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, i; 658 659 tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING); 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; 668 669 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 { 726 struct vscsiif_back_ring *ring = &info->ring; 727 struct vscsiif_request ring_req; 728 struct vscsibk_pend *pending_req; 729 RING_IDX rc, rp; 730 int more_to_do; 731 uint32_t result; 732 733 rc = ring->req_cons; 734 rp = ring->sring->req_prod; 735 rmb(); /* guest system is accessing ring, too */ 736 737 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) { 738 rc = ring->rsp_prod_pvt; 739 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n", 740 info->domid, rp, rc, rp - rc); 741 info->ring_error = 1; 742 return 0; 743 } 744 745 while ((rc != rp)) { 746 if (RING_REQUEST_CONS_OVERFLOW(ring, rc)) 747 break; 748 749 RING_COPY_REQUEST(ring, rc, &ring_req); 750 ring->req_cons = ++rc; 751 752 pending_req = prepare_pending_reqs(info, ring, &ring_req); 753 if (IS_ERR(pending_req)) { 754 switch (PTR_ERR(pending_req)) { 755 case -ENODEV: 756 result = DID_NO_CONNECT; 757 break; 758 default: 759 result = DRIVER_ERROR; 760 break; 761 } 762 scsiback_send_response(info, NULL, result << 24, 0, 763 ring_req.rqid); 764 return 1; 765 } 766 767 switch (ring_req.act) { 768 case VSCSIIF_ACT_SCSI_CDB: 769 if (scsiback_gnttab_data_map(&ring_req, pending_req)) { 770 scsiback_fast_flush_area(pending_req); 771 scsiback_do_resp_with_sense(NULL, 772 DRIVER_ERROR << 24, 0, pending_req); 773 transport_generic_free_cmd(&pending_req->se_cmd, 0); 774 } else { 775 scsiback_cmd_exec(pending_req); 776 } 777 break; 778 case VSCSIIF_ACT_SCSI_ABORT: 779 scsiback_device_action(pending_req, TMR_ABORT_TASK, 780 ring_req.ref_rqid); 781 break; 782 case VSCSIIF_ACT_SCSI_RESET: 783 scsiback_device_action(pending_req, TMR_LUN_RESET, 0); 784 break; 785 default: 786 pr_err_ratelimited("invalid request\n"); 787 scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24, 0, 788 pending_req); 789 transport_generic_free_cmd(&pending_req->se_cmd, 0); 790 break; 791 } 792 793 /* Yield point for this unbounded loop. */ 794 cond_resched(); 795 } 796 797 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do); 798 return more_to_do; 799 } 800 801 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id) 802 { 803 struct vscsibk_info *info = dev_id; 804 805 if (info->ring_error) 806 return IRQ_HANDLED; 807 808 while (scsiback_do_cmd_fn(info)) 809 cond_resched(); 810 811 return IRQ_HANDLED; 812 } 813 814 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref, 815 evtchn_port_t evtchn) 816 { 817 void *area; 818 struct vscsiif_sring *sring; 819 int err; 820 821 if (info->irq) 822 return -1; 823 824 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area); 825 if (err) 826 return err; 827 828 sring = (struct vscsiif_sring *)area; 829 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE); 830 831 err = bind_interdomain_evtchn_to_irq(info->domid, evtchn); 832 if (err < 0) 833 goto unmap_page; 834 835 info->irq = err; 836 837 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn, 838 IRQF_ONESHOT, "vscsiif-backend", info); 839 if (err) 840 goto free_irq; 841 842 return 0; 843 844 free_irq: 845 unbind_from_irqhandler(info->irq, info); 846 info->irq = 0; 847 unmap_page: 848 xenbus_unmap_ring_vfree(info->dev, area); 849 850 return err; 851 } 852 853 static int scsiback_map(struct vscsibk_info *info) 854 { 855 struct xenbus_device *dev = info->dev; 856 unsigned int ring_ref, evtchn; 857 int err; 858 859 err = xenbus_gather(XBT_NIL, dev->otherend, 860 "ring-ref", "%u", &ring_ref, 861 "event-channel", "%u", &evtchn, NULL); 862 if (err) { 863 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend); 864 return err; 865 } 866 867 return scsiback_init_sring(info, ring_ref, evtchn); 868 } 869 870 /* 871 Check for a translation entry being present 872 */ 873 static struct v2p_entry *scsiback_chk_translation_entry( 874 struct vscsibk_info *info, struct ids_tuple *v) 875 { 876 struct list_head *head = &(info->v2p_entry_lists); 877 struct v2p_entry *entry; 878 879 list_for_each_entry(entry, head, l) 880 if ((entry->v.chn == v->chn) && 881 (entry->v.tgt == v->tgt) && 882 (entry->v.lun == v->lun)) 883 return entry; 884 885 return NULL; 886 } 887 888 /* 889 Add a new translation entry 890 */ 891 static int scsiback_add_translation_entry(struct vscsibk_info *info, 892 char *phy, struct ids_tuple *v) 893 { 894 int err = 0; 895 struct v2p_entry *new; 896 unsigned long flags; 897 char *lunp; 898 unsigned long long unpacked_lun; 899 struct se_lun *se_lun; 900 struct scsiback_tpg *tpg_entry, *tpg = NULL; 901 char *error = "doesn't exist"; 902 903 lunp = strrchr(phy, ':'); 904 if (!lunp) { 905 pr_err("illegal format of physical device %s\n", phy); 906 return -EINVAL; 907 } 908 *lunp = 0; 909 lunp++; 910 err = kstrtoull(lunp, 10, &unpacked_lun); 911 if (err < 0) { 912 pr_err("lun number not valid: %s\n", lunp); 913 return err; 914 } 915 916 mutex_lock(&scsiback_mutex); 917 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) { 918 if (!strcmp(phy, tpg_entry->tport->tport_name) || 919 !strcmp(phy, tpg_entry->param_alias)) { 920 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex); 921 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) { 922 if (se_lun->unpacked_lun == unpacked_lun) { 923 if (!tpg_entry->tpg_nexus) 924 error = "nexus undefined"; 925 else 926 tpg = tpg_entry; 927 break; 928 } 929 } 930 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex); 931 break; 932 } 933 } 934 if (tpg) { 935 mutex_lock(&tpg->tv_tpg_mutex); 936 tpg->tv_tpg_fe_count++; 937 mutex_unlock(&tpg->tv_tpg_mutex); 938 } 939 mutex_unlock(&scsiback_mutex); 940 941 if (!tpg) { 942 pr_err("%s:%llu %s\n", phy, unpacked_lun, error); 943 return -ENODEV; 944 } 945 946 new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL); 947 if (new == NULL) { 948 err = -ENOMEM; 949 goto out_free; 950 } 951 952 spin_lock_irqsave(&info->v2p_lock, flags); 953 954 /* Check double assignment to identical virtual ID */ 955 if (scsiback_chk_translation_entry(info, v)) { 956 pr_warn("Virtual ID is already used. Assignment was not performed.\n"); 957 err = -EEXIST; 958 goto out; 959 } 960 961 /* Create a new translation entry and add to the list */ 962 kref_init(&new->kref); 963 new->v = *v; 964 new->tpg = tpg; 965 new->lun = unpacked_lun; 966 list_add_tail(&new->l, &info->v2p_entry_lists); 967 968 out: 969 spin_unlock_irqrestore(&info->v2p_lock, flags); 970 971 out_free: 972 if (err) { 973 mutex_lock(&tpg->tv_tpg_mutex); 974 tpg->tv_tpg_fe_count--; 975 mutex_unlock(&tpg->tv_tpg_mutex); 976 kfree(new); 977 } 978 979 return err; 980 } 981 982 static void __scsiback_del_translation_entry(struct v2p_entry *entry) 983 { 984 list_del(&entry->l); 985 kref_put(&entry->kref, scsiback_free_translation_entry); 986 } 987 988 /* 989 Delete the translation entry specified 990 */ 991 static int scsiback_del_translation_entry(struct vscsibk_info *info, 992 struct ids_tuple *v) 993 { 994 struct v2p_entry *entry; 995 unsigned long flags; 996 int ret = 0; 997 998 spin_lock_irqsave(&info->v2p_lock, flags); 999 /* Find out the translation entry specified */ 1000 entry = scsiback_chk_translation_entry(info, v); 1001 if (entry) 1002 __scsiback_del_translation_entry(entry); 1003 else 1004 ret = -ENOENT; 1005 1006 spin_unlock_irqrestore(&info->v2p_lock, flags); 1007 return ret; 1008 } 1009 1010 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state, 1011 char *phy, struct ids_tuple *vir, int try) 1012 { 1013 struct v2p_entry *entry; 1014 unsigned long flags; 1015 int err; 1016 1017 if (try) { 1018 spin_lock_irqsave(&info->v2p_lock, flags); 1019 entry = scsiback_chk_translation_entry(info, vir); 1020 spin_unlock_irqrestore(&info->v2p_lock, flags); 1021 if (entry) 1022 return; 1023 } 1024 if (!scsiback_add_translation_entry(info, phy, vir)) { 1025 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1026 "%d", XenbusStateInitialised)) { 1027 pr_err("xenbus_printf error %s\n", state); 1028 scsiback_del_translation_entry(info, vir); 1029 } 1030 } else if (!try) { 1031 err = xenbus_printf(XBT_NIL, info->dev->nodename, state, 1032 "%d", XenbusStateClosed); 1033 if (err) 1034 xenbus_dev_error(info->dev, err, 1035 "%s: writing %s", __func__, state); 1036 } 1037 } 1038 1039 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state, 1040 struct ids_tuple *vir) 1041 { 1042 if (!scsiback_del_translation_entry(info, vir)) { 1043 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1044 "%d", XenbusStateClosed)) 1045 pr_err("xenbus_printf error %s\n", state); 1046 } 1047 } 1048 1049 #define VSCSIBACK_OP_ADD_OR_DEL_LUN 1 1050 #define VSCSIBACK_OP_UPDATEDEV_STATE 2 1051 1052 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op, 1053 char *ent) 1054 { 1055 int err; 1056 struct ids_tuple vir; 1057 char *val; 1058 int device_state; 1059 char phy[VSCSI_NAMELEN]; 1060 char str[64]; 1061 char state[64]; 1062 struct xenbus_device *dev = info->dev; 1063 1064 /* read status */ 1065 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent); 1066 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state); 1067 if (XENBUS_EXIST_ERR(err)) 1068 return; 1069 1070 /* physical SCSI device */ 1071 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent); 1072 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL); 1073 if (IS_ERR(val)) { 1074 err = xenbus_printf(XBT_NIL, dev->nodename, state, 1075 "%d", XenbusStateClosed); 1076 if (err) 1077 xenbus_dev_error(info->dev, err, 1078 "%s: writing %s", __func__, state); 1079 return; 1080 } 1081 strlcpy(phy, val, VSCSI_NAMELEN); 1082 kfree(val); 1083 1084 /* virtual SCSI device */ 1085 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent); 1086 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u", 1087 &vir.hst, &vir.chn, &vir.tgt, &vir.lun); 1088 if (XENBUS_EXIST_ERR(err)) { 1089 err = xenbus_printf(XBT_NIL, dev->nodename, state, 1090 "%d", XenbusStateClosed); 1091 if (err) 1092 xenbus_dev_error(info->dev, err, 1093 "%s: writing %s", __func__, state); 1094 return; 1095 } 1096 1097 switch (op) { 1098 case VSCSIBACK_OP_ADD_OR_DEL_LUN: 1099 switch (device_state) { 1100 case XenbusStateInitialising: 1101 scsiback_do_add_lun(info, state, phy, &vir, 0); 1102 break; 1103 case XenbusStateConnected: 1104 scsiback_do_add_lun(info, state, phy, &vir, 1); 1105 break; 1106 case XenbusStateClosing: 1107 scsiback_do_del_lun(info, state, &vir); 1108 break; 1109 default: 1110 break; 1111 } 1112 break; 1113 1114 case VSCSIBACK_OP_UPDATEDEV_STATE: 1115 if (device_state == XenbusStateInitialised) { 1116 /* modify vscsi-devs/dev-x/state */ 1117 if (xenbus_printf(XBT_NIL, dev->nodename, state, 1118 "%d", XenbusStateConnected)) { 1119 pr_err("xenbus_printf error %s\n", str); 1120 scsiback_del_translation_entry(info, &vir); 1121 xenbus_printf(XBT_NIL, dev->nodename, state, 1122 "%d", XenbusStateClosed); 1123 } 1124 } 1125 break; 1126 /* When it is necessary, processing is added here. */ 1127 default: 1128 break; 1129 } 1130 } 1131 1132 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op) 1133 { 1134 int i; 1135 char **dir; 1136 unsigned int ndir = 0; 1137 1138 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs", 1139 &ndir); 1140 if (IS_ERR(dir)) 1141 return; 1142 1143 for (i = 0; i < ndir; i++) 1144 scsiback_do_1lun_hotplug(info, op, dir[i]); 1145 1146 kfree(dir); 1147 } 1148 1149 static void scsiback_frontend_changed(struct xenbus_device *dev, 1150 enum xenbus_state frontend_state) 1151 { 1152 struct vscsibk_info *info = dev_get_drvdata(&dev->dev); 1153 1154 switch (frontend_state) { 1155 case XenbusStateInitialising: 1156 break; 1157 1158 case XenbusStateInitialised: 1159 if (scsiback_map(info)) 1160 break; 1161 1162 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); 1163 xenbus_switch_state(dev, XenbusStateConnected); 1164 break; 1165 1166 case XenbusStateConnected: 1167 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE); 1168 1169 if (dev->state == XenbusStateConnected) 1170 break; 1171 1172 xenbus_switch_state(dev, XenbusStateConnected); 1173 break; 1174 1175 case XenbusStateClosing: 1176 if (info->irq) 1177 scsiback_disconnect(info); 1178 1179 xenbus_switch_state(dev, XenbusStateClosing); 1180 break; 1181 1182 case XenbusStateClosed: 1183 xenbus_switch_state(dev, XenbusStateClosed); 1184 if (xenbus_dev_is_online(dev)) 1185 break; 1186 /* fall through if not online */ 1187 case XenbusStateUnknown: 1188 device_unregister(&dev->dev); 1189 break; 1190 1191 case XenbusStateReconfiguring: 1192 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); 1193 xenbus_switch_state(dev, XenbusStateReconfigured); 1194 1195 break; 1196 1197 default: 1198 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", 1199 frontend_state); 1200 break; 1201 } 1202 } 1203 1204 /* 1205 Release the translation entry specfied 1206 */ 1207 static void scsiback_release_translation_entry(struct vscsibk_info *info) 1208 { 1209 struct v2p_entry *entry, *tmp; 1210 struct list_head *head = &(info->v2p_entry_lists); 1211 unsigned long flags; 1212 1213 spin_lock_irqsave(&info->v2p_lock, flags); 1214 1215 list_for_each_entry_safe(entry, tmp, head, l) 1216 __scsiback_del_translation_entry(entry); 1217 1218 spin_unlock_irqrestore(&info->v2p_lock, flags); 1219 } 1220 1221 static int scsiback_remove(struct xenbus_device *dev) 1222 { 1223 struct vscsibk_info *info = dev_get_drvdata(&dev->dev); 1224 1225 if (info->irq) 1226 scsiback_disconnect(info); 1227 1228 scsiback_release_translation_entry(info); 1229 1230 dev_set_drvdata(&dev->dev, NULL); 1231 1232 return 0; 1233 } 1234 1235 static int scsiback_probe(struct xenbus_device *dev, 1236 const struct xenbus_device_id *id) 1237 { 1238 int err; 1239 1240 struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info), 1241 GFP_KERNEL); 1242 1243 pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); 1244 1245 if (!info) { 1246 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure"); 1247 return -ENOMEM; 1248 } 1249 info->dev = dev; 1250 dev_set_drvdata(&dev->dev, info); 1251 1252 info->domid = dev->otherend_id; 1253 spin_lock_init(&info->ring_lock); 1254 info->ring_error = 0; 1255 atomic_set(&info->nr_unreplied_reqs, 0); 1256 init_waitqueue_head(&info->waiting_to_free); 1257 info->dev = dev; 1258 info->irq = 0; 1259 INIT_LIST_HEAD(&info->v2p_entry_lists); 1260 spin_lock_init(&info->v2p_lock); 1261 1262 err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u", 1263 SG_ALL); 1264 if (err) 1265 xenbus_dev_error(dev, err, "writing feature-sg-grant"); 1266 1267 err = xenbus_switch_state(dev, XenbusStateInitWait); 1268 if (err) 1269 goto fail; 1270 1271 return 0; 1272 1273 fail: 1274 pr_warn("%s failed\n", __func__); 1275 scsiback_remove(dev); 1276 1277 return err; 1278 } 1279 1280 static char *scsiback_dump_proto_id(struct scsiback_tport *tport) 1281 { 1282 switch (tport->tport_proto_id) { 1283 case SCSI_PROTOCOL_SAS: 1284 return "SAS"; 1285 case SCSI_PROTOCOL_FCP: 1286 return "FCP"; 1287 case SCSI_PROTOCOL_ISCSI: 1288 return "iSCSI"; 1289 default: 1290 break; 1291 } 1292 1293 return "Unknown"; 1294 } 1295 1296 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg) 1297 { 1298 struct scsiback_tpg *tpg = container_of(se_tpg, 1299 struct scsiback_tpg, se_tpg); 1300 struct scsiback_tport *tport = tpg->tport; 1301 1302 return &tport->tport_name[0]; 1303 } 1304 1305 static u16 scsiback_get_tag(struct se_portal_group *se_tpg) 1306 { 1307 struct scsiback_tpg *tpg = container_of(se_tpg, 1308 struct scsiback_tpg, se_tpg); 1309 return tpg->tport_tpgt; 1310 } 1311 1312 static struct se_wwn * 1313 scsiback_make_tport(struct target_fabric_configfs *tf, 1314 struct config_group *group, 1315 const char *name) 1316 { 1317 struct scsiback_tport *tport; 1318 char *ptr; 1319 u64 wwpn = 0; 1320 int off = 0; 1321 1322 tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL); 1323 if (!tport) 1324 return ERR_PTR(-ENOMEM); 1325 1326 tport->tport_wwpn = wwpn; 1327 /* 1328 * Determine the emulated Protocol Identifier and Target Port Name 1329 * based on the incoming configfs directory name. 1330 */ 1331 ptr = strstr(name, "naa."); 1332 if (ptr) { 1333 tport->tport_proto_id = SCSI_PROTOCOL_SAS; 1334 goto check_len; 1335 } 1336 ptr = strstr(name, "fc."); 1337 if (ptr) { 1338 tport->tport_proto_id = SCSI_PROTOCOL_FCP; 1339 off = 3; /* Skip over "fc." */ 1340 goto check_len; 1341 } 1342 ptr = strstr(name, "iqn."); 1343 if (ptr) { 1344 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI; 1345 goto check_len; 1346 } 1347 1348 pr_err("Unable to locate prefix for emulated Target Port: %s\n", name); 1349 kfree(tport); 1350 return ERR_PTR(-EINVAL); 1351 1352 check_len: 1353 if (strlen(name) >= VSCSI_NAMELEN) { 1354 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name, 1355 scsiback_dump_proto_id(tport), VSCSI_NAMELEN); 1356 kfree(tport); 1357 return ERR_PTR(-EINVAL); 1358 } 1359 snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]); 1360 1361 pr_debug("Allocated emulated Target %s Address: %s\n", 1362 scsiback_dump_proto_id(tport), name); 1363 1364 return &tport->tport_wwn; 1365 } 1366 1367 static void scsiback_drop_tport(struct se_wwn *wwn) 1368 { 1369 struct scsiback_tport *tport = container_of(wwn, 1370 struct scsiback_tport, tport_wwn); 1371 1372 pr_debug("Deallocating emulated Target %s Address: %s\n", 1373 scsiback_dump_proto_id(tport), tport->tport_name); 1374 1375 kfree(tport); 1376 } 1377 1378 static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg) 1379 { 1380 return 1; 1381 } 1382 1383 static int scsiback_check_stop_free(struct se_cmd *se_cmd) 1384 { 1385 return transport_generic_free_cmd(se_cmd, 0); 1386 } 1387 1388 static void scsiback_release_cmd(struct se_cmd *se_cmd) 1389 { 1390 struct se_session *se_sess = se_cmd->se_sess; 1391 1392 percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag); 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 int scsiback_write_pending_status(struct se_cmd *se_cmd) 1409 { 1410 return 0; 1411 } 1412 1413 static void scsiback_set_default_node_attrs(struct se_node_acl *nacl) 1414 { 1415 } 1416 1417 static int scsiback_get_cmd_state(struct se_cmd *se_cmd) 1418 { 1419 return 0; 1420 } 1421 1422 static int scsiback_queue_data_in(struct se_cmd *se_cmd) 1423 { 1424 struct vscsibk_pend *pending_req = container_of(se_cmd, 1425 struct vscsibk_pend, se_cmd); 1426 1427 pending_req->result = SAM_STAT_GOOD; 1428 scsiback_cmd_done(pending_req); 1429 return 0; 1430 } 1431 1432 static int scsiback_queue_status(struct se_cmd *se_cmd) 1433 { 1434 struct vscsibk_pend *pending_req = container_of(se_cmd, 1435 struct vscsibk_pend, se_cmd); 1436 1437 if (se_cmd->sense_buffer && 1438 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) || 1439 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) 1440 pending_req->result = (DRIVER_SENSE << 24) | 1441 SAM_STAT_CHECK_CONDITION; 1442 else 1443 pending_req->result = se_cmd->scsi_status; 1444 1445 scsiback_cmd_done(pending_req); 1446 return 0; 1447 } 1448 1449 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd) 1450 { 1451 struct vscsibk_pend *pending_req = container_of(se_cmd, 1452 struct vscsibk_pend, se_cmd); 1453 1454 complete(&pending_req->tmr_done); 1455 } 1456 1457 static void scsiback_aborted_task(struct se_cmd *se_cmd) 1458 { 1459 } 1460 1461 static ssize_t scsiback_tpg_param_alias_show(struct config_item *item, 1462 char *page) 1463 { 1464 struct se_portal_group *se_tpg = param_to_tpg(item); 1465 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1466 se_tpg); 1467 ssize_t rb; 1468 1469 mutex_lock(&tpg->tv_tpg_mutex); 1470 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias); 1471 mutex_unlock(&tpg->tv_tpg_mutex); 1472 1473 return rb; 1474 } 1475 1476 static ssize_t scsiback_tpg_param_alias_store(struct config_item *item, 1477 const char *page, size_t count) 1478 { 1479 struct se_portal_group *se_tpg = param_to_tpg(item); 1480 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1481 se_tpg); 1482 int len; 1483 1484 if (strlen(page) >= VSCSI_NAMELEN) { 1485 pr_err("param alias: %s, exceeds max: %d\n", page, 1486 VSCSI_NAMELEN); 1487 return -EINVAL; 1488 } 1489 1490 mutex_lock(&tpg->tv_tpg_mutex); 1491 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page); 1492 if (tpg->param_alias[len - 1] == '\n') 1493 tpg->param_alias[len - 1] = '\0'; 1494 mutex_unlock(&tpg->tv_tpg_mutex); 1495 1496 return count; 1497 } 1498 1499 CONFIGFS_ATTR(scsiback_tpg_param_, alias); 1500 1501 static struct configfs_attribute *scsiback_param_attrs[] = { 1502 &scsiback_tpg_param_attr_alias, 1503 NULL, 1504 }; 1505 1506 static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg, 1507 struct se_session *se_sess, void *p) 1508 { 1509 struct scsiback_tpg *tpg = container_of(se_tpg, 1510 struct scsiback_tpg, se_tpg); 1511 1512 tpg->tpg_nexus = p; 1513 return 0; 1514 } 1515 1516 static int scsiback_make_nexus(struct scsiback_tpg *tpg, 1517 const char *name) 1518 { 1519 struct scsiback_nexus *tv_nexus; 1520 int ret = 0; 1521 1522 mutex_lock(&tpg->tv_tpg_mutex); 1523 if (tpg->tpg_nexus) { 1524 pr_debug("tpg->tpg_nexus already exists\n"); 1525 ret = -EEXIST; 1526 goto out_unlock; 1527 } 1528 1529 tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL); 1530 if (!tv_nexus) { 1531 ret = -ENOMEM; 1532 goto out_unlock; 1533 } 1534 1535 tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg, 1536 VSCSI_DEFAULT_SESSION_TAGS, 1537 sizeof(struct vscsibk_pend), 1538 TARGET_PROT_NORMAL, name, 1539 tv_nexus, scsiback_alloc_sess_cb); 1540 if (IS_ERR(tv_nexus->tvn_se_sess)) { 1541 kfree(tv_nexus); 1542 ret = -ENOMEM; 1543 goto out_unlock; 1544 } 1545 1546 out_unlock: 1547 mutex_unlock(&tpg->tv_tpg_mutex); 1548 return ret; 1549 } 1550 1551 static int scsiback_drop_nexus(struct scsiback_tpg *tpg) 1552 { 1553 struct se_session *se_sess; 1554 struct scsiback_nexus *tv_nexus; 1555 1556 mutex_lock(&tpg->tv_tpg_mutex); 1557 tv_nexus = tpg->tpg_nexus; 1558 if (!tv_nexus) { 1559 mutex_unlock(&tpg->tv_tpg_mutex); 1560 return -ENODEV; 1561 } 1562 1563 se_sess = tv_nexus->tvn_se_sess; 1564 if (!se_sess) { 1565 mutex_unlock(&tpg->tv_tpg_mutex); 1566 return -ENODEV; 1567 } 1568 1569 if (tpg->tv_tpg_port_count != 0) { 1570 mutex_unlock(&tpg->tv_tpg_mutex); 1571 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n", 1572 tpg->tv_tpg_port_count); 1573 return -EBUSY; 1574 } 1575 1576 if (tpg->tv_tpg_fe_count != 0) { 1577 mutex_unlock(&tpg->tv_tpg_mutex); 1578 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n", 1579 tpg->tv_tpg_fe_count); 1580 return -EBUSY; 1581 } 1582 1583 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n", 1584 scsiback_dump_proto_id(tpg->tport), 1585 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1586 1587 /* 1588 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port 1589 */ 1590 transport_deregister_session(tv_nexus->tvn_se_sess); 1591 tpg->tpg_nexus = NULL; 1592 mutex_unlock(&tpg->tv_tpg_mutex); 1593 1594 kfree(tv_nexus); 1595 return 0; 1596 } 1597 1598 static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page) 1599 { 1600 struct se_portal_group *se_tpg = to_tpg(item); 1601 struct scsiback_tpg *tpg = container_of(se_tpg, 1602 struct scsiback_tpg, se_tpg); 1603 struct scsiback_nexus *tv_nexus; 1604 ssize_t ret; 1605 1606 mutex_lock(&tpg->tv_tpg_mutex); 1607 tv_nexus = tpg->tpg_nexus; 1608 if (!tv_nexus) { 1609 mutex_unlock(&tpg->tv_tpg_mutex); 1610 return -ENODEV; 1611 } 1612 ret = snprintf(page, PAGE_SIZE, "%s\n", 1613 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1614 mutex_unlock(&tpg->tv_tpg_mutex); 1615 1616 return ret; 1617 } 1618 1619 static ssize_t scsiback_tpg_nexus_store(struct config_item *item, 1620 const char *page, size_t count) 1621 { 1622 struct se_portal_group *se_tpg = to_tpg(item); 1623 struct scsiback_tpg *tpg = container_of(se_tpg, 1624 struct scsiback_tpg, se_tpg); 1625 struct scsiback_tport *tport_wwn = tpg->tport; 1626 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr; 1627 int ret; 1628 /* 1629 * Shutdown the active I_T nexus if 'NULL' is passed. 1630 */ 1631 if (!strncmp(page, "NULL", 4)) { 1632 ret = scsiback_drop_nexus(tpg); 1633 return (!ret) ? count : ret; 1634 } 1635 /* 1636 * Otherwise make sure the passed virtual Initiator port WWN matches 1637 * the fabric protocol_id set in scsiback_make_tport(), and call 1638 * scsiback_make_nexus(). 1639 */ 1640 if (strlen(page) >= VSCSI_NAMELEN) { 1641 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n", 1642 page, VSCSI_NAMELEN); 1643 return -EINVAL; 1644 } 1645 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page); 1646 1647 ptr = strstr(i_port, "naa."); 1648 if (ptr) { 1649 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) { 1650 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n", 1651 i_port, scsiback_dump_proto_id(tport_wwn)); 1652 return -EINVAL; 1653 } 1654 port_ptr = &i_port[0]; 1655 goto check_newline; 1656 } 1657 ptr = strstr(i_port, "fc."); 1658 if (ptr) { 1659 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) { 1660 pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n", 1661 i_port, scsiback_dump_proto_id(tport_wwn)); 1662 return -EINVAL; 1663 } 1664 port_ptr = &i_port[3]; /* Skip over "fc." */ 1665 goto check_newline; 1666 } 1667 ptr = strstr(i_port, "iqn."); 1668 if (ptr) { 1669 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) { 1670 pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n", 1671 i_port, scsiback_dump_proto_id(tport_wwn)); 1672 return -EINVAL; 1673 } 1674 port_ptr = &i_port[0]; 1675 goto check_newline; 1676 } 1677 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n", 1678 i_port); 1679 return -EINVAL; 1680 /* 1681 * Clear any trailing newline for the NAA WWN 1682 */ 1683 check_newline: 1684 if (i_port[strlen(i_port) - 1] == '\n') 1685 i_port[strlen(i_port) - 1] = '\0'; 1686 1687 ret = scsiback_make_nexus(tpg, port_ptr); 1688 if (ret < 0) 1689 return ret; 1690 1691 return count; 1692 } 1693 1694 CONFIGFS_ATTR(scsiback_tpg_, nexus); 1695 1696 static struct configfs_attribute *scsiback_tpg_attrs[] = { 1697 &scsiback_tpg_attr_nexus, 1698 NULL, 1699 }; 1700 1701 static ssize_t 1702 scsiback_wwn_version_show(struct config_item *item, char *page) 1703 { 1704 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on " 1705 UTS_RELEASE"\n", 1706 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1707 } 1708 1709 CONFIGFS_ATTR_RO(scsiback_wwn_, version); 1710 1711 static struct configfs_attribute *scsiback_wwn_attrs[] = { 1712 &scsiback_wwn_attr_version, 1713 NULL, 1714 }; 1715 1716 static char *scsiback_get_fabric_name(void) 1717 { 1718 return "xen-pvscsi"; 1719 } 1720 1721 static int scsiback_port_link(struct se_portal_group *se_tpg, 1722 struct se_lun *lun) 1723 { 1724 struct scsiback_tpg *tpg = container_of(se_tpg, 1725 struct scsiback_tpg, se_tpg); 1726 1727 mutex_lock(&tpg->tv_tpg_mutex); 1728 tpg->tv_tpg_port_count++; 1729 mutex_unlock(&tpg->tv_tpg_mutex); 1730 1731 return 0; 1732 } 1733 1734 static void scsiback_port_unlink(struct se_portal_group *se_tpg, 1735 struct se_lun *lun) 1736 { 1737 struct scsiback_tpg *tpg = container_of(se_tpg, 1738 struct scsiback_tpg, se_tpg); 1739 1740 mutex_lock(&tpg->tv_tpg_mutex); 1741 tpg->tv_tpg_port_count--; 1742 mutex_unlock(&tpg->tv_tpg_mutex); 1743 } 1744 1745 static struct se_portal_group * 1746 scsiback_make_tpg(struct se_wwn *wwn, 1747 struct config_group *group, 1748 const char *name) 1749 { 1750 struct scsiback_tport *tport = container_of(wwn, 1751 struct scsiback_tport, tport_wwn); 1752 1753 struct scsiback_tpg *tpg; 1754 u16 tpgt; 1755 int ret; 1756 1757 if (strstr(name, "tpgt_") != name) 1758 return ERR_PTR(-EINVAL); 1759 ret = kstrtou16(name + 5, 10, &tpgt); 1760 if (ret) 1761 return ERR_PTR(ret); 1762 1763 tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL); 1764 if (!tpg) 1765 return ERR_PTR(-ENOMEM); 1766 1767 mutex_init(&tpg->tv_tpg_mutex); 1768 INIT_LIST_HEAD(&tpg->tv_tpg_list); 1769 INIT_LIST_HEAD(&tpg->info_list); 1770 tpg->tport = tport; 1771 tpg->tport_tpgt = tpgt; 1772 1773 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id); 1774 if (ret < 0) { 1775 kfree(tpg); 1776 return NULL; 1777 } 1778 mutex_lock(&scsiback_mutex); 1779 list_add_tail(&tpg->tv_tpg_list, &scsiback_list); 1780 mutex_unlock(&scsiback_mutex); 1781 1782 return &tpg->se_tpg; 1783 } 1784 1785 static void scsiback_drop_tpg(struct se_portal_group *se_tpg) 1786 { 1787 struct scsiback_tpg *tpg = container_of(se_tpg, 1788 struct scsiback_tpg, se_tpg); 1789 1790 mutex_lock(&scsiback_mutex); 1791 list_del(&tpg->tv_tpg_list); 1792 mutex_unlock(&scsiback_mutex); 1793 /* 1794 * Release the virtual I_T Nexus for this xen-pvscsi TPG 1795 */ 1796 scsiback_drop_nexus(tpg); 1797 /* 1798 * Deregister the se_tpg from TCM. 1799 */ 1800 core_tpg_deregister(se_tpg); 1801 kfree(tpg); 1802 } 1803 1804 static int scsiback_check_true(struct se_portal_group *se_tpg) 1805 { 1806 return 1; 1807 } 1808 1809 static int scsiback_check_false(struct se_portal_group *se_tpg) 1810 { 1811 return 0; 1812 } 1813 1814 static const struct target_core_fabric_ops scsiback_ops = { 1815 .module = THIS_MODULE, 1816 .name = "xen-pvscsi", 1817 .get_fabric_name = scsiback_get_fabric_name, 1818 .tpg_get_wwn = scsiback_get_fabric_wwn, 1819 .tpg_get_tag = scsiback_get_tag, 1820 .tpg_check_demo_mode = scsiback_check_true, 1821 .tpg_check_demo_mode_cache = scsiback_check_true, 1822 .tpg_check_demo_mode_write_protect = scsiback_check_false, 1823 .tpg_check_prod_mode_write_protect = scsiback_check_false, 1824 .tpg_get_inst_index = scsiback_tpg_get_inst_index, 1825 .check_stop_free = scsiback_check_stop_free, 1826 .release_cmd = scsiback_release_cmd, 1827 .sess_get_index = scsiback_sess_get_index, 1828 .sess_get_initiator_sid = NULL, 1829 .write_pending = scsiback_write_pending, 1830 .write_pending_status = scsiback_write_pending_status, 1831 .set_default_node_attributes = scsiback_set_default_node_attrs, 1832 .get_cmd_state = scsiback_get_cmd_state, 1833 .queue_data_in = scsiback_queue_data_in, 1834 .queue_status = scsiback_queue_status, 1835 .queue_tm_rsp = scsiback_queue_tm_rsp, 1836 .aborted_task = scsiback_aborted_task, 1837 /* 1838 * Setup callers for generic logic in target_core_fabric_configfs.c 1839 */ 1840 .fabric_make_wwn = scsiback_make_tport, 1841 .fabric_drop_wwn = scsiback_drop_tport, 1842 .fabric_make_tpg = scsiback_make_tpg, 1843 .fabric_drop_tpg = scsiback_drop_tpg, 1844 .fabric_post_link = scsiback_port_link, 1845 .fabric_pre_unlink = scsiback_port_unlink, 1846 1847 .tfc_wwn_attrs = scsiback_wwn_attrs, 1848 .tfc_tpg_base_attrs = scsiback_tpg_attrs, 1849 .tfc_tpg_param_attrs = scsiback_param_attrs, 1850 }; 1851 1852 static const struct xenbus_device_id scsiback_ids[] = { 1853 { "vscsi" }, 1854 { "" } 1855 }; 1856 1857 static struct xenbus_driver scsiback_driver = { 1858 .ids = scsiback_ids, 1859 .probe = scsiback_probe, 1860 .remove = scsiback_remove, 1861 .otherend_changed = scsiback_frontend_changed 1862 }; 1863 1864 static int __init scsiback_init(void) 1865 { 1866 int ret; 1867 1868 if (!xen_domain()) 1869 return -ENODEV; 1870 1871 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n", 1872 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1873 1874 ret = xenbus_register_backend(&scsiback_driver); 1875 if (ret) 1876 goto out; 1877 1878 ret = target_register_template(&scsiback_ops); 1879 if (ret) 1880 goto out_unregister_xenbus; 1881 1882 return 0; 1883 1884 out_unregister_xenbus: 1885 xenbus_unregister_driver(&scsiback_driver); 1886 out: 1887 pr_err("%s: error %d\n", __func__, ret); 1888 return ret; 1889 } 1890 1891 static void __exit scsiback_exit(void) 1892 { 1893 struct page *page; 1894 1895 while (free_pages_num) { 1896 if (get_free_page(&page)) 1897 BUG(); 1898 gnttab_free_pages(1, &page); 1899 } 1900 target_unregister_template(&scsiback_ops); 1901 xenbus_unregister_driver(&scsiback_driver); 1902 } 1903 1904 module_init(scsiback_init); 1905 module_exit(scsiback_exit); 1906 1907 MODULE_DESCRIPTION("Xen SCSI backend driver"); 1908 MODULE_LICENSE("Dual BSD/GPL"); 1909 MODULE_ALIAS("xen-backend:vscsi"); 1910 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>"); 1911