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