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 <linux/module.h> 37 #include <linux/utsname.h> 38 #include <linux/interrupt.h> 39 #include <linux/slab.h> 40 #include <linux/wait.h> 41 #include <linux/sched.h> 42 #include <linux/list.h> 43 #include <linux/gfp.h> 44 #include <linux/delay.h> 45 #include <linux/spinlock.h> 46 #include <linux/configfs.h> 47 48 #include <generated/utsrelease.h> 49 50 #include <scsi/scsi_host.h> /* SG_ALL */ 51 52 #include <target/target_core_base.h> 53 #include <target/target_core_fabric.h> 54 55 #include <asm/hypervisor.h> 56 57 #include <xen/xen.h> 58 #include <xen/balloon.h> 59 #include <xen/events.h> 60 #include <xen/xenbus.h> 61 #include <xen/grant_table.h> 62 #include <xen/page.h> 63 64 #include <xen/interface/grant_table.h> 65 #include <xen/interface/io/vscsiif.h> 66 67 #define VSCSI_VERSION "v0.1" 68 #define VSCSI_NAMELEN 32 69 70 struct ids_tuple { 71 unsigned int hst; /* host */ 72 unsigned int chn; /* channel */ 73 unsigned int tgt; /* target */ 74 unsigned int lun; /* LUN */ 75 }; 76 77 struct v2p_entry { 78 struct ids_tuple v; /* translate from */ 79 struct scsiback_tpg *tpg; /* translate to */ 80 unsigned int lun; 81 struct kref kref; 82 struct list_head l; 83 }; 84 85 struct vscsibk_info { 86 struct xenbus_device *dev; 87 88 domid_t domid; 89 unsigned int irq; 90 91 struct vscsiif_back_ring ring; 92 93 spinlock_t ring_lock; 94 atomic_t nr_unreplied_reqs; 95 96 spinlock_t v2p_lock; 97 struct list_head v2p_entry_lists; 98 99 wait_queue_head_t waiting_to_free; 100 101 struct gnttab_page_cache free_pages; 102 }; 103 104 /* theoretical maximum of grants for one request */ 105 #define VSCSI_MAX_GRANTS (SG_ALL + VSCSIIF_SG_TABLESIZE) 106 107 /* 108 * VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one 109 * call to map/unmap grants. Don't choose it too large, as there are arrays 110 * with VSCSI_GRANT_BATCH elements allocated on the stack. 111 */ 112 #define VSCSI_GRANT_BATCH 16 113 114 struct vscsibk_pend { 115 uint16_t rqid; 116 117 uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE]; 118 uint8_t cmd_len; 119 120 uint8_t sc_data_direction; 121 uint16_t n_sg; /* real length of SG list */ 122 uint16_t n_grants; /* SG pages and potentially SG list */ 123 uint32_t data_len; 124 uint32_t result; 125 126 struct vscsibk_info *info; 127 struct v2p_entry *v2p; 128 struct scatterlist *sgl; 129 130 uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE]; 131 132 grant_handle_t grant_handles[VSCSI_MAX_GRANTS]; 133 struct page *pages[VSCSI_MAX_GRANTS]; 134 135 struct se_cmd se_cmd; 136 137 struct completion tmr_done; 138 }; 139 140 #define VSCSI_DEFAULT_SESSION_TAGS 128 141 142 struct scsiback_nexus { 143 /* Pointer to TCM session for I_T Nexus */ 144 struct se_session *tvn_se_sess; 145 }; 146 147 struct scsiback_tport { 148 /* SCSI protocol the tport is providing */ 149 u8 tport_proto_id; 150 /* Binary World Wide unique Port Name for pvscsi Target port */ 151 u64 tport_wwpn; 152 /* ASCII formatted WWPN for pvscsi Target port */ 153 char tport_name[VSCSI_NAMELEN]; 154 /* Returned by scsiback_make_tport() */ 155 struct se_wwn tport_wwn; 156 }; 157 158 struct scsiback_tpg { 159 /* scsiback port target portal group tag for TCM */ 160 u16 tport_tpgt; 161 /* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */ 162 int tv_tpg_port_count; 163 /* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */ 164 int tv_tpg_fe_count; 165 /* list for scsiback_list */ 166 struct list_head tv_tpg_list; 167 /* Used to protect access for tpg_nexus */ 168 struct mutex tv_tpg_mutex; 169 /* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */ 170 struct scsiback_nexus *tpg_nexus; 171 /* Pointer back to scsiback_tport */ 172 struct scsiback_tport *tport; 173 /* Returned by scsiback_make_tpg() */ 174 struct se_portal_group se_tpg; 175 /* alias used in xenstore */ 176 char param_alias[VSCSI_NAMELEN]; 177 /* list of info structures related to this target portal group */ 178 struct list_head info_list; 179 }; 180 181 #define SCSIBACK_INVALID_HANDLE (~0) 182 183 static bool log_print_stat; 184 module_param(log_print_stat, bool, 0644); 185 186 static int scsiback_max_buffer_pages = 1024; 187 module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644); 188 MODULE_PARM_DESC(max_buffer_pages, 189 "Maximum number of free pages to keep in backend buffer"); 190 191 /* Global spinlock to protect scsiback TPG list */ 192 static DEFINE_MUTEX(scsiback_mutex); 193 static LIST_HEAD(scsiback_list); 194 195 static void scsiback_get(struct vscsibk_info *info) 196 { 197 atomic_inc(&info->nr_unreplied_reqs); 198 } 199 200 static void scsiback_put(struct vscsibk_info *info) 201 { 202 if (atomic_dec_and_test(&info->nr_unreplied_reqs)) 203 wake_up(&info->waiting_to_free); 204 } 205 206 static unsigned long vaddr_page(struct page *page) 207 { 208 unsigned long pfn = page_to_pfn(page); 209 210 return (unsigned long)pfn_to_kaddr(pfn); 211 } 212 213 static unsigned long vaddr(struct vscsibk_pend *req, int seg) 214 { 215 return vaddr_page(req->pages[seg]); 216 } 217 218 static void scsiback_print_status(char *sense_buffer, int errors, 219 struct vscsibk_pend *pending_req) 220 { 221 struct scsiback_tpg *tpg = pending_req->v2p->tpg; 222 223 pr_err("[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x\n", 224 tpg->tport->tport_name, pending_req->v2p->lun, 225 pending_req->cmnd[0], errors & 0xff, COMMAND_COMPLETE, 226 host_byte(errors)); 227 } 228 229 static void scsiback_fast_flush_area(struct vscsibk_pend *req) 230 { 231 struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH]; 232 struct page *pages[VSCSI_GRANT_BATCH]; 233 unsigned int i, invcount = 0; 234 grant_handle_t handle; 235 int err; 236 237 kfree(req->sgl); 238 req->sgl = NULL; 239 req->n_sg = 0; 240 241 if (!req->n_grants) 242 return; 243 244 for (i = 0; i < req->n_grants; i++) { 245 handle = req->grant_handles[i]; 246 if (handle == SCSIBACK_INVALID_HANDLE) 247 continue; 248 gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i), 249 GNTMAP_host_map, handle); 250 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE; 251 pages[invcount] = req->pages[i]; 252 put_page(pages[invcount]); 253 invcount++; 254 if (invcount < VSCSI_GRANT_BATCH) 255 continue; 256 err = gnttab_unmap_refs(unmap, NULL, pages, invcount); 257 BUG_ON(err); 258 invcount = 0; 259 } 260 261 if (invcount) { 262 err = gnttab_unmap_refs(unmap, NULL, pages, invcount); 263 BUG_ON(err); 264 } 265 266 gnttab_page_cache_put(&req->info->free_pages, req->pages, 267 req->n_grants); 268 req->n_grants = 0; 269 } 270 271 static void scsiback_free_translation_entry(struct kref *kref) 272 { 273 struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref); 274 struct scsiback_tpg *tpg = entry->tpg; 275 276 mutex_lock(&tpg->tv_tpg_mutex); 277 tpg->tv_tpg_fe_count--; 278 mutex_unlock(&tpg->tv_tpg_mutex); 279 280 kfree(entry); 281 } 282 283 static int32_t scsiback_result(int32_t result) 284 { 285 int32_t host_status; 286 287 switch (XEN_VSCSIIF_RSLT_HOST(result)) { 288 case DID_OK: 289 host_status = XEN_VSCSIIF_RSLT_HOST_OK; 290 break; 291 case DID_NO_CONNECT: 292 host_status = XEN_VSCSIIF_RSLT_HOST_NO_CONNECT; 293 break; 294 case DID_BUS_BUSY: 295 host_status = XEN_VSCSIIF_RSLT_HOST_BUS_BUSY; 296 break; 297 case DID_TIME_OUT: 298 host_status = XEN_VSCSIIF_RSLT_HOST_TIME_OUT; 299 break; 300 case DID_BAD_TARGET: 301 host_status = XEN_VSCSIIF_RSLT_HOST_BAD_TARGET; 302 break; 303 case DID_ABORT: 304 host_status = XEN_VSCSIIF_RSLT_HOST_ABORT; 305 break; 306 case DID_PARITY: 307 host_status = XEN_VSCSIIF_RSLT_HOST_PARITY; 308 break; 309 case DID_ERROR: 310 host_status = XEN_VSCSIIF_RSLT_HOST_ERROR; 311 break; 312 case DID_RESET: 313 host_status = XEN_VSCSIIF_RSLT_HOST_RESET; 314 break; 315 case DID_BAD_INTR: 316 host_status = XEN_VSCSIIF_RSLT_HOST_BAD_INTR; 317 break; 318 case DID_PASSTHROUGH: 319 host_status = XEN_VSCSIIF_RSLT_HOST_PASSTHROUGH; 320 break; 321 case DID_SOFT_ERROR: 322 host_status = XEN_VSCSIIF_RSLT_HOST_SOFT_ERROR; 323 break; 324 case DID_IMM_RETRY: 325 host_status = XEN_VSCSIIF_RSLT_HOST_IMM_RETRY; 326 break; 327 case DID_REQUEUE: 328 host_status = XEN_VSCSIIF_RSLT_HOST_REQUEUE; 329 break; 330 case DID_TRANSPORT_DISRUPTED: 331 host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_DISRUPTED; 332 break; 333 case DID_TRANSPORT_FAILFAST: 334 host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_FAILFAST; 335 break; 336 case DID_TARGET_FAILURE: 337 host_status = XEN_VSCSIIF_RSLT_HOST_TARGET_FAILURE; 338 break; 339 case DID_NEXUS_FAILURE: 340 host_status = XEN_VSCSIIF_RSLT_HOST_NEXUS_FAILURE; 341 break; 342 case DID_ALLOC_FAILURE: 343 host_status = XEN_VSCSIIF_RSLT_HOST_ALLOC_FAILURE; 344 break; 345 case DID_MEDIUM_ERROR: 346 host_status = XEN_VSCSIIF_RSLT_HOST_MEDIUM_ERROR; 347 break; 348 case DID_TRANSPORT_MARGINAL: 349 host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_MARGINAL; 350 break; 351 default: 352 host_status = XEN_VSCSIIF_RSLT_HOST_ERROR; 353 break; 354 } 355 356 return (host_status << 16) | (result & 0x00ffff); 357 } 358 359 static void scsiback_send_response(struct vscsibk_info *info, 360 char *sense_buffer, int32_t result, uint32_t resid, 361 uint16_t rqid) 362 { 363 struct vscsiif_response *ring_res; 364 int notify; 365 struct scsi_sense_hdr sshdr; 366 unsigned long flags; 367 unsigned len; 368 369 spin_lock_irqsave(&info->ring_lock, flags); 370 371 ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt); 372 info->ring.rsp_prod_pvt++; 373 374 ring_res->rslt = scsiback_result(result); 375 ring_res->rqid = rqid; 376 377 if (sense_buffer != NULL && 378 scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE, 379 &sshdr)) { 380 len = min_t(unsigned, 8 + sense_buffer[7], 381 VSCSIIF_SENSE_BUFFERSIZE); 382 memcpy(ring_res->sense_buffer, sense_buffer, len); 383 ring_res->sense_len = len; 384 } else { 385 ring_res->sense_len = 0; 386 } 387 388 ring_res->residual_len = resid; 389 390 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify); 391 spin_unlock_irqrestore(&info->ring_lock, flags); 392 393 if (notify) 394 notify_remote_via_irq(info->irq); 395 } 396 397 static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result, 398 uint32_t resid, struct vscsibk_pend *pending_req) 399 { 400 scsiback_send_response(pending_req->info, sense_buffer, result, 401 resid, pending_req->rqid); 402 403 if (pending_req->v2p) 404 kref_put(&pending_req->v2p->kref, 405 scsiback_free_translation_entry); 406 } 407 408 static void scsiback_cmd_done(struct vscsibk_pend *pending_req) 409 { 410 struct vscsibk_info *info = pending_req->info; 411 unsigned char *sense_buffer; 412 unsigned int resid; 413 int errors; 414 415 sense_buffer = pending_req->sense_buffer; 416 resid = pending_req->se_cmd.residual_count; 417 errors = pending_req->result; 418 419 if (errors && log_print_stat) 420 scsiback_print_status(sense_buffer, errors, pending_req); 421 422 scsiback_fast_flush_area(pending_req); 423 scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req); 424 scsiback_put(info); 425 /* 426 * Drop the extra KREF_ACK reference taken by target_submit_cmd_map_sgls() 427 * ahead of scsiback_check_stop_free() -> transport_generic_free_cmd() 428 * final se_cmd->cmd_kref put. 429 */ 430 target_put_sess_cmd(&pending_req->se_cmd); 431 } 432 433 static void scsiback_cmd_exec(struct vscsibk_pend *pending_req) 434 { 435 struct se_cmd *se_cmd = &pending_req->se_cmd; 436 struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess; 437 438 scsiback_get(pending_req->info); 439 se_cmd->tag = pending_req->rqid; 440 target_init_cmd(se_cmd, sess, pending_req->sense_buffer, 441 pending_req->v2p->lun, pending_req->data_len, 0, 442 pending_req->sc_data_direction, TARGET_SCF_ACK_KREF); 443 444 if (target_submit_prep(se_cmd, pending_req->cmnd, pending_req->sgl, 445 pending_req->n_sg, NULL, 0, NULL, 0, GFP_KERNEL)) 446 return; 447 448 target_submit(se_cmd); 449 } 450 451 static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map, 452 struct page **pg, grant_handle_t *grant, int cnt) 453 { 454 int err, i; 455 456 if (!cnt) 457 return 0; 458 459 err = gnttab_map_refs(map, NULL, pg, cnt); 460 for (i = 0; i < cnt; i++) { 461 if (unlikely(map[i].status != GNTST_okay)) { 462 pr_err("invalid buffer -- could not remap it\n"); 463 map[i].handle = SCSIBACK_INVALID_HANDLE; 464 if (!err) 465 err = -ENOMEM; 466 } else { 467 get_page(pg[i]); 468 } 469 grant[i] = map[i].handle; 470 } 471 return err; 472 } 473 474 static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req, 475 struct scsiif_request_segment *seg, struct page **pg, 476 grant_handle_t *grant, int cnt, u32 flags) 477 { 478 int mapcount = 0, i, err = 0; 479 struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH]; 480 struct vscsibk_info *info = pending_req->info; 481 482 for (i = 0; i < cnt; i++) { 483 if (gnttab_page_cache_get(&info->free_pages, pg + mapcount)) { 484 gnttab_page_cache_put(&info->free_pages, pg, mapcount); 485 pr_err("no grant page\n"); 486 return -ENOMEM; 487 } 488 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]), 489 flags, seg[i].gref, info->domid); 490 mapcount++; 491 if (mapcount < VSCSI_GRANT_BATCH) 492 continue; 493 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount); 494 pg += mapcount; 495 grant += mapcount; 496 pending_req->n_grants += mapcount; 497 if (err) 498 return err; 499 mapcount = 0; 500 } 501 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount); 502 pending_req->n_grants += mapcount; 503 return err; 504 } 505 506 static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req, 507 struct vscsibk_pend *pending_req) 508 { 509 u32 flags; 510 int i, err, n_segs, i_seg = 0; 511 struct page **pg; 512 struct scsiif_request_segment *seg; 513 unsigned long end_seg = 0; 514 unsigned int nr_segments = (unsigned int)ring_req->nr_segments; 515 unsigned int nr_sgl = 0; 516 struct scatterlist *sg; 517 grant_handle_t *grant; 518 519 pending_req->n_sg = 0; 520 pending_req->n_grants = 0; 521 pending_req->data_len = 0; 522 523 nr_segments &= ~VSCSIIF_SG_GRANT; 524 if (!nr_segments) 525 return 0; 526 527 if (nr_segments > VSCSIIF_SG_TABLESIZE) { 528 pr_debug("invalid parameter nr_seg = %d\n", 529 ring_req->nr_segments); 530 return -EINVAL; 531 } 532 533 if (ring_req->nr_segments & VSCSIIF_SG_GRANT) { 534 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg, 535 pending_req->pages, pending_req->grant_handles, 536 nr_segments, GNTMAP_host_map | GNTMAP_readonly); 537 if (err) 538 return err; 539 nr_sgl = nr_segments; 540 nr_segments = 0; 541 for (i = 0; i < nr_sgl; i++) { 542 n_segs = ring_req->seg[i].length / 543 sizeof(struct scsiif_request_segment); 544 if ((unsigned)ring_req->seg[i].offset + 545 (unsigned)ring_req->seg[i].length > PAGE_SIZE || 546 n_segs * sizeof(struct scsiif_request_segment) != 547 ring_req->seg[i].length) 548 return -EINVAL; 549 nr_segments += n_segs; 550 } 551 if (nr_segments > SG_ALL) { 552 pr_debug("invalid nr_seg = %d\n", nr_segments); 553 return -EINVAL; 554 } 555 } 556 557 /* free of (sgl) in fast_flush_area() */ 558 pending_req->sgl = kmalloc_array(nr_segments, 559 sizeof(struct scatterlist), GFP_KERNEL); 560 if (!pending_req->sgl) 561 return -ENOMEM; 562 563 sg_init_table(pending_req->sgl, nr_segments); 564 pending_req->n_sg = nr_segments; 565 566 flags = GNTMAP_host_map; 567 if (pending_req->sc_data_direction == DMA_TO_DEVICE) 568 flags |= GNTMAP_readonly; 569 570 pg = pending_req->pages + nr_sgl; 571 grant = pending_req->grant_handles + nr_sgl; 572 if (!nr_sgl) { 573 seg = ring_req->seg; 574 err = scsiback_gnttab_data_map_list(pending_req, seg, 575 pg, grant, nr_segments, flags); 576 if (err) 577 return err; 578 } else { 579 for (i = 0; i < nr_sgl; i++) { 580 seg = (struct scsiif_request_segment *)( 581 vaddr(pending_req, i) + ring_req->seg[i].offset); 582 n_segs = ring_req->seg[i].length / 583 sizeof(struct scsiif_request_segment); 584 err = scsiback_gnttab_data_map_list(pending_req, seg, 585 pg, grant, n_segs, flags); 586 if (err) 587 return err; 588 pg += n_segs; 589 grant += n_segs; 590 } 591 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset; 592 seg = (struct scsiif_request_segment *)end_seg; 593 end_seg += ring_req->seg[0].length; 594 pg = pending_req->pages + nr_sgl; 595 } 596 597 for_each_sg(pending_req->sgl, sg, nr_segments, i) { 598 sg_set_page(sg, pg[i], seg->length, seg->offset); 599 pending_req->data_len += seg->length; 600 seg++; 601 if (nr_sgl && (unsigned long)seg >= end_seg) { 602 i_seg++; 603 end_seg = vaddr(pending_req, i_seg) + 604 ring_req->seg[i_seg].offset; 605 seg = (struct scsiif_request_segment *)end_seg; 606 end_seg += ring_req->seg[i_seg].length; 607 } 608 if (sg->offset >= PAGE_SIZE || 609 sg->length > PAGE_SIZE || 610 sg->offset + sg->length > PAGE_SIZE) 611 return -EINVAL; 612 } 613 614 return 0; 615 } 616 617 static void scsiback_disconnect(struct vscsibk_info *info) 618 { 619 wait_event(info->waiting_to_free, 620 atomic_read(&info->nr_unreplied_reqs) == 0); 621 622 unbind_from_irqhandler(info->irq, info); 623 info->irq = 0; 624 xenbus_unmap_ring_vfree(info->dev, info->ring.sring); 625 } 626 627 static void scsiback_device_action(struct vscsibk_pend *pending_req, 628 enum tcm_tmreq_table act, int tag) 629 { 630 struct scsiback_tpg *tpg = pending_req->v2p->tpg; 631 struct scsiback_nexus *nexus = tpg->tpg_nexus; 632 struct se_cmd *se_cmd = &pending_req->se_cmd; 633 u64 unpacked_lun = pending_req->v2p->lun; 634 int rc, err = XEN_VSCSIIF_RSLT_RESET_FAILED; 635 636 init_completion(&pending_req->tmr_done); 637 638 rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess, 639 &pending_req->sense_buffer[0], 640 unpacked_lun, NULL, act, GFP_KERNEL, 641 tag, TARGET_SCF_ACK_KREF); 642 if (rc) 643 goto err; 644 645 wait_for_completion(&pending_req->tmr_done); 646 647 err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ? 648 XEN_VSCSIIF_RSLT_RESET_SUCCESS : XEN_VSCSIIF_RSLT_RESET_FAILED; 649 650 scsiback_do_resp_with_sense(NULL, err, 0, pending_req); 651 transport_generic_free_cmd(&pending_req->se_cmd, 0); 652 return; 653 654 err: 655 scsiback_do_resp_with_sense(NULL, err, 0, pending_req); 656 } 657 658 /* 659 Perform virtual to physical translation 660 */ 661 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info, 662 struct ids_tuple *v) 663 { 664 struct v2p_entry *entry; 665 struct list_head *head = &(info->v2p_entry_lists); 666 unsigned long flags; 667 668 spin_lock_irqsave(&info->v2p_lock, flags); 669 list_for_each_entry(entry, head, l) { 670 if ((entry->v.chn == v->chn) && 671 (entry->v.tgt == v->tgt) && 672 (entry->v.lun == v->lun)) { 673 kref_get(&entry->kref); 674 goto out; 675 } 676 } 677 entry = NULL; 678 679 out: 680 spin_unlock_irqrestore(&info->v2p_lock, flags); 681 return entry; 682 } 683 684 static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring, 685 struct v2p_entry *v2p) 686 { 687 struct scsiback_tpg *tpg = v2p->tpg; 688 struct scsiback_nexus *nexus = tpg->tpg_nexus; 689 struct se_session *se_sess = nexus->tvn_se_sess; 690 struct vscsibk_pend *req; 691 int tag, cpu, i; 692 693 tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu); 694 if (tag < 0) { 695 pr_err("Unable to obtain tag for vscsiif_request\n"); 696 return ERR_PTR(-ENOMEM); 697 } 698 699 req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag]; 700 memset(req, 0, sizeof(*req)); 701 req->se_cmd.map_tag = tag; 702 req->se_cmd.map_cpu = cpu; 703 704 for (i = 0; i < VSCSI_MAX_GRANTS; i++) 705 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE; 706 707 return req; 708 } 709 710 static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info, 711 struct vscsiif_back_ring *ring, 712 struct vscsiif_request *ring_req) 713 { 714 struct vscsibk_pend *pending_req; 715 struct v2p_entry *v2p; 716 struct ids_tuple vir; 717 718 /* request range check from frontend */ 719 if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) && 720 (ring_req->sc_data_direction != DMA_TO_DEVICE) && 721 (ring_req->sc_data_direction != DMA_FROM_DEVICE) && 722 (ring_req->sc_data_direction != DMA_NONE)) { 723 pr_debug("invalid parameter data_dir = %d\n", 724 ring_req->sc_data_direction); 725 return ERR_PTR(-EINVAL); 726 } 727 if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) { 728 pr_debug("invalid parameter cmd_len = %d\n", 729 ring_req->cmd_len); 730 return ERR_PTR(-EINVAL); 731 } 732 733 vir.chn = ring_req->channel; 734 vir.tgt = ring_req->id; 735 vir.lun = ring_req->lun; 736 737 v2p = scsiback_do_translation(info, &vir); 738 if (!v2p) { 739 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n", 740 vir.chn, vir.tgt, vir.lun); 741 return ERR_PTR(-ENODEV); 742 } 743 744 pending_req = scsiback_get_pend_req(ring, v2p); 745 if (IS_ERR(pending_req)) { 746 kref_put(&v2p->kref, scsiback_free_translation_entry); 747 return ERR_PTR(-ENOMEM); 748 } 749 pending_req->rqid = ring_req->rqid; 750 pending_req->info = info; 751 pending_req->v2p = v2p; 752 pending_req->sc_data_direction = ring_req->sc_data_direction; 753 pending_req->cmd_len = ring_req->cmd_len; 754 memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len); 755 756 return pending_req; 757 } 758 759 static int scsiback_do_cmd_fn(struct vscsibk_info *info, 760 unsigned int *eoi_flags) 761 { 762 struct vscsiif_back_ring *ring = &info->ring; 763 struct vscsiif_request ring_req; 764 struct vscsibk_pend *pending_req; 765 RING_IDX rc, rp; 766 int more_to_do; 767 uint32_t result; 768 769 rc = ring->req_cons; 770 rp = ring->sring->req_prod; 771 rmb(); /* guest system is accessing ring, too */ 772 773 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) { 774 rc = ring->rsp_prod_pvt; 775 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n", 776 info->domid, rp, rc, rp - rc); 777 return -EINVAL; 778 } 779 780 while ((rc != rp)) { 781 *eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS; 782 783 if (RING_REQUEST_CONS_OVERFLOW(ring, rc)) 784 break; 785 786 RING_COPY_REQUEST(ring, rc, &ring_req); 787 ring->req_cons = ++rc; 788 789 pending_req = prepare_pending_reqs(info, ring, &ring_req); 790 if (IS_ERR(pending_req)) { 791 switch (PTR_ERR(pending_req)) { 792 case -ENODEV: 793 result = DID_NO_CONNECT; 794 break; 795 default: 796 result = DID_ERROR; 797 break; 798 } 799 scsiback_send_response(info, NULL, result << 16, 0, 800 ring_req.rqid); 801 return 1; 802 } 803 804 switch (ring_req.act) { 805 case VSCSIIF_ACT_SCSI_CDB: 806 if (scsiback_gnttab_data_map(&ring_req, pending_req)) { 807 scsiback_fast_flush_area(pending_req); 808 scsiback_do_resp_with_sense(NULL, 809 DID_ERROR << 16, 0, pending_req); 810 transport_generic_free_cmd(&pending_req->se_cmd, 0); 811 } else { 812 scsiback_cmd_exec(pending_req); 813 } 814 break; 815 case VSCSIIF_ACT_SCSI_ABORT: 816 scsiback_device_action(pending_req, TMR_ABORT_TASK, 817 ring_req.ref_rqid); 818 break; 819 case VSCSIIF_ACT_SCSI_RESET: 820 scsiback_device_action(pending_req, TMR_LUN_RESET, 0); 821 break; 822 default: 823 pr_err_ratelimited("invalid request\n"); 824 scsiback_do_resp_with_sense(NULL, DID_ERROR << 16, 0, 825 pending_req); 826 transport_generic_free_cmd(&pending_req->se_cmd, 0); 827 break; 828 } 829 830 /* Yield point for this unbounded loop. */ 831 cond_resched(); 832 } 833 834 gnttab_page_cache_shrink(&info->free_pages, scsiback_max_buffer_pages); 835 836 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do); 837 return more_to_do; 838 } 839 840 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id) 841 { 842 struct vscsibk_info *info = dev_id; 843 int rc; 844 unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS; 845 846 while ((rc = scsiback_do_cmd_fn(info, &eoi_flags)) > 0) 847 cond_resched(); 848 849 /* In case of a ring error we keep the event channel masked. */ 850 if (!rc) 851 xen_irq_lateeoi(irq, eoi_flags); 852 853 return IRQ_HANDLED; 854 } 855 856 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref, 857 evtchn_port_t evtchn) 858 { 859 void *area; 860 struct vscsiif_sring *sring; 861 int err; 862 863 if (info->irq) 864 return -1; 865 866 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area); 867 if (err) 868 return err; 869 870 sring = (struct vscsiif_sring *)area; 871 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE); 872 873 err = bind_interdomain_evtchn_to_irq_lateeoi(info->dev, evtchn); 874 if (err < 0) 875 goto unmap_page; 876 877 info->irq = err; 878 879 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn, 880 IRQF_ONESHOT, "vscsiif-backend", info); 881 if (err) 882 goto free_irq; 883 884 return 0; 885 886 free_irq: 887 unbind_from_irqhandler(info->irq, info); 888 info->irq = 0; 889 unmap_page: 890 xenbus_unmap_ring_vfree(info->dev, area); 891 892 return err; 893 } 894 895 static int scsiback_map(struct vscsibk_info *info) 896 { 897 struct xenbus_device *dev = info->dev; 898 unsigned int ring_ref; 899 evtchn_port_t evtchn; 900 int err; 901 902 err = xenbus_gather(XBT_NIL, dev->otherend, 903 "ring-ref", "%u", &ring_ref, 904 "event-channel", "%u", &evtchn, NULL); 905 if (err) { 906 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend); 907 return err; 908 } 909 910 return scsiback_init_sring(info, ring_ref, evtchn); 911 } 912 913 /* 914 Check for a translation entry being present 915 */ 916 static struct v2p_entry *scsiback_chk_translation_entry( 917 struct vscsibk_info *info, struct ids_tuple *v) 918 { 919 struct list_head *head = &(info->v2p_entry_lists); 920 struct v2p_entry *entry; 921 922 list_for_each_entry(entry, head, l) 923 if ((entry->v.chn == v->chn) && 924 (entry->v.tgt == v->tgt) && 925 (entry->v.lun == v->lun)) 926 return entry; 927 928 return NULL; 929 } 930 931 /* 932 Add a new translation entry 933 */ 934 static int scsiback_add_translation_entry(struct vscsibk_info *info, 935 char *phy, struct ids_tuple *v) 936 { 937 int err = 0; 938 struct v2p_entry *new; 939 unsigned long flags; 940 char *lunp; 941 unsigned long long unpacked_lun; 942 struct se_lun *se_lun; 943 struct scsiback_tpg *tpg_entry, *tpg = NULL; 944 char *error = "doesn't exist"; 945 946 lunp = strrchr(phy, ':'); 947 if (!lunp) { 948 pr_err("illegal format of physical device %s\n", phy); 949 return -EINVAL; 950 } 951 *lunp = 0; 952 lunp++; 953 err = kstrtoull(lunp, 10, &unpacked_lun); 954 if (err < 0) { 955 pr_err("lun number not valid: %s\n", lunp); 956 return err; 957 } 958 959 mutex_lock(&scsiback_mutex); 960 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) { 961 if (!strcmp(phy, tpg_entry->tport->tport_name) || 962 !strcmp(phy, tpg_entry->param_alias)) { 963 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex); 964 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) { 965 if (se_lun->unpacked_lun == unpacked_lun) { 966 if (!tpg_entry->tpg_nexus) 967 error = "nexus undefined"; 968 else 969 tpg = tpg_entry; 970 break; 971 } 972 } 973 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex); 974 break; 975 } 976 } 977 if (tpg) { 978 mutex_lock(&tpg->tv_tpg_mutex); 979 tpg->tv_tpg_fe_count++; 980 mutex_unlock(&tpg->tv_tpg_mutex); 981 } 982 mutex_unlock(&scsiback_mutex); 983 984 if (!tpg) { 985 pr_err("%s:%llu %s\n", phy, unpacked_lun, error); 986 return -ENODEV; 987 } 988 989 new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL); 990 if (new == NULL) { 991 err = -ENOMEM; 992 goto out_free; 993 } 994 995 spin_lock_irqsave(&info->v2p_lock, flags); 996 997 /* Check double assignment to identical virtual ID */ 998 if (scsiback_chk_translation_entry(info, v)) { 999 pr_warn("Virtual ID is already used. Assignment was not performed.\n"); 1000 err = -EEXIST; 1001 goto out; 1002 } 1003 1004 /* Create a new translation entry and add to the list */ 1005 kref_init(&new->kref); 1006 new->v = *v; 1007 new->tpg = tpg; 1008 new->lun = unpacked_lun; 1009 list_add_tail(&new->l, &info->v2p_entry_lists); 1010 1011 out: 1012 spin_unlock_irqrestore(&info->v2p_lock, flags); 1013 1014 out_free: 1015 if (err) { 1016 mutex_lock(&tpg->tv_tpg_mutex); 1017 tpg->tv_tpg_fe_count--; 1018 mutex_unlock(&tpg->tv_tpg_mutex); 1019 kfree(new); 1020 } 1021 1022 return err; 1023 } 1024 1025 static void __scsiback_del_translation_entry(struct v2p_entry *entry) 1026 { 1027 list_del(&entry->l); 1028 kref_put(&entry->kref, scsiback_free_translation_entry); 1029 } 1030 1031 /* 1032 Delete the translation entry specified 1033 */ 1034 static int scsiback_del_translation_entry(struct vscsibk_info *info, 1035 struct ids_tuple *v) 1036 { 1037 struct v2p_entry *entry; 1038 unsigned long flags; 1039 int ret = 0; 1040 1041 spin_lock_irqsave(&info->v2p_lock, flags); 1042 /* Find out the translation entry specified */ 1043 entry = scsiback_chk_translation_entry(info, v); 1044 if (entry) 1045 __scsiback_del_translation_entry(entry); 1046 else 1047 ret = -ENOENT; 1048 1049 spin_unlock_irqrestore(&info->v2p_lock, flags); 1050 return ret; 1051 } 1052 1053 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state, 1054 char *phy, struct ids_tuple *vir, int try) 1055 { 1056 struct v2p_entry *entry; 1057 unsigned long flags; 1058 int err; 1059 1060 if (try) { 1061 spin_lock_irqsave(&info->v2p_lock, flags); 1062 entry = scsiback_chk_translation_entry(info, vir); 1063 spin_unlock_irqrestore(&info->v2p_lock, flags); 1064 if (entry) 1065 return; 1066 } 1067 if (!scsiback_add_translation_entry(info, phy, vir)) { 1068 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1069 "%d", XenbusStateInitialised)) { 1070 pr_err("xenbus_printf error %s\n", state); 1071 scsiback_del_translation_entry(info, vir); 1072 } 1073 } else if (!try) { 1074 err = xenbus_printf(XBT_NIL, info->dev->nodename, state, 1075 "%d", XenbusStateClosed); 1076 if (err) 1077 xenbus_dev_error(info->dev, err, 1078 "%s: writing %s", __func__, state); 1079 } 1080 } 1081 1082 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state, 1083 struct ids_tuple *vir) 1084 { 1085 if (!scsiback_del_translation_entry(info, vir)) { 1086 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1087 "%d", XenbusStateClosed)) 1088 pr_err("xenbus_printf error %s\n", state); 1089 } 1090 } 1091 1092 #define VSCSIBACK_OP_ADD_OR_DEL_LUN 1 1093 #define VSCSIBACK_OP_UPDATEDEV_STATE 2 1094 1095 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op, 1096 char *ent) 1097 { 1098 int err; 1099 struct ids_tuple vir; 1100 char *val; 1101 int device_state; 1102 char phy[VSCSI_NAMELEN]; 1103 char str[64]; 1104 char state[64]; 1105 struct xenbus_device *dev = info->dev; 1106 1107 /* read status */ 1108 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent); 1109 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state); 1110 if (XENBUS_EXIST_ERR(err)) 1111 return; 1112 1113 /* physical SCSI device */ 1114 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent); 1115 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL); 1116 if (IS_ERR(val)) { 1117 err = xenbus_printf(XBT_NIL, dev->nodename, state, 1118 "%d", XenbusStateClosed); 1119 if (err) 1120 xenbus_dev_error(info->dev, err, 1121 "%s: writing %s", __func__, state); 1122 return; 1123 } 1124 strlcpy(phy, val, VSCSI_NAMELEN); 1125 kfree(val); 1126 1127 /* virtual SCSI device */ 1128 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent); 1129 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u", 1130 &vir.hst, &vir.chn, &vir.tgt, &vir.lun); 1131 if (XENBUS_EXIST_ERR(err)) { 1132 err = xenbus_printf(XBT_NIL, dev->nodename, state, 1133 "%d", XenbusStateClosed); 1134 if (err) 1135 xenbus_dev_error(info->dev, err, 1136 "%s: writing %s", __func__, state); 1137 return; 1138 } 1139 1140 switch (op) { 1141 case VSCSIBACK_OP_ADD_OR_DEL_LUN: 1142 switch (device_state) { 1143 case XenbusStateInitialising: 1144 scsiback_do_add_lun(info, state, phy, &vir, 0); 1145 break; 1146 case XenbusStateConnected: 1147 scsiback_do_add_lun(info, state, phy, &vir, 1); 1148 break; 1149 case XenbusStateClosing: 1150 scsiback_do_del_lun(info, state, &vir); 1151 break; 1152 default: 1153 break; 1154 } 1155 break; 1156 1157 case VSCSIBACK_OP_UPDATEDEV_STATE: 1158 if (device_state == XenbusStateInitialised) { 1159 /* modify vscsi-devs/dev-x/state */ 1160 if (xenbus_printf(XBT_NIL, dev->nodename, state, 1161 "%d", XenbusStateConnected)) { 1162 pr_err("xenbus_printf error %s\n", str); 1163 scsiback_del_translation_entry(info, &vir); 1164 xenbus_printf(XBT_NIL, dev->nodename, state, 1165 "%d", XenbusStateClosed); 1166 } 1167 } 1168 break; 1169 /* When it is necessary, processing is added here. */ 1170 default: 1171 break; 1172 } 1173 } 1174 1175 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op) 1176 { 1177 int i; 1178 char **dir; 1179 unsigned int ndir = 0; 1180 1181 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs", 1182 &ndir); 1183 if (IS_ERR(dir)) 1184 return; 1185 1186 for (i = 0; i < ndir; i++) 1187 scsiback_do_1lun_hotplug(info, op, dir[i]); 1188 1189 kfree(dir); 1190 } 1191 1192 static void scsiback_frontend_changed(struct xenbus_device *dev, 1193 enum xenbus_state frontend_state) 1194 { 1195 struct vscsibk_info *info = dev_get_drvdata(&dev->dev); 1196 1197 switch (frontend_state) { 1198 case XenbusStateInitialising: 1199 break; 1200 1201 case XenbusStateInitialised: 1202 if (scsiback_map(info)) 1203 break; 1204 1205 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); 1206 xenbus_switch_state(dev, XenbusStateConnected); 1207 break; 1208 1209 case XenbusStateConnected: 1210 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE); 1211 1212 if (dev->state == XenbusStateConnected) 1213 break; 1214 1215 xenbus_switch_state(dev, XenbusStateConnected); 1216 break; 1217 1218 case XenbusStateClosing: 1219 if (info->irq) 1220 scsiback_disconnect(info); 1221 1222 xenbus_switch_state(dev, XenbusStateClosing); 1223 break; 1224 1225 case XenbusStateClosed: 1226 xenbus_switch_state(dev, XenbusStateClosed); 1227 if (xenbus_dev_is_online(dev)) 1228 break; 1229 fallthrough; /* if not online */ 1230 case XenbusStateUnknown: 1231 device_unregister(&dev->dev); 1232 break; 1233 1234 case XenbusStateReconfiguring: 1235 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); 1236 xenbus_switch_state(dev, XenbusStateReconfigured); 1237 1238 break; 1239 1240 default: 1241 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", 1242 frontend_state); 1243 break; 1244 } 1245 } 1246 1247 /* 1248 Release the translation entry specfied 1249 */ 1250 static void scsiback_release_translation_entry(struct vscsibk_info *info) 1251 { 1252 struct v2p_entry *entry, *tmp; 1253 struct list_head *head = &(info->v2p_entry_lists); 1254 unsigned long flags; 1255 1256 spin_lock_irqsave(&info->v2p_lock, flags); 1257 1258 list_for_each_entry_safe(entry, tmp, head, l) 1259 __scsiback_del_translation_entry(entry); 1260 1261 spin_unlock_irqrestore(&info->v2p_lock, flags); 1262 } 1263 1264 static int scsiback_remove(struct xenbus_device *dev) 1265 { 1266 struct vscsibk_info *info = dev_get_drvdata(&dev->dev); 1267 1268 if (info->irq) 1269 scsiback_disconnect(info); 1270 1271 scsiback_release_translation_entry(info); 1272 1273 gnttab_page_cache_shrink(&info->free_pages, 0); 1274 1275 dev_set_drvdata(&dev->dev, NULL); 1276 1277 return 0; 1278 } 1279 1280 static int scsiback_probe(struct xenbus_device *dev, 1281 const struct xenbus_device_id *id) 1282 { 1283 int err; 1284 1285 struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info), 1286 GFP_KERNEL); 1287 1288 pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); 1289 1290 if (!info) { 1291 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure"); 1292 return -ENOMEM; 1293 } 1294 info->dev = dev; 1295 dev_set_drvdata(&dev->dev, info); 1296 1297 info->domid = dev->otherend_id; 1298 spin_lock_init(&info->ring_lock); 1299 atomic_set(&info->nr_unreplied_reqs, 0); 1300 init_waitqueue_head(&info->waiting_to_free); 1301 info->dev = dev; 1302 info->irq = 0; 1303 INIT_LIST_HEAD(&info->v2p_entry_lists); 1304 spin_lock_init(&info->v2p_lock); 1305 gnttab_page_cache_init(&info->free_pages); 1306 1307 err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u", 1308 SG_ALL); 1309 if (err) 1310 xenbus_dev_error(dev, err, "writing feature-sg-grant"); 1311 1312 err = xenbus_switch_state(dev, XenbusStateInitWait); 1313 if (err) 1314 goto fail; 1315 1316 return 0; 1317 1318 fail: 1319 pr_warn("%s failed\n", __func__); 1320 scsiback_remove(dev); 1321 1322 return err; 1323 } 1324 1325 static char *scsiback_dump_proto_id(struct scsiback_tport *tport) 1326 { 1327 switch (tport->tport_proto_id) { 1328 case SCSI_PROTOCOL_SAS: 1329 return "SAS"; 1330 case SCSI_PROTOCOL_FCP: 1331 return "FCP"; 1332 case SCSI_PROTOCOL_ISCSI: 1333 return "iSCSI"; 1334 default: 1335 break; 1336 } 1337 1338 return "Unknown"; 1339 } 1340 1341 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg) 1342 { 1343 struct scsiback_tpg *tpg = container_of(se_tpg, 1344 struct scsiback_tpg, se_tpg); 1345 struct scsiback_tport *tport = tpg->tport; 1346 1347 return &tport->tport_name[0]; 1348 } 1349 1350 static u16 scsiback_get_tag(struct se_portal_group *se_tpg) 1351 { 1352 struct scsiback_tpg *tpg = container_of(se_tpg, 1353 struct scsiback_tpg, se_tpg); 1354 return tpg->tport_tpgt; 1355 } 1356 1357 static struct se_wwn * 1358 scsiback_make_tport(struct target_fabric_configfs *tf, 1359 struct config_group *group, 1360 const char *name) 1361 { 1362 struct scsiback_tport *tport; 1363 char *ptr; 1364 u64 wwpn = 0; 1365 int off = 0; 1366 1367 tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL); 1368 if (!tport) 1369 return ERR_PTR(-ENOMEM); 1370 1371 tport->tport_wwpn = wwpn; 1372 /* 1373 * Determine the emulated Protocol Identifier and Target Port Name 1374 * based on the incoming configfs directory name. 1375 */ 1376 ptr = strstr(name, "naa."); 1377 if (ptr) { 1378 tport->tport_proto_id = SCSI_PROTOCOL_SAS; 1379 goto check_len; 1380 } 1381 ptr = strstr(name, "fc."); 1382 if (ptr) { 1383 tport->tport_proto_id = SCSI_PROTOCOL_FCP; 1384 off = 3; /* Skip over "fc." */ 1385 goto check_len; 1386 } 1387 ptr = strstr(name, "iqn."); 1388 if (ptr) { 1389 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI; 1390 goto check_len; 1391 } 1392 1393 pr_err("Unable to locate prefix for emulated Target Port: %s\n", name); 1394 kfree(tport); 1395 return ERR_PTR(-EINVAL); 1396 1397 check_len: 1398 if (strlen(name) >= VSCSI_NAMELEN) { 1399 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name, 1400 scsiback_dump_proto_id(tport), VSCSI_NAMELEN); 1401 kfree(tport); 1402 return ERR_PTR(-EINVAL); 1403 } 1404 snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]); 1405 1406 pr_debug("Allocated emulated Target %s Address: %s\n", 1407 scsiback_dump_proto_id(tport), name); 1408 1409 return &tport->tport_wwn; 1410 } 1411 1412 static void scsiback_drop_tport(struct se_wwn *wwn) 1413 { 1414 struct scsiback_tport *tport = container_of(wwn, 1415 struct scsiback_tport, tport_wwn); 1416 1417 pr_debug("Deallocating emulated Target %s Address: %s\n", 1418 scsiback_dump_proto_id(tport), tport->tport_name); 1419 1420 kfree(tport); 1421 } 1422 1423 static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg) 1424 { 1425 return 1; 1426 } 1427 1428 static int scsiback_check_stop_free(struct se_cmd *se_cmd) 1429 { 1430 return transport_generic_free_cmd(se_cmd, 0); 1431 } 1432 1433 static void scsiback_release_cmd(struct se_cmd *se_cmd) 1434 { 1435 target_free_tag(se_cmd->se_sess, se_cmd); 1436 } 1437 1438 static u32 scsiback_sess_get_index(struct se_session *se_sess) 1439 { 1440 return 0; 1441 } 1442 1443 static int scsiback_write_pending(struct se_cmd *se_cmd) 1444 { 1445 /* Go ahead and process the write immediately */ 1446 target_execute_cmd(se_cmd); 1447 1448 return 0; 1449 } 1450 1451 static void scsiback_set_default_node_attrs(struct se_node_acl *nacl) 1452 { 1453 } 1454 1455 static int scsiback_get_cmd_state(struct se_cmd *se_cmd) 1456 { 1457 return 0; 1458 } 1459 1460 static int scsiback_queue_data_in(struct se_cmd *se_cmd) 1461 { 1462 struct vscsibk_pend *pending_req = container_of(se_cmd, 1463 struct vscsibk_pend, se_cmd); 1464 1465 pending_req->result = SAM_STAT_GOOD; 1466 scsiback_cmd_done(pending_req); 1467 return 0; 1468 } 1469 1470 static int scsiback_queue_status(struct se_cmd *se_cmd) 1471 { 1472 struct vscsibk_pend *pending_req = container_of(se_cmd, 1473 struct vscsibk_pend, se_cmd); 1474 1475 if (se_cmd->sense_buffer && 1476 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) || 1477 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) 1478 pending_req->result = SAM_STAT_CHECK_CONDITION; 1479 else 1480 pending_req->result = se_cmd->scsi_status; 1481 1482 scsiback_cmd_done(pending_req); 1483 return 0; 1484 } 1485 1486 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd) 1487 { 1488 struct vscsibk_pend *pending_req = container_of(se_cmd, 1489 struct vscsibk_pend, se_cmd); 1490 1491 complete(&pending_req->tmr_done); 1492 } 1493 1494 static void scsiback_aborted_task(struct se_cmd *se_cmd) 1495 { 1496 } 1497 1498 static ssize_t scsiback_tpg_param_alias_show(struct config_item *item, 1499 char *page) 1500 { 1501 struct se_portal_group *se_tpg = param_to_tpg(item); 1502 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1503 se_tpg); 1504 ssize_t rb; 1505 1506 mutex_lock(&tpg->tv_tpg_mutex); 1507 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias); 1508 mutex_unlock(&tpg->tv_tpg_mutex); 1509 1510 return rb; 1511 } 1512 1513 static ssize_t scsiback_tpg_param_alias_store(struct config_item *item, 1514 const char *page, size_t count) 1515 { 1516 struct se_portal_group *se_tpg = param_to_tpg(item); 1517 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1518 se_tpg); 1519 int len; 1520 1521 if (strlen(page) >= VSCSI_NAMELEN) { 1522 pr_err("param alias: %s, exceeds max: %d\n", page, 1523 VSCSI_NAMELEN); 1524 return -EINVAL; 1525 } 1526 1527 mutex_lock(&tpg->tv_tpg_mutex); 1528 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page); 1529 if (tpg->param_alias[len - 1] == '\n') 1530 tpg->param_alias[len - 1] = '\0'; 1531 mutex_unlock(&tpg->tv_tpg_mutex); 1532 1533 return count; 1534 } 1535 1536 CONFIGFS_ATTR(scsiback_tpg_param_, alias); 1537 1538 static struct configfs_attribute *scsiback_param_attrs[] = { 1539 &scsiback_tpg_param_attr_alias, 1540 NULL, 1541 }; 1542 1543 static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg, 1544 struct se_session *se_sess, void *p) 1545 { 1546 struct scsiback_tpg *tpg = container_of(se_tpg, 1547 struct scsiback_tpg, se_tpg); 1548 1549 tpg->tpg_nexus = p; 1550 return 0; 1551 } 1552 1553 static int scsiback_make_nexus(struct scsiback_tpg *tpg, 1554 const char *name) 1555 { 1556 struct scsiback_nexus *tv_nexus; 1557 int ret = 0; 1558 1559 mutex_lock(&tpg->tv_tpg_mutex); 1560 if (tpg->tpg_nexus) { 1561 pr_debug("tpg->tpg_nexus already exists\n"); 1562 ret = -EEXIST; 1563 goto out_unlock; 1564 } 1565 1566 tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL); 1567 if (!tv_nexus) { 1568 ret = -ENOMEM; 1569 goto out_unlock; 1570 } 1571 1572 tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg, 1573 VSCSI_DEFAULT_SESSION_TAGS, 1574 sizeof(struct vscsibk_pend), 1575 TARGET_PROT_NORMAL, name, 1576 tv_nexus, scsiback_alloc_sess_cb); 1577 if (IS_ERR(tv_nexus->tvn_se_sess)) { 1578 kfree(tv_nexus); 1579 ret = -ENOMEM; 1580 goto out_unlock; 1581 } 1582 1583 out_unlock: 1584 mutex_unlock(&tpg->tv_tpg_mutex); 1585 return ret; 1586 } 1587 1588 static int scsiback_drop_nexus(struct scsiback_tpg *tpg) 1589 { 1590 struct se_session *se_sess; 1591 struct scsiback_nexus *tv_nexus; 1592 1593 mutex_lock(&tpg->tv_tpg_mutex); 1594 tv_nexus = tpg->tpg_nexus; 1595 if (!tv_nexus) { 1596 mutex_unlock(&tpg->tv_tpg_mutex); 1597 return -ENODEV; 1598 } 1599 1600 se_sess = tv_nexus->tvn_se_sess; 1601 if (!se_sess) { 1602 mutex_unlock(&tpg->tv_tpg_mutex); 1603 return -ENODEV; 1604 } 1605 1606 if (tpg->tv_tpg_port_count != 0) { 1607 mutex_unlock(&tpg->tv_tpg_mutex); 1608 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n", 1609 tpg->tv_tpg_port_count); 1610 return -EBUSY; 1611 } 1612 1613 if (tpg->tv_tpg_fe_count != 0) { 1614 mutex_unlock(&tpg->tv_tpg_mutex); 1615 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n", 1616 tpg->tv_tpg_fe_count); 1617 return -EBUSY; 1618 } 1619 1620 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n", 1621 scsiback_dump_proto_id(tpg->tport), 1622 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1623 1624 /* 1625 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port 1626 */ 1627 target_remove_session(se_sess); 1628 tpg->tpg_nexus = NULL; 1629 mutex_unlock(&tpg->tv_tpg_mutex); 1630 1631 kfree(tv_nexus); 1632 return 0; 1633 } 1634 1635 static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page) 1636 { 1637 struct se_portal_group *se_tpg = to_tpg(item); 1638 struct scsiback_tpg *tpg = container_of(se_tpg, 1639 struct scsiback_tpg, se_tpg); 1640 struct scsiback_nexus *tv_nexus; 1641 ssize_t ret; 1642 1643 mutex_lock(&tpg->tv_tpg_mutex); 1644 tv_nexus = tpg->tpg_nexus; 1645 if (!tv_nexus) { 1646 mutex_unlock(&tpg->tv_tpg_mutex); 1647 return -ENODEV; 1648 } 1649 ret = snprintf(page, PAGE_SIZE, "%s\n", 1650 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1651 mutex_unlock(&tpg->tv_tpg_mutex); 1652 1653 return ret; 1654 } 1655 1656 static ssize_t scsiback_tpg_nexus_store(struct config_item *item, 1657 const char *page, size_t count) 1658 { 1659 struct se_portal_group *se_tpg = to_tpg(item); 1660 struct scsiback_tpg *tpg = container_of(se_tpg, 1661 struct scsiback_tpg, se_tpg); 1662 struct scsiback_tport *tport_wwn = tpg->tport; 1663 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr; 1664 int ret; 1665 /* 1666 * Shutdown the active I_T nexus if 'NULL' is passed. 1667 */ 1668 if (!strncmp(page, "NULL", 4)) { 1669 ret = scsiback_drop_nexus(tpg); 1670 return (!ret) ? count : ret; 1671 } 1672 /* 1673 * Otherwise make sure the passed virtual Initiator port WWN matches 1674 * the fabric protocol_id set in scsiback_make_tport(), and call 1675 * scsiback_make_nexus(). 1676 */ 1677 if (strlen(page) >= VSCSI_NAMELEN) { 1678 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n", 1679 page, VSCSI_NAMELEN); 1680 return -EINVAL; 1681 } 1682 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page); 1683 1684 ptr = strstr(i_port, "naa."); 1685 if (ptr) { 1686 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) { 1687 pr_err("Passed SAS 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 ptr = strstr(i_port, "fc."); 1695 if (ptr) { 1696 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) { 1697 pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n", 1698 i_port, scsiback_dump_proto_id(tport_wwn)); 1699 return -EINVAL; 1700 } 1701 port_ptr = &i_port[3]; /* Skip over "fc." */ 1702 goto check_newline; 1703 } 1704 ptr = strstr(i_port, "iqn."); 1705 if (ptr) { 1706 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) { 1707 pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n", 1708 i_port, scsiback_dump_proto_id(tport_wwn)); 1709 return -EINVAL; 1710 } 1711 port_ptr = &i_port[0]; 1712 goto check_newline; 1713 } 1714 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n", 1715 i_port); 1716 return -EINVAL; 1717 /* 1718 * Clear any trailing newline for the NAA WWN 1719 */ 1720 check_newline: 1721 if (i_port[strlen(i_port) - 1] == '\n') 1722 i_port[strlen(i_port) - 1] = '\0'; 1723 1724 ret = scsiback_make_nexus(tpg, port_ptr); 1725 if (ret < 0) 1726 return ret; 1727 1728 return count; 1729 } 1730 1731 CONFIGFS_ATTR(scsiback_tpg_, nexus); 1732 1733 static struct configfs_attribute *scsiback_tpg_attrs[] = { 1734 &scsiback_tpg_attr_nexus, 1735 NULL, 1736 }; 1737 1738 static ssize_t 1739 scsiback_wwn_version_show(struct config_item *item, char *page) 1740 { 1741 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on " 1742 UTS_RELEASE"\n", 1743 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1744 } 1745 1746 CONFIGFS_ATTR_RO(scsiback_wwn_, version); 1747 1748 static struct configfs_attribute *scsiback_wwn_attrs[] = { 1749 &scsiback_wwn_attr_version, 1750 NULL, 1751 }; 1752 1753 static int scsiback_port_link(struct se_portal_group *se_tpg, 1754 struct se_lun *lun) 1755 { 1756 struct scsiback_tpg *tpg = container_of(se_tpg, 1757 struct scsiback_tpg, se_tpg); 1758 1759 mutex_lock(&tpg->tv_tpg_mutex); 1760 tpg->tv_tpg_port_count++; 1761 mutex_unlock(&tpg->tv_tpg_mutex); 1762 1763 return 0; 1764 } 1765 1766 static void scsiback_port_unlink(struct se_portal_group *se_tpg, 1767 struct se_lun *lun) 1768 { 1769 struct scsiback_tpg *tpg = container_of(se_tpg, 1770 struct scsiback_tpg, se_tpg); 1771 1772 mutex_lock(&tpg->tv_tpg_mutex); 1773 tpg->tv_tpg_port_count--; 1774 mutex_unlock(&tpg->tv_tpg_mutex); 1775 } 1776 1777 static struct se_portal_group * 1778 scsiback_make_tpg(struct se_wwn *wwn, const char *name) 1779 { 1780 struct scsiback_tport *tport = container_of(wwn, 1781 struct scsiback_tport, tport_wwn); 1782 1783 struct scsiback_tpg *tpg; 1784 u16 tpgt; 1785 int ret; 1786 1787 if (strstr(name, "tpgt_") != name) 1788 return ERR_PTR(-EINVAL); 1789 ret = kstrtou16(name + 5, 10, &tpgt); 1790 if (ret) 1791 return ERR_PTR(ret); 1792 1793 tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL); 1794 if (!tpg) 1795 return ERR_PTR(-ENOMEM); 1796 1797 mutex_init(&tpg->tv_tpg_mutex); 1798 INIT_LIST_HEAD(&tpg->tv_tpg_list); 1799 INIT_LIST_HEAD(&tpg->info_list); 1800 tpg->tport = tport; 1801 tpg->tport_tpgt = tpgt; 1802 1803 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id); 1804 if (ret < 0) { 1805 kfree(tpg); 1806 return NULL; 1807 } 1808 mutex_lock(&scsiback_mutex); 1809 list_add_tail(&tpg->tv_tpg_list, &scsiback_list); 1810 mutex_unlock(&scsiback_mutex); 1811 1812 return &tpg->se_tpg; 1813 } 1814 1815 static void scsiback_drop_tpg(struct se_portal_group *se_tpg) 1816 { 1817 struct scsiback_tpg *tpg = container_of(se_tpg, 1818 struct scsiback_tpg, se_tpg); 1819 1820 mutex_lock(&scsiback_mutex); 1821 list_del(&tpg->tv_tpg_list); 1822 mutex_unlock(&scsiback_mutex); 1823 /* 1824 * Release the virtual I_T Nexus for this xen-pvscsi TPG 1825 */ 1826 scsiback_drop_nexus(tpg); 1827 /* 1828 * Deregister the se_tpg from TCM. 1829 */ 1830 core_tpg_deregister(se_tpg); 1831 kfree(tpg); 1832 } 1833 1834 static int scsiback_check_true(struct se_portal_group *se_tpg) 1835 { 1836 return 1; 1837 } 1838 1839 static int scsiback_check_false(struct se_portal_group *se_tpg) 1840 { 1841 return 0; 1842 } 1843 1844 static const struct target_core_fabric_ops scsiback_ops = { 1845 .module = THIS_MODULE, 1846 .fabric_name = "xen-pvscsi", 1847 .tpg_get_wwn = scsiback_get_fabric_wwn, 1848 .tpg_get_tag = scsiback_get_tag, 1849 .tpg_check_demo_mode = scsiback_check_true, 1850 .tpg_check_demo_mode_cache = scsiback_check_true, 1851 .tpg_check_demo_mode_write_protect = scsiback_check_false, 1852 .tpg_check_prod_mode_write_protect = scsiback_check_false, 1853 .tpg_get_inst_index = scsiback_tpg_get_inst_index, 1854 .check_stop_free = scsiback_check_stop_free, 1855 .release_cmd = scsiback_release_cmd, 1856 .sess_get_index = scsiback_sess_get_index, 1857 .sess_get_initiator_sid = NULL, 1858 .write_pending = scsiback_write_pending, 1859 .set_default_node_attributes = scsiback_set_default_node_attrs, 1860 .get_cmd_state = scsiback_get_cmd_state, 1861 .queue_data_in = scsiback_queue_data_in, 1862 .queue_status = scsiback_queue_status, 1863 .queue_tm_rsp = scsiback_queue_tm_rsp, 1864 .aborted_task = scsiback_aborted_task, 1865 /* 1866 * Setup callers for generic logic in target_core_fabric_configfs.c 1867 */ 1868 .fabric_make_wwn = scsiback_make_tport, 1869 .fabric_drop_wwn = scsiback_drop_tport, 1870 .fabric_make_tpg = scsiback_make_tpg, 1871 .fabric_drop_tpg = scsiback_drop_tpg, 1872 .fabric_post_link = scsiback_port_link, 1873 .fabric_pre_unlink = scsiback_port_unlink, 1874 1875 .tfc_wwn_attrs = scsiback_wwn_attrs, 1876 .tfc_tpg_base_attrs = scsiback_tpg_attrs, 1877 .tfc_tpg_param_attrs = scsiback_param_attrs, 1878 }; 1879 1880 static const struct xenbus_device_id scsiback_ids[] = { 1881 { "vscsi" }, 1882 { "" } 1883 }; 1884 1885 static struct xenbus_driver scsiback_driver = { 1886 .ids = scsiback_ids, 1887 .probe = scsiback_probe, 1888 .remove = scsiback_remove, 1889 .otherend_changed = scsiback_frontend_changed 1890 }; 1891 1892 static int __init scsiback_init(void) 1893 { 1894 int ret; 1895 1896 if (!xen_domain()) 1897 return -ENODEV; 1898 1899 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n", 1900 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1901 1902 ret = xenbus_register_backend(&scsiback_driver); 1903 if (ret) 1904 goto out; 1905 1906 ret = target_register_template(&scsiback_ops); 1907 if (ret) 1908 goto out_unregister_xenbus; 1909 1910 return 0; 1911 1912 out_unregister_xenbus: 1913 xenbus_unregister_driver(&scsiback_driver); 1914 out: 1915 pr_err("%s: error %d\n", __func__, ret); 1916 return ret; 1917 } 1918 1919 static void __exit scsiback_exit(void) 1920 { 1921 target_unregister_template(&scsiback_ops); 1922 xenbus_unregister_driver(&scsiback_driver); 1923 } 1924 1925 module_init(scsiback_init); 1926 module_exit(scsiback_exit); 1927 1928 MODULE_DESCRIPTION("Xen SCSI backend driver"); 1929 MODULE_LICENSE("Dual BSD/GPL"); 1930 MODULE_ALIAS("xen-backend:vscsi"); 1931 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>"); 1932