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