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 1016 if (try) { 1017 spin_lock_irqsave(&info->v2p_lock, flags); 1018 entry = scsiback_chk_translation_entry(info, vir); 1019 spin_unlock_irqrestore(&info->v2p_lock, flags); 1020 if (entry) 1021 return; 1022 } 1023 if (!scsiback_add_translation_entry(info, phy, vir)) { 1024 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1025 "%d", XenbusStateInitialised)) { 1026 pr_err("xenbus_printf error %s\n", state); 1027 scsiback_del_translation_entry(info, vir); 1028 } 1029 } else if (!try) { 1030 xenbus_printf(XBT_NIL, info->dev->nodename, state, 1031 "%d", XenbusStateClosed); 1032 } 1033 } 1034 1035 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state, 1036 struct ids_tuple *vir) 1037 { 1038 if (!scsiback_del_translation_entry(info, vir)) { 1039 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1040 "%d", XenbusStateClosed)) 1041 pr_err("xenbus_printf error %s\n", state); 1042 } 1043 } 1044 1045 #define VSCSIBACK_OP_ADD_OR_DEL_LUN 1 1046 #define VSCSIBACK_OP_UPDATEDEV_STATE 2 1047 1048 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op, 1049 char *ent) 1050 { 1051 int err; 1052 struct ids_tuple vir; 1053 char *val; 1054 int device_state; 1055 char phy[VSCSI_NAMELEN]; 1056 char str[64]; 1057 char state[64]; 1058 struct xenbus_device *dev = info->dev; 1059 1060 /* read status */ 1061 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent); 1062 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state); 1063 if (XENBUS_EXIST_ERR(err)) 1064 return; 1065 1066 /* physical SCSI device */ 1067 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent); 1068 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL); 1069 if (IS_ERR(val)) { 1070 xenbus_printf(XBT_NIL, dev->nodename, state, 1071 "%d", XenbusStateClosed); 1072 return; 1073 } 1074 strlcpy(phy, val, VSCSI_NAMELEN); 1075 kfree(val); 1076 1077 /* virtual SCSI device */ 1078 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent); 1079 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u", 1080 &vir.hst, &vir.chn, &vir.tgt, &vir.lun); 1081 if (XENBUS_EXIST_ERR(err)) { 1082 xenbus_printf(XBT_NIL, dev->nodename, state, 1083 "%d", XenbusStateClosed); 1084 return; 1085 } 1086 1087 switch (op) { 1088 case VSCSIBACK_OP_ADD_OR_DEL_LUN: 1089 switch (device_state) { 1090 case XenbusStateInitialising: 1091 scsiback_do_add_lun(info, state, phy, &vir, 0); 1092 break; 1093 case XenbusStateConnected: 1094 scsiback_do_add_lun(info, state, phy, &vir, 1); 1095 break; 1096 case XenbusStateClosing: 1097 scsiback_do_del_lun(info, state, &vir); 1098 break; 1099 default: 1100 break; 1101 } 1102 break; 1103 1104 case VSCSIBACK_OP_UPDATEDEV_STATE: 1105 if (device_state == XenbusStateInitialised) { 1106 /* modify vscsi-devs/dev-x/state */ 1107 if (xenbus_printf(XBT_NIL, dev->nodename, state, 1108 "%d", XenbusStateConnected)) { 1109 pr_err("xenbus_printf error %s\n", str); 1110 scsiback_del_translation_entry(info, &vir); 1111 xenbus_printf(XBT_NIL, dev->nodename, state, 1112 "%d", XenbusStateClosed); 1113 } 1114 } 1115 break; 1116 /* When it is necessary, processing is added here. */ 1117 default: 1118 break; 1119 } 1120 } 1121 1122 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op) 1123 { 1124 int i; 1125 char **dir; 1126 unsigned int ndir = 0; 1127 1128 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs", 1129 &ndir); 1130 if (IS_ERR(dir)) 1131 return; 1132 1133 for (i = 0; i < ndir; i++) 1134 scsiback_do_1lun_hotplug(info, op, dir[i]); 1135 1136 kfree(dir); 1137 } 1138 1139 static void scsiback_frontend_changed(struct xenbus_device *dev, 1140 enum xenbus_state frontend_state) 1141 { 1142 struct vscsibk_info *info = dev_get_drvdata(&dev->dev); 1143 1144 switch (frontend_state) { 1145 case XenbusStateInitialising: 1146 break; 1147 1148 case XenbusStateInitialised: 1149 if (scsiback_map(info)) 1150 break; 1151 1152 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); 1153 xenbus_switch_state(dev, XenbusStateConnected); 1154 break; 1155 1156 case XenbusStateConnected: 1157 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE); 1158 1159 if (dev->state == XenbusStateConnected) 1160 break; 1161 1162 xenbus_switch_state(dev, XenbusStateConnected); 1163 break; 1164 1165 case XenbusStateClosing: 1166 if (info->irq) 1167 scsiback_disconnect(info); 1168 1169 xenbus_switch_state(dev, XenbusStateClosing); 1170 break; 1171 1172 case XenbusStateClosed: 1173 xenbus_switch_state(dev, XenbusStateClosed); 1174 if (xenbus_dev_is_online(dev)) 1175 break; 1176 /* fall through if not online */ 1177 case XenbusStateUnknown: 1178 device_unregister(&dev->dev); 1179 break; 1180 1181 case XenbusStateReconfiguring: 1182 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); 1183 xenbus_switch_state(dev, XenbusStateReconfigured); 1184 1185 break; 1186 1187 default: 1188 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", 1189 frontend_state); 1190 break; 1191 } 1192 } 1193 1194 /* 1195 Release the translation entry specfied 1196 */ 1197 static void scsiback_release_translation_entry(struct vscsibk_info *info) 1198 { 1199 struct v2p_entry *entry, *tmp; 1200 struct list_head *head = &(info->v2p_entry_lists); 1201 unsigned long flags; 1202 1203 spin_lock_irqsave(&info->v2p_lock, flags); 1204 1205 list_for_each_entry_safe(entry, tmp, head, l) 1206 __scsiback_del_translation_entry(entry); 1207 1208 spin_unlock_irqrestore(&info->v2p_lock, flags); 1209 } 1210 1211 static int scsiback_remove(struct xenbus_device *dev) 1212 { 1213 struct vscsibk_info *info = dev_get_drvdata(&dev->dev); 1214 1215 if (info->irq) 1216 scsiback_disconnect(info); 1217 1218 scsiback_release_translation_entry(info); 1219 1220 dev_set_drvdata(&dev->dev, NULL); 1221 1222 return 0; 1223 } 1224 1225 static int scsiback_probe(struct xenbus_device *dev, 1226 const struct xenbus_device_id *id) 1227 { 1228 int err; 1229 1230 struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info), 1231 GFP_KERNEL); 1232 1233 pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); 1234 1235 if (!info) { 1236 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure"); 1237 return -ENOMEM; 1238 } 1239 info->dev = dev; 1240 dev_set_drvdata(&dev->dev, info); 1241 1242 info->domid = dev->otherend_id; 1243 spin_lock_init(&info->ring_lock); 1244 info->ring_error = 0; 1245 atomic_set(&info->nr_unreplied_reqs, 0); 1246 init_waitqueue_head(&info->waiting_to_free); 1247 info->dev = dev; 1248 info->irq = 0; 1249 INIT_LIST_HEAD(&info->v2p_entry_lists); 1250 spin_lock_init(&info->v2p_lock); 1251 1252 err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u", 1253 SG_ALL); 1254 if (err) 1255 xenbus_dev_error(dev, err, "writing feature-sg-grant"); 1256 1257 err = xenbus_switch_state(dev, XenbusStateInitWait); 1258 if (err) 1259 goto fail; 1260 1261 return 0; 1262 1263 fail: 1264 pr_warn("%s failed\n", __func__); 1265 scsiback_remove(dev); 1266 1267 return err; 1268 } 1269 1270 static char *scsiback_dump_proto_id(struct scsiback_tport *tport) 1271 { 1272 switch (tport->tport_proto_id) { 1273 case SCSI_PROTOCOL_SAS: 1274 return "SAS"; 1275 case SCSI_PROTOCOL_FCP: 1276 return "FCP"; 1277 case SCSI_PROTOCOL_ISCSI: 1278 return "iSCSI"; 1279 default: 1280 break; 1281 } 1282 1283 return "Unknown"; 1284 } 1285 1286 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg) 1287 { 1288 struct scsiback_tpg *tpg = container_of(se_tpg, 1289 struct scsiback_tpg, se_tpg); 1290 struct scsiback_tport *tport = tpg->tport; 1291 1292 return &tport->tport_name[0]; 1293 } 1294 1295 static u16 scsiback_get_tag(struct se_portal_group *se_tpg) 1296 { 1297 struct scsiback_tpg *tpg = container_of(se_tpg, 1298 struct scsiback_tpg, se_tpg); 1299 return tpg->tport_tpgt; 1300 } 1301 1302 static struct se_wwn * 1303 scsiback_make_tport(struct target_fabric_configfs *tf, 1304 struct config_group *group, 1305 const char *name) 1306 { 1307 struct scsiback_tport *tport; 1308 char *ptr; 1309 u64 wwpn = 0; 1310 int off = 0; 1311 1312 tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL); 1313 if (!tport) 1314 return ERR_PTR(-ENOMEM); 1315 1316 tport->tport_wwpn = wwpn; 1317 /* 1318 * Determine the emulated Protocol Identifier and Target Port Name 1319 * based on the incoming configfs directory name. 1320 */ 1321 ptr = strstr(name, "naa."); 1322 if (ptr) { 1323 tport->tport_proto_id = SCSI_PROTOCOL_SAS; 1324 goto check_len; 1325 } 1326 ptr = strstr(name, "fc."); 1327 if (ptr) { 1328 tport->tport_proto_id = SCSI_PROTOCOL_FCP; 1329 off = 3; /* Skip over "fc." */ 1330 goto check_len; 1331 } 1332 ptr = strstr(name, "iqn."); 1333 if (ptr) { 1334 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI; 1335 goto check_len; 1336 } 1337 1338 pr_err("Unable to locate prefix for emulated Target Port: %s\n", name); 1339 kfree(tport); 1340 return ERR_PTR(-EINVAL); 1341 1342 check_len: 1343 if (strlen(name) >= VSCSI_NAMELEN) { 1344 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name, 1345 scsiback_dump_proto_id(tport), VSCSI_NAMELEN); 1346 kfree(tport); 1347 return ERR_PTR(-EINVAL); 1348 } 1349 snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]); 1350 1351 pr_debug("Allocated emulated Target %s Address: %s\n", 1352 scsiback_dump_proto_id(tport), name); 1353 1354 return &tport->tport_wwn; 1355 } 1356 1357 static void scsiback_drop_tport(struct se_wwn *wwn) 1358 { 1359 struct scsiback_tport *tport = container_of(wwn, 1360 struct scsiback_tport, tport_wwn); 1361 1362 pr_debug("Deallocating emulated Target %s Address: %s\n", 1363 scsiback_dump_proto_id(tport), tport->tport_name); 1364 1365 kfree(tport); 1366 } 1367 1368 static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg) 1369 { 1370 return 1; 1371 } 1372 1373 static int scsiback_check_stop_free(struct se_cmd *se_cmd) 1374 { 1375 return transport_generic_free_cmd(se_cmd, 0); 1376 } 1377 1378 static void scsiback_release_cmd(struct se_cmd *se_cmd) 1379 { 1380 struct se_session *se_sess = se_cmd->se_sess; 1381 1382 percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag); 1383 } 1384 1385 static u32 scsiback_sess_get_index(struct se_session *se_sess) 1386 { 1387 return 0; 1388 } 1389 1390 static int scsiback_write_pending(struct se_cmd *se_cmd) 1391 { 1392 /* Go ahead and process the write immediately */ 1393 target_execute_cmd(se_cmd); 1394 1395 return 0; 1396 } 1397 1398 static int scsiback_write_pending_status(struct se_cmd *se_cmd) 1399 { 1400 return 0; 1401 } 1402 1403 static void scsiback_set_default_node_attrs(struct se_node_acl *nacl) 1404 { 1405 } 1406 1407 static int scsiback_get_cmd_state(struct se_cmd *se_cmd) 1408 { 1409 return 0; 1410 } 1411 1412 static int scsiback_queue_data_in(struct se_cmd *se_cmd) 1413 { 1414 struct vscsibk_pend *pending_req = container_of(se_cmd, 1415 struct vscsibk_pend, se_cmd); 1416 1417 pending_req->result = SAM_STAT_GOOD; 1418 scsiback_cmd_done(pending_req); 1419 return 0; 1420 } 1421 1422 static int scsiback_queue_status(struct se_cmd *se_cmd) 1423 { 1424 struct vscsibk_pend *pending_req = container_of(se_cmd, 1425 struct vscsibk_pend, se_cmd); 1426 1427 if (se_cmd->sense_buffer && 1428 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) || 1429 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) 1430 pending_req->result = (DRIVER_SENSE << 24) | 1431 SAM_STAT_CHECK_CONDITION; 1432 else 1433 pending_req->result = se_cmd->scsi_status; 1434 1435 scsiback_cmd_done(pending_req); 1436 return 0; 1437 } 1438 1439 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd) 1440 { 1441 struct vscsibk_pend *pending_req = container_of(se_cmd, 1442 struct vscsibk_pend, se_cmd); 1443 1444 complete(&pending_req->tmr_done); 1445 } 1446 1447 static void scsiback_aborted_task(struct se_cmd *se_cmd) 1448 { 1449 } 1450 1451 static ssize_t scsiback_tpg_param_alias_show(struct config_item *item, 1452 char *page) 1453 { 1454 struct se_portal_group *se_tpg = param_to_tpg(item); 1455 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1456 se_tpg); 1457 ssize_t rb; 1458 1459 mutex_lock(&tpg->tv_tpg_mutex); 1460 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias); 1461 mutex_unlock(&tpg->tv_tpg_mutex); 1462 1463 return rb; 1464 } 1465 1466 static ssize_t scsiback_tpg_param_alias_store(struct config_item *item, 1467 const char *page, size_t count) 1468 { 1469 struct se_portal_group *se_tpg = param_to_tpg(item); 1470 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1471 se_tpg); 1472 int len; 1473 1474 if (strlen(page) >= VSCSI_NAMELEN) { 1475 pr_err("param alias: %s, exceeds max: %d\n", page, 1476 VSCSI_NAMELEN); 1477 return -EINVAL; 1478 } 1479 1480 mutex_lock(&tpg->tv_tpg_mutex); 1481 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page); 1482 if (tpg->param_alias[len - 1] == '\n') 1483 tpg->param_alias[len - 1] = '\0'; 1484 mutex_unlock(&tpg->tv_tpg_mutex); 1485 1486 return count; 1487 } 1488 1489 CONFIGFS_ATTR(scsiback_tpg_param_, alias); 1490 1491 static struct configfs_attribute *scsiback_param_attrs[] = { 1492 &scsiback_tpg_param_attr_alias, 1493 NULL, 1494 }; 1495 1496 static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg, 1497 struct se_session *se_sess, void *p) 1498 { 1499 struct scsiback_tpg *tpg = container_of(se_tpg, 1500 struct scsiback_tpg, se_tpg); 1501 1502 tpg->tpg_nexus = p; 1503 return 0; 1504 } 1505 1506 static int scsiback_make_nexus(struct scsiback_tpg *tpg, 1507 const char *name) 1508 { 1509 struct scsiback_nexus *tv_nexus; 1510 int ret = 0; 1511 1512 mutex_lock(&tpg->tv_tpg_mutex); 1513 if (tpg->tpg_nexus) { 1514 pr_debug("tpg->tpg_nexus already exists\n"); 1515 ret = -EEXIST; 1516 goto out_unlock; 1517 } 1518 1519 tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL); 1520 if (!tv_nexus) { 1521 ret = -ENOMEM; 1522 goto out_unlock; 1523 } 1524 1525 tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg, 1526 VSCSI_DEFAULT_SESSION_TAGS, 1527 sizeof(struct vscsibk_pend), 1528 TARGET_PROT_NORMAL, name, 1529 tv_nexus, scsiback_alloc_sess_cb); 1530 if (IS_ERR(tv_nexus->tvn_se_sess)) { 1531 kfree(tv_nexus); 1532 ret = -ENOMEM; 1533 goto out_unlock; 1534 } 1535 1536 out_unlock: 1537 mutex_unlock(&tpg->tv_tpg_mutex); 1538 return ret; 1539 } 1540 1541 static int scsiback_drop_nexus(struct scsiback_tpg *tpg) 1542 { 1543 struct se_session *se_sess; 1544 struct scsiback_nexus *tv_nexus; 1545 1546 mutex_lock(&tpg->tv_tpg_mutex); 1547 tv_nexus = tpg->tpg_nexus; 1548 if (!tv_nexus) { 1549 mutex_unlock(&tpg->tv_tpg_mutex); 1550 return -ENODEV; 1551 } 1552 1553 se_sess = tv_nexus->tvn_se_sess; 1554 if (!se_sess) { 1555 mutex_unlock(&tpg->tv_tpg_mutex); 1556 return -ENODEV; 1557 } 1558 1559 if (tpg->tv_tpg_port_count != 0) { 1560 mutex_unlock(&tpg->tv_tpg_mutex); 1561 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n", 1562 tpg->tv_tpg_port_count); 1563 return -EBUSY; 1564 } 1565 1566 if (tpg->tv_tpg_fe_count != 0) { 1567 mutex_unlock(&tpg->tv_tpg_mutex); 1568 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n", 1569 tpg->tv_tpg_fe_count); 1570 return -EBUSY; 1571 } 1572 1573 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n", 1574 scsiback_dump_proto_id(tpg->tport), 1575 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1576 1577 /* 1578 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port 1579 */ 1580 transport_deregister_session(tv_nexus->tvn_se_sess); 1581 tpg->tpg_nexus = NULL; 1582 mutex_unlock(&tpg->tv_tpg_mutex); 1583 1584 kfree(tv_nexus); 1585 return 0; 1586 } 1587 1588 static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page) 1589 { 1590 struct se_portal_group *se_tpg = to_tpg(item); 1591 struct scsiback_tpg *tpg = container_of(se_tpg, 1592 struct scsiback_tpg, se_tpg); 1593 struct scsiback_nexus *tv_nexus; 1594 ssize_t ret; 1595 1596 mutex_lock(&tpg->tv_tpg_mutex); 1597 tv_nexus = tpg->tpg_nexus; 1598 if (!tv_nexus) { 1599 mutex_unlock(&tpg->tv_tpg_mutex); 1600 return -ENODEV; 1601 } 1602 ret = snprintf(page, PAGE_SIZE, "%s\n", 1603 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1604 mutex_unlock(&tpg->tv_tpg_mutex); 1605 1606 return ret; 1607 } 1608 1609 static ssize_t scsiback_tpg_nexus_store(struct config_item *item, 1610 const char *page, size_t count) 1611 { 1612 struct se_portal_group *se_tpg = to_tpg(item); 1613 struct scsiback_tpg *tpg = container_of(se_tpg, 1614 struct scsiback_tpg, se_tpg); 1615 struct scsiback_tport *tport_wwn = tpg->tport; 1616 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr; 1617 int ret; 1618 /* 1619 * Shutdown the active I_T nexus if 'NULL' is passed. 1620 */ 1621 if (!strncmp(page, "NULL", 4)) { 1622 ret = scsiback_drop_nexus(tpg); 1623 return (!ret) ? count : ret; 1624 } 1625 /* 1626 * Otherwise make sure the passed virtual Initiator port WWN matches 1627 * the fabric protocol_id set in scsiback_make_tport(), and call 1628 * scsiback_make_nexus(). 1629 */ 1630 if (strlen(page) >= VSCSI_NAMELEN) { 1631 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n", 1632 page, VSCSI_NAMELEN); 1633 return -EINVAL; 1634 } 1635 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page); 1636 1637 ptr = strstr(i_port, "naa."); 1638 if (ptr) { 1639 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) { 1640 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n", 1641 i_port, scsiback_dump_proto_id(tport_wwn)); 1642 return -EINVAL; 1643 } 1644 port_ptr = &i_port[0]; 1645 goto check_newline; 1646 } 1647 ptr = strstr(i_port, "fc."); 1648 if (ptr) { 1649 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) { 1650 pr_err("Passed FCP 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[3]; /* Skip over "fc." */ 1655 goto check_newline; 1656 } 1657 ptr = strstr(i_port, "iqn."); 1658 if (ptr) { 1659 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) { 1660 pr_err("Passed iSCSI 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[0]; 1665 goto check_newline; 1666 } 1667 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n", 1668 i_port); 1669 return -EINVAL; 1670 /* 1671 * Clear any trailing newline for the NAA WWN 1672 */ 1673 check_newline: 1674 if (i_port[strlen(i_port) - 1] == '\n') 1675 i_port[strlen(i_port) - 1] = '\0'; 1676 1677 ret = scsiback_make_nexus(tpg, port_ptr); 1678 if (ret < 0) 1679 return ret; 1680 1681 return count; 1682 } 1683 1684 CONFIGFS_ATTR(scsiback_tpg_, nexus); 1685 1686 static struct configfs_attribute *scsiback_tpg_attrs[] = { 1687 &scsiback_tpg_attr_nexus, 1688 NULL, 1689 }; 1690 1691 static ssize_t 1692 scsiback_wwn_version_show(struct config_item *item, char *page) 1693 { 1694 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on " 1695 UTS_RELEASE"\n", 1696 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1697 } 1698 1699 CONFIGFS_ATTR_RO(scsiback_wwn_, version); 1700 1701 static struct configfs_attribute *scsiback_wwn_attrs[] = { 1702 &scsiback_wwn_attr_version, 1703 NULL, 1704 }; 1705 1706 static char *scsiback_get_fabric_name(void) 1707 { 1708 return "xen-pvscsi"; 1709 } 1710 1711 static int scsiback_port_link(struct se_portal_group *se_tpg, 1712 struct se_lun *lun) 1713 { 1714 struct scsiback_tpg *tpg = container_of(se_tpg, 1715 struct scsiback_tpg, se_tpg); 1716 1717 mutex_lock(&tpg->tv_tpg_mutex); 1718 tpg->tv_tpg_port_count++; 1719 mutex_unlock(&tpg->tv_tpg_mutex); 1720 1721 return 0; 1722 } 1723 1724 static void scsiback_port_unlink(struct se_portal_group *se_tpg, 1725 struct se_lun *lun) 1726 { 1727 struct scsiback_tpg *tpg = container_of(se_tpg, 1728 struct scsiback_tpg, se_tpg); 1729 1730 mutex_lock(&tpg->tv_tpg_mutex); 1731 tpg->tv_tpg_port_count--; 1732 mutex_unlock(&tpg->tv_tpg_mutex); 1733 } 1734 1735 static struct se_portal_group * 1736 scsiback_make_tpg(struct se_wwn *wwn, 1737 struct config_group *group, 1738 const char *name) 1739 { 1740 struct scsiback_tport *tport = container_of(wwn, 1741 struct scsiback_tport, tport_wwn); 1742 1743 struct scsiback_tpg *tpg; 1744 u16 tpgt; 1745 int ret; 1746 1747 if (strstr(name, "tpgt_") != name) 1748 return ERR_PTR(-EINVAL); 1749 ret = kstrtou16(name + 5, 10, &tpgt); 1750 if (ret) 1751 return ERR_PTR(ret); 1752 1753 tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL); 1754 if (!tpg) 1755 return ERR_PTR(-ENOMEM); 1756 1757 mutex_init(&tpg->tv_tpg_mutex); 1758 INIT_LIST_HEAD(&tpg->tv_tpg_list); 1759 INIT_LIST_HEAD(&tpg->info_list); 1760 tpg->tport = tport; 1761 tpg->tport_tpgt = tpgt; 1762 1763 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id); 1764 if (ret < 0) { 1765 kfree(tpg); 1766 return NULL; 1767 } 1768 mutex_lock(&scsiback_mutex); 1769 list_add_tail(&tpg->tv_tpg_list, &scsiback_list); 1770 mutex_unlock(&scsiback_mutex); 1771 1772 return &tpg->se_tpg; 1773 } 1774 1775 static void scsiback_drop_tpg(struct se_portal_group *se_tpg) 1776 { 1777 struct scsiback_tpg *tpg = container_of(se_tpg, 1778 struct scsiback_tpg, se_tpg); 1779 1780 mutex_lock(&scsiback_mutex); 1781 list_del(&tpg->tv_tpg_list); 1782 mutex_unlock(&scsiback_mutex); 1783 /* 1784 * Release the virtual I_T Nexus for this xen-pvscsi TPG 1785 */ 1786 scsiback_drop_nexus(tpg); 1787 /* 1788 * Deregister the se_tpg from TCM. 1789 */ 1790 core_tpg_deregister(se_tpg); 1791 kfree(tpg); 1792 } 1793 1794 static int scsiback_check_true(struct se_portal_group *se_tpg) 1795 { 1796 return 1; 1797 } 1798 1799 static int scsiback_check_false(struct se_portal_group *se_tpg) 1800 { 1801 return 0; 1802 } 1803 1804 static const struct target_core_fabric_ops scsiback_ops = { 1805 .module = THIS_MODULE, 1806 .name = "xen-pvscsi", 1807 .get_fabric_name = scsiback_get_fabric_name, 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 .write_pending_status = scsiback_write_pending_status, 1821 .set_default_node_attributes = scsiback_set_default_node_attrs, 1822 .get_cmd_state = scsiback_get_cmd_state, 1823 .queue_data_in = scsiback_queue_data_in, 1824 .queue_status = scsiback_queue_status, 1825 .queue_tm_rsp = scsiback_queue_tm_rsp, 1826 .aborted_task = scsiback_aborted_task, 1827 /* 1828 * Setup callers for generic logic in target_core_fabric_configfs.c 1829 */ 1830 .fabric_make_wwn = scsiback_make_tport, 1831 .fabric_drop_wwn = scsiback_drop_tport, 1832 .fabric_make_tpg = scsiback_make_tpg, 1833 .fabric_drop_tpg = scsiback_drop_tpg, 1834 .fabric_post_link = scsiback_port_link, 1835 .fabric_pre_unlink = scsiback_port_unlink, 1836 1837 .tfc_wwn_attrs = scsiback_wwn_attrs, 1838 .tfc_tpg_base_attrs = scsiback_tpg_attrs, 1839 .tfc_tpg_param_attrs = scsiback_param_attrs, 1840 }; 1841 1842 static const struct xenbus_device_id scsiback_ids[] = { 1843 { "vscsi" }, 1844 { "" } 1845 }; 1846 1847 static struct xenbus_driver scsiback_driver = { 1848 .ids = scsiback_ids, 1849 .probe = scsiback_probe, 1850 .remove = scsiback_remove, 1851 .otherend_changed = scsiback_frontend_changed 1852 }; 1853 1854 static int __init scsiback_init(void) 1855 { 1856 int ret; 1857 1858 if (!xen_domain()) 1859 return -ENODEV; 1860 1861 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n", 1862 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1863 1864 ret = xenbus_register_backend(&scsiback_driver); 1865 if (ret) 1866 goto out; 1867 1868 ret = target_register_template(&scsiback_ops); 1869 if (ret) 1870 goto out_unregister_xenbus; 1871 1872 return 0; 1873 1874 out_unregister_xenbus: 1875 xenbus_unregister_driver(&scsiback_driver); 1876 out: 1877 pr_err("%s: error %d\n", __func__, ret); 1878 return ret; 1879 } 1880 1881 static void __exit scsiback_exit(void) 1882 { 1883 struct page *page; 1884 1885 while (free_pages_num) { 1886 if (get_free_page(&page)) 1887 BUG(); 1888 gnttab_free_pages(1, &page); 1889 } 1890 target_unregister_template(&scsiback_ops); 1891 xenbus_unregister_driver(&scsiback_driver); 1892 } 1893 1894 module_init(scsiback_init); 1895 module_exit(scsiback_exit); 1896 1897 MODULE_DESCRIPTION("Xen SCSI backend driver"); 1898 MODULE_LICENSE("Dual BSD/GPL"); 1899 MODULE_ALIAS("xen-backend:vscsi"); 1900 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>"); 1901