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Merge tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block
[linux/fpc-iii.git] / drivers / xen / xen-scsiback.c
blob862162dca33cf4221f81008a6214479dbfb4dbc9
1 /*
2 * Xen SCSI backend driver
3 *
4 * Copyright (c) 2008, FUJITSU Limited
5 *
6 * Based on the blkback driver code.
7 * Adaption to kernel taget core infrastructure taken from vhost/scsi.c
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation; or, when distributed
12 * separately from the Linux kernel or incorporated into other
13 * software packages, subject to the following license:
14 *
15 * Permission is hereby granted, free of charge, to any person obtaining a copy
16 * of this source file (the "Software"), to deal in the Software without
17 * restriction, including without limitation the rights to use, copy, modify,
18 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
19 * and to permit persons to whom the Software is furnished to do so, subject to
20 * the following conditions:
21 *
22 * The above copyright notice and this permission notice shall be included in
23 * all copies or substantial portions of the Software.
24 *
25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
28 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
29 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
30 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
31 * IN THE SOFTWARE.
32 */
33
34 #define pr_fmt(fmt) "xen-pvscsi: " fmt
35
36 #include <stdarg.h>
37
38 #include <linux/module.h>
39 #include <linux/utsname.h>
40 #include <linux/interrupt.h>
41 #include <linux/slab.h>
42 #include <linux/wait.h>
43 #include <linux/sched.h>
44 #include <linux/list.h>
45 #include <linux/gfp.h>
46 #include <linux/delay.h>
47 #include <linux/spinlock.h>
48 #include <linux/configfs.h>
49
50 #include <generated/utsrelease.h>
51
52 #include <scsi/scsi_host.h> /* SG_ALL */
53
54 #include <target/target_core_base.h>
55 #include <target/target_core_fabric.h>
56
57 #include <asm/hypervisor.h>
58
59 #include <xen/xen.h>
60 #include <xen/balloon.h>
61 #include <xen/events.h>
62 #include <xen/xenbus.h>
63 #include <xen/grant_table.h>
64 #include <xen/page.h>
65
66 #include <xen/interface/grant_table.h>
67 #include <xen/interface/io/vscsiif.h>
68
69 #define VSCSI_VERSION "v0.1"
70 #define VSCSI_NAMELEN 32
71
72 struct ids_tuple {
73 unsigned int hst; /* host */
74 unsigned int chn; /* channel */
75 unsigned int tgt; /* target */
76 unsigned int lun; /* LUN */
77 };
78
79 struct v2p_entry {
80 struct ids_tuple v; /* translate from */
81 struct scsiback_tpg *tpg; /* translate to */
82 unsigned int lun;
83 struct kref kref;
84 struct list_head l;
85 };
86
87 struct vscsibk_info {
88 struct xenbus_device *dev;
89
90 domid_t domid;
91 unsigned int irq;
92
93 struct vscsiif_back_ring ring;
94
95 spinlock_t ring_lock;
96 atomic_t nr_unreplied_reqs;
97
98 spinlock_t v2p_lock;
99 struct list_head v2p_entry_lists;
100
101 wait_queue_head_t waiting_to_free;
102
103 struct gnttab_page_cache free_pages;
104 };
105
106 /* theoretical maximum of grants for one request */
107 #define VSCSI_MAX_GRANTS (SG_ALL + VSCSIIF_SG_TABLESIZE)
108
109 /*
110 * VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one
111 * call to map/unmap grants. Don't choose it too large, as there are arrays
112 * with VSCSI_GRANT_BATCH elements allocated on the stack.
113 */
114 #define VSCSI_GRANT_BATCH 16
115
116 struct vscsibk_pend {
117 uint16_t rqid;
118
119 uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE];
120 uint8_t cmd_len;
121
122 uint8_t sc_data_direction;
123 uint16_t n_sg; /* real length of SG list */
124 uint16_t n_grants; /* SG pages and potentially SG list */
125 uint32_t data_len;
126 uint32_t result;
127
128 struct vscsibk_info *info;
129 struct v2p_entry *v2p;
130 struct scatterlist *sgl;
131
132 uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE];
133
134 grant_handle_t grant_handles[VSCSI_MAX_GRANTS];
135 struct page *pages[VSCSI_MAX_GRANTS];
136
137 struct se_cmd se_cmd;
138
139 struct completion tmr_done;
140 };
141
142 #define VSCSI_DEFAULT_SESSION_TAGS 128
143
144 struct scsiback_nexus {
145 /* Pointer to TCM session for I_T Nexus */
146 struct se_session *tvn_se_sess;
147 };
148
149 struct scsiback_tport {
150 /* SCSI protocol the tport is providing */
151 u8 tport_proto_id;
152 /* Binary World Wide unique Port Name for pvscsi Target port */
153 u64 tport_wwpn;
154 /* ASCII formatted WWPN for pvscsi Target port */
155 char tport_name[VSCSI_NAMELEN];
156 /* Returned by scsiback_make_tport() */
157 struct se_wwn tport_wwn;
158 };
159
160 struct scsiback_tpg {
161 /* scsiback port target portal group tag for TCM */
162 u16 tport_tpgt;
163 /* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */
164 int tv_tpg_port_count;
165 /* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */
166 int tv_tpg_fe_count;
167 /* list for scsiback_list */
168 struct list_head tv_tpg_list;
169 /* Used to protect access for tpg_nexus */
170 struct mutex tv_tpg_mutex;
171 /* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */
172 struct scsiback_nexus *tpg_nexus;
173 /* Pointer back to scsiback_tport */
174 struct scsiback_tport *tport;
175 /* Returned by scsiback_make_tpg() */
176 struct se_portal_group se_tpg;
177 /* alias used in xenstore */
178 char param_alias[VSCSI_NAMELEN];
179 /* list of info structures related to this target portal group */
180 struct list_head info_list;
181 };
182
183 #define SCSIBACK_INVALID_HANDLE (~0)
184
185 static bool log_print_stat;
186 module_param(log_print_stat, bool, 0644);
187
188 static int scsiback_max_buffer_pages = 1024;
189 module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644);
190 MODULE_PARM_DESC(max_buffer_pages,
191 "Maximum number of free pages to keep in backend buffer");
192
193 /* Global spinlock to protect scsiback TPG list */
194 static DEFINE_MUTEX(scsiback_mutex);
195 static LIST_HEAD(scsiback_list);
196
197 static void scsiback_get(struct vscsibk_info *info)
198 {
199 atomic_inc(&info->nr_unreplied_reqs);
200 }
201
202 static void scsiback_put(struct vscsibk_info *info)
203 {
204 if (atomic_dec_and_test(&info->nr_unreplied_reqs))
205 wake_up(&info->waiting_to_free);
206 }
207
208 static unsigned long vaddr_page(struct page *page)
209 {
210 unsigned long pfn = page_to_pfn(page);
211
212 return (unsigned long)pfn_to_kaddr(pfn);
213 }
214
215 static unsigned long vaddr(struct vscsibk_pend *req, int seg)
216 {
217 return vaddr_page(req->pages[seg]);
218 }
219
220 static void scsiback_print_status(char *sense_buffer, int errors,
221 struct vscsibk_pend *pending_req)
222 {
223 struct scsiback_tpg *tpg = pending_req->v2p->tpg;
224
225 pr_err("[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x drv=%02x\n",
226 tpg->tport->tport_name, pending_req->v2p->lun,
227 pending_req->cmnd[0], status_byte(errors), msg_byte(errors),
228 host_byte(errors), driver_byte(errors));
229 }
230
231 static void scsiback_fast_flush_area(struct vscsibk_pend *req)
232 {
233 struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH];
234 struct page *pages[VSCSI_GRANT_BATCH];
235 unsigned int i, invcount = 0;
236 grant_handle_t handle;
237 int err;
238
239 kfree(req->sgl);
240 req->sgl = NULL;
241 req->n_sg = 0;
242
243 if (!req->n_grants)
244 return;
245
246 for (i = 0; i < req->n_grants; i++) {
247 handle = req->grant_handles[i];
248 if (handle == SCSIBACK_INVALID_HANDLE)
249 continue;
250 gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
251 GNTMAP_host_map, handle);
252 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
253 pages[invcount] = req->pages[i];
254 put_page(pages[invcount]);
255 invcount++;
256 if (invcount < VSCSI_GRANT_BATCH)
257 continue;
258 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
259 BUG_ON(err);
260 invcount = 0;
261 }
262
263 if (invcount) {
264 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
265 BUG_ON(err);
266 }
267
268 gnttab_page_cache_put(&req->info->free_pages, req->pages,
269 req->n_grants);
270 req->n_grants = 0;
271 }
272
273 static void scsiback_free_translation_entry(struct kref *kref)
274 {
275 struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref);
276 struct scsiback_tpg *tpg = entry->tpg;
277
278 mutex_lock(&tpg->tv_tpg_mutex);
279 tpg->tv_tpg_fe_count--;
280 mutex_unlock(&tpg->tv_tpg_mutex);
281
282 kfree(entry);
283 }
284
285 static void scsiback_send_response(struct vscsibk_info *info,
286 char *sense_buffer, int32_t result, uint32_t resid,
287 uint16_t rqid)
288 {
289 struct vscsiif_response *ring_res;
290 int notify;
291 struct scsi_sense_hdr sshdr;
292 unsigned long flags;
293 unsigned len;
294
295 spin_lock_irqsave(&info->ring_lock, flags);
296
297 ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt);
298 info->ring.rsp_prod_pvt++;
299
300 ring_res->rslt = result;
301 ring_res->rqid = rqid;
302
303 if (sense_buffer != NULL &&
304 scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
305 &sshdr)) {
306 len = min_t(unsigned, 8 + sense_buffer[7],
307 VSCSIIF_SENSE_BUFFERSIZE);
308 memcpy(ring_res->sense_buffer, sense_buffer, len);
309 ring_res->sense_len = len;
310 } else {
311 ring_res->sense_len = 0;
312 }
313
314 ring_res->residual_len = resid;
315
316 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify);
317 spin_unlock_irqrestore(&info->ring_lock, flags);
318
319 if (notify)
320 notify_remote_via_irq(info->irq);
321 }
322
323 static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
324 uint32_t resid, struct vscsibk_pend *pending_req)
325 {
326 scsiback_send_response(pending_req->info, sense_buffer, result,
327 resid, pending_req->rqid);
328
329 if (pending_req->v2p)
330 kref_put(&pending_req->v2p->kref,
331 scsiback_free_translation_entry);
332 }
333
334 static void scsiback_cmd_done(struct vscsibk_pend *pending_req)
335 {
336 struct vscsibk_info *info = pending_req->info;
337 unsigned char *sense_buffer;
338 unsigned int resid;
339 int errors;
340
341 sense_buffer = pending_req->sense_buffer;
342 resid = pending_req->se_cmd.residual_count;
343 errors = pending_req->result;
344
345 if (errors && log_print_stat)
346 scsiback_print_status(sense_buffer, errors, pending_req);
347
348 scsiback_fast_flush_area(pending_req);
349 scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
350 scsiback_put(info);
351 /*
352 * Drop the extra KREF_ACK reference taken by target_submit_cmd_map_sgls()
353 * ahead of scsiback_check_stop_free() -> transport_generic_free_cmd()
354 * final se_cmd->cmd_kref put.
355 */
356 target_put_sess_cmd(&pending_req->se_cmd);
357 }
358
359 static void scsiback_cmd_exec(struct vscsibk_pend *pending_req)
360 {
361 struct se_cmd *se_cmd = &pending_req->se_cmd;
362 struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess;
363 int rc;
364
365 scsiback_get(pending_req->info);
366 se_cmd->tag = pending_req->rqid;
367 rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd,
368 pending_req->sense_buffer, pending_req->v2p->lun,
369 pending_req->data_len, 0,
370 pending_req->sc_data_direction, TARGET_SCF_ACK_KREF,
371 pending_req->sgl, pending_req->n_sg,
372 NULL, 0, NULL, 0);
373 if (rc < 0) {
374 transport_send_check_condition_and_sense(se_cmd,
375 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
376 transport_generic_free_cmd(se_cmd, 0);
377 }
378 }
379
380 static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
381 struct page **pg, grant_handle_t *grant, int cnt)
382 {
383 int err, i;
384
385 if (!cnt)
386 return 0;
387
388 err = gnttab_map_refs(map, NULL, pg, cnt);
389 BUG_ON(err);
390 for (i = 0; i < cnt; i++) {
391 if (unlikely(map[i].status != GNTST_okay)) {
392 pr_err("invalid buffer -- could not remap it\n");
393 map[i].handle = SCSIBACK_INVALID_HANDLE;
394 err = -ENOMEM;
395 } else {
396 get_page(pg[i]);
397 }
398 grant[i] = map[i].handle;
399 }
400 return err;
401 }
402
403 static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req,
404 struct scsiif_request_segment *seg, struct page **pg,
405 grant_handle_t *grant, int cnt, u32 flags)
406 {
407 int mapcount = 0, i, err = 0;
408 struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH];
409 struct vscsibk_info *info = pending_req->info;
410
411 for (i = 0; i < cnt; i++) {
412 if (gnttab_page_cache_get(&info->free_pages, pg + mapcount)) {
413 gnttab_page_cache_put(&info->free_pages, pg, mapcount);
414 pr_err("no grant page\n");
415 return -ENOMEM;
416 }
417 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]),
418 flags, seg[i].gref, info->domid);
419 mapcount++;
420 if (mapcount < VSCSI_GRANT_BATCH)
421 continue;
422 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
423 pg += mapcount;
424 grant += mapcount;
425 pending_req->n_grants += mapcount;
426 if (err)
427 return err;
428 mapcount = 0;
429 }
430 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
431 pending_req->n_grants += mapcount;
432 return err;
433 }
434
435 static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req,
436 struct vscsibk_pend *pending_req)
437 {
438 u32 flags;
439 int i, err, n_segs, i_seg = 0;
440 struct page **pg;
441 struct scsiif_request_segment *seg;
442 unsigned long end_seg = 0;
443 unsigned int nr_segments = (unsigned int)ring_req->nr_segments;
444 unsigned int nr_sgl = 0;
445 struct scatterlist *sg;
446 grant_handle_t *grant;
447
448 pending_req->n_sg = 0;
449 pending_req->n_grants = 0;
450 pending_req->data_len = 0;
451
452 nr_segments &= ~VSCSIIF_SG_GRANT;
453 if (!nr_segments)
454 return 0;
455
456 if (nr_segments > VSCSIIF_SG_TABLESIZE) {
457 pr_debug("invalid parameter nr_seg = %d\n",
458 ring_req->nr_segments);
459 return -EINVAL;
460 }
461
462 if (ring_req->nr_segments & VSCSIIF_SG_GRANT) {
463 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg,
464 pending_req->pages, pending_req->grant_handles,
465 nr_segments, GNTMAP_host_map | GNTMAP_readonly);
466 if (err)
467 return err;
468 nr_sgl = nr_segments;
469 nr_segments = 0;
470 for (i = 0; i < nr_sgl; i++) {
471 n_segs = ring_req->seg[i].length /
472 sizeof(struct scsiif_request_segment);
473 if ((unsigned)ring_req->seg[i].offset +
474 (unsigned)ring_req->seg[i].length > PAGE_SIZE ||
475 n_segs * sizeof(struct scsiif_request_segment) !=
476 ring_req->seg[i].length)
477 return -EINVAL;
478 nr_segments += n_segs;
479 }
480 if (nr_segments > SG_ALL) {
481 pr_debug("invalid nr_seg = %d\n", nr_segments);
482 return -EINVAL;
483 }
484 }
485
486 /* free of (sgl) in fast_flush_area() */
487 pending_req->sgl = kmalloc_array(nr_segments,
488 sizeof(struct scatterlist), GFP_KERNEL);
489 if (!pending_req->sgl)
490 return -ENOMEM;
491
492 sg_init_table(pending_req->sgl, nr_segments);
493 pending_req->n_sg = nr_segments;
494
495 flags = GNTMAP_host_map;
496 if (pending_req->sc_data_direction == DMA_TO_DEVICE)
497 flags |= GNTMAP_readonly;
498
499 pg = pending_req->pages + nr_sgl;
500 grant = pending_req->grant_handles + nr_sgl;
501 if (!nr_sgl) {
502 seg = ring_req->seg;
503 err = scsiback_gnttab_data_map_list(pending_req, seg,
504 pg, grant, nr_segments, flags);
505 if (err)
506 return err;
507 } else {
508 for (i = 0; i < nr_sgl; i++) {
509 seg = (struct scsiif_request_segment *)(
510 vaddr(pending_req, i) + ring_req->seg[i].offset);
511 n_segs = ring_req->seg[i].length /
512 sizeof(struct scsiif_request_segment);
513 err = scsiback_gnttab_data_map_list(pending_req, seg,
514 pg, grant, n_segs, flags);
515 if (err)
516 return err;
517 pg += n_segs;
518 grant += n_segs;
519 }
520 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
521 seg = (struct scsiif_request_segment *)end_seg;
522 end_seg += ring_req->seg[0].length;
523 pg = pending_req->pages + nr_sgl;
524 }
525
526 for_each_sg(pending_req->sgl, sg, nr_segments, i) {
527 sg_set_page(sg, pg[i], seg->length, seg->offset);
528 pending_req->data_len += seg->length;
529 seg++;
530 if (nr_sgl && (unsigned long)seg >= end_seg) {
531 i_seg++;
532 end_seg = vaddr(pending_req, i_seg) +
533 ring_req->seg[i_seg].offset;
534 seg = (struct scsiif_request_segment *)end_seg;
535 end_seg += ring_req->seg[i_seg].length;
536 }
537 if (sg->offset >= PAGE_SIZE ||
538 sg->length > PAGE_SIZE ||
539 sg->offset + sg->length > PAGE_SIZE)
540 return -EINVAL;
541 }
542
543 return 0;
544 }
545
546 static void scsiback_disconnect(struct vscsibk_info *info)
547 {
548 wait_event(info->waiting_to_free,
549 atomic_read(&info->nr_unreplied_reqs) == 0);
550
551 unbind_from_irqhandler(info->irq, info);
552 info->irq = 0;
553 xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
554 }
555
556 static void scsiback_device_action(struct vscsibk_pend *pending_req,
557 enum tcm_tmreq_table act, int tag)
558 {
559 struct scsiback_tpg *tpg = pending_req->v2p->tpg;
560 struct scsiback_nexus *nexus = tpg->tpg_nexus;
561 struct se_cmd *se_cmd = &pending_req->se_cmd;
562 u64 unpacked_lun = pending_req->v2p->lun;
563 int rc, err = FAILED;
564
565 init_completion(&pending_req->tmr_done);
566
567 rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess,
568 &pending_req->sense_buffer[0],
569 unpacked_lun, NULL, act, GFP_KERNEL,
570 tag, TARGET_SCF_ACK_KREF);
571 if (rc)
572 goto err;
573
574 wait_for_completion(&pending_req->tmr_done);
575
576 err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
577 SUCCESS : FAILED;
578
579 scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
580 transport_generic_free_cmd(&pending_req->se_cmd, 0);
581 return;
582
583 err:
584 scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
585 }
586
587 /*
588 Perform virtual to physical translation
589 */
590 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
591 struct ids_tuple *v)
592 {
593 struct v2p_entry *entry;
594 struct list_head *head = &(info->v2p_entry_lists);
595 unsigned long flags;
596
597 spin_lock_irqsave(&info->v2p_lock, flags);
598 list_for_each_entry(entry, head, l) {
599 if ((entry->v.chn == v->chn) &&
600 (entry->v.tgt == v->tgt) &&
601 (entry->v.lun == v->lun)) {
602 kref_get(&entry->kref);
603 goto out;
604 }
605 }
606 entry = NULL;
607
608 out:
609 spin_unlock_irqrestore(&info->v2p_lock, flags);
610 return entry;
611 }
612
613 static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring,
614 struct v2p_entry *v2p)
615 {
616 struct scsiback_tpg *tpg = v2p->tpg;
617 struct scsiback_nexus *nexus = tpg->tpg_nexus;
618 struct se_session *se_sess = nexus->tvn_se_sess;
619 struct vscsibk_pend *req;
620 int tag, cpu, i;
621
622 tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
623 if (tag < 0) {
624 pr_err("Unable to obtain tag for vscsiif_request\n");
625 return ERR_PTR(-ENOMEM);
626 }
627
628 req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag];
629 memset(req, 0, sizeof(*req));
630 req->se_cmd.map_tag = tag;
631 req->se_cmd.map_cpu = cpu;
632
633 for (i = 0; i < VSCSI_MAX_GRANTS; i++)
634 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
635
636 return req;
637 }
638
639 static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info,
640 struct vscsiif_back_ring *ring,
641 struct vscsiif_request *ring_req)
642 {
643 struct vscsibk_pend *pending_req;
644 struct v2p_entry *v2p;
645 struct ids_tuple vir;
646
647 /* request range check from frontend */
648 if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
649 (ring_req->sc_data_direction != DMA_TO_DEVICE) &&
650 (ring_req->sc_data_direction != DMA_FROM_DEVICE) &&
651 (ring_req->sc_data_direction != DMA_NONE)) {
652 pr_debug("invalid parameter data_dir = %d\n",
653 ring_req->sc_data_direction);
654 return ERR_PTR(-EINVAL);
655 }
656 if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
657 pr_debug("invalid parameter cmd_len = %d\n",
658 ring_req->cmd_len);
659 return ERR_PTR(-EINVAL);
660 }
661
662 vir.chn = ring_req->channel;
663 vir.tgt = ring_req->id;
664 vir.lun = ring_req->lun;
665
666 v2p = scsiback_do_translation(info, &vir);
667 if (!v2p) {
668 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n",
669 vir.chn, vir.tgt, vir.lun);
670 return ERR_PTR(-ENODEV);
671 }
672
673 pending_req = scsiback_get_pend_req(ring, v2p);
674 if (IS_ERR(pending_req)) {
675 kref_put(&v2p->kref, scsiback_free_translation_entry);
676 return ERR_PTR(-ENOMEM);
677 }
678 pending_req->rqid = ring_req->rqid;
679 pending_req->info = info;
680 pending_req->v2p = v2p;
681 pending_req->sc_data_direction = ring_req->sc_data_direction;
682 pending_req->cmd_len = ring_req->cmd_len;
683 memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
684
685 return pending_req;
686 }
687
688 static int scsiback_do_cmd_fn(struct vscsibk_info *info,
689 unsigned int *eoi_flags)
690 {
691 struct vscsiif_back_ring *ring = &info->ring;
692 struct vscsiif_request ring_req;
693 struct vscsibk_pend *pending_req;
694 RING_IDX rc, rp;
695 int more_to_do;
696 uint32_t result;
697
698 rc = ring->req_cons;
699 rp = ring->sring->req_prod;
700 rmb(); /* guest system is accessing ring, too */
701
702 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
703 rc = ring->rsp_prod_pvt;
704 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
705 info->domid, rp, rc, rp - rc);
706 return -EINVAL;
707 }
708
709 while ((rc != rp)) {
710 *eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS;
711
712 if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
713 break;
714
715 RING_COPY_REQUEST(ring, rc, &ring_req);
716 ring->req_cons = ++rc;
717
718 pending_req = prepare_pending_reqs(info, ring, &ring_req);
719 if (IS_ERR(pending_req)) {
720 switch (PTR_ERR(pending_req)) {
721 case -ENODEV:
722 result = DID_NO_CONNECT;
723 break;
724 default:
725 result = DRIVER_ERROR;
726 break;
727 }
728 scsiback_send_response(info, NULL, result << 24, 0,
729 ring_req.rqid);
730 return 1;
731 }
732
733 switch (ring_req.act) {
734 case VSCSIIF_ACT_SCSI_CDB:
735 if (scsiback_gnttab_data_map(&ring_req, pending_req)) {
736 scsiback_fast_flush_area(pending_req);
737 scsiback_do_resp_with_sense(NULL,
738 DRIVER_ERROR << 24, 0, pending_req);
739 transport_generic_free_cmd(&pending_req->se_cmd, 0);
740 } else {
741 scsiback_cmd_exec(pending_req);
742 }
743 break;
744 case VSCSIIF_ACT_SCSI_ABORT:
745 scsiback_device_action(pending_req, TMR_ABORT_TASK,
746 ring_req.ref_rqid);
747 break;
748 case VSCSIIF_ACT_SCSI_RESET:
749 scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
750 break;
751 default:
752 pr_err_ratelimited("invalid request\n");
753 scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24, 0,
754 pending_req);
755 transport_generic_free_cmd(&pending_req->se_cmd, 0);
756 break;
757 }
758
759 /* Yield point for this unbounded loop. */
760 cond_resched();
761 }
762
763 gnttab_page_cache_shrink(&info->free_pages, scsiback_max_buffer_pages);
764
765 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
766 return more_to_do;
767 }
768
769 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
770 {
771 struct vscsibk_info *info = dev_id;
772 int rc;
773 unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
774
775 while ((rc = scsiback_do_cmd_fn(info, &eoi_flags)) > 0)
776 cond_resched();
777
778 /* In case of a ring error we keep the event channel masked. */
779 if (!rc)
780 xen_irq_lateeoi(irq, eoi_flags);
781
782 return IRQ_HANDLED;
783 }
784
785 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
786 evtchn_port_t evtchn)
787 {
788 void *area;
789 struct vscsiif_sring *sring;
790 int err;
791
792 if (info->irq)
793 return -1;
794
795 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area);
796 if (err)
797 return err;
798
799 sring = (struct vscsiif_sring *)area;
800 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
801
802 err = bind_interdomain_evtchn_to_irq_lateeoi(info->domid, evtchn);
803 if (err < 0)
804 goto unmap_page;
805
806 info->irq = err;
807
808 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
809 IRQF_ONESHOT, "vscsiif-backend", info);
810 if (err)
811 goto free_irq;
812
813 return 0;
814
815 free_irq:
816 unbind_from_irqhandler(info->irq, info);
817 info->irq = 0;
818 unmap_page:
819 xenbus_unmap_ring_vfree(info->dev, area);
820
821 return err;
822 }
823
824 static int scsiback_map(struct vscsibk_info *info)
825 {
826 struct xenbus_device *dev = info->dev;
827 unsigned int ring_ref;
828 evtchn_port_t evtchn;
829 int err;
830
831 err = xenbus_gather(XBT_NIL, dev->otherend,
832 "ring-ref", "%u", &ring_ref,
833 "event-channel", "%u", &evtchn, NULL);
834 if (err) {
835 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
836 return err;
837 }
838
839 return scsiback_init_sring(info, ring_ref, evtchn);
840 }
841
842 /*
843 Check for a translation entry being present
844 */
845 static struct v2p_entry *scsiback_chk_translation_entry(
846 struct vscsibk_info *info, struct ids_tuple *v)
847 {
848 struct list_head *head = &(info->v2p_entry_lists);
849 struct v2p_entry *entry;
850
851 list_for_each_entry(entry, head, l)
852 if ((entry->v.chn == v->chn) &&
853 (entry->v.tgt == v->tgt) &&
854 (entry->v.lun == v->lun))
855 return entry;
856
857 return NULL;
858 }
859
860 /*
861 Add a new translation entry
862 */
863 static int scsiback_add_translation_entry(struct vscsibk_info *info,
864 char *phy, struct ids_tuple *v)
865 {
866 int err = 0;
867 struct v2p_entry *new;
868 unsigned long flags;
869 char *lunp;
870 unsigned long long unpacked_lun;
871 struct se_lun *se_lun;
872 struct scsiback_tpg *tpg_entry, *tpg = NULL;
873 char *error = "doesn't exist";
874
875 lunp = strrchr(phy, ':');
876 if (!lunp) {
877 pr_err("illegal format of physical device %s\n", phy);
878 return -EINVAL;
879 }
880 *lunp = 0;
881 lunp++;
882 err = kstrtoull(lunp, 10, &unpacked_lun);
883 if (err < 0) {
884 pr_err("lun number not valid: %s\n", lunp);
885 return err;
886 }
887
888 mutex_lock(&scsiback_mutex);
889 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
890 if (!strcmp(phy, tpg_entry->tport->tport_name) ||
891 !strcmp(phy, tpg_entry->param_alias)) {
892 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex);
893 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) {
894 if (se_lun->unpacked_lun == unpacked_lun) {
895 if (!tpg_entry->tpg_nexus)
896 error = "nexus undefined";
897 else
898 tpg = tpg_entry;
899 break;
900 }
901 }
902 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex);
903 break;
904 }
905 }
906 if (tpg) {
907 mutex_lock(&tpg->tv_tpg_mutex);
908 tpg->tv_tpg_fe_count++;
909 mutex_unlock(&tpg->tv_tpg_mutex);
910 }
911 mutex_unlock(&scsiback_mutex);
912
913 if (!tpg) {
914 pr_err("%s:%llu %s\n", phy, unpacked_lun, error);
915 return -ENODEV;
916 }
917
918 new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
919 if (new == NULL) {
920 err = -ENOMEM;
921 goto out_free;
922 }
923
924 spin_lock_irqsave(&info->v2p_lock, flags);
925
926 /* Check double assignment to identical virtual ID */
927 if (scsiback_chk_translation_entry(info, v)) {
928 pr_warn("Virtual ID is already used. Assignment was not performed.\n");
929 err = -EEXIST;
930 goto out;
931 }
932
933 /* Create a new translation entry and add to the list */
934 kref_init(&new->kref);
935 new->v = *v;
936 new->tpg = tpg;
937 new->lun = unpacked_lun;
938 list_add_tail(&new->l, &info->v2p_entry_lists);
939
940 out:
941 spin_unlock_irqrestore(&info->v2p_lock, flags);
942
943 out_free:
944 if (err) {
945 mutex_lock(&tpg->tv_tpg_mutex);
946 tpg->tv_tpg_fe_count--;
947 mutex_unlock(&tpg->tv_tpg_mutex);
948 kfree(new);
949 }
950
951 return err;
952 }
953
954 static void __scsiback_del_translation_entry(struct v2p_entry *entry)
955 {
956 list_del(&entry->l);
957 kref_put(&entry->kref, scsiback_free_translation_entry);
958 }
959
960 /*
961 Delete the translation entry specified
962 */
963 static int scsiback_del_translation_entry(struct vscsibk_info *info,
964 struct ids_tuple *v)
965 {
966 struct v2p_entry *entry;
967 unsigned long flags;
968 int ret = 0;
969
970 spin_lock_irqsave(&info->v2p_lock, flags);
971 /* Find out the translation entry specified */
972 entry = scsiback_chk_translation_entry(info, v);
973 if (entry)
974 __scsiback_del_translation_entry(entry);
975 else
976 ret = -ENOENT;
977
978 spin_unlock_irqrestore(&info->v2p_lock, flags);
979 return ret;
980 }
981
982 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
983 char *phy, struct ids_tuple *vir, int try)
984 {
985 struct v2p_entry *entry;
986 unsigned long flags;
987 int err;
988
989 if (try) {
990 spin_lock_irqsave(&info->v2p_lock, flags);
991 entry = scsiback_chk_translation_entry(info, vir);
992 spin_unlock_irqrestore(&info->v2p_lock, flags);
993 if (entry)
994 return;
995 }
996 if (!scsiback_add_translation_entry(info, phy, vir)) {
997 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
998 "%d", XenbusStateInitialised)) {
999 pr_err("xenbus_printf error %s\n", state);
1000 scsiback_del_translation_entry(info, vir);
1001 }
1002 } else if (!try) {
1003 err = xenbus_printf(XBT_NIL, info->dev->nodename, state,
1004 "%d", XenbusStateClosed);
1005 if (err)
1006 xenbus_dev_error(info->dev, err,
1007 "%s: writing %s", __func__, state);
1008 }
1009 }
1010
1011 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1012 struct ids_tuple *vir)
1013 {
1014 if (!scsiback_del_translation_entry(info, vir)) {
1015 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1016 "%d", XenbusStateClosed))
1017 pr_err("xenbus_printf error %s\n", state);
1018 }
1019 }
1020
1021 #define VSCSIBACK_OP_ADD_OR_DEL_LUN 1
1022 #define VSCSIBACK_OP_UPDATEDEV_STATE 2
1023
1024 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1025 char *ent)
1026 {
1027 int err;
1028 struct ids_tuple vir;
1029 char *val;
1030 int device_state;
1031 char phy[VSCSI_NAMELEN];
1032 char str[64];
1033 char state[64];
1034 struct xenbus_device *dev = info->dev;
1035
1036 /* read status */
1037 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1038 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1039 if (XENBUS_EXIST_ERR(err))
1040 return;
1041
1042 /* physical SCSI device */
1043 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1044 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1045 if (IS_ERR(val)) {
1046 err = xenbus_printf(XBT_NIL, dev->nodename, state,
1047 "%d", XenbusStateClosed);
1048 if (err)
1049 xenbus_dev_error(info->dev, err,
1050 "%s: writing %s", __func__, state);
1051 return;
1052 }
1053 strlcpy(phy, val, VSCSI_NAMELEN);
1054 kfree(val);
1055
1056 /* virtual SCSI device */
1057 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1058 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1059 &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1060 if (XENBUS_EXIST_ERR(err)) {
1061 err = xenbus_printf(XBT_NIL, dev->nodename, state,
1062 "%d", XenbusStateClosed);
1063 if (err)
1064 xenbus_dev_error(info->dev, err,
1065 "%s: writing %s", __func__, state);
1066 return;
1067 }
1068
1069 switch (op) {
1070 case VSCSIBACK_OP_ADD_OR_DEL_LUN:
1071 switch (device_state) {
1072 case XenbusStateInitialising:
1073 scsiback_do_add_lun(info, state, phy, &vir, 0);
1074 break;
1075 case XenbusStateConnected:
1076 scsiback_do_add_lun(info, state, phy, &vir, 1);
1077 break;
1078 case XenbusStateClosing:
1079 scsiback_do_del_lun(info, state, &vir);
1080 break;
1081 default:
1082 break;
1083 }
1084 break;
1085
1086 case VSCSIBACK_OP_UPDATEDEV_STATE:
1087 if (device_state == XenbusStateInitialised) {
1088 /* modify vscsi-devs/dev-x/state */
1089 if (xenbus_printf(XBT_NIL, dev->nodename, state,
1090 "%d", XenbusStateConnected)) {
1091 pr_err("xenbus_printf error %s\n", str);
1092 scsiback_del_translation_entry(info, &vir);
1093 xenbus_printf(XBT_NIL, dev->nodename, state,
1094 "%d", XenbusStateClosed);
1095 }
1096 }
1097 break;
1098 /* When it is necessary, processing is added here. */
1099 default:
1100 break;
1101 }
1102 }
1103
1104 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1105 {
1106 int i;
1107 char **dir;
1108 unsigned int ndir = 0;
1109
1110 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1111 &ndir);
1112 if (IS_ERR(dir))
1113 return;
1114
1115 for (i = 0; i < ndir; i++)
1116 scsiback_do_1lun_hotplug(info, op, dir[i]);
1117
1118 kfree(dir);
1119 }
1120
1121 static void scsiback_frontend_changed(struct xenbus_device *dev,
1122 enum xenbus_state frontend_state)
1123 {
1124 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1125
1126 switch (frontend_state) {
1127 case XenbusStateInitialising:
1128 break;
1129
1130 case XenbusStateInitialised:
1131 if (scsiback_map(info))
1132 break;
1133
1134 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1135 xenbus_switch_state(dev, XenbusStateConnected);
1136 break;
1137
1138 case XenbusStateConnected:
1139 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1140
1141 if (dev->state == XenbusStateConnected)
1142 break;
1143
1144 xenbus_switch_state(dev, XenbusStateConnected);
1145 break;
1146
1147 case XenbusStateClosing:
1148 if (info->irq)
1149 scsiback_disconnect(info);
1150
1151 xenbus_switch_state(dev, XenbusStateClosing);
1152 break;
1153
1154 case XenbusStateClosed:
1155 xenbus_switch_state(dev, XenbusStateClosed);
1156 if (xenbus_dev_is_online(dev))
1157 break;
1158 fallthrough; /* if not online */
1159 case XenbusStateUnknown:
1160 device_unregister(&dev->dev);
1161 break;
1162
1163 case XenbusStateReconfiguring:
1164 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1165 xenbus_switch_state(dev, XenbusStateReconfigured);
1166
1167 break;
1168
1169 default:
1170 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1171 frontend_state);
1172 break;
1173 }
1174 }
1175
1176 /*
1177 Release the translation entry specfied
1178 */
1179 static void scsiback_release_translation_entry(struct vscsibk_info *info)
1180 {
1181 struct v2p_entry *entry, *tmp;
1182 struct list_head *head = &(info->v2p_entry_lists);
1183 unsigned long flags;
1184
1185 spin_lock_irqsave(&info->v2p_lock, flags);
1186
1187 list_for_each_entry_safe(entry, tmp, head, l)
1188 __scsiback_del_translation_entry(entry);
1189
1190 spin_unlock_irqrestore(&info->v2p_lock, flags);
1191 }
1192
1193 static int scsiback_remove(struct xenbus_device *dev)
1194 {
1195 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1196
1197 if (info->irq)
1198 scsiback_disconnect(info);
1199
1200 scsiback_release_translation_entry(info);
1201
1202 gnttab_page_cache_shrink(&info->free_pages, 0);
1203
1204 dev_set_drvdata(&dev->dev, NULL);
1205
1206 return 0;
1207 }
1208
1209 static int scsiback_probe(struct xenbus_device *dev,
1210 const struct xenbus_device_id *id)
1211 {
1212 int err;
1213
1214 struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
1215 GFP_KERNEL);
1216
1217 pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id);
1218
1219 if (!info) {
1220 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
1221 return -ENOMEM;
1222 }
1223 info->dev = dev;
1224 dev_set_drvdata(&dev->dev, info);
1225
1226 info->domid = dev->otherend_id;
1227 spin_lock_init(&info->ring_lock);
1228 atomic_set(&info->nr_unreplied_reqs, 0);
1229 init_waitqueue_head(&info->waiting_to_free);
1230 info->dev = dev;
1231 info->irq = 0;
1232 INIT_LIST_HEAD(&info->v2p_entry_lists);
1233 spin_lock_init(&info->v2p_lock);
1234 gnttab_page_cache_init(&info->free_pages);
1235
1236 err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
1237 SG_ALL);
1238 if (err)
1239 xenbus_dev_error(dev, err, "writing feature-sg-grant");
1240
1241 err = xenbus_switch_state(dev, XenbusStateInitWait);
1242 if (err)
1243 goto fail;
1244
1245 return 0;
1246
1247 fail:
1248 pr_warn("%s failed\n", __func__);
1249 scsiback_remove(dev);
1250
1251 return err;
1252 }
1253
1254 static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
1255 {
1256 switch (tport->tport_proto_id) {
1257 case SCSI_PROTOCOL_SAS:
1258 return "SAS";
1259 case SCSI_PROTOCOL_FCP:
1260 return "FCP";
1261 case SCSI_PROTOCOL_ISCSI:
1262 return "iSCSI";
1263 default:
1264 break;
1265 }
1266
1267 return "Unknown";
1268 }
1269
1270 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
1271 {
1272 struct scsiback_tpg *tpg = container_of(se_tpg,
1273 struct scsiback_tpg, se_tpg);
1274 struct scsiback_tport *tport = tpg->tport;
1275
1276 return &tport->tport_name[0];
1277 }
1278
1279 static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
1280 {
1281 struct scsiback_tpg *tpg = container_of(se_tpg,
1282 struct scsiback_tpg, se_tpg);
1283 return tpg->tport_tpgt;
1284 }
1285
1286 static struct se_wwn *
1287 scsiback_make_tport(struct target_fabric_configfs *tf,
1288 struct config_group *group,
1289 const char *name)
1290 {
1291 struct scsiback_tport *tport;
1292 char *ptr;
1293 u64 wwpn = 0;
1294 int off = 0;
1295
1296 tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL);
1297 if (!tport)
1298 return ERR_PTR(-ENOMEM);
1299
1300 tport->tport_wwpn = wwpn;
1301 /*
1302 * Determine the emulated Protocol Identifier and Target Port Name
1303 * based on the incoming configfs directory name.
1304 */
1305 ptr = strstr(name, "naa.");
1306 if (ptr) {
1307 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1308 goto check_len;
1309 }
1310 ptr = strstr(name, "fc.");
1311 if (ptr) {
1312 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1313 off = 3; /* Skip over "fc." */
1314 goto check_len;
1315 }
1316 ptr = strstr(name, "iqn.");
1317 if (ptr) {
1318 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1319 goto check_len;
1320 }
1321
1322 pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
1323 kfree(tport);
1324 return ERR_PTR(-EINVAL);
1325
1326 check_len:
1327 if (strlen(name) >= VSCSI_NAMELEN) {
1328 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
1329 scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
1330 kfree(tport);
1331 return ERR_PTR(-EINVAL);
1332 }
1333 snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
1334
1335 pr_debug("Allocated emulated Target %s Address: %s\n",
1336 scsiback_dump_proto_id(tport), name);
1337
1338 return &tport->tport_wwn;
1339 }
1340
1341 static void scsiback_drop_tport(struct se_wwn *wwn)
1342 {
1343 struct scsiback_tport *tport = container_of(wwn,
1344 struct scsiback_tport, tport_wwn);
1345
1346 pr_debug("Deallocating emulated Target %s Address: %s\n",
1347 scsiback_dump_proto_id(tport), tport->tport_name);
1348
1349 kfree(tport);
1350 }
1351
1352 static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg)
1353 {
1354 return 1;
1355 }
1356
1357 static int scsiback_check_stop_free(struct se_cmd *se_cmd)
1358 {
1359 return transport_generic_free_cmd(se_cmd, 0);
1360 }
1361
1362 static void scsiback_release_cmd(struct se_cmd *se_cmd)
1363 {
1364 target_free_tag(se_cmd->se_sess, se_cmd);
1365 }
1366
1367 static u32 scsiback_sess_get_index(struct se_session *se_sess)
1368 {
1369 return 0;
1370 }
1371
1372 static int scsiback_write_pending(struct se_cmd *se_cmd)
1373 {
1374 /* Go ahead and process the write immediately */
1375 target_execute_cmd(se_cmd);
1376
1377 return 0;
1378 }
1379
1380 static void scsiback_set_default_node_attrs(struct se_node_acl *nacl)
1381 {
1382 }
1383
1384 static int scsiback_get_cmd_state(struct se_cmd *se_cmd)
1385 {
1386 return 0;
1387 }
1388
1389 static int scsiback_queue_data_in(struct se_cmd *se_cmd)
1390 {
1391 struct vscsibk_pend *pending_req = container_of(se_cmd,
1392 struct vscsibk_pend, se_cmd);
1393
1394 pending_req->result = SAM_STAT_GOOD;
1395 scsiback_cmd_done(pending_req);
1396 return 0;
1397 }
1398
1399 static int scsiback_queue_status(struct se_cmd *se_cmd)
1400 {
1401 struct vscsibk_pend *pending_req = container_of(se_cmd,
1402 struct vscsibk_pend, se_cmd);
1403
1404 if (se_cmd->sense_buffer &&
1405 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1406 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
1407 pending_req->result = (DRIVER_SENSE << 24) |
1408 SAM_STAT_CHECK_CONDITION;
1409 else
1410 pending_req->result = se_cmd->scsi_status;
1411
1412 scsiback_cmd_done(pending_req);
1413 return 0;
1414 }
1415
1416 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
1417 {
1418 struct vscsibk_pend *pending_req = container_of(se_cmd,
1419 struct vscsibk_pend, se_cmd);
1420
1421 complete(&pending_req->tmr_done);
1422 }
1423
1424 static void scsiback_aborted_task(struct se_cmd *se_cmd)
1425 {
1426 }
1427
1428 static ssize_t scsiback_tpg_param_alias_show(struct config_item *item,
1429 char *page)
1430 {
1431 struct se_portal_group *se_tpg = param_to_tpg(item);
1432 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1433 se_tpg);
1434 ssize_t rb;
1435
1436 mutex_lock(&tpg->tv_tpg_mutex);
1437 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
1438 mutex_unlock(&tpg->tv_tpg_mutex);
1439
1440 return rb;
1441 }
1442
1443 static ssize_t scsiback_tpg_param_alias_store(struct config_item *item,
1444 const char *page, size_t count)
1445 {
1446 struct se_portal_group *se_tpg = param_to_tpg(item);
1447 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1448 se_tpg);
1449 int len;
1450
1451 if (strlen(page) >= VSCSI_NAMELEN) {
1452 pr_err("param alias: %s, exceeds max: %d\n", page,
1453 VSCSI_NAMELEN);
1454 return -EINVAL;
1455 }
1456
1457 mutex_lock(&tpg->tv_tpg_mutex);
1458 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
1459 if (tpg->param_alias[len - 1] == '\n')
1460 tpg->param_alias[len - 1] = '\0';
1461 mutex_unlock(&tpg->tv_tpg_mutex);
1462
1463 return count;
1464 }
1465
1466 CONFIGFS_ATTR(scsiback_tpg_param_, alias);
1467
1468 static struct configfs_attribute *scsiback_param_attrs[] = {
1469 &scsiback_tpg_param_attr_alias,
1470 NULL,
1471 };
1472
1473 static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg,
1474 struct se_session *se_sess, void *p)
1475 {
1476 struct scsiback_tpg *tpg = container_of(se_tpg,
1477 struct scsiback_tpg, se_tpg);
1478
1479 tpg->tpg_nexus = p;
1480 return 0;
1481 }
1482
1483 static int scsiback_make_nexus(struct scsiback_tpg *tpg,
1484 const char *name)
1485 {
1486 struct scsiback_nexus *tv_nexus;
1487 int ret = 0;
1488
1489 mutex_lock(&tpg->tv_tpg_mutex);
1490 if (tpg->tpg_nexus) {
1491 pr_debug("tpg->tpg_nexus already exists\n");
1492 ret = -EEXIST;
1493 goto out_unlock;
1494 }
1495
1496 tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
1497 if (!tv_nexus) {
1498 ret = -ENOMEM;
1499 goto out_unlock;
1500 }
1501
1502 tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg,
1503 VSCSI_DEFAULT_SESSION_TAGS,
1504 sizeof(struct vscsibk_pend),
1505 TARGET_PROT_NORMAL, name,
1506 tv_nexus, scsiback_alloc_sess_cb);
1507 if (IS_ERR(tv_nexus->tvn_se_sess)) {
1508 kfree(tv_nexus);
1509 ret = -ENOMEM;
1510 goto out_unlock;
1511 }
1512
1513 out_unlock:
1514 mutex_unlock(&tpg->tv_tpg_mutex);
1515 return ret;
1516 }
1517
1518 static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1519 {
1520 struct se_session *se_sess;
1521 struct scsiback_nexus *tv_nexus;
1522
1523 mutex_lock(&tpg->tv_tpg_mutex);
1524 tv_nexus = tpg->tpg_nexus;
1525 if (!tv_nexus) {
1526 mutex_unlock(&tpg->tv_tpg_mutex);
1527 return -ENODEV;
1528 }
1529
1530 se_sess = tv_nexus->tvn_se_sess;
1531 if (!se_sess) {
1532 mutex_unlock(&tpg->tv_tpg_mutex);
1533 return -ENODEV;
1534 }
1535
1536 if (tpg->tv_tpg_port_count != 0) {
1537 mutex_unlock(&tpg->tv_tpg_mutex);
1538 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1539 tpg->tv_tpg_port_count);
1540 return -EBUSY;
1541 }
1542
1543 if (tpg->tv_tpg_fe_count != 0) {
1544 mutex_unlock(&tpg->tv_tpg_mutex);
1545 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1546 tpg->tv_tpg_fe_count);
1547 return -EBUSY;
1548 }
1549
1550 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n",
1551 scsiback_dump_proto_id(tpg->tport),
1552 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1553
1554 /*
1555 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1556 */
1557 target_remove_session(se_sess);
1558 tpg->tpg_nexus = NULL;
1559 mutex_unlock(&tpg->tv_tpg_mutex);
1560
1561 kfree(tv_nexus);
1562 return 0;
1563 }
1564
1565 static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page)
1566 {
1567 struct se_portal_group *se_tpg = to_tpg(item);
1568 struct scsiback_tpg *tpg = container_of(se_tpg,
1569 struct scsiback_tpg, se_tpg);
1570 struct scsiback_nexus *tv_nexus;
1571 ssize_t ret;
1572
1573 mutex_lock(&tpg->tv_tpg_mutex);
1574 tv_nexus = tpg->tpg_nexus;
1575 if (!tv_nexus) {
1576 mutex_unlock(&tpg->tv_tpg_mutex);
1577 return -ENODEV;
1578 }
1579 ret = snprintf(page, PAGE_SIZE, "%s\n",
1580 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1581 mutex_unlock(&tpg->tv_tpg_mutex);
1582
1583 return ret;
1584 }
1585
1586 static ssize_t scsiback_tpg_nexus_store(struct config_item *item,
1587 const char *page, size_t count)
1588 {
1589 struct se_portal_group *se_tpg = to_tpg(item);
1590 struct scsiback_tpg *tpg = container_of(se_tpg,
1591 struct scsiback_tpg, se_tpg);
1592 struct scsiback_tport *tport_wwn = tpg->tport;
1593 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1594 int ret;
1595 /*
1596 * Shutdown the active I_T nexus if 'NULL' is passed.
1597 */
1598 if (!strncmp(page, "NULL", 4)) {
1599 ret = scsiback_drop_nexus(tpg);
1600 return (!ret) ? count : ret;
1601 }
1602 /*
1603 * Otherwise make sure the passed virtual Initiator port WWN matches
1604 * the fabric protocol_id set in scsiback_make_tport(), and call
1605 * scsiback_make_nexus().
1606 */
1607 if (strlen(page) >= VSCSI_NAMELEN) {
1608 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1609 page, VSCSI_NAMELEN);
1610 return -EINVAL;
1611 }
1612 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1613
1614 ptr = strstr(i_port, "naa.");
1615 if (ptr) {
1616 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1617 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1618 i_port, scsiback_dump_proto_id(tport_wwn));
1619 return -EINVAL;
1620 }
1621 port_ptr = &i_port[0];
1622 goto check_newline;
1623 }
1624 ptr = strstr(i_port, "fc.");
1625 if (ptr) {
1626 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1627 pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
1628 i_port, scsiback_dump_proto_id(tport_wwn));
1629 return -EINVAL;
1630 }
1631 port_ptr = &i_port[3]; /* Skip over "fc." */
1632 goto check_newline;
1633 }
1634 ptr = strstr(i_port, "iqn.");
1635 if (ptr) {
1636 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1637 pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
1638 i_port, scsiback_dump_proto_id(tport_wwn));
1639 return -EINVAL;
1640 }
1641 port_ptr = &i_port[0];
1642 goto check_newline;
1643 }
1644 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1645 i_port);
1646 return -EINVAL;
1647 /*
1648 * Clear any trailing newline for the NAA WWN
1649 */
1650 check_newline:
1651 if (i_port[strlen(i_port) - 1] == '\n')
1652 i_port[strlen(i_port) - 1] = '\0';
1653
1654 ret = scsiback_make_nexus(tpg, port_ptr);
1655 if (ret < 0)
1656 return ret;
1657
1658 return count;
1659 }
1660
1661 CONFIGFS_ATTR(scsiback_tpg_, nexus);
1662
1663 static struct configfs_attribute *scsiback_tpg_attrs[] = {
1664 &scsiback_tpg_attr_nexus,
1665 NULL,
1666 };
1667
1668 static ssize_t
1669 scsiback_wwn_version_show(struct config_item *item, char *page)
1670 {
1671 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1672 UTS_RELEASE"\n",
1673 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1674 }
1675
1676 CONFIGFS_ATTR_RO(scsiback_wwn_, version);
1677
1678 static struct configfs_attribute *scsiback_wwn_attrs[] = {
1679 &scsiback_wwn_attr_version,
1680 NULL,
1681 };
1682
1683 static int scsiback_port_link(struct se_portal_group *se_tpg,
1684 struct se_lun *lun)
1685 {
1686 struct scsiback_tpg *tpg = container_of(se_tpg,
1687 struct scsiback_tpg, se_tpg);
1688
1689 mutex_lock(&tpg->tv_tpg_mutex);
1690 tpg->tv_tpg_port_count++;
1691 mutex_unlock(&tpg->tv_tpg_mutex);
1692
1693 return 0;
1694 }
1695
1696 static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1697 struct se_lun *lun)
1698 {
1699 struct scsiback_tpg *tpg = container_of(se_tpg,
1700 struct scsiback_tpg, se_tpg);
1701
1702 mutex_lock(&tpg->tv_tpg_mutex);
1703 tpg->tv_tpg_port_count--;
1704 mutex_unlock(&tpg->tv_tpg_mutex);
1705 }
1706
1707 static struct se_portal_group *
1708 scsiback_make_tpg(struct se_wwn *wwn, const char *name)
1709 {
1710 struct scsiback_tport *tport = container_of(wwn,
1711 struct scsiback_tport, tport_wwn);
1712
1713 struct scsiback_tpg *tpg;
1714 u16 tpgt;
1715 int ret;
1716
1717 if (strstr(name, "tpgt_") != name)
1718 return ERR_PTR(-EINVAL);
1719 ret = kstrtou16(name + 5, 10, &tpgt);
1720 if (ret)
1721 return ERR_PTR(ret);
1722
1723 tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
1724 if (!tpg)
1725 return ERR_PTR(-ENOMEM);
1726
1727 mutex_init(&tpg->tv_tpg_mutex);
1728 INIT_LIST_HEAD(&tpg->tv_tpg_list);
1729 INIT_LIST_HEAD(&tpg->info_list);
1730 tpg->tport = tport;
1731 tpg->tport_tpgt = tpgt;
1732
1733 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
1734 if (ret < 0) {
1735 kfree(tpg);
1736 return NULL;
1737 }
1738 mutex_lock(&scsiback_mutex);
1739 list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1740 mutex_unlock(&scsiback_mutex);
1741
1742 return &tpg->se_tpg;
1743 }
1744
1745 static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1746 {
1747 struct scsiback_tpg *tpg = container_of(se_tpg,
1748 struct scsiback_tpg, se_tpg);
1749
1750 mutex_lock(&scsiback_mutex);
1751 list_del(&tpg->tv_tpg_list);
1752 mutex_unlock(&scsiback_mutex);
1753 /*
1754 * Release the virtual I_T Nexus for this xen-pvscsi TPG
1755 */
1756 scsiback_drop_nexus(tpg);
1757 /*
1758 * Deregister the se_tpg from TCM.
1759 */
1760 core_tpg_deregister(se_tpg);
1761 kfree(tpg);
1762 }
1763
1764 static int scsiback_check_true(struct se_portal_group *se_tpg)
1765 {
1766 return 1;
1767 }
1768
1769 static int scsiback_check_false(struct se_portal_group *se_tpg)
1770 {
1771 return 0;
1772 }
1773
1774 static const struct target_core_fabric_ops scsiback_ops = {
1775 .module = THIS_MODULE,
1776 .fabric_name = "xen-pvscsi",
1777 .tpg_get_wwn = scsiback_get_fabric_wwn,
1778 .tpg_get_tag = scsiback_get_tag,
1779 .tpg_check_demo_mode = scsiback_check_true,
1780 .tpg_check_demo_mode_cache = scsiback_check_true,
1781 .tpg_check_demo_mode_write_protect = scsiback_check_false,
1782 .tpg_check_prod_mode_write_protect = scsiback_check_false,
1783 .tpg_get_inst_index = scsiback_tpg_get_inst_index,
1784 .check_stop_free = scsiback_check_stop_free,
1785 .release_cmd = scsiback_release_cmd,
1786 .sess_get_index = scsiback_sess_get_index,
1787 .sess_get_initiator_sid = NULL,
1788 .write_pending = scsiback_write_pending,
1789 .set_default_node_attributes = scsiback_set_default_node_attrs,
1790 .get_cmd_state = scsiback_get_cmd_state,
1791 .queue_data_in = scsiback_queue_data_in,
1792 .queue_status = scsiback_queue_status,
1793 .queue_tm_rsp = scsiback_queue_tm_rsp,
1794 .aborted_task = scsiback_aborted_task,
1795 /*
1796 * Setup callers for generic logic in target_core_fabric_configfs.c
1797 */
1798 .fabric_make_wwn = scsiback_make_tport,
1799 .fabric_drop_wwn = scsiback_drop_tport,
1800 .fabric_make_tpg = scsiback_make_tpg,
1801 .fabric_drop_tpg = scsiback_drop_tpg,
1802 .fabric_post_link = scsiback_port_link,
1803 .fabric_pre_unlink = scsiback_port_unlink,
1804
1805 .tfc_wwn_attrs = scsiback_wwn_attrs,
1806 .tfc_tpg_base_attrs = scsiback_tpg_attrs,
1807 .tfc_tpg_param_attrs = scsiback_param_attrs,
1808 };
1809
1810 static const struct xenbus_device_id scsiback_ids[] = {
1811 { "vscsi" },
1812 { "" }
1813 };
1814
1815 static struct xenbus_driver scsiback_driver = {
1816 .ids = scsiback_ids,
1817 .probe = scsiback_probe,
1818 .remove = scsiback_remove,
1819 .otherend_changed = scsiback_frontend_changed
1820 };
1821
1822 static int __init scsiback_init(void)
1823 {
1824 int ret;
1825
1826 if (!xen_domain())
1827 return -ENODEV;
1828
1829 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
1830 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1831
1832 ret = xenbus_register_backend(&scsiback_driver);
1833 if (ret)
1834 goto out;
1835
1836 ret = target_register_template(&scsiback_ops);
1837 if (ret)
1838 goto out_unregister_xenbus;
1839
1840 return 0;
1841
1842 out_unregister_xenbus:
1843 xenbus_unregister_driver(&scsiback_driver);
1844 out:
1845 pr_err("%s: error %d\n", __func__, ret);
1846 return ret;
1847 }
1848
1849 static void __exit scsiback_exit(void)
1850 {
1851 target_unregister_template(&scsiback_ops);
1852 xenbus_unregister_driver(&scsiback_driver);
1853 }
1854
1855 module_init(scsiback_init);
1856 module_exit(scsiback_exit);
1857
1858 MODULE_DESCRIPTION("Xen SCSI backend driver");
1859 MODULE_LICENSE("Dual BSD/GPL");
1860 MODULE_ALIAS("xen-backend:vscsi");
1861 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");
Linux with added FPC-III support