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_TRANSPORT_MARGINAL: 337 host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_MARGINAL; 338 break; 339 default: 340 host_status = XEN_VSCSIIF_RSLT_HOST_ERROR; 341 break; 342 } 343 344 return (host_status << 16) | (result & 0x00ffff); 345 } 346 347 static void scsiback_send_response(struct vscsibk_info *info, 348 char *sense_buffer, int32_t result, uint32_t resid, 349 uint16_t rqid) 350 { 351 struct vscsiif_response *ring_res; 352 int notify; 353 struct scsi_sense_hdr sshdr; 354 unsigned long flags; 355 unsigned len; 356 357 spin_lock_irqsave(&info->ring_lock, flags); 358 359 ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt); 360 info->ring.rsp_prod_pvt++; 361 362 ring_res->rslt = scsiback_result(result); 363 ring_res->rqid = rqid; 364 365 if (sense_buffer != NULL && 366 scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE, 367 &sshdr)) { 368 len = min_t(unsigned, 8 + sense_buffer[7], 369 VSCSIIF_SENSE_BUFFERSIZE); 370 memcpy(ring_res->sense_buffer, sense_buffer, len); 371 ring_res->sense_len = len; 372 } else { 373 ring_res->sense_len = 0; 374 } 375 376 ring_res->residual_len = resid; 377 378 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify); 379 spin_unlock_irqrestore(&info->ring_lock, flags); 380 381 if (notify) 382 notify_remote_via_irq(info->irq); 383 } 384 385 static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result, 386 uint32_t resid, struct vscsibk_pend *pending_req) 387 { 388 scsiback_send_response(pending_req->info, sense_buffer, result, 389 resid, pending_req->rqid); 390 391 if (pending_req->v2p) 392 kref_put(&pending_req->v2p->kref, 393 scsiback_free_translation_entry); 394 } 395 396 static void scsiback_cmd_done(struct vscsibk_pend *pending_req) 397 { 398 struct vscsibk_info *info = pending_req->info; 399 unsigned char *sense_buffer; 400 unsigned int resid; 401 int errors; 402 403 sense_buffer = pending_req->sense_buffer; 404 resid = pending_req->se_cmd.residual_count; 405 errors = pending_req->result; 406 407 if (errors && log_print_stat) 408 scsiback_print_status(sense_buffer, errors, pending_req); 409 410 scsiback_fast_flush_area(pending_req); 411 scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req); 412 scsiback_put(info); 413 /* 414 * Drop the extra KREF_ACK reference taken by target_submit_cmd_map_sgls() 415 * ahead of scsiback_check_stop_free() -> transport_generic_free_cmd() 416 * final se_cmd->cmd_kref put. 417 */ 418 target_put_sess_cmd(&pending_req->se_cmd); 419 } 420 421 static void scsiback_cmd_exec(struct vscsibk_pend *pending_req) 422 { 423 struct se_cmd *se_cmd = &pending_req->se_cmd; 424 struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess; 425 426 scsiback_get(pending_req->info); 427 se_cmd->tag = pending_req->rqid; 428 target_init_cmd(se_cmd, sess, pending_req->sense_buffer, 429 pending_req->v2p->lun, pending_req->data_len, 0, 430 pending_req->sc_data_direction, TARGET_SCF_ACK_KREF); 431 432 if (target_submit_prep(se_cmd, pending_req->cmnd, pending_req->sgl, 433 pending_req->n_sg, NULL, 0, NULL, 0, GFP_KERNEL)) 434 return; 435 436 target_submit(se_cmd); 437 } 438 439 static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map, 440 struct page **pg, grant_handle_t *grant, int cnt) 441 { 442 int err, i; 443 444 if (!cnt) 445 return 0; 446 447 err = gnttab_map_refs(map, NULL, pg, cnt); 448 for (i = 0; i < cnt; i++) { 449 if (unlikely(map[i].status != GNTST_okay)) { 450 pr_err("invalid buffer -- could not remap it\n"); 451 map[i].handle = SCSIBACK_INVALID_HANDLE; 452 if (!err) 453 err = -ENOMEM; 454 } else { 455 get_page(pg[i]); 456 } 457 grant[i] = map[i].handle; 458 } 459 return err; 460 } 461 462 static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req, 463 struct scsiif_request_segment *seg, struct page **pg, 464 grant_handle_t *grant, int cnt, u32 flags) 465 { 466 int mapcount = 0, i, err = 0; 467 struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH]; 468 struct vscsibk_info *info = pending_req->info; 469 470 for (i = 0; i < cnt; i++) { 471 if (gnttab_page_cache_get(&info->free_pages, pg + mapcount)) { 472 gnttab_page_cache_put(&info->free_pages, pg, mapcount); 473 pr_err("no grant page\n"); 474 return -ENOMEM; 475 } 476 gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]), 477 flags, seg[i].gref, info->domid); 478 mapcount++; 479 if (mapcount < VSCSI_GRANT_BATCH) 480 continue; 481 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount); 482 pg += mapcount; 483 grant += mapcount; 484 pending_req->n_grants += mapcount; 485 if (err) 486 return err; 487 mapcount = 0; 488 } 489 err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount); 490 pending_req->n_grants += mapcount; 491 return err; 492 } 493 494 static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req, 495 struct vscsibk_pend *pending_req) 496 { 497 u32 flags; 498 int i, err, n_segs, i_seg = 0; 499 struct page **pg; 500 struct scsiif_request_segment *seg; 501 unsigned long end_seg = 0; 502 unsigned int nr_segments = (unsigned int)ring_req->nr_segments; 503 unsigned int nr_sgl = 0; 504 struct scatterlist *sg; 505 grant_handle_t *grant; 506 507 pending_req->n_sg = 0; 508 pending_req->n_grants = 0; 509 pending_req->data_len = 0; 510 511 nr_segments &= ~VSCSIIF_SG_GRANT; 512 if (!nr_segments) 513 return 0; 514 515 if (nr_segments > VSCSIIF_SG_TABLESIZE) { 516 pr_debug("invalid parameter nr_seg = %d\n", 517 ring_req->nr_segments); 518 return -EINVAL; 519 } 520 521 if (ring_req->nr_segments & VSCSIIF_SG_GRANT) { 522 err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg, 523 pending_req->pages, pending_req->grant_handles, 524 nr_segments, GNTMAP_host_map | GNTMAP_readonly); 525 if (err) 526 return err; 527 nr_sgl = nr_segments; 528 nr_segments = 0; 529 for (i = 0; i < nr_sgl; i++) { 530 n_segs = ring_req->seg[i].length / 531 sizeof(struct scsiif_request_segment); 532 if ((unsigned)ring_req->seg[i].offset + 533 (unsigned)ring_req->seg[i].length > PAGE_SIZE || 534 n_segs * sizeof(struct scsiif_request_segment) != 535 ring_req->seg[i].length) 536 return -EINVAL; 537 nr_segments += n_segs; 538 } 539 if (nr_segments > SG_ALL) { 540 pr_debug("invalid nr_seg = %d\n", nr_segments); 541 return -EINVAL; 542 } 543 } 544 545 /* free of (sgl) in fast_flush_area() */ 546 pending_req->sgl = kmalloc_objs(struct scatterlist, nr_segments); 547 if (!pending_req->sgl) 548 return -ENOMEM; 549 550 sg_init_table(pending_req->sgl, nr_segments); 551 pending_req->n_sg = nr_segments; 552 553 flags = GNTMAP_host_map; 554 if (pending_req->sc_data_direction == DMA_TO_DEVICE) 555 flags |= GNTMAP_readonly; 556 557 pg = pending_req->pages + nr_sgl; 558 grant = pending_req->grant_handles + nr_sgl; 559 if (!nr_sgl) { 560 seg = ring_req->seg; 561 err = scsiback_gnttab_data_map_list(pending_req, seg, 562 pg, grant, nr_segments, flags); 563 if (err) 564 return err; 565 } else { 566 for (i = 0; i < nr_sgl; i++) { 567 seg = (struct scsiif_request_segment *)( 568 vaddr(pending_req, i) + ring_req->seg[i].offset); 569 n_segs = ring_req->seg[i].length / 570 sizeof(struct scsiif_request_segment); 571 err = scsiback_gnttab_data_map_list(pending_req, seg, 572 pg, grant, n_segs, flags); 573 if (err) 574 return err; 575 pg += n_segs; 576 grant += n_segs; 577 } 578 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset; 579 seg = (struct scsiif_request_segment *)end_seg; 580 end_seg += ring_req->seg[0].length; 581 pg = pending_req->pages + nr_sgl; 582 } 583 584 for_each_sg(pending_req->sgl, sg, nr_segments, i) { 585 sg_set_page(sg, pg[i], seg->length, seg->offset); 586 pending_req->data_len += seg->length; 587 seg++; 588 if (nr_sgl && (unsigned long)seg >= end_seg) { 589 i_seg++; 590 end_seg = vaddr(pending_req, i_seg) + 591 ring_req->seg[i_seg].offset; 592 seg = (struct scsiif_request_segment *)end_seg; 593 end_seg += ring_req->seg[i_seg].length; 594 } 595 if (sg->offset >= PAGE_SIZE || 596 sg->length > PAGE_SIZE || 597 sg->offset + sg->length > PAGE_SIZE) 598 return -EINVAL; 599 } 600 601 return 0; 602 } 603 604 static void scsiback_disconnect(struct vscsibk_info *info) 605 { 606 wait_event(info->waiting_to_free, 607 atomic_read(&info->nr_unreplied_reqs) == 0); 608 609 unbind_from_irqhandler(info->irq, info); 610 info->irq = 0; 611 xenbus_unmap_ring_vfree(info->dev, info->ring.sring); 612 } 613 614 static void scsiback_device_action(struct vscsibk_pend *pending_req, 615 enum tcm_tmreq_table act, int tag) 616 { 617 struct scsiback_tpg *tpg = pending_req->v2p->tpg; 618 struct scsiback_nexus *nexus = tpg->tpg_nexus; 619 struct se_cmd *se_cmd = &pending_req->se_cmd; 620 u64 unpacked_lun = pending_req->v2p->lun; 621 int rc, err = XEN_VSCSIIF_RSLT_RESET_FAILED; 622 623 init_completion(&pending_req->tmr_done); 624 625 rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess, 626 &pending_req->sense_buffer[0], 627 unpacked_lun, NULL, act, GFP_KERNEL, 628 tag, TARGET_SCF_ACK_KREF); 629 if (rc) 630 goto err; 631 632 wait_for_completion(&pending_req->tmr_done); 633 634 err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ? 635 XEN_VSCSIIF_RSLT_RESET_SUCCESS : XEN_VSCSIIF_RSLT_RESET_FAILED; 636 637 scsiback_do_resp_with_sense(NULL, err, 0, pending_req); 638 transport_generic_free_cmd(&pending_req->se_cmd, 0); 639 return; 640 641 err: 642 scsiback_do_resp_with_sense(NULL, err, 0, pending_req); 643 } 644 645 /* 646 Perform virtual to physical translation 647 */ 648 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info, 649 struct ids_tuple *v) 650 { 651 struct v2p_entry *entry; 652 struct list_head *head = &(info->v2p_entry_lists); 653 unsigned long flags; 654 655 spin_lock_irqsave(&info->v2p_lock, flags); 656 list_for_each_entry(entry, head, l) { 657 if ((entry->v.chn == v->chn) && 658 (entry->v.tgt == v->tgt) && 659 (entry->v.lun == v->lun)) { 660 kref_get(&entry->kref); 661 goto out; 662 } 663 } 664 entry = NULL; 665 666 out: 667 spin_unlock_irqrestore(&info->v2p_lock, flags); 668 return entry; 669 } 670 671 static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring, 672 struct v2p_entry *v2p) 673 { 674 struct scsiback_tpg *tpg = v2p->tpg; 675 struct scsiback_nexus *nexus = tpg->tpg_nexus; 676 struct se_session *se_sess = nexus->tvn_se_sess; 677 struct vscsibk_pend *req; 678 int tag, cpu, i; 679 680 tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu); 681 if (tag < 0) { 682 pr_err("Unable to obtain tag for vscsiif_request\n"); 683 return ERR_PTR(-ENOMEM); 684 } 685 686 req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag]; 687 memset(req, 0, sizeof(*req)); 688 req->se_cmd.map_tag = tag; 689 req->se_cmd.map_cpu = cpu; 690 691 for (i = 0; i < VSCSI_MAX_GRANTS; i++) 692 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE; 693 694 return req; 695 } 696 697 static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info, 698 struct vscsiif_back_ring *ring, 699 struct vscsiif_request *ring_req) 700 { 701 struct vscsibk_pend *pending_req; 702 struct v2p_entry *v2p; 703 struct ids_tuple vir; 704 705 /* request range check from frontend */ 706 if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) && 707 (ring_req->sc_data_direction != DMA_TO_DEVICE) && 708 (ring_req->sc_data_direction != DMA_FROM_DEVICE) && 709 (ring_req->sc_data_direction != DMA_NONE)) { 710 pr_debug("invalid parameter data_dir = %d\n", 711 ring_req->sc_data_direction); 712 return ERR_PTR(-EINVAL); 713 } 714 if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) { 715 pr_debug("invalid parameter cmd_len = %d\n", 716 ring_req->cmd_len); 717 return ERR_PTR(-EINVAL); 718 } 719 720 vir.chn = ring_req->channel; 721 vir.tgt = ring_req->id; 722 vir.lun = ring_req->lun; 723 724 v2p = scsiback_do_translation(info, &vir); 725 if (!v2p) { 726 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n", 727 vir.chn, vir.tgt, vir.lun); 728 return ERR_PTR(-ENODEV); 729 } 730 731 pending_req = scsiback_get_pend_req(ring, v2p); 732 if (IS_ERR(pending_req)) { 733 kref_put(&v2p->kref, scsiback_free_translation_entry); 734 return ERR_PTR(-ENOMEM); 735 } 736 pending_req->rqid = ring_req->rqid; 737 pending_req->info = info; 738 pending_req->v2p = v2p; 739 pending_req->sc_data_direction = ring_req->sc_data_direction; 740 pending_req->cmd_len = ring_req->cmd_len; 741 memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len); 742 743 return pending_req; 744 } 745 746 static int scsiback_do_cmd_fn(struct vscsibk_info *info, 747 unsigned int *eoi_flags) 748 { 749 struct vscsiif_back_ring *ring = &info->ring; 750 struct vscsiif_request ring_req; 751 struct vscsibk_pend *pending_req; 752 RING_IDX rc, rp; 753 int more_to_do; 754 uint32_t result; 755 756 rc = ring->req_cons; 757 rp = ring->sring->req_prod; 758 rmb(); /* guest system is accessing ring, too */ 759 760 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) { 761 rc = ring->rsp_prod_pvt; 762 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n", 763 info->domid, rp, rc, rp - rc); 764 return -EINVAL; 765 } 766 767 while ((rc != rp)) { 768 *eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS; 769 770 if (RING_REQUEST_CONS_OVERFLOW(ring, rc)) 771 break; 772 773 RING_COPY_REQUEST(ring, rc, &ring_req); 774 ring->req_cons = ++rc; 775 776 pending_req = prepare_pending_reqs(info, ring, &ring_req); 777 if (IS_ERR(pending_req)) { 778 switch (PTR_ERR(pending_req)) { 779 case -ENODEV: 780 result = DID_NO_CONNECT; 781 break; 782 default: 783 result = DID_ERROR; 784 break; 785 } 786 scsiback_send_response(info, NULL, result << 16, 0, 787 ring_req.rqid); 788 return 1; 789 } 790 791 switch (ring_req.act) { 792 case VSCSIIF_ACT_SCSI_CDB: 793 if (scsiback_gnttab_data_map(&ring_req, pending_req)) { 794 scsiback_fast_flush_area(pending_req); 795 scsiback_do_resp_with_sense(NULL, 796 DID_ERROR << 16, 0, pending_req); 797 transport_generic_free_cmd(&pending_req->se_cmd, 0); 798 } else { 799 scsiback_cmd_exec(pending_req); 800 } 801 break; 802 case VSCSIIF_ACT_SCSI_ABORT: 803 scsiback_device_action(pending_req, TMR_ABORT_TASK, 804 ring_req.ref_rqid); 805 break; 806 case VSCSIIF_ACT_SCSI_RESET: 807 scsiback_device_action(pending_req, TMR_LUN_RESET, 0); 808 break; 809 default: 810 pr_err_ratelimited("invalid request\n"); 811 scsiback_do_resp_with_sense(NULL, DID_ERROR << 16, 0, 812 pending_req); 813 transport_generic_free_cmd(&pending_req->se_cmd, 0); 814 break; 815 } 816 817 /* Yield point for this unbounded loop. */ 818 cond_resched(); 819 } 820 821 gnttab_page_cache_shrink(&info->free_pages, scsiback_max_buffer_pages); 822 823 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do); 824 return more_to_do; 825 } 826 827 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id) 828 { 829 struct vscsibk_info *info = dev_id; 830 int rc; 831 unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS; 832 833 while ((rc = scsiback_do_cmd_fn(info, &eoi_flags)) > 0) 834 cond_resched(); 835 836 /* In case of a ring error we keep the event channel masked. */ 837 if (!rc) 838 xen_irq_lateeoi(irq, eoi_flags); 839 840 return IRQ_HANDLED; 841 } 842 843 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref, 844 evtchn_port_t evtchn) 845 { 846 void *area; 847 struct vscsiif_sring *sring; 848 int err; 849 850 if (info->irq) 851 return -1; 852 853 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area); 854 if (err) 855 return err; 856 857 sring = (struct vscsiif_sring *)area; 858 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE); 859 860 err = bind_interdomain_evtchn_to_irq_lateeoi(info->dev, evtchn); 861 if (err < 0) 862 goto unmap_page; 863 864 info->irq = err; 865 866 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn, 867 IRQF_ONESHOT, "vscsiif-backend", info); 868 if (err) 869 goto free_irq; 870 871 return 0; 872 873 free_irq: 874 unbind_from_irqhandler(info->irq, info); 875 info->irq = 0; 876 unmap_page: 877 xenbus_unmap_ring_vfree(info->dev, area); 878 879 return err; 880 } 881 882 static int scsiback_map(struct vscsibk_info *info) 883 { 884 struct xenbus_device *dev = info->dev; 885 unsigned int ring_ref; 886 evtchn_port_t evtchn; 887 int err; 888 889 err = xenbus_gather(XBT_NIL, dev->otherend, 890 "ring-ref", "%u", &ring_ref, 891 "event-channel", "%u", &evtchn, NULL); 892 if (err) { 893 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend); 894 return err; 895 } 896 897 return scsiback_init_sring(info, ring_ref, evtchn); 898 } 899 900 /* 901 Check for a translation entry being present 902 */ 903 static struct v2p_entry *scsiback_chk_translation_entry( 904 struct vscsibk_info *info, struct ids_tuple *v) 905 { 906 struct list_head *head = &(info->v2p_entry_lists); 907 struct v2p_entry *entry; 908 909 list_for_each_entry(entry, head, l) 910 if ((entry->v.chn == v->chn) && 911 (entry->v.tgt == v->tgt) && 912 (entry->v.lun == v->lun)) 913 return entry; 914 915 return NULL; 916 } 917 918 /* 919 Add a new translation entry 920 */ 921 static int scsiback_add_translation_entry(struct vscsibk_info *info, 922 char *phy, struct ids_tuple *v) 923 { 924 int err = 0; 925 struct v2p_entry *new; 926 unsigned long flags; 927 char *lunp; 928 unsigned long long unpacked_lun; 929 struct se_lun *se_lun; 930 struct scsiback_tpg *tpg_entry, *tpg = NULL; 931 char *error = "doesn't exist"; 932 933 lunp = strrchr(phy, ':'); 934 if (!lunp) { 935 pr_err("illegal format of physical device %s\n", phy); 936 return -EINVAL; 937 } 938 *lunp = 0; 939 lunp++; 940 err = kstrtoull(lunp, 10, &unpacked_lun); 941 if (err < 0) { 942 pr_err("lun number not valid: %s\n", lunp); 943 return err; 944 } 945 946 mutex_lock(&scsiback_mutex); 947 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) { 948 if (!strcmp(phy, tpg_entry->tport->tport_name) || 949 !strcmp(phy, tpg_entry->param_alias)) { 950 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex); 951 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) { 952 if (se_lun->unpacked_lun == unpacked_lun) { 953 if (!tpg_entry->tpg_nexus) 954 error = "nexus undefined"; 955 else 956 tpg = tpg_entry; 957 break; 958 } 959 } 960 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex); 961 break; 962 } 963 } 964 if (tpg) { 965 mutex_lock(&tpg->tv_tpg_mutex); 966 tpg->tv_tpg_fe_count++; 967 mutex_unlock(&tpg->tv_tpg_mutex); 968 } 969 mutex_unlock(&scsiback_mutex); 970 971 if (!tpg) { 972 pr_err("%s:%llu %s\n", phy, unpacked_lun, error); 973 return -ENODEV; 974 } 975 976 new = kmalloc_obj(struct v2p_entry); 977 if (new == NULL) { 978 err = -ENOMEM; 979 goto out_free; 980 } 981 982 spin_lock_irqsave(&info->v2p_lock, flags); 983 984 /* Check double assignment to identical virtual ID */ 985 if (scsiback_chk_translation_entry(info, v)) { 986 pr_warn("Virtual ID is already used. Assignment was not performed.\n"); 987 err = -EEXIST; 988 goto out; 989 } 990 991 /* Create a new translation entry and add to the list */ 992 kref_init(&new->kref); 993 new->v = *v; 994 new->tpg = tpg; 995 new->lun = unpacked_lun; 996 list_add_tail(&new->l, &info->v2p_entry_lists); 997 998 out: 999 spin_unlock_irqrestore(&info->v2p_lock, flags); 1000 1001 out_free: 1002 if (err) { 1003 mutex_lock(&tpg->tv_tpg_mutex); 1004 tpg->tv_tpg_fe_count--; 1005 mutex_unlock(&tpg->tv_tpg_mutex); 1006 kfree(new); 1007 } 1008 1009 return err; 1010 } 1011 1012 /* 1013 Delete the translation entry specified 1014 */ 1015 static int scsiback_del_translation_entry(struct vscsibk_info *info, 1016 struct ids_tuple *v) 1017 { 1018 struct v2p_entry *entry; 1019 unsigned long flags; 1020 1021 spin_lock_irqsave(&info->v2p_lock, flags); 1022 /* Find out the translation entry specified */ 1023 entry = scsiback_chk_translation_entry(info, v); 1024 if (entry) 1025 list_del(&entry->l); 1026 1027 spin_unlock_irqrestore(&info->v2p_lock, flags); 1028 1029 if (!entry) 1030 return -ENOENT; 1031 1032 kref_put(&entry->kref, scsiback_free_translation_entry); 1033 return 0; 1034 } 1035 1036 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state, 1037 char *phy, struct ids_tuple *vir, int try) 1038 { 1039 struct v2p_entry *entry; 1040 unsigned long flags; 1041 int err; 1042 1043 if (try) { 1044 spin_lock_irqsave(&info->v2p_lock, flags); 1045 entry = scsiback_chk_translation_entry(info, vir); 1046 spin_unlock_irqrestore(&info->v2p_lock, flags); 1047 if (entry) 1048 return; 1049 } 1050 if (!scsiback_add_translation_entry(info, phy, vir)) { 1051 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1052 "%d", XenbusStateInitialised)) { 1053 pr_err("xenbus_printf error %s\n", state); 1054 scsiback_del_translation_entry(info, vir); 1055 } 1056 } else if (!try) { 1057 err = xenbus_printf(XBT_NIL, info->dev->nodename, state, 1058 "%d", XenbusStateClosed); 1059 if (err) 1060 xenbus_dev_error(info->dev, err, 1061 "%s: writing %s", __func__, state); 1062 } 1063 } 1064 1065 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state, 1066 struct ids_tuple *vir) 1067 { 1068 if (!scsiback_del_translation_entry(info, vir)) { 1069 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1070 "%d", XenbusStateClosed)) 1071 pr_err("xenbus_printf error %s\n", state); 1072 } 1073 } 1074 1075 #define VSCSIBACK_OP_ADD_OR_DEL_LUN 1 1076 #define VSCSIBACK_OP_UPDATEDEV_STATE 2 1077 1078 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op, 1079 char *ent) 1080 { 1081 int err; 1082 struct ids_tuple vir; 1083 char *val; 1084 int device_state; 1085 char phy[VSCSI_NAMELEN]; 1086 char str[64]; 1087 char state[64]; 1088 struct xenbus_device *dev = info->dev; 1089 1090 /* read status */ 1091 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent); 1092 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state); 1093 if (XENBUS_EXIST_ERR(err)) 1094 return; 1095 1096 /* physical SCSI device */ 1097 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent); 1098 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL); 1099 if (IS_ERR(val)) { 1100 err = xenbus_printf(XBT_NIL, dev->nodename, state, 1101 "%d", XenbusStateClosed); 1102 if (err) 1103 xenbus_dev_error(info->dev, err, 1104 "%s: writing %s", __func__, state); 1105 return; 1106 } 1107 strscpy(phy, val, VSCSI_NAMELEN); 1108 kfree(val); 1109 1110 /* virtual SCSI device */ 1111 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent); 1112 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u", 1113 &vir.hst, &vir.chn, &vir.tgt, &vir.lun); 1114 if (XENBUS_EXIST_ERR(err)) { 1115 err = xenbus_printf(XBT_NIL, dev->nodename, state, 1116 "%d", XenbusStateClosed); 1117 if (err) 1118 xenbus_dev_error(info->dev, err, 1119 "%s: writing %s", __func__, state); 1120 return; 1121 } 1122 1123 switch (op) { 1124 case VSCSIBACK_OP_ADD_OR_DEL_LUN: 1125 switch (device_state) { 1126 case XenbusStateInitialising: 1127 scsiback_do_add_lun(info, state, phy, &vir, 0); 1128 break; 1129 case XenbusStateConnected: 1130 scsiback_do_add_lun(info, state, phy, &vir, 1); 1131 break; 1132 case XenbusStateClosing: 1133 scsiback_do_del_lun(info, state, &vir); 1134 break; 1135 default: 1136 break; 1137 } 1138 break; 1139 1140 case VSCSIBACK_OP_UPDATEDEV_STATE: 1141 if (device_state == XenbusStateInitialised) { 1142 /* modify vscsi-devs/dev-x/state */ 1143 if (xenbus_printf(XBT_NIL, dev->nodename, state, 1144 "%d", XenbusStateConnected)) { 1145 pr_err("xenbus_printf error %s\n", str); 1146 scsiback_del_translation_entry(info, &vir); 1147 xenbus_printf(XBT_NIL, dev->nodename, state, 1148 "%d", XenbusStateClosed); 1149 } 1150 } 1151 break; 1152 /* When it is necessary, processing is added here. */ 1153 default: 1154 break; 1155 } 1156 } 1157 1158 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op) 1159 { 1160 int i; 1161 char **dir; 1162 unsigned int ndir = 0; 1163 1164 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs", 1165 &ndir); 1166 if (IS_ERR(dir)) 1167 return; 1168 1169 for (i = 0; i < ndir; i++) 1170 scsiback_do_1lun_hotplug(info, op, dir[i]); 1171 1172 kfree(dir); 1173 } 1174 1175 static void scsiback_frontend_changed(struct xenbus_device *dev, 1176 enum xenbus_state frontend_state) 1177 { 1178 struct vscsibk_info *info = dev_get_drvdata(&dev->dev); 1179 1180 switch (frontend_state) { 1181 case XenbusStateInitialising: 1182 break; 1183 1184 case XenbusStateInitialised: 1185 if (scsiback_map(info)) 1186 break; 1187 1188 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); 1189 xenbus_switch_state(dev, XenbusStateConnected); 1190 break; 1191 1192 case XenbusStateConnected: 1193 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE); 1194 1195 if (dev->state == XenbusStateConnected) 1196 break; 1197 1198 xenbus_switch_state(dev, XenbusStateConnected); 1199 break; 1200 1201 case XenbusStateClosing: 1202 if (info->irq) 1203 scsiback_disconnect(info); 1204 1205 xenbus_switch_state(dev, XenbusStateClosing); 1206 break; 1207 1208 case XenbusStateClosed: 1209 xenbus_switch_state(dev, XenbusStateClosed); 1210 if (xenbus_dev_is_online(dev)) 1211 break; 1212 fallthrough; /* if not online */ 1213 case XenbusStateUnknown: 1214 device_unregister(&dev->dev); 1215 break; 1216 1217 case XenbusStateReconfiguring: 1218 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); 1219 xenbus_switch_state(dev, XenbusStateReconfigured); 1220 1221 break; 1222 1223 default: 1224 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", 1225 frontend_state); 1226 break; 1227 } 1228 } 1229 1230 /* 1231 Release the translation entry specfied 1232 */ 1233 static void scsiback_release_translation_entry(struct vscsibk_info *info) 1234 { 1235 struct v2p_entry *entry, *tmp; 1236 struct list_head *head = &(info->v2p_entry_lists); 1237 struct list_head tmp_list; 1238 unsigned long flags; 1239 1240 spin_lock_irqsave(&info->v2p_lock, flags); 1241 1242 list_cut_before(&tmp_list, head, head); 1243 1244 spin_unlock_irqrestore(&info->v2p_lock, flags); 1245 1246 list_for_each_entry_safe(entry, tmp, &tmp_list, l) { 1247 list_del(&entry->l); 1248 kref_put(&entry->kref, scsiback_free_translation_entry); 1249 } 1250 } 1251 1252 static void scsiback_remove(struct xenbus_device *dev) 1253 { 1254 struct vscsibk_info *info = dev_get_drvdata(&dev->dev); 1255 1256 if (info->irq) 1257 scsiback_disconnect(info); 1258 1259 scsiback_release_translation_entry(info); 1260 1261 gnttab_page_cache_shrink(&info->free_pages, 0); 1262 1263 dev_set_drvdata(&dev->dev, NULL); 1264 kfree(info); 1265 } 1266 1267 static int scsiback_probe(struct xenbus_device *dev, 1268 const struct xenbus_device_id *id) 1269 { 1270 int err; 1271 1272 struct vscsibk_info *info = kzalloc_obj(struct vscsibk_info); 1273 1274 pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); 1275 1276 if (!info) { 1277 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure"); 1278 return -ENOMEM; 1279 } 1280 info->dev = dev; 1281 dev_set_drvdata(&dev->dev, info); 1282 1283 info->domid = dev->otherend_id; 1284 spin_lock_init(&info->ring_lock); 1285 atomic_set(&info->nr_unreplied_reqs, 0); 1286 init_waitqueue_head(&info->waiting_to_free); 1287 info->dev = dev; 1288 info->irq = 0; 1289 INIT_LIST_HEAD(&info->v2p_entry_lists); 1290 spin_lock_init(&info->v2p_lock); 1291 gnttab_page_cache_init(&info->free_pages); 1292 1293 err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u", 1294 SG_ALL); 1295 if (err) 1296 xenbus_dev_error(dev, err, "writing feature-sg-grant"); 1297 1298 err = xenbus_switch_state(dev, XenbusStateInitWait); 1299 if (err) 1300 goto fail; 1301 1302 return 0; 1303 1304 fail: 1305 pr_warn("%s failed\n", __func__); 1306 scsiback_remove(dev); 1307 1308 return err; 1309 } 1310 1311 static char *scsiback_dump_proto_id(struct scsiback_tport *tport) 1312 { 1313 switch (tport->tport_proto_id) { 1314 case SCSI_PROTOCOL_SAS: 1315 return "SAS"; 1316 case SCSI_PROTOCOL_FCP: 1317 return "FCP"; 1318 case SCSI_PROTOCOL_ISCSI: 1319 return "iSCSI"; 1320 default: 1321 break; 1322 } 1323 1324 return "Unknown"; 1325 } 1326 1327 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg) 1328 { 1329 struct scsiback_tpg *tpg = container_of(se_tpg, 1330 struct scsiback_tpg, se_tpg); 1331 struct scsiback_tport *tport = tpg->tport; 1332 1333 return &tport->tport_name[0]; 1334 } 1335 1336 static u16 scsiback_get_tag(struct se_portal_group *se_tpg) 1337 { 1338 struct scsiback_tpg *tpg = container_of(se_tpg, 1339 struct scsiback_tpg, se_tpg); 1340 return tpg->tport_tpgt; 1341 } 1342 1343 static struct se_wwn * 1344 scsiback_make_tport(struct target_fabric_configfs *tf, 1345 struct config_group *group, 1346 const char *name) 1347 { 1348 struct scsiback_tport *tport; 1349 char *ptr; 1350 u64 wwpn = 0; 1351 int off = 0; 1352 1353 tport = kzalloc_obj(struct scsiback_tport); 1354 if (!tport) 1355 return ERR_PTR(-ENOMEM); 1356 1357 tport->tport_wwpn = wwpn; 1358 /* 1359 * Determine the emulated Protocol Identifier and Target Port Name 1360 * based on the incoming configfs directory name. 1361 */ 1362 ptr = strstr(name, "naa."); 1363 if (ptr) { 1364 tport->tport_proto_id = SCSI_PROTOCOL_SAS; 1365 goto check_len; 1366 } 1367 ptr = strstr(name, "fc."); 1368 if (ptr) { 1369 tport->tport_proto_id = SCSI_PROTOCOL_FCP; 1370 off = 3; /* Skip over "fc." */ 1371 goto check_len; 1372 } 1373 ptr = strstr(name, "iqn."); 1374 if (ptr) { 1375 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI; 1376 goto check_len; 1377 } 1378 1379 pr_err("Unable to locate prefix for emulated Target Port: %s\n", name); 1380 kfree(tport); 1381 return ERR_PTR(-EINVAL); 1382 1383 check_len: 1384 if (strlen(name) >= VSCSI_NAMELEN) { 1385 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name, 1386 scsiback_dump_proto_id(tport), VSCSI_NAMELEN); 1387 kfree(tport); 1388 return ERR_PTR(-EINVAL); 1389 } 1390 snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]); 1391 1392 pr_debug("Allocated emulated Target %s Address: %s\n", 1393 scsiback_dump_proto_id(tport), name); 1394 1395 return &tport->tport_wwn; 1396 } 1397 1398 static void scsiback_drop_tport(struct se_wwn *wwn) 1399 { 1400 struct scsiback_tport *tport = container_of(wwn, 1401 struct scsiback_tport, tport_wwn); 1402 1403 pr_debug("Deallocating emulated Target %s Address: %s\n", 1404 scsiback_dump_proto_id(tport), tport->tport_name); 1405 1406 kfree(tport); 1407 } 1408 1409 static int scsiback_check_stop_free(struct se_cmd *se_cmd) 1410 { 1411 return transport_generic_free_cmd(se_cmd, 0); 1412 } 1413 1414 static void scsiback_release_cmd(struct se_cmd *se_cmd) 1415 { 1416 target_free_tag(se_cmd->se_sess, se_cmd); 1417 } 1418 1419 static int scsiback_write_pending(struct se_cmd *se_cmd) 1420 { 1421 /* Go ahead and process the write immediately */ 1422 target_execute_cmd(se_cmd); 1423 1424 return 0; 1425 } 1426 1427 static int scsiback_queue_data_in(struct se_cmd *se_cmd) 1428 { 1429 struct vscsibk_pend *pending_req = container_of(se_cmd, 1430 struct vscsibk_pend, se_cmd); 1431 1432 pending_req->result = SAM_STAT_GOOD; 1433 scsiback_cmd_done(pending_req); 1434 return 0; 1435 } 1436 1437 static int scsiback_queue_status(struct se_cmd *se_cmd) 1438 { 1439 struct vscsibk_pend *pending_req = container_of(se_cmd, 1440 struct vscsibk_pend, se_cmd); 1441 1442 if (se_cmd->sense_buffer && 1443 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) || 1444 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) 1445 pending_req->result = SAM_STAT_CHECK_CONDITION; 1446 else 1447 pending_req->result = se_cmd->scsi_status; 1448 1449 scsiback_cmd_done(pending_req); 1450 return 0; 1451 } 1452 1453 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd) 1454 { 1455 struct vscsibk_pend *pending_req = container_of(se_cmd, 1456 struct vscsibk_pend, se_cmd); 1457 1458 complete(&pending_req->tmr_done); 1459 } 1460 1461 static void scsiback_aborted_task(struct se_cmd *se_cmd) 1462 { 1463 } 1464 1465 static ssize_t scsiback_tpg_param_alias_show(struct config_item *item, 1466 char *page) 1467 { 1468 struct se_portal_group *se_tpg = param_to_tpg(item); 1469 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1470 se_tpg); 1471 ssize_t rb; 1472 1473 mutex_lock(&tpg->tv_tpg_mutex); 1474 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias); 1475 mutex_unlock(&tpg->tv_tpg_mutex); 1476 1477 return rb; 1478 } 1479 1480 static ssize_t scsiback_tpg_param_alias_store(struct config_item *item, 1481 const char *page, size_t count) 1482 { 1483 struct se_portal_group *se_tpg = param_to_tpg(item); 1484 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1485 se_tpg); 1486 int len; 1487 1488 if (strlen(page) >= VSCSI_NAMELEN) { 1489 pr_err("param alias: %s, exceeds max: %d\n", page, 1490 VSCSI_NAMELEN); 1491 return -EINVAL; 1492 } 1493 1494 mutex_lock(&tpg->tv_tpg_mutex); 1495 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page); 1496 if (tpg->param_alias[len - 1] == '\n') 1497 tpg->param_alias[len - 1] = '\0'; 1498 mutex_unlock(&tpg->tv_tpg_mutex); 1499 1500 return count; 1501 } 1502 1503 CONFIGFS_ATTR(scsiback_tpg_param_, alias); 1504 1505 static struct configfs_attribute *scsiback_param_attrs[] = { 1506 &scsiback_tpg_param_attr_alias, 1507 NULL, 1508 }; 1509 1510 static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg, 1511 struct se_session *se_sess, void *p) 1512 { 1513 struct scsiback_tpg *tpg = container_of(se_tpg, 1514 struct scsiback_tpg, se_tpg); 1515 1516 tpg->tpg_nexus = p; 1517 return 0; 1518 } 1519 1520 static int scsiback_make_nexus(struct scsiback_tpg *tpg, 1521 const char *name) 1522 { 1523 struct scsiback_nexus *tv_nexus; 1524 int ret = 0; 1525 1526 mutex_lock(&tpg->tv_tpg_mutex); 1527 if (tpg->tpg_nexus) { 1528 pr_debug("tpg->tpg_nexus already exists\n"); 1529 ret = -EEXIST; 1530 goto out_unlock; 1531 } 1532 1533 tv_nexus = kzalloc_obj(struct scsiback_nexus); 1534 if (!tv_nexus) { 1535 ret = -ENOMEM; 1536 goto out_unlock; 1537 } 1538 1539 tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg, 1540 VSCSI_DEFAULT_SESSION_TAGS, 1541 sizeof(struct vscsibk_pend), 1542 TARGET_PROT_NORMAL, name, 1543 tv_nexus, scsiback_alloc_sess_cb); 1544 if (IS_ERR(tv_nexus->tvn_se_sess)) { 1545 kfree(tv_nexus); 1546 ret = -ENOMEM; 1547 goto out_unlock; 1548 } 1549 1550 out_unlock: 1551 mutex_unlock(&tpg->tv_tpg_mutex); 1552 return ret; 1553 } 1554 1555 static int scsiback_drop_nexus(struct scsiback_tpg *tpg) 1556 { 1557 struct se_session *se_sess; 1558 struct scsiback_nexus *tv_nexus; 1559 1560 mutex_lock(&tpg->tv_tpg_mutex); 1561 tv_nexus = tpg->tpg_nexus; 1562 if (!tv_nexus) { 1563 mutex_unlock(&tpg->tv_tpg_mutex); 1564 return -ENODEV; 1565 } 1566 1567 se_sess = tv_nexus->tvn_se_sess; 1568 if (!se_sess) { 1569 mutex_unlock(&tpg->tv_tpg_mutex); 1570 return -ENODEV; 1571 } 1572 1573 if (tpg->tv_tpg_port_count != 0) { 1574 mutex_unlock(&tpg->tv_tpg_mutex); 1575 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n", 1576 tpg->tv_tpg_port_count); 1577 return -EBUSY; 1578 } 1579 1580 if (tpg->tv_tpg_fe_count != 0) { 1581 mutex_unlock(&tpg->tv_tpg_mutex); 1582 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n", 1583 tpg->tv_tpg_fe_count); 1584 return -EBUSY; 1585 } 1586 1587 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n", 1588 scsiback_dump_proto_id(tpg->tport), 1589 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1590 1591 /* 1592 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port 1593 */ 1594 target_remove_session(se_sess); 1595 tpg->tpg_nexus = NULL; 1596 mutex_unlock(&tpg->tv_tpg_mutex); 1597 1598 kfree(tv_nexus); 1599 return 0; 1600 } 1601 1602 static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page) 1603 { 1604 struct se_portal_group *se_tpg = to_tpg(item); 1605 struct scsiback_tpg *tpg = container_of(se_tpg, 1606 struct scsiback_tpg, se_tpg); 1607 struct scsiback_nexus *tv_nexus; 1608 ssize_t ret; 1609 1610 mutex_lock(&tpg->tv_tpg_mutex); 1611 tv_nexus = tpg->tpg_nexus; 1612 if (!tv_nexus) { 1613 mutex_unlock(&tpg->tv_tpg_mutex); 1614 return -ENODEV; 1615 } 1616 ret = snprintf(page, PAGE_SIZE, "%s\n", 1617 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1618 mutex_unlock(&tpg->tv_tpg_mutex); 1619 1620 return ret; 1621 } 1622 1623 static ssize_t scsiback_tpg_nexus_store(struct config_item *item, 1624 const char *page, size_t count) 1625 { 1626 struct se_portal_group *se_tpg = to_tpg(item); 1627 struct scsiback_tpg *tpg = container_of(se_tpg, 1628 struct scsiback_tpg, se_tpg); 1629 struct scsiback_tport *tport_wwn = tpg->tport; 1630 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr; 1631 int ret; 1632 /* 1633 * Shutdown the active I_T nexus if 'NULL' is passed. 1634 */ 1635 if (!strncmp(page, "NULL", 4)) { 1636 ret = scsiback_drop_nexus(tpg); 1637 return (!ret) ? count : ret; 1638 } 1639 /* 1640 * Otherwise make sure the passed virtual Initiator port WWN matches 1641 * the fabric protocol_id set in scsiback_make_tport(), and call 1642 * scsiback_make_nexus(). 1643 */ 1644 if (strlen(page) >= VSCSI_NAMELEN) { 1645 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n", 1646 page, VSCSI_NAMELEN); 1647 return -EINVAL; 1648 } 1649 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page); 1650 1651 ptr = strstr(i_port, "naa."); 1652 if (ptr) { 1653 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) { 1654 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n", 1655 i_port, scsiback_dump_proto_id(tport_wwn)); 1656 return -EINVAL; 1657 } 1658 port_ptr = &i_port[0]; 1659 goto check_newline; 1660 } 1661 ptr = strstr(i_port, "fc."); 1662 if (ptr) { 1663 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) { 1664 pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n", 1665 i_port, scsiback_dump_proto_id(tport_wwn)); 1666 return -EINVAL; 1667 } 1668 port_ptr = &i_port[3]; /* Skip over "fc." */ 1669 goto check_newline; 1670 } 1671 ptr = strstr(i_port, "iqn."); 1672 if (ptr) { 1673 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) { 1674 pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n", 1675 i_port, scsiback_dump_proto_id(tport_wwn)); 1676 return -EINVAL; 1677 } 1678 port_ptr = &i_port[0]; 1679 goto check_newline; 1680 } 1681 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n", 1682 i_port); 1683 return -EINVAL; 1684 /* 1685 * Clear any trailing newline for the NAA WWN 1686 */ 1687 check_newline: 1688 if (i_port[strlen(i_port) - 1] == '\n') 1689 i_port[strlen(i_port) - 1] = '\0'; 1690 1691 ret = scsiback_make_nexus(tpg, port_ptr); 1692 if (ret < 0) 1693 return ret; 1694 1695 return count; 1696 } 1697 1698 CONFIGFS_ATTR(scsiback_tpg_, nexus); 1699 1700 static struct configfs_attribute *scsiback_tpg_attrs[] = { 1701 &scsiback_tpg_attr_nexus, 1702 NULL, 1703 }; 1704 1705 static ssize_t 1706 scsiback_wwn_version_show(struct config_item *item, char *page) 1707 { 1708 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on " 1709 UTS_RELEASE"\n", 1710 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1711 } 1712 1713 CONFIGFS_ATTR_RO(scsiback_wwn_, version); 1714 1715 static struct configfs_attribute *scsiback_wwn_attrs[] = { 1716 &scsiback_wwn_attr_version, 1717 NULL, 1718 }; 1719 1720 static int scsiback_port_link(struct se_portal_group *se_tpg, 1721 struct se_lun *lun) 1722 { 1723 struct scsiback_tpg *tpg = container_of(se_tpg, 1724 struct scsiback_tpg, se_tpg); 1725 1726 mutex_lock(&tpg->tv_tpg_mutex); 1727 tpg->tv_tpg_port_count++; 1728 mutex_unlock(&tpg->tv_tpg_mutex); 1729 1730 return 0; 1731 } 1732 1733 static void scsiback_port_unlink(struct se_portal_group *se_tpg, 1734 struct se_lun *lun) 1735 { 1736 struct scsiback_tpg *tpg = container_of(se_tpg, 1737 struct scsiback_tpg, se_tpg); 1738 1739 mutex_lock(&tpg->tv_tpg_mutex); 1740 tpg->tv_tpg_port_count--; 1741 mutex_unlock(&tpg->tv_tpg_mutex); 1742 } 1743 1744 static struct se_portal_group * 1745 scsiback_make_tpg(struct se_wwn *wwn, const char *name) 1746 { 1747 struct scsiback_tport *tport = container_of(wwn, 1748 struct scsiback_tport, tport_wwn); 1749 1750 struct scsiback_tpg *tpg; 1751 u16 tpgt; 1752 int ret; 1753 1754 if (strstr(name, "tpgt_") != name) 1755 return ERR_PTR(-EINVAL); 1756 ret = kstrtou16(name + 5, 10, &tpgt); 1757 if (ret) 1758 return ERR_PTR(ret); 1759 1760 tpg = kzalloc_obj(struct scsiback_tpg); 1761 if (!tpg) 1762 return ERR_PTR(-ENOMEM); 1763 1764 mutex_init(&tpg->tv_tpg_mutex); 1765 INIT_LIST_HEAD(&tpg->tv_tpg_list); 1766 INIT_LIST_HEAD(&tpg->info_list); 1767 tpg->tport = tport; 1768 tpg->tport_tpgt = tpgt; 1769 1770 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id); 1771 if (ret < 0) { 1772 kfree(tpg); 1773 return NULL; 1774 } 1775 mutex_lock(&scsiback_mutex); 1776 list_add_tail(&tpg->tv_tpg_list, &scsiback_list); 1777 mutex_unlock(&scsiback_mutex); 1778 1779 return &tpg->se_tpg; 1780 } 1781 1782 static void scsiback_drop_tpg(struct se_portal_group *se_tpg) 1783 { 1784 struct scsiback_tpg *tpg = container_of(se_tpg, 1785 struct scsiback_tpg, se_tpg); 1786 1787 mutex_lock(&scsiback_mutex); 1788 list_del(&tpg->tv_tpg_list); 1789 mutex_unlock(&scsiback_mutex); 1790 /* 1791 * Release the virtual I_T Nexus for this xen-pvscsi TPG 1792 */ 1793 scsiback_drop_nexus(tpg); 1794 /* 1795 * Deregister the se_tpg from TCM. 1796 */ 1797 core_tpg_deregister(se_tpg); 1798 kfree(tpg); 1799 } 1800 1801 static int scsiback_check_true(struct se_portal_group *se_tpg) 1802 { 1803 return 1; 1804 } 1805 1806 static const struct target_core_fabric_ops scsiback_ops = { 1807 .module = THIS_MODULE, 1808 .fabric_name = "xen-pvscsi", 1809 .tpg_get_wwn = scsiback_get_fabric_wwn, 1810 .tpg_get_tag = scsiback_get_tag, 1811 .tpg_check_demo_mode = scsiback_check_true, 1812 .tpg_check_demo_mode_cache = scsiback_check_true, 1813 .check_stop_free = scsiback_check_stop_free, 1814 .release_cmd = scsiback_release_cmd, 1815 .sess_get_initiator_sid = NULL, 1816 .write_pending = scsiback_write_pending, 1817 .queue_data_in = scsiback_queue_data_in, 1818 .queue_status = scsiback_queue_status, 1819 .queue_tm_rsp = scsiback_queue_tm_rsp, 1820 .aborted_task = scsiback_aborted_task, 1821 /* 1822 * Setup callers for generic logic in target_core_fabric_configfs.c 1823 */ 1824 .fabric_make_wwn = scsiback_make_tport, 1825 .fabric_drop_wwn = scsiback_drop_tport, 1826 .fabric_make_tpg = scsiback_make_tpg, 1827 .fabric_drop_tpg = scsiback_drop_tpg, 1828 .fabric_post_link = scsiback_port_link, 1829 .fabric_pre_unlink = scsiback_port_unlink, 1830 1831 .tfc_wwn_attrs = scsiback_wwn_attrs, 1832 .tfc_tpg_base_attrs = scsiback_tpg_attrs, 1833 .tfc_tpg_param_attrs = scsiback_param_attrs, 1834 1835 .default_submit_type = TARGET_DIRECT_SUBMIT, 1836 .direct_submit_supp = 1, 1837 }; 1838 1839 static const struct xenbus_device_id scsiback_ids[] = { 1840 { "vscsi" }, 1841 { "" } 1842 }; 1843 1844 static struct xenbus_driver scsiback_driver = { 1845 .ids = scsiback_ids, 1846 .probe = scsiback_probe, 1847 .remove = scsiback_remove, 1848 .otherend_changed = scsiback_frontend_changed 1849 }; 1850 1851 static int __init scsiback_init(void) 1852 { 1853 int ret; 1854 1855 if (!xen_domain()) 1856 return -ENODEV; 1857 1858 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n", 1859 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1860 1861 ret = xenbus_register_backend(&scsiback_driver); 1862 if (ret) 1863 goto out; 1864 1865 ret = target_register_template(&scsiback_ops); 1866 if (ret) 1867 goto out_unregister_xenbus; 1868 1869 return 0; 1870 1871 out_unregister_xenbus: 1872 xenbus_unregister_driver(&scsiback_driver); 1873 out: 1874 pr_err("%s: error %d\n", __func__, ret); 1875 return ret; 1876 } 1877 1878 static void __exit scsiback_exit(void) 1879 { 1880 target_unregister_template(&scsiback_ops); 1881 xenbus_unregister_driver(&scsiback_driver); 1882 } 1883 1884 module_init(scsiback_init); 1885 module_exit(scsiback_exit); 1886 1887 MODULE_DESCRIPTION("Xen SCSI backend driver"); 1888 MODULE_LICENSE("Dual BSD/GPL"); 1889 MODULE_ALIAS("xen-backend:vscsi"); 1890 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>"); 1891