softc(dev);
480 	MPASS(offset == VIRTIO_PCI_QUEUE_NOTIFY);
481 
482 	vtpci_legacy_write_header_2(sc, offset, queue);
483 }
484 
485 static uint8_t
vtpci_legacy_get_status(struct vtpci_legacy_softc * sc)486 vtpci_legacy_get_status(struct vtpci_legacy_softc *sc)
487 {
488 	return (vtpci_legacy_read_config_1(sc, VIRTIO_PCI_STATUS));
489 }
490 
491 static void
vtpci_legacy_set_status(struct vtpci_legacy_softc * sc,uint8_t status)492 vtpci_legacy_set_status(struct vtpci_legacy_softc *sc, uint8_t status)
493 {
494 	if (status != VIRTIO_CONFIG_STATUS_RESET)
495 		status |= vtpci_legacy_get_status(sc);
496 
497 	vtpci_legacy_write_config_1(sc, VIRTIO_PCI_STATUS, status);
498 }
499 
500 static void
vtpci_legacy_read_dev_config(device_t dev,bus_size_t offset,void * dst,int length)501 vtpci_legacy_read_dev_config(device_t dev, bus_size_t offset,
502     void *dst, int length)
503 {
504 	struct vtpci_legacy_softc *sc;
505 	bus_size_t off;
506 	uint8_t *d;
507 	int i;
508 
509 	sc = device_get_softc(dev);
510 	off = VIRTIO_PCI_LEGACY_CONFIG(sc) + offset;
511 
512 	d = dst;
513 	for (i = 0; i < length; i++) {
514 		d[i] = vtpci_legacy_read_config_1(sc, off + i);
515 	}
516 }
517 
518 static void
vtpci_legacy_write_dev_config(device_t dev,bus_size_t offset,const void * src,int length)519 vtpci_legacy_write_dev_config(device_t dev, bus_size_t offset,
520     const void *src, int length)
521 {
522 	struct vtpci_legacy_softc *sc;
523 	bus_size_t off;
524 	const uint8_t *s;
525 	int i;
526 
527 	sc = device_get_softc(dev);
528 	off = VIRTIO_PCI_LEGACY_CONFIG(sc) + offset;
529 
530 	s = src;
531 	for (i = 0; i < length; i++) {
532 		vtpci_legacy_write_config_1(sc, off + i, s[i]);
533 	}
534 }
535 
536 static bool
vtpci_legacy_setup_msix(struct vtpci_legacy_softc * sc)537 vtpci_legacy_setup_msix(struct vtpci_legacy_softc *sc)
538 {
539 	device_t dev;
540 	int rid, table_rid;
541 
542 	dev = sc->vtpci_dev;
543 
544 	rid = table_rid = pci_msix_table_bar(dev);
545 	if (rid != PCIR_BAR(0)) {
546 		sc->vtpci_msix_table_res = bus_alloc_resource_any(
547 		    dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
548 		if (sc->vtpci_msix_table_res == NULL)
549 			return (false);
550 	}
551 
552 	rid = pci_msix_pba_bar(dev);
553 	if (rid != table_rid && rid != PCIR_BAR(0)) {
554 		sc->vtpci_msix_pba_res = bus_alloc_resource_any(
555 		    dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
556 		if (sc->vtpci_msix_pba_res == NULL)
557 			return (false);
558 	}
559 
560 	return (true);
561 }
562 
563 static void
vtpci_legacy_teardown_msix(struct vtpci_legacy_softc * sc)564 vtpci_legacy_teardown_msix(struct vtpci_legacy_softc *sc)
565 {
566 	device_t dev;
567 
568 	dev = sc->vtpci_dev;
569 
570 	if (sc->vtpci_msix_pba_res != NULL) {
571 		bus_release_resource(dev, SYS_RES_MEMORY,
572 		    rman_get_rid(sc->vtpci_msix_pba_res),
573 		    sc->vtpci_msix_pba_res);
574 		sc->vtpci_msix_pba_res = NULL;
575 	}
576 	if (sc->vtpci_msix_table_res != NULL) {
577 		bus_release_resource(dev, SYS_RES_MEMORY,
578 		    rman_get_rid(sc->vtpci_msix_table_res),
579 		    sc->vtpci_msix_table_res);
580 		sc->vtpci_msix_table_res = NULL;
581 	}
582 }
583 
584 static int
vtpci_legacy_alloc_resources(struct vtpci_legacy_softc * sc)585 vtpci_legacy_alloc_resources(struct vtpci_legacy_softc *sc)
586 {
587 	const int res_types[] = { SYS_RES_IOPORT, SYS_RES_MEMORY };
588 	device_t dev;
589 	int rid, i;
590 
591 	dev = sc->vtpci_dev;
592 
593 	/*
594 	 * Most hypervisors export the common configuration structure in IO
595 	 * space, but some use memory space; try both.
596 	 */
597 	for (i = 0; nitems(res_types); i++) {
598 		rid = PCIR_BAR(0);
599 		sc->vtpci_res_type = res_types[i];
600 		sc->vtpci_res = bus_alloc_resource_any(dev, res_types[i], &rid,
601 		    RF_ACTIVE);
602 		if (sc->vtpci_res != NULL)
603 			break;
604 	}
605 	if (sc->vtpci_res == NULL)
606 		return (ENXIO);
607 
608 	return (0);
609 }
610 
611 static void
vtpci_legacy_free_resources(struct vtpci_legacy_softc * sc)612 vtpci_legacy_free_resources(struct vtpci_legacy_softc *sc)
613 {
614 	device_t dev;
615 
616 	dev = sc->vtpci_dev;
617 
618 	if (sc->vtpci_res != NULL) {
619 		bus_release_resource(dev, sc->vtpci_res_type, PCIR_BAR(0),
620 		    sc->vtpci_res);
621 		sc->vtpci_res = NULL;
622 	}
623 }
624 
625 static void
vtpci_legacy_probe_and_attach_child(struct vtpci_legacy_softc * sc)626 vtpci_legacy_probe_and_attach_child(struct vtpci_legacy_softc *sc)
627 {
628 	device_t dev, child;
629 
630 	dev = sc->vtpci_dev;
631 	child = vtpci_child_device(&sc->vtpci_common);
632 
633 	if (child == NULL || device_get_state(child) != DS_NOTPRESENT)
634 		return;
635 
636 	if (device_probe(child) != 0)
637 		return;
638 
639 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER);
640 
641 	if (device_attach(child) != 0) {
642 		vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_FAILED);
643 		/* Reset status for future attempt. */
644 		vtpci_legacy_child_detached(dev, child);
645 	} else {
646 		vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER_OK);
647 		VIRTIO_ATTACH_COMPLETED(child);
648 	}
649 }
650 
651 static int
vtpci_legacy_register_msix(struct vtpci_legacy_softc * sc,int offset,struct vtpci_interrupt * intr)652 vtpci_legacy_register_msix(struct vtpci_legacy_softc *sc, int offset,
653     struct vtpci_interrupt *intr)
654 {
655 	uint16_t vector;
656 
657 	if (intr != NULL) {
658 		/* Map from guest rid to host vector. */
659 		vector = intr->vti_rid - 1;
660 	} else
661 		vector = VIRTIO_MSI_NO_VECTOR;
662 
663 	vtpci_legacy_write_header_2(sc, offset, vector);
664 	return (vtpci_legacy_read_header_2(sc, offset) == vector ? 0 : ENODEV);
665 }
666 
667 static int
vtpci_legacy_register_cfg_msix(device_t dev,struct vtpci_interrupt * intr)668 vtpci_legacy_register_cfg_msix(device_t dev, struct vtpci_interrupt *intr)
669 {
670 	struct vtpci_legacy_softc *sc;
671 	int error;
672 
673 	sc = device_get_softc(dev);
674 
675 	error = vtpci_legacy_register_msix(sc, VIRTIO_MSI_CONFIG_VECTOR, intr);
676 	if (error) {
677 		device_printf(dev,
678 		    "unable to register config MSIX interrupt\n");
679 		return (error);
680 	}
681 
682 	return (0);
683 }
684 
685 static int
vtpci_legacy_register_vq_msix(device_t dev,int idx,struct vtpci_interrupt * intr)686 vtpci_legacy_register_vq_msix(device_t dev, int idx,
687     struct vtpci_interrupt *intr)
688 {
689 	struct vtpci_legacy_softc *sc;
690 	int error;
691 
692 	sc = device_get_softc(dev);
693 
694 	vtpci_legacy_select_virtqueue(sc, idx);
695 	error = vtpci_legacy_register_msix(sc, VIRTIO_MSI_QUEUE_VECTOR, intr);
696 	if (error) {
697 		device_printf(dev,
698 		    "unable to register virtqueue MSIX interrupt\n");
699 		return (error);
700 	}
701 
702 	return (0);
703 }
704 
705 static void
vtpci_legacy_reset(struct vtpci_legacy_softc * sc)706 vtpci_legacy_reset(struct vtpci_legacy_softc *sc)
707 {
708 	/*
709 	 * Setting the status to RESET sets the host device to the
710 	 * original, uninitialized state.
711 	 */
712 	vtpci_legacy_set_status(sc, VIRTIO_CONFIG_STATUS_RESET);
713 	(void) vtpci_legacy_get_status(sc);
714 }
715 
716 static void
vtpci_legacy_select_virtqueue(struct vtpci_legacy_softc * sc,int idx)717 vtpci_legacy_select_virtqueue(struct vtpci_legacy_softc *sc, int idx)
718 {
719 	vtpci_legacy_write_header_2(sc, VIRTIO_PCI_QUEUE_SEL, idx);
720 }
721 
722 static uint8_t
vtpci_legacy_read_isr(device_t dev)723 vtpci_legacy_read_isr(device_t dev)
724 {
725 	struct vtpci_legacy_softc *sc;
726 
727 	sc = device_get_softc(dev);
728 
729 	return (vtpci_legacy_read_config_1(sc, VIRTIO_PCI_ISR));
730 }
731 
732 static uint16_t
vtpci_legacy_get_vq_size(device_t dev,int idx)733 vtpci_legacy_get_vq_size(device_t dev, int idx)
734 {
735 	struct vtpci_legacy_softc *sc;
736 
737 	sc = device_get_softc(dev);
738 
739 	vtpci_legacy_select_virtqueue(sc, idx);
740 	return (vtpci_legacy_read_header_2(sc, VIRTIO_PCI_QUEUE_NUM));
741 }
742 
743 static bus_size_t
vtpci_legacy_get_vq_notify_off(device_t dev,int idx)744 vtpci_legacy_get_vq_notify_off(device_t dev, int idx)
745 {
746 	return (VIRTIO_PCI_QUEUE_NOTIFY);
747 }
748 
749 static void
vtpci_legacy_set_vq(device_t dev,struct virtqueue * vq)750 vtpci_legacy_set_vq(device_t dev, struct virtqueue *vq)
751 {
752 	struct vtpci_legacy_softc *sc;
753 
754 	sc = device_get_softc(dev);
755 
756 	vtpci_legacy_select_virtqueue(sc, virtqueue_index(vq));
757 	vtpci_legacy_write_header_4(sc, VIRTIO_PCI_QUEUE_PFN,
758 	    virtqueue_paddr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT);
759 }
760 
761 static void
vtpci_legacy_disable_vq(device_t dev,int idx)762 vtpci_legacy_disable_vq(device_t dev, int idx)
763 {
764 	struct vtpci_legacy_softc *sc;
765 
766 	sc = device_get_softc(dev);
767 
768 	vtpci_legacy_select_virtqueue(sc, idx);
769 	vtpci_legacy_write_header_4(sc, VIRTIO_PCI_QUEUE_PFN, 0);
770 }
771