1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2011, Bryan Venteicher <[email protected]>
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 VirtIO block devices. */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/bio.h>
38 #include <sys/malloc.h>
39 #include <sys/module.h>
40 #include <sys/sglist.h>
41 #include <sys/sysctl.h>
42 #include <sys/lock.h>
43 #include <sys/mutex.h>
44 #include <sys/queue.h>
45
46 #include <geom/geom.h>
47 #include <geom/geom_disk.h>
48
49 #include <machine/bus.h>
50 #include <machine/resource.h>
51 #include <sys/bus.h>
52 #include <sys/rman.h>
53
54 #include <dev/virtio/virtio.h>
55 #include <dev/virtio/virtqueue.h>
56 #include <dev/virtio/block/virtio_blk.h>
57
58 #include "virtio_if.h"
59
60 struct vtblk_request {
61 struct virtio_blk_outhdr vbr_hdr;
62 struct bio *vbr_bp;
63 uint8_t vbr_ack;
64 TAILQ_ENTRY(vtblk_request) vbr_link;
65 };
66
67 enum vtblk_cache_mode {
68 VTBLK_CACHE_WRITETHROUGH,
69 VTBLK_CACHE_WRITEBACK,
70 VTBLK_CACHE_MAX
71 };
72
73 struct vtblk_softc {
74 device_t vtblk_dev;
75 struct mtx vtblk_mtx;
76 uint64_t vtblk_features;
77 uint32_t vtblk_flags;
78 #define VTBLK_FLAG_INDIRECT 0x0001
79 #define VTBLK_FLAG_DETACH 0x0002
80 #define VTBLK_FLAG_SUSPEND 0x0004
81 #define VTBLK_FLAG_BARRIER 0x0008
82 #define VTBLK_FLAG_WCE_CONFIG 0x0010
83
84 struct virtqueue *vtblk_vq;
85 struct sglist *vtblk_sglist;
86 struct disk *vtblk_disk;
87
88 struct bio_queue_head vtblk_bioq;
89 TAILQ_HEAD(, vtblk_request)
90 vtblk_req_free;
91 TAILQ_HEAD(, vtblk_request)
92 vtblk_req_ready;
93 struct vtblk_request *vtblk_req_ordered;
94
95 int vtblk_max_nsegs;
96 int vtblk_request_count;
97 enum vtblk_cache_mode vtblk_write_cache;
98
99 struct bio_queue vtblk_dump_queue;
100 struct vtblk_request vtblk_dump_request;
101 };
102
103 static struct virtio_feature_desc vtblk_feature_desc[] = {
104 { VIRTIO_BLK_F_BARRIER, "HostBarrier" },
105 { VIRTIO_BLK_F_SIZE_MAX, "MaxSegSize" },
106 { VIRTIO_BLK_F_SEG_MAX, "MaxNumSegs" },
107 { VIRTIO_BLK_F_GEOMETRY, "DiskGeometry" },
108 { VIRTIO_BLK_F_RO, "ReadOnly" },
109 { VIRTIO_BLK_F_BLK_SIZE, "BlockSize" },
110 { VIRTIO_BLK_F_SCSI, "SCSICmds" },
111 { VIRTIO_BLK_F_FLUSH, "FlushCmd" },
112 { VIRTIO_BLK_F_TOPOLOGY, "Topology" },
113 { VIRTIO_BLK_F_CONFIG_WCE, "ConfigWCE" },
114 { VIRTIO_BLK_F_MQ, "Multiqueue" },
115 { VIRTIO_BLK_F_DISCARD, "Discard" },
116 { VIRTIO_BLK_F_WRITE_ZEROES, "WriteZeros" },
117
118 { 0, NULL }
119 };
120
121 static int vtblk_modevent(module_t, int, void *);
122
123 static int vtblk_probe(device_t);
124 static int vtblk_attach(device_t);
125 static int vtblk_detach(device_t);
126 static int vtblk_suspend(device_t);
127 static int vtblk_resume(device_t);
128 static int vtblk_shutdown(device_t);
129 static int vtblk_attach_completed(device_t);
130 static int vtblk_config_change(device_t);
131
132 static int vtblk_open(struct disk *);
133 static int vtblk_close(struct disk *);
134 static int vtblk_ioctl(struct disk *, u_long, void *, int,
135 struct thread *);
136 static int vtblk_dump(void *, void *, vm_offset_t, off_t, size_t);
137 static void vtblk_strategy(struct bio *);
138
139 static int vtblk_negotiate_features(struct vtblk_softc *);
140 static int vtblk_setup_features(struct vtblk_softc *);
141 static int vtblk_maximum_segments(struct vtblk_softc *,
142 struct virtio_blk_config *);
143 static int vtblk_alloc_virtqueue(struct vtblk_softc *);
144 static void vtblk_resize_disk(struct vtblk_softc *, uint64_t);
145 static void vtblk_alloc_disk(struct vtblk_softc *,
146 struct virtio_blk_config *);
147 static void vtblk_create_disk(struct vtblk_softc *);
148
149 static int vtblk_request_prealloc(struct vtblk_softc *);
150 static void vtblk_request_free(struct vtblk_softc *);
151 static struct vtblk_request *
152 vtblk_request_dequeue(struct vtblk_softc *);
153 static void vtblk_request_enqueue(struct vtblk_softc *,
154 struct vtblk_request *);
155 static struct vtblk_request *
156 vtblk_request_next_ready(struct vtblk_softc *);
157 static void vtblk_request_requeue_ready(struct vtblk_softc *,
158 struct vtblk_request *);
159 static struct vtblk_request *
160 vtblk_request_next(struct vtblk_softc *);
161 static struct vtblk_request *
162 vtblk_request_bio(struct vtblk_softc *);
163 static int vtblk_request_execute(struct vtblk_softc *,
164 struct vtblk_request *);
165 static int vtblk_request_error(struct vtblk_request *);
166
167 static void vtblk_queue_completed(struct vtblk_softc *,
168 struct bio_queue *);
169 static void vtblk_done_completed(struct vtblk_softc *,
170 struct bio_queue *);
171 static void vtblk_drain_vq(struct vtblk_softc *);
172 static void vtblk_drain(struct vtblk_softc *);
173
174 static void vtblk_startio(struct vtblk_softc *);
175 static void vtblk_bio_done(struct vtblk_softc *, struct bio *, int);
176
177 static void vtblk_read_config(struct vtblk_softc *,
178 struct virtio_blk_config *);
179 static void vtblk_ident(struct vtblk_softc *);
180 static int vtblk_poll_request(struct vtblk_softc *,
181 struct vtblk_request *);
182 static int vtblk_quiesce(struct vtblk_softc *);
183 static void vtblk_vq_intr(void *);
184 static void vtblk_stop(struct vtblk_softc *);
185
186 static void vtblk_dump_quiesce(struct vtblk_softc *);
187 static int vtblk_dump_write(struct vtblk_softc *, void *, off_t, size_t);
188 static int vtblk_dump_flush(struct vtblk_softc *);
189 static void vtblk_dump_complete(struct vtblk_softc *);
190
191 static void vtblk_set_write_cache(struct vtblk_softc *, int);
192 static int vtblk_write_cache_enabled(struct vtblk_softc *sc,
193 struct virtio_blk_config *);
194 static int vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS);
195
196 static void vtblk_setup_sysctl(struct vtblk_softc *);
197 static int vtblk_tunable_int(struct vtblk_softc *, const char *, int);
198
199 #define vtblk_modern(_sc) (((_sc)->vtblk_features & VIRTIO_F_VERSION_1) != 0)
200 #define vtblk_htog16(_sc, _val) virtio_htog16(vtblk_modern(_sc), _val)
201 #define vtblk_htog32(_sc, _val) virtio_htog32(vtblk_modern(_sc), _val)
202 #define vtblk_htog64(_sc, _val) virtio_htog64(vtblk_modern(_sc), _val)
203 #define vtblk_gtoh16(_sc, _val) virtio_gtoh16(vtblk_modern(_sc), _val)
204 #define vtblk_gtoh32(_sc, _val) virtio_gtoh32(vtblk_modern(_sc), _val)
205 #define vtblk_gtoh64(_sc, _val) virtio_gtoh64(vtblk_modern(_sc), _val)
206
207 /* Tunables. */
208 static int vtblk_no_ident = 0;
209 TUNABLE_INT("hw.vtblk.no_ident", &vtblk_no_ident);
210 static int vtblk_writecache_mode = -1;
211 TUNABLE_INT("hw.vtblk.writecache_mode", &vtblk_writecache_mode);
212
213 #define VTBLK_COMMON_FEATURES \
214 (VIRTIO_BLK_F_SIZE_MAX | \
215 VIRTIO_BLK_F_SEG_MAX | \
216 VIRTIO_BLK_F_GEOMETRY | \
217 VIRTIO_BLK_F_RO | \
218 VIRTIO_BLK_F_BLK_SIZE | \
219 VIRTIO_BLK_F_FLUSH | \
220 VIRTIO_BLK_F_TOPOLOGY | \
221 VIRTIO_BLK_F_CONFIG_WCE | \
222 VIRTIO_BLK_F_DISCARD | \
223 VIRTIO_RING_F_INDIRECT_DESC)
224
225 #define VTBLK_MODERN_FEATURES (VTBLK_COMMON_FEATURES)
226 #define VTBLK_LEGACY_FEATURES (VIRTIO_BLK_F_BARRIER | VTBLK_COMMON_FEATURES)
227
228 #define VTBLK_MTX(_sc) &(_sc)->vtblk_mtx
229 #define VTBLK_LOCK_INIT(_sc, _name) \
230 mtx_init(VTBLK_MTX((_sc)), (_name), \
231 "VirtIO Block Lock", MTX_DEF)
232 #define VTBLK_LOCK(_sc) mtx_lock(VTBLK_MTX((_sc)))
233 #define VTBLK_UNLOCK(_sc) mtx_unlock(VTBLK_MTX((_sc)))
234 #define VTBLK_LOCK_DESTROY(_sc) mtx_destroy(VTBLK_MTX((_sc)))
235 #define VTBLK_LOCK_ASSERT(_sc) mtx_assert(VTBLK_MTX((_sc)), MA_OWNED)
236 #define VTBLK_LOCK_ASSERT_NOTOWNED(_sc) \
237 mtx_assert(VTBLK_MTX((_sc)), MA_NOTOWNED)
238
239 #define VTBLK_DISK_NAME "vtbd"
240 #define VTBLK_QUIESCE_TIMEOUT (30 * hz)
241 #define VTBLK_BSIZE 512
242
243 /*
244 * Each block request uses at least two segments - one for the header
245 * and one for the status.
246 */
247 #define VTBLK_MIN_SEGMENTS 2
248
249 static device_method_t vtblk_methods[] = {
250 /* Device methods. */
251 DEVMETHOD(device_probe, vtblk_probe),
252 DEVMETHOD(device_attach, vtblk_attach),
253 DEVMETHOD(device_detach, vtblk_detach),
254 DEVMETHOD(device_suspend, vtblk_suspend),
255 DEVMETHOD(device_resume, vtblk_resume),
256 DEVMETHOD(device_shutdown, vtblk_shutdown),
257
258 /* VirtIO methods. */
259 DEVMETHOD(virtio_attach_completed, vtblk_attach_completed),
260 DEVMETHOD(virtio_config_change, vtblk_config_change),
261
262 DEVMETHOD_END
263 };
264
265 static driver_t vtblk_driver = {
266 "vtblk",
267 vtblk_methods,
268 sizeof(struct vtblk_softc)
269 };
270 static devclass_t vtblk_devclass;
271
272 VIRTIO_DRIVER_MODULE(virtio_blk, vtblk_driver, vtblk_devclass,
273 vtblk_modevent, 0);
274 MODULE_VERSION(virtio_blk, 1);
275 MODULE_DEPEND(virtio_blk, virtio, 1, 1, 1);
276
277 VIRTIO_SIMPLE_PNPINFO(virtio_blk, VIRTIO_ID_BLOCK, "VirtIO Block Adapter");
278
279 static int
vtblk_modevent(module_t mod,int type,void * unused)280 vtblk_modevent(module_t mod, int type, void *unused)
281 {
282 int error;
283
284 error = 0;
285
286 switch (type) {
287 case MOD_LOAD:
288 case MOD_QUIESCE:
289 case MOD_UNLOAD:
290 case MOD_SHUTDOWN:
291 break;
292 default:
293 error = EOPNOTSUPP;
294 break;
295 }
296
297 return (error);
298 }
299
300 static int
vtblk_probe(device_t dev)301 vtblk_probe(device_t dev)
302 {
303 return (VIRTIO_SIMPLE_PROBE(dev, virtio_blk));
304 }
305
306 static int
vtblk_attach(device_t dev)307 vtblk_attach(device_t dev)
308 {
309 struct vtblk_softc *sc;
310 struct virtio_blk_config blkcfg;
311 int error;
312
313 sc = device_get_softc(dev);
314 sc->vtblk_dev = dev;
315 virtio_set_feature_desc(dev, vtblk_feature_desc);
316
317 VTBLK_LOCK_INIT(sc, device_get_nameunit(dev));
318 bioq_init(&sc->vtblk_bioq);
319 TAILQ_INIT(&sc->vtblk_dump_queue);
320 TAILQ_INIT(&sc->vtblk_req_free);
321 TAILQ_INIT(&sc->vtblk_req_ready);
322
323 vtblk_setup_sysctl(sc);
324
325 error = vtblk_setup_features(sc);
326 if (error) {
327 device_printf(dev, "cannot setup features\n");
328 goto fail;
329 }
330
331 vtblk_read_config(sc, &blkcfg);
332
333 /*
334 * With the current sglist(9) implementation, it is not easy
335 * for us to support a maximum segment size as adjacent
336 * segments are coalesced. For now, just make sure it's larger
337 * than the maximum supported transfer size.
338 */
339 if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) {
340 if (blkcfg.size_max < maxphys) {
341 error = ENOTSUP;
342 device_printf(dev, "host requires unsupported "
343 "maximum segment size feature\n");
344 goto fail;
345 }
346 }
347
348 sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg);
349 if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) {
350 error = EINVAL;
351 device_printf(dev, "fewer than minimum number of segments "
352 "allowed: %d\n", sc->vtblk_max_nsegs);
353 goto fail;
354 }
355
356 sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT);
357 if (sc->vtblk_sglist == NULL) {
358 error = ENOMEM;
359 device_printf(dev, "cannot allocate sglist\n");
360 goto fail;
361 }
362
363 error = vtblk_alloc_virtqueue(sc);
364 if (error) {
365 device_printf(dev, "cannot allocate virtqueue\n");
366 goto fail;
367 }
368
369 error = vtblk_request_prealloc(sc);
370 if (error) {
371 device_printf(dev, "cannot preallocate requests\n");
372 goto fail;
373 }
374
375 vtblk_alloc_disk(sc, &blkcfg);
376
377 error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY);
378 if (error) {
379 device_printf(dev, "cannot setup virtqueue interrupt\n");
380 goto fail;
381 }
382
383 virtqueue_enable_intr(sc->vtblk_vq);
384
385 fail:
386 if (error)
387 vtblk_detach(dev);
388
389 return (error);
390 }
391
392 static int
vtblk_detach(device_t dev)393 vtblk_detach(device_t dev)
394 {
395 struct vtblk_softc *sc;
396
397 sc = device_get_softc(dev);
398
399 VTBLK_LOCK(sc);
400 sc->vtblk_flags |= VTBLK_FLAG_DETACH;
401 if (device_is_attached(dev))
402 vtblk_stop(sc);
403 VTBLK_UNLOCK(sc);
404
405 vtblk_drain(sc);
406
407 if (sc->vtblk_disk != NULL) {
408 disk_destroy(sc->vtblk_disk);
409 sc->vtblk_disk = NULL;
410 }
411
412 if (sc->vtblk_sglist != NULL) {
413 sglist_free(sc->vtblk_sglist);
414 sc->vtblk_sglist = NULL;
415 }
416
417 VTBLK_LOCK_DESTROY(sc);
418
419 return (0);
420 }
421
422 static int
vtblk_suspend(device_t dev)423 vtblk_suspend(device_t dev)
424 {
425 struct vtblk_softc *sc;
426 int error;
427
428 sc = device_get_softc(dev);
429
430 VTBLK_LOCK(sc);
431 sc->vtblk_flags |= VTBLK_FLAG_SUSPEND;
432 /* XXX BMV: virtio_stop(), etc needed here? */
433 error = vtblk_quiesce(sc);
434 if (error)
435 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND;
436 VTBLK_UNLOCK(sc);
437
438 return (error);
439 }
440
441 static int
vtblk_resume(device_t dev)442 vtblk_resume(device_t dev)
443 {
444 struct vtblk_softc *sc;
445
446 sc = device_get_softc(dev);
447
448 VTBLK_LOCK(sc);
449 /* XXX BMV: virtio_reinit(), etc needed here? */
450 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND;
451 vtblk_startio(sc);
452 VTBLK_UNLOCK(sc);
453
454 return (0);
455 }
456
457 static int
vtblk_shutdown(device_t dev)458 vtblk_shutdown(device_t dev)
459 {
460
461 return (0);
462 }
463
464 static int
vtblk_attach_completed(device_t dev)465 vtblk_attach_completed(device_t dev)
466 {
467 struct vtblk_softc *sc;
468
469 sc = device_get_softc(dev);
470
471 /*
472 * Create disk after attach as VIRTIO_BLK_T_GET_ID can only be
473 * processed after the device acknowledged
474 * VIRTIO_CONFIG_STATUS_DRIVER_OK.
475 */
476 vtblk_create_disk(sc);
477 return (0);
478 }
479
480 static int
vtblk_config_change(device_t dev)481 vtblk_config_change(device_t dev)
482 {
483 struct vtblk_softc *sc;
484 struct virtio_blk_config blkcfg;
485 uint64_t capacity;
486
487 sc = device_get_softc(dev);
488
489 vtblk_read_config(sc, &blkcfg);
490
491 /* Capacity is always in 512-byte units. */
492 capacity = blkcfg.capacity * VTBLK_BSIZE;
493
494 if (sc->vtblk_disk->d_mediasize != capacity)
495 vtblk_resize_disk(sc, capacity);
496
497 return (0);
498 }
499
500 static int
vtblk_open(struct disk * dp)501 vtblk_open(struct disk *dp)
502 {
503 struct vtblk_softc *sc;
504
505 if ((sc = dp->d_drv1) == NULL)
506 return (ENXIO);
507
508 return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0);
509 }
510
511 static int
vtblk_close(struct disk * dp)512 vtblk_close(struct disk *dp)
513 {
514 struct vtblk_softc *sc;
515
516 if ((sc = dp->d_drv1) == NULL)
517 return (ENXIO);
518
519 return (0);
520 }
521
522 static int
vtblk_ioctl(struct disk * dp,u_long cmd,void * addr,int flag,struct thread * td)523 vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag,
524 struct thread *td)
525 {
526 struct vtblk_softc *sc;
527
528 if ((sc = dp->d_drv1) == NULL)
529 return (ENXIO);
530
531 return (ENOTTY);
532 }
533
534 static int
vtblk_dump(void * arg,void * virtual,vm_offset_t physical,off_t offset,size_t length)535 vtblk_dump(void *arg, void *virtual, vm_offset_t physical, off_t offset,
536 size_t length)
537 {
538 struct disk *dp;
539 struct vtblk_softc *sc;
540 int error;
541
542 dp = arg;
543 error = 0;
544
545 if ((sc = dp->d_drv1) == NULL)
546 return (ENXIO);
547
548 VTBLK_LOCK(sc);
549
550 vtblk_dump_quiesce(sc);
551
552 if (length > 0)
553 error = vtblk_dump_write(sc, virtual, offset, length);
554 if (error || (virtual == NULL && offset == 0))
555 vtblk_dump_complete(sc);
556
557 VTBLK_UNLOCK(sc);
558
559 return (error);
560 }
561
562 static void
vtblk_strategy(struct bio * bp)563 vtblk_strategy(struct bio *bp)
564 {
565 struct vtblk_softc *sc;
566
567 if ((sc = bp->bio_disk->d_drv1) == NULL) {
568 vtblk_bio_done(NULL, bp, EINVAL);
569 return;
570 }
571
572 if ((bp->bio_cmd != BIO_READ) && (bp->bio_cmd != BIO_WRITE) &&
573 (bp->bio_cmd != BIO_FLUSH) && (bp->bio_cmd != BIO_DELETE)) {
574 vtblk_bio_done(sc, bp, EOPNOTSUPP);
575 return;
576 }
577
578 VTBLK_LOCK(sc);
579
580 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) {
581 VTBLK_UNLOCK(sc);
582 vtblk_bio_done(sc, bp, ENXIO);
583 return;
584 }
585
586 bioq_insert_tail(&sc->vtblk_bioq, bp);
587 vtblk_startio(sc);
588
589 VTBLK_UNLOCK(sc);
590 }
591
592 static int
vtblk_negotiate_features(struct vtblk_softc * sc)593 vtblk_negotiate_features(struct vtblk_softc *sc)
594 {
595 device_t dev;
596 uint64_t features;
597
598 dev = sc->vtblk_dev;
599 features = virtio_bus_is_modern(dev) ? VTBLK_MODERN_FEATURES :
600 VTBLK_LEGACY_FEATURES;
601
602 sc->vtblk_features = virtio_negotiate_features(dev, features);
603 return (virtio_finalize_features(dev));
604 }
605
606 static int
vtblk_setup_features(struct vtblk_softc * sc)607 vtblk_setup_features(struct vtblk_softc *sc)
608 {
609 device_t dev;
610 int error;
611
612 dev = sc->vtblk_dev;
613
614 error = vtblk_negotiate_features(sc);
615 if (error)
616 return (error);
617
618 if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC))
619 sc->vtblk_flags |= VTBLK_FLAG_INDIRECT;
620 if (virtio_with_feature(dev, VIRTIO_BLK_F_CONFIG_WCE))
621 sc->vtblk_flags |= VTBLK_FLAG_WCE_CONFIG;
622
623 /* Legacy. */
624 if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER))
625 sc->vtblk_flags |= VTBLK_FLAG_BARRIER;
626
627 return (0);
628 }
629
630 static int
vtblk_maximum_segments(struct vtblk_softc * sc,struct virtio_blk_config * blkcfg)631 vtblk_maximum_segments(struct vtblk_softc *sc,
632 struct virtio_blk_config *blkcfg)
633 {
634 device_t dev;
635 int nsegs;
636
637 dev = sc->vtblk_dev;
638 nsegs = VTBLK_MIN_SEGMENTS;
639
640 if (virtio_with_feature(dev, VIRTIO_BLK_F_SEG_MAX)) {
641 nsegs += MIN(blkcfg->seg_max, maxphys / PAGE_SIZE + 1);
642 if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT)
643 nsegs = MIN(nsegs, VIRTIO_MAX_INDIRECT);
644 } else
645 nsegs += 1;
646
647 return (nsegs);
648 }
649
650 static int
vtblk_alloc_virtqueue(struct vtblk_softc * sc)651 vtblk_alloc_virtqueue(struct vtblk_softc *sc)
652 {
653 device_t dev;
654 struct vq_alloc_info vq_info;
655
656 dev = sc->vtblk_dev;
657
658 VQ_ALLOC_INFO_INIT(&vq_info, sc->vtblk_max_nsegs,
659 vtblk_vq_intr, sc, &sc->vtblk_vq,
660 "%s request", device_get_nameunit(dev));
661
662 return (virtio_alloc_virtqueues(dev, 0, 1, &vq_info));
663 }
664
665 static void
vtblk_resize_disk(struct vtblk_softc * sc,uint64_t new_capacity)666 vtblk_resize_disk(struct vtblk_softc *sc, uint64_t new_capacity)
667 {
668 device_t dev;
669 struct disk *dp;
670 int error;
671
672 dev = sc->vtblk_dev;
673 dp = sc->vtblk_disk;
674
675 dp->d_mediasize = new_capacity;
676 if (bootverbose) {
677 device_printf(dev, "resized to %juMB (%ju %u byte sectors)\n",
678 (uintmax_t) dp->d_mediasize >> 20,
679 (uintmax_t) dp->d_mediasize / dp->d_sectorsize,
680 dp->d_sectorsize);
681 }
682
683 error = disk_resize(dp, M_NOWAIT);
684 if (error) {
685 device_printf(dev,
686 "disk_resize(9) failed, error: %d\n", error);
687 }
688 }
689
690 static void
vtblk_alloc_disk(struct vtblk_softc * sc,struct virtio_blk_config * blkcfg)691 vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg)
692 {
693 device_t dev;
694 struct disk *dp;
695
696 dev = sc->vtblk_dev;
697
698 sc->vtblk_disk = dp = disk_alloc();
699 dp->d_open = vtblk_open;
700 dp->d_close = vtblk_close;
701 dp->d_ioctl = vtblk_ioctl;
702 dp->d_strategy = vtblk_strategy;
703 dp->d_name = VTBLK_DISK_NAME;
704 dp->d_unit = device_get_unit(dev);
705 dp->d_drv1 = sc;
706 dp->d_flags = DISKFLAG_UNMAPPED_BIO | DISKFLAG_DIRECT_COMPLETION;
707 dp->d_hba_vendor = virtio_get_vendor(dev);
708 dp->d_hba_device = virtio_get_device(dev);
709 dp->d_hba_subvendor = virtio_get_subvendor(dev);
710 dp->d_hba_subdevice = virtio_get_subdevice(dev);
711
712 if (virtio_with_feature(dev, VIRTIO_BLK_F_RO))
713 dp->d_flags |= DISKFLAG_WRITE_PROTECT;
714 else {
715 if (virtio_with_feature(dev, VIRTIO_BLK_F_FLUSH))
716 dp->d_flags |= DISKFLAG_CANFLUSHCACHE;
717 dp->d_dump = vtblk_dump;
718 }
719
720 /* Capacity is always in 512-byte units. */
721 dp->d_mediasize = blkcfg->capacity * VTBLK_BSIZE;
722
723 if (virtio_with_feature(dev, VIRTIO_BLK_F_BLK_SIZE))
724 dp->d_sectorsize = blkcfg->blk_size;
725 else
726 dp->d_sectorsize = VTBLK_BSIZE;
727
728 /*
729 * The VirtIO maximum I/O size is given in terms of segments.
730 * However, FreeBSD limits I/O size by logical buffer size, not
731 * by physically contiguous pages. Therefore, we have to assume
732 * no pages are contiguous. This may impose an artificially low
733 * maximum I/O size. But in practice, since QEMU advertises 128
734 * segments, this gives us a maximum IO size of 125 * PAGE_SIZE,
735 * which is typically greater than maxphys. Eventually we should
736 * just advertise maxphys and split buffers that are too big.
737 *
738 * Note we must subtract one additional segment in case of non
739 * page aligned buffers.
740 */
741 dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS - 1) *
742 PAGE_SIZE;
743 if (dp->d_maxsize < PAGE_SIZE)
744 dp->d_maxsize = PAGE_SIZE; /* XXX */
745
746 if (virtio_with_feature(dev, VIRTIO_BLK_F_GEOMETRY)) {
747 dp->d_fwsectors = blkcfg->geometry.sectors;
748 dp->d_fwheads = blkcfg->geometry.heads;
749 }
750
751 if (virtio_with_feature(dev, VIRTIO_BLK_F_TOPOLOGY) &&
752 blkcfg->topology.physical_block_exp > 0) {
753 dp->d_stripesize = dp->d_sectorsize *
754 (1 << blkcfg->topology.physical_block_exp);
755 dp->d_stripeoffset = (dp->d_stripesize -
756 blkcfg->topology.alignment_offset * dp->d_sectorsize) %
757 dp->d_stripesize;
758 }
759
760 if (virtio_with_feature(dev, VIRTIO_BLK_F_DISCARD)) {
761 dp->d_flags |= DISKFLAG_CANDELETE;
762 dp->d_delmaxsize = blkcfg->max_discard_sectors * VTBLK_BSIZE;
763 }
764
765 if (vtblk_write_cache_enabled(sc, blkcfg) != 0)
766 sc->vtblk_write_cache = VTBLK_CACHE_WRITEBACK;
767 else
768 sc->vtblk_write_cache = VTBLK_CACHE_WRITETHROUGH;
769 }
770
771 static void
vtblk_create_disk(struct vtblk_softc * sc)772 vtblk_create_disk(struct vtblk_softc *sc)
773 {
774 struct disk *dp;
775
776 dp = sc->vtblk_disk;
777
778 vtblk_ident(sc);
779
780 device_printf(sc->vtblk_dev, "%juMB (%ju %u byte sectors)\n",
781 (uintmax_t) dp->d_mediasize >> 20,
782 (uintmax_t) dp->d_mediasize / dp->d_sectorsize,
783 dp->d_sectorsize);
784
785 disk_create(dp, DISK_VERSION);
786 }
787
788 static int
vtblk_request_prealloc(struct vtblk_softc * sc)789 vtblk_request_prealloc(struct vtblk_softc *sc)
790 {
791 struct vtblk_request *req;
792 int i, nreqs;
793
794 nreqs = virtqueue_size(sc->vtblk_vq);
795
796 /*
797 * Preallocate sufficient requests to keep the virtqueue full. Each
798 * request consumes VTBLK_MIN_SEGMENTS or more descriptors so reduce
799 * the number allocated when indirect descriptors are not available.
800 */
801 if ((sc->vtblk_flags & VTBLK_FLAG_INDIRECT) == 0)
802 nreqs /= VTBLK_MIN_SEGMENTS;
803
804 for (i = 0; i < nreqs; i++) {
805 req = malloc(sizeof(struct vtblk_request), M_DEVBUF, M_NOWAIT);
806 if (req == NULL)
807 return (ENOMEM);
808
809 MPASS(sglist_count(&req->vbr_hdr, sizeof(req->vbr_hdr)) == 1);
810 MPASS(sglist_count(&req->vbr_ack, sizeof(req->vbr_ack)) == 1);
811
812 sc->vtblk_request_count++;
813 vtblk_request_enqueue(sc, req);
814 }
815
816 return (0);
817 }
818
819 static void
vtblk_request_free(struct vtblk_softc * sc)820 vtblk_request_free(struct vtblk_softc *sc)
821 {
822 struct vtblk_request *req;
823
824 MPASS(TAILQ_EMPTY(&sc->vtblk_req_ready));
825
826 while ((req = vtblk_request_dequeue(sc)) != NULL) {
827 sc->vtblk_request_count--;
828 free(req, M_DEVBUF);
829 }
830
831 KASSERT(sc->vtblk_request_count == 0,
832 ("%s: leaked %d requests", __func__, sc->vtblk_request_count));
833 }
834
835 static struct vtblk_request *
vtblk_request_dequeue(struct vtblk_softc * sc)836 vtblk_request_dequeue(struct vtblk_softc *sc)
837 {
838 struct vtblk_request *req;
839
840 req = TAILQ_FIRST(&sc->vtblk_req_free);
841 if (req != NULL) {
842 TAILQ_REMOVE(&sc->vtblk_req_free, req, vbr_link);
843 bzero(req, sizeof(struct vtblk_request));
844 }
845
846 return (req);
847 }
848
849 static void
vtblk_request_enqueue(struct vtblk_softc * sc,struct vtblk_request * req)850 vtblk_request_enqueue(struct vtblk_softc *sc, struct vtblk_request *req)
851 {
852
853 TAILQ_INSERT_HEAD(&sc->vtblk_req_free, req, vbr_link);
854 }
855
856 static struct vtblk_request *
vtblk_request_next_ready(struct vtblk_softc * sc)857 vtblk_request_next_ready(struct vtblk_softc *sc)
858 {
859 struct vtblk_request *req;
860
861 req = TAILQ_FIRST(&sc->vtblk_req_ready);
862 if (req != NULL)
863 TAILQ_REMOVE(&sc->vtblk_req_ready, req, vbr_link);
864
865 return (req);
866 }
867
868 static void
vtblk_request_requeue_ready(struct vtblk_softc * sc,struct vtblk_request * req)869 vtblk_request_requeue_ready(struct vtblk_softc *sc, struct vtblk_request *req)
870 {
871
872 /* NOTE: Currently, there will be at most one request in the queue. */
873 TAILQ_INSERT_HEAD(&sc->vtblk_req_ready, req, vbr_link);
874 }
875
876 static struct vtblk_request *
vtblk_request_next(struct vtblk_softc * sc)877 vtblk_request_next(struct vtblk_softc *sc)
878 {
879 struct vtblk_request *req;
880
881 req = vtblk_request_next_ready(sc);
882 if (req != NULL)
883 return (req);
884
885 return (vtblk_request_bio(sc));
886 }
887
888 static struct vtblk_request *
vtblk_request_bio(struct vtblk_softc * sc)889 vtblk_request_bio(struct vtblk_softc *sc)
890 {
891 struct bio_queue_head *bioq;
892 struct vtblk_request *req;
893 struct bio *bp;
894
895 bioq = &sc->vtblk_bioq;
896
897 if (bioq_first(bioq) == NULL)
898 return (NULL);
899
900 req = vtblk_request_dequeue(sc);
901 if (req == NULL)
902 return (NULL);
903
904 bp = bioq_takefirst(bioq);
905 req->vbr_bp = bp;
906 req->vbr_ack = -1;
907 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1);
908
909 switch (bp->bio_cmd) {
910 case BIO_FLUSH:
911 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH);
912 req->vbr_hdr.sector = 0;
913 break;
914 case BIO_READ:
915 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_IN);
916 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE);
917 break;
918 case BIO_WRITE:
919 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT);
920 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE);
921 break;
922 case BIO_DELETE:
923 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_DISCARD);
924 req->vbr_hdr.sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE);
925 break;
926 default:
927 panic("%s: bio with unhandled cmd: %d", __func__, bp->bio_cmd);
928 }
929
930 if (bp->bio_flags & BIO_ORDERED)
931 req->vbr_hdr.type |= vtblk_gtoh32(sc, VIRTIO_BLK_T_BARRIER);
932
933 return (req);
934 }
935
936 static int
vtblk_request_execute(struct vtblk_softc * sc,struct vtblk_request * req)937 vtblk_request_execute(struct vtblk_softc *sc, struct vtblk_request *req)
938 {
939 struct virtqueue *vq;
940 struct sglist *sg;
941 struct bio *bp;
942 int ordered, readable, writable, error;
943
944 vq = sc->vtblk_vq;
945 sg = sc->vtblk_sglist;
946 bp = req->vbr_bp;
947 ordered = 0;
948 writable = 0;
949
950 /*
951 * Some hosts (such as bhyve) do not implement the barrier feature,
952 * so we emulate it in the driver by allowing the barrier request
953 * to be the only one in flight.
954 */
955 if ((sc->vtblk_flags & VTBLK_FLAG_BARRIER) == 0) {
956 if (sc->vtblk_req_ordered != NULL)
957 return (EBUSY);
958 if (bp->bio_flags & BIO_ORDERED) {
959 if (!virtqueue_empty(vq))
960 return (EBUSY);
961 ordered = 1;
962 req->vbr_hdr.type &= vtblk_gtoh32(sc,
963 ~VIRTIO_BLK_T_BARRIER);
964 }
965 }
966
967 sglist_reset(sg);
968 sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr));
969
970 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) {
971 error = sglist_append_bio(sg, bp);
972 if (error || sg->sg_nseg == sg->sg_maxseg) {
973 panic("%s: bio %p data buffer too big %d",
974 __func__, bp, error);
975 }
976
977 /* BIO_READ means the host writes into our buffer. */
978 if (bp->bio_cmd == BIO_READ)
979 writable = sg->sg_nseg - 1;
980 } else if (bp->bio_cmd == BIO_DELETE) {
981 struct virtio_blk_discard_write_zeroes *discard;
982
983 discard = malloc(sizeof(*discard), M_DEVBUF, M_NOWAIT | M_ZERO);
984 if (discard == NULL)
985 return (ENOMEM);
986
987 bp->bio_driver1 = discard;
988 discard->sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE);
989 discard->num_sectors = vtblk_gtoh32(sc, bp->bio_bcount / VTBLK_BSIZE);
990 error = sglist_append(sg, discard, sizeof(*discard));
991 if (error || sg->sg_nseg == sg->sg_maxseg) {
992 panic("%s: bio %p data buffer too big %d",
993 __func__, bp, error);
994 }
995 }
996
997 writable++;
998 sglist_append(sg, &req->vbr_ack, sizeof(uint8_t));
999 readable = sg->sg_nseg - writable;
1000
1001 error = virtqueue_enqueue(vq, req, sg, readable, writable);
1002 if (error == 0 && ordered)
1003 sc->vtblk_req_ordered = req;
1004
1005 return (error);
1006 }
1007
1008 static int
vtblk_request_error(struct vtblk_request * req)1009 vtblk_request_error(struct vtblk_request *req)
1010 {
1011 int error;
1012
1013 switch (req->vbr_ack) {
1014 case VIRTIO_BLK_S_OK:
1015 error = 0;
1016 break;
1017 case VIRTIO_BLK_S_UNSUPP:
1018 error = ENOTSUP;
1019 break;
1020 default:
1021 error = EIO;
1022 break;
1023 }
1024
1025 return (error);
1026 }
1027
1028 static void
vtblk_queue_completed(struct vtblk_softc * sc,struct bio_queue * queue)1029 vtblk_queue_completed(struct vtblk_softc *sc, struct bio_queue *queue)
1030 {
1031 struct vtblk_request *req;
1032 struct bio *bp;
1033
1034 while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) {
1035 if (sc->vtblk_req_ordered != NULL) {
1036 MPASS(sc->vtblk_req_ordered == req);
1037 sc->vtblk_req_ordered = NULL;
1038 }
1039
1040 bp = req->vbr_bp;
1041 bp->bio_error = vtblk_request_error(req);
1042 TAILQ_INSERT_TAIL(queue, bp, bio_queue);
1043
1044 vtblk_request_enqueue(sc, req);
1045 }
1046 }
1047
1048 static void
vtblk_done_completed(struct vtblk_softc * sc,struct bio_queue * queue)1049 vtblk_done_completed(struct vtblk_softc *sc, struct bio_queue *queue)
1050 {
1051 struct bio *bp, *tmp;
1052
1053 TAILQ_FOREACH_SAFE(bp, queue, bio_queue, tmp) {
1054 if (bp->bio_error != 0)
1055 disk_err(bp, "hard error", -1, 1);
1056 vtblk_bio_done(sc, bp, bp->bio_error);
1057 }
1058 }
1059
1060 static void
vtblk_drain_vq(struct vtblk_softc * sc)1061 vtblk_drain_vq(struct vtblk_softc *sc)
1062 {
1063 struct virtqueue *vq;
1064 struct vtblk_request *req;
1065 int last;
1066
1067 vq = sc->vtblk_vq;
1068 last = 0;
1069
1070 while ((req = virtqueue_drain(vq, &last)) != NULL) {
1071 vtblk_bio_done(sc, req->vbr_bp, ENXIO);
1072 vtblk_request_enqueue(sc, req);
1073 }
1074
1075 sc->vtblk_req_ordered = NULL;
1076 KASSERT(virtqueue_empty(vq), ("virtqueue not empty"));
1077 }
1078
1079 static void
vtblk_drain(struct vtblk_softc * sc)1080 vtblk_drain(struct vtblk_softc *sc)
1081 {
1082 struct bio_queue_head *bioq;
1083 struct vtblk_request *req;
1084 struct bio *bp;
1085
1086 bioq = &sc->vtblk_bioq;
1087
1088 if (sc->vtblk_vq != NULL) {
1089 struct bio_queue queue;
1090
1091 TAILQ_INIT(&queue);
1092 vtblk_queue_completed(sc, &queue);
1093 vtblk_done_completed(sc, &queue);
1094
1095 vtblk_drain_vq(sc);
1096 }
1097
1098 while ((req = vtblk_request_next_ready(sc)) != NULL) {
1099 vtblk_bio_done(sc, req->vbr_bp, ENXIO);
1100 vtblk_request_enqueue(sc, req);
1101 }
1102
1103 while (bioq_first(bioq) != NULL) {
1104 bp = bioq_takefirst(bioq);
1105 vtblk_bio_done(sc, bp, ENXIO);
1106 }
1107
1108 vtblk_request_free(sc);
1109 }
1110
1111 static void
vtblk_startio(struct vtblk_softc * sc)1112 vtblk_startio(struct vtblk_softc *sc)
1113 {
1114 struct virtqueue *vq;
1115 struct vtblk_request *req;
1116 int enq;
1117
1118 VTBLK_LOCK_ASSERT(sc);
1119 vq = sc->vtblk_vq;
1120 enq = 0;
1121
1122 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND)
1123 return;
1124
1125 while (!virtqueue_full(vq)) {
1126 req = vtblk_request_next(sc);
1127 if (req == NULL)
1128 break;
1129
1130 if (vtblk_request_execute(sc, req) != 0) {
1131 vtblk_request_requeue_ready(sc, req);
1132 break;
1133 }
1134
1135 enq++;
1136 }
1137
1138 if (enq > 0)
1139 virtqueue_notify(vq);
1140 }
1141
1142 static void
vtblk_bio_done(struct vtblk_softc * sc,struct bio * bp,int error)1143 vtblk_bio_done(struct vtblk_softc *sc, struct bio *bp, int error)
1144 {
1145
1146 /* Because of GEOM direct dispatch, we cannot hold any locks. */
1147 if (sc != NULL)
1148 VTBLK_LOCK_ASSERT_NOTOWNED(sc);
1149
1150 if (error) {
1151 bp->bio_resid = bp->bio_bcount;
1152 bp->bio_error = error;
1153 bp->bio_flags |= BIO_ERROR;
1154 }
1155
1156 if (bp->bio_driver1 != NULL) {
1157 free(bp->bio_driver1, M_DEVBUF);
1158 bp->bio_driver1 = NULL;
1159 }
1160
1161 biodone(bp);
1162 }
1163
1164 #define VTBLK_GET_CONFIG(_dev, _feature, _field, _cfg) \
1165 if (virtio_with_feature(_dev, _feature)) { \
1166 virtio_read_device_config(_dev, \
1167 offsetof(struct virtio_blk_config, _field), \
1168 &(_cfg)->_field, sizeof((_cfg)->_field)); \
1169 }
1170
1171 static void
vtblk_read_config(struct vtblk_softc * sc,struct virtio_blk_config * blkcfg)1172 vtblk_read_config(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg)
1173 {
1174 device_t dev;
1175
1176 dev = sc->vtblk_dev;
1177
1178 bzero(blkcfg, sizeof(struct virtio_blk_config));
1179
1180 /* The capacity is always available. */
1181 virtio_read_device_config(dev, offsetof(struct virtio_blk_config,
1182 capacity), &blkcfg->capacity, sizeof(blkcfg->capacity));
1183
1184 /* Read the configuration if the feature was negotiated. */
1185 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SIZE_MAX, size_max, blkcfg);
1186 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SEG_MAX, seg_max, blkcfg);
1187 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY,
1188 geometry.cylinders, blkcfg);
1189 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY,
1190 geometry.heads, blkcfg);
1191 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY,
1192 geometry.sectors, blkcfg);
1193 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_BLK_SIZE, blk_size, blkcfg);
1194 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY,
1195 topology.physical_block_exp, blkcfg);
1196 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY,
1197 topology.alignment_offset, blkcfg);
1198 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY,
1199 topology.min_io_size, blkcfg);
1200 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY,
1201 topology.opt_io_size, blkcfg);
1202 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_CONFIG_WCE, wce, blkcfg);
1203 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_sectors,
1204 blkcfg);
1205 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_seg, blkcfg);
1206 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, discard_sector_alignment,
1207 blkcfg);
1208 }
1209
1210 #undef VTBLK_GET_CONFIG
1211
1212 static void
vtblk_ident(struct vtblk_softc * sc)1213 vtblk_ident(struct vtblk_softc *sc)
1214 {
1215 struct bio buf;
1216 struct disk *dp;
1217 struct vtblk_request *req;
1218 int len, error;
1219
1220 dp = sc->vtblk_disk;
1221 len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE);
1222
1223 if (vtblk_tunable_int(sc, "no_ident", vtblk_no_ident) != 0)
1224 return;
1225
1226 req = vtblk_request_dequeue(sc);
1227 if (req == NULL)
1228 return;
1229
1230 req->vbr_ack = -1;
1231 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_GET_ID);
1232 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1);
1233 req->vbr_hdr.sector = 0;
1234
1235 req->vbr_bp = &buf;
1236 g_reset_bio(&buf);
1237
1238 buf.bio_cmd = BIO_READ;
1239 buf.bio_data = dp->d_ident;
1240 buf.bio_bcount = len;
1241
1242 VTBLK_LOCK(sc);
1243 error = vtblk_poll_request(sc, req);
1244 VTBLK_UNLOCK(sc);
1245
1246 vtblk_request_enqueue(sc, req);
1247
1248 if (error) {
1249 device_printf(sc->vtblk_dev,
1250 "error getting device identifier: %d\n", error);
1251 }
1252 }
1253
1254 static int
vtblk_poll_request(struct vtblk_softc * sc,struct vtblk_request * req)1255 vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req)
1256 {
1257 struct virtqueue *vq;
1258 int error;
1259
1260 vq = sc->vtblk_vq;
1261
1262 if (!virtqueue_empty(vq))
1263 return (EBUSY);
1264
1265 error = vtblk_request_execute(sc, req);
1266 if (error)
1267 return (error);
1268
1269 virtqueue_notify(vq);
1270 virtqueue_poll(vq, NULL);
1271
1272 error = vtblk_request_error(req);
1273 if (error && bootverbose) {
1274 device_printf(sc->vtblk_dev,
1275 "%s: IO error: %d\n", __func__, error);
1276 }
1277
1278 return (error);
1279 }
1280
1281 static int
vtblk_quiesce(struct vtblk_softc * sc)1282 vtblk_quiesce(struct vtblk_softc *sc)
1283 {
1284 int error;
1285
1286 VTBLK_LOCK_ASSERT(sc);
1287 error = 0;
1288
1289 while (!virtqueue_empty(sc->vtblk_vq)) {
1290 if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq",
1291 VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) {
1292 error = EBUSY;
1293 break;
1294 }
1295 }
1296
1297 return (error);
1298 }
1299
1300 static void
vtblk_vq_intr(void * xsc)1301 vtblk_vq_intr(void *xsc)
1302 {
1303 struct vtblk_softc *sc;
1304 struct virtqueue *vq;
1305 struct bio_queue queue;
1306
1307 sc = xsc;
1308 vq = sc->vtblk_vq;
1309 TAILQ_INIT(&queue);
1310
1311 VTBLK_LOCK(sc);
1312
1313 again:
1314 if (sc->vtblk_flags & VTBLK_FLAG_DETACH)
1315 goto out;
1316
1317 vtblk_queue_completed(sc, &queue);
1318 vtblk_startio(sc);
1319
1320 if (virtqueue_enable_intr(vq) != 0) {
1321 virtqueue_disable_intr(vq);
1322 goto again;
1323 }
1324
1325 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND)
1326 wakeup(&sc->vtblk_vq);
1327
1328 out:
1329 VTBLK_UNLOCK(sc);
1330 vtblk_done_completed(sc, &queue);
1331 }
1332
1333 static void
vtblk_stop(struct vtblk_softc * sc)1334 vtblk_stop(struct vtblk_softc *sc)
1335 {
1336
1337 virtqueue_disable_intr(sc->vtblk_vq);
1338 virtio_stop(sc->vtblk_dev);
1339 }
1340
1341 static void
vtblk_dump_quiesce(struct vtblk_softc * sc)1342 vtblk_dump_quiesce(struct vtblk_softc *sc)
1343 {
1344
1345 /*
1346 * Spin here until all the requests in-flight at the time of the
1347 * dump are completed and queued. The queued requests will be
1348 * biodone'd once the dump is finished.
1349 */
1350 while (!virtqueue_empty(sc->vtblk_vq))
1351 vtblk_queue_completed(sc, &sc->vtblk_dump_queue);
1352 }
1353
1354 static int
vtblk_dump_write(struct vtblk_softc * sc,void * virtual,off_t offset,size_t length)1355 vtblk_dump_write(struct vtblk_softc *sc, void *virtual, off_t offset,
1356 size_t length)
1357 {
1358 struct bio buf;
1359 struct vtblk_request *req;
1360
1361 req = &sc->vtblk_dump_request;
1362 req->vbr_ack = -1;
1363 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT);
1364 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1);
1365 req->vbr_hdr.sector = vtblk_gtoh64(sc, offset / VTBLK_BSIZE);
1366
1367 req->vbr_bp = &buf;
1368 g_reset_bio(&buf);
1369
1370 buf.bio_cmd = BIO_WRITE;
1371 buf.bio_data = virtual;
1372 buf.bio_bcount = length;
1373
1374 return (vtblk_poll_request(sc, req));
1375 }
1376
1377 static int
vtblk_dump_flush(struct vtblk_softc * sc)1378 vtblk_dump_flush(struct vtblk_softc *sc)
1379 {
1380 struct bio buf;
1381 struct vtblk_request *req;
1382
1383 req = &sc->vtblk_dump_request;
1384 req->vbr_ack = -1;
1385 req->vbr_hdr.type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH);
1386 req->vbr_hdr.ioprio = vtblk_gtoh32(sc, 1);
1387 req->vbr_hdr.sector = 0;
1388
1389 req->vbr_bp = &buf;
1390 g_reset_bio(&buf);
1391
1392 buf.bio_cmd = BIO_FLUSH;
1393
1394 return (vtblk_poll_request(sc, req));
1395 }
1396
1397 static void
vtblk_dump_complete(struct vtblk_softc * sc)1398 vtblk_dump_complete(struct vtblk_softc *sc)
1399 {
1400
1401 vtblk_dump_flush(sc);
1402
1403 VTBLK_UNLOCK(sc);
1404 vtblk_done_completed(sc, &sc->vtblk_dump_queue);
1405 VTBLK_LOCK(sc);
1406 }
1407
1408 static void
vtblk_set_write_cache(struct vtblk_softc * sc,int wc)1409 vtblk_set_write_cache(struct vtblk_softc *sc, int wc)
1410 {
1411
1412 /* Set either writeback (1) or writethrough (0) mode. */
1413 virtio_write_dev_config_1(sc->vtblk_dev,
1414 offsetof(struct virtio_blk_config, wce), wc);
1415 }
1416
1417 static int
vtblk_write_cache_enabled(struct vtblk_softc * sc,struct virtio_blk_config * blkcfg)1418 vtblk_write_cache_enabled(struct vtblk_softc *sc,
1419 struct virtio_blk_config *blkcfg)
1420 {
1421 int wc;
1422
1423 if (sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) {
1424 wc = vtblk_tunable_int(sc, "writecache_mode",
1425 vtblk_writecache_mode);
1426 if (wc >= 0 && wc < VTBLK_CACHE_MAX)
1427 vtblk_set_write_cache(sc, wc);
1428 else
1429 wc = blkcfg->wce;
1430 } else
1431 wc = virtio_with_feature(sc->vtblk_dev, VIRTIO_BLK_F_FLUSH);
1432
1433 return (wc);
1434 }
1435
1436 static int
vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS)1437 vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS)
1438 {
1439 struct vtblk_softc *sc;
1440 int wc, error;
1441
1442 sc = oidp->oid_arg1;
1443 wc = sc->vtblk_write_cache;
1444
1445 error = sysctl_handle_int(oidp, &wc, 0, req);
1446 if (error || req->newptr == NULL)
1447 return (error);
1448 if ((sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) == 0)
1449 return (EPERM);
1450 if (wc < 0 || wc >= VTBLK_CACHE_MAX)
1451 return (EINVAL);
1452
1453 VTBLK_LOCK(sc);
1454 sc->vtblk_write_cache = wc;
1455 vtblk_set_write_cache(sc, sc->vtblk_write_cache);
1456 VTBLK_UNLOCK(sc);
1457
1458 return (0);
1459 }
1460
1461 static void
vtblk_setup_sysctl(struct vtblk_softc * sc)1462 vtblk_setup_sysctl(struct vtblk_softc *sc)
1463 {
1464 device_t dev;
1465 struct sysctl_ctx_list *ctx;
1466 struct sysctl_oid *tree;
1467 struct sysctl_oid_list *child;
1468
1469 dev = sc->vtblk_dev;
1470 ctx = device_get_sysctl_ctx(dev);
1471 tree = device_get_sysctl_tree(dev);
1472 child = SYSCTL_CHILDREN(tree);
1473
1474 SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "writecache_mode",
1475 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, sc, 0,
1476 vtblk_write_cache_sysctl, "I",
1477 "Write cache mode (writethrough (0) or writeback (1))");
1478 }
1479
1480 static int
vtblk_tunable_int(struct vtblk_softc * sc,const char * knob,int def)1481 vtblk_tunable_int(struct vtblk_softc *sc, const char *knob, int def)
1482 {
1483 char path[64];
1484
1485 snprintf(path, sizeof(path),
1486 "hw.vtblk.%d.%s", device_get_unit(sc->vtblk_dev), knob);
1487 TUNABLE_INT_FETCH(path, &def);
1488
1489 return (def);
1490 }
1491