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
scsiback_device_action(struct vscsibk_pend * pending_req,enum tcm_tmreq_table act,int tag)614 static void scsiback_device_action(struct vscsibk_pend *pending_req,
615 enum tcm_tmreq_table act, int tag)
616 {
617 struct scsiback_tpg *tpg = pending_req->v2p->tpg;
618 struct scsiback_nexus *nexus = tpg->tpg_nexus;
619 struct se_cmd *se_cmd = &pending_req->se_cmd;
620 u64 unpacked_lun = pending_req->v2p->lun;
621 int rc, err = XEN_VSCSIIF_RSLT_RESET_FAILED;
622
623 init_completion(&pending_req->tmr_done);
624
625 rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess,
626 &pending_req->sense_buffer[0],
627 unpacked_lun, NULL, act, GFP_KERNEL,
628 tag, TARGET_SCF_ACK_KREF);
629 if (rc)
630 goto err;
631
632 wait_for_completion(&pending_req->tmr_done);
633
634 err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
635 XEN_VSCSIIF_RSLT_RESET_SUCCESS : XEN_VSCSIIF_RSLT_RESET_FAILED;
636
637 scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
638 transport_generic_free_cmd(&pending_req->se_cmd, 0);
639 return;
640
641 err:
642 scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
643 }
644
645 /*
646 Perform virtual to physical translation
647 */
scsiback_do_translation(struct vscsibk_info * info,struct ids_tuple * v)648 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
649 struct ids_tuple *v)
650 {
651 struct v2p_entry *entry;
652 struct list_head *head = &(info->v2p_entry_lists);
653 unsigned long flags;
654
655 spin_lock_irqsave(&info->v2p_lock, flags);
656 list_for_each_entry(entry, head, l) {
657 if ((entry->v.chn == v->chn) &&
658 (entry->v.tgt == v->tgt) &&
659 (entry->v.lun == v->lun)) {
660 kref_get(&entry->kref);
661 goto out;
662 }
663 }
664 entry = NULL;
665
666 out:
667 spin_unlock_irqrestore(&info->v2p_lock, flags);
668 return entry;
669 }
670
scsiback_get_pend_req(struct vscsiif_back_ring * ring,struct v2p_entry * v2p)671 static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring,
672 struct v2p_entry *v2p)
673 {
674 struct scsiback_tpg *tpg = v2p->tpg;
675 struct scsiback_nexus *nexus = tpg->tpg_nexus;
676 struct se_session *se_sess = nexus->tvn_se_sess;
677 struct vscsibk_pend *req;
678 int tag, cpu, i;
679
680 tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
681 if (tag < 0) {
682 pr_err("Unable to obtain tag for vscsiif_request\n");
683 return ERR_PTR(-ENOMEM);
684 }
685
686 req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag];
687 memset(req, 0, sizeof(*req));
688 req->se_cmd.map_tag = tag;
689 req->se_cmd.map_cpu = cpu;
690
691 for (i = 0; i < VSCSI_MAX_GRANTS; i++)
692 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
693
694 return req;
695 }
696
prepare_pending_reqs(struct vscsibk_info * info,struct vscsiif_back_ring * ring,struct vscsiif_request * ring_req)697 static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info,
698 struct vscsiif_back_ring *ring,
699 struct vscsiif_request *ring_req)
700 {
701 struct vscsibk_pend *pending_req;
702 struct v2p_entry *v2p;
703 struct ids_tuple vir;
704
705 /* request range check from frontend */
706 if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
707 (ring_req->sc_data_direction != DMA_TO_DEVICE) &&
708 (ring_req->sc_data_direction != DMA_FROM_DEVICE) &&
709 (ring_req->sc_data_direction != DMA_NONE)) {
710 pr_debug("invalid parameter data_dir = %d\n",
711 ring_req->sc_data_direction);
712 return ERR_PTR(-EINVAL);
713 }
714 if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
715 pr_debug("invalid parameter cmd_len = %d\n",
716 ring_req->cmd_len);
717 return ERR_PTR(-EINVAL);
718 }
719
720 vir.chn = ring_req->channel;
721 vir.tgt = ring_req->id;
722 vir.lun = ring_req->lun;
723
724 v2p = scsiback_do_translation(info, &vir);
725 if (!v2p) {
726 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n",
727 vir.chn, vir.tgt, vir.lun);
728 return ERR_PTR(-ENODEV);
729 }
730
731 pending_req = scsiback_get_pend_req(ring, v2p);
732 if (IS_ERR(pending_req)) {
733 kref_put(&v2p->kref, scsiback_free_translation_entry);
734 return ERR_PTR(-ENOMEM);
735 }
736 pending_req->rqid = ring_req->rqid;
737 pending_req->info = info;
738 pending_req->v2p = v2p;
739 pending_req->sc_data_direction = ring_req->sc_data_direction;
740 pending_req->cmd_len = ring_req->cmd_len;
741 memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
742
743 return pending_req;
744 }
745
scsiback_do_cmd_fn(struct vscsibk_info * info,unsigned int * eoi_flags)746 static int scsiback_do_cmd_fn(struct vscsibk_info *info,
747 unsigned int *eoi_flags)
748 {
749 struct vscsiif_back_ring *ring = &info->ring;
750 struct vscsiif_request ring_req;
751 struct vscsibk_pend *pending_req;
752 RING_IDX rc, rp;
753 int more_to_do;
754 uint32_t result;
755
756 rc = ring->req_cons;
757 rp = ring->sring->req_prod;
758 rmb(); /* guest system is accessing ring, too */
759
760 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
761 rc = ring->rsp_prod_pvt;
762 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
763 info->domid, rp, rc, rp - rc);
764 return -EINVAL;
765 }
766
767 while ((rc != rp)) {
768 *eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS;
769
770 if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
771 break;
772
773 RING_COPY_REQUEST(ring, rc, &ring_req);
774 ring->req_cons = ++rc;
775
776 pending_req = prepare_pending_reqs(info, ring, &ring_req);
777 if (IS_ERR(pending_req)) {
778 switch (PTR_ERR(pending_req)) {
779 case -ENODEV:
780 result = DID_NO_CONNECT;
781 break;
782 default:
783 result = DID_ERROR;
784 break;
785 }
786 scsiback_send_response(info, NULL, result << 16, 0,
787 ring_req.rqid);
788 return 1;
789 }
790
791 switch (ring_req.act) {
792 case VSCSIIF_ACT_SCSI_CDB:
793 if (scsiback_gnttab_data_map(&ring_req, pending_req)) {
794 scsiback_fast_flush_area(pending_req);
795 scsiback_do_resp_with_sense(NULL,
796 DID_ERROR << 16, 0, pending_req);
797 transport_generic_free_cmd(&pending_req->se_cmd, 0);
798 } else {
799 scsiback_cmd_exec(pending_req);
800 }
801 break;
802 case VSCSIIF_ACT_SCSI_ABORT:
803 scsiback_device_action(pending_req, TMR_ABORT_TASK,
804 ring_req.ref_rqid);
805 break;
806 case VSCSIIF_ACT_SCSI_RESET:
807 scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
808 break;
809 default:
810 pr_err_ratelimited("invalid request\n");
811 scsiback_do_resp_with_sense(NULL, DID_ERROR << 16, 0,
812 pending_req);
813 transport_generic_free_cmd(&pending_req->se_cmd, 0);
814 break;
815 }
816
817 /* Yield point for this unbounded loop. */
818 cond_resched();
819 }
820
821 gnttab_page_cache_shrink(&info->free_pages, scsiback_max_buffer_pages);
822
823 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
824 return more_to_do;
825 }
826
scsiback_irq_fn(int irq,void * dev_id)827 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
828 {
829 struct vscsibk_info *info = dev_id;
830 int rc;
831 unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
832
833 while ((rc = scsiback_do_cmd_fn(info, &eoi_flags)) > 0)
834 cond_resched();
835
836 /* In case of a ring error we keep the event channel masked. */
837 if (!rc)
838 xen_irq_lateeoi(irq, eoi_flags);
839
840 return IRQ_HANDLED;
841 }
842
scsiback_init_sring(struct vscsibk_info * info,grant_ref_t ring_ref,evtchn_port_t evtchn)843 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
844 evtchn_port_t evtchn)
845 {
846 void *area;
847 struct vscsiif_sring *sring;
848 int err;
849
850 if (info->irq)
851 return -1;
852
853 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area);
854 if (err)
855 return err;
856
857 sring = (struct vscsiif_sring *)area;
858 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
859
860 err = bind_interdomain_evtchn_to_irq_lateeoi(info->dev, evtchn);
861 if (err < 0)
862 goto unmap_page;
863
864 info->irq = err;
865
866 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
867 IRQF_ONESHOT, "vscsiif-backend", info);
868 if (err)
869 goto free_irq;
870
871 return 0;
872
873 free_irq:
874 unbind_from_irqhandler(info->irq, info);
875 info->irq = 0;
876 unmap_page:
877 xenbus_unmap_ring_vfree(info->dev, area);
878
879 return err;
880 }
881
scsiback_map(struct vscsibk_info * info)882 static int scsiback_map(struct vscsibk_info *info)
883 {
884 struct xenbus_device *dev = info->dev;
885 unsigned int ring_ref;
886 evtchn_port_t evtchn;
887 int err;
888
889 err = xenbus_gather(XBT_NIL, dev->otherend,
890 "ring-ref", "%u", &ring_ref,
891 "event-channel", "%u", &evtchn, NULL);
892 if (err) {
893 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
894 return err;
895 }
896
897 return scsiback_init_sring(info, ring_ref, evtchn);
898 }
899
900 /*
901 Check for a translation entry being present
902 */
scsiback_chk_translation_entry(struct vscsibk_info * info,struct ids_tuple * v)903 static struct v2p_entry *scsiback_chk_translation_entry(
904 struct vscsibk_info *info, struct ids_tuple *v)
905 {
906 struct list_head *head = &(info->v2p_entry_lists);
907 struct v2p_entry *entry;
908
909 list_for_each_entry(entry, head, l)
910 if ((entry->v.chn == v->chn) &&
911 (entry->v.tgt == v->tgt) &&
912 (entry->v.lun == v->lun))
913 return entry;
914
915 return NULL;
916 }
917
918 /*
919 Add a new translation entry
920 */
scsiback_add_translation_entry(struct vscsibk_info * info,char * phy,struct ids_tuple * v)921 static int scsiback_add_translation_entry(struct vscsibk_info *info,
922 char *phy, struct ids_tuple *v)
923 {
924 int err = 0;
925 struct v2p_entry *new;
926 unsigned long flags;
927 char *lunp;
928 unsigned long long unpacked_lun;
929 struct se_lun *se_lun;
930 struct scsiback_tpg *tpg_entry, *tpg = NULL;
931 char *error = "doesn't exist";
932
933 lunp = strrchr(phy, ':');
934 if (!lunp) {
935 pr_err("illegal format of physical device %s\n", phy);
936 return -EINVAL;
937 }
938 *lunp = 0;
939 lunp++;
940 err = kstrtoull(lunp, 10, &unpacked_lun);
941 if (err < 0) {
942 pr_err("lun number not valid: %s\n", lunp);
943 return err;
944 }
945
946 mutex_lock(&scsiback_mutex);
947 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
948 if (!strcmp(phy, tpg_entry->tport->tport_name) ||
949 !strcmp(phy, tpg_entry->param_alias)) {
950 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex);
951 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) {
952 if (se_lun->unpacked_lun == unpacked_lun) {
953 if (!tpg_entry->tpg_nexus)
954 error = "nexus undefined";
955 else
956 tpg = tpg_entry;
957 break;
958 }
959 }
960 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex);
961 break;
962 }
963 }
964 if (tpg) {
965 mutex_lock(&tpg->tv_tpg_mutex);
966 tpg->tv_tpg_fe_count++;
967 mutex_unlock(&tpg->tv_tpg_mutex);
968 }
969 mutex_unlock(&scsiback_mutex);
970
971 if (!tpg) {
972 pr_err("%s:%llu %s\n", phy, unpacked_lun, error);
973 return -ENODEV;
974 }
975
976 new = kmalloc_obj(struct v2p_entry);
977 if (new == NULL) {
978 err = -ENOMEM;
979 goto out_free;
980 }
981
982 spin_lock_irqsave(&info->v2p_lock, flags);
983
984 /* Check double assignment to identical virtual ID */
985 if (scsiback_chk_translation_entry(info, v)) {
986 pr_warn("Virtual ID is already used. Assignment was not performed.\n");
987 err = -EEXIST;
988 goto out;
989 }
990
991 /* Create a new translation entry and add to the list */
992 kref_init(&new->kref);
993 new->v = *v;
994 new->tpg = tpg;
995 new->lun = unpacked_lun;
996 list_add_tail(&new->l, &info->v2p_entry_lists);
997
998 out:
999 spin_unlock_irqrestore(&info->v2p_lock, flags);
1000
1001 out_free:
1002 if (err) {
1003 mutex_lock(&tpg->tv_tpg_mutex);
1004 tpg->tv_tpg_fe_count--;
1005 mutex_unlock(&tpg->tv_tpg_mutex);
1006 kfree(new);
1007 }
1008
1009 return err;
1010 }
1011
1012 /*
1013 Delete the translation entry specified
1014 */
scsiback_del_translation_entry(struct vscsibk_info * info,struct ids_tuple * v)1015 static int scsiback_del_translation_entry(struct vscsibk_info *info,
1016 struct ids_tuple *v)
1017 {
1018 struct v2p_entry *entry;
1019 unsigned long flags;
1020
1021 spin_lock_irqsave(&info->v2p_lock, flags);
1022 /* Find out the translation entry specified */
1023 entry = scsiback_chk_translation_entry(info, v);
1024 if (entry)
1025 list_del(&entry->l);
1026
1027 spin_unlock_irqrestore(&info->v2p_lock, flags);
1028
1029 if (!entry)
1030 return -ENOENT;
1031
1032 kref_put(&entry->kref, scsiback_free_translation_entry);
1033 return 0;
1034 }
1035
scsiback_do_add_lun(struct vscsibk_info * info,const char * state,char * phy,struct ids_tuple * vir,int try)1036 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
1037 char *phy, struct ids_tuple *vir, int try)
1038 {
1039 struct v2p_entry *entry;
1040 unsigned long flags;
1041 int err;
1042
1043 if (try) {
1044 spin_lock_irqsave(&info->v2p_lock, flags);
1045 entry = scsiback_chk_translation_entry(info, vir);
1046 spin_unlock_irqrestore(&info->v2p_lock, flags);
1047 if (entry)
1048 return;
1049 }
1050 if (!scsiback_add_translation_entry(info, phy, vir)) {
1051 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1052 "%d", XenbusStateInitialised)) {
1053 pr_err("xenbus_printf error %s\n", state);
1054 scsiback_del_translation_entry(info, vir);
1055 }
1056 } else if (!try) {
1057 err = xenbus_printf(XBT_NIL, info->dev->nodename, state,
1058 "%d", XenbusStateClosed);
1059 if (err)
1060 xenbus_dev_error(info->dev, err,
1061 "%s: writing %s", __func__, state);
1062 }
1063 }
1064
scsiback_do_del_lun(struct vscsibk_info * info,const char * state,struct ids_tuple * vir)1065 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1066 struct ids_tuple *vir)
1067 {
1068 if (!scsiback_del_translation_entry(info, vir)) {
1069 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1070 "%d", XenbusStateClosed))
1071 pr_err("xenbus_printf error %s\n", state);
1072 }
1073 }
1074
1075 #define VSCSIBACK_OP_ADD_OR_DEL_LUN 1
1076 #define VSCSIBACK_OP_UPDATEDEV_STATE 2
1077
scsiback_do_1lun_hotplug(struct vscsibk_info * info,int op,char * ent)1078 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1079 char *ent)
1080 {
1081 int err;
1082 struct ids_tuple vir;
1083 char *val;
1084 int device_state;
1085 char phy[VSCSI_NAMELEN];
1086 char str[64];
1087 char state[64];
1088 struct xenbus_device *dev = info->dev;
1089
1090 /* read status */
1091 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1092 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1093 if (XENBUS_EXIST_ERR(err))
1094 return;
1095
1096 /* physical SCSI device */
1097 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1098 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1099 if (IS_ERR(val)) {
1100 err = xenbus_printf(XBT_NIL, dev->nodename, state,
1101 "%d", XenbusStateClosed);
1102 if (err)
1103 xenbus_dev_error(info->dev, err,
1104 "%s: writing %s", __func__, state);
1105 return;
1106 }
1107 strscpy(phy, val, VSCSI_NAMELEN);
1108 kfree(val);
1109
1110 /* virtual SCSI device */
1111 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1112 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1113 &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1114 if (XENBUS_EXIST_ERR(err)) {
1115 err = xenbus_printf(XBT_NIL, dev->nodename, state,
1116 "%d", XenbusStateClosed);
1117 if (err)
1118 xenbus_dev_error(info->dev, err,
1119 "%s: writing %s", __func__, state);
1120 return;
1121 }
1122
1123 switch (op) {
1124 case VSCSIBACK_OP_ADD_OR_DEL_LUN:
1125 switch (device_state) {
1126 case XenbusStateInitialising:
1127 scsiback_do_add_lun(info, state, phy, &vir, 0);
1128 break;
1129 case XenbusStateConnected:
1130 scsiback_do_add_lun(info, state, phy, &vir, 1);
1131 break;
1132 case XenbusStateClosing:
1133 scsiback_do_del_lun(info, state, &vir);
1134 break;
1135 default:
1136 break;
1137 }
1138 break;
1139
1140 case VSCSIBACK_OP_UPDATEDEV_STATE:
1141 if (device_state == XenbusStateInitialised) {
1142 /* modify vscsi-devs/dev-x/state */
1143 if (xenbus_printf(XBT_NIL, dev->nodename, state,
1144 "%d", XenbusStateConnected)) {
1145 pr_err("xenbus_printf error %s\n", str);
1146 scsiback_del_translation_entry(info, &vir);
1147 xenbus_printf(XBT_NIL, dev->nodename, state,
1148 "%d", XenbusStateClosed);
1149 }
1150 }
1151 break;
1152 /* When it is necessary, processing is added here. */
1153 default:
1154 break;
1155 }
1156 }
1157
scsiback_do_lun_hotplug(struct vscsibk_info * info,int op)1158 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1159 {
1160 int i;
1161 char **dir;
1162 unsigned int ndir = 0;
1163
1164 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1165 &ndir);
1166 if (IS_ERR(dir))
1167 return;
1168
1169 for (i = 0; i < ndir; i++)
1170 scsiback_do_1lun_hotplug(info, op, dir[i]);
1171
1172 kfree(dir);
1173 }
1174
scsiback_frontend_changed(struct xenbus_device * dev,enum xenbus_state frontend_state)1175 static void scsiback_frontend_changed(struct xenbus_device *dev,
1176 enum xenbus_state frontend_state)
1177 {
1178 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1179
1180 switch (frontend_state) {
1181 case XenbusStateInitialising:
1182 break;
1183
1184 case XenbusStateInitialised:
1185 if (scsiback_map(info))
1186 break;
1187
1188 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1189 xenbus_switch_state(dev, XenbusStateConnected);
1190 break;
1191
1192 case XenbusStateConnected:
1193 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1194
1195 if (dev->state == XenbusStateConnected)
1196 break;
1197
1198 xenbus_switch_state(dev, XenbusStateConnected);
1199 break;
1200
1201 case XenbusStateClosing:
1202 if (info->irq)
1203 scsiback_disconnect(info);
1204
1205 xenbus_switch_state(dev, XenbusStateClosing);
1206 break;
1207
1208 case XenbusStateClosed:
1209 xenbus_switch_state(dev, XenbusStateClosed);
1210 if (xenbus_dev_is_online(dev))
1211 break;
1212 fallthrough; /* if not online */
1213 case XenbusStateUnknown:
1214 device_unregister(&dev->dev);
1215 break;
1216
1217 case XenbusStateReconfiguring:
1218 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1219 xenbus_switch_state(dev, XenbusStateReconfigured);
1220
1221 break;
1222
1223 default:
1224 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1225 frontend_state);
1226 break;
1227 }
1228 }
1229
1230 /*
1231 Release the translation entry specfied
1232 */
scsiback_release_translation_entry(struct vscsibk_info * info)1233 static void scsiback_release_translation_entry(struct vscsibk_info *info)
1234 {
1235 struct v2p_entry *entry, *tmp;
1236 struct list_head *head = &(info->v2p_entry_lists);
1237 struct list_head tmp_list;
1238 unsigned long flags;
1239
1240 spin_lock_irqsave(&info->v2p_lock, flags);
1241
1242 list_cut_before(&tmp_list, head, head);
1243
1244 spin_unlock_irqrestore(&info->v2p_lock, flags);
1245
1246 list_for_each_entry_safe(entry, tmp, &tmp_list, l) {
1247 list_del(&entry->l);
1248 kref_put(&entry->kref, scsiback_free_translation_entry);
1249 }
1250 }
1251
scsiback_remove(struct xenbus_device * dev)1252 static void scsiback_remove(struct xenbus_device *dev)
1253 {
1254 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1255
1256 if (info->irq)
1257 scsiback_disconnect(info);
1258
1259 scsiback_release_translation_entry(info);
1260
1261 gnttab_page_cache_shrink(&info->free_pages, 0);
1262
1263 dev_set_drvdata(&dev->dev, NULL);
1264 kfree(info);
1265 }
1266
scsiback_probe(struct xenbus_device * dev,const struct xenbus_device_id * id)1267 static int scsiback_probe(struct xenbus_device *dev,
1268 const struct xenbus_device_id *id)
1269 {
1270 int err;
1271
1272 struct vscsibk_info *info = kzalloc_obj(struct vscsibk_info);
1273
1274 pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id);
1275
1276 if (!info) {
1277 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
1278 return -ENOMEM;
1279 }
1280 info->dev = dev;
1281 dev_set_drvdata(&dev->dev, info);
1282
1283 info->domid = dev->otherend_id;
1284 spin_lock_init(&info->ring_lock);
1285 atomic_set(&info->nr_unreplied_reqs, 0);
1286 init_waitqueue_head(&info->waiting_to_free);
1287 info->dev = dev;
1288 info->irq = 0;
1289 INIT_LIST_HEAD(&info->v2p_entry_lists);
1290 spin_lock_init(&info->v2p_lock);
1291 gnttab_page_cache_init(&info->free_pages);
1292
1293 err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
1294 SG_ALL);
1295 if (err)
1296 xenbus_dev_error(dev, err, "writing feature-sg-grant");
1297
1298 err = xenbus_switch_state(dev, XenbusStateInitWait);
1299 if (err)
1300 goto fail;
1301
1302 return 0;
1303
1304 fail:
1305 pr_warn("%s failed\n", __func__);
1306 scsiback_remove(dev);
1307
1308 return err;
1309 }
1310
scsiback_dump_proto_id(struct scsiback_tport * tport)1311 static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
1312 {
1313 switch (tport->tport_proto_id) {
1314 case SCSI_PROTOCOL_SAS:
1315 return "SAS";
1316 case SCSI_PROTOCOL_FCP:
1317 return "FCP";
1318 case SCSI_PROTOCOL_ISCSI:
1319 return "iSCSI";
1320 default:
1321 break;
1322 }
1323
1324 return "Unknown";
1325 }
1326
scsiback_get_fabric_wwn(struct se_portal_group * se_tpg)1327 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
1328 {
1329 struct scsiback_tpg *tpg = container_of(se_tpg,
1330 struct scsiback_tpg, se_tpg);
1331 struct scsiback_tport *tport = tpg->tport;
1332
1333 return &tport->tport_name[0];
1334 }
1335
scsiback_get_tag(struct se_portal_group * se_tpg)1336 static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
1337 {
1338 struct scsiback_tpg *tpg = container_of(se_tpg,
1339 struct scsiback_tpg, se_tpg);
1340 return tpg->tport_tpgt;
1341 }
1342
1343 static struct se_wwn *
scsiback_make_tport(struct target_fabric_configfs * tf,struct config_group * group,const char * name)1344 scsiback_make_tport(struct target_fabric_configfs *tf,
1345 struct config_group *group,
1346 const char *name)
1347 {
1348 struct scsiback_tport *tport;
1349 char *ptr;
1350 u64 wwpn = 0;
1351 int off = 0;
1352
1353 tport = kzalloc_obj(struct scsiback_tport);
1354 if (!tport)
1355 return ERR_PTR(-ENOMEM);
1356
1357 tport->tport_wwpn = wwpn;
1358 /*
1359 * Determine the emulated Protocol Identifier and Target Port Name
1360 * based on the incoming configfs directory name.
1361 */
1362 ptr = strstr(name, "naa.");
1363 if (ptr) {
1364 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1365 goto check_len;
1366 }
1367 ptr = strstr(name, "fc.");
1368 if (ptr) {
1369 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1370 off = 3; /* Skip over "fc." */
1371 goto check_len;
1372 }
1373 ptr = strstr(name, "iqn.");
1374 if (ptr) {
1375 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1376 goto check_len;
1377 }
1378
1379 pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
1380 kfree(tport);
1381 return ERR_PTR(-EINVAL);
1382
1383 check_len:
1384 if (strlen(name) >= VSCSI_NAMELEN) {
1385 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
1386 scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
1387 kfree(tport);
1388 return ERR_PTR(-EINVAL);
1389 }
1390 snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
1391
1392 pr_debug("Allocated emulated Target %s Address: %s\n",
1393 scsiback_dump_proto_id(tport), name);
1394
1395 return &tport->tport_wwn;
1396 }
1397
scsiback_drop_tport(struct se_wwn * wwn)1398 static void scsiback_drop_tport(struct se_wwn *wwn)
1399 {
1400 struct scsiback_tport *tport = container_of(wwn,
1401 struct scsiback_tport, tport_wwn);
1402
1403 pr_debug("Deallocating emulated Target %s Address: %s\n",
1404 scsiback_dump_proto_id(tport), tport->tport_name);
1405
1406 kfree(tport);
1407 }
1408
scsiback_check_stop_free(struct se_cmd * se_cmd)1409 static int scsiback_check_stop_free(struct se_cmd *se_cmd)
1410 {
1411 return transport_generic_free_cmd(se_cmd, 0);
1412 }
1413
scsiback_release_cmd(struct se_cmd * se_cmd)1414 static void scsiback_release_cmd(struct se_cmd *se_cmd)
1415 {
1416 target_free_tag(se_cmd->se_sess, se_cmd);
1417 }
1418
scsiback_write_pending(struct se_cmd * se_cmd)1419 static int scsiback_write_pending(struct se_cmd *se_cmd)
1420 {
1421 /* Go ahead and process the write immediately */
1422 target_execute_cmd(se_cmd);
1423
1424 return 0;
1425 }
1426
scsiback_queue_data_in(struct se_cmd * se_cmd)1427 static int scsiback_queue_data_in(struct se_cmd *se_cmd)
1428 {
1429 struct vscsibk_pend *pending_req = container_of(se_cmd,
1430 struct vscsibk_pend, se_cmd);
1431
1432 pending_req->result = SAM_STAT_GOOD;
1433 scsiback_cmd_done(pending_req);
1434 return 0;
1435 }
1436
scsiback_queue_status(struct se_cmd * se_cmd)1437 static int scsiback_queue_status(struct se_cmd *se_cmd)
1438 {
1439 struct vscsibk_pend *pending_req = container_of(se_cmd,
1440 struct vscsibk_pend, se_cmd);
1441
1442 if (se_cmd->sense_buffer &&
1443 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1444 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
1445 pending_req->result = SAM_STAT_CHECK_CONDITION;
1446 else
1447 pending_req->result = se_cmd->scsi_status;
1448
1449 scsiback_cmd_done(pending_req);
1450 return 0;
1451 }
1452
scsiback_queue_tm_rsp(struct se_cmd * se_cmd)1453 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
1454 {
1455 struct vscsibk_pend *pending_req = container_of(se_cmd,
1456 struct vscsibk_pend, se_cmd);
1457
1458 complete(&pending_req->tmr_done);
1459 }
1460
scsiback_aborted_task(struct se_cmd * se_cmd)1461 static void scsiback_aborted_task(struct se_cmd *se_cmd)
1462 {
1463 }
1464
scsiback_tpg_param_alias_show(struct config_item * item,char * page)1465 static ssize_t scsiback_tpg_param_alias_show(struct config_item *item,
1466 char *page)
1467 {
1468 struct se_portal_group *se_tpg = param_to_tpg(item);
1469 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1470 se_tpg);
1471 ssize_t rb;
1472
1473 mutex_lock(&tpg->tv_tpg_mutex);
1474 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
1475 mutex_unlock(&tpg->tv_tpg_mutex);
1476
1477 return rb;
1478 }
1479
scsiback_tpg_param_alias_store(struct config_item * item,const char * page,size_t count)1480 static ssize_t scsiback_tpg_param_alias_store(struct config_item *item,
1481 const char *page, size_t count)
1482 {
1483 struct se_portal_group *se_tpg = param_to_tpg(item);
1484 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1485 se_tpg);
1486 int len;
1487
1488 if (strlen(page) >= VSCSI_NAMELEN) {
1489 pr_err("param alias: %s, exceeds max: %d\n", page,
1490 VSCSI_NAMELEN);
1491 return -EINVAL;
1492 }
1493
1494 mutex_lock(&tpg->tv_tpg_mutex);
1495 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
1496 if (tpg->param_alias[len - 1] == '\n')
1497 tpg->param_alias[len - 1] = '\0';
1498 mutex_unlock(&tpg->tv_tpg_mutex);
1499
1500 return count;
1501 }
1502
1503 CONFIGFS_ATTR(scsiback_tpg_param_, alias);
1504
1505 static struct configfs_attribute *scsiback_param_attrs[] = {
1506 &scsiback_tpg_param_attr_alias,
1507 NULL,
1508 };
1509
scsiback_alloc_sess_cb(struct se_portal_group * se_tpg,struct se_session * se_sess,void * p)1510 static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg,
1511 struct se_session *se_sess, void *p)
1512 {
1513 struct scsiback_tpg *tpg = container_of(se_tpg,
1514 struct scsiback_tpg, se_tpg);
1515
1516 tpg->tpg_nexus = p;
1517 return 0;
1518 }
1519
scsiback_make_nexus(struct scsiback_tpg * tpg,const char * name)1520 static int scsiback_make_nexus(struct scsiback_tpg *tpg,
1521 const char *name)
1522 {
1523 struct scsiback_nexus *tv_nexus;
1524 int ret = 0;
1525
1526 mutex_lock(&tpg->tv_tpg_mutex);
1527 if (tpg->tpg_nexus) {
1528 pr_debug("tpg->tpg_nexus already exists\n");
1529 ret = -EEXIST;
1530 goto out_unlock;
1531 }
1532
1533 tv_nexus = kzalloc_obj(struct scsiback_nexus);
1534 if (!tv_nexus) {
1535 ret = -ENOMEM;
1536 goto out_unlock;
1537 }
1538
1539 tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg,
1540 VSCSI_DEFAULT_SESSION_TAGS,
1541 sizeof(struct vscsibk_pend),
1542 TARGET_PROT_NORMAL, name,
1543 tv_nexus, scsiback_alloc_sess_cb);
1544 if (IS_ERR(tv_nexus->tvn_se_sess)) {
1545 kfree(tv_nexus);
1546 ret = -ENOMEM;
1547 goto out_unlock;
1548 }
1549
1550 out_unlock:
1551 mutex_unlock(&tpg->tv_tpg_mutex);
1552 return ret;
1553 }
1554
scsiback_drop_nexus(struct scsiback_tpg * tpg)1555 static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1556 {
1557 struct se_session *se_sess;
1558 struct scsiback_nexus *tv_nexus;
1559
1560 mutex_lock(&tpg->tv_tpg_mutex);
1561 tv_nexus = tpg->tpg_nexus;
1562 if (!tv_nexus) {
1563 mutex_unlock(&tpg->tv_tpg_mutex);
1564 return -ENODEV;
1565 }
1566
1567 se_sess = tv_nexus->tvn_se_sess;
1568 if (!se_sess) {
1569 mutex_unlock(&tpg->tv_tpg_mutex);
1570 return -ENODEV;
1571 }
1572
1573 if (tpg->tv_tpg_port_count != 0) {
1574 mutex_unlock(&tpg->tv_tpg_mutex);
1575 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1576 tpg->tv_tpg_port_count);
1577 return -EBUSY;
1578 }
1579
1580 if (tpg->tv_tpg_fe_count != 0) {
1581 mutex_unlock(&tpg->tv_tpg_mutex);
1582 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1583 tpg->tv_tpg_fe_count);
1584 return -EBUSY;
1585 }
1586
1587 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n",
1588 scsiback_dump_proto_id(tpg->tport),
1589 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1590
1591 /*
1592 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1593 */
1594 target_remove_session(se_sess);
1595 tpg->tpg_nexus = NULL;
1596 mutex_unlock(&tpg->tv_tpg_mutex);
1597
1598 kfree(tv_nexus);
1599 return 0;
1600 }
1601
scsiback_tpg_nexus_show(struct config_item * item,char * page)1602 static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page)
1603 {
1604 struct se_portal_group *se_tpg = to_tpg(item);
1605 struct scsiback_tpg *tpg = container_of(se_tpg,
1606 struct scsiback_tpg, se_tpg);
1607 struct scsiback_nexus *tv_nexus;
1608 ssize_t ret;
1609
1610 mutex_lock(&tpg->tv_tpg_mutex);
1611 tv_nexus = tpg->tpg_nexus;
1612 if (!tv_nexus) {
1613 mutex_unlock(&tpg->tv_tpg_mutex);
1614 return -ENODEV;
1615 }
1616 ret = snprintf(page, PAGE_SIZE, "%s\n",
1617 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1618 mutex_unlock(&tpg->tv_tpg_mutex);
1619
1620 return ret;
1621 }
1622
scsiback_tpg_nexus_store(struct config_item * item,const char * page,size_t count)1623 static ssize_t scsiback_tpg_nexus_store(struct config_item *item,
1624 const char *page, size_t count)
1625 {
1626 struct se_portal_group *se_tpg = to_tpg(item);
1627 struct scsiback_tpg *tpg = container_of(se_tpg,
1628 struct scsiback_tpg, se_tpg);
1629 struct scsiback_tport *tport_wwn = tpg->tport;
1630 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1631 int ret;
1632 /*
1633 * Shutdown the active I_T nexus if 'NULL' is passed.
1634 */
1635 if (!strncmp(page, "NULL", 4)) {
1636 ret = scsiback_drop_nexus(tpg);
1637 return (!ret) ? count : ret;
1638 }
1639 /*
1640 * Otherwise make sure the passed virtual Initiator port WWN matches
1641 * the fabric protocol_id set in scsiback_make_tport(), and call
1642 * scsiback_make_nexus().
1643 */
1644 if (strlen(page) >= VSCSI_NAMELEN) {
1645 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1646 page, VSCSI_NAMELEN);
1647 return -EINVAL;
1648 }
1649 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1650
1651 ptr = strstr(i_port, "naa.");
1652 if (ptr) {
1653 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1654 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1655 i_port, scsiback_dump_proto_id(tport_wwn));
1656 return -EINVAL;
1657 }
1658 port_ptr = &i_port[0];
1659 goto check_newline;
1660 }
1661 ptr = strstr(i_port, "fc.");
1662 if (ptr) {
1663 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1664 pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
1665 i_port, scsiback_dump_proto_id(tport_wwn));
1666 return -EINVAL;
1667 }
1668 port_ptr = &i_port[3]; /* Skip over "fc." */
1669 goto check_newline;
1670 }
1671 ptr = strstr(i_port, "iqn.");
1672 if (ptr) {
1673 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1674 pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
1675 i_port, scsiback_dump_proto_id(tport_wwn));
1676 return -EINVAL;
1677 }
1678 port_ptr = &i_port[0];
1679 goto check_newline;
1680 }
1681 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1682 i_port);
1683 return -EINVAL;
1684 /*
1685 * Clear any trailing newline for the NAA WWN
1686 */
1687 check_newline:
1688 if (i_port[strlen(i_port) - 1] == '\n')
1689 i_port[strlen(i_port) - 1] = '\0';
1690
1691 ret = scsiback_make_nexus(tpg, port_ptr);
1692 if (ret < 0)
1693 return ret;
1694
1695 return count;
1696 }
1697
1698 CONFIGFS_ATTR(scsiback_tpg_, nexus);
1699
1700 static struct configfs_attribute *scsiback_tpg_attrs[] = {
1701 &scsiback_tpg_attr_nexus,
1702 NULL,
1703 };
1704
1705 static ssize_t
scsiback_wwn_version_show(struct config_item * item,char * page)1706 scsiback_wwn_version_show(struct config_item *item, char *page)
1707 {
1708 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1709 UTS_RELEASE"\n",
1710 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1711 }
1712
1713 CONFIGFS_ATTR_RO(scsiback_wwn_, version);
1714
1715 static struct configfs_attribute *scsiback_wwn_attrs[] = {
1716 &scsiback_wwn_attr_version,
1717 NULL,
1718 };
1719
scsiback_port_link(struct se_portal_group * se_tpg,struct se_lun * lun)1720 static int scsiback_port_link(struct se_portal_group *se_tpg,
1721 struct se_lun *lun)
1722 {
1723 struct scsiback_tpg *tpg = container_of(se_tpg,
1724 struct scsiback_tpg, se_tpg);
1725
1726 mutex_lock(&tpg->tv_tpg_mutex);
1727 tpg->tv_tpg_port_count++;
1728 mutex_unlock(&tpg->tv_tpg_mutex);
1729
1730 return 0;
1731 }
1732
scsiback_port_unlink(struct se_portal_group * se_tpg,struct se_lun * lun)1733 static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1734 struct se_lun *lun)
1735 {
1736 struct scsiback_tpg *tpg = container_of(se_tpg,
1737 struct scsiback_tpg, se_tpg);
1738
1739 mutex_lock(&tpg->tv_tpg_mutex);
1740 tpg->tv_tpg_port_count--;
1741 mutex_unlock(&tpg->tv_tpg_mutex);
1742 }
1743
1744 static struct se_portal_group *
scsiback_make_tpg(struct se_wwn * wwn,const char * name)1745 scsiback_make_tpg(struct se_wwn *wwn, const char *name)
1746 {
1747 struct scsiback_tport *tport = container_of(wwn,
1748 struct scsiback_tport, tport_wwn);
1749
1750 struct scsiback_tpg *tpg;
1751 u16 tpgt;
1752 int ret;
1753
1754 if (strstr(name, "tpgt_") != name)
1755 return ERR_PTR(-EINVAL);
1756 ret = kstrtou16(name + 5, 10, &tpgt);
1757 if (ret)
1758 return ERR_PTR(ret);
1759
1760 tpg = kzalloc_obj(struct scsiback_tpg);
1761 if (!tpg)
1762 return ERR_PTR(-ENOMEM);
1763
1764 mutex_init(&tpg->tv_tpg_mutex);
1765 INIT_LIST_HEAD(&tpg->tv_tpg_list);
1766 INIT_LIST_HEAD(&tpg->info_list);
1767 tpg->tport = tport;
1768 tpg->tport_tpgt = tpgt;
1769
1770 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
1771 if (ret < 0) {
1772 kfree(tpg);
1773 return NULL;
1774 }
1775 mutex_lock(&scsiback_mutex);
1776 list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1777 mutex_unlock(&scsiback_mutex);
1778
1779 return &tpg->se_tpg;
1780 }
1781
scsiback_drop_tpg(struct se_portal_group * se_tpg)1782 static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1783 {
1784 struct scsiback_tpg *tpg = container_of(se_tpg,
1785 struct scsiback_tpg, se_tpg);
1786
1787 mutex_lock(&scsiback_mutex);
1788 list_del(&tpg->tv_tpg_list);
1789 mutex_unlock(&scsiback_mutex);
1790 /*
1791 * Release the virtual I_T Nexus for this xen-pvscsi TPG
1792 */
1793 scsiback_drop_nexus(tpg);
1794 /*
1795 * Deregister the se_tpg from TCM.
1796 */
1797 core_tpg_deregister(se_tpg);
1798 kfree(tpg);
1799 }
1800
scsiback_check_true(struct se_portal_group * se_tpg)1801 static int scsiback_check_true(struct se_portal_group *se_tpg)
1802 {
1803 return 1;
1804 }
1805
1806 static const struct target_core_fabric_ops scsiback_ops = {
1807 .module = THIS_MODULE,
1808 .fabric_name = "xen-pvscsi",
1809 .tpg_get_wwn = scsiback_get_fabric_wwn,
1810 .tpg_get_tag = scsiback_get_tag,
1811 .tpg_check_demo_mode = scsiback_check_true,
1812 .tpg_check_demo_mode_cache = scsiback_check_true,
1813 .check_stop_free = scsiback_check_stop_free,
1814 .release_cmd = scsiback_release_cmd,
1815 .sess_get_initiator_sid = NULL,
1816 .write_pending = scsiback_write_pending,
1817 .queue_data_in = scsiback_queue_data_in,
1818 .queue_status = scsiback_queue_status,
1819 .queue_tm_rsp = scsiback_queue_tm_rsp,
1820 .aborted_task = scsiback_aborted_task,
1821 /*
1822 * Setup callers for generic logic in target_core_fabric_configfs.c
1823 */
1824 .fabric_make_wwn = scsiback_make_tport,
1825 .fabric_drop_wwn = scsiback_drop_tport,
1826 .fabric_make_tpg = scsiback_make_tpg,
1827 .fabric_drop_tpg = scsiback_drop_tpg,
1828 .fabric_post_link = scsiback_port_link,
1829 .fabric_pre_unlink = scsiback_port_unlink,
1830
1831 .tfc_wwn_attrs = scsiback_wwn_attrs,
1832 .tfc_tpg_base_attrs = scsiback_tpg_attrs,
1833 .tfc_tpg_param_attrs = scsiback_param_attrs,
1834
1835 .default_submit_type = TARGET_DIRECT_SUBMIT,
1836 .direct_submit_supp = 1,
1837 };
1838
1839 static const struct xenbus_device_id scsiback_ids[] = {
1840 { "vscsi" },
1841 { "" }
1842 };
1843
1844 static struct xenbus_driver scsiback_driver = {
1845 .ids = scsiback_ids,
1846 .probe = scsiback_probe,
1847 .remove = scsiback_remove,
1848 .otherend_changed = scsiback_frontend_changed
1849 };
1850
scsiback_init(void)1851 static int __init scsiback_init(void)
1852 {
1853 int ret;
1854
1855 if (!xen_domain())
1856 return -ENODEV;
1857
1858 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
1859 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1860
1861 ret = xenbus_register_backend(&scsiback_driver);
1862 if (ret)
1863 goto out;
1864
1865 ret = target_register_template(&scsiback_ops);
1866 if (ret)
1867 goto out_unregister_xenbus;
1868
1869 return 0;
1870
1871 out_unregister_xenbus:
1872 xenbus_unregister_driver(&scsiback_driver);
1873 out:
1874 pr_err("%s: error %d\n", __func__, ret);
1875 return ret;
1876 }
1877
scsiback_exit(void)1878 static void __exit scsiback_exit(void)
1879 {
1880 target_unregister_template(&scsiback_ops);
1881 xenbus_unregister_driver(&scsiback_driver);
1882 }
1883
1884 module_init(scsiback_init);
1885 module_exit(scsiback_exit);
1886
1887 MODULE_DESCRIPTION("Xen SCSI backend driver");
1888 MODULE_LICENSE("Dual BSD/GPL");
1889 MODULE_ALIAS("xen-backend:vscsi");
1890 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");
1891