xref: /freebsd/sys/dev/virtio/mmio/virtio_mmio.c (revision 4740d47238cf2d707aae8f060fa37ac046bd06dc)
1 /*-
2  * Copyright (c) 2014 Ruslan Bukin <br@bsdpad.com>
3  * Copyright (c) 2014 The FreeBSD Foundation
4  * All rights reserved.
5  *
6  * This software was developed by SRI International and the University of
7  * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
8  * ("CTSRD"), as part of the DARPA CRASH research programme.
9  *
10  * Portions of this software were developed by Andrew Turner
11  * under sponsorship from the FreeBSD Foundation.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 /*
36  * VirtIO MMIO interface.
37  * This driver is heavily based on VirtIO PCI interface driver.
38  */
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/bus.h>
43 #include <sys/kernel.h>
44 #include <sys/module.h>
45 #include <sys/malloc.h>
46 #include <sys/rman.h>
47 #include <sys/endian.h>
48 
49 #include <machine/bus.h>
50 #include <machine/resource.h>
51 
52 #include <dev/virtio/virtio.h>
53 #include <dev/virtio/virtqueue.h>
54 #include <dev/virtio/mmio/virtio_mmio.h>
55 
56 #include "virtio_bus_if.h"
57 #include "virtio_if.h"
58 
59 struct vtmmio_virtqueue {
60 	struct virtqueue	*vtv_vq;
61 	int			 vtv_no_intr;
62 };
63 
64 static int	vtmmio_detach(device_t);
65 static int	vtmmio_suspend(device_t);
66 static int	vtmmio_resume(device_t);
67 static int	vtmmio_shutdown(device_t);
68 static void	vtmmio_driver_added(device_t, driver_t *);
69 static void	vtmmio_child_detached(device_t, device_t);
70 static int	vtmmio_read_ivar(device_t, device_t, int, uintptr_t *);
71 static int	vtmmio_write_ivar(device_t, device_t, int, uintptr_t);
72 static uint64_t	vtmmio_negotiate_features(device_t, uint64_t);
73 static int	vtmmio_finalize_features(device_t);
74 static bool	vtmmio_with_feature(device_t, uint64_t);
75 static void	vtmmio_set_virtqueue(struct vtmmio_softc *sc,
76 		    struct virtqueue *vq, uint32_t size);
77 static int	vtmmio_alloc_virtqueues(device_t, int,
78 		    struct vq_alloc_info *);
79 static int	vtmmio_setup_intr(device_t, enum intr_type);
80 static void	vtmmio_stop(device_t);
81 static int	vtmmio_reinit(device_t, uint64_t);
82 static void	vtmmio_reinit_complete(device_t);
83 static void	vtmmio_notify_virtqueue(device_t, uint16_t, bus_size_t);
84 static int	vtmmio_config_generation(device_t);
85 static uint8_t	vtmmio_get_status(device_t);
86 static void	vtmmio_set_status(device_t, uint8_t);
87 static void	vtmmio_read_dev_config(device_t, bus_size_t, void *, int);
88 static uint64_t	vtmmio_read_dev_config_8(struct vtmmio_softc *, bus_size_t);
89 static void	vtmmio_write_dev_config(device_t, bus_size_t, const void *, int);
90 static void	vtmmio_describe_features(struct vtmmio_softc *, const char *,
91 		    uint64_t);
92 static void	vtmmio_probe_and_attach_child(struct vtmmio_softc *);
93 static int	vtmmio_reinit_virtqueue(struct vtmmio_softc *, int);
94 static void	vtmmio_free_interrupts(struct vtmmio_softc *);
95 static void	vtmmio_free_virtqueues(struct vtmmio_softc *);
96 static void	vtmmio_release_child_resources(struct vtmmio_softc *);
97 static void	vtmmio_reset(struct vtmmio_softc *);
98 static void	vtmmio_select_virtqueue(struct vtmmio_softc *, int);
99 static void	vtmmio_vq_intr(void *);
100 
101 /*
102  * I/O port read/write wrappers.
103  */
104 #define vtmmio_write_config_1(sc, o, v)				\
105 	bus_write_1((sc)->res[0], (o), (v))
106 #define vtmmio_write_config_2(sc, o, v)				\
107 	bus_write_2((sc)->res[0], (o), (v))
108 #define vtmmio_write_config_4(sc, o, v)				\
109 	bus_write_4((sc)->res[0], (o), (v))
110 
111 #define vtmmio_read_config_1(sc, o) \
112 	bus_read_1((sc)->res[0], (o))
113 #define vtmmio_read_config_2(sc, o) \
114 	bus_read_2((sc)->res[0], (o))
115 #define vtmmio_read_config_4(sc, o) \
116 	bus_read_4((sc)->res[0], (o))
117 
118 static device_method_t vtmmio_methods[] = {
119 	/* Device interface. */
120 	DEVMETHOD(device_attach,		  vtmmio_attach),
121 	DEVMETHOD(device_detach,		  vtmmio_detach),
122 	DEVMETHOD(device_suspend,		  vtmmio_suspend),
123 	DEVMETHOD(device_resume,		  vtmmio_resume),
124 	DEVMETHOD(device_shutdown,		  vtmmio_shutdown),
125 
126 	/* Bus interface. */
127 	DEVMETHOD(bus_driver_added,		  vtmmio_driver_added),
128 	DEVMETHOD(bus_child_detached,		  vtmmio_child_detached),
129 	DEVMETHOD(bus_child_pnpinfo,		  virtio_child_pnpinfo),
130 	DEVMETHOD(bus_read_ivar,		  vtmmio_read_ivar),
131 	DEVMETHOD(bus_write_ivar,		  vtmmio_write_ivar),
132 
133 	/* VirtIO bus interface. */
134 	DEVMETHOD(virtio_bus_negotiate_features,  vtmmio_negotiate_features),
135 	DEVMETHOD(virtio_bus_finalize_features,	  vtmmio_finalize_features),
136 	DEVMETHOD(virtio_bus_with_feature,	  vtmmio_with_feature),
137 	DEVMETHOD(virtio_bus_alloc_virtqueues,	  vtmmio_alloc_virtqueues),
138 	DEVMETHOD(virtio_bus_setup_intr,	  vtmmio_setup_intr),
139 	DEVMETHOD(virtio_bus_stop,		  vtmmio_stop),
140 	DEVMETHOD(virtio_bus_reinit,		  vtmmio_reinit),
141 	DEVMETHOD(virtio_bus_reinit_complete,	  vtmmio_reinit_complete),
142 	DEVMETHOD(virtio_bus_notify_vq,		  vtmmio_notify_virtqueue),
143 	DEVMETHOD(virtio_bus_config_generation,	  vtmmio_config_generation),
144 	DEVMETHOD(virtio_bus_read_device_config,  vtmmio_read_dev_config),
145 	DEVMETHOD(virtio_bus_write_device_config, vtmmio_write_dev_config),
146 
147 	DEVMETHOD_END
148 };
149 
150 DEFINE_CLASS_0(virtio_mmio, vtmmio_driver, vtmmio_methods,
151     sizeof(struct vtmmio_softc));
152 
153 MODULE_VERSION(virtio_mmio, 1);
154 
155 int
vtmmio_probe(device_t dev)156 vtmmio_probe(device_t dev)
157 {
158 	struct vtmmio_softc *sc;
159 	int rid;
160 	uint32_t magic, version;
161 
162 	sc = device_get_softc(dev);
163 
164 	rid = 0;
165 	sc->res[0] = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
166 	    RF_ACTIVE);
167 	if (sc->res[0] == NULL) {
168 		device_printf(dev, "Cannot allocate memory window.\n");
169 		return (ENXIO);
170 	}
171 
172 	magic = vtmmio_read_config_4(sc, VIRTIO_MMIO_MAGIC_VALUE);
173 	if (magic != VIRTIO_MMIO_MAGIC_VIRT) {
174 		device_printf(dev, "Bad magic value %#x\n", magic);
175 		bus_release_resource(dev, SYS_RES_MEMORY, rid, sc->res[0]);
176 		return (ENXIO);
177 	}
178 
179 	version = vtmmio_read_config_4(sc, VIRTIO_MMIO_VERSION);
180 	if (version < 1 || version > 2) {
181 		device_printf(dev, "Unsupported version: %#x\n", version);
182 		bus_release_resource(dev, SYS_RES_MEMORY, rid, sc->res[0]);
183 		return (ENXIO);
184 	}
185 
186 	if (vtmmio_read_config_4(sc, VIRTIO_MMIO_DEVICE_ID) == 0) {
187 		bus_release_resource(dev, SYS_RES_MEMORY, rid, sc->res[0]);
188 		return (ENXIO);
189 	}
190 
191 	bus_release_resource(dev, SYS_RES_MEMORY, rid, sc->res[0]);
192 
193 	device_set_desc(dev, "VirtIO MMIO adapter");
194 	return (BUS_PROBE_DEFAULT);
195 }
196 
197 static int
vtmmio_setup_intr(device_t dev,enum intr_type type)198 vtmmio_setup_intr(device_t dev, enum intr_type type)
199 {
200 	struct vtmmio_softc *sc;
201 	int rid;
202 
203 	sc = device_get_softc(dev);
204 
205 	rid = 0;
206 	sc->res[1] = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
207 		RF_ACTIVE);
208 	if (!sc->res[1]) {
209 		device_printf(dev, "Can't allocate interrupt\n");
210 		return (ENXIO);
211 	}
212 
213 	if (bus_setup_intr(dev, sc->res[1], type | INTR_MPSAFE,
214 		NULL, vtmmio_vq_intr, sc, &sc->ih)) {
215 		device_printf(dev, "Can't setup the interrupt\n");
216 		return (ENXIO);
217 	}
218 
219 	return (0);
220 }
221 
222 int
vtmmio_attach(device_t dev)223 vtmmio_attach(device_t dev)
224 {
225 	struct vtmmio_softc *sc;
226 	device_t child;
227 	int rid;
228 
229 	sc = device_get_softc(dev);
230 	sc->dev = dev;
231 
232 	rid = 0;
233 	sc->res[0] = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
234 			RF_ACTIVE);
235 	if (sc->res[0] == NULL) {
236 		device_printf(dev, "Cannot allocate memory window.\n");
237 		return (ENXIO);
238 	}
239 
240 	sc->vtmmio_version = vtmmio_read_config_4(sc, VIRTIO_MMIO_VERSION);
241 
242 	vtmmio_reset(sc);
243 
244 	/* Tell the host we've noticed this device. */
245 	vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_ACK);
246 
247 	if ((child = device_add_child(dev, NULL, DEVICE_UNIT_ANY)) == NULL) {
248 		device_printf(dev, "Cannot create child device.\n");
249 		vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_FAILED);
250 		vtmmio_detach(dev);
251 		return (ENOMEM);
252 	}
253 
254 	sc->vtmmio_child_dev = child;
255 	vtmmio_probe_and_attach_child(sc);
256 
257 	return (0);
258 }
259 
260 static int
vtmmio_detach(device_t dev)261 vtmmio_detach(device_t dev)
262 {
263 	struct vtmmio_softc *sc;
264 	int error;
265 
266 	sc = device_get_softc(dev);
267 
268 	error = bus_generic_detach(dev);
269 	if (error)
270 		return (error);
271 
272 	vtmmio_reset(sc);
273 
274 	if (sc->res[0] != NULL) {
275 		bus_release_resource(dev, SYS_RES_MEMORY, 0,
276 		    sc->res[0]);
277 		sc->res[0] = NULL;
278 	}
279 
280 	return (0);
281 }
282 
283 static int
vtmmio_suspend(device_t dev)284 vtmmio_suspend(device_t dev)
285 {
286 
287 	return (bus_generic_suspend(dev));
288 }
289 
290 static int
vtmmio_resume(device_t dev)291 vtmmio_resume(device_t dev)
292 {
293 
294 	return (bus_generic_resume(dev));
295 }
296 
297 static int
vtmmio_shutdown(device_t dev)298 vtmmio_shutdown(device_t dev)
299 {
300 
301 	(void) bus_generic_shutdown(dev);
302 
303 	/* Forcibly stop the host device. */
304 	vtmmio_stop(dev);
305 
306 	return (0);
307 }
308 
309 static void
vtmmio_driver_added(device_t dev,driver_t * driver)310 vtmmio_driver_added(device_t dev, driver_t *driver)
311 {
312 	struct vtmmio_softc *sc;
313 
314 	sc = device_get_softc(dev);
315 
316 	vtmmio_probe_and_attach_child(sc);
317 }
318 
319 static void
vtmmio_child_detached(device_t dev,device_t child)320 vtmmio_child_detached(device_t dev, device_t child)
321 {
322 	struct vtmmio_softc *sc;
323 
324 	sc = device_get_softc(dev);
325 
326 	vtmmio_reset(sc);
327 	vtmmio_release_child_resources(sc);
328 }
329 
330 static int
vtmmio_read_ivar(device_t dev,device_t child,int index,uintptr_t * result)331 vtmmio_read_ivar(device_t dev, device_t child, int index, uintptr_t *result)
332 {
333 	struct vtmmio_softc *sc;
334 
335 	sc = device_get_softc(dev);
336 
337 	if (sc->vtmmio_child_dev != child)
338 		return (ENOENT);
339 
340 	switch (index) {
341 	case VIRTIO_IVAR_DEVTYPE:
342 	case VIRTIO_IVAR_SUBDEVICE:
343 		*result = vtmmio_read_config_4(sc, VIRTIO_MMIO_DEVICE_ID);
344 		break;
345 	case VIRTIO_IVAR_VENDOR:
346 		*result = vtmmio_read_config_4(sc, VIRTIO_MMIO_VENDOR_ID);
347 		break;
348 	case VIRTIO_IVAR_SUBVENDOR:
349 	case VIRTIO_IVAR_DEVICE:
350 		/*
351 		 * Dummy value for fields not present in this bus.  Used by
352 		 * bus-agnostic virtio_child_pnpinfo.
353 		 */
354 		*result = 0;
355 		break;
356 	case VIRTIO_IVAR_MODERN:
357 		/*
358 		 * There are several modern (aka MMIO v2) spec compliance
359 		 * issues with this driver, but keep the status quo.
360 		 */
361 		*result = sc->vtmmio_version > 1;
362 		break;
363 	default:
364 		return (ENOENT);
365 	}
366 
367 	return (0);
368 }
369 
370 static int
vtmmio_write_ivar(device_t dev,device_t child,int index,uintptr_t value)371 vtmmio_write_ivar(device_t dev, device_t child, int index, uintptr_t value)
372 {
373 	struct vtmmio_softc *sc;
374 
375 	sc = device_get_softc(dev);
376 
377 	if (sc->vtmmio_child_dev != child)
378 		return (ENOENT);
379 
380 	switch (index) {
381 	case VIRTIO_IVAR_FEATURE_DESC:
382 		sc->vtmmio_child_feat_desc = (void *) value;
383 		break;
384 	default:
385 		return (ENOENT);
386 	}
387 
388 	return (0);
389 }
390 
391 static uint64_t
vtmmio_negotiate_features(device_t dev,uint64_t child_features)392 vtmmio_negotiate_features(device_t dev, uint64_t child_features)
393 {
394 	struct vtmmio_softc *sc;
395 	uint64_t host_features, features;
396 
397 	sc = device_get_softc(dev);
398 
399 	if (sc->vtmmio_version > 1) {
400 		child_features |= VIRTIO_F_VERSION_1;
401 	}
402 
403 	vtmmio_write_config_4(sc, VIRTIO_MMIO_HOST_FEATURES_SEL, 1);
404 	host_features = vtmmio_read_config_4(sc, VIRTIO_MMIO_HOST_FEATURES);
405 	host_features <<= 32;
406 
407 	vtmmio_write_config_4(sc, VIRTIO_MMIO_HOST_FEATURES_SEL, 0);
408 	host_features |= vtmmio_read_config_4(sc, VIRTIO_MMIO_HOST_FEATURES);
409 
410 	vtmmio_describe_features(sc, "host", host_features);
411 
412 	/*
413 	 * Limit negotiated features to what the driver, virtqueue, and
414 	 * host all support.
415 	 */
416 	features = host_features & child_features;
417 	features = virtio_filter_transport_features(features);
418 	sc->vtmmio_features = features;
419 
420 	vtmmio_describe_features(sc, "negotiated", features);
421 
422 	vtmmio_write_config_4(sc, VIRTIO_MMIO_GUEST_FEATURES_SEL, 1);
423 	vtmmio_write_config_4(sc, VIRTIO_MMIO_GUEST_FEATURES, features >> 32);
424 
425 	vtmmio_write_config_4(sc, VIRTIO_MMIO_GUEST_FEATURES_SEL, 0);
426 	vtmmio_write_config_4(sc, VIRTIO_MMIO_GUEST_FEATURES, features);
427 
428 	return (features);
429 }
430 
431 static int
vtmmio_finalize_features(device_t dev)432 vtmmio_finalize_features(device_t dev)
433 {
434 	struct vtmmio_softc *sc;
435 	uint8_t status;
436 
437 	sc = device_get_softc(dev);
438 
439 	if (sc->vtmmio_version > 1) {
440 		/*
441 		 * Must re-read the status after setting it to verify the
442 		 * negotiated features were accepted by the device.
443 		 */
444 		vtmmio_set_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
445 
446 		status = vtmmio_get_status(dev);
447 		if ((status & VIRTIO_CONFIG_S_FEATURES_OK) == 0) {
448 			device_printf(dev, "desired features were not accepted\n");
449 			return (ENOTSUP);
450 		}
451 	}
452 
453 	return (0);
454 }
455 
456 static bool
vtmmio_with_feature(device_t dev,uint64_t feature)457 vtmmio_with_feature(device_t dev, uint64_t feature)
458 {
459 	struct vtmmio_softc *sc;
460 
461 	sc = device_get_softc(dev);
462 
463 	return ((sc->vtmmio_features & feature) != 0);
464 }
465 
466 static void
vtmmio_set_virtqueue(struct vtmmio_softc * sc,struct virtqueue * vq,uint32_t size)467 vtmmio_set_virtqueue(struct vtmmio_softc *sc, struct virtqueue *vq,
468     uint32_t size)
469 {
470 	vm_paddr_t paddr;
471 
472 	vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_NUM, size);
473 
474 	if (sc->vtmmio_version == 1) {
475 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_ALIGN,
476 		    VIRTIO_MMIO_VRING_ALIGN);
477 		paddr = virtqueue_paddr(vq);
478 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_PFN,
479 		    paddr >> PAGE_SHIFT);
480 	} else {
481 		paddr = virtqueue_desc_paddr(vq);
482 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_DESC_LOW,
483 		    paddr);
484 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_DESC_HIGH,
485 		    ((uint64_t)paddr) >> 32);
486 
487 		paddr = virtqueue_avail_paddr(vq);
488 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_AVAIL_LOW,
489 		    paddr);
490 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_AVAIL_HIGH,
491 		    ((uint64_t)paddr) >> 32);
492 
493 		paddr = virtqueue_used_paddr(vq);
494 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_USED_LOW,
495 		    paddr);
496 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_USED_HIGH,
497 		    ((uint64_t)paddr) >> 32);
498 
499 		vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_READY, 1);
500 	}
501 }
502 
503 static int
vtmmio_alloc_virtqueues(device_t dev,int nvqs,struct vq_alloc_info * vq_info)504 vtmmio_alloc_virtqueues(device_t dev, int nvqs,
505     struct vq_alloc_info *vq_info)
506 {
507 	struct vtmmio_virtqueue *vqx;
508 	struct vq_alloc_info *info;
509 	struct vtmmio_softc *sc;
510 	struct virtqueue *vq;
511 	uint32_t size;
512 	int idx, error;
513 
514 	sc = device_get_softc(dev);
515 
516 	if (sc->vtmmio_nvqs != 0)
517 		return (EALREADY);
518 	if (nvqs <= 0)
519 		return (EINVAL);
520 
521 	sc->vtmmio_vqs = malloc(nvqs * sizeof(struct vtmmio_virtqueue),
522 	    M_DEVBUF, M_NOWAIT | M_ZERO);
523 	if (sc->vtmmio_vqs == NULL)
524 		return (ENOMEM);
525 
526 	if (sc->vtmmio_version == 1) {
527 		vtmmio_write_config_4(sc, VIRTIO_MMIO_GUEST_PAGE_SIZE,
528 		    (1 << PAGE_SHIFT));
529 	}
530 
531 	for (idx = 0; idx < nvqs; idx++) {
532 		vqx = &sc->vtmmio_vqs[idx];
533 		info = &vq_info[idx];
534 
535 		vtmmio_select_virtqueue(sc, idx);
536 		size = vtmmio_read_config_4(sc, VIRTIO_MMIO_QUEUE_NUM_MAX);
537 
538 		error = virtqueue_alloc(dev, idx, size,
539 		    VIRTIO_MMIO_QUEUE_NOTIFY, VIRTIO_MMIO_VRING_ALIGN,
540 		    ~(vm_paddr_t)0, info, &vq);
541 		if (error) {
542 			device_printf(dev,
543 			    "cannot allocate virtqueue %d: %d\n",
544 			    idx, error);
545 			break;
546 		}
547 
548 		vtmmio_set_virtqueue(sc, vq, size);
549 
550 		vqx->vtv_vq = *info->vqai_vq = vq;
551 		vqx->vtv_no_intr = info->vqai_intr == NULL;
552 
553 		sc->vtmmio_nvqs++;
554 	}
555 
556 	if (error)
557 		vtmmio_free_virtqueues(sc);
558 
559 	return (error);
560 }
561 
562 static void
vtmmio_stop(device_t dev)563 vtmmio_stop(device_t dev)
564 {
565 
566 	vtmmio_reset(device_get_softc(dev));
567 }
568 
569 static int
vtmmio_reinit(device_t dev,uint64_t features)570 vtmmio_reinit(device_t dev, uint64_t features)
571 {
572 	struct vtmmio_softc *sc;
573 	int idx, error;
574 
575 	sc = device_get_softc(dev);
576 
577 	if (vtmmio_get_status(dev) != VIRTIO_CONFIG_STATUS_RESET)
578 		vtmmio_stop(dev);
579 
580 	/*
581 	 * Quickly drive the status through ACK and DRIVER. The device
582 	 * does not become usable again until vtmmio_reinit_complete().
583 	 */
584 	vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_ACK);
585 	vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER);
586 
587 	/*
588 	 * TODO: Check that features are not added as to what was
589 	 * originally negotiated.
590 	 */
591 	vtmmio_negotiate_features(dev, features);
592 	error = vtmmio_finalize_features(dev);
593 	if (error) {
594 		device_printf(dev, "cannot finalize features during reinit\n");
595 		return (error);
596 	}
597 
598 	if (sc->vtmmio_version == 1) {
599 		vtmmio_write_config_4(sc, VIRTIO_MMIO_GUEST_PAGE_SIZE,
600 		    (1 << PAGE_SHIFT));
601 	}
602 
603 	for (idx = 0; idx < sc->vtmmio_nvqs; idx++) {
604 		error = vtmmio_reinit_virtqueue(sc, idx);
605 		if (error)
606 			return (error);
607 	}
608 
609 	return (0);
610 }
611 
612 static void
vtmmio_reinit_complete(device_t dev)613 vtmmio_reinit_complete(device_t dev)
614 {
615 
616 	vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER_OK);
617 }
618 
619 static void
vtmmio_notify_virtqueue(device_t dev,uint16_t queue,bus_size_t offset)620 vtmmio_notify_virtqueue(device_t dev, uint16_t queue, bus_size_t offset)
621 {
622 	struct vtmmio_softc *sc;
623 
624 	sc = device_get_softc(dev);
625 	MPASS(offset == VIRTIO_MMIO_QUEUE_NOTIFY);
626 
627 	vtmmio_write_config_4(sc, offset, queue);
628 }
629 
630 static int
vtmmio_config_generation(device_t dev)631 vtmmio_config_generation(device_t dev)
632 {
633 	struct vtmmio_softc *sc;
634 	uint32_t gen;
635 
636 	sc = device_get_softc(dev);
637 
638 	if (sc->vtmmio_version > 1)
639 		gen = vtmmio_read_config_4(sc, VIRTIO_MMIO_CONFIG_GENERATION);
640 	else
641 		gen = 0;
642 
643 	return (gen);
644 }
645 
646 static uint8_t
vtmmio_get_status(device_t dev)647 vtmmio_get_status(device_t dev)
648 {
649 	struct vtmmio_softc *sc;
650 
651 	sc = device_get_softc(dev);
652 
653 	return (vtmmio_read_config_4(sc, VIRTIO_MMIO_STATUS));
654 }
655 
656 static void
vtmmio_set_status(device_t dev,uint8_t status)657 vtmmio_set_status(device_t dev, uint8_t status)
658 {
659 	struct vtmmio_softc *sc;
660 
661 	sc = device_get_softc(dev);
662 
663 	if (status != VIRTIO_CONFIG_STATUS_RESET)
664 		status |= vtmmio_get_status(dev);
665 
666 	vtmmio_write_config_4(sc, VIRTIO_MMIO_STATUS, status);
667 }
668 
669 static void
vtmmio_read_dev_config(device_t dev,bus_size_t offset,void * dst,int length)670 vtmmio_read_dev_config(device_t dev, bus_size_t offset,
671     void *dst, int length)
672 {
673 	struct vtmmio_softc *sc;
674 	bus_size_t off;
675 	uint8_t *d;
676 	int size;
677 
678 	sc = device_get_softc(dev);
679 	off = VIRTIO_MMIO_CONFIG + offset;
680 
681 	/*
682 	 * The non-legacy MMIO specification adds the following restriction:
683 	 *
684 	 *   4.2.2.2: For the device-specific configuration space, the driver
685 	 *   MUST use 8 bit wide accesses for 8 bit wide fields, 16 bit wide
686 	 *   and aligned accesses for 16 bit wide fields and 32 bit wide and
687 	 *   aligned accesses for 32 and 64 bit wide fields.
688 	 *
689 	 * The endianness also varies between non-legacy and legacy:
690 	 *
691 	 *   2.4: Note: The device configuration space uses the little-endian
692 	 *   format for multi-byte fields.
693 	 *
694 	 *   2.4.3: Note that for legacy interfaces, device configuration space
695 	 *   is generally the guest’s native endian, rather than PCI’s
696 	 *   little-endian. The correct endian-ness is documented for each
697 	 *   device.
698 	 */
699 	if (sc->vtmmio_version > 1) {
700 		switch (length) {
701 		case 1:
702 			*(uint8_t *)dst = vtmmio_read_config_1(sc, off);
703 			break;
704 		case 2:
705 			*(uint16_t *)dst =
706 			    le16toh(vtmmio_read_config_2(sc, off));
707 			break;
708 		case 4:
709 			*(uint32_t *)dst =
710 			    le32toh(vtmmio_read_config_4(sc, off));
711 			break;
712 		case 8:
713 			*(uint64_t *)dst = vtmmio_read_dev_config_8(sc, off);
714 			break;
715 		default:
716 			panic("%s: invalid length %d\n", __func__, length);
717 		}
718 
719 		return;
720 	}
721 
722 	for (d = dst; length > 0; d += size, off += size, length -= size) {
723 #ifdef ALLOW_WORD_ALIGNED_ACCESS
724 		if (length >= 4) {
725 			size = 4;
726 			*(uint32_t *)d = vtmmio_read_config_4(sc, off);
727 		} else if (length >= 2) {
728 			size = 2;
729 			*(uint16_t *)d = vtmmio_read_config_2(sc, off);
730 		} else
731 #endif
732 		{
733 			size = 1;
734 			*d = vtmmio_read_config_1(sc, off);
735 		}
736 	}
737 }
738 
739 static uint64_t
vtmmio_read_dev_config_8(struct vtmmio_softc * sc,bus_size_t off)740 vtmmio_read_dev_config_8(struct vtmmio_softc *sc, bus_size_t off)
741 {
742 	device_t dev;
743 	int gen;
744 	uint32_t val0, val1;
745 
746 	dev = sc->dev;
747 
748 	do {
749 		gen = vtmmio_config_generation(dev);
750 		val0 = le32toh(vtmmio_read_config_4(sc, off));
751 		val1 = le32toh(vtmmio_read_config_4(sc, off + 4));
752 	} while (gen != vtmmio_config_generation(dev));
753 
754 	return (((uint64_t) val1 << 32) | val0);
755 }
756 
757 static void
vtmmio_write_dev_config(device_t dev,bus_size_t offset,const void * src,int length)758 vtmmio_write_dev_config(device_t dev, bus_size_t offset,
759     const void *src, int length)
760 {
761 	struct vtmmio_softc *sc;
762 	bus_size_t off;
763 	const uint8_t *s;
764 	int size;
765 
766 	sc = device_get_softc(dev);
767 	off = VIRTIO_MMIO_CONFIG + offset;
768 
769 	/*
770 	 * The non-legacy MMIO specification adds size and alignment
771 	 * restrctions. It also changes the endianness from native-endian to
772 	 * little-endian. See vtmmio_read_dev_config.
773 	 */
774 	if (sc->vtmmio_version > 1) {
775 		switch (length) {
776 		case 1:
777 			vtmmio_write_config_1(sc, off, *(const uint8_t *)src);
778 			break;
779 		case 2:
780 			vtmmio_write_config_2(sc, off,
781 			    htole16(*(const uint16_t *)src));
782 			break;
783 		case 4:
784 			vtmmio_write_config_4(sc, off,
785 			    htole32(*(const uint32_t *)src));
786 			break;
787 		case 8:
788 			vtmmio_write_config_4(sc, off,
789 			    htole32(*(const uint64_t *)src));
790 			vtmmio_write_config_4(sc, off + 4,
791 			    htole32((*(const uint64_t *)src) >> 32));
792 			break;
793 		default:
794 			panic("%s: invalid length %d\n", __func__, length);
795 		}
796 
797 		return;
798 	}
799 
800 	for (s = src; length > 0; s += size, off += size, length -= size) {
801 #ifdef ALLOW_WORD_ALIGNED_ACCESS
802 		if (length >= 4) {
803 			size = 4;
804 			vtmmio_write_config_4(sc, off, *(uint32_t *)s);
805 		} else if (length >= 2) {
806 			size = 2;
807 			vtmmio_write_config_2(sc, off, *(uint16_t *)s);
808 		} else
809 #endif
810 		{
811 			size = 1;
812 			vtmmio_write_config_1(sc, off, *s);
813 		}
814 	}
815 }
816 
817 static void
vtmmio_describe_features(struct vtmmio_softc * sc,const char * msg,uint64_t features)818 vtmmio_describe_features(struct vtmmio_softc *sc, const char *msg,
819     uint64_t features)
820 {
821 	device_t dev, child;
822 
823 	dev = sc->dev;
824 	child = sc->vtmmio_child_dev;
825 
826 	if (device_is_attached(child) || bootverbose == 0)
827 		return;
828 
829 	virtio_describe(dev, msg, features, sc->vtmmio_child_feat_desc);
830 }
831 
832 static void
vtmmio_probe_and_attach_child(struct vtmmio_softc * sc)833 vtmmio_probe_and_attach_child(struct vtmmio_softc *sc)
834 {
835 	device_t dev, child;
836 
837 	dev = sc->dev;
838 	child = sc->vtmmio_child_dev;
839 
840 	if (child == NULL)
841 		return;
842 
843 	if (device_get_state(child) != DS_NOTPRESENT) {
844 		return;
845 	}
846 
847 	if (device_probe(child) != 0) {
848 		return;
849 	}
850 
851 	vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER);
852 	if (device_attach(child) != 0) {
853 		vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_FAILED);
854 		vtmmio_reset(sc);
855 		vtmmio_release_child_resources(sc);
856 		/* Reset status for future attempt. */
857 		vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_ACK);
858 	} else {
859 		vtmmio_set_status(dev, VIRTIO_CONFIG_STATUS_DRIVER_OK);
860 		VIRTIO_ATTACH_COMPLETED(child);
861 	}
862 }
863 
864 static int
vtmmio_reinit_virtqueue(struct vtmmio_softc * sc,int idx)865 vtmmio_reinit_virtqueue(struct vtmmio_softc *sc, int idx)
866 {
867 	struct vtmmio_virtqueue *vqx;
868 	struct virtqueue *vq;
869 	int error;
870 	uint16_t size;
871 
872 	vqx = &sc->vtmmio_vqs[idx];
873 	vq = vqx->vtv_vq;
874 
875 	KASSERT(vq != NULL, ("%s: vq %d not allocated", __func__, idx));
876 
877 	vtmmio_select_virtqueue(sc, idx);
878 	size = vtmmio_read_config_4(sc, VIRTIO_MMIO_QUEUE_NUM_MAX);
879 
880 	error = virtqueue_reinit(vq, size);
881 	if (error)
882 		return (error);
883 
884 	vtmmio_set_virtqueue(sc, vq, size);
885 
886 	return (0);
887 }
888 
889 static void
vtmmio_free_interrupts(struct vtmmio_softc * sc)890 vtmmio_free_interrupts(struct vtmmio_softc *sc)
891 {
892 
893 	if (sc->ih != NULL)
894 		bus_teardown_intr(sc->dev, sc->res[1], sc->ih);
895 
896 	if (sc->res[1] != NULL)
897 		bus_release_resource(sc->dev, SYS_RES_IRQ, 0, sc->res[1]);
898 }
899 
900 static void
vtmmio_free_virtqueues(struct vtmmio_softc * sc)901 vtmmio_free_virtqueues(struct vtmmio_softc *sc)
902 {
903 	struct vtmmio_virtqueue *vqx;
904 	int idx;
905 
906 	for (idx = 0; idx < sc->vtmmio_nvqs; idx++) {
907 		vqx = &sc->vtmmio_vqs[idx];
908 
909 		vtmmio_select_virtqueue(sc, idx);
910 		if (sc->vtmmio_version > 1) {
911 			vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_READY, 0);
912 			vtmmio_read_config_4(sc, VIRTIO_MMIO_QUEUE_READY);
913 		} else
914 			vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_PFN, 0);
915 
916 		virtqueue_free(vqx->vtv_vq);
917 		vqx->vtv_vq = NULL;
918 	}
919 
920 	free(sc->vtmmio_vqs, M_DEVBUF);
921 	sc->vtmmio_vqs = NULL;
922 	sc->vtmmio_nvqs = 0;
923 }
924 
925 static void
vtmmio_release_child_resources(struct vtmmio_softc * sc)926 vtmmio_release_child_resources(struct vtmmio_softc *sc)
927 {
928 
929 	vtmmio_free_interrupts(sc);
930 	vtmmio_free_virtqueues(sc);
931 }
932 
933 static void
vtmmio_reset(struct vtmmio_softc * sc)934 vtmmio_reset(struct vtmmio_softc *sc)
935 {
936 
937 	/*
938 	 * Setting the status to RESET sets the host device to
939 	 * the original, uninitialized state.
940 	 */
941 	vtmmio_set_status(sc->dev, VIRTIO_CONFIG_STATUS_RESET);
942 }
943 
944 static void
vtmmio_select_virtqueue(struct vtmmio_softc * sc,int idx)945 vtmmio_select_virtqueue(struct vtmmio_softc *sc, int idx)
946 {
947 
948 	vtmmio_write_config_4(sc, VIRTIO_MMIO_QUEUE_SEL, idx);
949 }
950 
951 static void
vtmmio_vq_intr(void * arg)952 vtmmio_vq_intr(void *arg)
953 {
954 	struct vtmmio_virtqueue *vqx;
955 	struct vtmmio_softc *sc;
956 	struct virtqueue *vq;
957 	uint32_t status;
958 	int idx;
959 
960 	sc = arg;
961 
962 	status = vtmmio_read_config_4(sc, VIRTIO_MMIO_INTERRUPT_STATUS);
963 	vtmmio_write_config_4(sc, VIRTIO_MMIO_INTERRUPT_ACK, status);
964 
965 	/* The config changed */
966 	if (status & VIRTIO_MMIO_INT_CONFIG)
967 		if (sc->vtmmio_child_dev != NULL)
968 			VIRTIO_CONFIG_CHANGE(sc->vtmmio_child_dev);
969 
970 	/* Notify all virtqueues. */
971 	if (status & VIRTIO_MMIO_INT_VRING) {
972 		for (idx = 0; idx < sc->vtmmio_nvqs; idx++) {
973 			vqx = &sc->vtmmio_vqs[idx];
974 			if (vqx->vtv_no_intr == 0) {
975 				vq = vqx->vtv_vq;
976 				virtqueue_intr(vq);
977 			}
978 		}
979 	}
980 }
981