1 /* 2 * Xen SCSI backend driver 3 * 4 * Copyright (c) 2008, FUJITSU Limited 5 * 6 * Based on the blkback driver code. 7 * Adaption to kernel taget core infrastructure taken from vhost/scsi.c 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License version 2 11 * as published by the Free Software Foundation; or, when distributed 12 * separately from the Linux kernel or incorporated into other 13 * software packages, subject to the following license: 14 * 15 * Permission is hereby granted, free of charge, to any person obtaining a copy 16 * of this source file (the "Software"), to deal in the Software without 17 * restriction, including without limitation the rights to use, copy, modify, 18 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 19 * and to permit persons to whom the Software is furnished to do so, subject to 20 * the following conditions: 21 * 22 * The above copyright notice and this permission notice shall be included in 23 * all copies or substantial portions of the Software. 24 * 25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 28 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 29 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 30 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 31 * IN THE SOFTWARE. 32 */ 33 34 #define pr_fmt(fmt) "xen-pvscsi: " fmt 35 36 #include <stdarg.h> 37 38 #include <linux/module.h> 39 #include <linux/utsname.h> 40 #include <linux/interrupt.h> 41 #include <linux/slab.h> 42 #include <linux/wait.h> 43 #include <linux/sched.h> 44 #include <linux/list.h> 45 #include <linux/gfp.h> 46 #include <linux/delay.h> 47 #include <linux/spinlock.h> 48 #include <linux/configfs.h> 49 50 #include <generated/utsrelease.h> 51 52 #include <scsi/scsi_host.h> /* SG_ALL */ 53 54 #include <target/target_core_base.h> 55 #include <target/target_core_fabric.h> 56 57 #include <asm/hypervisor.h> 58 59 #include <xen/xen.h> 60 #include <xen/balloon.h> 61 #include <xen/events.h> 62 #include <xen/xenbus.h> 63 #include <xen/grant_table.h> 64 #include <xen/page.h> 65 66 #include <xen/interface/grant_table.h> 67 #include <xen/interface/io/vscsiif.h> 68 69 #define VSCSI_VERSION "v0.1" 70 #define VSCSI_NAMELEN 32 71 72 struct ids_tuple { 73 unsigned int hst; /* host */ 74 unsigned int chn; /* channel */ 75 unsigned int tgt; /* target */ 76 unsigned int lun; /* LUN */ 77 }; 78 79 struct v2p_entry { 80 struct ids_tuple v; /* translate from */ 81 struct scsiback_tpg *tpg; /* translate to */ 82 unsigned int lun; 83 struct kref kref; 84 struct list_head l; 85 }; 86 87 struct vscsibk_info { 88 struct xenbus_device *dev; 89 90 domid_t domid; 91 unsigned int irq; 92 93 struct vscsiif_back_ring ring; 94 int ring_error; 95 96 spinlock_t ring_lock; 97 atomic_t nr_unreplied_reqs; 98 99 spinlock_t v2p_lock; 100 struct list_head v2p_entry_lists; 101 102 wait_queue_head_t waiting_to_free; 103 }; 104 105 /* theoretical maximum of grants for one request */ 106 #define VSCSI_MAX_GRANTS (SG_ALL + VSCSIIF_SG_TABLESIZE) 107 108 /* 109 * VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one 110 * call to map/unmap grants. Don't choose it too large, as there are arrays 111 * with VSCSI_GRANT_BATCH elements allocated on the stack. 112 */ 113 #define VSCSI_GRANT_BATCH 16 114 115 struct vscsibk_pend { 116 uint16_t rqid; 117 118 uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE]; 119 uint8_t cmd_len; 120 121 uint8_t sc_data_direction; 122 uint16_t n_sg; /* real length of SG list */ 123 uint16_t n_grants; /* SG pages and potentially SG list */ 124 uint32_t data_len; 125 uint32_t result; 126 127 struct vscsibk_info *info; 128 struct v2p_entry *v2p; 129 struct scatterlist *sgl; 130 131 uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE]; 132 133 grant_handle_t grant_handles[VSCSI_MAX_GRANTS]; 134 struct page *pages[VSCSI_MAX_GRANTS]; 135 136 struct se_cmd se_cmd; 137 138 struct completion tmr_done; 139 }; 140 141 #define VSCSI_DEFAULT_SESSION_TAGS 128 142 143 struct scsiback_nexus { 144 /* Pointer to TCM session for I_T Nexus */ 145 struct se_session *tvn_se_sess; 146 }; 147 148 struct scsiback_tport { 149 /* SCSI protocol the tport is providing */ 150 u8 tport_proto_id; 151 /* Binary World Wide unique Port Name for pvscsi Target port */ 152 u64 tport_wwpn; 153 /* ASCII formatted WWPN for pvscsi Target port */ 154 char tport_name[VSCSI_NAMELEN]; 155 /* Returned by scsiback_make_tport() */ 156 struct se_wwn tport_wwn; 157 }; 158 159 struct scsiback_tpg { 160 /* scsiback port target portal group tag for TCM */ 161 u16 tport_tpgt; 162 /* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */ 163 int tv_tpg_port_count; 164 /* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */ 165 int tv_tpg_fe_count; 166 /* list for scsiback_list */ 167 struct list_head tv_tpg_list; 168 /* Used to protect access for tpg_nexus */ 169 struct mutex tv_tpg_mutex; 170 /* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */ 171 struct scsiback_nexus *tpg_nexus; 172 /* Pointer back to scsiback_tport */ 173 struct scsiback_tport *tport; 174 /* Returned by scsiback_make_tpg() */ 175 struct se_portal_group se_tpg; 176 /* alias used in xenstore */ 177 char param_alias[VSCSI_NAMELEN]; 178 /* list of info structures related to this target portal group */ 179 struct list_head info_list; 180 }; 181 182 #define SCSIBACK_INVALID_HANDLE (~0) 183 184 static bool log_print_stat; 185 module_param(log_print_stat, bool, 0644); 186 187 static int scsiback_max_buffer_pages = 1024; 188 module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644); 189 MODULE_PARM_DESC(max_buffer_pages, 190 "Maximum number of free pages to keep in backend buffer"); 191 192 static DEFINE_SPINLOCK(free_pages_lock); 193 static int free_pages_num; 194 static LIST_HEAD(scsiback_free_pages); 195 196 /* Global spinlock to protect scsiback TPG list */ 197 static DEFINE_MUTEX(scsiback_mutex); 198 static LIST_HEAD(scsiback_list); 199 200 static void scsiback_get(struct vscsibk_info *info) 201 { 202 atomic_inc(&info->nr_unreplied_reqs); 203 } 204 205 static void scsiback_put(struct vscsibk_info *info) 206 { 207 if (atomic_dec_and_test(&info->nr_unreplied_reqs)) 208 wake_up(&info->waiting_to_free); 209 } 210 211 static void put_free_pages(struct page **page, int num) 212 { 213 unsigned long flags; 214 int i = free_pages_num + num, n = num; 215 216 if (num == 0) 217 return; 218 if (i > scsiback_max_buffer_pages) { 219 n = min(num, i - scsiback_max_buffer_pages); 220 gnttab_free_pages(n, page + num - n); 221 n = num - n; 222 } 223 spin_lock_irqsave(&free_pages_lock, flags); 224 for (i = 0; i < n; i++) 225 list_add(&page[i]->lru, &scsiback_free_pages); 226 free_pages_num += n; 227 spin_unlock_irqrestore(&free_pages_lock, flags); 228 } 229 230 static int get_free_page(struct page **page) 231 { 232 unsigned long flags; 233 234 spin_lock_irqsave(&free_pages_lock, flags); 235 if (list_empty(&scsiback_free_pages)) { 236 spin_unlock_irqrestore(&free_pages_lock, flags); 237 return gnttab_alloc_pages(1, page); 238 } 239 page[0] = list_first_entry(&scsiback_free_pages, struct page, lru); 240 list_del(&page[0]->lru); 241 free_pages_num--; 242 spin_unlock_irqrestore(&free_pages_lock, flags); 243 return 0; 244 } 245 246 static unsigned long vaddr_page(struct page *page) 247 { 248 unsigned long pfn = page_to_pfn(page); 249 250 return (unsigned long)pfn_to_kaddr(pfn); 251 } 252 253 static unsigned long vaddr(struct vscsibk_pend *req, int seg) 254 { 255 return vaddr_page(req->pages[seg]); 256 } 257 258 static void scsiback_print_status(char *sense_buffer, int errors, 259 struct vscsibk_pend *pending_req) 260 { 261 struct scsiback_tpg *tpg = pending_req->v2p->tpg; 262 263 pr_err("[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x drv=%02x\n", 264 tpg->tport->tport_name, pending_req->v2p->lun, 265 pending_req->cmnd[0], status_byte(errors), msg_byte(errors), 266 host_byte(errors), driver_byte(errors)); 267 } 268 269 static void scsiback_fast_flush_area(struct vscsibk_pend *req) 270 { 271 struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH]; 272 struct page *pages[VSCSI_GRANT_BATCH]; 273 unsigned int i, invcount = 0; 274 grant_handle_t handle; 275 int err; 276 277 kfree(req->sgl); 278 req->sgl = NULL; 279 req->n_sg = 0; 280 281 if (!req->n_grants) 282 return; 283 284 for (i = 0; i < req->n_grants; i++) { 285 handle = req->grant_handles[i]; 286 if (handle == SCSIBACK_INVALID_HANDLE) 287 continue; 288 gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i), 289 GNTMAP_host_map, handle); 290 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE; 291 pages[invcount] = req->pages[i]; 292 put_page(pages[invcount]); 293 invcount++; 294 if (invcount < VSCSI_GRANT_BATCH) 295 continue; 296 err = gnttab_unmap_refs(unmap, NULL, pages, invcount); 297 BUG_ON(err); 298 invcount = 0; 299 } 300 301 if (invcount) { 302 err = gnttab_unmap_refs(unmap, NULL, pages, invcount); 303 BUG_ON(err); 304 } 305 306 put_free_pages(req->pages, req->n_grants); 307 req->n_grants = 0; 308 } 309 310 static void scsiback_free_translation_entry(struct kref *kref) 311 { 312 struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref); 313 struct scsiback_tpg *tpg = entry->tpg; 314 315 mutex_lock(&tpg->tv_tpg_mutex); 316 tpg->tv_tpg_fe_count--; 317 mutex_unlock(&tpg->tv_tpg_mutex); 318 319 kfree(entry); 320 } 321 322 static void scsiback_send_response(struct vscsibk_info *info, 323 char *sense_buffer, int32_t result, uint32_t resid, 324 uint16_t rqid) 325 { 326 struct vscsiif_response *ring_res; 327 int notify; 328 struct scsi_sense_hdr sshdr; 329 unsigned long flags; 330 unsigned len; 331 332 spin_lock_irqsave(&info->ring_lock, flags); 333 334 ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt); 335 info->ring.rsp_prod_pvt++; 336 337 ring_res->rslt = result; 338 ring_res->rqid = rqid; 339 340 if (sense_buffer != NULL && 341 scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE, 342 &sshdr)) { 343 len = min_t(unsigned, 8 + sense_buffer[7], 344 VSCSIIF_SENSE_BUFFERSIZE); 345 memcpy(ring_res->sense_buffer, sense_buffer, len); 346 ring_res->sense_len = len; 347 } else { 348 ring_res->sense_len = 0; 349 } 350 351 ring_res->residual_len = resid; 352 353 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify); 354 spin_unlock_irqrestore(&info->ring_lock, flags); 355 356 if (notify) 357 notify_remote_via_irq(info->irq); 358 } 359 360 static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result, 361 uint32_t resid, struct vscsibk_pend *pending_req) 362 { 363 scsiback_send_response(pending_req->info, sense_buffer, result, 364 resid, pending_req->rqid); 365 366 if (pending_req->v2p) 367 kref_put(&pending_req->v2p->kref, 368 scsiback_free_translation_entry); 369 } 370 371 static void scsiback_cmd_done(struct vscsibk_pend *pending_req) 372 { 373 struct vscsibk_info *info = pending_req->info; 374 unsigned char *sense_buffer; 375 unsigned int resid; 376 int errors; 377 378 sense_buffer = pending_req->sense_buffer; 379 resid = pending_req->se_cmd.residual_count; 380 errors = pending_req->result; 381 382 if (errors && log_print_stat) 383 scsiback_print_status(sense_buffer, errors, pending_req); 384 385 scsiback_fast_flush_area(pending_req); 386 scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req); 387 scsiback_put(info); 388 /* 389 * Drop the extra KREF_ACK reference taken by target_submit_cmd_map_sgls() 390 * ahead of scsiback_check_stop_free() -> transport_generic_free_cmd() 391 * final se_cmd->cmd_kref put. 392 */ 393 target_put_sess_cmd(&pending_req->se_cmd); 394 } 395 396 static void scsiback_cmd_exec(struct vscsibk_pend *pending_req) 397 { 398 struct se_cmd *se_cmd = &pending_req->se_cmd; 399 struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess; 400 int rc; 401 402 scsiback_get(pending_req->info); 403 se_cmd->tag = pending_req->rqid; 404 rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd, 405 pending_req->sense_buffer, pending_req->v2p->lun, 406 pending_req->data_len, 0, 407 pending_req->sc_data_direction, TARGET_SCF_ACK_KREF, 408 pending_req->sgl, pending_req->n_sg, 409 NULL, 0, NULL, 0); 410 if (rc < 0) { 411 transport_send_check_condition_and_sense(se_cmd, 412 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0); 413 transport_generic_free_cmd(se_cmd, 0); 414 } 415 } 416 417 static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map, 418 struct page **pg, grant_handle_t *grant, int cnt) 419 { 420 int err, i; 421 422 if (!cnt) 423 return 0; 424 425 err = gnttab_map_refs(map, NULL, pg, cnt); 426 BUG_ON(err); 427 for (i = 0; i < cnt; i++) { 428 if (unlikely(map[i].status != GNTST_okay)) { 429 pr_err("invalid buffer -- could not remap it\n"); 430 map[i].handle = SCSIBACK_INVALID_HANDLE; 431 err = -ENOMEM; 432 } else { 433 get_page(pg[i]); 434 } 435 grant[i] = map[i].handle; 436 } 437 return err; 438 } 439 440 static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req, 441 struct scsiif_request_segment *seg, struct page **pg, 442 grant_handle_t *grant, int cnt, u32 flags) 443 { 444 int mapcount = 0, i, err = 0; 445 struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH]; 446 struct vscsibk_info *info = pending_req->info; 447 448 for (i = 0; i < cnt; i++) { 449 if (get_free_page(pg + mapcount)) { 450 put_free_pages(pg, mapcount); 451 pr_err("no grant page\n"); 452 return -ENOMEM; 453 } 454 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]), 455 flags, seg[i].gref, info->domid); 456 mapcount++; 457 if (mapcount < VSCSI_GRANT_BATCH) 458 continue; 459 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount); 460 pg += mapcount; 461 grant += mapcount; 462 pending_req->n_grants += mapcount; 463 if (err) 464 return err; 465 mapcount = 0; 466 } 467 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount); 468 pending_req->n_grants += mapcount; 469 return err; 470 } 471 472 static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req, 473 struct vscsibk_pend *pending_req) 474 { 475 u32 flags; 476 int i, err, n_segs, i_seg = 0; 477 struct page **pg; 478 struct scsiif_request_segment *seg; 479 unsigned long end_seg = 0; 480 unsigned int nr_segments = (unsigned int)ring_req->nr_segments; 481 unsigned int nr_sgl = 0; 482 struct scatterlist *sg; 483 grant_handle_t *grant; 484 485 pending_req->n_sg = 0; 486 pending_req->n_grants = 0; 487 pending_req->data_len = 0; 488 489 nr_segments &= ~VSCSIIF_SG_GRANT; 490 if (!nr_segments) 491 return 0; 492 493 if (nr_segments > VSCSIIF_SG_TABLESIZE) { 494 pr_debug("invalid parameter nr_seg = %d\n", 495 ring_req->nr_segments); 496 return -EINVAL; 497 } 498 499 if (ring_req->nr_segments & VSCSIIF_SG_GRANT) { 500 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg, 501 pending_req->pages, pending_req->grant_handles, 502 nr_segments, GNTMAP_host_map | GNTMAP_readonly); 503 if (err) 504 return err; 505 nr_sgl = nr_segments; 506 nr_segments = 0; 507 for (i = 0; i < nr_sgl; i++) { 508 n_segs = ring_req->seg[i].length / 509 sizeof(struct scsiif_request_segment); 510 if ((unsigned)ring_req->seg[i].offset + 511 (unsigned)ring_req->seg[i].length > PAGE_SIZE || 512 n_segs * sizeof(struct scsiif_request_segment) != 513 ring_req->seg[i].length) 514 return -EINVAL; 515 nr_segments += n_segs; 516 } 517 if (nr_segments > SG_ALL) { 518 pr_debug("invalid nr_seg = %d\n", nr_segments); 519 return -EINVAL; 520 } 521 } 522 523 /* free of (sgl) in fast_flush_area() */ 524 pending_req->sgl = kmalloc_array(nr_segments, 525 sizeof(struct scatterlist), GFP_KERNEL); 526 if (!pending_req->sgl) 527 return -ENOMEM; 528 529 sg_init_table(pending_req->sgl, nr_segments); 530 pending_req->n_sg = nr_segments; 531 532 flags = GNTMAP_host_map; 533 if (pending_req->sc_data_direction == DMA_TO_DEVICE) 534 flags |= GNTMAP_readonly; 535 536 pg = pending_req->pages + nr_sgl; 537 grant = pending_req->grant_handles + nr_sgl; 538 if (!nr_sgl) { 539 seg = ring_req->seg; 540 err = scsiback_gnttab_data_map_list(pending_req, seg, 541 pg, grant, nr_segments, flags); 542 if (err) 543 return err; 544 } else { 545 for (i = 0; i < nr_sgl; i++) { 546 seg = (struct scsiif_request_segment *)( 547 vaddr(pending_req, i) + ring_req->seg[i].offset); 548 n_segs = ring_req->seg[i].length / 549 sizeof(struct scsiif_request_segment); 550 err = scsiback_gnttab_data_map_list(pending_req, seg, 551 pg, grant, n_segs, flags); 552 if (err) 553 return err; 554 pg += n_segs; 555 grant += n_segs; 556 } 557 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset; 558 seg = (struct scsiif_request_segment *)end_seg; 559 end_seg += ring_req->seg[0].length; 560 pg = pending_req->pages + nr_sgl; 561 } 562 563 for_each_sg(pending_req->sgl, sg, nr_segments, i) { 564 sg_set_page(sg, pg[i], seg->length, seg->offset); 565 pending_req->data_len += seg->length; 566 seg++; 567 if (nr_sgl && (unsigned long)seg >= end_seg) { 568 i_seg++; 569 end_seg = vaddr(pending_req, i_seg) + 570 ring_req->seg[i_seg].offset; 571 seg = (struct scsiif_request_segment *)end_seg; 572 end_seg += ring_req->seg[i_seg].length; 573 } 574 if (sg->offset >= PAGE_SIZE || 575 sg->length > PAGE_SIZE || 576 sg->offset + sg->length > PAGE_SIZE) 577 return -EINVAL; 578 } 579 580 return 0; 581 } 582 583 static void scsiback_disconnect(struct vscsibk_info *info) 584 { 585 wait_event(info->waiting_to_free, 586 atomic_read(&info->nr_unreplied_reqs) == 0); 587 588 unbind_from_irqhandler(info->irq, info); 589 info->irq = 0; 590 xenbus_unmap_ring_vfree(info->dev, info->ring.sring); 591 } 592 593 static void scsiback_device_action(struct vscsibk_pend *pending_req, 594 enum tcm_tmreq_table act, int tag) 595 { 596 struct scsiback_tpg *tpg = pending_req->v2p->tpg; 597 struct scsiback_nexus *nexus = tpg->tpg_nexus; 598 struct se_cmd *se_cmd = &pending_req->se_cmd; 599 u64 unpacked_lun = pending_req->v2p->lun; 600 int rc, err = FAILED; 601 602 init_completion(&pending_req->tmr_done); 603 604 rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess, 605 &pending_req->sense_buffer[0], 606 unpacked_lun, NULL, act, GFP_KERNEL, 607 tag, TARGET_SCF_ACK_KREF); 608 if (rc) 609 goto err; 610 611 wait_for_completion(&pending_req->tmr_done); 612 613 err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ? 614 SUCCESS : FAILED; 615 616 scsiback_do_resp_with_sense(NULL, err, 0, pending_req); 617 transport_generic_free_cmd(&pending_req->se_cmd, 0); 618 return; 619 620 err: 621 scsiback_do_resp_with_sense(NULL, err, 0, pending_req); 622 } 623 624 /* 625 Perform virtual to physical translation 626 */ 627 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info, 628 struct ids_tuple *v) 629 { 630 struct v2p_entry *entry; 631 struct list_head *head = &(info->v2p_entry_lists); 632 unsigned long flags; 633 634 spin_lock_irqsave(&info->v2p_lock, flags); 635 list_for_each_entry(entry, head, l) { 636 if ((entry->v.chn == v->chn) && 637 (entry->v.tgt == v->tgt) && 638 (entry->v.lun == v->lun)) { 639 kref_get(&entry->kref); 640 goto out; 641 } 642 } 643 entry = NULL; 644 645 out: 646 spin_unlock_irqrestore(&info->v2p_lock, flags); 647 return entry; 648 } 649 650 static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring, 651 struct v2p_entry *v2p) 652 { 653 struct scsiback_tpg *tpg = v2p->tpg; 654 struct scsiback_nexus *nexus = tpg->tpg_nexus; 655 struct se_session *se_sess = nexus->tvn_se_sess; 656 struct vscsibk_pend *req; 657 int tag, cpu, i; 658 659 tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu); 660 if (tag < 0) { 661 pr_err("Unable to obtain tag for vscsiif_request\n"); 662 return ERR_PTR(-ENOMEM); 663 } 664 665 req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag]; 666 memset(req, 0, sizeof(*req)); 667 req->se_cmd.map_tag = tag; 668 req->se_cmd.map_cpu = cpu; 669 670 for (i = 0; i < VSCSI_MAX_GRANTS; i++) 671 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE; 672 673 return req; 674 } 675 676 static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info, 677 struct vscsiif_back_ring *ring, 678 struct vscsiif_request *ring_req) 679 { 680 struct vscsibk_pend *pending_req; 681 struct v2p_entry *v2p; 682 struct ids_tuple vir; 683 684 /* request range check from frontend */ 685 if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) && 686 (ring_req->sc_data_direction != DMA_TO_DEVICE) && 687 (ring_req->sc_data_direction != DMA_FROM_DEVICE) && 688 (ring_req->sc_data_direction != DMA_NONE)) { 689 pr_debug("invalid parameter data_dir = %d\n", 690 ring_req->sc_data_direction); 691 return ERR_PTR(-EINVAL); 692 } 693 if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) { 694 pr_debug("invalid parameter cmd_len = %d\n", 695 ring_req->cmd_len); 696 return ERR_PTR(-EINVAL); 697 } 698 699 vir.chn = ring_req->channel; 700 vir.tgt = ring_req->id; 701 vir.lun = ring_req->lun; 702 703 v2p = scsiback_do_translation(info, &vir); 704 if (!v2p) { 705 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n", 706 vir.chn, vir.tgt, vir.lun); 707 return ERR_PTR(-ENODEV); 708 } 709 710 pending_req = scsiback_get_pend_req(ring, v2p); 711 if (IS_ERR(pending_req)) { 712 kref_put(&v2p->kref, scsiback_free_translation_entry); 713 return ERR_PTR(-ENOMEM); 714 } 715 pending_req->rqid = ring_req->rqid; 716 pending_req->info = info; 717 pending_req->v2p = v2p; 718 pending_req->sc_data_direction = ring_req->sc_data_direction; 719 pending_req->cmd_len = ring_req->cmd_len; 720 memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len); 721 722 return pending_req; 723 } 724 725 static int scsiback_do_cmd_fn(struct vscsibk_info *info) 726 { 727 struct vscsiif_back_ring *ring = &info->ring; 728 struct vscsiif_request ring_req; 729 struct vscsibk_pend *pending_req; 730 RING_IDX rc, rp; 731 int more_to_do; 732 uint32_t result; 733 734 rc = ring->req_cons; 735 rp = ring->sring->req_prod; 736 rmb(); /* guest system is accessing ring, too */ 737 738 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) { 739 rc = ring->rsp_prod_pvt; 740 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n", 741 info->domid, rp, rc, rp - rc); 742 info->ring_error = 1; 743 return 0; 744 } 745 746 while ((rc != rp)) { 747 if (RING_REQUEST_CONS_OVERFLOW(ring, rc)) 748 break; 749 750 RING_COPY_REQUEST(ring, rc, &ring_req); 751 ring->req_cons = ++rc; 752 753 pending_req = prepare_pending_reqs(info, ring, &ring_req); 754 if (IS_ERR(pending_req)) { 755 switch (PTR_ERR(pending_req)) { 756 case -ENODEV: 757 result = DID_NO_CONNECT; 758 break; 759 default: 760 result = DRIVER_ERROR; 761 break; 762 } 763 scsiback_send_response(info, NULL, result << 24, 0, 764 ring_req.rqid); 765 return 1; 766 } 767 768 switch (ring_req.act) { 769 case VSCSIIF_ACT_SCSI_CDB: 770 if (scsiback_gnttab_data_map(&ring_req, pending_req)) { 771 scsiback_fast_flush_area(pending_req); 772 scsiback_do_resp_with_sense(NULL, 773 DRIVER_ERROR << 24, 0, pending_req); 774 transport_generic_free_cmd(&pending_req->se_cmd, 0); 775 } else { 776 scsiback_cmd_exec(pending_req); 777 } 778 break; 779 case VSCSIIF_ACT_SCSI_ABORT: 780 scsiback_device_action(pending_req, TMR_ABORT_TASK, 781 ring_req.ref_rqid); 782 break; 783 case VSCSIIF_ACT_SCSI_RESET: 784 scsiback_device_action(pending_req, TMR_LUN_RESET, 0); 785 break; 786 default: 787 pr_err_ratelimited("invalid request\n"); 788 scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24, 0, 789 pending_req); 790 transport_generic_free_cmd(&pending_req->se_cmd, 0); 791 break; 792 } 793 794 /* Yield point for this unbounded loop. */ 795 cond_resched(); 796 } 797 798 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do); 799 return more_to_do; 800 } 801 802 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id) 803 { 804 struct vscsibk_info *info = dev_id; 805 806 if (info->ring_error) 807 return IRQ_HANDLED; 808 809 while (scsiback_do_cmd_fn(info)) 810 cond_resched(); 811 812 return IRQ_HANDLED; 813 } 814 815 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref, 816 evtchn_port_t evtchn) 817 { 818 void *area; 819 struct vscsiif_sring *sring; 820 int err; 821 822 if (info->irq) 823 return -1; 824 825 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area); 826 if (err) 827 return err; 828 829 sring = (struct vscsiif_sring *)area; 830 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE); 831 832 err = bind_interdomain_evtchn_to_irq(info->domid, evtchn); 833 if (err < 0) 834 goto unmap_page; 835 836 info->irq = err; 837 838 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn, 839 IRQF_ONESHOT, "vscsiif-backend", info); 840 if (err) 841 goto free_irq; 842 843 return 0; 844 845 free_irq: 846 unbind_from_irqhandler(info->irq, info); 847 info->irq = 0; 848 unmap_page: 849 xenbus_unmap_ring_vfree(info->dev, area); 850 851 return err; 852 } 853 854 static int scsiback_map(struct vscsibk_info *info) 855 { 856 struct xenbus_device *dev = info->dev; 857 unsigned int ring_ref, evtchn; 858 int err; 859 860 err = xenbus_gather(XBT_NIL, dev->otherend, 861 "ring-ref", "%u", &ring_ref, 862 "event-channel", "%u", &evtchn, NULL); 863 if (err) { 864 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend); 865 return err; 866 } 867 868 return scsiback_init_sring(info, ring_ref, evtchn); 869 } 870 871 /* 872 Check for a translation entry being present 873 */ 874 static struct v2p_entry *scsiback_chk_translation_entry( 875 struct vscsibk_info *info, struct ids_tuple *v) 876 { 877 struct list_head *head = &(info->v2p_entry_lists); 878 struct v2p_entry *entry; 879 880 list_for_each_entry(entry, head, l) 881 if ((entry->v.chn == v->chn) && 882 (entry->v.tgt == v->tgt) && 883 (entry->v.lun == v->lun)) 884 return entry; 885 886 return NULL; 887 } 888 889 /* 890 Add a new translation entry 891 */ 892 static int scsiback_add_translation_entry(struct vscsibk_info *info, 893 char *phy, struct ids_tuple *v) 894 { 895 int err = 0; 896 struct v2p_entry *new; 897 unsigned long flags; 898 char *lunp; 899 unsigned long long unpacked_lun; 900 struct se_lun *se_lun; 901 struct scsiback_tpg *tpg_entry, *tpg = NULL; 902 char *error = "doesn't exist"; 903 904 lunp = strrchr(phy, ':'); 905 if (!lunp) { 906 pr_err("illegal format of physical device %s\n", phy); 907 return -EINVAL; 908 } 909 *lunp = 0; 910 lunp++; 911 err = kstrtoull(lunp, 10, &unpacked_lun); 912 if (err < 0) { 913 pr_err("lun number not valid: %s\n", lunp); 914 return err; 915 } 916 917 mutex_lock(&scsiback_mutex); 918 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) { 919 if (!strcmp(phy, tpg_entry->tport->tport_name) || 920 !strcmp(phy, tpg_entry->param_alias)) { 921 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex); 922 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) { 923 if (se_lun->unpacked_lun == unpacked_lun) { 924 if (!tpg_entry->tpg_nexus) 925 error = "nexus undefined"; 926 else 927 tpg = tpg_entry; 928 break; 929 } 930 } 931 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex); 932 break; 933 } 934 } 935 if (tpg) { 936 mutex_lock(&tpg->tv_tpg_mutex); 937 tpg->tv_tpg_fe_count++; 938 mutex_unlock(&tpg->tv_tpg_mutex); 939 } 940 mutex_unlock(&scsiback_mutex); 941 942 if (!tpg) { 943 pr_err("%s:%llu %s\n", phy, unpacked_lun, error); 944 return -ENODEV; 945 } 946 947 new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL); 948 if (new == NULL) { 949 err = -ENOMEM; 950 goto out_free; 951 } 952 953 spin_lock_irqsave(&info->v2p_lock, flags); 954 955 /* Check double assignment to identical virtual ID */ 956 if (scsiback_chk_translation_entry(info, v)) { 957 pr_warn("Virtual ID is already used. Assignment was not performed.\n"); 958 err = -EEXIST; 959 goto out; 960 } 961 962 /* Create a new translation entry and add to the list */ 963 kref_init(&new->kref); 964 new->v = *v; 965 new->tpg = tpg; 966 new->lun = unpacked_lun; 967 list_add_tail(&new->l, &info->v2p_entry_lists); 968 969 out: 970 spin_unlock_irqrestore(&info->v2p_lock, flags); 971 972 out_free: 973 if (err) { 974 mutex_lock(&tpg->tv_tpg_mutex); 975 tpg->tv_tpg_fe_count--; 976 mutex_unlock(&tpg->tv_tpg_mutex); 977 kfree(new); 978 } 979 980 return err; 981 } 982 983 static void __scsiback_del_translation_entry(struct v2p_entry *entry) 984 { 985 list_del(&entry->l); 986 kref_put(&entry->kref, scsiback_free_translation_entry); 987 } 988 989 /* 990 Delete the translation entry specified 991 */ 992 static int scsiback_del_translation_entry(struct vscsibk_info *info, 993 struct ids_tuple *v) 994 { 995 struct v2p_entry *entry; 996 unsigned long flags; 997 int ret = 0; 998 999 spin_lock_irqsave(&info->v2p_lock, flags); 1000 /* Find out the translation entry specified */ 1001 entry = scsiback_chk_translation_entry(info, v); 1002 if (entry) 1003 __scsiback_del_translation_entry(entry); 1004 else 1005 ret = -ENOENT; 1006 1007 spin_unlock_irqrestore(&info->v2p_lock, flags); 1008 return ret; 1009 } 1010 1011 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state, 1012 char *phy, struct ids_tuple *vir, int try) 1013 { 1014 struct v2p_entry *entry; 1015 unsigned long flags; 1016 int err; 1017 1018 if (try) { 1019 spin_lock_irqsave(&info->v2p_lock, flags); 1020 entry = scsiback_chk_translation_entry(info, vir); 1021 spin_unlock_irqrestore(&info->v2p_lock, flags); 1022 if (entry) 1023 return; 1024 } 1025 if (!scsiback_add_translation_entry(info, phy, vir)) { 1026 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1027 "%d", XenbusStateInitialised)) { 1028 pr_err("xenbus_printf error %s\n", state); 1029 scsiback_del_translation_entry(info, vir); 1030 } 1031 } else if (!try) { 1032 err = xenbus_printf(XBT_NIL, info->dev->nodename, state, 1033 "%d", XenbusStateClosed); 1034 if (err) 1035 xenbus_dev_error(info->dev, err, 1036 "%s: writing %s", __func__, state); 1037 } 1038 } 1039 1040 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state, 1041 struct ids_tuple *vir) 1042 { 1043 if (!scsiback_del_translation_entry(info, vir)) { 1044 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1045 "%d", XenbusStateClosed)) 1046 pr_err("xenbus_printf error %s\n", state); 1047 } 1048 } 1049 1050 #define VSCSIBACK_OP_ADD_OR_DEL_LUN 1 1051 #define VSCSIBACK_OP_UPDATEDEV_STATE 2 1052 1053 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op, 1054 char *ent) 1055 { 1056 int err; 1057 struct ids_tuple vir; 1058 char *val; 1059 int device_state; 1060 char phy[VSCSI_NAMELEN]; 1061 char str[64]; 1062 char state[64]; 1063 struct xenbus_device *dev = info->dev; 1064 1065 /* read status */ 1066 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent); 1067 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state); 1068 if (XENBUS_EXIST_ERR(err)) 1069 return; 1070 1071 /* physical SCSI device */ 1072 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent); 1073 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL); 1074 if (IS_ERR(val)) { 1075 err = xenbus_printf(XBT_NIL, dev->nodename, state, 1076 "%d", XenbusStateClosed); 1077 if (err) 1078 xenbus_dev_error(info->dev, err, 1079 "%s: writing %s", __func__, state); 1080 return; 1081 } 1082 strlcpy(phy, val, VSCSI_NAMELEN); 1083 kfree(val); 1084 1085 /* virtual SCSI device */ 1086 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent); 1087 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u", 1088 &vir.hst, &vir.chn, &vir.tgt, &vir.lun); 1089 if (XENBUS_EXIST_ERR(err)) { 1090 err = xenbus_printf(XBT_NIL, dev->nodename, state, 1091 "%d", XenbusStateClosed); 1092 if (err) 1093 xenbus_dev_error(info->dev, err, 1094 "%s: writing %s", __func__, state); 1095 return; 1096 } 1097 1098 switch (op) { 1099 case VSCSIBACK_OP_ADD_OR_DEL_LUN: 1100 switch (device_state) { 1101 case XenbusStateInitialising: 1102 scsiback_do_add_lun(info, state, phy, &vir, 0); 1103 break; 1104 case XenbusStateConnected: 1105 scsiback_do_add_lun(info, state, phy, &vir, 1); 1106 break; 1107 case XenbusStateClosing: 1108 scsiback_do_del_lun(info, state, &vir); 1109 break; 1110 default: 1111 break; 1112 } 1113 break; 1114 1115 case VSCSIBACK_OP_UPDATEDEV_STATE: 1116 if (device_state == XenbusStateInitialised) { 1117 /* modify vscsi-devs/dev-x/state */ 1118 if (xenbus_printf(XBT_NIL, dev->nodename, state, 1119 "%d", XenbusStateConnected)) { 1120 pr_err("xenbus_printf error %s\n", str); 1121 scsiback_del_translation_entry(info, &vir); 1122 xenbus_printf(XBT_NIL, dev->nodename, state, 1123 "%d", XenbusStateClosed); 1124 } 1125 } 1126 break; 1127 /* When it is necessary, processing is added here. */ 1128 default: 1129 break; 1130 } 1131 } 1132 1133 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op) 1134 { 1135 int i; 1136 char **dir; 1137 unsigned int ndir = 0; 1138 1139 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs", 1140 &ndir); 1141 if (IS_ERR(dir)) 1142 return; 1143 1144 for (i = 0; i < ndir; i++) 1145 scsiback_do_1lun_hotplug(info, op, dir[i]); 1146 1147 kfree(dir); 1148 } 1149 1150 static void scsiback_frontend_changed(struct xenbus_device *dev, 1151 enum xenbus_state frontend_state) 1152 { 1153 struct vscsibk_info *info = dev_get_drvdata(&dev->dev); 1154 1155 switch (frontend_state) { 1156 case XenbusStateInitialising: 1157 break; 1158 1159 case XenbusStateInitialised: 1160 if (scsiback_map(info)) 1161 break; 1162 1163 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); 1164 xenbus_switch_state(dev, XenbusStateConnected); 1165 break; 1166 1167 case XenbusStateConnected: 1168 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE); 1169 1170 if (dev->state == XenbusStateConnected) 1171 break; 1172 1173 xenbus_switch_state(dev, XenbusStateConnected); 1174 break; 1175 1176 case XenbusStateClosing: 1177 if (info->irq) 1178 scsiback_disconnect(info); 1179 1180 xenbus_switch_state(dev, XenbusStateClosing); 1181 break; 1182 1183 case XenbusStateClosed: 1184 xenbus_switch_state(dev, XenbusStateClosed); 1185 if (xenbus_dev_is_online(dev)) 1186 break; 1187 /* fall through if not online */ 1188 case XenbusStateUnknown: 1189 device_unregister(&dev->dev); 1190 break; 1191 1192 case XenbusStateReconfiguring: 1193 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); 1194 xenbus_switch_state(dev, XenbusStateReconfigured); 1195 1196 break; 1197 1198 default: 1199 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", 1200 frontend_state); 1201 break; 1202 } 1203 } 1204 1205 /* 1206 Release the translation entry specfied 1207 */ 1208 static void scsiback_release_translation_entry(struct vscsibk_info *info) 1209 { 1210 struct v2p_entry *entry, *tmp; 1211 struct list_head *head = &(info->v2p_entry_lists); 1212 unsigned long flags; 1213 1214 spin_lock_irqsave(&info->v2p_lock, flags); 1215 1216 list_for_each_entry_safe(entry, tmp, head, l) 1217 __scsiback_del_translation_entry(entry); 1218 1219 spin_unlock_irqrestore(&info->v2p_lock, flags); 1220 } 1221 1222 static int scsiback_remove(struct xenbus_device *dev) 1223 { 1224 struct vscsibk_info *info = dev_get_drvdata(&dev->dev); 1225 1226 if (info->irq) 1227 scsiback_disconnect(info); 1228 1229 scsiback_release_translation_entry(info); 1230 1231 dev_set_drvdata(&dev->dev, NULL); 1232 1233 return 0; 1234 } 1235 1236 static int scsiback_probe(struct xenbus_device *dev, 1237 const struct xenbus_device_id *id) 1238 { 1239 int err; 1240 1241 struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info), 1242 GFP_KERNEL); 1243 1244 pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); 1245 1246 if (!info) { 1247 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure"); 1248 return -ENOMEM; 1249 } 1250 info->dev = dev; 1251 dev_set_drvdata(&dev->dev, info); 1252 1253 info->domid = dev->otherend_id; 1254 spin_lock_init(&info->ring_lock); 1255 info->ring_error = 0; 1256 atomic_set(&info->nr_unreplied_reqs, 0); 1257 init_waitqueue_head(&info->waiting_to_free); 1258 info->dev = dev; 1259 info->irq = 0; 1260 INIT_LIST_HEAD(&info->v2p_entry_lists); 1261 spin_lock_init(&info->v2p_lock); 1262 1263 err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u", 1264 SG_ALL); 1265 if (err) 1266 xenbus_dev_error(dev, err, "writing feature-sg-grant"); 1267 1268 err = xenbus_switch_state(dev, XenbusStateInitWait); 1269 if (err) 1270 goto fail; 1271 1272 return 0; 1273 1274 fail: 1275 pr_warn("%s failed\n", __func__); 1276 scsiback_remove(dev); 1277 1278 return err; 1279 } 1280 1281 static char *scsiback_dump_proto_id(struct scsiback_tport *tport) 1282 { 1283 switch (tport->tport_proto_id) { 1284 case SCSI_PROTOCOL_SAS: 1285 return "SAS"; 1286 case SCSI_PROTOCOL_FCP: 1287 return "FCP"; 1288 case SCSI_PROTOCOL_ISCSI: 1289 return "iSCSI"; 1290 default: 1291 break; 1292 } 1293 1294 return "Unknown"; 1295 } 1296 1297 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg) 1298 { 1299 struct scsiback_tpg *tpg = container_of(se_tpg, 1300 struct scsiback_tpg, se_tpg); 1301 struct scsiback_tport *tport = tpg->tport; 1302 1303 return &tport->tport_name[0]; 1304 } 1305 1306 static u16 scsiback_get_tag(struct se_portal_group *se_tpg) 1307 { 1308 struct scsiback_tpg *tpg = container_of(se_tpg, 1309 struct scsiback_tpg, se_tpg); 1310 return tpg->tport_tpgt; 1311 } 1312 1313 static struct se_wwn * 1314 scsiback_make_tport(struct target_fabric_configfs *tf, 1315 struct config_group *group, 1316 const char *name) 1317 { 1318 struct scsiback_tport *tport; 1319 char *ptr; 1320 u64 wwpn = 0; 1321 int off = 0; 1322 1323 tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL); 1324 if (!tport) 1325 return ERR_PTR(-ENOMEM); 1326 1327 tport->tport_wwpn = wwpn; 1328 /* 1329 * Determine the emulated Protocol Identifier and Target Port Name 1330 * based on the incoming configfs directory name. 1331 */ 1332 ptr = strstr(name, "naa."); 1333 if (ptr) { 1334 tport->tport_proto_id = SCSI_PROTOCOL_SAS; 1335 goto check_len; 1336 } 1337 ptr = strstr(name, "fc."); 1338 if (ptr) { 1339 tport->tport_proto_id = SCSI_PROTOCOL_FCP; 1340 off = 3; /* Skip over "fc." */ 1341 goto check_len; 1342 } 1343 ptr = strstr(name, "iqn."); 1344 if (ptr) { 1345 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI; 1346 goto check_len; 1347 } 1348 1349 pr_err("Unable to locate prefix for emulated Target Port: %s\n", name); 1350 kfree(tport); 1351 return ERR_PTR(-EINVAL); 1352 1353 check_len: 1354 if (strlen(name) >= VSCSI_NAMELEN) { 1355 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name, 1356 scsiback_dump_proto_id(tport), VSCSI_NAMELEN); 1357 kfree(tport); 1358 return ERR_PTR(-EINVAL); 1359 } 1360 snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]); 1361 1362 pr_debug("Allocated emulated Target %s Address: %s\n", 1363 scsiback_dump_proto_id(tport), name); 1364 1365 return &tport->tport_wwn; 1366 } 1367 1368 static void scsiback_drop_tport(struct se_wwn *wwn) 1369 { 1370 struct scsiback_tport *tport = container_of(wwn, 1371 struct scsiback_tport, tport_wwn); 1372 1373 pr_debug("Deallocating emulated Target %s Address: %s\n", 1374 scsiback_dump_proto_id(tport), tport->tport_name); 1375 1376 kfree(tport); 1377 } 1378 1379 static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg) 1380 { 1381 return 1; 1382 } 1383 1384 static int scsiback_check_stop_free(struct se_cmd *se_cmd) 1385 { 1386 return transport_generic_free_cmd(se_cmd, 0); 1387 } 1388 1389 static void scsiback_release_cmd(struct se_cmd *se_cmd) 1390 { 1391 target_free_tag(se_cmd->se_sess, se_cmd); 1392 } 1393 1394 static u32 scsiback_sess_get_index(struct se_session *se_sess) 1395 { 1396 return 0; 1397 } 1398 1399 static int scsiback_write_pending(struct se_cmd *se_cmd) 1400 { 1401 /* Go ahead and process the write immediately */ 1402 target_execute_cmd(se_cmd); 1403 1404 return 0; 1405 } 1406 1407 static int scsiback_write_pending_status(struct se_cmd *se_cmd) 1408 { 1409 return 0; 1410 } 1411 1412 static void scsiback_set_default_node_attrs(struct se_node_acl *nacl) 1413 { 1414 } 1415 1416 static int scsiback_get_cmd_state(struct se_cmd *se_cmd) 1417 { 1418 return 0; 1419 } 1420 1421 static int scsiback_queue_data_in(struct se_cmd *se_cmd) 1422 { 1423 struct vscsibk_pend *pending_req = container_of(se_cmd, 1424 struct vscsibk_pend, se_cmd); 1425 1426 pending_req->result = SAM_STAT_GOOD; 1427 scsiback_cmd_done(pending_req); 1428 return 0; 1429 } 1430 1431 static int scsiback_queue_status(struct se_cmd *se_cmd) 1432 { 1433 struct vscsibk_pend *pending_req = container_of(se_cmd, 1434 struct vscsibk_pend, se_cmd); 1435 1436 if (se_cmd->sense_buffer && 1437 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) || 1438 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) 1439 pending_req->result = (DRIVER_SENSE << 24) | 1440 SAM_STAT_CHECK_CONDITION; 1441 else 1442 pending_req->result = se_cmd->scsi_status; 1443 1444 scsiback_cmd_done(pending_req); 1445 return 0; 1446 } 1447 1448 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd) 1449 { 1450 struct vscsibk_pend *pending_req = container_of(se_cmd, 1451 struct vscsibk_pend, se_cmd); 1452 1453 complete(&pending_req->tmr_done); 1454 } 1455 1456 static void scsiback_aborted_task(struct se_cmd *se_cmd) 1457 { 1458 } 1459 1460 static ssize_t scsiback_tpg_param_alias_show(struct config_item *item, 1461 char *page) 1462 { 1463 struct se_portal_group *se_tpg = param_to_tpg(item); 1464 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1465 se_tpg); 1466 ssize_t rb; 1467 1468 mutex_lock(&tpg->tv_tpg_mutex); 1469 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias); 1470 mutex_unlock(&tpg->tv_tpg_mutex); 1471 1472 return rb; 1473 } 1474 1475 static ssize_t scsiback_tpg_param_alias_store(struct config_item *item, 1476 const char *page, size_t count) 1477 { 1478 struct se_portal_group *se_tpg = param_to_tpg(item); 1479 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1480 se_tpg); 1481 int len; 1482 1483 if (strlen(page) >= VSCSI_NAMELEN) { 1484 pr_err("param alias: %s, exceeds max: %d\n", page, 1485 VSCSI_NAMELEN); 1486 return -EINVAL; 1487 } 1488 1489 mutex_lock(&tpg->tv_tpg_mutex); 1490 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page); 1491 if (tpg->param_alias[len - 1] == '\n') 1492 tpg->param_alias[len - 1] = '\0'; 1493 mutex_unlock(&tpg->tv_tpg_mutex); 1494 1495 return count; 1496 } 1497 1498 CONFIGFS_ATTR(scsiback_tpg_param_, alias); 1499 1500 static struct configfs_attribute *scsiback_param_attrs[] = { 1501 &scsiback_tpg_param_attr_alias, 1502 NULL, 1503 }; 1504 1505 static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg, 1506 struct se_session *se_sess, void *p) 1507 { 1508 struct scsiback_tpg *tpg = container_of(se_tpg, 1509 struct scsiback_tpg, se_tpg); 1510 1511 tpg->tpg_nexus = p; 1512 return 0; 1513 } 1514 1515 static int scsiback_make_nexus(struct scsiback_tpg *tpg, 1516 const char *name) 1517 { 1518 struct scsiback_nexus *tv_nexus; 1519 int ret = 0; 1520 1521 mutex_lock(&tpg->tv_tpg_mutex); 1522 if (tpg->tpg_nexus) { 1523 pr_debug("tpg->tpg_nexus already exists\n"); 1524 ret = -EEXIST; 1525 goto out_unlock; 1526 } 1527 1528 tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL); 1529 if (!tv_nexus) { 1530 ret = -ENOMEM; 1531 goto out_unlock; 1532 } 1533 1534 tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg, 1535 VSCSI_DEFAULT_SESSION_TAGS, 1536 sizeof(struct vscsibk_pend), 1537 TARGET_PROT_NORMAL, name, 1538 tv_nexus, scsiback_alloc_sess_cb); 1539 if (IS_ERR(tv_nexus->tvn_se_sess)) { 1540 kfree(tv_nexus); 1541 ret = -ENOMEM; 1542 goto out_unlock; 1543 } 1544 1545 out_unlock: 1546 mutex_unlock(&tpg->tv_tpg_mutex); 1547 return ret; 1548 } 1549 1550 static int scsiback_drop_nexus(struct scsiback_tpg *tpg) 1551 { 1552 struct se_session *se_sess; 1553 struct scsiback_nexus *tv_nexus; 1554 1555 mutex_lock(&tpg->tv_tpg_mutex); 1556 tv_nexus = tpg->tpg_nexus; 1557 if (!tv_nexus) { 1558 mutex_unlock(&tpg->tv_tpg_mutex); 1559 return -ENODEV; 1560 } 1561 1562 se_sess = tv_nexus->tvn_se_sess; 1563 if (!se_sess) { 1564 mutex_unlock(&tpg->tv_tpg_mutex); 1565 return -ENODEV; 1566 } 1567 1568 if (tpg->tv_tpg_port_count != 0) { 1569 mutex_unlock(&tpg->tv_tpg_mutex); 1570 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n", 1571 tpg->tv_tpg_port_count); 1572 return -EBUSY; 1573 } 1574 1575 if (tpg->tv_tpg_fe_count != 0) { 1576 mutex_unlock(&tpg->tv_tpg_mutex); 1577 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n", 1578 tpg->tv_tpg_fe_count); 1579 return -EBUSY; 1580 } 1581 1582 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n", 1583 scsiback_dump_proto_id(tpg->tport), 1584 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1585 1586 /* 1587 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port 1588 */ 1589 target_remove_session(se_sess); 1590 tpg->tpg_nexus = NULL; 1591 mutex_unlock(&tpg->tv_tpg_mutex); 1592 1593 kfree(tv_nexus); 1594 return 0; 1595 } 1596 1597 static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page) 1598 { 1599 struct se_portal_group *se_tpg = to_tpg(item); 1600 struct scsiback_tpg *tpg = container_of(se_tpg, 1601 struct scsiback_tpg, se_tpg); 1602 struct scsiback_nexus *tv_nexus; 1603 ssize_t ret; 1604 1605 mutex_lock(&tpg->tv_tpg_mutex); 1606 tv_nexus = tpg->tpg_nexus; 1607 if (!tv_nexus) { 1608 mutex_unlock(&tpg->tv_tpg_mutex); 1609 return -ENODEV; 1610 } 1611 ret = snprintf(page, PAGE_SIZE, "%s\n", 1612 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1613 mutex_unlock(&tpg->tv_tpg_mutex); 1614 1615 return ret; 1616 } 1617 1618 static ssize_t scsiback_tpg_nexus_store(struct config_item *item, 1619 const char *page, size_t count) 1620 { 1621 struct se_portal_group *se_tpg = to_tpg(item); 1622 struct scsiback_tpg *tpg = container_of(se_tpg, 1623 struct scsiback_tpg, se_tpg); 1624 struct scsiback_tport *tport_wwn = tpg->tport; 1625 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr; 1626 int ret; 1627 /* 1628 * Shutdown the active I_T nexus if 'NULL' is passed. 1629 */ 1630 if (!strncmp(page, "NULL", 4)) { 1631 ret = scsiback_drop_nexus(tpg); 1632 return (!ret) ? count : ret; 1633 } 1634 /* 1635 * Otherwise make sure the passed virtual Initiator port WWN matches 1636 * the fabric protocol_id set in scsiback_make_tport(), and call 1637 * scsiback_make_nexus(). 1638 */ 1639 if (strlen(page) >= VSCSI_NAMELEN) { 1640 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n", 1641 page, VSCSI_NAMELEN); 1642 return -EINVAL; 1643 } 1644 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page); 1645 1646 ptr = strstr(i_port, "naa."); 1647 if (ptr) { 1648 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) { 1649 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n", 1650 i_port, scsiback_dump_proto_id(tport_wwn)); 1651 return -EINVAL; 1652 } 1653 port_ptr = &i_port[0]; 1654 goto check_newline; 1655 } 1656 ptr = strstr(i_port, "fc."); 1657 if (ptr) { 1658 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) { 1659 pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n", 1660 i_port, scsiback_dump_proto_id(tport_wwn)); 1661 return -EINVAL; 1662 } 1663 port_ptr = &i_port[3]; /* Skip over "fc." */ 1664 goto check_newline; 1665 } 1666 ptr = strstr(i_port, "iqn."); 1667 if (ptr) { 1668 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) { 1669 pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n", 1670 i_port, scsiback_dump_proto_id(tport_wwn)); 1671 return -EINVAL; 1672 } 1673 port_ptr = &i_port[0]; 1674 goto check_newline; 1675 } 1676 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n", 1677 i_port); 1678 return -EINVAL; 1679 /* 1680 * Clear any trailing newline for the NAA WWN 1681 */ 1682 check_newline: 1683 if (i_port[strlen(i_port) - 1] == '\n') 1684 i_port[strlen(i_port) - 1] = '\0'; 1685 1686 ret = scsiback_make_nexus(tpg, port_ptr); 1687 if (ret < 0) 1688 return ret; 1689 1690 return count; 1691 } 1692 1693 CONFIGFS_ATTR(scsiback_tpg_, nexus); 1694 1695 static struct configfs_attribute *scsiback_tpg_attrs[] = { 1696 &scsiback_tpg_attr_nexus, 1697 NULL, 1698 }; 1699 1700 static ssize_t 1701 scsiback_wwn_version_show(struct config_item *item, char *page) 1702 { 1703 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on " 1704 UTS_RELEASE"\n", 1705 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1706 } 1707 1708 CONFIGFS_ATTR_RO(scsiback_wwn_, version); 1709 1710 static struct configfs_attribute *scsiback_wwn_attrs[] = { 1711 &scsiback_wwn_attr_version, 1712 NULL, 1713 }; 1714 1715 static char *scsiback_get_fabric_name(void) 1716 { 1717 return "xen-pvscsi"; 1718 } 1719 1720 static int scsiback_port_link(struct se_portal_group *se_tpg, 1721 struct se_lun *lun) 1722 { 1723 struct scsiback_tpg *tpg = container_of(se_tpg, 1724 struct scsiback_tpg, se_tpg); 1725 1726 mutex_lock(&tpg->tv_tpg_mutex); 1727 tpg->tv_tpg_port_count++; 1728 mutex_unlock(&tpg->tv_tpg_mutex); 1729 1730 return 0; 1731 } 1732 1733 static void scsiback_port_unlink(struct se_portal_group *se_tpg, 1734 struct se_lun *lun) 1735 { 1736 struct scsiback_tpg *tpg = container_of(se_tpg, 1737 struct scsiback_tpg, se_tpg); 1738 1739 mutex_lock(&tpg->tv_tpg_mutex); 1740 tpg->tv_tpg_port_count--; 1741 mutex_unlock(&tpg->tv_tpg_mutex); 1742 } 1743 1744 static struct se_portal_group * 1745 scsiback_make_tpg(struct se_wwn *wwn, const char *name) 1746 { 1747 struct scsiback_tport *tport = container_of(wwn, 1748 struct scsiback_tport, tport_wwn); 1749 1750 struct scsiback_tpg *tpg; 1751 u16 tpgt; 1752 int ret; 1753 1754 if (strstr(name, "tpgt_") != name) 1755 return ERR_PTR(-EINVAL); 1756 ret = kstrtou16(name + 5, 10, &tpgt); 1757 if (ret) 1758 return ERR_PTR(ret); 1759 1760 tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL); 1761 if (!tpg) 1762 return ERR_PTR(-ENOMEM); 1763 1764 mutex_init(&tpg->tv_tpg_mutex); 1765 INIT_LIST_HEAD(&tpg->tv_tpg_list); 1766 INIT_LIST_HEAD(&tpg->info_list); 1767 tpg->tport = tport; 1768 tpg->tport_tpgt = tpgt; 1769 1770 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id); 1771 if (ret < 0) { 1772 kfree(tpg); 1773 return NULL; 1774 } 1775 mutex_lock(&scsiback_mutex); 1776 list_add_tail(&tpg->tv_tpg_list, &scsiback_list); 1777 mutex_unlock(&scsiback_mutex); 1778 1779 return &tpg->se_tpg; 1780 } 1781 1782 static void scsiback_drop_tpg(struct se_portal_group *se_tpg) 1783 { 1784 struct scsiback_tpg *tpg = container_of(se_tpg, 1785 struct scsiback_tpg, se_tpg); 1786 1787 mutex_lock(&scsiback_mutex); 1788 list_del(&tpg->tv_tpg_list); 1789 mutex_unlock(&scsiback_mutex); 1790 /* 1791 * Release the virtual I_T Nexus for this xen-pvscsi TPG 1792 */ 1793 scsiback_drop_nexus(tpg); 1794 /* 1795 * Deregister the se_tpg from TCM. 1796 */ 1797 core_tpg_deregister(se_tpg); 1798 kfree(tpg); 1799 } 1800 1801 static int scsiback_check_true(struct se_portal_group *se_tpg) 1802 { 1803 return 1; 1804 } 1805 1806 static int scsiback_check_false(struct se_portal_group *se_tpg) 1807 { 1808 return 0; 1809 } 1810 1811 static const struct target_core_fabric_ops scsiback_ops = { 1812 .module = THIS_MODULE, 1813 .name = "xen-pvscsi", 1814 .get_fabric_name = scsiback_get_fabric_name, 1815 .tpg_get_wwn = scsiback_get_fabric_wwn, 1816 .tpg_get_tag = scsiback_get_tag, 1817 .tpg_check_demo_mode = scsiback_check_true, 1818 .tpg_check_demo_mode_cache = scsiback_check_true, 1819 .tpg_check_demo_mode_write_protect = scsiback_check_false, 1820 .tpg_check_prod_mode_write_protect = scsiback_check_false, 1821 .tpg_get_inst_index = scsiback_tpg_get_inst_index, 1822 .check_stop_free = scsiback_check_stop_free, 1823 .release_cmd = scsiback_release_cmd, 1824 .sess_get_index = scsiback_sess_get_index, 1825 .sess_get_initiator_sid = NULL, 1826 .write_pending = scsiback_write_pending, 1827 .write_pending_status = scsiback_write_pending_status, 1828 .set_default_node_attributes = scsiback_set_default_node_attrs, 1829 .get_cmd_state = scsiback_get_cmd_state, 1830 .queue_data_in = scsiback_queue_data_in, 1831 .queue_status = scsiback_queue_status, 1832 .queue_tm_rsp = scsiback_queue_tm_rsp, 1833 .aborted_task = scsiback_aborted_task, 1834 /* 1835 * Setup callers for generic logic in target_core_fabric_configfs.c 1836 */ 1837 .fabric_make_wwn = scsiback_make_tport, 1838 .fabric_drop_wwn = scsiback_drop_tport, 1839 .fabric_make_tpg = scsiback_make_tpg, 1840 .fabric_drop_tpg = scsiback_drop_tpg, 1841 .fabric_post_link = scsiback_port_link, 1842 .fabric_pre_unlink = scsiback_port_unlink, 1843 1844 .tfc_wwn_attrs = scsiback_wwn_attrs, 1845 .tfc_tpg_base_attrs = scsiback_tpg_attrs, 1846 .tfc_tpg_param_attrs = scsiback_param_attrs, 1847 }; 1848 1849 static const struct xenbus_device_id scsiback_ids[] = { 1850 { "vscsi" }, 1851 { "" } 1852 }; 1853 1854 static struct xenbus_driver scsiback_driver = { 1855 .ids = scsiback_ids, 1856 .probe = scsiback_probe, 1857 .remove = scsiback_remove, 1858 .otherend_changed = scsiback_frontend_changed 1859 }; 1860 1861 static int __init scsiback_init(void) 1862 { 1863 int ret; 1864 1865 if (!xen_domain()) 1866 return -ENODEV; 1867 1868 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n", 1869 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1870 1871 ret = xenbus_register_backend(&scsiback_driver); 1872 if (ret) 1873 goto out; 1874 1875 ret = target_register_template(&scsiback_ops); 1876 if (ret) 1877 goto out_unregister_xenbus; 1878 1879 return 0; 1880 1881 out_unregister_xenbus: 1882 xenbus_unregister_driver(&scsiback_driver); 1883 out: 1884 pr_err("%s: error %d\n", __func__, ret); 1885 return ret; 1886 } 1887 1888 static void __exit scsiback_exit(void) 1889 { 1890 struct page *page; 1891 1892 while (free_pages_num) { 1893 if (get_free_page(&page)) 1894 BUG(); 1895 gnttab_free_pages(1, &page); 1896 } 1897 target_unregister_template(&scsiback_ops); 1898 xenbus_unregister_driver(&scsiback_driver); 1899 } 1900 1901 module_init(scsiback_init); 1902 module_exit(scsiback_exit); 1903 1904 MODULE_DESCRIPTION("Xen SCSI backend driver"); 1905 MODULE_LICENSE("Dual BSD/GPL"); 1906 MODULE_ALIAS("xen-backend:vscsi"); 1907 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>"); 1908