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_array(nr_segments, 547 sizeof(struct scatterlist), GFP_KERNEL); 548 if (!pending_req->sgl) 549 return -ENOMEM; 550 551 sg_init_table(pending_req->sgl, nr_segments); 552 pending_req->n_sg = nr_segments; 553 554 flags = GNTMAP_host_map; 555 if (pending_req->sc_data_direction == DMA_TO_DEVICE) 556 flags |= GNTMAP_readonly; 557 558 pg = pending_req->pages + nr_sgl; 559 grant = pending_req->grant_handles + nr_sgl; 560 if (!nr_sgl) { 561 seg = ring_req->seg; 562 err = scsiback_gnttab_data_map_list(pending_req, seg, 563 pg, grant, nr_segments, flags); 564 if (err) 565 return err; 566 } else { 567 for (i = 0; i < nr_sgl; i++) { 568 seg = (struct scsiif_request_segment *)( 569 vaddr(pending_req, i) + ring_req->seg[i].offset); 570 n_segs = ring_req->seg[i].length / 571 sizeof(struct scsiif_request_segment); 572 err = scsiback_gnttab_data_map_list(pending_req, seg, 573 pg, grant, n_segs, flags); 574 if (err) 575 return err; 576 pg += n_segs; 577 grant += n_segs; 578 } 579 end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset; 580 seg = (struct scsiif_request_segment *)end_seg; 581 end_seg += ring_req->seg[0].length; 582 pg = pending_req->pages + nr_sgl; 583 } 584 585 for_each_sg(pending_req->sgl, sg, nr_segments, i) { 586 sg_set_page(sg, pg[i], seg->length, seg->offset); 587 pending_req->data_len += seg->length; 588 seg++; 589 if (nr_sgl && (unsigned long)seg >= end_seg) { 590 i_seg++; 591 end_seg = vaddr(pending_req, i_seg) + 592 ring_req->seg[i_seg].offset; 593 seg = (struct scsiif_request_segment *)end_seg; 594 end_seg += ring_req->seg[i_seg].length; 595 } 596 if (sg->offset >= PAGE_SIZE || 597 sg->length > PAGE_SIZE || 598 sg->offset + sg->length > PAGE_SIZE) 599 return -EINVAL; 600 } 601 602 return 0; 603 } 604 605 static void scsiback_disconnect(struct vscsibk_info *info) 606 { 607 wait_event(info->waiting_to_free, 608 atomic_read(&info->nr_unreplied_reqs) == 0); 609 610 unbind_from_irqhandler(info->irq, info); 611 info->irq = 0; 612 xenbus_unmap_ring_vfree(info->dev, info->ring.sring); 613 } 614 615 static void scsiback_device_action(struct vscsibk_pend *pending_req, 616 enum tcm_tmreq_table act, int tag) 617 { 618 struct scsiback_tpg *tpg = pending_req->v2p->tpg; 619 struct scsiback_nexus *nexus = tpg->tpg_nexus; 620 struct se_cmd *se_cmd = &pending_req->se_cmd; 621 u64 unpacked_lun = pending_req->v2p->lun; 622 int rc, err = XEN_VSCSIIF_RSLT_RESET_FAILED; 623 624 init_completion(&pending_req->tmr_done); 625 626 rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess, 627 &pending_req->sense_buffer[0], 628 unpacked_lun, NULL, act, GFP_KERNEL, 629 tag, TARGET_SCF_ACK_KREF); 630 if (rc) 631 goto err; 632 633 wait_for_completion(&pending_req->tmr_done); 634 635 err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ? 636 XEN_VSCSIIF_RSLT_RESET_SUCCESS : XEN_VSCSIIF_RSLT_RESET_FAILED; 637 638 scsiback_do_resp_with_sense(NULL, err, 0, pending_req); 639 transport_generic_free_cmd(&pending_req->se_cmd, 0); 640 return; 641 642 err: 643 scsiback_do_resp_with_sense(NULL, err, 0, pending_req); 644 } 645 646 /* 647 Perform virtual to physical translation 648 */ 649 static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info, 650 struct ids_tuple *v) 651 { 652 struct v2p_entry *entry; 653 struct list_head *head = &(info->v2p_entry_lists); 654 unsigned long flags; 655 656 spin_lock_irqsave(&info->v2p_lock, flags); 657 list_for_each_entry(entry, head, l) { 658 if ((entry->v.chn == v->chn) && 659 (entry->v.tgt == v->tgt) && 660 (entry->v.lun == v->lun)) { 661 kref_get(&entry->kref); 662 goto out; 663 } 664 } 665 entry = NULL; 666 667 out: 668 spin_unlock_irqrestore(&info->v2p_lock, flags); 669 return entry; 670 } 671 672 static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring, 673 struct v2p_entry *v2p) 674 { 675 struct scsiback_tpg *tpg = v2p->tpg; 676 struct scsiback_nexus *nexus = tpg->tpg_nexus; 677 struct se_session *se_sess = nexus->tvn_se_sess; 678 struct vscsibk_pend *req; 679 int tag, cpu, i; 680 681 tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu); 682 if (tag < 0) { 683 pr_err("Unable to obtain tag for vscsiif_request\n"); 684 return ERR_PTR(-ENOMEM); 685 } 686 687 req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag]; 688 memset(req, 0, sizeof(*req)); 689 req->se_cmd.map_tag = tag; 690 req->se_cmd.map_cpu = cpu; 691 692 for (i = 0; i < VSCSI_MAX_GRANTS; i++) 693 req->grant_handles[i] = SCSIBACK_INVALID_HANDLE; 694 695 return req; 696 } 697 698 static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info, 699 struct vscsiif_back_ring *ring, 700 struct vscsiif_request *ring_req) 701 { 702 struct vscsibk_pend *pending_req; 703 struct v2p_entry *v2p; 704 struct ids_tuple vir; 705 706 /* request range check from frontend */ 707 if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) && 708 (ring_req->sc_data_direction != DMA_TO_DEVICE) && 709 (ring_req->sc_data_direction != DMA_FROM_DEVICE) && 710 (ring_req->sc_data_direction != DMA_NONE)) { 711 pr_debug("invalid parameter data_dir = %d\n", 712 ring_req->sc_data_direction); 713 return ERR_PTR(-EINVAL); 714 } 715 if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) { 716 pr_debug("invalid parameter cmd_len = %d\n", 717 ring_req->cmd_len); 718 return ERR_PTR(-EINVAL); 719 } 720 721 vir.chn = ring_req->channel; 722 vir.tgt = ring_req->id; 723 vir.lun = ring_req->lun; 724 725 v2p = scsiback_do_translation(info, &vir); 726 if (!v2p) { 727 pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n", 728 vir.chn, vir.tgt, vir.lun); 729 return ERR_PTR(-ENODEV); 730 } 731 732 pending_req = scsiback_get_pend_req(ring, v2p); 733 if (IS_ERR(pending_req)) { 734 kref_put(&v2p->kref, scsiback_free_translation_entry); 735 return ERR_PTR(-ENOMEM); 736 } 737 pending_req->rqid = ring_req->rqid; 738 pending_req->info = info; 739 pending_req->v2p = v2p; 740 pending_req->sc_data_direction = ring_req->sc_data_direction; 741 pending_req->cmd_len = ring_req->cmd_len; 742 memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len); 743 744 return pending_req; 745 } 746 747 static int scsiback_do_cmd_fn(struct vscsibk_info *info, 748 unsigned int *eoi_flags) 749 { 750 struct vscsiif_back_ring *ring = &info->ring; 751 struct vscsiif_request ring_req; 752 struct vscsibk_pend *pending_req; 753 RING_IDX rc, rp; 754 int more_to_do; 755 uint32_t result; 756 757 rc = ring->req_cons; 758 rp = ring->sring->req_prod; 759 rmb(); /* guest system is accessing ring, too */ 760 761 if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) { 762 rc = ring->rsp_prod_pvt; 763 pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n", 764 info->domid, rp, rc, rp - rc); 765 return -EINVAL; 766 } 767 768 while ((rc != rp)) { 769 *eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS; 770 771 if (RING_REQUEST_CONS_OVERFLOW(ring, rc)) 772 break; 773 774 RING_COPY_REQUEST(ring, rc, &ring_req); 775 ring->req_cons = ++rc; 776 777 pending_req = prepare_pending_reqs(info, ring, &ring_req); 778 if (IS_ERR(pending_req)) { 779 switch (PTR_ERR(pending_req)) { 780 case -ENODEV: 781 result = DID_NO_CONNECT; 782 break; 783 default: 784 result = DID_ERROR; 785 break; 786 } 787 scsiback_send_response(info, NULL, result << 16, 0, 788 ring_req.rqid); 789 return 1; 790 } 791 792 switch (ring_req.act) { 793 case VSCSIIF_ACT_SCSI_CDB: 794 if (scsiback_gnttab_data_map(&ring_req, pending_req)) { 795 scsiback_fast_flush_area(pending_req); 796 scsiback_do_resp_with_sense(NULL, 797 DID_ERROR << 16, 0, pending_req); 798 transport_generic_free_cmd(&pending_req->se_cmd, 0); 799 } else { 800 scsiback_cmd_exec(pending_req); 801 } 802 break; 803 case VSCSIIF_ACT_SCSI_ABORT: 804 scsiback_device_action(pending_req, TMR_ABORT_TASK, 805 ring_req.ref_rqid); 806 break; 807 case VSCSIIF_ACT_SCSI_RESET: 808 scsiback_device_action(pending_req, TMR_LUN_RESET, 0); 809 break; 810 default: 811 pr_err_ratelimited("invalid request\n"); 812 scsiback_do_resp_with_sense(NULL, DID_ERROR << 16, 0, 813 pending_req); 814 transport_generic_free_cmd(&pending_req->se_cmd, 0); 815 break; 816 } 817 818 /* Yield point for this unbounded loop. */ 819 cond_resched(); 820 } 821 822 gnttab_page_cache_shrink(&info->free_pages, scsiback_max_buffer_pages); 823 824 RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do); 825 return more_to_do; 826 } 827 828 static irqreturn_t scsiback_irq_fn(int irq, void *dev_id) 829 { 830 struct vscsibk_info *info = dev_id; 831 int rc; 832 unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS; 833 834 while ((rc = scsiback_do_cmd_fn(info, &eoi_flags)) > 0) 835 cond_resched(); 836 837 /* In case of a ring error we keep the event channel masked. */ 838 if (!rc) 839 xen_irq_lateeoi(irq, eoi_flags); 840 841 return IRQ_HANDLED; 842 } 843 844 static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref, 845 evtchn_port_t evtchn) 846 { 847 void *area; 848 struct vscsiif_sring *sring; 849 int err; 850 851 if (info->irq) 852 return -1; 853 854 err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area); 855 if (err) 856 return err; 857 858 sring = (struct vscsiif_sring *)area; 859 BACK_RING_INIT(&info->ring, sring, PAGE_SIZE); 860 861 err = bind_interdomain_evtchn_to_irq_lateeoi(info->dev, evtchn); 862 if (err < 0) 863 goto unmap_page; 864 865 info->irq = err; 866 867 err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn, 868 IRQF_ONESHOT, "vscsiif-backend", info); 869 if (err) 870 goto free_irq; 871 872 return 0; 873 874 free_irq: 875 unbind_from_irqhandler(info->irq, info); 876 info->irq = 0; 877 unmap_page: 878 xenbus_unmap_ring_vfree(info->dev, area); 879 880 return err; 881 } 882 883 static int scsiback_map(struct vscsibk_info *info) 884 { 885 struct xenbus_device *dev = info->dev; 886 unsigned int ring_ref; 887 evtchn_port_t evtchn; 888 int err; 889 890 err = xenbus_gather(XBT_NIL, dev->otherend, 891 "ring-ref", "%u", &ring_ref, 892 "event-channel", "%u", &evtchn, NULL); 893 if (err) { 894 xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend); 895 return err; 896 } 897 898 return scsiback_init_sring(info, ring_ref, evtchn); 899 } 900 901 /* 902 Check for a translation entry being present 903 */ 904 static struct v2p_entry *scsiback_chk_translation_entry( 905 struct vscsibk_info *info, struct ids_tuple *v) 906 { 907 struct list_head *head = &(info->v2p_entry_lists); 908 struct v2p_entry *entry; 909 910 list_for_each_entry(entry, head, l) 911 if ((entry->v.chn == v->chn) && 912 (entry->v.tgt == v->tgt) && 913 (entry->v.lun == v->lun)) 914 return entry; 915 916 return NULL; 917 } 918 919 /* 920 Add a new translation entry 921 */ 922 static int scsiback_add_translation_entry(struct vscsibk_info *info, 923 char *phy, struct ids_tuple *v) 924 { 925 int err = 0; 926 struct v2p_entry *new; 927 unsigned long flags; 928 char *lunp; 929 unsigned long long unpacked_lun; 930 struct se_lun *se_lun; 931 struct scsiback_tpg *tpg_entry, *tpg = NULL; 932 char *error = "doesn't exist"; 933 934 lunp = strrchr(phy, ':'); 935 if (!lunp) { 936 pr_err("illegal format of physical device %s\n", phy); 937 return -EINVAL; 938 } 939 *lunp = 0; 940 lunp++; 941 err = kstrtoull(lunp, 10, &unpacked_lun); 942 if (err < 0) { 943 pr_err("lun number not valid: %s\n", lunp); 944 return err; 945 } 946 947 mutex_lock(&scsiback_mutex); 948 list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) { 949 if (!strcmp(phy, tpg_entry->tport->tport_name) || 950 !strcmp(phy, tpg_entry->param_alias)) { 951 mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex); 952 hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) { 953 if (se_lun->unpacked_lun == unpacked_lun) { 954 if (!tpg_entry->tpg_nexus) 955 error = "nexus undefined"; 956 else 957 tpg = tpg_entry; 958 break; 959 } 960 } 961 mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex); 962 break; 963 } 964 } 965 if (tpg) { 966 mutex_lock(&tpg->tv_tpg_mutex); 967 tpg->tv_tpg_fe_count++; 968 mutex_unlock(&tpg->tv_tpg_mutex); 969 } 970 mutex_unlock(&scsiback_mutex); 971 972 if (!tpg) { 973 pr_err("%s:%llu %s\n", phy, unpacked_lun, error); 974 return -ENODEV; 975 } 976 977 new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL); 978 if (new == NULL) { 979 err = -ENOMEM; 980 goto out_free; 981 } 982 983 spin_lock_irqsave(&info->v2p_lock, flags); 984 985 /* Check double assignment to identical virtual ID */ 986 if (scsiback_chk_translation_entry(info, v)) { 987 pr_warn("Virtual ID is already used. Assignment was not performed.\n"); 988 err = -EEXIST; 989 goto out; 990 } 991 992 /* Create a new translation entry and add to the list */ 993 kref_init(&new->kref); 994 new->v = *v; 995 new->tpg = tpg; 996 new->lun = unpacked_lun; 997 list_add_tail(&new->l, &info->v2p_entry_lists); 998 999 out: 1000 spin_unlock_irqrestore(&info->v2p_lock, flags); 1001 1002 out_free: 1003 if (err) { 1004 mutex_lock(&tpg->tv_tpg_mutex); 1005 tpg->tv_tpg_fe_count--; 1006 mutex_unlock(&tpg->tv_tpg_mutex); 1007 kfree(new); 1008 } 1009 1010 return err; 1011 } 1012 1013 /* 1014 Delete the translation entry specified 1015 */ 1016 static int scsiback_del_translation_entry(struct vscsibk_info *info, 1017 struct ids_tuple *v) 1018 { 1019 struct v2p_entry *entry; 1020 unsigned long flags; 1021 1022 spin_lock_irqsave(&info->v2p_lock, flags); 1023 /* Find out the translation entry specified */ 1024 entry = scsiback_chk_translation_entry(info, v); 1025 if (entry) 1026 list_del(&entry->l); 1027 1028 spin_unlock_irqrestore(&info->v2p_lock, flags); 1029 1030 if (!entry) 1031 return -ENOENT; 1032 1033 kref_put(&entry->kref, scsiback_free_translation_entry); 1034 return 0; 1035 } 1036 1037 static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state, 1038 char *phy, struct ids_tuple *vir, int try) 1039 { 1040 struct v2p_entry *entry; 1041 unsigned long flags; 1042 int err; 1043 1044 if (try) { 1045 spin_lock_irqsave(&info->v2p_lock, flags); 1046 entry = scsiback_chk_translation_entry(info, vir); 1047 spin_unlock_irqrestore(&info->v2p_lock, flags); 1048 if (entry) 1049 return; 1050 } 1051 if (!scsiback_add_translation_entry(info, phy, vir)) { 1052 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1053 "%d", XenbusStateInitialised)) { 1054 pr_err("xenbus_printf error %s\n", state); 1055 scsiback_del_translation_entry(info, vir); 1056 } 1057 } else if (!try) { 1058 err = xenbus_printf(XBT_NIL, info->dev->nodename, state, 1059 "%d", XenbusStateClosed); 1060 if (err) 1061 xenbus_dev_error(info->dev, err, 1062 "%s: writing %s", __func__, state); 1063 } 1064 } 1065 1066 static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state, 1067 struct ids_tuple *vir) 1068 { 1069 if (!scsiback_del_translation_entry(info, vir)) { 1070 if (xenbus_printf(XBT_NIL, info->dev->nodename, state, 1071 "%d", XenbusStateClosed)) 1072 pr_err("xenbus_printf error %s\n", state); 1073 } 1074 } 1075 1076 #define VSCSIBACK_OP_ADD_OR_DEL_LUN 1 1077 #define VSCSIBACK_OP_UPDATEDEV_STATE 2 1078 1079 static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op, 1080 char *ent) 1081 { 1082 int err; 1083 struct ids_tuple vir; 1084 char *val; 1085 int device_state; 1086 char phy[VSCSI_NAMELEN]; 1087 char str[64]; 1088 char state[64]; 1089 struct xenbus_device *dev = info->dev; 1090 1091 /* read status */ 1092 snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent); 1093 err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state); 1094 if (XENBUS_EXIST_ERR(err)) 1095 return; 1096 1097 /* physical SCSI device */ 1098 snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent); 1099 val = xenbus_read(XBT_NIL, dev->nodename, str, NULL); 1100 if (IS_ERR(val)) { 1101 err = xenbus_printf(XBT_NIL, dev->nodename, state, 1102 "%d", XenbusStateClosed); 1103 if (err) 1104 xenbus_dev_error(info->dev, err, 1105 "%s: writing %s", __func__, state); 1106 return; 1107 } 1108 strscpy(phy, val, VSCSI_NAMELEN); 1109 kfree(val); 1110 1111 /* virtual SCSI device */ 1112 snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent); 1113 err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u", 1114 &vir.hst, &vir.chn, &vir.tgt, &vir.lun); 1115 if (XENBUS_EXIST_ERR(err)) { 1116 err = xenbus_printf(XBT_NIL, dev->nodename, state, 1117 "%d", XenbusStateClosed); 1118 if (err) 1119 xenbus_dev_error(info->dev, err, 1120 "%s: writing %s", __func__, state); 1121 return; 1122 } 1123 1124 switch (op) { 1125 case VSCSIBACK_OP_ADD_OR_DEL_LUN: 1126 switch (device_state) { 1127 case XenbusStateInitialising: 1128 scsiback_do_add_lun(info, state, phy, &vir, 0); 1129 break; 1130 case XenbusStateConnected: 1131 scsiback_do_add_lun(info, state, phy, &vir, 1); 1132 break; 1133 case XenbusStateClosing: 1134 scsiback_do_del_lun(info, state, &vir); 1135 break; 1136 default: 1137 break; 1138 } 1139 break; 1140 1141 case VSCSIBACK_OP_UPDATEDEV_STATE: 1142 if (device_state == XenbusStateInitialised) { 1143 /* modify vscsi-devs/dev-x/state */ 1144 if (xenbus_printf(XBT_NIL, dev->nodename, state, 1145 "%d", XenbusStateConnected)) { 1146 pr_err("xenbus_printf error %s\n", str); 1147 scsiback_del_translation_entry(info, &vir); 1148 xenbus_printf(XBT_NIL, dev->nodename, state, 1149 "%d", XenbusStateClosed); 1150 } 1151 } 1152 break; 1153 /* When it is necessary, processing is added here. */ 1154 default: 1155 break; 1156 } 1157 } 1158 1159 static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op) 1160 { 1161 int i; 1162 char **dir; 1163 unsigned int ndir = 0; 1164 1165 dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs", 1166 &ndir); 1167 if (IS_ERR(dir)) 1168 return; 1169 1170 for (i = 0; i < ndir; i++) 1171 scsiback_do_1lun_hotplug(info, op, dir[i]); 1172 1173 kfree(dir); 1174 } 1175 1176 static void scsiback_frontend_changed(struct xenbus_device *dev, 1177 enum xenbus_state frontend_state) 1178 { 1179 struct vscsibk_info *info = dev_get_drvdata(&dev->dev); 1180 1181 switch (frontend_state) { 1182 case XenbusStateInitialising: 1183 break; 1184 1185 case XenbusStateInitialised: 1186 if (scsiback_map(info)) 1187 break; 1188 1189 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); 1190 xenbus_switch_state(dev, XenbusStateConnected); 1191 break; 1192 1193 case XenbusStateConnected: 1194 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE); 1195 1196 if (dev->state == XenbusStateConnected) 1197 break; 1198 1199 xenbus_switch_state(dev, XenbusStateConnected); 1200 break; 1201 1202 case XenbusStateClosing: 1203 if (info->irq) 1204 scsiback_disconnect(info); 1205 1206 xenbus_switch_state(dev, XenbusStateClosing); 1207 break; 1208 1209 case XenbusStateClosed: 1210 xenbus_switch_state(dev, XenbusStateClosed); 1211 if (xenbus_dev_is_online(dev)) 1212 break; 1213 fallthrough; /* if not online */ 1214 case XenbusStateUnknown: 1215 device_unregister(&dev->dev); 1216 break; 1217 1218 case XenbusStateReconfiguring: 1219 scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN); 1220 xenbus_switch_state(dev, XenbusStateReconfigured); 1221 1222 break; 1223 1224 default: 1225 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", 1226 frontend_state); 1227 break; 1228 } 1229 } 1230 1231 /* 1232 Release the translation entry specfied 1233 */ 1234 static void scsiback_release_translation_entry(struct vscsibk_info *info) 1235 { 1236 struct v2p_entry *entry, *tmp; 1237 struct list_head *head = &(info->v2p_entry_lists); 1238 struct list_head tmp_list; 1239 unsigned long flags; 1240 1241 spin_lock_irqsave(&info->v2p_lock, flags); 1242 1243 list_cut_before(&tmp_list, head, head); 1244 1245 spin_unlock_irqrestore(&info->v2p_lock, flags); 1246 1247 list_for_each_entry_safe(entry, tmp, &tmp_list, l) { 1248 list_del(&entry->l); 1249 kref_put(&entry->kref, scsiback_free_translation_entry); 1250 } 1251 } 1252 1253 static void scsiback_remove(struct xenbus_device *dev) 1254 { 1255 struct vscsibk_info *info = dev_get_drvdata(&dev->dev); 1256 1257 if (info->irq) 1258 scsiback_disconnect(info); 1259 1260 scsiback_release_translation_entry(info); 1261 1262 gnttab_page_cache_shrink(&info->free_pages, 0); 1263 1264 dev_set_drvdata(&dev->dev, NULL); 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(sizeof(struct vscsibk_info), 1273 GFP_KERNEL); 1274 1275 pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); 1276 1277 if (!info) { 1278 xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure"); 1279 return -ENOMEM; 1280 } 1281 info->dev = dev; 1282 dev_set_drvdata(&dev->dev, info); 1283 1284 info->domid = dev->otherend_id; 1285 spin_lock_init(&info->ring_lock); 1286 atomic_set(&info->nr_unreplied_reqs, 0); 1287 init_waitqueue_head(&info->waiting_to_free); 1288 info->dev = dev; 1289 info->irq = 0; 1290 INIT_LIST_HEAD(&info->v2p_entry_lists); 1291 spin_lock_init(&info->v2p_lock); 1292 gnttab_page_cache_init(&info->free_pages); 1293 1294 err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u", 1295 SG_ALL); 1296 if (err) 1297 xenbus_dev_error(dev, err, "writing feature-sg-grant"); 1298 1299 err = xenbus_switch_state(dev, XenbusStateInitWait); 1300 if (err) 1301 goto fail; 1302 1303 return 0; 1304 1305 fail: 1306 pr_warn("%s failed\n", __func__); 1307 scsiback_remove(dev); 1308 1309 return err; 1310 } 1311 1312 static char *scsiback_dump_proto_id(struct scsiback_tport *tport) 1313 { 1314 switch (tport->tport_proto_id) { 1315 case SCSI_PROTOCOL_SAS: 1316 return "SAS"; 1317 case SCSI_PROTOCOL_FCP: 1318 return "FCP"; 1319 case SCSI_PROTOCOL_ISCSI: 1320 return "iSCSI"; 1321 default: 1322 break; 1323 } 1324 1325 return "Unknown"; 1326 } 1327 1328 static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg) 1329 { 1330 struct scsiback_tpg *tpg = container_of(se_tpg, 1331 struct scsiback_tpg, se_tpg); 1332 struct scsiback_tport *tport = tpg->tport; 1333 1334 return &tport->tport_name[0]; 1335 } 1336 1337 static u16 scsiback_get_tag(struct se_portal_group *se_tpg) 1338 { 1339 struct scsiback_tpg *tpg = container_of(se_tpg, 1340 struct scsiback_tpg, se_tpg); 1341 return tpg->tport_tpgt; 1342 } 1343 1344 static struct se_wwn * 1345 scsiback_make_tport(struct target_fabric_configfs *tf, 1346 struct config_group *group, 1347 const char *name) 1348 { 1349 struct scsiback_tport *tport; 1350 char *ptr; 1351 u64 wwpn = 0; 1352 int off = 0; 1353 1354 tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL); 1355 if (!tport) 1356 return ERR_PTR(-ENOMEM); 1357 1358 tport->tport_wwpn = wwpn; 1359 /* 1360 * Determine the emulated Protocol Identifier and Target Port Name 1361 * based on the incoming configfs directory name. 1362 */ 1363 ptr = strstr(name, "naa."); 1364 if (ptr) { 1365 tport->tport_proto_id = SCSI_PROTOCOL_SAS; 1366 goto check_len; 1367 } 1368 ptr = strstr(name, "fc."); 1369 if (ptr) { 1370 tport->tport_proto_id = SCSI_PROTOCOL_FCP; 1371 off = 3; /* Skip over "fc." */ 1372 goto check_len; 1373 } 1374 ptr = strstr(name, "iqn."); 1375 if (ptr) { 1376 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI; 1377 goto check_len; 1378 } 1379 1380 pr_err("Unable to locate prefix for emulated Target Port: %s\n", name); 1381 kfree(tport); 1382 return ERR_PTR(-EINVAL); 1383 1384 check_len: 1385 if (strlen(name) >= VSCSI_NAMELEN) { 1386 pr_err("Emulated %s Address: %s, exceeds max: %d\n", name, 1387 scsiback_dump_proto_id(tport), VSCSI_NAMELEN); 1388 kfree(tport); 1389 return ERR_PTR(-EINVAL); 1390 } 1391 snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]); 1392 1393 pr_debug("Allocated emulated Target %s Address: %s\n", 1394 scsiback_dump_proto_id(tport), name); 1395 1396 return &tport->tport_wwn; 1397 } 1398 1399 static void scsiback_drop_tport(struct se_wwn *wwn) 1400 { 1401 struct scsiback_tport *tport = container_of(wwn, 1402 struct scsiback_tport, tport_wwn); 1403 1404 pr_debug("Deallocating emulated Target %s Address: %s\n", 1405 scsiback_dump_proto_id(tport), tport->tport_name); 1406 1407 kfree(tport); 1408 } 1409 1410 static int scsiback_check_stop_free(struct se_cmd *se_cmd) 1411 { 1412 return transport_generic_free_cmd(se_cmd, 0); 1413 } 1414 1415 static void scsiback_release_cmd(struct se_cmd *se_cmd) 1416 { 1417 target_free_tag(se_cmd->se_sess, se_cmd); 1418 } 1419 1420 static int scsiback_write_pending(struct se_cmd *se_cmd) 1421 { 1422 /* Go ahead and process the write immediately */ 1423 target_execute_cmd(se_cmd); 1424 1425 return 0; 1426 } 1427 1428 static int scsiback_queue_data_in(struct se_cmd *se_cmd) 1429 { 1430 struct vscsibk_pend *pending_req = container_of(se_cmd, 1431 struct vscsibk_pend, se_cmd); 1432 1433 pending_req->result = SAM_STAT_GOOD; 1434 scsiback_cmd_done(pending_req); 1435 return 0; 1436 } 1437 1438 static int scsiback_queue_status(struct se_cmd *se_cmd) 1439 { 1440 struct vscsibk_pend *pending_req = container_of(se_cmd, 1441 struct vscsibk_pend, se_cmd); 1442 1443 if (se_cmd->sense_buffer && 1444 ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) || 1445 (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) 1446 pending_req->result = SAM_STAT_CHECK_CONDITION; 1447 else 1448 pending_req->result = se_cmd->scsi_status; 1449 1450 scsiback_cmd_done(pending_req); 1451 return 0; 1452 } 1453 1454 static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd) 1455 { 1456 struct vscsibk_pend *pending_req = container_of(se_cmd, 1457 struct vscsibk_pend, se_cmd); 1458 1459 complete(&pending_req->tmr_done); 1460 } 1461 1462 static void scsiback_aborted_task(struct se_cmd *se_cmd) 1463 { 1464 } 1465 1466 static ssize_t scsiback_tpg_param_alias_show(struct config_item *item, 1467 char *page) 1468 { 1469 struct se_portal_group *se_tpg = param_to_tpg(item); 1470 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1471 se_tpg); 1472 ssize_t rb; 1473 1474 mutex_lock(&tpg->tv_tpg_mutex); 1475 rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias); 1476 mutex_unlock(&tpg->tv_tpg_mutex); 1477 1478 return rb; 1479 } 1480 1481 static ssize_t scsiback_tpg_param_alias_store(struct config_item *item, 1482 const char *page, size_t count) 1483 { 1484 struct se_portal_group *se_tpg = param_to_tpg(item); 1485 struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg, 1486 se_tpg); 1487 int len; 1488 1489 if (strlen(page) >= VSCSI_NAMELEN) { 1490 pr_err("param alias: %s, exceeds max: %d\n", page, 1491 VSCSI_NAMELEN); 1492 return -EINVAL; 1493 } 1494 1495 mutex_lock(&tpg->tv_tpg_mutex); 1496 len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page); 1497 if (tpg->param_alias[len - 1] == '\n') 1498 tpg->param_alias[len - 1] = '\0'; 1499 mutex_unlock(&tpg->tv_tpg_mutex); 1500 1501 return count; 1502 } 1503 1504 CONFIGFS_ATTR(scsiback_tpg_param_, alias); 1505 1506 static struct configfs_attribute *scsiback_param_attrs[] = { 1507 &scsiback_tpg_param_attr_alias, 1508 NULL, 1509 }; 1510 1511 static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg, 1512 struct se_session *se_sess, void *p) 1513 { 1514 struct scsiback_tpg *tpg = container_of(se_tpg, 1515 struct scsiback_tpg, se_tpg); 1516 1517 tpg->tpg_nexus = p; 1518 return 0; 1519 } 1520 1521 static int scsiback_make_nexus(struct scsiback_tpg *tpg, 1522 const char *name) 1523 { 1524 struct scsiback_nexus *tv_nexus; 1525 int ret = 0; 1526 1527 mutex_lock(&tpg->tv_tpg_mutex); 1528 if (tpg->tpg_nexus) { 1529 pr_debug("tpg->tpg_nexus already exists\n"); 1530 ret = -EEXIST; 1531 goto out_unlock; 1532 } 1533 1534 tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL); 1535 if (!tv_nexus) { 1536 ret = -ENOMEM; 1537 goto out_unlock; 1538 } 1539 1540 tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg, 1541 VSCSI_DEFAULT_SESSION_TAGS, 1542 sizeof(struct vscsibk_pend), 1543 TARGET_PROT_NORMAL, name, 1544 tv_nexus, scsiback_alloc_sess_cb); 1545 if (IS_ERR(tv_nexus->tvn_se_sess)) { 1546 kfree(tv_nexus); 1547 ret = -ENOMEM; 1548 goto out_unlock; 1549 } 1550 1551 out_unlock: 1552 mutex_unlock(&tpg->tv_tpg_mutex); 1553 return ret; 1554 } 1555 1556 static int scsiback_drop_nexus(struct scsiback_tpg *tpg) 1557 { 1558 struct se_session *se_sess; 1559 struct scsiback_nexus *tv_nexus; 1560 1561 mutex_lock(&tpg->tv_tpg_mutex); 1562 tv_nexus = tpg->tpg_nexus; 1563 if (!tv_nexus) { 1564 mutex_unlock(&tpg->tv_tpg_mutex); 1565 return -ENODEV; 1566 } 1567 1568 se_sess = tv_nexus->tvn_se_sess; 1569 if (!se_sess) { 1570 mutex_unlock(&tpg->tv_tpg_mutex); 1571 return -ENODEV; 1572 } 1573 1574 if (tpg->tv_tpg_port_count != 0) { 1575 mutex_unlock(&tpg->tv_tpg_mutex); 1576 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n", 1577 tpg->tv_tpg_port_count); 1578 return -EBUSY; 1579 } 1580 1581 if (tpg->tv_tpg_fe_count != 0) { 1582 mutex_unlock(&tpg->tv_tpg_mutex); 1583 pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n", 1584 tpg->tv_tpg_fe_count); 1585 return -EBUSY; 1586 } 1587 1588 pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n", 1589 scsiback_dump_proto_id(tpg->tport), 1590 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1591 1592 /* 1593 * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port 1594 */ 1595 target_remove_session(se_sess); 1596 tpg->tpg_nexus = NULL; 1597 mutex_unlock(&tpg->tv_tpg_mutex); 1598 1599 kfree(tv_nexus); 1600 return 0; 1601 } 1602 1603 static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page) 1604 { 1605 struct se_portal_group *se_tpg = to_tpg(item); 1606 struct scsiback_tpg *tpg = container_of(se_tpg, 1607 struct scsiback_tpg, se_tpg); 1608 struct scsiback_nexus *tv_nexus; 1609 ssize_t ret; 1610 1611 mutex_lock(&tpg->tv_tpg_mutex); 1612 tv_nexus = tpg->tpg_nexus; 1613 if (!tv_nexus) { 1614 mutex_unlock(&tpg->tv_tpg_mutex); 1615 return -ENODEV; 1616 } 1617 ret = snprintf(page, PAGE_SIZE, "%s\n", 1618 tv_nexus->tvn_se_sess->se_node_acl->initiatorname); 1619 mutex_unlock(&tpg->tv_tpg_mutex); 1620 1621 return ret; 1622 } 1623 1624 static ssize_t scsiback_tpg_nexus_store(struct config_item *item, 1625 const char *page, size_t count) 1626 { 1627 struct se_portal_group *se_tpg = to_tpg(item); 1628 struct scsiback_tpg *tpg = container_of(se_tpg, 1629 struct scsiback_tpg, se_tpg); 1630 struct scsiback_tport *tport_wwn = tpg->tport; 1631 unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr; 1632 int ret; 1633 /* 1634 * Shutdown the active I_T nexus if 'NULL' is passed. 1635 */ 1636 if (!strncmp(page, "NULL", 4)) { 1637 ret = scsiback_drop_nexus(tpg); 1638 return (!ret) ? count : ret; 1639 } 1640 /* 1641 * Otherwise make sure the passed virtual Initiator port WWN matches 1642 * the fabric protocol_id set in scsiback_make_tport(), and call 1643 * scsiback_make_nexus(). 1644 */ 1645 if (strlen(page) >= VSCSI_NAMELEN) { 1646 pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n", 1647 page, VSCSI_NAMELEN); 1648 return -EINVAL; 1649 } 1650 snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page); 1651 1652 ptr = strstr(i_port, "naa."); 1653 if (ptr) { 1654 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) { 1655 pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n", 1656 i_port, scsiback_dump_proto_id(tport_wwn)); 1657 return -EINVAL; 1658 } 1659 port_ptr = &i_port[0]; 1660 goto check_newline; 1661 } 1662 ptr = strstr(i_port, "fc."); 1663 if (ptr) { 1664 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) { 1665 pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n", 1666 i_port, scsiback_dump_proto_id(tport_wwn)); 1667 return -EINVAL; 1668 } 1669 port_ptr = &i_port[3]; /* Skip over "fc." */ 1670 goto check_newline; 1671 } 1672 ptr = strstr(i_port, "iqn."); 1673 if (ptr) { 1674 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) { 1675 pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n", 1676 i_port, scsiback_dump_proto_id(tport_wwn)); 1677 return -EINVAL; 1678 } 1679 port_ptr = &i_port[0]; 1680 goto check_newline; 1681 } 1682 pr_err("Unable to locate prefix for emulated Initiator Port: %s\n", 1683 i_port); 1684 return -EINVAL; 1685 /* 1686 * Clear any trailing newline for the NAA WWN 1687 */ 1688 check_newline: 1689 if (i_port[strlen(i_port) - 1] == '\n') 1690 i_port[strlen(i_port) - 1] = '\0'; 1691 1692 ret = scsiback_make_nexus(tpg, port_ptr); 1693 if (ret < 0) 1694 return ret; 1695 1696 return count; 1697 } 1698 1699 CONFIGFS_ATTR(scsiback_tpg_, nexus); 1700 1701 static struct configfs_attribute *scsiback_tpg_attrs[] = { 1702 &scsiback_tpg_attr_nexus, 1703 NULL, 1704 }; 1705 1706 static ssize_t 1707 scsiback_wwn_version_show(struct config_item *item, char *page) 1708 { 1709 return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on " 1710 UTS_RELEASE"\n", 1711 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1712 } 1713 1714 CONFIGFS_ATTR_RO(scsiback_wwn_, version); 1715 1716 static struct configfs_attribute *scsiback_wwn_attrs[] = { 1717 &scsiback_wwn_attr_version, 1718 NULL, 1719 }; 1720 1721 static int scsiback_port_link(struct se_portal_group *se_tpg, 1722 struct se_lun *lun) 1723 { 1724 struct scsiback_tpg *tpg = container_of(se_tpg, 1725 struct scsiback_tpg, se_tpg); 1726 1727 mutex_lock(&tpg->tv_tpg_mutex); 1728 tpg->tv_tpg_port_count++; 1729 mutex_unlock(&tpg->tv_tpg_mutex); 1730 1731 return 0; 1732 } 1733 1734 static void scsiback_port_unlink(struct se_portal_group *se_tpg, 1735 struct se_lun *lun) 1736 { 1737 struct scsiback_tpg *tpg = container_of(se_tpg, 1738 struct scsiback_tpg, se_tpg); 1739 1740 mutex_lock(&tpg->tv_tpg_mutex); 1741 tpg->tv_tpg_port_count--; 1742 mutex_unlock(&tpg->tv_tpg_mutex); 1743 } 1744 1745 static struct se_portal_group * 1746 scsiback_make_tpg(struct se_wwn *wwn, const char *name) 1747 { 1748 struct scsiback_tport *tport = container_of(wwn, 1749 struct scsiback_tport, tport_wwn); 1750 1751 struct scsiback_tpg *tpg; 1752 u16 tpgt; 1753 int ret; 1754 1755 if (strstr(name, "tpgt_") != name) 1756 return ERR_PTR(-EINVAL); 1757 ret = kstrtou16(name + 5, 10, &tpgt); 1758 if (ret) 1759 return ERR_PTR(ret); 1760 1761 tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL); 1762 if (!tpg) 1763 return ERR_PTR(-ENOMEM); 1764 1765 mutex_init(&tpg->tv_tpg_mutex); 1766 INIT_LIST_HEAD(&tpg->tv_tpg_list); 1767 INIT_LIST_HEAD(&tpg->info_list); 1768 tpg->tport = tport; 1769 tpg->tport_tpgt = tpgt; 1770 1771 ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id); 1772 if (ret < 0) { 1773 kfree(tpg); 1774 return NULL; 1775 } 1776 mutex_lock(&scsiback_mutex); 1777 list_add_tail(&tpg->tv_tpg_list, &scsiback_list); 1778 mutex_unlock(&scsiback_mutex); 1779 1780 return &tpg->se_tpg; 1781 } 1782 1783 static void scsiback_drop_tpg(struct se_portal_group *se_tpg) 1784 { 1785 struct scsiback_tpg *tpg = container_of(se_tpg, 1786 struct scsiback_tpg, se_tpg); 1787 1788 mutex_lock(&scsiback_mutex); 1789 list_del(&tpg->tv_tpg_list); 1790 mutex_unlock(&scsiback_mutex); 1791 /* 1792 * Release the virtual I_T Nexus for this xen-pvscsi TPG 1793 */ 1794 scsiback_drop_nexus(tpg); 1795 /* 1796 * Deregister the se_tpg from TCM. 1797 */ 1798 core_tpg_deregister(se_tpg); 1799 kfree(tpg); 1800 } 1801 1802 static int scsiback_check_true(struct se_portal_group *se_tpg) 1803 { 1804 return 1; 1805 } 1806 1807 static const struct target_core_fabric_ops scsiback_ops = { 1808 .module = THIS_MODULE, 1809 .fabric_name = "xen-pvscsi", 1810 .tpg_get_wwn = scsiback_get_fabric_wwn, 1811 .tpg_get_tag = scsiback_get_tag, 1812 .tpg_check_demo_mode = scsiback_check_true, 1813 .tpg_check_demo_mode_cache = scsiback_check_true, 1814 .check_stop_free = scsiback_check_stop_free, 1815 .release_cmd = scsiback_release_cmd, 1816 .sess_get_initiator_sid = NULL, 1817 .write_pending = scsiback_write_pending, 1818 .queue_data_in = scsiback_queue_data_in, 1819 .queue_status = scsiback_queue_status, 1820 .queue_tm_rsp = scsiback_queue_tm_rsp, 1821 .aborted_task = scsiback_aborted_task, 1822 /* 1823 * Setup callers for generic logic in target_core_fabric_configfs.c 1824 */ 1825 .fabric_make_wwn = scsiback_make_tport, 1826 .fabric_drop_wwn = scsiback_drop_tport, 1827 .fabric_make_tpg = scsiback_make_tpg, 1828 .fabric_drop_tpg = scsiback_drop_tpg, 1829 .fabric_post_link = scsiback_port_link, 1830 .fabric_pre_unlink = scsiback_port_unlink, 1831 1832 .tfc_wwn_attrs = scsiback_wwn_attrs, 1833 .tfc_tpg_base_attrs = scsiback_tpg_attrs, 1834 .tfc_tpg_param_attrs = scsiback_param_attrs, 1835 1836 .default_submit_type = TARGET_DIRECT_SUBMIT, 1837 .direct_submit_supp = 1, 1838 }; 1839 1840 static const struct xenbus_device_id scsiback_ids[] = { 1841 { "vscsi" }, 1842 { "" } 1843 }; 1844 1845 static struct xenbus_driver scsiback_driver = { 1846 .ids = scsiback_ids, 1847 .probe = scsiback_probe, 1848 .remove = scsiback_remove, 1849 .otherend_changed = scsiback_frontend_changed 1850 }; 1851 1852 static int __init scsiback_init(void) 1853 { 1854 int ret; 1855 1856 if (!xen_domain()) 1857 return -ENODEV; 1858 1859 pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n", 1860 VSCSI_VERSION, utsname()->sysname, utsname()->machine); 1861 1862 ret = xenbus_register_backend(&scsiback_driver); 1863 if (ret) 1864 goto out; 1865 1866 ret = target_register_template(&scsiback_ops); 1867 if (ret) 1868 goto out_unregister_xenbus; 1869 1870 return 0; 1871 1872 out_unregister_xenbus: 1873 xenbus_unregister_driver(&scsiback_driver); 1874 out: 1875 pr_err("%s: error %d\n", __func__, ret); 1876 return ret; 1877 } 1878 1879 static void __exit scsiback_exit(void) 1880 { 1881 target_unregister_template(&scsiback_ops); 1882 xenbus_unregister_driver(&scsiback_driver); 1883 } 1884 1885 module_init(scsiback_init); 1886 module_exit(scsiback_exit); 1887 1888 MODULE_DESCRIPTION("Xen SCSI backend driver"); 1889 MODULE_LICENSE("Dual BSD/GPL"); 1890 MODULE_ALIAS("xen-backend:vscsi"); 1891 MODULE_AUTHOR("Juergen Gross <jgross@suse.com>"); 1892