xref: /openbmc/linux/drivers/vhost/scsi.c (revision 5a170e9e)
1 /*******************************************************************************
2  * Vhost kernel TCM fabric driver for virtio SCSI initiators
3  *
4  * (C) Copyright 2010-2013 Datera, Inc.
5  * (C) Copyright 2010-2012 IBM Corp.
6  *
7  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
8  *
9  * Authors: Nicholas A. Bellinger <nab@daterainc.com>
10  *          Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  ****************************************************************************/
23 
24 #include <linux/module.h>
25 #include <linux/moduleparam.h>
26 #include <generated/utsrelease.h>
27 #include <linux/utsname.h>
28 #include <linux/init.h>
29 #include <linux/slab.h>
30 #include <linux/kthread.h>
31 #include <linux/types.h>
32 #include <linux/string.h>
33 #include <linux/configfs.h>
34 #include <linux/ctype.h>
35 #include <linux/compat.h>
36 #include <linux/eventfd.h>
37 #include <linux/fs.h>
38 #include <linux/vmalloc.h>
39 #include <linux/miscdevice.h>
40 #include <asm/unaligned.h>
41 #include <scsi/scsi_common.h>
42 #include <scsi/scsi_proto.h>
43 #include <target/target_core_base.h>
44 #include <target/target_core_fabric.h>
45 #include <linux/vhost.h>
46 #include <linux/virtio_scsi.h>
47 #include <linux/llist.h>
48 #include <linux/bitmap.h>
49 
50 #include "vhost.h"
51 
52 #define VHOST_SCSI_VERSION  "v0.1"
53 #define VHOST_SCSI_NAMELEN 256
54 #define VHOST_SCSI_MAX_CDB_SIZE 32
55 #define VHOST_SCSI_DEFAULT_TAGS 256
56 #define VHOST_SCSI_PREALLOC_SGLS 2048
57 #define VHOST_SCSI_PREALLOC_UPAGES 2048
58 #define VHOST_SCSI_PREALLOC_PROT_SGLS 2048
59 
60 struct vhost_scsi_inflight {
61 	/* Wait for the flush operation to finish */
62 	struct completion comp;
63 	/* Refcount for the inflight reqs */
64 	struct kref kref;
65 };
66 
67 struct vhost_scsi_cmd {
68 	/* Descriptor from vhost_get_vq_desc() for virt_queue segment */
69 	int tvc_vq_desc;
70 	/* virtio-scsi initiator task attribute */
71 	int tvc_task_attr;
72 	/* virtio-scsi response incoming iovecs */
73 	int tvc_in_iovs;
74 	/* virtio-scsi initiator data direction */
75 	enum dma_data_direction tvc_data_direction;
76 	/* Expected data transfer length from virtio-scsi header */
77 	u32 tvc_exp_data_len;
78 	/* The Tag from include/linux/virtio_scsi.h:struct virtio_scsi_cmd_req */
79 	u64 tvc_tag;
80 	/* The number of scatterlists associated with this cmd */
81 	u32 tvc_sgl_count;
82 	u32 tvc_prot_sgl_count;
83 	/* Saved unpacked SCSI LUN for vhost_scsi_submission_work() */
84 	u32 tvc_lun;
85 	/* Pointer to the SGL formatted memory from virtio-scsi */
86 	struct scatterlist *tvc_sgl;
87 	struct scatterlist *tvc_prot_sgl;
88 	struct page **tvc_upages;
89 	/* Pointer to response header iovec */
90 	struct iovec tvc_resp_iov;
91 	/* Pointer to vhost_scsi for our device */
92 	struct vhost_scsi *tvc_vhost;
93 	/* Pointer to vhost_virtqueue for the cmd */
94 	struct vhost_virtqueue *tvc_vq;
95 	/* Pointer to vhost nexus memory */
96 	struct vhost_scsi_nexus *tvc_nexus;
97 	/* The TCM I/O descriptor that is accessed via container_of() */
98 	struct se_cmd tvc_se_cmd;
99 	/* work item used for cmwq dispatch to vhost_scsi_submission_work() */
100 	struct work_struct work;
101 	/* Copy of the incoming SCSI command descriptor block (CDB) */
102 	unsigned char tvc_cdb[VHOST_SCSI_MAX_CDB_SIZE];
103 	/* Sense buffer that will be mapped into outgoing status */
104 	unsigned char tvc_sense_buf[TRANSPORT_SENSE_BUFFER];
105 	/* Completed commands list, serviced from vhost worker thread */
106 	struct llist_node tvc_completion_list;
107 	/* Used to track inflight cmd */
108 	struct vhost_scsi_inflight *inflight;
109 };
110 
111 struct vhost_scsi_nexus {
112 	/* Pointer to TCM session for I_T Nexus */
113 	struct se_session *tvn_se_sess;
114 };
115 
116 struct vhost_scsi_tpg {
117 	/* Vhost port target portal group tag for TCM */
118 	u16 tport_tpgt;
119 	/* Used to track number of TPG Port/Lun Links wrt to explict I_T Nexus shutdown */
120 	int tv_tpg_port_count;
121 	/* Used for vhost_scsi device reference to tpg_nexus, protected by tv_tpg_mutex */
122 	int tv_tpg_vhost_count;
123 	/* Used for enabling T10-PI with legacy devices */
124 	int tv_fabric_prot_type;
125 	/* list for vhost_scsi_list */
126 	struct list_head tv_tpg_list;
127 	/* Used to protect access for tpg_nexus */
128 	struct mutex tv_tpg_mutex;
129 	/* Pointer to the TCM VHost I_T Nexus for this TPG endpoint */
130 	struct vhost_scsi_nexus *tpg_nexus;
131 	/* Pointer back to vhost_scsi_tport */
132 	struct vhost_scsi_tport *tport;
133 	/* Returned by vhost_scsi_make_tpg() */
134 	struct se_portal_group se_tpg;
135 	/* Pointer back to vhost_scsi, protected by tv_tpg_mutex */
136 	struct vhost_scsi *vhost_scsi;
137 };
138 
139 struct vhost_scsi_tport {
140 	/* SCSI protocol the tport is providing */
141 	u8 tport_proto_id;
142 	/* Binary World Wide unique Port Name for Vhost Target port */
143 	u64 tport_wwpn;
144 	/* ASCII formatted WWPN for Vhost Target port */
145 	char tport_name[VHOST_SCSI_NAMELEN];
146 	/* Returned by vhost_scsi_make_tport() */
147 	struct se_wwn tport_wwn;
148 };
149 
150 struct vhost_scsi_evt {
151 	/* event to be sent to guest */
152 	struct virtio_scsi_event event;
153 	/* event list, serviced from vhost worker thread */
154 	struct llist_node list;
155 };
156 
157 enum {
158 	VHOST_SCSI_VQ_CTL = 0,
159 	VHOST_SCSI_VQ_EVT = 1,
160 	VHOST_SCSI_VQ_IO = 2,
161 };
162 
163 /* Note: can't set VIRTIO_F_VERSION_1 yet, since that implies ANY_LAYOUT. */
164 enum {
165 	VHOST_SCSI_FEATURES = VHOST_FEATURES | (1ULL << VIRTIO_SCSI_F_HOTPLUG) |
166 					       (1ULL << VIRTIO_SCSI_F_T10_PI)
167 };
168 
169 #define VHOST_SCSI_MAX_TARGET	256
170 #define VHOST_SCSI_MAX_VQ	128
171 #define VHOST_SCSI_MAX_EVENT	128
172 
173 struct vhost_scsi_virtqueue {
174 	struct vhost_virtqueue vq;
175 	/*
176 	 * Reference counting for inflight reqs, used for flush operation. At
177 	 * each time, one reference tracks new commands submitted, while we
178 	 * wait for another one to reach 0.
179 	 */
180 	struct vhost_scsi_inflight inflights[2];
181 	/*
182 	 * Indicate current inflight in use, protected by vq->mutex.
183 	 * Writers must also take dev mutex and flush under it.
184 	 */
185 	int inflight_idx;
186 };
187 
188 struct vhost_scsi {
189 	/* Protected by vhost_scsi->dev.mutex */
190 	struct vhost_scsi_tpg **vs_tpg;
191 	char vs_vhost_wwpn[TRANSPORT_IQN_LEN];
192 
193 	struct vhost_dev dev;
194 	struct vhost_scsi_virtqueue vqs[VHOST_SCSI_MAX_VQ];
195 
196 	struct vhost_work vs_completion_work; /* cmd completion work item */
197 	struct llist_head vs_completion_list; /* cmd completion queue */
198 
199 	struct vhost_work vs_event_work; /* evt injection work item */
200 	struct llist_head vs_event_list; /* evt injection queue */
201 
202 	bool vs_events_missed; /* any missed events, protected by vq->mutex */
203 	int vs_events_nr; /* num of pending events, protected by vq->mutex */
204 };
205 
206 /*
207  * Context for processing request and control queue operations.
208  */
209 struct vhost_scsi_ctx {
210 	int head;
211 	unsigned int out, in;
212 	size_t req_size, rsp_size;
213 	size_t out_size, in_size;
214 	u8 *target, *lunp;
215 	void *req;
216 	struct iov_iter out_iter;
217 };
218 
219 static struct workqueue_struct *vhost_scsi_workqueue;
220 
221 /* Global spinlock to protect vhost_scsi TPG list for vhost IOCTL access */
222 static DEFINE_MUTEX(vhost_scsi_mutex);
223 static LIST_HEAD(vhost_scsi_list);
224 
225 static void vhost_scsi_done_inflight(struct kref *kref)
226 {
227 	struct vhost_scsi_inflight *inflight;
228 
229 	inflight = container_of(kref, struct vhost_scsi_inflight, kref);
230 	complete(&inflight->comp);
231 }
232 
233 static void vhost_scsi_init_inflight(struct vhost_scsi *vs,
234 				    struct vhost_scsi_inflight *old_inflight[])
235 {
236 	struct vhost_scsi_inflight *new_inflight;
237 	struct vhost_virtqueue *vq;
238 	int idx, i;
239 
240 	for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
241 		vq = &vs->vqs[i].vq;
242 
243 		mutex_lock(&vq->mutex);
244 
245 		/* store old infight */
246 		idx = vs->vqs[i].inflight_idx;
247 		if (old_inflight)
248 			old_inflight[i] = &vs->vqs[i].inflights[idx];
249 
250 		/* setup new infight */
251 		vs->vqs[i].inflight_idx = idx ^ 1;
252 		new_inflight = &vs->vqs[i].inflights[idx ^ 1];
253 		kref_init(&new_inflight->kref);
254 		init_completion(&new_inflight->comp);
255 
256 		mutex_unlock(&vq->mutex);
257 	}
258 }
259 
260 static struct vhost_scsi_inflight *
261 vhost_scsi_get_inflight(struct vhost_virtqueue *vq)
262 {
263 	struct vhost_scsi_inflight *inflight;
264 	struct vhost_scsi_virtqueue *svq;
265 
266 	svq = container_of(vq, struct vhost_scsi_virtqueue, vq);
267 	inflight = &svq->inflights[svq->inflight_idx];
268 	kref_get(&inflight->kref);
269 
270 	return inflight;
271 }
272 
273 static void vhost_scsi_put_inflight(struct vhost_scsi_inflight *inflight)
274 {
275 	kref_put(&inflight->kref, vhost_scsi_done_inflight);
276 }
277 
278 static int vhost_scsi_check_true(struct se_portal_group *se_tpg)
279 {
280 	return 1;
281 }
282 
283 static int vhost_scsi_check_false(struct se_portal_group *se_tpg)
284 {
285 	return 0;
286 }
287 
288 static char *vhost_scsi_get_fabric_wwn(struct se_portal_group *se_tpg)
289 {
290 	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
291 				struct vhost_scsi_tpg, se_tpg);
292 	struct vhost_scsi_tport *tport = tpg->tport;
293 
294 	return &tport->tport_name[0];
295 }
296 
297 static u16 vhost_scsi_get_tpgt(struct se_portal_group *se_tpg)
298 {
299 	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
300 				struct vhost_scsi_tpg, se_tpg);
301 	return tpg->tport_tpgt;
302 }
303 
304 static int vhost_scsi_check_prot_fabric_only(struct se_portal_group *se_tpg)
305 {
306 	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
307 				struct vhost_scsi_tpg, se_tpg);
308 
309 	return tpg->tv_fabric_prot_type;
310 }
311 
312 static u32 vhost_scsi_tpg_get_inst_index(struct se_portal_group *se_tpg)
313 {
314 	return 1;
315 }
316 
317 static void vhost_scsi_release_cmd(struct se_cmd *se_cmd)
318 {
319 	struct vhost_scsi_cmd *tv_cmd = container_of(se_cmd,
320 				struct vhost_scsi_cmd, tvc_se_cmd);
321 	struct se_session *se_sess = tv_cmd->tvc_nexus->tvn_se_sess;
322 	int i;
323 
324 	if (tv_cmd->tvc_sgl_count) {
325 		for (i = 0; i < tv_cmd->tvc_sgl_count; i++)
326 			put_page(sg_page(&tv_cmd->tvc_sgl[i]));
327 	}
328 	if (tv_cmd->tvc_prot_sgl_count) {
329 		for (i = 0; i < tv_cmd->tvc_prot_sgl_count; i++)
330 			put_page(sg_page(&tv_cmd->tvc_prot_sgl[i]));
331 	}
332 
333 	vhost_scsi_put_inflight(tv_cmd->inflight);
334 	target_free_tag(se_sess, se_cmd);
335 }
336 
337 static u32 vhost_scsi_sess_get_index(struct se_session *se_sess)
338 {
339 	return 0;
340 }
341 
342 static int vhost_scsi_write_pending(struct se_cmd *se_cmd)
343 {
344 	/* Go ahead and process the write immediately */
345 	target_execute_cmd(se_cmd);
346 	return 0;
347 }
348 
349 static int vhost_scsi_write_pending_status(struct se_cmd *se_cmd)
350 {
351 	return 0;
352 }
353 
354 static void vhost_scsi_set_default_node_attrs(struct se_node_acl *nacl)
355 {
356 	return;
357 }
358 
359 static int vhost_scsi_get_cmd_state(struct se_cmd *se_cmd)
360 {
361 	return 0;
362 }
363 
364 static void vhost_scsi_complete_cmd(struct vhost_scsi_cmd *cmd)
365 {
366 	struct vhost_scsi *vs = cmd->tvc_vhost;
367 
368 	llist_add(&cmd->tvc_completion_list, &vs->vs_completion_list);
369 
370 	vhost_work_queue(&vs->dev, &vs->vs_completion_work);
371 }
372 
373 static int vhost_scsi_queue_data_in(struct se_cmd *se_cmd)
374 {
375 	struct vhost_scsi_cmd *cmd = container_of(se_cmd,
376 				struct vhost_scsi_cmd, tvc_se_cmd);
377 	vhost_scsi_complete_cmd(cmd);
378 	return 0;
379 }
380 
381 static int vhost_scsi_queue_status(struct se_cmd *se_cmd)
382 {
383 	struct vhost_scsi_cmd *cmd = container_of(se_cmd,
384 				struct vhost_scsi_cmd, tvc_se_cmd);
385 	vhost_scsi_complete_cmd(cmd);
386 	return 0;
387 }
388 
389 static void vhost_scsi_queue_tm_rsp(struct se_cmd *se_cmd)
390 {
391 	return;
392 }
393 
394 static void vhost_scsi_aborted_task(struct se_cmd *se_cmd)
395 {
396 	return;
397 }
398 
399 static void vhost_scsi_free_evt(struct vhost_scsi *vs, struct vhost_scsi_evt *evt)
400 {
401 	vs->vs_events_nr--;
402 	kfree(evt);
403 }
404 
405 static struct vhost_scsi_evt *
406 vhost_scsi_allocate_evt(struct vhost_scsi *vs,
407 		       u32 event, u32 reason)
408 {
409 	struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
410 	struct vhost_scsi_evt *evt;
411 
412 	if (vs->vs_events_nr > VHOST_SCSI_MAX_EVENT) {
413 		vs->vs_events_missed = true;
414 		return NULL;
415 	}
416 
417 	evt = kzalloc(sizeof(*evt), GFP_KERNEL);
418 	if (!evt) {
419 		vq_err(vq, "Failed to allocate vhost_scsi_evt\n");
420 		vs->vs_events_missed = true;
421 		return NULL;
422 	}
423 
424 	evt->event.event = cpu_to_vhost32(vq, event);
425 	evt->event.reason = cpu_to_vhost32(vq, reason);
426 	vs->vs_events_nr++;
427 
428 	return evt;
429 }
430 
431 static void vhost_scsi_free_cmd(struct vhost_scsi_cmd *cmd)
432 {
433 	struct se_cmd *se_cmd = &cmd->tvc_se_cmd;
434 
435 	/* TODO locking against target/backend threads? */
436 	transport_generic_free_cmd(se_cmd, 0);
437 
438 }
439 
440 static int vhost_scsi_check_stop_free(struct se_cmd *se_cmd)
441 {
442 	return target_put_sess_cmd(se_cmd);
443 }
444 
445 static void
446 vhost_scsi_do_evt_work(struct vhost_scsi *vs, struct vhost_scsi_evt *evt)
447 {
448 	struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
449 	struct virtio_scsi_event *event = &evt->event;
450 	struct virtio_scsi_event __user *eventp;
451 	unsigned out, in;
452 	int head, ret;
453 
454 	if (!vq->private_data) {
455 		vs->vs_events_missed = true;
456 		return;
457 	}
458 
459 again:
460 	vhost_disable_notify(&vs->dev, vq);
461 	head = vhost_get_vq_desc(vq, vq->iov,
462 			ARRAY_SIZE(vq->iov), &out, &in,
463 			NULL, NULL);
464 	if (head < 0) {
465 		vs->vs_events_missed = true;
466 		return;
467 	}
468 	if (head == vq->num) {
469 		if (vhost_enable_notify(&vs->dev, vq))
470 			goto again;
471 		vs->vs_events_missed = true;
472 		return;
473 	}
474 
475 	if ((vq->iov[out].iov_len != sizeof(struct virtio_scsi_event))) {
476 		vq_err(vq, "Expecting virtio_scsi_event, got %zu bytes\n",
477 				vq->iov[out].iov_len);
478 		vs->vs_events_missed = true;
479 		return;
480 	}
481 
482 	if (vs->vs_events_missed) {
483 		event->event |= cpu_to_vhost32(vq, VIRTIO_SCSI_T_EVENTS_MISSED);
484 		vs->vs_events_missed = false;
485 	}
486 
487 	eventp = vq->iov[out].iov_base;
488 	ret = __copy_to_user(eventp, event, sizeof(*event));
489 	if (!ret)
490 		vhost_add_used_and_signal(&vs->dev, vq, head, 0);
491 	else
492 		vq_err(vq, "Faulted on vhost_scsi_send_event\n");
493 }
494 
495 static void vhost_scsi_evt_work(struct vhost_work *work)
496 {
497 	struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
498 					vs_event_work);
499 	struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
500 	struct vhost_scsi_evt *evt, *t;
501 	struct llist_node *llnode;
502 
503 	mutex_lock(&vq->mutex);
504 	llnode = llist_del_all(&vs->vs_event_list);
505 	llist_for_each_entry_safe(evt, t, llnode, list) {
506 		vhost_scsi_do_evt_work(vs, evt);
507 		vhost_scsi_free_evt(vs, evt);
508 	}
509 	mutex_unlock(&vq->mutex);
510 }
511 
512 /* Fill in status and signal that we are done processing this command
513  *
514  * This is scheduled in the vhost work queue so we are called with the owner
515  * process mm and can access the vring.
516  */
517 static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
518 {
519 	struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
520 					vs_completion_work);
521 	DECLARE_BITMAP(signal, VHOST_SCSI_MAX_VQ);
522 	struct virtio_scsi_cmd_resp v_rsp;
523 	struct vhost_scsi_cmd *cmd, *t;
524 	struct llist_node *llnode;
525 	struct se_cmd *se_cmd;
526 	struct iov_iter iov_iter;
527 	int ret, vq;
528 
529 	bitmap_zero(signal, VHOST_SCSI_MAX_VQ);
530 	llnode = llist_del_all(&vs->vs_completion_list);
531 	llist_for_each_entry_safe(cmd, t, llnode, tvc_completion_list) {
532 		se_cmd = &cmd->tvc_se_cmd;
533 
534 		pr_debug("%s tv_cmd %p resid %u status %#02x\n", __func__,
535 			cmd, se_cmd->residual_count, se_cmd->scsi_status);
536 
537 		memset(&v_rsp, 0, sizeof(v_rsp));
538 		v_rsp.resid = cpu_to_vhost32(cmd->tvc_vq, se_cmd->residual_count);
539 		/* TODO is status_qualifier field needed? */
540 		v_rsp.status = se_cmd->scsi_status;
541 		v_rsp.sense_len = cpu_to_vhost32(cmd->tvc_vq,
542 						 se_cmd->scsi_sense_length);
543 		memcpy(v_rsp.sense, cmd->tvc_sense_buf,
544 		       se_cmd->scsi_sense_length);
545 
546 		iov_iter_init(&iov_iter, READ, &cmd->tvc_resp_iov,
547 			      cmd->tvc_in_iovs, sizeof(v_rsp));
548 		ret = copy_to_iter(&v_rsp, sizeof(v_rsp), &iov_iter);
549 		if (likely(ret == sizeof(v_rsp))) {
550 			struct vhost_scsi_virtqueue *q;
551 			vhost_add_used(cmd->tvc_vq, cmd->tvc_vq_desc, 0);
552 			q = container_of(cmd->tvc_vq, struct vhost_scsi_virtqueue, vq);
553 			vq = q - vs->vqs;
554 			__set_bit(vq, signal);
555 		} else
556 			pr_err("Faulted on virtio_scsi_cmd_resp\n");
557 
558 		vhost_scsi_free_cmd(cmd);
559 	}
560 
561 	vq = -1;
562 	while ((vq = find_next_bit(signal, VHOST_SCSI_MAX_VQ, vq + 1))
563 		< VHOST_SCSI_MAX_VQ)
564 		vhost_signal(&vs->dev, &vs->vqs[vq].vq);
565 }
566 
567 static struct vhost_scsi_cmd *
568 vhost_scsi_get_tag(struct vhost_virtqueue *vq, struct vhost_scsi_tpg *tpg,
569 		   unsigned char *cdb, u64 scsi_tag, u16 lun, u8 task_attr,
570 		   u32 exp_data_len, int data_direction)
571 {
572 	struct vhost_scsi_cmd *cmd;
573 	struct vhost_scsi_nexus *tv_nexus;
574 	struct se_session *se_sess;
575 	struct scatterlist *sg, *prot_sg;
576 	struct page **pages;
577 	int tag, cpu;
578 
579 	tv_nexus = tpg->tpg_nexus;
580 	if (!tv_nexus) {
581 		pr_err("Unable to locate active struct vhost_scsi_nexus\n");
582 		return ERR_PTR(-EIO);
583 	}
584 	se_sess = tv_nexus->tvn_se_sess;
585 
586 	tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
587 	if (tag < 0) {
588 		pr_err("Unable to obtain tag for vhost_scsi_cmd\n");
589 		return ERR_PTR(-ENOMEM);
590 	}
591 
592 	cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[tag];
593 	sg = cmd->tvc_sgl;
594 	prot_sg = cmd->tvc_prot_sgl;
595 	pages = cmd->tvc_upages;
596 	memset(cmd, 0, sizeof(*cmd));
597 	cmd->tvc_sgl = sg;
598 	cmd->tvc_prot_sgl = prot_sg;
599 	cmd->tvc_upages = pages;
600 	cmd->tvc_se_cmd.map_tag = tag;
601 	cmd->tvc_se_cmd.map_cpu = cpu;
602 	cmd->tvc_tag = scsi_tag;
603 	cmd->tvc_lun = lun;
604 	cmd->tvc_task_attr = task_attr;
605 	cmd->tvc_exp_data_len = exp_data_len;
606 	cmd->tvc_data_direction = data_direction;
607 	cmd->tvc_nexus = tv_nexus;
608 	cmd->inflight = vhost_scsi_get_inflight(vq);
609 
610 	memcpy(cmd->tvc_cdb, cdb, VHOST_SCSI_MAX_CDB_SIZE);
611 
612 	return cmd;
613 }
614 
615 /*
616  * Map a user memory range into a scatterlist
617  *
618  * Returns the number of scatterlist entries used or -errno on error.
619  */
620 static int
621 vhost_scsi_map_to_sgl(struct vhost_scsi_cmd *cmd,
622 		      struct iov_iter *iter,
623 		      struct scatterlist *sgl,
624 		      bool write)
625 {
626 	struct page **pages = cmd->tvc_upages;
627 	struct scatterlist *sg = sgl;
628 	ssize_t bytes;
629 	size_t offset;
630 	unsigned int npages = 0;
631 
632 	bytes = iov_iter_get_pages(iter, pages, LONG_MAX,
633 				VHOST_SCSI_PREALLOC_UPAGES, &offset);
634 	/* No pages were pinned */
635 	if (bytes <= 0)
636 		return bytes < 0 ? bytes : -EFAULT;
637 
638 	iov_iter_advance(iter, bytes);
639 
640 	while (bytes) {
641 		unsigned n = min_t(unsigned, PAGE_SIZE - offset, bytes);
642 		sg_set_page(sg++, pages[npages++], n, offset);
643 		bytes -= n;
644 		offset = 0;
645 	}
646 	return npages;
647 }
648 
649 static int
650 vhost_scsi_calc_sgls(struct iov_iter *iter, size_t bytes, int max_sgls)
651 {
652 	int sgl_count = 0;
653 
654 	if (!iter || !iter->iov) {
655 		pr_err("%s: iter->iov is NULL, but expected bytes: %zu"
656 		       " present\n", __func__, bytes);
657 		return -EINVAL;
658 	}
659 
660 	sgl_count = iov_iter_npages(iter, 0xffff);
661 	if (sgl_count > max_sgls) {
662 		pr_err("%s: requested sgl_count: %d exceeds pre-allocated"
663 		       " max_sgls: %d\n", __func__, sgl_count, max_sgls);
664 		return -EINVAL;
665 	}
666 	return sgl_count;
667 }
668 
669 static int
670 vhost_scsi_iov_to_sgl(struct vhost_scsi_cmd *cmd, bool write,
671 		      struct iov_iter *iter,
672 		      struct scatterlist *sg, int sg_count)
673 {
674 	struct scatterlist *p = sg;
675 	int ret;
676 
677 	while (iov_iter_count(iter)) {
678 		ret = vhost_scsi_map_to_sgl(cmd, iter, sg, write);
679 		if (ret < 0) {
680 			while (p < sg) {
681 				struct page *page = sg_page(p++);
682 				if (page)
683 					put_page(page);
684 			}
685 			return ret;
686 		}
687 		sg += ret;
688 	}
689 	return 0;
690 }
691 
692 static int
693 vhost_scsi_mapal(struct vhost_scsi_cmd *cmd,
694 		 size_t prot_bytes, struct iov_iter *prot_iter,
695 		 size_t data_bytes, struct iov_iter *data_iter)
696 {
697 	int sgl_count, ret;
698 	bool write = (cmd->tvc_data_direction == DMA_FROM_DEVICE);
699 
700 	if (prot_bytes) {
701 		sgl_count = vhost_scsi_calc_sgls(prot_iter, prot_bytes,
702 						 VHOST_SCSI_PREALLOC_PROT_SGLS);
703 		if (sgl_count < 0)
704 			return sgl_count;
705 
706 		sg_init_table(cmd->tvc_prot_sgl, sgl_count);
707 		cmd->tvc_prot_sgl_count = sgl_count;
708 		pr_debug("%s prot_sg %p prot_sgl_count %u\n", __func__,
709 			 cmd->tvc_prot_sgl, cmd->tvc_prot_sgl_count);
710 
711 		ret = vhost_scsi_iov_to_sgl(cmd, write, prot_iter,
712 					    cmd->tvc_prot_sgl,
713 					    cmd->tvc_prot_sgl_count);
714 		if (ret < 0) {
715 			cmd->tvc_prot_sgl_count = 0;
716 			return ret;
717 		}
718 	}
719 	sgl_count = vhost_scsi_calc_sgls(data_iter, data_bytes,
720 					 VHOST_SCSI_PREALLOC_SGLS);
721 	if (sgl_count < 0)
722 		return sgl_count;
723 
724 	sg_init_table(cmd->tvc_sgl, sgl_count);
725 	cmd->tvc_sgl_count = sgl_count;
726 	pr_debug("%s data_sg %p data_sgl_count %u\n", __func__,
727 		  cmd->tvc_sgl, cmd->tvc_sgl_count);
728 
729 	ret = vhost_scsi_iov_to_sgl(cmd, write, data_iter,
730 				    cmd->tvc_sgl, cmd->tvc_sgl_count);
731 	if (ret < 0) {
732 		cmd->tvc_sgl_count = 0;
733 		return ret;
734 	}
735 	return 0;
736 }
737 
738 static int vhost_scsi_to_tcm_attr(int attr)
739 {
740 	switch (attr) {
741 	case VIRTIO_SCSI_S_SIMPLE:
742 		return TCM_SIMPLE_TAG;
743 	case VIRTIO_SCSI_S_ORDERED:
744 		return TCM_ORDERED_TAG;
745 	case VIRTIO_SCSI_S_HEAD:
746 		return TCM_HEAD_TAG;
747 	case VIRTIO_SCSI_S_ACA:
748 		return TCM_ACA_TAG;
749 	default:
750 		break;
751 	}
752 	return TCM_SIMPLE_TAG;
753 }
754 
755 static void vhost_scsi_submission_work(struct work_struct *work)
756 {
757 	struct vhost_scsi_cmd *cmd =
758 		container_of(work, struct vhost_scsi_cmd, work);
759 	struct vhost_scsi_nexus *tv_nexus;
760 	struct se_cmd *se_cmd = &cmd->tvc_se_cmd;
761 	struct scatterlist *sg_ptr, *sg_prot_ptr = NULL;
762 	int rc;
763 
764 	/* FIXME: BIDI operation */
765 	if (cmd->tvc_sgl_count) {
766 		sg_ptr = cmd->tvc_sgl;
767 
768 		if (cmd->tvc_prot_sgl_count)
769 			sg_prot_ptr = cmd->tvc_prot_sgl;
770 		else
771 			se_cmd->prot_pto = true;
772 	} else {
773 		sg_ptr = NULL;
774 	}
775 	tv_nexus = cmd->tvc_nexus;
776 
777 	se_cmd->tag = 0;
778 	rc = target_submit_cmd_map_sgls(se_cmd, tv_nexus->tvn_se_sess,
779 			cmd->tvc_cdb, &cmd->tvc_sense_buf[0],
780 			cmd->tvc_lun, cmd->tvc_exp_data_len,
781 			vhost_scsi_to_tcm_attr(cmd->tvc_task_attr),
782 			cmd->tvc_data_direction, TARGET_SCF_ACK_KREF,
783 			sg_ptr, cmd->tvc_sgl_count, NULL, 0, sg_prot_ptr,
784 			cmd->tvc_prot_sgl_count);
785 	if (rc < 0) {
786 		transport_send_check_condition_and_sense(se_cmd,
787 				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
788 		transport_generic_free_cmd(se_cmd, 0);
789 	}
790 }
791 
792 static void
793 vhost_scsi_send_bad_target(struct vhost_scsi *vs,
794 			   struct vhost_virtqueue *vq,
795 			   int head, unsigned out)
796 {
797 	struct virtio_scsi_cmd_resp __user *resp;
798 	struct virtio_scsi_cmd_resp rsp;
799 	int ret;
800 
801 	memset(&rsp, 0, sizeof(rsp));
802 	rsp.response = VIRTIO_SCSI_S_BAD_TARGET;
803 	resp = vq->iov[out].iov_base;
804 	ret = __copy_to_user(resp, &rsp, sizeof(rsp));
805 	if (!ret)
806 		vhost_add_used_and_signal(&vs->dev, vq, head, 0);
807 	else
808 		pr_err("Faulted on virtio_scsi_cmd_resp\n");
809 }
810 
811 static int
812 vhost_scsi_get_desc(struct vhost_scsi *vs, struct vhost_virtqueue *vq,
813 		    struct vhost_scsi_ctx *vc)
814 {
815 	int ret = -ENXIO;
816 
817 	vc->head = vhost_get_vq_desc(vq, vq->iov,
818 				     ARRAY_SIZE(vq->iov), &vc->out, &vc->in,
819 				     NULL, NULL);
820 
821 	pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n",
822 		 vc->head, vc->out, vc->in);
823 
824 	/* On error, stop handling until the next kick. */
825 	if (unlikely(vc->head < 0))
826 		goto done;
827 
828 	/* Nothing new?  Wait for eventfd to tell us they refilled. */
829 	if (vc->head == vq->num) {
830 		if (unlikely(vhost_enable_notify(&vs->dev, vq))) {
831 			vhost_disable_notify(&vs->dev, vq);
832 			ret = -EAGAIN;
833 		}
834 		goto done;
835 	}
836 
837 	/*
838 	 * Get the size of request and response buffers.
839 	 * FIXME: Not correct for BIDI operation
840 	 */
841 	vc->out_size = iov_length(vq->iov, vc->out);
842 	vc->in_size = iov_length(&vq->iov[vc->out], vc->in);
843 
844 	/*
845 	 * Copy over the virtio-scsi request header, which for a
846 	 * ANY_LAYOUT enabled guest may span multiple iovecs, or a
847 	 * single iovec may contain both the header + outgoing
848 	 * WRITE payloads.
849 	 *
850 	 * copy_from_iter() will advance out_iter, so that it will
851 	 * point at the start of the outgoing WRITE payload, if
852 	 * DMA_TO_DEVICE is set.
853 	 */
854 	iov_iter_init(&vc->out_iter, WRITE, vq->iov, vc->out, vc->out_size);
855 	ret = 0;
856 
857 done:
858 	return ret;
859 }
860 
861 static int
862 vhost_scsi_chk_size(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc)
863 {
864 	if (unlikely(vc->in_size < vc->rsp_size)) {
865 		vq_err(vq,
866 		       "Response buf too small, need min %zu bytes got %zu",
867 		       vc->rsp_size, vc->in_size);
868 		return -EINVAL;
869 	} else if (unlikely(vc->out_size < vc->req_size)) {
870 		vq_err(vq,
871 		       "Request buf too small, need min %zu bytes got %zu",
872 		       vc->req_size, vc->out_size);
873 		return -EIO;
874 	}
875 
876 	return 0;
877 }
878 
879 static int
880 vhost_scsi_get_req(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc,
881 		   struct vhost_scsi_tpg **tpgp)
882 {
883 	int ret = -EIO;
884 
885 	if (unlikely(!copy_from_iter_full(vc->req, vc->req_size,
886 					  &vc->out_iter))) {
887 		vq_err(vq, "Faulted on copy_from_iter_full\n");
888 	} else if (unlikely(*vc->lunp != 1)) {
889 		/* virtio-scsi spec requires byte 0 of the lun to be 1 */
890 		vq_err(vq, "Illegal virtio-scsi lun: %u\n", *vc->lunp);
891 	} else {
892 		struct vhost_scsi_tpg **vs_tpg, *tpg;
893 
894 		vs_tpg = vq->private_data;	/* validated at handler entry */
895 
896 		tpg = READ_ONCE(vs_tpg[*vc->target]);
897 		if (unlikely(!tpg)) {
898 			vq_err(vq, "Target 0x%x does not exist\n", *vc->target);
899 		} else {
900 			if (tpgp)
901 				*tpgp = tpg;
902 			ret = 0;
903 		}
904 	}
905 
906 	return ret;
907 }
908 
909 static void
910 vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
911 {
912 	struct vhost_scsi_tpg **vs_tpg, *tpg;
913 	struct virtio_scsi_cmd_req v_req;
914 	struct virtio_scsi_cmd_req_pi v_req_pi;
915 	struct vhost_scsi_ctx vc;
916 	struct vhost_scsi_cmd *cmd;
917 	struct iov_iter in_iter, prot_iter, data_iter;
918 	u64 tag;
919 	u32 exp_data_len, data_direction;
920 	int ret, prot_bytes;
921 	u16 lun;
922 	u8 task_attr;
923 	bool t10_pi = vhost_has_feature(vq, VIRTIO_SCSI_F_T10_PI);
924 	void *cdb;
925 
926 	mutex_lock(&vq->mutex);
927 	/*
928 	 * We can handle the vq only after the endpoint is setup by calling the
929 	 * VHOST_SCSI_SET_ENDPOINT ioctl.
930 	 */
931 	vs_tpg = vq->private_data;
932 	if (!vs_tpg)
933 		goto out;
934 
935 	memset(&vc, 0, sizeof(vc));
936 	vc.rsp_size = sizeof(struct virtio_scsi_cmd_resp);
937 
938 	vhost_disable_notify(&vs->dev, vq);
939 
940 	for (;;) {
941 		ret = vhost_scsi_get_desc(vs, vq, &vc);
942 		if (ret)
943 			goto err;
944 
945 		/*
946 		 * Setup pointers and values based upon different virtio-scsi
947 		 * request header if T10_PI is enabled in KVM guest.
948 		 */
949 		if (t10_pi) {
950 			vc.req = &v_req_pi;
951 			vc.req_size = sizeof(v_req_pi);
952 			vc.lunp = &v_req_pi.lun[0];
953 			vc.target = &v_req_pi.lun[1];
954 		} else {
955 			vc.req = &v_req;
956 			vc.req_size = sizeof(v_req);
957 			vc.lunp = &v_req.lun[0];
958 			vc.target = &v_req.lun[1];
959 		}
960 
961 		/*
962 		 * Validate the size of request and response buffers.
963 		 * Check for a sane response buffer so we can report
964 		 * early errors back to the guest.
965 		 */
966 		ret = vhost_scsi_chk_size(vq, &vc);
967 		if (ret)
968 			goto err;
969 
970 		ret = vhost_scsi_get_req(vq, &vc, &tpg);
971 		if (ret)
972 			goto err;
973 
974 		ret = -EIO;	/* bad target on any error from here on */
975 
976 		/*
977 		 * Determine data_direction by calculating the total outgoing
978 		 * iovec sizes + incoming iovec sizes vs. virtio-scsi request +
979 		 * response headers respectively.
980 		 *
981 		 * For DMA_TO_DEVICE this is out_iter, which is already pointing
982 		 * to the right place.
983 		 *
984 		 * For DMA_FROM_DEVICE, the iovec will be just past the end
985 		 * of the virtio-scsi response header in either the same
986 		 * or immediately following iovec.
987 		 *
988 		 * Any associated T10_PI bytes for the outgoing / incoming
989 		 * payloads are included in calculation of exp_data_len here.
990 		 */
991 		prot_bytes = 0;
992 
993 		if (vc.out_size > vc.req_size) {
994 			data_direction = DMA_TO_DEVICE;
995 			exp_data_len = vc.out_size - vc.req_size;
996 			data_iter = vc.out_iter;
997 		} else if (vc.in_size > vc.rsp_size) {
998 			data_direction = DMA_FROM_DEVICE;
999 			exp_data_len = vc.in_size - vc.rsp_size;
1000 
1001 			iov_iter_init(&in_iter, READ, &vq->iov[vc.out], vc.in,
1002 				      vc.rsp_size + exp_data_len);
1003 			iov_iter_advance(&in_iter, vc.rsp_size);
1004 			data_iter = in_iter;
1005 		} else {
1006 			data_direction = DMA_NONE;
1007 			exp_data_len = 0;
1008 		}
1009 		/*
1010 		 * If T10_PI header + payload is present, setup prot_iter values
1011 		 * and recalculate data_iter for vhost_scsi_mapal() mapping to
1012 		 * host scatterlists via get_user_pages_fast().
1013 		 */
1014 		if (t10_pi) {
1015 			if (v_req_pi.pi_bytesout) {
1016 				if (data_direction != DMA_TO_DEVICE) {
1017 					vq_err(vq, "Received non zero pi_bytesout,"
1018 						" but wrong data_direction\n");
1019 					goto err;
1020 				}
1021 				prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesout);
1022 			} else if (v_req_pi.pi_bytesin) {
1023 				if (data_direction != DMA_FROM_DEVICE) {
1024 					vq_err(vq, "Received non zero pi_bytesin,"
1025 						" but wrong data_direction\n");
1026 					goto err;
1027 				}
1028 				prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin);
1029 			}
1030 			/*
1031 			 * Set prot_iter to data_iter and truncate it to
1032 			 * prot_bytes, and advance data_iter past any
1033 			 * preceeding prot_bytes that may be present.
1034 			 *
1035 			 * Also fix up the exp_data_len to reflect only the
1036 			 * actual data payload length.
1037 			 */
1038 			if (prot_bytes) {
1039 				exp_data_len -= prot_bytes;
1040 				prot_iter = data_iter;
1041 				iov_iter_truncate(&prot_iter, prot_bytes);
1042 				iov_iter_advance(&data_iter, prot_bytes);
1043 			}
1044 			tag = vhost64_to_cpu(vq, v_req_pi.tag);
1045 			task_attr = v_req_pi.task_attr;
1046 			cdb = &v_req_pi.cdb[0];
1047 			lun = ((v_req_pi.lun[2] << 8) | v_req_pi.lun[3]) & 0x3FFF;
1048 		} else {
1049 			tag = vhost64_to_cpu(vq, v_req.tag);
1050 			task_attr = v_req.task_attr;
1051 			cdb = &v_req.cdb[0];
1052 			lun = ((v_req.lun[2] << 8) | v_req.lun[3]) & 0x3FFF;
1053 		}
1054 		/*
1055 		 * Check that the received CDB size does not exceeded our
1056 		 * hardcoded max for vhost-scsi, then get a pre-allocated
1057 		 * cmd descriptor for the new virtio-scsi tag.
1058 		 *
1059 		 * TODO what if cdb was too small for varlen cdb header?
1060 		 */
1061 		if (unlikely(scsi_command_size(cdb) > VHOST_SCSI_MAX_CDB_SIZE)) {
1062 			vq_err(vq, "Received SCSI CDB with command_size: %d that"
1063 				" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1064 				scsi_command_size(cdb), VHOST_SCSI_MAX_CDB_SIZE);
1065 				goto err;
1066 		}
1067 		cmd = vhost_scsi_get_tag(vq, tpg, cdb, tag, lun, task_attr,
1068 					 exp_data_len + prot_bytes,
1069 					 data_direction);
1070 		if (IS_ERR(cmd)) {
1071 			vq_err(vq, "vhost_scsi_get_tag failed %ld\n",
1072 			       PTR_ERR(cmd));
1073 			goto err;
1074 		}
1075 		cmd->tvc_vhost = vs;
1076 		cmd->tvc_vq = vq;
1077 		cmd->tvc_resp_iov = vq->iov[vc.out];
1078 		cmd->tvc_in_iovs = vc.in;
1079 
1080 		pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",
1081 			 cmd->tvc_cdb[0], cmd->tvc_lun);
1082 		pr_debug("cmd: %p exp_data_len: %d, prot_bytes: %d data_direction:"
1083 			 " %d\n", cmd, exp_data_len, prot_bytes, data_direction);
1084 
1085 		if (data_direction != DMA_NONE) {
1086 			if (unlikely(vhost_scsi_mapal(cmd, prot_bytes,
1087 						      &prot_iter, exp_data_len,
1088 						      &data_iter))) {
1089 				vq_err(vq, "Failed to map iov to sgl\n");
1090 				vhost_scsi_release_cmd(&cmd->tvc_se_cmd);
1091 				goto err;
1092 			}
1093 		}
1094 		/*
1095 		 * Save the descriptor from vhost_get_vq_desc() to be used to
1096 		 * complete the virtio-scsi request in TCM callback context via
1097 		 * vhost_scsi_queue_data_in() and vhost_scsi_queue_status()
1098 		 */
1099 		cmd->tvc_vq_desc = vc.head;
1100 		/*
1101 		 * Dispatch cmd descriptor for cmwq execution in process
1102 		 * context provided by vhost_scsi_workqueue.  This also ensures
1103 		 * cmd is executed on the same kworker CPU as this vhost
1104 		 * thread to gain positive L2 cache locality effects.
1105 		 */
1106 		INIT_WORK(&cmd->work, vhost_scsi_submission_work);
1107 		queue_work(vhost_scsi_workqueue, &cmd->work);
1108 		ret = 0;
1109 err:
1110 		/*
1111 		 * ENXIO:  No more requests, or read error, wait for next kick
1112 		 * EINVAL: Invalid response buffer, drop the request
1113 		 * EIO:    Respond with bad target
1114 		 * EAGAIN: Pending request
1115 		 */
1116 		if (ret == -ENXIO)
1117 			break;
1118 		else if (ret == -EIO)
1119 			vhost_scsi_send_bad_target(vs, vq, vc.head, vc.out);
1120 	}
1121 out:
1122 	mutex_unlock(&vq->mutex);
1123 }
1124 
1125 static void
1126 vhost_scsi_send_tmf_reject(struct vhost_scsi *vs,
1127 			   struct vhost_virtqueue *vq,
1128 			   struct vhost_scsi_ctx *vc)
1129 {
1130 	struct virtio_scsi_ctrl_tmf_resp __user *resp;
1131 	struct virtio_scsi_ctrl_tmf_resp rsp;
1132 	int ret;
1133 
1134 	pr_debug("%s\n", __func__);
1135 	memset(&rsp, 0, sizeof(rsp));
1136 	rsp.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
1137 	resp = vq->iov[vc->out].iov_base;
1138 	ret = __copy_to_user(resp, &rsp, sizeof(rsp));
1139 	if (!ret)
1140 		vhost_add_used_and_signal(&vs->dev, vq, vc->head, 0);
1141 	else
1142 		pr_err("Faulted on virtio_scsi_ctrl_tmf_resp\n");
1143 }
1144 
1145 static void
1146 vhost_scsi_send_an_resp(struct vhost_scsi *vs,
1147 			struct vhost_virtqueue *vq,
1148 			struct vhost_scsi_ctx *vc)
1149 {
1150 	struct virtio_scsi_ctrl_an_resp __user *resp;
1151 	struct virtio_scsi_ctrl_an_resp rsp;
1152 	int ret;
1153 
1154 	pr_debug("%s\n", __func__);
1155 	memset(&rsp, 0, sizeof(rsp));	/* event_actual = 0 */
1156 	rsp.response = VIRTIO_SCSI_S_OK;
1157 	resp = vq->iov[vc->out].iov_base;
1158 	ret = __copy_to_user(resp, &rsp, sizeof(rsp));
1159 	if (!ret)
1160 		vhost_add_used_and_signal(&vs->dev, vq, vc->head, 0);
1161 	else
1162 		pr_err("Faulted on virtio_scsi_ctrl_an_resp\n");
1163 }
1164 
1165 static void
1166 vhost_scsi_ctl_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
1167 {
1168 	union {
1169 		__virtio32 type;
1170 		struct virtio_scsi_ctrl_an_req an;
1171 		struct virtio_scsi_ctrl_tmf_req tmf;
1172 	} v_req;
1173 	struct vhost_scsi_ctx vc;
1174 	size_t typ_size;
1175 	int ret;
1176 
1177 	mutex_lock(&vq->mutex);
1178 	/*
1179 	 * We can handle the vq only after the endpoint is setup by calling the
1180 	 * VHOST_SCSI_SET_ENDPOINT ioctl.
1181 	 */
1182 	if (!vq->private_data)
1183 		goto out;
1184 
1185 	memset(&vc, 0, sizeof(vc));
1186 
1187 	vhost_disable_notify(&vs->dev, vq);
1188 
1189 	for (;;) {
1190 		ret = vhost_scsi_get_desc(vs, vq, &vc);
1191 		if (ret)
1192 			goto err;
1193 
1194 		/*
1195 		 * Get the request type first in order to setup
1196 		 * other parameters dependent on the type.
1197 		 */
1198 		vc.req = &v_req.type;
1199 		typ_size = sizeof(v_req.type);
1200 
1201 		if (unlikely(!copy_from_iter_full(vc.req, typ_size,
1202 						  &vc.out_iter))) {
1203 			vq_err(vq, "Faulted on copy_from_iter tmf type\n");
1204 			/*
1205 			 * The size of the response buffer depends on the
1206 			 * request type and must be validated against it.
1207 			 * Since the request type is not known, don't send
1208 			 * a response.
1209 			 */
1210 			continue;
1211 		}
1212 
1213 		switch (v_req.type) {
1214 		case VIRTIO_SCSI_T_TMF:
1215 			vc.req = &v_req.tmf;
1216 			vc.req_size = sizeof(struct virtio_scsi_ctrl_tmf_req);
1217 			vc.rsp_size = sizeof(struct virtio_scsi_ctrl_tmf_resp);
1218 			vc.lunp = &v_req.tmf.lun[0];
1219 			vc.target = &v_req.tmf.lun[1];
1220 			break;
1221 		case VIRTIO_SCSI_T_AN_QUERY:
1222 		case VIRTIO_SCSI_T_AN_SUBSCRIBE:
1223 			vc.req = &v_req.an;
1224 			vc.req_size = sizeof(struct virtio_scsi_ctrl_an_req);
1225 			vc.rsp_size = sizeof(struct virtio_scsi_ctrl_an_resp);
1226 			vc.lunp = &v_req.an.lun[0];
1227 			vc.target = NULL;
1228 			break;
1229 		default:
1230 			vq_err(vq, "Unknown control request %d", v_req.type);
1231 			continue;
1232 		}
1233 
1234 		/*
1235 		 * Validate the size of request and response buffers.
1236 		 * Check for a sane response buffer so we can report
1237 		 * early errors back to the guest.
1238 		 */
1239 		ret = vhost_scsi_chk_size(vq, &vc);
1240 		if (ret)
1241 			goto err;
1242 
1243 		/*
1244 		 * Get the rest of the request now that its size is known.
1245 		 */
1246 		vc.req += typ_size;
1247 		vc.req_size -= typ_size;
1248 
1249 		ret = vhost_scsi_get_req(vq, &vc, NULL);
1250 		if (ret)
1251 			goto err;
1252 
1253 		if (v_req.type == VIRTIO_SCSI_T_TMF)
1254 			vhost_scsi_send_tmf_reject(vs, vq, &vc);
1255 		else
1256 			vhost_scsi_send_an_resp(vs, vq, &vc);
1257 err:
1258 		/*
1259 		 * ENXIO:  No more requests, or read error, wait for next kick
1260 		 * EINVAL: Invalid response buffer, drop the request
1261 		 * EIO:    Respond with bad target
1262 		 * EAGAIN: Pending request
1263 		 */
1264 		if (ret == -ENXIO)
1265 			break;
1266 		else if (ret == -EIO)
1267 			vhost_scsi_send_bad_target(vs, vq, vc.head, vc.out);
1268 	}
1269 out:
1270 	mutex_unlock(&vq->mutex);
1271 }
1272 
1273 static void vhost_scsi_ctl_handle_kick(struct vhost_work *work)
1274 {
1275 	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1276 						poll.work);
1277 	struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1278 
1279 	pr_debug("%s: The handling func for control queue.\n", __func__);
1280 	vhost_scsi_ctl_handle_vq(vs, vq);
1281 }
1282 
1283 static void
1284 vhost_scsi_send_evt(struct vhost_scsi *vs,
1285 		   struct vhost_scsi_tpg *tpg,
1286 		   struct se_lun *lun,
1287 		   u32 event,
1288 		   u32 reason)
1289 {
1290 	struct vhost_scsi_evt *evt;
1291 
1292 	evt = vhost_scsi_allocate_evt(vs, event, reason);
1293 	if (!evt)
1294 		return;
1295 
1296 	if (tpg && lun) {
1297 		/* TODO: share lun setup code with virtio-scsi.ko */
1298 		/*
1299 		 * Note: evt->event is zeroed when we allocate it and
1300 		 * lun[4-7] need to be zero according to virtio-scsi spec.
1301 		 */
1302 		evt->event.lun[0] = 0x01;
1303 		evt->event.lun[1] = tpg->tport_tpgt;
1304 		if (lun->unpacked_lun >= 256)
1305 			evt->event.lun[2] = lun->unpacked_lun >> 8 | 0x40 ;
1306 		evt->event.lun[3] = lun->unpacked_lun & 0xFF;
1307 	}
1308 
1309 	llist_add(&evt->list, &vs->vs_event_list);
1310 	vhost_work_queue(&vs->dev, &vs->vs_event_work);
1311 }
1312 
1313 static void vhost_scsi_evt_handle_kick(struct vhost_work *work)
1314 {
1315 	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1316 						poll.work);
1317 	struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1318 
1319 	mutex_lock(&vq->mutex);
1320 	if (!vq->private_data)
1321 		goto out;
1322 
1323 	if (vs->vs_events_missed)
1324 		vhost_scsi_send_evt(vs, NULL, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
1325 out:
1326 	mutex_unlock(&vq->mutex);
1327 }
1328 
1329 static void vhost_scsi_handle_kick(struct vhost_work *work)
1330 {
1331 	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1332 						poll.work);
1333 	struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1334 
1335 	vhost_scsi_handle_vq(vs, vq);
1336 }
1337 
1338 static void vhost_scsi_flush_vq(struct vhost_scsi *vs, int index)
1339 {
1340 	vhost_poll_flush(&vs->vqs[index].vq.poll);
1341 }
1342 
1343 /* Callers must hold dev mutex */
1344 static void vhost_scsi_flush(struct vhost_scsi *vs)
1345 {
1346 	struct vhost_scsi_inflight *old_inflight[VHOST_SCSI_MAX_VQ];
1347 	int i;
1348 
1349 	/* Init new inflight and remember the old inflight */
1350 	vhost_scsi_init_inflight(vs, old_inflight);
1351 
1352 	/*
1353 	 * The inflight->kref was initialized to 1. We decrement it here to
1354 	 * indicate the start of the flush operation so that it will reach 0
1355 	 * when all the reqs are finished.
1356 	 */
1357 	for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1358 		kref_put(&old_inflight[i]->kref, vhost_scsi_done_inflight);
1359 
1360 	/* Flush both the vhost poll and vhost work */
1361 	for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1362 		vhost_scsi_flush_vq(vs, i);
1363 	vhost_work_flush(&vs->dev, &vs->vs_completion_work);
1364 	vhost_work_flush(&vs->dev, &vs->vs_event_work);
1365 
1366 	/* Wait for all reqs issued before the flush to be finished */
1367 	for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1368 		wait_for_completion(&old_inflight[i]->comp);
1369 }
1370 
1371 /*
1372  * Called from vhost_scsi_ioctl() context to walk the list of available
1373  * vhost_scsi_tpg with an active struct vhost_scsi_nexus
1374  *
1375  *  The lock nesting rule is:
1376  *    vhost_scsi_mutex -> vs->dev.mutex -> tpg->tv_tpg_mutex -> vq->mutex
1377  */
1378 static int
1379 vhost_scsi_set_endpoint(struct vhost_scsi *vs,
1380 			struct vhost_scsi_target *t)
1381 {
1382 	struct se_portal_group *se_tpg;
1383 	struct vhost_scsi_tport *tv_tport;
1384 	struct vhost_scsi_tpg *tpg;
1385 	struct vhost_scsi_tpg **vs_tpg;
1386 	struct vhost_virtqueue *vq;
1387 	int index, ret, i, len;
1388 	bool match = false;
1389 
1390 	mutex_lock(&vhost_scsi_mutex);
1391 	mutex_lock(&vs->dev.mutex);
1392 
1393 	/* Verify that ring has been setup correctly. */
1394 	for (index = 0; index < vs->dev.nvqs; ++index) {
1395 		/* Verify that ring has been setup correctly. */
1396 		if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1397 			ret = -EFAULT;
1398 			goto out;
1399 		}
1400 	}
1401 
1402 	len = sizeof(vs_tpg[0]) * VHOST_SCSI_MAX_TARGET;
1403 	vs_tpg = kzalloc(len, GFP_KERNEL);
1404 	if (!vs_tpg) {
1405 		ret = -ENOMEM;
1406 		goto out;
1407 	}
1408 	if (vs->vs_tpg)
1409 		memcpy(vs_tpg, vs->vs_tpg, len);
1410 
1411 	list_for_each_entry(tpg, &vhost_scsi_list, tv_tpg_list) {
1412 		mutex_lock(&tpg->tv_tpg_mutex);
1413 		if (!tpg->tpg_nexus) {
1414 			mutex_unlock(&tpg->tv_tpg_mutex);
1415 			continue;
1416 		}
1417 		if (tpg->tv_tpg_vhost_count != 0) {
1418 			mutex_unlock(&tpg->tv_tpg_mutex);
1419 			continue;
1420 		}
1421 		tv_tport = tpg->tport;
1422 
1423 		if (!strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1424 			if (vs->vs_tpg && vs->vs_tpg[tpg->tport_tpgt]) {
1425 				kfree(vs_tpg);
1426 				mutex_unlock(&tpg->tv_tpg_mutex);
1427 				ret = -EEXIST;
1428 				goto out;
1429 			}
1430 			/*
1431 			 * In order to ensure individual vhost-scsi configfs
1432 			 * groups cannot be removed while in use by vhost ioctl,
1433 			 * go ahead and take an explicit se_tpg->tpg_group.cg_item
1434 			 * dependency now.
1435 			 */
1436 			se_tpg = &tpg->se_tpg;
1437 			ret = target_depend_item(&se_tpg->tpg_group.cg_item);
1438 			if (ret) {
1439 				pr_warn("target_depend_item() failed: %d\n", ret);
1440 				kfree(vs_tpg);
1441 				mutex_unlock(&tpg->tv_tpg_mutex);
1442 				goto out;
1443 			}
1444 			tpg->tv_tpg_vhost_count++;
1445 			tpg->vhost_scsi = vs;
1446 			vs_tpg[tpg->tport_tpgt] = tpg;
1447 			smp_mb__after_atomic();
1448 			match = true;
1449 		}
1450 		mutex_unlock(&tpg->tv_tpg_mutex);
1451 	}
1452 
1453 	if (match) {
1454 		memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn,
1455 		       sizeof(vs->vs_vhost_wwpn));
1456 		for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1457 			vq = &vs->vqs[i].vq;
1458 			mutex_lock(&vq->mutex);
1459 			vq->private_data = vs_tpg;
1460 			vhost_vq_init_access(vq);
1461 			mutex_unlock(&vq->mutex);
1462 		}
1463 		ret = 0;
1464 	} else {
1465 		ret = -EEXIST;
1466 	}
1467 
1468 	/*
1469 	 * Act as synchronize_rcu to make sure access to
1470 	 * old vs->vs_tpg is finished.
1471 	 */
1472 	vhost_scsi_flush(vs);
1473 	kfree(vs->vs_tpg);
1474 	vs->vs_tpg = vs_tpg;
1475 
1476 out:
1477 	mutex_unlock(&vs->dev.mutex);
1478 	mutex_unlock(&vhost_scsi_mutex);
1479 	return ret;
1480 }
1481 
1482 static int
1483 vhost_scsi_clear_endpoint(struct vhost_scsi *vs,
1484 			  struct vhost_scsi_target *t)
1485 {
1486 	struct se_portal_group *se_tpg;
1487 	struct vhost_scsi_tport *tv_tport;
1488 	struct vhost_scsi_tpg *tpg;
1489 	struct vhost_virtqueue *vq;
1490 	bool match = false;
1491 	int index, ret, i;
1492 	u8 target;
1493 
1494 	mutex_lock(&vhost_scsi_mutex);
1495 	mutex_lock(&vs->dev.mutex);
1496 	/* Verify that ring has been setup correctly. */
1497 	for (index = 0; index < vs->dev.nvqs; ++index) {
1498 		if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1499 			ret = -EFAULT;
1500 			goto err_dev;
1501 		}
1502 	}
1503 
1504 	if (!vs->vs_tpg) {
1505 		ret = 0;
1506 		goto err_dev;
1507 	}
1508 
1509 	for (i = 0; i < VHOST_SCSI_MAX_TARGET; i++) {
1510 		target = i;
1511 		tpg = vs->vs_tpg[target];
1512 		if (!tpg)
1513 			continue;
1514 
1515 		mutex_lock(&tpg->tv_tpg_mutex);
1516 		tv_tport = tpg->tport;
1517 		if (!tv_tport) {
1518 			ret = -ENODEV;
1519 			goto err_tpg;
1520 		}
1521 
1522 		if (strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1523 			pr_warn("tv_tport->tport_name: %s, tpg->tport_tpgt: %hu"
1524 				" does not match t->vhost_wwpn: %s, t->vhost_tpgt: %hu\n",
1525 				tv_tport->tport_name, tpg->tport_tpgt,
1526 				t->vhost_wwpn, t->vhost_tpgt);
1527 			ret = -EINVAL;
1528 			goto err_tpg;
1529 		}
1530 		tpg->tv_tpg_vhost_count--;
1531 		tpg->vhost_scsi = NULL;
1532 		vs->vs_tpg[target] = NULL;
1533 		match = true;
1534 		mutex_unlock(&tpg->tv_tpg_mutex);
1535 		/*
1536 		 * Release se_tpg->tpg_group.cg_item configfs dependency now
1537 		 * to allow vhost-scsi WWPN se_tpg->tpg_group shutdown to occur.
1538 		 */
1539 		se_tpg = &tpg->se_tpg;
1540 		target_undepend_item(&se_tpg->tpg_group.cg_item);
1541 	}
1542 	if (match) {
1543 		for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1544 			vq = &vs->vqs[i].vq;
1545 			mutex_lock(&vq->mutex);
1546 			vq->private_data = NULL;
1547 			mutex_unlock(&vq->mutex);
1548 		}
1549 	}
1550 	/*
1551 	 * Act as synchronize_rcu to make sure access to
1552 	 * old vs->vs_tpg is finished.
1553 	 */
1554 	vhost_scsi_flush(vs);
1555 	kfree(vs->vs_tpg);
1556 	vs->vs_tpg = NULL;
1557 	WARN_ON(vs->vs_events_nr);
1558 	mutex_unlock(&vs->dev.mutex);
1559 	mutex_unlock(&vhost_scsi_mutex);
1560 	return 0;
1561 
1562 err_tpg:
1563 	mutex_unlock(&tpg->tv_tpg_mutex);
1564 err_dev:
1565 	mutex_unlock(&vs->dev.mutex);
1566 	mutex_unlock(&vhost_scsi_mutex);
1567 	return ret;
1568 }
1569 
1570 static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
1571 {
1572 	struct vhost_virtqueue *vq;
1573 	int i;
1574 
1575 	if (features & ~VHOST_SCSI_FEATURES)
1576 		return -EOPNOTSUPP;
1577 
1578 	mutex_lock(&vs->dev.mutex);
1579 	if ((features & (1 << VHOST_F_LOG_ALL)) &&
1580 	    !vhost_log_access_ok(&vs->dev)) {
1581 		mutex_unlock(&vs->dev.mutex);
1582 		return -EFAULT;
1583 	}
1584 
1585 	for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1586 		vq = &vs->vqs[i].vq;
1587 		mutex_lock(&vq->mutex);
1588 		vq->acked_features = features;
1589 		mutex_unlock(&vq->mutex);
1590 	}
1591 	mutex_unlock(&vs->dev.mutex);
1592 	return 0;
1593 }
1594 
1595 static int vhost_scsi_open(struct inode *inode, struct file *f)
1596 {
1597 	struct vhost_scsi *vs;
1598 	struct vhost_virtqueue **vqs;
1599 	int r = -ENOMEM, i;
1600 
1601 	vs = kzalloc(sizeof(*vs), GFP_KERNEL | __GFP_NOWARN | __GFP_RETRY_MAYFAIL);
1602 	if (!vs) {
1603 		vs = vzalloc(sizeof(*vs));
1604 		if (!vs)
1605 			goto err_vs;
1606 	}
1607 
1608 	vqs = kmalloc_array(VHOST_SCSI_MAX_VQ, sizeof(*vqs), GFP_KERNEL);
1609 	if (!vqs)
1610 		goto err_vqs;
1611 
1612 	vhost_work_init(&vs->vs_completion_work, vhost_scsi_complete_cmd_work);
1613 	vhost_work_init(&vs->vs_event_work, vhost_scsi_evt_work);
1614 
1615 	vs->vs_events_nr = 0;
1616 	vs->vs_events_missed = false;
1617 
1618 	vqs[VHOST_SCSI_VQ_CTL] = &vs->vqs[VHOST_SCSI_VQ_CTL].vq;
1619 	vqs[VHOST_SCSI_VQ_EVT] = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1620 	vs->vqs[VHOST_SCSI_VQ_CTL].vq.handle_kick = vhost_scsi_ctl_handle_kick;
1621 	vs->vqs[VHOST_SCSI_VQ_EVT].vq.handle_kick = vhost_scsi_evt_handle_kick;
1622 	for (i = VHOST_SCSI_VQ_IO; i < VHOST_SCSI_MAX_VQ; i++) {
1623 		vqs[i] = &vs->vqs[i].vq;
1624 		vs->vqs[i].vq.handle_kick = vhost_scsi_handle_kick;
1625 	}
1626 	vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ);
1627 
1628 	vhost_scsi_init_inflight(vs, NULL);
1629 
1630 	f->private_data = vs;
1631 	return 0;
1632 
1633 err_vqs:
1634 	kvfree(vs);
1635 err_vs:
1636 	return r;
1637 }
1638 
1639 static int vhost_scsi_release(struct inode *inode, struct file *f)
1640 {
1641 	struct vhost_scsi *vs = f->private_data;
1642 	struct vhost_scsi_target t;
1643 
1644 	mutex_lock(&vs->dev.mutex);
1645 	memcpy(t.vhost_wwpn, vs->vs_vhost_wwpn, sizeof(t.vhost_wwpn));
1646 	mutex_unlock(&vs->dev.mutex);
1647 	vhost_scsi_clear_endpoint(vs, &t);
1648 	vhost_dev_stop(&vs->dev);
1649 	vhost_dev_cleanup(&vs->dev);
1650 	/* Jobs can re-queue themselves in evt kick handler. Do extra flush. */
1651 	vhost_scsi_flush(vs);
1652 	kfree(vs->dev.vqs);
1653 	kvfree(vs);
1654 	return 0;
1655 }
1656 
1657 static long
1658 vhost_scsi_ioctl(struct file *f,
1659 		 unsigned int ioctl,
1660 		 unsigned long arg)
1661 {
1662 	struct vhost_scsi *vs = f->private_data;
1663 	struct vhost_scsi_target backend;
1664 	void __user *argp = (void __user *)arg;
1665 	u64 __user *featurep = argp;
1666 	u32 __user *eventsp = argp;
1667 	u32 events_missed;
1668 	u64 features;
1669 	int r, abi_version = VHOST_SCSI_ABI_VERSION;
1670 	struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1671 
1672 	switch (ioctl) {
1673 	case VHOST_SCSI_SET_ENDPOINT:
1674 		if (copy_from_user(&backend, argp, sizeof backend))
1675 			return -EFAULT;
1676 		if (backend.reserved != 0)
1677 			return -EOPNOTSUPP;
1678 
1679 		return vhost_scsi_set_endpoint(vs, &backend);
1680 	case VHOST_SCSI_CLEAR_ENDPOINT:
1681 		if (copy_from_user(&backend, argp, sizeof backend))
1682 			return -EFAULT;
1683 		if (backend.reserved != 0)
1684 			return -EOPNOTSUPP;
1685 
1686 		return vhost_scsi_clear_endpoint(vs, &backend);
1687 	case VHOST_SCSI_GET_ABI_VERSION:
1688 		if (copy_to_user(argp, &abi_version, sizeof abi_version))
1689 			return -EFAULT;
1690 		return 0;
1691 	case VHOST_SCSI_SET_EVENTS_MISSED:
1692 		if (get_user(events_missed, eventsp))
1693 			return -EFAULT;
1694 		mutex_lock(&vq->mutex);
1695 		vs->vs_events_missed = events_missed;
1696 		mutex_unlock(&vq->mutex);
1697 		return 0;
1698 	case VHOST_SCSI_GET_EVENTS_MISSED:
1699 		mutex_lock(&vq->mutex);
1700 		events_missed = vs->vs_events_missed;
1701 		mutex_unlock(&vq->mutex);
1702 		if (put_user(events_missed, eventsp))
1703 			return -EFAULT;
1704 		return 0;
1705 	case VHOST_GET_FEATURES:
1706 		features = VHOST_SCSI_FEATURES;
1707 		if (copy_to_user(featurep, &features, sizeof features))
1708 			return -EFAULT;
1709 		return 0;
1710 	case VHOST_SET_FEATURES:
1711 		if (copy_from_user(&features, featurep, sizeof features))
1712 			return -EFAULT;
1713 		return vhost_scsi_set_features(vs, features);
1714 	default:
1715 		mutex_lock(&vs->dev.mutex);
1716 		r = vhost_dev_ioctl(&vs->dev, ioctl, argp);
1717 		/* TODO: flush backend after dev ioctl. */
1718 		if (r == -ENOIOCTLCMD)
1719 			r = vhost_vring_ioctl(&vs->dev, ioctl, argp);
1720 		mutex_unlock(&vs->dev.mutex);
1721 		return r;
1722 	}
1723 }
1724 
1725 #ifdef CONFIG_COMPAT
1726 static long vhost_scsi_compat_ioctl(struct file *f, unsigned int ioctl,
1727 				unsigned long arg)
1728 {
1729 	return vhost_scsi_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
1730 }
1731 #endif
1732 
1733 static const struct file_operations vhost_scsi_fops = {
1734 	.owner          = THIS_MODULE,
1735 	.release        = vhost_scsi_release,
1736 	.unlocked_ioctl = vhost_scsi_ioctl,
1737 #ifdef CONFIG_COMPAT
1738 	.compat_ioctl	= vhost_scsi_compat_ioctl,
1739 #endif
1740 	.open           = vhost_scsi_open,
1741 	.llseek		= noop_llseek,
1742 };
1743 
1744 static struct miscdevice vhost_scsi_misc = {
1745 	MISC_DYNAMIC_MINOR,
1746 	"vhost-scsi",
1747 	&vhost_scsi_fops,
1748 };
1749 
1750 static int __init vhost_scsi_register(void)
1751 {
1752 	return misc_register(&vhost_scsi_misc);
1753 }
1754 
1755 static void vhost_scsi_deregister(void)
1756 {
1757 	misc_deregister(&vhost_scsi_misc);
1758 }
1759 
1760 static char *vhost_scsi_dump_proto_id(struct vhost_scsi_tport *tport)
1761 {
1762 	switch (tport->tport_proto_id) {
1763 	case SCSI_PROTOCOL_SAS:
1764 		return "SAS";
1765 	case SCSI_PROTOCOL_FCP:
1766 		return "FCP";
1767 	case SCSI_PROTOCOL_ISCSI:
1768 		return "iSCSI";
1769 	default:
1770 		break;
1771 	}
1772 
1773 	return "Unknown";
1774 }
1775 
1776 static void
1777 vhost_scsi_do_plug(struct vhost_scsi_tpg *tpg,
1778 		  struct se_lun *lun, bool plug)
1779 {
1780 
1781 	struct vhost_scsi *vs = tpg->vhost_scsi;
1782 	struct vhost_virtqueue *vq;
1783 	u32 reason;
1784 
1785 	if (!vs)
1786 		return;
1787 
1788 	mutex_lock(&vs->dev.mutex);
1789 
1790 	if (plug)
1791 		reason = VIRTIO_SCSI_EVT_RESET_RESCAN;
1792 	else
1793 		reason = VIRTIO_SCSI_EVT_RESET_REMOVED;
1794 
1795 	vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1796 	mutex_lock(&vq->mutex);
1797 	if (vhost_has_feature(vq, VIRTIO_SCSI_F_HOTPLUG))
1798 		vhost_scsi_send_evt(vs, tpg, lun,
1799 				   VIRTIO_SCSI_T_TRANSPORT_RESET, reason);
1800 	mutex_unlock(&vq->mutex);
1801 	mutex_unlock(&vs->dev.mutex);
1802 }
1803 
1804 static void vhost_scsi_hotplug(struct vhost_scsi_tpg *tpg, struct se_lun *lun)
1805 {
1806 	vhost_scsi_do_plug(tpg, lun, true);
1807 }
1808 
1809 static void vhost_scsi_hotunplug(struct vhost_scsi_tpg *tpg, struct se_lun *lun)
1810 {
1811 	vhost_scsi_do_plug(tpg, lun, false);
1812 }
1813 
1814 static int vhost_scsi_port_link(struct se_portal_group *se_tpg,
1815 			       struct se_lun *lun)
1816 {
1817 	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1818 				struct vhost_scsi_tpg, se_tpg);
1819 
1820 	mutex_lock(&vhost_scsi_mutex);
1821 
1822 	mutex_lock(&tpg->tv_tpg_mutex);
1823 	tpg->tv_tpg_port_count++;
1824 	mutex_unlock(&tpg->tv_tpg_mutex);
1825 
1826 	vhost_scsi_hotplug(tpg, lun);
1827 
1828 	mutex_unlock(&vhost_scsi_mutex);
1829 
1830 	return 0;
1831 }
1832 
1833 static void vhost_scsi_port_unlink(struct se_portal_group *se_tpg,
1834 				  struct se_lun *lun)
1835 {
1836 	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1837 				struct vhost_scsi_tpg, se_tpg);
1838 
1839 	mutex_lock(&vhost_scsi_mutex);
1840 
1841 	mutex_lock(&tpg->tv_tpg_mutex);
1842 	tpg->tv_tpg_port_count--;
1843 	mutex_unlock(&tpg->tv_tpg_mutex);
1844 
1845 	vhost_scsi_hotunplug(tpg, lun);
1846 
1847 	mutex_unlock(&vhost_scsi_mutex);
1848 }
1849 
1850 static void vhost_scsi_free_cmd_map_res(struct se_session *se_sess)
1851 {
1852 	struct vhost_scsi_cmd *tv_cmd;
1853 	unsigned int i;
1854 
1855 	if (!se_sess->sess_cmd_map)
1856 		return;
1857 
1858 	for (i = 0; i < VHOST_SCSI_DEFAULT_TAGS; i++) {
1859 		tv_cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[i];
1860 
1861 		kfree(tv_cmd->tvc_sgl);
1862 		kfree(tv_cmd->tvc_prot_sgl);
1863 		kfree(tv_cmd->tvc_upages);
1864 	}
1865 }
1866 
1867 static ssize_t vhost_scsi_tpg_attrib_fabric_prot_type_store(
1868 		struct config_item *item, const char *page, size_t count)
1869 {
1870 	struct se_portal_group *se_tpg = attrib_to_tpg(item);
1871 	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1872 				struct vhost_scsi_tpg, se_tpg);
1873 	unsigned long val;
1874 	int ret = kstrtoul(page, 0, &val);
1875 
1876 	if (ret) {
1877 		pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
1878 		return ret;
1879 	}
1880 	if (val != 0 && val != 1 && val != 3) {
1881 		pr_err("Invalid vhost_scsi fabric_prot_type: %lu\n", val);
1882 		return -EINVAL;
1883 	}
1884 	tpg->tv_fabric_prot_type = val;
1885 
1886 	return count;
1887 }
1888 
1889 static ssize_t vhost_scsi_tpg_attrib_fabric_prot_type_show(
1890 		struct config_item *item, char *page)
1891 {
1892 	struct se_portal_group *se_tpg = attrib_to_tpg(item);
1893 	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1894 				struct vhost_scsi_tpg, se_tpg);
1895 
1896 	return sprintf(page, "%d\n", tpg->tv_fabric_prot_type);
1897 }
1898 
1899 CONFIGFS_ATTR(vhost_scsi_tpg_attrib_, fabric_prot_type);
1900 
1901 static struct configfs_attribute *vhost_scsi_tpg_attrib_attrs[] = {
1902 	&vhost_scsi_tpg_attrib_attr_fabric_prot_type,
1903 	NULL,
1904 };
1905 
1906 static int vhost_scsi_nexus_cb(struct se_portal_group *se_tpg,
1907 			       struct se_session *se_sess, void *p)
1908 {
1909 	struct vhost_scsi_cmd *tv_cmd;
1910 	unsigned int i;
1911 
1912 	for (i = 0; i < VHOST_SCSI_DEFAULT_TAGS; i++) {
1913 		tv_cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[i];
1914 
1915 		tv_cmd->tvc_sgl = kcalloc(VHOST_SCSI_PREALLOC_SGLS,
1916 					  sizeof(struct scatterlist),
1917 					  GFP_KERNEL);
1918 		if (!tv_cmd->tvc_sgl) {
1919 			pr_err("Unable to allocate tv_cmd->tvc_sgl\n");
1920 			goto out;
1921 		}
1922 
1923 		tv_cmd->tvc_upages = kcalloc(VHOST_SCSI_PREALLOC_UPAGES,
1924 					     sizeof(struct page *),
1925 					     GFP_KERNEL);
1926 		if (!tv_cmd->tvc_upages) {
1927 			pr_err("Unable to allocate tv_cmd->tvc_upages\n");
1928 			goto out;
1929 		}
1930 
1931 		tv_cmd->tvc_prot_sgl = kcalloc(VHOST_SCSI_PREALLOC_PROT_SGLS,
1932 					       sizeof(struct scatterlist),
1933 					       GFP_KERNEL);
1934 		if (!tv_cmd->tvc_prot_sgl) {
1935 			pr_err("Unable to allocate tv_cmd->tvc_prot_sgl\n");
1936 			goto out;
1937 		}
1938 	}
1939 	return 0;
1940 out:
1941 	vhost_scsi_free_cmd_map_res(se_sess);
1942 	return -ENOMEM;
1943 }
1944 
1945 static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
1946 				const char *name)
1947 {
1948 	struct vhost_scsi_nexus *tv_nexus;
1949 
1950 	mutex_lock(&tpg->tv_tpg_mutex);
1951 	if (tpg->tpg_nexus) {
1952 		mutex_unlock(&tpg->tv_tpg_mutex);
1953 		pr_debug("tpg->tpg_nexus already exists\n");
1954 		return -EEXIST;
1955 	}
1956 
1957 	tv_nexus = kzalloc(sizeof(*tv_nexus), GFP_KERNEL);
1958 	if (!tv_nexus) {
1959 		mutex_unlock(&tpg->tv_tpg_mutex);
1960 		pr_err("Unable to allocate struct vhost_scsi_nexus\n");
1961 		return -ENOMEM;
1962 	}
1963 	/*
1964 	 * Since we are running in 'demo mode' this call with generate a
1965 	 * struct se_node_acl for the vhost_scsi struct se_portal_group with
1966 	 * the SCSI Initiator port name of the passed configfs group 'name'.
1967 	 */
1968 	tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg,
1969 					VHOST_SCSI_DEFAULT_TAGS,
1970 					sizeof(struct vhost_scsi_cmd),
1971 					TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
1972 					(unsigned char *)name, tv_nexus,
1973 					vhost_scsi_nexus_cb);
1974 	if (IS_ERR(tv_nexus->tvn_se_sess)) {
1975 		mutex_unlock(&tpg->tv_tpg_mutex);
1976 		kfree(tv_nexus);
1977 		return -ENOMEM;
1978 	}
1979 	tpg->tpg_nexus = tv_nexus;
1980 
1981 	mutex_unlock(&tpg->tv_tpg_mutex);
1982 	return 0;
1983 }
1984 
1985 static int vhost_scsi_drop_nexus(struct vhost_scsi_tpg *tpg)
1986 {
1987 	struct se_session *se_sess;
1988 	struct vhost_scsi_nexus *tv_nexus;
1989 
1990 	mutex_lock(&tpg->tv_tpg_mutex);
1991 	tv_nexus = tpg->tpg_nexus;
1992 	if (!tv_nexus) {
1993 		mutex_unlock(&tpg->tv_tpg_mutex);
1994 		return -ENODEV;
1995 	}
1996 
1997 	se_sess = tv_nexus->tvn_se_sess;
1998 	if (!se_sess) {
1999 		mutex_unlock(&tpg->tv_tpg_mutex);
2000 		return -ENODEV;
2001 	}
2002 
2003 	if (tpg->tv_tpg_port_count != 0) {
2004 		mutex_unlock(&tpg->tv_tpg_mutex);
2005 		pr_err("Unable to remove TCM_vhost I_T Nexus with"
2006 			" active TPG port count: %d\n",
2007 			tpg->tv_tpg_port_count);
2008 		return -EBUSY;
2009 	}
2010 
2011 	if (tpg->tv_tpg_vhost_count != 0) {
2012 		mutex_unlock(&tpg->tv_tpg_mutex);
2013 		pr_err("Unable to remove TCM_vhost I_T Nexus with"
2014 			" active TPG vhost count: %d\n",
2015 			tpg->tv_tpg_vhost_count);
2016 		return -EBUSY;
2017 	}
2018 
2019 	pr_debug("TCM_vhost_ConfigFS: Removing I_T Nexus to emulated"
2020 		" %s Initiator Port: %s\n", vhost_scsi_dump_proto_id(tpg->tport),
2021 		tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
2022 
2023 	vhost_scsi_free_cmd_map_res(se_sess);
2024 	/*
2025 	 * Release the SCSI I_T Nexus to the emulated vhost Target Port
2026 	 */
2027 	target_remove_session(se_sess);
2028 	tpg->tpg_nexus = NULL;
2029 	mutex_unlock(&tpg->tv_tpg_mutex);
2030 
2031 	kfree(tv_nexus);
2032 	return 0;
2033 }
2034 
2035 static ssize_t vhost_scsi_tpg_nexus_show(struct config_item *item, char *page)
2036 {
2037 	struct se_portal_group *se_tpg = to_tpg(item);
2038 	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2039 				struct vhost_scsi_tpg, se_tpg);
2040 	struct vhost_scsi_nexus *tv_nexus;
2041 	ssize_t ret;
2042 
2043 	mutex_lock(&tpg->tv_tpg_mutex);
2044 	tv_nexus = tpg->tpg_nexus;
2045 	if (!tv_nexus) {
2046 		mutex_unlock(&tpg->tv_tpg_mutex);
2047 		return -ENODEV;
2048 	}
2049 	ret = snprintf(page, PAGE_SIZE, "%s\n",
2050 			tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
2051 	mutex_unlock(&tpg->tv_tpg_mutex);
2052 
2053 	return ret;
2054 }
2055 
2056 static ssize_t vhost_scsi_tpg_nexus_store(struct config_item *item,
2057 		const char *page, size_t count)
2058 {
2059 	struct se_portal_group *se_tpg = to_tpg(item);
2060 	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2061 				struct vhost_scsi_tpg, se_tpg);
2062 	struct vhost_scsi_tport *tport_wwn = tpg->tport;
2063 	unsigned char i_port[VHOST_SCSI_NAMELEN], *ptr, *port_ptr;
2064 	int ret;
2065 	/*
2066 	 * Shutdown the active I_T nexus if 'NULL' is passed..
2067 	 */
2068 	if (!strncmp(page, "NULL", 4)) {
2069 		ret = vhost_scsi_drop_nexus(tpg);
2070 		return (!ret) ? count : ret;
2071 	}
2072 	/*
2073 	 * Otherwise make sure the passed virtual Initiator port WWN matches
2074 	 * the fabric protocol_id set in vhost_scsi_make_tport(), and call
2075 	 * vhost_scsi_make_nexus().
2076 	 */
2077 	if (strlen(page) >= VHOST_SCSI_NAMELEN) {
2078 		pr_err("Emulated NAA Sas Address: %s, exceeds"
2079 				" max: %d\n", page, VHOST_SCSI_NAMELEN);
2080 		return -EINVAL;
2081 	}
2082 	snprintf(&i_port[0], VHOST_SCSI_NAMELEN, "%s", page);
2083 
2084 	ptr = strstr(i_port, "naa.");
2085 	if (ptr) {
2086 		if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
2087 			pr_err("Passed SAS Initiator Port %s does not"
2088 				" match target port protoid: %s\n", i_port,
2089 				vhost_scsi_dump_proto_id(tport_wwn));
2090 			return -EINVAL;
2091 		}
2092 		port_ptr = &i_port[0];
2093 		goto check_newline;
2094 	}
2095 	ptr = strstr(i_port, "fc.");
2096 	if (ptr) {
2097 		if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
2098 			pr_err("Passed FCP Initiator Port %s does not"
2099 				" match target port protoid: %s\n", i_port,
2100 				vhost_scsi_dump_proto_id(tport_wwn));
2101 			return -EINVAL;
2102 		}
2103 		port_ptr = &i_port[3]; /* Skip over "fc." */
2104 		goto check_newline;
2105 	}
2106 	ptr = strstr(i_port, "iqn.");
2107 	if (ptr) {
2108 		if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
2109 			pr_err("Passed iSCSI Initiator Port %s does not"
2110 				" match target port protoid: %s\n", i_port,
2111 				vhost_scsi_dump_proto_id(tport_wwn));
2112 			return -EINVAL;
2113 		}
2114 		port_ptr = &i_port[0];
2115 		goto check_newline;
2116 	}
2117 	pr_err("Unable to locate prefix for emulated Initiator Port:"
2118 			" %s\n", i_port);
2119 	return -EINVAL;
2120 	/*
2121 	 * Clear any trailing newline for the NAA WWN
2122 	 */
2123 check_newline:
2124 	if (i_port[strlen(i_port)-1] == '\n')
2125 		i_port[strlen(i_port)-1] = '\0';
2126 
2127 	ret = vhost_scsi_make_nexus(tpg, port_ptr);
2128 	if (ret < 0)
2129 		return ret;
2130 
2131 	return count;
2132 }
2133 
2134 CONFIGFS_ATTR(vhost_scsi_tpg_, nexus);
2135 
2136 static struct configfs_attribute *vhost_scsi_tpg_attrs[] = {
2137 	&vhost_scsi_tpg_attr_nexus,
2138 	NULL,
2139 };
2140 
2141 static struct se_portal_group *
2142 vhost_scsi_make_tpg(struct se_wwn *wwn, const char *name)
2143 {
2144 	struct vhost_scsi_tport *tport = container_of(wwn,
2145 			struct vhost_scsi_tport, tport_wwn);
2146 
2147 	struct vhost_scsi_tpg *tpg;
2148 	u16 tpgt;
2149 	int ret;
2150 
2151 	if (strstr(name, "tpgt_") != name)
2152 		return ERR_PTR(-EINVAL);
2153 	if (kstrtou16(name + 5, 10, &tpgt) || tpgt >= VHOST_SCSI_MAX_TARGET)
2154 		return ERR_PTR(-EINVAL);
2155 
2156 	tpg = kzalloc(sizeof(*tpg), GFP_KERNEL);
2157 	if (!tpg) {
2158 		pr_err("Unable to allocate struct vhost_scsi_tpg");
2159 		return ERR_PTR(-ENOMEM);
2160 	}
2161 	mutex_init(&tpg->tv_tpg_mutex);
2162 	INIT_LIST_HEAD(&tpg->tv_tpg_list);
2163 	tpg->tport = tport;
2164 	tpg->tport_tpgt = tpgt;
2165 
2166 	ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
2167 	if (ret < 0) {
2168 		kfree(tpg);
2169 		return NULL;
2170 	}
2171 	mutex_lock(&vhost_scsi_mutex);
2172 	list_add_tail(&tpg->tv_tpg_list, &vhost_scsi_list);
2173 	mutex_unlock(&vhost_scsi_mutex);
2174 
2175 	return &tpg->se_tpg;
2176 }
2177 
2178 static void vhost_scsi_drop_tpg(struct se_portal_group *se_tpg)
2179 {
2180 	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2181 				struct vhost_scsi_tpg, se_tpg);
2182 
2183 	mutex_lock(&vhost_scsi_mutex);
2184 	list_del(&tpg->tv_tpg_list);
2185 	mutex_unlock(&vhost_scsi_mutex);
2186 	/*
2187 	 * Release the virtual I_T Nexus for this vhost TPG
2188 	 */
2189 	vhost_scsi_drop_nexus(tpg);
2190 	/*
2191 	 * Deregister the se_tpg from TCM..
2192 	 */
2193 	core_tpg_deregister(se_tpg);
2194 	kfree(tpg);
2195 }
2196 
2197 static struct se_wwn *
2198 vhost_scsi_make_tport(struct target_fabric_configfs *tf,
2199 		     struct config_group *group,
2200 		     const char *name)
2201 {
2202 	struct vhost_scsi_tport *tport;
2203 	char *ptr;
2204 	u64 wwpn = 0;
2205 	int off = 0;
2206 
2207 	/* if (vhost_scsi_parse_wwn(name, &wwpn, 1) < 0)
2208 		return ERR_PTR(-EINVAL); */
2209 
2210 	tport = kzalloc(sizeof(*tport), GFP_KERNEL);
2211 	if (!tport) {
2212 		pr_err("Unable to allocate struct vhost_scsi_tport");
2213 		return ERR_PTR(-ENOMEM);
2214 	}
2215 	tport->tport_wwpn = wwpn;
2216 	/*
2217 	 * Determine the emulated Protocol Identifier and Target Port Name
2218 	 * based on the incoming configfs directory name.
2219 	 */
2220 	ptr = strstr(name, "naa.");
2221 	if (ptr) {
2222 		tport->tport_proto_id = SCSI_PROTOCOL_SAS;
2223 		goto check_len;
2224 	}
2225 	ptr = strstr(name, "fc.");
2226 	if (ptr) {
2227 		tport->tport_proto_id = SCSI_PROTOCOL_FCP;
2228 		off = 3; /* Skip over "fc." */
2229 		goto check_len;
2230 	}
2231 	ptr = strstr(name, "iqn.");
2232 	if (ptr) {
2233 		tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
2234 		goto check_len;
2235 	}
2236 
2237 	pr_err("Unable to locate prefix for emulated Target Port:"
2238 			" %s\n", name);
2239 	kfree(tport);
2240 	return ERR_PTR(-EINVAL);
2241 
2242 check_len:
2243 	if (strlen(name) >= VHOST_SCSI_NAMELEN) {
2244 		pr_err("Emulated %s Address: %s, exceeds"
2245 			" max: %d\n", name, vhost_scsi_dump_proto_id(tport),
2246 			VHOST_SCSI_NAMELEN);
2247 		kfree(tport);
2248 		return ERR_PTR(-EINVAL);
2249 	}
2250 	snprintf(&tport->tport_name[0], VHOST_SCSI_NAMELEN, "%s", &name[off]);
2251 
2252 	pr_debug("TCM_VHost_ConfigFS: Allocated emulated Target"
2253 		" %s Address: %s\n", vhost_scsi_dump_proto_id(tport), name);
2254 
2255 	return &tport->tport_wwn;
2256 }
2257 
2258 static void vhost_scsi_drop_tport(struct se_wwn *wwn)
2259 {
2260 	struct vhost_scsi_tport *tport = container_of(wwn,
2261 				struct vhost_scsi_tport, tport_wwn);
2262 
2263 	pr_debug("TCM_VHost_ConfigFS: Deallocating emulated Target"
2264 		" %s Address: %s\n", vhost_scsi_dump_proto_id(tport),
2265 		tport->tport_name);
2266 
2267 	kfree(tport);
2268 }
2269 
2270 static ssize_t
2271 vhost_scsi_wwn_version_show(struct config_item *item, char *page)
2272 {
2273 	return sprintf(page, "TCM_VHOST fabric module %s on %s/%s"
2274 		"on "UTS_RELEASE"\n", VHOST_SCSI_VERSION, utsname()->sysname,
2275 		utsname()->machine);
2276 }
2277 
2278 CONFIGFS_ATTR_RO(vhost_scsi_wwn_, version);
2279 
2280 static struct configfs_attribute *vhost_scsi_wwn_attrs[] = {
2281 	&vhost_scsi_wwn_attr_version,
2282 	NULL,
2283 };
2284 
2285 static const struct target_core_fabric_ops vhost_scsi_ops = {
2286 	.module				= THIS_MODULE,
2287 	.fabric_name			= "vhost",
2288 	.tpg_get_wwn			= vhost_scsi_get_fabric_wwn,
2289 	.tpg_get_tag			= vhost_scsi_get_tpgt,
2290 	.tpg_check_demo_mode		= vhost_scsi_check_true,
2291 	.tpg_check_demo_mode_cache	= vhost_scsi_check_true,
2292 	.tpg_check_demo_mode_write_protect = vhost_scsi_check_false,
2293 	.tpg_check_prod_mode_write_protect = vhost_scsi_check_false,
2294 	.tpg_check_prot_fabric_only	= vhost_scsi_check_prot_fabric_only,
2295 	.tpg_get_inst_index		= vhost_scsi_tpg_get_inst_index,
2296 	.release_cmd			= vhost_scsi_release_cmd,
2297 	.check_stop_free		= vhost_scsi_check_stop_free,
2298 	.sess_get_index			= vhost_scsi_sess_get_index,
2299 	.sess_get_initiator_sid		= NULL,
2300 	.write_pending			= vhost_scsi_write_pending,
2301 	.write_pending_status		= vhost_scsi_write_pending_status,
2302 	.set_default_node_attributes	= vhost_scsi_set_default_node_attrs,
2303 	.get_cmd_state			= vhost_scsi_get_cmd_state,
2304 	.queue_data_in			= vhost_scsi_queue_data_in,
2305 	.queue_status			= vhost_scsi_queue_status,
2306 	.queue_tm_rsp			= vhost_scsi_queue_tm_rsp,
2307 	.aborted_task			= vhost_scsi_aborted_task,
2308 	/*
2309 	 * Setup callers for generic logic in target_core_fabric_configfs.c
2310 	 */
2311 	.fabric_make_wwn		= vhost_scsi_make_tport,
2312 	.fabric_drop_wwn		= vhost_scsi_drop_tport,
2313 	.fabric_make_tpg		= vhost_scsi_make_tpg,
2314 	.fabric_drop_tpg		= vhost_scsi_drop_tpg,
2315 	.fabric_post_link		= vhost_scsi_port_link,
2316 	.fabric_pre_unlink		= vhost_scsi_port_unlink,
2317 
2318 	.tfc_wwn_attrs			= vhost_scsi_wwn_attrs,
2319 	.tfc_tpg_base_attrs		= vhost_scsi_tpg_attrs,
2320 	.tfc_tpg_attrib_attrs		= vhost_scsi_tpg_attrib_attrs,
2321 };
2322 
2323 static int __init vhost_scsi_init(void)
2324 {
2325 	int ret = -ENOMEM;
2326 
2327 	pr_debug("TCM_VHOST fabric module %s on %s/%s"
2328 		" on "UTS_RELEASE"\n", VHOST_SCSI_VERSION, utsname()->sysname,
2329 		utsname()->machine);
2330 
2331 	/*
2332 	 * Use our own dedicated workqueue for submitting I/O into
2333 	 * target core to avoid contention within system_wq.
2334 	 */
2335 	vhost_scsi_workqueue = alloc_workqueue("vhost_scsi", 0, 0);
2336 	if (!vhost_scsi_workqueue)
2337 		goto out;
2338 
2339 	ret = vhost_scsi_register();
2340 	if (ret < 0)
2341 		goto out_destroy_workqueue;
2342 
2343 	ret = target_register_template(&vhost_scsi_ops);
2344 	if (ret < 0)
2345 		goto out_vhost_scsi_deregister;
2346 
2347 	return 0;
2348 
2349 out_vhost_scsi_deregister:
2350 	vhost_scsi_deregister();
2351 out_destroy_workqueue:
2352 	destroy_workqueue(vhost_scsi_workqueue);
2353 out:
2354 	return ret;
2355 };
2356 
2357 static void vhost_scsi_exit(void)
2358 {
2359 	target_unregister_template(&vhost_scsi_ops);
2360 	vhost_scsi_deregister();
2361 	destroy_workqueue(vhost_scsi_workqueue);
2362 };
2363 
2364 MODULE_DESCRIPTION("VHOST_SCSI series fabric driver");
2365 MODULE_ALIAS("tcm_vhost");
2366 MODULE_LICENSE("GPL");
2367 module_init(vhost_scsi_init);
2368 module_exit(vhost_scsi_exit);
2369