xref: /freebsd/sys/dev/virtio/pci/virtio_pci_modern.c (revision 7cd22ac43418da08448d0bab1009ff3cbda85120)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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/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 
41 #include <machine/bus.h>
42 #include <machine/cpu.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_modern_var.h>
54 
55 #include "virtio_bus_if.h"
56 #include "virtio_pci_if.h"
57 #include "virtio_if.h"
58 
59 struct vtpci_modern_resource_map {
60 	struct resource_map	vtrm_map;
61 	int			vtrm_cap_offset;
62 	int			vtrm_bar;
63 	int			vtrm_offset;
64 	int			vtrm_length;
65 	int			vtrm_type;	/* SYS_RES_{MEMORY, IOPORT} */
66 };
67 
68 struct vtpci_modern_bar_resource {
69 	struct resource		*vtbr_res;
70 	int			 vtbr_type;
71 };
72 
73 struct vtpci_modern_softc {
74 	device_t			 vtpci_dev;
75 	struct vtpci_common		 vtpci_common;
76 	uint32_t			 vtpci_notify_offset_multiplier;
77 	uint16_t			 vtpci_devid;
78 	int				 vtpci_msix_bar;
79 	struct resource			*vtpci_msix_res;
80 
81 	struct vtpci_modern_resource_map vtpci_common_res_map;
82 	struct vtpci_modern_resource_map vtpci_notify_res_map;
83 	struct vtpci_modern_resource_map vtpci_isr_res_map;
84 	struct vtpci_modern_resource_map vtpci_device_res_map;
85 
86 #define VTPCI_MODERN_MAX_BARS		6
87 	struct vtpci_modern_bar_resource vtpci_bar_res[VTPCI_MODERN_MAX_BARS];
88 };
89 
90 static int	vtpci_modern_probe(device_t);
91 static int	vtpci_modern_attach(device_t);
92 static int	vtpci_modern_detach(device_t);
93 static int	vtpci_modern_suspend(device_t);
94 static int	vtpci_modern_resume(device_t);
95 static int	vtpci_modern_shutdown(device_t);
96 
97 static void	vtpci_modern_driver_added(device_t, driver_t *);
98 static void	vtpci_modern_child_detached(device_t, device_t);
99 static int	vtpci_modern_read_ivar(device_t, device_t, int, uintptr_t *);
100 static int	vtpci_modern_write_ivar(device_t, device_t, int, uintptr_t);
101 
102 static uint8_t	vtpci_modern_read_isr(device_t);
103 static uint16_t	vtpci_modern_get_vq_size(device_t, int);
104 static bus_size_t vtpci_modern_get_vq_notify_off(device_t, int);
105 static void	vtpci_modern_set_vq(device_t, struct virtqueue *);
106 static void	vtpci_modern_disable_vq(device_t, int);
107 static int	vtpci_modern_register_msix(struct vtpci_modern_softc *, int,
108 		    struct vtpci_interrupt *);
109 static int	vtpci_modern_register_cfg_msix(device_t,
110 		    struct vtpci_interrupt *);
111 static int	vtpci_modern_register_vq_msix(device_t, int idx,
112 		    struct vtpci_interrupt *);
113 
114 static uint64_t	vtpci_modern_negotiate_features(device_t, uint64_t);
115 static int	vtpci_modern_finalize_features(device_t);
116 static int	vtpci_modern_with_feature(device_t, uint64_t);
117 static int	vtpci_modern_alloc_virtqueues(device_t, int, int,
118 		    struct vq_alloc_info *);
119 static int	vtpci_modern_setup_interrupts(device_t, enum intr_type);
120 static void	vtpci_modern_stop(device_t);
121 static int	vtpci_modern_reinit(device_t, uint64_t);
122 static void	vtpci_modern_reinit_complete(device_t);
123 static void	vtpci_modern_notify_vq(device_t, uint16_t, bus_size_t);
124 static int	vtpci_modern_config_generation(device_t);
125 static void	vtpci_modern_read_dev_config(device_t, bus_size_t, void *, int);
126 static void	vtpci_modern_write_dev_config(device_t, bus_size_t, void *, int);
127 
128 static int	vtpci_modern_probe_configs(device_t);
129 static int	vtpci_modern_find_cap(device_t, uint8_t, int *);
130 static int	vtpci_modern_map_configs(struct vtpci_modern_softc *);
131 static void	vtpci_modern_unmap_configs(struct vtpci_modern_softc *);
132 static int	vtpci_modern_find_cap_resource(struct vtpci_modern_softc *,
133 		     uint8_t, int, int, struct vtpci_modern_resource_map *);
134 static int	vtpci_modern_bar_type(struct vtpci_modern_softc *, int);
135 static struct resource *vtpci_modern_get_bar_resource(
136 		    struct vtpci_modern_softc *, int, int);
137 static struct resource *vtpci_modern_alloc_bar_resource(
138 		    struct vtpci_modern_softc *, int, int);
139 static void	vtpci_modern_free_bar_resources(struct vtpci_modern_softc *);
140 static int	vtpci_modern_alloc_resource_map(struct vtpci_modern_softc *,
141 		    struct vtpci_modern_resource_map *);
142 static void	vtpci_modern_free_resource_map(struct vtpci_modern_softc *,
143 		    struct vtpci_modern_resource_map *);
144 static void	vtpci_modern_alloc_msix_resource(struct vtpci_modern_softc *);
145 static void	vtpci_modern_free_msix_resource(struct vtpci_modern_softc *);
146 
147 static void	vtpci_modern_probe_and_attach_child(struct vtpci_modern_softc *);
148 
149 static uint64_t vtpci_modern_read_features(struct vtpci_modern_softc *);
150 static void	vtpci_modern_write_features(struct vtpci_modern_softc *,
151 		    uint64_t);
152 static void	vtpci_modern_select_virtqueue(struct vtpci_modern_softc *, int);
153 static uint8_t	vtpci_modern_get_status(struct vtpci_modern_softc *);
154 static void	vtpci_modern_set_status(struct vtpci_modern_softc *, uint8_t);
155 static void	vtpci_modern_reset(struct vtpci_modern_softc *);
156 static void	vtpci_modern_enable_virtqueues(struct vtpci_modern_softc *);
157 
158 static uint8_t	vtpci_modern_read_common_1(struct vtpci_modern_softc *,
159 		    bus_size_t);
160 static uint16_t vtpci_modern_read_common_2(struct vtpci_modern_softc *,
161 		    bus_size_t);
162 static uint32_t vtpci_modern_read_common_4(struct vtpci_modern_softc *,
163 		    bus_size_t);
164 static void	vtpci_modern_write_common_1(struct vtpci_modern_softc *,
165 		     bus_size_t, uint8_t);
166 static void	vtpci_modern_write_common_2(struct vtpci_modern_softc *,
167 		     bus_size_t, uint16_t);
168 static void	vtpci_modern_write_common_4(struct vtpci_modern_softc *,
169 		    bus_size_t, uint32_t);
170 static void	vtpci_modern_write_common_8(struct vtpci_modern_softc *,
171 		    bus_size_t, uint64_t);
172 static void	vtpci_modern_write_notify_2(struct vtpci_modern_softc *,
173 		    bus_size_t, uint16_t);
174 static uint8_t  vtpci_modern_read_isr_1(struct vtpci_modern_softc *,
175 		    bus_size_t);
176 static uint8_t	vtpci_modern_read_device_1(struct vtpci_modern_softc *,
177 		    bus_size_t);
178 static uint16_t vtpci_modern_read_device_2(struct vtpci_modern_softc *,
179 		    bus_size_t);
180 static uint32_t vtpci_modern_read_device_4(struct vtpci_modern_softc *,
181 		    bus_size_t);
182 static uint64_t vtpci_modern_read_device_8(struct vtpci_modern_softc *,
183 		    bus_size_t);
184 static void	vtpci_modern_write_device_1(struct vtpci_modern_softc *,
185 		    bus_size_t, uint8_t);
186 static void	vtpci_modern_write_device_2(struct vtpci_modern_softc *,
187 		    bus_size_t, uint16_t);
188 static void	vtpci_modern_write_device_4(struct vtpci_modern_softc *,
189 		    bus_size_t, uint32_t);
190 static void	vtpci_modern_write_device_8(struct vtpci_modern_softc *,
191 		    bus_size_t, uint64_t);
192 
193 /* Tunables. */
194 static int vtpci_modern_transitional = 0;
195 TUNABLE_INT("hw.virtio.pci.transitional", &vtpci_modern_transitional);
196 
197 static device_method_t vtpci_modern_methods[] = {
198 	/* Device interface. */
199 	DEVMETHOD(device_probe,			vtpci_modern_probe),
200 	DEVMETHOD(device_attach,		vtpci_modern_attach),
201 	DEVMETHOD(device_detach,		vtpci_modern_detach),
202 	DEVMETHOD(device_suspend,		vtpci_modern_suspend),
203 	DEVMETHOD(device_resume,		vtpci_modern_resume),
204 	DEVMETHOD(device_shutdown,		vtpci_modern_shutdown),
205 
206 	/* Bus interface. */
207 	DEVMETHOD(bus_driver_added,		vtpci_modern_driver_added),
208 	DEVMETHOD(bus_child_detached,		vtpci_modern_child_detached),
209 	DEVMETHOD(bus_child_pnpinfo,		virtio_child_pnpinfo),
210 	DEVMETHOD(bus_read_ivar,		vtpci_modern_read_ivar),
211 	DEVMETHOD(bus_write_ivar,		vtpci_modern_write_ivar),
212 
213 	/* VirtIO PCI interface. */
214 	DEVMETHOD(virtio_pci_read_isr,		 vtpci_modern_read_isr),
215 	DEVMETHOD(virtio_pci_get_vq_size,	 vtpci_modern_get_vq_size),
216 	DEVMETHOD(virtio_pci_get_vq_notify_off,	 vtpci_modern_get_vq_notify_off),
217 	DEVMETHOD(virtio_pci_set_vq,		 vtpci_modern_set_vq),
218 	DEVMETHOD(virtio_pci_disable_vq,	 vtpci_modern_disable_vq),
219 	DEVMETHOD(virtio_pci_register_cfg_msix,	 vtpci_modern_register_cfg_msix),
220 	DEVMETHOD(virtio_pci_register_vq_msix,	 vtpci_modern_register_vq_msix),
221 
222 	/* VirtIO bus interface. */
223 	DEVMETHOD(virtio_bus_negotiate_features,  vtpci_modern_negotiate_features),
224 	DEVMETHOD(virtio_bus_finalize_features,	  vtpci_modern_finalize_features),
225 	DEVMETHOD(virtio_bus_with_feature,	  vtpci_modern_with_feature),
226 	DEVMETHOD(virtio_bus_alloc_virtqueues,	  vtpci_modern_alloc_virtqueues),
227 	DEVMETHOD(virtio_bus_setup_intr,	  vtpci_modern_setup_interrupts),
228 	DEVMETHOD(virtio_bus_stop,		  vtpci_modern_stop),
229 	DEVMETHOD(virtio_bus_reinit,		  vtpci_modern_reinit),
230 	DEVMETHOD(virtio_bus_reinit_complete,	  vtpci_modern_reinit_complete),
231 	DEVMETHOD(virtio_bus_notify_vq,		  vtpci_modern_notify_vq),
232 	DEVMETHOD(virtio_bus_config_generation,	  vtpci_modern_config_generation),
233 	DEVMETHOD(virtio_bus_read_device_config,  vtpci_modern_read_dev_config),
234 	DEVMETHOD(virtio_bus_write_device_config, vtpci_modern_write_dev_config),
235 
236 	DEVMETHOD_END
237 };
238 
239 static driver_t vtpci_modern_driver = {
240 	.name = "virtio_pci",
241 	.methods = vtpci_modern_methods,
242 	.size = sizeof(struct vtpci_modern_softc)
243 };
244 
245 devclass_t vtpci_modern_devclass;
246 
247 DRIVER_MODULE(virtio_pci_modern, pci, vtpci_modern_driver,
248     vtpci_modern_devclass, 0, 0);
249 
250 static int
251 vtpci_modern_probe(device_t dev)
252 {
253 	char desc[64];
254 	const char *name;
255 	uint16_t devid;
256 
257 	if (pci_get_vendor(dev) != VIRTIO_PCI_VENDORID)
258 		return (ENXIO);
259 
260 	if (pci_get_device(dev) < VIRTIO_PCI_DEVICEID_MIN ||
261 	    pci_get_device(dev) > VIRTIO_PCI_DEVICEID_MODERN_MAX)
262 		return (ENXIO);
263 
264 	if (pci_get_device(dev) < VIRTIO_PCI_DEVICEID_MODERN_MIN) {
265 		if (!vtpci_modern_transitional)
266 			return (ENXIO);
267 		devid = pci_get_subdevice(dev);
268 	} else
269 		devid = pci_get_device(dev) - VIRTIO_PCI_DEVICEID_MODERN_MIN;
270 
271 	if (vtpci_modern_probe_configs(dev) != 0)
272 		return (ENXIO);
273 
274 	name = virtio_device_name(devid);
275 	if (name == NULL)
276 		name = "Unknown";
277 
278 	snprintf(desc, sizeof(desc), "VirtIO PCI (modern) %s adapter", name);
279 	device_set_desc_copy(dev, desc);
280 
281 	return (BUS_PROBE_DEFAULT);
282 }
283 
284 static int
285 vtpci_modern_attach(device_t dev)
286 {
287 	struct vtpci_modern_softc *sc;
288 	int error;
289 
290 	sc = device_get_softc(dev);
291 	sc->vtpci_dev = dev;
292 	vtpci_init(&sc->vtpci_common, dev, true);
293 
294 	if (pci_get_device(dev) < VIRTIO_PCI_DEVICEID_MODERN_MIN)
295 		sc->vtpci_devid = pci_get_subdevice(dev);
296 	else
297 		sc->vtpci_devid = pci_get_device(dev) -
298 		    VIRTIO_PCI_DEVICEID_MODERN_MIN;
299 
300 	error = vtpci_modern_map_configs(sc);
301 	if (error) {
302 		device_printf(dev, "cannot map configs\n");
303 		vtpci_modern_unmap_configs(sc);
304 		return (error);
305 	}
306 
307 	vtpci_modern_reset(sc);
308 
309 	/* Tell the host we've noticed this device. */
310 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_ACK);
311 
312 	error = vtpci_add_child(&sc->vtpci_common);
313 	if (error)
314 		goto fail;
315 
316 	vtpci_modern_probe_and_attach_child(sc);
317 
318 	return (0);
319 
320 fail:
321 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_FAILED);
322 	vtpci_modern_detach(dev);
323 
324 	return (error);
325 }
326 
327 static int
328 vtpci_modern_detach(device_t dev)
329 {
330 	struct vtpci_modern_softc *sc;
331 	int error;
332 
333 	sc = device_get_softc(dev);
334 
335 	error = vtpci_delete_child(&sc->vtpci_common);
336 	if (error)
337 		return (error);
338 
339 	vtpci_modern_reset(sc);
340 	vtpci_modern_unmap_configs(sc);
341 
342 	return (0);
343 }
344 
345 static int
346 vtpci_modern_suspend(device_t dev)
347 {
348 	return (bus_generic_suspend(dev));
349 }
350 
351 static int
352 vtpci_modern_resume(device_t dev)
353 {
354 	return (bus_generic_resume(dev));
355 }
356 
357 static int
358 vtpci_modern_shutdown(device_t dev)
359 {
360 	(void) bus_generic_shutdown(dev);
361 	/* Forcibly stop the host device. */
362 	vtpci_modern_stop(dev);
363 
364 	return (0);
365 }
366 
367 static void
368 vtpci_modern_driver_added(device_t dev, driver_t *driver)
369 {
370 	vtpci_modern_probe_and_attach_child(device_get_softc(dev));
371 }
372 
373 static void
374 vtpci_modern_child_detached(device_t dev, device_t child)
375 {
376 	struct vtpci_modern_softc *sc;
377 
378 	sc = device_get_softc(dev);
379 
380 	vtpci_modern_reset(sc);
381 	vtpci_child_detached(&sc->vtpci_common);
382 
383 	/* After the reset, retell the host we've noticed this device. */
384 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_ACK);
385 }
386 
387 static int
388 vtpci_modern_read_ivar(device_t dev, device_t child, int index,
389     uintptr_t *result)
390 {
391 	struct vtpci_modern_softc *sc;
392 	struct vtpci_common *cn;
393 
394 	sc = device_get_softc(dev);
395 	cn = &sc->vtpci_common;
396 
397 	if (vtpci_child_device(cn) != child)
398 		return (ENOENT);
399 
400 	switch (index) {
401 	case VIRTIO_IVAR_DEVTYPE:
402 		*result = sc->vtpci_devid;
403 		break;
404 	default:
405 		return (vtpci_read_ivar(cn, index, result));
406 	}
407 
408 	return (0);
409 }
410 
411 static int
412 vtpci_modern_write_ivar(device_t dev, device_t child, int index,
413     uintptr_t value)
414 {
415 	struct vtpci_modern_softc *sc;
416 	struct vtpci_common *cn;
417 
418 	sc = device_get_softc(dev);
419 	cn = &sc->vtpci_common;
420 
421 	if (vtpci_child_device(cn) != child)
422 		return (ENOENT);
423 
424 	switch (index) {
425 	default:
426 		return (vtpci_write_ivar(cn, index, value));
427 	}
428 
429 	return (0);
430 }
431 
432 static uint64_t
433 vtpci_modern_negotiate_features(device_t dev, uint64_t child_features)
434 {
435 	struct vtpci_modern_softc *sc;
436 	uint64_t host_features, features;
437 
438 	sc = device_get_softc(dev);
439 	host_features = vtpci_modern_read_features(sc);
440 
441 	/*
442 	 * Since the driver was added as a child of the modern PCI bus,
443 	 * always add the V1 flag.
444 	 */
445 	child_features |= VIRTIO_F_VERSION_1;
446 
447 	features = vtpci_negotiate_features(&sc->vtpci_common,
448 	    child_features, host_features);
449 	vtpci_modern_write_features(sc, features);
450 
451 	return (features);
452 }
453 
454 static int
455 vtpci_modern_finalize_features(device_t dev)
456 {
457 	struct vtpci_modern_softc *sc;
458 	uint8_t status;
459 
460 	sc = device_get_softc(dev);
461 
462 	/*
463 	 * Must re-read the status after setting it to verify the negotiated
464 	 * features were accepted by the device.
465 	 */
466 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_S_FEATURES_OK);
467 
468 	status = vtpci_modern_get_status(sc);
469 	if ((status & VIRTIO_CONFIG_S_FEATURES_OK) == 0) {
470 		device_printf(dev, "desired features were not accepted\n");
471 		return (ENOTSUP);
472 	}
473 
474 	return (0);
475 }
476 
477 static int
478 vtpci_modern_with_feature(device_t dev, uint64_t feature)
479 {
480 	struct vtpci_modern_softc *sc;
481 
482 	sc = device_get_softc(dev);
483 
484 	return (vtpci_with_feature(&sc->vtpci_common, feature));
485 }
486 
487 static uint64_t
488 vtpci_modern_read_features(struct vtpci_modern_softc *sc)
489 {
490 	uint32_t features0, features1;
491 
492 	vtpci_modern_write_common_4(sc, VIRTIO_PCI_COMMON_DFSELECT, 0);
493 	features0 = vtpci_modern_read_common_4(sc, VIRTIO_PCI_COMMON_DF);
494 	vtpci_modern_write_common_4(sc, VIRTIO_PCI_COMMON_DFSELECT, 1);
495 	features1 = vtpci_modern_read_common_4(sc, VIRTIO_PCI_COMMON_DF);
496 
497 	return (((uint64_t) features1 << 32) | features0);
498 }
499 
500 static void
501 vtpci_modern_write_features(struct vtpci_modern_softc *sc, uint64_t features)
502 {
503 	uint32_t features0, features1;
504 
505 	features0 = features;
506 	features1 = features >> 32;
507 
508 	vtpci_modern_write_common_4(sc, VIRTIO_PCI_COMMON_GFSELECT, 0);
509 	vtpci_modern_write_common_4(sc, VIRTIO_PCI_COMMON_GF, features0);
510 	vtpci_modern_write_common_4(sc, VIRTIO_PCI_COMMON_GFSELECT, 1);
511 	vtpci_modern_write_common_4(sc, VIRTIO_PCI_COMMON_GF, features1);
512 }
513 
514 static int
515 vtpci_modern_alloc_virtqueues(device_t dev, int flags, int nvqs,
516     struct vq_alloc_info *vq_info)
517 {
518 	struct vtpci_modern_softc *sc;
519 	struct vtpci_common *cn;
520 	uint16_t max_nvqs;
521 
522 	sc = device_get_softc(dev);
523 	cn = &sc->vtpci_common;
524 
525 	max_nvqs = vtpci_modern_read_common_2(sc, VIRTIO_PCI_COMMON_NUMQ);
526 	if (nvqs > max_nvqs) {
527 		device_printf(sc->vtpci_dev, "requested virtqueue count %d "
528 		    "exceeds max %d\n", nvqs, max_nvqs);
529 		return (E2BIG);
530 	}
531 
532 	return (vtpci_alloc_virtqueues(cn, flags, nvqs, vq_info));
533 }
534 
535 static int
536 vtpci_modern_setup_interrupts(device_t dev, enum intr_type type)
537 {
538 	struct vtpci_modern_softc *sc;
539 	int error;
540 
541 	sc = device_get_softc(dev);
542 
543 	error = vtpci_setup_interrupts(&sc->vtpci_common, type);
544 	if (error == 0)
545 		vtpci_modern_enable_virtqueues(sc);
546 
547 	return (error);
548 }
549 
550 static void
551 vtpci_modern_stop(device_t dev)
552 {
553 	vtpci_modern_reset(device_get_softc(dev));
554 }
555 
556 static int
557 vtpci_modern_reinit(device_t dev, uint64_t features)
558 {
559 	struct vtpci_modern_softc *sc;
560 	struct vtpci_common *cn;
561 	int error;
562 
563 	sc = device_get_softc(dev);
564 	cn = &sc->vtpci_common;
565 
566 	/*
567 	 * Redrive the device initialization. This is a bit of an abuse of
568 	 * the specification, but VirtualBox, QEMU/KVM, and BHyVe seem to
569 	 * play nice.
570 	 *
571 	 * We do not allow the host device to change from what was originally
572 	 * negotiated beyond what the guest driver changed. MSIX state should
573 	 * not change, number of virtqueues and their size remain the same, etc.
574 	 * This will need to be rethought when we want to support migration.
575 	 */
576 
577 	if (vtpci_modern_get_status(sc) != VIRTIO_CONFIG_STATUS_RESET)
578 		vtpci_modern_stop(dev);
579 
580 	/*
581 	 * Quickly drive the status through ACK and DRIVER. The device does
582 	 * not become usable again until DRIVER_OK in reinit complete.
583 	 */
584 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_ACK);
585 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER);
586 
587 	/*
588 	 * TODO: Check that features are not added as to what was
589 	 * originally negotiated.
590 	 */
591 	vtpci_modern_negotiate_features(dev, features);
592 	error = vtpci_modern_finalize_features(dev);
593 	if (error) {
594 		device_printf(dev, "cannot finalize features during reinit\n");
595 		return (error);
596 	}
597 
598 	error = vtpci_reinit(cn);
599 	if (error)
600 		return (error);
601 
602 	return (0);
603 }
604 
605 static void
606 vtpci_modern_reinit_complete(device_t dev)
607 {
608 	struct vtpci_modern_softc *sc;
609 
610 	sc = device_get_softc(dev);
611 
612 	vtpci_modern_enable_virtqueues(sc);
613 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER_OK);
614 }
615 
616 static void
617 vtpci_modern_notify_vq(device_t dev, uint16_t queue, bus_size_t offset)
618 {
619 	struct vtpci_modern_softc *sc;
620 
621 	sc = device_get_softc(dev);
622 
623 	vtpci_modern_write_notify_2(sc, offset, queue);
624 }
625 
626 static uint8_t
627 vtpci_modern_get_status(struct vtpci_modern_softc *sc)
628 {
629 	return (vtpci_modern_read_common_1(sc, VIRTIO_PCI_COMMON_STATUS));
630 }
631 
632 static void
633 vtpci_modern_set_status(struct vtpci_modern_softc *sc, uint8_t status)
634 {
635 	if (status != VIRTIO_CONFIG_STATUS_RESET)
636 		status |= vtpci_modern_get_status(sc);
637 
638 	vtpci_modern_write_common_1(sc, VIRTIO_PCI_COMMON_STATUS, status);
639 }
640 
641 static int
642 vtpci_modern_config_generation(device_t dev)
643 {
644 	struct vtpci_modern_softc *sc;
645 	uint8_t gen;
646 
647 	sc = device_get_softc(dev);
648 	gen = vtpci_modern_read_common_1(sc, VIRTIO_PCI_COMMON_CFGGENERATION);
649 
650 	return (gen);
651 }
652 
653 static void
654 vtpci_modern_read_dev_config(device_t dev, bus_size_t offset, void *dst,
655     int length)
656 {
657 	struct vtpci_modern_softc *sc;
658 
659 	sc = device_get_softc(dev);
660 
661 	if (sc->vtpci_device_res_map.vtrm_map.r_size == 0) {
662 		panic("%s: attempt to read dev config but not present",
663 		    __func__);
664 	}
665 
666 	switch (length) {
667 	case 1:
668 		*(uint8_t *) dst = vtpci_modern_read_device_1(sc, offset);
669 		break;
670 	case 2:
671 		*(uint16_t *) dst = virtio_htog16(true,
672 		    vtpci_modern_read_device_2(sc, offset));
673 		break;
674 	case 4:
675 		*(uint32_t *) dst = virtio_htog32(true,
676 		    vtpci_modern_read_device_4(sc, offset));
677 		break;
678 	case 8:
679 		*(uint64_t *) dst = virtio_htog64(true,
680 		    vtpci_modern_read_device_8(sc, offset));
681 		break;
682 	default:
683 		panic("%s: device %s invalid device read length %d offset %d",
684 		    __func__, device_get_nameunit(dev), length, (int) offset);
685 	}
686 }
687 
688 static void
689 vtpci_modern_write_dev_config(device_t dev, bus_size_t offset, void *src,
690     int length)
691 {
692 	struct vtpci_modern_softc *sc;
693 
694 	sc = device_get_softc(dev);
695 
696 	if (sc->vtpci_device_res_map.vtrm_map.r_size == 0) {
697 		panic("%s: attempt to write dev config but not present",
698 		    __func__);
699 	}
700 
701 	switch (length) {
702 	case 1:
703 		vtpci_modern_write_device_1(sc, offset, *(uint8_t *) src);
704 		break;
705 	case 2: {
706 		uint16_t val = virtio_gtoh16(true, *(uint16_t *) src);
707 		vtpci_modern_write_device_2(sc, offset, val);
708 		break;
709 	}
710 	case 4: {
711 		uint32_t val = virtio_gtoh32(true, *(uint32_t *) src);
712 		vtpci_modern_write_device_4(sc, offset, val);
713 		break;
714 	}
715 	case 8: {
716 		uint64_t val = virtio_gtoh64(true, *(uint64_t *) src);
717 		vtpci_modern_write_device_8(sc, offset, val);
718 		break;
719 	}
720 	default:
721 		panic("%s: device %s invalid device write length %d offset %d",
722 		    __func__, device_get_nameunit(dev), length, (int) offset);
723 	}
724 }
725 
726 static int
727 vtpci_modern_probe_configs(device_t dev)
728 {
729 	int error;
730 
731 	/*
732 	 * These config capabilities must be present. The DEVICE_CFG
733 	 * capability is only present if the device requires it.
734 	 */
735 
736 	error = vtpci_modern_find_cap(dev, VIRTIO_PCI_CAP_COMMON_CFG, NULL);
737 	if (error) {
738 		device_printf(dev, "cannot find COMMON_CFG capability\n");
739 		return (error);
740 	}
741 
742 	error = vtpci_modern_find_cap(dev, VIRTIO_PCI_CAP_NOTIFY_CFG, NULL);
743 	if (error) {
744 		device_printf(dev, "cannot find NOTIFY_CFG capability\n");
745 		return (error);
746 	}
747 
748 	error = vtpci_modern_find_cap(dev, VIRTIO_PCI_CAP_ISR_CFG, NULL);
749 	if (error) {
750 		device_printf(dev, "cannot find ISR_CFG capability\n");
751 		return (error);
752 	}
753 
754 	return (0);
755 }
756 
757 static int
758 vtpci_modern_find_cap(device_t dev, uint8_t cfg_type, int *cap_offset)
759 {
760 	uint32_t type, bar;
761 	int capreg, error;
762 
763 	for (error = pci_find_cap(dev, PCIY_VENDOR, &capreg);
764 	     error == 0;
765 	     error = pci_find_next_cap(dev, PCIY_VENDOR, capreg, &capreg)) {
766 
767 		type = pci_read_config(dev, capreg +
768 		    offsetof(struct virtio_pci_cap, cfg_type), 1);
769 		bar = pci_read_config(dev, capreg +
770 		    offsetof(struct virtio_pci_cap, bar), 1);
771 
772 		/* Must ignore reserved BARs. */
773 		if (bar >= VTPCI_MODERN_MAX_BARS)
774 			continue;
775 
776 		if (type == cfg_type) {
777 			if (cap_offset != NULL)
778 				*cap_offset = capreg;
779 			break;
780 		}
781 	}
782 
783 	return (error);
784 }
785 
786 static int
787 vtpci_modern_map_common_config(struct vtpci_modern_softc *sc)
788 {
789 	device_t dev;
790 	int error;
791 
792 	dev = sc->vtpci_dev;
793 
794 	error = vtpci_modern_find_cap_resource(sc, VIRTIO_PCI_CAP_COMMON_CFG,
795 	    sizeof(struct virtio_pci_common_cfg), 4, &sc->vtpci_common_res_map);
796 	if (error) {
797 		device_printf(dev, "cannot find cap COMMON_CFG resource\n");
798 		return (error);
799 	}
800 
801 	error = vtpci_modern_alloc_resource_map(sc, &sc->vtpci_common_res_map);
802 	if (error) {
803 		device_printf(dev, "cannot alloc resource for COMMON_CFG\n");
804 		return (error);
805 	}
806 
807 	return (0);
808 }
809 
810 static int
811 vtpci_modern_map_notify_config(struct vtpci_modern_softc *sc)
812 {
813 	device_t dev;
814 	int cap_offset, error;
815 
816 	dev = sc->vtpci_dev;
817 
818 	error = vtpci_modern_find_cap_resource(sc, VIRTIO_PCI_CAP_NOTIFY_CFG,
819 	    -1, 2, &sc->vtpci_notify_res_map);
820 	if (error) {
821 		device_printf(dev, "cannot find cap NOTIFY_CFG resource\n");
822 		return (error);
823 	}
824 
825 	cap_offset = sc->vtpci_notify_res_map.vtrm_cap_offset;
826 
827 	sc->vtpci_notify_offset_multiplier = pci_read_config(dev, cap_offset +
828 	    offsetof(struct virtio_pci_notify_cap, notify_off_multiplier), 4);
829 
830 	error = vtpci_modern_alloc_resource_map(sc, &sc->vtpci_notify_res_map);
831 	if (error) {
832 		device_printf(dev, "cannot alloc resource for NOTIFY_CFG\n");
833 		return (error);
834 	}
835 
836 	return (0);
837 }
838 
839 static int
840 vtpci_modern_map_isr_config(struct vtpci_modern_softc *sc)
841 {
842 	device_t dev;
843 	int error;
844 
845 	dev = sc->vtpci_dev;
846 
847 	error = vtpci_modern_find_cap_resource(sc, VIRTIO_PCI_CAP_ISR_CFG,
848 	    sizeof(uint8_t), 1, &sc->vtpci_isr_res_map);
849 	if (error) {
850 		device_printf(dev, "cannot find cap ISR_CFG resource\n");
851 		return (error);
852 	}
853 
854 	error = vtpci_modern_alloc_resource_map(sc, &sc->vtpci_isr_res_map);
855 	if (error) {
856 		device_printf(dev, "cannot alloc resource for ISR_CFG\n");
857 		return (error);
858 	}
859 
860 	return (0);
861 }
862 
863 static int
864 vtpci_modern_map_device_config(struct vtpci_modern_softc *sc)
865 {
866 	device_t dev;
867 	int error;
868 
869 	dev = sc->vtpci_dev;
870 
871 	error = vtpci_modern_find_cap_resource(sc, VIRTIO_PCI_CAP_DEVICE_CFG,
872 	    -1, 4, &sc->vtpci_device_res_map);
873 	if (error == ENOENT) {
874 		/* Device configuration is optional depending on device. */
875 		return (0);
876 	} else if (error) {
877 		device_printf(dev, "cannot find cap DEVICE_CFG resource\n");
878 		return (error);
879 	}
880 
881 	error = vtpci_modern_alloc_resource_map(sc, &sc->vtpci_device_res_map);
882 	if (error) {
883 		device_printf(dev, "cannot alloc resource for DEVICE_CFG\n");
884 		return (error);
885 	}
886 
887 	return (0);
888 }
889 
890 static int
891 vtpci_modern_map_configs(struct vtpci_modern_softc *sc)
892 {
893 	int error;
894 
895 	error = vtpci_modern_map_common_config(sc);
896 	if (error)
897 		return (error);
898 
899 	error = vtpci_modern_map_notify_config(sc);
900 	if (error)
901 		return (error);
902 
903 	error = vtpci_modern_map_isr_config(sc);
904 	if (error)
905 		return (error);
906 
907 	error = vtpci_modern_map_device_config(sc);
908 	if (error)
909 		return (error);
910 
911 	vtpci_modern_alloc_msix_resource(sc);
912 
913 	return (0);
914 }
915 
916 static void
917 vtpci_modern_unmap_configs(struct vtpci_modern_softc *sc)
918 {
919 
920 	vtpci_modern_free_resource_map(sc, &sc->vtpci_common_res_map);
921 	vtpci_modern_free_resource_map(sc, &sc->vtpci_notify_res_map);
922 	vtpci_modern_free_resource_map(sc, &sc->vtpci_isr_res_map);
923 	vtpci_modern_free_resource_map(sc, &sc->vtpci_device_res_map);
924 
925 	vtpci_modern_free_bar_resources(sc);
926 	vtpci_modern_free_msix_resource(sc);
927 
928 	sc->vtpci_notify_offset_multiplier = 0;
929 }
930 
931 static int
932 vtpci_modern_find_cap_resource(struct vtpci_modern_softc *sc, uint8_t cfg_type,
933     int min_size, int alignment, struct vtpci_modern_resource_map *res)
934 {
935 	device_t dev;
936 	int cap_offset, offset, length, error;
937 	uint8_t bar, cap_length;
938 
939 	dev = sc->vtpci_dev;
940 
941 	error = vtpci_modern_find_cap(dev, cfg_type, &cap_offset);
942 	if (error)
943 		return (error);
944 
945 	cap_length = pci_read_config(dev,
946 	    cap_offset + offsetof(struct virtio_pci_cap, cap_len), 1);
947 
948 	if (cap_length < sizeof(struct virtio_pci_cap)) {
949 		device_printf(dev, "cap %u length %d less than expected\n",
950 		    cfg_type, cap_length);
951 		return (ENXIO);
952 	}
953 
954 	bar = pci_read_config(dev,
955 	    cap_offset + offsetof(struct virtio_pci_cap, bar), 1);
956 	offset = pci_read_config(dev,
957 	    cap_offset + offsetof(struct virtio_pci_cap, offset), 4);
958 	length = pci_read_config(dev,
959 	    cap_offset + offsetof(struct virtio_pci_cap, length), 4);
960 
961 	if (min_size != -1 && length < min_size) {
962 		device_printf(dev, "cap %u struct length %d less than min %d\n",
963 		    cfg_type, length, min_size);
964 		return (ENXIO);
965 	}
966 
967 	if (offset % alignment) {
968 		device_printf(dev, "cap %u struct offset %d not aligned to %d\n",
969 		    cfg_type, offset, alignment);
970 		return (ENXIO);
971 	}
972 
973 	/* BMV: TODO Can we determine the size of the BAR here? */
974 
975 	res->vtrm_cap_offset = cap_offset;
976 	res->vtrm_bar = bar;
977 	res->vtrm_offset = offset;
978 	res->vtrm_length = length;
979 	res->vtrm_type = vtpci_modern_bar_type(sc, bar);
980 
981 	return (0);
982 }
983 
984 static int
985 vtpci_modern_bar_type(struct vtpci_modern_softc *sc, int bar)
986 {
987 	uint32_t val;
988 
989 	/*
990 	 * The BAR described by a config capability may be either an IOPORT or
991 	 * MEM, but we must know the type when calling bus_alloc_resource().
992 	 */
993 	val = pci_read_config(sc->vtpci_dev, PCIR_BAR(bar), 4);
994 	if (PCI_BAR_IO(val))
995 		return (SYS_RES_IOPORT);
996 	else
997 		return (SYS_RES_MEMORY);
998 }
999 
1000 static struct resource *
1001 vtpci_modern_get_bar_resource(struct vtpci_modern_softc *sc, int bar, int type)
1002 {
1003 	struct resource *res;
1004 
1005 	MPASS(bar >= 0 && bar < VTPCI_MODERN_MAX_BARS);
1006 	res = sc->vtpci_bar_res[bar].vtbr_res;
1007 	MPASS(res == NULL || sc->vtpci_bar_res[bar].vtbr_type == type);
1008 
1009 	return (res);
1010 }
1011 
1012 static struct resource *
1013 vtpci_modern_alloc_bar_resource(struct vtpci_modern_softc *sc, int bar,
1014     int type)
1015 {
1016 	struct resource *res;
1017 	int rid;
1018 
1019 	MPASS(bar >= 0 && bar < VTPCI_MODERN_MAX_BARS);
1020 	MPASS(type == SYS_RES_MEMORY || type == SYS_RES_IOPORT);
1021 
1022 	res = sc->vtpci_bar_res[bar].vtbr_res;
1023 	if (res != NULL) {
1024 		MPASS(sc->vtpci_bar_res[bar].vtbr_type == type);
1025 		return (res);
1026 	}
1027 
1028 	rid = PCIR_BAR(bar);
1029 	res = bus_alloc_resource_any(sc->vtpci_dev, type, &rid,
1030 	    RF_ACTIVE | RF_UNMAPPED);
1031 	if (res != NULL) {
1032 		sc->vtpci_bar_res[bar].vtbr_res = res;
1033 		sc->vtpci_bar_res[bar].vtbr_type = type;
1034 	}
1035 
1036 	return (res);
1037 }
1038 
1039 static void
1040 vtpci_modern_free_bar_resources(struct vtpci_modern_softc *sc)
1041 {
1042 	device_t dev;
1043 	struct resource *res;
1044 	int bar, rid, type;
1045 
1046 	dev = sc->vtpci_dev;
1047 
1048 	for (bar = 0; bar < VTPCI_MODERN_MAX_BARS; bar++) {
1049 		res = sc->vtpci_bar_res[bar].vtbr_res;
1050 		type = sc->vtpci_bar_res[bar].vtbr_type;
1051 
1052 		if (res != NULL) {
1053 			rid = PCIR_BAR(bar);
1054 			bus_release_resource(dev, type, rid, res);
1055 			sc->vtpci_bar_res[bar].vtbr_res = NULL;
1056 			sc->vtpci_bar_res[bar].vtbr_type = 0;
1057 		}
1058 	}
1059 }
1060 
1061 static int
1062 vtpci_modern_alloc_resource_map(struct vtpci_modern_softc *sc,
1063     struct vtpci_modern_resource_map *map)
1064 {
1065 	struct resource_map_request req;
1066 	struct resource *res;
1067 	int type;
1068 
1069 	type = map->vtrm_type;
1070 
1071 	res = vtpci_modern_alloc_bar_resource(sc, map->vtrm_bar, type);
1072 	if (res == NULL)
1073 		return (ENXIO);
1074 
1075 	resource_init_map_request(&req);
1076 	req.offset = map->vtrm_offset;
1077 	req.length = map->vtrm_length;
1078 
1079 	return (bus_map_resource(sc->vtpci_dev, type, res, &req,
1080 	    &map->vtrm_map));
1081 }
1082 
1083 static void
1084 vtpci_modern_free_resource_map(struct vtpci_modern_softc *sc,
1085     struct vtpci_modern_resource_map *map)
1086 {
1087 	struct resource *res;
1088 	int type;
1089 
1090 	type = map->vtrm_type;
1091 	res = vtpci_modern_get_bar_resource(sc, map->vtrm_bar, type);
1092 
1093 	if (res != NULL && map->vtrm_map.r_size != 0) {
1094 		bus_unmap_resource(sc->vtpci_dev, type, res, &map->vtrm_map);
1095 		bzero(map, sizeof(struct vtpci_modern_resource_map));
1096 	}
1097 }
1098 
1099 static void
1100 vtpci_modern_alloc_msix_resource(struct vtpci_modern_softc *sc)
1101 {
1102 	device_t dev;
1103 	int bar;
1104 
1105 	dev = sc->vtpci_dev;
1106 
1107 	if (!vtpci_is_msix_available(&sc->vtpci_common) ||
1108 	    (bar = pci_msix_table_bar(dev)) == -1)
1109 		return;
1110 
1111 	/* TODO: Can this BAR be in the 0-5 range? */
1112 	sc->vtpci_msix_bar = bar;
1113 	if ((sc->vtpci_msix_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
1114 	    &bar, RF_ACTIVE)) == NULL)
1115 		device_printf(dev, "Unable to map MSIX table\n");
1116 }
1117 
1118 static void
1119 vtpci_modern_free_msix_resource(struct vtpci_modern_softc *sc)
1120 {
1121 	device_t dev;
1122 
1123 	dev = sc->vtpci_dev;
1124 
1125 	if (sc->vtpci_msix_res != NULL) {
1126 		bus_release_resource(dev, SYS_RES_MEMORY, sc->vtpci_msix_bar,
1127 		    sc->vtpci_msix_res);
1128 		sc->vtpci_msix_bar = 0;
1129 		sc->vtpci_msix_res = NULL;
1130 	}
1131 }
1132 
1133 static void
1134 vtpci_modern_probe_and_attach_child(struct vtpci_modern_softc *sc)
1135 {
1136 	device_t dev, child;
1137 
1138 	dev = sc->vtpci_dev;
1139 	child = vtpci_child_device(&sc->vtpci_common);
1140 
1141 	if (child == NULL || device_get_state(child) != DS_NOTPRESENT)
1142 		return;
1143 
1144 	if (device_probe(child) != 0)
1145 		return;
1146 
1147 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER);
1148 
1149 	if (device_attach(child) != 0) {
1150 		vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_FAILED);
1151 		/* Reset state for later attempt. */
1152 		vtpci_modern_child_detached(dev, child);
1153 	} else {
1154 		vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_DRIVER_OK);
1155 		VIRTIO_ATTACH_COMPLETED(child);
1156 	}
1157 }
1158 
1159 static int
1160 vtpci_modern_register_msix(struct vtpci_modern_softc *sc, int offset,
1161     struct vtpci_interrupt *intr)
1162 {
1163 	uint16_t vector;
1164 
1165 	if (intr != NULL) {
1166 		/* Map from guest rid to host vector. */
1167 		vector = intr->vti_rid - 1;
1168 	} else
1169 		vector = VIRTIO_MSI_NO_VECTOR;
1170 
1171 	vtpci_modern_write_common_2(sc, offset, vector);
1172 	return (vtpci_modern_read_common_2(sc, offset) == vector ? 0 : ENODEV);
1173 }
1174 
1175 static int
1176 vtpci_modern_register_cfg_msix(device_t dev, struct vtpci_interrupt *intr)
1177 {
1178 	struct vtpci_modern_softc *sc;
1179 	int error;
1180 
1181 	sc = device_get_softc(dev);
1182 
1183 	error = vtpci_modern_register_msix(sc, VIRTIO_PCI_COMMON_MSIX, intr);
1184 	if (error) {
1185 		device_printf(dev,
1186 		    "unable to register config MSIX interrupt\n");
1187 		return (error);
1188 	}
1189 
1190 	return (0);
1191 }
1192 
1193 static int
1194 vtpci_modern_register_vq_msix(device_t dev, int idx,
1195     struct vtpci_interrupt *intr)
1196 {
1197 	struct vtpci_modern_softc *sc;
1198 	int error;
1199 
1200 	sc = device_get_softc(dev);
1201 
1202 	vtpci_modern_select_virtqueue(sc, idx);
1203 	error = vtpci_modern_register_msix(sc, VIRTIO_PCI_COMMON_Q_MSIX, intr);
1204 	if (error) {
1205 		device_printf(dev,
1206 		    "unable to register virtqueue MSIX interrupt\n");
1207 		return (error);
1208 	}
1209 
1210 	return (0);
1211 }
1212 
1213 static void
1214 vtpci_modern_reset(struct vtpci_modern_softc *sc)
1215 {
1216 	/*
1217 	 * Setting the status to RESET sets the host device to the
1218 	 * original, uninitialized state. Must poll the status until
1219 	 * the reset is complete.
1220 	 */
1221 	vtpci_modern_set_status(sc, VIRTIO_CONFIG_STATUS_RESET);
1222 
1223 	while (vtpci_modern_get_status(sc) != VIRTIO_CONFIG_STATUS_RESET)
1224 		cpu_spinwait();
1225 }
1226 
1227 static void
1228 vtpci_modern_select_virtqueue(struct vtpci_modern_softc *sc, int idx)
1229 {
1230 	vtpci_modern_write_common_2(sc, VIRTIO_PCI_COMMON_Q_SELECT, idx);
1231 }
1232 
1233 static uint8_t
1234 vtpci_modern_read_isr(device_t dev)
1235 {
1236 	return (vtpci_modern_read_isr_1(device_get_softc(dev), 0));
1237 }
1238 
1239 static uint16_t
1240 vtpci_modern_get_vq_size(device_t dev, int idx)
1241 {
1242 	struct vtpci_modern_softc *sc;
1243 
1244 	sc = device_get_softc(dev);
1245 
1246 	vtpci_modern_select_virtqueue(sc, idx);
1247 	return (vtpci_modern_read_common_2(sc, VIRTIO_PCI_COMMON_Q_SIZE));
1248 }
1249 
1250 static bus_size_t
1251 vtpci_modern_get_vq_notify_off(device_t dev, int idx)
1252 {
1253 	struct vtpci_modern_softc *sc;
1254 	uint16_t q_notify_off;
1255 
1256 	sc = device_get_softc(dev);
1257 
1258 	vtpci_modern_select_virtqueue(sc, idx);
1259 	q_notify_off = vtpci_modern_read_common_2(sc, VIRTIO_PCI_COMMON_Q_NOFF);
1260 
1261 	return (q_notify_off * sc->vtpci_notify_offset_multiplier);
1262 }
1263 
1264 static void
1265 vtpci_modern_set_vq(device_t dev, struct virtqueue *vq)
1266 {
1267 	struct vtpci_modern_softc *sc;
1268 
1269 	sc = device_get_softc(dev);
1270 
1271 	vtpci_modern_select_virtqueue(sc, virtqueue_index(vq));
1272 
1273 	/* BMV: Currently we never adjust the device's proposed VQ size. */
1274 	vtpci_modern_write_common_2(sc,
1275 	    VIRTIO_PCI_COMMON_Q_SIZE, virtqueue_size(vq));
1276 
1277 	vtpci_modern_write_common_8(sc,
1278 	    VIRTIO_PCI_COMMON_Q_DESCLO, virtqueue_desc_paddr(vq));
1279 	vtpci_modern_write_common_8(sc,
1280 	    VIRTIO_PCI_COMMON_Q_AVAILLO, virtqueue_avail_paddr(vq));
1281         vtpci_modern_write_common_8(sc,
1282 	    VIRTIO_PCI_COMMON_Q_USEDLO, virtqueue_used_paddr(vq));
1283 }
1284 
1285 static void
1286 vtpci_modern_disable_vq(device_t dev, int idx)
1287 {
1288 	struct vtpci_modern_softc *sc;
1289 
1290 	sc = device_get_softc(dev);
1291 
1292 	vtpci_modern_select_virtqueue(sc, idx);
1293 	vtpci_modern_write_common_8(sc, VIRTIO_PCI_COMMON_Q_DESCLO, 0ULL);
1294 	vtpci_modern_write_common_8(sc, VIRTIO_PCI_COMMON_Q_AVAILLO, 0ULL);
1295         vtpci_modern_write_common_8(sc, VIRTIO_PCI_COMMON_Q_USEDLO, 0ULL);
1296 }
1297 
1298 static void
1299 vtpci_modern_enable_virtqueues(struct vtpci_modern_softc *sc)
1300 {
1301 	int idx;
1302 
1303 	for (idx = 0; idx < sc->vtpci_common.vtpci_nvqs; idx++) {
1304 		vtpci_modern_select_virtqueue(sc, idx);
1305 		vtpci_modern_write_common_2(sc, VIRTIO_PCI_COMMON_Q_ENABLE, 1);
1306 	}
1307 }
1308 
1309 static uint8_t
1310 vtpci_modern_read_common_1(struct vtpci_modern_softc *sc, bus_size_t off)
1311 {
1312 	return (bus_read_1(&sc->vtpci_common_res_map.vtrm_map, off));
1313 }
1314 
1315 static uint16_t
1316 vtpci_modern_read_common_2(struct vtpci_modern_softc *sc, bus_size_t off)
1317 {
1318 	return virtio_htog16(true,
1319 			bus_read_2(&sc->vtpci_common_res_map.vtrm_map, off));
1320 }
1321 
1322 static uint32_t
1323 vtpci_modern_read_common_4(struct vtpci_modern_softc *sc, bus_size_t off)
1324 {
1325 	return virtio_htog32(true,
1326 			bus_read_4(&sc->vtpci_common_res_map.vtrm_map, off));
1327 }
1328 
1329 static void
1330 vtpci_modern_write_common_1(struct vtpci_modern_softc *sc, bus_size_t off,
1331     uint8_t val)
1332 {
1333 	bus_write_1(&sc->vtpci_common_res_map.vtrm_map, off, val);
1334 }
1335 
1336 static void
1337 vtpci_modern_write_common_2(struct vtpci_modern_softc *sc, bus_size_t off,
1338     uint16_t val)
1339 {
1340 	bus_write_2(&sc->vtpci_common_res_map.vtrm_map,
1341 			off, virtio_gtoh16(true, val));
1342 }
1343 
1344 static void
1345 vtpci_modern_write_common_4(struct vtpci_modern_softc *sc, bus_size_t off,
1346     uint32_t val)
1347 {
1348 	bus_write_4(&sc->vtpci_common_res_map.vtrm_map,
1349 			off, virtio_gtoh32(true, val));
1350 }
1351 
1352 static void
1353 vtpci_modern_write_common_8(struct vtpci_modern_softc *sc, bus_size_t off,
1354     uint64_t val)
1355 {
1356 	uint32_t val0, val1;
1357 
1358 	val0 = (uint32_t) val;
1359 	val1 = val >> 32;
1360 
1361 	vtpci_modern_write_common_4(sc, off, val0);
1362 	vtpci_modern_write_common_4(sc, off + 4, val1);
1363 }
1364 
1365 static void
1366 vtpci_modern_write_notify_2(struct vtpci_modern_softc *sc, bus_size_t off,
1367     uint16_t val)
1368 {
1369 	bus_write_2(&sc->vtpci_notify_res_map.vtrm_map, off, val);
1370 }
1371 
1372 static uint8_t
1373 vtpci_modern_read_isr_1(struct vtpci_modern_softc *sc, bus_size_t off)
1374 {
1375 	return (bus_read_1(&sc->vtpci_isr_res_map.vtrm_map, off));
1376 }
1377 
1378 static uint8_t
1379 vtpci_modern_read_device_1(struct vtpci_modern_softc *sc, bus_size_t off)
1380 {
1381 	return (bus_read_1(&sc->vtpci_device_res_map.vtrm_map, off));
1382 }
1383 
1384 static uint16_t
1385 vtpci_modern_read_device_2(struct vtpci_modern_softc *sc, bus_size_t off)
1386 {
1387 	return (bus_read_2(&sc->vtpci_device_res_map.vtrm_map, off));
1388 }
1389 
1390 static uint32_t
1391 vtpci_modern_read_device_4(struct vtpci_modern_softc *sc, bus_size_t off)
1392 {
1393 	return (bus_read_4(&sc->vtpci_device_res_map.vtrm_map, off));
1394 }
1395 
1396 static uint64_t
1397 vtpci_modern_read_device_8(struct vtpci_modern_softc *sc, bus_size_t off)
1398 {
1399 	device_t dev;
1400 	int gen;
1401 	uint32_t val0, val1;
1402 
1403 	dev = sc->vtpci_dev;
1404 
1405 	/*
1406 	 * Treat the 64-bit field as two 32-bit fields. Use the generation
1407 	 * to ensure a consistent read.
1408 	 */
1409 	do {
1410 		gen = vtpci_modern_config_generation(dev);
1411 		val0 = vtpci_modern_read_device_4(sc, off);
1412 		val1 = vtpci_modern_read_device_4(sc, off + 4);
1413 	} while (gen != vtpci_modern_config_generation(dev));
1414 
1415 	return (((uint64_t) val1 << 32) | val0);
1416 }
1417 
1418 static void
1419 vtpci_modern_write_device_1(struct vtpci_modern_softc *sc, bus_size_t off,
1420     uint8_t val)
1421 {
1422 	bus_write_1(&sc->vtpci_device_res_map.vtrm_map, off, val);
1423 }
1424 
1425 static void
1426 vtpci_modern_write_device_2(struct vtpci_modern_softc *sc, bus_size_t off,
1427     uint16_t val)
1428 {
1429 	bus_write_2(&sc->vtpci_device_res_map.vtrm_map, off, val);
1430 }
1431 
1432 static void
1433 vtpci_modern_write_device_4(struct vtpci_modern_softc *sc, bus_size_t off,
1434     uint32_t val)
1435 {
1436 	bus_write_4(&sc->vtpci_device_res_map.vtrm_map, off, val);
1437 }
1438 
1439 static void
1440 vtpci_modern_write_device_8(struct vtpci_modern_softc *sc, bus_size_t off,
1441     uint64_t val)
1442 {
1443 	uint32_t val0, val1;
1444 
1445 	val0 = (uint32_t) val;
1446 	val1 = val >> 32;
1447 
1448 	vtpci_modern_write_device_4(sc, off, val0);
1449 	vtpci_modern_write_device_4(sc, off + 4, val1);
1450 }
1451