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