xref: /spdk/module/bdev/virtio/bdev_virtio_scsi.c (revision d73077b84a71985da1db1c9847ea7c042189bae2)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation.
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  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include "spdk/stdinc.h"
35 
36 #include "spdk/bdev.h"
37 #include "spdk/endian.h"
38 #include "spdk/env.h"
39 #include "spdk/thread.h"
40 #include "spdk/scsi_spec.h"
41 #include "spdk/string.h"
42 #include "spdk/util.h"
43 #include "spdk/json.h"
44 
45 #include "spdk/bdev_module.h"
46 #include "spdk/log.h"
47 #include "spdk_internal/virtio.h"
48 #include "spdk_internal/vhost_user.h"
49 
50 #include <linux/virtio_scsi.h>
51 
52 #include "bdev_virtio.h"
53 
54 #define BDEV_VIRTIO_MAX_TARGET 64
55 #define BDEV_VIRTIO_SCAN_PAYLOAD_SIZE 256
56 #define MGMT_POLL_PERIOD_US (1000 * 5)
57 #define CTRLQ_RING_SIZE 16
58 #define SCAN_REQUEST_RETRIES 5
59 
60 /* Number of non-request queues - eventq and controlq */
61 #define SPDK_VIRTIO_SCSI_QUEUE_NUM_FIXED 2
62 
63 #define VIRTIO_SCSI_EVENTQ_BUFFER_COUNT 16
64 
65 #define VIRTIO_SCSI_CONTROLQ	0
66 #define VIRTIO_SCSI_EVENTQ	1
67 #define VIRTIO_SCSI_REQUESTQ	2
68 
69 static int bdev_virtio_initialize(void);
70 static void bdev_virtio_finish(void);
71 
72 struct virtio_scsi_dev {
73 	/* Generic virtio device data. */
74 	struct virtio_dev		vdev;
75 
76 	/** Detected SCSI LUNs */
77 	TAILQ_HEAD(, virtio_scsi_disk)	luns;
78 
79 	/** Context for the SCSI target scan. */
80 	struct virtio_scsi_scan_base	*scan_ctx;
81 
82 	/** Controlq poller. */
83 	struct spdk_poller		*mgmt_poller;
84 
85 	/** Controlq messages to be sent. */
86 	struct spdk_ring		*ctrlq_ring;
87 
88 	/** Buffers for the eventq. */
89 	struct virtio_scsi_eventq_io	*eventq_ios;
90 
91 	/** Device marked for removal. */
92 	bool				removed;
93 
94 	/** Callback to be called after vdev removal. */
95 	bdev_virtio_remove_cb		remove_cb;
96 
97 	/** Context for the `remove_cb`. */
98 	void				*remove_ctx;
99 
100 	TAILQ_ENTRY(virtio_scsi_dev) tailq;
101 };
102 
103 struct virtio_scsi_io_ctx {
104 	struct iovec			iov_req;
105 	struct iovec			iov_resp;
106 	union {
107 		struct virtio_scsi_cmd_req req;
108 		struct virtio_scsi_ctrl_tmf_req tmf_req;
109 	};
110 	union {
111 		struct virtio_scsi_cmd_resp resp;
112 		struct virtio_scsi_ctrl_tmf_resp tmf_resp;
113 	};
114 };
115 
116 struct virtio_scsi_eventq_io {
117 	struct iovec			iov;
118 	struct virtio_scsi_event	ev;
119 };
120 
121 struct virtio_scsi_scan_info {
122 	uint64_t			num_blocks;
123 	uint32_t			block_size;
124 	uint8_t				target;
125 	bool				unmap_supported;
126 	TAILQ_ENTRY(virtio_scsi_scan_info) tailq;
127 };
128 
129 struct virtio_scsi_scan_base {
130 	struct virtio_scsi_dev		*svdev;
131 
132 	/** I/O channel used for the scan I/O. */
133 	struct bdev_virtio_io_channel	*channel;
134 
135 	bdev_virtio_create_cb		cb_fn;
136 	void				*cb_arg;
137 
138 	/** Scan all targets on the device. */
139 	bool				full_scan;
140 
141 	/** Start a full rescan after receiving next scan I/O response. */
142 	bool				restart;
143 
144 	/** Additional targets to be (re)scanned. */
145 	TAILQ_HEAD(, virtio_scsi_scan_info) scan_queue;
146 
147 	/** Remaining attempts for sending the current request. */
148 	unsigned                        retries;
149 
150 	/** If set, the last scan I/O needs to be resent */
151 	bool				needs_resend;
152 
153 	struct virtio_scsi_io_ctx	io_ctx;
154 	struct iovec			iov;
155 	uint8_t				payload[BDEV_VIRTIO_SCAN_PAYLOAD_SIZE];
156 
157 	/** Scan results for the current target. */
158 	struct virtio_scsi_scan_info	info;
159 };
160 
161 struct virtio_scsi_disk {
162 	struct spdk_bdev		bdev;
163 	struct virtio_scsi_dev		*svdev;
164 	struct virtio_scsi_scan_info	info;
165 
166 	/** Descriptor opened just to be notified of external bdev hotremove. */
167 	struct spdk_bdev_desc		*notify_desc;
168 
169 	/** Disk marked for removal. */
170 	bool				removed;
171 	TAILQ_ENTRY(virtio_scsi_disk)	link;
172 };
173 
174 struct bdev_virtio_io_channel {
175 	struct virtio_scsi_dev	*svdev;
176 
177 	/** Virtqueue exclusively assigned to this channel. */
178 	struct virtqueue	*vq;
179 
180 	/** Virtio response poller. */
181 	struct spdk_poller	*poller;
182 };
183 
184 static TAILQ_HEAD(, virtio_scsi_dev) g_virtio_scsi_devs =
185 	TAILQ_HEAD_INITIALIZER(g_virtio_scsi_devs);
186 
187 static pthread_mutex_t g_virtio_scsi_mutex = PTHREAD_MUTEX_INITIALIZER;
188 
189 /** Module finish in progress */
190 static bool g_bdev_virtio_finish = false;
191 
192 /* Features desired/implemented by this driver. */
193 #define VIRTIO_SCSI_DEV_SUPPORTED_FEATURES		\
194 	(1ULL << VIRTIO_SCSI_F_INOUT		|	\
195 	 1ULL << VIRTIO_SCSI_F_HOTPLUG		|	\
196 	 1ULL << VIRTIO_RING_F_EVENT_IDX	|	\
197 	 1ULL << VHOST_USER_F_PROTOCOL_FEATURES)
198 
199 static void virtio_scsi_dev_unregister_cb(void *io_device);
200 static void virtio_scsi_dev_remove(struct virtio_scsi_dev *svdev,
201 				   bdev_virtio_remove_cb cb_fn, void *cb_arg);
202 static int bdev_virtio_scsi_ch_create_cb(void *io_device, void *ctx_buf);
203 static void bdev_virtio_scsi_ch_destroy_cb(void *io_device, void *ctx_buf);
204 static void process_scan_resp(struct virtio_scsi_scan_base *base);
205 static int bdev_virtio_mgmt_poll(void *arg);
206 
207 static int
208 virtio_scsi_dev_send_eventq_io(struct virtqueue *vq, struct virtio_scsi_eventq_io *io)
209 {
210 	int rc;
211 
212 	rc = virtqueue_req_start(vq, io, 1);
213 	if (rc != 0) {
214 		return -1;
215 	}
216 
217 	virtqueue_req_add_iovs(vq, &io->iov, 1, SPDK_VIRTIO_DESC_WR);
218 	virtqueue_req_flush(vq);
219 
220 	return 0;
221 }
222 
223 static int
224 virtio_scsi_dev_init(struct virtio_scsi_dev *svdev, uint16_t max_queues)
225 {
226 	struct virtio_dev *vdev = &svdev->vdev;
227 	struct spdk_ring *ctrlq_ring;
228 	struct virtio_scsi_eventq_io *eventq_io;
229 	struct virtqueue *eventq;
230 	uint16_t i, num_events;
231 	int rc;
232 
233 	rc = virtio_dev_reset(vdev, VIRTIO_SCSI_DEV_SUPPORTED_FEATURES);
234 	if (rc != 0) {
235 		return rc;
236 	}
237 
238 	rc = virtio_dev_start(vdev, max_queues, SPDK_VIRTIO_SCSI_QUEUE_NUM_FIXED);
239 	if (rc != 0) {
240 		return rc;
241 	}
242 
243 	ctrlq_ring = spdk_ring_create(SPDK_RING_TYPE_MP_SC, CTRLQ_RING_SIZE,
244 				      SPDK_ENV_SOCKET_ID_ANY);
245 	if (ctrlq_ring == NULL) {
246 		SPDK_ERRLOG("Failed to allocate send ring for the controlq.\n");
247 		return -1;
248 	}
249 
250 	rc = virtio_dev_acquire_queue(vdev, VIRTIO_SCSI_CONTROLQ);
251 	if (rc != 0) {
252 		SPDK_ERRLOG("Failed to acquire the controlq.\n");
253 		spdk_ring_free(ctrlq_ring);
254 		return -1;
255 	}
256 
257 	rc = virtio_dev_acquire_queue(vdev, VIRTIO_SCSI_EVENTQ);
258 	if (rc != 0) {
259 		SPDK_ERRLOG("Failed to acquire the eventq.\n");
260 		virtio_dev_release_queue(vdev, VIRTIO_SCSI_CONTROLQ);
261 		spdk_ring_free(ctrlq_ring);
262 		return -1;
263 	}
264 
265 	eventq = vdev->vqs[VIRTIO_SCSI_EVENTQ];
266 	num_events = spdk_min(eventq->vq_nentries, VIRTIO_SCSI_EVENTQ_BUFFER_COUNT);
267 	svdev->eventq_ios = spdk_zmalloc(sizeof(*svdev->eventq_ios) * num_events,
268 					 0, NULL, SPDK_ENV_LCORE_ID_ANY,
269 					 SPDK_MALLOC_DMA);
270 	if (svdev->eventq_ios == NULL) {
271 		SPDK_ERRLOG("cannot allocate memory for %"PRIu16" eventq buffers\n",
272 			    num_events);
273 		virtio_dev_release_queue(vdev, VIRTIO_SCSI_EVENTQ);
274 		virtio_dev_release_queue(vdev, VIRTIO_SCSI_CONTROLQ);
275 		spdk_ring_free(ctrlq_ring);
276 		return -1;
277 	}
278 
279 	for (i = 0; i < num_events; i++) {
280 		eventq_io = &svdev->eventq_ios[i];
281 		eventq_io->iov.iov_base = &eventq_io->ev;
282 		eventq_io->iov.iov_len = sizeof(eventq_io->ev);
283 		virtio_scsi_dev_send_eventq_io(eventq, eventq_io);
284 	}
285 
286 	svdev->ctrlq_ring = ctrlq_ring;
287 
288 	svdev->mgmt_poller = SPDK_POLLER_REGISTER(bdev_virtio_mgmt_poll, svdev,
289 			     MGMT_POLL_PERIOD_US);
290 
291 	TAILQ_INIT(&svdev->luns);
292 	svdev->scan_ctx = NULL;
293 	svdev->removed = false;
294 	svdev->remove_cb = NULL;
295 	svdev->remove_ctx = NULL;
296 
297 	spdk_io_device_register(svdev, bdev_virtio_scsi_ch_create_cb,
298 				bdev_virtio_scsi_ch_destroy_cb,
299 				sizeof(struct bdev_virtio_io_channel),
300 				svdev->vdev.name);
301 
302 	pthread_mutex_lock(&g_virtio_scsi_mutex);
303 	TAILQ_INSERT_TAIL(&g_virtio_scsi_devs, svdev, tailq);
304 	pthread_mutex_unlock(&g_virtio_scsi_mutex);
305 	return 0;
306 }
307 
308 static struct virtio_scsi_dev *
309 virtio_pci_scsi_dev_create(const char *name, struct virtio_pci_ctx *pci_ctx)
310 {
311 	static int pci_dev_counter = 0;
312 	struct virtio_scsi_dev *svdev;
313 	struct virtio_dev *vdev;
314 	char *default_name = NULL;
315 	uint32_t num_queues;
316 	int rc;
317 
318 	svdev = calloc(1, sizeof(*svdev));
319 	if (svdev == NULL) {
320 		SPDK_ERRLOG("virtio device calloc failed\n");
321 		return NULL;
322 	}
323 
324 	vdev = &svdev->vdev;
325 	if (name == NULL) {
326 		default_name = spdk_sprintf_alloc("VirtioScsi%"PRIu32, pci_dev_counter++);
327 		if (default_name == NULL) {
328 			free(vdev);
329 			return NULL;
330 		}
331 		name = default_name;
332 	}
333 
334 	rc = virtio_pci_dev_init(vdev, name, pci_ctx);
335 	free(default_name);
336 
337 	if (rc != 0) {
338 		free(svdev);
339 		return NULL;
340 	}
341 
342 	rc = virtio_dev_read_dev_config(vdev, offsetof(struct virtio_scsi_config, num_queues),
343 					&num_queues, sizeof(num_queues));
344 	if (rc) {
345 		SPDK_ERRLOG("%s: config read failed: %s\n", vdev->name, spdk_strerror(-rc));
346 		goto fail;
347 	}
348 
349 	rc = virtio_scsi_dev_init(svdev, num_queues);
350 	if (rc != 0) {
351 		goto fail;
352 	}
353 
354 	return svdev;
355 
356 fail:
357 	vdev->ctx = NULL;
358 	virtio_dev_destruct(vdev);
359 	free(svdev);
360 	return NULL;
361 }
362 
363 static struct virtio_scsi_dev *
364 virtio_user_scsi_dev_create(const char *name, const char *path,
365 			    uint16_t num_queues, uint32_t queue_size)
366 {
367 	struct virtio_scsi_dev *svdev;
368 	struct virtio_dev *vdev;
369 	int rc;
370 
371 	svdev = calloc(1, sizeof(*svdev));
372 	if (svdev == NULL) {
373 		SPDK_ERRLOG("calloc failed for virtio device %s: %s\n", name, path);
374 		return NULL;
375 	}
376 
377 	vdev = &svdev->vdev;
378 	rc = virtio_user_dev_init(vdev, name, path, queue_size);
379 	if (rc != 0) {
380 		SPDK_ERRLOG("Failed to create virito device %s: %s\n", name, path);
381 		free(svdev);
382 		return NULL;
383 	}
384 
385 	rc = virtio_scsi_dev_init(svdev, num_queues);
386 	if (rc != 0) {
387 		virtio_dev_destruct(vdev);
388 		free(svdev);
389 		return NULL;
390 	}
391 
392 	return svdev;
393 }
394 
395 static struct virtio_scsi_disk *
396 virtio_scsi_dev_get_disk_by_id(struct virtio_scsi_dev *svdev, uint8_t target_id)
397 {
398 	struct virtio_scsi_disk *disk;
399 
400 	TAILQ_FOREACH(disk, &svdev->luns, link) {
401 		if (disk->info.target == target_id) {
402 			return disk;
403 		}
404 	}
405 
406 	return NULL;
407 }
408 
409 static int virtio_scsi_dev_scan(struct virtio_scsi_dev *svdev,
410 				bdev_virtio_create_cb cb_fn, void *cb_arg);
411 static int send_scan_io(struct virtio_scsi_scan_base *base);
412 static void _virtio_scsi_dev_scan_tgt(struct virtio_scsi_scan_base *base, uint8_t target);
413 static int _virtio_scsi_dev_scan_next(struct virtio_scsi_scan_base *base, int rc);
414 static void _virtio_scsi_dev_scan_finish(struct virtio_scsi_scan_base *base, int errnum);
415 static int virtio_scsi_dev_scan_tgt(struct virtio_scsi_dev *svdev, uint8_t target);
416 
417 static int
418 bdev_virtio_get_ctx_size(void)
419 {
420 	return sizeof(struct virtio_scsi_io_ctx);
421 }
422 
423 static int
424 bdev_virtio_scsi_config_json(struct spdk_json_write_ctx *w)
425 {
426 	struct virtio_scsi_dev *svdev;
427 
428 	pthread_mutex_lock(&g_virtio_scsi_mutex);
429 	TAILQ_FOREACH(svdev, &g_virtio_scsi_devs, tailq) {
430 		spdk_json_write_object_begin(w);
431 
432 		spdk_json_write_named_string(w, "method", "bdev_virtio_attach_controller");
433 
434 		spdk_json_write_named_object_begin(w, "params");
435 		spdk_json_write_named_string(w, "name", svdev->vdev.name);
436 		spdk_json_write_named_string(w, "dev_type", "scsi");
437 
438 		/* Write transport specific parameters. */
439 		svdev->vdev.backend_ops->write_json_config(&svdev->vdev, w);
440 
441 		spdk_json_write_object_end(w);
442 
443 		spdk_json_write_object_end(w);
444 
445 	}
446 	pthread_mutex_unlock(&g_virtio_scsi_mutex);
447 
448 	return 0;
449 }
450 
451 
452 static struct spdk_bdev_module virtio_scsi_if = {
453 	.name = "virtio_scsi",
454 	.module_init = bdev_virtio_initialize,
455 	.module_fini = bdev_virtio_finish,
456 	.get_ctx_size = bdev_virtio_get_ctx_size,
457 	.config_json = bdev_virtio_scsi_config_json,
458 	.async_fini = true,
459 };
460 
461 SPDK_BDEV_MODULE_REGISTER(virtio_scsi, &virtio_scsi_if)
462 
463 static struct virtio_scsi_io_ctx *
464 bdev_virtio_init_io_vreq(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
465 {
466 	struct virtio_scsi_cmd_req *req;
467 	struct virtio_scsi_cmd_resp *resp;
468 	struct virtio_scsi_disk *disk = (struct virtio_scsi_disk *)bdev_io->bdev;
469 	struct virtio_scsi_io_ctx *io_ctx = (struct virtio_scsi_io_ctx *)bdev_io->driver_ctx;
470 
471 	req = &io_ctx->req;
472 	resp = &io_ctx->resp;
473 
474 	io_ctx->iov_req.iov_base = req;
475 	io_ctx->iov_req.iov_len = sizeof(*req);
476 
477 	io_ctx->iov_resp.iov_base = resp;
478 	io_ctx->iov_resp.iov_len = sizeof(*resp);
479 
480 	memset(req, 0, sizeof(*req));
481 	req->lun[0] = 1;
482 	req->lun[1] = disk->info.target;
483 
484 	return io_ctx;
485 }
486 
487 static struct virtio_scsi_io_ctx *
488 bdev_virtio_init_tmf_vreq(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
489 {
490 	struct virtio_scsi_ctrl_tmf_req *tmf_req;
491 	struct virtio_scsi_ctrl_tmf_resp *tmf_resp;
492 	struct virtio_scsi_disk *disk = SPDK_CONTAINEROF(bdev_io->bdev, struct virtio_scsi_disk, bdev);
493 	struct virtio_scsi_io_ctx *io_ctx = (struct virtio_scsi_io_ctx *)bdev_io->driver_ctx;
494 
495 	tmf_req = &io_ctx->tmf_req;
496 	tmf_resp = &io_ctx->tmf_resp;
497 
498 	io_ctx->iov_req.iov_base = tmf_req;
499 	io_ctx->iov_req.iov_len = sizeof(*tmf_req);
500 	io_ctx->iov_resp.iov_base = tmf_resp;
501 	io_ctx->iov_resp.iov_len = sizeof(*tmf_resp);
502 
503 	memset(tmf_req, 0, sizeof(*tmf_req));
504 	tmf_req->lun[0] = 1;
505 	tmf_req->lun[1] = disk->info.target;
506 
507 	return io_ctx;
508 }
509 
510 static void
511 bdev_virtio_send_io(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
512 {
513 	struct bdev_virtio_io_channel *virtio_channel = spdk_io_channel_get_ctx(ch);
514 	struct virtqueue *vq = virtio_channel->vq;
515 	struct virtio_scsi_io_ctx *io_ctx = (struct virtio_scsi_io_ctx *)bdev_io->driver_ctx;
516 	int rc;
517 
518 	rc = virtqueue_req_start(vq, bdev_io, bdev_io->u.bdev.iovcnt + 2);
519 	if (rc == -ENOMEM) {
520 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_NOMEM);
521 		return;
522 	} else if (rc != 0) {
523 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
524 		return;
525 	}
526 
527 	virtqueue_req_add_iovs(vq, &io_ctx->iov_req, 1, SPDK_VIRTIO_DESC_RO);
528 	if (bdev_io->type == SPDK_BDEV_IO_TYPE_READ) {
529 		virtqueue_req_add_iovs(vq, &io_ctx->iov_resp, 1, SPDK_VIRTIO_DESC_WR);
530 		virtqueue_req_add_iovs(vq, bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
531 				       SPDK_VIRTIO_DESC_WR);
532 	} else {
533 		virtqueue_req_add_iovs(vq, bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
534 				       SPDK_VIRTIO_DESC_RO);
535 		virtqueue_req_add_iovs(vq, &io_ctx->iov_resp, 1, SPDK_VIRTIO_DESC_WR);
536 	}
537 
538 	virtqueue_req_flush(vq);
539 }
540 
541 static void
542 bdev_virtio_rw(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
543 {
544 	struct virtio_scsi_disk *disk = SPDK_CONTAINEROF(bdev_io->bdev, struct virtio_scsi_disk, bdev);
545 	struct virtio_scsi_io_ctx *io_ctx = bdev_virtio_init_io_vreq(ch, bdev_io);
546 	struct virtio_scsi_cmd_req *req = &io_ctx->req;
547 	bool is_write = bdev_io->type == SPDK_BDEV_IO_TYPE_WRITE;
548 
549 	if (disk->info.num_blocks > (1ULL << 32)) {
550 		req->cdb[0] = is_write ? SPDK_SBC_WRITE_16 : SPDK_SBC_READ_16;
551 		to_be64(&req->cdb[2], bdev_io->u.bdev.offset_blocks);
552 		to_be32(&req->cdb[10], bdev_io->u.bdev.num_blocks);
553 	} else {
554 		req->cdb[0] = is_write ? SPDK_SBC_WRITE_10 : SPDK_SBC_READ_10;
555 		to_be32(&req->cdb[2], bdev_io->u.bdev.offset_blocks);
556 		to_be16(&req->cdb[7], bdev_io->u.bdev.num_blocks);
557 	}
558 
559 	bdev_virtio_send_io(ch, bdev_io);
560 }
561 
562 static void
563 bdev_virtio_reset(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
564 {
565 	struct bdev_virtio_io_channel *virtio_ch = spdk_io_channel_get_ctx(ch);
566 	struct virtio_scsi_io_ctx *io_ctx = bdev_virtio_init_tmf_vreq(ch, bdev_io);
567 	struct virtio_scsi_ctrl_tmf_req *tmf_req = &io_ctx->tmf_req;
568 	struct virtio_scsi_dev *svdev = virtio_ch->svdev;
569 	size_t enqueued_count;
570 
571 	tmf_req->type = VIRTIO_SCSI_T_TMF;
572 	tmf_req->subtype = VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET;
573 
574 	enqueued_count = spdk_ring_enqueue(svdev->ctrlq_ring, (void **)&bdev_io, 1, NULL);
575 	if (spdk_likely(enqueued_count == 1)) {
576 		return;
577 	} else {
578 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_NOMEM);
579 	}
580 }
581 
582 static void
583 bdev_virtio_unmap(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io, bool success)
584 {
585 	struct virtio_scsi_io_ctx *io_ctx = bdev_virtio_init_io_vreq(ch, bdev_io);
586 	struct virtio_scsi_cmd_req *req = &io_ctx->req;
587 	struct spdk_scsi_unmap_bdesc *desc, *first_desc;
588 	uint8_t *buf;
589 	uint64_t offset_blocks, num_blocks;
590 	uint16_t cmd_len;
591 
592 	if (!success) {
593 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
594 		return;
595 	}
596 
597 	buf = bdev_io->u.bdev.iovs[0].iov_base;
598 
599 	offset_blocks = bdev_io->u.bdev.offset_blocks;
600 	num_blocks = bdev_io->u.bdev.num_blocks;
601 
602 	/* (n-1) * 16-byte descriptors */
603 	first_desc = desc = (struct spdk_scsi_unmap_bdesc *)&buf[8];
604 	while (num_blocks > UINT32_MAX) {
605 		to_be64(&desc->lba, offset_blocks);
606 		to_be32(&desc->block_count, UINT32_MAX);
607 		memset(&desc->reserved, 0, sizeof(desc->reserved));
608 		offset_blocks += UINT32_MAX;
609 		num_blocks -= UINT32_MAX;
610 		desc++;
611 	}
612 
613 	/* The last descriptor with block_count <= UINT32_MAX */
614 	to_be64(&desc->lba, offset_blocks);
615 	to_be32(&desc->block_count, num_blocks);
616 	memset(&desc->reserved, 0, sizeof(desc->reserved));
617 
618 	/* 8-byte header + n * 16-byte block descriptor */
619 	cmd_len = 8 + (desc - first_desc + 1) *  sizeof(struct spdk_scsi_unmap_bdesc);
620 
621 	req->cdb[0] = SPDK_SBC_UNMAP;
622 	to_be16(&req->cdb[7], cmd_len);
623 
624 	/* 8-byte header */
625 	to_be16(&buf[0], cmd_len - 2); /* total length (excluding the length field) */
626 	to_be16(&buf[2], cmd_len - 8); /* length of block descriptors */
627 	memset(&buf[4], 0, 4); /* reserved */
628 
629 	bdev_virtio_send_io(ch, bdev_io);
630 }
631 
632 static void
633 bdev_virtio_get_buf_cb(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io,
634 		       bool success)
635 {
636 	if (!success) {
637 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
638 		return;
639 	}
640 
641 	bdev_virtio_rw(ch, bdev_io);
642 }
643 
644 static int _bdev_virtio_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
645 {
646 	struct virtio_scsi_disk *disk = SPDK_CONTAINEROF(bdev_io->bdev, struct virtio_scsi_disk, bdev);
647 
648 	switch (bdev_io->type) {
649 	case SPDK_BDEV_IO_TYPE_READ:
650 		spdk_bdev_io_get_buf(bdev_io, bdev_virtio_get_buf_cb,
651 				     bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen);
652 		return 0;
653 	case SPDK_BDEV_IO_TYPE_WRITE:
654 		bdev_virtio_rw(ch, bdev_io);
655 		return 0;
656 	case SPDK_BDEV_IO_TYPE_RESET:
657 		bdev_virtio_reset(ch, bdev_io);
658 		return 0;
659 	case SPDK_BDEV_IO_TYPE_UNMAP: {
660 		uint64_t buf_len = 8 /* header size */ +
661 				   (bdev_io->u.bdev.num_blocks + UINT32_MAX - 1) /
662 				   UINT32_MAX * sizeof(struct spdk_scsi_unmap_bdesc);
663 
664 		if (!disk->info.unmap_supported) {
665 			return -1;
666 		}
667 
668 		if (buf_len > SPDK_BDEV_LARGE_BUF_MAX_SIZE) {
669 			SPDK_ERRLOG("Trying to UNMAP too many blocks: %"PRIu64"\n",
670 				    bdev_io->u.bdev.num_blocks);
671 			return -1;
672 		}
673 		spdk_bdev_io_get_buf(bdev_io, bdev_virtio_unmap, buf_len);
674 		return 0;
675 	}
676 	case SPDK_BDEV_IO_TYPE_FLUSH:
677 	default:
678 		return -1;
679 	}
680 	return 0;
681 }
682 
683 static void bdev_virtio_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
684 {
685 	if (_bdev_virtio_submit_request(ch, bdev_io) < 0) {
686 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
687 	}
688 }
689 
690 static bool
691 bdev_virtio_io_type_supported(void *ctx, enum spdk_bdev_io_type io_type)
692 {
693 	struct virtio_scsi_disk *disk = ctx;
694 
695 	switch (io_type) {
696 	case SPDK_BDEV_IO_TYPE_READ:
697 	case SPDK_BDEV_IO_TYPE_WRITE:
698 	case SPDK_BDEV_IO_TYPE_FLUSH:
699 	case SPDK_BDEV_IO_TYPE_RESET:
700 		return true;
701 
702 	case SPDK_BDEV_IO_TYPE_UNMAP:
703 		return disk->info.unmap_supported;
704 
705 	default:
706 		return false;
707 	}
708 }
709 
710 static struct spdk_io_channel *
711 bdev_virtio_get_io_channel(void *ctx)
712 {
713 	struct virtio_scsi_disk *disk = ctx;
714 
715 	return spdk_get_io_channel(disk->svdev);
716 }
717 
718 static int
719 bdev_virtio_disk_destruct(void *ctx)
720 {
721 	struct virtio_scsi_disk *disk = ctx;
722 	struct virtio_scsi_dev *svdev = disk->svdev;
723 
724 	TAILQ_REMOVE(&svdev->luns, disk, link);
725 	free(disk->bdev.name);
726 	free(disk);
727 
728 	if (svdev->removed && TAILQ_EMPTY(&svdev->luns)) {
729 		spdk_io_device_unregister(svdev, virtio_scsi_dev_unregister_cb);
730 	}
731 
732 	return 0;
733 }
734 
735 static int
736 bdev_virtio_dump_info_json(void *ctx, struct spdk_json_write_ctx *w)
737 {
738 	struct virtio_scsi_disk *disk = ctx;
739 
740 	virtio_dev_dump_json_info(&disk->svdev->vdev, w);
741 	return 0;
742 }
743 
744 static void
745 bdev_virtio_write_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w)
746 {
747 	/* SCSI targets and LUNS are discovered during scan process so nothing
748 	 * to save here.
749 	 */
750 }
751 
752 static const struct spdk_bdev_fn_table virtio_fn_table = {
753 	.destruct		= bdev_virtio_disk_destruct,
754 	.submit_request		= bdev_virtio_submit_request,
755 	.io_type_supported	= bdev_virtio_io_type_supported,
756 	.get_io_channel		= bdev_virtio_get_io_channel,
757 	.dump_info_json		= bdev_virtio_dump_info_json,
758 	.write_config_json	= bdev_virtio_write_config_json,
759 };
760 
761 static void
762 get_scsi_status(struct virtio_scsi_cmd_resp *resp, int *sk, int *asc, int *ascq)
763 {
764 	/* see spdk_scsi_task_build_sense_data() for sense data details */
765 	*sk = 0;
766 	*asc = 0;
767 	*ascq = 0;
768 
769 	if (resp->sense_len < 3) {
770 		return;
771 	}
772 
773 	*sk = resp->sense[2] & 0xf;
774 
775 	if (resp->sense_len < 13) {
776 		return;
777 	}
778 
779 	*asc = resp->sense[12];
780 
781 	if (resp->sense_len < 14) {
782 		return;
783 	}
784 
785 	*ascq = resp->sense[13];
786 }
787 
788 static void
789 bdev_virtio_io_cpl(struct spdk_bdev_io *bdev_io)
790 {
791 	struct virtio_scsi_io_ctx *io_ctx = (struct virtio_scsi_io_ctx *)bdev_io->driver_ctx;
792 	int sk, asc, ascq;
793 
794 	get_scsi_status(&io_ctx->resp, &sk, &asc, &ascq);
795 	spdk_bdev_io_complete_scsi_status(bdev_io, io_ctx->resp.status, sk, asc, ascq);
796 }
797 
798 static int
799 bdev_virtio_poll(void *arg)
800 {
801 	struct bdev_virtio_io_channel *ch = arg;
802 	struct virtio_scsi_dev *svdev = ch->svdev;
803 	struct virtio_scsi_scan_base *scan_ctx = svdev->scan_ctx;
804 	void *io[32];
805 	uint32_t io_len[32];
806 	uint16_t i, cnt;
807 	int rc;
808 
809 	cnt = virtio_recv_pkts(ch->vq, (void **)io, io_len, SPDK_COUNTOF(io));
810 	for (i = 0; i < cnt; ++i) {
811 		if (spdk_unlikely(scan_ctx && io[i] == &scan_ctx->io_ctx)) {
812 			if (svdev->removed) {
813 				_virtio_scsi_dev_scan_finish(scan_ctx, -EINTR);
814 				return SPDK_POLLER_BUSY;
815 			}
816 
817 			if (scan_ctx->restart) {
818 				scan_ctx->restart = false;
819 				scan_ctx->full_scan = true;
820 				_virtio_scsi_dev_scan_tgt(scan_ctx, 0);
821 				continue;
822 			}
823 
824 			process_scan_resp(scan_ctx);
825 			continue;
826 		}
827 
828 		bdev_virtio_io_cpl(io[i]);
829 	}
830 
831 	if (spdk_unlikely(scan_ctx && scan_ctx->needs_resend)) {
832 		if (svdev->removed) {
833 			_virtio_scsi_dev_scan_finish(scan_ctx, -EINTR);
834 			return SPDK_POLLER_BUSY;
835 		} else if (cnt == 0) {
836 			return SPDK_POLLER_IDLE;
837 		}
838 
839 		rc = send_scan_io(scan_ctx);
840 		if (rc != 0) {
841 			assert(scan_ctx->retries > 0);
842 			scan_ctx->retries--;
843 			if (scan_ctx->retries == 0) {
844 				SPDK_ERRLOG("Target scan failed unrecoverably with rc = %d.\n", rc);
845 				_virtio_scsi_dev_scan_finish(scan_ctx, rc);
846 			}
847 		}
848 	}
849 
850 	return cnt;
851 }
852 
853 static void
854 bdev_virtio_tmf_cpl_cb(void *ctx)
855 {
856 	struct spdk_bdev_io *bdev_io = ctx;
857 	struct virtio_scsi_io_ctx *io_ctx = (struct virtio_scsi_io_ctx *)bdev_io->driver_ctx;
858 
859 	if (io_ctx->tmf_resp.response == VIRTIO_SCSI_S_OK) {
860 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_SUCCESS);
861 	} else {
862 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
863 	}
864 }
865 
866 static void
867 bdev_virtio_tmf_cpl(struct spdk_bdev_io *bdev_io)
868 {
869 	spdk_thread_send_msg(spdk_bdev_io_get_thread(bdev_io), bdev_virtio_tmf_cpl_cb, bdev_io);
870 }
871 
872 static void
873 bdev_virtio_eventq_io_cpl(struct virtio_scsi_dev *svdev, struct virtio_scsi_eventq_io *io)
874 {
875 	struct virtio_scsi_event *ev = &io->ev;
876 	struct virtio_scsi_disk *disk;
877 
878 	if (ev->lun[0] != 1) {
879 		SPDK_WARNLOG("Received an event with invalid data layout.\n");
880 		goto out;
881 	}
882 
883 	if (ev->event & VIRTIO_SCSI_T_EVENTS_MISSED) {
884 		ev->event &= ~VIRTIO_SCSI_T_EVENTS_MISSED;
885 		virtio_scsi_dev_scan(svdev, NULL, NULL);
886 	}
887 
888 	switch (ev->event) {
889 	case VIRTIO_SCSI_T_NO_EVENT:
890 		break;
891 	case VIRTIO_SCSI_T_TRANSPORT_RESET:
892 		switch (ev->reason) {
893 		case VIRTIO_SCSI_EVT_RESET_RESCAN:
894 			virtio_scsi_dev_scan_tgt(svdev, ev->lun[1]);
895 			break;
896 		case VIRTIO_SCSI_EVT_RESET_REMOVED:
897 			disk = virtio_scsi_dev_get_disk_by_id(svdev, ev->lun[1]);
898 			if (disk != NULL) {
899 				spdk_bdev_unregister(&disk->bdev, NULL, NULL);
900 			}
901 			break;
902 		default:
903 			break;
904 		}
905 		break;
906 	default:
907 		break;
908 	}
909 
910 out:
911 	virtio_scsi_dev_send_eventq_io(svdev->vdev.vqs[VIRTIO_SCSI_EVENTQ], io);
912 }
913 
914 static void
915 bdev_virtio_tmf_abort_nomem_cb(void *ctx)
916 {
917 	struct spdk_bdev_io *bdev_io = ctx;
918 
919 	spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_NOMEM);
920 }
921 
922 static void
923 bdev_virtio_tmf_abort_ioerr_cb(void *ctx)
924 {
925 	struct spdk_bdev_io *bdev_io = ctx;
926 
927 	spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
928 }
929 
930 static void
931 bdev_virtio_tmf_abort(struct spdk_bdev_io *bdev_io, int status)
932 {
933 	spdk_msg_fn fn;
934 
935 	if (status == -ENOMEM) {
936 		fn = bdev_virtio_tmf_abort_nomem_cb;
937 	} else {
938 		fn = bdev_virtio_tmf_abort_ioerr_cb;
939 	}
940 
941 	spdk_thread_send_msg(spdk_bdev_io_get_thread(bdev_io), fn, bdev_io);
942 }
943 
944 static int
945 bdev_virtio_send_tmf_io(struct virtqueue *ctrlq, struct spdk_bdev_io *bdev_io)
946 {
947 	struct virtio_scsi_io_ctx *io_ctx = (struct virtio_scsi_io_ctx *)bdev_io->driver_ctx;
948 	int rc;
949 
950 	rc = virtqueue_req_start(ctrlq, bdev_io, 2);
951 	if (rc != 0) {
952 		return rc;
953 	}
954 
955 	virtqueue_req_add_iovs(ctrlq, &io_ctx->iov_req, 1, SPDK_VIRTIO_DESC_RO);
956 	virtqueue_req_add_iovs(ctrlq, &io_ctx->iov_resp, 1, SPDK_VIRTIO_DESC_WR);
957 
958 	virtqueue_req_flush(ctrlq);
959 	return 0;
960 }
961 
962 static int
963 bdev_virtio_mgmt_poll(void *arg)
964 {
965 	struct virtio_scsi_dev *svdev = arg;
966 	struct virtio_dev *vdev = &svdev->vdev;
967 	struct virtqueue *eventq = vdev->vqs[VIRTIO_SCSI_EVENTQ];
968 	struct virtqueue *ctrlq = vdev->vqs[VIRTIO_SCSI_CONTROLQ];
969 	struct spdk_ring *send_ring = svdev->ctrlq_ring;
970 	void *io[16];
971 	uint32_t io_len[16];
972 	uint16_t i, cnt;
973 	int rc;
974 	int total = 0;
975 
976 	cnt = spdk_ring_dequeue(send_ring, io, SPDK_COUNTOF(io));
977 	total += cnt;
978 	for (i = 0; i < cnt; ++i) {
979 		rc = bdev_virtio_send_tmf_io(ctrlq, io[i]);
980 		if (rc != 0) {
981 			bdev_virtio_tmf_abort(io[i], rc);
982 		}
983 	}
984 
985 	cnt = virtio_recv_pkts(ctrlq, io, io_len, SPDK_COUNTOF(io));
986 	total += cnt;
987 	for (i = 0; i < cnt; ++i) {
988 		bdev_virtio_tmf_cpl(io[i]);
989 	}
990 
991 	cnt = virtio_recv_pkts(eventq, io, io_len, SPDK_COUNTOF(io));
992 	total += cnt;
993 	for (i = 0; i < cnt; ++i) {
994 		bdev_virtio_eventq_io_cpl(svdev, io[i]);
995 	}
996 
997 	return total;
998 }
999 
1000 static int
1001 bdev_virtio_scsi_ch_create_cb(void *io_device, void *ctx_buf)
1002 {
1003 	struct virtio_scsi_dev *svdev = io_device;
1004 	struct virtio_dev *vdev = &svdev->vdev;
1005 	struct bdev_virtio_io_channel *ch = ctx_buf;
1006 	struct virtqueue *vq;
1007 	int32_t queue_idx;
1008 
1009 	queue_idx = virtio_dev_find_and_acquire_queue(vdev, VIRTIO_SCSI_REQUESTQ);
1010 	if (queue_idx < 0) {
1011 		SPDK_ERRLOG("Couldn't get an unused queue for the io_channel.\n");
1012 		return -1;
1013 	}
1014 
1015 	vq = vdev->vqs[queue_idx];
1016 
1017 	ch->svdev = svdev;
1018 	ch->vq = vq;
1019 
1020 	ch->poller = SPDK_POLLER_REGISTER(bdev_virtio_poll, ch, 0);
1021 
1022 	return 0;
1023 }
1024 
1025 static void
1026 bdev_virtio_scsi_ch_destroy_cb(void *io_device, void *ctx_buf)
1027 {
1028 	struct bdev_virtio_io_channel *ch = ctx_buf;
1029 	struct virtio_scsi_dev *svdev = ch->svdev;
1030 	struct virtio_dev *vdev = &svdev->vdev;
1031 	struct virtqueue *vq = ch->vq;
1032 
1033 	spdk_poller_unregister(&ch->poller);
1034 	virtio_dev_release_queue(vdev, vq->vq_queue_index);
1035 }
1036 
1037 static void
1038 _virtio_scsi_dev_scan_finish(struct virtio_scsi_scan_base *base, int errnum)
1039 {
1040 	struct virtio_scsi_dev *svdev = base->svdev;
1041 	size_t bdevs_cnt;
1042 	struct spdk_bdev *bdevs[BDEV_VIRTIO_MAX_TARGET];
1043 	struct virtio_scsi_disk *disk;
1044 	struct virtio_scsi_scan_info *tgt, *next_tgt;
1045 
1046 	spdk_put_io_channel(spdk_io_channel_from_ctx(base->channel));
1047 	base->svdev->scan_ctx = NULL;
1048 
1049 	TAILQ_FOREACH_SAFE(tgt, &base->scan_queue, tailq, next_tgt) {
1050 		TAILQ_REMOVE(&base->scan_queue, tgt, tailq);
1051 		free(tgt);
1052 	}
1053 
1054 	if (base->cb_fn == NULL) {
1055 		spdk_free(base);
1056 		return;
1057 	}
1058 
1059 	bdevs_cnt = 0;
1060 	if (errnum == 0) {
1061 		TAILQ_FOREACH(disk, &svdev->luns, link) {
1062 			bdevs[bdevs_cnt] = &disk->bdev;
1063 			bdevs_cnt++;
1064 		}
1065 	}
1066 
1067 	base->cb_fn(base->cb_arg, errnum, bdevs, bdevs_cnt);
1068 	spdk_free(base);
1069 }
1070 
1071 static int
1072 send_scan_io(struct virtio_scsi_scan_base *base)
1073 {
1074 	struct virtio_scsi_io_ctx *io_ctx = &base->io_ctx;
1075 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1076 	struct virtqueue *vq = base->channel->vq;
1077 	int payload_iov_cnt = base->iov.iov_len > 0 ? 1 : 0;
1078 	int rc;
1079 
1080 	req->lun[0] = 1;
1081 	req->lun[1] = base->info.target;
1082 
1083 	rc = virtqueue_req_start(vq, io_ctx, 2 + payload_iov_cnt);
1084 	if (rc != 0) {
1085 		base->needs_resend = true;
1086 		return -1;
1087 	}
1088 
1089 	virtqueue_req_add_iovs(vq, &io_ctx->iov_req, 1, SPDK_VIRTIO_DESC_RO);
1090 	virtqueue_req_add_iovs(vq, &io_ctx->iov_resp, 1, SPDK_VIRTIO_DESC_WR);
1091 	virtqueue_req_add_iovs(vq, &base->iov, payload_iov_cnt, SPDK_VIRTIO_DESC_WR);
1092 
1093 	virtqueue_req_flush(vq);
1094 	return 0;
1095 }
1096 
1097 static int
1098 send_inquiry(struct virtio_scsi_scan_base *base)
1099 {
1100 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1101 	struct spdk_scsi_cdb_inquiry *cdb;
1102 
1103 	memset(req, 0, sizeof(*req));
1104 
1105 	base->iov.iov_len = BDEV_VIRTIO_SCAN_PAYLOAD_SIZE;
1106 	cdb = (struct spdk_scsi_cdb_inquiry *)req->cdb;
1107 	cdb->opcode = SPDK_SPC_INQUIRY;
1108 	to_be16(cdb->alloc_len, BDEV_VIRTIO_SCAN_PAYLOAD_SIZE);
1109 
1110 	return send_scan_io(base);
1111 }
1112 
1113 static int
1114 send_inquiry_vpd(struct virtio_scsi_scan_base *base, uint8_t page_code)
1115 {
1116 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1117 	struct spdk_scsi_cdb_inquiry *inquiry_cdb = (struct spdk_scsi_cdb_inquiry *)req->cdb;
1118 
1119 	memset(req, 0, sizeof(*req));
1120 
1121 	base->iov.iov_len = BDEV_VIRTIO_SCAN_PAYLOAD_SIZE;
1122 	inquiry_cdb->opcode = SPDK_SPC_INQUIRY;
1123 	inquiry_cdb->evpd = 1;
1124 	inquiry_cdb->page_code = page_code;
1125 	to_be16(inquiry_cdb->alloc_len, base->iov.iov_len);
1126 
1127 	return send_scan_io(base);
1128 }
1129 
1130 static int
1131 send_read_cap_10(struct virtio_scsi_scan_base *base)
1132 {
1133 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1134 
1135 	memset(req, 0, sizeof(*req));
1136 
1137 	base->iov.iov_len = 8;
1138 	req->cdb[0] = SPDK_SBC_READ_CAPACITY_10;
1139 
1140 	return send_scan_io(base);
1141 }
1142 
1143 static int
1144 send_read_cap_16(struct virtio_scsi_scan_base *base)
1145 {
1146 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1147 
1148 	memset(req, 0, sizeof(*req));
1149 
1150 	base->iov.iov_len = 32;
1151 	req->cdb[0] = SPDK_SPC_SERVICE_ACTION_IN_16;
1152 	req->cdb[1] = SPDK_SBC_SAI_READ_CAPACITY_16;
1153 	to_be32(&req->cdb[10], base->iov.iov_len);
1154 
1155 	return send_scan_io(base);
1156 }
1157 
1158 static int
1159 send_test_unit_ready(struct virtio_scsi_scan_base *base)
1160 {
1161 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1162 
1163 	memset(req, 0, sizeof(*req));
1164 	req->cdb[0] = SPDK_SPC_TEST_UNIT_READY;
1165 	base->iov.iov_len = 0;
1166 
1167 	return send_scan_io(base);
1168 }
1169 
1170 static int
1171 send_start_stop_unit(struct virtio_scsi_scan_base *base)
1172 {
1173 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1174 
1175 	memset(req, 0, sizeof(*req));
1176 	req->cdb[0] = SPDK_SBC_START_STOP_UNIT;
1177 	req->cdb[4] = SPDK_SBC_START_STOP_UNIT_START_BIT;
1178 	base->iov.iov_len = 0;
1179 
1180 	return send_scan_io(base);
1181 }
1182 
1183 static int
1184 process_scan_start_stop_unit(struct virtio_scsi_scan_base *base)
1185 {
1186 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1187 
1188 	if (resp->status == SPDK_SCSI_STATUS_GOOD) {
1189 		return send_inquiry_vpd(base, SPDK_SPC_VPD_SUPPORTED_VPD_PAGES);
1190 	}
1191 
1192 	return -1;
1193 }
1194 
1195 static int
1196 process_scan_test_unit_ready(struct virtio_scsi_scan_base *base)
1197 {
1198 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1199 	int sk, asc, ascq;
1200 
1201 	get_scsi_status(resp, &sk, &asc, &ascq);
1202 
1203 	/* check response, get VPD if spun up otherwise send SSU */
1204 	if (resp->status == SPDK_SCSI_STATUS_GOOD) {
1205 		return send_inquiry_vpd(base, SPDK_SPC_VPD_SUPPORTED_VPD_PAGES);
1206 	} else if (resp->response == VIRTIO_SCSI_S_OK &&
1207 		   resp->status == SPDK_SCSI_STATUS_CHECK_CONDITION &&
1208 		   sk == SPDK_SCSI_SENSE_UNIT_ATTENTION &&
1209 		   asc == SPDK_SCSI_ASC_LOGICAL_UNIT_NOT_READY) {
1210 		return send_start_stop_unit(base);
1211 	} else {
1212 		return -1;
1213 	}
1214 }
1215 
1216 static int
1217 process_scan_inquiry_standard(struct virtio_scsi_scan_base *base)
1218 {
1219 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1220 	struct spdk_scsi_cdb_inquiry_data *inquiry_data =
1221 		(struct spdk_scsi_cdb_inquiry_data *)base->payload;
1222 
1223 	if (resp->status != SPDK_SCSI_STATUS_GOOD) {
1224 		return -1;
1225 	}
1226 
1227 	/* check to make sure its a supported device */
1228 	if (inquiry_data->peripheral_device_type != SPDK_SPC_PERIPHERAL_DEVICE_TYPE_DISK ||
1229 	    inquiry_data->peripheral_qualifier != SPDK_SPC_PERIPHERAL_QUALIFIER_CONNECTED) {
1230 		SPDK_WARNLOG("Unsupported peripheral device type 0x%02x (qualifier 0x%02x)\n",
1231 			     inquiry_data->peripheral_device_type,
1232 			     inquiry_data->peripheral_qualifier);
1233 		return -1;
1234 	}
1235 
1236 	return send_test_unit_ready(base);
1237 }
1238 
1239 static int
1240 process_scan_inquiry_vpd_supported_vpd_pages(struct virtio_scsi_scan_base *base)
1241 {
1242 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1243 	bool block_provisioning_page_supported = false;
1244 
1245 	if (resp->status == SPDK_SCSI_STATUS_GOOD) {
1246 		const uint8_t *vpd_data = base->payload;
1247 		const uint8_t *supported_vpd_pages = vpd_data + 4;
1248 		uint16_t page_length;
1249 		uint16_t num_supported_pages;
1250 		uint16_t i;
1251 
1252 		page_length = from_be16(vpd_data + 2);
1253 		num_supported_pages = spdk_min(page_length, base->iov.iov_len - 4);
1254 
1255 		for (i = 0; i < num_supported_pages; i++) {
1256 			if (supported_vpd_pages[i] == SPDK_SPC_VPD_BLOCK_THIN_PROVISION) {
1257 				block_provisioning_page_supported = true;
1258 				break;
1259 			}
1260 		}
1261 	}
1262 
1263 	if (block_provisioning_page_supported) {
1264 		return send_inquiry_vpd(base, SPDK_SPC_VPD_BLOCK_THIN_PROVISION);
1265 	} else {
1266 		return send_read_cap_10(base);
1267 	}
1268 }
1269 
1270 static int
1271 process_scan_inquiry_vpd_block_thin_provision(struct virtio_scsi_scan_base *base)
1272 {
1273 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1274 
1275 	base->info.unmap_supported = false;
1276 
1277 	if (resp->status == SPDK_SCSI_STATUS_GOOD) {
1278 		uint8_t *vpd_data = base->payload;
1279 
1280 		base->info.unmap_supported = !!(vpd_data[5] & SPDK_SCSI_UNMAP_LBPU);
1281 	}
1282 
1283 	SPDK_INFOLOG(virtio, "Target %u: unmap supported = %d\n",
1284 		     base->info.target, (int)base->info.unmap_supported);
1285 
1286 	return send_read_cap_10(base);
1287 }
1288 
1289 static int
1290 process_scan_inquiry(struct virtio_scsi_scan_base *base)
1291 {
1292 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1293 	struct spdk_scsi_cdb_inquiry *inquiry_cdb = (struct spdk_scsi_cdb_inquiry *)req->cdb;
1294 
1295 	if ((inquiry_cdb->evpd & 1) == 0) {
1296 		return process_scan_inquiry_standard(base);
1297 	}
1298 
1299 	switch (inquiry_cdb->page_code) {
1300 	case SPDK_SPC_VPD_SUPPORTED_VPD_PAGES:
1301 		return process_scan_inquiry_vpd_supported_vpd_pages(base);
1302 	case SPDK_SPC_VPD_BLOCK_THIN_PROVISION:
1303 		return process_scan_inquiry_vpd_block_thin_provision(base);
1304 	default:
1305 		SPDK_DEBUGLOG(virtio, "Unexpected VPD page 0x%02x\n", inquiry_cdb->page_code);
1306 		return -1;
1307 	}
1308 }
1309 
1310 static void
1311 bdev_virtio_disk_notify_remove(struct virtio_scsi_disk *disk)
1312 {
1313 	disk->removed = true;
1314 	spdk_bdev_close(disk->notify_desc);
1315 }
1316 
1317 static void
1318 bdev_virtio_disk_notify_event_cb(enum spdk_bdev_event_type type, struct spdk_bdev *bdev,
1319 				 void *event_ctx)
1320 {
1321 	switch (type) {
1322 	case SPDK_BDEV_EVENT_REMOVE:
1323 		bdev_virtio_disk_notify_remove(event_ctx);
1324 		break;
1325 	default:
1326 		SPDK_NOTICELOG("Unsupported bdev event: type %d\n", type);
1327 		break;
1328 	}
1329 }
1330 
1331 /* To be called only from the thread performing target scan */
1332 static int
1333 virtio_scsi_dev_add_tgt(struct virtio_scsi_dev *svdev, struct virtio_scsi_scan_info *info)
1334 {
1335 	struct virtio_scsi_disk *disk;
1336 	struct spdk_bdev *bdev;
1337 	int rc;
1338 
1339 	TAILQ_FOREACH(disk, &svdev->luns, link) {
1340 		if (disk->info.target == info->target) {
1341 			/* Target is already attached and param change is not supported */
1342 			return 0;
1343 		}
1344 	}
1345 
1346 	if (info->block_size == 0 || info->num_blocks == 0) {
1347 		SPDK_ERRLOG("%s: invalid target %u: bs=%"PRIu32" blocks=%"PRIu64"\n",
1348 			    svdev->vdev.name, info->target, info->block_size, info->num_blocks);
1349 		return -EINVAL;
1350 	}
1351 
1352 	disk = calloc(1, sizeof(*disk));
1353 	if (disk == NULL) {
1354 		SPDK_ERRLOG("could not allocate disk\n");
1355 		return -ENOMEM;
1356 	}
1357 
1358 	disk->svdev = svdev;
1359 	memcpy(&disk->info, info, sizeof(*info));
1360 
1361 	bdev = &disk->bdev;
1362 	bdev->name = spdk_sprintf_alloc("%st%"PRIu8, svdev->vdev.name, info->target);
1363 	if (bdev->name == NULL) {
1364 		SPDK_ERRLOG("Couldn't alloc memory for the bdev name.\n");
1365 		free(disk);
1366 		return -ENOMEM;
1367 	}
1368 
1369 	bdev->product_name = "Virtio SCSI Disk";
1370 	bdev->write_cache = 0;
1371 	bdev->blocklen = disk->info.block_size;
1372 	bdev->blockcnt = disk->info.num_blocks;
1373 
1374 	bdev->ctxt = disk;
1375 	bdev->fn_table = &virtio_fn_table;
1376 	bdev->module = &virtio_scsi_if;
1377 
1378 	rc = spdk_bdev_register(&disk->bdev);
1379 	if (rc) {
1380 		SPDK_ERRLOG("Failed to register bdev name=%s\n", disk->bdev.name);
1381 		free(bdev->name);
1382 		free(disk);
1383 		return rc;
1384 	}
1385 
1386 	rc = spdk_bdev_open_ext(bdev->name, false, bdev_virtio_disk_notify_event_cb,
1387 				disk, &disk->notify_desc);
1388 	if (rc) {
1389 		assert(false);
1390 	}
1391 
1392 	TAILQ_INSERT_TAIL(&svdev->luns, disk, link);
1393 	return 0;
1394 }
1395 
1396 static int
1397 process_read_cap_10(struct virtio_scsi_scan_base *base)
1398 {
1399 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1400 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1401 	uint64_t max_block;
1402 	uint32_t block_size;
1403 	uint8_t target_id = req->lun[1];
1404 	int rc;
1405 
1406 	if (resp->response != VIRTIO_SCSI_S_OK || resp->status != SPDK_SCSI_STATUS_GOOD) {
1407 		SPDK_ERRLOG("READ CAPACITY (10) failed for target %"PRIu8".\n", target_id);
1408 		return -1;
1409 	}
1410 
1411 	block_size = from_be32(base->payload + 4);
1412 	max_block = from_be32(base->payload);
1413 
1414 	if (max_block == 0xffffffff) {
1415 		return send_read_cap_16(base);
1416 	}
1417 
1418 	base->info.num_blocks = (uint64_t)max_block + 1;
1419 	base->info.block_size = block_size;
1420 
1421 	rc = virtio_scsi_dev_add_tgt(base->svdev, &base->info);
1422 	if (rc != 0) {
1423 		return rc;
1424 	}
1425 
1426 	return _virtio_scsi_dev_scan_next(base, 0);
1427 }
1428 
1429 static int
1430 process_read_cap_16(struct virtio_scsi_scan_base *base)
1431 {
1432 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1433 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1434 	uint8_t target_id = req->lun[1];
1435 	int rc;
1436 
1437 	if (resp->response != VIRTIO_SCSI_S_OK || resp->status != SPDK_SCSI_STATUS_GOOD) {
1438 		SPDK_ERRLOG("READ CAPACITY (16) failed for target %"PRIu8".\n", target_id);
1439 		return -1;
1440 	}
1441 
1442 	base->info.num_blocks = from_be64(base->payload) + 1;
1443 	base->info.block_size = from_be32(base->payload + 8);
1444 	rc = virtio_scsi_dev_add_tgt(base->svdev, &base->info);
1445 	if (rc != 0) {
1446 		return rc;
1447 	}
1448 
1449 	return _virtio_scsi_dev_scan_next(base, 0);
1450 }
1451 
1452 static void
1453 process_scan_resp(struct virtio_scsi_scan_base *base)
1454 {
1455 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1456 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1457 	int rc, sk, asc, ascq;
1458 	uint8_t target_id;
1459 
1460 	if (base->io_ctx.iov_req.iov_len < sizeof(struct virtio_scsi_cmd_req) ||
1461 	    base->io_ctx.iov_resp.iov_len < sizeof(struct virtio_scsi_cmd_resp)) {
1462 		SPDK_ERRLOG("Received target scan message with invalid length.\n");
1463 		_virtio_scsi_dev_scan_next(base, -EIO);
1464 		return;
1465 	}
1466 
1467 	get_scsi_status(resp, &sk, &asc, &ascq);
1468 	target_id = req->lun[1];
1469 
1470 	if (resp->response == VIRTIO_SCSI_S_BAD_TARGET ||
1471 	    resp->response == VIRTIO_SCSI_S_INCORRECT_LUN) {
1472 		_virtio_scsi_dev_scan_next(base, -ENODEV);
1473 		return;
1474 	}
1475 
1476 	if (resp->response != VIRTIO_SCSI_S_OK ||
1477 	    (resp->status == SPDK_SCSI_STATUS_CHECK_CONDITION &&
1478 	     sk != SPDK_SCSI_SENSE_ILLEGAL_REQUEST)) {
1479 		assert(base->retries > 0);
1480 		base->retries--;
1481 		if (base->retries == 0) {
1482 			SPDK_NOTICELOG("Target %"PRIu8" is present, but unavailable.\n", target_id);
1483 			SPDK_LOGDUMP(virtio, "CDB", req->cdb, sizeof(req->cdb));
1484 			SPDK_LOGDUMP(virtio, "SENSE DATA", resp->sense, sizeof(resp->sense));
1485 			_virtio_scsi_dev_scan_next(base, -EBUSY);
1486 			return;
1487 		}
1488 
1489 		/* resend the same request */
1490 		rc = send_scan_io(base);
1491 		if (rc != 0) {
1492 			/* Let response poller do the resend */
1493 		}
1494 		return;
1495 	}
1496 
1497 	base->retries = SCAN_REQUEST_RETRIES;
1498 
1499 	switch (req->cdb[0]) {
1500 	case SPDK_SPC_INQUIRY:
1501 		rc = process_scan_inquiry(base);
1502 		break;
1503 	case SPDK_SPC_TEST_UNIT_READY:
1504 		rc = process_scan_test_unit_ready(base);
1505 		break;
1506 	case SPDK_SBC_START_STOP_UNIT:
1507 		rc = process_scan_start_stop_unit(base);
1508 		break;
1509 	case SPDK_SBC_READ_CAPACITY_10:
1510 		rc = process_read_cap_10(base);
1511 		break;
1512 	case SPDK_SPC_SERVICE_ACTION_IN_16:
1513 		rc = process_read_cap_16(base);
1514 		break;
1515 	default:
1516 		SPDK_ERRLOG("Received invalid target scan message: cdb[0] = %"PRIu8".\n", req->cdb[0]);
1517 		rc = -1;
1518 		break;
1519 	}
1520 
1521 	if (rc != 0) {
1522 		if (base->needs_resend) {
1523 			return; /* Let response poller do the resend */
1524 		}
1525 
1526 		_virtio_scsi_dev_scan_next(base, rc);
1527 	}
1528 }
1529 
1530 static int
1531 _virtio_scsi_dev_scan_next(struct virtio_scsi_scan_base *base, int rc)
1532 {
1533 	struct virtio_scsi_scan_info *next;
1534 	struct virtio_scsi_disk *disk;
1535 	uint8_t target_id;
1536 
1537 	if (base->full_scan) {
1538 		if (rc != 0) {
1539 			disk = virtio_scsi_dev_get_disk_by_id(base->svdev,
1540 							      base->info.target);
1541 			if (disk != NULL) {
1542 				spdk_bdev_unregister(&disk->bdev, NULL, NULL);
1543 			}
1544 		}
1545 
1546 		target_id = base->info.target + 1;
1547 		if (target_id < BDEV_VIRTIO_MAX_TARGET) {
1548 			_virtio_scsi_dev_scan_tgt(base, target_id);
1549 			return 0;
1550 		}
1551 
1552 		base->full_scan = false;
1553 	}
1554 
1555 	next = TAILQ_FIRST(&base->scan_queue);
1556 	if (next == NULL) {
1557 		_virtio_scsi_dev_scan_finish(base, 0);
1558 		return 0;
1559 	}
1560 
1561 	TAILQ_REMOVE(&base->scan_queue, next, tailq);
1562 	target_id = next->target;
1563 	free(next);
1564 
1565 	_virtio_scsi_dev_scan_tgt(base, target_id);
1566 	return 0;
1567 }
1568 
1569 static int
1570 _virtio_scsi_dev_scan_init(struct virtio_scsi_dev *svdev)
1571 {
1572 	struct virtio_scsi_scan_base *base;
1573 	struct spdk_io_channel *io_ch;
1574 	struct virtio_scsi_io_ctx *io_ctx;
1575 	struct virtio_scsi_cmd_req *req;
1576 	struct virtio_scsi_cmd_resp *resp;
1577 
1578 	io_ch = spdk_get_io_channel(svdev);
1579 	if (io_ch == NULL) {
1580 		return -EBUSY;
1581 	}
1582 
1583 	base = spdk_zmalloc(sizeof(*base), 64, NULL,
1584 			    SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
1585 	if (base == NULL) {
1586 		SPDK_ERRLOG("couldn't allocate memory for scsi target scan.\n");
1587 		return -ENOMEM;
1588 	}
1589 
1590 	base->svdev = svdev;
1591 
1592 	base->channel = spdk_io_channel_get_ctx(io_ch);
1593 	TAILQ_INIT(&base->scan_queue);
1594 	svdev->scan_ctx = base;
1595 
1596 	base->iov.iov_base = base->payload;
1597 	io_ctx = &base->io_ctx;
1598 	req = &io_ctx->req;
1599 	resp = &io_ctx->resp;
1600 	io_ctx->iov_req.iov_base = req;
1601 	io_ctx->iov_req.iov_len = sizeof(*req);
1602 	io_ctx->iov_resp.iov_base = resp;
1603 	io_ctx->iov_resp.iov_len = sizeof(*resp);
1604 
1605 	base->retries = SCAN_REQUEST_RETRIES;
1606 	return 0;
1607 }
1608 
1609 static void
1610 _virtio_scsi_dev_scan_tgt(struct virtio_scsi_scan_base *base, uint8_t target)
1611 {
1612 	int rc;
1613 
1614 	memset(&base->info, 0, sizeof(base->info));
1615 	base->info.target = target;
1616 
1617 	rc = send_inquiry(base);
1618 	if (rc) {
1619 		/* Let response poller do the resend */
1620 	}
1621 }
1622 
1623 static int
1624 virtio_scsi_dev_scan(struct virtio_scsi_dev *svdev, bdev_virtio_create_cb cb_fn,
1625 		     void *cb_arg)
1626 {
1627 	struct virtio_scsi_scan_base *base;
1628 	struct virtio_scsi_scan_info *tgt, *next_tgt;
1629 	int rc;
1630 
1631 	if (svdev->scan_ctx) {
1632 		if (svdev->scan_ctx->full_scan) {
1633 			return -EEXIST;
1634 		}
1635 
1636 		/* We're about to start a full rescan, so there's no need
1637 		 * to scan particular targets afterwards.
1638 		 */
1639 		TAILQ_FOREACH_SAFE(tgt, &svdev->scan_ctx->scan_queue, tailq, next_tgt) {
1640 			TAILQ_REMOVE(&svdev->scan_ctx->scan_queue, tgt, tailq);
1641 			free(tgt);
1642 		}
1643 
1644 		svdev->scan_ctx->cb_fn = cb_fn;
1645 		svdev->scan_ctx->cb_arg = cb_arg;
1646 		svdev->scan_ctx->restart = true;
1647 		return 0;
1648 	}
1649 
1650 	rc = _virtio_scsi_dev_scan_init(svdev);
1651 	if (rc != 0) {
1652 		return rc;
1653 	}
1654 
1655 	base = svdev->scan_ctx;
1656 	base->cb_fn = cb_fn;
1657 	base->cb_arg = cb_arg;
1658 	base->full_scan = true;
1659 
1660 	_virtio_scsi_dev_scan_tgt(base, 0);
1661 	return 0;
1662 }
1663 
1664 static int
1665 virtio_scsi_dev_scan_tgt(struct virtio_scsi_dev *svdev, uint8_t target)
1666 {
1667 	struct virtio_scsi_scan_base *base;
1668 	struct virtio_scsi_scan_info *info;
1669 	int rc;
1670 
1671 	base = svdev->scan_ctx;
1672 	if (base) {
1673 		info = calloc(1, sizeof(*info));
1674 		if (info == NULL) {
1675 			SPDK_ERRLOG("calloc failed\n");
1676 			return -ENOMEM;
1677 		}
1678 
1679 		info->target = target;
1680 		TAILQ_INSERT_TAIL(&base->scan_queue, info, tailq);
1681 		return 0;
1682 	}
1683 
1684 	rc = _virtio_scsi_dev_scan_init(svdev);
1685 	if (rc != 0) {
1686 		return rc;
1687 	}
1688 
1689 	base = svdev->scan_ctx;
1690 	base->full_scan = true;
1691 	_virtio_scsi_dev_scan_tgt(base, target);
1692 	return 0;
1693 }
1694 
1695 static int
1696 bdev_virtio_initialize(void)
1697 {
1698 	return 0;
1699 }
1700 
1701 static void
1702 _virtio_scsi_dev_unregister_cb(void *io_device)
1703 {
1704 	struct virtio_scsi_dev *svdev = io_device;
1705 	struct virtio_dev *vdev = &svdev->vdev;
1706 	bool finish_module;
1707 	bdev_virtio_remove_cb remove_cb;
1708 	void *remove_ctx;
1709 
1710 	assert(spdk_ring_count(svdev->ctrlq_ring) == 0);
1711 	spdk_ring_free(svdev->ctrlq_ring);
1712 	spdk_poller_unregister(&svdev->mgmt_poller);
1713 
1714 	virtio_dev_release_queue(vdev, VIRTIO_SCSI_EVENTQ);
1715 	virtio_dev_release_queue(vdev, VIRTIO_SCSI_CONTROLQ);
1716 
1717 	virtio_dev_stop(vdev);
1718 	virtio_dev_destruct(vdev);
1719 
1720 	pthread_mutex_lock(&g_virtio_scsi_mutex);
1721 	TAILQ_REMOVE(&g_virtio_scsi_devs, svdev, tailq);
1722 	pthread_mutex_unlock(&g_virtio_scsi_mutex);
1723 
1724 	remove_cb = svdev->remove_cb;
1725 	remove_ctx = svdev->remove_ctx;
1726 	spdk_free(svdev->eventq_ios);
1727 	free(svdev);
1728 
1729 	if (remove_cb) {
1730 		remove_cb(remove_ctx, 0);
1731 	}
1732 
1733 	finish_module = TAILQ_EMPTY(&g_virtio_scsi_devs);
1734 
1735 	if (g_bdev_virtio_finish && finish_module) {
1736 		spdk_bdev_module_finish_done();
1737 	}
1738 }
1739 
1740 static void
1741 virtio_scsi_dev_unregister_cb(void *io_device)
1742 {
1743 	struct virtio_scsi_dev *svdev = io_device;
1744 	struct spdk_thread *thread;
1745 
1746 	thread = virtio_dev_queue_get_thread(&svdev->vdev, VIRTIO_SCSI_CONTROLQ);
1747 	spdk_thread_send_msg(thread, _virtio_scsi_dev_unregister_cb, io_device);
1748 }
1749 
1750 static void
1751 virtio_scsi_dev_remove(struct virtio_scsi_dev *svdev,
1752 		       bdev_virtio_remove_cb cb_fn, void *cb_arg)
1753 {
1754 	struct virtio_scsi_disk *disk, *disk_tmp;
1755 	bool do_remove = true;
1756 
1757 	if (svdev->removed) {
1758 		if (cb_fn) {
1759 			cb_fn(cb_arg, -EBUSY);
1760 		}
1761 		return;
1762 	}
1763 
1764 	svdev->remove_cb = cb_fn;
1765 	svdev->remove_ctx = cb_arg;
1766 	svdev->removed = true;
1767 
1768 	if (svdev->scan_ctx) {
1769 		/* The removal will continue after we receive a pending scan I/O. */
1770 		return;
1771 	}
1772 
1773 	TAILQ_FOREACH_SAFE(disk, &svdev->luns, link, disk_tmp) {
1774 		if (!disk->removed) {
1775 			spdk_bdev_unregister(&disk->bdev, NULL, NULL);
1776 		}
1777 		do_remove = false;
1778 	}
1779 
1780 	if (do_remove) {
1781 		spdk_io_device_unregister(svdev, virtio_scsi_dev_unregister_cb);
1782 	}
1783 }
1784 
1785 static void
1786 bdev_virtio_finish(void)
1787 {
1788 	struct virtio_scsi_dev *svdev, *next;
1789 
1790 	g_bdev_virtio_finish = true;
1791 
1792 	pthread_mutex_lock(&g_virtio_scsi_mutex);
1793 	if (TAILQ_EMPTY(&g_virtio_scsi_devs)) {
1794 		pthread_mutex_unlock(&g_virtio_scsi_mutex);
1795 		spdk_bdev_module_finish_done();
1796 		return;
1797 	}
1798 
1799 	/* Defer module finish until all controllers are removed. */
1800 	TAILQ_FOREACH_SAFE(svdev, &g_virtio_scsi_devs, tailq, next) {
1801 		virtio_scsi_dev_remove(svdev, NULL, NULL);
1802 	}
1803 	pthread_mutex_unlock(&g_virtio_scsi_mutex);
1804 }
1805 
1806 int
1807 bdev_virtio_user_scsi_dev_create(const char *base_name, const char *path,
1808 				 unsigned num_queues, unsigned queue_size,
1809 				 bdev_virtio_create_cb cb_fn, void *cb_arg)
1810 {
1811 	struct virtio_scsi_dev *svdev;
1812 	int rc;
1813 
1814 	svdev = virtio_user_scsi_dev_create(base_name, path, num_queues, queue_size);
1815 	if (svdev == NULL) {
1816 		return -1;
1817 	}
1818 
1819 	rc = virtio_scsi_dev_scan(svdev, cb_fn, cb_arg);
1820 	if (rc) {
1821 		virtio_scsi_dev_remove(svdev, NULL, NULL);
1822 	}
1823 
1824 	return rc;
1825 }
1826 
1827 struct bdev_virtio_pci_dev_create_ctx {
1828 	const char *name;
1829 	bdev_virtio_create_cb cb_fn;
1830 	void *cb_arg;
1831 };
1832 
1833 static int
1834 bdev_virtio_pci_scsi_dev_create_cb(struct virtio_pci_ctx *pci_ctx, void *ctx)
1835 {
1836 	struct virtio_scsi_dev *svdev;
1837 	struct bdev_virtio_pci_dev_create_ctx *create_ctx = ctx;
1838 	int rc;
1839 
1840 	svdev = virtio_pci_scsi_dev_create(create_ctx->name, pci_ctx);
1841 	if (svdev == NULL) {
1842 		return -1;
1843 	}
1844 
1845 	rc = virtio_scsi_dev_scan(svdev, create_ctx->cb_fn, create_ctx->cb_arg);
1846 	if (rc) {
1847 		svdev->vdev.ctx = NULL;
1848 		virtio_scsi_dev_remove(svdev, NULL, NULL);
1849 	}
1850 
1851 	return rc;
1852 }
1853 
1854 int
1855 bdev_virtio_pci_scsi_dev_create(const char *name, struct spdk_pci_addr *pci_addr,
1856 				bdev_virtio_create_cb cb_fn, void *cb_arg)
1857 {
1858 	struct bdev_virtio_pci_dev_create_ctx create_ctx;
1859 
1860 	create_ctx.name = name;
1861 	create_ctx.cb_fn = cb_fn;
1862 	create_ctx.cb_arg = cb_arg;
1863 
1864 	return virtio_pci_dev_attach(bdev_virtio_pci_scsi_dev_create_cb, &create_ctx,
1865 				     PCI_DEVICE_ID_VIRTIO_SCSI_MODERN, pci_addr);
1866 }
1867 
1868 int
1869 bdev_virtio_scsi_dev_remove(const char *name, bdev_virtio_remove_cb cb_fn, void *cb_arg)
1870 {
1871 	struct virtio_scsi_dev *svdev;
1872 
1873 	pthread_mutex_lock(&g_virtio_scsi_mutex);
1874 	TAILQ_FOREACH(svdev, &g_virtio_scsi_devs, tailq) {
1875 		if (strcmp(svdev->vdev.name, name) == 0) {
1876 			break;
1877 		}
1878 	}
1879 
1880 	if (svdev == NULL) {
1881 		pthread_mutex_unlock(&g_virtio_scsi_mutex);
1882 		SPDK_ERRLOG("Cannot find Virtio-SCSI device named '%s'\n", name);
1883 		return -ENODEV;
1884 	}
1885 
1886 	virtio_scsi_dev_remove(svdev, cb_fn, cb_arg);
1887 	pthread_mutex_unlock(&g_virtio_scsi_mutex);
1888 
1889 	return 0;
1890 }
1891 
1892 void
1893 bdev_virtio_scsi_dev_list(struct spdk_json_write_ctx *w)
1894 {
1895 	struct virtio_scsi_dev *svdev;
1896 
1897 	spdk_json_write_array_begin(w);
1898 
1899 	pthread_mutex_lock(&g_virtio_scsi_mutex);
1900 	TAILQ_FOREACH(svdev, &g_virtio_scsi_devs, tailq) {
1901 		spdk_json_write_object_begin(w);
1902 
1903 		spdk_json_write_named_string(w, "name", svdev->vdev.name);
1904 
1905 		virtio_dev_dump_json_info(&svdev->vdev, w);
1906 
1907 		spdk_json_write_object_end(w);
1908 	}
1909 	pthread_mutex_unlock(&g_virtio_scsi_mutex);
1910 
1911 	spdk_json_write_array_end(w);
1912 }
1913 
1914 SPDK_LOG_REGISTER_COMPONENT(virtio)
1915