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 }; 138 139 struct scsiback_tmr { 140 atomic_t tmr_complete; 141 wait_queue_head_t tmr_wait; 142 }; 143 144 #define VSCSI_DEFAULT_SESSION_TAGS 128 145 146 struct scsiback_nexus { 147 /* Pointer to TCM session for I_T Nexus */ 148 struct se_session *tvn_se_sess; 149 }; 150 151 struct scsiback_tport { 152 /* SCSI protocol the tport is providing */ 153 u8 tport_proto_id; 154 /* Binary World Wide unique Port Name for pvscsi Target port */ 155 u64 tport_wwpn; 156 /* ASCII formatted WWPN for pvscsi Target port */ 157 char tport_name[VSCSI_NAMELEN]; 158 /* Returned by scsiback_make_tport() */ 159 struct se_wwn tport_wwn; 160 }; 161 162 struct scsiback_tpg { 163 /* scsiback port target portal group tag for TCM */ 164 u16 tport_tpgt; 165 /* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */ 166 int tv_tpg_port_count; 167 /* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */ 168 int tv_tpg_fe_count; 169 /* list for scsiback_list */ 170 struct list_head tv_tpg_list; 171 /* Used to protect access for tpg_nexus */ 172 struct mutex tv_tpg_mutex; 173 /* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */ 174 struct scsiback_nexus *tpg_nexus; 175 /* Pointer back to scsiback_tport */ 176 struct scsiback_tport *tport; 177 /* Returned by scsiback_make_tpg() */ 178 struct se_portal_group se_tpg; 179 /* alias used in xenstore */ 180 char param_alias[VSCSI_NAMELEN]; 181 /* list of info structures related to this target portal group */ 182 struct list_head info_list; 183 }; 184 185 #define SCSIBACK_INVALID_HANDLE (~0) 186 187 static bool log_print_stat; 188 module_param(log_print_stat, bool, 0644); 189 190 static int scsiback_max_buffer_pages = 1024; 191 module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644); 192 MODULE_PARM_DESC(max_buffer_pages, 193 "Maximum number of free pages to keep in backend buffer"); 194 195 static DEFINE_SPINLOCK(free_pages_lock); 196 static int free_pages_num; 197 static LIST_HEAD(scsiback_free_pages); 198 199 /* Global spinlock to protect scsiback TPG list */ 200 static DEFINE_MUTEX(scsiback_mutex); 201 static LIST_HEAD(scsiback_list); 202 203 static void scsiback_get(struct vscsibk_info *info) 204 { 205 atomic_inc(&info->nr_unreplied_reqs); 206 } 207 208 static void scsiback_put(struct vscsibk_info *info) 209 { 210 if (atomic_dec_and_test(&info->nr_unreplied_reqs)) 211 wake_up(&info->waiting_to_free); 212 } 213 214 static void put_free_pages(struct page **page, int num) 215 { 216 unsigned long flags; 217 int i = free_pages_num + num, n = num; 218 219 if (num == 0) 220 return; 221 if (i > scsiback_max_buffer_pages) { 222 n = min(num, i - scsiback_max_buffer_pages); 223 gnttab_free_pages(n, page + num - n); 224 n = num - n; 225 } 226 spin_lock_irqsave(&free_pages_lock, flags); 227 for (i = 0; i < n; i++) 228 list_add(&page[i]->lru, &scsiback_free_pages); 229 free_pages_num += n; 230 spin_unlock_irqrestore(&free_pages_lock, flags); 231 } 232 233 static int get_free_page(struct page **page) 234 { 235 unsigned long flags; 236 237 spin_lock_irqsave(&free_pages_lock, flags); 238 if (list_empty(&scsiback_free_pages)) { 239 spin_unlock_irqrestore(&free_pages_lock, flags); 240 return gnttab_alloc_pages(1, page); 241 } 242 page[0] = list_first_entry(&scsiback_free_pages, struct page, lru); 243 list_del(&page[0]->lru); 244 free_pages_num--; 245 spin_unlock_irqrestore(&free_pages_lock, flags); 246 return 0; 247 } 248 249 static unsigned long vaddr_page(struct page *page) 250 { 251 unsigned long pfn = page_to_pfn(page); 252 253 return (unsigned long)pfn_to_kaddr(pfn); 254 } 255 256 static unsigned long vaddr(struct vscsibk_pend *req, int seg) 257 { 258 return vaddr_page(req->pages[seg]); 259 } 260 261 static void scsiback_print_status(char *sense_buffer, int errors, 262 struct vscsibk_pend *pending_req) 263 { 264 struct scsiback_tpg *tpg = pending_req->v2p->tpg; 265 266 pr_err("[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x drv=%02x\n", 267 tpg->tport->tport_name, pending_req->v2p->lun, 268 pending_req->cmnd[0], status_byte(errors), msg_byte(errors), 269 host_byte(errors), driver_byte(errors)); 270 } 271 272 static void scsiback_fast_flush_area(struct vscsibk_pend *req) 273 { 274 struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH]; 275 struct page *pages[VSCSI_GRANT_BATCH]; 276 unsigned int i, invcount = 0; 277 grant_handle_t handle; 278 int err; 279 280 kfree(req->sgl); 281 req->sgl = NULL; 282 req->n_sg = 0; 283 284 if (!req->n_grants) 285 return; 286 287 for (i = 0; i < req->n_grants; i++) { 288 handle = req->grant_handles[i]; 289 if (handle == SCSIBACK_INVALID_HANDLE) 290 continue; 291 gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i), 292 GNTMAP_host_map, handle); 293 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE; 294 pages[invcount] = req->pages[i]; 295 put_page(pages[invcount]); 296 invcount++; 297 if (invcount < VSCSI_GRANT_BATCH) 298 continue; 299 err = gnttab_unmap_refs(unmap, NULL, pages, invcount); 300 BUG_ON(err); 301 invcount = 0; 302 } 303 304 if (invcount) { 305 err = gnttab_unmap_refs(unmap, NULL, pages, invcount); 306 BUG_ON(err); 307 } 308 309 put_free_pages(req->pages, req->n_grants); 310 req->n_grants = 0; 311 } 312 313 static void scsiback_free_translation_entry(struct kref *kref) 314 { 315 struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref); 316 struct scsiback_tpg *tpg = entry->tpg; 317 318 mutex_lock(&tpg->tv_tpg_mutex); 319 tpg->tv_tpg_fe_count--; 320 mutex_unlock(&tpg->tv_tpg_mutex); 321 322 kfree(entry); 323 } 324 325 static void scsiback_send_response(struct vscsibk_info *info, 326 char *sense_buffer, int32_t result, uint32_t resid, 327 uint16_t rqid) 328 { 329 struct vscsiif_response *ring_res; 330 int notify; 331 struct scsi_sense_hdr sshdr; 332 unsigned long flags; 333 unsigned len; 334 335 spin_lock_irqsave(&info->ring_lock, flags); 336 337 ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt); 338 info->ring.rsp_prod_pvt++; 339 340 ring_res->rslt = result; 341 ring_res->rqid = rqid; 342 343 if (sense_buffer != NULL && 344 scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE, 345 &sshdr)) { 346 len = min_t(unsigned, 8 + sense_buffer[7], 347 VSCSIIF_SENSE_BUFFERSIZE); 348 memcpy(ring_res->sense_buffer, sense_buffer, len); 349 ring_res->sense_len = len; 350 } else { 351 ring_res->sense_len = 0; 352 } 353 354 ring_res->residual_len = resid; 355 356 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify); 357 spin_unlock_irqrestore(&info->ring_lock, flags); 358 359 if (notify) 360 notify_remote_via_irq(info->irq); 361 } 362 363 static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result, 364 uint32_t resid, struct vscsibk_pend *pending_req) 365 { 366 scsiback_send_response(pending_req->info, sense_buffer, result, 367 resid, pending_req->rqid); 368 369 if (pending_req->v2p) 370 kref_put(&pending_req->v2p->kref, 371 scsiback_free_translation_entry); 372 } 373 374 static void scsiback_cmd_done(struct vscsibk_pend *pending_req) 375 { 376 struct vscsibk_info *info = pending_req->info; 377 unsigned char *sense_buffer; 378 unsigned int resid; 379 int errors; 380 381 sense_buffer = pending_req->sense_buffer; 382 resid = pending_req->se_cmd.residual_count; 383 errors = pending_req->result; 384 385 if (errors && log_print_stat) 386 scsiback_print_status(sense_buffer, errors, pending_req); 387 388 scsiback_fast_flush_area(pending_req); 389 scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req); 390 scsiback_put(info); 391 /* 392 * Drop the extra KREF_ACK reference taken by target_submit_cmd_map_sgls() 393 * ahead of scsiback_check_stop_free() -> transport_generic_free_cmd() 394 * final se_cmd->cmd_kref put. 395 */ 396 target_put_sess_cmd(&pending_req->se_cmd); 397 } 398 399 static void scsiback_cmd_exec(struct vscsibk_pend *pending_req) 400 { 401 struct se_cmd *se_cmd = &pending_req->se_cmd; 402 struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess; 403 int rc; 404 405 scsiback_get(pending_req->info); 406 se_cmd->tag = pending_req->rqid; 407 rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd, 408 pending_req->sense_buffer, pending_req->v2p->lun, 409 pending_req->data_len, 0, 410 pending_req->sc_data_direction, TARGET_SCF_ACK_KREF, 411 pending_req->sgl, pending_req->n_sg, 412 NULL, 0, NULL, 0); 413 if (rc < 0) { 414 transport_send_check_condition_and_sense(se_cmd, 415 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0); 416 transport_generic_free_cmd(se_cmd, 0); 417 } 418 } 419 420 static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map, 421 struct page **pg, grant_handle_t *grant, int cnt) 422 { 423 int err, i; 424 425 if (!cnt) 426 return 0; 427 428 err = gnttab_map_refs(map, NULL, pg, cnt); 429 BUG_ON(err); 430 for (i = 0; i < cnt; i++) { 431 if (unlikely(map[i].status != GNTST_okay)) { 432 pr_err("invalid buffer -- could not remap it\n"); 433 map[i].handle = SCSIBACK_INVALID_HANDLE; 434 err = -ENOMEM; 435 } else { 436 get_page(pg[i]); 437 } 438 grant[i] = map[i].handle; 439 } 440 return err; 441 } 442 443 static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req, 444 struct scsiif_request_segment *seg, struct page **pg, 445 grant_handle_t *grant, int cnt, u32 flags) 446 { 447 int mapcount = 0, i, err = 0; 448 struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH]; 449 struct vscsibk_info *info = pending_req->info; 450 451 for (i = 0; i < cnt; i++) { 452 if (get_free_page(pg + mapcount)) { 453 put_free_pages(pg, mapcount); 454 pr_err("no grant page\n"); 455 return -ENOMEM; 456 } 457 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]), 458 flags, seg[i].gref, info->domid); 459 mapcount++; 460 if (mapcount < VSCSI_GRANT_BATCH) 461 continue; 462 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount); 463 pg += mapcount; 464 grant += mapcount; 465 pending_req->n_grants += mapcount; 466 if (err) 467 return err; 468 mapcount = 0; 469 } 470 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount); 471 pending_req->n_grants += mapcount; 472 return err; 473 } 474 475 static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req, 476 struct vscsibk_pend *pending_req) 477 { 478 u32 flags; 479 int i, err, n_segs, i_seg = 0; 480 struct page **pg; 481 struct scsiif_request_segment *seg; 482 unsigned long end_seg = 0; 483 unsigned int nr_segments = (unsigned int)ring_req->nr_segments; 484 unsigned int nr_sgl = 0; 485 struct scatterlist *sg; 486 grant_handle_t *grant; 487 488 pending_req->n_sg = 0; 489 pending_req->n_grants = 0; 490 pending_req->data_len = 0; 491 492 nr_segments &= ~VSCSIIF_SG_GRANT; 493 if (!nr_segments) 494 return 0; 495 496 if (nr_segments > VSCSIIF_SG_TABLESIZE) { 497 pr_debug("invalid parameter nr_seg = %d\n", 498 ring_req->nr_segments); 499 return -EINVAL; 500 } 501 502 if (ring_req->nr_segments & VSCSIIF_SG_GRANT) { 503 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg, 504 pending_req->pages, pending_req->grant_handles, 505 nr_segments, GNTMAP_host_map | GNTMAP_readonly); 506 if (err) 507 return err; 508 nr_sgl = nr_segments; 509 nr_segments = 0; 510 for (i = 0; i < nr_sgl; i++) { 511 n_segs = ring_req->seg[i].length / 512 sizeof(struct scsiif_request_segment); 513 if ((unsigned)ring_req->seg[i].offset + 514 (unsigned)ring_req->seg[i].length > PAGE_SIZE || 515 n_segs * sizeof(struct scsiif_request_segment) != 516 ring_req->seg[i].length) 517 return -EINVAL; 518 nr_segments += n_segs; 519 } 520 if (nr_segments > SG_ALL) { 521 pr_debug("invalid nr_seg = %d\n", nr_segments); 522 return -EINVAL; 523 } 524 } 525 526 /* free of (sgl) in fast_flush_area() */ 527 pending_req->sgl = kmalloc_array(nr_segments, 528 sizeof(struct scatterlist), GFP_KERNEL); 529 if (!pending_req->sgl) 530 return -ENOMEM; 531 532 sg_init_table(pending_req->sgl, nr_segments); 533 pending_req->n_sg = nr_segments; 534 535 flags = GNTMAP_host_map; 536 if (pending_req->sc_data_direction == DMA_TO_DEVICE) 537 flags |= GNTMAP_readonly; 538 539 pg = pending_req->pages + nr_sgl; 540 grant = pending_req->grant_handles + nr_sgl; 541 if (!nr_sgl) { 542 seg = ring_req->seg; 543 err = scsiback_gnttab_data_map_list(pending_req, seg, 544 pg, grant, nr_segments, flags); 545 if (err) 546 return err; 547 } else { 548 for (i = 0; i < nr_sgl; i++) { 549 seg = (struct scsiif_request_segment *)( 550 vaddr(pending_req, i) + ring_req->seg[i].offset); 551 n_segs = ring_req->seg[i].length / 552 sizeof(struct scsiif_request_segment); 553 err = scsiback_gnttab_data_map_list(pending_req, seg, 554 pg, grant, n_segs, flags); 555 if (err) 556 return err; 557 pg += n_segs; 558 grant += n_segs; 559 } 560 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset; 561 seg = (struct scsiif_request_segment *)end_seg; 562 end_seg += ring_req->seg[0].length; 563 pg = pending_req->pages + nr_sgl; 564 } 565 566 for_each_sg(pending_req->sgl, sg, nr_segments, i) { 567 sg_set_page(sg, pg[i], seg->length, seg->offset); 568 pending_req->data_len += seg->length; 569 seg++; 570 if (nr_sgl && (unsigned long)seg >= end_seg) { 571 i_seg++; 572 end_seg = vaddr(pending_req, i_seg) + 573 ring_req->seg[i_seg].offset; 574 seg = (struct scsiif_request_segment *)end_seg; 575 end_seg += ring_req->seg[i_seg].length; 576 } 577 if (sg->offset >= PAGE_SIZE || 578 sg->length > PAGE_SIZE || 579 sg->offset + sg->length > PAGE_SIZE) 580 return -EINVAL; 581 } 582 583 return 0; 584 } 585 586 static void scsiback_disconnect(struct vscsibk_info *info) 587 { 588 wait_event(info->waiting_to_free, 589 atomic_read(&info->nr_unreplied_reqs) == 0); 590 591 unbind_from_irqhandler(info->irq, info); 592 info->irq = 0; 593 xenbus_unmap_ring_vfree(info->dev, info->ring.sring); 594 } 595 596 static void scsiback_device_action(struct vscsibk_pend *pending_req, 597 enum tcm_tmreq_table act, int tag) 598 { 599 struct scsiback_tpg *tpg = pending_req->v2p->tpg; 600 struct scsiback_nexus *nexus = tpg->tpg_nexus; 601 struct se_cmd *se_cmd = &pending_req->se_cmd; 602 struct scsiback_tmr *tmr; 603 u64 unpacked_lun = pending_req->v2p->lun; 604 int rc, err = FAILED; 605 606 tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL); 607 if (!tmr) { 608 target_put_sess_cmd(se_cmd); 609 goto err; 610 } 611 612 init_waitqueue_head(&tmr->tmr_wait); 613 614 rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess, 615 &pending_req->sense_buffer[0], 616 unpacked_lun, tmr, act, GFP_KERNEL, 617 tag, TARGET_SCF_ACK_KREF); 618 if (rc) 619 goto err; 620 621 wait_event(tmr->tmr_wait, atomic_read(&tmr->tmr_complete)); 622 623 err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ? 624 SUCCESS : FAILED; 625 626 scsiback_do_resp_with_sense(NULL, err, 0, pending_req); 627 transport_generic_free_cmd(&pending_req->se_cmd, 1); 628 return; 629 err: 630 if (tmr) 631 kfree(tmr); 632 scsiback_do_resp_with_sense(NULL, err, 0, pending_req); 633 } 634 635 /* 636 Perform virtual to physical translation 637 */ 638 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info, 639 struct ids_tuple *v) 640 { 641 struct v2p_entry *entry; 642 struct list_head *head = &(info->v2p_entry_lists); 643 unsigned long flags; 644 645 spin_lock_irqsave(&info->v2p_lock, flags); 646 list_for_each_entry(entry, head, l) { 647 if ((entry->v.chn == v->chn) && 648 (entry->v.tgt == v->tgt) && 649 (entry->v.lun == v->lun)) { 650 kref_get(&entry->kref); 651 goto out; 652 } 653 } 654 entry = NULL; 655 656 out: 657 spin_unlock_irqrestore(&info->v2p_lock, flags); 658 return entry; 659 } 660 661 static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring, 662 struct v2p_entry *v2p) 663 { 664 struct scsiback_tpg *tpg = v2p->tpg; 665 struct scsiback_nexus *nexus = tpg->tpg_nexus; 666 struct se_session *se_sess = nexus->tvn_se_sess; 667 struct vscsibk_pend *req; 668 int tag, i; 669 670 tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING); 671 if (tag < 0) { 672 pr_err("Unable to obtain tag for vscsiif_request\n"); 673 return ERR_PTR(-ENOMEM); 674 } 675 676 req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag]; 677 memset(req, 0, sizeof(*req)); 678 req->se_cmd.map_tag = tag; 679 680 for (i = 0; i < VSCSI_MAX_GRANTS; i++) 681 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE; 682 683 return req; 684 } 685 686 static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info, 687 struct vscsiif_back_ring *ring, 688 struct vscsiif_request *ring_req) 689 { 690 struct vscsibk_pend *pending_req; 691 struct v2p_entry *v2p; 692 struct ids_tuple vir; 693 694 /* request range check from frontend */ 695 if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) && 696 (ring_req->sc_data_direction != DMA_TO_DEVICE) && 697 (ring_req->sc_data_direction != DMA_FROM_DEVICE) && 698 (ring_req->sc_data_direction != DMA_NONE)) { 699 pr_debug("invalid parameter data_dir = %d\n", 700 ring_req->sc_data_direction); 701 return ERR_PTR(-EINVAL); 702 } 703 if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) { 704 pr_debug("invalid parameter cmd_len = %d\n", 705 ring_req->cmd_len); 706 return ERR_PTR(-EINVAL); 707 } 708 709 vir.chn = ring_req->channel; 710 vir.tgt = ring_req->id; 711 vir.lun = ring_req->lun; 712 713 v2p = scsiback_do_translation(info, &vir); 714 if (!v2p) { 715 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n", 716 vir.chn, vir.tgt, vir.lun); 717 return ERR_PTR(-ENODEV); 718 } 719 720 pending_req = scsiback_get_pend_req(ring, v2p); 721 if (IS_ERR(pending_req)) { 722 kref_put(&v2p->kref, scsiback_free_translation_entry); 723 return ERR_PTR(-ENOMEM); 724 } 725 pending_req->rqid = ring_req->rqid; 726 pending_req->info = info; 727 pending_req->v2p = v2p; 728 pending_req->sc_data_direction = ring_req->sc_data_direction; 729 pending_req->cmd_len = ring_req->cmd_len; 730 memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len); 731 732 return pending_req; 733 } 734 735 static int scsiback_do_cmd_fn(struct vscsibk_info *info) 736 { 737 struct vscsiif_back_ring *ring = &info->ring; 738 struct vscsiif_request ring_req; 739 struct vscsibk_pend *pending_req; 740 RING_IDX rc, rp; 741 int more_to_do; 742 uint32_t result; 743 744 rc = ring->req_cons; 745 rp = ring->sring->req_prod; 746 rmb(); /* guest system is accessing ring, too */ 747 748 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) { 749 rc = ring->rsp_prod_pvt; 750 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n", 751 info->domid, rp, rc, rp - rc); 752 info->ring_error = 1; 753 return 0; 754 } 755 756 while ((rc != rp)) { 757 if (RING_REQUEST_CONS_OVERFLOW(ring, rc)) 758 break; 759 760 RING_COPY_REQUEST(ring, rc, &ring_req); 761 ring->req_cons = ++rc; 762 763 pending_req = prepare_pending_reqs(info, ring, &ring_req); 764 if (IS_ERR(pending_req)) { 765 switch (PTR_ERR(pending_req)) { 766 case -ENODEV: 767 result = DID_NO_CONNECT; 768 break; 769 default: 770 result = DRIVER_ERROR; 771 break; 772 } 773 scsiback_send_response(info, NULL, result << 24, 0, 774 ring_req.rqid); 775 return 1; 776 } 777 778 switch (ring_req.act) { 779 case VSCSIIF_ACT_SCSI_CDB: 780 if (scsiback_gnttab_data_map(&ring_req, pending_req)) { 781 scsiback_fast_flush_area(pending_req); 782 scsiback_do_resp_with_sense(NULL, 783 DRIVER_ERROR << 24, 0, pending_req); 784 transport_generic_free_cmd(&pending_req->se_cmd, 0); 785 } else { 786 scsiback_cmd_exec(pending_req); 787 } 788 break; 789 case VSCSIIF_ACT_SCSI_ABORT: 790 scsiback_device_action(pending_req, TMR_ABORT_TASK, 791 ring_req.ref_rqid); 792 break; 793 case VSCSIIF_ACT_SCSI_RESET: 794 scsiback_device_action(pending_req, TMR_LUN_RESET, 0); 795 break; 796 default: 797 pr_err_ratelimited("invalid request\n"); 798 scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24, 0, 799 pending_req); 800 transport_generic_free_cmd(&pending_req->se_cmd, 0); 801 break; 802 } 803 804 /* Yield point for this unbounded loop. */ 805 cond_resched(); 806 } 807 808 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do); 809 return more_to_do; 810 } 811 812 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id) 813 { 814 struct vscsibk_info *info = dev_id; 815 816 if (info->ring_error) 817 return IRQ_HANDLED; 818 819 while (scsiback_do_cmd_fn(info)) 820 cond_resched(); 821 822 return IRQ_HANDLED; 823 } 824 825 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref, 826 evtchn_port_t evtchn) 827 { 828 void *area; 829 struct vscsiif_sring *sring; 830 int err; 831 832 if (info->irq) 833 return -1; 834 835 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area); 836 if (err) 837 return err; 838 839 sring = (struct vscsiif_sring *)area; 840 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE); 841 842 err = bind_interdomain_evtchn_to_irq(info->domid, evtchn); 843 if (err < 0) 844 goto unmap_page; 845 846 info->irq = err; 847 848 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn, 849 IRQF_ONESHOT, "vscsiif-backend", info); 850 if (err) 851 goto free_irq; 852 853 return 0; 854 855 free_irq: 856 unbind_from_irqhandler(info->irq, info); 857 info->irq = 0; 858 unmap_page: 859 xenbus_unmap_ring_vfree(info->dev, area); 860 861 return err; 862 } 863 864 static int scsiback_map(struct vscsibk_info *info) 865 { 866 struct xenbus_device *dev = info->dev; 867 unsigned int ring_ref, evtchn; 868 int err; 869 870 err = xenbus_gather(XBT_NIL, dev->otherend, 871 "ring-ref", "%u", &ring_ref, 872 "event-channel", "%u", &evtchn, NULL); 873 if (err) { 874 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend); 875 return err; 876 } 877 878 return scsiback_init_sring(info, ring_ref, evtchn); 879 } 880 881 /* 882 Check for a translation entry being present 883 */ 884 static struct v2p_entry *scsiback_chk_translation_entry( 885 struct vscsibk_info *info, struct ids_tuple *v) 886 { 887 struct list_head *head = &(info->v2p_entry_lists); 888 struct v2p_entry *entry; 889 890 list_for_each_entry(entry, head, l) 891 if ((entry->v.chn == v->chn) && 892 (entry->v.tgt == v->tgt) && 893 (entry->v.lun == v->lun)) 894 return entry; 895 896 return NULL; 897 } 898 899 /* 900 Add a new translation entry 901 */ 902 static int scsiback_add_translation_entry(struct vscsibk_info *info, 903 char *phy, struct ids_tuple *v) 904 { 905 int err = 0; 906 struct v2p_entry *new; 907 unsigned long flags; 908 char *lunp; 909 unsigned long long unpacked_lun; 910 struct se_lun *se_lun; 911 struct scsiback_tpg *tpg_entry, *tpg = NULL; 912 char *error = "doesn't exist"; 913 914 lunp = strrchr(phy, ':'); 915 if (!lunp) { 916 pr_err("illegal format of physical device %s\n", phy); 917 return -EINVAL; 918 } 919 *lunp = 0; 920 lunp++; 921 err = kstrtoull(lunp, 10, &unpacked_lun); 922 if (err < 0) { 923 pr_err("lun number not valid: %s\n", lunp); 924 return err; 925 } 926 927 mutex_lock(&scsiback_mutex); 928 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) { 929 if (!strcmp(phy, tpg_entry->tport->tport_name) || 930 !strcmp(phy, tpg_entry->param_alias)) { 931 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex); 932 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) { 933 if (se_lun->unpacked_lun == unpacked_lun) { 934 if (!tpg_entry->tpg_nexus) 935 error = "nexus undefined"; 936 else 937 tpg = tpg_entry; 938 break; 939 } 940 } 941 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex); 942 break; 943 } 944 } 945 if (tpg) { 946 mutex_lock(&tpg->tv_tpg_mutex); 947 tpg->tv_tpg_fe_count++; 948 mutex_unlock(&tpg->tv_tpg_mutex); 949 } 950 mutex_unlock(&scsiback_mutex); 951 952 if (!tpg) { 953 pr_err("%s:%llu %s\n", phy, unpacked_lun, error); 954 return -ENODEV; 955 } 956 957 new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL); 958 if (new == NULL) { 959 err = -ENOMEM; 960 goto out_free; 961 } 962 963 spin_lock_irqsave(&info->v2p_lock, flags); 964 965 /* Check double assignment to identical virtual ID */ 966 if (scsiback_chk_translation_entry(info, v)) { 967 pr_warn("Virtual ID is already used. Assignment was not performed.\n"); 968 err = -EEXIST; 969 goto out; 970 } 971 972 /* Create a new translation entry and add to the list */ 973 kref_init(&new->kref); 974 new->v = *v; 975 new->tpg = tpg; 976 new->lun = unpacked_lun; 977 list_add_tail(&new->l, &info->v2p_entry_lists); 978 979 out: 980 spin_unlock_irqrestore(&info->v2p_lock, flags); 981 982 out_free: 983 if (err) { 984 mutex_lock(&tpg->tv_tpg_mutex); 985 tpg->tv_tpg_fe_count--; 986 mutex_unlock(&tpg->tv_tpg_mutex); 987 kfree(new); 988 } 989 990 return err; 991 } 992 993 static void __scsiback_del_translation_entry(struct v2p_entry *entry) 994 { 995 list_del(&entry->l); 996 kref_put(&entry->kref, scsiback_free_translation_entry); 997 } 998 999 /* 1000 Delete the translation entry specified 1001 */ 1002 static int scsiback_del_translation_entry(struct vscsibk_info *info, 1003 struct ids_tuple *v) 1004 { 1005 struct v2p_entry *entry; 1006 unsigned long flags; 1007 int ret = 0; 1008 1009 spin_lock_irqsave(&info->v2p_lock, flags); 1010 /* Find out the translation entry specified */ 1011 entry = scsiback_chk_translation_entry(info, v); 1012 if (entry) 1013 __scsiback_del_translation_entry(entry); 1014 else 1015 ret = -ENOENT; 1016 1017 spin_unlock_irqrestore(&info->v2p_lock, flags); 1018 return ret; 1019 } 1020 1021 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state, 1022 char *phy, struct ids_tuple *vir, int try) 1023 { 1024 struct v2p_entry *entry; 1025 unsigned long flags; 1026 1027 if (try) { 1028 spin_lock_irqsave(&info->v2p_lock, flags); 1029 entry = scsiback_chk_translation_entry(info, vir); 1030 spin_unlock_irqrestore(&info->v2p_lock, flags); 1031 if (entry) 1032 return; 1033 } 1034 if (!scsiback_add_translation_entry(info, phy, vir)) { 1035 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1036 "%d", XenbusStateInitialised)) { 1037 pr_err("xenbus_printf error %s\n", state); 1038 scsiback_del_translation_entry(info, vir); 1039 } 1040 } else if (!try) { 1041 xenbus_printf(XBT_NIL, info->dev->nodename, state, 1042 "%d", XenbusStateClosed); 1043 } 1044 } 1045 1046 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state, 1047 struct ids_tuple *vir) 1048 { 1049 if (!scsiback_del_translation_entry(info, vir)) { 1050 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1051 "%d", XenbusStateClosed)) 1052 pr_err("xenbus_printf error %s\n", state); 1053 } 1054 } 1055 1056 #define VSCSIBACK_OP_ADD_OR_DEL_LUN 1 1057 #define VSCSIBACK_OP_UPDATEDEV_STATE 2 1058 1059 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op, 1060 char *ent) 1061 { 1062 int err; 1063 struct ids_tuple vir; 1064 char *val; 1065 int device_state; 1066 char phy[VSCSI_NAMELEN]; 1067 char str[64]; 1068 char state[64]; 1069 struct xenbus_device *dev = info->dev; 1070 1071 /* read status */ 1072 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent); 1073 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state); 1074 if (XENBUS_EXIST_ERR(err)) 1075 return; 1076 1077 /* physical SCSI device */ 1078 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent); 1079 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL); 1080 if (IS_ERR(val)) { 1081 xenbus_printf(XBT_NIL, dev->nodename, state, 1082 "%d", XenbusStateClosed); 1083 return; 1084 } 1085 strlcpy(phy, val, VSCSI_NAMELEN); 1086 kfree(val); 1087 1088 /* virtual SCSI device */ 1089 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent); 1090 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u", 1091 &vir.hst, &vir.chn, &vir.tgt, &vir.lun); 1092 if (XENBUS_EXIST_ERR(err)) { 1093 xenbus_printf(XBT_NIL, dev->nodename, state, 1094 "%d", XenbusStateClosed); 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 struct se_session *se_sess = se_cmd->se_sess; 1392 struct se_tmr_req *se_tmr = se_cmd->se_tmr_req; 1393 1394 if (se_tmr && se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) { 1395 struct scsiback_tmr *tmr = se_tmr->fabric_tmr_ptr; 1396 kfree(tmr); 1397 } 1398 1399 percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag); 1400 } 1401 1402 static int scsiback_shutdown_session(struct se_session *se_sess) 1403 { 1404 return 0; 1405 } 1406 1407 static void scsiback_close_session(struct se_session *se_sess) 1408 { 1409 } 1410 1411 static u32 scsiback_sess_get_index(struct se_session *se_sess) 1412 { 1413 return 0; 1414 } 1415 1416 static int scsiback_write_pending(struct se_cmd *se_cmd) 1417 { 1418 /* Go ahead and process the write immediately */ 1419 target_execute_cmd(se_cmd); 1420 1421 return 0; 1422 } 1423 1424 static int scsiback_write_pending_status(struct se_cmd *se_cmd) 1425 { 1426 return 0; 1427 } 1428 1429 static void scsiback_set_default_node_attrs(struct se_node_acl *nacl) 1430 { 1431 } 1432 1433 static int scsiback_get_cmd_state(struct se_cmd *se_cmd) 1434 { 1435 return 0; 1436 } 1437 1438 static int scsiback_queue_data_in(struct se_cmd *se_cmd) 1439 { 1440 struct vscsibk_pend *pending_req = container_of(se_cmd, 1441 struct vscsibk_pend, se_cmd); 1442 1443 pending_req->result = SAM_STAT_GOOD; 1444 scsiback_cmd_done(pending_req); 1445 return 0; 1446 } 1447 1448 static int scsiback_queue_status(struct se_cmd *se_cmd) 1449 { 1450 struct vscsibk_pend *pending_req = container_of(se_cmd, 1451 struct vscsibk_pend, se_cmd); 1452 1453 if (se_cmd->sense_buffer && 1454 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) || 1455 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) 1456 pending_req->result = (DRIVER_SENSE << 24) | 1457 SAM_STAT_CHECK_CONDITION; 1458 else 1459 pending_req->result = se_cmd->scsi_status; 1460 1461 scsiback_cmd_done(pending_req); 1462 return 0; 1463 } 1464 1465 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd) 1466 { 1467 struct se_tmr_req *se_tmr = se_cmd->se_tmr_req; 1468 struct scsiback_tmr *tmr = se_tmr->fabric_tmr_ptr; 1469 1470 atomic_set(&tmr->tmr_complete, 1); 1471 wake_up(&tmr->tmr_wait); 1472 } 1473 1474 static void scsiback_aborted_task(struct se_cmd *se_cmd) 1475 { 1476 } 1477 1478 static ssize_t scsiback_tpg_param_alias_show(struct config_item *item, 1479 char *page) 1480 { 1481 struct se_portal_group *se_tpg = param_to_tpg(item); 1482 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1483 se_tpg); 1484 ssize_t rb; 1485 1486 mutex_lock(&tpg->tv_tpg_mutex); 1487 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias); 1488 mutex_unlock(&tpg->tv_tpg_mutex); 1489 1490 return rb; 1491 } 1492 1493 static ssize_t scsiback_tpg_param_alias_store(struct config_item *item, 1494 const char *page, size_t count) 1495 { 1496 struct se_portal_group *se_tpg = param_to_tpg(item); 1497 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1498 se_tpg); 1499 int len; 1500 1501 if (strlen(page) >= VSCSI_NAMELEN) { 1502 pr_err("param alias: %s, exceeds max: %d\n", page, 1503 VSCSI_NAMELEN); 1504 return -EINVAL; 1505 } 1506 1507 mutex_lock(&tpg->tv_tpg_mutex); 1508 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page); 1509 if (tpg->param_alias[len - 1] == '\n') 1510 tpg->param_alias[len - 1] = '\0'; 1511 mutex_unlock(&tpg->tv_tpg_mutex); 1512 1513 return count; 1514 } 1515 1516 CONFIGFS_ATTR(scsiback_tpg_param_, alias); 1517 1518 static struct configfs_attribute *scsiback_param_attrs[] = { 1519 &scsiback_tpg_param_attr_alias, 1520 NULL, 1521 }; 1522 1523 static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg, 1524 struct se_session *se_sess, void *p) 1525 { 1526 struct scsiback_tpg *tpg = container_of(se_tpg, 1527 struct scsiback_tpg, se_tpg); 1528 1529 tpg->tpg_nexus = p; 1530 return 0; 1531 } 1532 1533 static int scsiback_make_nexus(struct scsiback_tpg *tpg, 1534 const char *name) 1535 { 1536 struct scsiback_nexus *tv_nexus; 1537 int ret = 0; 1538 1539 mutex_lock(&tpg->tv_tpg_mutex); 1540 if (tpg->tpg_nexus) { 1541 pr_debug("tpg->tpg_nexus already exists\n"); 1542 ret = -EEXIST; 1543 goto out_unlock; 1544 } 1545 1546 tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL); 1547 if (!tv_nexus) { 1548 ret = -ENOMEM; 1549 goto out_unlock; 1550 } 1551 1552 tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg, 1553 VSCSI_DEFAULT_SESSION_TAGS, 1554 sizeof(struct vscsibk_pend), 1555 TARGET_PROT_NORMAL, name, 1556 tv_nexus, scsiback_alloc_sess_cb); 1557 if (IS_ERR(tv_nexus->tvn_se_sess)) { 1558 kfree(tv_nexus); 1559 ret = -ENOMEM; 1560 goto out_unlock; 1561 } 1562 1563 out_unlock: 1564 mutex_unlock(&tpg->tv_tpg_mutex); 1565 return ret; 1566 } 1567 1568 static int scsiback_drop_nexus(struct scsiback_tpg *tpg) 1569 { 1570 struct se_session *se_sess; 1571 struct scsiback_nexus *tv_nexus; 1572 1573 mutex_lock(&tpg->tv_tpg_mutex); 1574 tv_nexus = tpg->tpg_nexus; 1575 if (!tv_nexus) { 1576 mutex_unlock(&tpg->tv_tpg_mutex); 1577 return -ENODEV; 1578 } 1579 1580 se_sess = tv_nexus->tvn_se_sess; 1581 if (!se_sess) { 1582 mutex_unlock(&tpg->tv_tpg_mutex); 1583 return -ENODEV; 1584 } 1585 1586 if (tpg->tv_tpg_port_count != 0) { 1587 mutex_unlock(&tpg->tv_tpg_mutex); 1588 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n", 1589 tpg->tv_tpg_port_count); 1590 return -EBUSY; 1591 } 1592 1593 if (tpg->tv_tpg_fe_count != 0) { 1594 mutex_unlock(&tpg->tv_tpg_mutex); 1595 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n", 1596 tpg->tv_tpg_fe_count); 1597 return -EBUSY; 1598 } 1599 1600 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n", 1601 scsiback_dump_proto_id(tpg->tport), 1602 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1603 1604 /* 1605 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port 1606 */ 1607 transport_deregister_session(tv_nexus->tvn_se_sess); 1608 tpg->tpg_nexus = NULL; 1609 mutex_unlock(&tpg->tv_tpg_mutex); 1610 1611 kfree(tv_nexus); 1612 return 0; 1613 } 1614 1615 static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page) 1616 { 1617 struct se_portal_group *se_tpg = to_tpg(item); 1618 struct scsiback_tpg *tpg = container_of(se_tpg, 1619 struct scsiback_tpg, se_tpg); 1620 struct scsiback_nexus *tv_nexus; 1621 ssize_t ret; 1622 1623 mutex_lock(&tpg->tv_tpg_mutex); 1624 tv_nexus = tpg->tpg_nexus; 1625 if (!tv_nexus) { 1626 mutex_unlock(&tpg->tv_tpg_mutex); 1627 return -ENODEV; 1628 } 1629 ret = snprintf(page, PAGE_SIZE, "%s\n", 1630 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1631 mutex_unlock(&tpg->tv_tpg_mutex); 1632 1633 return ret; 1634 } 1635 1636 static ssize_t scsiback_tpg_nexus_store(struct config_item *item, 1637 const char *page, size_t count) 1638 { 1639 struct se_portal_group *se_tpg = to_tpg(item); 1640 struct scsiback_tpg *tpg = container_of(se_tpg, 1641 struct scsiback_tpg, se_tpg); 1642 struct scsiback_tport *tport_wwn = tpg->tport; 1643 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr; 1644 int ret; 1645 /* 1646 * Shutdown the active I_T nexus if 'NULL' is passed. 1647 */ 1648 if (!strncmp(page, "NULL", 4)) { 1649 ret = scsiback_drop_nexus(tpg); 1650 return (!ret) ? count : ret; 1651 } 1652 /* 1653 * Otherwise make sure the passed virtual Initiator port WWN matches 1654 * the fabric protocol_id set in scsiback_make_tport(), and call 1655 * scsiback_make_nexus(). 1656 */ 1657 if (strlen(page) >= VSCSI_NAMELEN) { 1658 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n", 1659 page, VSCSI_NAMELEN); 1660 return -EINVAL; 1661 } 1662 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page); 1663 1664 ptr = strstr(i_port, "naa."); 1665 if (ptr) { 1666 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) { 1667 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n", 1668 i_port, scsiback_dump_proto_id(tport_wwn)); 1669 return -EINVAL; 1670 } 1671 port_ptr = &i_port[0]; 1672 goto check_newline; 1673 } 1674 ptr = strstr(i_port, "fc."); 1675 if (ptr) { 1676 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) { 1677 pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n", 1678 i_port, scsiback_dump_proto_id(tport_wwn)); 1679 return -EINVAL; 1680 } 1681 port_ptr = &i_port[3]; /* Skip over "fc." */ 1682 goto check_newline; 1683 } 1684 ptr = strstr(i_port, "iqn."); 1685 if (ptr) { 1686 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) { 1687 pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n", 1688 i_port, scsiback_dump_proto_id(tport_wwn)); 1689 return -EINVAL; 1690 } 1691 port_ptr = &i_port[0]; 1692 goto check_newline; 1693 } 1694 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n", 1695 i_port); 1696 return -EINVAL; 1697 /* 1698 * Clear any trailing newline for the NAA WWN 1699 */ 1700 check_newline: 1701 if (i_port[strlen(i_port) - 1] == '\n') 1702 i_port[strlen(i_port) - 1] = '\0'; 1703 1704 ret = scsiback_make_nexus(tpg, port_ptr); 1705 if (ret < 0) 1706 return ret; 1707 1708 return count; 1709 } 1710 1711 CONFIGFS_ATTR(scsiback_tpg_, nexus); 1712 1713 static struct configfs_attribute *scsiback_tpg_attrs[] = { 1714 &scsiback_tpg_attr_nexus, 1715 NULL, 1716 }; 1717 1718 static ssize_t 1719 scsiback_wwn_version_show(struct config_item *item, char *page) 1720 { 1721 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on " 1722 UTS_RELEASE"\n", 1723 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1724 } 1725 1726 CONFIGFS_ATTR_RO(scsiback_wwn_, version); 1727 1728 static struct configfs_attribute *scsiback_wwn_attrs[] = { 1729 &scsiback_wwn_attr_version, 1730 NULL, 1731 }; 1732 1733 static char *scsiback_get_fabric_name(void) 1734 { 1735 return "xen-pvscsi"; 1736 } 1737 1738 static int scsiback_port_link(struct se_portal_group *se_tpg, 1739 struct se_lun *lun) 1740 { 1741 struct scsiback_tpg *tpg = container_of(se_tpg, 1742 struct scsiback_tpg, se_tpg); 1743 1744 mutex_lock(&tpg->tv_tpg_mutex); 1745 tpg->tv_tpg_port_count++; 1746 mutex_unlock(&tpg->tv_tpg_mutex); 1747 1748 return 0; 1749 } 1750 1751 static void scsiback_port_unlink(struct se_portal_group *se_tpg, 1752 struct se_lun *lun) 1753 { 1754 struct scsiback_tpg *tpg = container_of(se_tpg, 1755 struct scsiback_tpg, se_tpg); 1756 1757 mutex_lock(&tpg->tv_tpg_mutex); 1758 tpg->tv_tpg_port_count--; 1759 mutex_unlock(&tpg->tv_tpg_mutex); 1760 } 1761 1762 static struct se_portal_group * 1763 scsiback_make_tpg(struct se_wwn *wwn, 1764 struct config_group *group, 1765 const char *name) 1766 { 1767 struct scsiback_tport *tport = container_of(wwn, 1768 struct scsiback_tport, tport_wwn); 1769 1770 struct scsiback_tpg *tpg; 1771 u16 tpgt; 1772 int ret; 1773 1774 if (strstr(name, "tpgt_") != name) 1775 return ERR_PTR(-EINVAL); 1776 ret = kstrtou16(name + 5, 10, &tpgt); 1777 if (ret) 1778 return ERR_PTR(ret); 1779 1780 tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL); 1781 if (!tpg) 1782 return ERR_PTR(-ENOMEM); 1783 1784 mutex_init(&tpg->tv_tpg_mutex); 1785 INIT_LIST_HEAD(&tpg->tv_tpg_list); 1786 INIT_LIST_HEAD(&tpg->info_list); 1787 tpg->tport = tport; 1788 tpg->tport_tpgt = tpgt; 1789 1790 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id); 1791 if (ret < 0) { 1792 kfree(tpg); 1793 return NULL; 1794 } 1795 mutex_lock(&scsiback_mutex); 1796 list_add_tail(&tpg->tv_tpg_list, &scsiback_list); 1797 mutex_unlock(&scsiback_mutex); 1798 1799 return &tpg->se_tpg; 1800 } 1801 1802 static void scsiback_drop_tpg(struct se_portal_group *se_tpg) 1803 { 1804 struct scsiback_tpg *tpg = container_of(se_tpg, 1805 struct scsiback_tpg, se_tpg); 1806 1807 mutex_lock(&scsiback_mutex); 1808 list_del(&tpg->tv_tpg_list); 1809 mutex_unlock(&scsiback_mutex); 1810 /* 1811 * Release the virtual I_T Nexus for this xen-pvscsi TPG 1812 */ 1813 scsiback_drop_nexus(tpg); 1814 /* 1815 * Deregister the se_tpg from TCM. 1816 */ 1817 core_tpg_deregister(se_tpg); 1818 kfree(tpg); 1819 } 1820 1821 static int scsiback_check_true(struct se_portal_group *se_tpg) 1822 { 1823 return 1; 1824 } 1825 1826 static int scsiback_check_false(struct se_portal_group *se_tpg) 1827 { 1828 return 0; 1829 } 1830 1831 static const struct target_core_fabric_ops scsiback_ops = { 1832 .module = THIS_MODULE, 1833 .name = "xen-pvscsi", 1834 .get_fabric_name = scsiback_get_fabric_name, 1835 .tpg_get_wwn = scsiback_get_fabric_wwn, 1836 .tpg_get_tag = scsiback_get_tag, 1837 .tpg_check_demo_mode = scsiback_check_true, 1838 .tpg_check_demo_mode_cache = scsiback_check_true, 1839 .tpg_check_demo_mode_write_protect = scsiback_check_false, 1840 .tpg_check_prod_mode_write_protect = scsiback_check_false, 1841 .tpg_get_inst_index = scsiback_tpg_get_inst_index, 1842 .check_stop_free = scsiback_check_stop_free, 1843 .release_cmd = scsiback_release_cmd, 1844 .shutdown_session = scsiback_shutdown_session, 1845 .close_session = scsiback_close_session, 1846 .sess_get_index = scsiback_sess_get_index, 1847 .sess_get_initiator_sid = NULL, 1848 .write_pending = scsiback_write_pending, 1849 .write_pending_status = scsiback_write_pending_status, 1850 .set_default_node_attributes = scsiback_set_default_node_attrs, 1851 .get_cmd_state = scsiback_get_cmd_state, 1852 .queue_data_in = scsiback_queue_data_in, 1853 .queue_status = scsiback_queue_status, 1854 .queue_tm_rsp = scsiback_queue_tm_rsp, 1855 .aborted_task = scsiback_aborted_task, 1856 /* 1857 * Setup callers for generic logic in target_core_fabric_configfs.c 1858 */ 1859 .fabric_make_wwn = scsiback_make_tport, 1860 .fabric_drop_wwn = scsiback_drop_tport, 1861 .fabric_make_tpg = scsiback_make_tpg, 1862 .fabric_drop_tpg = scsiback_drop_tpg, 1863 .fabric_post_link = scsiback_port_link, 1864 .fabric_pre_unlink = scsiback_port_unlink, 1865 1866 .tfc_wwn_attrs = scsiback_wwn_attrs, 1867 .tfc_tpg_base_attrs = scsiback_tpg_attrs, 1868 .tfc_tpg_param_attrs = scsiback_param_attrs, 1869 }; 1870 1871 static const struct xenbus_device_id scsiback_ids[] = { 1872 { "vscsi" }, 1873 { "" } 1874 }; 1875 1876 static struct xenbus_driver scsiback_driver = { 1877 .ids = scsiback_ids, 1878 .probe = scsiback_probe, 1879 .remove = scsiback_remove, 1880 .otherend_changed = scsiback_frontend_changed 1881 }; 1882 1883 static int __init scsiback_init(void) 1884 { 1885 int ret; 1886 1887 if (!xen_domain()) 1888 return -ENODEV; 1889 1890 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n", 1891 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1892 1893 ret = xenbus_register_backend(&scsiback_driver); 1894 if (ret) 1895 goto out; 1896 1897 ret = target_register_template(&scsiback_ops); 1898 if (ret) 1899 goto out_unregister_xenbus; 1900 1901 return 0; 1902 1903 out_unregister_xenbus: 1904 xenbus_unregister_driver(&scsiback_driver); 1905 out: 1906 pr_err("%s: error %d\n", __func__, ret); 1907 return ret; 1908 } 1909 1910 static void __exit scsiback_exit(void) 1911 { 1912 struct page *page; 1913 1914 while (free_pages_num) { 1915 if (get_free_page(&page)) 1916 BUG(); 1917 gnttab_free_pages(1, &page); 1918 } 1919 target_unregister_template(&scsiback_ops); 1920 xenbus_unregister_driver(&scsiback_driver); 1921 } 1922 1923 module_init(scsiback_init); 1924 module_exit(scsiback_exit); 1925 1926 MODULE_DESCRIPTION("Xen SCSI backend driver"); 1927 MODULE_LICENSE("Dual BSD/GPL"); 1928 MODULE_ALIAS("xen-backend:vscsi"); 1929 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>"); 1930