Loading...
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
70struct ids_tuple {
71 unsigned int hst; /* host */
72 unsigned int chn; /* channel */
73 unsigned int tgt; /* target */
74 unsigned int lun; /* LUN */
75};
76
77struct 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
85struct 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
114struct 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
142struct scsiback_nexus {
143 /* Pointer to TCM session for I_T Nexus */
144 struct se_session *tvn_se_sess;
145};
146
147struct 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
158struct 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
183static bool log_print_stat;
184module_param(log_print_stat, bool, 0644);
185
186static int scsiback_max_buffer_pages = 1024;
187module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644);
188MODULE_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 */
192static DEFINE_MUTEX(scsiback_mutex);
193static LIST_HEAD(scsiback_list);
194
195static void scsiback_get(struct vscsibk_info *info)
196{
197 atomic_inc(&info->nr_unreplied_reqs);
198}
199
200static 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
206static 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
213static unsigned long vaddr(struct vscsibk_pend *req, int seg)
214{
215 return vaddr_page(req->pages[seg]);
216}
217
218static 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
229static 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
271static 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
283static 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
347static 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
385static 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
396static 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
421static 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
439static 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
462static 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
494static 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_array(nr_segments,
547 sizeof(struct scatterlist), GFP_KERNEL);
548 if (!pending_req->sgl)
549 return -ENOMEM;
550
551 sg_init_table(pending_req->sgl, nr_segments);
552 pending_req->n_sg = nr_segments;
553
554 flags = GNTMAP_host_map;
555 if (pending_req->sc_data_direction == DMA_TO_DEVICE)
556 flags |= GNTMAP_readonly;
557
558 pg = pending_req->pages + nr_sgl;
559 grant = pending_req->grant_handles + nr_sgl;
560 if (!nr_sgl) {
561 seg = ring_req->seg;
562 err = scsiback_gnttab_data_map_list(pending_req, seg,
563 pg, grant, nr_segments, flags);
564 if (err)
565 return err;
566 } else {
567 for (i = 0; i < nr_sgl; i++) {
568 seg = (struct scsiif_request_segment *)(
569 vaddr(pending_req, i) + ring_req->seg[i].offset);
570 n_segs = ring_req->seg[i].length /
571 sizeof(struct scsiif_request_segment);
572 err = scsiback_gnttab_data_map_list(pending_req, seg,
573 pg, grant, n_segs, flags);
574 if (err)
575 return err;
576 pg += n_segs;
577 grant += n_segs;
578 }
579 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
580 seg = (struct scsiif_request_segment *)end_seg;
581 end_seg += ring_req->seg[0].length;
582 pg = pending_req->pages + nr_sgl;
583 }
584
585 for_each_sg(pending_req->sgl, sg, nr_segments, i) {
586 sg_set_page(sg, pg[i], seg->length, seg->offset);
587 pending_req->data_len += seg->length;
588 seg++;
589 if (nr_sgl && (unsigned long)seg >= end_seg) {
590 i_seg++;
591 end_seg = vaddr(pending_req, i_seg) +
592 ring_req->seg[i_seg].offset;
593 seg = (struct scsiif_request_segment *)end_seg;
594 end_seg += ring_req->seg[i_seg].length;
595 }
596 if (sg->offset >= PAGE_SIZE ||
597 sg->length > PAGE_SIZE ||
598 sg->offset + sg->length > PAGE_SIZE)
599 return -EINVAL;
600 }
601
602 return 0;
603}
604
605static void scsiback_disconnect(struct vscsibk_info *info)
606{
607 wait_event(info->waiting_to_free,
608 atomic_read(&info->nr_unreplied_reqs) == 0);
609
610 unbind_from_irqhandler(info->irq, info);
611 info->irq = 0;
612 xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
613}
614
615static void scsiback_device_action(struct vscsibk_pend *pending_req,
616 enum tcm_tmreq_table act, int tag)
617{
618 struct scsiback_tpg *tpg = pending_req->v2p->tpg;
619 struct scsiback_nexus *nexus = tpg->tpg_nexus;
620 struct se_cmd *se_cmd = &pending_req->se_cmd;
621 u64 unpacked_lun = pending_req->v2p->lun;
622 int rc, err = XEN_VSCSIIF_RSLT_RESET_FAILED;
623
624 init_completion(&pending_req->tmr_done);
625
626 rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess,
627 &pending_req->sense_buffer[0],
628 unpacked_lun, NULL, act, GFP_KERNEL,
629 tag, TARGET_SCF_ACK_KREF);
630 if (rc)
631 goto err;
632
633 wait_for_completion(&pending_req->tmr_done);
634
635 err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
636 XEN_VSCSIIF_RSLT_RESET_SUCCESS : XEN_VSCSIIF_RSLT_RESET_FAILED;
637
638 scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
639 transport_generic_free_cmd(&pending_req->se_cmd, 0);
640 return;
641
642err:
643 scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
644}
645
646/*
647 Perform virtual to physical translation
648*/
649static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
650 struct ids_tuple *v)
651{
652 struct v2p_entry *entry;
653 struct list_head *head = &(info->v2p_entry_lists);
654 unsigned long flags;
655
656 spin_lock_irqsave(&info->v2p_lock, flags);
657 list_for_each_entry(entry, head, l) {
658 if ((entry->v.chn == v->chn) &&
659 (entry->v.tgt == v->tgt) &&
660 (entry->v.lun == v->lun)) {
661 kref_get(&entry->kref);
662 goto out;
663 }
664 }
665 entry = NULL;
666
667out:
668 spin_unlock_irqrestore(&info->v2p_lock, flags);
669 return entry;
670}
671
672static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring,
673 struct v2p_entry *v2p)
674{
675 struct scsiback_tpg *tpg = v2p->tpg;
676 struct scsiback_nexus *nexus = tpg->tpg_nexus;
677 struct se_session *se_sess = nexus->tvn_se_sess;
678 struct vscsibk_pend *req;
679 int tag, cpu, i;
680
681 tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
682 if (tag < 0) {
683 pr_err("Unable to obtain tag for vscsiif_request\n");
684 return ERR_PTR(-ENOMEM);
685 }
686
687 req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag];
688 memset(req, 0, sizeof(*req));
689 req->se_cmd.map_tag = tag;
690 req->se_cmd.map_cpu = cpu;
691
692 for (i = 0; i < VSCSI_MAX_GRANTS; i++)
693 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
694
695 return req;
696}
697
698static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info,
699 struct vscsiif_back_ring *ring,
700 struct vscsiif_request *ring_req)
701{
702 struct vscsibk_pend *pending_req;
703 struct v2p_entry *v2p;
704 struct ids_tuple vir;
705
706 /* request range check from frontend */
707 if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
708 (ring_req->sc_data_direction != DMA_TO_DEVICE) &&
709 (ring_req->sc_data_direction != DMA_FROM_DEVICE) &&
710 (ring_req->sc_data_direction != DMA_NONE)) {
711 pr_debug("invalid parameter data_dir = %d\n",
712 ring_req->sc_data_direction);
713 return ERR_PTR(-EINVAL);
714 }
715 if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
716 pr_debug("invalid parameter cmd_len = %d\n",
717 ring_req->cmd_len);
718 return ERR_PTR(-EINVAL);
719 }
720
721 vir.chn = ring_req->channel;
722 vir.tgt = ring_req->id;
723 vir.lun = ring_req->lun;
724
725 v2p = scsiback_do_translation(info, &vir);
726 if (!v2p) {
727 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n",
728 vir.chn, vir.tgt, vir.lun);
729 return ERR_PTR(-ENODEV);
730 }
731
732 pending_req = scsiback_get_pend_req(ring, v2p);
733 if (IS_ERR(pending_req)) {
734 kref_put(&v2p->kref, scsiback_free_translation_entry);
735 return ERR_PTR(-ENOMEM);
736 }
737 pending_req->rqid = ring_req->rqid;
738 pending_req->info = info;
739 pending_req->v2p = v2p;
740 pending_req->sc_data_direction = ring_req->sc_data_direction;
741 pending_req->cmd_len = ring_req->cmd_len;
742 memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
743
744 return pending_req;
745}
746
747static int scsiback_do_cmd_fn(struct vscsibk_info *info,
748 unsigned int *eoi_flags)
749{
750 struct vscsiif_back_ring *ring = &info->ring;
751 struct vscsiif_request ring_req;
752 struct vscsibk_pend *pending_req;
753 RING_IDX rc, rp;
754 int more_to_do;
755 uint32_t result;
756
757 rc = ring->req_cons;
758 rp = ring->sring->req_prod;
759 rmb(); /* guest system is accessing ring, too */
760
761 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
762 rc = ring->rsp_prod_pvt;
763 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
764 info->domid, rp, rc, rp - rc);
765 return -EINVAL;
766 }
767
768 while ((rc != rp)) {
769 *eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS;
770
771 if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
772 break;
773
774 RING_COPY_REQUEST(ring, rc, &ring_req);
775 ring->req_cons = ++rc;
776
777 pending_req = prepare_pending_reqs(info, ring, &ring_req);
778 if (IS_ERR(pending_req)) {
779 switch (PTR_ERR(pending_req)) {
780 case -ENODEV:
781 result = DID_NO_CONNECT;
782 break;
783 default:
784 result = DID_ERROR;
785 break;
786 }
787 scsiback_send_response(info, NULL, result << 16, 0,
788 ring_req.rqid);
789 return 1;
790 }
791
792 switch (ring_req.act) {
793 case VSCSIIF_ACT_SCSI_CDB:
794 if (scsiback_gnttab_data_map(&ring_req, pending_req)) {
795 scsiback_fast_flush_area(pending_req);
796 scsiback_do_resp_with_sense(NULL,
797 DID_ERROR << 16, 0, pending_req);
798 transport_generic_free_cmd(&pending_req->se_cmd, 0);
799 } else {
800 scsiback_cmd_exec(pending_req);
801 }
802 break;
803 case VSCSIIF_ACT_SCSI_ABORT:
804 scsiback_device_action(pending_req, TMR_ABORT_TASK,
805 ring_req.ref_rqid);
806 break;
807 case VSCSIIF_ACT_SCSI_RESET:
808 scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
809 break;
810 default:
811 pr_err_ratelimited("invalid request\n");
812 scsiback_do_resp_with_sense(NULL, DID_ERROR << 16, 0,
813 pending_req);
814 transport_generic_free_cmd(&pending_req->se_cmd, 0);
815 break;
816 }
817
818 /* Yield point for this unbounded loop. */
819 cond_resched();
820 }
821
822 gnttab_page_cache_shrink(&info->free_pages, scsiback_max_buffer_pages);
823
824 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
825 return more_to_do;
826}
827
828static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
829{
830 struct vscsibk_info *info = dev_id;
831 int rc;
832 unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
833
834 while ((rc = scsiback_do_cmd_fn(info, &eoi_flags)) > 0)
835 cond_resched();
836
837 /* In case of a ring error we keep the event channel masked. */
838 if (!rc)
839 xen_irq_lateeoi(irq, eoi_flags);
840
841 return IRQ_HANDLED;
842}
843
844static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
845 evtchn_port_t evtchn)
846{
847 void *area;
848 struct vscsiif_sring *sring;
849 int err;
850
851 if (info->irq)
852 return -1;
853
854 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area);
855 if (err)
856 return err;
857
858 sring = (struct vscsiif_sring *)area;
859 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
860
861 err = bind_interdomain_evtchn_to_irq_lateeoi(info->dev, evtchn);
862 if (err < 0)
863 goto unmap_page;
864
865 info->irq = err;
866
867 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
868 IRQF_ONESHOT, "vscsiif-backend", info);
869 if (err)
870 goto free_irq;
871
872 return 0;
873
874free_irq:
875 unbind_from_irqhandler(info->irq, info);
876 info->irq = 0;
877unmap_page:
878 xenbus_unmap_ring_vfree(info->dev, area);
879
880 return err;
881}
882
883static int scsiback_map(struct vscsibk_info *info)
884{
885 struct xenbus_device *dev = info->dev;
886 unsigned int ring_ref;
887 evtchn_port_t evtchn;
888 int err;
889
890 err = xenbus_gather(XBT_NIL, dev->otherend,
891 "ring-ref", "%u", &ring_ref,
892 "event-channel", "%u", &evtchn, NULL);
893 if (err) {
894 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
895 return err;
896 }
897
898 return scsiback_init_sring(info, ring_ref, evtchn);
899}
900
901/*
902 Check for a translation entry being present
903*/
904static struct v2p_entry *scsiback_chk_translation_entry(
905 struct vscsibk_info *info, struct ids_tuple *v)
906{
907 struct list_head *head = &(info->v2p_entry_lists);
908 struct v2p_entry *entry;
909
910 list_for_each_entry(entry, head, l)
911 if ((entry->v.chn == v->chn) &&
912 (entry->v.tgt == v->tgt) &&
913 (entry->v.lun == v->lun))
914 return entry;
915
916 return NULL;
917}
918
919/*
920 Add a new translation entry
921*/
922static int scsiback_add_translation_entry(struct vscsibk_info *info,
923 char *phy, struct ids_tuple *v)
924{
925 int err = 0;
926 struct v2p_entry *new;
927 unsigned long flags;
928 char *lunp;
929 unsigned long long unpacked_lun;
930 struct se_lun *se_lun;
931 struct scsiback_tpg *tpg_entry, *tpg = NULL;
932 char *error = "doesn't exist";
933
934 lunp = strrchr(phy, ':');
935 if (!lunp) {
936 pr_err("illegal format of physical device %s\n", phy);
937 return -EINVAL;
938 }
939 *lunp = 0;
940 lunp++;
941 err = kstrtoull(lunp, 10, &unpacked_lun);
942 if (err < 0) {
943 pr_err("lun number not valid: %s\n", lunp);
944 return err;
945 }
946
947 mutex_lock(&scsiback_mutex);
948 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
949 if (!strcmp(phy, tpg_entry->tport->tport_name) ||
950 !strcmp(phy, tpg_entry->param_alias)) {
951 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex);
952 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) {
953 if (se_lun->unpacked_lun == unpacked_lun) {
954 if (!tpg_entry->tpg_nexus)
955 error = "nexus undefined";
956 else
957 tpg = tpg_entry;
958 break;
959 }
960 }
961 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex);
962 break;
963 }
964 }
965 if (tpg) {
966 mutex_lock(&tpg->tv_tpg_mutex);
967 tpg->tv_tpg_fe_count++;
968 mutex_unlock(&tpg->tv_tpg_mutex);
969 }
970 mutex_unlock(&scsiback_mutex);
971
972 if (!tpg) {
973 pr_err("%s:%llu %s\n", phy, unpacked_lun, error);
974 return -ENODEV;
975 }
976
977 new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
978 if (new == NULL) {
979 err = -ENOMEM;
980 goto out_free;
981 }
982
983 spin_lock_irqsave(&info->v2p_lock, flags);
984
985 /* Check double assignment to identical virtual ID */
986 if (scsiback_chk_translation_entry(info, v)) {
987 pr_warn("Virtual ID is already used. Assignment was not performed.\n");
988 err = -EEXIST;
989 goto out;
990 }
991
992 /* Create a new translation entry and add to the list */
993 kref_init(&new->kref);
994 new->v = *v;
995 new->tpg = tpg;
996 new->lun = unpacked_lun;
997 list_add_tail(&new->l, &info->v2p_entry_lists);
998
999out:
1000 spin_unlock_irqrestore(&info->v2p_lock, flags);
1001
1002out_free:
1003 if (err) {
1004 mutex_lock(&tpg->tv_tpg_mutex);
1005 tpg->tv_tpg_fe_count--;
1006 mutex_unlock(&tpg->tv_tpg_mutex);
1007 kfree(new);
1008 }
1009
1010 return err;
1011}
1012
1013static void __scsiback_del_translation_entry(struct v2p_entry *entry)
1014{
1015 list_del(&entry->l);
1016 kref_put(&entry->kref, scsiback_free_translation_entry);
1017}
1018
1019/*
1020 Delete the translation entry specified
1021*/
1022static int scsiback_del_translation_entry(struct vscsibk_info *info,
1023 struct ids_tuple *v)
1024{
1025 struct v2p_entry *entry;
1026 unsigned long flags;
1027 int ret = 0;
1028
1029 spin_lock_irqsave(&info->v2p_lock, flags);
1030 /* Find out the translation entry specified */
1031 entry = scsiback_chk_translation_entry(info, v);
1032 if (entry)
1033 __scsiback_del_translation_entry(entry);
1034 else
1035 ret = -ENOENT;
1036
1037 spin_unlock_irqrestore(&info->v2p_lock, flags);
1038 return ret;
1039}
1040
1041static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
1042 char *phy, struct ids_tuple *vir, int try)
1043{
1044 struct v2p_entry *entry;
1045 unsigned long flags;
1046 int err;
1047
1048 if (try) {
1049 spin_lock_irqsave(&info->v2p_lock, flags);
1050 entry = scsiback_chk_translation_entry(info, vir);
1051 spin_unlock_irqrestore(&info->v2p_lock, flags);
1052 if (entry)
1053 return;
1054 }
1055 if (!scsiback_add_translation_entry(info, phy, vir)) {
1056 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1057 "%d", XenbusStateInitialised)) {
1058 pr_err("xenbus_printf error %s\n", state);
1059 scsiback_del_translation_entry(info, vir);
1060 }
1061 } else if (!try) {
1062 err = xenbus_printf(XBT_NIL, info->dev->nodename, state,
1063 "%d", XenbusStateClosed);
1064 if (err)
1065 xenbus_dev_error(info->dev, err,
1066 "%s: writing %s", __func__, state);
1067 }
1068}
1069
1070static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1071 struct ids_tuple *vir)
1072{
1073 if (!scsiback_del_translation_entry(info, vir)) {
1074 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1075 "%d", XenbusStateClosed))
1076 pr_err("xenbus_printf error %s\n", state);
1077 }
1078}
1079
1080#define VSCSIBACK_OP_ADD_OR_DEL_LUN 1
1081#define VSCSIBACK_OP_UPDATEDEV_STATE 2
1082
1083static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1084 char *ent)
1085{
1086 int err;
1087 struct ids_tuple vir;
1088 char *val;
1089 int device_state;
1090 char phy[VSCSI_NAMELEN];
1091 char str[64];
1092 char state[64];
1093 struct xenbus_device *dev = info->dev;
1094
1095 /* read status */
1096 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1097 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1098 if (XENBUS_EXIST_ERR(err))
1099 return;
1100
1101 /* physical SCSI device */
1102 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1103 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1104 if (IS_ERR(val)) {
1105 err = xenbus_printf(XBT_NIL, dev->nodename, state,
1106 "%d", XenbusStateClosed);
1107 if (err)
1108 xenbus_dev_error(info->dev, err,
1109 "%s: writing %s", __func__, state);
1110 return;
1111 }
1112 strscpy(phy, val, VSCSI_NAMELEN);
1113 kfree(val);
1114
1115 /* virtual SCSI device */
1116 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1117 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1118 &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1119 if (XENBUS_EXIST_ERR(err)) {
1120 err = xenbus_printf(XBT_NIL, dev->nodename, state,
1121 "%d", XenbusStateClosed);
1122 if (err)
1123 xenbus_dev_error(info->dev, err,
1124 "%s: writing %s", __func__, state);
1125 return;
1126 }
1127
1128 switch (op) {
1129 case VSCSIBACK_OP_ADD_OR_DEL_LUN:
1130 switch (device_state) {
1131 case XenbusStateInitialising:
1132 scsiback_do_add_lun(info, state, phy, &vir, 0);
1133 break;
1134 case XenbusStateConnected:
1135 scsiback_do_add_lun(info, state, phy, &vir, 1);
1136 break;
1137 case XenbusStateClosing:
1138 scsiback_do_del_lun(info, state, &vir);
1139 break;
1140 default:
1141 break;
1142 }
1143 break;
1144
1145 case VSCSIBACK_OP_UPDATEDEV_STATE:
1146 if (device_state == XenbusStateInitialised) {
1147 /* modify vscsi-devs/dev-x/state */
1148 if (xenbus_printf(XBT_NIL, dev->nodename, state,
1149 "%d", XenbusStateConnected)) {
1150 pr_err("xenbus_printf error %s\n", str);
1151 scsiback_del_translation_entry(info, &vir);
1152 xenbus_printf(XBT_NIL, dev->nodename, state,
1153 "%d", XenbusStateClosed);
1154 }
1155 }
1156 break;
1157 /* When it is necessary, processing is added here. */
1158 default:
1159 break;
1160 }
1161}
1162
1163static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1164{
1165 int i;
1166 char **dir;
1167 unsigned int ndir = 0;
1168
1169 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1170 &ndir);
1171 if (IS_ERR(dir))
1172 return;
1173
1174 for (i = 0; i < ndir; i++)
1175 scsiback_do_1lun_hotplug(info, op, dir[i]);
1176
1177 kfree(dir);
1178}
1179
1180static void scsiback_frontend_changed(struct xenbus_device *dev,
1181 enum xenbus_state frontend_state)
1182{
1183 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1184
1185 switch (frontend_state) {
1186 case XenbusStateInitialising:
1187 break;
1188
1189 case XenbusStateInitialised:
1190 if (scsiback_map(info))
1191 break;
1192
1193 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1194 xenbus_switch_state(dev, XenbusStateConnected);
1195 break;
1196
1197 case XenbusStateConnected:
1198 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1199
1200 if (dev->state == XenbusStateConnected)
1201 break;
1202
1203 xenbus_switch_state(dev, XenbusStateConnected);
1204 break;
1205
1206 case XenbusStateClosing:
1207 if (info->irq)
1208 scsiback_disconnect(info);
1209
1210 xenbus_switch_state(dev, XenbusStateClosing);
1211 break;
1212
1213 case XenbusStateClosed:
1214 xenbus_switch_state(dev, XenbusStateClosed);
1215 if (xenbus_dev_is_online(dev))
1216 break;
1217 fallthrough; /* if not online */
1218 case XenbusStateUnknown:
1219 device_unregister(&dev->dev);
1220 break;
1221
1222 case XenbusStateReconfiguring:
1223 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1224 xenbus_switch_state(dev, XenbusStateReconfigured);
1225
1226 break;
1227
1228 default:
1229 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1230 frontend_state);
1231 break;
1232 }
1233}
1234
1235/*
1236 Release the translation entry specfied
1237*/
1238static void scsiback_release_translation_entry(struct vscsibk_info *info)
1239{
1240 struct v2p_entry *entry, *tmp;
1241 struct list_head *head = &(info->v2p_entry_lists);
1242 unsigned long flags;
1243
1244 spin_lock_irqsave(&info->v2p_lock, flags);
1245
1246 list_for_each_entry_safe(entry, tmp, head, l)
1247 __scsiback_del_translation_entry(entry);
1248
1249 spin_unlock_irqrestore(&info->v2p_lock, flags);
1250}
1251
1252static 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}
1265
1266static int scsiback_probe(struct xenbus_device *dev,
1267 const struct xenbus_device_id *id)
1268{
1269 int err;
1270
1271 struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
1272 GFP_KERNEL);
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
1304fail:
1305 pr_warn("%s failed\n", __func__);
1306 scsiback_remove(dev);
1307
1308 return err;
1309}
1310
1311static 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
1327static 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
1336static 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
1343static struct se_wwn *
1344scsiback_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(sizeof(struct scsiback_tport), GFP_KERNEL);
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
1383check_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
1398static 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
1409static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg)
1410{
1411 return 1;
1412}
1413
1414static int scsiback_check_stop_free(struct se_cmd *se_cmd)
1415{
1416 return transport_generic_free_cmd(se_cmd, 0);
1417}
1418
1419static void scsiback_release_cmd(struct se_cmd *se_cmd)
1420{
1421 target_free_tag(se_cmd->se_sess, se_cmd);
1422}
1423
1424static u32 scsiback_sess_get_index(struct se_session *se_sess)
1425{
1426 return 0;
1427}
1428
1429static int scsiback_write_pending(struct se_cmd *se_cmd)
1430{
1431 /* Go ahead and process the write immediately */
1432 target_execute_cmd(se_cmd);
1433
1434 return 0;
1435}
1436
1437static void scsiback_set_default_node_attrs(struct se_node_acl *nacl)
1438{
1439}
1440
1441static int scsiback_get_cmd_state(struct se_cmd *se_cmd)
1442{
1443 return 0;
1444}
1445
1446static int scsiback_queue_data_in(struct se_cmd *se_cmd)
1447{
1448 struct vscsibk_pend *pending_req = container_of(se_cmd,
1449 struct vscsibk_pend, se_cmd);
1450
1451 pending_req->result = SAM_STAT_GOOD;
1452 scsiback_cmd_done(pending_req);
1453 return 0;
1454}
1455
1456static int scsiback_queue_status(struct se_cmd *se_cmd)
1457{
1458 struct vscsibk_pend *pending_req = container_of(se_cmd,
1459 struct vscsibk_pend, se_cmd);
1460
1461 if (se_cmd->sense_buffer &&
1462 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1463 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
1464 pending_req->result = SAM_STAT_CHECK_CONDITION;
1465 else
1466 pending_req->result = se_cmd->scsi_status;
1467
1468 scsiback_cmd_done(pending_req);
1469 return 0;
1470}
1471
1472static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
1473{
1474 struct vscsibk_pend *pending_req = container_of(se_cmd,
1475 struct vscsibk_pend, se_cmd);
1476
1477 complete(&pending_req->tmr_done);
1478}
1479
1480static void scsiback_aborted_task(struct se_cmd *se_cmd)
1481{
1482}
1483
1484static ssize_t scsiback_tpg_param_alias_show(struct config_item *item,
1485 char *page)
1486{
1487 struct se_portal_group *se_tpg = param_to_tpg(item);
1488 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1489 se_tpg);
1490 ssize_t rb;
1491
1492 mutex_lock(&tpg->tv_tpg_mutex);
1493 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
1494 mutex_unlock(&tpg->tv_tpg_mutex);
1495
1496 return rb;
1497}
1498
1499static ssize_t scsiback_tpg_param_alias_store(struct config_item *item,
1500 const char *page, size_t count)
1501{
1502 struct se_portal_group *se_tpg = param_to_tpg(item);
1503 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1504 se_tpg);
1505 int len;
1506
1507 if (strlen(page) >= VSCSI_NAMELEN) {
1508 pr_err("param alias: %s, exceeds max: %d\n", page,
1509 VSCSI_NAMELEN);
1510 return -EINVAL;
1511 }
1512
1513 mutex_lock(&tpg->tv_tpg_mutex);
1514 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
1515 if (tpg->param_alias[len - 1] == '\n')
1516 tpg->param_alias[len - 1] = '\0';
1517 mutex_unlock(&tpg->tv_tpg_mutex);
1518
1519 return count;
1520}
1521
1522CONFIGFS_ATTR(scsiback_tpg_param_, alias);
1523
1524static struct configfs_attribute *scsiback_param_attrs[] = {
1525 &scsiback_tpg_param_attr_alias,
1526 NULL,
1527};
1528
1529static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg,
1530 struct se_session *se_sess, void *p)
1531{
1532 struct scsiback_tpg *tpg = container_of(se_tpg,
1533 struct scsiback_tpg, se_tpg);
1534
1535 tpg->tpg_nexus = p;
1536 return 0;
1537}
1538
1539static int scsiback_make_nexus(struct scsiback_tpg *tpg,
1540 const char *name)
1541{
1542 struct scsiback_nexus *tv_nexus;
1543 int ret = 0;
1544
1545 mutex_lock(&tpg->tv_tpg_mutex);
1546 if (tpg->tpg_nexus) {
1547 pr_debug("tpg->tpg_nexus already exists\n");
1548 ret = -EEXIST;
1549 goto out_unlock;
1550 }
1551
1552 tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
1553 if (!tv_nexus) {
1554 ret = -ENOMEM;
1555 goto out_unlock;
1556 }
1557
1558 tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg,
1559 VSCSI_DEFAULT_SESSION_TAGS,
1560 sizeof(struct vscsibk_pend),
1561 TARGET_PROT_NORMAL, name,
1562 tv_nexus, scsiback_alloc_sess_cb);
1563 if (IS_ERR(tv_nexus->tvn_se_sess)) {
1564 kfree(tv_nexus);
1565 ret = -ENOMEM;
1566 goto out_unlock;
1567 }
1568
1569out_unlock:
1570 mutex_unlock(&tpg->tv_tpg_mutex);
1571 return ret;
1572}
1573
1574static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1575{
1576 struct se_session *se_sess;
1577 struct scsiback_nexus *tv_nexus;
1578
1579 mutex_lock(&tpg->tv_tpg_mutex);
1580 tv_nexus = tpg->tpg_nexus;
1581 if (!tv_nexus) {
1582 mutex_unlock(&tpg->tv_tpg_mutex);
1583 return -ENODEV;
1584 }
1585
1586 se_sess = tv_nexus->tvn_se_sess;
1587 if (!se_sess) {
1588 mutex_unlock(&tpg->tv_tpg_mutex);
1589 return -ENODEV;
1590 }
1591
1592 if (tpg->tv_tpg_port_count != 0) {
1593 mutex_unlock(&tpg->tv_tpg_mutex);
1594 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1595 tpg->tv_tpg_port_count);
1596 return -EBUSY;
1597 }
1598
1599 if (tpg->tv_tpg_fe_count != 0) {
1600 mutex_unlock(&tpg->tv_tpg_mutex);
1601 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1602 tpg->tv_tpg_fe_count);
1603 return -EBUSY;
1604 }
1605
1606 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n",
1607 scsiback_dump_proto_id(tpg->tport),
1608 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1609
1610 /*
1611 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1612 */
1613 target_remove_session(se_sess);
1614 tpg->tpg_nexus = NULL;
1615 mutex_unlock(&tpg->tv_tpg_mutex);
1616
1617 kfree(tv_nexus);
1618 return 0;
1619}
1620
1621static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page)
1622{
1623 struct se_portal_group *se_tpg = to_tpg(item);
1624 struct scsiback_tpg *tpg = container_of(se_tpg,
1625 struct scsiback_tpg, se_tpg);
1626 struct scsiback_nexus *tv_nexus;
1627 ssize_t ret;
1628
1629 mutex_lock(&tpg->tv_tpg_mutex);
1630 tv_nexus = tpg->tpg_nexus;
1631 if (!tv_nexus) {
1632 mutex_unlock(&tpg->tv_tpg_mutex);
1633 return -ENODEV;
1634 }
1635 ret = snprintf(page, PAGE_SIZE, "%s\n",
1636 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1637 mutex_unlock(&tpg->tv_tpg_mutex);
1638
1639 return ret;
1640}
1641
1642static ssize_t scsiback_tpg_nexus_store(struct config_item *item,
1643 const char *page, size_t count)
1644{
1645 struct se_portal_group *se_tpg = to_tpg(item);
1646 struct scsiback_tpg *tpg = container_of(se_tpg,
1647 struct scsiback_tpg, se_tpg);
1648 struct scsiback_tport *tport_wwn = tpg->tport;
1649 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1650 int ret;
1651 /*
1652 * Shutdown the active I_T nexus if 'NULL' is passed.
1653 */
1654 if (!strncmp(page, "NULL", 4)) {
1655 ret = scsiback_drop_nexus(tpg);
1656 return (!ret) ? count : ret;
1657 }
1658 /*
1659 * Otherwise make sure the passed virtual Initiator port WWN matches
1660 * the fabric protocol_id set in scsiback_make_tport(), and call
1661 * scsiback_make_nexus().
1662 */
1663 if (strlen(page) >= VSCSI_NAMELEN) {
1664 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1665 page, VSCSI_NAMELEN);
1666 return -EINVAL;
1667 }
1668 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1669
1670 ptr = strstr(i_port, "naa.");
1671 if (ptr) {
1672 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1673 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1674 i_port, scsiback_dump_proto_id(tport_wwn));
1675 return -EINVAL;
1676 }
1677 port_ptr = &i_port[0];
1678 goto check_newline;
1679 }
1680 ptr = strstr(i_port, "fc.");
1681 if (ptr) {
1682 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1683 pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
1684 i_port, scsiback_dump_proto_id(tport_wwn));
1685 return -EINVAL;
1686 }
1687 port_ptr = &i_port[3]; /* Skip over "fc." */
1688 goto check_newline;
1689 }
1690 ptr = strstr(i_port, "iqn.");
1691 if (ptr) {
1692 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1693 pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
1694 i_port, scsiback_dump_proto_id(tport_wwn));
1695 return -EINVAL;
1696 }
1697 port_ptr = &i_port[0];
1698 goto check_newline;
1699 }
1700 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1701 i_port);
1702 return -EINVAL;
1703 /*
1704 * Clear any trailing newline for the NAA WWN
1705 */
1706check_newline:
1707 if (i_port[strlen(i_port) - 1] == '\n')
1708 i_port[strlen(i_port) - 1] = '\0';
1709
1710 ret = scsiback_make_nexus(tpg, port_ptr);
1711 if (ret < 0)
1712 return ret;
1713
1714 return count;
1715}
1716
1717CONFIGFS_ATTR(scsiback_tpg_, nexus);
1718
1719static struct configfs_attribute *scsiback_tpg_attrs[] = {
1720 &scsiback_tpg_attr_nexus,
1721 NULL,
1722};
1723
1724static ssize_t
1725scsiback_wwn_version_show(struct config_item *item, char *page)
1726{
1727 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1728 UTS_RELEASE"\n",
1729 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1730}
1731
1732CONFIGFS_ATTR_RO(scsiback_wwn_, version);
1733
1734static struct configfs_attribute *scsiback_wwn_attrs[] = {
1735 &scsiback_wwn_attr_version,
1736 NULL,
1737};
1738
1739static int scsiback_port_link(struct se_portal_group *se_tpg,
1740 struct se_lun *lun)
1741{
1742 struct scsiback_tpg *tpg = container_of(se_tpg,
1743 struct scsiback_tpg, se_tpg);
1744
1745 mutex_lock(&tpg->tv_tpg_mutex);
1746 tpg->tv_tpg_port_count++;
1747 mutex_unlock(&tpg->tv_tpg_mutex);
1748
1749 return 0;
1750}
1751
1752static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1753 struct se_lun *lun)
1754{
1755 struct scsiback_tpg *tpg = container_of(se_tpg,
1756 struct scsiback_tpg, se_tpg);
1757
1758 mutex_lock(&tpg->tv_tpg_mutex);
1759 tpg->tv_tpg_port_count--;
1760 mutex_unlock(&tpg->tv_tpg_mutex);
1761}
1762
1763static struct se_portal_group *
1764scsiback_make_tpg(struct se_wwn *wwn, const char *name)
1765{
1766 struct scsiback_tport *tport = container_of(wwn,
1767 struct scsiback_tport, tport_wwn);
1768
1769 struct scsiback_tpg *tpg;
1770 u16 tpgt;
1771 int ret;
1772
1773 if (strstr(name, "tpgt_") != name)
1774 return ERR_PTR(-EINVAL);
1775 ret = kstrtou16(name + 5, 10, &tpgt);
1776 if (ret)
1777 return ERR_PTR(ret);
1778
1779 tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
1780 if (!tpg)
1781 return ERR_PTR(-ENOMEM);
1782
1783 mutex_init(&tpg->tv_tpg_mutex);
1784 INIT_LIST_HEAD(&tpg->tv_tpg_list);
1785 INIT_LIST_HEAD(&tpg->info_list);
1786 tpg->tport = tport;
1787 tpg->tport_tpgt = tpgt;
1788
1789 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
1790 if (ret < 0) {
1791 kfree(tpg);
1792 return NULL;
1793 }
1794 mutex_lock(&scsiback_mutex);
1795 list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1796 mutex_unlock(&scsiback_mutex);
1797
1798 return &tpg->se_tpg;
1799}
1800
1801static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1802{
1803 struct scsiback_tpg *tpg = container_of(se_tpg,
1804 struct scsiback_tpg, se_tpg);
1805
1806 mutex_lock(&scsiback_mutex);
1807 list_del(&tpg->tv_tpg_list);
1808 mutex_unlock(&scsiback_mutex);
1809 /*
1810 * Release the virtual I_T Nexus for this xen-pvscsi TPG
1811 */
1812 scsiback_drop_nexus(tpg);
1813 /*
1814 * Deregister the se_tpg from TCM.
1815 */
1816 core_tpg_deregister(se_tpg);
1817 kfree(tpg);
1818}
1819
1820static int scsiback_check_true(struct se_portal_group *se_tpg)
1821{
1822 return 1;
1823}
1824
1825static int scsiback_check_false(struct se_portal_group *se_tpg)
1826{
1827 return 0;
1828}
1829
1830static const struct target_core_fabric_ops scsiback_ops = {
1831 .module = THIS_MODULE,
1832 .fabric_name = "xen-pvscsi",
1833 .tpg_get_wwn = scsiback_get_fabric_wwn,
1834 .tpg_get_tag = scsiback_get_tag,
1835 .tpg_check_demo_mode = scsiback_check_true,
1836 .tpg_check_demo_mode_cache = scsiback_check_true,
1837 .tpg_check_demo_mode_write_protect = scsiback_check_false,
1838 .tpg_check_prod_mode_write_protect = scsiback_check_false,
1839 .tpg_get_inst_index = scsiback_tpg_get_inst_index,
1840 .check_stop_free = scsiback_check_stop_free,
1841 .release_cmd = scsiback_release_cmd,
1842 .sess_get_index = scsiback_sess_get_index,
1843 .sess_get_initiator_sid = NULL,
1844 .write_pending = scsiback_write_pending,
1845 .set_default_node_attributes = scsiback_set_default_node_attrs,
1846 .get_cmd_state = scsiback_get_cmd_state,
1847 .queue_data_in = scsiback_queue_data_in,
1848 .queue_status = scsiback_queue_status,
1849 .queue_tm_rsp = scsiback_queue_tm_rsp,
1850 .aborted_task = scsiback_aborted_task,
1851 /*
1852 * Setup callers for generic logic in target_core_fabric_configfs.c
1853 */
1854 .fabric_make_wwn = scsiback_make_tport,
1855 .fabric_drop_wwn = scsiback_drop_tport,
1856 .fabric_make_tpg = scsiback_make_tpg,
1857 .fabric_drop_tpg = scsiback_drop_tpg,
1858 .fabric_post_link = scsiback_port_link,
1859 .fabric_pre_unlink = scsiback_port_unlink,
1860
1861 .tfc_wwn_attrs = scsiback_wwn_attrs,
1862 .tfc_tpg_base_attrs = scsiback_tpg_attrs,
1863 .tfc_tpg_param_attrs = scsiback_param_attrs,
1864};
1865
1866static const struct xenbus_device_id scsiback_ids[] = {
1867 { "vscsi" },
1868 { "" }
1869};
1870
1871static struct xenbus_driver scsiback_driver = {
1872 .ids = scsiback_ids,
1873 .probe = scsiback_probe,
1874 .remove = scsiback_remove,
1875 .otherend_changed = scsiback_frontend_changed
1876};
1877
1878static int __init scsiback_init(void)
1879{
1880 int ret;
1881
1882 if (!xen_domain())
1883 return -ENODEV;
1884
1885 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
1886 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1887
1888 ret = xenbus_register_backend(&scsiback_driver);
1889 if (ret)
1890 goto out;
1891
1892 ret = target_register_template(&scsiback_ops);
1893 if (ret)
1894 goto out_unregister_xenbus;
1895
1896 return 0;
1897
1898out_unregister_xenbus:
1899 xenbus_unregister_driver(&scsiback_driver);
1900out:
1901 pr_err("%s: error %d\n", __func__, ret);
1902 return ret;
1903}
1904
1905static void __exit scsiback_exit(void)
1906{
1907 target_unregister_template(&scsiback_ops);
1908 xenbus_unregister_driver(&scsiback_driver);
1909}
1910
1911module_init(scsiback_init);
1912module_exit(scsiback_exit);
1913
1914MODULE_DESCRIPTION("Xen SCSI backend driver");
1915MODULE_LICENSE("Dual BSD/GPL");
1916MODULE_ALIAS("xen-backend:vscsi");
1917MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");
1/*
2 * Xen SCSI backend driver
3 *
4 * Copyright (c) 2008, FUJITSU Limited
5 *
6 * Based on the blkback driver code.
7 * Adaption to kernel taget core infrastructure taken from vhost/scsi.c
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation; or, when distributed
12 * separately from the Linux kernel or incorporated into other
13 * software packages, subject to the following license:
14 *
15 * Permission is hereby granted, free of charge, to any person obtaining a copy
16 * of this source file (the "Software"), to deal in the Software without
17 * restriction, including without limitation the rights to use, copy, modify,
18 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
19 * and to permit persons to whom the Software is furnished to do so, subject to
20 * the following conditions:
21 *
22 * The above copyright notice and this permission notice shall be included in
23 * all copies or substantial portions of the Software.
24 *
25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
28 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
29 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
30 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
31 * IN THE SOFTWARE.
32 */
33
34#define pr_fmt(fmt) "xen-pvscsi: " fmt
35
36#include <stdarg.h>
37
38#include <linux/module.h>
39#include <linux/utsname.h>
40#include <linux/interrupt.h>
41#include <linux/slab.h>
42#include <linux/wait.h>
43#include <linux/sched.h>
44#include <linux/list.h>
45#include <linux/gfp.h>
46#include <linux/delay.h>
47#include <linux/spinlock.h>
48#include <linux/configfs.h>
49
50#include <generated/utsrelease.h>
51
52#include <scsi/scsi_host.h> /* SG_ALL */
53
54#include <target/target_core_base.h>
55#include <target/target_core_fabric.h>
56
57#include <asm/hypervisor.h>
58
59#include <xen/xen.h>
60#include <xen/balloon.h>
61#include <xen/events.h>
62#include <xen/xenbus.h>
63#include <xen/grant_table.h>
64#include <xen/page.h>
65
66#include <xen/interface/grant_table.h>
67#include <xen/interface/io/vscsiif.h>
68
69#define VSCSI_VERSION "v0.1"
70#define VSCSI_NAMELEN 32
71
72struct ids_tuple {
73 unsigned int hst; /* host */
74 unsigned int chn; /* channel */
75 unsigned int tgt; /* target */
76 unsigned int lun; /* LUN */
77};
78
79struct v2p_entry {
80 struct ids_tuple v; /* translate from */
81 struct scsiback_tpg *tpg; /* translate to */
82 unsigned int lun;
83 struct kref kref;
84 struct list_head l;
85};
86
87struct vscsibk_info {
88 struct xenbus_device *dev;
89
90 domid_t domid;
91 unsigned int irq;
92
93 struct vscsiif_back_ring ring;
94
95 spinlock_t ring_lock;
96 atomic_t nr_unreplied_reqs;
97
98 spinlock_t v2p_lock;
99 struct list_head v2p_entry_lists;
100
101 wait_queue_head_t waiting_to_free;
102
103 struct gnttab_page_cache free_pages;
104};
105
106/* theoretical maximum of grants for one request */
107#define VSCSI_MAX_GRANTS (SG_ALL + VSCSIIF_SG_TABLESIZE)
108
109/*
110 * VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one
111 * call to map/unmap grants. Don't choose it too large, as there are arrays
112 * with VSCSI_GRANT_BATCH elements allocated on the stack.
113 */
114#define VSCSI_GRANT_BATCH 16
115
116struct vscsibk_pend {
117 uint16_t rqid;
118
119 uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE];
120 uint8_t cmd_len;
121
122 uint8_t sc_data_direction;
123 uint16_t n_sg; /* real length of SG list */
124 uint16_t n_grants; /* SG pages and potentially SG list */
125 uint32_t data_len;
126 uint32_t result;
127
128 struct vscsibk_info *info;
129 struct v2p_entry *v2p;
130 struct scatterlist *sgl;
131
132 uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE];
133
134 grant_handle_t grant_handles[VSCSI_MAX_GRANTS];
135 struct page *pages[VSCSI_MAX_GRANTS];
136
137 struct se_cmd se_cmd;
138
139 struct completion tmr_done;
140};
141
142#define VSCSI_DEFAULT_SESSION_TAGS 128
143
144struct scsiback_nexus {
145 /* Pointer to TCM session for I_T Nexus */
146 struct se_session *tvn_se_sess;
147};
148
149struct scsiback_tport {
150 /* SCSI protocol the tport is providing */
151 u8 tport_proto_id;
152 /* Binary World Wide unique Port Name for pvscsi Target port */
153 u64 tport_wwpn;
154 /* ASCII formatted WWPN for pvscsi Target port */
155 char tport_name[VSCSI_NAMELEN];
156 /* Returned by scsiback_make_tport() */
157 struct se_wwn tport_wwn;
158};
159
160struct scsiback_tpg {
161 /* scsiback port target portal group tag for TCM */
162 u16 tport_tpgt;
163 /* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */
164 int tv_tpg_port_count;
165 /* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */
166 int tv_tpg_fe_count;
167 /* list for scsiback_list */
168 struct list_head tv_tpg_list;
169 /* Used to protect access for tpg_nexus */
170 struct mutex tv_tpg_mutex;
171 /* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */
172 struct scsiback_nexus *tpg_nexus;
173 /* Pointer back to scsiback_tport */
174 struct scsiback_tport *tport;
175 /* Returned by scsiback_make_tpg() */
176 struct se_portal_group se_tpg;
177 /* alias used in xenstore */
178 char param_alias[VSCSI_NAMELEN];
179 /* list of info structures related to this target portal group */
180 struct list_head info_list;
181};
182
183#define SCSIBACK_INVALID_HANDLE (~0)
184
185static bool log_print_stat;
186module_param(log_print_stat, bool, 0644);
187
188static int scsiback_max_buffer_pages = 1024;
189module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644);
190MODULE_PARM_DESC(max_buffer_pages,
191"Maximum number of free pages to keep in backend buffer");
192
193/* Global spinlock to protect scsiback TPG list */
194static DEFINE_MUTEX(scsiback_mutex);
195static LIST_HEAD(scsiback_list);
196
197static void scsiback_get(struct vscsibk_info *info)
198{
199 atomic_inc(&info->nr_unreplied_reqs);
200}
201
202static void scsiback_put(struct vscsibk_info *info)
203{
204 if (atomic_dec_and_test(&info->nr_unreplied_reqs))
205 wake_up(&info->waiting_to_free);
206}
207
208static unsigned long vaddr_page(struct page *page)
209{
210 unsigned long pfn = page_to_pfn(page);
211
212 return (unsigned long)pfn_to_kaddr(pfn);
213}
214
215static unsigned long vaddr(struct vscsibk_pend *req, int seg)
216{
217 return vaddr_page(req->pages[seg]);
218}
219
220static void scsiback_print_status(char *sense_buffer, int errors,
221 struct vscsibk_pend *pending_req)
222{
223 struct scsiback_tpg *tpg = pending_req->v2p->tpg;
224
225 pr_err("[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x\n",
226 tpg->tport->tport_name, pending_req->v2p->lun,
227 pending_req->cmnd[0], errors & 0xff, COMMAND_COMPLETE,
228 host_byte(errors));
229}
230
231static void scsiback_fast_flush_area(struct vscsibk_pend *req)
232{
233 struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH];
234 struct page *pages[VSCSI_GRANT_BATCH];
235 unsigned int i, invcount = 0;
236 grant_handle_t handle;
237 int err;
238
239 kfree(req->sgl);
240 req->sgl = NULL;
241 req->n_sg = 0;
242
243 if (!req->n_grants)
244 return;
245
246 for (i = 0; i < req->n_grants; i++) {
247 handle = req->grant_handles[i];
248 if (handle == SCSIBACK_INVALID_HANDLE)
249 continue;
250 gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
251 GNTMAP_host_map, handle);
252 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
253 pages[invcount] = req->pages[i];
254 put_page(pages[invcount]);
255 invcount++;
256 if (invcount < VSCSI_GRANT_BATCH)
257 continue;
258 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
259 BUG_ON(err);
260 invcount = 0;
261 }
262
263 if (invcount) {
264 err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
265 BUG_ON(err);
266 }
267
268 gnttab_page_cache_put(&req->info->free_pages, req->pages,
269 req->n_grants);
270 req->n_grants = 0;
271}
272
273static void scsiback_free_translation_entry(struct kref *kref)
274{
275 struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref);
276 struct scsiback_tpg *tpg = entry->tpg;
277
278 mutex_lock(&tpg->tv_tpg_mutex);
279 tpg->tv_tpg_fe_count--;
280 mutex_unlock(&tpg->tv_tpg_mutex);
281
282 kfree(entry);
283}
284
285static void scsiback_send_response(struct vscsibk_info *info,
286 char *sense_buffer, int32_t result, uint32_t resid,
287 uint16_t rqid)
288{
289 struct vscsiif_response *ring_res;
290 int notify;
291 struct scsi_sense_hdr sshdr;
292 unsigned long flags;
293 unsigned len;
294
295 spin_lock_irqsave(&info->ring_lock, flags);
296
297 ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt);
298 info->ring.rsp_prod_pvt++;
299
300 ring_res->rslt = result;
301 ring_res->rqid = rqid;
302
303 if (sense_buffer != NULL &&
304 scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
305 &sshdr)) {
306 len = min_t(unsigned, 8 + sense_buffer[7],
307 VSCSIIF_SENSE_BUFFERSIZE);
308 memcpy(ring_res->sense_buffer, sense_buffer, len);
309 ring_res->sense_len = len;
310 } else {
311 ring_res->sense_len = 0;
312 }
313
314 ring_res->residual_len = resid;
315
316 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify);
317 spin_unlock_irqrestore(&info->ring_lock, flags);
318
319 if (notify)
320 notify_remote_via_irq(info->irq);
321}
322
323static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
324 uint32_t resid, struct vscsibk_pend *pending_req)
325{
326 scsiback_send_response(pending_req->info, sense_buffer, result,
327 resid, pending_req->rqid);
328
329 if (pending_req->v2p)
330 kref_put(&pending_req->v2p->kref,
331 scsiback_free_translation_entry);
332}
333
334static void scsiback_cmd_done(struct vscsibk_pend *pending_req)
335{
336 struct vscsibk_info *info = pending_req->info;
337 unsigned char *sense_buffer;
338 unsigned int resid;
339 int errors;
340
341 sense_buffer = pending_req->sense_buffer;
342 resid = pending_req->se_cmd.residual_count;
343 errors = pending_req->result;
344
345 if (errors && log_print_stat)
346 scsiback_print_status(sense_buffer, errors, pending_req);
347
348 scsiback_fast_flush_area(pending_req);
349 scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
350 scsiback_put(info);
351 /*
352 * Drop the extra KREF_ACK reference taken by target_submit_cmd_map_sgls()
353 * ahead of scsiback_check_stop_free() -> transport_generic_free_cmd()
354 * final se_cmd->cmd_kref put.
355 */
356 target_put_sess_cmd(&pending_req->se_cmd);
357}
358
359static void scsiback_cmd_exec(struct vscsibk_pend *pending_req)
360{
361 struct se_cmd *se_cmd = &pending_req->se_cmd;
362 struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess;
363
364 scsiback_get(pending_req->info);
365 se_cmd->tag = pending_req->rqid;
366 target_init_cmd(se_cmd, sess, pending_req->sense_buffer,
367 pending_req->v2p->lun, pending_req->data_len, 0,
368 pending_req->sc_data_direction, TARGET_SCF_ACK_KREF);
369
370 if (target_submit_prep(se_cmd, pending_req->cmnd, pending_req->sgl,
371 pending_req->n_sg, NULL, 0, NULL, 0, GFP_KERNEL))
372 return;
373
374 target_submit(se_cmd);
375}
376
377static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
378 struct page **pg, grant_handle_t *grant, int cnt)
379{
380 int err, i;
381
382 if (!cnt)
383 return 0;
384
385 err = gnttab_map_refs(map, NULL, pg, cnt);
386 for (i = 0; i < cnt; i++) {
387 if (unlikely(map[i].status != GNTST_okay)) {
388 pr_err("invalid buffer -- could not remap it\n");
389 map[i].handle = SCSIBACK_INVALID_HANDLE;
390 if (!err)
391 err = -ENOMEM;
392 } else {
393 get_page(pg[i]);
394 }
395 grant[i] = map[i].handle;
396 }
397 return err;
398}
399
400static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req,
401 struct scsiif_request_segment *seg, struct page **pg,
402 grant_handle_t *grant, int cnt, u32 flags)
403{
404 int mapcount = 0, i, err = 0;
405 struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH];
406 struct vscsibk_info *info = pending_req->info;
407
408 for (i = 0; i < cnt; i++) {
409 if (gnttab_page_cache_get(&info->free_pages, pg + mapcount)) {
410 gnttab_page_cache_put(&info->free_pages, pg, mapcount);
411 pr_err("no grant page\n");
412 return -ENOMEM;
413 }
414 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]),
415 flags, seg[i].gref, info->domid);
416 mapcount++;
417 if (mapcount < VSCSI_GRANT_BATCH)
418 continue;
419 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
420 pg += mapcount;
421 grant += mapcount;
422 pending_req->n_grants += mapcount;
423 if (err)
424 return err;
425 mapcount = 0;
426 }
427 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
428 pending_req->n_grants += mapcount;
429 return err;
430}
431
432static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req,
433 struct vscsibk_pend *pending_req)
434{
435 u32 flags;
436 int i, err, n_segs, i_seg = 0;
437 struct page **pg;
438 struct scsiif_request_segment *seg;
439 unsigned long end_seg = 0;
440 unsigned int nr_segments = (unsigned int)ring_req->nr_segments;
441 unsigned int nr_sgl = 0;
442 struct scatterlist *sg;
443 grant_handle_t *grant;
444
445 pending_req->n_sg = 0;
446 pending_req->n_grants = 0;
447 pending_req->data_len = 0;
448
449 nr_segments &= ~VSCSIIF_SG_GRANT;
450 if (!nr_segments)
451 return 0;
452
453 if (nr_segments > VSCSIIF_SG_TABLESIZE) {
454 pr_debug("invalid parameter nr_seg = %d\n",
455 ring_req->nr_segments);
456 return -EINVAL;
457 }
458
459 if (ring_req->nr_segments & VSCSIIF_SG_GRANT) {
460 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg,
461 pending_req->pages, pending_req->grant_handles,
462 nr_segments, GNTMAP_host_map | GNTMAP_readonly);
463 if (err)
464 return err;
465 nr_sgl = nr_segments;
466 nr_segments = 0;
467 for (i = 0; i < nr_sgl; i++) {
468 n_segs = ring_req->seg[i].length /
469 sizeof(struct scsiif_request_segment);
470 if ((unsigned)ring_req->seg[i].offset +
471 (unsigned)ring_req->seg[i].length > PAGE_SIZE ||
472 n_segs * sizeof(struct scsiif_request_segment) !=
473 ring_req->seg[i].length)
474 return -EINVAL;
475 nr_segments += n_segs;
476 }
477 if (nr_segments > SG_ALL) {
478 pr_debug("invalid nr_seg = %d\n", nr_segments);
479 return -EINVAL;
480 }
481 }
482
483 /* free of (sgl) in fast_flush_area() */
484 pending_req->sgl = kmalloc_array(nr_segments,
485 sizeof(struct scatterlist), GFP_KERNEL);
486 if (!pending_req->sgl)
487 return -ENOMEM;
488
489 sg_init_table(pending_req->sgl, nr_segments);
490 pending_req->n_sg = nr_segments;
491
492 flags = GNTMAP_host_map;
493 if (pending_req->sc_data_direction == DMA_TO_DEVICE)
494 flags |= GNTMAP_readonly;
495
496 pg = pending_req->pages + nr_sgl;
497 grant = pending_req->grant_handles + nr_sgl;
498 if (!nr_sgl) {
499 seg = ring_req->seg;
500 err = scsiback_gnttab_data_map_list(pending_req, seg,
501 pg, grant, nr_segments, flags);
502 if (err)
503 return err;
504 } else {
505 for (i = 0; i < nr_sgl; i++) {
506 seg = (struct scsiif_request_segment *)(
507 vaddr(pending_req, i) + ring_req->seg[i].offset);
508 n_segs = ring_req->seg[i].length /
509 sizeof(struct scsiif_request_segment);
510 err = scsiback_gnttab_data_map_list(pending_req, seg,
511 pg, grant, n_segs, flags);
512 if (err)
513 return err;
514 pg += n_segs;
515 grant += n_segs;
516 }
517 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
518 seg = (struct scsiif_request_segment *)end_seg;
519 end_seg += ring_req->seg[0].length;
520 pg = pending_req->pages + nr_sgl;
521 }
522
523 for_each_sg(pending_req->sgl, sg, nr_segments, i) {
524 sg_set_page(sg, pg[i], seg->length, seg->offset);
525 pending_req->data_len += seg->length;
526 seg++;
527 if (nr_sgl && (unsigned long)seg >= end_seg) {
528 i_seg++;
529 end_seg = vaddr(pending_req, i_seg) +
530 ring_req->seg[i_seg].offset;
531 seg = (struct scsiif_request_segment *)end_seg;
532 end_seg += ring_req->seg[i_seg].length;
533 }
534 if (sg->offset >= PAGE_SIZE ||
535 sg->length > PAGE_SIZE ||
536 sg->offset + sg->length > PAGE_SIZE)
537 return -EINVAL;
538 }
539
540 return 0;
541}
542
543static void scsiback_disconnect(struct vscsibk_info *info)
544{
545 wait_event(info->waiting_to_free,
546 atomic_read(&info->nr_unreplied_reqs) == 0);
547
548 unbind_from_irqhandler(info->irq, info);
549 info->irq = 0;
550 xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
551}
552
553static void scsiback_device_action(struct vscsibk_pend *pending_req,
554 enum tcm_tmreq_table act, int tag)
555{
556 struct scsiback_tpg *tpg = pending_req->v2p->tpg;
557 struct scsiback_nexus *nexus = tpg->tpg_nexus;
558 struct se_cmd *se_cmd = &pending_req->se_cmd;
559 u64 unpacked_lun = pending_req->v2p->lun;
560 int rc, err = FAILED;
561
562 init_completion(&pending_req->tmr_done);
563
564 rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess,
565 &pending_req->sense_buffer[0],
566 unpacked_lun, NULL, act, GFP_KERNEL,
567 tag, TARGET_SCF_ACK_KREF);
568 if (rc)
569 goto err;
570
571 wait_for_completion(&pending_req->tmr_done);
572
573 err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
574 SUCCESS : FAILED;
575
576 scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
577 transport_generic_free_cmd(&pending_req->se_cmd, 0);
578 return;
579
580err:
581 scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
582}
583
584/*
585 Perform virtual to physical translation
586*/
587static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
588 struct ids_tuple *v)
589{
590 struct v2p_entry *entry;
591 struct list_head *head = &(info->v2p_entry_lists);
592 unsigned long flags;
593
594 spin_lock_irqsave(&info->v2p_lock, flags);
595 list_for_each_entry(entry, head, l) {
596 if ((entry->v.chn == v->chn) &&
597 (entry->v.tgt == v->tgt) &&
598 (entry->v.lun == v->lun)) {
599 kref_get(&entry->kref);
600 goto out;
601 }
602 }
603 entry = NULL;
604
605out:
606 spin_unlock_irqrestore(&info->v2p_lock, flags);
607 return entry;
608}
609
610static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring,
611 struct v2p_entry *v2p)
612{
613 struct scsiback_tpg *tpg = v2p->tpg;
614 struct scsiback_nexus *nexus = tpg->tpg_nexus;
615 struct se_session *se_sess = nexus->tvn_se_sess;
616 struct vscsibk_pend *req;
617 int tag, cpu, i;
618
619 tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
620 if (tag < 0) {
621 pr_err("Unable to obtain tag for vscsiif_request\n");
622 return ERR_PTR(-ENOMEM);
623 }
624
625 req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag];
626 memset(req, 0, sizeof(*req));
627 req->se_cmd.map_tag = tag;
628 req->se_cmd.map_cpu = cpu;
629
630 for (i = 0; i < VSCSI_MAX_GRANTS; i++)
631 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
632
633 return req;
634}
635
636static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info,
637 struct vscsiif_back_ring *ring,
638 struct vscsiif_request *ring_req)
639{
640 struct vscsibk_pend *pending_req;
641 struct v2p_entry *v2p;
642 struct ids_tuple vir;
643
644 /* request range check from frontend */
645 if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
646 (ring_req->sc_data_direction != DMA_TO_DEVICE) &&
647 (ring_req->sc_data_direction != DMA_FROM_DEVICE) &&
648 (ring_req->sc_data_direction != DMA_NONE)) {
649 pr_debug("invalid parameter data_dir = %d\n",
650 ring_req->sc_data_direction);
651 return ERR_PTR(-EINVAL);
652 }
653 if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
654 pr_debug("invalid parameter cmd_len = %d\n",
655 ring_req->cmd_len);
656 return ERR_PTR(-EINVAL);
657 }
658
659 vir.chn = ring_req->channel;
660 vir.tgt = ring_req->id;
661 vir.lun = ring_req->lun;
662
663 v2p = scsiback_do_translation(info, &vir);
664 if (!v2p) {
665 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n",
666 vir.chn, vir.tgt, vir.lun);
667 return ERR_PTR(-ENODEV);
668 }
669
670 pending_req = scsiback_get_pend_req(ring, v2p);
671 if (IS_ERR(pending_req)) {
672 kref_put(&v2p->kref, scsiback_free_translation_entry);
673 return ERR_PTR(-ENOMEM);
674 }
675 pending_req->rqid = ring_req->rqid;
676 pending_req->info = info;
677 pending_req->v2p = v2p;
678 pending_req->sc_data_direction = ring_req->sc_data_direction;
679 pending_req->cmd_len = ring_req->cmd_len;
680 memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
681
682 return pending_req;
683}
684
685static int scsiback_do_cmd_fn(struct vscsibk_info *info,
686 unsigned int *eoi_flags)
687{
688 struct vscsiif_back_ring *ring = &info->ring;
689 struct vscsiif_request ring_req;
690 struct vscsibk_pend *pending_req;
691 RING_IDX rc, rp;
692 int more_to_do;
693 uint32_t result;
694
695 rc = ring->req_cons;
696 rp = ring->sring->req_prod;
697 rmb(); /* guest system is accessing ring, too */
698
699 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
700 rc = ring->rsp_prod_pvt;
701 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
702 info->domid, rp, rc, rp - rc);
703 return -EINVAL;
704 }
705
706 while ((rc != rp)) {
707 *eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS;
708
709 if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
710 break;
711
712 RING_COPY_REQUEST(ring, rc, &ring_req);
713 ring->req_cons = ++rc;
714
715 pending_req = prepare_pending_reqs(info, ring, &ring_req);
716 if (IS_ERR(pending_req)) {
717 switch (PTR_ERR(pending_req)) {
718 case -ENODEV:
719 result = DID_NO_CONNECT;
720 break;
721 default:
722 result = DID_ERROR;
723 break;
724 }
725 scsiback_send_response(info, NULL, result << 16, 0,
726 ring_req.rqid);
727 return 1;
728 }
729
730 switch (ring_req.act) {
731 case VSCSIIF_ACT_SCSI_CDB:
732 if (scsiback_gnttab_data_map(&ring_req, pending_req)) {
733 scsiback_fast_flush_area(pending_req);
734 scsiback_do_resp_with_sense(NULL,
735 DID_ERROR << 16, 0, pending_req);
736 transport_generic_free_cmd(&pending_req->se_cmd, 0);
737 } else {
738 scsiback_cmd_exec(pending_req);
739 }
740 break;
741 case VSCSIIF_ACT_SCSI_ABORT:
742 scsiback_device_action(pending_req, TMR_ABORT_TASK,
743 ring_req.ref_rqid);
744 break;
745 case VSCSIIF_ACT_SCSI_RESET:
746 scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
747 break;
748 default:
749 pr_err_ratelimited("invalid request\n");
750 scsiback_do_resp_with_sense(NULL, DID_ERROR << 16, 0,
751 pending_req);
752 transport_generic_free_cmd(&pending_req->se_cmd, 0);
753 break;
754 }
755
756 /* Yield point for this unbounded loop. */
757 cond_resched();
758 }
759
760 gnttab_page_cache_shrink(&info->free_pages, scsiback_max_buffer_pages);
761
762 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
763 return more_to_do;
764}
765
766static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
767{
768 struct vscsibk_info *info = dev_id;
769 int rc;
770 unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
771
772 while ((rc = scsiback_do_cmd_fn(info, &eoi_flags)) > 0)
773 cond_resched();
774
775 /* In case of a ring error we keep the event channel masked. */
776 if (!rc)
777 xen_irq_lateeoi(irq, eoi_flags);
778
779 return IRQ_HANDLED;
780}
781
782static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
783 evtchn_port_t evtchn)
784{
785 void *area;
786 struct vscsiif_sring *sring;
787 int err;
788
789 if (info->irq)
790 return -1;
791
792 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area);
793 if (err)
794 return err;
795
796 sring = (struct vscsiif_sring *)area;
797 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
798
799 err = bind_interdomain_evtchn_to_irq_lateeoi(info->dev, evtchn);
800 if (err < 0)
801 goto unmap_page;
802
803 info->irq = err;
804
805 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
806 IRQF_ONESHOT, "vscsiif-backend", info);
807 if (err)
808 goto free_irq;
809
810 return 0;
811
812free_irq:
813 unbind_from_irqhandler(info->irq, info);
814 info->irq = 0;
815unmap_page:
816 xenbus_unmap_ring_vfree(info->dev, area);
817
818 return err;
819}
820
821static int scsiback_map(struct vscsibk_info *info)
822{
823 struct xenbus_device *dev = info->dev;
824 unsigned int ring_ref;
825 evtchn_port_t evtchn;
826 int err;
827
828 err = xenbus_gather(XBT_NIL, dev->otherend,
829 "ring-ref", "%u", &ring_ref,
830 "event-channel", "%u", &evtchn, NULL);
831 if (err) {
832 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
833 return err;
834 }
835
836 return scsiback_init_sring(info, ring_ref, evtchn);
837}
838
839/*
840 Check for a translation entry being present
841*/
842static struct v2p_entry *scsiback_chk_translation_entry(
843 struct vscsibk_info *info, struct ids_tuple *v)
844{
845 struct list_head *head = &(info->v2p_entry_lists);
846 struct v2p_entry *entry;
847
848 list_for_each_entry(entry, head, l)
849 if ((entry->v.chn == v->chn) &&
850 (entry->v.tgt == v->tgt) &&
851 (entry->v.lun == v->lun))
852 return entry;
853
854 return NULL;
855}
856
857/*
858 Add a new translation entry
859*/
860static int scsiback_add_translation_entry(struct vscsibk_info *info,
861 char *phy, struct ids_tuple *v)
862{
863 int err = 0;
864 struct v2p_entry *new;
865 unsigned long flags;
866 char *lunp;
867 unsigned long long unpacked_lun;
868 struct se_lun *se_lun;
869 struct scsiback_tpg *tpg_entry, *tpg = NULL;
870 char *error = "doesn't exist";
871
872 lunp = strrchr(phy, ':');
873 if (!lunp) {
874 pr_err("illegal format of physical device %s\n", phy);
875 return -EINVAL;
876 }
877 *lunp = 0;
878 lunp++;
879 err = kstrtoull(lunp, 10, &unpacked_lun);
880 if (err < 0) {
881 pr_err("lun number not valid: %s\n", lunp);
882 return err;
883 }
884
885 mutex_lock(&scsiback_mutex);
886 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
887 if (!strcmp(phy, tpg_entry->tport->tport_name) ||
888 !strcmp(phy, tpg_entry->param_alias)) {
889 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex);
890 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) {
891 if (se_lun->unpacked_lun == unpacked_lun) {
892 if (!tpg_entry->tpg_nexus)
893 error = "nexus undefined";
894 else
895 tpg = tpg_entry;
896 break;
897 }
898 }
899 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex);
900 break;
901 }
902 }
903 if (tpg) {
904 mutex_lock(&tpg->tv_tpg_mutex);
905 tpg->tv_tpg_fe_count++;
906 mutex_unlock(&tpg->tv_tpg_mutex);
907 }
908 mutex_unlock(&scsiback_mutex);
909
910 if (!tpg) {
911 pr_err("%s:%llu %s\n", phy, unpacked_lun, error);
912 return -ENODEV;
913 }
914
915 new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
916 if (new == NULL) {
917 err = -ENOMEM;
918 goto out_free;
919 }
920
921 spin_lock_irqsave(&info->v2p_lock, flags);
922
923 /* Check double assignment to identical virtual ID */
924 if (scsiback_chk_translation_entry(info, v)) {
925 pr_warn("Virtual ID is already used. Assignment was not performed.\n");
926 err = -EEXIST;
927 goto out;
928 }
929
930 /* Create a new translation entry and add to the list */
931 kref_init(&new->kref);
932 new->v = *v;
933 new->tpg = tpg;
934 new->lun = unpacked_lun;
935 list_add_tail(&new->l, &info->v2p_entry_lists);
936
937out:
938 spin_unlock_irqrestore(&info->v2p_lock, flags);
939
940out_free:
941 if (err) {
942 mutex_lock(&tpg->tv_tpg_mutex);
943 tpg->tv_tpg_fe_count--;
944 mutex_unlock(&tpg->tv_tpg_mutex);
945 kfree(new);
946 }
947
948 return err;
949}
950
951static void __scsiback_del_translation_entry(struct v2p_entry *entry)
952{
953 list_del(&entry->l);
954 kref_put(&entry->kref, scsiback_free_translation_entry);
955}
956
957/*
958 Delete the translation entry specified
959*/
960static int scsiback_del_translation_entry(struct vscsibk_info *info,
961 struct ids_tuple *v)
962{
963 struct v2p_entry *entry;
964 unsigned long flags;
965 int ret = 0;
966
967 spin_lock_irqsave(&info->v2p_lock, flags);
968 /* Find out the translation entry specified */
969 entry = scsiback_chk_translation_entry(info, v);
970 if (entry)
971 __scsiback_del_translation_entry(entry);
972 else
973 ret = -ENOENT;
974
975 spin_unlock_irqrestore(&info->v2p_lock, flags);
976 return ret;
977}
978
979static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
980 char *phy, struct ids_tuple *vir, int try)
981{
982 struct v2p_entry *entry;
983 unsigned long flags;
984 int err;
985
986 if (try) {
987 spin_lock_irqsave(&info->v2p_lock, flags);
988 entry = scsiback_chk_translation_entry(info, vir);
989 spin_unlock_irqrestore(&info->v2p_lock, flags);
990 if (entry)
991 return;
992 }
993 if (!scsiback_add_translation_entry(info, phy, vir)) {
994 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
995 "%d", XenbusStateInitialised)) {
996 pr_err("xenbus_printf error %s\n", state);
997 scsiback_del_translation_entry(info, vir);
998 }
999 } else if (!try) {
1000 err = xenbus_printf(XBT_NIL, info->dev->nodename, state,
1001 "%d", XenbusStateClosed);
1002 if (err)
1003 xenbus_dev_error(info->dev, err,
1004 "%s: writing %s", __func__, state);
1005 }
1006}
1007
1008static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
1009 struct ids_tuple *vir)
1010{
1011 if (!scsiback_del_translation_entry(info, vir)) {
1012 if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
1013 "%d", XenbusStateClosed))
1014 pr_err("xenbus_printf error %s\n", state);
1015 }
1016}
1017
1018#define VSCSIBACK_OP_ADD_OR_DEL_LUN 1
1019#define VSCSIBACK_OP_UPDATEDEV_STATE 2
1020
1021static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
1022 char *ent)
1023{
1024 int err;
1025 struct ids_tuple vir;
1026 char *val;
1027 int device_state;
1028 char phy[VSCSI_NAMELEN];
1029 char str[64];
1030 char state[64];
1031 struct xenbus_device *dev = info->dev;
1032
1033 /* read status */
1034 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
1035 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
1036 if (XENBUS_EXIST_ERR(err))
1037 return;
1038
1039 /* physical SCSI device */
1040 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
1041 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
1042 if (IS_ERR(val)) {
1043 err = xenbus_printf(XBT_NIL, dev->nodename, state,
1044 "%d", XenbusStateClosed);
1045 if (err)
1046 xenbus_dev_error(info->dev, err,
1047 "%s: writing %s", __func__, state);
1048 return;
1049 }
1050 strlcpy(phy, val, VSCSI_NAMELEN);
1051 kfree(val);
1052
1053 /* virtual SCSI device */
1054 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
1055 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
1056 &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
1057 if (XENBUS_EXIST_ERR(err)) {
1058 err = xenbus_printf(XBT_NIL, dev->nodename, state,
1059 "%d", XenbusStateClosed);
1060 if (err)
1061 xenbus_dev_error(info->dev, err,
1062 "%s: writing %s", __func__, state);
1063 return;
1064 }
1065
1066 switch (op) {
1067 case VSCSIBACK_OP_ADD_OR_DEL_LUN:
1068 switch (device_state) {
1069 case XenbusStateInitialising:
1070 scsiback_do_add_lun(info, state, phy, &vir, 0);
1071 break;
1072 case XenbusStateConnected:
1073 scsiback_do_add_lun(info, state, phy, &vir, 1);
1074 break;
1075 case XenbusStateClosing:
1076 scsiback_do_del_lun(info, state, &vir);
1077 break;
1078 default:
1079 break;
1080 }
1081 break;
1082
1083 case VSCSIBACK_OP_UPDATEDEV_STATE:
1084 if (device_state == XenbusStateInitialised) {
1085 /* modify vscsi-devs/dev-x/state */
1086 if (xenbus_printf(XBT_NIL, dev->nodename, state,
1087 "%d", XenbusStateConnected)) {
1088 pr_err("xenbus_printf error %s\n", str);
1089 scsiback_del_translation_entry(info, &vir);
1090 xenbus_printf(XBT_NIL, dev->nodename, state,
1091 "%d", XenbusStateClosed);
1092 }
1093 }
1094 break;
1095 /* When it is necessary, processing is added here. */
1096 default:
1097 break;
1098 }
1099}
1100
1101static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
1102{
1103 int i;
1104 char **dir;
1105 unsigned int ndir = 0;
1106
1107 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
1108 &ndir);
1109 if (IS_ERR(dir))
1110 return;
1111
1112 for (i = 0; i < ndir; i++)
1113 scsiback_do_1lun_hotplug(info, op, dir[i]);
1114
1115 kfree(dir);
1116}
1117
1118static void scsiback_frontend_changed(struct xenbus_device *dev,
1119 enum xenbus_state frontend_state)
1120{
1121 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1122
1123 switch (frontend_state) {
1124 case XenbusStateInitialising:
1125 break;
1126
1127 case XenbusStateInitialised:
1128 if (scsiback_map(info))
1129 break;
1130
1131 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1132 xenbus_switch_state(dev, XenbusStateConnected);
1133 break;
1134
1135 case XenbusStateConnected:
1136 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
1137
1138 if (dev->state == XenbusStateConnected)
1139 break;
1140
1141 xenbus_switch_state(dev, XenbusStateConnected);
1142 break;
1143
1144 case XenbusStateClosing:
1145 if (info->irq)
1146 scsiback_disconnect(info);
1147
1148 xenbus_switch_state(dev, XenbusStateClosing);
1149 break;
1150
1151 case XenbusStateClosed:
1152 xenbus_switch_state(dev, XenbusStateClosed);
1153 if (xenbus_dev_is_online(dev))
1154 break;
1155 fallthrough; /* if not online */
1156 case XenbusStateUnknown:
1157 device_unregister(&dev->dev);
1158 break;
1159
1160 case XenbusStateReconfiguring:
1161 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
1162 xenbus_switch_state(dev, XenbusStateReconfigured);
1163
1164 break;
1165
1166 default:
1167 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
1168 frontend_state);
1169 break;
1170 }
1171}
1172
1173/*
1174 Release the translation entry specfied
1175*/
1176static void scsiback_release_translation_entry(struct vscsibk_info *info)
1177{
1178 struct v2p_entry *entry, *tmp;
1179 struct list_head *head = &(info->v2p_entry_lists);
1180 unsigned long flags;
1181
1182 spin_lock_irqsave(&info->v2p_lock, flags);
1183
1184 list_for_each_entry_safe(entry, tmp, head, l)
1185 __scsiback_del_translation_entry(entry);
1186
1187 spin_unlock_irqrestore(&info->v2p_lock, flags);
1188}
1189
1190static int scsiback_remove(struct xenbus_device *dev)
1191{
1192 struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
1193
1194 if (info->irq)
1195 scsiback_disconnect(info);
1196
1197 scsiback_release_translation_entry(info);
1198
1199 gnttab_page_cache_shrink(&info->free_pages, 0);
1200
1201 dev_set_drvdata(&dev->dev, NULL);
1202
1203 return 0;
1204}
1205
1206static int scsiback_probe(struct xenbus_device *dev,
1207 const struct xenbus_device_id *id)
1208{
1209 int err;
1210
1211 struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
1212 GFP_KERNEL);
1213
1214 pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id);
1215
1216 if (!info) {
1217 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
1218 return -ENOMEM;
1219 }
1220 info->dev = dev;
1221 dev_set_drvdata(&dev->dev, info);
1222
1223 info->domid = dev->otherend_id;
1224 spin_lock_init(&info->ring_lock);
1225 atomic_set(&info->nr_unreplied_reqs, 0);
1226 init_waitqueue_head(&info->waiting_to_free);
1227 info->dev = dev;
1228 info->irq = 0;
1229 INIT_LIST_HEAD(&info->v2p_entry_lists);
1230 spin_lock_init(&info->v2p_lock);
1231 gnttab_page_cache_init(&info->free_pages);
1232
1233 err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
1234 SG_ALL);
1235 if (err)
1236 xenbus_dev_error(dev, err, "writing feature-sg-grant");
1237
1238 err = xenbus_switch_state(dev, XenbusStateInitWait);
1239 if (err)
1240 goto fail;
1241
1242 return 0;
1243
1244fail:
1245 pr_warn("%s failed\n", __func__);
1246 scsiback_remove(dev);
1247
1248 return err;
1249}
1250
1251static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
1252{
1253 switch (tport->tport_proto_id) {
1254 case SCSI_PROTOCOL_SAS:
1255 return "SAS";
1256 case SCSI_PROTOCOL_FCP:
1257 return "FCP";
1258 case SCSI_PROTOCOL_ISCSI:
1259 return "iSCSI";
1260 default:
1261 break;
1262 }
1263
1264 return "Unknown";
1265}
1266
1267static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
1268{
1269 struct scsiback_tpg *tpg = container_of(se_tpg,
1270 struct scsiback_tpg, se_tpg);
1271 struct scsiback_tport *tport = tpg->tport;
1272
1273 return &tport->tport_name[0];
1274}
1275
1276static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
1277{
1278 struct scsiback_tpg *tpg = container_of(se_tpg,
1279 struct scsiback_tpg, se_tpg);
1280 return tpg->tport_tpgt;
1281}
1282
1283static struct se_wwn *
1284scsiback_make_tport(struct target_fabric_configfs *tf,
1285 struct config_group *group,
1286 const char *name)
1287{
1288 struct scsiback_tport *tport;
1289 char *ptr;
1290 u64 wwpn = 0;
1291 int off = 0;
1292
1293 tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL);
1294 if (!tport)
1295 return ERR_PTR(-ENOMEM);
1296
1297 tport->tport_wwpn = wwpn;
1298 /*
1299 * Determine the emulated Protocol Identifier and Target Port Name
1300 * based on the incoming configfs directory name.
1301 */
1302 ptr = strstr(name, "naa.");
1303 if (ptr) {
1304 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1305 goto check_len;
1306 }
1307 ptr = strstr(name, "fc.");
1308 if (ptr) {
1309 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1310 off = 3; /* Skip over "fc." */
1311 goto check_len;
1312 }
1313 ptr = strstr(name, "iqn.");
1314 if (ptr) {
1315 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1316 goto check_len;
1317 }
1318
1319 pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
1320 kfree(tport);
1321 return ERR_PTR(-EINVAL);
1322
1323check_len:
1324 if (strlen(name) >= VSCSI_NAMELEN) {
1325 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
1326 scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
1327 kfree(tport);
1328 return ERR_PTR(-EINVAL);
1329 }
1330 snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
1331
1332 pr_debug("Allocated emulated Target %s Address: %s\n",
1333 scsiback_dump_proto_id(tport), name);
1334
1335 return &tport->tport_wwn;
1336}
1337
1338static void scsiback_drop_tport(struct se_wwn *wwn)
1339{
1340 struct scsiback_tport *tport = container_of(wwn,
1341 struct scsiback_tport, tport_wwn);
1342
1343 pr_debug("Deallocating emulated Target %s Address: %s\n",
1344 scsiback_dump_proto_id(tport), tport->tport_name);
1345
1346 kfree(tport);
1347}
1348
1349static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg)
1350{
1351 return 1;
1352}
1353
1354static int scsiback_check_stop_free(struct se_cmd *se_cmd)
1355{
1356 return transport_generic_free_cmd(se_cmd, 0);
1357}
1358
1359static void scsiback_release_cmd(struct se_cmd *se_cmd)
1360{
1361 target_free_tag(se_cmd->se_sess, se_cmd);
1362}
1363
1364static u32 scsiback_sess_get_index(struct se_session *se_sess)
1365{
1366 return 0;
1367}
1368
1369static int scsiback_write_pending(struct se_cmd *se_cmd)
1370{
1371 /* Go ahead and process the write immediately */
1372 target_execute_cmd(se_cmd);
1373
1374 return 0;
1375}
1376
1377static void scsiback_set_default_node_attrs(struct se_node_acl *nacl)
1378{
1379}
1380
1381static int scsiback_get_cmd_state(struct se_cmd *se_cmd)
1382{
1383 return 0;
1384}
1385
1386static int scsiback_queue_data_in(struct se_cmd *se_cmd)
1387{
1388 struct vscsibk_pend *pending_req = container_of(se_cmd,
1389 struct vscsibk_pend, se_cmd);
1390
1391 pending_req->result = SAM_STAT_GOOD;
1392 scsiback_cmd_done(pending_req);
1393 return 0;
1394}
1395
1396static int scsiback_queue_status(struct se_cmd *se_cmd)
1397{
1398 struct vscsibk_pend *pending_req = container_of(se_cmd,
1399 struct vscsibk_pend, se_cmd);
1400
1401 if (se_cmd->sense_buffer &&
1402 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
1403 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
1404 pending_req->result = SAM_STAT_CHECK_CONDITION;
1405 else
1406 pending_req->result = se_cmd->scsi_status;
1407
1408 scsiback_cmd_done(pending_req);
1409 return 0;
1410}
1411
1412static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
1413{
1414 struct vscsibk_pend *pending_req = container_of(se_cmd,
1415 struct vscsibk_pend, se_cmd);
1416
1417 complete(&pending_req->tmr_done);
1418}
1419
1420static void scsiback_aborted_task(struct se_cmd *se_cmd)
1421{
1422}
1423
1424static ssize_t scsiback_tpg_param_alias_show(struct config_item *item,
1425 char *page)
1426{
1427 struct se_portal_group *se_tpg = param_to_tpg(item);
1428 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1429 se_tpg);
1430 ssize_t rb;
1431
1432 mutex_lock(&tpg->tv_tpg_mutex);
1433 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
1434 mutex_unlock(&tpg->tv_tpg_mutex);
1435
1436 return rb;
1437}
1438
1439static ssize_t scsiback_tpg_param_alias_store(struct config_item *item,
1440 const char *page, size_t count)
1441{
1442 struct se_portal_group *se_tpg = param_to_tpg(item);
1443 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
1444 se_tpg);
1445 int len;
1446
1447 if (strlen(page) >= VSCSI_NAMELEN) {
1448 pr_err("param alias: %s, exceeds max: %d\n", page,
1449 VSCSI_NAMELEN);
1450 return -EINVAL;
1451 }
1452
1453 mutex_lock(&tpg->tv_tpg_mutex);
1454 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
1455 if (tpg->param_alias[len - 1] == '\n')
1456 tpg->param_alias[len - 1] = '\0';
1457 mutex_unlock(&tpg->tv_tpg_mutex);
1458
1459 return count;
1460}
1461
1462CONFIGFS_ATTR(scsiback_tpg_param_, alias);
1463
1464static struct configfs_attribute *scsiback_param_attrs[] = {
1465 &scsiback_tpg_param_attr_alias,
1466 NULL,
1467};
1468
1469static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg,
1470 struct se_session *se_sess, void *p)
1471{
1472 struct scsiback_tpg *tpg = container_of(se_tpg,
1473 struct scsiback_tpg, se_tpg);
1474
1475 tpg->tpg_nexus = p;
1476 return 0;
1477}
1478
1479static int scsiback_make_nexus(struct scsiback_tpg *tpg,
1480 const char *name)
1481{
1482 struct scsiback_nexus *tv_nexus;
1483 int ret = 0;
1484
1485 mutex_lock(&tpg->tv_tpg_mutex);
1486 if (tpg->tpg_nexus) {
1487 pr_debug("tpg->tpg_nexus already exists\n");
1488 ret = -EEXIST;
1489 goto out_unlock;
1490 }
1491
1492 tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
1493 if (!tv_nexus) {
1494 ret = -ENOMEM;
1495 goto out_unlock;
1496 }
1497
1498 tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg,
1499 VSCSI_DEFAULT_SESSION_TAGS,
1500 sizeof(struct vscsibk_pend),
1501 TARGET_PROT_NORMAL, name,
1502 tv_nexus, scsiback_alloc_sess_cb);
1503 if (IS_ERR(tv_nexus->tvn_se_sess)) {
1504 kfree(tv_nexus);
1505 ret = -ENOMEM;
1506 goto out_unlock;
1507 }
1508
1509out_unlock:
1510 mutex_unlock(&tpg->tv_tpg_mutex);
1511 return ret;
1512}
1513
1514static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
1515{
1516 struct se_session *se_sess;
1517 struct scsiback_nexus *tv_nexus;
1518
1519 mutex_lock(&tpg->tv_tpg_mutex);
1520 tv_nexus = tpg->tpg_nexus;
1521 if (!tv_nexus) {
1522 mutex_unlock(&tpg->tv_tpg_mutex);
1523 return -ENODEV;
1524 }
1525
1526 se_sess = tv_nexus->tvn_se_sess;
1527 if (!se_sess) {
1528 mutex_unlock(&tpg->tv_tpg_mutex);
1529 return -ENODEV;
1530 }
1531
1532 if (tpg->tv_tpg_port_count != 0) {
1533 mutex_unlock(&tpg->tv_tpg_mutex);
1534 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
1535 tpg->tv_tpg_port_count);
1536 return -EBUSY;
1537 }
1538
1539 if (tpg->tv_tpg_fe_count != 0) {
1540 mutex_unlock(&tpg->tv_tpg_mutex);
1541 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
1542 tpg->tv_tpg_fe_count);
1543 return -EBUSY;
1544 }
1545
1546 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n",
1547 scsiback_dump_proto_id(tpg->tport),
1548 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1549
1550 /*
1551 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
1552 */
1553 target_remove_session(se_sess);
1554 tpg->tpg_nexus = NULL;
1555 mutex_unlock(&tpg->tv_tpg_mutex);
1556
1557 kfree(tv_nexus);
1558 return 0;
1559}
1560
1561static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page)
1562{
1563 struct se_portal_group *se_tpg = to_tpg(item);
1564 struct scsiback_tpg *tpg = container_of(se_tpg,
1565 struct scsiback_tpg, se_tpg);
1566 struct scsiback_nexus *tv_nexus;
1567 ssize_t ret;
1568
1569 mutex_lock(&tpg->tv_tpg_mutex);
1570 tv_nexus = tpg->tpg_nexus;
1571 if (!tv_nexus) {
1572 mutex_unlock(&tpg->tv_tpg_mutex);
1573 return -ENODEV;
1574 }
1575 ret = snprintf(page, PAGE_SIZE, "%s\n",
1576 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1577 mutex_unlock(&tpg->tv_tpg_mutex);
1578
1579 return ret;
1580}
1581
1582static ssize_t scsiback_tpg_nexus_store(struct config_item *item,
1583 const char *page, size_t count)
1584{
1585 struct se_portal_group *se_tpg = to_tpg(item);
1586 struct scsiback_tpg *tpg = container_of(se_tpg,
1587 struct scsiback_tpg, se_tpg);
1588 struct scsiback_tport *tport_wwn = tpg->tport;
1589 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
1590 int ret;
1591 /*
1592 * Shutdown the active I_T nexus if 'NULL' is passed.
1593 */
1594 if (!strncmp(page, "NULL", 4)) {
1595 ret = scsiback_drop_nexus(tpg);
1596 return (!ret) ? count : ret;
1597 }
1598 /*
1599 * Otherwise make sure the passed virtual Initiator port WWN matches
1600 * the fabric protocol_id set in scsiback_make_tport(), and call
1601 * scsiback_make_nexus().
1602 */
1603 if (strlen(page) >= VSCSI_NAMELEN) {
1604 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
1605 page, VSCSI_NAMELEN);
1606 return -EINVAL;
1607 }
1608 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
1609
1610 ptr = strstr(i_port, "naa.");
1611 if (ptr) {
1612 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1613 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
1614 i_port, scsiback_dump_proto_id(tport_wwn));
1615 return -EINVAL;
1616 }
1617 port_ptr = &i_port[0];
1618 goto check_newline;
1619 }
1620 ptr = strstr(i_port, "fc.");
1621 if (ptr) {
1622 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1623 pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
1624 i_port, scsiback_dump_proto_id(tport_wwn));
1625 return -EINVAL;
1626 }
1627 port_ptr = &i_port[3]; /* Skip over "fc." */
1628 goto check_newline;
1629 }
1630 ptr = strstr(i_port, "iqn.");
1631 if (ptr) {
1632 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1633 pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
1634 i_port, scsiback_dump_proto_id(tport_wwn));
1635 return -EINVAL;
1636 }
1637 port_ptr = &i_port[0];
1638 goto check_newline;
1639 }
1640 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
1641 i_port);
1642 return -EINVAL;
1643 /*
1644 * Clear any trailing newline for the NAA WWN
1645 */
1646check_newline:
1647 if (i_port[strlen(i_port) - 1] == '\n')
1648 i_port[strlen(i_port) - 1] = '\0';
1649
1650 ret = scsiback_make_nexus(tpg, port_ptr);
1651 if (ret < 0)
1652 return ret;
1653
1654 return count;
1655}
1656
1657CONFIGFS_ATTR(scsiback_tpg_, nexus);
1658
1659static struct configfs_attribute *scsiback_tpg_attrs[] = {
1660 &scsiback_tpg_attr_nexus,
1661 NULL,
1662};
1663
1664static ssize_t
1665scsiback_wwn_version_show(struct config_item *item, char *page)
1666{
1667 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
1668 UTS_RELEASE"\n",
1669 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1670}
1671
1672CONFIGFS_ATTR_RO(scsiback_wwn_, version);
1673
1674static struct configfs_attribute *scsiback_wwn_attrs[] = {
1675 &scsiback_wwn_attr_version,
1676 NULL,
1677};
1678
1679static int scsiback_port_link(struct se_portal_group *se_tpg,
1680 struct se_lun *lun)
1681{
1682 struct scsiback_tpg *tpg = container_of(se_tpg,
1683 struct scsiback_tpg, se_tpg);
1684
1685 mutex_lock(&tpg->tv_tpg_mutex);
1686 tpg->tv_tpg_port_count++;
1687 mutex_unlock(&tpg->tv_tpg_mutex);
1688
1689 return 0;
1690}
1691
1692static void scsiback_port_unlink(struct se_portal_group *se_tpg,
1693 struct se_lun *lun)
1694{
1695 struct scsiback_tpg *tpg = container_of(se_tpg,
1696 struct scsiback_tpg, se_tpg);
1697
1698 mutex_lock(&tpg->tv_tpg_mutex);
1699 tpg->tv_tpg_port_count--;
1700 mutex_unlock(&tpg->tv_tpg_mutex);
1701}
1702
1703static struct se_portal_group *
1704scsiback_make_tpg(struct se_wwn *wwn, const char *name)
1705{
1706 struct scsiback_tport *tport = container_of(wwn,
1707 struct scsiback_tport, tport_wwn);
1708
1709 struct scsiback_tpg *tpg;
1710 u16 tpgt;
1711 int ret;
1712
1713 if (strstr(name, "tpgt_") != name)
1714 return ERR_PTR(-EINVAL);
1715 ret = kstrtou16(name + 5, 10, &tpgt);
1716 if (ret)
1717 return ERR_PTR(ret);
1718
1719 tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
1720 if (!tpg)
1721 return ERR_PTR(-ENOMEM);
1722
1723 mutex_init(&tpg->tv_tpg_mutex);
1724 INIT_LIST_HEAD(&tpg->tv_tpg_list);
1725 INIT_LIST_HEAD(&tpg->info_list);
1726 tpg->tport = tport;
1727 tpg->tport_tpgt = tpgt;
1728
1729 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
1730 if (ret < 0) {
1731 kfree(tpg);
1732 return NULL;
1733 }
1734 mutex_lock(&scsiback_mutex);
1735 list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
1736 mutex_unlock(&scsiback_mutex);
1737
1738 return &tpg->se_tpg;
1739}
1740
1741static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
1742{
1743 struct scsiback_tpg *tpg = container_of(se_tpg,
1744 struct scsiback_tpg, se_tpg);
1745
1746 mutex_lock(&scsiback_mutex);
1747 list_del(&tpg->tv_tpg_list);
1748 mutex_unlock(&scsiback_mutex);
1749 /*
1750 * Release the virtual I_T Nexus for this xen-pvscsi TPG
1751 */
1752 scsiback_drop_nexus(tpg);
1753 /*
1754 * Deregister the se_tpg from TCM.
1755 */
1756 core_tpg_deregister(se_tpg);
1757 kfree(tpg);
1758}
1759
1760static int scsiback_check_true(struct se_portal_group *se_tpg)
1761{
1762 return 1;
1763}
1764
1765static int scsiback_check_false(struct se_portal_group *se_tpg)
1766{
1767 return 0;
1768}
1769
1770static const struct target_core_fabric_ops scsiback_ops = {
1771 .module = THIS_MODULE,
1772 .fabric_name = "xen-pvscsi",
1773 .tpg_get_wwn = scsiback_get_fabric_wwn,
1774 .tpg_get_tag = scsiback_get_tag,
1775 .tpg_check_demo_mode = scsiback_check_true,
1776 .tpg_check_demo_mode_cache = scsiback_check_true,
1777 .tpg_check_demo_mode_write_protect = scsiback_check_false,
1778 .tpg_check_prod_mode_write_protect = scsiback_check_false,
1779 .tpg_get_inst_index = scsiback_tpg_get_inst_index,
1780 .check_stop_free = scsiback_check_stop_free,
1781 .release_cmd = scsiback_release_cmd,
1782 .sess_get_index = scsiback_sess_get_index,
1783 .sess_get_initiator_sid = NULL,
1784 .write_pending = scsiback_write_pending,
1785 .set_default_node_attributes = scsiback_set_default_node_attrs,
1786 .get_cmd_state = scsiback_get_cmd_state,
1787 .queue_data_in = scsiback_queue_data_in,
1788 .queue_status = scsiback_queue_status,
1789 .queue_tm_rsp = scsiback_queue_tm_rsp,
1790 .aborted_task = scsiback_aborted_task,
1791 /*
1792 * Setup callers for generic logic in target_core_fabric_configfs.c
1793 */
1794 .fabric_make_wwn = scsiback_make_tport,
1795 .fabric_drop_wwn = scsiback_drop_tport,
1796 .fabric_make_tpg = scsiback_make_tpg,
1797 .fabric_drop_tpg = scsiback_drop_tpg,
1798 .fabric_post_link = scsiback_port_link,
1799 .fabric_pre_unlink = scsiback_port_unlink,
1800
1801 .tfc_wwn_attrs = scsiback_wwn_attrs,
1802 .tfc_tpg_base_attrs = scsiback_tpg_attrs,
1803 .tfc_tpg_param_attrs = scsiback_param_attrs,
1804};
1805
1806static const struct xenbus_device_id scsiback_ids[] = {
1807 { "vscsi" },
1808 { "" }
1809};
1810
1811static struct xenbus_driver scsiback_driver = {
1812 .ids = scsiback_ids,
1813 .probe = scsiback_probe,
1814 .remove = scsiback_remove,
1815 .otherend_changed = scsiback_frontend_changed
1816};
1817
1818static int __init scsiback_init(void)
1819{
1820 int ret;
1821
1822 if (!xen_domain())
1823 return -ENODEV;
1824
1825 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
1826 VSCSI_VERSION, utsname()->sysname, utsname()->machine);
1827
1828 ret = xenbus_register_backend(&scsiback_driver);
1829 if (ret)
1830 goto out;
1831
1832 ret = target_register_template(&scsiback_ops);
1833 if (ret)
1834 goto out_unregister_xenbus;
1835
1836 return 0;
1837
1838out_unregister_xenbus:
1839 xenbus_unregister_driver(&scsiback_driver);
1840out:
1841 pr_err("%s: error %d\n", __func__, ret);
1842 return ret;
1843}
1844
1845static void __exit scsiback_exit(void)
1846{
1847 target_unregister_template(&scsiback_ops);
1848 xenbus_unregister_driver(&scsiback_driver);
1849}
1850
1851module_init(scsiback_init);
1852module_exit(scsiback_exit);
1853
1854MODULE_DESCRIPTION("Xen SCSI backend driver");
1855MODULE_LICENSE("Dual BSD/GPL");
1856MODULE_ALIAS("xen-backend:vscsi");
1857MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");