1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2011, Bryan Venteicher <bryanv@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice unmodified, this list of conditions, and the following
12 * disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 /* Driver for VirtIO block devices. */
30
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/kernel.h>
34 #include <sys/bio.h>
35 #include <sys/malloc.h>
36 #include <sys/module.h>
37 #include <sys/msan.h>
38 #include <sys/sglist.h>
39 #include <sys/sysctl.h>
40 #include <sys/lock.h>
41 #include <sys/mutex.h>
42 #include <sys/queue.h>
43
44 #include <geom/geom.h>
45 #include <geom/geom_disk.h>
46
47 #include <machine/bus.h>
48 #include <machine/resource.h>
49 #include <sys/bus.h>
50 #include <sys/rman.h>
51
52 #include <dev/virtio/virtio.h>
53 #include <dev/virtio/virtqueue.h>
54 #include <dev/virtio/block/virtio_blk.h>
55
56 #include "virtio_if.h"
57
58 struct vtblk_request {
59 struct vtblk_softc *vbr_sc;
60 bus_dmamap_t vbr_mapp;
61
62 struct virtio_blk_outhdr *vbr_hdr;
63 vm_paddr_t vbr_hdr_paddr;
64 bus_dmamap_t vbr_hdr_mapp;
65 uint8_t *vbr_ack;
66 vm_paddr_t vbr_ack_paddr;
67 bus_dmamap_t vbr_ack_mapp;
68
69 /* Fields after this point are zeroed for each request. */
70 struct bio *vbr_bp;
71 uint8_t vbr_requeue_on_error;
72 uint8_t vbr_busdma_wait;
73 int vbr_error;
74 TAILQ_ENTRY(vtblk_request) vbr_link;
75 };
76
77 enum vtblk_cache_mode {
78 VTBLK_CACHE_WRITETHROUGH,
79 VTBLK_CACHE_WRITEBACK,
80 VTBLK_CACHE_MAX
81 };
82
83 struct vtblk_softc {
84 device_t vtblk_dev;
85 struct mtx vtblk_mtx;
86 struct mtx vtblk_hdr_mtx;
87 struct mtx vtblk_ack_mtx;
88 uint64_t vtblk_features;
89 uint32_t vtblk_flags;
90 #define VTBLK_FLAG_INDIRECT 0x0001
91 #define VTBLK_FLAG_DETACH 0x0002
92 #define VTBLK_FLAG_SUSPEND 0x0004
93 #define VTBLK_FLAG_BARRIER 0x0008
94 #define VTBLK_FLAG_WCE_CONFIG 0x0010
95 #define VTBLK_FLAG_BUSDMA_WAIT 0x0020
96 #define VTBLK_FLAG_BUSDMA_ALIGN 0x0040
97
98 struct virtqueue *vtblk_vq;
99 struct sglist *vtblk_sglist;
100 bus_dma_tag_t vtblk_dmat;
101 bus_dma_tag_t vtblk_hdr_dmat;
102 bus_dma_tag_t vtblk_ack_dmat;
103 struct disk *vtblk_disk;
104
105 struct bio_queue_head vtblk_bioq;
106 TAILQ_HEAD(, vtblk_request)
107 vtblk_req_free;
108 TAILQ_HEAD(, vtblk_request)
109 vtblk_req_ready;
110 struct vtblk_request *vtblk_req_ordered;
111
112 int vtblk_max_nsegs;
113 int vtblk_request_count;
114 enum vtblk_cache_mode vtblk_write_cache;
115
116 struct bio_queue vtblk_dump_queue;
117 struct vtblk_request vtblk_dump_request;
118 };
119
120 static struct virtio_feature_desc vtblk_feature_desc[] = {
121 { VIRTIO_BLK_F_BARRIER, "HostBarrier" },
122 { VIRTIO_BLK_F_SIZE_MAX, "MaxSegSize" },
123 { VIRTIO_BLK_F_SEG_MAX, "MaxNumSegs" },
124 { VIRTIO_BLK_F_GEOMETRY, "DiskGeometry" },
125 { VIRTIO_BLK_F_RO, "ReadOnly" },
126 { VIRTIO_BLK_F_BLK_SIZE, "BlockSize" },
127 { VIRTIO_BLK_F_SCSI, "SCSICmds" },
128 { VIRTIO_BLK_F_FLUSH, "FlushCmd" },
129 { VIRTIO_BLK_F_TOPOLOGY, "Topology" },
130 { VIRTIO_BLK_F_CONFIG_WCE, "ConfigWCE" },
131 { VIRTIO_BLK_F_MQ, "Multiqueue" },
132 { VIRTIO_BLK_F_DISCARD, "Discard" },
133 { VIRTIO_BLK_F_WRITE_ZEROES, "WriteZeros" },
134
135 { 0, NULL }
136 };
137
138 static int vtblk_modevent(module_t, int, void *);
139
140 static int vtblk_probe(device_t);
141 static int vtblk_attach(device_t);
142 static int vtblk_detach(device_t);
143 static int vtblk_suspend(device_t);
144 static int vtblk_resume(device_t);
145 static int vtblk_shutdown(device_t);
146 static int vtblk_attach_completed(device_t);
147 static int vtblk_config_change(device_t);
148
149 static int vtblk_open(struct disk *);
150 static int vtblk_close(struct disk *);
151 static int vtblk_ioctl(struct disk *, u_long, void *, int,
152 struct thread *);
153 static int vtblk_dump(void *, void *, off_t, size_t);
154 static void vtblk_strategy(struct bio *);
155
156 static int vtblk_negotiate_features(struct vtblk_softc *);
157 static int vtblk_setup_features(struct vtblk_softc *);
158 static int vtblk_maximum_segments(struct vtblk_softc *,
159 struct virtio_blk_config *);
160 static int vtblk_alloc_virtqueue(struct vtblk_softc *);
161 static void vtblk_resize_disk(struct vtblk_softc *, uint64_t);
162 static void vtblk_alloc_disk(struct vtblk_softc *,
163 struct virtio_blk_config *);
164 static void vtblk_create_disk(struct vtblk_softc *);
165
166 static int vtblk_request_prealloc(struct vtblk_softc *);
167 static void vtblk_request_free(struct vtblk_softc *);
168 static struct vtblk_request *
169 vtblk_request_dequeue(struct vtblk_softc *);
170 static void vtblk_request_enqueue(struct vtblk_softc *,
171 struct vtblk_request *);
172 static struct vtblk_request *
173 vtblk_request_next_ready(struct vtblk_softc *);
174 static void vtblk_request_requeue_ready(struct vtblk_softc *,
175 struct vtblk_request *);
176 static struct vtblk_request *
177 vtblk_request_next(struct vtblk_softc *);
178 static struct vtblk_request *
179 vtblk_request_bio(struct vtblk_softc *);
180 static int vtblk_request_execute(struct vtblk_request *, int);
181 static void vtblk_request_execute_cb(void *,
182 bus_dma_segment_t *, int, int);
183 static int vtblk_request_error(struct vtblk_request *);
184
185 static void vtblk_queue_completed(struct vtblk_softc *,
186 struct bio_queue *);
187 static void vtblk_done_completed(struct vtblk_softc *,
188 struct bio_queue *);
189 static void vtblk_drain_vq(struct vtblk_softc *);
190 static void vtblk_drain(struct vtblk_softc *);
191
192 static void vtblk_startio(struct vtblk_softc *);
193 static void vtblk_bio_done(struct vtblk_softc *, struct bio *, int);
194
195 static void vtblk_read_config(struct vtblk_softc *,
196 struct virtio_blk_config *);
197 static void vtblk_ident(struct vtblk_softc *);
198 static int vtblk_poll_request(struct vtblk_softc *,
199 struct vtblk_request *);
200 static int vtblk_quiesce(struct vtblk_softc *);
201 static void vtblk_vq_intr(void *);
202 static void vtblk_stop(struct vtblk_softc *);
203
204 static void vtblk_dump_quiesce(struct vtblk_softc *);
205 static int vtblk_dump_write(struct vtblk_softc *, void *, off_t, size_t);
206 static int vtblk_dump_flush(struct vtblk_softc *);
207 static void vtblk_dump_complete(struct vtblk_softc *);
208
209 static void vtblk_set_write_cache(struct vtblk_softc *, int);
210 static int vtblk_write_cache_enabled(struct vtblk_softc *sc,
211 struct virtio_blk_config *);
212 static int vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS);
213
214 static void vtblk_setup_sysctl(struct vtblk_softc *);
215 static int vtblk_tunable_int(struct vtblk_softc *, const char *, int);
216
217 #define vtblk_modern(_sc) (((_sc)->vtblk_features & VIRTIO_F_VERSION_1) != 0)
218 #define vtblk_htog16(_sc, _val) virtio_htog16(vtblk_modern(_sc), _val)
219 #define vtblk_htog32(_sc, _val) virtio_htog32(vtblk_modern(_sc), _val)
220 #define vtblk_htog64(_sc, _val) virtio_htog64(vtblk_modern(_sc), _val)
221 #define vtblk_gtoh16(_sc, _val) virtio_gtoh16(vtblk_modern(_sc), _val)
222 #define vtblk_gtoh32(_sc, _val) virtio_gtoh32(vtblk_modern(_sc), _val)
223 #define vtblk_gtoh64(_sc, _val) virtio_gtoh64(vtblk_modern(_sc), _val)
224
225 /* Tunables. */
226 static int vtblk_no_ident = 0;
227 TUNABLE_INT("hw.vtblk.no_ident", &vtblk_no_ident);
228 static int vtblk_writecache_mode = -1;
229 TUNABLE_INT("hw.vtblk.writecache_mode", &vtblk_writecache_mode);
230
231 #define VTBLK_COMMON_FEATURES \
232 (VIRTIO_BLK_F_SIZE_MAX | \
233 VIRTIO_BLK_F_SEG_MAX | \
234 VIRTIO_BLK_F_GEOMETRY | \
235 VIRTIO_BLK_F_RO | \
236 VIRTIO_BLK_F_BLK_SIZE | \
237 VIRTIO_BLK_F_FLUSH | \
238 VIRTIO_BLK_F_TOPOLOGY | \
239 VIRTIO_BLK_F_CONFIG_WCE | \
240 VIRTIO_BLK_F_DISCARD | \
241 VIRTIO_RING_F_INDIRECT_DESC)
242
243 #define VTBLK_MODERN_FEATURES (VTBLK_COMMON_FEATURES)
244 #define VTBLK_LEGACY_FEATURES (VIRTIO_BLK_F_BARRIER | VTBLK_COMMON_FEATURES)
245
246 #define VTBLK_MTX(_sc) &(_sc)->vtblk_mtx
247 #define VTBLK_LOCK_INIT(_sc, _name) \
248 mtx_init(VTBLK_MTX((_sc)), (_name), \
249 "VirtIO Block Lock", MTX_DEF)
250 #define VTBLK_LOCK(_sc) mtx_lock(VTBLK_MTX((_sc)))
251 #define VTBLK_UNLOCK(_sc) mtx_unlock(VTBLK_MTX((_sc)))
252 #define VTBLK_LOCK_DESTROY(_sc) mtx_destroy(VTBLK_MTX((_sc)))
253 #define VTBLK_LOCK_ASSERT(_sc) mtx_assert(VTBLK_MTX((_sc)), MA_OWNED)
254 #define VTBLK_LOCK_ASSERT_NOTOWNED(_sc) \
255 mtx_assert(VTBLK_MTX((_sc)), MA_NOTOWNED)
256
257 #define VTBLK_DISK_NAME "vtbd"
258 #define VTBLK_QUIESCE_TIMEOUT (30 * hz)
259 #define VTBLK_BSIZE 512
260
261 /*
262 * Each block request uses at least two segments - one for the header
263 * and one for the status.
264 */
265 #define VTBLK_MIN_SEGMENTS 2
266
267 static device_method_t vtblk_methods[] = {
268 /* Device methods. */
269 DEVMETHOD(device_probe, vtblk_probe),
270 DEVMETHOD(device_attach, vtblk_attach),
271 DEVMETHOD(device_detach, vtblk_detach),
272 DEVMETHOD(device_suspend, vtblk_suspend),
273 DEVMETHOD(device_resume, vtblk_resume),
274 DEVMETHOD(device_shutdown, vtblk_shutdown),
275
276 /* VirtIO methods. */
277 DEVMETHOD(virtio_attach_completed, vtblk_attach_completed),
278 DEVMETHOD(virtio_config_change, vtblk_config_change),
279
280 DEVMETHOD_END
281 };
282
283 static driver_t vtblk_driver = {
284 "vtblk",
285 vtblk_methods,
286 sizeof(struct vtblk_softc)
287 };
288
289 VIRTIO_DRIVER_MODULE(virtio_blk, vtblk_driver, vtblk_modevent, NULL);
290 MODULE_VERSION(virtio_blk, 1);
291 MODULE_DEPEND(virtio_blk, virtio, 1, 1, 1);
292
293 VIRTIO_SIMPLE_PNPINFO(virtio_blk, VIRTIO_ID_BLOCK, "VirtIO Block Adapter");
294
295 static int
vtblk_modevent(module_t mod,int type,void * unused)296 vtblk_modevent(module_t mod, int type, void *unused)
297 {
298 int error;
299
300 error = 0;
301
302 switch (type) {
303 case MOD_LOAD:
304 case MOD_QUIESCE:
305 case MOD_UNLOAD:
306 case MOD_SHUTDOWN:
307 break;
308 default:
309 error = EOPNOTSUPP;
310 break;
311 }
312
313 return (error);
314 }
315
316 static int
vtblk_probe(device_t dev)317 vtblk_probe(device_t dev)
318 {
319 return (VIRTIO_SIMPLE_PROBE(dev, virtio_blk));
320 }
321
322 static int
vtblk_attach(device_t dev)323 vtblk_attach(device_t dev)
324 {
325 struct vtblk_softc *sc;
326 struct virtio_blk_config blkcfg;
327 int error;
328
329 sc = device_get_softc(dev);
330 sc->vtblk_dev = dev;
331 virtio_set_feature_desc(dev, vtblk_feature_desc);
332
333 VTBLK_LOCK_INIT(sc, device_get_nameunit(dev));
334 bioq_init(&sc->vtblk_bioq);
335 TAILQ_INIT(&sc->vtblk_dump_queue);
336 TAILQ_INIT(&sc->vtblk_req_free);
337 TAILQ_INIT(&sc->vtblk_req_ready);
338
339 vtblk_setup_sysctl(sc);
340
341 error = vtblk_setup_features(sc);
342 if (error) {
343 device_printf(dev, "cannot setup features\n");
344 goto fail;
345 }
346
347 vtblk_read_config(sc, &blkcfg);
348
349 /*
350 * With the current sglist(9) implementation, it is not easy
351 * for us to support a maximum segment size as adjacent
352 * segments are coalesced. For now, just make sure it's larger
353 * than the maximum supported transfer size.
354 */
355 if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) {
356 if (blkcfg.size_max < maxphys) {
357 error = ENOTSUP;
358 device_printf(dev, "host requires unsupported "
359 "maximum segment size feature\n");
360 goto fail;
361 }
362 }
363
364 sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg);
365 if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) {
366 error = EINVAL;
367 device_printf(dev, "fewer than minimum number of segments "
368 "allowed: %d\n", sc->vtblk_max_nsegs);
369 goto fail;
370 }
371
372 sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT);
373 if (sc->vtblk_sglist == NULL) {
374 error = ENOMEM;
375 device_printf(dev, "cannot allocate sglist\n");
376 goto fail;
377 }
378
379 /*
380 * If vtblk_max_nsegs == VTBLK_MIN_SEGMENTS + 1, the device only
381 * supports a single data segment; in that case we need busdma to
382 * align to a page boundary so we can send a *contiguous* page size
383 * request to the host.
384 */
385 if (sc->vtblk_max_nsegs == VTBLK_MIN_SEGMENTS + 1)
386 sc->vtblk_flags |= VTBLK_FLAG_BUSDMA_ALIGN;
387 error = bus_dma_tag_create(
388 bus_get_dma_tag(dev), /* parent */
389 (sc->vtblk_flags & VTBLK_FLAG_BUSDMA_ALIGN) ? PAGE_SIZE : 1,
390 0, /* boundary */
391 BUS_SPACE_MAXADDR, /* lowaddr */
392 BUS_SPACE_MAXADDR, /* highaddr */
393 NULL, NULL, /* filter, filterarg */
394 maxphys, /* max request size */
395 sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS, /* max # segments */
396 maxphys, /* maxsegsize */
397 BUS_DMA_COHERENT, /* flags */
398 busdma_lock_mutex, /* lockfunc */
399 &sc->vtblk_mtx, /* lockarg */
400 &sc->vtblk_dmat);
401 if (error) {
402 device_printf(dev, "cannot create bus dma tag\n");
403 goto fail;
404 }
405
406 error = bus_dma_tag_create(
407 bus_get_dma_tag(dev), /* parent */
408 (sc->vtblk_flags & VTBLK_FLAG_BUSDMA_ALIGN) ? PAGE_SIZE :
409 sizeof(struct virtio_blk_outhdr), /* alignment */
410 0, /* boundary */
411 BUS_SPACE_MAXADDR, /* lowaddr */
412 BUS_SPACE_MAXADDR, /* highaddr */
413 NULL, NULL, /* filter, filterarg */
414 sizeof(struct virtio_blk_outhdr), /* max request size */
415 1, /* max # segments */
416 sizeof(struct virtio_blk_outhdr), /* maxsegsize */
417 BUS_DMA_COHERENT, /* flags */
418 busdma_lock_mutex, /* lockfunc */
419 &sc->vtblk_hdr_mtx, /* lockarg */
420 &sc->vtblk_hdr_dmat);
421 if (error) {
422 device_printf(dev, "cannot create hdr bus dma tag\n");
423 goto fail;
424 }
425
426 error = bus_dma_tag_create(
427 bus_get_dma_tag(dev), /* parent */
428 (sc->vtblk_flags & VTBLK_FLAG_BUSDMA_ALIGN) ? PAGE_SIZE :
429 sizeof(uint8_t), /* alignment */
430 0, /* boundary */
431 BUS_SPACE_MAXADDR, /* lowaddr */
432 BUS_SPACE_MAXADDR, /* highaddr */
433 NULL, NULL, /* filter, filterarg */
434 sizeof(uint8_t), /* max request size */
435 1, /* max # segments */
436 sizeof(uint8_t), /* maxsegsize */
437 BUS_DMA_COHERENT, /* flags */
438 busdma_lock_mutex, /* lockfunc */
439 &sc->vtblk_ack_mtx, /* lockarg */
440 &sc->vtblk_ack_dmat);
441 if (error) {
442 device_printf(dev, "cannot create ack bus dma tag\n");
443 goto fail;
444 }
445
446 #ifdef __powerpc__
447 /*
448 * Virtio uses physical addresses rather than bus addresses, so we
449 * need to ask busdma to skip the iommu physical->bus mapping. At
450 * present, this is only a thing on the powerpc architectures.
451 */
452 bus_dma_tag_set_iommu(sc->vtblk_dmat, NULL, NULL);
453 bus_dma_tag_set_iommu(sc->vtblk_hdr_dmat, NULL, NULL);
454 bus_dma_tag_set_iommu(sc->vtblk_ack_dmat, NULL, NULL);
455 #endif
456
457 error = vtblk_alloc_virtqueue(sc);
458 if (error) {
459 device_printf(dev, "cannot allocate virtqueue\n");
460 goto fail;
461 }
462
463 error = vtblk_request_prealloc(sc);
464 if (error) {
465 device_printf(dev, "cannot preallocate requests\n");
466 goto fail;
467 }
468
469 vtblk_alloc_disk(sc, &blkcfg);
470
471 error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY);
472 if (error) {
473 device_printf(dev, "cannot setup virtqueue interrupt\n");
474 goto fail;
475 }
476
477 virtqueue_enable_intr(sc->vtblk_vq);
478
479 fail:
480 if (error)
481 vtblk_detach(dev);
482
483 return (error);
484 }
485
486 static int
vtblk_detach(device_t dev)487 vtblk_detach(device_t dev)
488 {
489 struct vtblk_softc *sc;
490
491 sc = device_get_softc(dev);
492
493 VTBLK_LOCK(sc);
494 sc->vtblk_flags |= VTBLK_FLAG_DETACH;
495 if (device_is_attached(dev))
496 vtblk_stop(sc);
497 VTBLK_UNLOCK(sc);
498
499 vtblk_drain(sc);
500
501 if (sc->vtblk_disk != NULL) {
502 disk_destroy(sc->vtblk_disk);
503 sc->vtblk_disk = NULL;
504 }
505
506 if (sc->vtblk_ack_dmat != NULL) {
507 bus_dma_tag_destroy(sc->vtblk_ack_dmat);
508 sc->vtblk_ack_dmat = NULL;
509 }
510
511 if (sc->vtblk_hdr_dmat != NULL) {
512 bus_dma_tag_destroy(sc->vtblk_hdr_dmat);
513 sc->vtblk_hdr_dmat = NULL;
514 }
515
516 if (sc->vtblk_dmat != NULL) {
517 bus_dma_tag_destroy(sc->vtblk_dmat);
518 sc->vtblk_dmat = NULL;
519 }
520
521 if (sc->vtblk_sglist != NULL) {
522 sglist_free(sc->vtblk_sglist);
523 sc->vtblk_sglist = NULL;
524 }
525
526 VTBLK_LOCK_DESTROY(sc);
527
528 return (0);
529 }
530
531 static int
vtblk_suspend(device_t dev)532 vtblk_suspend(device_t dev)
533 {
534 struct vtblk_softc *sc;
535 int error;
536
537 sc = device_get_softc(dev);
538
539 VTBLK_LOCK(sc);
540 sc->vtblk_flags |= VTBLK_FLAG_SUSPEND;
541 /* XXX BMV: virtio_stop(), etc needed here? */
542 error = vtblk_quiesce(sc);
543 if (error)
544 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND;
545 VTBLK_UNLOCK(sc);
546
547 return (error);
548 }
549
550 static int
vtblk_resume(device_t dev)551 vtblk_resume(device_t dev)
552 {
553 struct vtblk_softc *sc;
554
555 sc = device_get_softc(dev);
556
557 VTBLK_LOCK(sc);
558 /* XXX BMV: virtio_reinit(), etc needed here? */
559 sc->vtblk_flags &= ~VTBLK_FLAG_SUSPEND;
560 vtblk_startio(sc);
561 VTBLK_UNLOCK(sc);
562
563 return (0);
564 }
565
566 static int
vtblk_shutdown(device_t dev)567 vtblk_shutdown(device_t dev)
568 {
569
570 return (0);
571 }
572
573 static int
vtblk_attach_completed(device_t dev)574 vtblk_attach_completed(device_t dev)
575 {
576 struct vtblk_softc *sc;
577
578 sc = device_get_softc(dev);
579
580 /*
581 * Create disk after attach as VIRTIO_BLK_T_GET_ID can only be
582 * processed after the device acknowledged
583 * VIRTIO_CONFIG_STATUS_DRIVER_OK.
584 */
585 vtblk_create_disk(sc);
586 return (0);
587 }
588
589 static int
vtblk_config_change(device_t dev)590 vtblk_config_change(device_t dev)
591 {
592 struct vtblk_softc *sc;
593 struct virtio_blk_config blkcfg;
594 uint64_t capacity;
595
596 sc = device_get_softc(dev);
597
598 vtblk_read_config(sc, &blkcfg);
599
600 /* Capacity is always in 512-byte units. */
601 capacity = blkcfg.capacity * VTBLK_BSIZE;
602
603 if (sc->vtblk_disk->d_mediasize != capacity)
604 vtblk_resize_disk(sc, capacity);
605
606 return (0);
607 }
608
609 static int
vtblk_open(struct disk * dp)610 vtblk_open(struct disk *dp)
611 {
612 struct vtblk_softc *sc;
613
614 if ((sc = dp->d_drv1) == NULL)
615 return (ENXIO);
616
617 return (sc->vtblk_flags & VTBLK_FLAG_DETACH ? ENXIO : 0);
618 }
619
620 static int
vtblk_close(struct disk * dp)621 vtblk_close(struct disk *dp)
622 {
623 struct vtblk_softc *sc;
624
625 if ((sc = dp->d_drv1) == NULL)
626 return (ENXIO);
627
628 return (0);
629 }
630
631 static int
vtblk_ioctl(struct disk * dp,u_long cmd,void * addr,int flag,struct thread * td)632 vtblk_ioctl(struct disk *dp, u_long cmd, void *addr, int flag,
633 struct thread *td)
634 {
635 struct vtblk_softc *sc;
636
637 if ((sc = dp->d_drv1) == NULL)
638 return (ENXIO);
639
640 return (ENOTTY);
641 }
642
643 static int
vtblk_dump(void * arg,void * virtual,off_t offset,size_t length)644 vtblk_dump(void *arg, void *virtual, off_t offset, size_t length)
645 {
646 struct disk *dp;
647 struct vtblk_softc *sc;
648 int error;
649
650 dp = arg;
651 error = 0;
652
653 if ((sc = dp->d_drv1) == NULL)
654 return (ENXIO);
655
656 VTBLK_LOCK(sc);
657
658 vtblk_dump_quiesce(sc);
659
660 if (length > 0)
661 error = vtblk_dump_write(sc, virtual, offset, length);
662 if (error || (virtual == NULL && offset == 0))
663 vtblk_dump_complete(sc);
664
665 VTBLK_UNLOCK(sc);
666
667 return (error);
668 }
669
670 static void
vtblk_strategy(struct bio * bp)671 vtblk_strategy(struct bio *bp)
672 {
673 struct vtblk_softc *sc;
674
675 if ((sc = bp->bio_disk->d_drv1) == NULL) {
676 vtblk_bio_done(NULL, bp, EINVAL);
677 return;
678 }
679
680 if ((bp->bio_cmd != BIO_READ) && (bp->bio_cmd != BIO_WRITE) &&
681 (bp->bio_cmd != BIO_FLUSH) && (bp->bio_cmd != BIO_DELETE)) {
682 vtblk_bio_done(sc, bp, EOPNOTSUPP);
683 return;
684 }
685
686 VTBLK_LOCK(sc);
687
688 if (sc->vtblk_flags & VTBLK_FLAG_DETACH) {
689 VTBLK_UNLOCK(sc);
690 vtblk_bio_done(sc, bp, ENXIO);
691 return;
692 }
693
694 bioq_insert_tail(&sc->vtblk_bioq, bp);
695 vtblk_startio(sc);
696
697 VTBLK_UNLOCK(sc);
698 }
699
700 static int
vtblk_negotiate_features(struct vtblk_softc * sc)701 vtblk_negotiate_features(struct vtblk_softc *sc)
702 {
703 device_t dev;
704 uint64_t features;
705
706 dev = sc->vtblk_dev;
707 features = virtio_bus_is_modern(dev) ? VTBLK_MODERN_FEATURES :
708 VTBLK_LEGACY_FEATURES;
709
710 sc->vtblk_features = virtio_negotiate_features(dev, features);
711 return (virtio_finalize_features(dev));
712 }
713
714 static int
vtblk_setup_features(struct vtblk_softc * sc)715 vtblk_setup_features(struct vtblk_softc *sc)
716 {
717 device_t dev;
718 int error;
719
720 dev = sc->vtblk_dev;
721
722 error = vtblk_negotiate_features(sc);
723 if (error)
724 return (error);
725
726 if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC))
727 sc->vtblk_flags |= VTBLK_FLAG_INDIRECT;
728 if (virtio_with_feature(dev, VIRTIO_BLK_F_CONFIG_WCE))
729 sc->vtblk_flags |= VTBLK_FLAG_WCE_CONFIG;
730
731 /* Legacy. */
732 if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER))
733 sc->vtblk_flags |= VTBLK_FLAG_BARRIER;
734
735 return (0);
736 }
737
738 static int
vtblk_maximum_segments(struct vtblk_softc * sc,struct virtio_blk_config * blkcfg)739 vtblk_maximum_segments(struct vtblk_softc *sc,
740 struct virtio_blk_config *blkcfg)
741 {
742 device_t dev;
743 int nsegs;
744
745 dev = sc->vtblk_dev;
746 nsegs = VTBLK_MIN_SEGMENTS;
747
748 if (virtio_with_feature(dev, VIRTIO_BLK_F_SEG_MAX)) {
749 nsegs += MIN(blkcfg->seg_max, maxphys / PAGE_SIZE + 1);
750 if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT)
751 nsegs = MIN(nsegs, VIRTIO_MAX_INDIRECT);
752 } else
753 nsegs += 1;
754
755 return (nsegs);
756 }
757
758 static int
vtblk_alloc_virtqueue(struct vtblk_softc * sc)759 vtblk_alloc_virtqueue(struct vtblk_softc *sc)
760 {
761 device_t dev;
762 struct vq_alloc_info vq_info;
763 int indir_segs;
764
765 dev = sc->vtblk_dev;
766
767 indir_segs = 0;
768 if (sc->vtblk_flags & VTBLK_FLAG_INDIRECT)
769 indir_segs = sc->vtblk_max_nsegs;
770 VQ_ALLOC_INFO_INIT(&vq_info, indir_segs,
771 vtblk_vq_intr, sc, &sc->vtblk_vq,
772 "%s request", device_get_nameunit(dev));
773
774 return (virtio_alloc_virtqueues(dev, 1, &vq_info));
775 }
776
777 static void
vtblk_resize_disk(struct vtblk_softc * sc,uint64_t new_capacity)778 vtblk_resize_disk(struct vtblk_softc *sc, uint64_t new_capacity)
779 {
780 device_t dev;
781 struct disk *dp;
782 int error;
783
784 dev = sc->vtblk_dev;
785 dp = sc->vtblk_disk;
786
787 dp->d_mediasize = new_capacity;
788 if (bootverbose) {
789 device_printf(dev, "resized to %juMB (%ju %u byte sectors)\n",
790 (uintmax_t) dp->d_mediasize >> 20,
791 (uintmax_t) dp->d_mediasize / dp->d_sectorsize,
792 dp->d_sectorsize);
793 }
794
795 error = disk_resize(dp, M_NOWAIT);
796 if (error) {
797 device_printf(dev,
798 "disk_resize(9) failed, error: %d\n", error);
799 }
800 }
801
802 static void
vtblk_alloc_disk(struct vtblk_softc * sc,struct virtio_blk_config * blkcfg)803 vtblk_alloc_disk(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg)
804 {
805 device_t dev;
806 struct disk *dp;
807
808 dev = sc->vtblk_dev;
809
810 sc->vtblk_disk = dp = disk_alloc();
811 dp->d_open = vtblk_open;
812 dp->d_close = vtblk_close;
813 dp->d_ioctl = vtblk_ioctl;
814 dp->d_strategy = vtblk_strategy;
815 dp->d_name = VTBLK_DISK_NAME;
816 dp->d_unit = device_get_unit(dev);
817 dp->d_drv1 = sc;
818 dp->d_flags = DISKFLAG_UNMAPPED_BIO | DISKFLAG_DIRECT_COMPLETION;
819 dp->d_hba_vendor = virtio_get_vendor(dev);
820 dp->d_hba_device = virtio_get_device(dev);
821 dp->d_hba_subvendor = virtio_get_subvendor(dev);
822 dp->d_hba_subdevice = virtio_get_subdevice(dev);
823 strlcpy(dp->d_attachment, device_get_nameunit(dev),
824 sizeof(dp->d_attachment));
825
826 if (virtio_with_feature(dev, VIRTIO_BLK_F_RO))
827 dp->d_flags |= DISKFLAG_WRITE_PROTECT;
828 else {
829 if (virtio_with_feature(dev, VIRTIO_BLK_F_FLUSH))
830 dp->d_flags |= DISKFLAG_CANFLUSHCACHE;
831 dp->d_dump = vtblk_dump;
832 }
833
834 /* Capacity is always in 512-byte units. */
835 dp->d_mediasize = blkcfg->capacity * VTBLK_BSIZE;
836
837 if (virtio_with_feature(dev, VIRTIO_BLK_F_BLK_SIZE))
838 dp->d_sectorsize = blkcfg->blk_size;
839 else
840 dp->d_sectorsize = VTBLK_BSIZE;
841
842 /*
843 * The VirtIO maximum I/O size is given in terms of segments.
844 * However, FreeBSD limits I/O size by logical buffer size, not
845 * by physically contiguous pages. Therefore, we have to assume
846 * no pages are contiguous. This may impose an artificially low
847 * maximum I/O size. But in practice, since QEMU advertises 128
848 * segments, this gives us a maximum IO size of 125 * PAGE_SIZE,
849 * which is typically greater than maxphys. Eventually we should
850 * just advertise maxphys and split buffers that are too big.
851 *
852 * If we're not asking busdma to align data to page boundaries, the
853 * maximum I/O size is reduced by PAGE_SIZE in order to accommodate
854 * unaligned I/Os.
855 */
856 dp->d_maxsize = (sc->vtblk_max_nsegs - VTBLK_MIN_SEGMENTS) *
857 PAGE_SIZE;
858 if ((sc->vtblk_flags & VTBLK_FLAG_BUSDMA_ALIGN) == 0)
859 dp->d_maxsize -= PAGE_SIZE;
860
861 if (virtio_with_feature(dev, VIRTIO_BLK_F_GEOMETRY)) {
862 dp->d_fwsectors = blkcfg->geometry.sectors;
863 dp->d_fwheads = blkcfg->geometry.heads;
864 }
865
866 if (virtio_with_feature(dev, VIRTIO_BLK_F_TOPOLOGY) &&
867 blkcfg->topology.physical_block_exp > 0) {
868 dp->d_stripesize = dp->d_sectorsize *
869 (1 << blkcfg->topology.physical_block_exp);
870 dp->d_stripeoffset = (dp->d_stripesize -
871 blkcfg->topology.alignment_offset * dp->d_sectorsize) %
872 dp->d_stripesize;
873 }
874
875 if (virtio_with_feature(dev, VIRTIO_BLK_F_DISCARD)) {
876 dp->d_flags |= DISKFLAG_CANDELETE;
877 dp->d_delmaxsize = blkcfg->max_discard_sectors * VTBLK_BSIZE;
878 }
879
880 if (vtblk_write_cache_enabled(sc, blkcfg) != 0)
881 sc->vtblk_write_cache = VTBLK_CACHE_WRITEBACK;
882 else
883 sc->vtblk_write_cache = VTBLK_CACHE_WRITETHROUGH;
884 }
885
886 static void
vtblk_create_disk(struct vtblk_softc * sc)887 vtblk_create_disk(struct vtblk_softc *sc)
888 {
889 struct disk *dp;
890
891 dp = sc->vtblk_disk;
892
893 vtblk_ident(sc);
894
895 device_printf(sc->vtblk_dev, "%juMB (%ju %u byte sectors)\n",
896 (uintmax_t) dp->d_mediasize >> 20,
897 (uintmax_t) dp->d_mediasize / dp->d_sectorsize,
898 dp->d_sectorsize);
899
900 disk_create(dp, DISK_VERSION);
901 }
902
903 static void
vtblk_ack_load_callback(void * arg,bus_dma_segment_t * segs,int nsegs,int error)904 vtblk_ack_load_callback(void *arg, bus_dma_segment_t *segs, int nsegs,
905 int error)
906 {
907 struct vtblk_request *req;
908
909 if (error != 0)
910 return;
911
912 KASSERT(nsegs == 1, ("%s: %d segments returned!", __func__, nsegs));
913
914 req = (struct vtblk_request *)arg;
915 req->vbr_ack_paddr = segs[0].ds_addr;
916 }
917
918 static void
vtblk_hdr_load_callback(void * arg,bus_dma_segment_t * segs,int nsegs,int error)919 vtblk_hdr_load_callback(void *arg, bus_dma_segment_t *segs, int nsegs,
920 int error)
921 {
922 struct vtblk_request *req;
923
924 if (error != 0)
925 return;
926
927 KASSERT(nsegs == 1, ("%s: %d segments returned!", __func__, nsegs));
928
929 req = (struct vtblk_request *)arg;
930 req->vbr_hdr_paddr = segs[0].ds_addr;
931 }
932
933 static int
vtblk_create_request(struct vtblk_softc * sc,struct vtblk_request * req)934 vtblk_create_request(struct vtblk_softc *sc, struct vtblk_request *req)
935 {
936 req->vbr_sc = sc;
937
938 if (bus_dmamap_create(sc->vtblk_dmat, 0, &req->vbr_mapp))
939 goto error_free;
940
941 if (bus_dmamem_alloc(sc->vtblk_hdr_dmat, (void **)&req->vbr_hdr,
942 BUS_DMA_NOWAIT | BUS_DMA_ZERO | BUS_DMA_COHERENT,
943 &req->vbr_hdr_mapp))
944 goto error_destroy;
945
946 if (bus_dmamem_alloc(sc->vtblk_ack_dmat, (void **)&req->vbr_ack,
947 BUS_DMA_NOWAIT | BUS_DMA_ZERO | BUS_DMA_COHERENT,
948 &req->vbr_ack_mapp))
949 goto error_hdr_free;
950
951 MPASS(sglist_count(req->vbr_hdr, sizeof(*req->vbr_hdr)) == 1);
952 MPASS(sglist_count(req->vbr_ack, sizeof(*req->vbr_ack)) == 1);
953
954 if (bus_dmamap_load(sc->vtblk_hdr_dmat, req->vbr_hdr_mapp,
955 req->vbr_hdr, sizeof(struct virtio_blk_outhdr),
956 vtblk_hdr_load_callback, req, BUS_DMA_NOWAIT))
957 goto error_ack_free;
958
959 if (bus_dmamap_load(sc->vtblk_ack_dmat, req->vbr_ack_mapp,
960 req->vbr_ack, sizeof(uint8_t), vtblk_ack_load_callback,
961 req, BUS_DMA_NOWAIT))
962 goto error_hdr_unload;
963
964 return (0);
965
966 error_hdr_unload:
967 bus_dmamap_unload(sc->vtblk_hdr_dmat, req->vbr_hdr_mapp);
968 error_ack_free:
969 bus_dmamem_free(sc->vtblk_ack_dmat, req->vbr_ack, req->vbr_ack_mapp);
970 error_hdr_free:
971 bus_dmamem_free(sc->vtblk_hdr_dmat, req->vbr_hdr, req->vbr_hdr_mapp);
972 error_destroy:
973 bus_dmamap_destroy(sc->vtblk_dmat, req->vbr_mapp);
974 error_free:
975
976 return (ENOMEM);
977 }
978
979 static int
vtblk_request_prealloc(struct vtblk_softc * sc)980 vtblk_request_prealloc(struct vtblk_softc *sc)
981 {
982 struct vtblk_request *req;
983 int i, nreqs;
984 int error;
985
986 nreqs = virtqueue_size(sc->vtblk_vq);
987
988 /*
989 * Preallocate sufficient requests to keep the virtqueue full. Each
990 * request consumes VTBLK_MIN_SEGMENTS or more descriptors so reduce
991 * the number allocated when indirect descriptors are not available.
992 */
993 if ((sc->vtblk_flags & VTBLK_FLAG_INDIRECT) == 0)
994 nreqs /= VTBLK_MIN_SEGMENTS;
995
996 for (i = 0; i < nreqs; i++) {
997 req = malloc(sizeof(struct vtblk_request), M_DEVBUF, M_NOWAIT);
998 if (req == NULL)
999 return (ENOMEM);
1000
1001 error = vtblk_create_request(sc, req);
1002 if (error) {
1003 free(req, M_DEVBUF);
1004 return (error);
1005 }
1006
1007 sc->vtblk_request_count++;
1008 vtblk_request_enqueue(sc, req);
1009 }
1010
1011 error = vtblk_create_request(sc, &sc->vtblk_dump_request);
1012
1013 return (error);
1014 }
1015
1016 static void
vtblk_request_free(struct vtblk_softc * sc)1017 vtblk_request_free(struct vtblk_softc *sc)
1018 {
1019 struct vtblk_request *req;
1020
1021 MPASS(TAILQ_EMPTY(&sc->vtblk_req_ready));
1022
1023 while ((req = vtblk_request_dequeue(sc)) != NULL) {
1024 sc->vtblk_request_count--;
1025 bus_dmamap_unload(sc->vtblk_ack_dmat, req->vbr_ack_mapp);
1026 bus_dmamem_free(sc->vtblk_ack_dmat, req->vbr_ack,
1027 req->vbr_ack_mapp);
1028 bus_dmamap_unload(sc->vtblk_hdr_dmat, req->vbr_hdr_mapp);
1029 bus_dmamem_free(sc->vtblk_hdr_dmat, req->vbr_hdr,
1030 req->vbr_hdr_mapp);
1031 bus_dmamap_destroy(sc->vtblk_dmat, req->vbr_mapp);
1032 }
1033
1034 KASSERT(sc->vtblk_request_count == 0,
1035 ("%s: leaked %d requests", __func__, sc->vtblk_request_count));
1036 }
1037
1038 static struct vtblk_request *
vtblk_request_dequeue(struct vtblk_softc * sc)1039 vtblk_request_dequeue(struct vtblk_softc *sc)
1040 {
1041 struct vtblk_request *req;
1042
1043 req = TAILQ_FIRST(&sc->vtblk_req_free);
1044 if (req != NULL) {
1045 TAILQ_REMOVE(&sc->vtblk_req_free, req, vbr_link);
1046 bzero(req->vbr_hdr, sizeof(struct virtio_blk_outhdr));
1047 *req->vbr_ack = 0;
1048 bzero(&req->vbr_bp, sizeof(struct vtblk_request) -
1049 offsetof(struct vtblk_request, vbr_bp));
1050 }
1051
1052 return (req);
1053 }
1054
1055 static void
vtblk_request_enqueue(struct vtblk_softc * sc,struct vtblk_request * req)1056 vtblk_request_enqueue(struct vtblk_softc *sc, struct vtblk_request *req)
1057 {
1058
1059 TAILQ_INSERT_HEAD(&sc->vtblk_req_free, req, vbr_link);
1060 }
1061
1062 static struct vtblk_request *
vtblk_request_next_ready(struct vtblk_softc * sc)1063 vtblk_request_next_ready(struct vtblk_softc *sc)
1064 {
1065 struct vtblk_request *req;
1066
1067 req = TAILQ_FIRST(&sc->vtblk_req_ready);
1068 if (req != NULL)
1069 TAILQ_REMOVE(&sc->vtblk_req_ready, req, vbr_link);
1070
1071 return (req);
1072 }
1073
1074 static void
vtblk_request_requeue_ready(struct vtblk_softc * sc,struct vtblk_request * req)1075 vtblk_request_requeue_ready(struct vtblk_softc *sc, struct vtblk_request *req)
1076 {
1077
1078 /* NOTE: Currently, there will be at most one request in the queue. */
1079 TAILQ_INSERT_HEAD(&sc->vtblk_req_ready, req, vbr_link);
1080 }
1081
1082 static struct vtblk_request *
vtblk_request_next(struct vtblk_softc * sc)1083 vtblk_request_next(struct vtblk_softc *sc)
1084 {
1085 struct vtblk_request *req;
1086
1087 req = vtblk_request_next_ready(sc);
1088 if (req != NULL)
1089 return (req);
1090
1091 return (vtblk_request_bio(sc));
1092 }
1093
1094 static struct vtblk_request *
vtblk_request_bio(struct vtblk_softc * sc)1095 vtblk_request_bio(struct vtblk_softc *sc)
1096 {
1097 struct bio_queue_head *bioq;
1098 struct vtblk_request *req;
1099 struct bio *bp;
1100
1101 bioq = &sc->vtblk_bioq;
1102
1103 if (bioq_first(bioq) == NULL)
1104 return (NULL);
1105
1106 req = vtblk_request_dequeue(sc);
1107 if (req == NULL)
1108 return (NULL);
1109
1110 bp = bioq_takefirst(bioq);
1111 req->vbr_bp = bp;
1112 *req->vbr_ack = -1;
1113 req->vbr_hdr->ioprio = vtblk_gtoh32(sc, 1);
1114
1115 switch (bp->bio_cmd) {
1116 case BIO_FLUSH:
1117 req->vbr_hdr->type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH);
1118 req->vbr_hdr->sector = 0;
1119 break;
1120 case BIO_READ:
1121 req->vbr_hdr->type = vtblk_gtoh32(sc, VIRTIO_BLK_T_IN);
1122 req->vbr_hdr->sector = vtblk_gtoh64(sc, bp->bio_offset /
1123 VTBLK_BSIZE);
1124 break;
1125 case BIO_WRITE:
1126 req->vbr_hdr->type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT);
1127 req->vbr_hdr->sector = vtblk_gtoh64(sc, bp->bio_offset /
1128 VTBLK_BSIZE);
1129 break;
1130 case BIO_DELETE:
1131 req->vbr_hdr->type = vtblk_gtoh32(sc, VIRTIO_BLK_T_DISCARD);
1132 req->vbr_hdr->sector = vtblk_gtoh64(sc, bp->bio_offset /
1133 VTBLK_BSIZE);
1134 break;
1135 default:
1136 panic("%s: bio with unhandled cmd: %d", __func__, bp->bio_cmd);
1137 }
1138
1139 if (bp->bio_flags & BIO_ORDERED)
1140 req->vbr_hdr->type |= vtblk_gtoh32(sc, VIRTIO_BLK_T_BARRIER);
1141
1142 return (req);
1143 }
1144
1145 static int
vtblk_request_execute(struct vtblk_request * req,int flags)1146 vtblk_request_execute(struct vtblk_request *req, int flags)
1147 {
1148 struct vtblk_softc *sc = req->vbr_sc;
1149 struct bio *bp = req->vbr_bp;
1150 int error = 0;
1151
1152 /*
1153 * Call via bus_dmamap_load_bio or directly depending on whether we
1154 * have a buffer we need to map. If we don't have a busdma map,
1155 * try to perform the I/O directly and hope that it works (this will
1156 * happen when dumping).
1157 */
1158 if ((req->vbr_mapp != NULL) &&
1159 (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE)) {
1160 error = bus_dmamap_load_bio(sc->vtblk_dmat, req->vbr_mapp,
1161 req->vbr_bp, vtblk_request_execute_cb, req, flags);
1162 if (error == EINPROGRESS) {
1163 req->vbr_busdma_wait = 1;
1164 sc->vtblk_flags |= VTBLK_FLAG_BUSDMA_WAIT;
1165 }
1166 } else {
1167 vtblk_request_execute_cb(req, NULL, 0, 0);
1168 }
1169
1170 return (error ? error : req->vbr_error);
1171 }
1172
1173 static void
vtblk_request_execute_cb(void * callback_arg,bus_dma_segment_t * segs,int nseg,int error)1174 vtblk_request_execute_cb(void * callback_arg, bus_dma_segment_t * segs,
1175 int nseg, int error)
1176 {
1177 struct vtblk_request *req;
1178 struct vtblk_softc *sc;
1179 struct virtqueue *vq;
1180 struct sglist *sg;
1181 struct bio *bp;
1182 int ordered, readable, writable, i;
1183
1184 req = (struct vtblk_request *)callback_arg;
1185 sc = req->vbr_sc;
1186 vq = sc->vtblk_vq;
1187 sg = sc->vtblk_sglist;
1188 bp = req->vbr_bp;
1189 ordered = 0;
1190 writable = 0;
1191
1192 /*
1193 * If we paused request queueing while we waited for busdma to call us
1194 * asynchronously, unpause it now; this request made it through so we
1195 * don't need to worry about others getting ahead of us. (Note that we
1196 * hold the device mutex so nothing will happen until after we return
1197 * anyway.)
1198 */
1199 if (req->vbr_busdma_wait)
1200 sc->vtblk_flags &= ~VTBLK_FLAG_BUSDMA_WAIT;
1201
1202 /* Fail on errors from busdma. */
1203 if (error)
1204 goto out1;
1205
1206 /*
1207 * Some hosts (such as bhyve) do not implement the barrier feature,
1208 * so we emulate it in the driver by allowing the barrier request
1209 * to be the only one in flight.
1210 */
1211 if ((sc->vtblk_flags & VTBLK_FLAG_BARRIER) == 0) {
1212 if (sc->vtblk_req_ordered != NULL) {
1213 error = EBUSY;
1214 goto out;
1215 }
1216 if (bp->bio_flags & BIO_ORDERED) {
1217 if (!virtqueue_empty(vq)) {
1218 error = EBUSY;
1219 goto out;
1220 }
1221 ordered = 1;
1222 req->vbr_hdr->type &= vtblk_gtoh32(sc,
1223 ~VIRTIO_BLK_T_BARRIER);
1224 }
1225 }
1226
1227 bus_dmamap_sync(sc->vtblk_hdr_dmat, req->vbr_hdr_mapp,
1228 BUS_DMASYNC_PREWRITE);
1229
1230 sglist_reset(sg);
1231 sglist_append_phys(sg, req->vbr_hdr_paddr,
1232 sizeof(struct virtio_blk_outhdr));
1233
1234 if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) {
1235 /*
1236 * We cast bus_addr_t to vm_paddr_t here; since we skip the
1237 * iommu mapping (see vtblk_attach) this should be safe.
1238 */
1239 for (i = 0; i < nseg; i++) {
1240 error = sglist_append_phys(sg,
1241 (vm_paddr_t)segs[i].ds_addr, segs[i].ds_len);
1242 if (error || sg->sg_nseg == sg->sg_maxseg) {
1243 panic("%s: bio %p data buffer too big %d",
1244 __func__, bp, error);
1245 }
1246 }
1247
1248 /* Special handling for dump, which bypasses busdma. */
1249 if (req->vbr_mapp == NULL) {
1250 error = sglist_append_bio(sg, bp);
1251 if (error || sg->sg_nseg == sg->sg_maxseg) {
1252 panic("%s: bio %p data buffer too big %d",
1253 __func__, bp, error);
1254 }
1255 }
1256
1257 /* BIO_READ means the host writes into our buffer. */
1258 if (bp->bio_cmd == BIO_READ)
1259 writable = sg->sg_nseg - 1;
1260 } else if (bp->bio_cmd == BIO_DELETE) {
1261 struct virtio_blk_discard_write_zeroes *discard;
1262
1263 discard = malloc(sizeof(*discard), M_DEVBUF, M_NOWAIT | M_ZERO);
1264 if (discard == NULL) {
1265 error = ENOMEM;
1266 goto out;
1267 }
1268
1269 bp->bio_driver1 = discard;
1270 discard->sector = vtblk_gtoh64(sc, bp->bio_offset / VTBLK_BSIZE);
1271 discard->num_sectors = vtblk_gtoh32(sc, bp->bio_bcount / VTBLK_BSIZE);
1272 error = sglist_append(sg, discard, sizeof(*discard));
1273 if (error || sg->sg_nseg == sg->sg_maxseg) {
1274 panic("%s: bio %p data buffer too big %d",
1275 __func__, bp, error);
1276 }
1277 }
1278
1279 bus_dmamap_sync(sc->vtblk_ack_dmat, req->vbr_ack_mapp,
1280 BUS_DMASYNC_PREREAD);
1281
1282 writable++;
1283 sglist_append_phys(sg, req->vbr_ack_paddr, sizeof(uint8_t));
1284 readable = sg->sg_nseg - writable;
1285
1286 if (req->vbr_mapp != NULL) {
1287 switch (bp->bio_cmd) {
1288 case BIO_READ:
1289 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp,
1290 BUS_DMASYNC_PREREAD);
1291 break;
1292 case BIO_WRITE:
1293 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp,
1294 BUS_DMASYNC_PREWRITE);
1295 break;
1296 }
1297 }
1298
1299 error = virtqueue_enqueue(vq, req, sg, readable, writable);
1300 if (error == 0 && ordered)
1301 sc->vtblk_req_ordered = req;
1302
1303 /*
1304 * If we were called asynchronously, we need to notify the queue that
1305 * we've added a new request, since the notification from startio was
1306 * performed already.
1307 */
1308 if (error == 0 && req->vbr_busdma_wait)
1309 virtqueue_notify(vq);
1310
1311 out:
1312 if (error && (req->vbr_mapp != NULL))
1313 bus_dmamap_unload(sc->vtblk_dmat, req->vbr_mapp);
1314 out1:
1315 if (error && req->vbr_requeue_on_error)
1316 vtblk_request_requeue_ready(sc, req);
1317 req->vbr_error = error;
1318 }
1319
1320 static int
vtblk_request_error(struct vtblk_request * req)1321 vtblk_request_error(struct vtblk_request *req)
1322 {
1323 int error;
1324
1325 bus_dmamap_sync(req->vbr_sc->vtblk_ack_dmat, req->vbr_ack_mapp,
1326 BUS_DMASYNC_POSTREAD);
1327
1328 switch (*req->vbr_ack) {
1329 case VIRTIO_BLK_S_OK:
1330 error = 0;
1331 break;
1332 case VIRTIO_BLK_S_UNSUPP:
1333 error = ENOTSUP;
1334 break;
1335 default:
1336 error = EIO;
1337 break;
1338 }
1339
1340 return (error);
1341 }
1342
1343 static struct bio *
vtblk_queue_complete_one(struct vtblk_softc * sc,struct vtblk_request * req)1344 vtblk_queue_complete_one(struct vtblk_softc *sc, struct vtblk_request *req)
1345 {
1346 struct bio *bp;
1347
1348 if (sc->vtblk_req_ordered != NULL) {
1349 MPASS(sc->vtblk_req_ordered == req);
1350 sc->vtblk_req_ordered = NULL;
1351 }
1352
1353 bp = req->vbr_bp;
1354 if (req->vbr_mapp != NULL) {
1355 switch (bp->bio_cmd) {
1356 case BIO_READ:
1357 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp,
1358 BUS_DMASYNC_POSTREAD);
1359 bus_dmamap_unload(sc->vtblk_dmat, req->vbr_mapp);
1360 break;
1361 case BIO_WRITE:
1362 bus_dmamap_sync(sc->vtblk_dmat, req->vbr_mapp,
1363 BUS_DMASYNC_POSTWRITE);
1364 bus_dmamap_unload(sc->vtblk_dmat, req->vbr_mapp);
1365 break;
1366 }
1367 }
1368 bp->bio_error = vtblk_request_error(req);
1369 return (bp);
1370 }
1371
1372 static void
vtblk_queue_completed(struct vtblk_softc * sc,struct bio_queue * queue)1373 vtblk_queue_completed(struct vtblk_softc *sc, struct bio_queue *queue)
1374 {
1375 struct vtblk_request *req;
1376 struct bio *bp;
1377
1378 while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) {
1379 bp = vtblk_queue_complete_one(sc, req);
1380
1381 TAILQ_INSERT_TAIL(queue, bp, bio_queue);
1382 vtblk_request_enqueue(sc, req);
1383 }
1384 }
1385
1386 static void
vtblk_done_completed(struct vtblk_softc * sc,struct bio_queue * queue)1387 vtblk_done_completed(struct vtblk_softc *sc, struct bio_queue *queue)
1388 {
1389 struct bio *bp, *tmp;
1390
1391 TAILQ_FOREACH_SAFE(bp, queue, bio_queue, tmp) {
1392 if (bp->bio_error != 0)
1393 disk_err(bp, "hard error", -1, 1);
1394 vtblk_bio_done(sc, bp, bp->bio_error);
1395 }
1396 }
1397
1398 static void
vtblk_drain_vq(struct vtblk_softc * sc)1399 vtblk_drain_vq(struct vtblk_softc *sc)
1400 {
1401 struct virtqueue *vq;
1402 struct vtblk_request *req;
1403 int last;
1404
1405 vq = sc->vtblk_vq;
1406 last = 0;
1407
1408 while ((req = virtqueue_drain(vq, &last)) != NULL) {
1409 vtblk_bio_done(sc, req->vbr_bp, ENXIO);
1410 vtblk_request_enqueue(sc, req);
1411 }
1412
1413 sc->vtblk_req_ordered = NULL;
1414 KASSERT(virtqueue_empty(vq), ("virtqueue not empty"));
1415 }
1416
1417 static void
vtblk_drain(struct vtblk_softc * sc)1418 vtblk_drain(struct vtblk_softc *sc)
1419 {
1420 struct bio_queue_head *bioq;
1421 struct vtblk_request *req;
1422 struct bio *bp;
1423
1424 bioq = &sc->vtblk_bioq;
1425
1426 if (sc->vtblk_vq != NULL) {
1427 struct bio_queue queue;
1428
1429 TAILQ_INIT(&queue);
1430 vtblk_queue_completed(sc, &queue);
1431 vtblk_done_completed(sc, &queue);
1432
1433 vtblk_drain_vq(sc);
1434 }
1435
1436 while ((req = vtblk_request_next_ready(sc)) != NULL) {
1437 vtblk_bio_done(sc, req->vbr_bp, ENXIO);
1438 vtblk_request_enqueue(sc, req);
1439 }
1440
1441 while (bioq_first(bioq) != NULL) {
1442 bp = bioq_takefirst(bioq);
1443 vtblk_bio_done(sc, bp, ENXIO);
1444 }
1445
1446 vtblk_request_free(sc);
1447 }
1448
1449 static void
vtblk_startio(struct vtblk_softc * sc)1450 vtblk_startio(struct vtblk_softc *sc)
1451 {
1452 struct virtqueue *vq;
1453 struct vtblk_request *req;
1454 int enq;
1455
1456 VTBLK_LOCK_ASSERT(sc);
1457 vq = sc->vtblk_vq;
1458 enq = 0;
1459
1460 if (sc->vtblk_flags & (VTBLK_FLAG_SUSPEND | VTBLK_FLAG_BUSDMA_WAIT))
1461 return;
1462
1463 while (!virtqueue_full(vq)) {
1464 req = vtblk_request_next(sc);
1465 if (req == NULL)
1466 break;
1467
1468 req->vbr_requeue_on_error = 1;
1469 if (vtblk_request_execute(req, BUS_DMA_WAITOK))
1470 break;
1471
1472 enq++;
1473 }
1474
1475 if (enq > 0)
1476 virtqueue_notify(vq);
1477 }
1478
1479 static void
vtblk_bio_done(struct vtblk_softc * sc,struct bio * bp,int error)1480 vtblk_bio_done(struct vtblk_softc *sc, struct bio *bp, int error)
1481 {
1482
1483 /* Because of GEOM direct dispatch, we cannot hold any locks. */
1484 if (sc != NULL)
1485 VTBLK_LOCK_ASSERT_NOTOWNED(sc);
1486
1487 if (error) {
1488 bp->bio_resid = bp->bio_bcount;
1489 bp->bio_error = error;
1490 bp->bio_flags |= BIO_ERROR;
1491 } else {
1492 kmsan_mark_bio(bp, KMSAN_STATE_INITED);
1493 }
1494
1495 if (bp->bio_driver1 != NULL) {
1496 free(bp->bio_driver1, M_DEVBUF);
1497 bp->bio_driver1 = NULL;
1498 }
1499
1500 biodone(bp);
1501 }
1502
1503 #define VTBLK_GET_CONFIG(_dev, _feature, _field, _cfg) \
1504 if (virtio_with_feature(_dev, _feature)) { \
1505 virtio_read_device_config(_dev, \
1506 offsetof(struct virtio_blk_config, _field), \
1507 &(_cfg)->_field, sizeof((_cfg)->_field)); \
1508 }
1509
1510 static void
vtblk_read_config(struct vtblk_softc * sc,struct virtio_blk_config * blkcfg)1511 vtblk_read_config(struct vtblk_softc *sc, struct virtio_blk_config *blkcfg)
1512 {
1513 device_t dev;
1514
1515 dev = sc->vtblk_dev;
1516
1517 bzero(blkcfg, sizeof(struct virtio_blk_config));
1518
1519 /* The capacity is always available. */
1520 virtio_read_device_config(dev, offsetof(struct virtio_blk_config,
1521 capacity), &blkcfg->capacity, sizeof(blkcfg->capacity));
1522
1523 /* Read the configuration if the feature was negotiated. */
1524 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SIZE_MAX, size_max, blkcfg);
1525 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_SEG_MAX, seg_max, blkcfg);
1526 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY,
1527 geometry.cylinders, blkcfg);
1528 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY,
1529 geometry.heads, blkcfg);
1530 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_GEOMETRY,
1531 geometry.sectors, blkcfg);
1532 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_BLK_SIZE, blk_size, blkcfg);
1533 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY,
1534 topology.physical_block_exp, blkcfg);
1535 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY,
1536 topology.alignment_offset, blkcfg);
1537 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY,
1538 topology.min_io_size, blkcfg);
1539 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_TOPOLOGY,
1540 topology.opt_io_size, blkcfg);
1541 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_CONFIG_WCE, wce, blkcfg);
1542 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_sectors,
1543 blkcfg);
1544 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, max_discard_seg, blkcfg);
1545 VTBLK_GET_CONFIG(dev, VIRTIO_BLK_F_DISCARD, discard_sector_alignment,
1546 blkcfg);
1547 }
1548
1549 #undef VTBLK_GET_CONFIG
1550
1551 static void
vtblk_ident(struct vtblk_softc * sc)1552 vtblk_ident(struct vtblk_softc *sc)
1553 {
1554 struct bio buf;
1555 struct disk *dp;
1556 struct vtblk_request *req;
1557 int len, error;
1558
1559 dp = sc->vtblk_disk;
1560 len = MIN(VIRTIO_BLK_ID_BYTES, DISK_IDENT_SIZE);
1561
1562 if (vtblk_tunable_int(sc, "no_ident", vtblk_no_ident) != 0)
1563 return;
1564
1565 req = vtblk_request_dequeue(sc);
1566 if (req == NULL)
1567 return;
1568
1569 *req->vbr_ack = -1;
1570 req->vbr_hdr->type = vtblk_gtoh32(sc, VIRTIO_BLK_T_GET_ID);
1571 req->vbr_hdr->ioprio = vtblk_gtoh32(sc, 1);
1572 req->vbr_hdr->sector = 0;
1573
1574 req->vbr_bp = &buf;
1575 g_reset_bio(&buf);
1576
1577 buf.bio_cmd = BIO_READ;
1578 buf.bio_data = dp->d_ident;
1579 buf.bio_bcount = len;
1580
1581 VTBLK_LOCK(sc);
1582 error = vtblk_poll_request(sc, req);
1583 VTBLK_UNLOCK(sc);
1584
1585 if (error) {
1586 device_printf(sc->vtblk_dev,
1587 "error getting device identifier: %d\n", error);
1588 }
1589 }
1590
1591 static int
vtblk_poll_request(struct vtblk_softc * sc,struct vtblk_request * req)1592 vtblk_poll_request(struct vtblk_softc *sc, struct vtblk_request *req)
1593 {
1594 struct vtblk_request *req1 __diagused;
1595 struct virtqueue *vq;
1596 struct bio *bp;
1597 int error;
1598
1599 vq = sc->vtblk_vq;
1600
1601 if (!virtqueue_empty(vq))
1602 return (EBUSY);
1603
1604 error = vtblk_request_execute(req, BUS_DMA_NOWAIT);
1605 if (error)
1606 return (error);
1607
1608 virtqueue_notify(vq);
1609 req1 = virtqueue_poll(vq, NULL);
1610 KASSERT(req == req1,
1611 ("%s: polling completed %p not %p", __func__, req1, req));
1612
1613 bp = vtblk_queue_complete_one(sc, req);
1614 error = bp->bio_error;
1615 if (error && bootverbose) {
1616 device_printf(sc->vtblk_dev,
1617 "%s: IO error: %d\n", __func__, error);
1618 }
1619 if (req != &sc->vtblk_dump_request)
1620 vtblk_request_enqueue(sc, req);
1621
1622 return (error);
1623 }
1624
1625 static int
vtblk_quiesce(struct vtblk_softc * sc)1626 vtblk_quiesce(struct vtblk_softc *sc)
1627 {
1628 int error;
1629
1630 VTBLK_LOCK_ASSERT(sc);
1631 error = 0;
1632
1633 while (!virtqueue_empty(sc->vtblk_vq)) {
1634 if (mtx_sleep(&sc->vtblk_vq, VTBLK_MTX(sc), PRIBIO, "vtblkq",
1635 VTBLK_QUIESCE_TIMEOUT) == EWOULDBLOCK) {
1636 error = EBUSY;
1637 break;
1638 }
1639 }
1640
1641 return (error);
1642 }
1643
1644 static void
vtblk_vq_intr(void * xsc)1645 vtblk_vq_intr(void *xsc)
1646 {
1647 struct vtblk_softc *sc;
1648 struct virtqueue *vq;
1649 struct bio_queue queue;
1650
1651 sc = xsc;
1652 vq = sc->vtblk_vq;
1653 TAILQ_INIT(&queue);
1654
1655 VTBLK_LOCK(sc);
1656
1657 again:
1658 if (sc->vtblk_flags & VTBLK_FLAG_DETACH)
1659 goto out;
1660
1661 vtblk_queue_completed(sc, &queue);
1662 vtblk_startio(sc);
1663
1664 if (virtqueue_enable_intr(vq) != 0) {
1665 virtqueue_disable_intr(vq);
1666 goto again;
1667 }
1668
1669 if (sc->vtblk_flags & VTBLK_FLAG_SUSPEND)
1670 wakeup(&sc->vtblk_vq);
1671
1672 out:
1673 VTBLK_UNLOCK(sc);
1674 vtblk_done_completed(sc, &queue);
1675 }
1676
1677 static void
vtblk_stop(struct vtblk_softc * sc)1678 vtblk_stop(struct vtblk_softc *sc)
1679 {
1680
1681 virtqueue_disable_intr(sc->vtblk_vq);
1682 virtio_stop(sc->vtblk_dev);
1683 }
1684
1685 static void
vtblk_dump_quiesce(struct vtblk_softc * sc)1686 vtblk_dump_quiesce(struct vtblk_softc *sc)
1687 {
1688
1689 /*
1690 * Spin here until all the requests in-flight at the time of the
1691 * dump are completed and queued. The queued requests will be
1692 * biodone'd once the dump is finished.
1693 */
1694 while (!virtqueue_empty(sc->vtblk_vq))
1695 vtblk_queue_completed(sc, &sc->vtblk_dump_queue);
1696 }
1697
1698 static int
vtblk_dump_write(struct vtblk_softc * sc,void * virtual,off_t offset,size_t length)1699 vtblk_dump_write(struct vtblk_softc *sc, void *virtual, off_t offset,
1700 size_t length)
1701 {
1702 struct bio buf;
1703 struct vtblk_request *req;
1704
1705 req = &sc->vtblk_dump_request;
1706 req->vbr_sc = sc;
1707 *req->vbr_ack = -1;
1708 req->vbr_hdr->type = vtblk_gtoh32(sc, VIRTIO_BLK_T_OUT);
1709 req->vbr_hdr->ioprio = vtblk_gtoh32(sc, 1);
1710 req->vbr_hdr->sector = vtblk_gtoh64(sc, offset / VTBLK_BSIZE);
1711
1712 req->vbr_bp = &buf;
1713 g_reset_bio(&buf);
1714
1715 buf.bio_cmd = BIO_WRITE;
1716 buf.bio_data = virtual;
1717 buf.bio_bcount = length;
1718
1719 return (vtblk_poll_request(sc, req));
1720 }
1721
1722 static int
vtblk_dump_flush(struct vtblk_softc * sc)1723 vtblk_dump_flush(struct vtblk_softc *sc)
1724 {
1725 struct bio buf;
1726 struct vtblk_request *req;
1727
1728 req = &sc->vtblk_dump_request;
1729 req->vbr_sc = sc;
1730 *req->vbr_ack = -1;
1731 req->vbr_hdr->type = vtblk_gtoh32(sc, VIRTIO_BLK_T_FLUSH);
1732 req->vbr_hdr->ioprio = vtblk_gtoh32(sc, 1);
1733 req->vbr_hdr->sector = 0;
1734
1735 req->vbr_bp = &buf;
1736 g_reset_bio(&buf);
1737
1738 buf.bio_cmd = BIO_FLUSH;
1739
1740 return (vtblk_poll_request(sc, req));
1741 }
1742
1743 static void
vtblk_dump_complete(struct vtblk_softc * sc)1744 vtblk_dump_complete(struct vtblk_softc *sc)
1745 {
1746
1747 vtblk_dump_flush(sc);
1748
1749 VTBLK_UNLOCK(sc);
1750 vtblk_done_completed(sc, &sc->vtblk_dump_queue);
1751 VTBLK_LOCK(sc);
1752 }
1753
1754 static void
vtblk_set_write_cache(struct vtblk_softc * sc,int wc)1755 vtblk_set_write_cache(struct vtblk_softc *sc, int wc)
1756 {
1757
1758 /* Set either writeback (1) or writethrough (0) mode. */
1759 virtio_write_dev_config_1(sc->vtblk_dev,
1760 offsetof(struct virtio_blk_config, wce), wc);
1761 }
1762
1763 static int
vtblk_write_cache_enabled(struct vtblk_softc * sc,struct virtio_blk_config * blkcfg)1764 vtblk_write_cache_enabled(struct vtblk_softc *sc,
1765 struct virtio_blk_config *blkcfg)
1766 {
1767 int wc;
1768
1769 if (sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) {
1770 wc = vtblk_tunable_int(sc, "writecache_mode",
1771 vtblk_writecache_mode);
1772 if (wc >= 0 && wc < VTBLK_CACHE_MAX)
1773 vtblk_set_write_cache(sc, wc);
1774 else
1775 wc = blkcfg->wce;
1776 } else
1777 wc = virtio_with_feature(sc->vtblk_dev, VIRTIO_BLK_F_FLUSH);
1778
1779 return (wc);
1780 }
1781
1782 static int
vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS)1783 vtblk_write_cache_sysctl(SYSCTL_HANDLER_ARGS)
1784 {
1785 struct vtblk_softc *sc;
1786 int wc, error;
1787
1788 sc = oidp->oid_arg1;
1789 wc = sc->vtblk_write_cache;
1790
1791 error = sysctl_handle_int(oidp, &wc, 0, req);
1792 if (error || req->newptr == NULL)
1793 return (error);
1794 if ((sc->vtblk_flags & VTBLK_FLAG_WCE_CONFIG) == 0)
1795 return (EPERM);
1796 if (wc < 0 || wc >= VTBLK_CACHE_MAX)
1797 return (EINVAL);
1798
1799 VTBLK_LOCK(sc);
1800 sc->vtblk_write_cache = wc;
1801 vtblk_set_write_cache(sc, sc->vtblk_write_cache);
1802 VTBLK_UNLOCK(sc);
1803
1804 return (0);
1805 }
1806
1807 static void
vtblk_setup_sysctl(struct vtblk_softc * sc)1808 vtblk_setup_sysctl(struct vtblk_softc *sc)
1809 {
1810 device_t dev;
1811 struct sysctl_ctx_list *ctx;
1812 struct sysctl_oid *tree;
1813 struct sysctl_oid_list *child;
1814
1815 dev = sc->vtblk_dev;
1816 ctx = device_get_sysctl_ctx(dev);
1817 tree = device_get_sysctl_tree(dev);
1818 child = SYSCTL_CHILDREN(tree);
1819
1820 SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "writecache_mode",
1821 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, sc, 0,
1822 vtblk_write_cache_sysctl, "I",
1823 "Write cache mode (writethrough (0) or writeback (1))");
1824 }
1825
1826 static int
vtblk_tunable_int(struct vtblk_softc * sc,const char * knob,int def)1827 vtblk_tunable_int(struct vtblk_softc *sc, const char *knob, int def)
1828 {
1829 char path[64];
1830
1831 snprintf(path, sizeof(path),
1832 "hw.vtblk.%d.%s", device_get_unit(sc->vtblk_dev), knob);
1833 TUNABLE_INT_FETCH(path, &def);
1834
1835 return (def);
1836 }
1837