drivers/vhost/scsi.c

   1 /*******************************************************************************
   2  * Vhost kernel TCM fabric driver for virtio SCSI initiators
   3  *
   4  * (C) Copyright 2010-2013 Datera, Inc.
   5  * (C) Copyright 2010-2012 IBM Corp.
   6  *
   7  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
   8  *
   9  * Authors: Nicholas A. Bellinger <nab@daterainc.com>
  10  *          Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  ****************************************************************************/
  23
  24 #include <linux/module.h>
  25 #include <linux/moduleparam.h>
  26 #include <generated/utsrelease.h>
  27 #include <linux/utsname.h>
  28 #include <linux/init.h>
  29 #include <linux/slab.h>
  30 #include <linux/kthread.h>
  31 #include <linux/types.h>
  32 #include <linux/string.h>
  33 #include <linux/configfs.h>
  34 #include <linux/ctype.h>
  35 #include <linux/compat.h>
  36 #include <linux/eventfd.h>
  37 #include <linux/fs.h>
  38 #include <linux/miscdevice.h>
  39 #include <asm/unaligned.h>
  40 #include <scsi/scsi.h>
  41 #include <target/target_core_base.h>
  42 #include <target/target_core_fabric.h>
  43 #include <target/target_core_fabric_configfs.h>
  44 #include <target/target_core_configfs.h>
  45 #include <target/configfs_macros.h>
  46 #include <linux/vhost.h>
  47 #include <linux/virtio_scsi.h>
  48 #include <linux/llist.h>
  49 #include <linux/bitmap.h>
  50 #include <linux/percpu_ida.h>
  51
  52 #include "vhost.h"
  53
  54 #define VHOST_SCSI_VERSION  "v0.1"
  55 #define VHOST_SCSI_NAMELEN 256
  56 #define VHOST_SCSI_MAX_CDB_SIZE 32
  57 #define VHOST_SCSI_DEFAULT_TAGS 256
  58 #define VHOST_SCSI_PREALLOC_SGLS 2048
  59 #define VHOST_SCSI_PREALLOC_UPAGES 2048
  60 #define VHOST_SCSI_PREALLOC_PROT_SGLS 512
  61
  62 struct vhost_scsi_inflight {
  63         /* Wait for the flush operation to finish */
  64         struct completion comp;
  65         /* Refcount for the inflight reqs */
  66         struct kref kref;
  67 };
  68
  69 struct vhost_scsi_cmd {
  70         /* Descriptor from vhost_get_vq_desc() for virt_queue segment */
  71         int tvc_vq_desc;
  72         /* virtio-scsi initiator task attribute */
  73         int tvc_task_attr;
  74         /* virtio-scsi response incoming iovecs */
  75         int tvc_in_iovs;
  76         /* virtio-scsi initiator data direction */
  77         enum dma_data_direction tvc_data_direction;
  78         /* Expected data transfer length from virtio-scsi header */
  79         u32 tvc_exp_data_len;
  80         /* The Tag from include/linux/virtio_scsi.h:struct virtio_scsi_cmd_req */
  81         u64 tvc_tag;
  82         /* The number of scatterlists associated with this cmd */
  83         u32 tvc_sgl_count;
  84         u32 tvc_prot_sgl_count;
  85         /* Saved unpacked SCSI LUN for vhost_scsi_submission_work() */
  86         u32 tvc_lun;
  87         /* Pointer to the SGL formatted memory from virtio-scsi */
  88         struct scatterlist *tvc_sgl;
  89         struct scatterlist *tvc_prot_sgl;
  90         struct page **tvc_upages;
  91         /* Pointer to response header iovec */
  92         struct iovec *tvc_resp_iov;
  93         /* Pointer to vhost_scsi for our device */
  94         struct vhost_scsi *tvc_vhost;
  95         /* Pointer to vhost_virtqueue for the cmd */
  96         struct vhost_virtqueue *tvc_vq;
  97         /* Pointer to vhost nexus memory */
  98         struct vhost_scsi_nexus *tvc_nexus;
  99         /* The TCM I/O descriptor that is accessed via container_of() */
 100         struct se_cmd tvc_se_cmd;
 101         /* work item used for cmwq dispatch to vhost_scsi_submission_work() */
 102         struct work_struct work;
 103         /* Copy of the incoming SCSI command descriptor block (CDB) */
 104         unsigned char tvc_cdb[VHOST_SCSI_MAX_CDB_SIZE];
 105         /* Sense buffer that will be mapped into outgoing status */
 106         unsigned char tvc_sense_buf[TRANSPORT_SENSE_BUFFER];
 107         /* Completed commands list, serviced from vhost worker thread */
 108         struct llist_node tvc_completion_list;
 109         /* Used to track inflight cmd */
 110         struct vhost_scsi_inflight *inflight;
 111 };
 112
 113 struct vhost_scsi_nexus {
 114         /* Pointer to TCM session for I_T Nexus */
 115         struct se_session *tvn_se_sess;
 116 };
 117
 118 struct vhost_scsi_tpg {
 119         /* Vhost port target portal group tag for TCM */
 120         u16 tport_tpgt;
 121         /* Used to track number of TPG Port/Lun Links wrt to explict I_T Nexus shutdown */
 122         int tv_tpg_port_count;
 123         /* Used for vhost_scsi device reference to tpg_nexus, protected by tv_tpg_mutex */
 124         int tv_tpg_vhost_count;
 125         /* Used for enabling T10-PI with legacy devices */
 126         int tv_fabric_prot_type;
 127         /* list for vhost_scsi_list */
 128         struct list_head tv_tpg_list;
 129         /* Used to protect access for tpg_nexus */
 130         struct mutex tv_tpg_mutex;
 131         /* Pointer to the TCM VHost I_T Nexus for this TPG endpoint */
 132         struct vhost_scsi_nexus *tpg_nexus;
 133         /* Pointer back to vhost_scsi_tport */
 134         struct vhost_scsi_tport *tport;
 135         /* Returned by vhost_scsi_make_tpg() */
 136         struct se_portal_group se_tpg;
 137         /* Pointer back to vhost_scsi, protected by tv_tpg_mutex */
 138         struct vhost_scsi *vhost_scsi;
 139 };
 140
 141 struct vhost_scsi_tport {
 142         /* SCSI protocol the tport is providing */
 143         u8 tport_proto_id;
 144         /* Binary World Wide unique Port Name for Vhost Target port */
 145         u64 tport_wwpn;
 146         /* ASCII formatted WWPN for Vhost Target port */
 147         char tport_name[VHOST_SCSI_NAMELEN];
 148         /* Returned by vhost_scsi_make_tport() */
 149         struct se_wwn tport_wwn;
 150 };
 151
 152 struct vhost_scsi_evt {
 153         /* event to be sent to guest */
 154         struct virtio_scsi_event event;
 155         /* event list, serviced from vhost worker thread */
 156         struct llist_node list;
 157 };
 158
 159 enum {
 160         VHOST_SCSI_VQ_CTL = 0,
 161         VHOST_SCSI_VQ_EVT = 1,
 162         VHOST_SCSI_VQ_IO = 2,
 163 };
 164
 165 /* Note: can't set VIRTIO_F_VERSION_1 yet, since that implies ANY_LAYOUT. */
 166 enum {
 167         VHOST_SCSI_FEATURES = VHOST_FEATURES | (1ULL << VIRTIO_SCSI_F_HOTPLUG) |
 168                                                (1ULL << VIRTIO_SCSI_F_T10_PI) |
 169                                                (1ULL << VIRTIO_F_ANY_LAYOUT) |
 170                                                (1ULL << VIRTIO_F_VERSION_1)
 171 };
 172
 173 #define VHOST_SCSI_MAX_TARGET   256
 174 #define VHOST_SCSI_MAX_VQ       128
 175 #define VHOST_SCSI_MAX_EVENT    128
 176
 177 struct vhost_scsi_virtqueue {
 178         struct vhost_virtqueue vq;
 179         /*
 180          * Reference counting for inflight reqs, used for flush operation. At
 181          * each time, one reference tracks new commands submitted, while we
 182          * wait for another one to reach 0.
 183          */
 184         struct vhost_scsi_inflight inflights[2];
 185         /*
 186          * Indicate current inflight in use, protected by vq->mutex.
 187          * Writers must also take dev mutex and flush under it.
 188          */
 189         int inflight_idx;
 190 };
 191
 192 struct vhost_scsi {
 193         /* Protected by vhost_scsi->dev.mutex */
 194         struct vhost_scsi_tpg **vs_tpg;
 195         char vs_vhost_wwpn[TRANSPORT_IQN_LEN];
 196
 197         struct vhost_dev dev;
 198         struct vhost_scsi_virtqueue vqs[VHOST_SCSI_MAX_VQ];
 199
 200         struct vhost_work vs_completion_work; /* cmd completion work item */
 201         struct llist_head vs_completion_list; /* cmd completion queue */
 202
 203         struct vhost_work vs_event_work; /* evt injection work item */
 204         struct llist_head vs_event_list; /* evt injection queue */
 205
 206         bool vs_events_missed; /* any missed events, protected by vq->mutex */
 207         int vs_events_nr; /* num of pending events, protected by vq->mutex */
 208 };
 209
 210 static struct target_core_fabric_ops vhost_scsi_ops;
 211 static struct workqueue_struct *vhost_scsi_workqueue;
 212
 213 /* Global spinlock to protect vhost_scsi TPG list for vhost IOCTL access */
 214 static DEFINE_MUTEX(vhost_scsi_mutex);
 215 static LIST_HEAD(vhost_scsi_list);
 216
 217 static int iov_num_pages(void __user *iov_base, size_t iov_len)
 218 {
 219         return (PAGE_ALIGN((unsigned long)iov_base + iov_len) -
 220                ((unsigned long)iov_base & PAGE_MASK)) >> PAGE_SHIFT;
 221 }
 222
 223 static void vhost_scsi_done_inflight(struct kref *kref)
 224 {
 225         struct vhost_scsi_inflight *inflight;
 226
 227         inflight = container_of(kref, struct vhost_scsi_inflight, kref);
 228         complete(&inflight->comp);
 229 }
 230
 231 static void vhost_scsi_init_inflight(struct vhost_scsi *vs,
 232                                     struct vhost_scsi_inflight *old_inflight[])
 233 {
 234         struct vhost_scsi_inflight *new_inflight;
 235         struct vhost_virtqueue *vq;
 236         int idx, i;
 237
 238         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
 239                 vq = &vs->vqs[i].vq;
 240
 241                 mutex_lock(&vq->mutex);
 242
 243                 /* store old infight */
 244                 idx = vs->vqs[i].inflight_idx;
 245                 if (old_inflight)
 246                         old_inflight[i] = &vs->vqs[i].inflights[idx];
 247
 248                 /* setup new infight */
 249                 vs->vqs[i].inflight_idx = idx ^ 1;
 250                 new_inflight = &vs->vqs[i].inflights[idx ^ 1];
 251                 kref_init(&new_inflight->kref);
 252                 init_completion(&new_inflight->comp);
 253
 254                 mutex_unlock(&vq->mutex);
 255         }
 256 }
 257
 258 static struct vhost_scsi_inflight *
 259 vhost_scsi_get_inflight(struct vhost_virtqueue *vq)
 260 {
 261         struct vhost_scsi_inflight *inflight;
 262         struct vhost_scsi_virtqueue *svq;
 263
 264         svq = container_of(vq, struct vhost_scsi_virtqueue, vq);
 265         inflight = &svq->inflights[svq->inflight_idx];
 266         kref_get(&inflight->kref);
 267
 268         return inflight;
 269 }
 270
 271 static void vhost_scsi_put_inflight(struct vhost_scsi_inflight *inflight)
 272 {
 273         kref_put(&inflight->kref, vhost_scsi_done_inflight);
 274 }
 275
 276 static int vhost_scsi_check_true(struct se_portal_group *se_tpg)
 277 {
 278         return 1;
 279 }
 280
 281 static int vhost_scsi_check_false(struct se_portal_group *se_tpg)
 282 {
 283         return 0;
 284 }
 285
 286 static char *vhost_scsi_get_fabric_name(void)
 287 {
 288         return "vhost";
 289 }
 290
 291 static u8 vhost_scsi_get_fabric_proto_ident(struct se_portal_group *se_tpg)
 292 {
 293         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
 294                                 struct vhost_scsi_tpg, se_tpg);
 295         struct vhost_scsi_tport *tport = tpg->tport;
 296
 297         switch (tport->tport_proto_id) {
 298         case SCSI_PROTOCOL_SAS:
 299                 return sas_get_fabric_proto_ident(se_tpg);
 300         case SCSI_PROTOCOL_FCP:
 301                 return fc_get_fabric_proto_ident(se_tpg);
 302         case SCSI_PROTOCOL_ISCSI:
 303                 return iscsi_get_fabric_proto_ident(se_tpg);
 304         default:
 305                 pr_err("Unknown tport_proto_id: 0x%02x, using"
 306                         " SAS emulation\n", tport->tport_proto_id);
 307                 break;
 308         }
 309
 310         return sas_get_fabric_proto_ident(se_tpg);
 311 }
 312
 313 static char *vhost_scsi_get_fabric_wwn(struct se_portal_group *se_tpg)
 314 {
 315         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
 316                                 struct vhost_scsi_tpg, se_tpg);
 317         struct vhost_scsi_tport *tport = tpg->tport;
 318
 319         return &tport->tport_name[0];
 320 }
 321
 322 static u16 vhost_scsi_get_tpgt(struct se_portal_group *se_tpg)
 323 {
 324         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
 325                                 struct vhost_scsi_tpg, se_tpg);
 326         return tpg->tport_tpgt;
 327 }
 328
 329 static u32
 330 vhost_scsi_get_pr_transport_id(struct se_portal_group *se_tpg,
 331                               struct se_node_acl *se_nacl,
 332                               struct t10_pr_registration *pr_reg,
 333                               int *format_code,
 334                               unsigned char *buf)
 335 {
 336         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
 337                                 struct vhost_scsi_tpg, se_tpg);
 338         struct vhost_scsi_tport *tport = tpg->tport;
 339
 340         switch (tport->tport_proto_id) {
 341         case SCSI_PROTOCOL_SAS:
 342                 return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 343                                         format_code, buf);
 344         case SCSI_PROTOCOL_FCP:
 345                 return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 346                                         format_code, buf);
 347         case SCSI_PROTOCOL_ISCSI:
 348                 return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 349                                         format_code, buf);
 350         default:
 351                 pr_err("Unknown tport_proto_id: 0x%02x, using"
 352                         " SAS emulation\n", tport->tport_proto_id);
 353                 break;
 354         }
 355
 356         return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 357                         format_code, buf);
 358 }
 359
 360 static u32
 361 vhost_scsi_get_pr_transport_id_len(struct se_portal_group *se_tpg,
 362                                   struct se_node_acl *se_nacl,
 363                                   struct t10_pr_registration *pr_reg,
 364                                   int *format_code)
 365 {
 366         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
 367                                 struct vhost_scsi_tpg, se_tpg);
 368         struct vhost_scsi_tport *tport = tpg->tport;
 369
 370         switch (tport->tport_proto_id) {
 371         case SCSI_PROTOCOL_SAS:
 372                 return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 373                                         format_code);
 374         case SCSI_PROTOCOL_FCP:
 375                 return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 376                                         format_code);
 377         case SCSI_PROTOCOL_ISCSI:
 378                 return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 379                                         format_code);
 380         default:
 381                 pr_err("Unknown tport_proto_id: 0x%02x, using"
 382                         " SAS emulation\n", tport->tport_proto_id);
 383                 break;
 384         }
 385
 386         return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 387                         format_code);
 388 }
 389
 390 static char *
 391 vhost_scsi_parse_pr_out_transport_id(struct se_portal_group *se_tpg,
 392                                     const char *buf,
 393                                     u32 *out_tid_len,
 394                                     char **port_nexus_ptr)
 395 {
 396         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
 397                                 struct vhost_scsi_tpg, se_tpg);
 398         struct vhost_scsi_tport *tport = tpg->tport;
 399
 400         switch (tport->tport_proto_id) {
 401         case SCSI_PROTOCOL_SAS:
 402                 return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 403                                         port_nexus_ptr);
 404         case SCSI_PROTOCOL_FCP:
 405                 return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 406                                         port_nexus_ptr);
 407         case SCSI_PROTOCOL_ISCSI:
 408                 return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 409                                         port_nexus_ptr);
 410         default:
 411                 pr_err("Unknown tport_proto_id: 0x%02x, using"
 412                         " SAS emulation\n", tport->tport_proto_id);
 413                 break;
 414         }
 415
 416         return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 417                         port_nexus_ptr);
 418 }
 419
 420 static int vhost_scsi_check_prot_fabric_only(struct se_portal_group *se_tpg)
 421 {
 422         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
 423                                 struct vhost_scsi_tpg, se_tpg);
 424
 425         return tpg->tv_fabric_prot_type;
 426 }
 427
 428 static u32 vhost_scsi_tpg_get_inst_index(struct se_portal_group *se_tpg)
 429 {
 430         return 1;
 431 }
 432
 433 static void vhost_scsi_release_cmd(struct se_cmd *se_cmd)
 434 {
 435         struct vhost_scsi_cmd *tv_cmd = container_of(se_cmd,
 436                                 struct vhost_scsi_cmd, tvc_se_cmd);
 437         struct se_session *se_sess = tv_cmd->tvc_nexus->tvn_se_sess;
 438         int i;
 439
 440         if (tv_cmd->tvc_sgl_count) {
 441                 for (i = 0; i < tv_cmd->tvc_sgl_count; i++)
 442                         put_page(sg_page(&tv_cmd->tvc_sgl[i]));
 443         }
 444         if (tv_cmd->tvc_prot_sgl_count) {
 445                 for (i = 0; i < tv_cmd->tvc_prot_sgl_count; i++)
 446                         put_page(sg_page(&tv_cmd->tvc_prot_sgl[i]));
 447         }
 448
 449         vhost_scsi_put_inflight(tv_cmd->inflight);
 450         percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag);
 451 }
 452
 453 static int vhost_scsi_shutdown_session(struct se_session *se_sess)
 454 {
 455         return 0;
 456 }
 457
 458 static void vhost_scsi_close_session(struct se_session *se_sess)
 459 {
 460         return;
 461 }
 462
 463 static u32 vhost_scsi_sess_get_index(struct se_session *se_sess)
 464 {
 465         return 0;
 466 }
 467
 468 static int vhost_scsi_write_pending(struct se_cmd *se_cmd)
 469 {
 470         /* Go ahead and process the write immediately */
 471         target_execute_cmd(se_cmd);
 472         return 0;
 473 }
 474
 475 static int vhost_scsi_write_pending_status(struct se_cmd *se_cmd)
 476 {
 477         return 0;
 478 }
 479
 480 static void vhost_scsi_set_default_node_attrs(struct se_node_acl *nacl)
 481 {
 482         return;
 483 }
 484
 485 static u32 vhost_scsi_get_task_tag(struct se_cmd *se_cmd)
 486 {
 487         return 0;
 488 }
 489
 490 static int vhost_scsi_get_cmd_state(struct se_cmd *se_cmd)
 491 {
 492         return 0;
 493 }
 494
 495 static void vhost_scsi_complete_cmd(struct vhost_scsi_cmd *cmd)
 496 {
 497         struct vhost_scsi *vs = cmd->tvc_vhost;
 498
 499         llist_add(&cmd->tvc_completion_list, &vs->vs_completion_list);
 500
 501         vhost_work_queue(&vs->dev, &vs->vs_completion_work);
 502 }
 503
 504 static int vhost_scsi_queue_data_in(struct se_cmd *se_cmd)
 505 {
 506         struct vhost_scsi_cmd *cmd = container_of(se_cmd,
 507                                 struct vhost_scsi_cmd, tvc_se_cmd);
 508         vhost_scsi_complete_cmd(cmd);
 509         return 0;
 510 }
 511
 512 static int vhost_scsi_queue_status(struct se_cmd *se_cmd)
 513 {
 514         struct vhost_scsi_cmd *cmd = container_of(se_cmd,
 515                                 struct vhost_scsi_cmd, tvc_se_cmd);
 516         vhost_scsi_complete_cmd(cmd);
 517         return 0;
 518 }
 519
 520 static void vhost_scsi_queue_tm_rsp(struct se_cmd *se_cmd)
 521 {
 522         return;
 523 }
 524
 525 static void vhost_scsi_aborted_task(struct se_cmd *se_cmd)
 526 {
 527         return;
 528 }
 529
 530 static void vhost_scsi_free_evt(struct vhost_scsi *vs, struct vhost_scsi_evt *evt)
 531 {
 532         vs->vs_events_nr--;
 533         kfree(evt);
 534 }
 535
 536 static struct vhost_scsi_evt *
 537 vhost_scsi_allocate_evt(struct vhost_scsi *vs,
 538                        u32 event, u32 reason)
 539 {
 540         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 541         struct vhost_scsi_evt *evt;
 542
 543         if (vs->vs_events_nr > VHOST_SCSI_MAX_EVENT) {
 544                 vs->vs_events_missed = true;
 545                 return NULL;
 546         }
 547
 548         evt = kzalloc(sizeof(*evt), GFP_KERNEL);
 549         if (!evt) {
 550                 vq_err(vq, "Failed to allocate vhost_scsi_evt\n");
 551                 vs->vs_events_missed = true;
 552                 return NULL;
 553         }
 554
 555         evt->event.event = cpu_to_vhost32(vq, event);
 556         evt->event.reason = cpu_to_vhost32(vq, reason);
 557         vs->vs_events_nr++;
 558
 559         return evt;
 560 }
 561
 562 static void vhost_scsi_free_cmd(struct vhost_scsi_cmd *cmd)
 563 {
 564         struct se_cmd *se_cmd = &cmd->tvc_se_cmd;
 565
 566         /* TODO locking against target/backend threads? */
 567         transport_generic_free_cmd(se_cmd, 0);
 568
 569 }
 570
 571 static int vhost_scsi_check_stop_free(struct se_cmd *se_cmd)
 572 {
 573         return target_put_sess_cmd(se_cmd);
 574 }
 575
 576 static void
 577 vhost_scsi_do_evt_work(struct vhost_scsi *vs, struct vhost_scsi_evt *evt)
 578 {
 579         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 580         struct virtio_scsi_event *event = &evt->event;
 581         struct virtio_scsi_event __user *eventp;
 582         unsigned out, in;
 583         int head, ret;
 584
 585         if (!vq->private_data) {
 586                 vs->vs_events_missed = true;
 587                 return;
 588         }
 589
 590 again:
 591         vhost_disable_notify(&vs->dev, vq);
 592         head = vhost_get_vq_desc(vq, vq->iov,
 593                         ARRAY_SIZE(vq->iov), &out, &in,
 594                         NULL, NULL);
 595         if (head < 0) {
 596                 vs->vs_events_missed = true;
 597                 return;
 598         }
 599         if (head == vq->num) {
 600                 if (vhost_enable_notify(&vs->dev, vq))
 601                         goto again;
 602                 vs->vs_events_missed = true;
 603                 return;
 604         }
 605
 606         if ((vq->iov[out].iov_len != sizeof(struct virtio_scsi_event))) {
 607                 vq_err(vq, "Expecting virtio_scsi_event, got %zu bytes\n",
 608                                 vq->iov[out].iov_len);
 609                 vs->vs_events_missed = true;
 610                 return;
 611         }
 612
 613         if (vs->vs_events_missed) {
 614                 event->event |= cpu_to_vhost32(vq, VIRTIO_SCSI_T_EVENTS_MISSED);
 615                 vs->vs_events_missed = false;
 616         }
 617
 618         eventp = vq->iov[out].iov_base;
 619         ret = __copy_to_user(eventp, event, sizeof(*event));
 620         if (!ret)
 621                 vhost_add_used_and_signal(&vs->dev, vq, head, 0);
 622         else
 623                 vq_err(vq, "Faulted on vhost_scsi_send_event\n");
 624 }
 625
 626 static void vhost_scsi_evt_work(struct vhost_work *work)
 627 {
 628         struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
 629                                         vs_event_work);
 630         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 631         struct vhost_scsi_evt *evt;
 632         struct llist_node *llnode;
 633
 634         mutex_lock(&vq->mutex);
 635         llnode = llist_del_all(&vs->vs_event_list);
 636         while (llnode) {
 637                 evt = llist_entry(llnode, struct vhost_scsi_evt, list);
 638                 llnode = llist_next(llnode);
 639                 vhost_scsi_do_evt_work(vs, evt);
 640                 vhost_scsi_free_evt(vs, evt);
 641         }
 642         mutex_unlock(&vq->mutex);
 643 }
 644
 645 /* Fill in status and signal that we are done processing this command
 646  *
 647  * This is scheduled in the vhost work queue so we are called with the owner
 648  * process mm and can access the vring.
 649  */
 650 static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
 651 {
 652         struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
 653                                         vs_completion_work);
 654         DECLARE_BITMAP(signal, VHOST_SCSI_MAX_VQ);
 655         struct virtio_scsi_cmd_resp v_rsp;
 656         struct vhost_scsi_cmd *cmd;
 657         struct llist_node *llnode;
 658         struct se_cmd *se_cmd;
 659         struct iov_iter iov_iter;
 660         int ret, vq;
 661
 662         bitmap_zero(signal, VHOST_SCSI_MAX_VQ);
 663         llnode = llist_del_all(&vs->vs_completion_list);
 664         while (llnode) {
 665                 cmd = llist_entry(llnode, struct vhost_scsi_cmd,
 666                                      tvc_completion_list);
 667                 llnode = llist_next(llnode);
 668                 se_cmd = &cmd->tvc_se_cmd;
 669
 670                 pr_debug("%s tv_cmd %p resid %u status %#02x\n", __func__,
 671                         cmd, se_cmd->residual_count, se_cmd->scsi_status);
 672
 673                 memset(&v_rsp, 0, sizeof(v_rsp));
 674                 v_rsp.resid = cpu_to_vhost32(cmd->tvc_vq, se_cmd->residual_count);
 675                 /* TODO is status_qualifier field needed? */
 676                 v_rsp.status = se_cmd->scsi_status;
 677                 v_rsp.sense_len = cpu_to_vhost32(cmd->tvc_vq,
 678                                                  se_cmd->scsi_sense_length);
 679                 memcpy(v_rsp.sense, cmd->tvc_sense_buf,
 680                        se_cmd->scsi_sense_length);
 681
 682                 iov_iter_init(&iov_iter, READ, cmd->tvc_resp_iov,
 683                               cmd->tvc_in_iovs, sizeof(v_rsp));
 684                 ret = copy_to_iter(&v_rsp, sizeof(v_rsp), &iov_iter);
 685                 if (likely(ret == sizeof(v_rsp))) {
 686                         struct vhost_scsi_virtqueue *q;
 687                         vhost_add_used(cmd->tvc_vq, cmd->tvc_vq_desc, 0);
 688                         q = container_of(cmd->tvc_vq, struct vhost_scsi_virtqueue, vq);
 689                         vq = q - vs->vqs;
 690                         __set_bit(vq, signal);
 691                 } else
 692                         pr_err("Faulted on virtio_scsi_cmd_resp\n");
 693
 694                 vhost_scsi_free_cmd(cmd);
 695         }
 696
 697         vq = -1;
 698         while ((vq = find_next_bit(signal, VHOST_SCSI_MAX_VQ, vq + 1))
 699                 < VHOST_SCSI_MAX_VQ)
 700                 vhost_signal(&vs->dev, &vs->vqs[vq].vq);
 701 }
 702
 703 static struct vhost_scsi_cmd *
 704 vhost_scsi_get_tag(struct vhost_virtqueue *vq, struct vhost_scsi_tpg *tpg,
 705                    unsigned char *cdb, u64 scsi_tag, u16 lun, u8 task_attr,
 706                    u32 exp_data_len, int data_direction)
 707 {
 708         struct vhost_scsi_cmd *cmd;
 709         struct vhost_scsi_nexus *tv_nexus;
 710         struct se_session *se_sess;
 711         struct scatterlist *sg, *prot_sg;
 712         struct page **pages;
 713         int tag;
 714
 715         tv_nexus = tpg->tpg_nexus;
 716         if (!tv_nexus) {
 717                 pr_err("Unable to locate active struct vhost_scsi_nexus\n");
 718                 return ERR_PTR(-EIO);
 719         }
 720         se_sess = tv_nexus->tvn_se_sess;
 721
 722         tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
 723         if (tag < 0) {
 724                 pr_err("Unable to obtain tag for vhost_scsi_cmd\n");
 725                 return ERR_PTR(-ENOMEM);
 726         }
 727
 728         cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[tag];
 729         sg = cmd->tvc_sgl;
 730         prot_sg = cmd->tvc_prot_sgl;
 731         pages = cmd->tvc_upages;
 732         memset(cmd, 0, sizeof(struct vhost_scsi_cmd));
 733
 734         cmd->tvc_sgl = sg;
 735         cmd->tvc_prot_sgl = prot_sg;
 736         cmd->tvc_upages = pages;
 737         cmd->tvc_se_cmd.map_tag = tag;
 738         cmd->tvc_tag = scsi_tag;
 739         cmd->tvc_lun = lun;
 740         cmd->tvc_task_attr = task_attr;
 741         cmd->tvc_exp_data_len = exp_data_len;
 742         cmd->tvc_data_direction = data_direction;
 743         cmd->tvc_nexus = tv_nexus;
 744         cmd->inflight = vhost_scsi_get_inflight(vq);
 745
 746         memcpy(cmd->tvc_cdb, cdb, VHOST_SCSI_MAX_CDB_SIZE);
 747
 748         return cmd;
 749 }
 750
 751 /*
 752  * Map a user memory range into a scatterlist
 753  *
 754  * Returns the number of scatterlist entries used or -errno on error.
 755  */
 756 static int
 757 vhost_scsi_map_to_sgl(struct vhost_scsi_cmd *cmd,
 758                       void __user *ptr,
 759                       size_t len,
 760                       struct scatterlist *sgl,
 761                       bool write)
 762 {
 763         unsigned int npages = 0, offset, nbytes;
 764         unsigned int pages_nr = iov_num_pages(ptr, len);
 765         struct scatterlist *sg = sgl;
 766         struct page **pages = cmd->tvc_upages;
 767         int ret, i;
 768
 769         if (pages_nr > VHOST_SCSI_PREALLOC_UPAGES) {
 770                 pr_err("vhost_scsi_map_to_sgl() pages_nr: %u greater than"
 771                        " preallocated VHOST_SCSI_PREALLOC_UPAGES: %u\n",
 772                         pages_nr, VHOST_SCSI_PREALLOC_UPAGES);
 773                 return -ENOBUFS;
 774         }
 775
 776         ret = get_user_pages_fast((unsigned long)ptr, pages_nr, write, pages);
 777         /* No pages were pinned */
 778         if (ret < 0)
 779                 goto out;
 780         /* Less pages pinned than wanted */
 781         if (ret != pages_nr) {
 782                 for (i = 0; i < ret; i++)
 783                         put_page(pages[i]);
 784                 ret = -EFAULT;
 785                 goto out;
 786         }
 787
 788         while (len > 0) {
 789                 offset = (uintptr_t)ptr & ~PAGE_MASK;
 790                 nbytes = min_t(unsigned int, PAGE_SIZE - offset, len);
 791                 sg_set_page(sg, pages[npages], nbytes, offset);
 792                 ptr += nbytes;
 793                 len -= nbytes;
 794                 sg++;
 795                 npages++;
 796         }
 797
 798 out:
 799         return ret;
 800 }
 801
 802 static int
 803 vhost_scsi_calc_sgls(struct iov_iter *iter, size_t bytes, int max_sgls)
 804 {
 805         int sgl_count = 0;
 806
 807         if (!iter || !iter->iov) {
 808                 pr_err("%s: iter->iov is NULL, but expected bytes: %zu"
 809                        " present\n", __func__, bytes);
 810                 return -EINVAL;
 811         }
 812
 813         sgl_count = iov_iter_npages(iter, 0xffff);
 814         if (sgl_count > max_sgls) {
 815                 pr_err("%s: requested sgl_count: %d exceeds pre-allocated"
 816                        " max_sgls: %d\n", __func__, sgl_count, max_sgls);
 817                 return -EINVAL;
 818         }
 819         return sgl_count;
 820 }
 821
 822 static int
 823 vhost_scsi_iov_to_sgl(struct vhost_scsi_cmd *cmd, bool write,
 824                       struct iov_iter *iter,
 825                       struct scatterlist *sg, int sg_count)
 826 {
 827         size_t off = iter->iov_offset;
 828         int i, ret;
 829
 830         for (i = 0; i < iter->nr_segs; i++) {
 831                 void __user *base = iter->iov[i].iov_base + off;
 832                 size_t len = iter->iov[i].iov_len - off;
 833
 834                 ret = vhost_scsi_map_to_sgl(cmd, base, len, sg, write);
 835                 if (ret < 0) {
 836                         for (i = 0; i < sg_count; i++) {
 837                                 struct page *page = sg_page(&sg[i]);
 838                                 if (page)
 839                                         put_page(page);
 840                         }
 841                         return ret;
 842                 }
 843                 sg += ret;
 844                 off = 0;
 845         }
 846         return 0;
 847 }
 848
 849 static int
 850 vhost_scsi_mapal(struct vhost_scsi_cmd *cmd,
 851                  size_t prot_bytes, struct iov_iter *prot_iter,
 852                  size_t data_bytes, struct iov_iter *data_iter)
 853 {
 854         int sgl_count, ret;
 855         bool write = (cmd->tvc_data_direction == DMA_FROM_DEVICE);
 856
 857         if (prot_bytes) {
 858                 sgl_count = vhost_scsi_calc_sgls(prot_iter, prot_bytes,
 859                                                  VHOST_SCSI_PREALLOC_PROT_SGLS);
 860                 if (sgl_count < 0)
 861                         return sgl_count;
 862
 863                 sg_init_table(cmd->tvc_prot_sgl, sgl_count);
 864                 cmd->tvc_prot_sgl_count = sgl_count;
 865                 pr_debug("%s prot_sg %p prot_sgl_count %u\n", __func__,
 866                          cmd->tvc_prot_sgl, cmd->tvc_prot_sgl_count);
 867
 868                 ret = vhost_scsi_iov_to_sgl(cmd, write, prot_iter,
 869                                             cmd->tvc_prot_sgl,
 870                                             cmd->tvc_prot_sgl_count);
 871                 if (ret < 0) {
 872                         cmd->tvc_prot_sgl_count = 0;
 873                         return ret;
 874                 }
 875         }
 876         sgl_count = vhost_scsi_calc_sgls(data_iter, data_bytes,
 877                                          VHOST_SCSI_PREALLOC_SGLS);
 878         if (sgl_count < 0)
 879                 return sgl_count;
 880
 881         sg_init_table(cmd->tvc_sgl, sgl_count);
 882         cmd->tvc_sgl_count = sgl_count;
 883         pr_debug("%s data_sg %p data_sgl_count %u\n", __func__,
 884                   cmd->tvc_sgl, cmd->tvc_sgl_count);
 885
 886         ret = vhost_scsi_iov_to_sgl(cmd, write, data_iter,
 887                                     cmd->tvc_sgl, cmd->tvc_sgl_count);
 888         if (ret < 0) {
 889                 cmd->tvc_sgl_count = 0;
 890                 return ret;
 891         }
 892         return 0;
 893 }
 894
 895 static int vhost_scsi_to_tcm_attr(int attr)
 896 {
 897         switch (attr) {
 898         case VIRTIO_SCSI_S_SIMPLE:
 899                 return TCM_SIMPLE_TAG;
 900         case VIRTIO_SCSI_S_ORDERED:
 901                 return TCM_ORDERED_TAG;
 902         case VIRTIO_SCSI_S_HEAD:
 903                 return TCM_HEAD_TAG;
 904         case VIRTIO_SCSI_S_ACA:
 905                 return TCM_ACA_TAG;
 906         default:
 907                 break;
 908         }
 909         return TCM_SIMPLE_TAG;
 910 }
 911
 912 static void vhost_scsi_submission_work(struct work_struct *work)
 913 {
 914         struct vhost_scsi_cmd *cmd =
 915                 container_of(work, struct vhost_scsi_cmd, work);
 916         struct vhost_scsi_nexus *tv_nexus;
 917         struct se_cmd *se_cmd = &cmd->tvc_se_cmd;
 918         struct scatterlist *sg_ptr, *sg_prot_ptr = NULL;
 919         int rc;
 920
 921         /* FIXME: BIDI operation */
 922         if (cmd->tvc_sgl_count) {
 923                 sg_ptr = cmd->tvc_sgl;
 924
 925                 if (cmd->tvc_prot_sgl_count)
 926                         sg_prot_ptr = cmd->tvc_prot_sgl;
 927                 else
 928                         se_cmd->prot_pto = true;
 929         } else {
 930                 sg_ptr = NULL;
 931         }
 932         tv_nexus = cmd->tvc_nexus;
 933
 934         rc = target_submit_cmd_map_sgls(se_cmd, tv_nexus->tvn_se_sess,
 935                         cmd->tvc_cdb, &cmd->tvc_sense_buf[0],
 936                         cmd->tvc_lun, cmd->tvc_exp_data_len,
 937                         vhost_scsi_to_tcm_attr(cmd->tvc_task_attr),
 938                         cmd->tvc_data_direction, TARGET_SCF_ACK_KREF,
 939                         sg_ptr, cmd->tvc_sgl_count, NULL, 0, sg_prot_ptr,
 940                         cmd->tvc_prot_sgl_count);
 941         if (rc < 0) {
 942                 transport_send_check_condition_and_sense(se_cmd,
 943                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
 944                 transport_generic_free_cmd(se_cmd, 0);
 945         }
 946 }
 947
 948 static void
 949 vhost_scsi_send_bad_target(struct vhost_scsi *vs,
 950                            struct vhost_virtqueue *vq,
 951                            int head, unsigned out)
 952 {
 953         struct virtio_scsi_cmd_resp __user *resp;
 954         struct virtio_scsi_cmd_resp rsp;
 955         int ret;
 956
 957         memset(&rsp, 0, sizeof(rsp));
 958         rsp.response = VIRTIO_SCSI_S_BAD_TARGET;
 959         resp = vq->iov[out].iov_base;
 960         ret = __copy_to_user(resp, &rsp, sizeof(rsp));
 961         if (!ret)
 962                 vhost_add_used_and_signal(&vs->dev, vq, head, 0);
 963         else
 964                 pr_err("Faulted on virtio_scsi_cmd_resp\n");
 965 }
 966
 967 static void
 968 vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 969 {
 970         struct vhost_scsi_tpg **vs_tpg, *tpg;
 971         struct virtio_scsi_cmd_req v_req;
 972         struct virtio_scsi_cmd_req_pi v_req_pi;
 973         struct vhost_scsi_cmd *cmd;
 974         struct iov_iter out_iter, in_iter, prot_iter, data_iter;
 975         u64 tag;
 976         u32 exp_data_len, data_direction;
 977         unsigned out, in;
 978         int head, ret, prot_bytes;
 979         size_t req_size, rsp_size = sizeof(struct virtio_scsi_cmd_resp);
 980         size_t out_size, in_size;
 981         u16 lun;
 982         u8 *target, *lunp, task_attr;
 983         bool t10_pi = vhost_has_feature(vq, VIRTIO_SCSI_F_T10_PI);
 984         void *req, *cdb;
 985
 986         mutex_lock(&vq->mutex);
 987         /*
 988          * We can handle the vq only after the endpoint is setup by calling the
 989          * VHOST_SCSI_SET_ENDPOINT ioctl.
 990          */
 991         vs_tpg = vq->private_data;
 992         if (!vs_tpg)
 993                 goto out;
 994
 995         vhost_disable_notify(&vs->dev, vq);
 996
 997         for (;;) {
 998                 head = vhost_get_vq_desc(vq, vq->iov,
 999                                          ARRAY_SIZE(vq->iov), &out, &in,
1000                                          NULL, NULL);
1001                 pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n",
1002                          head, out, in);
1003                 /* On error, stop handling until the next kick. */
1004                 if (unlikely(head < 0))
1005                         break;
1006                 /* Nothing new?  Wait for eventfd to tell us they refilled. */
1007                 if (head == vq->num) {
1008                         if (unlikely(vhost_enable_notify(&vs->dev, vq))) {
1009                                 vhost_disable_notify(&vs->dev, vq);
1010                                 continue;
1011                         }
1012                         break;
1013                 }
1014                 /*
1015                  * Check for a sane response buffer so we can report early
1016                  * errors back to the guest.
1017                  */
1018                 if (unlikely(vq->iov[out].iov_len < rsp_size)) {
1019                         vq_err(vq, "Expecting at least virtio_scsi_cmd_resp"
1020                                 " size, got %zu bytes\n", vq->iov[out].iov_len);
1021                         break;
1022                 }
1023                 /*
1024                  * Setup pointers and values based upon different virtio-scsi
1025                  * request header if T10_PI is enabled in KVM guest.
1026                  */
1027                 if (t10_pi) {
1028                         req = &v_req_pi;
1029                         req_size = sizeof(v_req_pi);
1030                         lunp = &v_req_pi.lun[0];
1031                         target = &v_req_pi.lun[1];
1032                 } else {
1033                         req = &v_req;
1034                         req_size = sizeof(v_req);
1035                         lunp = &v_req.lun[0];
1036                         target = &v_req.lun[1];
1037                 }
1038                 /*
1039                  * FIXME: Not correct for BIDI operation
1040                  */
1041                 out_size = iov_length(vq->iov, out);
1042                 in_size = iov_length(&vq->iov[out], in);
1043
1044                 /*
1045                  * Copy over the virtio-scsi request header, which for a
1046                  * ANY_LAYOUT enabled guest may span multiple iovecs, or a
1047                  * single iovec may contain both the header + outgoing
1048                  * WRITE payloads.
1049                  *
1050                  * copy_from_iter() will advance out_iter, so that it will
1051                  * point at the start of the outgoing WRITE payload, if
1052                  * DMA_TO_DEVICE is set.
1053                  */
1054                 iov_iter_init(&out_iter, WRITE, vq->iov, out, out_size);
1055
1056                 ret = copy_from_iter(req, req_size, &out_iter);
1057                 if (unlikely(ret != req_size)) {
1058                         vq_err(vq, "Faulted on copy_from_iter\n");
1059                         vhost_scsi_send_bad_target(vs, vq, head, out);
1060                         continue;
1061                 }
1062                 /* virtio-scsi spec requires byte 0 of the lun to be 1 */
1063                 if (unlikely(*lunp != 1)) {
1064                         vq_err(vq, "Illegal virtio-scsi lun: %u\n", *lunp);
1065                         vhost_scsi_send_bad_target(vs, vq, head, out);
1066                         continue;
1067                 }
1068
1069                 tpg = ACCESS_ONCE(vs_tpg[*target]);
1070                 if (unlikely(!tpg)) {
1071                         /* Target does not exist, fail the request */
1072                         vhost_scsi_send_bad_target(vs, vq, head, out);
1073                         continue;
1074                 }
1075                 /*
1076                  * Determine data_direction by calculating the total outgoing
1077                  * iovec sizes + incoming iovec sizes vs. virtio-scsi request +
1078                  * response headers respectively.
1079                  *
1080                  * For DMA_TO_DEVICE this is out_iter, which is already pointing
1081                  * to the right place.
1082                  *
1083                  * For DMA_FROM_DEVICE, the iovec will be just past the end
1084                  * of the virtio-scsi response header in either the same
1085                  * or immediately following iovec.
1086                  *
1087                  * Any associated T10_PI bytes for the outgoing / incoming
1088                  * payloads are included in calculation of exp_data_len here.
1089                  */
1090                 prot_bytes = 0;
1091
1092                 if (out_size > req_size) {
1093                         data_direction = DMA_TO_DEVICE;
1094                         exp_data_len = out_size - req_size;
1095                         data_iter = out_iter;
1096                 } else if (in_size > rsp_size) {
1097                         data_direction = DMA_FROM_DEVICE;
1098                         exp_data_len = in_size - rsp_size;
1099
1100                         iov_iter_init(&in_iter, READ, &vq->iov[out], in,
1101                                       rsp_size + exp_data_len);
1102                         iov_iter_advance(&in_iter, rsp_size);
1103                         data_iter = in_iter;
1104                 } else {
1105                         data_direction = DMA_NONE;
1106                         exp_data_len = 0;
1107                 }
1108                 /*
1109                  * If T10_PI header + payload is present, setup prot_iter values
1110                  * and recalculate data_iter for vhost_scsi_mapal() mapping to
1111                  * host scatterlists via get_user_pages_fast().
1112                  */
1113                 if (t10_pi) {
1114                         if (v_req_pi.pi_bytesout) {
1115                                 if (data_direction != DMA_TO_DEVICE) {
1116                                         vq_err(vq, "Received non zero pi_bytesout,"
1117                                                 " but wrong data_direction\n");
1118                                         vhost_scsi_send_bad_target(vs, vq, head, out);
1119                                         continue;
1120                                 }
1121                                 prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesout);
1122                         } else if (v_req_pi.pi_bytesin) {
1123                                 if (data_direction != DMA_FROM_DEVICE) {
1124                                         vq_err(vq, "Received non zero pi_bytesin,"
1125                                                 " but wrong data_direction\n");
1126                                         vhost_scsi_send_bad_target(vs, vq, head, out);
1127                                         continue;
1128                                 }
1129                                 prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin);
1130                         }
1131                         /*
1132                          * Set prot_iter to data_iter, and advance past any
1133                          * preceeding prot_bytes that may be present.
1134                          *
1135                          * Also fix up the exp_data_len to reflect only the
1136                          * actual data payload length.
1137                          */
1138                         if (prot_bytes) {
1139                                 exp_data_len -= prot_bytes;
1140                                 prot_iter = data_iter;
1141                                 iov_iter_advance(&data_iter, prot_bytes);
1142                         }
1143                         tag = vhost64_to_cpu(vq, v_req_pi.tag);
1144                         task_attr = v_req_pi.task_attr;
1145                         cdb = &v_req_pi.cdb[0];
1146                         lun = ((v_req_pi.lun[2] << 8) | v_req_pi.lun[3]) & 0x3FFF;
1147                 } else {
1148                         tag = vhost64_to_cpu(vq, v_req.tag);
1149                         task_attr = v_req.task_attr;
1150                         cdb = &v_req.cdb[0];
1151                         lun = ((v_req.lun[2] << 8) | v_req.lun[3]) & 0x3FFF;
1152                 }
1153                 /*
1154                  * Check that the received CDB size does not exceeded our
1155                  * hardcoded max for vhost-scsi, then get a pre-allocated
1156                  * cmd descriptor for the new virtio-scsi tag.
1157                  *
1158                  * TODO what if cdb was too small for varlen cdb header?
1159                  */
1160                 if (unlikely(scsi_command_size(cdb) > VHOST_SCSI_MAX_CDB_SIZE)) {
1161                         vq_err(vq, "Received SCSI CDB with command_size: %d that"
1162                                 " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1163                                 scsi_command_size(cdb), VHOST_SCSI_MAX_CDB_SIZE);
1164                         vhost_scsi_send_bad_target(vs, vq, head, out);
1165                         continue;
1166                 }
1167                 cmd = vhost_scsi_get_tag(vq, tpg, cdb, tag, lun, task_attr,
1168                                          exp_data_len + prot_bytes,
1169                                          data_direction);
1170                 if (IS_ERR(cmd)) {
1171                         vq_err(vq, "vhost_scsi_get_tag failed %ld\n",
1172                                PTR_ERR(cmd));
1173                         vhost_scsi_send_bad_target(vs, vq, head, out);
1174                         continue;
1175                 }
1176                 cmd->tvc_vhost = vs;
1177                 cmd->tvc_vq = vq;
1178                 cmd->tvc_resp_iov = &vq->iov[out];
1179                 cmd->tvc_in_iovs = in;
1180
1181                 pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",
1182                          cmd->tvc_cdb[0], cmd->tvc_lun);
1183                 pr_debug("cmd: %p exp_data_len: %d, prot_bytes: %d data_direction:"
1184                          " %d\n", cmd, exp_data_len, prot_bytes, data_direction);
1185
1186                 if (data_direction != DMA_NONE) {
1187                         ret = vhost_scsi_mapal(cmd,
1188                                                prot_bytes, &prot_iter,
1189                                                exp_data_len, &data_iter);
1190                         if (unlikely(ret)) {
1191                                 vq_err(vq, "Failed to map iov to sgl\n");
1192                                 vhost_scsi_release_cmd(&cmd->tvc_se_cmd);
1193                                 vhost_scsi_send_bad_target(vs, vq, head, out);
1194                                 continue;
1195                         }
1196                 }
1197                 /*
1198                  * Save the descriptor from vhost_get_vq_desc() to be used to
1199                  * complete the virtio-scsi request in TCM callback context via
1200                  * vhost_scsi_queue_data_in() and vhost_scsi_queue_status()
1201                  */
1202                 cmd->tvc_vq_desc = head;
1203                 /*
1204                  * Dispatch cmd descriptor for cmwq execution in process
1205                  * context provided by vhost_scsi_workqueue.  This also ensures
1206                  * cmd is executed on the same kworker CPU as this vhost
1207                  * thread to gain positive L2 cache locality effects.
1208                  */
1209                 INIT_WORK(&cmd->work, vhost_scsi_submission_work);
1210                 queue_work(vhost_scsi_workqueue, &cmd->work);
1211         }
1212 out:
1213         mutex_unlock(&vq->mutex);
1214 }
1215
1216 static void vhost_scsi_ctl_handle_kick(struct vhost_work *work)
1217 {
1218         pr_debug("%s: The handling func for control queue.\n", __func__);
1219 }
1220
1221 static void
1222 vhost_scsi_send_evt(struct vhost_scsi *vs,
1223                    struct vhost_scsi_tpg *tpg,
1224                    struct se_lun *lun,
1225                    u32 event,
1226                    u32 reason)
1227 {
1228         struct vhost_scsi_evt *evt;
1229
1230         evt = vhost_scsi_allocate_evt(vs, event, reason);
1231         if (!evt)
1232                 return;
1233
1234         if (tpg && lun) {
1235                 /* TODO: share lun setup code with virtio-scsi.ko */
1236                 /*
1237                  * Note: evt->event is zeroed when we allocate it and
1238                  * lun[4-7] need to be zero according to virtio-scsi spec.
1239                  */
1240                 evt->event.lun[0] = 0x01;
1241                 evt->event.lun[1] = tpg->tport_tpgt;
1242                 if (lun->unpacked_lun >= 256)
1243                         evt->event.lun[2] = lun->unpacked_lun >> 8 | 0x40 ;
1244                 evt->event.lun[3] = lun->unpacked_lun & 0xFF;
1245         }
1246
1247         llist_add(&evt->list, &vs->vs_event_list);
1248         vhost_work_queue(&vs->dev, &vs->vs_event_work);
1249 }
1250
1251 static void vhost_scsi_evt_handle_kick(struct vhost_work *work)
1252 {
1253         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1254                                                 poll.work);
1255         struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1256
1257         mutex_lock(&vq->mutex);
1258         if (!vq->private_data)
1259                 goto out;
1260
1261         if (vs->vs_events_missed)
1262                 vhost_scsi_send_evt(vs, NULL, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
1263 out:
1264         mutex_unlock(&vq->mutex);
1265 }
1266
1267 static void vhost_scsi_handle_kick(struct vhost_work *work)
1268 {
1269         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1270                                                 poll.work);
1271         struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1272
1273         vhost_scsi_handle_vq(vs, vq);
1274 }
1275
1276 static void vhost_scsi_flush_vq(struct vhost_scsi *vs, int index)
1277 {
1278         vhost_poll_flush(&vs->vqs[index].vq.poll);
1279 }
1280
1281 /* Callers must hold dev mutex */
1282 static void vhost_scsi_flush(struct vhost_scsi *vs)
1283 {
1284         struct vhost_scsi_inflight *old_inflight[VHOST_SCSI_MAX_VQ];
1285         int i;
1286
1287         /* Init new inflight and remember the old inflight */
1288         vhost_scsi_init_inflight(vs, old_inflight);
1289
1290         /*
1291          * The inflight->kref was initialized to 1. We decrement it here to
1292          * indicate the start of the flush operation so that it will reach 0
1293          * when all the reqs are finished.
1294          */
1295         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1296                 kref_put(&old_inflight[i]->kref, vhost_scsi_done_inflight);
1297
1298         /* Flush both the vhost poll and vhost work */
1299         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1300                 vhost_scsi_flush_vq(vs, i);
1301         vhost_work_flush(&vs->dev, &vs->vs_completion_work);
1302         vhost_work_flush(&vs->dev, &vs->vs_event_work);
1303
1304         /* Wait for all reqs issued before the flush to be finished */
1305         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1306                 wait_for_completion(&old_inflight[i]->comp);
1307 }
1308
1309 /*
1310  * Called from vhost_scsi_ioctl() context to walk the list of available
1311  * vhost_scsi_tpg with an active struct vhost_scsi_nexus
1312  *
1313  *  The lock nesting rule is:
1314  *    vhost_scsi_mutex -> vs->dev.mutex -> tpg->tv_tpg_mutex -> vq->mutex
1315  */
1316 static int
1317 vhost_scsi_set_endpoint(struct vhost_scsi *vs,
1318                         struct vhost_scsi_target *t)
1319 {
1320         struct se_portal_group *se_tpg;
1321         struct vhost_scsi_tport *tv_tport;
1322         struct vhost_scsi_tpg *tpg;
1323         struct vhost_scsi_tpg **vs_tpg;
1324         struct vhost_virtqueue *vq;
1325         int index, ret, i, len;
1326         bool match = false;
1327
1328         mutex_lock(&vhost_scsi_mutex);
1329         mutex_lock(&vs->dev.mutex);
1330
1331         /* Verify that ring has been setup correctly. */
1332         for (index = 0; index < vs->dev.nvqs; ++index) {
1333                 /* Verify that ring has been setup correctly. */
1334                 if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1335                         ret = -EFAULT;
1336                         goto out;
1337                 }
1338         }
1339
1340         len = sizeof(vs_tpg[0]) * VHOST_SCSI_MAX_TARGET;
1341         vs_tpg = kzalloc(len, GFP_KERNEL);
1342         if (!vs_tpg) {
1343                 ret = -ENOMEM;
1344                 goto out;
1345         }
1346         if (vs->vs_tpg)
1347                 memcpy(vs_tpg, vs->vs_tpg, len);
1348
1349         list_for_each_entry(tpg, &vhost_scsi_list, tv_tpg_list) {
1350                 mutex_lock(&tpg->tv_tpg_mutex);
1351                 if (!tpg->tpg_nexus) {
1352                         mutex_unlock(&tpg->tv_tpg_mutex);
1353                         continue;
1354                 }
1355                 if (tpg->tv_tpg_vhost_count != 0) {
1356                         mutex_unlock(&tpg->tv_tpg_mutex);
1357                         continue;
1358                 }
1359                 tv_tport = tpg->tport;
1360
1361                 if (!strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1362                         if (vs->vs_tpg && vs->vs_tpg[tpg->tport_tpgt]) {
1363                                 kfree(vs_tpg);
1364                                 mutex_unlock(&tpg->tv_tpg_mutex);
1365                                 ret = -EEXIST;
1366                                 goto out;
1367                         }
1368                         /*
1369                          * In order to ensure individual vhost-scsi configfs
1370                          * groups cannot be removed while in use by vhost ioctl,
1371                          * go ahead and take an explicit se_tpg->tpg_group.cg_item
1372                          * dependency now.
1373                          */
1374                         se_tpg = &tpg->se_tpg;
1375                         ret = target_depend_item(&se_tpg->tpg_group.cg_item);
1376                         if (ret) {
1377                                 pr_warn("configfs_depend_item() failed: %d\n", ret);
1378                                 kfree(vs_tpg);
1379                                 mutex_unlock(&tpg->tv_tpg_mutex);
1380                                 goto out;
1381                         }
1382                         tpg->tv_tpg_vhost_count++;
1383                         tpg->vhost_scsi = vs;
1384                         vs_tpg[tpg->tport_tpgt] = tpg;
1385                         smp_mb__after_atomic();
1386                         match = true;
1387                 }
1388                 mutex_unlock(&tpg->tv_tpg_mutex);
1389         }
1390
1391         if (match) {
1392                 memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn,
1393                        sizeof(vs->vs_vhost_wwpn));
1394                 for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1395                         vq = &vs->vqs[i].vq;
1396                         mutex_lock(&vq->mutex);
1397                         vq->private_data = vs_tpg;
1398                         vhost_init_used(vq);
1399                         mutex_unlock(&vq->mutex);
1400                 }
1401                 ret = 0;
1402         } else {
1403                 ret = -EEXIST;
1404         }
1405
1406         /*
1407          * Act as synchronize_rcu to make sure access to
1408          * old vs->vs_tpg is finished.
1409          */
1410         vhost_scsi_flush(vs);
1411         kfree(vs->vs_tpg);
1412         vs->vs_tpg = vs_tpg;
1413
1414 out:
1415         mutex_unlock(&vs->dev.mutex);
1416         mutex_unlock(&vhost_scsi_mutex);
1417         return ret;
1418 }
1419
1420 static int
1421 vhost_scsi_clear_endpoint(struct vhost_scsi *vs,
1422                           struct vhost_scsi_target *t)
1423 {
1424         struct se_portal_group *se_tpg;
1425         struct vhost_scsi_tport *tv_tport;
1426         struct vhost_scsi_tpg *tpg;
1427         struct vhost_virtqueue *vq;
1428         bool match = false;
1429         int index, ret, i;
1430         u8 target;
1431
1432         mutex_lock(&vhost_scsi_mutex);
1433         mutex_lock(&vs->dev.mutex);
1434         /* Verify that ring has been setup correctly. */
1435         for (index = 0; index < vs->dev.nvqs; ++index) {
1436                 if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1437                         ret = -EFAULT;
1438                         goto err_dev;
1439                 }
1440         }
1441
1442         if (!vs->vs_tpg) {
1443                 ret = 0;
1444                 goto err_dev;
1445         }
1446
1447         for (i = 0; i < VHOST_SCSI_MAX_TARGET; i++) {
1448                 target = i;
1449                 tpg = vs->vs_tpg[target];
1450                 if (!tpg)
1451                         continue;
1452
1453                 mutex_lock(&tpg->tv_tpg_mutex);
1454                 tv_tport = tpg->tport;
1455                 if (!tv_tport) {
1456                         ret = -ENODEV;
1457                         goto err_tpg;
1458                 }
1459
1460                 if (strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1461                         pr_warn("tv_tport->tport_name: %s, tpg->tport_tpgt: %hu"
1462                                 " does not match t->vhost_wwpn: %s, t->vhost_tpgt: %hu\n",
1463                                 tv_tport->tport_name, tpg->tport_tpgt,
1464                                 t->vhost_wwpn, t->vhost_tpgt);
1465                         ret = -EINVAL;
1466                         goto err_tpg;
1467                 }
1468                 tpg->tv_tpg_vhost_count--;
1469                 tpg->vhost_scsi = NULL;
1470                 vs->vs_tpg[target] = NULL;
1471                 match = true;
1472                 mutex_unlock(&tpg->tv_tpg_mutex);
1473                 /*
1474                  * Release se_tpg->tpg_group.cg_item configfs dependency now
1475                  * to allow vhost-scsi WWPN se_tpg->tpg_group shutdown to occur.
1476                  */
1477                 se_tpg = &tpg->se_tpg;
1478                 target_undepend_item(&se_tpg->tpg_group.cg_item);
1479         }
1480         if (match) {
1481                 for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1482                         vq = &vs->vqs[i].vq;
1483                         mutex_lock(&vq->mutex);
1484                         vq->private_data = NULL;
1485                         mutex_unlock(&vq->mutex);
1486                 }
1487         }
1488         /*
1489          * Act as synchronize_rcu to make sure access to
1490          * old vs->vs_tpg is finished.
1491          */
1492         vhost_scsi_flush(vs);
1493         kfree(vs->vs_tpg);
1494         vs->vs_tpg = NULL;
1495         WARN_ON(vs->vs_events_nr);
1496         mutex_unlock(&vs->dev.mutex);
1497         mutex_unlock(&vhost_scsi_mutex);
1498         return 0;
1499
1500 err_tpg:
1501         mutex_unlock(&tpg->tv_tpg_mutex);
1502 err_dev:
1503         mutex_unlock(&vs->dev.mutex);
1504         mutex_unlock(&vhost_scsi_mutex);
1505         return ret;
1506 }
1507
1508 static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
1509 {
1510         struct vhost_virtqueue *vq;
1511         int i;
1512
1513         if (features & ~VHOST_SCSI_FEATURES)
1514                 return -EOPNOTSUPP;
1515
1516         mutex_lock(&vs->dev.mutex);
1517         if ((features & (1 << VHOST_F_LOG_ALL)) &&
1518             !vhost_log_access_ok(&vs->dev)) {
1519                 mutex_unlock(&vs->dev.mutex);
1520                 return -EFAULT;
1521         }
1522
1523         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1524                 vq = &vs->vqs[i].vq;
1525                 mutex_lock(&vq->mutex);
1526                 vq->acked_features = features;
1527                 mutex_unlock(&vq->mutex);
1528         }
1529         mutex_unlock(&vs->dev.mutex);
1530         return 0;
1531 }
1532
1533 static int vhost_scsi_open(struct inode *inode, struct file *f)
1534 {
1535         struct vhost_scsi *vs;
1536         struct vhost_virtqueue **vqs;
1537         int r = -ENOMEM, i;
1538
1539         vs = kzalloc(sizeof(*vs), GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
1540         if (!vs) {
1541                 vs = vzalloc(sizeof(*vs));
1542                 if (!vs)
1543                         goto err_vs;
1544         }
1545
1546         vqs = kmalloc(VHOST_SCSI_MAX_VQ * sizeof(*vqs), GFP_KERNEL);
1547         if (!vqs)
1548                 goto err_vqs;
1549
1550         vhost_work_init(&vs->vs_completion_work, vhost_scsi_complete_cmd_work);
1551         vhost_work_init(&vs->vs_event_work, vhost_scsi_evt_work);
1552
1553         vs->vs_events_nr = 0;
1554         vs->vs_events_missed = false;
1555
1556         vqs[VHOST_SCSI_VQ_CTL] = &vs->vqs[VHOST_SCSI_VQ_CTL].vq;
1557         vqs[VHOST_SCSI_VQ_EVT] = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1558         vs->vqs[VHOST_SCSI_VQ_CTL].vq.handle_kick = vhost_scsi_ctl_handle_kick;
1559         vs->vqs[VHOST_SCSI_VQ_EVT].vq.handle_kick = vhost_scsi_evt_handle_kick;
1560         for (i = VHOST_SCSI_VQ_IO; i < VHOST_SCSI_MAX_VQ; i++) {
1561                 vqs[i] = &vs->vqs[i].vq;
1562                 vs->vqs[i].vq.handle_kick = vhost_scsi_handle_kick;
1563         }
1564         vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ);
1565
1566         vhost_scsi_init_inflight(vs, NULL);
1567
1568         f->private_data = vs;
1569         return 0;
1570
1571 err_vqs:
1572         kvfree(vs);
1573 err_vs:
1574         return r;
1575 }
1576
1577 static int vhost_scsi_release(struct inode *inode, struct file *f)
1578 {
1579         struct vhost_scsi *vs = f->private_data;
1580         struct vhost_scsi_target t;
1581
1582         mutex_lock(&vs->dev.mutex);
1583         memcpy(t.vhost_wwpn, vs->vs_vhost_wwpn, sizeof(t.vhost_wwpn));
1584         mutex_unlock(&vs->dev.mutex);
1585         vhost_scsi_clear_endpoint(vs, &t);
1586         vhost_dev_stop(&vs->dev);
1587         vhost_dev_cleanup(&vs->dev, false);
1588         /* Jobs can re-queue themselves in evt kick handler. Do extra flush. */
1589         vhost_scsi_flush(vs);
1590         kfree(vs->dev.vqs);
1591         kvfree(vs);
1592         return 0;
1593 }
1594
1595 static long
1596 vhost_scsi_ioctl(struct file *f,
1597                  unsigned int ioctl,
1598                  unsigned long arg)
1599 {
1600         struct vhost_scsi *vs = f->private_data;
1601         struct vhost_scsi_target backend;
1602         void __user *argp = (void __user *)arg;
1603         u64 __user *featurep = argp;
1604         u32 __user *eventsp = argp;
1605         u32 events_missed;
1606         u64 features;
1607         int r, abi_version = VHOST_SCSI_ABI_VERSION;
1608         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1609
1610         switch (ioctl) {
1611         case VHOST_SCSI_SET_ENDPOINT:
1612                 if (copy_from_user(&backend, argp, sizeof backend))
1613                         return -EFAULT;
1614                 if (backend.reserved != 0)
1615                         return -EOPNOTSUPP;
1616
1617                 return vhost_scsi_set_endpoint(vs, &backend);
1618         case VHOST_SCSI_CLEAR_ENDPOINT:
1619                 if (copy_from_user(&backend, argp, sizeof backend))
1620                         return -EFAULT;
1621                 if (backend.reserved != 0)
1622                         return -EOPNOTSUPP;
1623
1624                 return vhost_scsi_clear_endpoint(vs, &backend);
1625         case VHOST_SCSI_GET_ABI_VERSION:
1626                 if (copy_to_user(argp, &abi_version, sizeof abi_version))
1627                         return -EFAULT;
1628                 return 0;
1629         case VHOST_SCSI_SET_EVENTS_MISSED:
1630                 if (get_user(events_missed, eventsp))
1631                         return -EFAULT;
1632                 mutex_lock(&vq->mutex);
1633                 vs->vs_events_missed = events_missed;
1634                 mutex_unlock(&vq->mutex);
1635                 return 0;
1636         case VHOST_SCSI_GET_EVENTS_MISSED:
1637                 mutex_lock(&vq->mutex);
1638                 events_missed = vs->vs_events_missed;
1639                 mutex_unlock(&vq->mutex);
1640                 if (put_user(events_missed, eventsp))
1641                         return -EFAULT;
1642                 return 0;
1643         case VHOST_GET_FEATURES:
1644                 features = VHOST_SCSI_FEATURES;
1645                 if (copy_to_user(featurep, &features, sizeof features))
1646                         return -EFAULT;
1647                 return 0;
1648         case VHOST_SET_FEATURES:
1649                 if (copy_from_user(&features, featurep, sizeof features))
1650                         return -EFAULT;
1651                 return vhost_scsi_set_features(vs, features);
1652         default:
1653                 mutex_lock(&vs->dev.mutex);
1654                 r = vhost_dev_ioctl(&vs->dev, ioctl, argp);
1655                 /* TODO: flush backend after dev ioctl. */
1656                 if (r == -ENOIOCTLCMD)
1657                         r = vhost_vring_ioctl(&vs->dev, ioctl, argp);
1658                 mutex_unlock(&vs->dev.mutex);
1659                 return r;
1660         }
1661 }
1662
1663 #ifdef CONFIG_COMPAT
1664 static long vhost_scsi_compat_ioctl(struct file *f, unsigned int ioctl,
1665                                 unsigned long arg)
1666 {
1667         return vhost_scsi_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
1668 }
1669 #endif
1670
1671 static const struct file_operations vhost_scsi_fops = {
1672         .owner          = THIS_MODULE,
1673         .release        = vhost_scsi_release,
1674         .unlocked_ioctl = vhost_scsi_ioctl,
1675 #ifdef CONFIG_COMPAT
1676         .compat_ioctl   = vhost_scsi_compat_ioctl,
1677 #endif
1678         .open           = vhost_scsi_open,
1679         .llseek         = noop_llseek,
1680 };
1681
1682 static struct miscdevice vhost_scsi_misc = {
1683         MISC_DYNAMIC_MINOR,
1684         "vhost-scsi",
1685         &vhost_scsi_fops,
1686 };
1687
1688 static int __init vhost_scsi_register(void)
1689 {
1690         return misc_register(&vhost_scsi_misc);
1691 }
1692
1693 static int vhost_scsi_deregister(void)
1694 {
1695         return misc_deregister(&vhost_scsi_misc);
1696 }
1697
1698 static char *vhost_scsi_dump_proto_id(struct vhost_scsi_tport *tport)
1699 {
1700         switch (tport->tport_proto_id) {
1701         case SCSI_PROTOCOL_SAS:
1702                 return "SAS";
1703         case SCSI_PROTOCOL_FCP:
1704                 return "FCP";
1705         case SCSI_PROTOCOL_ISCSI:
1706                 return "iSCSI";
1707         default:
1708                 break;
1709         }
1710
1711         return "Unknown";
1712 }
1713
1714 static void
1715 vhost_scsi_do_plug(struct vhost_scsi_tpg *tpg,
1716                   struct se_lun *lun, bool plug)
1717 {
1718
1719         struct vhost_scsi *vs = tpg->vhost_scsi;
1720         struct vhost_virtqueue *vq;
1721         u32 reason;
1722
1723         if (!vs)
1724                 return;
1725
1726         mutex_lock(&vs->dev.mutex);
1727
1728         if (plug)
1729                 reason = VIRTIO_SCSI_EVT_RESET_RESCAN;
1730         else
1731                 reason = VIRTIO_SCSI_EVT_RESET_REMOVED;
1732
1733         vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1734         mutex_lock(&vq->mutex);
1735         if (vhost_has_feature(vq, VIRTIO_SCSI_F_HOTPLUG))
1736                 vhost_scsi_send_evt(vs, tpg, lun,
1737                                    VIRTIO_SCSI_T_TRANSPORT_RESET, reason);
1738         mutex_unlock(&vq->mutex);
1739         mutex_unlock(&vs->dev.mutex);
1740 }
1741
1742 static void vhost_scsi_hotplug(struct vhost_scsi_tpg *tpg, struct se_lun *lun)
1743 {
1744         vhost_scsi_do_plug(tpg, lun, true);
1745 }
1746
1747 static void vhost_scsi_hotunplug(struct vhost_scsi_tpg *tpg, struct se_lun *lun)
1748 {
1749         vhost_scsi_do_plug(tpg, lun, false);
1750 }
1751
1752 static int vhost_scsi_port_link(struct se_portal_group *se_tpg,
1753                                struct se_lun *lun)
1754 {
1755         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1756                                 struct vhost_scsi_tpg, se_tpg);
1757
1758         mutex_lock(&vhost_scsi_mutex);
1759
1760         mutex_lock(&tpg->tv_tpg_mutex);
1761         tpg->tv_tpg_port_count++;
1762         mutex_unlock(&tpg->tv_tpg_mutex);
1763
1764         vhost_scsi_hotplug(tpg, lun);
1765
1766         mutex_unlock(&vhost_scsi_mutex);
1767
1768         return 0;
1769 }
1770
1771 static void vhost_scsi_port_unlink(struct se_portal_group *se_tpg,
1772                                   struct se_lun *lun)
1773 {
1774         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1775                                 struct vhost_scsi_tpg, se_tpg);
1776
1777         mutex_lock(&vhost_scsi_mutex);
1778
1779         mutex_lock(&tpg->tv_tpg_mutex);
1780         tpg->tv_tpg_port_count--;
1781         mutex_unlock(&tpg->tv_tpg_mutex);
1782
1783         vhost_scsi_hotunplug(tpg, lun);
1784
1785         mutex_unlock(&vhost_scsi_mutex);
1786 }
1787
1788 static void vhost_scsi_free_cmd_map_res(struct vhost_scsi_nexus *nexus,
1789                                        struct se_session *se_sess)
1790 {
1791         struct vhost_scsi_cmd *tv_cmd;
1792         unsigned int i;
1793
1794         if (!se_sess->sess_cmd_map)
1795                 return;
1796
1797         for (i = 0; i < VHOST_SCSI_DEFAULT_TAGS; i++) {
1798                 tv_cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[i];
1799
1800                 kfree(tv_cmd->tvc_sgl);
1801                 kfree(tv_cmd->tvc_prot_sgl);
1802                 kfree(tv_cmd->tvc_upages);
1803         }
1804 }
1805
1806 static ssize_t vhost_scsi_tpg_attrib_store_fabric_prot_type(
1807         struct se_portal_group *se_tpg,
1808         const char *page,
1809         size_t count)
1810 {
1811         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1812                                 struct vhost_scsi_tpg, se_tpg);
1813         unsigned long val;
1814         int ret = kstrtoul(page, 0, &val);
1815
1816         if (ret) {
1817                 pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
1818                 return ret;
1819         }
1820         if (val != 0 && val != 1 && val != 3) {
1821                 pr_err("Invalid vhost_scsi fabric_prot_type: %lu\n", val);
1822                 return -EINVAL;
1823         }
1824         tpg->tv_fabric_prot_type = val;
1825
1826         return count;
1827 }
1828
1829 static ssize_t vhost_scsi_tpg_attrib_show_fabric_prot_type(
1830         struct se_portal_group *se_tpg,
1831         char *page)
1832 {
1833         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1834                                 struct vhost_scsi_tpg, se_tpg);
1835
1836         return sprintf(page, "%d\n", tpg->tv_fabric_prot_type);
1837 }
1838 TF_TPG_ATTRIB_ATTR(vhost_scsi, fabric_prot_type, S_IRUGO | S_IWUSR);
1839
1840 static struct configfs_attribute *vhost_scsi_tpg_attrib_attrs[] = {
1841         &vhost_scsi_tpg_attrib_fabric_prot_type.attr,
1842         NULL,
1843 };
1844
1845 static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
1846                                 const char *name)
1847 {
1848         struct se_portal_group *se_tpg;
1849         struct se_session *se_sess;
1850         struct vhost_scsi_nexus *tv_nexus;
1851         struct vhost_scsi_cmd *tv_cmd;
1852         unsigned int i;
1853
1854         mutex_lock(&tpg->tv_tpg_mutex);
1855         if (tpg->tpg_nexus) {
1856                 mutex_unlock(&tpg->tv_tpg_mutex);
1857                 pr_debug("tpg->tpg_nexus already exists\n");
1858                 return -EEXIST;
1859         }
1860         se_tpg = &tpg->se_tpg;
1861
1862         tv_nexus = kzalloc(sizeof(struct vhost_scsi_nexus), GFP_KERNEL);
1863         if (!tv_nexus) {
1864                 mutex_unlock(&tpg->tv_tpg_mutex);
1865                 pr_err("Unable to allocate struct vhost_scsi_nexus\n");
1866                 return -ENOMEM;
1867         }
1868         /*
1869          *  Initialize the struct se_session pointer and setup tagpool
1870          *  for struct vhost_scsi_cmd descriptors
1871          */
1872         tv_nexus->tvn_se_sess = transport_init_session_tags(
1873                                         VHOST_SCSI_DEFAULT_TAGS,
1874                                         sizeof(struct vhost_scsi_cmd),
1875                                         TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS);
1876         if (IS_ERR(tv_nexus->tvn_se_sess)) {
1877                 mutex_unlock(&tpg->tv_tpg_mutex);
1878                 kfree(tv_nexus);
1879                 return -ENOMEM;
1880         }
1881         se_sess = tv_nexus->tvn_se_sess;
1882         for (i = 0; i < VHOST_SCSI_DEFAULT_TAGS; i++) {
1883                 tv_cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[i];
1884
1885                 tv_cmd->tvc_sgl = kzalloc(sizeof(struct scatterlist) *
1886                                         VHOST_SCSI_PREALLOC_SGLS, GFP_KERNEL);
1887                 if (!tv_cmd->tvc_sgl) {
1888                         mutex_unlock(&tpg->tv_tpg_mutex);
1889                         pr_err("Unable to allocate tv_cmd->tvc_sgl\n");
1890                         goto out;
1891                 }
1892
1893                 tv_cmd->tvc_upages = kzalloc(sizeof(struct page *) *
1894                                         VHOST_SCSI_PREALLOC_UPAGES, GFP_KERNEL);
1895                 if (!tv_cmd->tvc_upages) {
1896                         mutex_unlock(&tpg->tv_tpg_mutex);
1897                         pr_err("Unable to allocate tv_cmd->tvc_upages\n");
1898                         goto out;
1899                 }
1900
1901                 tv_cmd->tvc_prot_sgl = kzalloc(sizeof(struct scatterlist) *
1902                                         VHOST_SCSI_PREALLOC_PROT_SGLS, GFP_KERNEL);
1903                 if (!tv_cmd->tvc_prot_sgl) {
1904                         mutex_unlock(&tpg->tv_tpg_mutex);
1905                         pr_err("Unable to allocate tv_cmd->tvc_prot_sgl\n");
1906                         goto out;
1907                 }
1908         }
1909         /*
1910          * Since we are running in 'demo mode' this call with generate a
1911          * struct se_node_acl for the vhost_scsi struct se_portal_group with
1912          * the SCSI Initiator port name of the passed configfs group 'name'.
1913          */
1914         tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1915                                 se_tpg, (unsigned char *)name);
1916         if (!tv_nexus->tvn_se_sess->se_node_acl) {
1917                 mutex_unlock(&tpg->tv_tpg_mutex);
1918                 pr_debug("core_tpg_check_initiator_node_acl() failed"
1919                                 " for %s\n", name);
1920                 goto out;
1921         }
1922         /*
1923          * Now register the TCM vhost virtual I_T Nexus as active.
1924          */
1925         transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
1926                         tv_nexus->tvn_se_sess, tv_nexus);
1927         tpg->tpg_nexus = tv_nexus;
1928
1929         mutex_unlock(&tpg->tv_tpg_mutex);
1930         return 0;
1931
1932 out:
1933         vhost_scsi_free_cmd_map_res(tv_nexus, se_sess);
1934         transport_free_session(se_sess);
1935         kfree(tv_nexus);
1936         return -ENOMEM;
1937 }
1938
1939 static int vhost_scsi_drop_nexus(struct vhost_scsi_tpg *tpg)
1940 {
1941         struct se_session *se_sess;
1942         struct vhost_scsi_nexus *tv_nexus;
1943
1944         mutex_lock(&tpg->tv_tpg_mutex);
1945         tv_nexus = tpg->tpg_nexus;
1946         if (!tv_nexus) {
1947                 mutex_unlock(&tpg->tv_tpg_mutex);
1948                 return -ENODEV;
1949         }
1950
1951         se_sess = tv_nexus->tvn_se_sess;
1952         if (!se_sess) {
1953                 mutex_unlock(&tpg->tv_tpg_mutex);
1954                 return -ENODEV;
1955         }
1956
1957         if (tpg->tv_tpg_port_count != 0) {
1958                 mutex_unlock(&tpg->tv_tpg_mutex);
1959                 pr_err("Unable to remove TCM_vhost I_T Nexus with"
1960                         " active TPG port count: %d\n",
1961                         tpg->tv_tpg_port_count);
1962                 return -EBUSY;
1963         }
1964
1965         if (tpg->tv_tpg_vhost_count != 0) {
1966                 mutex_unlock(&tpg->tv_tpg_mutex);
1967                 pr_err("Unable to remove TCM_vhost I_T Nexus with"
1968                         " active TPG vhost count: %d\n",
1969                         tpg->tv_tpg_vhost_count);
1970                 return -EBUSY;
1971         }
1972
1973         pr_debug("TCM_vhost_ConfigFS: Removing I_T Nexus to emulated"
1974                 " %s Initiator Port: %s\n", vhost_scsi_dump_proto_id(tpg->tport),
1975                 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1976
1977         vhost_scsi_free_cmd_map_res(tv_nexus, se_sess);
1978         /*
1979          * Release the SCSI I_T Nexus to the emulated vhost Target Port
1980          */
1981         transport_deregister_session(tv_nexus->tvn_se_sess);
1982         tpg->tpg_nexus = NULL;
1983         mutex_unlock(&tpg->tv_tpg_mutex);
1984
1985         kfree(tv_nexus);
1986         return 0;
1987 }
1988
1989 static ssize_t vhost_scsi_tpg_show_nexus(struct se_portal_group *se_tpg,
1990                                         char *page)
1991 {
1992         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1993                                 struct vhost_scsi_tpg, se_tpg);
1994         struct vhost_scsi_nexus *tv_nexus;
1995         ssize_t ret;
1996
1997         mutex_lock(&tpg->tv_tpg_mutex);
1998         tv_nexus = tpg->tpg_nexus;
1999         if (!tv_nexus) {
2000                 mutex_unlock(&tpg->tv_tpg_mutex);
2001                 return -ENODEV;
2002         }
2003         ret = snprintf(page, PAGE_SIZE, "%s\n",
2004                         tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
2005         mutex_unlock(&tpg->tv_tpg_mutex);
2006
2007         return ret;
2008 }
2009
2010 static ssize_t vhost_scsi_tpg_store_nexus(struct se_portal_group *se_tpg,
2011                                          const char *page,
2012                                          size_t count)
2013 {
2014         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2015                                 struct vhost_scsi_tpg, se_tpg);
2016         struct vhost_scsi_tport *tport_wwn = tpg->tport;
2017         unsigned char i_port[VHOST_SCSI_NAMELEN], *ptr, *port_ptr;
2018         int ret;
2019         /*
2020          * Shutdown the active I_T nexus if 'NULL' is passed..
2021          */
2022         if (!strncmp(page, "NULL", 4)) {
2023                 ret = vhost_scsi_drop_nexus(tpg);
2024                 return (!ret) ? count : ret;
2025         }
2026         /*
2027          * Otherwise make sure the passed virtual Initiator port WWN matches
2028          * the fabric protocol_id set in vhost_scsi_make_tport(), and call
2029          * vhost_scsi_make_nexus().
2030          */
2031         if (strlen(page) >= VHOST_SCSI_NAMELEN) {
2032                 pr_err("Emulated NAA Sas Address: %s, exceeds"
2033                                 " max: %d\n", page, VHOST_SCSI_NAMELEN);
2034                 return -EINVAL;
2035         }
2036         snprintf(&i_port[0], VHOST_SCSI_NAMELEN, "%s", page);
2037
2038         ptr = strstr(i_port, "naa.");
2039         if (ptr) {
2040                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
2041                         pr_err("Passed SAS Initiator Port %s does not"
2042                                 " match target port protoid: %s\n", i_port,
2043                                 vhost_scsi_dump_proto_id(tport_wwn));
2044                         return -EINVAL;
2045                 }
2046                 port_ptr = &i_port[0];
2047                 goto check_newline;
2048         }
2049         ptr = strstr(i_port, "fc.");
2050         if (ptr) {
2051                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
2052                         pr_err("Passed FCP Initiator Port %s does not"
2053                                 " match target port protoid: %s\n", i_port,
2054                                 vhost_scsi_dump_proto_id(tport_wwn));
2055                         return -EINVAL;
2056                 }
2057                 port_ptr = &i_port[3]; /* Skip over "fc." */
2058                 goto check_newline;
2059         }
2060         ptr = strstr(i_port, "iqn.");
2061         if (ptr) {
2062                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
2063                         pr_err("Passed iSCSI Initiator Port %s does not"
2064                                 " match target port protoid: %s\n", i_port,
2065                                 vhost_scsi_dump_proto_id(tport_wwn));
2066                         return -EINVAL;
2067                 }
2068                 port_ptr = &i_port[0];
2069                 goto check_newline;
2070         }
2071         pr_err("Unable to locate prefix for emulated Initiator Port:"
2072                         " %s\n", i_port);
2073         return -EINVAL;
2074         /*
2075          * Clear any trailing newline for the NAA WWN
2076          */
2077 check_newline:
2078         if (i_port[strlen(i_port)-1] == '\n')
2079                 i_port[strlen(i_port)-1] = '\0';
2080
2081         ret = vhost_scsi_make_nexus(tpg, port_ptr);
2082         if (ret < 0)
2083                 return ret;
2084
2085         return count;
2086 }
2087
2088 TF_TPG_BASE_ATTR(vhost_scsi, nexus, S_IRUGO | S_IWUSR);
2089
2090 static struct configfs_attribute *vhost_scsi_tpg_attrs[] = {
2091         &vhost_scsi_tpg_nexus.attr,
2092         NULL,
2093 };
2094
2095 static struct se_portal_group *
2096 vhost_scsi_make_tpg(struct se_wwn *wwn,
2097                    struct config_group *group,
2098                    const char *name)
2099 {
2100         struct vhost_scsi_tport *tport = container_of(wwn,
2101                         struct vhost_scsi_tport, tport_wwn);
2102
2103         struct vhost_scsi_tpg *tpg;
2104         u16 tpgt;
2105         int ret;
2106
2107         if (strstr(name, "tpgt_") != name)
2108                 return ERR_PTR(-EINVAL);
2109         if (kstrtou16(name + 5, 10, &tpgt) || tpgt >= VHOST_SCSI_MAX_TARGET)
2110                 return ERR_PTR(-EINVAL);
2111
2112         tpg = kzalloc(sizeof(struct vhost_scsi_tpg), GFP_KERNEL);
2113         if (!tpg) {
2114                 pr_err("Unable to allocate struct vhost_scsi_tpg");
2115                 return ERR_PTR(-ENOMEM);
2116         }
2117         mutex_init(&tpg->tv_tpg_mutex);
2118         INIT_LIST_HEAD(&tpg->tv_tpg_list);
2119         tpg->tport = tport;
2120         tpg->tport_tpgt = tpgt;
2121
2122         ret = core_tpg_register(&vhost_scsi_ops, wwn,
2123                                 &tpg->se_tpg, tpg, TRANSPORT_TPG_TYPE_NORMAL);
2124         if (ret < 0) {
2125                 kfree(tpg);
2126                 return NULL;
2127         }
2128         mutex_lock(&vhost_scsi_mutex);
2129         list_add_tail(&tpg->tv_tpg_list, &vhost_scsi_list);
2130         mutex_unlock(&vhost_scsi_mutex);
2131
2132         return &tpg->se_tpg;
2133 }
2134
2135 static void vhost_scsi_drop_tpg(struct se_portal_group *se_tpg)
2136 {
2137         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2138                                 struct vhost_scsi_tpg, se_tpg);
2139
2140         mutex_lock(&vhost_scsi_mutex);
2141         list_del(&tpg->tv_tpg_list);
2142         mutex_unlock(&vhost_scsi_mutex);
2143         /*
2144          * Release the virtual I_T Nexus for this vhost TPG
2145          */
2146         vhost_scsi_drop_nexus(tpg);
2147         /*
2148          * Deregister the se_tpg from TCM..
2149          */
2150         core_tpg_deregister(se_tpg);
2151         kfree(tpg);
2152 }
2153
2154 static struct se_wwn *
2155 vhost_scsi_make_tport(struct target_fabric_configfs *tf,
2156                      struct config_group *group,
2157                      const char *name)
2158 {
2159         struct vhost_scsi_tport *tport;
2160         char *ptr;
2161         u64 wwpn = 0;
2162         int off = 0;
2163
2164         /* if (vhost_scsi_parse_wwn(name, &wwpn, 1) < 0)
2165                 return ERR_PTR(-EINVAL); */
2166
2167         tport = kzalloc(sizeof(struct vhost_scsi_tport), GFP_KERNEL);
2168         if (!tport) {
2169                 pr_err("Unable to allocate struct vhost_scsi_tport");
2170                 return ERR_PTR(-ENOMEM);
2171         }
2172         tport->tport_wwpn = wwpn;
2173         /*
2174          * Determine the emulated Protocol Identifier and Target Port Name
2175          * based on the incoming configfs directory name.
2176          */
2177         ptr = strstr(name, "naa.");
2178         if (ptr) {
2179                 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
2180                 goto check_len;
2181         }
2182         ptr = strstr(name, "fc.");
2183         if (ptr) {
2184                 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
2185                 off = 3; /* Skip over "fc." */
2186                 goto check_len;
2187         }
2188         ptr = strstr(name, "iqn.");
2189         if (ptr) {
2190                 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
2191                 goto check_len;
2192         }
2193
2194         pr_err("Unable to locate prefix for emulated Target Port:"
2195                         " %s\n", name);
2196         kfree(tport);
2197         return ERR_PTR(-EINVAL);
2198
2199 check_len:
2200         if (strlen(name) >= VHOST_SCSI_NAMELEN) {
2201                 pr_err("Emulated %s Address: %s, exceeds"
2202                         " max: %d\n", name, vhost_scsi_dump_proto_id(tport),
2203                         VHOST_SCSI_NAMELEN);
2204                 kfree(tport);
2205                 return ERR_PTR(-EINVAL);
2206         }
2207         snprintf(&tport->tport_name[0], VHOST_SCSI_NAMELEN, "%s", &name[off]);
2208
2209         pr_debug("TCM_VHost_ConfigFS: Allocated emulated Target"
2210                 " %s Address: %s\n", vhost_scsi_dump_proto_id(tport), name);
2211
2212         return &tport->tport_wwn;
2213 }
2214
2215 static void vhost_scsi_drop_tport(struct se_wwn *wwn)
2216 {
2217         struct vhost_scsi_tport *tport = container_of(wwn,
2218                                 struct vhost_scsi_tport, tport_wwn);
2219
2220         pr_debug("TCM_VHost_ConfigFS: Deallocating emulated Target"
2221                 " %s Address: %s\n", vhost_scsi_dump_proto_id(tport),
2222                 tport->tport_name);
2223
2224         kfree(tport);
2225 }
2226
2227 static ssize_t
2228 vhost_scsi_wwn_show_attr_version(struct target_fabric_configfs *tf,
2229                                 char *page)
2230 {
2231         return sprintf(page, "TCM_VHOST fabric module %s on %s/%s"
2232                 "on "UTS_RELEASE"\n", VHOST_SCSI_VERSION, utsname()->sysname,
2233                 utsname()->machine);
2234 }
2235
2236 TF_WWN_ATTR_RO(vhost_scsi, version);
2237
2238 static struct configfs_attribute *vhost_scsi_wwn_attrs[] = {
2239         &vhost_scsi_wwn_version.attr,
2240         NULL,
2241 };
2242
2243 static struct target_core_fabric_ops vhost_scsi_ops = {
2244         .module                         = THIS_MODULE,
2245         .name                           = "vhost",
2246         .get_fabric_name                = vhost_scsi_get_fabric_name,
2247         .get_fabric_proto_ident         = vhost_scsi_get_fabric_proto_ident,
2248         .tpg_get_wwn                    = vhost_scsi_get_fabric_wwn,
2249         .tpg_get_tag                    = vhost_scsi_get_tpgt,
2250         .tpg_get_pr_transport_id        = vhost_scsi_get_pr_transport_id,
2251         .tpg_get_pr_transport_id_len    = vhost_scsi_get_pr_transport_id_len,
2252         .tpg_parse_pr_out_transport_id  = vhost_scsi_parse_pr_out_transport_id,
2253         .tpg_check_demo_mode            = vhost_scsi_check_true,
2254         .tpg_check_demo_mode_cache      = vhost_scsi_check_true,
2255         .tpg_check_demo_mode_write_protect = vhost_scsi_check_false,
2256         .tpg_check_prod_mode_write_protect = vhost_scsi_check_false,
2257         .tpg_check_prot_fabric_only     = vhost_scsi_check_prot_fabric_only,
2258         .tpg_get_inst_index             = vhost_scsi_tpg_get_inst_index,
2259         .release_cmd                    = vhost_scsi_release_cmd,
2260         .check_stop_free                = vhost_scsi_check_stop_free,
2261         .shutdown_session               = vhost_scsi_shutdown_session,
2262         .close_session                  = vhost_scsi_close_session,
2263         .sess_get_index                 = vhost_scsi_sess_get_index,
2264         .sess_get_initiator_sid         = NULL,
2265         .write_pending                  = vhost_scsi_write_pending,
2266         .write_pending_status           = vhost_scsi_write_pending_status,
2267         .set_default_node_attributes    = vhost_scsi_set_default_node_attrs,
2268         .get_task_tag                   = vhost_scsi_get_task_tag,
2269         .get_cmd_state                  = vhost_scsi_get_cmd_state,
2270         .queue_data_in                  = vhost_scsi_queue_data_in,
2271         .queue_status                   = vhost_scsi_queue_status,
2272         .queue_tm_rsp                   = vhost_scsi_queue_tm_rsp,
2273         .aborted_task                   = vhost_scsi_aborted_task,
2274         /*
2275          * Setup callers for generic logic in target_core_fabric_configfs.c
2276          */
2277         .fabric_make_wwn                = vhost_scsi_make_tport,
2278         .fabric_drop_wwn                = vhost_scsi_drop_tport,
2279         .fabric_make_tpg                = vhost_scsi_make_tpg,
2280         .fabric_drop_tpg                = vhost_scsi_drop_tpg,
2281         .fabric_post_link               = vhost_scsi_port_link,
2282         .fabric_pre_unlink              = vhost_scsi_port_unlink,
2283
2284         .tfc_wwn_attrs                  = vhost_scsi_wwn_attrs,
2285         .tfc_tpg_base_attrs             = vhost_scsi_tpg_attrs,
2286         .tfc_tpg_attrib_attrs           = vhost_scsi_tpg_attrib_attrs,
2287 };
2288
2289 static int __init vhost_scsi_init(void)
2290 {
2291         int ret = -ENOMEM;
2292
2293         pr_debug("TCM_VHOST fabric module %s on %s/%s"
2294                 " on "UTS_RELEASE"\n", VHOST_SCSI_VERSION, utsname()->sysname,
2295                 utsname()->machine);
2296
2297         /*
2298          * Use our own dedicated workqueue for submitting I/O into
2299          * target core to avoid contention within system_wq.
2300          */
2301         vhost_scsi_workqueue = alloc_workqueue("vhost_scsi", 0, 0);
2302         if (!vhost_scsi_workqueue)
2303                 goto out;
2304
2305         ret = vhost_scsi_register();
2306         if (ret < 0)
2307                 goto out_destroy_workqueue;
2308
2309         ret = target_register_template(&vhost_scsi_ops);
2310         if (ret < 0)
2311                 goto out_vhost_scsi_deregister;
2312
2313         return 0;
2314
2315 out_vhost_scsi_deregister:
2316         vhost_scsi_deregister();
2317 out_destroy_workqueue:
2318         destroy_workqueue(vhost_scsi_workqueue);
2319 out:
2320         return ret;
2321 };
2322
2323 static void vhost_scsi_exit(void)
2324 {
2325         target_unregister_template(&vhost_scsi_ops);
2326         vhost_scsi_deregister();
2327         destroy_workqueue(vhost_scsi_workqueue);
2328 };
2329
2330 MODULE_DESCRIPTION("VHOST_SCSI series fabric driver");
2331 MODULE_ALIAS("tcm_vhost");
2332 MODULE_LICENSE("GPL");
2333 module_init(vhost_scsi_init);
2334 module_exit(vhost_scsi_exit);