xref: /freebsd/sys/dev/virtio/pci/virtio_pci_modern.c (revision 1db64f89363c97858961c4df0b7d02f3223723cf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2017, 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 modern VirtIO PCI interface. */
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/bus.h>
34 #include <sys/lock.h>
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 
38 #include <machine/bus.h>
39 #include <machine/cpu.h>
40 #include <machine/resource.h>
41 #include <sys/bus.h>
42 #include <sys/rman.h>
43 
44 #include <dev/pci/pcivar.h>
45 #include <dev/pci/pcireg.h>
46 
47 #include <dev/virtio/virtio.h>
48 #include <dev/virtio/virtqueue.h>
49 #include <dev/virtio/pci/virtio_pci.h>
50 #include <dev/virtio/pci/virtio_pci_modern_var.h>
51 
52 #include "virtio_bus_if.h"
53 #include "virtio_pci_if.h"
54 #include "virtio_if.h"
55 
56 struct vtpci_modern_resource_map {
57 	struct resource_map	vtrm_map;
58 	int			vtrm_cap_offset;
59 	int			vtrm_bar;
60 	int			vtrm_offset;
61 	int			vtrm_length;
62 	int			vtrm_type;	/* SYS_RES_{MEMORY, IOPORT} */
63 };
64 
65 struct vtpci_modern_bar_resource {
66 	struct resource		*vtbr_res;
67 	int			 vtbr_type;
68 };
69 
70 struct vtpci_modern_softc {
71 	device_t			 vtpci_dev;
72 	struct vtpci_common		 vtpci_common;
73 	uint32_t			 vtpci_notify_offset_multiplier;
74 	uint16_t			 vtpci_devid;
75 	int				 vtpci_msix_bar;
76 	struct resource			*vtpci_msix_res;
77 
78 	struct vtpci_modern_resource_map vtpci_common_res_map;
79 	struct vtpci_modern_resource_map vtpci_notify_res_map;
80 	struct vtpci_modern_resource_map vtpci_isr_res_map;
81 	struct vtpci_modern_resource_map vtpci_device_res_map;
82 
83 #define VTPCI_MODERN_MAX_BARS		6
84 	struct vtpci_modern_bar_resource vtpci_bar_res[VTPCI_MODERN_MAX_BARS];
85 };
86 
87 static int	vtpci_modern_probe(device_t);
88 static int	vtpci_modern_attach(device_t);
89 static int	vtpci_modern_detach(device_t);
90 static int	vtpci_modern_suspend(device_t);
91 static int	vtpci_modern_resume(device_t);
92 static int	vtpci_modern_shutdown(device_t);
93 
94 static void	vtpci_modern_driver_added(device_t, driver_t *);
95 static void	vtpci_modern_child_detached(device_t, device_t);
96 static int	vtpci_modern_read_ivar(device_t, device_t, int, uintptr_t *);
97 static int	vtpci_modern_write_ivar(device_t, device_t, int, uintptr_t);
98 
99 static uint8_t	vtpci_modern_read_isr(device_t);
100 static uint16_t	vtpci_modern_get_vq_size(device_t, int);
101 static bus_size_t vtpci_modern_get_vq_notify_off(device_t, int);
102 static void	vtpci_modern_set_vq(device_t, struct virtqueue *);
103 static void	vtpci_modern_disable_vq(device_t, int);
104 static int	vtpci_modern_register_msix(struct vtpci_modern_softc *, int,
105 		    struct vtpci_interrupt *);
106 static int	vtpci_modern_register_cfg_msix(device_t,
107 		    struct vtpci_interrupt *);
108 static int	vtpci_modern_register_vq_msix(device_t, int idx,
109 		    struct vtpci_interrupt *);
110 
111 static uint64_t	vtpci_modern_negotiate_features(device_t, uint64_t);
112 static int	vtpci_modern_finalize_features(device_t);
113 static bool	vtpci_modern_with_feature(device_t, uint64_t);
114 static int	vtpci_modern_alloc_virtqueues(device_t, int,
115 		    struct vq_alloc_info *);
116 static int	vtpci_modern_setup_interrupts(device_t, enum intr_type);
117 static void	vtpci_modern_stop(device_t);
118 static int	vtpci_modern_reinit(device_t, uint64_t);
119 static void	vtpci_modern_reinit_complete(device_t);
120 static void	vtpci_modern_notify_vq(device_t, uint16_t, bus_size_t);
121 static int	vtpci_modern_config_generation(device_t);
122 static void	vtpci_modern_read_dev_config(device_t, bus_size_t, void *, int);
123 static void	vtpci_modern_write_dev_config(device_t, bus_size_t, const void *, int);
124 
125 static int	vtpci_modern_probe_configs(device_t);
126 static int	vtpci_modern_find_cap(device_t, uint8_t, int *);
127 static int	vtpci_modern_map_configs(struct vtpci_modern_softc *);
128 static void	vtpci_modern_unmap_configs(struct vtpci_modern_softc *);
129 static int	vtpci_modern_find_cap_resource(struct vtpci_modern_softc *,
130 		     uint8_t, int, int, struct vtpci_modern_resource_map *);
131 static int	vtpci_modern_bar_type(struct vtpci_modern_softc *, int);
132 static struct resource *vtpci_modern_get_bar_resource(
133 		    struct vtpci_modern_softc *, int, int);
134 static struct resource *vtpci_modern_alloc_bar_resource(
135 		    struct vtpci_modern_softc *, int, int);
136 static void	vtpci_modern_free_bar_resources(struct vtpci_modern_softc *);
137 static int	vtpci_modern_alloc_resource_map(struct vtpci_modern_softc *,
138 		    struct vtpci_modern_resource_map *);
139 static void	vtpci_modern_free_resource_map(struct vtpci_modern_softc *,
140 		    struct vtpci_modern_resource_map *);
141 static void	vtpci_modern_alloc_msix_resource(struct vtpci_modern_softc *);
142 static void	vtpci_modern_free_msix_resource(struct vtpci_modern_softc *);
143 
144 static void	vtpci_modern_probe_and_attach_child(struct vtpci_modern_softc *);
145 
146 static uint64_t vtpci_modern_read_features(struct vtpci_modern_softc *);
147 static void	vtpci_modern_write_features(struct vtpci_modern_softc *,
148 		    uint64_t);
149 static void	vtpci_modern_select_virtqueue(struct vtpci_modern_softc *, int);
150 static uint8_t	vtpci_modern_get_status(struct vtpci_modern_softc *);
151 static void	vtpci_modern_set_status(struct vtpci_modern_softc *, uint8_t);
152 static void	vtpci_modern_reset(struct vtpci_modern_softc *);
153 static void	vtpci_modern_enable_virtqueues(struct vtpci_modern_softc *);
154 
155 static uint8_t	vtpci_modern_read_common_1(struct vtpci_modern_softc *,
156 		    bus_size_t);
157 static uint16_t vtpci_modern_read_common_2(struct vtpci_modern_softc *,
158 		    bus_size_t);
159 static uint32_t vtpci_modern_read_common_4(struct vtpci_modern_softc *,
160 		    bus_size_t);
161 static void	vtpci_modern_write_common_1(struct vtpci_modern_softc *,
162 		     bus_size_t, uint8_t);
163 static void	vtpci_modern_write_common_2(struct vtpci_modern_softc *,
164 		     bus_size_t, uint16_t);
165 static void	vtpci_modern_write_common_4(struct vtpci_modern_softc *,
166 		    bus_size_t, uint32_t);
167 static void	vtpci_modern_write_common_8(struct vtpci_modern_softc *,
168 		    bus_size_t, uint64_t);
169 static void	vtpci_modern_write_notify_2(struct vtpci_modern_softc *,
170 		    bus_size_t, uint16_t);
171 static uint8_t  vtpci_modern_read_isr_1(struct vtpci_modern_softc *,
172 		    bus_size_t);
173 static uint8_t	vtpci_modern_read_device_1(struct vtpci_modern_softc *,
174 		    bus_size_t);
175 static uint16_t vtpci_modern_read_device_2(struct vtpci_modern_softc *,
176 		    bus_size_t);
177 static uint32_t vtpci_modern_read_device_4(struct vtpci_modern_softc *,
178 		    bus_size_t);
179 static uint64_t vtpci_modern_read_device_8(struct vtpci_modern_softc *,
180 		    bus_size_t);
181 static void	vtpci_modern_write_device_1(struct vtpci_modern_softc *,
182 		    bus_size_t, uint8_t);
183 static void	vtpci_modern_write_device_2(struct vtpci_modern_softc *,
184 		    bus_size_t, uint16_t);
185 static void	vtpci_modern_write_device_4(struct vtpci_modern_softc *,
186 		    bus_size_t, uint32_t);
187 static void	vtpci_modern_write_device_8(struct vtpci_modern_softc *,
188 		    bus_size_t, uint64_t);
189 
190 /* Tunables. */
191 static int vtpci_modern_transitional = 0;
192 TUNABLE_INT("hw.virtio.pci.transitional", &vtpci_modern_transitional);
193 
194 static device_method_t vtpci_modern_methods[] = {
195 	/* Device interface. */
196 	DEVMETHOD(device_probe,			vtpci_modern_probe),
197 	DEVMETHOD(device_attach,		vtpci_modern_attach),
198 	DEVMETHOD(device_detach,		vtpci_modern_detach),
199 	DEVMETHOD(device_suspend,		vtpci_modern_suspend),
200 	DEVMETHOD(device_resume,		vtpci_modern_resume),
201 	DEVMETHOD(device_shutdown,		vtpci_modern_shutdown),
202 
203 	/* Bus interface. */
204 	DEVMETHOD(bus_driver_added,		vtpci_modern_driver_added),
205 	DEVMETHOD(bus_child_detached,		vtpci_modern_child_detached),
206 	DEVMETHOD(bus_child_pnpinfo,		virtio_child_pnpinfo),
207 	DEVMETHOD(bus_read_ivar,		vtpci_modern_read_ivar),
208 	DEVMETHOD(bus_write_ivar,		vtpci_modern_write_ivar),
209 
210 	/* VirtIO PCI interface. */
211 	DEVMETHOD(virtio_pci_read_isr,		 vtpci_modern_read_isr),
212 	DEVMETHOD(virtio_pci_get_vq_size,	 vtpci_modern_get_vq_size),
213 	DEVMETHOD(virtio_pci_get_vq_notify_off,	 vtpci_modern_get_vq_notify_off),
214 	DEVMETHOD(virtio_pci_set_vq,		 vtpci_modern_set_vq),
215 	DEVMETHOD(virtio_pci_disable_vq,	 vtpci_modern_disable_vq),
216 	DEVMETHOD(virtio_pci_register_cfg_msix,	 vtpci_modern_register_cfg_msix),
217 	DEVMETHOD(virtio_pci_register_vq_msix,	 vtpci_modern_register_vq_msix),
218 
219 	/* VirtIO bus interface. */
220 	DEVMETHOD(virtio_bus_negotiate_features,  vtpci_modern_negotiate_features),
221 	DEVMETHOD(virtio_bus_finalize_features,	  vtpci_modern_finalize_features),
222 	DEVMETHOD(virtio_bus_with_feature,	  vtpci_modern_with_feature),
223 	DEVMETHOD(virtio_bus_alloc_virtqueues,	  vtpci_modern_alloc_virtqueues),
224 	DEVMETHOD(virtio_bus_setup_intr,	  vtpci_modern_setup_interrupts),
225 	DEVMETHOD(virtio_bus_stop,		  vtpci_modern_stop),
226 	DEVMETHOD(virtio_bus_reinit,		  vtpci_modern_reinit),
227 	DEVMETHOD(virtio_bus_reinit_complete,	  vtpci_modern_reinit_complete),
228 	DEVMETHOD(virtio_bus_notify_vq,		  vtpci_modern_notify_vq),
229 	DEVMETHOD(virtio_bus_config_generation,	  vtpci_modern_config_generation),
230 	DEVMETHOD(virtio_bus_read_device_config,  vtpci_modern_read_dev_config),
231 	DEVMETHOD(virtio_bus_write_device_config, vtpci_modern_write_dev_config),
232 
233 	DEVMETHOD_END
234 };
235 
236 static driver_t vtpci_modern_driver = {
237 	.name = "virtio_pci",
238 	.methods = vtpci_modern_methods,
239 	.size = sizeof(struct vtpci_modern_softc)
240 };
241 
242 DRIVER_MODULE(virtio_pci_modern, pci, vtpci_modern_driver, 0, 0);
243 
244 static int
245 vtpci_modern_probe(device_t dev)
246 {
247 	char desc[64];
248 	const char *name;
249 	uint16_t devid;
250 
251 	if (pci_get_vendor(dev) != VIRTIO_PCI_VENDORID)
252 		return (ENXIO);
253 
254 	if (pci_get_device(dev) < VIRTIO_PCI_DEVICEID_MIN ||
255 	    pci_get_device(dev) > VIRTIO_PCI_DEVICEID_MODERN_MAX)
256 		return (ENXIO);
257 
258 	if (pci_get_device(dev) < VIRTIO_PCI_DEVICEID_MODERN_MIN) {
259 		if (!vtpci_modern_transitional)
260 			return (ENXIO);
261 		devid = pci_get_subdevice(dev);
262 	} else
263 		devid = pci_get_device(dev) - VIRTIO_PCI_DEVICEID_MODERN_MIN;
264 
265 	if (vtpci_modern_probe_configs(dev) != 0)
266 		return (ENXIO);
267 
268 	name = virtio_device_name(devid);
269 	if (name == NULL)
270 		name = "Unknown";
271 
272 	snprintf(desc, sizeof(desc), "VirtIO PCI (modern) %s adapter", name);
273 	device_set_desc_copy(dev, desc);
274 
275 	return (BUS_PROBE_DEFAULT);
276 }
277 
278 static int
279 vtpci_modern_attach(device_t dev)
280 {
281 	struct vtpci_modern_softc *sc;
282 	int error;
283 
284 	sc = device_get_softc(dev);
285 	sc->vtpci_dev = dev;
286 	vtpci_init(&sc->vtpci_common, dev, true);
287 
288 	if (pci_get_device(dev) < VIRTIO_PCI_DEVICEID_MODERN_MIN)
289 		sc->vtpci_devid = pci_get_subdevice(dev);
290 	else
291 		sc->vtpci_devid = pci_get_device(dev) -
292 		    VIRTIO_PCI_DEVICEID_MODERN_MIN;
293 
294 	error = vtpci_modern_map_configs(sc);
295 	if (error) {
296 		device_printf(dev, "cannot map configs\n");
297 		vtpci_modern_unmap_configs(sc);
298 		return (error);
299 	}
300 
301 	vtpci_modern_reset(sc);
302 
303 	/* Tell the host we've noticed this device. */
304 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_ACK);
305 
306 	error = vtpci_add_child(&sc->vtpci_common);
307 	if (error)
308 		goto fail;
309 
310 	vtpci_modern_probe_and_attach_child(sc);
311 
312 	return (0);
313 
314 fail:
315 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_FAILED);
316 	vtpci_modern_detach(dev);
317 
318 	return (error);
319 }
320 
321 static int
322 vtpci_modern_detach(device_t dev)
323 {
324 	struct vtpci_modern_softc *sc;
325 	int error;
326 
327 	sc = device_get_softc(dev);
328 
329 	error = vtpci_delete_child(&sc->vtpci_common);
330 	if (error)
331 		return (error);
332 
333 	vtpci_modern_reset(sc);
334 	vtpci_modern_unmap_configs(sc);
335 
336 	return (0);
337 }
338 
339 static int
340 vtpci_modern_suspend(device_t dev)
341 {
342 	return (bus_generic_suspend(dev));
343 }
344 
345 static int
346 vtpci_modern_resume(device_t dev)
347 {
348 	return (bus_generic_resume(dev));
349 }
350 
351 static int
352 vtpci_modern_shutdown(device_t dev)
353 {
354 	(void) bus_generic_shutdown(dev);
355 	/* Forcibly stop the host device. */
356 	vtpci_modern_stop(dev);
357 
358 	return (0);
359 }
360 
361 static void
362 vtpci_modern_driver_added(device_t dev, driver_t *driver)
363 {
364 	vtpci_modern_probe_and_attach_child(device_get_softc(dev));
365 }
366 
367 static void
368 vtpci_modern_child_detached(device_t dev, device_t child)
369 {
370 	struct vtpci_modern_softc *sc;
371 
372 	sc = device_get_softc(dev);
373 
374 	vtpci_modern_reset(sc);
375 	vtpci_child_detached(&sc->vtpci_common);
376 
377 	/* After the reset, retell the host we've noticed this device. */
378 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_ACK);
379 }
380 
381 static int
382 vtpci_modern_read_ivar(device_t dev, device_t child, int index,
383     uintptr_t *result)
384 {
385 	struct vtpci_modern_softc *sc;
386 	struct vtpci_common *cn;
387 
388 	sc = device_get_softc(dev);
389 	cn = &sc->vtpci_common;
390 
391 	if (vtpci_child_device(cn) != child)
392 		return (ENOENT);
393 
394 	switch (index) {
395 	case VIRTIO_IVAR_DEVTYPE:
396 		*result = sc->vtpci_devid;
397 		break;
398 	default:
399 		return (vtpci_read_ivar(cn, index, result));
400 	}
401 
402 	return (0);
403 }
404 
405 static int
406 vtpci_modern_write_ivar(device_t dev, device_t child, int index,
407     uintptr_t value)
408 {
409 	struct vtpci_modern_softc *sc;
410 	struct vtpci_common *cn;
411 
412 	sc = device_get_softc(dev);
413 	cn = &sc->vtpci_common;
414 
415 	if (vtpci_child_device(cn) != child)
416 		return (ENOENT);
417 
418 	switch (index) {
419 	default:
420 		return (vtpci_write_ivar(cn, index, value));
421 	}
422 
423 	return (0);
424 }
425 
426 static uint64_t
427 vtpci_modern_negotiate_features(device_t dev, uint64_t child_features)
428 {
429 	struct vtpci_modern_softc *sc;
430 	uint64_t host_features, features;
431 
432 	sc = device_get_softc(dev);
433 	host_features = vtpci_modern_read_features(sc);
434 
435 	/*
436 	 * Since the driver was added as a child of the modern PCI bus,
437 	 * always add the V1 flag.
438 	 */
439 	child_features |= VIRTIO_F_VERSION_1;
440 
441 	features = vtpci_negotiate_features(&sc->vtpci_common,
442 	    child_features, host_features);
443 	vtpci_modern_write_features(sc, features);
444 
445 	return (features);
446 }
447 
448 static int
449 vtpci_modern_finalize_features(device_t dev)
450 {
451 	struct vtpci_modern_softc *sc;
452 	uint8_t status;
453 
454 	sc = device_get_softc(dev);
455 
456 	/*
457 	 * Must re-read the status after setting it to verify the negotiated
458 	 * features were accepted by the device.
459 	 */
460 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_S_FEATURES_OK);
461 
462 	status = vtpci_modern_get_status(sc);
463 	if ((status & VIRTIO_CONFIG_S_FEATURES_OK) == 0) {
464 		device_printf(dev, "desired features were not accepted\n");
465 		return (ENOTSUP);
466 	}
467 
468 	return (0);
469 }
470 
471 static bool
472 vtpci_modern_with_feature(device_t dev, uint64_t feature)
473 {
474 	struct vtpci_modern_softc *sc;
475 
476 	sc = device_get_softc(dev);
477 
478 	return (vtpci_with_feature(&sc->vtpci_common, feature));
479 }
480 
481 static uint64_t
482 vtpci_modern_read_features(struct vtpci_modern_softc *sc)
483 {
484 	uint32_t features0, features1;
485 
486 	vtpci_modern_write_common_4(sc, VIRTIO_PCI_COMMON_DFSELECT, 0);
487 	features0 = vtpci_modern_read_common_4(sc, VIRTIO_PCI_COMMON_DF);
488 	vtpci_modern_write_common_4(sc, VIRTIO_PCI_COMMON_DFSELECT, 1);
489 	features1 = vtpci_modern_read_common_4(sc, VIRTIO_PCI_COMMON_DF);
490 
491 	return (((uint64_t) features1 << 32) | features0);
492 }
493 
494 static void
495 vtpci_modern_write_features(struct vtpci_modern_softc *sc, uint64_t features)
496 {
497 	uint32_t features0, features1;
498 
499 	features0 = features;
500 	features1 = features >> 32;
501 
502 	vtpci_modern_write_common_4(sc, VIRTIO_PCI_COMMON_GFSELECT, 0);
503 	vtpci_modern_write_common_4(sc, VIRTIO_PCI_COMMON_GF, features0);
504 	vtpci_modern_write_common_4(sc, VIRTIO_PCI_COMMON_GFSELECT, 1);
505 	vtpci_modern_write_common_4(sc, VIRTIO_PCI_COMMON_GF, features1);
506 }
507 
508 static int
509 vtpci_modern_alloc_virtqueues(device_t dev, int nvqs,
510     struct vq_alloc_info *vq_info)
511 {
512 	struct vtpci_modern_softc *sc;
513 	struct vtpci_common *cn;
514 	uint16_t max_nvqs;
515 
516 	sc = device_get_softc(dev);
517 	cn = &sc->vtpci_common;
518 
519 	max_nvqs = vtpci_modern_read_common_2(sc, VIRTIO_PCI_COMMON_NUMQ);
520 	if (nvqs > max_nvqs) {
521 		device_printf(sc->vtpci_dev, "requested virtqueue count %d "
522 		    "exceeds max %d\n", nvqs, max_nvqs);
523 		return (E2BIG);
524 	}
525 
526 	return (vtpci_alloc_virtqueues(cn, nvqs, vq_info));
527 }
528 
529 static int
530 vtpci_modern_setup_interrupts(device_t dev, enum intr_type type)
531 {
532 	struct vtpci_modern_softc *sc;
533 	int error;
534 
535 	sc = device_get_softc(dev);
536 
537 	error = vtpci_setup_interrupts(&sc->vtpci_common, type);
538 	if (error == 0)
539 		vtpci_modern_enable_virtqueues(sc);
540 
541 	return (error);
542 }
543 
544 static void
545 vtpci_modern_stop(device_t dev)
546 {
547 	vtpci_modern_reset(device_get_softc(dev));
548 }
549 
550 static int
551 vtpci_modern_reinit(device_t dev, uint64_t features)
552 {
553 	struct vtpci_modern_softc *sc;
554 	struct vtpci_common *cn;
555 	int error;
556 
557 	sc = device_get_softc(dev);
558 	cn = &sc->vtpci_common;
559 
560 	/*
561 	 * Redrive the device initialization. This is a bit of an abuse of
562 	 * the specification, but VirtualBox, QEMU/KVM, and BHyVe seem to
563 	 * play nice.
564 	 *
565 	 * We do not allow the host device to change from what was originally
566 	 * negotiated beyond what the guest driver changed. MSIX state should
567 	 * not change, number of virtqueues and their size remain the same, etc.
568 	 * This will need to be rethought when we want to support migration.
569 	 */
570 
571 	if (vtpci_modern_get_status(sc) != VIRTIO_CONFIG_STATUS_RESET)
572 		vtpci_modern_stop(dev);
573 
574 	/*
575 	 * Quickly drive the status through ACK and DRIVER. The device does
576 	 * not become usable again until DRIVER_OK in reinit complete.
577 	 */
578 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_ACK);
579 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER);
580 
581 	/*
582 	 * TODO: Check that features are not added as to what was
583 	 * originally negotiated.
584 	 */
585 	vtpci_modern_negotiate_features(dev, features);
586 	error = vtpci_modern_finalize_features(dev);
587 	if (error) {
588 		device_printf(dev, "cannot finalize features during reinit\n");
589 		return (error);
590 	}
591 
592 	error = vtpci_reinit(cn);
593 	if (error)
594 		return (error);
595 
596 	return (0);
597 }
598 
599 static void
600 vtpci_modern_reinit_complete(device_t dev)
601 {
602 	struct vtpci_modern_softc *sc;
603 
604 	sc = device_get_softc(dev);
605 
606 	vtpci_modern_enable_virtqueues(sc);
607 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER_OK);
608 }
609 
610 static void
611 vtpci_modern_notify_vq(device_t dev, uint16_t queue, bus_size_t offset)
612 {
613 	struct vtpci_modern_softc *sc;
614 
615 	sc = device_get_softc(dev);
616 
617 	vtpci_modern_write_notify_2(sc, offset, queue);
618 }
619 
620 static uint8_t
621 vtpci_modern_get_status(struct vtpci_modern_softc *sc)
622 {
623 	return (vtpci_modern_read_common_1(sc, VIRTIO_PCI_COMMON_STATUS));
624 }
625 
626 static void
627 vtpci_modern_set_status(struct vtpci_modern_softc *sc, uint8_t status)
628 {
629 	if (status != VIRTIO_CONFIG_STATUS_RESET)
630 		status |= vtpci_modern_get_status(sc);
631 
632 	vtpci_modern_write_common_1(sc, VIRTIO_PCI_COMMON_STATUS, status);
633 }
634 
635 static int
636 vtpci_modern_config_generation(device_t dev)
637 {
638 	struct vtpci_modern_softc *sc;
639 	uint8_t gen;
640 
641 	sc = device_get_softc(dev);
642 	gen = vtpci_modern_read_common_1(sc, VIRTIO_PCI_COMMON_CFGGENERATION);
643 
644 	return (gen);
645 }
646 
647 static void
648 vtpci_modern_read_dev_config(device_t dev, bus_size_t offset, void *dst,
649     int length)
650 {
651 	struct vtpci_modern_softc *sc;
652 
653 	sc = device_get_softc(dev);
654 
655 	if (sc->vtpci_device_res_map.vtrm_map.r_size == 0) {
656 		panic("%s: attempt to read dev config but not present",
657 		    __func__);
658 	}
659 
660 	switch (length) {
661 	case 1:
662 		*(uint8_t *) dst = vtpci_modern_read_device_1(sc, offset);
663 		break;
664 	case 2:
665 		*(uint16_t *) dst = virtio_htog16(true,
666 		    vtpci_modern_read_device_2(sc, offset));
667 		break;
668 	case 4:
669 		*(uint32_t *) dst = virtio_htog32(true,
670 		    vtpci_modern_read_device_4(sc, offset));
671 		break;
672 	case 8:
673 		*(uint64_t *) dst = virtio_htog64(true,
674 		    vtpci_modern_read_device_8(sc, offset));
675 		break;
676 	default:
677 		panic("%s: device %s invalid device read length %d offset %d",
678 		    __func__, device_get_nameunit(dev), length, (int) offset);
679 	}
680 }
681 
682 static void
683 vtpci_modern_write_dev_config(device_t dev, bus_size_t offset, const void *src,
684     int length)
685 {
686 	struct vtpci_modern_softc *sc;
687 
688 	sc = device_get_softc(dev);
689 
690 	if (sc->vtpci_device_res_map.vtrm_map.r_size == 0) {
691 		panic("%s: attempt to write dev config but not present",
692 		    __func__);
693 	}
694 
695 	switch (length) {
696 	case 1:
697 		vtpci_modern_write_device_1(sc, offset, *(const uint8_t *) src);
698 		break;
699 	case 2: {
700 		uint16_t val = virtio_gtoh16(true, *(const uint16_t *) src);
701 		vtpci_modern_write_device_2(sc, offset, val);
702 		break;
703 	}
704 	case 4: {
705 		uint32_t val = virtio_gtoh32(true, *(const uint32_t *) src);
706 		vtpci_modern_write_device_4(sc, offset, val);
707 		break;
708 	}
709 	case 8: {
710 		uint64_t val = virtio_gtoh64(true, *(const uint64_t *) src);
711 		vtpci_modern_write_device_8(sc, offset, val);
712 		break;
713 	}
714 	default:
715 		panic("%s: device %s invalid device write length %d offset %d",
716 		    __func__, device_get_nameunit(dev), length, (int) offset);
717 	}
718 }
719 
720 static int
721 vtpci_modern_probe_configs(device_t dev)
722 {
723 	int error;
724 
725 	/*
726 	 * These config capabilities must be present. The DEVICE_CFG
727 	 * capability is only present if the device requires it.
728 	 */
729 
730 	error = vtpci_modern_find_cap(dev, VIRTIO_PCI_CAP_COMMON_CFG, NULL);
731 	if (error) {
732 		device_printf(dev, "cannot find COMMON_CFG capability\n");
733 		return (error);
734 	}
735 
736 	error = vtpci_modern_find_cap(dev, VIRTIO_PCI_CAP_NOTIFY_CFG, NULL);
737 	if (error) {
738 		device_printf(dev, "cannot find NOTIFY_CFG capability\n");
739 		return (error);
740 	}
741 
742 	error = vtpci_modern_find_cap(dev, VIRTIO_PCI_CAP_ISR_CFG, NULL);
743 	if (error) {
744 		device_printf(dev, "cannot find ISR_CFG capability\n");
745 		return (error);
746 	}
747 
748 	return (0);
749 }
750 
751 static int
752 vtpci_modern_find_cap(device_t dev, uint8_t cfg_type, int *cap_offset)
753 {
754 	uint32_t type, bar;
755 	int capreg, error;
756 
757 	for (error = pci_find_cap(dev, PCIY_VENDOR, &capreg);
758 	     error == 0;
759 	     error = pci_find_next_cap(dev, PCIY_VENDOR, capreg, &capreg)) {
760 
761 		type = pci_read_config(dev, capreg +
762 		    offsetof(struct virtio_pci_cap, cfg_type), 1);
763 		bar = pci_read_config(dev, capreg +
764 		    offsetof(struct virtio_pci_cap, bar), 1);
765 
766 		/* Must ignore reserved BARs. */
767 		if (bar >= VTPCI_MODERN_MAX_BARS)
768 			continue;
769 
770 		if (type == cfg_type) {
771 			if (cap_offset != NULL)
772 				*cap_offset = capreg;
773 			break;
774 		}
775 	}
776 
777 	return (error);
778 }
779 
780 static int
781 vtpci_modern_map_common_config(struct vtpci_modern_softc *sc)
782 {
783 	device_t dev;
784 	int error;
785 
786 	dev = sc->vtpci_dev;
787 
788 	error = vtpci_modern_find_cap_resource(sc, VIRTIO_PCI_CAP_COMMON_CFG,
789 	    sizeof(struct virtio_pci_common_cfg), 4, &sc->vtpci_common_res_map);
790 	if (error) {
791 		device_printf(dev, "cannot find cap COMMON_CFG resource\n");
792 		return (error);
793 	}
794 
795 	error = vtpci_modern_alloc_resource_map(sc, &sc->vtpci_common_res_map);
796 	if (error) {
797 		device_printf(dev, "cannot alloc resource for COMMON_CFG\n");
798 		return (error);
799 	}
800 
801 	return (0);
802 }
803 
804 static int
805 vtpci_modern_map_notify_config(struct vtpci_modern_softc *sc)
806 {
807 	device_t dev;
808 	int cap_offset, error;
809 
810 	dev = sc->vtpci_dev;
811 
812 	error = vtpci_modern_find_cap_resource(sc, VIRTIO_PCI_CAP_NOTIFY_CFG,
813 	    -1, 2, &sc->vtpci_notify_res_map);
814 	if (error) {
815 		device_printf(dev, "cannot find cap NOTIFY_CFG resource\n");
816 		return (error);
817 	}
818 
819 	cap_offset = sc->vtpci_notify_res_map.vtrm_cap_offset;
820 
821 	sc->vtpci_notify_offset_multiplier = pci_read_config(dev, cap_offset +
822 	    offsetof(struct virtio_pci_notify_cap, notify_off_multiplier), 4);
823 
824 	error = vtpci_modern_alloc_resource_map(sc, &sc->vtpci_notify_res_map);
825 	if (error) {
826 		device_printf(dev, "cannot alloc resource for NOTIFY_CFG\n");
827 		return (error);
828 	}
829 
830 	return (0);
831 }
832 
833 static int
834 vtpci_modern_map_isr_config(struct vtpci_modern_softc *sc)
835 {
836 	device_t dev;
837 	int error;
838 
839 	dev = sc->vtpci_dev;
840 
841 	error = vtpci_modern_find_cap_resource(sc, VIRTIO_PCI_CAP_ISR_CFG,
842 	    sizeof(uint8_t), 1, &sc->vtpci_isr_res_map);
843 	if (error) {
844 		device_printf(dev, "cannot find cap ISR_CFG resource\n");
845 		return (error);
846 	}
847 
848 	error = vtpci_modern_alloc_resource_map(sc, &sc->vtpci_isr_res_map);
849 	if (error) {
850 		device_printf(dev, "cannot alloc resource for ISR_CFG\n");
851 		return (error);
852 	}
853 
854 	return (0);
855 }
856 
857 static int
858 vtpci_modern_map_device_config(struct vtpci_modern_softc *sc)
859 {
860 	device_t dev;
861 	int error;
862 
863 	dev = sc->vtpci_dev;
864 
865 	error = vtpci_modern_find_cap_resource(sc, VIRTIO_PCI_CAP_DEVICE_CFG,
866 	    -1, 4, &sc->vtpci_device_res_map);
867 	if (error == ENOENT) {
868 		/* Device configuration is optional depending on device. */
869 		return (0);
870 	} else if (error) {
871 		device_printf(dev, "cannot find cap DEVICE_CFG resource\n");
872 		return (error);
873 	}
874 
875 	error = vtpci_modern_alloc_resource_map(sc, &sc->vtpci_device_res_map);
876 	if (error) {
877 		device_printf(dev, "cannot alloc resource for DEVICE_CFG\n");
878 		return (error);
879 	}
880 
881 	return (0);
882 }
883 
884 static int
885 vtpci_modern_map_configs(struct vtpci_modern_softc *sc)
886 {
887 	int error;
888 
889 	error = vtpci_modern_map_common_config(sc);
890 	if (error)
891 		return (error);
892 
893 	error = vtpci_modern_map_notify_config(sc);
894 	if (error)
895 		return (error);
896 
897 	error = vtpci_modern_map_isr_config(sc);
898 	if (error)
899 		return (error);
900 
901 	error = vtpci_modern_map_device_config(sc);
902 	if (error)
903 		return (error);
904 
905 	vtpci_modern_alloc_msix_resource(sc);
906 
907 	return (0);
908 }
909 
910 static void
911 vtpci_modern_unmap_configs(struct vtpci_modern_softc *sc)
912 {
913 
914 	vtpci_modern_free_resource_map(sc, &sc->vtpci_common_res_map);
915 	vtpci_modern_free_resource_map(sc, &sc->vtpci_notify_res_map);
916 	vtpci_modern_free_resource_map(sc, &sc->vtpci_isr_res_map);
917 	vtpci_modern_free_resource_map(sc, &sc->vtpci_device_res_map);
918 
919 	vtpci_modern_free_bar_resources(sc);
920 	vtpci_modern_free_msix_resource(sc);
921 
922 	sc->vtpci_notify_offset_multiplier = 0;
923 }
924 
925 static int
926 vtpci_modern_find_cap_resource(struct vtpci_modern_softc *sc, uint8_t cfg_type,
927     int min_size, int alignment, struct vtpci_modern_resource_map *res)
928 {
929 	device_t dev;
930 	int cap_offset, offset, length, error;
931 	uint8_t bar, cap_length;
932 
933 	dev = sc->vtpci_dev;
934 
935 	error = vtpci_modern_find_cap(dev, cfg_type, &cap_offset);
936 	if (error)
937 		return (error);
938 
939 	cap_length = pci_read_config(dev,
940 	    cap_offset + offsetof(struct virtio_pci_cap, cap_len), 1);
941 
942 	if (cap_length < sizeof(struct virtio_pci_cap)) {
943 		device_printf(dev, "cap %u length %d less than expected\n",
944 		    cfg_type, cap_length);
945 		return (ENXIO);
946 	}
947 
948 	bar = pci_read_config(dev,
949 	    cap_offset + offsetof(struct virtio_pci_cap, bar), 1);
950 	offset = pci_read_config(dev,
951 	    cap_offset + offsetof(struct virtio_pci_cap, offset), 4);
952 	length = pci_read_config(dev,
953 	    cap_offset + offsetof(struct virtio_pci_cap, length), 4);
954 
955 	if (min_size != -1 && length < min_size) {
956 		device_printf(dev, "cap %u struct length %d less than min %d\n",
957 		    cfg_type, length, min_size);
958 		return (ENXIO);
959 	}
960 
961 	if (offset % alignment) {
962 		device_printf(dev, "cap %u struct offset %d not aligned to %d\n",
963 		    cfg_type, offset, alignment);
964 		return (ENXIO);
965 	}
966 
967 	/* BMV: TODO Can we determine the size of the BAR here? */
968 
969 	res->vtrm_cap_offset = cap_offset;
970 	res->vtrm_bar = bar;
971 	res->vtrm_offset = offset;
972 	res->vtrm_length = length;
973 	res->vtrm_type = vtpci_modern_bar_type(sc, bar);
974 
975 	return (0);
976 }
977 
978 static int
979 vtpci_modern_bar_type(struct vtpci_modern_softc *sc, int bar)
980 {
981 	uint32_t val;
982 
983 	/*
984 	 * The BAR described by a config capability may be either an IOPORT or
985 	 * MEM, but we must know the type when calling bus_alloc_resource().
986 	 */
987 	val = pci_read_config(sc->vtpci_dev, PCIR_BAR(bar), 4);
988 	if (PCI_BAR_IO(val))
989 		return (SYS_RES_IOPORT);
990 	else
991 		return (SYS_RES_MEMORY);
992 }
993 
994 static struct resource *
995 vtpci_modern_get_bar_resource(struct vtpci_modern_softc *sc, int bar, int type)
996 {
997 	struct resource *res;
998 
999 	MPASS(bar >= 0 && bar < VTPCI_MODERN_MAX_BARS);
1000 	res = sc->vtpci_bar_res[bar].vtbr_res;
1001 	MPASS(res == NULL || sc->vtpci_bar_res[bar].vtbr_type == type);
1002 
1003 	return (res);
1004 }
1005 
1006 static struct resource *
1007 vtpci_modern_alloc_bar_resource(struct vtpci_modern_softc *sc, int bar,
1008     int type)
1009 {
1010 	struct resource *res;
1011 	int rid;
1012 
1013 	MPASS(bar >= 0 && bar < VTPCI_MODERN_MAX_BARS);
1014 	MPASS(type == SYS_RES_MEMORY || type == SYS_RES_IOPORT);
1015 
1016 	res = sc->vtpci_bar_res[bar].vtbr_res;
1017 	if (res != NULL) {
1018 		MPASS(sc->vtpci_bar_res[bar].vtbr_type == type);
1019 		return (res);
1020 	}
1021 
1022 	rid = PCIR_BAR(bar);
1023 	res = bus_alloc_resource_any(sc->vtpci_dev, type, &rid,
1024 	    RF_ACTIVE | RF_UNMAPPED);
1025 	if (res != NULL) {
1026 		sc->vtpci_bar_res[bar].vtbr_res = res;
1027 		sc->vtpci_bar_res[bar].vtbr_type = type;
1028 	}
1029 
1030 	return (res);
1031 }
1032 
1033 static void
1034 vtpci_modern_free_bar_resources(struct vtpci_modern_softc *sc)
1035 {
1036 	device_t dev;
1037 	struct resource *res;
1038 	int bar, rid, type;
1039 
1040 	dev = sc->vtpci_dev;
1041 
1042 	for (bar = 0; bar < VTPCI_MODERN_MAX_BARS; bar++) {
1043 		res = sc->vtpci_bar_res[bar].vtbr_res;
1044 		type = sc->vtpci_bar_res[bar].vtbr_type;
1045 
1046 		if (res != NULL) {
1047 			rid = PCIR_BAR(bar);
1048 			bus_release_resource(dev, type, rid, res);
1049 			sc->vtpci_bar_res[bar].vtbr_res = NULL;
1050 			sc->vtpci_bar_res[bar].vtbr_type = 0;
1051 		}
1052 	}
1053 }
1054 
1055 static int
1056 vtpci_modern_alloc_resource_map(struct vtpci_modern_softc *sc,
1057     struct vtpci_modern_resource_map *map)
1058 {
1059 	struct resource_map_request req;
1060 	struct resource *res;
1061 	int type;
1062 
1063 	type = map->vtrm_type;
1064 
1065 	res = vtpci_modern_alloc_bar_resource(sc, map->vtrm_bar, type);
1066 	if (res == NULL)
1067 		return (ENXIO);
1068 
1069 	resource_init_map_request(&req);
1070 	req.offset = map->vtrm_offset;
1071 	req.length = map->vtrm_length;
1072 
1073 	return (bus_map_resource(sc->vtpci_dev, type, res, &req,
1074 	    &map->vtrm_map));
1075 }
1076 
1077 static void
1078 vtpci_modern_free_resource_map(struct vtpci_modern_softc *sc,
1079     struct vtpci_modern_resource_map *map)
1080 {
1081 	struct resource *res;
1082 	int type;
1083 
1084 	type = map->vtrm_type;
1085 	res = vtpci_modern_get_bar_resource(sc, map->vtrm_bar, type);
1086 
1087 	if (res != NULL && map->vtrm_map.r_size != 0) {
1088 		bus_unmap_resource(sc->vtpci_dev, type, res, &map->vtrm_map);
1089 		bzero(map, sizeof(struct vtpci_modern_resource_map));
1090 	}
1091 }
1092 
1093 static void
1094 vtpci_modern_alloc_msix_resource(struct vtpci_modern_softc *sc)
1095 {
1096 	device_t dev;
1097 	int bar;
1098 
1099 	dev = sc->vtpci_dev;
1100 
1101 	if (!vtpci_is_msix_available(&sc->vtpci_common) ||
1102 	    (bar = pci_msix_table_bar(dev)) == -1)
1103 		return;
1104 
1105 	/* TODO: Can this BAR be in the 0-5 range? */
1106 	sc->vtpci_msix_bar = bar;
1107 	if ((sc->vtpci_msix_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
1108 	    &bar, RF_ACTIVE)) == NULL)
1109 		device_printf(dev, "Unable to map MSIX table\n");
1110 }
1111 
1112 static void
1113 vtpci_modern_free_msix_resource(struct vtpci_modern_softc *sc)
1114 {
1115 	device_t dev;
1116 
1117 	dev = sc->vtpci_dev;
1118 
1119 	if (sc->vtpci_msix_res != NULL) {
1120 		bus_release_resource(dev, SYS_RES_MEMORY, sc->vtpci_msix_bar,
1121 		    sc->vtpci_msix_res);
1122 		sc->vtpci_msix_bar = 0;
1123 		sc->vtpci_msix_res = NULL;
1124 	}
1125 }
1126 
1127 static void
1128 vtpci_modern_probe_and_attach_child(struct vtpci_modern_softc *sc)
1129 {
1130 	device_t dev, child;
1131 
1132 	dev = sc->vtpci_dev;
1133 	child = vtpci_child_device(&sc->vtpci_common);
1134 
1135 	if (child == NULL || device_get_state(child) != DS_NOTPRESENT)
1136 		return;
1137 
1138 	if (device_probe(child) != 0)
1139 		return;
1140 
1141 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER);
1142 
1143 	if (device_attach(child) != 0) {
1144 		vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_FAILED);
1145 		/* Reset state for later attempt. */
1146 		vtpci_modern_child_detached(dev, child);
1147 	} else {
1148 		vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER_OK);
1149 		VIRTIO_ATTACH_COMPLETED(child);
1150 	}
1151 }
1152 
1153 static int
1154 vtpci_modern_register_msix(struct vtpci_modern_softc *sc, int offset,
1155     struct vtpci_interrupt *intr)
1156 {
1157 	uint16_t vector;
1158 
1159 	if (intr != NULL) {
1160 		/* Map from guest rid to host vector. */
1161 		vector = intr->vti_rid - 1;
1162 	} else
1163 		vector = VIRTIO_MSI_NO_VECTOR;
1164 
1165 	vtpci_modern_write_common_2(sc, offset, vector);
1166 	return (vtpci_modern_read_common_2(sc, offset) == vector ? 0 : ENODEV);
1167 }
1168 
1169 static int
1170 vtpci_modern_register_cfg_msix(device_t dev, struct vtpci_interrupt *intr)
1171 {
1172 	struct vtpci_modern_softc *sc;
1173 	int error;
1174 
1175 	sc = device_get_softc(dev);
1176 
1177 	error = vtpci_modern_register_msix(sc, VIRTIO_PCI_COMMON_MSIX, intr);
1178 	if (error) {
1179 		device_printf(dev,
1180 		    "unable to register config MSIX interrupt\n");
1181 		return (error);
1182 	}
1183 
1184 	return (0);
1185 }
1186 
1187 static int
1188 vtpci_modern_register_vq_msix(device_t dev, int idx,
1189     struct vtpci_interrupt *intr)
1190 {
1191 	struct vtpci_modern_softc *sc;
1192 	int error;
1193 
1194 	sc = device_get_softc(dev);
1195 
1196 	vtpci_modern_select_virtqueue(sc, idx);
1197 	error = vtpci_modern_register_msix(sc, VIRTIO_PCI_COMMON_Q_MSIX, intr);
1198 	if (error) {
1199 		device_printf(dev,
1200 		    "unable to register virtqueue MSIX interrupt\n");
1201 		return (error);
1202 	}
1203 
1204 	return (0);
1205 }
1206 
1207 static void
1208 vtpci_modern_reset(struct vtpci_modern_softc *sc)
1209 {
1210 	/*
1211 	 * Setting the status to RESET sets the host device to the
1212 	 * original, uninitialized state. Must poll the status until
1213 	 * the reset is complete.
1214 	 */
1215 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_RESET);
1216 
1217 	while (vtpci_modern_get_status(sc) != VIRTIO_CONFIG_STATUS_RESET)
1218 		cpu_spinwait();
1219 }
1220 
1221 static void
1222 vtpci_modern_select_virtqueue(struct vtpci_modern_softc *sc, int idx)
1223 {
1224 	vtpci_modern_write_common_2(sc, VIRTIO_PCI_COMMON_Q_SELECT, idx);
1225 }
1226 
1227 static uint8_t
1228 vtpci_modern_read_isr(device_t dev)
1229 {
1230 	return (vtpci_modern_read_isr_1(device_get_softc(dev), 0));
1231 }
1232 
1233 static uint16_t
1234 vtpci_modern_get_vq_size(device_t dev, int idx)
1235 {
1236 	struct vtpci_modern_softc *sc;
1237 
1238 	sc = device_get_softc(dev);
1239 
1240 	vtpci_modern_select_virtqueue(sc, idx);
1241 	return (vtpci_modern_read_common_2(sc, VIRTIO_PCI_COMMON_Q_SIZE));
1242 }
1243 
1244 static bus_size_t
1245 vtpci_modern_get_vq_notify_off(device_t dev, int idx)
1246 {
1247 	struct vtpci_modern_softc *sc;
1248 	uint16_t q_notify_off;
1249 
1250 	sc = device_get_softc(dev);
1251 
1252 	vtpci_modern_select_virtqueue(sc, idx);
1253 	q_notify_off = vtpci_modern_read_common_2(sc, VIRTIO_PCI_COMMON_Q_NOFF);
1254 
1255 	return (q_notify_off * sc->vtpci_notify_offset_multiplier);
1256 }
1257 
1258 static void
1259 vtpci_modern_set_vq(device_t dev, struct virtqueue *vq)
1260 {
1261 	struct vtpci_modern_softc *sc;
1262 
1263 	sc = device_get_softc(dev);
1264 
1265 	vtpci_modern_select_virtqueue(sc, virtqueue_index(vq));
1266 
1267 	/* BMV: Currently we never adjust the device's proposed VQ size. */
1268 	vtpci_modern_write_common_2(sc,
1269 	    VIRTIO_PCI_COMMON_Q_SIZE, virtqueue_size(vq));
1270 
1271 	vtpci_modern_write_common_8(sc,
1272 	    VIRTIO_PCI_COMMON_Q_DESCLO, virtqueue_desc_paddr(vq));
1273 	vtpci_modern_write_common_8(sc,
1274 	    VIRTIO_PCI_COMMON_Q_AVAILLO, virtqueue_avail_paddr(vq));
1275         vtpci_modern_write_common_8(sc,
1276 	    VIRTIO_PCI_COMMON_Q_USEDLO, virtqueue_used_paddr(vq));
1277 }
1278 
1279 static void
1280 vtpci_modern_disable_vq(device_t dev, int idx)
1281 {
1282 	struct vtpci_modern_softc *sc;
1283 
1284 	sc = device_get_softc(dev);
1285 
1286 	vtpci_modern_select_virtqueue(sc, idx);
1287 	vtpci_modern_write_common_8(sc, VIRTIO_PCI_COMMON_Q_DESCLO, 0ULL);
1288 	vtpci_modern_write_common_8(sc, VIRTIO_PCI_COMMON_Q_AVAILLO, 0ULL);
1289         vtpci_modern_write_common_8(sc, VIRTIO_PCI_COMMON_Q_USEDLO, 0ULL);
1290 }
1291 
1292 static void
1293 vtpci_modern_enable_virtqueues(struct vtpci_modern_softc *sc)
1294 {
1295 	int idx;
1296 
1297 	for (idx = 0; idx < sc->vtpci_common.vtpci_nvqs; idx++) {
1298 		vtpci_modern_select_virtqueue(sc, idx);
1299 		vtpci_modern_write_common_2(sc, VIRTIO_PCI_COMMON_Q_ENABLE, 1);
1300 	}
1301 }
1302 
1303 static uint8_t
1304 vtpci_modern_read_common_1(struct vtpci_modern_softc *sc, bus_size_t off)
1305 {
1306 	return (bus_read_1(&sc->vtpci_common_res_map.vtrm_map, off));
1307 }
1308 
1309 static uint16_t
1310 vtpci_modern_read_common_2(struct vtpci_modern_softc *sc, bus_size_t off)
1311 {
1312 	return virtio_htog16(true,
1313 			bus_read_2(&sc->vtpci_common_res_map.vtrm_map, off));
1314 }
1315 
1316 static uint32_t
1317 vtpci_modern_read_common_4(struct vtpci_modern_softc *sc, bus_size_t off)
1318 {
1319 	return virtio_htog32(true,
1320 			bus_read_4(&sc->vtpci_common_res_map.vtrm_map, off));
1321 }
1322 
1323 static void
1324 vtpci_modern_write_common_1(struct vtpci_modern_softc *sc, bus_size_t off,
1325     uint8_t val)
1326 {
1327 	bus_write_1(&sc->vtpci_common_res_map.vtrm_map, off, val);
1328 }
1329 
1330 static void
1331 vtpci_modern_write_common_2(struct vtpci_modern_softc *sc, bus_size_t off,
1332     uint16_t val)
1333 {
1334 	bus_write_2(&sc->vtpci_common_res_map.vtrm_map,
1335 			off, virtio_gtoh16(true, val));
1336 }
1337 
1338 static void
1339 vtpci_modern_write_common_4(struct vtpci_modern_softc *sc, bus_size_t off,
1340     uint32_t val)
1341 {
1342 	bus_write_4(&sc->vtpci_common_res_map.vtrm_map,
1343 			off, virtio_gtoh32(true, val));
1344 }
1345 
1346 static void
1347 vtpci_modern_write_common_8(struct vtpci_modern_softc *sc, bus_size_t off,
1348     uint64_t val)
1349 {
1350 	uint32_t val0, val1;
1351 
1352 	val0 = (uint32_t) val;
1353 	val1 = val >> 32;
1354 
1355 	vtpci_modern_write_common_4(sc, off, val0);
1356 	vtpci_modern_write_common_4(sc, off + 4, val1);
1357 }
1358 
1359 static void
1360 vtpci_modern_write_notify_2(struct vtpci_modern_softc *sc, bus_size_t off,
1361     uint16_t val)
1362 {
1363 	bus_write_2(&sc->vtpci_notify_res_map.vtrm_map, off, val);
1364 }
1365 
1366 static uint8_t
1367 vtpci_modern_read_isr_1(struct vtpci_modern_softc *sc, bus_size_t off)
1368 {
1369 	return (bus_read_1(&sc->vtpci_isr_res_map.vtrm_map, off));
1370 }
1371 
1372 static uint8_t
1373 vtpci_modern_read_device_1(struct vtpci_modern_softc *sc, bus_size_t off)
1374 {
1375 	return (bus_read_1(&sc->vtpci_device_res_map.vtrm_map, off));
1376 }
1377 
1378 static uint16_t
1379 vtpci_modern_read_device_2(struct vtpci_modern_softc *sc, bus_size_t off)
1380 {
1381 	return (bus_read_2(&sc->vtpci_device_res_map.vtrm_map, off));
1382 }
1383 
1384 static uint32_t
1385 vtpci_modern_read_device_4(struct vtpci_modern_softc *sc, bus_size_t off)
1386 {
1387 	return (bus_read_4(&sc->vtpci_device_res_map.vtrm_map, off));
1388 }
1389 
1390 static uint64_t
1391 vtpci_modern_read_device_8(struct vtpci_modern_softc *sc, bus_size_t off)
1392 {
1393 	device_t dev;
1394 	int gen;
1395 	uint32_t val0, val1;
1396 
1397 	dev = sc->vtpci_dev;
1398 
1399 	/*
1400 	 * Treat the 64-bit field as two 32-bit fields. Use the generation
1401 	 * to ensure a consistent read.
1402 	 */
1403 	do {
1404 		gen = vtpci_modern_config_generation(dev);
1405 		val0 = vtpci_modern_read_device_4(sc, off);
1406 		val1 = vtpci_modern_read_device_4(sc, off + 4);
1407 	} while (gen != vtpci_modern_config_generation(dev));
1408 
1409 	return (((uint64_t) val1 << 32) | val0);
1410 }
1411 
1412 static void
1413 vtpci_modern_write_device_1(struct vtpci_modern_softc *sc, bus_size_t off,
1414     uint8_t val)
1415 {
1416 	bus_write_1(&sc->vtpci_device_res_map.vtrm_map, off, val);
1417 }
1418 
1419 static void
1420 vtpci_modern_write_device_2(struct vtpci_modern_softc *sc, bus_size_t off,
1421     uint16_t val)
1422 {
1423 	bus_write_2(&sc->vtpci_device_res_map.vtrm_map, off, val);
1424 }
1425 
1426 static void
1427 vtpci_modern_write_device_4(struct vtpci_modern_softc *sc, bus_size_t off,
1428     uint32_t val)
1429 {
1430 	bus_write_4(&sc->vtpci_device_res_map.vtrm_map, off, val);
1431 }
1432 
1433 static void
1434 vtpci_modern_write_device_8(struct vtpci_modern_softc *sc, bus_size_t off,
1435     uint64_t val)
1436 {
1437 	uint32_t val0, val1;
1438 
1439 	val0 = (uint32_t) val;
1440 	val1 = val >> 32;
1441 
1442 	vtpci_modern_write_device_4(sc, off, val0);
1443 	vtpci_modern_write_device_4(sc, off + 4, val1);
1444 }
1445