xref: /spdk/module/bdev/virtio/bdev_virtio_scsi.c (revision 927f1fd57bd004df581518466ec4c1b8083e5d23)
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 #include <linux/virtio_ids.h>
52 
53 #include "bdev_virtio.h"
54 
55 #define BDEV_VIRTIO_MAX_TARGET 64
56 #define BDEV_VIRTIO_SCAN_PAYLOAD_SIZE 256
57 #define MGMT_POLL_PERIOD_US (1000 * 5)
58 #define CTRLQ_RING_SIZE 16
59 #define SCAN_REQUEST_RETRIES 5
60 
61 /* Number of non-request queues - eventq and controlq */
62 #define SPDK_VIRTIO_SCSI_QUEUE_NUM_FIXED 2
63 
64 #define VIRTIO_SCSI_EVENTQ_BUFFER_COUNT 16
65 
66 #define VIRTIO_SCSI_CONTROLQ	0
67 #define VIRTIO_SCSI_EVENTQ	1
68 #define VIRTIO_SCSI_REQUESTQ	2
69 
70 static int bdev_virtio_initialize(void);
71 static void bdev_virtio_finish(void);
72 
73 struct virtio_scsi_dev {
74 	/* Generic virtio device data. */
75 	struct virtio_dev		vdev;
76 
77 	/** Detected SCSI LUNs */
78 	TAILQ_HEAD(, virtio_scsi_disk)	luns;
79 
80 	/** Context for the SCSI target scan. */
81 	struct virtio_scsi_scan_base	*scan_ctx;
82 
83 	/** Controlq poller. */
84 	struct spdk_poller		*mgmt_poller;
85 
86 	/** Controlq messages to be sent. */
87 	struct spdk_ring		*ctrlq_ring;
88 
89 	/** Buffers for the eventq. */
90 	struct virtio_scsi_eventq_io	*eventq_ios;
91 
92 	/** Device marked for removal. */
93 	bool				removed;
94 
95 	/** Callback to be called after vdev removal. */
96 	bdev_virtio_remove_cb		remove_cb;
97 
98 	/** Context for the `remove_cb`. */
99 	void				*remove_ctx;
100 
101 	TAILQ_ENTRY(virtio_scsi_dev) tailq;
102 };
103 
104 struct virtio_scsi_io_ctx {
105 	struct iovec			iov_req;
106 	struct iovec			iov_resp;
107 	union {
108 		struct virtio_scsi_cmd_req req;
109 		struct virtio_scsi_ctrl_tmf_req tmf_req;
110 	};
111 	union {
112 		struct virtio_scsi_cmd_resp resp;
113 		struct virtio_scsi_ctrl_tmf_resp tmf_resp;
114 	};
115 };
116 
117 struct virtio_scsi_eventq_io {
118 	struct iovec			iov;
119 	struct virtio_scsi_event	ev;
120 };
121 
122 struct virtio_scsi_scan_info {
123 	uint64_t			num_blocks;
124 	uint32_t			block_size;
125 	uint8_t				target;
126 	bool				unmap_supported;
127 	TAILQ_ENTRY(virtio_scsi_scan_info) tailq;
128 };
129 
130 struct virtio_scsi_scan_base {
131 	struct virtio_scsi_dev		*svdev;
132 
133 	/** I/O channel used for the scan I/O. */
134 	struct bdev_virtio_io_channel	*channel;
135 
136 	bdev_virtio_create_cb		cb_fn;
137 	void				*cb_arg;
138 
139 	/** Scan all targets on the device. */
140 	bool				full_scan;
141 
142 	/** Start a full rescan after receiving next scan I/O response. */
143 	bool				restart;
144 
145 	/** Additional targets to be (re)scanned. */
146 	TAILQ_HEAD(, virtio_scsi_scan_info) scan_queue;
147 
148 	/** Remaining attempts for sending the current request. */
149 	unsigned                        retries;
150 
151 	/** If set, the last scan I/O needs to be resent */
152 	bool				needs_resend;
153 
154 	struct virtio_scsi_io_ctx	io_ctx;
155 	struct iovec			iov;
156 	uint8_t				payload[BDEV_VIRTIO_SCAN_PAYLOAD_SIZE];
157 
158 	/** Scan results for the current target. */
159 	struct virtio_scsi_scan_info	info;
160 };
161 
162 struct virtio_scsi_disk {
163 	struct spdk_bdev		bdev;
164 	struct virtio_scsi_dev		*svdev;
165 	struct virtio_scsi_scan_info	info;
166 
167 	/** Descriptor opened just to be notified of external bdev hotremove. */
168 	struct spdk_bdev_desc		*notify_desc;
169 
170 	/** Disk marked for removal. */
171 	bool				removed;
172 	TAILQ_ENTRY(virtio_scsi_disk)	link;
173 };
174 
175 struct bdev_virtio_io_channel {
176 	struct virtio_scsi_dev	*svdev;
177 
178 	/** Virtqueue exclusively assigned to this channel. */
179 	struct virtqueue	*vq;
180 
181 	/** Virtio response poller. */
182 	struct spdk_poller	*poller;
183 };
184 
185 static TAILQ_HEAD(, virtio_scsi_dev) g_virtio_scsi_devs =
186 	TAILQ_HEAD_INITIALIZER(g_virtio_scsi_devs);
187 
188 static pthread_mutex_t g_virtio_scsi_mutex = PTHREAD_MUTEX_INITIALIZER;
189 
190 /** Module finish in progress */
191 static bool g_bdev_virtio_finish = false;
192 
193 /* Features desired/implemented by this driver. */
194 #define VIRTIO_SCSI_DEV_SUPPORTED_FEATURES		\
195 	(1ULL << VIRTIO_SCSI_F_INOUT		|	\
196 	 1ULL << VIRTIO_SCSI_F_HOTPLUG		|	\
197 	 1ULL << VIRTIO_RING_F_EVENT_IDX	|	\
198 	 1ULL << VHOST_USER_F_PROTOCOL_FEATURES)
199 
200 static void virtio_scsi_dev_unregister_cb(void *io_device);
201 static void virtio_scsi_dev_remove(struct virtio_scsi_dev *svdev,
202 				   bdev_virtio_remove_cb cb_fn, void *cb_arg);
203 static int bdev_virtio_scsi_ch_create_cb(void *io_device, void *ctx_buf);
204 static void bdev_virtio_scsi_ch_destroy_cb(void *io_device, void *ctx_buf);
205 static void process_scan_resp(struct virtio_scsi_scan_base *base);
206 static int bdev_virtio_mgmt_poll(void *arg);
207 
208 static int
209 virtio_scsi_dev_send_eventq_io(struct virtqueue *vq, struct virtio_scsi_eventq_io *io)
210 {
211 	int rc;
212 
213 	rc = virtqueue_req_start(vq, io, 1);
214 	if (rc != 0) {
215 		return -1;
216 	}
217 
218 	virtqueue_req_add_iovs(vq, &io->iov, 1, SPDK_VIRTIO_DESC_WR);
219 	virtqueue_req_flush(vq);
220 
221 	return 0;
222 }
223 
224 static int
225 virtio_scsi_dev_init(struct virtio_scsi_dev *svdev, uint16_t max_queues)
226 {
227 	struct virtio_dev *vdev = &svdev->vdev;
228 	struct spdk_ring *ctrlq_ring;
229 	struct virtio_scsi_eventq_io *eventq_io;
230 	struct virtqueue *eventq;
231 	uint16_t i, num_events;
232 	int rc;
233 
234 	rc = virtio_dev_reset(vdev, VIRTIO_SCSI_DEV_SUPPORTED_FEATURES);
235 	if (rc != 0) {
236 		return rc;
237 	}
238 
239 	rc = virtio_dev_start(vdev, max_queues, SPDK_VIRTIO_SCSI_QUEUE_NUM_FIXED);
240 	if (rc != 0) {
241 		return rc;
242 	}
243 
244 	ctrlq_ring = spdk_ring_create(SPDK_RING_TYPE_MP_SC, CTRLQ_RING_SIZE,
245 				      SPDK_ENV_SOCKET_ID_ANY);
246 	if (ctrlq_ring == NULL) {
247 		SPDK_ERRLOG("Failed to allocate send ring for the controlq.\n");
248 		return -1;
249 	}
250 
251 	rc = virtio_dev_acquire_queue(vdev, VIRTIO_SCSI_CONTROLQ);
252 	if (rc != 0) {
253 		SPDK_ERRLOG("Failed to acquire the controlq.\n");
254 		spdk_ring_free(ctrlq_ring);
255 		return -1;
256 	}
257 
258 	rc = virtio_dev_acquire_queue(vdev, VIRTIO_SCSI_EVENTQ);
259 	if (rc != 0) {
260 		SPDK_ERRLOG("Failed to acquire the eventq.\n");
261 		virtio_dev_release_queue(vdev, VIRTIO_SCSI_CONTROLQ);
262 		spdk_ring_free(ctrlq_ring);
263 		return -1;
264 	}
265 
266 	eventq = vdev->vqs[VIRTIO_SCSI_EVENTQ];
267 	num_events = spdk_min(eventq->vq_nentries, VIRTIO_SCSI_EVENTQ_BUFFER_COUNT);
268 	svdev->eventq_ios = spdk_zmalloc(sizeof(*svdev->eventq_ios) * num_events,
269 					 0, NULL, SPDK_ENV_LCORE_ID_ANY,
270 					 SPDK_MALLOC_DMA);
271 	if (svdev->eventq_ios == NULL) {
272 		SPDK_ERRLOG("cannot allocate memory for %"PRIu16" eventq buffers\n",
273 			    num_events);
274 		virtio_dev_release_queue(vdev, VIRTIO_SCSI_EVENTQ);
275 		virtio_dev_release_queue(vdev, VIRTIO_SCSI_CONTROLQ);
276 		spdk_ring_free(ctrlq_ring);
277 		return -1;
278 	}
279 
280 	for (i = 0; i < num_events; i++) {
281 		eventq_io = &svdev->eventq_ios[i];
282 		eventq_io->iov.iov_base = &eventq_io->ev;
283 		eventq_io->iov.iov_len = sizeof(eventq_io->ev);
284 		virtio_scsi_dev_send_eventq_io(eventq, eventq_io);
285 	}
286 
287 	svdev->ctrlq_ring = ctrlq_ring;
288 
289 	svdev->mgmt_poller = SPDK_POLLER_REGISTER(bdev_virtio_mgmt_poll, svdev,
290 			     MGMT_POLL_PERIOD_US);
291 
292 	TAILQ_INIT(&svdev->luns);
293 	svdev->scan_ctx = NULL;
294 	svdev->removed = false;
295 	svdev->remove_cb = NULL;
296 	svdev->remove_ctx = NULL;
297 
298 	spdk_io_device_register(svdev, bdev_virtio_scsi_ch_create_cb,
299 				bdev_virtio_scsi_ch_destroy_cb,
300 				sizeof(struct bdev_virtio_io_channel),
301 				svdev->vdev.name);
302 
303 	pthread_mutex_lock(&g_virtio_scsi_mutex);
304 	TAILQ_INSERT_TAIL(&g_virtio_scsi_devs, svdev, tailq);
305 	pthread_mutex_unlock(&g_virtio_scsi_mutex);
306 	return 0;
307 }
308 
309 static struct virtio_scsi_dev *
310 virtio_pci_scsi_dev_create(const char *name, struct virtio_pci_ctx *pci_ctx)
311 {
312 	static int pci_dev_counter = 0;
313 	struct virtio_scsi_dev *svdev;
314 	struct virtio_dev *vdev;
315 	char *default_name = NULL;
316 	uint32_t num_queues;
317 	int rc;
318 
319 	svdev = calloc(1, sizeof(*svdev));
320 	if (svdev == NULL) {
321 		SPDK_ERRLOG("virtio device calloc failed\n");
322 		return NULL;
323 	}
324 
325 	vdev = &svdev->vdev;
326 	if (name == NULL) {
327 		default_name = spdk_sprintf_alloc("VirtioScsi%"PRIu32, pci_dev_counter++);
328 		if (default_name == NULL) {
329 			free(vdev);
330 			return NULL;
331 		}
332 		name = default_name;
333 	}
334 
335 	rc = virtio_pci_dev_init(vdev, name, pci_ctx);
336 	free(default_name);
337 
338 	if (rc != 0) {
339 		free(svdev);
340 		return NULL;
341 	}
342 
343 	rc = virtio_dev_read_dev_config(vdev, offsetof(struct virtio_scsi_config, num_queues),
344 					&num_queues, sizeof(num_queues));
345 	if (rc) {
346 		SPDK_ERRLOG("%s: config read failed: %s\n", vdev->name, spdk_strerror(-rc));
347 		goto fail;
348 	}
349 
350 	rc = virtio_scsi_dev_init(svdev, num_queues);
351 	if (rc != 0) {
352 		goto fail;
353 	}
354 
355 	return svdev;
356 
357 fail:
358 	vdev->ctx = NULL;
359 	virtio_dev_destruct(vdev);
360 	free(svdev);
361 	return NULL;
362 }
363 
364 static struct virtio_scsi_dev *
365 virtio_user_scsi_dev_create(const char *name, const char *path,
366 			    uint16_t num_queues, uint32_t queue_size)
367 {
368 	struct virtio_scsi_dev *svdev;
369 	struct virtio_dev *vdev;
370 	int rc;
371 
372 	svdev = calloc(1, sizeof(*svdev));
373 	if (svdev == NULL) {
374 		SPDK_ERRLOG("calloc failed for virtio device %s: %s\n", name, path);
375 		return NULL;
376 	}
377 
378 	vdev = &svdev->vdev;
379 	rc = virtio_user_dev_init(vdev, name, path, queue_size);
380 	if (rc != 0) {
381 		SPDK_ERRLOG("Failed to create virito device %s: %s\n", name, path);
382 		free(svdev);
383 		return NULL;
384 	}
385 
386 	rc = virtio_scsi_dev_init(svdev, num_queues);
387 	if (rc != 0) {
388 		virtio_dev_destruct(vdev);
389 		free(svdev);
390 		return NULL;
391 	}
392 
393 	return svdev;
394 }
395 
396 static struct virtio_scsi_disk *
397 virtio_scsi_dev_get_disk_by_id(struct virtio_scsi_dev *svdev, uint8_t target_id)
398 {
399 	struct virtio_scsi_disk *disk;
400 
401 	TAILQ_FOREACH(disk, &svdev->luns, link) {
402 		if (disk->info.target == target_id) {
403 			return disk;
404 		}
405 	}
406 
407 	return NULL;
408 }
409 
410 static int virtio_scsi_dev_scan(struct virtio_scsi_dev *svdev,
411 				bdev_virtio_create_cb cb_fn, void *cb_arg);
412 static int send_scan_io(struct virtio_scsi_scan_base *base);
413 static void _virtio_scsi_dev_scan_tgt(struct virtio_scsi_scan_base *base, uint8_t target);
414 static int _virtio_scsi_dev_scan_next(struct virtio_scsi_scan_base *base, int rc);
415 static void _virtio_scsi_dev_scan_finish(struct virtio_scsi_scan_base *base, int errnum);
416 static int virtio_scsi_dev_scan_tgt(struct virtio_scsi_dev *svdev, uint8_t target);
417 
418 static int
419 bdev_virtio_get_ctx_size(void)
420 {
421 	return sizeof(struct virtio_scsi_io_ctx);
422 }
423 
424 static int
425 bdev_virtio_scsi_config_json(struct spdk_json_write_ctx *w)
426 {
427 	struct virtio_scsi_dev *svdev;
428 
429 	pthread_mutex_lock(&g_virtio_scsi_mutex);
430 	TAILQ_FOREACH(svdev, &g_virtio_scsi_devs, tailq) {
431 		spdk_json_write_object_begin(w);
432 
433 		spdk_json_write_named_string(w, "method", "bdev_virtio_attach_controller");
434 
435 		spdk_json_write_named_object_begin(w, "params");
436 		spdk_json_write_named_string(w, "name", svdev->vdev.name);
437 		spdk_json_write_named_string(w, "dev_type", "scsi");
438 
439 		/* Write transport specific parameters. */
440 		svdev->vdev.backend_ops->write_json_config(&svdev->vdev, w);
441 
442 		spdk_json_write_object_end(w);
443 
444 		spdk_json_write_object_end(w);
445 
446 	}
447 	pthread_mutex_unlock(&g_virtio_scsi_mutex);
448 
449 	return 0;
450 }
451 
452 
453 static struct spdk_bdev_module virtio_scsi_if = {
454 	.name = "virtio_scsi",
455 	.module_init = bdev_virtio_initialize,
456 	.module_fini = bdev_virtio_finish,
457 	.get_ctx_size = bdev_virtio_get_ctx_size,
458 	.config_json = bdev_virtio_scsi_config_json,
459 	.async_fini = true,
460 };
461 
462 SPDK_BDEV_MODULE_REGISTER(virtio_scsi, &virtio_scsi_if)
463 
464 static struct virtio_scsi_io_ctx *
465 bdev_virtio_init_io_vreq(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
466 {
467 	struct virtio_scsi_cmd_req *req;
468 	struct virtio_scsi_cmd_resp *resp;
469 	struct virtio_scsi_disk *disk = (struct virtio_scsi_disk *)bdev_io->bdev;
470 	struct virtio_scsi_io_ctx *io_ctx = (struct virtio_scsi_io_ctx *)bdev_io->driver_ctx;
471 
472 	req = &io_ctx->req;
473 	resp = &io_ctx->resp;
474 
475 	io_ctx->iov_req.iov_base = req;
476 	io_ctx->iov_req.iov_len = sizeof(*req);
477 
478 	io_ctx->iov_resp.iov_base = resp;
479 	io_ctx->iov_resp.iov_len = sizeof(*resp);
480 
481 	memset(req, 0, sizeof(*req));
482 	req->lun[0] = 1;
483 	req->lun[1] = disk->info.target;
484 
485 	return io_ctx;
486 }
487 
488 static struct virtio_scsi_io_ctx *
489 bdev_virtio_init_tmf_vreq(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
490 {
491 	struct virtio_scsi_ctrl_tmf_req *tmf_req;
492 	struct virtio_scsi_ctrl_tmf_resp *tmf_resp;
493 	struct virtio_scsi_disk *disk = SPDK_CONTAINEROF(bdev_io->bdev, struct virtio_scsi_disk, bdev);
494 	struct virtio_scsi_io_ctx *io_ctx = (struct virtio_scsi_io_ctx *)bdev_io->driver_ctx;
495 
496 	tmf_req = &io_ctx->tmf_req;
497 	tmf_resp = &io_ctx->tmf_resp;
498 
499 	io_ctx->iov_req.iov_base = tmf_req;
500 	io_ctx->iov_req.iov_len = sizeof(*tmf_req);
501 	io_ctx->iov_resp.iov_base = tmf_resp;
502 	io_ctx->iov_resp.iov_len = sizeof(*tmf_resp);
503 
504 	memset(tmf_req, 0, sizeof(*tmf_req));
505 	tmf_req->lun[0] = 1;
506 	tmf_req->lun[1] = disk->info.target;
507 
508 	return io_ctx;
509 }
510 
511 static void
512 bdev_virtio_send_io(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
513 {
514 	struct bdev_virtio_io_channel *virtio_channel = spdk_io_channel_get_ctx(ch);
515 	struct virtqueue *vq = virtio_channel->vq;
516 	struct virtio_scsi_io_ctx *io_ctx = (struct virtio_scsi_io_ctx *)bdev_io->driver_ctx;
517 	int rc;
518 
519 	rc = virtqueue_req_start(vq, bdev_io, bdev_io->u.bdev.iovcnt + 2);
520 	if (rc == -ENOMEM) {
521 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_NOMEM);
522 		return;
523 	} else if (rc != 0) {
524 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
525 		return;
526 	}
527 
528 	virtqueue_req_add_iovs(vq, &io_ctx->iov_req, 1, SPDK_VIRTIO_DESC_RO);
529 	if (bdev_io->type == SPDK_BDEV_IO_TYPE_READ) {
530 		virtqueue_req_add_iovs(vq, &io_ctx->iov_resp, 1, SPDK_VIRTIO_DESC_WR);
531 		virtqueue_req_add_iovs(vq, bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
532 				       SPDK_VIRTIO_DESC_WR);
533 	} else {
534 		virtqueue_req_add_iovs(vq, bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
535 				       SPDK_VIRTIO_DESC_RO);
536 		virtqueue_req_add_iovs(vq, &io_ctx->iov_resp, 1, SPDK_VIRTIO_DESC_WR);
537 	}
538 
539 	virtqueue_req_flush(vq);
540 }
541 
542 static void
543 bdev_virtio_rw(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
544 {
545 	struct virtio_scsi_disk *disk = SPDK_CONTAINEROF(bdev_io->bdev, struct virtio_scsi_disk, bdev);
546 	struct virtio_scsi_io_ctx *io_ctx = bdev_virtio_init_io_vreq(ch, bdev_io);
547 	struct virtio_scsi_cmd_req *req = &io_ctx->req;
548 	bool is_write = bdev_io->type == SPDK_BDEV_IO_TYPE_WRITE;
549 
550 	if (disk->info.num_blocks > (1ULL << 32)) {
551 		req->cdb[0] = is_write ? SPDK_SBC_WRITE_16 : SPDK_SBC_READ_16;
552 		to_be64(&req->cdb[2], bdev_io->u.bdev.offset_blocks);
553 		to_be32(&req->cdb[10], bdev_io->u.bdev.num_blocks);
554 	} else {
555 		req->cdb[0] = is_write ? SPDK_SBC_WRITE_10 : SPDK_SBC_READ_10;
556 		to_be32(&req->cdb[2], bdev_io->u.bdev.offset_blocks);
557 		to_be16(&req->cdb[7], bdev_io->u.bdev.num_blocks);
558 	}
559 
560 	bdev_virtio_send_io(ch, bdev_io);
561 }
562 
563 static void
564 bdev_virtio_reset(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
565 {
566 	struct bdev_virtio_io_channel *virtio_ch = spdk_io_channel_get_ctx(ch);
567 	struct virtio_scsi_io_ctx *io_ctx = bdev_virtio_init_tmf_vreq(ch, bdev_io);
568 	struct virtio_scsi_ctrl_tmf_req *tmf_req = &io_ctx->tmf_req;
569 	struct virtio_scsi_dev *svdev = virtio_ch->svdev;
570 	size_t enqueued_count;
571 
572 	tmf_req->type = VIRTIO_SCSI_T_TMF;
573 	tmf_req->subtype = VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET;
574 
575 	enqueued_count = spdk_ring_enqueue(svdev->ctrlq_ring, (void **)&bdev_io, 1, NULL);
576 	if (spdk_likely(enqueued_count == 1)) {
577 		return;
578 	} else {
579 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_NOMEM);
580 	}
581 }
582 
583 static void
584 bdev_virtio_unmap(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io, bool success)
585 {
586 	struct virtio_scsi_io_ctx *io_ctx = bdev_virtio_init_io_vreq(ch, bdev_io);
587 	struct virtio_scsi_cmd_req *req = &io_ctx->req;
588 	struct spdk_scsi_unmap_bdesc *desc, *first_desc;
589 	uint8_t *buf;
590 	uint64_t offset_blocks, num_blocks;
591 	uint16_t cmd_len;
592 
593 	if (!success) {
594 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
595 		return;
596 	}
597 
598 	buf = bdev_io->u.bdev.iovs[0].iov_base;
599 
600 	offset_blocks = bdev_io->u.bdev.offset_blocks;
601 	num_blocks = bdev_io->u.bdev.num_blocks;
602 
603 	/* (n-1) * 16-byte descriptors */
604 	first_desc = desc = (struct spdk_scsi_unmap_bdesc *)&buf[8];
605 	while (num_blocks > UINT32_MAX) {
606 		to_be64(&desc->lba, offset_blocks);
607 		to_be32(&desc->block_count, UINT32_MAX);
608 		memset(&desc->reserved, 0, sizeof(desc->reserved));
609 		offset_blocks += UINT32_MAX;
610 		num_blocks -= UINT32_MAX;
611 		desc++;
612 	}
613 
614 	/* The last descriptor with block_count <= UINT32_MAX */
615 	to_be64(&desc->lba, offset_blocks);
616 	to_be32(&desc->block_count, num_blocks);
617 	memset(&desc->reserved, 0, sizeof(desc->reserved));
618 
619 	/* 8-byte header + n * 16-byte block descriptor */
620 	cmd_len = 8 + (desc - first_desc + 1) *  sizeof(struct spdk_scsi_unmap_bdesc);
621 
622 	req->cdb[0] = SPDK_SBC_UNMAP;
623 	to_be16(&req->cdb[7], cmd_len);
624 
625 	/* 8-byte header */
626 	to_be16(&buf[0], cmd_len - 2); /* total length (excluding the length field) */
627 	to_be16(&buf[2], cmd_len - 8); /* length of block descriptors */
628 	memset(&buf[4], 0, 4); /* reserved */
629 
630 	bdev_virtio_send_io(ch, bdev_io);
631 }
632 
633 static void
634 bdev_virtio_get_buf_cb(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io,
635 		       bool success)
636 {
637 	if (!success) {
638 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
639 		return;
640 	}
641 
642 	bdev_virtio_rw(ch, bdev_io);
643 }
644 
645 static int _bdev_virtio_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
646 {
647 	struct virtio_scsi_disk *disk = SPDK_CONTAINEROF(bdev_io->bdev, struct virtio_scsi_disk, bdev);
648 
649 	switch (bdev_io->type) {
650 	case SPDK_BDEV_IO_TYPE_READ:
651 		spdk_bdev_io_get_buf(bdev_io, bdev_virtio_get_buf_cb,
652 				     bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen);
653 		return 0;
654 	case SPDK_BDEV_IO_TYPE_WRITE:
655 		bdev_virtio_rw(ch, bdev_io);
656 		return 0;
657 	case SPDK_BDEV_IO_TYPE_RESET:
658 		bdev_virtio_reset(ch, bdev_io);
659 		return 0;
660 	case SPDK_BDEV_IO_TYPE_UNMAP: {
661 		uint64_t buf_len = 8 /* header size */ +
662 				   (bdev_io->u.bdev.num_blocks + UINT32_MAX - 1) /
663 				   UINT32_MAX * sizeof(struct spdk_scsi_unmap_bdesc);
664 
665 		if (!disk->info.unmap_supported) {
666 			return -1;
667 		}
668 
669 		if (buf_len > SPDK_BDEV_LARGE_BUF_MAX_SIZE) {
670 			SPDK_ERRLOG("Trying to UNMAP too many blocks: %"PRIu64"\n",
671 				    bdev_io->u.bdev.num_blocks);
672 			return -1;
673 		}
674 		spdk_bdev_io_get_buf(bdev_io, bdev_virtio_unmap, buf_len);
675 		return 0;
676 	}
677 	case SPDK_BDEV_IO_TYPE_FLUSH:
678 	default:
679 		return -1;
680 	}
681 	return 0;
682 }
683 
684 static void bdev_virtio_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
685 {
686 	if (_bdev_virtio_submit_request(ch, bdev_io) < 0) {
687 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
688 	}
689 }
690 
691 static bool
692 bdev_virtio_io_type_supported(void *ctx, enum spdk_bdev_io_type io_type)
693 {
694 	struct virtio_scsi_disk *disk = ctx;
695 
696 	switch (io_type) {
697 	case SPDK_BDEV_IO_TYPE_READ:
698 	case SPDK_BDEV_IO_TYPE_WRITE:
699 	case SPDK_BDEV_IO_TYPE_FLUSH:
700 	case SPDK_BDEV_IO_TYPE_RESET:
701 		return true;
702 
703 	case SPDK_BDEV_IO_TYPE_UNMAP:
704 		return disk->info.unmap_supported;
705 
706 	default:
707 		return false;
708 	}
709 }
710 
711 static struct spdk_io_channel *
712 bdev_virtio_get_io_channel(void *ctx)
713 {
714 	struct virtio_scsi_disk *disk = ctx;
715 
716 	return spdk_get_io_channel(disk->svdev);
717 }
718 
719 static int
720 bdev_virtio_disk_destruct(void *ctx)
721 {
722 	struct virtio_scsi_disk *disk = ctx;
723 	struct virtio_scsi_dev *svdev = disk->svdev;
724 
725 	TAILQ_REMOVE(&svdev->luns, disk, link);
726 	free(disk->bdev.name);
727 	free(disk);
728 
729 	if (svdev->removed && TAILQ_EMPTY(&svdev->luns)) {
730 		spdk_io_device_unregister(svdev, virtio_scsi_dev_unregister_cb);
731 	}
732 
733 	return 0;
734 }
735 
736 static int
737 bdev_virtio_dump_info_json(void *ctx, struct spdk_json_write_ctx *w)
738 {
739 	struct virtio_scsi_disk *disk = ctx;
740 
741 	virtio_dev_dump_json_info(&disk->svdev->vdev, w);
742 	return 0;
743 }
744 
745 static void
746 bdev_virtio_write_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w)
747 {
748 	/* SCSI targets and LUNS are discovered during scan process so nothing
749 	 * to save here.
750 	 */
751 }
752 
753 static const struct spdk_bdev_fn_table virtio_fn_table = {
754 	.destruct		= bdev_virtio_disk_destruct,
755 	.submit_request		= bdev_virtio_submit_request,
756 	.io_type_supported	= bdev_virtio_io_type_supported,
757 	.get_io_channel		= bdev_virtio_get_io_channel,
758 	.dump_info_json		= bdev_virtio_dump_info_json,
759 	.write_config_json	= bdev_virtio_write_config_json,
760 };
761 
762 static void
763 get_scsi_status(struct virtio_scsi_cmd_resp *resp, int *sk, int *asc, int *ascq)
764 {
765 	/* see spdk_scsi_task_build_sense_data() for sense data details */
766 	*sk = 0;
767 	*asc = 0;
768 	*ascq = 0;
769 
770 	if (resp->sense_len < 3) {
771 		return;
772 	}
773 
774 	*sk = resp->sense[2] & 0xf;
775 
776 	if (resp->sense_len < 13) {
777 		return;
778 	}
779 
780 	*asc = resp->sense[12];
781 
782 	if (resp->sense_len < 14) {
783 		return;
784 	}
785 
786 	*ascq = resp->sense[13];
787 }
788 
789 static void
790 bdev_virtio_io_cpl(struct spdk_bdev_io *bdev_io)
791 {
792 	struct virtio_scsi_io_ctx *io_ctx = (struct virtio_scsi_io_ctx *)bdev_io->driver_ctx;
793 	int sk, asc, ascq;
794 
795 	get_scsi_status(&io_ctx->resp, &sk, &asc, &ascq);
796 	spdk_bdev_io_complete_scsi_status(bdev_io, io_ctx->resp.status, sk, asc, ascq);
797 }
798 
799 static int
800 bdev_virtio_poll(void *arg)
801 {
802 	struct bdev_virtio_io_channel *ch = arg;
803 	struct virtio_scsi_dev *svdev = ch->svdev;
804 	struct virtio_scsi_scan_base *scan_ctx = svdev->scan_ctx;
805 	void *io[32];
806 	uint32_t io_len[32];
807 	uint16_t i, cnt;
808 	int rc;
809 
810 	cnt = virtio_recv_pkts(ch->vq, (void **)io, io_len, SPDK_COUNTOF(io));
811 	for (i = 0; i < cnt; ++i) {
812 		if (spdk_unlikely(scan_ctx && io[i] == &scan_ctx->io_ctx)) {
813 			if (svdev->removed) {
814 				_virtio_scsi_dev_scan_finish(scan_ctx, -EINTR);
815 				return SPDK_POLLER_BUSY;
816 			}
817 
818 			if (scan_ctx->restart) {
819 				scan_ctx->restart = false;
820 				scan_ctx->full_scan = true;
821 				_virtio_scsi_dev_scan_tgt(scan_ctx, 0);
822 				continue;
823 			}
824 
825 			process_scan_resp(scan_ctx);
826 			continue;
827 		}
828 
829 		bdev_virtio_io_cpl(io[i]);
830 	}
831 
832 	if (spdk_unlikely(scan_ctx && scan_ctx->needs_resend)) {
833 		if (svdev->removed) {
834 			_virtio_scsi_dev_scan_finish(scan_ctx, -EINTR);
835 			return SPDK_POLLER_BUSY;
836 		} else if (cnt == 0) {
837 			return SPDK_POLLER_IDLE;
838 		}
839 
840 		rc = send_scan_io(scan_ctx);
841 		if (rc != 0) {
842 			assert(scan_ctx->retries > 0);
843 			scan_ctx->retries--;
844 			if (scan_ctx->retries == 0) {
845 				SPDK_ERRLOG("Target scan failed unrecoverably with rc = %d.\n", rc);
846 				_virtio_scsi_dev_scan_finish(scan_ctx, rc);
847 			}
848 		}
849 	}
850 
851 	return cnt;
852 }
853 
854 static void
855 bdev_virtio_tmf_cpl_cb(void *ctx)
856 {
857 	struct spdk_bdev_io *bdev_io = ctx;
858 	struct virtio_scsi_io_ctx *io_ctx = (struct virtio_scsi_io_ctx *)bdev_io->driver_ctx;
859 
860 	if (io_ctx->tmf_resp.response == VIRTIO_SCSI_S_OK) {
861 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_SUCCESS);
862 	} else {
863 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
864 	}
865 }
866 
867 static void
868 bdev_virtio_tmf_cpl(struct spdk_bdev_io *bdev_io)
869 {
870 	spdk_thread_send_msg(spdk_bdev_io_get_thread(bdev_io), bdev_virtio_tmf_cpl_cb, bdev_io);
871 }
872 
873 static void
874 bdev_virtio_eventq_io_cpl(struct virtio_scsi_dev *svdev, struct virtio_scsi_eventq_io *io)
875 {
876 	struct virtio_scsi_event *ev = &io->ev;
877 	struct virtio_scsi_disk *disk;
878 
879 	if (ev->lun[0] != 1) {
880 		SPDK_WARNLOG("Received an event with invalid data layout.\n");
881 		goto out;
882 	}
883 
884 	if (ev->event & VIRTIO_SCSI_T_EVENTS_MISSED) {
885 		ev->event &= ~VIRTIO_SCSI_T_EVENTS_MISSED;
886 		virtio_scsi_dev_scan(svdev, NULL, NULL);
887 	}
888 
889 	switch (ev->event) {
890 	case VIRTIO_SCSI_T_NO_EVENT:
891 		break;
892 	case VIRTIO_SCSI_T_TRANSPORT_RESET:
893 		switch (ev->reason) {
894 		case VIRTIO_SCSI_EVT_RESET_RESCAN:
895 			virtio_scsi_dev_scan_tgt(svdev, ev->lun[1]);
896 			break;
897 		case VIRTIO_SCSI_EVT_RESET_REMOVED:
898 			disk = virtio_scsi_dev_get_disk_by_id(svdev, ev->lun[1]);
899 			if (disk != NULL) {
900 				spdk_bdev_unregister(&disk->bdev, NULL, NULL);
901 			}
902 			break;
903 		default:
904 			break;
905 		}
906 		break;
907 	default:
908 		break;
909 	}
910 
911 out:
912 	virtio_scsi_dev_send_eventq_io(svdev->vdev.vqs[VIRTIO_SCSI_EVENTQ], io);
913 }
914 
915 static void
916 bdev_virtio_tmf_abort_nomem_cb(void *ctx)
917 {
918 	struct spdk_bdev_io *bdev_io = ctx;
919 
920 	spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_NOMEM);
921 }
922 
923 static void
924 bdev_virtio_tmf_abort_ioerr_cb(void *ctx)
925 {
926 	struct spdk_bdev_io *bdev_io = ctx;
927 
928 	spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
929 }
930 
931 static void
932 bdev_virtio_tmf_abort(struct spdk_bdev_io *bdev_io, int status)
933 {
934 	spdk_msg_fn fn;
935 
936 	if (status == -ENOMEM) {
937 		fn = bdev_virtio_tmf_abort_nomem_cb;
938 	} else {
939 		fn = bdev_virtio_tmf_abort_ioerr_cb;
940 	}
941 
942 	spdk_thread_send_msg(spdk_bdev_io_get_thread(bdev_io), fn, bdev_io);
943 }
944 
945 static int
946 bdev_virtio_send_tmf_io(struct virtqueue *ctrlq, struct spdk_bdev_io *bdev_io)
947 {
948 	struct virtio_scsi_io_ctx *io_ctx = (struct virtio_scsi_io_ctx *)bdev_io->driver_ctx;
949 	int rc;
950 
951 	rc = virtqueue_req_start(ctrlq, bdev_io, 2);
952 	if (rc != 0) {
953 		return rc;
954 	}
955 
956 	virtqueue_req_add_iovs(ctrlq, &io_ctx->iov_req, 1, SPDK_VIRTIO_DESC_RO);
957 	virtqueue_req_add_iovs(ctrlq, &io_ctx->iov_resp, 1, SPDK_VIRTIO_DESC_WR);
958 
959 	virtqueue_req_flush(ctrlq);
960 	return 0;
961 }
962 
963 static int
964 bdev_virtio_mgmt_poll(void *arg)
965 {
966 	struct virtio_scsi_dev *svdev = arg;
967 	struct virtio_dev *vdev = &svdev->vdev;
968 	struct virtqueue *eventq = vdev->vqs[VIRTIO_SCSI_EVENTQ];
969 	struct virtqueue *ctrlq = vdev->vqs[VIRTIO_SCSI_CONTROLQ];
970 	struct spdk_ring *send_ring = svdev->ctrlq_ring;
971 	void *io[16];
972 	uint32_t io_len[16];
973 	uint16_t i, cnt;
974 	int rc;
975 	int total = 0;
976 
977 	cnt = spdk_ring_dequeue(send_ring, io, SPDK_COUNTOF(io));
978 	total += cnt;
979 	for (i = 0; i < cnt; ++i) {
980 		rc = bdev_virtio_send_tmf_io(ctrlq, io[i]);
981 		if (rc != 0) {
982 			bdev_virtio_tmf_abort(io[i], rc);
983 		}
984 	}
985 
986 	cnt = virtio_recv_pkts(ctrlq, io, io_len, SPDK_COUNTOF(io));
987 	total += cnt;
988 	for (i = 0; i < cnt; ++i) {
989 		bdev_virtio_tmf_cpl(io[i]);
990 	}
991 
992 	cnt = virtio_recv_pkts(eventq, io, io_len, SPDK_COUNTOF(io));
993 	total += cnt;
994 	for (i = 0; i < cnt; ++i) {
995 		bdev_virtio_eventq_io_cpl(svdev, io[i]);
996 	}
997 
998 	return total;
999 }
1000 
1001 static int
1002 bdev_virtio_scsi_ch_create_cb(void *io_device, void *ctx_buf)
1003 {
1004 	struct virtio_scsi_dev *svdev = io_device;
1005 	struct virtio_dev *vdev = &svdev->vdev;
1006 	struct bdev_virtio_io_channel *ch = ctx_buf;
1007 	struct virtqueue *vq;
1008 	int32_t queue_idx;
1009 
1010 	queue_idx = virtio_dev_find_and_acquire_queue(vdev, VIRTIO_SCSI_REQUESTQ);
1011 	if (queue_idx < 0) {
1012 		SPDK_ERRLOG("Couldn't get an unused queue for the io_channel.\n");
1013 		return -1;
1014 	}
1015 
1016 	vq = vdev->vqs[queue_idx];
1017 
1018 	ch->svdev = svdev;
1019 	ch->vq = vq;
1020 
1021 	ch->poller = SPDK_POLLER_REGISTER(bdev_virtio_poll, ch, 0);
1022 
1023 	return 0;
1024 }
1025 
1026 static void
1027 bdev_virtio_scsi_ch_destroy_cb(void *io_device, void *ctx_buf)
1028 {
1029 	struct bdev_virtio_io_channel *ch = ctx_buf;
1030 	struct virtio_scsi_dev *svdev = ch->svdev;
1031 	struct virtio_dev *vdev = &svdev->vdev;
1032 	struct virtqueue *vq = ch->vq;
1033 
1034 	spdk_poller_unregister(&ch->poller);
1035 	virtio_dev_release_queue(vdev, vq->vq_queue_index);
1036 }
1037 
1038 static void
1039 _virtio_scsi_dev_scan_finish(struct virtio_scsi_scan_base *base, int errnum)
1040 {
1041 	struct virtio_scsi_dev *svdev = base->svdev;
1042 	size_t bdevs_cnt;
1043 	struct spdk_bdev *bdevs[BDEV_VIRTIO_MAX_TARGET];
1044 	struct virtio_scsi_disk *disk;
1045 	struct virtio_scsi_scan_info *tgt, *next_tgt;
1046 
1047 	spdk_put_io_channel(spdk_io_channel_from_ctx(base->channel));
1048 	base->svdev->scan_ctx = NULL;
1049 
1050 	TAILQ_FOREACH_SAFE(tgt, &base->scan_queue, tailq, next_tgt) {
1051 		TAILQ_REMOVE(&base->scan_queue, tgt, tailq);
1052 		free(tgt);
1053 	}
1054 
1055 	if (base->cb_fn == NULL) {
1056 		spdk_free(base);
1057 		return;
1058 	}
1059 
1060 	bdevs_cnt = 0;
1061 	if (errnum == 0) {
1062 		TAILQ_FOREACH(disk, &svdev->luns, link) {
1063 			bdevs[bdevs_cnt] = &disk->bdev;
1064 			bdevs_cnt++;
1065 		}
1066 	}
1067 
1068 	base->cb_fn(base->cb_arg, errnum, bdevs, bdevs_cnt);
1069 	spdk_free(base);
1070 }
1071 
1072 static int
1073 send_scan_io(struct virtio_scsi_scan_base *base)
1074 {
1075 	struct virtio_scsi_io_ctx *io_ctx = &base->io_ctx;
1076 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1077 	struct virtqueue *vq = base->channel->vq;
1078 	int payload_iov_cnt = base->iov.iov_len > 0 ? 1 : 0;
1079 	int rc;
1080 
1081 	req->lun[0] = 1;
1082 	req->lun[1] = base->info.target;
1083 
1084 	rc = virtqueue_req_start(vq, io_ctx, 2 + payload_iov_cnt);
1085 	if (rc != 0) {
1086 		base->needs_resend = true;
1087 		return -1;
1088 	}
1089 
1090 	virtqueue_req_add_iovs(vq, &io_ctx->iov_req, 1, SPDK_VIRTIO_DESC_RO);
1091 	virtqueue_req_add_iovs(vq, &io_ctx->iov_resp, 1, SPDK_VIRTIO_DESC_WR);
1092 	virtqueue_req_add_iovs(vq, &base->iov, payload_iov_cnt, SPDK_VIRTIO_DESC_WR);
1093 
1094 	virtqueue_req_flush(vq);
1095 	return 0;
1096 }
1097 
1098 static int
1099 send_inquiry(struct virtio_scsi_scan_base *base)
1100 {
1101 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1102 	struct spdk_scsi_cdb_inquiry *cdb;
1103 
1104 	memset(req, 0, sizeof(*req));
1105 
1106 	base->iov.iov_len = BDEV_VIRTIO_SCAN_PAYLOAD_SIZE;
1107 	cdb = (struct spdk_scsi_cdb_inquiry *)req->cdb;
1108 	cdb->opcode = SPDK_SPC_INQUIRY;
1109 	to_be16(cdb->alloc_len, BDEV_VIRTIO_SCAN_PAYLOAD_SIZE);
1110 
1111 	return send_scan_io(base);
1112 }
1113 
1114 static int
1115 send_inquiry_vpd(struct virtio_scsi_scan_base *base, uint8_t page_code)
1116 {
1117 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1118 	struct spdk_scsi_cdb_inquiry *inquiry_cdb = (struct spdk_scsi_cdb_inquiry *)req->cdb;
1119 
1120 	memset(req, 0, sizeof(*req));
1121 
1122 	base->iov.iov_len = BDEV_VIRTIO_SCAN_PAYLOAD_SIZE;
1123 	inquiry_cdb->opcode = SPDK_SPC_INQUIRY;
1124 	inquiry_cdb->evpd = 1;
1125 	inquiry_cdb->page_code = page_code;
1126 	to_be16(inquiry_cdb->alloc_len, base->iov.iov_len);
1127 
1128 	return send_scan_io(base);
1129 }
1130 
1131 static int
1132 send_read_cap_10(struct virtio_scsi_scan_base *base)
1133 {
1134 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1135 
1136 	memset(req, 0, sizeof(*req));
1137 
1138 	base->iov.iov_len = 8;
1139 	req->cdb[0] = SPDK_SBC_READ_CAPACITY_10;
1140 
1141 	return send_scan_io(base);
1142 }
1143 
1144 static int
1145 send_read_cap_16(struct virtio_scsi_scan_base *base)
1146 {
1147 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1148 
1149 	memset(req, 0, sizeof(*req));
1150 
1151 	base->iov.iov_len = 32;
1152 	req->cdb[0] = SPDK_SPC_SERVICE_ACTION_IN_16;
1153 	req->cdb[1] = SPDK_SBC_SAI_READ_CAPACITY_16;
1154 	to_be32(&req->cdb[10], base->iov.iov_len);
1155 
1156 	return send_scan_io(base);
1157 }
1158 
1159 static int
1160 send_test_unit_ready(struct virtio_scsi_scan_base *base)
1161 {
1162 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1163 
1164 	memset(req, 0, sizeof(*req));
1165 	req->cdb[0] = SPDK_SPC_TEST_UNIT_READY;
1166 	base->iov.iov_len = 0;
1167 
1168 	return send_scan_io(base);
1169 }
1170 
1171 static int
1172 send_start_stop_unit(struct virtio_scsi_scan_base *base)
1173 {
1174 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1175 
1176 	memset(req, 0, sizeof(*req));
1177 	req->cdb[0] = SPDK_SBC_START_STOP_UNIT;
1178 	req->cdb[4] = SPDK_SBC_START_STOP_UNIT_START_BIT;
1179 	base->iov.iov_len = 0;
1180 
1181 	return send_scan_io(base);
1182 }
1183 
1184 static int
1185 process_scan_start_stop_unit(struct virtio_scsi_scan_base *base)
1186 {
1187 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1188 
1189 	if (resp->status == SPDK_SCSI_STATUS_GOOD) {
1190 		return send_inquiry_vpd(base, SPDK_SPC_VPD_SUPPORTED_VPD_PAGES);
1191 	}
1192 
1193 	return -1;
1194 }
1195 
1196 static int
1197 process_scan_test_unit_ready(struct virtio_scsi_scan_base *base)
1198 {
1199 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1200 	int sk, asc, ascq;
1201 
1202 	get_scsi_status(resp, &sk, &asc, &ascq);
1203 
1204 	/* check response, get VPD if spun up otherwise send SSU */
1205 	if (resp->status == SPDK_SCSI_STATUS_GOOD) {
1206 		return send_inquiry_vpd(base, SPDK_SPC_VPD_SUPPORTED_VPD_PAGES);
1207 	} else if (resp->response == VIRTIO_SCSI_S_OK &&
1208 		   resp->status == SPDK_SCSI_STATUS_CHECK_CONDITION &&
1209 		   sk == SPDK_SCSI_SENSE_UNIT_ATTENTION &&
1210 		   asc == SPDK_SCSI_ASC_LOGICAL_UNIT_NOT_READY) {
1211 		return send_start_stop_unit(base);
1212 	} else {
1213 		return -1;
1214 	}
1215 }
1216 
1217 static int
1218 process_scan_inquiry_standard(struct virtio_scsi_scan_base *base)
1219 {
1220 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1221 	struct spdk_scsi_cdb_inquiry_data *inquiry_data =
1222 		(struct spdk_scsi_cdb_inquiry_data *)base->payload;
1223 
1224 	if (resp->status != SPDK_SCSI_STATUS_GOOD) {
1225 		return -1;
1226 	}
1227 
1228 	/* check to make sure its a supported device */
1229 	if (inquiry_data->peripheral_device_type != SPDK_SPC_PERIPHERAL_DEVICE_TYPE_DISK ||
1230 	    inquiry_data->peripheral_qualifier != SPDK_SPC_PERIPHERAL_QUALIFIER_CONNECTED) {
1231 		SPDK_WARNLOG("Unsupported peripheral device type 0x%02x (qualifier 0x%02x)\n",
1232 			     inquiry_data->peripheral_device_type,
1233 			     inquiry_data->peripheral_qualifier);
1234 		return -1;
1235 	}
1236 
1237 	return send_test_unit_ready(base);
1238 }
1239 
1240 static int
1241 process_scan_inquiry_vpd_supported_vpd_pages(struct virtio_scsi_scan_base *base)
1242 {
1243 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1244 	bool block_provisioning_page_supported = false;
1245 
1246 	if (resp->status == SPDK_SCSI_STATUS_GOOD) {
1247 		const uint8_t *vpd_data = base->payload;
1248 		const uint8_t *supported_vpd_pages = vpd_data + 4;
1249 		uint16_t page_length;
1250 		uint16_t num_supported_pages;
1251 		uint16_t i;
1252 
1253 		page_length = from_be16(vpd_data + 2);
1254 		num_supported_pages = spdk_min(page_length, base->iov.iov_len - 4);
1255 
1256 		for (i = 0; i < num_supported_pages; i++) {
1257 			if (supported_vpd_pages[i] == SPDK_SPC_VPD_BLOCK_THIN_PROVISION) {
1258 				block_provisioning_page_supported = true;
1259 				break;
1260 			}
1261 		}
1262 	}
1263 
1264 	if (block_provisioning_page_supported) {
1265 		return send_inquiry_vpd(base, SPDK_SPC_VPD_BLOCK_THIN_PROVISION);
1266 	} else {
1267 		return send_read_cap_10(base);
1268 	}
1269 }
1270 
1271 static int
1272 process_scan_inquiry_vpd_block_thin_provision(struct virtio_scsi_scan_base *base)
1273 {
1274 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1275 
1276 	base->info.unmap_supported = false;
1277 
1278 	if (resp->status == SPDK_SCSI_STATUS_GOOD) {
1279 		uint8_t *vpd_data = base->payload;
1280 
1281 		base->info.unmap_supported = !!(vpd_data[5] & SPDK_SCSI_UNMAP_LBPU);
1282 	}
1283 
1284 	SPDK_INFOLOG(virtio, "Target %u: unmap supported = %d\n",
1285 		     base->info.target, (int)base->info.unmap_supported);
1286 
1287 	return send_read_cap_10(base);
1288 }
1289 
1290 static int
1291 process_scan_inquiry(struct virtio_scsi_scan_base *base)
1292 {
1293 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1294 	struct spdk_scsi_cdb_inquiry *inquiry_cdb = (struct spdk_scsi_cdb_inquiry *)req->cdb;
1295 
1296 	if ((inquiry_cdb->evpd & 1) == 0) {
1297 		return process_scan_inquiry_standard(base);
1298 	}
1299 
1300 	switch (inquiry_cdb->page_code) {
1301 	case SPDK_SPC_VPD_SUPPORTED_VPD_PAGES:
1302 		return process_scan_inquiry_vpd_supported_vpd_pages(base);
1303 	case SPDK_SPC_VPD_BLOCK_THIN_PROVISION:
1304 		return process_scan_inquiry_vpd_block_thin_provision(base);
1305 	default:
1306 		SPDK_DEBUGLOG(virtio, "Unexpected VPD page 0x%02x\n", inquiry_cdb->page_code);
1307 		return -1;
1308 	}
1309 }
1310 
1311 static void
1312 bdev_virtio_disk_notify_remove(struct virtio_scsi_disk *disk)
1313 {
1314 	disk->removed = true;
1315 	spdk_bdev_close(disk->notify_desc);
1316 }
1317 
1318 static void
1319 bdev_virtio_disk_notify_event_cb(enum spdk_bdev_event_type type, struct spdk_bdev *bdev,
1320 				 void *event_ctx)
1321 {
1322 	switch (type) {
1323 	case SPDK_BDEV_EVENT_REMOVE:
1324 		bdev_virtio_disk_notify_remove(event_ctx);
1325 		break;
1326 	default:
1327 		SPDK_NOTICELOG("Unsupported bdev event: type %d\n", type);
1328 		break;
1329 	}
1330 }
1331 
1332 /* To be called only from the thread performing target scan */
1333 static int
1334 virtio_scsi_dev_add_tgt(struct virtio_scsi_dev *svdev, struct virtio_scsi_scan_info *info)
1335 {
1336 	struct virtio_scsi_disk *disk;
1337 	struct spdk_bdev *bdev;
1338 	int rc;
1339 
1340 	TAILQ_FOREACH(disk, &svdev->luns, link) {
1341 		if (disk->info.target == info->target) {
1342 			/* Target is already attached and param change is not supported */
1343 			return 0;
1344 		}
1345 	}
1346 
1347 	if (info->block_size == 0 || info->num_blocks == 0) {
1348 		SPDK_ERRLOG("%s: invalid target %u: bs=%"PRIu32" blocks=%"PRIu64"\n",
1349 			    svdev->vdev.name, info->target, info->block_size, info->num_blocks);
1350 		return -EINVAL;
1351 	}
1352 
1353 	disk = calloc(1, sizeof(*disk));
1354 	if (disk == NULL) {
1355 		SPDK_ERRLOG("could not allocate disk\n");
1356 		return -ENOMEM;
1357 	}
1358 
1359 	disk->svdev = svdev;
1360 	memcpy(&disk->info, info, sizeof(*info));
1361 
1362 	bdev = &disk->bdev;
1363 	bdev->name = spdk_sprintf_alloc("%st%"PRIu8, svdev->vdev.name, info->target);
1364 	if (bdev->name == NULL) {
1365 		SPDK_ERRLOG("Couldn't alloc memory for the bdev name.\n");
1366 		free(disk);
1367 		return -ENOMEM;
1368 	}
1369 
1370 	bdev->product_name = "Virtio SCSI Disk";
1371 	bdev->write_cache = 0;
1372 	bdev->blocklen = disk->info.block_size;
1373 	bdev->blockcnt = disk->info.num_blocks;
1374 
1375 	bdev->ctxt = disk;
1376 	bdev->fn_table = &virtio_fn_table;
1377 	bdev->module = &virtio_scsi_if;
1378 
1379 	rc = spdk_bdev_register(&disk->bdev);
1380 	if (rc) {
1381 		SPDK_ERRLOG("Failed to register bdev name=%s\n", disk->bdev.name);
1382 		free(bdev->name);
1383 		free(disk);
1384 		return rc;
1385 	}
1386 
1387 	rc = spdk_bdev_open_ext(bdev->name, false, bdev_virtio_disk_notify_event_cb,
1388 				disk, &disk->notify_desc);
1389 	if (rc) {
1390 		assert(false);
1391 	}
1392 
1393 	TAILQ_INSERT_TAIL(&svdev->luns, disk, link);
1394 	return 0;
1395 }
1396 
1397 static int
1398 process_read_cap_10(struct virtio_scsi_scan_base *base)
1399 {
1400 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1401 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1402 	uint64_t max_block;
1403 	uint32_t block_size;
1404 	uint8_t target_id = req->lun[1];
1405 	int rc;
1406 
1407 	if (resp->response != VIRTIO_SCSI_S_OK || resp->status != SPDK_SCSI_STATUS_GOOD) {
1408 		SPDK_ERRLOG("READ CAPACITY (10) failed for target %"PRIu8".\n", target_id);
1409 		return -1;
1410 	}
1411 
1412 	block_size = from_be32(base->payload + 4);
1413 	max_block = from_be32(base->payload);
1414 
1415 	if (max_block == 0xffffffff) {
1416 		return send_read_cap_16(base);
1417 	}
1418 
1419 	base->info.num_blocks = (uint64_t)max_block + 1;
1420 	base->info.block_size = block_size;
1421 
1422 	rc = virtio_scsi_dev_add_tgt(base->svdev, &base->info);
1423 	if (rc != 0) {
1424 		return rc;
1425 	}
1426 
1427 	return _virtio_scsi_dev_scan_next(base, 0);
1428 }
1429 
1430 static int
1431 process_read_cap_16(struct virtio_scsi_scan_base *base)
1432 {
1433 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1434 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1435 	uint8_t target_id = req->lun[1];
1436 	int rc;
1437 
1438 	if (resp->response != VIRTIO_SCSI_S_OK || resp->status != SPDK_SCSI_STATUS_GOOD) {
1439 		SPDK_ERRLOG("READ CAPACITY (16) failed for target %"PRIu8".\n", target_id);
1440 		return -1;
1441 	}
1442 
1443 	base->info.num_blocks = from_be64(base->payload) + 1;
1444 	base->info.block_size = from_be32(base->payload + 8);
1445 	rc = virtio_scsi_dev_add_tgt(base->svdev, &base->info);
1446 	if (rc != 0) {
1447 		return rc;
1448 	}
1449 
1450 	return _virtio_scsi_dev_scan_next(base, 0);
1451 }
1452 
1453 static void
1454 process_scan_resp(struct virtio_scsi_scan_base *base)
1455 {
1456 	struct virtio_scsi_cmd_req *req = &base->io_ctx.req;
1457 	struct virtio_scsi_cmd_resp *resp = &base->io_ctx.resp;
1458 	int rc, sk, asc, ascq;
1459 	uint8_t target_id;
1460 
1461 	if (base->io_ctx.iov_req.iov_len < sizeof(struct virtio_scsi_cmd_req) ||
1462 	    base->io_ctx.iov_resp.iov_len < sizeof(struct virtio_scsi_cmd_resp)) {
1463 		SPDK_ERRLOG("Received target scan message with invalid length.\n");
1464 		_virtio_scsi_dev_scan_next(base, -EIO);
1465 		return;
1466 	}
1467 
1468 	get_scsi_status(resp, &sk, &asc, &ascq);
1469 	target_id = req->lun[1];
1470 
1471 	if (resp->response == VIRTIO_SCSI_S_BAD_TARGET ||
1472 	    resp->response == VIRTIO_SCSI_S_INCORRECT_LUN) {
1473 		_virtio_scsi_dev_scan_next(base, -ENODEV);
1474 		return;
1475 	}
1476 
1477 	if (resp->response != VIRTIO_SCSI_S_OK ||
1478 	    (resp->status == SPDK_SCSI_STATUS_CHECK_CONDITION &&
1479 	     sk != SPDK_SCSI_SENSE_ILLEGAL_REQUEST)) {
1480 		assert(base->retries > 0);
1481 		base->retries--;
1482 		if (base->retries == 0) {
1483 			SPDK_NOTICELOG("Target %"PRIu8" is present, but unavailable.\n", target_id);
1484 			SPDK_LOGDUMP(virtio, "CDB", req->cdb, sizeof(req->cdb));
1485 			SPDK_LOGDUMP(virtio, "SENSE DATA", resp->sense, sizeof(resp->sense));
1486 			_virtio_scsi_dev_scan_next(base, -EBUSY);
1487 			return;
1488 		}
1489 
1490 		/* resend the same request */
1491 		rc = send_scan_io(base);
1492 		if (rc != 0) {
1493 			/* Let response poller do the resend */
1494 		}
1495 		return;
1496 	}
1497 
1498 	base->retries = SCAN_REQUEST_RETRIES;
1499 
1500 	switch (req->cdb[0]) {
1501 	case SPDK_SPC_INQUIRY:
1502 		rc = process_scan_inquiry(base);
1503 		break;
1504 	case SPDK_SPC_TEST_UNIT_READY:
1505 		rc = process_scan_test_unit_ready(base);
1506 		break;
1507 	case SPDK_SBC_START_STOP_UNIT:
1508 		rc = process_scan_start_stop_unit(base);
1509 		break;
1510 	case SPDK_SBC_READ_CAPACITY_10:
1511 		rc = process_read_cap_10(base);
1512 		break;
1513 	case SPDK_SPC_SERVICE_ACTION_IN_16:
1514 		rc = process_read_cap_16(base);
1515 		break;
1516 	default:
1517 		SPDK_ERRLOG("Received invalid target scan message: cdb[0] = %"PRIu8".\n", req->cdb[0]);
1518 		rc = -1;
1519 		break;
1520 	}
1521 
1522 	if (rc != 0) {
1523 		if (base->needs_resend) {
1524 			return; /* Let response poller do the resend */
1525 		}
1526 
1527 		_virtio_scsi_dev_scan_next(base, rc);
1528 	}
1529 }
1530 
1531 static int
1532 _virtio_scsi_dev_scan_next(struct virtio_scsi_scan_base *base, int rc)
1533 {
1534 	struct virtio_scsi_scan_info *next;
1535 	struct virtio_scsi_disk *disk;
1536 	uint8_t target_id;
1537 
1538 	if (base->full_scan) {
1539 		if (rc != 0) {
1540 			disk = virtio_scsi_dev_get_disk_by_id(base->svdev,
1541 							      base->info.target);
1542 			if (disk != NULL) {
1543 				spdk_bdev_unregister(&disk->bdev, NULL, NULL);
1544 			}
1545 		}
1546 
1547 		target_id = base->info.target + 1;
1548 		if (target_id < BDEV_VIRTIO_MAX_TARGET) {
1549 			_virtio_scsi_dev_scan_tgt(base, target_id);
1550 			return 0;
1551 		}
1552 
1553 		base->full_scan = false;
1554 	}
1555 
1556 	next = TAILQ_FIRST(&base->scan_queue);
1557 	if (next == NULL) {
1558 		_virtio_scsi_dev_scan_finish(base, 0);
1559 		return 0;
1560 	}
1561 
1562 	TAILQ_REMOVE(&base->scan_queue, next, tailq);
1563 	target_id = next->target;
1564 	free(next);
1565 
1566 	_virtio_scsi_dev_scan_tgt(base, target_id);
1567 	return 0;
1568 }
1569 
1570 static int
1571 _virtio_scsi_dev_scan_init(struct virtio_scsi_dev *svdev)
1572 {
1573 	struct virtio_scsi_scan_base *base;
1574 	struct spdk_io_channel *io_ch;
1575 	struct virtio_scsi_io_ctx *io_ctx;
1576 	struct virtio_scsi_cmd_req *req;
1577 	struct virtio_scsi_cmd_resp *resp;
1578 
1579 	io_ch = spdk_get_io_channel(svdev);
1580 	if (io_ch == NULL) {
1581 		return -EBUSY;
1582 	}
1583 
1584 	base = spdk_zmalloc(sizeof(*base), 64, NULL,
1585 			    SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
1586 	if (base == NULL) {
1587 		SPDK_ERRLOG("couldn't allocate memory for scsi target scan.\n");
1588 		return -ENOMEM;
1589 	}
1590 
1591 	base->svdev = svdev;
1592 
1593 	base->channel = spdk_io_channel_get_ctx(io_ch);
1594 	TAILQ_INIT(&base->scan_queue);
1595 	svdev->scan_ctx = base;
1596 
1597 	base->iov.iov_base = base->payload;
1598 	io_ctx = &base->io_ctx;
1599 	req = &io_ctx->req;
1600 	resp = &io_ctx->resp;
1601 	io_ctx->iov_req.iov_base = req;
1602 	io_ctx->iov_req.iov_len = sizeof(*req);
1603 	io_ctx->iov_resp.iov_base = resp;
1604 	io_ctx->iov_resp.iov_len = sizeof(*resp);
1605 
1606 	base->retries = SCAN_REQUEST_RETRIES;
1607 	return 0;
1608 }
1609 
1610 static void
1611 _virtio_scsi_dev_scan_tgt(struct virtio_scsi_scan_base *base, uint8_t target)
1612 {
1613 	int rc;
1614 
1615 	memset(&base->info, 0, sizeof(base->info));
1616 	base->info.target = target;
1617 
1618 	rc = send_inquiry(base);
1619 	if (rc) {
1620 		/* Let response poller do the resend */
1621 	}
1622 }
1623 
1624 static int
1625 virtio_scsi_dev_scan(struct virtio_scsi_dev *svdev, bdev_virtio_create_cb cb_fn,
1626 		     void *cb_arg)
1627 {
1628 	struct virtio_scsi_scan_base *base;
1629 	struct virtio_scsi_scan_info *tgt, *next_tgt;
1630 	int rc;
1631 
1632 	if (svdev->scan_ctx) {
1633 		if (svdev->scan_ctx->full_scan) {
1634 			return -EEXIST;
1635 		}
1636 
1637 		/* We're about to start a full rescan, so there's no need
1638 		 * to scan particular targets afterwards.
1639 		 */
1640 		TAILQ_FOREACH_SAFE(tgt, &svdev->scan_ctx->scan_queue, tailq, next_tgt) {
1641 			TAILQ_REMOVE(&svdev->scan_ctx->scan_queue, tgt, tailq);
1642 			free(tgt);
1643 		}
1644 
1645 		svdev->scan_ctx->cb_fn = cb_fn;
1646 		svdev->scan_ctx->cb_arg = cb_arg;
1647 		svdev->scan_ctx->restart = true;
1648 		return 0;
1649 	}
1650 
1651 	rc = _virtio_scsi_dev_scan_init(svdev);
1652 	if (rc != 0) {
1653 		return rc;
1654 	}
1655 
1656 	base = svdev->scan_ctx;
1657 	base->cb_fn = cb_fn;
1658 	base->cb_arg = cb_arg;
1659 	base->full_scan = true;
1660 
1661 	_virtio_scsi_dev_scan_tgt(base, 0);
1662 	return 0;
1663 }
1664 
1665 static int
1666 virtio_scsi_dev_scan_tgt(struct virtio_scsi_dev *svdev, uint8_t target)
1667 {
1668 	struct virtio_scsi_scan_base *base;
1669 	struct virtio_scsi_scan_info *info;
1670 	int rc;
1671 
1672 	base = svdev->scan_ctx;
1673 	if (base) {
1674 		info = calloc(1, sizeof(*info));
1675 		if (info == NULL) {
1676 			SPDK_ERRLOG("calloc failed\n");
1677 			return -ENOMEM;
1678 		}
1679 
1680 		info->target = target;
1681 		TAILQ_INSERT_TAIL(&base->scan_queue, info, tailq);
1682 		return 0;
1683 	}
1684 
1685 	rc = _virtio_scsi_dev_scan_init(svdev);
1686 	if (rc != 0) {
1687 		return rc;
1688 	}
1689 
1690 	base = svdev->scan_ctx;
1691 	base->full_scan = true;
1692 	_virtio_scsi_dev_scan_tgt(base, target);
1693 	return 0;
1694 }
1695 
1696 static int
1697 bdev_virtio_initialize(void)
1698 {
1699 	return 0;
1700 }
1701 
1702 static void
1703 _virtio_scsi_dev_unregister_cb(void *io_device)
1704 {
1705 	struct virtio_scsi_dev *svdev = io_device;
1706 	struct virtio_dev *vdev = &svdev->vdev;
1707 	bool finish_module;
1708 	bdev_virtio_remove_cb remove_cb;
1709 	void *remove_ctx;
1710 
1711 	assert(spdk_ring_count(svdev->ctrlq_ring) == 0);
1712 	spdk_ring_free(svdev->ctrlq_ring);
1713 	spdk_poller_unregister(&svdev->mgmt_poller);
1714 
1715 	virtio_dev_release_queue(vdev, VIRTIO_SCSI_EVENTQ);
1716 	virtio_dev_release_queue(vdev, VIRTIO_SCSI_CONTROLQ);
1717 
1718 	virtio_dev_stop(vdev);
1719 	virtio_dev_destruct(vdev);
1720 
1721 	pthread_mutex_lock(&g_virtio_scsi_mutex);
1722 	TAILQ_REMOVE(&g_virtio_scsi_devs, svdev, tailq);
1723 	pthread_mutex_unlock(&g_virtio_scsi_mutex);
1724 
1725 	remove_cb = svdev->remove_cb;
1726 	remove_ctx = svdev->remove_ctx;
1727 	spdk_free(svdev->eventq_ios);
1728 	free(svdev);
1729 
1730 	if (remove_cb) {
1731 		remove_cb(remove_ctx, 0);
1732 	}
1733 
1734 	finish_module = TAILQ_EMPTY(&g_virtio_scsi_devs);
1735 
1736 	if (g_bdev_virtio_finish && finish_module) {
1737 		spdk_bdev_module_fini_done();
1738 	}
1739 }
1740 
1741 static void
1742 virtio_scsi_dev_unregister_cb(void *io_device)
1743 {
1744 	struct virtio_scsi_dev *svdev = io_device;
1745 	struct spdk_thread *thread;
1746 
1747 	thread = virtio_dev_queue_get_thread(&svdev->vdev, VIRTIO_SCSI_CONTROLQ);
1748 	spdk_thread_send_msg(thread, _virtio_scsi_dev_unregister_cb, io_device);
1749 }
1750 
1751 static void
1752 virtio_scsi_dev_remove(struct virtio_scsi_dev *svdev,
1753 		       bdev_virtio_remove_cb cb_fn, void *cb_arg)
1754 {
1755 	struct virtio_scsi_disk *disk, *disk_tmp;
1756 	bool do_remove = true;
1757 
1758 	if (svdev->removed) {
1759 		if (cb_fn) {
1760 			cb_fn(cb_arg, -EBUSY);
1761 		}
1762 		return;
1763 	}
1764 
1765 	svdev->remove_cb = cb_fn;
1766 	svdev->remove_ctx = cb_arg;
1767 	svdev->removed = true;
1768 
1769 	if (svdev->scan_ctx) {
1770 		/* The removal will continue after we receive a pending scan I/O. */
1771 		return;
1772 	}
1773 
1774 	TAILQ_FOREACH_SAFE(disk, &svdev->luns, link, disk_tmp) {
1775 		if (!disk->removed) {
1776 			spdk_bdev_unregister(&disk->bdev, NULL, NULL);
1777 		}
1778 		do_remove = false;
1779 	}
1780 
1781 	if (do_remove) {
1782 		spdk_io_device_unregister(svdev, virtio_scsi_dev_unregister_cb);
1783 	}
1784 }
1785 
1786 static void
1787 bdev_virtio_finish(void)
1788 {
1789 	struct virtio_scsi_dev *svdev, *next;
1790 
1791 	g_bdev_virtio_finish = true;
1792 
1793 	pthread_mutex_lock(&g_virtio_scsi_mutex);
1794 	if (TAILQ_EMPTY(&g_virtio_scsi_devs)) {
1795 		pthread_mutex_unlock(&g_virtio_scsi_mutex);
1796 		spdk_bdev_module_fini_done();
1797 		return;
1798 	}
1799 
1800 	/* Defer module finish until all controllers are removed. */
1801 	TAILQ_FOREACH_SAFE(svdev, &g_virtio_scsi_devs, tailq, next) {
1802 		virtio_scsi_dev_remove(svdev, NULL, NULL);
1803 	}
1804 	pthread_mutex_unlock(&g_virtio_scsi_mutex);
1805 }
1806 
1807 int
1808 bdev_virtio_user_scsi_dev_create(const char *base_name, const char *path,
1809 				 unsigned num_queues, unsigned queue_size,
1810 				 bdev_virtio_create_cb cb_fn, void *cb_arg)
1811 {
1812 	struct virtio_scsi_dev *svdev;
1813 	int rc;
1814 
1815 	svdev = virtio_user_scsi_dev_create(base_name, path, num_queues, queue_size);
1816 	if (svdev == NULL) {
1817 		return -1;
1818 	}
1819 
1820 	rc = virtio_scsi_dev_scan(svdev, cb_fn, cb_arg);
1821 	if (rc) {
1822 		virtio_scsi_dev_remove(svdev, NULL, NULL);
1823 	}
1824 
1825 	return rc;
1826 }
1827 
1828 struct bdev_virtio_pci_dev_create_ctx {
1829 	const char *name;
1830 	bdev_virtio_create_cb cb_fn;
1831 	void *cb_arg;
1832 };
1833 
1834 static int
1835 bdev_virtio_pci_scsi_dev_create_cb(struct virtio_pci_ctx *pci_ctx, void *ctx)
1836 {
1837 	struct virtio_scsi_dev *svdev;
1838 	struct bdev_virtio_pci_dev_create_ctx *create_ctx = ctx;
1839 	int rc;
1840 
1841 	svdev = virtio_pci_scsi_dev_create(create_ctx->name, pci_ctx);
1842 	if (svdev == NULL) {
1843 		return -1;
1844 	}
1845 
1846 	rc = virtio_scsi_dev_scan(svdev, create_ctx->cb_fn, create_ctx->cb_arg);
1847 	if (rc) {
1848 		svdev->vdev.ctx = NULL;
1849 		virtio_scsi_dev_remove(svdev, NULL, NULL);
1850 	}
1851 
1852 	return rc;
1853 }
1854 
1855 int
1856 bdev_virtio_pci_scsi_dev_create(const char *name, struct spdk_pci_addr *pci_addr,
1857 				bdev_virtio_create_cb cb_fn, void *cb_arg)
1858 {
1859 	struct bdev_virtio_pci_dev_create_ctx create_ctx;
1860 
1861 	create_ctx.name = name;
1862 	create_ctx.cb_fn = cb_fn;
1863 	create_ctx.cb_arg = cb_arg;
1864 
1865 	return virtio_pci_dev_attach(bdev_virtio_pci_scsi_dev_create_cb, &create_ctx,
1866 				     VIRTIO_ID_SCSI, pci_addr);
1867 }
1868 
1869 int
1870 bdev_virtio_scsi_dev_remove(const char *name, bdev_virtio_remove_cb cb_fn, void *cb_arg)
1871 {
1872 	struct virtio_scsi_dev *svdev;
1873 
1874 	pthread_mutex_lock(&g_virtio_scsi_mutex);
1875 	TAILQ_FOREACH(svdev, &g_virtio_scsi_devs, tailq) {
1876 		if (strcmp(svdev->vdev.name, name) == 0) {
1877 			break;
1878 		}
1879 	}
1880 
1881 	if (svdev == NULL) {
1882 		pthread_mutex_unlock(&g_virtio_scsi_mutex);
1883 		SPDK_ERRLOG("Cannot find Virtio-SCSI device named '%s'\n", name);
1884 		return -ENODEV;
1885 	}
1886 
1887 	virtio_scsi_dev_remove(svdev, cb_fn, cb_arg);
1888 	pthread_mutex_unlock(&g_virtio_scsi_mutex);
1889 
1890 	return 0;
1891 }
1892 
1893 void
1894 bdev_virtio_scsi_dev_list(struct spdk_json_write_ctx *w)
1895 {
1896 	struct virtio_scsi_dev *svdev;
1897 
1898 	spdk_json_write_array_begin(w);
1899 
1900 	pthread_mutex_lock(&g_virtio_scsi_mutex);
1901 	TAILQ_FOREACH(svdev, &g_virtio_scsi_devs, tailq) {
1902 		spdk_json_write_object_begin(w);
1903 
1904 		spdk_json_write_named_string(w, "name", svdev->vdev.name);
1905 
1906 		virtio_dev_dump_json_info(&svdev->vdev, w);
1907 
1908 		spdk_json_write_object_end(w);
1909 	}
1910 	pthread_mutex_unlock(&g_virtio_scsi_mutex);
1911 
1912 	spdk_json_write_array_end(w);
1913 }
1914 
1915 SPDK_LOG_REGISTER_COMPONENT(virtio)
1916