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