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 struct scsiback_nexus { 145 /* Pointer to TCM session for I_T Nexus */ 146 struct se_session *tvn_se_sess; 147 }; 148 149 struct scsiback_tport { 150 /* SCSI protocol the tport is providing */ 151 u8 tport_proto_id; 152 /* Binary World Wide unique Port Name for pvscsi Target port */ 153 u64 tport_wwpn; 154 /* ASCII formatted WWPN for pvscsi Target port */ 155 char tport_name[VSCSI_NAMELEN]; 156 /* Returned by scsiback_make_tport() */ 157 struct se_wwn tport_wwn; 158 }; 159 160 struct scsiback_tpg { 161 /* scsiback port target portal group tag for TCM */ 162 u16 tport_tpgt; 163 /* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */ 164 int tv_tpg_port_count; 165 /* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */ 166 int tv_tpg_fe_count; 167 /* list for scsiback_list */ 168 struct list_head tv_tpg_list; 169 /* Used to protect access for tpg_nexus */ 170 struct mutex tv_tpg_mutex; 171 /* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */ 172 struct scsiback_nexus *tpg_nexus; 173 /* Pointer back to scsiback_tport */ 174 struct scsiback_tport *tport; 175 /* Returned by scsiback_make_tpg() */ 176 struct se_portal_group se_tpg; 177 /* alias used in xenstore */ 178 char param_alias[VSCSI_NAMELEN]; 179 /* list of info structures related to this target portal group */ 180 struct list_head info_list; 181 }; 182 183 #define SCSIBACK_INVALID_HANDLE (~0) 184 185 static bool log_print_stat; 186 module_param(log_print_stat, bool, 0644); 187 188 static int scsiback_max_buffer_pages = 1024; 189 module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644); 190 MODULE_PARM_DESC(max_buffer_pages, 191 "Maximum number of free pages to keep in backend buffer"); 192 193 static struct kmem_cache *scsiback_cachep; 194 static DEFINE_SPINLOCK(free_pages_lock); 195 static int free_pages_num; 196 static LIST_HEAD(scsiback_free_pages); 197 198 /* Global spinlock to protect scsiback TPG list */ 199 static DEFINE_MUTEX(scsiback_mutex); 200 static LIST_HEAD(scsiback_list); 201 202 static void scsiback_get(struct vscsibk_info *info) 203 { 204 atomic_inc(&info->nr_unreplied_reqs); 205 } 206 207 static void scsiback_put(struct vscsibk_info *info) 208 { 209 if (atomic_dec_and_test(&info->nr_unreplied_reqs)) 210 wake_up(&info->waiting_to_free); 211 } 212 213 static void put_free_pages(struct page **page, int num) 214 { 215 unsigned long flags; 216 int i = free_pages_num + num, n = num; 217 218 if (num == 0) 219 return; 220 if (i > scsiback_max_buffer_pages) { 221 n = min(num, i - scsiback_max_buffer_pages); 222 gnttab_free_pages(n, page + num - n); 223 n = num - n; 224 } 225 spin_lock_irqsave(&free_pages_lock, flags); 226 for (i = 0; i < n; i++) 227 list_add(&page[i]->lru, &scsiback_free_pages); 228 free_pages_num += n; 229 spin_unlock_irqrestore(&free_pages_lock, flags); 230 } 231 232 static int get_free_page(struct page **page) 233 { 234 unsigned long flags; 235 236 spin_lock_irqsave(&free_pages_lock, flags); 237 if (list_empty(&scsiback_free_pages)) { 238 spin_unlock_irqrestore(&free_pages_lock, flags); 239 return gnttab_alloc_pages(1, page); 240 } 241 page[0] = list_first_entry(&scsiback_free_pages, struct page, lru); 242 list_del(&page[0]->lru); 243 free_pages_num--; 244 spin_unlock_irqrestore(&free_pages_lock, flags); 245 return 0; 246 } 247 248 static unsigned long vaddr_page(struct page *page) 249 { 250 unsigned long pfn = page_to_pfn(page); 251 252 return (unsigned long)pfn_to_kaddr(pfn); 253 } 254 255 static unsigned long vaddr(struct vscsibk_pend *req, int seg) 256 { 257 return vaddr_page(req->pages[seg]); 258 } 259 260 static void scsiback_print_status(char *sense_buffer, int errors, 261 struct vscsibk_pend *pending_req) 262 { 263 struct scsiback_tpg *tpg = pending_req->v2p->tpg; 264 265 pr_err("[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x drv=%02x\n", 266 tpg->tport->tport_name, pending_req->v2p->lun, 267 pending_req->cmnd[0], status_byte(errors), msg_byte(errors), 268 host_byte(errors), driver_byte(errors)); 269 } 270 271 static void scsiback_fast_flush_area(struct vscsibk_pend *req) 272 { 273 struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH]; 274 struct page *pages[VSCSI_GRANT_BATCH]; 275 unsigned int i, invcount = 0; 276 grant_handle_t handle; 277 int err; 278 279 kfree(req->sgl); 280 req->sgl = NULL; 281 req->n_sg = 0; 282 283 if (!req->n_grants) 284 return; 285 286 for (i = 0; i < req->n_grants; i++) { 287 handle = req->grant_handles[i]; 288 if (handle == SCSIBACK_INVALID_HANDLE) 289 continue; 290 gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i), 291 GNTMAP_host_map, handle); 292 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE; 293 pages[invcount] = req->pages[i]; 294 put_page(pages[invcount]); 295 invcount++; 296 if (invcount < VSCSI_GRANT_BATCH) 297 continue; 298 err = gnttab_unmap_refs(unmap, NULL, pages, invcount); 299 BUG_ON(err); 300 invcount = 0; 301 } 302 303 if (invcount) { 304 err = gnttab_unmap_refs(unmap, NULL, pages, invcount); 305 BUG_ON(err); 306 } 307 308 put_free_pages(req->pages, req->n_grants); 309 req->n_grants = 0; 310 } 311 312 static void scsiback_free_translation_entry(struct kref *kref) 313 { 314 struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref); 315 struct scsiback_tpg *tpg = entry->tpg; 316 317 mutex_lock(&tpg->tv_tpg_mutex); 318 tpg->tv_tpg_fe_count--; 319 mutex_unlock(&tpg->tv_tpg_mutex); 320 321 kfree(entry); 322 } 323 324 static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result, 325 uint32_t resid, struct vscsibk_pend *pending_req) 326 { 327 struct vscsiif_response *ring_res; 328 struct vscsibk_info *info = pending_req->info; 329 int notify; 330 struct scsi_sense_hdr sshdr; 331 unsigned long flags; 332 unsigned len; 333 334 spin_lock_irqsave(&info->ring_lock, flags); 335 336 ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt); 337 info->ring.rsp_prod_pvt++; 338 339 ring_res->rslt = result; 340 ring_res->rqid = pending_req->rqid; 341 342 if (sense_buffer != NULL && 343 scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE, 344 &sshdr)) { 345 len = min_t(unsigned, 8 + sense_buffer[7], 346 VSCSIIF_SENSE_BUFFERSIZE); 347 memcpy(ring_res->sense_buffer, sense_buffer, len); 348 ring_res->sense_len = len; 349 } else { 350 ring_res->sense_len = 0; 351 } 352 353 ring_res->residual_len = resid; 354 355 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify); 356 spin_unlock_irqrestore(&info->ring_lock, flags); 357 358 if (notify) 359 notify_remote_via_irq(info->irq); 360 361 if (pending_req->v2p) 362 kref_put(&pending_req->v2p->kref, 363 scsiback_free_translation_entry); 364 } 365 366 static void scsiback_cmd_done(struct vscsibk_pend *pending_req) 367 { 368 struct vscsibk_info *info = pending_req->info; 369 unsigned char *sense_buffer; 370 unsigned int resid; 371 int errors; 372 373 sense_buffer = pending_req->sense_buffer; 374 resid = pending_req->se_cmd.residual_count; 375 errors = pending_req->result; 376 377 if (errors && log_print_stat) 378 scsiback_print_status(sense_buffer, errors, pending_req); 379 380 scsiback_fast_flush_area(pending_req); 381 scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req); 382 scsiback_put(info); 383 } 384 385 static void scsiback_cmd_exec(struct vscsibk_pend *pending_req) 386 { 387 struct se_cmd *se_cmd = &pending_req->se_cmd; 388 struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess; 389 int rc; 390 391 memset(pending_req->sense_buffer, 0, VSCSIIF_SENSE_BUFFERSIZE); 392 393 memset(se_cmd, 0, sizeof(*se_cmd)); 394 395 scsiback_get(pending_req->info); 396 se_cmd->tag = pending_req->rqid; 397 rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd, 398 pending_req->sense_buffer, pending_req->v2p->lun, 399 pending_req->data_len, 0, 400 pending_req->sc_data_direction, 0, 401 pending_req->sgl, pending_req->n_sg, 402 NULL, 0, NULL, 0); 403 if (rc < 0) { 404 transport_send_check_condition_and_sense(se_cmd, 405 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0); 406 transport_generic_free_cmd(se_cmd, 0); 407 } 408 } 409 410 static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map, 411 struct page **pg, grant_handle_t *grant, int cnt) 412 { 413 int err, i; 414 415 if (!cnt) 416 return 0; 417 418 err = gnttab_map_refs(map, NULL, pg, cnt); 419 BUG_ON(err); 420 for (i = 0; i < cnt; i++) { 421 if (unlikely(map[i].status != GNTST_okay)) { 422 pr_err("invalid buffer -- could not remap it\n"); 423 map[i].handle = SCSIBACK_INVALID_HANDLE; 424 err = -ENOMEM; 425 } else { 426 get_page(pg[i]); 427 } 428 grant[i] = map[i].handle; 429 } 430 return err; 431 } 432 433 static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req, 434 struct scsiif_request_segment *seg, struct page **pg, 435 grant_handle_t *grant, int cnt, u32 flags) 436 { 437 int mapcount = 0, i, err = 0; 438 struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH]; 439 struct vscsibk_info *info = pending_req->info; 440 441 for (i = 0; i < cnt; i++) { 442 if (get_free_page(pg + mapcount)) { 443 put_free_pages(pg, mapcount); 444 pr_err("no grant page\n"); 445 return -ENOMEM; 446 } 447 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]), 448 flags, seg[i].gref, info->domid); 449 mapcount++; 450 if (mapcount < VSCSI_GRANT_BATCH) 451 continue; 452 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount); 453 pg += mapcount; 454 grant += mapcount; 455 pending_req->n_grants += mapcount; 456 if (err) 457 return err; 458 mapcount = 0; 459 } 460 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount); 461 pending_req->n_grants += mapcount; 462 return err; 463 } 464 465 static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req, 466 struct vscsibk_pend *pending_req) 467 { 468 u32 flags; 469 int i, err, n_segs, i_seg = 0; 470 struct page **pg; 471 struct scsiif_request_segment *seg; 472 unsigned long end_seg = 0; 473 unsigned int nr_segments = (unsigned int)ring_req->nr_segments; 474 unsigned int nr_sgl = 0; 475 struct scatterlist *sg; 476 grant_handle_t *grant; 477 478 pending_req->n_sg = 0; 479 pending_req->n_grants = 0; 480 pending_req->data_len = 0; 481 482 nr_segments &= ~VSCSIIF_SG_GRANT; 483 if (!nr_segments) 484 return 0; 485 486 if (nr_segments > VSCSIIF_SG_TABLESIZE) { 487 pr_debug("invalid parameter nr_seg = %d\n", 488 ring_req->nr_segments); 489 return -EINVAL; 490 } 491 492 if (ring_req->nr_segments & VSCSIIF_SG_GRANT) { 493 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg, 494 pending_req->pages, pending_req->grant_handles, 495 nr_segments, GNTMAP_host_map | GNTMAP_readonly); 496 if (err) 497 return err; 498 nr_sgl = nr_segments; 499 nr_segments = 0; 500 for (i = 0; i < nr_sgl; i++) { 501 n_segs = ring_req->seg[i].length / 502 sizeof(struct scsiif_request_segment); 503 if ((unsigned)ring_req->seg[i].offset + 504 (unsigned)ring_req->seg[i].length > PAGE_SIZE || 505 n_segs * sizeof(struct scsiif_request_segment) != 506 ring_req->seg[i].length) 507 return -EINVAL; 508 nr_segments += n_segs; 509 } 510 if (nr_segments > SG_ALL) { 511 pr_debug("invalid nr_seg = %d\n", nr_segments); 512 return -EINVAL; 513 } 514 } 515 516 /* free of (sgl) in fast_flush_area() */ 517 pending_req->sgl = kmalloc_array(nr_segments, 518 sizeof(struct scatterlist), GFP_KERNEL); 519 if (!pending_req->sgl) 520 return -ENOMEM; 521 522 sg_init_table(pending_req->sgl, nr_segments); 523 pending_req->n_sg = nr_segments; 524 525 flags = GNTMAP_host_map; 526 if (pending_req->sc_data_direction == DMA_TO_DEVICE) 527 flags |= GNTMAP_readonly; 528 529 pg = pending_req->pages + nr_sgl; 530 grant = pending_req->grant_handles + nr_sgl; 531 if (!nr_sgl) { 532 seg = ring_req->seg; 533 err = scsiback_gnttab_data_map_list(pending_req, seg, 534 pg, grant, nr_segments, flags); 535 if (err) 536 return err; 537 } else { 538 for (i = 0; i < nr_sgl; i++) { 539 seg = (struct scsiif_request_segment *)( 540 vaddr(pending_req, i) + ring_req->seg[i].offset); 541 n_segs = ring_req->seg[i].length / 542 sizeof(struct scsiif_request_segment); 543 err = scsiback_gnttab_data_map_list(pending_req, seg, 544 pg, grant, n_segs, flags); 545 if (err) 546 return err; 547 pg += n_segs; 548 grant += n_segs; 549 } 550 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset; 551 seg = (struct scsiif_request_segment *)end_seg; 552 end_seg += ring_req->seg[0].length; 553 pg = pending_req->pages + nr_sgl; 554 } 555 556 for_each_sg(pending_req->sgl, sg, nr_segments, i) { 557 sg_set_page(sg, pg[i], seg->length, seg->offset); 558 pending_req->data_len += seg->length; 559 seg++; 560 if (nr_sgl && (unsigned long)seg >= end_seg) { 561 i_seg++; 562 end_seg = vaddr(pending_req, i_seg) + 563 ring_req->seg[i_seg].offset; 564 seg = (struct scsiif_request_segment *)end_seg; 565 end_seg += ring_req->seg[i_seg].length; 566 } 567 if (sg->offset >= PAGE_SIZE || 568 sg->length > PAGE_SIZE || 569 sg->offset + sg->length > PAGE_SIZE) 570 return -EINVAL; 571 } 572 573 return 0; 574 } 575 576 static void scsiback_disconnect(struct vscsibk_info *info) 577 { 578 wait_event(info->waiting_to_free, 579 atomic_read(&info->nr_unreplied_reqs) == 0); 580 581 unbind_from_irqhandler(info->irq, info); 582 info->irq = 0; 583 xenbus_unmap_ring_vfree(info->dev, info->ring.sring); 584 } 585 586 static void scsiback_device_action(struct vscsibk_pend *pending_req, 587 enum tcm_tmreq_table act, int tag) 588 { 589 int rc, err = FAILED; 590 struct scsiback_tpg *tpg = pending_req->v2p->tpg; 591 struct se_cmd *se_cmd = &pending_req->se_cmd; 592 struct scsiback_tmr *tmr; 593 594 tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL); 595 if (!tmr) 596 goto out; 597 598 init_waitqueue_head(&tmr->tmr_wait); 599 600 transport_init_se_cmd(se_cmd, tpg->se_tpg.se_tpg_tfo, 601 tpg->tpg_nexus->tvn_se_sess, 0, DMA_NONE, TCM_SIMPLE_TAG, 602 &pending_req->sense_buffer[0]); 603 604 rc = core_tmr_alloc_req(se_cmd, tmr, act, GFP_KERNEL); 605 if (rc < 0) 606 goto out; 607 608 se_cmd->se_tmr_req->ref_task_tag = tag; 609 610 if (transport_lookup_tmr_lun(se_cmd, pending_req->v2p->lun) < 0) 611 goto out; 612 613 transport_generic_handle_tmr(se_cmd); 614 wait_event(tmr->tmr_wait, atomic_read(&tmr->tmr_complete)); 615 616 err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ? 617 SUCCESS : FAILED; 618 619 out: 620 if (tmr) { 621 transport_generic_free_cmd(&pending_req->se_cmd, 1); 622 kfree(tmr); 623 } 624 625 scsiback_do_resp_with_sense(NULL, err, 0, pending_req); 626 627 kmem_cache_free(scsiback_cachep, pending_req); 628 } 629 630 /* 631 Perform virtual to physical translation 632 */ 633 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info, 634 struct ids_tuple *v) 635 { 636 struct v2p_entry *entry; 637 struct list_head *head = &(info->v2p_entry_lists); 638 unsigned long flags; 639 640 spin_lock_irqsave(&info->v2p_lock, flags); 641 list_for_each_entry(entry, head, l) { 642 if ((entry->v.chn == v->chn) && 643 (entry->v.tgt == v->tgt) && 644 (entry->v.lun == v->lun)) { 645 kref_get(&entry->kref); 646 goto out; 647 } 648 } 649 entry = NULL; 650 651 out: 652 spin_unlock_irqrestore(&info->v2p_lock, flags); 653 return entry; 654 } 655 656 static int prepare_pending_reqs(struct vscsibk_info *info, 657 struct vscsiif_request *ring_req, 658 struct vscsibk_pend *pending_req) 659 { 660 struct v2p_entry *v2p; 661 struct ids_tuple vir; 662 663 pending_req->rqid = ring_req->rqid; 664 pending_req->info = info; 665 666 vir.chn = ring_req->channel; 667 vir.tgt = ring_req->id; 668 vir.lun = ring_req->lun; 669 670 v2p = scsiback_do_translation(info, &vir); 671 if (!v2p) { 672 pending_req->v2p = NULL; 673 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n", 674 vir.chn, vir.tgt, vir.lun); 675 return -ENODEV; 676 } 677 pending_req->v2p = v2p; 678 679 /* request range check from frontend */ 680 pending_req->sc_data_direction = ring_req->sc_data_direction; 681 if ((pending_req->sc_data_direction != DMA_BIDIRECTIONAL) && 682 (pending_req->sc_data_direction != DMA_TO_DEVICE) && 683 (pending_req->sc_data_direction != DMA_FROM_DEVICE) && 684 (pending_req->sc_data_direction != DMA_NONE)) { 685 pr_debug("invalid parameter data_dir = %d\n", 686 pending_req->sc_data_direction); 687 return -EINVAL; 688 } 689 690 pending_req->cmd_len = ring_req->cmd_len; 691 if (pending_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) { 692 pr_debug("invalid parameter cmd_len = %d\n", 693 pending_req->cmd_len); 694 return -EINVAL; 695 } 696 memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len); 697 698 return 0; 699 } 700 701 static int scsiback_do_cmd_fn(struct vscsibk_info *info) 702 { 703 struct vscsiif_back_ring *ring = &info->ring; 704 struct vscsiif_request ring_req; 705 struct vscsibk_pend *pending_req; 706 RING_IDX rc, rp; 707 int err, more_to_do; 708 uint32_t result; 709 710 rc = ring->req_cons; 711 rp = ring->sring->req_prod; 712 rmb(); /* guest system is accessing ring, too */ 713 714 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) { 715 rc = ring->rsp_prod_pvt; 716 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n", 717 info->domid, rp, rc, rp - rc); 718 info->ring_error = 1; 719 return 0; 720 } 721 722 while ((rc != rp)) { 723 if (RING_REQUEST_CONS_OVERFLOW(ring, rc)) 724 break; 725 pending_req = kmem_cache_alloc(scsiback_cachep, GFP_KERNEL); 726 if (!pending_req) 727 return 1; 728 729 RING_COPY_REQUEST(ring, rc, &ring_req); 730 ring->req_cons = ++rc; 731 732 err = prepare_pending_reqs(info, &ring_req, pending_req); 733 if (err) { 734 switch (err) { 735 case -ENODEV: 736 result = DID_NO_CONNECT; 737 break; 738 default: 739 result = DRIVER_ERROR; 740 break; 741 } 742 scsiback_do_resp_with_sense(NULL, result << 24, 0, 743 pending_req); 744 kmem_cache_free(scsiback_cachep, pending_req); 745 return 1; 746 } 747 748 switch (ring_req.act) { 749 case VSCSIIF_ACT_SCSI_CDB: 750 if (scsiback_gnttab_data_map(&ring_req, pending_req)) { 751 scsiback_fast_flush_area(pending_req); 752 scsiback_do_resp_with_sense(NULL, 753 DRIVER_ERROR << 24, 0, pending_req); 754 kmem_cache_free(scsiback_cachep, pending_req); 755 } else { 756 scsiback_cmd_exec(pending_req); 757 } 758 break; 759 case VSCSIIF_ACT_SCSI_ABORT: 760 scsiback_device_action(pending_req, TMR_ABORT_TASK, 761 ring_req.ref_rqid); 762 break; 763 case VSCSIIF_ACT_SCSI_RESET: 764 scsiback_device_action(pending_req, TMR_LUN_RESET, 0); 765 break; 766 default: 767 pr_err_ratelimited("invalid request\n"); 768 scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24, 769 0, pending_req); 770 kmem_cache_free(scsiback_cachep, pending_req); 771 break; 772 } 773 774 /* Yield point for this unbounded loop. */ 775 cond_resched(); 776 } 777 778 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do); 779 return more_to_do; 780 } 781 782 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id) 783 { 784 struct vscsibk_info *info = dev_id; 785 786 if (info->ring_error) 787 return IRQ_HANDLED; 788 789 while (scsiback_do_cmd_fn(info)) 790 cond_resched(); 791 792 return IRQ_HANDLED; 793 } 794 795 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref, 796 evtchn_port_t evtchn) 797 { 798 void *area; 799 struct vscsiif_sring *sring; 800 int err; 801 802 if (info->irq) 803 return -1; 804 805 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area); 806 if (err) 807 return err; 808 809 sring = (struct vscsiif_sring *)area; 810 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE); 811 812 err = bind_interdomain_evtchn_to_irq(info->domid, evtchn); 813 if (err < 0) 814 goto unmap_page; 815 816 info->irq = err; 817 818 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn, 819 IRQF_ONESHOT, "vscsiif-backend", info); 820 if (err) 821 goto free_irq; 822 823 return 0; 824 825 free_irq: 826 unbind_from_irqhandler(info->irq, info); 827 info->irq = 0; 828 unmap_page: 829 xenbus_unmap_ring_vfree(info->dev, area); 830 831 return err; 832 } 833 834 static int scsiback_map(struct vscsibk_info *info) 835 { 836 struct xenbus_device *dev = info->dev; 837 unsigned int ring_ref, evtchn; 838 int err; 839 840 err = xenbus_gather(XBT_NIL, dev->otherend, 841 "ring-ref", "%u", &ring_ref, 842 "event-channel", "%u", &evtchn, NULL); 843 if (err) { 844 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend); 845 return err; 846 } 847 848 return scsiback_init_sring(info, ring_ref, evtchn); 849 } 850 851 /* 852 Check for a translation entry being present 853 */ 854 static struct v2p_entry *scsiback_chk_translation_entry( 855 struct vscsibk_info *info, struct ids_tuple *v) 856 { 857 struct list_head *head = &(info->v2p_entry_lists); 858 struct v2p_entry *entry; 859 860 list_for_each_entry(entry, head, l) 861 if ((entry->v.chn == v->chn) && 862 (entry->v.tgt == v->tgt) && 863 (entry->v.lun == v->lun)) 864 return entry; 865 866 return NULL; 867 } 868 869 /* 870 Add a new translation entry 871 */ 872 static int scsiback_add_translation_entry(struct vscsibk_info *info, 873 char *phy, struct ids_tuple *v) 874 { 875 int err = 0; 876 struct v2p_entry *new; 877 unsigned long flags; 878 char *lunp; 879 unsigned long long unpacked_lun; 880 struct se_lun *se_lun; 881 struct scsiback_tpg *tpg_entry, *tpg = NULL; 882 char *error = "doesn't exist"; 883 884 lunp = strrchr(phy, ':'); 885 if (!lunp) { 886 pr_err("illegal format of physical device %s\n", phy); 887 return -EINVAL; 888 } 889 *lunp = 0; 890 lunp++; 891 err = kstrtoull(lunp, 10, &unpacked_lun); 892 if (err < 0) { 893 pr_err("lun number not valid: %s\n", lunp); 894 return err; 895 } 896 897 mutex_lock(&scsiback_mutex); 898 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) { 899 if (!strcmp(phy, tpg_entry->tport->tport_name) || 900 !strcmp(phy, tpg_entry->param_alias)) { 901 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex); 902 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) { 903 if (se_lun->unpacked_lun == unpacked_lun) { 904 if (!tpg_entry->tpg_nexus) 905 error = "nexus undefined"; 906 else 907 tpg = tpg_entry; 908 break; 909 } 910 } 911 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex); 912 break; 913 } 914 } 915 if (tpg) { 916 mutex_lock(&tpg->tv_tpg_mutex); 917 tpg->tv_tpg_fe_count++; 918 mutex_unlock(&tpg->tv_tpg_mutex); 919 } 920 mutex_unlock(&scsiback_mutex); 921 922 if (!tpg) { 923 pr_err("%s:%llu %s\n", phy, unpacked_lun, error); 924 return -ENODEV; 925 } 926 927 new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL); 928 if (new == NULL) { 929 err = -ENOMEM; 930 goto out_free; 931 } 932 933 spin_lock_irqsave(&info->v2p_lock, flags); 934 935 /* Check double assignment to identical virtual ID */ 936 if (scsiback_chk_translation_entry(info, v)) { 937 pr_warn("Virtual ID is already used. Assignment was not performed.\n"); 938 err = -EEXIST; 939 goto out; 940 } 941 942 /* Create a new translation entry and add to the list */ 943 kref_init(&new->kref); 944 new->v = *v; 945 new->tpg = tpg; 946 new->lun = unpacked_lun; 947 list_add_tail(&new->l, &info->v2p_entry_lists); 948 949 out: 950 spin_unlock_irqrestore(&info->v2p_lock, flags); 951 952 out_free: 953 if (err) { 954 mutex_lock(&tpg->tv_tpg_mutex); 955 tpg->tv_tpg_fe_count--; 956 mutex_unlock(&tpg->tv_tpg_mutex); 957 kfree(new); 958 } 959 960 return err; 961 } 962 963 static void __scsiback_del_translation_entry(struct v2p_entry *entry) 964 { 965 list_del(&entry->l); 966 kref_put(&entry->kref, scsiback_free_translation_entry); 967 } 968 969 /* 970 Delete the translation entry specified 971 */ 972 static int scsiback_del_translation_entry(struct vscsibk_info *info, 973 struct ids_tuple *v) 974 { 975 struct v2p_entry *entry; 976 unsigned long flags; 977 int ret = 0; 978 979 spin_lock_irqsave(&info->v2p_lock, flags); 980 /* Find out the translation entry specified */ 981 entry = scsiback_chk_translation_entry(info, v); 982 if (entry) 983 __scsiback_del_translation_entry(entry); 984 else 985 ret = -ENOENT; 986 987 spin_unlock_irqrestore(&info->v2p_lock, flags); 988 return ret; 989 } 990 991 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state, 992 char *phy, struct ids_tuple *vir, int try) 993 { 994 struct v2p_entry *entry; 995 unsigned long flags; 996 997 if (try) { 998 spin_lock_irqsave(&info->v2p_lock, flags); 999 entry = scsiback_chk_translation_entry(info, vir); 1000 spin_unlock_irqrestore(&info->v2p_lock, flags); 1001 if (entry) 1002 return; 1003 } 1004 if (!scsiback_add_translation_entry(info, phy, vir)) { 1005 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1006 "%d", XenbusStateInitialised)) { 1007 pr_err("xenbus_printf error %s\n", state); 1008 scsiback_del_translation_entry(info, vir); 1009 } 1010 } else if (!try) { 1011 xenbus_printf(XBT_NIL, info->dev->nodename, state, 1012 "%d", XenbusStateClosed); 1013 } 1014 } 1015 1016 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state, 1017 struct ids_tuple *vir) 1018 { 1019 if (!scsiback_del_translation_entry(info, vir)) { 1020 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1021 "%d", XenbusStateClosed)) 1022 pr_err("xenbus_printf error %s\n", state); 1023 } 1024 } 1025 1026 #define VSCSIBACK_OP_ADD_OR_DEL_LUN 1 1027 #define VSCSIBACK_OP_UPDATEDEV_STATE 2 1028 1029 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op, 1030 char *ent) 1031 { 1032 int err; 1033 struct ids_tuple vir; 1034 char *val; 1035 int device_state; 1036 char phy[VSCSI_NAMELEN]; 1037 char str[64]; 1038 char state[64]; 1039 struct xenbus_device *dev = info->dev; 1040 1041 /* read status */ 1042 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent); 1043 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state); 1044 if (XENBUS_EXIST_ERR(err)) 1045 return; 1046 1047 /* physical SCSI device */ 1048 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent); 1049 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL); 1050 if (IS_ERR(val)) { 1051 xenbus_printf(XBT_NIL, dev->nodename, state, 1052 "%d", XenbusStateClosed); 1053 return; 1054 } 1055 strlcpy(phy, val, VSCSI_NAMELEN); 1056 kfree(val); 1057 1058 /* virtual SCSI device */ 1059 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent); 1060 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u", 1061 &vir.hst, &vir.chn, &vir.tgt, &vir.lun); 1062 if (XENBUS_EXIST_ERR(err)) { 1063 xenbus_printf(XBT_NIL, dev->nodename, state, 1064 "%d", XenbusStateClosed); 1065 return; 1066 } 1067 1068 switch (op) { 1069 case VSCSIBACK_OP_ADD_OR_DEL_LUN: 1070 switch (device_state) { 1071 case XenbusStateInitialising: 1072 scsiback_do_add_lun(info, state, phy, &vir, 0); 1073 break; 1074 case XenbusStateConnected: 1075 scsiback_do_add_lun(info, state, phy, &vir, 1); 1076 break; 1077 case XenbusStateClosing: 1078 scsiback_do_del_lun(info, state, &vir); 1079 break; 1080 default: 1081 break; 1082 } 1083 break; 1084 1085 case VSCSIBACK_OP_UPDATEDEV_STATE: 1086 if (device_state == XenbusStateInitialised) { 1087 /* modify vscsi-devs/dev-x/state */ 1088 if (xenbus_printf(XBT_NIL, dev->nodename, state, 1089 "%d", XenbusStateConnected)) { 1090 pr_err("xenbus_printf error %s\n", str); 1091 scsiback_del_translation_entry(info, &vir); 1092 xenbus_printf(XBT_NIL, dev->nodename, state, 1093 "%d", XenbusStateClosed); 1094 } 1095 } 1096 break; 1097 /* When it is necessary, processing is added here. */ 1098 default: 1099 break; 1100 } 1101 } 1102 1103 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op) 1104 { 1105 int i; 1106 char **dir; 1107 unsigned int ndir = 0; 1108 1109 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs", 1110 &ndir); 1111 if (IS_ERR(dir)) 1112 return; 1113 1114 for (i = 0; i < ndir; i++) 1115 scsiback_do_1lun_hotplug(info, op, dir[i]); 1116 1117 kfree(dir); 1118 } 1119 1120 static void scsiback_frontend_changed(struct xenbus_device *dev, 1121 enum xenbus_state frontend_state) 1122 { 1123 struct vscsibk_info *info = dev_get_drvdata(&dev->dev); 1124 1125 switch (frontend_state) { 1126 case XenbusStateInitialising: 1127 break; 1128 1129 case XenbusStateInitialised: 1130 if (scsiback_map(info)) 1131 break; 1132 1133 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); 1134 xenbus_switch_state(dev, XenbusStateConnected); 1135 break; 1136 1137 case XenbusStateConnected: 1138 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE); 1139 1140 if (dev->state == XenbusStateConnected) 1141 break; 1142 1143 xenbus_switch_state(dev, XenbusStateConnected); 1144 break; 1145 1146 case XenbusStateClosing: 1147 if (info->irq) 1148 scsiback_disconnect(info); 1149 1150 xenbus_switch_state(dev, XenbusStateClosing); 1151 break; 1152 1153 case XenbusStateClosed: 1154 xenbus_switch_state(dev, XenbusStateClosed); 1155 if (xenbus_dev_is_online(dev)) 1156 break; 1157 /* fall through if not online */ 1158 case XenbusStateUnknown: 1159 device_unregister(&dev->dev); 1160 break; 1161 1162 case XenbusStateReconfiguring: 1163 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); 1164 xenbus_switch_state(dev, XenbusStateReconfigured); 1165 1166 break; 1167 1168 default: 1169 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", 1170 frontend_state); 1171 break; 1172 } 1173 } 1174 1175 /* 1176 Release the translation entry specfied 1177 */ 1178 static void scsiback_release_translation_entry(struct vscsibk_info *info) 1179 { 1180 struct v2p_entry *entry, *tmp; 1181 struct list_head *head = &(info->v2p_entry_lists); 1182 unsigned long flags; 1183 1184 spin_lock_irqsave(&info->v2p_lock, flags); 1185 1186 list_for_each_entry_safe(entry, tmp, head, l) 1187 __scsiback_del_translation_entry(entry); 1188 1189 spin_unlock_irqrestore(&info->v2p_lock, flags); 1190 } 1191 1192 static int scsiback_remove(struct xenbus_device *dev) 1193 { 1194 struct vscsibk_info *info = dev_get_drvdata(&dev->dev); 1195 1196 if (info->irq) 1197 scsiback_disconnect(info); 1198 1199 scsiback_release_translation_entry(info); 1200 1201 dev_set_drvdata(&dev->dev, NULL); 1202 1203 return 0; 1204 } 1205 1206 static int scsiback_probe(struct xenbus_device *dev, 1207 const struct xenbus_device_id *id) 1208 { 1209 int err; 1210 1211 struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info), 1212 GFP_KERNEL); 1213 1214 pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); 1215 1216 if (!info) { 1217 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure"); 1218 return -ENOMEM; 1219 } 1220 info->dev = dev; 1221 dev_set_drvdata(&dev->dev, info); 1222 1223 info->domid = dev->otherend_id; 1224 spin_lock_init(&info->ring_lock); 1225 info->ring_error = 0; 1226 atomic_set(&info->nr_unreplied_reqs, 0); 1227 init_waitqueue_head(&info->waiting_to_free); 1228 info->dev = dev; 1229 info->irq = 0; 1230 INIT_LIST_HEAD(&info->v2p_entry_lists); 1231 spin_lock_init(&info->v2p_lock); 1232 1233 err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u", 1234 SG_ALL); 1235 if (err) 1236 xenbus_dev_error(dev, err, "writing feature-sg-grant"); 1237 1238 err = xenbus_switch_state(dev, XenbusStateInitWait); 1239 if (err) 1240 goto fail; 1241 1242 return 0; 1243 1244 fail: 1245 pr_warn("%s failed\n", __func__); 1246 scsiback_remove(dev); 1247 1248 return err; 1249 } 1250 1251 static char *scsiback_dump_proto_id(struct scsiback_tport *tport) 1252 { 1253 switch (tport->tport_proto_id) { 1254 case SCSI_PROTOCOL_SAS: 1255 return "SAS"; 1256 case SCSI_PROTOCOL_FCP: 1257 return "FCP"; 1258 case SCSI_PROTOCOL_ISCSI: 1259 return "iSCSI"; 1260 default: 1261 break; 1262 } 1263 1264 return "Unknown"; 1265 } 1266 1267 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg) 1268 { 1269 struct scsiback_tpg *tpg = container_of(se_tpg, 1270 struct scsiback_tpg, se_tpg); 1271 struct scsiback_tport *tport = tpg->tport; 1272 1273 return &tport->tport_name[0]; 1274 } 1275 1276 static u16 scsiback_get_tag(struct se_portal_group *se_tpg) 1277 { 1278 struct scsiback_tpg *tpg = container_of(se_tpg, 1279 struct scsiback_tpg, se_tpg); 1280 return tpg->tport_tpgt; 1281 } 1282 1283 static struct se_wwn * 1284 scsiback_make_tport(struct target_fabric_configfs *tf, 1285 struct config_group *group, 1286 const char *name) 1287 { 1288 struct scsiback_tport *tport; 1289 char *ptr; 1290 u64 wwpn = 0; 1291 int off = 0; 1292 1293 tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL); 1294 if (!tport) 1295 return ERR_PTR(-ENOMEM); 1296 1297 tport->tport_wwpn = wwpn; 1298 /* 1299 * Determine the emulated Protocol Identifier and Target Port Name 1300 * based on the incoming configfs directory name. 1301 */ 1302 ptr = strstr(name, "naa."); 1303 if (ptr) { 1304 tport->tport_proto_id = SCSI_PROTOCOL_SAS; 1305 goto check_len; 1306 } 1307 ptr = strstr(name, "fc."); 1308 if (ptr) { 1309 tport->tport_proto_id = SCSI_PROTOCOL_FCP; 1310 off = 3; /* Skip over "fc." */ 1311 goto check_len; 1312 } 1313 ptr = strstr(name, "iqn."); 1314 if (ptr) { 1315 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI; 1316 goto check_len; 1317 } 1318 1319 pr_err("Unable to locate prefix for emulated Target Port: %s\n", name); 1320 kfree(tport); 1321 return ERR_PTR(-EINVAL); 1322 1323 check_len: 1324 if (strlen(name) >= VSCSI_NAMELEN) { 1325 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name, 1326 scsiback_dump_proto_id(tport), VSCSI_NAMELEN); 1327 kfree(tport); 1328 return ERR_PTR(-EINVAL); 1329 } 1330 snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]); 1331 1332 pr_debug("Allocated emulated Target %s Address: %s\n", 1333 scsiback_dump_proto_id(tport), name); 1334 1335 return &tport->tport_wwn; 1336 } 1337 1338 static void scsiback_drop_tport(struct se_wwn *wwn) 1339 { 1340 struct scsiback_tport *tport = container_of(wwn, 1341 struct scsiback_tport, tport_wwn); 1342 1343 pr_debug("Deallocating emulated Target %s Address: %s\n", 1344 scsiback_dump_proto_id(tport), tport->tport_name); 1345 1346 kfree(tport); 1347 } 1348 1349 static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg) 1350 { 1351 return 1; 1352 } 1353 1354 static int scsiback_check_stop_free(struct se_cmd *se_cmd) 1355 { 1356 /* 1357 * Do not release struct se_cmd's containing a valid TMR pointer. 1358 * These will be released directly in scsiback_device_action() 1359 * with transport_generic_free_cmd(). 1360 */ 1361 if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) 1362 return 0; 1363 1364 transport_generic_free_cmd(se_cmd, 0); 1365 return 1; 1366 } 1367 1368 static void scsiback_release_cmd(struct se_cmd *se_cmd) 1369 { 1370 struct vscsibk_pend *pending_req = container_of(se_cmd, 1371 struct vscsibk_pend, se_cmd); 1372 1373 kmem_cache_free(scsiback_cachep, pending_req); 1374 } 1375 1376 static int scsiback_shutdown_session(struct se_session *se_sess) 1377 { 1378 return 0; 1379 } 1380 1381 static void scsiback_close_session(struct se_session *se_sess) 1382 { 1383 } 1384 1385 static u32 scsiback_sess_get_index(struct se_session *se_sess) 1386 { 1387 return 0; 1388 } 1389 1390 static int scsiback_write_pending(struct se_cmd *se_cmd) 1391 { 1392 /* Go ahead and process the write immediately */ 1393 target_execute_cmd(se_cmd); 1394 1395 return 0; 1396 } 1397 1398 static int scsiback_write_pending_status(struct se_cmd *se_cmd) 1399 { 1400 return 0; 1401 } 1402 1403 static void scsiback_set_default_node_attrs(struct se_node_acl *nacl) 1404 { 1405 } 1406 1407 static int scsiback_get_cmd_state(struct se_cmd *se_cmd) 1408 { 1409 return 0; 1410 } 1411 1412 static int scsiback_queue_data_in(struct se_cmd *se_cmd) 1413 { 1414 struct vscsibk_pend *pending_req = container_of(se_cmd, 1415 struct vscsibk_pend, se_cmd); 1416 1417 pending_req->result = SAM_STAT_GOOD; 1418 scsiback_cmd_done(pending_req); 1419 return 0; 1420 } 1421 1422 static int scsiback_queue_status(struct se_cmd *se_cmd) 1423 { 1424 struct vscsibk_pend *pending_req = container_of(se_cmd, 1425 struct vscsibk_pend, se_cmd); 1426 1427 if (se_cmd->sense_buffer && 1428 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) || 1429 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) 1430 pending_req->result = (DRIVER_SENSE << 24) | 1431 SAM_STAT_CHECK_CONDITION; 1432 else 1433 pending_req->result = se_cmd->scsi_status; 1434 1435 scsiback_cmd_done(pending_req); 1436 return 0; 1437 } 1438 1439 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd) 1440 { 1441 struct se_tmr_req *se_tmr = se_cmd->se_tmr_req; 1442 struct scsiback_tmr *tmr = se_tmr->fabric_tmr_ptr; 1443 1444 atomic_set(&tmr->tmr_complete, 1); 1445 wake_up(&tmr->tmr_wait); 1446 } 1447 1448 static void scsiback_aborted_task(struct se_cmd *se_cmd) 1449 { 1450 } 1451 1452 static ssize_t scsiback_tpg_param_alias_show(struct config_item *item, 1453 char *page) 1454 { 1455 struct se_portal_group *se_tpg = param_to_tpg(item); 1456 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1457 se_tpg); 1458 ssize_t rb; 1459 1460 mutex_lock(&tpg->tv_tpg_mutex); 1461 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias); 1462 mutex_unlock(&tpg->tv_tpg_mutex); 1463 1464 return rb; 1465 } 1466 1467 static ssize_t scsiback_tpg_param_alias_store(struct config_item *item, 1468 const char *page, size_t count) 1469 { 1470 struct se_portal_group *se_tpg = param_to_tpg(item); 1471 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1472 se_tpg); 1473 int len; 1474 1475 if (strlen(page) >= VSCSI_NAMELEN) { 1476 pr_err("param alias: %s, exceeds max: %d\n", page, 1477 VSCSI_NAMELEN); 1478 return -EINVAL; 1479 } 1480 1481 mutex_lock(&tpg->tv_tpg_mutex); 1482 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page); 1483 if (tpg->param_alias[len - 1] == '\n') 1484 tpg->param_alias[len - 1] = '\0'; 1485 mutex_unlock(&tpg->tv_tpg_mutex); 1486 1487 return count; 1488 } 1489 1490 CONFIGFS_ATTR(scsiback_tpg_param_, alias); 1491 1492 static struct configfs_attribute *scsiback_param_attrs[] = { 1493 &scsiback_tpg_param_attr_alias, 1494 NULL, 1495 }; 1496 1497 static int scsiback_make_nexus(struct scsiback_tpg *tpg, 1498 const char *name) 1499 { 1500 struct se_portal_group *se_tpg; 1501 struct se_session *se_sess; 1502 struct scsiback_nexus *tv_nexus; 1503 1504 mutex_lock(&tpg->tv_tpg_mutex); 1505 if (tpg->tpg_nexus) { 1506 mutex_unlock(&tpg->tv_tpg_mutex); 1507 pr_debug("tpg->tpg_nexus already exists\n"); 1508 return -EEXIST; 1509 } 1510 se_tpg = &tpg->se_tpg; 1511 1512 tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL); 1513 if (!tv_nexus) { 1514 mutex_unlock(&tpg->tv_tpg_mutex); 1515 return -ENOMEM; 1516 } 1517 /* 1518 * Initialize the struct se_session pointer 1519 */ 1520 tv_nexus->tvn_se_sess = transport_init_session(TARGET_PROT_NORMAL); 1521 if (IS_ERR(tv_nexus->tvn_se_sess)) { 1522 mutex_unlock(&tpg->tv_tpg_mutex); 1523 kfree(tv_nexus); 1524 return -ENOMEM; 1525 } 1526 se_sess = tv_nexus->tvn_se_sess; 1527 /* 1528 * Since we are running in 'demo mode' this call with generate a 1529 * struct se_node_acl for the scsiback struct se_portal_group with 1530 * the SCSI Initiator port name of the passed configfs group 'name'. 1531 */ 1532 tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl( 1533 se_tpg, (unsigned char *)name); 1534 if (!tv_nexus->tvn_se_sess->se_node_acl) { 1535 mutex_unlock(&tpg->tv_tpg_mutex); 1536 pr_debug("core_tpg_check_initiator_node_acl() failed for %s\n", 1537 name); 1538 goto out; 1539 } 1540 /* Now register the TCM pvscsi virtual I_T Nexus as active. */ 1541 transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl, 1542 tv_nexus->tvn_se_sess, tv_nexus); 1543 tpg->tpg_nexus = tv_nexus; 1544 1545 mutex_unlock(&tpg->tv_tpg_mutex); 1546 return 0; 1547 1548 out: 1549 transport_free_session(se_sess); 1550 kfree(tv_nexus); 1551 return -ENOMEM; 1552 } 1553 1554 static int scsiback_drop_nexus(struct scsiback_tpg *tpg) 1555 { 1556 struct se_session *se_sess; 1557 struct scsiback_nexus *tv_nexus; 1558 1559 mutex_lock(&tpg->tv_tpg_mutex); 1560 tv_nexus = tpg->tpg_nexus; 1561 if (!tv_nexus) { 1562 mutex_unlock(&tpg->tv_tpg_mutex); 1563 return -ENODEV; 1564 } 1565 1566 se_sess = tv_nexus->tvn_se_sess; 1567 if (!se_sess) { 1568 mutex_unlock(&tpg->tv_tpg_mutex); 1569 return -ENODEV; 1570 } 1571 1572 if (tpg->tv_tpg_port_count != 0) { 1573 mutex_unlock(&tpg->tv_tpg_mutex); 1574 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n", 1575 tpg->tv_tpg_port_count); 1576 return -EBUSY; 1577 } 1578 1579 if (tpg->tv_tpg_fe_count != 0) { 1580 mutex_unlock(&tpg->tv_tpg_mutex); 1581 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n", 1582 tpg->tv_tpg_fe_count); 1583 return -EBUSY; 1584 } 1585 1586 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n", 1587 scsiback_dump_proto_id(tpg->tport), 1588 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1589 1590 /* 1591 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port 1592 */ 1593 transport_deregister_session(tv_nexus->tvn_se_sess); 1594 tpg->tpg_nexus = NULL; 1595 mutex_unlock(&tpg->tv_tpg_mutex); 1596 1597 kfree(tv_nexus); 1598 return 0; 1599 } 1600 1601 static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page) 1602 { 1603 struct se_portal_group *se_tpg = to_tpg(item); 1604 struct scsiback_tpg *tpg = container_of(se_tpg, 1605 struct scsiback_tpg, se_tpg); 1606 struct scsiback_nexus *tv_nexus; 1607 ssize_t ret; 1608 1609 mutex_lock(&tpg->tv_tpg_mutex); 1610 tv_nexus = tpg->tpg_nexus; 1611 if (!tv_nexus) { 1612 mutex_unlock(&tpg->tv_tpg_mutex); 1613 return -ENODEV; 1614 } 1615 ret = snprintf(page, PAGE_SIZE, "%s\n", 1616 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1617 mutex_unlock(&tpg->tv_tpg_mutex); 1618 1619 return ret; 1620 } 1621 1622 static ssize_t scsiback_tpg_nexus_store(struct config_item *item, 1623 const char *page, size_t count) 1624 { 1625 struct se_portal_group *se_tpg = to_tpg(item); 1626 struct scsiback_tpg *tpg = container_of(se_tpg, 1627 struct scsiback_tpg, se_tpg); 1628 struct scsiback_tport *tport_wwn = tpg->tport; 1629 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr; 1630 int ret; 1631 /* 1632 * Shutdown the active I_T nexus if 'NULL' is passed. 1633 */ 1634 if (!strncmp(page, "NULL", 4)) { 1635 ret = scsiback_drop_nexus(tpg); 1636 return (!ret) ? count : ret; 1637 } 1638 /* 1639 * Otherwise make sure the passed virtual Initiator port WWN matches 1640 * the fabric protocol_id set in scsiback_make_tport(), and call 1641 * scsiback_make_nexus(). 1642 */ 1643 if (strlen(page) >= VSCSI_NAMELEN) { 1644 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n", 1645 page, VSCSI_NAMELEN); 1646 return -EINVAL; 1647 } 1648 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page); 1649 1650 ptr = strstr(i_port, "naa."); 1651 if (ptr) { 1652 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) { 1653 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n", 1654 i_port, scsiback_dump_proto_id(tport_wwn)); 1655 return -EINVAL; 1656 } 1657 port_ptr = &i_port[0]; 1658 goto check_newline; 1659 } 1660 ptr = strstr(i_port, "fc."); 1661 if (ptr) { 1662 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) { 1663 pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n", 1664 i_port, scsiback_dump_proto_id(tport_wwn)); 1665 return -EINVAL; 1666 } 1667 port_ptr = &i_port[3]; /* Skip over "fc." */ 1668 goto check_newline; 1669 } 1670 ptr = strstr(i_port, "iqn."); 1671 if (ptr) { 1672 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) { 1673 pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n", 1674 i_port, scsiback_dump_proto_id(tport_wwn)); 1675 return -EINVAL; 1676 } 1677 port_ptr = &i_port[0]; 1678 goto check_newline; 1679 } 1680 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n", 1681 i_port); 1682 return -EINVAL; 1683 /* 1684 * Clear any trailing newline for the NAA WWN 1685 */ 1686 check_newline: 1687 if (i_port[strlen(i_port) - 1] == '\n') 1688 i_port[strlen(i_port) - 1] = '\0'; 1689 1690 ret = scsiback_make_nexus(tpg, port_ptr); 1691 if (ret < 0) 1692 return ret; 1693 1694 return count; 1695 } 1696 1697 CONFIGFS_ATTR(scsiback_tpg_, nexus); 1698 1699 static struct configfs_attribute *scsiback_tpg_attrs[] = { 1700 &scsiback_tpg_attr_nexus, 1701 NULL, 1702 }; 1703 1704 static ssize_t 1705 scsiback_wwn_version_show(struct config_item *item, char *page) 1706 { 1707 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on " 1708 UTS_RELEASE"\n", 1709 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1710 } 1711 1712 CONFIGFS_ATTR_RO(scsiback_wwn_, version); 1713 1714 static struct configfs_attribute *scsiback_wwn_attrs[] = { 1715 &scsiback_wwn_attr_version, 1716 NULL, 1717 }; 1718 1719 static char *scsiback_get_fabric_name(void) 1720 { 1721 return "xen-pvscsi"; 1722 } 1723 1724 static int scsiback_port_link(struct se_portal_group *se_tpg, 1725 struct se_lun *lun) 1726 { 1727 struct scsiback_tpg *tpg = container_of(se_tpg, 1728 struct scsiback_tpg, se_tpg); 1729 1730 mutex_lock(&tpg->tv_tpg_mutex); 1731 tpg->tv_tpg_port_count++; 1732 mutex_unlock(&tpg->tv_tpg_mutex); 1733 1734 return 0; 1735 } 1736 1737 static void scsiback_port_unlink(struct se_portal_group *se_tpg, 1738 struct se_lun *lun) 1739 { 1740 struct scsiback_tpg *tpg = container_of(se_tpg, 1741 struct scsiback_tpg, se_tpg); 1742 1743 mutex_lock(&tpg->tv_tpg_mutex); 1744 tpg->tv_tpg_port_count--; 1745 mutex_unlock(&tpg->tv_tpg_mutex); 1746 } 1747 1748 static struct se_portal_group * 1749 scsiback_make_tpg(struct se_wwn *wwn, 1750 struct config_group *group, 1751 const char *name) 1752 { 1753 struct scsiback_tport *tport = container_of(wwn, 1754 struct scsiback_tport, tport_wwn); 1755 1756 struct scsiback_tpg *tpg; 1757 u16 tpgt; 1758 int ret; 1759 1760 if (strstr(name, "tpgt_") != name) 1761 return ERR_PTR(-EINVAL); 1762 ret = kstrtou16(name + 5, 10, &tpgt); 1763 if (ret) 1764 return ERR_PTR(ret); 1765 1766 tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL); 1767 if (!tpg) 1768 return ERR_PTR(-ENOMEM); 1769 1770 mutex_init(&tpg->tv_tpg_mutex); 1771 INIT_LIST_HEAD(&tpg->tv_tpg_list); 1772 INIT_LIST_HEAD(&tpg->info_list); 1773 tpg->tport = tport; 1774 tpg->tport_tpgt = tpgt; 1775 1776 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id); 1777 if (ret < 0) { 1778 kfree(tpg); 1779 return NULL; 1780 } 1781 mutex_lock(&scsiback_mutex); 1782 list_add_tail(&tpg->tv_tpg_list, &scsiback_list); 1783 mutex_unlock(&scsiback_mutex); 1784 1785 return &tpg->se_tpg; 1786 } 1787 1788 static void scsiback_drop_tpg(struct se_portal_group *se_tpg) 1789 { 1790 struct scsiback_tpg *tpg = container_of(se_tpg, 1791 struct scsiback_tpg, se_tpg); 1792 1793 mutex_lock(&scsiback_mutex); 1794 list_del(&tpg->tv_tpg_list); 1795 mutex_unlock(&scsiback_mutex); 1796 /* 1797 * Release the virtual I_T Nexus for this xen-pvscsi TPG 1798 */ 1799 scsiback_drop_nexus(tpg); 1800 /* 1801 * Deregister the se_tpg from TCM. 1802 */ 1803 core_tpg_deregister(se_tpg); 1804 kfree(tpg); 1805 } 1806 1807 static int scsiback_check_true(struct se_portal_group *se_tpg) 1808 { 1809 return 1; 1810 } 1811 1812 static int scsiback_check_false(struct se_portal_group *se_tpg) 1813 { 1814 return 0; 1815 } 1816 1817 static const struct target_core_fabric_ops scsiback_ops = { 1818 .module = THIS_MODULE, 1819 .name = "xen-pvscsi", 1820 .get_fabric_name = scsiback_get_fabric_name, 1821 .tpg_get_wwn = scsiback_get_fabric_wwn, 1822 .tpg_get_tag = scsiback_get_tag, 1823 .tpg_check_demo_mode = scsiback_check_true, 1824 .tpg_check_demo_mode_cache = scsiback_check_true, 1825 .tpg_check_demo_mode_write_protect = scsiback_check_false, 1826 .tpg_check_prod_mode_write_protect = scsiback_check_false, 1827 .tpg_get_inst_index = scsiback_tpg_get_inst_index, 1828 .check_stop_free = scsiback_check_stop_free, 1829 .release_cmd = scsiback_release_cmd, 1830 .shutdown_session = scsiback_shutdown_session, 1831 .close_session = scsiback_close_session, 1832 .sess_get_index = scsiback_sess_get_index, 1833 .sess_get_initiator_sid = NULL, 1834 .write_pending = scsiback_write_pending, 1835 .write_pending_status = scsiback_write_pending_status, 1836 .set_default_node_attributes = scsiback_set_default_node_attrs, 1837 .get_cmd_state = scsiback_get_cmd_state, 1838 .queue_data_in = scsiback_queue_data_in, 1839 .queue_status = scsiback_queue_status, 1840 .queue_tm_rsp = scsiback_queue_tm_rsp, 1841 .aborted_task = scsiback_aborted_task, 1842 /* 1843 * Setup callers for generic logic in target_core_fabric_configfs.c 1844 */ 1845 .fabric_make_wwn = scsiback_make_tport, 1846 .fabric_drop_wwn = scsiback_drop_tport, 1847 .fabric_make_tpg = scsiback_make_tpg, 1848 .fabric_drop_tpg = scsiback_drop_tpg, 1849 .fabric_post_link = scsiback_port_link, 1850 .fabric_pre_unlink = scsiback_port_unlink, 1851 1852 .tfc_wwn_attrs = scsiback_wwn_attrs, 1853 .tfc_tpg_base_attrs = scsiback_tpg_attrs, 1854 .tfc_tpg_param_attrs = scsiback_param_attrs, 1855 }; 1856 1857 static const struct xenbus_device_id scsiback_ids[] = { 1858 { "vscsi" }, 1859 { "" } 1860 }; 1861 1862 static struct xenbus_driver scsiback_driver = { 1863 .ids = scsiback_ids, 1864 .probe = scsiback_probe, 1865 .remove = scsiback_remove, 1866 .otherend_changed = scsiback_frontend_changed 1867 }; 1868 1869 static void scsiback_init_pend(void *p) 1870 { 1871 struct vscsibk_pend *pend = p; 1872 int i; 1873 1874 memset(pend, 0, sizeof(*pend)); 1875 for (i = 0; i < VSCSI_MAX_GRANTS; i++) 1876 pend->grant_handles[i] = SCSIBACK_INVALID_HANDLE; 1877 } 1878 1879 static int __init scsiback_init(void) 1880 { 1881 int ret; 1882 1883 if (!xen_domain()) 1884 return -ENODEV; 1885 1886 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n", 1887 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1888 1889 scsiback_cachep = kmem_cache_create("vscsiif_cache", 1890 sizeof(struct vscsibk_pend), 0, 0, scsiback_init_pend); 1891 if (!scsiback_cachep) 1892 return -ENOMEM; 1893 1894 ret = xenbus_register_backend(&scsiback_driver); 1895 if (ret) 1896 goto out_cache_destroy; 1897 1898 ret = target_register_template(&scsiback_ops); 1899 if (ret) 1900 goto out_unregister_xenbus; 1901 1902 return 0; 1903 1904 out_unregister_xenbus: 1905 xenbus_unregister_driver(&scsiback_driver); 1906 out_cache_destroy: 1907 kmem_cache_destroy(scsiback_cachep); 1908 pr_err("%s: error %d\n", __func__, ret); 1909 return ret; 1910 } 1911 1912 static void __exit scsiback_exit(void) 1913 { 1914 struct page *page; 1915 1916 while (free_pages_num) { 1917 if (get_free_page(&page)) 1918 BUG(); 1919 gnttab_free_pages(1, &page); 1920 } 1921 target_unregister_template(&scsiback_ops); 1922 xenbus_unregister_driver(&scsiback_driver); 1923 kmem_cache_destroy(scsiback_cachep); 1924 } 1925 1926 module_init(scsiback_init); 1927 module_exit(scsiback_exit); 1928 1929 MODULE_DESCRIPTION("Xen SCSI backend driver"); 1930 MODULE_LICENSE("Dual BSD/GPL"); 1931 MODULE_ALIAS("xen-backend:vscsi"); 1932 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>"); 1933