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 <linux/module.h>
37 #include <linux/utsname.h>
38 #include <linux/interrupt.h>
39 #include <linux/slab.h>
40 #include <linux/wait.h>
41 #include <linux/sched.h>
42 #include <linux/list.h>
43 #include <linux/gfp.h>
44 #include <linux/delay.h>
45 #include <linux/spinlock.h>
46 #include <linux/configfs.h>
47
48 #include <generated/utsrelease.h>
49
50 #include <scsi/scsi_host.h> /* SG_ALL */
51
52 #include <target/target_core_base.h>
53 #include <target/target_core_fabric.h>
54
55 #include <asm/hypervisor.h>
56
57 #include <xen/xen.h>
58 #include <xen/balloon.h>
59 #include <xen/events.h>
60 #include <xen/xenbus.h>
61 #include <xen/grant_table.h>
62 #include <xen/page.h>
63
64 #include <xen/interface/grant_table.h>
65 #include <xen/interface/io/vscsiif.h>
66
67 #define VSCSI_VERSION "v0.1"
68 #define VSCSI_NAMELEN 32
69
70 struct ids_tuple {
71 unsigned int hst; /* host */
72 unsigned int chn; /* channel */
73 unsigned int tgt; /* target */
74 unsigned int lun; /* LUN */
75 };
76
77 struct v2p_entry {
78 struct ids_tuple v; /* translate from */
79 struct scsiback_tpg *tpg; /* translate to */
80 unsigned int lun;
81 struct kref kref;
82 struct list_head l;
83 };
84
85 struct vscsibk_info {
86 struct xenbus_device *dev;
87
88 domid_t domid;
89 unsigned int irq;
90
91 struct vscsiif_back_ring ring;
92
93 spinlock_t ring_lock;
94 atomic_t nr_unreplied_reqs;
95
96 spinlock_t v2p_lock;
97 struct list_head v2p_entry_lists;
98
99 wait_queue_head_t waiting_to_free;
100
101 struct gnttab_page_cache free_pages;
102 };
103
104 /* theoretical maximum of grants for one request */
105 #define VSCSI_MAX_GRANTS (SG_ALL + VSCSIIF_SG_TABLESIZE)
106
107 /*
108 * VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one
109 * call to map/unmap grants. Don't choose it too large, as there are arrays
110 * with VSCSI_GRANT_BATCH elements allocated on the stack.
111 */
112 #define VSCSI_GRANT_BATCH 16
113
114 struct vscsibk_pend {
115 uint16_t rqid;
116
117 uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE];
118 uint8_t cmd_len;
119
120 uint8_t sc_data_direction;
121 uint16_t n_sg; /* real length of SG list */
122 uint16_t n_grants; /* SG pages and potentially SG list */
123 uint32_t data_len;
124 uint32_t result;
125
126 struct vscsibk_info *info;
127 struct v2p_entry *v2p;
128 struct scatterlist *sgl;
129
130 uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE];
131
132 grant_handle_t grant_handles[VSCSI_MAX_GRANTS];
133 struct page *pages[VSCSI_MAX_GRANTS];
134
135 struct se_cmd se_cmd;
136
137 struct completion tmr_done;
138 };
139
140 #define VSCSI_DEFAULT_SESSION_TAGS 128
141
142 struct scsiback_nexus {
143 /* Pointer to TCM session for I_T Nexus */
144 struct se_session *tvn_se_sess;
145 };
146
147 struct scsiback_tport {
148 /* SCSI protocol the tport is providing */
149 u8 tport_proto_id;
150 /* Binary World Wide unique Port Name for pvscsi Target port */
151 u64 tport_wwpn;
152 /* ASCII formatted WWPN for pvscsi Target port */
153 char tport_name[VSCSI_NAMELEN];
154 /* Returned by scsiback_make_tport() */
155 struct se_wwn tport_wwn;
156 };
157
158 struct scsiback_tpg {
159 /* scsiback port target portal group tag for TCM */
160 u16 tport_tpgt;
161 /* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */
162 int tv_tpg_port_count;
163 /* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */
164 int tv_tpg_fe_count;
165 /* list for scsiback_list */
166 struct list_head tv_tpg_list;
167 /* Used to protect access for tpg_nexus */
168 struct mutex tv_tpg_mutex;
169 /* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */
170 struct scsiback_nexus *tpg_nexus;
171 /* Pointer back to scsiback_tport */
172 struct scsiback_tport *tport;
173 /* Returned by scsiback_make_tpg() */
174 struct se_portal_group se_tpg;
175 /* alias used in xenstore */
176 char param_alias[VSCSI_NAMELEN];
177 /* list of info structures related to this target portal group */
178 struct list_head info_list;
179 };
180
181 #define SCSIBACK_INVALID_HANDLE (~0)
182
183 static bool log_print_stat;
184 module_param(log_print_stat, bool, 0644);
185
186 static int scsiback_max_buffer_pages = 1024;
187 module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644);
188 MODULE_PARM_DESC(max_buffer_pages,
189 "Maximum number of free pages to keep in backend buffer");
190
191 /* Global spinlock to protect scsiback TPG list */
192 static DEFINE_MUTEX(scsiback_mutex);
193 static LIST_HEAD(scsiback_list);
194
scsiback_get(struct vscsibk_info * info)195 static void scsiback_get(struct vscsibk_info *info)
196 {
197 atomic_inc(&info->nr_unreplied_reqs);
198 }
199
scsiback_put(struct vscsibk_info * info)200 static void scsiback_put(struct vscsibk_info *info)
201 {
202 if (atomic_dec_and_test(&info->nr_unreplied_reqs))
203 wake_up(&info->waiting_to_free);
204 }
205
vaddr_page(struct page * page)206 static unsigned long vaddr_page(struct page *page)
207 {
208 unsigned long pfn = page_to_pfn(page);
209
210 return (unsigned long)pfn_to_kaddr(pfn);
211 }
212
vaddr(struct vscsibk_pend * req,int seg)213 static unsigned long vaddr(struct vscsibk_pend *req, int seg)
214 {
215 return vaddr_page(req->pages[seg]);
216 }
217
scsiback_print_status(char * sense_buffer,int errors,struct vscsibk_pend * pending_req)218 static void scsiback_print_status(char *sense_buffer, int errors,
219 struct vscsibk_pend *pending_req)
220 {
221 struct scsiback_tpg *tpg = pending_req->v2p->tpg;
222
223 pr_err("[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x\n",
224 tpg->tport->tport_name, pending_req->v2p->lun,
225 pending_req->cmnd[0], errors & 0xff, COMMAND_COMPLETE,
226 host_byte(errors));
227 }
228
scsiback_fast_flush_area(struct vscsibk_pend * req)229 static void scsiback_fast_flush_area(struct vscsibk_pend *req)
230 {
231 struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH];
232 struct page *pages[VSCSI_GRANT_BATCH];
233 unsigned int i, invcount = 0;
234 grant_handle_t handle;
235 int err;
236
237 kfree(req->sgl);
238 req->sgl = NULL;
239 req->n_sg = 0;
240
241 if (!req->n_grants)
242 return;
243
244 for (i = 0; i < req->n_grants; i++) {
245 handle = req->grant_handles[i];
246 if (handle == SCSIBACK_INVALID_HANDLE)
247 continue;
248 gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
249 GNTMAP_host_map, handle);
250 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
251 pages[invcount] = req->pages[i];
252 put_page(pages[invcount]);
253 invcount++;
254 if (invcount < VSCSI_GRANT_BATCH)
255 continue;
256 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
257 BUG_ON(err);
258 invcount = 0;
259 }
260
261 if (invcount) {
262 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
263 BUG_ON(err);
264 }
265
266 gnttab_page_cache_put(&req->info->free_pages, req->pages,
267 req->n_grants);
268 req->n_grants = 0;
269 }
270
scsiback_free_translation_entry(struct kref * kref)271 static void scsiback_free_translation_entry(struct kref *kref)
272 {
273 struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref);
274 struct scsiback_tpg *tpg = entry->tpg;
275
276 mutex_lock(&tpg->tv_tpg_mutex);
277 tpg->tv_tpg_fe_count--;
278 mutex_unlock(&tpg->tv_tpg_mutex);
279
280 kfree(entry);
281 }
282
scsiback_result(int32_t result)283 static int32_t scsiback_result(int32_t result)
284 {
285 int32_t host_status;
286
287 switch (XEN_VSCSIIF_RSLT_HOST(result)) {
288 case DID_OK:
289 host_status = XEN_VSCSIIF_RSLT_HOST_OK;
290 break;
291 case DID_NO_CONNECT:
292 host_status = XEN_VSCSIIF_RSLT_HOST_NO_CONNECT;
293 break;
294 case DID_BUS_BUSY:
295 host_status = XEN_VSCSIIF_RSLT_HOST_BUS_BUSY;
296 break;
297 case DID_TIME_OUT:
298 host_status = XEN_VSCSIIF_RSLT_HOST_TIME_OUT;
299 break;
300 case DID_BAD_TARGET:
301 host_status = XEN_VSCSIIF_RSLT_HOST_BAD_TARGET;
302 break;
303 case DID_ABORT:
304 host_status = XEN_VSCSIIF_RSLT_HOST_ABORT;
305 break;
306 case DID_PARITY:
307 host_status = XEN_VSCSIIF_RSLT_HOST_PARITY;
308 break;
309 case DID_ERROR:
310 host_status = XEN_VSCSIIF_RSLT_HOST_ERROR;
311 break;
312 case DID_RESET:
313 host_status = XEN_VSCSIIF_RSLT_HOST_RESET;
314 break;
315 case DID_BAD_INTR:
316 host_status = XEN_VSCSIIF_RSLT_HOST_BAD_INTR;
317 break;
318 case DID_PASSTHROUGH:
319 host_status = XEN_VSCSIIF_RSLT_HOST_PASSTHROUGH;
320 break;
321 case DID_SOFT_ERROR:
322 host_status = XEN_VSCSIIF_RSLT_HOST_SOFT_ERROR;
323 break;
324 case DID_IMM_RETRY:
325 host_status = XEN_VSCSIIF_RSLT_HOST_IMM_RETRY;
326 break;
327 case DID_REQUEUE:
328 host_status = XEN_VSCSIIF_RSLT_HOST_REQUEUE;
329 break;
330 case DID_TRANSPORT_DISRUPTED:
331 host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_DISRUPTED;
332 break;
333 case DID_TRANSPORT_FAILFAST:
334 host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_FAILFAST;
335 break;
336 case DID_TRANSPORT_MARGINAL:
337 host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_MARGINAL;
338 break;
339 default:
340 host_status = XEN_VSCSIIF_RSLT_HOST_ERROR;
341 break;
342 }
343
344 return (host_status << 16) | (result & 0x00ffff);
345 }
346
scsiback_send_response(struct vscsibk_info * info,char * sense_buffer,int32_t result,uint32_t resid,uint16_t rqid)347 static void scsiback_send_response(struct vscsibk_info *info,
348 char *sense_buffer, int32_t result, uint32_t resid,
349 uint16_t rqid)
350 {
351 struct vscsiif_response *ring_res;
352 int notify;
353 struct scsi_sense_hdr sshdr;
354 unsigned long flags;
355 unsigned len;
356
357 spin_lock_irqsave(&info->ring_lock, flags);
358
359 ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt);
360 info->ring.rsp_prod_pvt++;
361
362 ring_res->rslt = scsiback_result(result);
363 ring_res->rqid = rqid;
364
365 if (sense_buffer != NULL &&
366 scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
367 &sshdr)) {
368 len = min_t(unsigned, 8 + sense_buffer[7],
369 VSCSIIF_SENSE_BUFFERSIZE);
370 memcpy(ring_res->sense_buffer, sense_buffer, len);
371 ring_res->sense_len = len;
372 } else {
373 ring_res->sense_len = 0;
374 }
375
376 ring_res->residual_len = resid;
377
378 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify);
379 spin_unlock_irqrestore(&info->ring_lock, flags);
380
381 if (notify)
382 notify_remote_via_irq(info->irq);
383 }
384
scsiback_do_resp_with_sense(char * sense_buffer,int32_t result,uint32_t resid,struct vscsibk_pend * pending_req)385 static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
386 uint32_t resid, struct vscsibk_pend *pending_req)
387 {
388 scsiback_send_response(pending_req->info, sense_buffer, result,
389 resid, pending_req->rqid);
390
391 if (pending_req->v2p)
392 kref_put(&pending_req->v2p->kref,
393 scsiback_free_translation_entry);
394 }
395
scsiback_cmd_done(struct vscsibk_pend * pending_req)396 static void scsiback_cmd_done(struct vscsibk_pend *pending_req)
397 {
398 struct vscsibk_info *info = pending_req->info;
399 unsigned char *sense_buffer;
400 unsigned int resid;
401 int errors;
402
403 sense_buffer = pending_req->sense_buffer;
404 resid = pending_req->se_cmd.residual_count;
405 errors = pending_req->result;
406
407 if (errors && log_print_stat)
408 scsiback_print_status(sense_buffer, errors, pending_req);
409
410 scsiback_fast_flush_area(pending_req);
411 scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
412 scsiback_put(info);
413 /*
414 * Drop the extra KREF_ACK reference taken by target_submit_cmd_map_sgls()
415 * ahead of scsiback_check_stop_free() -> transport_generic_free_cmd()
416 * final se_cmd->cmd_kref put.
417 */
418 target_put_sess_cmd(&pending_req->se_cmd);
419 }
420
scsiback_cmd_exec(struct vscsibk_pend * pending_req)421 static void scsiback_cmd_exec(struct vscsibk_pend *pending_req)
422 {
423 struct se_cmd *se_cmd = &pending_req->se_cmd;
424 struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess;
425
426 scsiback_get(pending_req->info);
427 se_cmd->tag = pending_req->rqid;
428 target_init_cmd(se_cmd, sess, pending_req->sense_buffer,
429 pending_req->v2p->lun, pending_req->data_len, 0,
430 pending_req->sc_data_direction, TARGET_SCF_ACK_KREF);
431
432 if (target_submit_prep(se_cmd, pending_req->cmnd, pending_req->sgl,
433 pending_req->n_sg, NULL, 0, NULL, 0, GFP_KERNEL))
434 return;
435
436 target_submit(se_cmd);
437 }
438
scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref * map,struct page ** pg,grant_handle_t * grant,int cnt)439 static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
440 struct page **pg, grant_handle_t *grant, int cnt)
441 {
442 int err, i;
443
444 if (!cnt)
445 return 0;
446
447 err = gnttab_map_refs(map, NULL, pg, cnt);
448 for (i = 0; i < cnt; i++) {
449 if (unlikely(map[i].status != GNTST_okay)) {
450 pr_err("invalid buffer -- could not remap it\n");
451 map[i].handle = SCSIBACK_INVALID_HANDLE;
452 if (!err)
453 err = -ENOMEM;
454 } else {
455 get_page(pg[i]);
456 }
457 grant[i] = map[i].handle;
458 }
459 return err;
460 }
461
scsiback_gnttab_data_map_list(struct vscsibk_pend * pending_req,struct scsiif_request_segment * seg,struct page ** pg,grant_handle_t * grant,int cnt,u32 flags)462 static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req,
463 struct scsiif_request_segment *seg, struct page **pg,
464 grant_handle_t *grant, int cnt, u32 flags)
465 {
466 int mapcount = 0, i, err = 0;
467 struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH];
468 struct vscsibk_info *info = pending_req->info;
469
470 for (i = 0; i < cnt; i++) {
471 if (gnttab_page_cache_get(&info->free_pages, pg + mapcount)) {
472 gnttab_page_cache_put(&info->free_pages, pg, mapcount);
473 pr_err("no grant page\n");
474 return -ENOMEM;
475 }
476 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]),
477 flags, seg[i].gref, info->domid);
478 mapcount++;
479 if (mapcount < VSCSI_GRANT_BATCH)
480 continue;
481 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
482 pg += mapcount;
483 grant += mapcount;
484 pending_req->n_grants += mapcount;
485 if (err)
486 return err;
487 mapcount = 0;
488 }
489 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
490 pending_req->n_grants += mapcount;
491 return err;
492 }
493
scsiback_gnttab_data_map(struct vscsiif_request * ring_req,struct vscsibk_pend * pending_req)494 static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req,
495 struct vscsibk_pend *pending_req)
496 {
497 u32 flags;
498 int i, err, n_segs, i_seg = 0;
499 struct page **pg;
500 struct scsiif_request_segment *seg;
501 unsigned long end_seg = 0;
502 unsigned int nr_segments = (unsigned int)ring_req->nr_segments;
503 unsigned int nr_sgl = 0;
504 struct scatterlist *sg;
505 grant_handle_t *grant;
506
507 pending_req->n_sg = 0;
508 pending_req->n_grants = 0;
509 pending_req->data_len = 0;
510
511 nr_segments &= ~VSCSIIF_SG_GRANT;
512 if (!nr_segments)
513 return 0;
514
515 if (nr_segments > VSCSIIF_SG_TABLESIZE) {
516 pr_debug("invalid parameter nr_seg = %d\n",
517 ring_req->nr_segments);
518 return -EINVAL;
519 }
520
521 if (ring_req->nr_segments & VSCSIIF_SG_GRANT) {
522 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg,
523 pending_req->pages, pending_req->grant_handles,
524 nr_segments, GNTMAP_host_map | GNTMAP_readonly);
525 if (err)
526 return err;
527 nr_sgl = nr_segments;
528 nr_segments = 0;
529 for (i = 0; i < nr_sgl; i++) {
530 n_segs = ring_req->seg[i].length /
531 sizeof(struct scsiif_request_segment);
532 if ((unsigned)ring_req->seg[i].offset +
533 (unsigned)ring_req->seg[i].length > PAGE_SIZE ||
534 n_segs * sizeof(struct scsiif_request_segment) !=
535 ring_req->seg[i].length)
536 return -EINVAL;
537 nr_segments += n_segs;
538 }
539 if (nr_segments > SG_ALL) {
540 pr_debug("invalid nr_seg = %d\n", nr_segments);
541 return -EINVAL;
542 }
543 }
544
545 /* free of (sgl) in fast_flush_area() */
546 pending_req->sgl = kmalloc_objs(struct scatterlist, nr_segments);
547 if (!pending_req->sgl)
548 return -ENOMEM;
549
550 sg_init_table(pending_req->sgl, nr_segments);
551 pending_req->n_sg = nr_segments;
552
553 flags = GNTMAP_host_map;
554 if (pending_req->sc_data_direction == DMA_TO_DEVICE)
555 flags |= GNTMAP_readonly;
556
557 pg = pending_req->pages + nr_sgl;
558 grant = pending_req->grant_handles + nr_sgl;
559 if (!nr_sgl) {
560 seg = ring_req->seg;
561 err = scsiback_gnttab_data_map_list(pending_req, seg,
562 pg, grant, nr_segments, flags);
563 if (err)
564 return err;
565 } else {
566 for (i = 0; i < nr_sgl; i++) {
567 seg = (struct scsiif_request_segment *)(
568 vaddr(pending_req, i) + ring_req->seg[i].offset);
569 n_segs = ring_req->seg[i].length /
570 sizeof(struct scsiif_request_segment);
571 err = scsiback_gnttab_data_map_list(pending_req, seg,
572 pg, grant, n_segs, flags);
573 if (err)
574 return err;
575 pg += n_segs;
576 grant += n_segs;
577 }
578 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
579 seg = (struct scsiif_request_segment *)end_seg;
580 end_seg += ring_req->seg[0].length;
581 pg = pending_req->pages + nr_sgl;
582 }
583
584 for_each_sg(pending_req->sgl, sg, nr_segments, i) {
585 sg_set_page(sg, pg[i], seg->length, seg->offset);
586 pending_req->data_len += seg->length;
587 seg++;
588 if (nr_sgl && (unsigned long)seg >= end_seg) {
589 i_seg++;
590 end_seg = vaddr(pending_req, i_seg) +
591 ring_req->seg[i_seg].offset;
592 seg = (struct scsiif_request_segment *)end_seg;
593 end_seg += ring_req->seg[i_seg].length;
594 }
595 if (sg->offset >= PAGE_SIZE ||
596 sg->length > PAGE_SIZE ||
597 sg->offset + sg->length > PAGE_SIZE)
598 return -EINVAL;
599 }
600
601 return 0;
602 }
603
scsiback_disconnect(struct vscsibk_info * info)604 static void scsiback_disconnect(struct vscsibk_info *info)
605 {
606 wait_event(info->waiting_to_free,
607 atomic_read(&info->nr_unreplied_reqs) == 0);
608
609 unbind_from_irqhandler(info->irq, info);
610 info->irq = 0;
611 xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
612 }
613
614 /*
615 * Send the error response for a request that did not reach the target core
616 * and return its tag. Free the tag before the response drops the v2p
617 * reference that keeps the session alive, and snapshot what the response
618 * needs since returning the tag can let the slot be reused.
619 */
scsiback_resp_and_free(struct vscsibk_pend * pending_req,int32_t result)620 static void scsiback_resp_and_free(struct vscsibk_pend *pending_req,
621 int32_t result)
622 {
623 struct vscsibk_info *info = pending_req->info;
624 struct v2p_entry *v2p = pending_req->v2p;
625 struct se_session *se_sess = v2p->tpg->tpg_nexus->tvn_se_sess;
626 u16 rqid = pending_req->rqid;
627
628 target_free_tag(se_sess, &pending_req->se_cmd);
629 scsiback_send_response(info, NULL, result, 0, rqid);
630 kref_put(&v2p->kref, scsiback_free_translation_entry);
631 }
632
scsiback_device_action(struct vscsibk_pend * pending_req,enum tcm_tmreq_table act,int tag)633 static void scsiback_device_action(struct vscsibk_pend *pending_req,
634 enum tcm_tmreq_table act, int tag)
635 {
636 struct scsiback_tpg *tpg = pending_req->v2p->tpg;
637 struct scsiback_nexus *nexus = tpg->tpg_nexus;
638 struct se_cmd *se_cmd = &pending_req->se_cmd;
639 u64 unpacked_lun = pending_req->v2p->lun;
640 int rc, err = XEN_VSCSIIF_RSLT_RESET_FAILED;
641
642 init_completion(&pending_req->tmr_done);
643
644 rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess,
645 &pending_req->sense_buffer[0],
646 unpacked_lun, NULL, act, GFP_KERNEL,
647 tag, TARGET_SCF_ACK_KREF);
648 if (rc)
649 goto err;
650
651 wait_for_completion(&pending_req->tmr_done);
652
653 err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
654 XEN_VSCSIIF_RSLT_RESET_SUCCESS : XEN_VSCSIIF_RSLT_RESET_FAILED;
655
656 scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
657 transport_generic_free_cmd(&pending_req->se_cmd, 0);
658 return;
659
660 err:
661 scsiback_resp_and_free(pending_req, err);
662 }
663
664 /*
665 Perform virtual to physical translation
666 */
scsiback_do_translation(struct vscsibk_info * info,struct ids_tuple * v)667 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
668 struct ids_tuple *v)
669 {
670 struct v2p_entry *entry;
671 struct list_head *head = &(info->v2p_entry_lists);
672 unsigned long flags;
673
674 spin_lock_irqsave(&info->v2p_lock, flags);
675 list_for_each_entry(entry, head, l) {
676 if ((entry->v.chn == v->chn) &&
677 (entry->v.tgt == v->tgt) &&
678 (entry->v.lun == v->lun)) {
679 kref_get(&entry->kref);
680 goto out;
681 }
682 }
683 entry = NULL;
684
685 out:
686 spin_unlock_irqrestore(&info->v2p_lock, flags);
687 return entry;
688 }
689
scsiback_get_pend_req(struct vscsiif_back_ring * ring,struct v2p_entry * v2p)690 static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring,
691 struct v2p_entry *v2p)
692 {
693 struct scsiback_tpg *tpg = v2p->tpg;
694 struct scsiback_nexus *nexus = tpg->tpg_nexus;
695 struct se_session *se_sess = nexus->tvn_se_sess;
696 struct vscsibk_pend *req;
697 int tag, cpu, i;
698
699 tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
700 if (tag < 0) {
701 pr_err("Unable to obtain tag for vscsiif_request\n");
702 return ERR_PTR(-ENOMEM);
703 }
704
705 req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag];
706 memset(req, 0, sizeof(*req));
707 req->se_cmd.map_tag = tag;
708 req->se_cmd.map_cpu = cpu;
709
710 for (i = 0; i < VSCSI_MAX_GRANTS; i++)
711 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
712
713 return req;
714 }
715
prepare_pending_reqs(struct vscsibk_info * info,struct vscsiif_back_ring * ring,struct vscsiif_request * ring_req)716 static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info,
717 struct vscsiif_back_ring *ring,
718 struct vscsiif_request *ring_req)
719 {
720 struct vscsibk_pend *pending_req;
721 struct v2p_entry *v2p;
722 struct ids_tuple vir;
723
724 /* request range check from frontend */
725 if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
726 (ring_req->sc_data_direction != DMA_TO_DEVICE) &&
727 (ring_req->sc_data_direction != DMA_FROM_DEVICE) &&
728 (ring_req->sc_data_direction != DMA_NONE)) {
729 pr_debug("invalid parameter data_dir = %d\n",
730 ring_req->sc_data_direction);
731 return ERR_PTR(-EINVAL);
732 }
733 if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
734 pr_debug("invalid parameter cmd_len = %d\n",
735 ring_req->cmd_len);
736 return ERR_PTR(-EINVAL);
737 }
738
739 vir.chn = ring_req->channel;
740 vir.tgt = ring_req->id;
741 vir.lun = ring_req->lun;
742
743 v2p = scsiback_do_translation(info, &vir);
744 if (!v2p) {
745 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n",
746 vir.chn, vir.tgt, vir.lun);
747 return ERR_PTR(-ENODEV);
748 }
749
750 pending_req = scsiback_get_pend_req(ring, v2p);
751 if (IS_ERR(pending_req)) {
752 kref_put(&v2p->kref, scsiback_free_translation_entry);
753 return ERR_PTR(-ENOMEM);
754 }
755 pending_req->rqid = ring_req->rqid;
756 pending_req->info = info;
757 pending_req->v2p = v2p;
758 pending_req->sc_data_direction = ring_req->sc_data_direction;
759 pending_req->cmd_len = ring_req->cmd_len;
760 memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
761
762 return pending_req;
763 }
764
scsiback_do_cmd_fn(struct vscsibk_info * info,unsigned int * eoi_flags)765 static int scsiback_do_cmd_fn(struct vscsibk_info *info,
766 unsigned int *eoi_flags)
767 {
768 struct vscsiif_back_ring *ring = &info->ring;
769 struct vscsiif_request ring_req;
770 struct vscsibk_pend *pending_req;
771 RING_IDX rc, rp;
772 int more_to_do;
773 uint32_t result;
774
775 rc = ring->req_cons;
776 rp = ring->sring->req_prod;
777 rmb(); /* guest system is accessing ring, too */
778
779 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
780 rc = ring->rsp_prod_pvt;
781 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
782 info->domid, rp, rc, rp - rc);
783 return -EINVAL;
784 }
785
786 while ((rc != rp)) {
787 *eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS;
788
789 if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
790 break;
791
792 RING_COPY_REQUEST(ring, rc, &ring_req);
793 ring->req_cons = ++rc;
794
795 pending_req = prepare_pending_reqs(info, ring, &ring_req);
796 if (IS_ERR(pending_req)) {
797 switch (PTR_ERR(pending_req)) {
798 case -ENODEV:
799 result = DID_NO_CONNECT;
800 break;
801 default:
802 result = DID_ERROR;
803 break;
804 }
805 scsiback_send_response(info, NULL, result << 16, 0,
806 ring_req.rqid);
807 return 1;
808 }
809
810 switch (ring_req.act) {
811 case VSCSIIF_ACT_SCSI_CDB:
812 if (scsiback_gnttab_data_map(&ring_req, pending_req)) {
813 scsiback_fast_flush_area(pending_req);
814 scsiback_resp_and_free(pending_req,
815 DID_ERROR << 16);
816 } else {
817 scsiback_cmd_exec(pending_req);
818 }
819 break;
820 case VSCSIIF_ACT_SCSI_ABORT:
821 scsiback_device_action(pending_req, TMR_ABORT_TASK,
822 ring_req.ref_rqid);
823 break;
824 case VSCSIIF_ACT_SCSI_RESET:
825 scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
826 break;
827 default:
828 pr_err_ratelimited("invalid request\n");
829 scsiback_resp_and_free(pending_req, DID_ERROR << 16);
830 break;
831 }
832
833 /* Yield point for this unbounded loop. */
834 cond_resched();
835 }
836
837 gnttab_page_cache_shrink(&info->free_pages, scsiback_max_buffer_pages);
838
839 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
840 return more_to_do;
841 }
842
scsiback_irq_fn(int irq,void * dev_id)843 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
844 {
845 struct vscsibk_info *info = dev_id;
846 int rc;
847 unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
848
849 while ((rc = scsiback_do_cmd_fn(info, &eoi_flags)) > 0)
850 cond_resched();
851
852 /* In case of a ring error we keep the event channel masked. */
853 if (!rc)
854 xen_irq_lateeoi(irq, eoi_flags);
855
856 return IRQ_HANDLED;
857 }
858
scsiback_init_sring(struct vscsibk_info * info,grant_ref_t ring_ref,evtchn_port_t evtchn)859 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
860 evtchn_port_t evtchn)
861 {
862 void *area;
863 struct vscsiif_sring *sring;
864 int err;
865
866 if (info->irq)
867 return -1;
868
869 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area);
870 if (err)
871 return err;
872
873 sring = (struct vscsiif_sring *)area;
874 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
875
876 err = bind_interdomain_evtchn_to_irq_lateeoi(info->dev, evtchn);
877 if (err < 0)
878 goto unmap_page;
879
880 info->irq = err;
881
882 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
883 IRQF_ONESHOT, "vscsiif-backend", info);
884 if (err)
885 goto free_irq;
886
887 return 0;
888
889 free_irq:
890 unbind_from_irqhandler(info->irq, info);
891 info->irq = 0;
892 unmap_page:
893 xenbus_unmap_ring_vfree(info->dev, area);
894
895 return err;
896 }
897
scsiback_map(struct vscsibk_info * info)898 static int scsiback_map(struct vscsibk_info *info)
899 {
900 struct xenbus_device *dev = info->dev;
901 unsigned int ring_ref;
902 evtchn_port_t evtchn;
903 int err;
904
905 err = xenbus_gather(XBT_NIL, dev->otherend,
906 "ring-ref", "%u", &ring_ref,
907 "event-channel", "%u", &evtchn, NULL);
908 if (err) {
909 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
910 return err;
911 }
912
913 return scsiback_init_sring(info, ring_ref, evtchn);
914 }
915
916 /*
917 Check for a translation entry being present
918 */
scsiback_chk_translation_entry(struct vscsibk_info * info,struct ids_tuple * v)919 static struct v2p_entry *scsiback_chk_translation_entry(
920 struct vscsibk_info *info, struct ids_tuple *v)
921 {
922 struct list_head *head = &(info->v2p_entry_lists);
923 struct v2p_entry *entry;
924
925 list_for_each_entry(entry, head, l)
926 if ((entry->v.chn == v->chn) &&
927 (entry->v.tgt == v->tgt) &&
928 (entry->v.lun == v->lun))
929 return entry;
930
931 return NULL;
932 }
933
934 /*
935 Add a new translation entry
936 */
scsiback_add_translation_entry(struct vscsibk_info * info,char * phy,struct ids_tuple * v)937 static int scsiback_add_translation_entry(struct vscsibk_info *info,
938 char *phy, struct ids_tuple *v)
939 {
940 int err = 0;
941 struct v2p_entry *new;
942 unsigned long flags;
943 char *lunp;
944 unsigned long long unpacked_lun;
945 struct se_lun *se_lun;
946 struct scsiback_tpg *tpg_entry, *tpg = NULL;
947 char *error = "doesn't exist";
948
949 lunp = strrchr(phy, ':');
950 if (!lunp) {
951 pr_err("illegal format of physical device %s\n", phy);
952 return -EINVAL;
953 }
954 *lunp = 0;
955 lunp++;
956 err = kstrtoull(lunp, 10, &unpacked_lun);
957 if (err < 0) {
958 pr_err("lun number not valid: %s\n", lunp);
959 return err;
960 }
961
962 mutex_lock(&scsiback_mutex);
963 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
964 if (!strcmp(phy, tpg_entry->tport->tport_name) ||
965 !strcmp(phy, tpg_entry->param_alias)) {
966 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex);
967 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) {
968 if (se_lun->unpacked_lun == unpacked_lun) {
969 if (!tpg_entry->tpg_nexus)
970 error = "nexus undefined";
971 else
972 tpg = tpg_entry;
973 break;
974 }
975 }
976 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex);
977 break;
978 }
979 }
980 if (tpg) {
981 mutex_lock(&tpg->tv_tpg_mutex);
982 tpg->tv_tpg_fe_count++;
983 mutex_unlock(&tpg->tv_tpg_mutex);
984 }
985 mutex_unlock(&scsiback_mutex);
986
987 if (!tpg) {
988 pr_err("%s:%llu %s\n", phy, unpacked_lun, error);
989 return -ENODEV;
990 }
991
992 new = kmalloc_obj(struct v2p_entry);
993 if (new == NULL) {
994 err = -ENOMEM;
995 goto out_free;
996 }
997
998 spin_lock_irqsave(&info->v2p_lock, flags);
999
1000 /* Check double assignment to identical virtual ID */
1001 if (scsiback_chk_translation_entry(info, v)) {
1002 pr_warn("Virtual ID is already used. Assignment was not performed.\n");
1003 err = -EEXIST;
1004 goto out;
1005 }
1006
1007 /* Create a new translation entry and add to the list */
1008 kref_init(&new->kref);
1009 new->v = *v;
1010 new->tpg = tpg;
1011 new->lun = unpacked_lun;
1012 list_add_tail(&new->l, &info->v2p_entry_lists);
1013
1014 out:
1015 spin_unlock_irqrestore(&info->v2p_lock, flags);
1016
1017 out_free:
1018 if (err) {
1019 mutex_lock(&tpg->tv_tpg_mutex);
1020 tpg->tv_tpg_fe_count--;
1021 mutex_unlock(&tpg->tv_tpg_mutex);
1022 kfree(new);
1023 }
1024
1025 return err;
1026 }
1027
1028 /*
1029 Delete the translation entry specified
1030 */
scsiback_del_translation_entry(struct vscsibk_info * info,struct ids_tuple * v)1031 static int scsiback_del_translation_entry(struct vscsibk_info *info,
1032 struct ids_tuple *v)
1033 {
1034 struct v2p_entry *entry;
1035 unsigned long flags;
1036
1037 spin_lock_irqsave(&info->v2p_lock, flags);
1038 /* Find out the translation entry specified */
1039 entry = scsiback_chk_translation_entry(info, v);
1040 if (entry)
1041 list_del(&entry->l);
1042
1043 spin_unlock_irqrestore(&info->v2p_lock, flags);
1044
1045 if (!entry)
1046 return -ENOENT;
1047
1048 kref_put(&entry->kref, scsiback_free_translation_entry);
1049 return 0;
1050 }
1051
scsiback_do_add_lun(struct vscsibk_info * info,const char * state,char * phy,struct ids_tuple * vir,int try)1052 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
1053 char *phy, struct ids_tuple *vir, int try)
1054 {
1055 struct v2p_entry *entry;
1056 unsigned long flags;
1057 int err;
1058
1059 if (try) {
1060 spin_lock_irqsave(&info->v2p_lock, flags);
1061 entry = scsiback_chk_translation_entry(info, vir);
1062 spin_unlock_irqrestore(&info->v2p_lock, flags);
1063 if (entry)
1064 return;
1065 }
1066 if (!scsiback_add_translation_entry(info, phy, vir)) {
1067 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1068 "%d", XenbusStateInitialised)) {
1069 pr_err("xenbus_printf error %s\n", state);
1070 scsiback_del_translation_entry(info, vir);
1071 }
1072 } else if (!try) {
1073 err = xenbus_printf(XBT_NIL, info->dev->nodename, state,
1074 "%d", XenbusStateClosed);
1075 if (err)
1076 xenbus_dev_error(info->dev, err,
1077 "%s: writing %s", __func__, state);
1078 }
1079 }
1080
scsiback_do_del_lun(struct vscsibk_info * info,const char * state,struct ids_tuple * vir)1081 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1082 struct ids_tuple *vir)
1083 {
1084 if (!scsiback_del_translation_entry(info, vir)) {
1085 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1086 "%d", XenbusStateClosed))
1087 pr_err("xenbus_printf error %s\n", state);
1088 }
1089 }
1090
1091 #define VSCSIBACK_OP_ADD_OR_DEL_LUN 1
1092 #define VSCSIBACK_OP_UPDATEDEV_STATE 2
1093
scsiback_do_1lun_hotplug(struct vscsibk_info * info,int op,char * ent)1094 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1095 char *ent)
1096 {
1097 int err;
1098 struct ids_tuple vir;
1099 char *val;
1100 int device_state;
1101 char phy[VSCSI_NAMELEN];
1102 char str[64];
1103 char state[64];
1104 struct xenbus_device *dev = info->dev;
1105
1106 /* read status */
1107 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1108 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1109 if (XENBUS_EXIST_ERR(err))
1110 return;
1111
1112 /* physical SCSI device */
1113 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1114 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1115 if (IS_ERR(val)) {
1116 err = xenbus_printf(XBT_NIL, dev->nodename, state,
1117 "%d", XenbusStateClosed);
1118 if (err)
1119 xenbus_dev_error(info->dev, err,
1120 "%s: writing %s", __func__, state);
1121 return;
1122 }
1123 strscpy(phy, val, VSCSI_NAMELEN);
1124 kfree(val);
1125
1126 /* virtual SCSI device */
1127 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1128 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1129 &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1130 if (XENBUS_EXIST_ERR(err)) {
1131 err = xenbus_printf(XBT_NIL, dev->nodename, state,
1132 "%d", XenbusStateClosed);
1133 if (err)
1134 xenbus_dev_error(info->dev, err,
1135 "%s: writing %s", __func__, state);
1136 return;
1137 }
1138
1139 switch (op) {
1140 case VSCSIBACK_OP_ADD_OR_DEL_LUN:
1141 switch (device_state) {
1142 case XenbusStateInitialising:
1143 scsiback_do_add_lun(info, state, phy, &vir, 0);
1144 break;
1145 case XenbusStateConnected:
1146 scsiback_do_add_lun(info, state, phy, &vir, 1);
1147 break;
1148 case XenbusStateClosing:
1149 scsiback_do_del_lun(info, state, &vir);
1150 break;
1151 default:
1152 break;
1153 }
1154 break;
1155
1156 case VSCSIBACK_OP_UPDATEDEV_STATE:
1157 if (device_state == XenbusStateInitialised) {
1158 /* modify vscsi-devs/dev-x/state */
1159 if (xenbus_printf(XBT_NIL, dev->nodename, state,
1160 "%d", XenbusStateConnected)) {
1161 pr_err("xenbus_printf error %s\n", str);
1162 scsiback_del_translation_entry(info, &vir);
1163 xenbus_printf(XBT_NIL, dev->nodename, state,
1164 "%d", XenbusStateClosed);
1165 }
1166 }
1167 break;
1168 /* When it is necessary, processing is added here. */
1169 default:
1170 break;
1171 }
1172 }
1173
scsiback_do_lun_hotplug(struct vscsibk_info * info,int op)1174 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1175 {
1176 int i;
1177 char **dir;
1178 unsigned int ndir = 0;
1179
1180 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1181 &ndir);
1182 if (IS_ERR(dir))
1183 return;
1184
1185 for (i = 0; i < ndir; i++)
1186 scsiback_do_1lun_hotplug(info, op, dir[i]);
1187
1188 kfree(dir);
1189 }
1190
scsiback_frontend_changed(struct xenbus_device * dev,enum xenbus_state frontend_state)1191 static void scsiback_frontend_changed(struct xenbus_device *dev,
1192 enum xenbus_state frontend_state)
1193 {
1194 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1195
1196 switch (frontend_state) {
1197 case XenbusStateInitialising:
1198 break;
1199
1200 case XenbusStateInitialised:
1201 if (scsiback_map(info))
1202 break;
1203
1204 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1205 xenbus_switch_state(dev, XenbusStateConnected);
1206 break;
1207
1208 case XenbusStateConnected:
1209 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1210
1211 if (dev->state == XenbusStateConnected)
1212 break;
1213
1214 xenbus_switch_state(dev, XenbusStateConnected);
1215 break;
1216
1217 case XenbusStateClosing:
1218 if (info->irq)
1219 scsiback_disconnect(info);
1220
1221 xenbus_switch_state(dev, XenbusStateClosing);
1222 break;
1223
1224 case XenbusStateClosed:
1225 xenbus_switch_state(dev, XenbusStateClosed);
1226 if (xenbus_dev_is_online(dev))
1227 break;
1228 fallthrough; /* if not online */
1229 case XenbusStateUnknown:
1230 device_unregister(&dev->dev);
1231 break;
1232
1233 case XenbusStateReconfiguring:
1234 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1235 xenbus_switch_state(dev, XenbusStateReconfigured);
1236
1237 break;
1238
1239 default:
1240 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1241 frontend_state);
1242 break;
1243 }
1244 }
1245
1246 /*
1247 Release the translation entry specfied
1248 */
scsiback_release_translation_entry(struct vscsibk_info * info)1249 static void scsiback_release_translation_entry(struct vscsibk_info *info)
1250 {
1251 struct v2p_entry *entry, *tmp;
1252 struct list_head *head = &(info->v2p_entry_lists);
1253 struct list_head tmp_list;
1254 unsigned long flags;
1255
1256 spin_lock_irqsave(&info->v2p_lock, flags);
1257
1258 list_cut_before(&tmp_list, head, head);
1259
1260 spin_unlock_irqrestore(&info->v2p_lock, flags);
1261
1262 list_for_each_entry_safe(entry, tmp, &tmp_list, l) {
1263 list_del(&entry->l);
1264 kref_put(&entry->kref, scsiback_free_translation_entry);
1265 }
1266 }
1267
scsiback_remove(struct xenbus_device * dev)1268 static void scsiback_remove(struct xenbus_device *dev)
1269 {
1270 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1271
1272 if (info->irq)
1273 scsiback_disconnect(info);
1274
1275 scsiback_release_translation_entry(info);
1276
1277 gnttab_page_cache_shrink(&info->free_pages, 0);
1278
1279 dev_set_drvdata(&dev->dev, NULL);
1280 kfree(info);
1281 }
1282
scsiback_probe(struct xenbus_device * dev,const struct xenbus_device_id * id)1283 static int scsiback_probe(struct xenbus_device *dev,
1284 const struct xenbus_device_id *id)
1285 {
1286 int err;
1287
1288 struct vscsibk_info *info = kzalloc_obj(struct vscsibk_info);
1289
1290 pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id);
1291
1292 if (!info) {
1293 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
1294 return -ENOMEM;
1295 }
1296 info->dev = dev;
1297 dev_set_drvdata(&dev->dev, info);
1298
1299 info->domid = dev->otherend_id;
1300 spin_lock_init(&info->ring_lock);
1301 atomic_set(&info->nr_unreplied_reqs, 0);
1302 init_waitqueue_head(&info->waiting_to_free);
1303 info->dev = dev;
1304 info->irq = 0;
1305 INIT_LIST_HEAD(&info->v2p_entry_lists);
1306 spin_lock_init(&info->v2p_lock);
1307 gnttab_page_cache_init(&info->free_pages);
1308
1309 err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
1310 SG_ALL);
1311 if (err)
1312 xenbus_dev_error(dev, err, "writing feature-sg-grant");
1313
1314 err = xenbus_switch_state(dev, XenbusStateInitWait);
1315 if (err)
1316 goto fail;
1317
1318 return 0;
1319
1320 fail:
1321 pr_warn("%s failed\n", __func__);
1322 scsiback_remove(dev);
1323
1324 return err;
1325 }
1326
scsiback_dump_proto_id(struct scsiback_tport * tport)1327 static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
1328 {
1329 switch (tport->tport_proto_id) {
1330 case SCSI_PROTOCOL_SAS:
1331 return "SAS";
1332 case SCSI_PROTOCOL_FCP:
1333 return "FCP";
1334 case SCSI_PROTOCOL_ISCSI:
1335 return "iSCSI";
1336 default:
1337 break;
1338 }
1339
1340 return "Unknown";
1341 }
1342
scsiback_get_fabric_wwn(struct se_portal_group * se_tpg)1343 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
1344 {
1345 struct scsiback_tpg *tpg = container_of(se_tpg,
1346 struct scsiback_tpg, se_tpg);
1347 struct scsiback_tport *tport = tpg->tport;
1348
1349 return &tport->tport_name[0];
1350 }
1351
scsiback_get_tag(struct se_portal_group * se_tpg)1352 static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
1353 {
1354 struct scsiback_tpg *tpg = container_of(se_tpg,
1355 struct scsiback_tpg, se_tpg);
1356 return tpg->tport_tpgt;
1357 }
1358
1359 static struct se_wwn *
scsiback_make_tport(struct target_fabric_configfs * tf,struct config_group * group,const char * name)1360 scsiback_make_tport(struct target_fabric_configfs *tf,
1361 struct config_group *group,
1362 const char *name)
1363 {
1364 struct scsiback_tport *tport;
1365 char *ptr;
1366 u64 wwpn = 0;
1367 int off = 0;
1368
1369 tport = kzalloc_obj(struct scsiback_tport);
1370 if (!tport)
1371 return ERR_PTR(-ENOMEM);
1372
1373 tport->tport_wwpn = wwpn;
1374 /*
1375 * Determine the emulated Protocol Identifier and Target Port Name
1376 * based on the incoming configfs directory name.
1377 */
1378 ptr = strstr(name, "naa.");
1379 if (ptr) {
1380 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1381 goto check_len;
1382 }
1383 ptr = strstr(name, "fc.");
1384 if (ptr) {
1385 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1386 off = 3; /* Skip over "fc." */
1387 goto check_len;
1388 }
1389 ptr = strstr(name, "iqn.");
1390 if (ptr) {
1391 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1392 goto check_len;
1393 }
1394
1395 pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
1396 kfree(tport);
1397 return ERR_PTR(-EINVAL);
1398
1399 check_len:
1400 if (strlen(name) >= VSCSI_NAMELEN) {
1401 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
1402 scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
1403 kfree(tport);
1404 return ERR_PTR(-EINVAL);
1405 }
1406 snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
1407
1408 pr_debug("Allocated emulated Target %s Address: %s\n",
1409 scsiback_dump_proto_id(tport), name);
1410
1411 return &tport->tport_wwn;
1412 }
1413
scsiback_drop_tport(struct se_wwn * wwn)1414 static void scsiback_drop_tport(struct se_wwn *wwn)
1415 {
1416 struct scsiback_tport *tport = container_of(wwn,
1417 struct scsiback_tport, tport_wwn);
1418
1419 pr_debug("Deallocating emulated Target %s Address: %s\n",
1420 scsiback_dump_proto_id(tport), tport->tport_name);
1421
1422 kfree(tport);
1423 }
1424
scsiback_check_stop_free(struct se_cmd * se_cmd)1425 static int scsiback_check_stop_free(struct se_cmd *se_cmd)
1426 {
1427 return transport_generic_free_cmd(se_cmd, 0);
1428 }
1429
scsiback_release_cmd(struct se_cmd * se_cmd)1430 static void scsiback_release_cmd(struct se_cmd *se_cmd)
1431 {
1432 target_free_tag(se_cmd->se_sess, se_cmd);
1433 }
1434
scsiback_write_pending(struct se_cmd * se_cmd)1435 static int scsiback_write_pending(struct se_cmd *se_cmd)
1436 {
1437 /* Go ahead and process the write immediately */
1438 target_execute_cmd(se_cmd);
1439
1440 return 0;
1441 }
1442
scsiback_queue_data_in(struct se_cmd * se_cmd)1443 static int scsiback_queue_data_in(struct se_cmd *se_cmd)
1444 {
1445 struct vscsibk_pend *pending_req = container_of(se_cmd,
1446 struct vscsibk_pend, se_cmd);
1447
1448 pending_req->result = SAM_STAT_GOOD;
1449 scsiback_cmd_done(pending_req);
1450 return 0;
1451 }
1452
scsiback_queue_status(struct se_cmd * se_cmd)1453 static int scsiback_queue_status(struct se_cmd *se_cmd)
1454 {
1455 struct vscsibk_pend *pending_req = container_of(se_cmd,
1456 struct vscsibk_pend, se_cmd);
1457
1458 if (se_cmd->sense_buffer &&
1459 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1460 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
1461 pending_req->result = SAM_STAT_CHECK_CONDITION;
1462 else
1463 pending_req->result = se_cmd->scsi_status;
1464
1465 scsiback_cmd_done(pending_req);
1466 return 0;
1467 }
1468
scsiback_queue_tm_rsp(struct se_cmd * se_cmd)1469 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
1470 {
1471 struct vscsibk_pend *pending_req = container_of(se_cmd,
1472 struct vscsibk_pend, se_cmd);
1473
1474 complete(&pending_req->tmr_done);
1475 }
1476
scsiback_aborted_task(struct se_cmd * se_cmd)1477 static void scsiback_aborted_task(struct se_cmd *se_cmd)
1478 {
1479 }
1480
scsiback_tpg_param_alias_show(struct config_item * item,char * page)1481 static ssize_t scsiback_tpg_param_alias_show(struct config_item *item,
1482 char *page)
1483 {
1484 struct se_portal_group *se_tpg = param_to_tpg(item);
1485 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1486 se_tpg);
1487 ssize_t rb;
1488
1489 mutex_lock(&tpg->tv_tpg_mutex);
1490 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
1491 mutex_unlock(&tpg->tv_tpg_mutex);
1492
1493 return rb;
1494 }
1495
scsiback_tpg_param_alias_store(struct config_item * item,const char * page,size_t count)1496 static ssize_t scsiback_tpg_param_alias_store(struct config_item *item,
1497 const char *page, size_t count)
1498 {
1499 struct se_portal_group *se_tpg = param_to_tpg(item);
1500 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1501 se_tpg);
1502 int len;
1503
1504 if (strlen(page) >= VSCSI_NAMELEN) {
1505 pr_err("param alias: %s, exceeds max: %d\n", page,
1506 VSCSI_NAMELEN);
1507 return -EINVAL;
1508 }
1509
1510 mutex_lock(&tpg->tv_tpg_mutex);
1511 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
1512 if (tpg->param_alias[len - 1] == '\n')
1513 tpg->param_alias[len - 1] = '\0';
1514 mutex_unlock(&tpg->tv_tpg_mutex);
1515
1516 return count;
1517 }
1518
1519 CONFIGFS_ATTR(scsiback_tpg_param_, alias);
1520
1521 static struct configfs_attribute *scsiback_param_attrs[] = {
1522 &scsiback_tpg_param_attr_alias,
1523 NULL,
1524 };
1525
scsiback_alloc_sess_cb(struct se_portal_group * se_tpg,struct se_session * se_sess,void * p)1526 static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg,
1527 struct se_session *se_sess, void *p)
1528 {
1529 struct scsiback_tpg *tpg = container_of(se_tpg,
1530 struct scsiback_tpg, se_tpg);
1531
1532 tpg->tpg_nexus = p;
1533 return 0;
1534 }
1535
scsiback_make_nexus(struct scsiback_tpg * tpg,const char * name)1536 static int scsiback_make_nexus(struct scsiback_tpg *tpg,
1537 const char *name)
1538 {
1539 struct scsiback_nexus *tv_nexus;
1540 int ret = 0;
1541
1542 mutex_lock(&tpg->tv_tpg_mutex);
1543 if (tpg->tpg_nexus) {
1544 pr_debug("tpg->tpg_nexus already exists\n");
1545 ret = -EEXIST;
1546 goto out_unlock;
1547 }
1548
1549 tv_nexus = kzalloc_obj(struct scsiback_nexus);
1550 if (!tv_nexus) {
1551 ret = -ENOMEM;
1552 goto out_unlock;
1553 }
1554
1555 tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg,
1556 VSCSI_DEFAULT_SESSION_TAGS,
1557 sizeof(struct vscsibk_pend),
1558 TARGET_PROT_NORMAL, name,
1559 tv_nexus, scsiback_alloc_sess_cb);
1560 if (IS_ERR(tv_nexus->tvn_se_sess)) {
1561 kfree(tv_nexus);
1562 ret = -ENOMEM;
1563 goto out_unlock;
1564 }
1565
1566 out_unlock:
1567 mutex_unlock(&tpg->tv_tpg_mutex);
1568 return ret;
1569 }
1570
scsiback_drop_nexus(struct scsiback_tpg * tpg)1571 static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1572 {
1573 struct se_session *se_sess;
1574 struct scsiback_nexus *tv_nexus;
1575
1576 mutex_lock(&tpg->tv_tpg_mutex);
1577 tv_nexus = tpg->tpg_nexus;
1578 if (!tv_nexus) {
1579 mutex_unlock(&tpg->tv_tpg_mutex);
1580 return -ENODEV;
1581 }
1582
1583 se_sess = tv_nexus->tvn_se_sess;
1584 if (!se_sess) {
1585 mutex_unlock(&tpg->tv_tpg_mutex);
1586 return -ENODEV;
1587 }
1588
1589 if (tpg->tv_tpg_port_count != 0) {
1590 mutex_unlock(&tpg->tv_tpg_mutex);
1591 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1592 tpg->tv_tpg_port_count);
1593 return -EBUSY;
1594 }
1595
1596 if (tpg->tv_tpg_fe_count != 0) {
1597 mutex_unlock(&tpg->tv_tpg_mutex);
1598 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1599 tpg->tv_tpg_fe_count);
1600 return -EBUSY;
1601 }
1602
1603 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n",
1604 scsiback_dump_proto_id(tpg->tport),
1605 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1606
1607 /*
1608 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1609 */
1610 target_remove_session(se_sess);
1611 tpg->tpg_nexus = NULL;
1612 mutex_unlock(&tpg->tv_tpg_mutex);
1613
1614 kfree(tv_nexus);
1615 return 0;
1616 }
1617
scsiback_tpg_nexus_show(struct config_item * item,char * page)1618 static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page)
1619 {
1620 struct se_portal_group *se_tpg = to_tpg(item);
1621 struct scsiback_tpg *tpg = container_of(se_tpg,
1622 struct scsiback_tpg, se_tpg);
1623 struct scsiback_nexus *tv_nexus;
1624 ssize_t ret;
1625
1626 mutex_lock(&tpg->tv_tpg_mutex);
1627 tv_nexus = tpg->tpg_nexus;
1628 if (!tv_nexus) {
1629 mutex_unlock(&tpg->tv_tpg_mutex);
1630 return -ENODEV;
1631 }
1632 ret = snprintf(page, PAGE_SIZE, "%s\n",
1633 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1634 mutex_unlock(&tpg->tv_tpg_mutex);
1635
1636 return ret;
1637 }
1638
scsiback_tpg_nexus_store(struct config_item * item,const char * page,size_t count)1639 static ssize_t scsiback_tpg_nexus_store(struct config_item *item,
1640 const char *page, size_t count)
1641 {
1642 struct se_portal_group *se_tpg = to_tpg(item);
1643 struct scsiback_tpg *tpg = container_of(se_tpg,
1644 struct scsiback_tpg, se_tpg);
1645 struct scsiback_tport *tport_wwn = tpg->tport;
1646 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1647 int ret;
1648 /*
1649 * Shutdown the active I_T nexus if 'NULL' is passed.
1650 */
1651 if (!strncmp(page, "NULL", 4)) {
1652 ret = scsiback_drop_nexus(tpg);
1653 return (!ret) ? count : ret;
1654 }
1655 /*
1656 * Otherwise make sure the passed virtual Initiator port WWN matches
1657 * the fabric protocol_id set in scsiback_make_tport(), and call
1658 * scsiback_make_nexus().
1659 */
1660 if (strlen(page) >= VSCSI_NAMELEN) {
1661 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1662 page, VSCSI_NAMELEN);
1663 return -EINVAL;
1664 }
1665 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1666
1667 ptr = strstr(i_port, "naa.");
1668 if (ptr) {
1669 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1670 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1671 i_port, scsiback_dump_proto_id(tport_wwn));
1672 return -EINVAL;
1673 }
1674 port_ptr = &i_port[0];
1675 goto check_newline;
1676 }
1677 ptr = strstr(i_port, "fc.");
1678 if (ptr) {
1679 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1680 pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
1681 i_port, scsiback_dump_proto_id(tport_wwn));
1682 return -EINVAL;
1683 }
1684 port_ptr = &i_port[3]; /* Skip over "fc." */
1685 goto check_newline;
1686 }
1687 ptr = strstr(i_port, "iqn.");
1688 if (ptr) {
1689 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1690 pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
1691 i_port, scsiback_dump_proto_id(tport_wwn));
1692 return -EINVAL;
1693 }
1694 port_ptr = &i_port[0];
1695 goto check_newline;
1696 }
1697 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1698 i_port);
1699 return -EINVAL;
1700 /*
1701 * Clear any trailing newline for the NAA WWN
1702 */
1703 check_newline:
1704 if (i_port[strlen(i_port) - 1] == '\n')
1705 i_port[strlen(i_port) - 1] = '\0';
1706
1707 ret = scsiback_make_nexus(tpg, port_ptr);
1708 if (ret < 0)
1709 return ret;
1710
1711 return count;
1712 }
1713
1714 CONFIGFS_ATTR(scsiback_tpg_, nexus);
1715
1716 static struct configfs_attribute *scsiback_tpg_attrs[] = {
1717 &scsiback_tpg_attr_nexus,
1718 NULL,
1719 };
1720
1721 static ssize_t
scsiback_wwn_version_show(struct config_item * item,char * page)1722 scsiback_wwn_version_show(struct config_item *item, char *page)
1723 {
1724 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1725 UTS_RELEASE"\n",
1726 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1727 }
1728
1729 CONFIGFS_ATTR_RO(scsiback_wwn_, version);
1730
1731 static struct configfs_attribute *scsiback_wwn_attrs[] = {
1732 &scsiback_wwn_attr_version,
1733 NULL,
1734 };
1735
scsiback_port_link(struct se_portal_group * se_tpg,struct se_lun * lun)1736 static int scsiback_port_link(struct se_portal_group *se_tpg,
1737 struct se_lun *lun)
1738 {
1739 struct scsiback_tpg *tpg = container_of(se_tpg,
1740 struct scsiback_tpg, se_tpg);
1741
1742 mutex_lock(&tpg->tv_tpg_mutex);
1743 tpg->tv_tpg_port_count++;
1744 mutex_unlock(&tpg->tv_tpg_mutex);
1745
1746 return 0;
1747 }
1748
scsiback_port_unlink(struct se_portal_group * se_tpg,struct se_lun * lun)1749 static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1750 struct se_lun *lun)
1751 {
1752 struct scsiback_tpg *tpg = container_of(se_tpg,
1753 struct scsiback_tpg, se_tpg);
1754
1755 mutex_lock(&tpg->tv_tpg_mutex);
1756 tpg->tv_tpg_port_count--;
1757 mutex_unlock(&tpg->tv_tpg_mutex);
1758 }
1759
1760 static struct se_portal_group *
scsiback_make_tpg(struct se_wwn * wwn,const char * name)1761 scsiback_make_tpg(struct se_wwn *wwn, const char *name)
1762 {
1763 struct scsiback_tport *tport = container_of(wwn,
1764 struct scsiback_tport, tport_wwn);
1765
1766 struct scsiback_tpg *tpg;
1767 u16 tpgt;
1768 int ret;
1769
1770 if (strstr(name, "tpgt_") != name)
1771 return ERR_PTR(-EINVAL);
1772 ret = kstrtou16(name + 5, 10, &tpgt);
1773 if (ret)
1774 return ERR_PTR(ret);
1775
1776 tpg = kzalloc_obj(struct scsiback_tpg);
1777 if (!tpg)
1778 return ERR_PTR(-ENOMEM);
1779
1780 mutex_init(&tpg->tv_tpg_mutex);
1781 INIT_LIST_HEAD(&tpg->tv_tpg_list);
1782 INIT_LIST_HEAD(&tpg->info_list);
1783 tpg->tport = tport;
1784 tpg->tport_tpgt = tpgt;
1785
1786 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
1787 if (ret < 0) {
1788 kfree(tpg);
1789 return NULL;
1790 }
1791 mutex_lock(&scsiback_mutex);
1792 list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1793 mutex_unlock(&scsiback_mutex);
1794
1795 return &tpg->se_tpg;
1796 }
1797
scsiback_drop_tpg(struct se_portal_group * se_tpg)1798 static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1799 {
1800 struct scsiback_tpg *tpg = container_of(se_tpg,
1801 struct scsiback_tpg, se_tpg);
1802
1803 mutex_lock(&scsiback_mutex);
1804 list_del(&tpg->tv_tpg_list);
1805 mutex_unlock(&scsiback_mutex);
1806 /*
1807 * Release the virtual I_T Nexus for this xen-pvscsi TPG
1808 */
1809 scsiback_drop_nexus(tpg);
1810 /*
1811 * Deregister the se_tpg from TCM.
1812 */
1813 core_tpg_deregister(se_tpg);
1814 kfree(tpg);
1815 }
1816
scsiback_check_true(struct se_portal_group * se_tpg)1817 static int scsiback_check_true(struct se_portal_group *se_tpg)
1818 {
1819 return 1;
1820 }
1821
1822 static const struct target_core_fabric_ops scsiback_ops = {
1823 .module = THIS_MODULE,
1824 .fabric_name = "xen-pvscsi",
1825 .tpg_get_wwn = scsiback_get_fabric_wwn,
1826 .tpg_get_tag = scsiback_get_tag,
1827 .tpg_check_demo_mode = scsiback_check_true,
1828 .tpg_check_demo_mode_cache = scsiback_check_true,
1829 .check_stop_free = scsiback_check_stop_free,
1830 .release_cmd = scsiback_release_cmd,
1831 .sess_get_initiator_sid = NULL,
1832 .write_pending = scsiback_write_pending,
1833 .queue_data_in = scsiback_queue_data_in,
1834 .queue_status = scsiback_queue_status,
1835 .queue_tm_rsp = scsiback_queue_tm_rsp,
1836 .aborted_task = scsiback_aborted_task,
1837 /*
1838 * Setup callers for generic logic in target_core_fabric_configfs.c
1839 */
1840 .fabric_make_wwn = scsiback_make_tport,
1841 .fabric_drop_wwn = scsiback_drop_tport,
1842 .fabric_make_tpg = scsiback_make_tpg,
1843 .fabric_drop_tpg = scsiback_drop_tpg,
1844 .fabric_post_link = scsiback_port_link,
1845 .fabric_pre_unlink = scsiback_port_unlink,
1846
1847 .tfc_wwn_attrs = scsiback_wwn_attrs,
1848 .tfc_tpg_base_attrs = scsiback_tpg_attrs,
1849 .tfc_tpg_param_attrs = scsiback_param_attrs,
1850
1851 .default_compl_type = TARGET_QUEUE_COMPL,
1852 .default_submit_type = TARGET_DIRECT_SUBMIT,
1853 .direct_submit_supp = 1,
1854 };
1855
1856 static const struct xenbus_device_id scsiback_ids[] = {
1857 { "vscsi" },
1858 { "" }
1859 };
1860
1861 static struct xenbus_driver scsiback_driver = {
1862 .ids = scsiback_ids,
1863 .probe = scsiback_probe,
1864 .remove = scsiback_remove,
1865 .otherend_changed = scsiback_frontend_changed
1866 };
1867
scsiback_init(void)1868 static int __init scsiback_init(void)
1869 {
1870 int ret;
1871
1872 if (!xen_domain())
1873 return -ENODEV;
1874
1875 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
1876 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1877
1878 ret = xenbus_register_backend(&scsiback_driver);
1879 if (ret)
1880 goto out;
1881
1882 ret = target_register_template(&scsiback_ops);
1883 if (ret)
1884 goto out_unregister_xenbus;
1885
1886 return 0;
1887
1888 out_unregister_xenbus:
1889 xenbus_unregister_driver(&scsiback_driver);
1890 out:
1891 pr_err("%s: error %d\n", __func__, ret);
1892 return ret;
1893 }
1894
scsiback_exit(void)1895 static void __exit scsiback_exit(void)
1896 {
1897 target_unregister_template(&scsiback_ops);
1898 xenbus_unregister_driver(&scsiback_driver);
1899 }
1900
1901 module_init(scsiback_init);
1902 module_exit(scsiback_exit);
1903
1904 MODULE_DESCRIPTION("Xen SCSI backend driver");
1905 MODULE_LICENSE("Dual BSD/GPL");
1906 MODULE_ALIAS("xen-backend:vscsi");
1907 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");
1908