xref: /spdk/lib/vhost/vhost_scsi.c (revision 7d38f16674f1bc7071d08f4d4dad68fc3ffad965)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright(c) Intel Corporation. All rights reserved.
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 <linux/virtio_scsi.h>
37 
38 #include "spdk/env.h"
39 #include "spdk/thread.h"
40 #include "spdk/scsi.h"
41 #include "spdk/scsi_spec.h"
42 #include "spdk/conf.h"
43 #include "spdk/event.h"
44 #include "spdk/util.h"
45 #include "spdk/likely.h"
46 
47 #include "spdk/vhost.h"
48 #include "vhost_internal.h"
49 
50 /* Features supported by SPDK VHOST lib. */
51 #define SPDK_VHOST_SCSI_FEATURES	(SPDK_VHOST_FEATURES | \
52 					(1ULL << VIRTIO_SCSI_F_INOUT) | \
53 					(1ULL << VIRTIO_SCSI_F_HOTPLUG) | \
54 					(1ULL << VIRTIO_SCSI_F_CHANGE ) | \
55 					(1ULL << VIRTIO_SCSI_F_T10_PI ))
56 
57 /* Features that are specified in VIRTIO SCSI but currently not supported:
58  * - Live migration not supported yet
59  * - T10 PI
60  */
61 #define SPDK_VHOST_SCSI_DISABLED_FEATURES	(SPDK_VHOST_DISABLED_FEATURES | \
62 						(1ULL << VIRTIO_SCSI_F_T10_PI ))
63 
64 #define MGMT_POLL_PERIOD_US (1000 * 5)
65 
66 #define VIRTIO_SCSI_CONTROLQ   0
67 #define VIRTIO_SCSI_EVENTQ   1
68 #define VIRTIO_SCSI_REQUESTQ   2
69 
70 struct spdk_scsi_dev_vhost_state {
71 	bool removed;
72 	spdk_vhost_event_fn remove_cb;
73 	void *remove_ctx;
74 };
75 
76 struct spdk_vhost_scsi_dev {
77 	struct spdk_vhost_dev vdev;
78 	struct spdk_scsi_dev *scsi_dev[SPDK_VHOST_SCSI_CTRLR_MAX_DEVS];
79 	struct spdk_scsi_dev_vhost_state scsi_dev_state[SPDK_VHOST_SCSI_CTRLR_MAX_DEVS];
80 
81 	struct spdk_poller *requestq_poller;
82 	struct spdk_poller *mgmt_poller;
83 	struct spdk_vhost_dev_destroy_ctx destroy_ctx;
84 } __rte_cache_aligned;
85 
86 struct spdk_vhost_scsi_task {
87 	struct spdk_scsi_task	scsi;
88 	struct iovec iovs[SPDK_VHOST_IOVS_MAX];
89 
90 	union {
91 		struct virtio_scsi_cmd_resp *resp;
92 		struct virtio_scsi_ctrl_tmf_resp *tmf_resp;
93 	};
94 
95 	struct spdk_vhost_scsi_dev *svdev;
96 	struct spdk_scsi_dev *scsi_dev;
97 
98 	/** Number of bytes that were written. */
99 	uint32_t used_len;
100 
101 	int req_idx;
102 
103 	/* If set, the task is currently used for I/O processing. */
104 	bool used;
105 
106 	struct spdk_vhost_virtqueue *vq;
107 };
108 
109 static int spdk_vhost_scsi_start(struct spdk_vhost_dev *, void *);
110 static int spdk_vhost_scsi_stop(struct spdk_vhost_dev *, void *);
111 static void spdk_vhost_scsi_dump_info_json(struct spdk_vhost_dev *vdev,
112 		struct spdk_json_write_ctx *w);
113 static void spdk_vhost_scsi_write_config_json(struct spdk_vhost_dev *vdev,
114 		struct spdk_json_write_ctx *w);
115 static int spdk_vhost_scsi_dev_remove(struct spdk_vhost_dev *vdev);
116 
117 const struct spdk_vhost_dev_backend spdk_vhost_scsi_device_backend = {
118 	.virtio_features = SPDK_VHOST_SCSI_FEATURES,
119 	.disabled_features = SPDK_VHOST_SCSI_DISABLED_FEATURES,
120 	.start_device =  spdk_vhost_scsi_start,
121 	.stop_device = spdk_vhost_scsi_stop,
122 	.dump_info_json = spdk_vhost_scsi_dump_info_json,
123 	.write_config_json = spdk_vhost_scsi_write_config_json,
124 	.remove_device = spdk_vhost_scsi_dev_remove,
125 };
126 
127 static void
128 spdk_vhost_scsi_task_put(struct spdk_vhost_scsi_task *task)
129 {
130 	spdk_scsi_task_put(&task->scsi);
131 }
132 
133 static void
134 spdk_vhost_scsi_task_free_cb(struct spdk_scsi_task *scsi_task)
135 {
136 	struct spdk_vhost_scsi_task *task = SPDK_CONTAINEROF(scsi_task, struct spdk_vhost_scsi_task, scsi);
137 
138 	assert(task->svdev->vdev.task_cnt > 0);
139 	task->svdev->vdev.task_cnt--;
140 	task->used = false;
141 }
142 
143 static void
144 process_removed_devs(struct spdk_vhost_scsi_dev *svdev)
145 {
146 	struct spdk_scsi_dev *dev;
147 	struct spdk_scsi_dev_vhost_state *state;
148 	int i;
149 
150 	for (i = 0; i < SPDK_VHOST_SCSI_CTRLR_MAX_DEVS; ++i) {
151 		dev = svdev->scsi_dev[i];
152 		state = &svdev->scsi_dev_state[i];
153 
154 		if (dev && state->removed && !spdk_scsi_dev_has_pending_tasks(dev)) {
155 			spdk_scsi_dev_free_io_channels(dev);
156 			svdev->scsi_dev[i] = NULL;
157 			spdk_scsi_dev_destruct(dev);
158 			if (state->remove_cb) {
159 				state->remove_cb(&svdev->vdev, state->remove_ctx);
160 				state->remove_cb = NULL;
161 			}
162 			SPDK_INFOLOG(SPDK_LOG_VHOST, "%s: hot-detached device 'Dev %u'.\n",
163 				     svdev->vdev.name, i);
164 		}
165 	}
166 }
167 
168 static void
169 eventq_enqueue(struct spdk_vhost_scsi_dev *svdev, unsigned scsi_dev_num, uint32_t event,
170 	       uint32_t reason)
171 {
172 	struct spdk_vhost_virtqueue *vq;
173 	struct vring_desc *desc, *desc_table;
174 	struct virtio_scsi_event *desc_ev;
175 	uint32_t desc_table_size, req_size = 0;
176 	uint16_t req;
177 	int rc;
178 
179 	assert(scsi_dev_num < SPDK_VHOST_SCSI_CTRLR_MAX_DEVS);
180 	vq = &svdev->vdev.virtqueue[VIRTIO_SCSI_EVENTQ];
181 
182 	if (spdk_vhost_vq_avail_ring_get(vq, &req, 1) != 1) {
183 		SPDK_ERRLOG("Controller %s: Failed to send virtio event (no avail ring entries?).\n",
184 			    svdev->vdev.name);
185 		return;
186 	}
187 
188 	rc = spdk_vhost_vq_get_desc(&svdev->vdev, vq, req, &desc, &desc_table, &desc_table_size);
189 	if (rc != 0 || desc->len < sizeof(*desc_ev)) {
190 		SPDK_ERRLOG("Controller %s: Invalid eventq descriptor at index %"PRIu16".\n",
191 			    svdev->vdev.name, req);
192 		goto out;
193 	}
194 
195 	desc_ev = spdk_vhost_gpa_to_vva(&svdev->vdev, desc->addr, sizeof(*desc_ev));
196 	if (desc_ev == NULL) {
197 		SPDK_ERRLOG("Controller %s: Eventq descriptor at index %"PRIu16" points to unmapped guest memory address %p.\n",
198 			    svdev->vdev.name, req, (void *)(uintptr_t)desc->addr);
199 		goto out;
200 	}
201 
202 	desc_ev->event = event;
203 	desc_ev->lun[0] = 1;
204 	desc_ev->lun[1] = scsi_dev_num;
205 	/* virtio LUN id 0 can refer either to the entire device
206 	 * or actual LUN 0 (the only supported by vhost for now)
207 	 */
208 	desc_ev->lun[2] = 0 >> 8;
209 	desc_ev->lun[3] = 0 & 0xFF;
210 	/* virtio doesn't specify any strict format for LUN id (bytes 2 and 3)
211 	 * current implementation relies on linux kernel sources
212 	 */
213 	memset(&desc_ev->lun[4], 0, 4);
214 	desc_ev->reason = reason;
215 	req_size = sizeof(*desc_ev);
216 
217 out:
218 	spdk_vhost_vq_used_ring_enqueue(&svdev->vdev, vq, req, req_size);
219 }
220 
221 static void
222 submit_completion(struct spdk_vhost_scsi_task *task)
223 {
224 	spdk_vhost_vq_used_ring_enqueue(&task->svdev->vdev, task->vq, task->req_idx,
225 					task->used_len);
226 	SPDK_DEBUGLOG(SPDK_LOG_VHOST_SCSI, "Finished task (%p) req_idx=%d\n", task, task->req_idx);
227 
228 	spdk_vhost_scsi_task_put(task);
229 }
230 
231 static void
232 spdk_vhost_scsi_task_mgmt_cpl(struct spdk_scsi_task *scsi_task)
233 {
234 	struct spdk_vhost_scsi_task *task = SPDK_CONTAINEROF(scsi_task, struct spdk_vhost_scsi_task, scsi);
235 
236 	submit_completion(task);
237 }
238 
239 static void
240 spdk_vhost_scsi_task_cpl(struct spdk_scsi_task *scsi_task)
241 {
242 	struct spdk_vhost_scsi_task *task = SPDK_CONTAINEROF(scsi_task, struct spdk_vhost_scsi_task, scsi);
243 
244 	/* The SCSI task has completed.  Do final processing and then post
245 	   notification to the virtqueue's "used" ring.
246 	 */
247 	task->resp->status = task->scsi.status;
248 
249 	if (task->scsi.status != SPDK_SCSI_STATUS_GOOD) {
250 		memcpy(task->resp->sense, task->scsi.sense_data, task->scsi.sense_data_len);
251 		task->resp->sense_len = task->scsi.sense_data_len;
252 		SPDK_DEBUGLOG(SPDK_LOG_VHOST_SCSI, "Task (%p) req_idx=%d failed - status=%u\n", task, task->req_idx,
253 			      task->scsi.status);
254 	}
255 	assert(task->scsi.transfer_len == task->scsi.length);
256 	task->resp->resid = task->scsi.length - task->scsi.data_transferred;
257 
258 	submit_completion(task);
259 }
260 
261 static void
262 task_submit(struct spdk_vhost_scsi_task *task)
263 {
264 	task->resp->response = VIRTIO_SCSI_S_OK;
265 	spdk_scsi_dev_queue_task(task->scsi_dev, &task->scsi);
266 }
267 
268 static void
269 mgmt_task_submit(struct spdk_vhost_scsi_task *task, enum spdk_scsi_task_func func)
270 {
271 	task->tmf_resp->response = VIRTIO_SCSI_S_OK;
272 	spdk_scsi_dev_queue_mgmt_task(task->scsi_dev, &task->scsi, func);
273 }
274 
275 static void
276 invalid_request(struct spdk_vhost_scsi_task *task)
277 {
278 	spdk_vhost_vq_used_ring_enqueue(&task->svdev->vdev, task->vq, task->req_idx,
279 					task->used_len);
280 	spdk_vhost_scsi_task_put(task);
281 
282 	SPDK_DEBUGLOG(SPDK_LOG_VHOST_SCSI, "Invalid request (status=%" PRIu8")\n",
283 		      task->resp ? task->resp->response : -1);
284 }
285 
286 static int
287 spdk_vhost_scsi_task_init_target(struct spdk_vhost_scsi_task *task, const __u8 *lun)
288 {
289 	struct spdk_scsi_dev *dev;
290 	uint16_t lun_id = (((uint16_t)lun[2] << 8) | lun[3]) & 0x3FFF;
291 
292 	SPDK_LOGDUMP(SPDK_LOG_VHOST_SCSI_QUEUE, "LUN", lun, 8);
293 
294 	/* First byte must be 1 and second is target */
295 	if (lun[0] != 1 || lun[1] >= SPDK_VHOST_SCSI_CTRLR_MAX_DEVS) {
296 		return -1;
297 	}
298 
299 	dev = task->svdev->scsi_dev[lun[1]];
300 	task->scsi_dev = dev;
301 	if (dev == NULL || task->svdev->scsi_dev_state[lun[1]].removed) {
302 		/* If dev has been hotdetached, return 0 to allow sending
303 		 * additional hotremove event via sense codes.
304 		 */
305 		return task->svdev->scsi_dev_state[lun[1]].removed ? 0 : -1;
306 	}
307 
308 	task->scsi.target_port = spdk_scsi_dev_find_port_by_id(task->scsi_dev, 0);
309 	task->scsi.lun = spdk_scsi_dev_get_lun(dev, lun_id);
310 	return 0;
311 }
312 
313 static void
314 process_ctrl_request(struct spdk_vhost_scsi_task *task)
315 {
316 	struct spdk_vhost_dev *vdev = &task->svdev->vdev;
317 	struct vring_desc *desc, *desc_table;
318 	struct virtio_scsi_ctrl_tmf_req *ctrl_req;
319 	struct virtio_scsi_ctrl_an_resp *an_resp;
320 	uint32_t desc_table_size, used_len = 0;
321 	int rc;
322 
323 	spdk_scsi_task_construct(&task->scsi, spdk_vhost_scsi_task_mgmt_cpl, spdk_vhost_scsi_task_free_cb);
324 	rc = spdk_vhost_vq_get_desc(vdev, task->vq, task->req_idx, &desc, &desc_table, &desc_table_size);
325 	if (spdk_unlikely(rc != 0)) {
326 		SPDK_ERRLOG("%s: Invalid controlq descriptor at index %d.\n",
327 			    vdev->name, task->req_idx);
328 		goto out;
329 	}
330 
331 	ctrl_req = spdk_vhost_gpa_to_vva(vdev, desc->addr, sizeof(*ctrl_req));
332 	if (ctrl_req == NULL) {
333 		SPDK_ERRLOG("%s: Invalid task management request at index %d.\n",
334 			    vdev->name, task->req_idx);
335 		goto out;
336 	}
337 
338 	SPDK_DEBUGLOG(SPDK_LOG_VHOST_SCSI_QUEUE,
339 		      "Processing controlq descriptor: desc %d/%p, desc_addr %p, len %d, flags %d, last_used_idx %d; kickfd %d; size %d\n",
340 		      task->req_idx, desc, (void *)desc->addr, desc->len, desc->flags, task->vq->vring.last_used_idx,
341 		      task->vq->vring.kickfd, task->vq->vring.size);
342 	SPDK_LOGDUMP(SPDK_LOG_VHOST_SCSI_QUEUE, "Request descriptor", (uint8_t *)ctrl_req, desc->len);
343 
344 	spdk_vhost_scsi_task_init_target(task, ctrl_req->lun);
345 
346 	spdk_vhost_vring_desc_get_next(&desc, desc_table, desc_table_size);
347 	if (spdk_unlikely(desc == NULL)) {
348 		SPDK_ERRLOG("%s: No response descriptor for controlq request %d.\n",
349 			    vdev->name, task->req_idx);
350 		goto out;
351 	}
352 
353 	/* Process the TMF request */
354 	switch (ctrl_req->type) {
355 	case VIRTIO_SCSI_T_TMF:
356 		task->tmf_resp = spdk_vhost_gpa_to_vva(vdev, desc->addr, sizeof(*task->tmf_resp));
357 		if (spdk_unlikely(desc->len < sizeof(struct virtio_scsi_ctrl_tmf_resp) || task->tmf_resp == NULL)) {
358 			SPDK_ERRLOG("%s: TMF response descriptor at index %d points to invalid guest memory region\n",
359 				    vdev->name, task->req_idx);
360 			goto out;
361 		}
362 
363 		/* Check if we are processing a valid request */
364 		if (task->scsi_dev == NULL) {
365 			task->tmf_resp->response = VIRTIO_SCSI_S_BAD_TARGET;
366 			break;
367 		}
368 
369 		switch (ctrl_req->subtype) {
370 		case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
371 			/* Handle LUN reset */
372 			SPDK_DEBUGLOG(SPDK_LOG_VHOST_SCSI_QUEUE, "LUN reset\n");
373 
374 			mgmt_task_submit(task, SPDK_SCSI_TASK_FUNC_LUN_RESET);
375 			return;
376 		default:
377 			task->tmf_resp->response = VIRTIO_SCSI_S_ABORTED;
378 			/* Unsupported command */
379 			SPDK_DEBUGLOG(SPDK_LOG_VHOST_SCSI_QUEUE, "Unsupported TMF command %x\n", ctrl_req->subtype);
380 			break;
381 		}
382 		break;
383 	case VIRTIO_SCSI_T_AN_QUERY:
384 	case VIRTIO_SCSI_T_AN_SUBSCRIBE: {
385 		an_resp = spdk_vhost_gpa_to_vva(vdev, desc->addr, sizeof(*an_resp));
386 		if (spdk_unlikely(desc->len < sizeof(struct virtio_scsi_ctrl_an_resp) || an_resp == NULL)) {
387 			SPDK_WARNLOG("%s: Asynchronous response descriptor points to invalid guest memory region\n",
388 				     vdev->name);
389 			goto out;
390 		}
391 
392 		an_resp->response = VIRTIO_SCSI_S_ABORTED;
393 		break;
394 	}
395 	default:
396 		SPDK_DEBUGLOG(SPDK_LOG_VHOST_SCSI_QUEUE, "Unsupported control command %x\n", ctrl_req->type);
397 		break;
398 	}
399 
400 	used_len = sizeof(struct virtio_scsi_ctrl_tmf_resp);
401 out:
402 	spdk_vhost_vq_used_ring_enqueue(vdev, task->vq, task->req_idx, used_len);
403 	spdk_vhost_scsi_task_put(task);
404 }
405 
406 /*
407  * Process task's descriptor chain and setup data related fields.
408  * Return
409  *   -1 if request is invalid and must be aborted,
410  *    0 if all data are set.
411  */
412 static int
413 task_data_setup(struct spdk_vhost_scsi_task *task,
414 		struct virtio_scsi_cmd_req **req)
415 {
416 	struct spdk_vhost_dev *vdev = &task->svdev->vdev;
417 	struct vring_desc *desc, *desc_table;
418 	struct iovec *iovs = task->iovs;
419 	uint16_t iovcnt = 0;
420 	uint32_t desc_table_len, len = 0;
421 	int rc;
422 
423 	spdk_scsi_task_construct(&task->scsi, spdk_vhost_scsi_task_cpl, spdk_vhost_scsi_task_free_cb);
424 
425 	rc = spdk_vhost_vq_get_desc(vdev, task->vq, task->req_idx, &desc, &desc_table, &desc_table_len);
426 	/* First descriptor must be readable */
427 	if (spdk_unlikely(rc != 0  || spdk_vhost_vring_desc_is_wr(desc) ||
428 			  desc->len < sizeof(struct virtio_scsi_cmd_req))) {
429 		SPDK_WARNLOG("%s: invalid first (request) descriptor at index %"PRIu16".\n",
430 			     vdev->name, task->req_idx);
431 		goto invalid_task;
432 	}
433 
434 	*req = spdk_vhost_gpa_to_vva(vdev, desc->addr, sizeof(**req));
435 	if (spdk_unlikely(*req == NULL)) {
436 		SPDK_WARNLOG("%s: Request descriptor at index %d points to invalid guest memory region\n",
437 			     vdev->name, task->req_idx);
438 		goto invalid_task;
439 	}
440 
441 	/* Each request must have at least 2 descriptors (e.g. request and response) */
442 	spdk_vhost_vring_desc_get_next(&desc, desc_table, desc_table_len);
443 	if (desc == NULL) {
444 		SPDK_WARNLOG("%s: Descriptor chain at index %d contains neither payload nor response buffer.\n",
445 			     vdev->name, task->req_idx);
446 		goto invalid_task;
447 	}
448 	task->scsi.dxfer_dir = spdk_vhost_vring_desc_is_wr(desc) ? SPDK_SCSI_DIR_FROM_DEV :
449 			       SPDK_SCSI_DIR_TO_DEV;
450 	task->scsi.iovs = iovs;
451 
452 	if (task->scsi.dxfer_dir == SPDK_SCSI_DIR_FROM_DEV) {
453 		/*
454 		 * FROM_DEV (READ): [RD_req][WR_resp][WR_buf0]...[WR_bufN]
455 		 */
456 		task->resp = spdk_vhost_gpa_to_vva(vdev, desc->addr, sizeof(*task->resp));
457 		if (spdk_unlikely(desc->len < sizeof(struct virtio_scsi_cmd_resp) || task->resp == NULL)) {
458 			SPDK_WARNLOG("%s: Response descriptor at index %d points to invalid guest memory region\n",
459 				     vdev->name, task->req_idx);
460 			goto invalid_task;
461 		}
462 		rc = spdk_vhost_vring_desc_get_next(&desc, desc_table, desc_table_len);
463 		if (spdk_unlikely(rc != 0)) {
464 			SPDK_WARNLOG("%s: invalid descriptor chain at request index %d (descriptor id overflow?).\n",
465 				     vdev->name, task->req_idx);
466 			goto invalid_task;
467 		}
468 
469 		if (desc == NULL) {
470 			/*
471 			 * TEST UNIT READY command and some others might not contain any payload and this is not an error.
472 			 */
473 			SPDK_DEBUGLOG(SPDK_LOG_VHOST_SCSI_DATA,
474 				      "No payload descriptors for FROM DEV command req_idx=%"PRIu16".\n", task->req_idx);
475 			SPDK_LOGDUMP(SPDK_LOG_VHOST_SCSI_DATA, "CDB=", (*req)->cdb, VIRTIO_SCSI_CDB_SIZE);
476 			task->used_len = sizeof(struct virtio_scsi_cmd_resp);
477 			task->scsi.iovcnt = 1;
478 			task->scsi.iovs[0].iov_len = 0;
479 			task->scsi.length = 0;
480 			task->scsi.transfer_len = 0;
481 			return 0;
482 		}
483 
484 		/* All remaining descriptors are data. */
485 		while (desc) {
486 			if (spdk_unlikely(!spdk_vhost_vring_desc_is_wr(desc))) {
487 				SPDK_WARNLOG("FROM DEV cmd: descriptor nr %" PRIu16" in payload chain is read only.\n", iovcnt);
488 				goto invalid_task;
489 			}
490 
491 			if (spdk_unlikely(spdk_vhost_vring_desc_to_iov(vdev, iovs, &iovcnt, desc))) {
492 				goto invalid_task;
493 			}
494 			len += desc->len;
495 
496 			rc = spdk_vhost_vring_desc_get_next(&desc, desc_table, desc_table_len);
497 			if (spdk_unlikely(rc != 0)) {
498 				SPDK_WARNLOG("%s: invalid payload in descriptor chain starting at index %d.\n",
499 					     vdev->name, task->req_idx);
500 				goto invalid_task;
501 			}
502 		}
503 
504 		task->used_len = sizeof(struct virtio_scsi_cmd_resp) + len;
505 	} else {
506 		SPDK_DEBUGLOG(SPDK_LOG_VHOST_SCSI_DATA, "TO DEV");
507 		/*
508 		 * TO_DEV (WRITE):[RD_req][RD_buf0]...[RD_bufN][WR_resp]
509 		 * No need to check descriptor WR flag as this is done while setting scsi.dxfer_dir.
510 		 */
511 
512 		/* Process descriptors up to response. */
513 		while (!spdk_vhost_vring_desc_is_wr(desc)) {
514 			if (spdk_unlikely(spdk_vhost_vring_desc_to_iov(vdev, iovs, &iovcnt, desc))) {
515 				goto invalid_task;
516 			}
517 			len += desc->len;
518 
519 			spdk_vhost_vring_desc_get_next(&desc, desc_table, desc_table_len);
520 			if (spdk_unlikely(desc == NULL)) {
521 				SPDK_WARNLOG("TO_DEV cmd: no response descriptor.\n");
522 				goto invalid_task;
523 			}
524 		}
525 
526 		task->resp = spdk_vhost_gpa_to_vva(vdev, desc->addr, sizeof(*task->resp));
527 		if (spdk_unlikely(desc->len < sizeof(struct virtio_scsi_cmd_resp) || task->resp == NULL)) {
528 			SPDK_WARNLOG("%s: Response descriptor at index %d points to invalid guest memory region\n",
529 				     vdev->name, task->req_idx);
530 			goto invalid_task;
531 		}
532 
533 		task->used_len = sizeof(struct virtio_scsi_cmd_resp);
534 	}
535 
536 	task->scsi.iovcnt = iovcnt;
537 	task->scsi.length = len;
538 	task->scsi.transfer_len = len;
539 	return 0;
540 
541 invalid_task:
542 	SPDK_DEBUGLOG(SPDK_LOG_VHOST_SCSI_DATA, "%s: Invalid task at index %"PRIu16".\n",
543 		      vdev->name, task->req_idx);
544 	return -1;
545 }
546 
547 static int
548 process_request(struct spdk_vhost_scsi_task *task)
549 {
550 	struct virtio_scsi_cmd_req *req;
551 	int result;
552 
553 	result = task_data_setup(task, &req);
554 	if (result) {
555 		return result;
556 	}
557 
558 	result = spdk_vhost_scsi_task_init_target(task, req->lun);
559 	if (spdk_unlikely(result != 0)) {
560 		task->resp->response = VIRTIO_SCSI_S_BAD_TARGET;
561 		return -1;
562 	}
563 
564 	task->scsi.cdb = req->cdb;
565 	SPDK_LOGDUMP(SPDK_LOG_VHOST_SCSI_DATA, "request CDB", req->cdb, VIRTIO_SCSI_CDB_SIZE);
566 
567 	if (spdk_unlikely(task->scsi.lun == NULL)) {
568 		spdk_scsi_task_process_null_lun(&task->scsi);
569 		task->resp->response = VIRTIO_SCSI_S_OK;
570 		return 1;
571 	}
572 
573 	return 0;
574 }
575 
576 static void
577 process_controlq(struct spdk_vhost_scsi_dev *svdev, struct spdk_vhost_virtqueue *vq)
578 {
579 	struct spdk_vhost_scsi_task *task;
580 	uint16_t reqs[32];
581 	uint16_t reqs_cnt, i;
582 
583 	reqs_cnt = spdk_vhost_vq_avail_ring_get(vq, reqs, SPDK_COUNTOF(reqs));
584 	for (i = 0; i < reqs_cnt; i++) {
585 		if (spdk_unlikely(reqs[i] >= vq->vring.size)) {
586 			SPDK_ERRLOG("%s: invalid entry in avail ring. Buffer '%"PRIu16"' exceeds virtqueue size (%"PRIu16")\n",
587 				    svdev->vdev.name, reqs[i], vq->vring.size);
588 			spdk_vhost_vq_used_ring_enqueue(&svdev->vdev, vq, reqs[i], 0);
589 			continue;
590 		}
591 
592 		task = &((struct spdk_vhost_scsi_task *)vq->tasks)[reqs[i]];
593 		if (spdk_unlikely(task->used)) {
594 			SPDK_ERRLOG("%s: invalid entry in avail ring. Buffer '%"PRIu16"' is still in use!\n",
595 				    svdev->vdev.name, reqs[i]);
596 			spdk_vhost_vq_used_ring_enqueue(&svdev->vdev, vq, reqs[i], 0);
597 			continue;
598 		}
599 
600 		svdev->vdev.task_cnt++;
601 		memset(&task->scsi, 0, sizeof(task->scsi));
602 		task->tmf_resp = NULL;
603 		task->used = true;
604 		process_ctrl_request(task);
605 	}
606 }
607 
608 static void
609 process_requestq(struct spdk_vhost_scsi_dev *svdev, struct spdk_vhost_virtqueue *vq)
610 {
611 	struct spdk_vhost_scsi_task *task;
612 	uint16_t reqs[32];
613 	uint16_t reqs_cnt, i;
614 	int result;
615 
616 	reqs_cnt = spdk_vhost_vq_avail_ring_get(vq, reqs, SPDK_COUNTOF(reqs));
617 	assert(reqs_cnt <= 32);
618 
619 	for (i = 0; i < reqs_cnt; i++) {
620 		SPDK_DEBUGLOG(SPDK_LOG_VHOST_SCSI, "====== Starting processing request idx %"PRIu16"======\n",
621 			      reqs[i]);
622 
623 		if (spdk_unlikely(reqs[i] >= vq->vring.size)) {
624 			SPDK_ERRLOG("%s: request idx '%"PRIu16"' exceeds virtqueue size (%"PRIu16").\n",
625 				    svdev->vdev.name, reqs[i], vq->vring.size);
626 			spdk_vhost_vq_used_ring_enqueue(&svdev->vdev, vq, reqs[i], 0);
627 			continue;
628 		}
629 
630 		task = &((struct spdk_vhost_scsi_task *)vq->tasks)[reqs[i]];
631 		if (spdk_unlikely(task->used)) {
632 			SPDK_ERRLOG("%s: request with idx '%"PRIu16"' is already pending.\n",
633 				    svdev->vdev.name, reqs[i]);
634 			spdk_vhost_vq_used_ring_enqueue(&svdev->vdev, vq, reqs[i], 0);
635 			continue;
636 		}
637 
638 		svdev->vdev.task_cnt++;
639 		memset(&task->scsi, 0, sizeof(task->scsi));
640 		task->resp = NULL;
641 		task->used = true;
642 		task->used_len = 0;
643 		result = process_request(task);
644 		if (likely(result == 0)) {
645 			task_submit(task);
646 			SPDK_DEBUGLOG(SPDK_LOG_VHOST_SCSI, "====== Task %p req_idx %d submitted ======\n", task,
647 				      task->req_idx);
648 		} else if (result > 0) {
649 			spdk_vhost_scsi_task_cpl(&task->scsi);
650 			SPDK_DEBUGLOG(SPDK_LOG_VHOST_SCSI, "====== Task %p req_idx %d finished early ======\n", task,
651 				      task->req_idx);
652 		} else {
653 			invalid_request(task);
654 			SPDK_DEBUGLOG(SPDK_LOG_VHOST_SCSI, "====== Task %p req_idx %d failed ======\n", task,
655 				      task->req_idx);
656 		}
657 	}
658 }
659 
660 static int
661 vdev_mgmt_worker(void *arg)
662 {
663 	struct spdk_vhost_scsi_dev *svdev = arg;
664 
665 	process_removed_devs(svdev);
666 	spdk_vhost_vq_used_signal(&svdev->vdev, &svdev->vdev.virtqueue[VIRTIO_SCSI_EVENTQ]);
667 
668 	process_controlq(svdev, &svdev->vdev.virtqueue[VIRTIO_SCSI_CONTROLQ]);
669 	spdk_vhost_vq_used_signal(&svdev->vdev, &svdev->vdev.virtqueue[VIRTIO_SCSI_CONTROLQ]);
670 
671 	return -1;
672 }
673 
674 static int
675 vdev_worker(void *arg)
676 {
677 	struct spdk_vhost_scsi_dev *svdev = arg;
678 	uint32_t q_idx;
679 
680 	for (q_idx = VIRTIO_SCSI_REQUESTQ; q_idx < svdev->vdev.max_queues; q_idx++) {
681 		process_requestq(svdev, &svdev->vdev.virtqueue[q_idx]);
682 	}
683 
684 	spdk_vhost_dev_used_signal(&svdev->vdev);
685 
686 	return -1;
687 }
688 
689 static struct spdk_vhost_scsi_dev *
690 to_scsi_dev(struct spdk_vhost_dev *ctrlr)
691 {
692 	if (ctrlr == NULL) {
693 		return NULL;
694 	}
695 
696 	if (ctrlr->backend != &spdk_vhost_scsi_device_backend) {
697 		SPDK_ERRLOG("%s: not a vhost-scsi device.\n", ctrlr->name);
698 		return NULL;
699 	}
700 
701 	return SPDK_CONTAINEROF(ctrlr, struct spdk_vhost_scsi_dev, vdev);
702 }
703 
704 int
705 spdk_vhost_scsi_dev_construct(const char *name, const char *cpumask)
706 {
707 	struct spdk_vhost_scsi_dev *svdev = spdk_dma_zmalloc(sizeof(struct spdk_vhost_scsi_dev),
708 					    SPDK_CACHE_LINE_SIZE, NULL);
709 	int rc;
710 
711 	if (svdev == NULL) {
712 		return -ENOMEM;
713 	}
714 
715 	spdk_vhost_lock();
716 	rc = spdk_vhost_dev_register(&svdev->vdev, name, cpumask,
717 				     &spdk_vhost_scsi_device_backend);
718 
719 	if (rc) {
720 		spdk_dma_free(svdev);
721 	}
722 
723 	spdk_vhost_unlock();
724 	return rc;
725 }
726 
727 static int
728 spdk_vhost_scsi_dev_remove(struct spdk_vhost_dev *vdev)
729 {
730 	struct spdk_vhost_scsi_dev *svdev = to_scsi_dev(vdev);
731 	int rc, i;
732 
733 	if (svdev == NULL) {
734 		return -EINVAL;
735 	}
736 
737 	for (i = 0; i < SPDK_VHOST_SCSI_CTRLR_MAX_DEVS; ++i) {
738 		if (svdev->scsi_dev[i]) {
739 			if (vdev->registered) {
740 				SPDK_ERRLOG("Trying to remove non-empty controller: %s.\n", vdev->name);
741 				return -EBUSY;
742 			}
743 
744 			rc = spdk_vhost_scsi_dev_remove_tgt(vdev, i, NULL, NULL);
745 			if (rc != 0) {
746 				SPDK_ERRLOG("%s: failed to force-remove target %d\n", vdev->name, i);
747 				return rc;
748 			}
749 		}
750 	}
751 
752 	rc = spdk_vhost_dev_unregister(vdev);
753 	if (rc != 0) {
754 		return rc;
755 	}
756 
757 	spdk_dma_free(svdev);
758 	return 0;
759 }
760 
761 struct spdk_scsi_dev *
762 spdk_vhost_scsi_dev_get_tgt(struct spdk_vhost_dev *vdev, uint8_t num)
763 {
764 	struct spdk_vhost_scsi_dev *svdev;
765 
766 	assert(num < SPDK_VHOST_SCSI_CTRLR_MAX_DEVS);
767 	svdev = to_scsi_dev(vdev);
768 
769 	return svdev ? svdev->scsi_dev[num] : NULL;
770 }
771 
772 static void
773 spdk_vhost_scsi_lun_hotremove(const struct spdk_scsi_lun *lun, void *arg)
774 {
775 	struct spdk_vhost_scsi_dev *svdev = arg;
776 	const struct spdk_scsi_dev *scsi_dev;
777 	unsigned scsi_dev_num;
778 
779 	assert(lun != NULL);
780 	assert(svdev != NULL);
781 	if (svdev->vdev.lcore != -1 &&
782 	    !spdk_vhost_dev_has_feature(&svdev->vdev, VIRTIO_SCSI_F_HOTPLUG)) {
783 		SPDK_WARNLOG("%s: hotremove is not enabled for this controller.\n", svdev->vdev.name);
784 		return;
785 	}
786 
787 	scsi_dev = spdk_scsi_lun_get_dev(lun);
788 	for (scsi_dev_num = 0; scsi_dev_num < SPDK_VHOST_SCSI_CTRLR_MAX_DEVS; scsi_dev_num++) {
789 		if (svdev->scsi_dev[scsi_dev_num] == scsi_dev) {
790 			break;
791 		}
792 	}
793 
794 	if (scsi_dev_num == SPDK_VHOST_SCSI_CTRLR_MAX_DEVS) {
795 		/* The entire device has been already removed. */
796 		return;
797 	}
798 
799 	/* remove entire device */
800 	spdk_vhost_scsi_dev_remove_tgt(&svdev->vdev, scsi_dev_num, NULL, NULL);
801 }
802 
803 int
804 spdk_vhost_scsi_dev_add_tgt(struct spdk_vhost_dev *vdev, unsigned scsi_tgt_num,
805 			    const char *bdev_name)
806 {
807 	struct spdk_vhost_scsi_dev *svdev;
808 	char target_name[SPDK_SCSI_DEV_MAX_NAME];
809 	int lun_id_list[1];
810 	const char *bdev_names_list[1];
811 
812 	svdev = to_scsi_dev(vdev);
813 	if (svdev == NULL) {
814 		return -EINVAL;
815 	}
816 
817 	if (scsi_tgt_num >= SPDK_VHOST_SCSI_CTRLR_MAX_DEVS) {
818 		SPDK_ERRLOG("Controller %d target number too big (max %d)\n", scsi_tgt_num,
819 			    SPDK_VHOST_SCSI_CTRLR_MAX_DEVS);
820 		return -EINVAL;
821 	}
822 
823 	if (bdev_name == NULL) {
824 		SPDK_ERRLOG("No lun name specified\n");
825 		return -EINVAL;
826 	}
827 
828 	if (svdev->scsi_dev[scsi_tgt_num] != NULL) {
829 		SPDK_ERRLOG("Controller %s target %u already occupied\n", vdev->name, scsi_tgt_num);
830 		return -EEXIST;
831 	}
832 
833 	/*
834 	 * At this stage only one LUN per target
835 	 */
836 	snprintf(target_name, sizeof(target_name), "Target %u", scsi_tgt_num);
837 	lun_id_list[0] = 0;
838 	bdev_names_list[0] = (char *)bdev_name;
839 
840 	svdev->scsi_dev_state[scsi_tgt_num].removed = false;
841 	svdev->scsi_dev[scsi_tgt_num] = spdk_scsi_dev_construct(target_name, bdev_names_list, lun_id_list,
842 					1,
843 					SPDK_SPC_PROTOCOL_IDENTIFIER_SAS, spdk_vhost_scsi_lun_hotremove, svdev);
844 
845 	if (svdev->scsi_dev[scsi_tgt_num] == NULL) {
846 		SPDK_ERRLOG("Couldn't create spdk SCSI target '%s' using bdev '%s' in controller: %s\n",
847 			    target_name, bdev_name, vdev->name);
848 		return -EINVAL;
849 	}
850 	spdk_scsi_dev_add_port(svdev->scsi_dev[scsi_tgt_num], 0, "vhost");
851 
852 	SPDK_INFOLOG(SPDK_LOG_VHOST, "Controller %s: defined target '%s' using bdev '%s'\n",
853 		     vdev->name, target_name, bdev_name);
854 
855 	if (vdev->lcore == -1) {
856 		/* All done. */
857 		return 0;
858 	}
859 
860 	spdk_scsi_dev_allocate_io_channels(svdev->scsi_dev[scsi_tgt_num]);
861 
862 	if (spdk_vhost_dev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
863 		eventq_enqueue(svdev, scsi_tgt_num, VIRTIO_SCSI_T_TRANSPORT_RESET,
864 			       VIRTIO_SCSI_EVT_RESET_RESCAN);
865 	} else {
866 		SPDK_NOTICELOG("Device %s does not support hotplug. "
867 			       "Please restart the driver or perform a rescan.\n",
868 			       vdev->name);
869 	}
870 
871 	return 0;
872 }
873 
874 int
875 spdk_vhost_scsi_dev_remove_tgt(struct spdk_vhost_dev *vdev, unsigned scsi_tgt_num,
876 			       spdk_vhost_event_fn cb_fn, void *cb_arg)
877 {
878 	struct spdk_vhost_scsi_dev *svdev;
879 	struct spdk_scsi_dev *scsi_dev;
880 	struct spdk_scsi_dev_vhost_state *scsi_dev_state;
881 	int rc = 0;
882 
883 	if (scsi_tgt_num >= SPDK_VHOST_SCSI_CTRLR_MAX_DEVS) {
884 		SPDK_ERRLOG("%s: invalid target number %d\n", vdev->name, scsi_tgt_num);
885 		return -EINVAL;
886 	}
887 
888 	svdev = to_scsi_dev(vdev);
889 	if (svdev == NULL) {
890 		return -ENODEV;
891 	}
892 
893 	scsi_dev = svdev->scsi_dev[scsi_tgt_num];
894 	if (scsi_dev == NULL) {
895 		SPDK_ERRLOG("Controller %s target %u is not occupied\n", vdev->name, scsi_tgt_num);
896 		return -ENODEV;
897 	}
898 
899 	if (svdev->vdev.lcore == -1) {
900 		/* controller is not in use, remove dev and exit */
901 		svdev->scsi_dev[scsi_tgt_num] = NULL;
902 		spdk_scsi_dev_destruct(scsi_dev);
903 		if (cb_fn) {
904 			rc = cb_fn(vdev, cb_arg);
905 		}
906 		SPDK_INFOLOG(SPDK_LOG_VHOST, "%s: removed target 'Target %u'\n",
907 			     vdev->name, scsi_tgt_num);
908 		return rc;
909 	}
910 
911 	if (!spdk_vhost_dev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
912 		SPDK_WARNLOG("%s: 'Target %u' is in use and hot-detach is not enabled for this controller.\n",
913 			     svdev->vdev.name, scsi_tgt_num);
914 		return -ENOTSUP;
915 	}
916 
917 	scsi_dev_state = &svdev->scsi_dev_state[scsi_tgt_num];
918 	if (scsi_dev_state->removed) {
919 		SPDK_WARNLOG("%s: 'Target %u' has been already marked to hotremove.\n", svdev->vdev.name,
920 			     scsi_tgt_num);
921 		return -EBUSY;
922 	}
923 
924 	scsi_dev_state->remove_cb = cb_fn;
925 	scsi_dev_state->remove_ctx = cb_arg;
926 	scsi_dev_state->removed = true;
927 	eventq_enqueue(svdev, scsi_tgt_num, VIRTIO_SCSI_T_TRANSPORT_RESET, VIRTIO_SCSI_EVT_RESET_REMOVED);
928 
929 	SPDK_INFOLOG(SPDK_LOG_VHOST, "%s: queued 'Target %u' for hot-detach.\n", vdev->name, scsi_tgt_num);
930 	return 0;
931 }
932 
933 int
934 spdk_vhost_scsi_controller_construct(void)
935 {
936 	struct spdk_conf_section *sp = spdk_conf_first_section(NULL);
937 	struct spdk_vhost_dev *vdev;
938 	int i, dev_num;
939 	unsigned ctrlr_num = 0;
940 	char *bdev_name, *tgt_num_str;
941 	char *cpumask;
942 	char *name;
943 	char *tgt = NULL;
944 
945 	while (sp != NULL) {
946 		if (!spdk_conf_section_match_prefix(sp, "VhostScsi")) {
947 			sp = spdk_conf_next_section(sp);
948 			continue;
949 		}
950 
951 		if (sscanf(spdk_conf_section_get_name(sp), "VhostScsi%u", &ctrlr_num) != 1) {
952 			SPDK_ERRLOG("Section '%s' has non-numeric suffix.\n",
953 				    spdk_conf_section_get_name(sp));
954 			return -1;
955 		}
956 
957 		name =  spdk_conf_section_get_val(sp, "Name");
958 		cpumask = spdk_conf_section_get_val(sp, "Cpumask");
959 
960 		if (spdk_vhost_scsi_dev_construct(name, cpumask) < 0) {
961 			return -1;
962 		}
963 
964 		vdev = spdk_vhost_dev_find(name);
965 		assert(vdev);
966 
967 		for (i = 0; ; i++) {
968 
969 			tgt = spdk_conf_section_get_nval(sp, "Target", i);
970 			if (tgt == NULL) {
971 				break;
972 			}
973 
974 			tgt_num_str = spdk_conf_section_get_nmval(sp, "Target", i, 0);
975 			if (tgt_num_str == NULL) {
976 				SPDK_ERRLOG("%s: Invalid or missing target number\n", name);
977 				return -1;
978 			}
979 
980 			dev_num = (int)strtol(tgt_num_str, NULL, 10);
981 			bdev_name = spdk_conf_section_get_nmval(sp, "Target", i, 1);
982 			if (bdev_name == NULL) {
983 				SPDK_ERRLOG("%s: Invalid or missing bdev name for target %d\n", name, dev_num);
984 				return -1;
985 			} else if (spdk_conf_section_get_nmval(sp, "Target", i, 2)) {
986 				SPDK_ERRLOG("%s: Only one LUN per vhost SCSI device supported\n", name);
987 				return -1;
988 			}
989 
990 			if (spdk_vhost_scsi_dev_add_tgt(vdev, dev_num, bdev_name) < 0) {
991 				return -1;
992 			}
993 		}
994 
995 		sp = spdk_conf_next_section(sp);
996 	}
997 
998 	return 0;
999 }
1000 
1001 static void
1002 free_task_pool(struct spdk_vhost_scsi_dev *svdev)
1003 {
1004 	struct spdk_vhost_virtqueue *vq;
1005 	uint16_t i;
1006 
1007 	for (i = 0; i < svdev->vdev.max_queues; i++) {
1008 		vq = &svdev->vdev.virtqueue[i];
1009 		if (vq->tasks == NULL) {
1010 			continue;
1011 		}
1012 
1013 		spdk_dma_free(vq->tasks);
1014 		vq->tasks = NULL;
1015 	}
1016 }
1017 
1018 static int
1019 alloc_task_pool(struct spdk_vhost_scsi_dev *svdev)
1020 {
1021 	struct spdk_vhost_virtqueue *vq;
1022 	struct spdk_vhost_scsi_task *task;
1023 	uint32_t task_cnt;
1024 	uint16_t i;
1025 	uint32_t j;
1026 
1027 	for (i = 0; i < svdev->vdev.max_queues; i++) {
1028 		vq = &svdev->vdev.virtqueue[i];
1029 		if (vq->vring.desc == NULL) {
1030 			continue;
1031 		}
1032 
1033 		task_cnt = vq->vring.size;
1034 		if (task_cnt > SPDK_VHOST_MAX_VQ_SIZE) {
1035 			/* sanity check */
1036 			SPDK_ERRLOG("Controller %s: virtuque %"PRIu16" is too big. (size = %"PRIu32", max = %"PRIu32")\n",
1037 				    svdev->vdev.name, i, task_cnt, SPDK_VHOST_MAX_VQ_SIZE);
1038 			free_task_pool(svdev);
1039 			return -1;
1040 		}
1041 		vq->tasks = spdk_dma_zmalloc(sizeof(struct spdk_vhost_scsi_task) * task_cnt,
1042 					     SPDK_CACHE_LINE_SIZE, NULL);
1043 		if (vq->tasks == NULL) {
1044 			SPDK_ERRLOG("Controller %s: failed to allocate %"PRIu32" tasks for virtqueue %"PRIu16"\n",
1045 				    svdev->vdev.name, task_cnt, i);
1046 			free_task_pool(svdev);
1047 			return -1;
1048 		}
1049 
1050 		for (j = 0; j < task_cnt; j++) {
1051 			task = &((struct spdk_vhost_scsi_task *)vq->tasks)[j];
1052 			task->svdev = svdev;
1053 			task->vq = vq;
1054 			task->req_idx = j;
1055 		}
1056 	}
1057 
1058 	return 0;
1059 }
1060 
1061 /*
1062  * A new device is added to a data core. First the device is added to the main linked list
1063  * and then allocated to a specific data core.
1064  */
1065 static int
1066 spdk_vhost_scsi_start(struct spdk_vhost_dev *vdev, void *event_ctx)
1067 {
1068 	struct spdk_vhost_scsi_dev *svdev;
1069 	uint32_t i;
1070 	int rc;
1071 
1072 	svdev = to_scsi_dev(vdev);
1073 	if (svdev == NULL) {
1074 		SPDK_ERRLOG("Trying to start non-scsi controller as a scsi one.\n");
1075 		rc = -1;
1076 		goto out;
1077 	}
1078 
1079 	/* validate all I/O queues are in a contiguous index range */
1080 	for (i = VIRTIO_SCSI_REQUESTQ; i < vdev->max_queues; i++) {
1081 		if (vdev->virtqueue[i].vring.desc == NULL) {
1082 			SPDK_ERRLOG("%s: queue %"PRIu32" is empty\n", vdev->name, i);
1083 			rc = -1;
1084 			goto out;
1085 		}
1086 	}
1087 
1088 	rc = alloc_task_pool(svdev);
1089 	if (rc != 0) {
1090 		SPDK_ERRLOG("%s: failed to alloc task pool.\n", vdev->name);
1091 		goto out;
1092 	}
1093 
1094 	for (i = 0; i < SPDK_VHOST_SCSI_CTRLR_MAX_DEVS; i++) {
1095 		if (svdev->scsi_dev[i] == NULL) {
1096 			continue;
1097 		}
1098 		spdk_scsi_dev_allocate_io_channels(svdev->scsi_dev[i]);
1099 	}
1100 	SPDK_INFOLOG(SPDK_LOG_VHOST, "Started poller for vhost controller %s on lcore %d\n",
1101 		     vdev->name, vdev->lcore);
1102 
1103 	svdev->requestq_poller = spdk_poller_register(vdev_worker, svdev, 0);
1104 	if (vdev->virtqueue[VIRTIO_SCSI_CONTROLQ].vring.desc &&
1105 	    vdev->virtqueue[VIRTIO_SCSI_EVENTQ].vring.desc) {
1106 		svdev->mgmt_poller = spdk_poller_register(vdev_mgmt_worker, svdev,
1107 				     MGMT_POLL_PERIOD_US);
1108 	}
1109 out:
1110 	spdk_vhost_dev_backend_event_done(event_ctx, rc);
1111 	return rc;
1112 }
1113 
1114 static int
1115 destroy_device_poller_cb(void *arg)
1116 {
1117 	struct spdk_vhost_scsi_dev *svdev = arg;
1118 	uint32_t i;
1119 
1120 	if (svdev->vdev.task_cnt > 0) {
1121 		return -1;
1122 	}
1123 
1124 
1125 	for (i = 0; i < svdev->vdev.max_queues; i++) {
1126 		spdk_vhost_vq_used_signal(&svdev->vdev, &svdev->vdev.virtqueue[i]);
1127 	}
1128 
1129 	for (i = 0; i < SPDK_VHOST_SCSI_CTRLR_MAX_DEVS; i++) {
1130 		if (svdev->scsi_dev[i] == NULL) {
1131 			continue;
1132 		}
1133 		spdk_scsi_dev_free_io_channels(svdev->scsi_dev[i]);
1134 	}
1135 
1136 	SPDK_INFOLOG(SPDK_LOG_VHOST, "Stopping poller for vhost controller %s\n", svdev->vdev.name);
1137 
1138 	free_task_pool(svdev);
1139 
1140 	spdk_poller_unregister(&svdev->destroy_ctx.poller);
1141 	spdk_vhost_dev_backend_event_done(svdev->destroy_ctx.event_ctx, 0);
1142 
1143 	return -1;
1144 }
1145 
1146 static int
1147 spdk_vhost_scsi_stop(struct spdk_vhost_dev *vdev, void *event_ctx)
1148 {
1149 	struct spdk_vhost_scsi_dev *svdev;
1150 
1151 	svdev = to_scsi_dev(vdev);
1152 	if (svdev == NULL) {
1153 		SPDK_ERRLOG("Trying to stop non-scsi controller as a scsi one.\n");
1154 		goto err;
1155 	}
1156 
1157 	svdev->destroy_ctx.event_ctx = event_ctx;
1158 	spdk_poller_unregister(&svdev->requestq_poller);
1159 	spdk_poller_unregister(&svdev->mgmt_poller);
1160 	svdev->destroy_ctx.poller = spdk_poller_register(destroy_device_poller_cb, svdev,
1161 				    1000);
1162 
1163 	return 0;
1164 
1165 err:
1166 	spdk_vhost_dev_backend_event_done(event_ctx, -1);
1167 	return -1;
1168 }
1169 
1170 static void
1171 spdk_vhost_scsi_dump_info_json(struct spdk_vhost_dev *vdev, struct spdk_json_write_ctx *w)
1172 {
1173 	struct spdk_scsi_dev *sdev;
1174 	struct spdk_scsi_lun *lun;
1175 	uint32_t dev_idx;
1176 	uint32_t lun_idx;
1177 
1178 	assert(vdev != NULL);
1179 	spdk_json_write_name(w, "scsi");
1180 	spdk_json_write_array_begin(w);
1181 	for (dev_idx = 0; dev_idx < SPDK_VHOST_SCSI_CTRLR_MAX_DEVS; dev_idx++) {
1182 		sdev = spdk_vhost_scsi_dev_get_tgt(vdev, dev_idx);
1183 		if (!sdev) {
1184 			continue;
1185 		}
1186 
1187 		spdk_json_write_object_begin(w);
1188 
1189 		spdk_json_write_name(w, "scsi_dev_num");
1190 		spdk_json_write_uint32(w, dev_idx);
1191 
1192 		spdk_json_write_name(w, "id");
1193 		spdk_json_write_int32(w, spdk_scsi_dev_get_id(sdev));
1194 
1195 		spdk_json_write_name(w, "target_name");
1196 		spdk_json_write_string(w, spdk_scsi_dev_get_name(sdev));
1197 
1198 		spdk_json_write_name(w, "luns");
1199 		spdk_json_write_array_begin(w);
1200 
1201 		for (lun_idx = 0; lun_idx < SPDK_SCSI_DEV_MAX_LUN; lun_idx++) {
1202 			lun = spdk_scsi_dev_get_lun(sdev, lun_idx);
1203 			if (!lun) {
1204 				continue;
1205 			}
1206 
1207 			spdk_json_write_object_begin(w);
1208 
1209 			spdk_json_write_name(w, "id");
1210 			spdk_json_write_int32(w, spdk_scsi_lun_get_id(lun));
1211 
1212 			spdk_json_write_name(w, "bdev_name");
1213 			spdk_json_write_string(w, spdk_scsi_lun_get_bdev_name(lun));
1214 
1215 			spdk_json_write_object_end(w);
1216 		}
1217 
1218 		spdk_json_write_array_end(w);
1219 		spdk_json_write_object_end(w);
1220 	}
1221 
1222 	spdk_json_write_array_end(w);
1223 }
1224 
1225 static void
1226 spdk_vhost_scsi_write_config_json(struct spdk_vhost_dev *vdev, struct spdk_json_write_ctx *w)
1227 {
1228 	struct spdk_vhost_scsi_dev *svdev;
1229 	struct spdk_scsi_lun *lun;
1230 	uint32_t i;
1231 
1232 	svdev = to_scsi_dev(vdev);
1233 	if (!svdev) {
1234 		return;
1235 	}
1236 
1237 	spdk_json_write_object_begin(w);
1238 	spdk_json_write_named_string(w, "method", "construct_vhost_scsi_controller");
1239 
1240 	spdk_json_write_named_object_begin(w, "params");
1241 	spdk_json_write_named_string(w, "ctrlr", vdev->name);
1242 	spdk_json_write_named_string(w, "cpumask", spdk_cpuset_fmt(vdev->cpumask));
1243 	spdk_json_write_object_end(w);
1244 
1245 	spdk_json_write_object_end(w);
1246 
1247 	for (i = 0; i < SPDK_COUNTOF(svdev->scsi_dev); i++) {
1248 		if (svdev->scsi_dev[i] == NULL || svdev->scsi_dev_state[i].removed) {
1249 			continue;
1250 		}
1251 
1252 		lun = spdk_scsi_dev_get_lun(svdev->scsi_dev[i], 0);
1253 
1254 		spdk_json_write_object_begin(w);
1255 		spdk_json_write_named_string(w, "method", "add_vhost_scsi_lun");
1256 
1257 		spdk_json_write_named_object_begin(w, "params");
1258 		spdk_json_write_named_string(w, "ctrlr", vdev->name);
1259 		spdk_json_write_named_uint32(w, "scsi_target_num", i);
1260 
1261 		spdk_json_write_named_string(w, "bdev_name", spdk_scsi_lun_get_bdev_name(lun));
1262 		spdk_json_write_object_end(w);
1263 
1264 		spdk_json_write_object_end(w);
1265 	}
1266 }
1267 
1268 SPDK_LOG_REGISTER_COMPONENT("vhost_scsi", SPDK_LOG_VHOST_SCSI)
1269 SPDK_LOG_REGISTER_COMPONENT("vhost_scsi_queue", SPDK_LOG_VHOST_SCSI_QUEUE)
1270 SPDK_LOG_REGISTER_COMPONENT("vhost_scsi_data", SPDK_LOG_VHOST_SCSI_DATA)
1271