drivers/vhost/scsi.c

   1 /*******************************************************************************
   2  * Vhost kernel TCM fabric driver for virtio SCSI initiators
   3  *
   4  * (C) Copyright 2010-2012 RisingTide Systems LLC.
   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@risingtidesystems.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 <scsi/scsi_tcq.h>
  42 #include <target/target_core_base.h>
  43 #include <target/target_core_fabric.h>
  44 #include <target/target_core_fabric_configfs.h>
  45 #include <target/target_core_configfs.h>
  46 #include <target/configfs_macros.h>
  47 #include <linux/vhost.h>
  48 #include <linux/virtio_scsi.h>
  49 #include <linux/llist.h>
  50 #include <linux/bitmap.h>
  51
  52 #include "vhost.c"
  53 #include "vhost.h"
  54
  55 #define TCM_VHOST_VERSION  "v0.1"
  56 #define TCM_VHOST_NAMELEN 256
  57 #define TCM_VHOST_MAX_CDB_SIZE 32
  58
  59 struct vhost_scsi_inflight {
  60         /* Wait for the flush operation to finish */
  61         struct completion comp;
  62         /* Refcount for the inflight reqs */
  63         struct kref kref;
  64 };
  65
  66 struct tcm_vhost_cmd {
  67         /* Descriptor from vhost_get_vq_desc() for virt_queue segment */
  68         int tvc_vq_desc;
  69         /* virtio-scsi initiator task attribute */
  70         int tvc_task_attr;
  71         /* virtio-scsi initiator data direction */
  72         enum dma_data_direction tvc_data_direction;
  73         /* Expected data transfer length from virtio-scsi header */
  74         u32 tvc_exp_data_len;
  75         /* The Tag from include/linux/virtio_scsi.h:struct virtio_scsi_cmd_req */
  76         u64 tvc_tag;
  77         /* The number of scatterlists associated with this cmd */
  78         u32 tvc_sgl_count;
  79         /* Saved unpacked SCSI LUN for tcm_vhost_submission_work() */
  80         u32 tvc_lun;
  81         /* Pointer to the SGL formatted memory from virtio-scsi */
  82         struct scatterlist *tvc_sgl;
  83         /* Pointer to response */
  84         struct virtio_scsi_cmd_resp __user *tvc_resp;
  85         /* Pointer to vhost_scsi for our device */
  86         struct vhost_scsi *tvc_vhost;
  87         /* Pointer to vhost_virtqueue for the cmd */
  88         struct vhost_virtqueue *tvc_vq;
  89         /* Pointer to vhost nexus memory */
  90         struct tcm_vhost_nexus *tvc_nexus;
  91         /* The TCM I/O descriptor that is accessed via container_of() */
  92         struct se_cmd tvc_se_cmd;
  93         /* work item used for cmwq dispatch to tcm_vhost_submission_work() */
  94         struct work_struct work;
  95         /* Copy of the incoming SCSI command descriptor block (CDB) */
  96         unsigned char tvc_cdb[TCM_VHOST_MAX_CDB_SIZE];
  97         /* Sense buffer that will be mapped into outgoing status */
  98         unsigned char tvc_sense_buf[TRANSPORT_SENSE_BUFFER];
  99         /* Completed commands list, serviced from vhost worker thread */
 100         struct llist_node tvc_completion_list;
 101         /* Used to track inflight cmd */
 102         struct vhost_scsi_inflight *inflight;
 103 };
 104
 105 struct tcm_vhost_nexus {
 106         /* Pointer to TCM session for I_T Nexus */
 107         struct se_session *tvn_se_sess;
 108 };
 109
 110 struct tcm_vhost_nacl {
 111         /* Binary World Wide unique Port Name for Vhost Initiator port */
 112         u64 iport_wwpn;
 113         /* ASCII formatted WWPN for Sas Initiator port */
 114         char iport_name[TCM_VHOST_NAMELEN];
 115         /* Returned by tcm_vhost_make_nodeacl() */
 116         struct se_node_acl se_node_acl;
 117 };
 118
 119 struct vhost_scsi;
 120 struct tcm_vhost_tpg {
 121         /* Vhost port target portal group tag for TCM */
 122         u16 tport_tpgt;
 123         /* Used to track number of TPG Port/Lun Links wrt to explict I_T Nexus shutdown */
 124         int tv_tpg_port_count;
 125         /* Used for vhost_scsi device reference to tpg_nexus, protected by tv_tpg_mutex */
 126         int tv_tpg_vhost_count;
 127         /* list for tcm_vhost_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 tcm_vhost_nexus *tpg_nexus;
 133         /* Pointer back to tcm_vhost_tport */
 134         struct tcm_vhost_tport *tport;
 135         /* Returned by tcm_vhost_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 tcm_vhost_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[TCM_VHOST_NAMELEN];
 148         /* Returned by tcm_vhost_make_tport() */
 149         struct se_wwn tport_wwn;
 150 };
 151
 152 struct tcm_vhost_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 enum {
 166         VHOST_SCSI_FEATURES = VHOST_FEATURES | (1ULL << VIRTIO_SCSI_F_HOTPLUG)
 167 };
 168
 169 #define VHOST_SCSI_MAX_TARGET   256
 170 #define VHOST_SCSI_MAX_VQ       128
 171 #define VHOST_SCSI_MAX_EVENT    128
 172
 173 struct vhost_scsi_virtqueue {
 174         struct vhost_virtqueue vq;
 175         /*
 176          * Reference counting for inflight reqs, used for flush operation. At
 177          * each time, one reference tracks new commands submitted, while we
 178          * wait for another one to reach 0.
 179          */
 180         struct vhost_scsi_inflight inflights[2];
 181         /*
 182          * Indicate current inflight in use, protected by vq->mutex.
 183          * Writers must also take dev mutex and flush under it.
 184          */
 185         int inflight_idx;
 186 };
 187
 188 struct vhost_scsi {
 189         /* Protected by vhost_scsi->dev.mutex */
 190         struct tcm_vhost_tpg **vs_tpg;
 191         char vs_vhost_wwpn[TRANSPORT_IQN_LEN];
 192
 193         struct vhost_dev dev;
 194         struct vhost_scsi_virtqueue vqs[VHOST_SCSI_MAX_VQ];
 195
 196         struct vhost_work vs_completion_work; /* cmd completion work item */
 197         struct llist_head vs_completion_list; /* cmd completion queue */
 198
 199         struct vhost_work vs_event_work; /* evt injection work item */
 200         struct llist_head vs_event_list; /* evt injection queue */
 201
 202         bool vs_events_missed; /* any missed events, protected by vq->mutex */
 203         int vs_events_nr; /* num of pending events, protected by vq->mutex */
 204 };
 205
 206 /* Local pointer to allocated TCM configfs fabric module */
 207 static struct target_fabric_configfs *tcm_vhost_fabric_configfs;
 208
 209 static struct workqueue_struct *tcm_vhost_workqueue;
 210
 211 /* Global spinlock to protect tcm_vhost TPG list for vhost IOCTL access */
 212 static DEFINE_MUTEX(tcm_vhost_mutex);
 213 static LIST_HEAD(tcm_vhost_list);
 214
 215 static int iov_num_pages(struct iovec *iov)
 216 {
 217         return (PAGE_ALIGN((unsigned long)iov->iov_base + iov->iov_len) -
 218                ((unsigned long)iov->iov_base & PAGE_MASK)) >> PAGE_SHIFT;
 219 }
 220
 221 void tcm_vhost_done_inflight(struct kref *kref)
 222 {
 223         struct vhost_scsi_inflight *inflight;
 224
 225         inflight = container_of(kref, struct vhost_scsi_inflight, kref);
 226         complete(&inflight->comp);
 227 }
 228
 229 static void tcm_vhost_init_inflight(struct vhost_scsi *vs,
 230                                     struct vhost_scsi_inflight *old_inflight[])
 231 {
 232         struct vhost_scsi_inflight *new_inflight;
 233         struct vhost_virtqueue *vq;
 234         int idx, i;
 235
 236         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
 237                 vq = &vs->vqs[i].vq;
 238
 239                 mutex_lock(&vq->mutex);
 240
 241                 /* store old infight */
 242                 idx = vs->vqs[i].inflight_idx;
 243                 if (old_inflight)
 244                         old_inflight[i] = &vs->vqs[i].inflights[idx];
 245
 246                 /* setup new infight */
 247                 vs->vqs[i].inflight_idx = idx ^ 1;
 248                 new_inflight = &vs->vqs[i].inflights[idx ^ 1];
 249                 kref_init(&new_inflight->kref);
 250                 init_completion(&new_inflight->comp);
 251
 252                 mutex_unlock(&vq->mutex);
 253         }
 254 }
 255
 256 static struct vhost_scsi_inflight *
 257 tcm_vhost_get_inflight(struct vhost_virtqueue *vq)
 258 {
 259         struct vhost_scsi_inflight *inflight;
 260         struct vhost_scsi_virtqueue *svq;
 261
 262         svq = container_of(vq, struct vhost_scsi_virtqueue, vq);
 263         inflight = &svq->inflights[svq->inflight_idx];
 264         kref_get(&inflight->kref);
 265
 266         return inflight;
 267 }
 268
 269 static void tcm_vhost_put_inflight(struct vhost_scsi_inflight *inflight)
 270 {
 271         kref_put(&inflight->kref, tcm_vhost_done_inflight);
 272 }
 273
 274 static int tcm_vhost_check_true(struct se_portal_group *se_tpg)
 275 {
 276         return 1;
 277 }
 278
 279 static int tcm_vhost_check_false(struct se_portal_group *se_tpg)
 280 {
 281         return 0;
 282 }
 283
 284 static char *tcm_vhost_get_fabric_name(void)
 285 {
 286         return "vhost";
 287 }
 288
 289 static u8 tcm_vhost_get_fabric_proto_ident(struct se_portal_group *se_tpg)
 290 {
 291         struct tcm_vhost_tpg *tpg = container_of(se_tpg,
 292                                 struct tcm_vhost_tpg, se_tpg);
 293         struct tcm_vhost_tport *tport = tpg->tport;
 294
 295         switch (tport->tport_proto_id) {
 296         case SCSI_PROTOCOL_SAS:
 297                 return sas_get_fabric_proto_ident(se_tpg);
 298         case SCSI_PROTOCOL_FCP:
 299                 return fc_get_fabric_proto_ident(se_tpg);
 300         case SCSI_PROTOCOL_ISCSI:
 301                 return iscsi_get_fabric_proto_ident(se_tpg);
 302         default:
 303                 pr_err("Unknown tport_proto_id: 0x%02x, using"
 304                         " SAS emulation\n", tport->tport_proto_id);
 305                 break;
 306         }
 307
 308         return sas_get_fabric_proto_ident(se_tpg);
 309 }
 310
 311 static char *tcm_vhost_get_fabric_wwn(struct se_portal_group *se_tpg)
 312 {
 313         struct tcm_vhost_tpg *tpg = container_of(se_tpg,
 314                                 struct tcm_vhost_tpg, se_tpg);
 315         struct tcm_vhost_tport *tport = tpg->tport;
 316
 317         return &tport->tport_name[0];
 318 }
 319
 320 static u16 tcm_vhost_get_tag(struct se_portal_group *se_tpg)
 321 {
 322         struct tcm_vhost_tpg *tpg = container_of(se_tpg,
 323                                 struct tcm_vhost_tpg, se_tpg);
 324         return tpg->tport_tpgt;
 325 }
 326
 327 static u32 tcm_vhost_get_default_depth(struct se_portal_group *se_tpg)
 328 {
 329         return 1;
 330 }
 331
 332 static u32 tcm_vhost_get_pr_transport_id(struct se_portal_group *se_tpg,
 333         struct se_node_acl *se_nacl,
 334         struct t10_pr_registration *pr_reg,
 335         int *format_code,
 336         unsigned char *buf)
 337 {
 338         struct tcm_vhost_tpg *tpg = container_of(se_tpg,
 339                                 struct tcm_vhost_tpg, se_tpg);
 340         struct tcm_vhost_tport *tport = tpg->tport;
 341
 342         switch (tport->tport_proto_id) {
 343         case SCSI_PROTOCOL_SAS:
 344                 return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 345                                         format_code, buf);
 346         case SCSI_PROTOCOL_FCP:
 347                 return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 348                                         format_code, buf);
 349         case SCSI_PROTOCOL_ISCSI:
 350                 return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 351                                         format_code, buf);
 352         default:
 353                 pr_err("Unknown tport_proto_id: 0x%02x, using"
 354                         " SAS emulation\n", tport->tport_proto_id);
 355                 break;
 356         }
 357
 358         return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 359                         format_code, buf);
 360 }
 361
 362 static u32 tcm_vhost_get_pr_transport_id_len(struct se_portal_group *se_tpg,
 363         struct se_node_acl *se_nacl,
 364         struct t10_pr_registration *pr_reg,
 365         int *format_code)
 366 {
 367         struct tcm_vhost_tpg *tpg = container_of(se_tpg,
 368                                 struct tcm_vhost_tpg, se_tpg);
 369         struct tcm_vhost_tport *tport = tpg->tport;
 370
 371         switch (tport->tport_proto_id) {
 372         case SCSI_PROTOCOL_SAS:
 373                 return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 374                                         format_code);
 375         case SCSI_PROTOCOL_FCP:
 376                 return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 377                                         format_code);
 378         case SCSI_PROTOCOL_ISCSI:
 379                 return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 380                                         format_code);
 381         default:
 382                 pr_err("Unknown tport_proto_id: 0x%02x, using"
 383                         " SAS emulation\n", tport->tport_proto_id);
 384                 break;
 385         }
 386
 387         return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 388                         format_code);
 389 }
 390
 391 static char *tcm_vhost_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 tcm_vhost_tpg *tpg = container_of(se_tpg,
 397                                 struct tcm_vhost_tpg, se_tpg);
 398         struct tcm_vhost_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 struct se_node_acl *tcm_vhost_alloc_fabric_acl(
 421         struct se_portal_group *se_tpg)
 422 {
 423         struct tcm_vhost_nacl *nacl;
 424
 425         nacl = kzalloc(sizeof(struct tcm_vhost_nacl), GFP_KERNEL);
 426         if (!nacl) {
 427                 pr_err("Unable to allocate struct tcm_vhost_nacl\n");
 428                 return NULL;
 429         }
 430
 431         return &nacl->se_node_acl;
 432 }
 433
 434 static void tcm_vhost_release_fabric_acl(struct se_portal_group *se_tpg,
 435         struct se_node_acl *se_nacl)
 436 {
 437         struct tcm_vhost_nacl *nacl = container_of(se_nacl,
 438                         struct tcm_vhost_nacl, se_node_acl);
 439         kfree(nacl);
 440 }
 441
 442 static u32 tcm_vhost_tpg_get_inst_index(struct se_portal_group *se_tpg)
 443 {
 444         return 1;
 445 }
 446
 447 static void tcm_vhost_release_cmd(struct se_cmd *se_cmd)
 448 {
 449         struct tcm_vhost_cmd *tv_cmd = container_of(se_cmd,
 450                                 struct tcm_vhost_cmd, tvc_se_cmd);
 451
 452         if (tv_cmd->tvc_sgl_count) {
 453                 u32 i;
 454                 for (i = 0; i < tv_cmd->tvc_sgl_count; i++)
 455                         put_page(sg_page(&tv_cmd->tvc_sgl[i]));
 456
 457                 kfree(tv_cmd->tvc_sgl);
 458         }
 459
 460         tcm_vhost_put_inflight(tv_cmd->inflight);
 461         kfree(tv_cmd);
 462 }
 463
 464 static int tcm_vhost_shutdown_session(struct se_session *se_sess)
 465 {
 466         return 0;
 467 }
 468
 469 static void tcm_vhost_close_session(struct se_session *se_sess)
 470 {
 471         return;
 472 }
 473
 474 static u32 tcm_vhost_sess_get_index(struct se_session *se_sess)
 475 {
 476         return 0;
 477 }
 478
 479 static int tcm_vhost_write_pending(struct se_cmd *se_cmd)
 480 {
 481         /* Go ahead and process the write immediately */
 482         target_execute_cmd(se_cmd);
 483         return 0;
 484 }
 485
 486 static int tcm_vhost_write_pending_status(struct se_cmd *se_cmd)
 487 {
 488         return 0;
 489 }
 490
 491 static void tcm_vhost_set_default_node_attrs(struct se_node_acl *nacl)
 492 {
 493         return;
 494 }
 495
 496 static u32 tcm_vhost_get_task_tag(struct se_cmd *se_cmd)
 497 {
 498         return 0;
 499 }
 500
 501 static int tcm_vhost_get_cmd_state(struct se_cmd *se_cmd)
 502 {
 503         return 0;
 504 }
 505
 506 static void vhost_scsi_complete_cmd(struct tcm_vhost_cmd *tv_cmd)
 507 {
 508         struct vhost_scsi *vs = tv_cmd->tvc_vhost;
 509
 510         llist_add(&tv_cmd->tvc_completion_list, &vs->vs_completion_list);
 511
 512         vhost_work_queue(&vs->dev, &vs->vs_completion_work);
 513 }
 514
 515 static int tcm_vhost_queue_data_in(struct se_cmd *se_cmd)
 516 {
 517         struct tcm_vhost_cmd *tv_cmd = container_of(se_cmd,
 518                                 struct tcm_vhost_cmd, tvc_se_cmd);
 519         vhost_scsi_complete_cmd(tv_cmd);
 520         return 0;
 521 }
 522
 523 static int tcm_vhost_queue_status(struct se_cmd *se_cmd)
 524 {
 525         struct tcm_vhost_cmd *tv_cmd = container_of(se_cmd,
 526                                 struct tcm_vhost_cmd, tvc_se_cmd);
 527         vhost_scsi_complete_cmd(tv_cmd);
 528         return 0;
 529 }
 530
 531 static void tcm_vhost_queue_tm_rsp(struct se_cmd *se_cmd)
 532 {
 533         return;
 534 }
 535
 536 static void tcm_vhost_free_evt(struct vhost_scsi *vs, struct tcm_vhost_evt *evt)
 537 {
 538         vs->vs_events_nr--;
 539         kfree(evt);
 540 }
 541
 542 static struct tcm_vhost_evt *tcm_vhost_allocate_evt(struct vhost_scsi *vs,
 543         u32 event, u32 reason)
 544 {
 545         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 546         struct tcm_vhost_evt *evt;
 547
 548         if (vs->vs_events_nr > VHOST_SCSI_MAX_EVENT) {
 549                 vs->vs_events_missed = true;
 550                 return NULL;
 551         }
 552
 553         evt = kzalloc(sizeof(*evt), GFP_KERNEL);
 554         if (!evt) {
 555                 vq_err(vq, "Failed to allocate tcm_vhost_evt\n");
 556                 vs->vs_events_missed = true;
 557                 return NULL;
 558         }
 559
 560         evt->event.event = event;
 561         evt->event.reason = reason;
 562         vs->vs_events_nr++;
 563
 564         return evt;
 565 }
 566
 567 static void vhost_scsi_free_cmd(struct tcm_vhost_cmd *tv_cmd)
 568 {
 569         struct se_cmd *se_cmd = &tv_cmd->tvc_se_cmd;
 570
 571         /* TODO locking against target/backend threads? */
 572         transport_generic_free_cmd(se_cmd, 0);
 573
 574 }
 575
 576 static int vhost_scsi_check_stop_free(struct se_cmd *se_cmd)
 577 {
 578         return target_put_sess_cmd(se_cmd->se_sess, se_cmd);
 579 }
 580
 581 static void tcm_vhost_do_evt_work(struct vhost_scsi *vs,
 582         struct tcm_vhost_evt *evt)
 583 {
 584         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 585         struct virtio_scsi_event *event = &evt->event;
 586         struct virtio_scsi_event __user *eventp;
 587         unsigned out, in;
 588         int head, ret;
 589
 590         if (!vq->private_data) {
 591                 vs->vs_events_missed = true;
 592                 return;
 593         }
 594
 595 again:
 596         vhost_disable_notify(&vs->dev, vq);
 597         head = vhost_get_vq_desc(&vs->dev, vq, vq->iov,
 598                         ARRAY_SIZE(vq->iov), &out, &in,
 599                         NULL, NULL);
 600         if (head < 0) {
 601                 vs->vs_events_missed = true;
 602                 return;
 603         }
 604         if (head == vq->num) {
 605                 if (vhost_enable_notify(&vs->dev, vq))
 606                         goto again;
 607                 vs->vs_events_missed = true;
 608                 return;
 609         }
 610
 611         if ((vq->iov[out].iov_len != sizeof(struct virtio_scsi_event))) {
 612                 vq_err(vq, "Expecting virtio_scsi_event, got %zu bytes\n",
 613                                 vq->iov[out].iov_len);
 614                 vs->vs_events_missed = true;
 615                 return;
 616         }
 617
 618         if (vs->vs_events_missed) {
 619                 event->event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 620                 vs->vs_events_missed = false;
 621         }
 622
 623         eventp = vq->iov[out].iov_base;
 624         ret = __copy_to_user(eventp, event, sizeof(*event));
 625         if (!ret)
 626                 vhost_add_used_and_signal(&vs->dev, vq, head, 0);
 627         else
 628                 vq_err(vq, "Faulted on tcm_vhost_send_event\n");
 629 }
 630
 631 static void tcm_vhost_evt_work(struct vhost_work *work)
 632 {
 633         struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
 634                                         vs_event_work);
 635         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 636         struct tcm_vhost_evt *evt;
 637         struct llist_node *llnode;
 638
 639         mutex_lock(&vq->mutex);
 640         llnode = llist_del_all(&vs->vs_event_list);
 641         while (llnode) {
 642                 evt = llist_entry(llnode, struct tcm_vhost_evt, list);
 643                 llnode = llist_next(llnode);
 644                 tcm_vhost_do_evt_work(vs, evt);
 645                 tcm_vhost_free_evt(vs, evt);
 646         }
 647         mutex_unlock(&vq->mutex);
 648 }
 649
 650 /* Fill in status and signal that we are done processing this command
 651  *
 652  * This is scheduled in the vhost work queue so we are called with the owner
 653  * process mm and can access the vring.
 654  */
 655 static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
 656 {
 657         struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
 658                                         vs_completion_work);
 659         DECLARE_BITMAP(signal, VHOST_SCSI_MAX_VQ);
 660         struct virtio_scsi_cmd_resp v_rsp;
 661         struct tcm_vhost_cmd *tv_cmd;
 662         struct llist_node *llnode;
 663         struct se_cmd *se_cmd;
 664         int ret, vq;
 665
 666         bitmap_zero(signal, VHOST_SCSI_MAX_VQ);
 667         llnode = llist_del_all(&vs->vs_completion_list);
 668         while (llnode) {
 669                 tv_cmd = llist_entry(llnode, struct tcm_vhost_cmd,
 670                                      tvc_completion_list);
 671                 llnode = llist_next(llnode);
 672                 se_cmd = &tv_cmd->tvc_se_cmd;
 673
 674                 pr_debug("%s tv_cmd %p resid %u status %#02x\n", __func__,
 675                         tv_cmd, se_cmd->residual_count, se_cmd->scsi_status);
 676
 677                 memset(&v_rsp, 0, sizeof(v_rsp));
 678                 v_rsp.resid = se_cmd->residual_count;
 679                 /* TODO is status_qualifier field needed? */
 680                 v_rsp.status = se_cmd->scsi_status;
 681                 v_rsp.sense_len = se_cmd->scsi_sense_length;
 682                 memcpy(v_rsp.sense, tv_cmd->tvc_sense_buf,
 683                        v_rsp.sense_len);
 684                 ret = copy_to_user(tv_cmd->tvc_resp, &v_rsp, sizeof(v_rsp));
 685                 if (likely(ret == 0)) {
 686                         struct vhost_scsi_virtqueue *q;
 687                         vhost_add_used(tv_cmd->tvc_vq, tv_cmd->tvc_vq_desc, 0);
 688                         q = container_of(tv_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(tv_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 tcm_vhost_cmd *vhost_scsi_allocate_cmd(
 704         struct vhost_virtqueue *vq,
 705         struct tcm_vhost_tpg *tv_tpg,
 706         struct virtio_scsi_cmd_req *v_req,
 707         u32 exp_data_len,
 708         int data_direction)
 709 {
 710         struct tcm_vhost_cmd *tv_cmd;
 711         struct tcm_vhost_nexus *tv_nexus;
 712
 713         tv_nexus = tv_tpg->tpg_nexus;
 714         if (!tv_nexus) {
 715                 pr_err("Unable to locate active struct tcm_vhost_nexus\n");
 716                 return ERR_PTR(-EIO);
 717         }
 718
 719         tv_cmd = kzalloc(sizeof(struct tcm_vhost_cmd), GFP_ATOMIC);
 720         if (!tv_cmd) {
 721                 pr_err("Unable to allocate struct tcm_vhost_cmd\n");
 722                 return ERR_PTR(-ENOMEM);
 723         }
 724         tv_cmd->tvc_tag = v_req->tag;
 725         tv_cmd->tvc_task_attr = v_req->task_attr;
 726         tv_cmd->tvc_exp_data_len = exp_data_len;
 727         tv_cmd->tvc_data_direction = data_direction;
 728         tv_cmd->tvc_nexus = tv_nexus;
 729         tv_cmd->inflight = tcm_vhost_get_inflight(vq);
 730
 731         return tv_cmd;
 732 }
 733
 734 /*
 735  * Map a user memory range into a scatterlist
 736  *
 737  * Returns the number of scatterlist entries used or -errno on error.
 738  */
 739 static int vhost_scsi_map_to_sgl(struct scatterlist *sgl,
 740         unsigned int sgl_count, struct iovec *iov, int write)
 741 {
 742         unsigned int npages = 0, pages_nr, offset, nbytes;
 743         struct scatterlist *sg = sgl;
 744         void __user *ptr = iov->iov_base;
 745         size_t len = iov->iov_len;
 746         struct page **pages;
 747         int ret, i;
 748
 749         pages_nr = iov_num_pages(iov);
 750         if (pages_nr > sgl_count)
 751                 return -ENOBUFS;
 752
 753         pages = kmalloc(pages_nr * sizeof(struct page *), GFP_KERNEL);
 754         if (!pages)
 755                 return -ENOMEM;
 756
 757         ret = get_user_pages_fast((unsigned long)ptr, pages_nr, write, pages);
 758         /* No pages were pinned */
 759         if (ret < 0)
 760                 goto out;
 761         /* Less pages pinned than wanted */
 762         if (ret != pages_nr) {
 763                 for (i = 0; i < ret; i++)
 764                         put_page(pages[i]);
 765                 ret = -EFAULT;
 766                 goto out;
 767         }
 768
 769         while (len > 0) {
 770                 offset = (uintptr_t)ptr & ~PAGE_MASK;
 771                 nbytes = min_t(unsigned int, PAGE_SIZE - offset, len);
 772                 sg_set_page(sg, pages[npages], nbytes, offset);
 773                 ptr += nbytes;
 774                 len -= nbytes;
 775                 sg++;
 776                 npages++;
 777         }
 778
 779 out:
 780         kfree(pages);
 781         return ret;
 782 }
 783
 784 static int vhost_scsi_map_iov_to_sgl(struct tcm_vhost_cmd *tv_cmd,
 785         struct iovec *iov, unsigned int niov, int write)
 786 {
 787         int ret;
 788         unsigned int i;
 789         u32 sgl_count;
 790         struct scatterlist *sg;
 791
 792         /*
 793          * Find out how long sglist needs to be
 794          */
 795         sgl_count = 0;
 796         for (i = 0; i < niov; i++)
 797                 sgl_count += iov_num_pages(&iov[i]);
 798
 799         /* TODO overflow checking */
 800
 801         sg = kmalloc(sizeof(tv_cmd->tvc_sgl[0]) * sgl_count, GFP_ATOMIC);
 802         if (!sg)
 803                 return -ENOMEM;
 804         pr_debug("%s sg %p sgl_count %u is_err %d\n", __func__,
 805                sg, sgl_count, !sg);
 806         sg_init_table(sg, sgl_count);
 807
 808         tv_cmd->tvc_sgl = sg;
 809         tv_cmd->tvc_sgl_count = sgl_count;
 810
 811         pr_debug("Mapping %u iovecs for %u pages\n", niov, sgl_count);
 812         for (i = 0; i < niov; i++) {
 813                 ret = vhost_scsi_map_to_sgl(sg, sgl_count, &iov[i], write);
 814                 if (ret < 0) {
 815                         for (i = 0; i < tv_cmd->tvc_sgl_count; i++)
 816                                 put_page(sg_page(&tv_cmd->tvc_sgl[i]));
 817                         kfree(tv_cmd->tvc_sgl);
 818                         tv_cmd->tvc_sgl = NULL;
 819                         tv_cmd->tvc_sgl_count = 0;
 820                         return ret;
 821                 }
 822
 823                 sg += ret;
 824                 sgl_count -= ret;
 825         }
 826         return 0;
 827 }
 828
 829 static void tcm_vhost_submission_work(struct work_struct *work)
 830 {
 831         struct tcm_vhost_cmd *tv_cmd =
 832                 container_of(work, struct tcm_vhost_cmd, work);
 833         struct tcm_vhost_nexus *tv_nexus;
 834         struct se_cmd *se_cmd = &tv_cmd->tvc_se_cmd;
 835         struct scatterlist *sg_ptr, *sg_bidi_ptr = NULL;
 836         int rc, sg_no_bidi = 0;
 837
 838         if (tv_cmd->tvc_sgl_count) {
 839                 sg_ptr = tv_cmd->tvc_sgl;
 840 /* FIXME: Fix BIDI operation in tcm_vhost_submission_work() */
 841 #if 0
 842                 if (se_cmd->se_cmd_flags & SCF_BIDI) {
 843                         sg_bidi_ptr = NULL;
 844                         sg_no_bidi = 0;
 845                 }
 846 #endif
 847         } else {
 848                 sg_ptr = NULL;
 849         }
 850         tv_nexus = tv_cmd->tvc_nexus;
 851
 852         rc = target_submit_cmd_map_sgls(se_cmd, tv_nexus->tvn_se_sess,
 853                         tv_cmd->tvc_cdb, &tv_cmd->tvc_sense_buf[0],
 854                         tv_cmd->tvc_lun, tv_cmd->tvc_exp_data_len,
 855                         tv_cmd->tvc_task_attr, tv_cmd->tvc_data_direction,
 856                         TARGET_SCF_ACK_KREF, sg_ptr, tv_cmd->tvc_sgl_count,
 857                         sg_bidi_ptr, sg_no_bidi);
 858         if (rc < 0) {
 859                 transport_send_check_condition_and_sense(se_cmd,
 860                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
 861                 transport_generic_free_cmd(se_cmd, 0);
 862         }
 863 }
 864
 865 static void vhost_scsi_send_bad_target(struct vhost_scsi *vs,
 866         struct vhost_virtqueue *vq, int head, unsigned out)
 867 {
 868         struct virtio_scsi_cmd_resp __user *resp;
 869         struct virtio_scsi_cmd_resp rsp;
 870         int ret;
 871
 872         memset(&rsp, 0, sizeof(rsp));
 873         rsp.response = VIRTIO_SCSI_S_BAD_TARGET;
 874         resp = vq->iov[out].iov_base;
 875         ret = __copy_to_user(resp, &rsp, sizeof(rsp));
 876         if (!ret)
 877                 vhost_add_used_and_signal(&vs->dev, vq, head, 0);
 878         else
 879                 pr_err("Faulted on virtio_scsi_cmd_resp\n");
 880 }
 881
 882 static void vhost_scsi_handle_vq(struct vhost_scsi *vs,
 883         struct vhost_virtqueue *vq)
 884 {
 885         struct tcm_vhost_tpg **vs_tpg;
 886         struct virtio_scsi_cmd_req v_req;
 887         struct tcm_vhost_tpg *tv_tpg;
 888         struct tcm_vhost_cmd *tv_cmd;
 889         u32 exp_data_len, data_first, data_num, data_direction;
 890         unsigned out, in, i;
 891         int head, ret;
 892         u8 target;
 893
 894         /*
 895          * We can handle the vq only after the endpoint is setup by calling the
 896          * VHOST_SCSI_SET_ENDPOINT ioctl.
 897          *
 898          * TODO: Check that we are running from vhost_worker which acts
 899          * as read-side critical section for vhost kind of RCU.
 900          * See the comments in struct vhost_virtqueue in drivers/vhost/vhost.h
 901          */
 902         vs_tpg = rcu_dereference_check(vq->private_data, 1);
 903         if (!vs_tpg)
 904                 return;
 905
 906         mutex_lock(&vq->mutex);
 907         vhost_disable_notify(&vs->dev, vq);
 908
 909         for (;;) {
 910                 head = vhost_get_vq_desc(&vs->dev, vq, vq->iov,
 911                                         ARRAY_SIZE(vq->iov), &out, &in,
 912                                         NULL, NULL);
 913                 pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n",
 914                                         head, out, in);
 915                 /* On error, stop handling until the next kick. */
 916                 if (unlikely(head < 0))
 917                         break;
 918                 /* Nothing new?  Wait for eventfd to tell us they refilled. */
 919                 if (head == vq->num) {
 920                         if (unlikely(vhost_enable_notify(&vs->dev, vq))) {
 921                                 vhost_disable_notify(&vs->dev, vq);
 922                                 continue;
 923                         }
 924                         break;
 925                 }
 926
 927 /* FIXME: BIDI operation */
 928                 if (out == 1 && in == 1) {
 929                         data_direction = DMA_NONE;
 930                         data_first = 0;
 931                         data_num = 0;
 932                 } else if (out == 1 && in > 1) {
 933                         data_direction = DMA_FROM_DEVICE;
 934                         data_first = out + 1;
 935                         data_num = in - 1;
 936                 } else if (out > 1 && in == 1) {
 937                         data_direction = DMA_TO_DEVICE;
 938                         data_first = 1;
 939                         data_num = out - 1;
 940                 } else {
 941                         vq_err(vq, "Invalid buffer layout out: %u in: %u\n",
 942                                         out, in);
 943                         break;
 944                 }
 945
 946                 /*
 947                  * Check for a sane resp buffer so we can report errors to
 948                  * the guest.
 949                  */
 950                 if (unlikely(vq->iov[out].iov_len !=
 951                                         sizeof(struct virtio_scsi_cmd_resp))) {
 952                         vq_err(vq, "Expecting virtio_scsi_cmd_resp, got %zu"
 953                                 " bytes\n", vq->iov[out].iov_len);
 954                         break;
 955                 }
 956
 957                 if (unlikely(vq->iov[0].iov_len != sizeof(v_req))) {
 958                         vq_err(vq, "Expecting virtio_scsi_cmd_req, got %zu"
 959                                 " bytes\n", vq->iov[0].iov_len);
 960                         break;
 961                 }
 962                 pr_debug("Calling __copy_from_user: vq->iov[0].iov_base: %p,"
 963                         " len: %zu\n", vq->iov[0].iov_base, sizeof(v_req));
 964                 ret = __copy_from_user(&v_req, vq->iov[0].iov_base,
 965                                 sizeof(v_req));
 966                 if (unlikely(ret)) {
 967                         vq_err(vq, "Faulted on virtio_scsi_cmd_req\n");
 968                         break;
 969                 }
 970
 971                 /* Extract the tpgt */
 972                 target = v_req.lun[1];
 973                 tv_tpg = ACCESS_ONCE(vs_tpg[target]);
 974
 975                 /* Target does not exist, fail the request */
 976                 if (unlikely(!tv_tpg)) {
 977                         vhost_scsi_send_bad_target(vs, vq, head, out);
 978                         continue;
 979                 }
 980
 981                 exp_data_len = 0;
 982                 for (i = 0; i < data_num; i++)
 983                         exp_data_len += vq->iov[data_first + i].iov_len;
 984
 985                 tv_cmd = vhost_scsi_allocate_cmd(vq, tv_tpg, &v_req,
 986                                         exp_data_len, data_direction);
 987                 if (IS_ERR(tv_cmd)) {
 988                         vq_err(vq, "vhost_scsi_allocate_cmd failed %ld\n",
 989                                         PTR_ERR(tv_cmd));
 990                         goto err_cmd;
 991                 }
 992                 pr_debug("Allocated tv_cmd: %p exp_data_len: %d, data_direction"
 993                         ": %d\n", tv_cmd, exp_data_len, data_direction);
 994
 995                 tv_cmd->tvc_vhost = vs;
 996                 tv_cmd->tvc_vq = vq;
 997                 tv_cmd->tvc_resp = vq->iov[out].iov_base;
 998
 999                 /*
1000                  * Copy in the recieved CDB descriptor into tv_cmd->tvc_cdb
1001                  * that will be used by tcm_vhost_new_cmd_map() and down into
1002                  * target_setup_cmd_from_cdb()
1003                  */
1004                 memcpy(tv_cmd->tvc_cdb, v_req.cdb, TCM_VHOST_MAX_CDB_SIZE);
1005                 /*
1006                  * Check that the recieved CDB size does not exceeded our
1007                  * hardcoded max for tcm_vhost
1008                  */
1009                 /* TODO what if cdb was too small for varlen cdb header? */
1010                 if (unlikely(scsi_command_size(tv_cmd->tvc_cdb) >
1011                                         TCM_VHOST_MAX_CDB_SIZE)) {
1012                         vq_err(vq, "Received SCSI CDB with command_size: %d that"
1013                                 " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1014                                 scsi_command_size(tv_cmd->tvc_cdb),
1015                                 TCM_VHOST_MAX_CDB_SIZE);
1016                         goto err_free;
1017                 }
1018                 tv_cmd->tvc_lun = ((v_req.lun[2] << 8) | v_req.lun[3]) & 0x3FFF;
1019
1020                 pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",
1021                         tv_cmd->tvc_cdb[0], tv_cmd->tvc_lun);
1022
1023                 if (data_direction != DMA_NONE) {
1024                         ret = vhost_scsi_map_iov_to_sgl(tv_cmd,
1025                                         &vq->iov[data_first], data_num,
1026                                         data_direction == DMA_TO_DEVICE);
1027                         if (unlikely(ret)) {
1028                                 vq_err(vq, "Failed to map iov to sgl\n");
1029                                 goto err_free;
1030                         }
1031                 }
1032
1033                 /*
1034                  * Save the descriptor from vhost_get_vq_desc() to be used to
1035                  * complete the virtio-scsi request in TCM callback context via
1036                  * tcm_vhost_queue_data_in() and tcm_vhost_queue_status()
1037                  */
1038                 tv_cmd->tvc_vq_desc = head;
1039                 /*
1040                  * Dispatch tv_cmd descriptor for cmwq execution in process
1041                  * context provided by tcm_vhost_workqueue.  This also ensures
1042                  * tv_cmd is executed on the same kworker CPU as this vhost
1043                  * thread to gain positive L2 cache locality effects..
1044                  */
1045                 INIT_WORK(&tv_cmd->work, tcm_vhost_submission_work);
1046                 queue_work(tcm_vhost_workqueue, &tv_cmd->work);
1047         }
1048
1049         mutex_unlock(&vq->mutex);
1050         return;
1051
1052 err_free:
1053         vhost_scsi_free_cmd(tv_cmd);
1054 err_cmd:
1055         vhost_scsi_send_bad_target(vs, vq, head, out);
1056         mutex_unlock(&vq->mutex);
1057 }
1058
1059 static void vhost_scsi_ctl_handle_kick(struct vhost_work *work)
1060 {
1061         pr_debug("%s: The handling func for control queue.\n", __func__);
1062 }
1063
1064 static void tcm_vhost_send_evt(struct vhost_scsi *vs, struct tcm_vhost_tpg *tpg,
1065         struct se_lun *lun, u32 event, u32 reason)
1066 {
1067         struct tcm_vhost_evt *evt;
1068
1069         evt = tcm_vhost_allocate_evt(vs, event, reason);
1070         if (!evt)
1071                 return;
1072
1073         if (tpg && lun) {
1074                 /* TODO: share lun setup code with virtio-scsi.ko */
1075                 /*
1076                  * Note: evt->event is zeroed when we allocate it and
1077                  * lun[4-7] need to be zero according to virtio-scsi spec.
1078                  */
1079                 evt->event.lun[0] = 0x01;
1080                 evt->event.lun[1] = tpg->tport_tpgt & 0xFF;
1081                 if (lun->unpacked_lun >= 256)
1082                         evt->event.lun[2] = lun->unpacked_lun >> 8 | 0x40 ;
1083                 evt->event.lun[3] = lun->unpacked_lun & 0xFF;
1084         }
1085
1086         llist_add(&evt->list, &vs->vs_event_list);
1087         vhost_work_queue(&vs->dev, &vs->vs_event_work);
1088 }
1089
1090 static void vhost_scsi_evt_handle_kick(struct vhost_work *work)
1091 {
1092         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1093                                                 poll.work);
1094         struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1095
1096         mutex_lock(&vq->mutex);
1097         if (!vq->private_data)
1098                 goto out;
1099
1100         if (vs->vs_events_missed)
1101                 tcm_vhost_send_evt(vs, NULL, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
1102 out:
1103         mutex_unlock(&vq->mutex);
1104 }
1105
1106 static void vhost_scsi_handle_kick(struct vhost_work *work)
1107 {
1108         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1109                                                 poll.work);
1110         struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1111
1112         vhost_scsi_handle_vq(vs, vq);
1113 }
1114
1115 static void vhost_scsi_flush_vq(struct vhost_scsi *vs, int index)
1116 {
1117         vhost_poll_flush(&vs->vqs[index].vq.poll);
1118 }
1119
1120 /* Callers must hold dev mutex */
1121 static void vhost_scsi_flush(struct vhost_scsi *vs)
1122 {
1123         struct vhost_scsi_inflight *old_inflight[VHOST_SCSI_MAX_VQ];
1124         int i;
1125
1126         /* Init new inflight and remember the old inflight */
1127         tcm_vhost_init_inflight(vs, old_inflight);
1128
1129         /*
1130          * The inflight->kref was initialized to 1. We decrement it here to
1131          * indicate the start of the flush operation so that it will reach 0
1132          * when all the reqs are finished.
1133          */
1134         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1135                 kref_put(&old_inflight[i]->kref, tcm_vhost_done_inflight);
1136
1137         /* Flush both the vhost poll and vhost work */
1138         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1139                 vhost_scsi_flush_vq(vs, i);
1140         vhost_work_flush(&vs->dev, &vs->vs_completion_work);
1141         vhost_work_flush(&vs->dev, &vs->vs_event_work);
1142
1143         /* Wait for all reqs issued before the flush to be finished */
1144         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1145                 wait_for_completion(&old_inflight[i]->comp);
1146 }
1147
1148 /*
1149  * Called from vhost_scsi_ioctl() context to walk the list of available
1150  * tcm_vhost_tpg with an active struct tcm_vhost_nexus
1151  *
1152  *  The lock nesting rule is:
1153  *    tcm_vhost_mutex -> vs->dev.mutex -> tpg->tv_tpg_mutex -> vq->mutex
1154  */
1155 static int vhost_scsi_set_endpoint(
1156         struct vhost_scsi *vs,
1157         struct vhost_scsi_target *t)
1158 {
1159         struct tcm_vhost_tport *tv_tport;
1160         struct tcm_vhost_tpg *tv_tpg;
1161         struct tcm_vhost_tpg **vs_tpg;
1162         struct vhost_virtqueue *vq;
1163         int index, ret, i, len;
1164         bool match = false;
1165
1166         mutex_lock(&tcm_vhost_mutex);
1167         mutex_lock(&vs->dev.mutex);
1168
1169         /* Verify that ring has been setup correctly. */
1170         for (index = 0; index < vs->dev.nvqs; ++index) {
1171                 /* Verify that ring has been setup correctly. */
1172                 if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1173                         ret = -EFAULT;
1174                         goto out;
1175                 }
1176         }
1177
1178         len = sizeof(vs_tpg[0]) * VHOST_SCSI_MAX_TARGET;
1179         vs_tpg = kzalloc(len, GFP_KERNEL);
1180         if (!vs_tpg) {
1181                 ret = -ENOMEM;
1182                 goto out;
1183         }
1184         if (vs->vs_tpg)
1185                 memcpy(vs_tpg, vs->vs_tpg, len);
1186
1187         list_for_each_entry(tv_tpg, &tcm_vhost_list, tv_tpg_list) {
1188                 mutex_lock(&tv_tpg->tv_tpg_mutex);
1189                 if (!tv_tpg->tpg_nexus) {
1190                         mutex_unlock(&tv_tpg->tv_tpg_mutex);
1191                         continue;
1192                 }
1193                 if (tv_tpg->tv_tpg_vhost_count != 0) {
1194                         mutex_unlock(&tv_tpg->tv_tpg_mutex);
1195                         continue;
1196                 }
1197                 tv_tport = tv_tpg->tport;
1198
1199                 if (!strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1200                         if (vs->vs_tpg && vs->vs_tpg[tv_tpg->tport_tpgt]) {
1201                                 kfree(vs_tpg);
1202                                 mutex_unlock(&tv_tpg->tv_tpg_mutex);
1203                                 ret = -EEXIST;
1204                                 goto out;
1205                         }
1206                         tv_tpg->tv_tpg_vhost_count++;
1207                         tv_tpg->vhost_scsi = vs;
1208                         vs_tpg[tv_tpg->tport_tpgt] = tv_tpg;
1209                         smp_mb__after_atomic_inc();
1210                         match = true;
1211                 }
1212                 mutex_unlock(&tv_tpg->tv_tpg_mutex);
1213         }
1214
1215         if (match) {
1216                 memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn,
1217                        sizeof(vs->vs_vhost_wwpn));
1218                 for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1219                         vq = &vs->vqs[i].vq;
1220                         /* Flushing the vhost_work acts as synchronize_rcu */
1221                         mutex_lock(&vq->mutex);
1222                         rcu_assign_pointer(vq->private_data, vs_tpg);
1223                         vhost_init_used(vq);
1224                         mutex_unlock(&vq->mutex);
1225                 }
1226                 ret = 0;
1227         } else {
1228                 ret = -EEXIST;
1229         }
1230
1231         /*
1232          * Act as synchronize_rcu to make sure access to
1233          * old vs->vs_tpg is finished.
1234          */
1235         vhost_scsi_flush(vs);
1236         kfree(vs->vs_tpg);
1237         vs->vs_tpg = vs_tpg;
1238
1239 out:
1240         mutex_unlock(&vs->dev.mutex);
1241         mutex_unlock(&tcm_vhost_mutex);
1242         return ret;
1243 }
1244
1245 static int vhost_scsi_clear_endpoint(
1246         struct vhost_scsi *vs,
1247         struct vhost_scsi_target *t)
1248 {
1249         struct tcm_vhost_tport *tv_tport;
1250         struct tcm_vhost_tpg *tv_tpg;
1251         struct vhost_virtqueue *vq;
1252         bool match = false;
1253         int index, ret, i;
1254         u8 target;
1255
1256         mutex_lock(&tcm_vhost_mutex);
1257         mutex_lock(&vs->dev.mutex);
1258         /* Verify that ring has been setup correctly. */
1259         for (index = 0; index < vs->dev.nvqs; ++index) {
1260                 if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1261                         ret = -EFAULT;
1262                         goto err_dev;
1263                 }
1264         }
1265
1266         if (!vs->vs_tpg) {
1267                 ret = 0;
1268                 goto err_dev;
1269         }
1270
1271         for (i = 0; i < VHOST_SCSI_MAX_TARGET; i++) {
1272                 target = i;
1273                 tv_tpg = vs->vs_tpg[target];
1274                 if (!tv_tpg)
1275                         continue;
1276
1277                 mutex_lock(&tv_tpg->tv_tpg_mutex);
1278                 tv_tport = tv_tpg->tport;
1279                 if (!tv_tport) {
1280                         ret = -ENODEV;
1281                         goto err_tpg;
1282                 }
1283
1284                 if (strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1285                         pr_warn("tv_tport->tport_name: %s, tv_tpg->tport_tpgt: %hu"
1286                                 " does not match t->vhost_wwpn: %s, t->vhost_tpgt: %hu\n",
1287                                 tv_tport->tport_name, tv_tpg->tport_tpgt,
1288                                 t->vhost_wwpn, t->vhost_tpgt);
1289                         ret = -EINVAL;
1290                         goto err_tpg;
1291                 }
1292                 tv_tpg->tv_tpg_vhost_count--;
1293                 tv_tpg->vhost_scsi = NULL;
1294                 vs->vs_tpg[target] = NULL;
1295                 match = true;
1296                 mutex_unlock(&tv_tpg->tv_tpg_mutex);
1297         }
1298         if (match) {
1299                 for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1300                         vq = &vs->vqs[i].vq;
1301                         /* Flushing the vhost_work acts as synchronize_rcu */
1302                         mutex_lock(&vq->mutex);
1303                         rcu_assign_pointer(vq->private_data, NULL);
1304                         mutex_unlock(&vq->mutex);
1305                 }
1306         }
1307         /*
1308          * Act as synchronize_rcu to make sure access to
1309          * old vs->vs_tpg is finished.
1310          */
1311         vhost_scsi_flush(vs);
1312         kfree(vs->vs_tpg);
1313         vs->vs_tpg = NULL;
1314         WARN_ON(vs->vs_events_nr);
1315         mutex_unlock(&vs->dev.mutex);
1316         mutex_unlock(&tcm_vhost_mutex);
1317         return 0;
1318
1319 err_tpg:
1320         mutex_unlock(&tv_tpg->tv_tpg_mutex);
1321 err_dev:
1322         mutex_unlock(&vs->dev.mutex);
1323         mutex_unlock(&tcm_vhost_mutex);
1324         return ret;
1325 }
1326
1327 static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
1328 {
1329         if (features & ~VHOST_SCSI_FEATURES)
1330                 return -EOPNOTSUPP;
1331
1332         mutex_lock(&vs->dev.mutex);
1333         if ((features & (1 << VHOST_F_LOG_ALL)) &&
1334             !vhost_log_access_ok(&vs->dev)) {
1335                 mutex_unlock(&vs->dev.mutex);
1336                 return -EFAULT;
1337         }
1338         vs->dev.acked_features = features;
1339         smp_wmb();
1340         vhost_scsi_flush(vs);
1341         mutex_unlock(&vs->dev.mutex);
1342         return 0;
1343 }
1344
1345 static int vhost_scsi_open(struct inode *inode, struct file *f)
1346 {
1347         struct vhost_scsi *s;
1348         struct vhost_virtqueue **vqs;
1349         int r, i;
1350
1351         s = kzalloc(sizeof(*s), GFP_KERNEL);
1352         if (!s)
1353                 return -ENOMEM;
1354
1355         vqs = kmalloc(VHOST_SCSI_MAX_VQ * sizeof(*vqs), GFP_KERNEL);
1356         if (!vqs) {
1357                 kfree(s);
1358                 return -ENOMEM;
1359         }
1360
1361         vhost_work_init(&s->vs_completion_work, vhost_scsi_complete_cmd_work);
1362         vhost_work_init(&s->vs_event_work, tcm_vhost_evt_work);
1363
1364         s->vs_events_nr = 0;
1365         s->vs_events_missed = false;
1366
1367         vqs[VHOST_SCSI_VQ_CTL] = &s->vqs[VHOST_SCSI_VQ_CTL].vq;
1368         vqs[VHOST_SCSI_VQ_EVT] = &s->vqs[VHOST_SCSI_VQ_EVT].vq;
1369         s->vqs[VHOST_SCSI_VQ_CTL].vq.handle_kick = vhost_scsi_ctl_handle_kick;
1370         s->vqs[VHOST_SCSI_VQ_EVT].vq.handle_kick = vhost_scsi_evt_handle_kick;
1371         for (i = VHOST_SCSI_VQ_IO; i < VHOST_SCSI_MAX_VQ; i++) {
1372                 vqs[i] = &s->vqs[i].vq;
1373                 s->vqs[i].vq.handle_kick = vhost_scsi_handle_kick;
1374         }
1375         r = vhost_dev_init(&s->dev, vqs, VHOST_SCSI_MAX_VQ);
1376
1377         tcm_vhost_init_inflight(s, NULL);
1378
1379         if (r < 0) {
1380                 kfree(vqs);
1381                 kfree(s);
1382                 return r;
1383         }
1384
1385         f->private_data = s;
1386         return 0;
1387 }
1388
1389 static int vhost_scsi_release(struct inode *inode, struct file *f)
1390 {
1391         struct vhost_scsi *s = f->private_data;
1392         struct vhost_scsi_target t;
1393
1394         mutex_lock(&s->dev.mutex);
1395         memcpy(t.vhost_wwpn, s->vs_vhost_wwpn, sizeof(t.vhost_wwpn));
1396         mutex_unlock(&s->dev.mutex);
1397         vhost_scsi_clear_endpoint(s, &t);
1398         vhost_dev_stop(&s->dev);
1399         vhost_dev_cleanup(&s->dev, false);
1400         /* Jobs can re-queue themselves in evt kick handler. Do extra flush. */
1401         vhost_scsi_flush(s);
1402         kfree(s->dev.vqs);
1403         kfree(s);
1404         return 0;
1405 }
1406
1407 static long vhost_scsi_ioctl(struct file *f, unsigned int ioctl,
1408                                 unsigned long arg)
1409 {
1410         struct vhost_scsi *vs = f->private_data;
1411         struct vhost_scsi_target backend;
1412         void __user *argp = (void __user *)arg;
1413         u64 __user *featurep = argp;
1414         u32 __user *eventsp = argp;
1415         u32 events_missed;
1416         u64 features;
1417         int r, abi_version = VHOST_SCSI_ABI_VERSION;
1418         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1419
1420         switch (ioctl) {
1421         case VHOST_SCSI_SET_ENDPOINT:
1422                 if (copy_from_user(&backend, argp, sizeof backend))
1423                         return -EFAULT;
1424                 if (backend.reserved != 0)
1425                         return -EOPNOTSUPP;
1426
1427                 return vhost_scsi_set_endpoint(vs, &backend);
1428         case VHOST_SCSI_CLEAR_ENDPOINT:
1429                 if (copy_from_user(&backend, argp, sizeof backend))
1430                         return -EFAULT;
1431                 if (backend.reserved != 0)
1432                         return -EOPNOTSUPP;
1433
1434                 return vhost_scsi_clear_endpoint(vs, &backend);
1435         case VHOST_SCSI_GET_ABI_VERSION:
1436                 if (copy_to_user(argp, &abi_version, sizeof abi_version))
1437                         return -EFAULT;
1438                 return 0;
1439         case VHOST_SCSI_SET_EVENTS_MISSED:
1440                 if (get_user(events_missed, eventsp))
1441                         return -EFAULT;
1442                 mutex_lock(&vq->mutex);
1443                 vs->vs_events_missed = events_missed;
1444                 mutex_unlock(&vq->mutex);
1445                 return 0;
1446         case VHOST_SCSI_GET_EVENTS_MISSED:
1447                 mutex_lock(&vq->mutex);
1448                 events_missed = vs->vs_events_missed;
1449                 mutex_unlock(&vq->mutex);
1450                 if (put_user(events_missed, eventsp))
1451                         return -EFAULT;
1452                 return 0;
1453         case VHOST_GET_FEATURES:
1454                 features = VHOST_SCSI_FEATURES;
1455                 if (copy_to_user(featurep, &features, sizeof features))
1456                         return -EFAULT;
1457                 return 0;
1458         case VHOST_SET_FEATURES:
1459                 if (copy_from_user(&features, featurep, sizeof features))
1460                         return -EFAULT;
1461                 return vhost_scsi_set_features(vs, features);
1462         default:
1463                 mutex_lock(&vs->dev.mutex);
1464                 r = vhost_dev_ioctl(&vs->dev, ioctl, argp);
1465                 /* TODO: flush backend after dev ioctl. */
1466                 if (r == -ENOIOCTLCMD)
1467                         r = vhost_vring_ioctl(&vs->dev, ioctl, argp);
1468                 mutex_unlock(&vs->dev.mutex);
1469                 return r;
1470         }
1471 }
1472
1473 #ifdef CONFIG_COMPAT
1474 static long vhost_scsi_compat_ioctl(struct file *f, unsigned int ioctl,
1475                                 unsigned long arg)
1476 {
1477         return vhost_scsi_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
1478 }
1479 #endif
1480
1481 static const struct file_operations vhost_scsi_fops = {
1482         .owner          = THIS_MODULE,
1483         .release        = vhost_scsi_release,
1484         .unlocked_ioctl = vhost_scsi_ioctl,
1485 #ifdef CONFIG_COMPAT
1486         .compat_ioctl   = vhost_scsi_compat_ioctl,
1487 #endif
1488         .open           = vhost_scsi_open,
1489         .llseek         = noop_llseek,
1490 };
1491
1492 static struct miscdevice vhost_scsi_misc = {
1493         MISC_DYNAMIC_MINOR,
1494         "vhost-scsi",
1495         &vhost_scsi_fops,
1496 };
1497
1498 static int __init vhost_scsi_register(void)
1499 {
1500         return misc_register(&vhost_scsi_misc);
1501 }
1502
1503 static int vhost_scsi_deregister(void)
1504 {
1505         return misc_deregister(&vhost_scsi_misc);
1506 }
1507
1508 static char *tcm_vhost_dump_proto_id(struct tcm_vhost_tport *tport)
1509 {
1510         switch (tport->tport_proto_id) {
1511         case SCSI_PROTOCOL_SAS:
1512                 return "SAS";
1513         case SCSI_PROTOCOL_FCP:
1514                 return "FCP";
1515         case SCSI_PROTOCOL_ISCSI:
1516                 return "iSCSI";
1517         default:
1518                 break;
1519         }
1520
1521         return "Unknown";
1522 }
1523
1524 static void tcm_vhost_do_plug(struct tcm_vhost_tpg *tpg,
1525         struct se_lun *lun, bool plug)
1526 {
1527
1528         struct vhost_scsi *vs = tpg->vhost_scsi;
1529         struct vhost_virtqueue *vq;
1530         u32 reason;
1531
1532         if (!vs)
1533                 return;
1534
1535         mutex_lock(&vs->dev.mutex);
1536         if (!vhost_has_feature(&vs->dev, VIRTIO_SCSI_F_HOTPLUG)) {
1537                 mutex_unlock(&vs->dev.mutex);
1538                 return;
1539         }
1540
1541         if (plug)
1542                 reason = VIRTIO_SCSI_EVT_RESET_RESCAN;
1543         else
1544                 reason = VIRTIO_SCSI_EVT_RESET_REMOVED;
1545
1546         vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1547         mutex_lock(&vq->mutex);
1548         tcm_vhost_send_evt(vs, tpg, lun,
1549                         VIRTIO_SCSI_T_TRANSPORT_RESET, reason);
1550         mutex_unlock(&vq->mutex);
1551         mutex_unlock(&vs->dev.mutex);
1552 }
1553
1554 static void tcm_vhost_hotplug(struct tcm_vhost_tpg *tpg, struct se_lun *lun)
1555 {
1556         tcm_vhost_do_plug(tpg, lun, true);
1557 }
1558
1559 static void tcm_vhost_hotunplug(struct tcm_vhost_tpg *tpg, struct se_lun *lun)
1560 {
1561         tcm_vhost_do_plug(tpg, lun, false);
1562 }
1563
1564 static int tcm_vhost_port_link(struct se_portal_group *se_tpg,
1565         struct se_lun *lun)
1566 {
1567         struct tcm_vhost_tpg *tv_tpg = container_of(se_tpg,
1568                                 struct tcm_vhost_tpg, se_tpg);
1569
1570         mutex_lock(&tcm_vhost_mutex);
1571
1572         mutex_lock(&tv_tpg->tv_tpg_mutex);
1573         tv_tpg->tv_tpg_port_count++;
1574         mutex_unlock(&tv_tpg->tv_tpg_mutex);
1575
1576         tcm_vhost_hotplug(tv_tpg, lun);
1577
1578         mutex_unlock(&tcm_vhost_mutex);
1579
1580         return 0;
1581 }
1582
1583 static void tcm_vhost_port_unlink(struct se_portal_group *se_tpg,
1584         struct se_lun *lun)
1585 {
1586         struct tcm_vhost_tpg *tv_tpg = container_of(se_tpg,
1587                                 struct tcm_vhost_tpg, se_tpg);
1588
1589         mutex_lock(&tcm_vhost_mutex);
1590
1591         mutex_lock(&tv_tpg->tv_tpg_mutex);
1592         tv_tpg->tv_tpg_port_count--;
1593         mutex_unlock(&tv_tpg->tv_tpg_mutex);
1594
1595         tcm_vhost_hotunplug(tv_tpg, lun);
1596
1597         mutex_unlock(&tcm_vhost_mutex);
1598 }
1599
1600 static struct se_node_acl *tcm_vhost_make_nodeacl(
1601         struct se_portal_group *se_tpg,
1602         struct config_group *group,
1603         const char *name)
1604 {
1605         struct se_node_acl *se_nacl, *se_nacl_new;
1606         struct tcm_vhost_nacl *nacl;
1607         u64 wwpn = 0;
1608         u32 nexus_depth;
1609
1610         /* tcm_vhost_parse_wwn(name, &wwpn, 1) < 0)
1611                 return ERR_PTR(-EINVAL); */
1612         se_nacl_new = tcm_vhost_alloc_fabric_acl(se_tpg);
1613         if (!se_nacl_new)
1614                 return ERR_PTR(-ENOMEM);
1615
1616         nexus_depth = 1;
1617         /*
1618          * se_nacl_new may be released by core_tpg_add_initiator_node_acl()
1619          * when converting a NodeACL from demo mode -> explict
1620          */
1621         se_nacl = core_tpg_add_initiator_node_acl(se_tpg, se_nacl_new,
1622                                 name, nexus_depth);
1623         if (IS_ERR(se_nacl)) {
1624                 tcm_vhost_release_fabric_acl(se_tpg, se_nacl_new);
1625                 return se_nacl;
1626         }
1627         /*
1628          * Locate our struct tcm_vhost_nacl and set the FC Nport WWPN
1629          */
1630         nacl = container_of(se_nacl, struct tcm_vhost_nacl, se_node_acl);
1631         nacl->iport_wwpn = wwpn;
1632
1633         return se_nacl;
1634 }
1635
1636 static void tcm_vhost_drop_nodeacl(struct se_node_acl *se_acl)
1637 {
1638         struct tcm_vhost_nacl *nacl = container_of(se_acl,
1639                                 struct tcm_vhost_nacl, se_node_acl);
1640         core_tpg_del_initiator_node_acl(se_acl->se_tpg, se_acl, 1);
1641         kfree(nacl);
1642 }
1643
1644 static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tv_tpg,
1645         const char *name)
1646 {
1647         struct se_portal_group *se_tpg;
1648         struct tcm_vhost_nexus *tv_nexus;
1649
1650         mutex_lock(&tv_tpg->tv_tpg_mutex);
1651         if (tv_tpg->tpg_nexus) {
1652                 mutex_unlock(&tv_tpg->tv_tpg_mutex);
1653                 pr_debug("tv_tpg->tpg_nexus already exists\n");
1654                 return -EEXIST;
1655         }
1656         se_tpg = &tv_tpg->se_tpg;
1657
1658         tv_nexus = kzalloc(sizeof(struct tcm_vhost_nexus), GFP_KERNEL);
1659         if (!tv_nexus) {
1660                 mutex_unlock(&tv_tpg->tv_tpg_mutex);
1661                 pr_err("Unable to allocate struct tcm_vhost_nexus\n");
1662                 return -ENOMEM;
1663         }
1664         /*
1665          *  Initialize the struct se_session pointer
1666          */
1667         tv_nexus->tvn_se_sess = transport_init_session();
1668         if (IS_ERR(tv_nexus->tvn_se_sess)) {
1669                 mutex_unlock(&tv_tpg->tv_tpg_mutex);
1670                 kfree(tv_nexus);
1671                 return -ENOMEM;
1672         }
1673         /*
1674          * Since we are running in 'demo mode' this call with generate a
1675          * struct se_node_acl for the tcm_vhost struct se_portal_group with
1676          * the SCSI Initiator port name of the passed configfs group 'name'.
1677          */
1678         tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1679                                 se_tpg, (unsigned char *)name);
1680         if (!tv_nexus->tvn_se_sess->se_node_acl) {
1681                 mutex_unlock(&tv_tpg->tv_tpg_mutex);
1682                 pr_debug("core_tpg_check_initiator_node_acl() failed"
1683                                 " for %s\n", name);
1684                 transport_free_session(tv_nexus->tvn_se_sess);
1685                 kfree(tv_nexus);
1686                 return -ENOMEM;
1687         }
1688         /*
1689          * Now register the TCM vhost virtual I_T Nexus as active with the
1690          * call to __transport_register_session()
1691          */
1692         __transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
1693                         tv_nexus->tvn_se_sess, tv_nexus);
1694         tv_tpg->tpg_nexus = tv_nexus;
1695
1696         mutex_unlock(&tv_tpg->tv_tpg_mutex);
1697         return 0;
1698 }
1699
1700 static int tcm_vhost_drop_nexus(struct tcm_vhost_tpg *tpg)
1701 {
1702         struct se_session *se_sess;
1703         struct tcm_vhost_nexus *tv_nexus;
1704
1705         mutex_lock(&tpg->tv_tpg_mutex);
1706         tv_nexus = tpg->tpg_nexus;
1707         if (!tv_nexus) {
1708                 mutex_unlock(&tpg->tv_tpg_mutex);
1709                 return -ENODEV;
1710         }
1711
1712         se_sess = tv_nexus->tvn_se_sess;
1713         if (!se_sess) {
1714                 mutex_unlock(&tpg->tv_tpg_mutex);
1715                 return -ENODEV;
1716         }
1717
1718         if (tpg->tv_tpg_port_count != 0) {
1719                 mutex_unlock(&tpg->tv_tpg_mutex);
1720                 pr_err("Unable to remove TCM_vhost I_T Nexus with"
1721                         " active TPG port count: %d\n",
1722                         tpg->tv_tpg_port_count);
1723                 return -EBUSY;
1724         }
1725
1726         if (tpg->tv_tpg_vhost_count != 0) {
1727                 mutex_unlock(&tpg->tv_tpg_mutex);
1728                 pr_err("Unable to remove TCM_vhost I_T Nexus with"
1729                         " active TPG vhost count: %d\n",
1730                         tpg->tv_tpg_vhost_count);
1731                 return -EBUSY;
1732         }
1733
1734         pr_debug("TCM_vhost_ConfigFS: Removing I_T Nexus to emulated"
1735                 " %s Initiator Port: %s\n", tcm_vhost_dump_proto_id(tpg->tport),
1736                 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1737         /*
1738          * Release the SCSI I_T Nexus to the emulated vhost Target Port
1739          */
1740         transport_deregister_session(tv_nexus->tvn_se_sess);
1741         tpg->tpg_nexus = NULL;
1742         mutex_unlock(&tpg->tv_tpg_mutex);
1743
1744         kfree(tv_nexus);
1745         return 0;
1746 }
1747
1748 static ssize_t tcm_vhost_tpg_show_nexus(struct se_portal_group *se_tpg,
1749         char *page)
1750 {
1751         struct tcm_vhost_tpg *tv_tpg = container_of(se_tpg,
1752                                 struct tcm_vhost_tpg, se_tpg);
1753         struct tcm_vhost_nexus *tv_nexus;
1754         ssize_t ret;
1755
1756         mutex_lock(&tv_tpg->tv_tpg_mutex);
1757         tv_nexus = tv_tpg->tpg_nexus;
1758         if (!tv_nexus) {
1759                 mutex_unlock(&tv_tpg->tv_tpg_mutex);
1760                 return -ENODEV;
1761         }
1762         ret = snprintf(page, PAGE_SIZE, "%s\n",
1763                         tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1764         mutex_unlock(&tv_tpg->tv_tpg_mutex);
1765
1766         return ret;
1767 }
1768
1769 static ssize_t tcm_vhost_tpg_store_nexus(struct se_portal_group *se_tpg,
1770         const char *page,
1771         size_t count)
1772 {
1773         struct tcm_vhost_tpg *tv_tpg = container_of(se_tpg,
1774                                 struct tcm_vhost_tpg, se_tpg);
1775         struct tcm_vhost_tport *tport_wwn = tv_tpg->tport;
1776         unsigned char i_port[TCM_VHOST_NAMELEN], *ptr, *port_ptr;
1777         int ret;
1778         /*
1779          * Shutdown the active I_T nexus if 'NULL' is passed..
1780          */
1781         if (!strncmp(page, "NULL", 4)) {
1782                 ret = tcm_vhost_drop_nexus(tv_tpg);
1783                 return (!ret) ? count : ret;
1784         }
1785         /*
1786          * Otherwise make sure the passed virtual Initiator port WWN matches
1787          * the fabric protocol_id set in tcm_vhost_make_tport(), and call
1788          * tcm_vhost_make_nexus().
1789          */
1790         if (strlen(page) >= TCM_VHOST_NAMELEN) {
1791                 pr_err("Emulated NAA Sas Address: %s, exceeds"
1792                                 " max: %d\n", page, TCM_VHOST_NAMELEN);
1793                 return -EINVAL;
1794         }
1795         snprintf(&i_port[0], TCM_VHOST_NAMELEN, "%s", page);
1796
1797         ptr = strstr(i_port, "naa.");
1798         if (ptr) {
1799                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1800                         pr_err("Passed SAS Initiator Port %s does not"
1801                                 " match target port protoid: %s\n", i_port,
1802                                 tcm_vhost_dump_proto_id(tport_wwn));
1803                         return -EINVAL;
1804                 }
1805                 port_ptr = &i_port[0];
1806                 goto check_newline;
1807         }
1808         ptr = strstr(i_port, "fc.");
1809         if (ptr) {
1810                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1811                         pr_err("Passed FCP Initiator Port %s does not"
1812                                 " match target port protoid: %s\n", i_port,
1813                                 tcm_vhost_dump_proto_id(tport_wwn));
1814                         return -EINVAL;
1815                 }
1816                 port_ptr = &i_port[3]; /* Skip over "fc." */
1817                 goto check_newline;
1818         }
1819         ptr = strstr(i_port, "iqn.");
1820         if (ptr) {
1821                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1822                         pr_err("Passed iSCSI Initiator Port %s does not"
1823                                 " match target port protoid: %s\n", i_port,
1824                                 tcm_vhost_dump_proto_id(tport_wwn));
1825                         return -EINVAL;
1826                 }
1827                 port_ptr = &i_port[0];
1828                 goto check_newline;
1829         }
1830         pr_err("Unable to locate prefix for emulated Initiator Port:"
1831                         " %s\n", i_port);
1832         return -EINVAL;
1833         /*
1834          * Clear any trailing newline for the NAA WWN
1835          */
1836 check_newline:
1837         if (i_port[strlen(i_port)-1] == '\n')
1838                 i_port[strlen(i_port)-1] = '\0';
1839
1840         ret = tcm_vhost_make_nexus(tv_tpg, port_ptr);
1841         if (ret < 0)
1842                 return ret;
1843
1844         return count;
1845 }
1846
1847 TF_TPG_BASE_ATTR(tcm_vhost, nexus, S_IRUGO | S_IWUSR);
1848
1849 static struct configfs_attribute *tcm_vhost_tpg_attrs[] = {
1850         &tcm_vhost_tpg_nexus.attr,
1851         NULL,
1852 };
1853
1854 static struct se_portal_group *tcm_vhost_make_tpg(struct se_wwn *wwn,
1855         struct config_group *group,
1856         const char *name)
1857 {
1858         struct tcm_vhost_tport *tport = container_of(wwn,
1859                         struct tcm_vhost_tport, tport_wwn);
1860
1861         struct tcm_vhost_tpg *tpg;
1862         unsigned long tpgt;
1863         int ret;
1864
1865         if (strstr(name, "tpgt_") != name)
1866                 return ERR_PTR(-EINVAL);
1867         if (kstrtoul(name + 5, 10, &tpgt) || tpgt > UINT_MAX)
1868                 return ERR_PTR(-EINVAL);
1869
1870         tpg = kzalloc(sizeof(struct tcm_vhost_tpg), GFP_KERNEL);
1871         if (!tpg) {
1872                 pr_err("Unable to allocate struct tcm_vhost_tpg");
1873                 return ERR_PTR(-ENOMEM);
1874         }
1875         mutex_init(&tpg->tv_tpg_mutex);
1876         INIT_LIST_HEAD(&tpg->tv_tpg_list);
1877         tpg->tport = tport;
1878         tpg->tport_tpgt = tpgt;
1879
1880         ret = core_tpg_register(&tcm_vhost_fabric_configfs->tf_ops, wwn,
1881                                 &tpg->se_tpg, tpg, TRANSPORT_TPG_TYPE_NORMAL);
1882         if (ret < 0) {
1883                 kfree(tpg);
1884                 return NULL;
1885         }
1886         mutex_lock(&tcm_vhost_mutex);
1887         list_add_tail(&tpg->tv_tpg_list, &tcm_vhost_list);
1888         mutex_unlock(&tcm_vhost_mutex);
1889
1890         return &tpg->se_tpg;
1891 }
1892
1893 static void tcm_vhost_drop_tpg(struct se_portal_group *se_tpg)
1894 {
1895         struct tcm_vhost_tpg *tpg = container_of(se_tpg,
1896                                 struct tcm_vhost_tpg, se_tpg);
1897
1898         mutex_lock(&tcm_vhost_mutex);
1899         list_del(&tpg->tv_tpg_list);
1900         mutex_unlock(&tcm_vhost_mutex);
1901         /*
1902          * Release the virtual I_T Nexus for this vhost TPG
1903          */
1904         tcm_vhost_drop_nexus(tpg);
1905         /*
1906          * Deregister the se_tpg from TCM..
1907          */
1908         core_tpg_deregister(se_tpg);
1909         kfree(tpg);
1910 }
1911
1912 static struct se_wwn *tcm_vhost_make_tport(struct target_fabric_configfs *tf,
1913         struct config_group *group,
1914         const char *name)
1915 {
1916         struct tcm_vhost_tport *tport;
1917         char *ptr;
1918         u64 wwpn = 0;
1919         int off = 0;
1920
1921         /* if (tcm_vhost_parse_wwn(name, &wwpn, 1) < 0)
1922                 return ERR_PTR(-EINVAL); */
1923
1924         tport = kzalloc(sizeof(struct tcm_vhost_tport), GFP_KERNEL);
1925         if (!tport) {
1926                 pr_err("Unable to allocate struct tcm_vhost_tport");
1927                 return ERR_PTR(-ENOMEM);
1928         }
1929         tport->tport_wwpn = wwpn;
1930         /*
1931          * Determine the emulated Protocol Identifier and Target Port Name
1932          * based on the incoming configfs directory name.
1933          */
1934         ptr = strstr(name, "naa.");
1935         if (ptr) {
1936                 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1937                 goto check_len;
1938         }
1939         ptr = strstr(name, "fc.");
1940         if (ptr) {
1941                 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1942                 off = 3; /* Skip over "fc." */
1943                 goto check_len;
1944         }
1945         ptr = strstr(name, "iqn.");
1946         if (ptr) {
1947                 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1948                 goto check_len;
1949         }
1950
1951         pr_err("Unable to locate prefix for emulated Target Port:"
1952                         " %s\n", name);
1953         kfree(tport);
1954         return ERR_PTR(-EINVAL);
1955
1956 check_len:
1957         if (strlen(name) >= TCM_VHOST_NAMELEN) {
1958                 pr_err("Emulated %s Address: %s, exceeds"
1959                         " max: %d\n", name, tcm_vhost_dump_proto_id(tport),
1960                         TCM_VHOST_NAMELEN);
1961                 kfree(tport);
1962                 return ERR_PTR(-EINVAL);
1963         }
1964         snprintf(&tport->tport_name[0], TCM_VHOST_NAMELEN, "%s", &name[off]);
1965
1966         pr_debug("TCM_VHost_ConfigFS: Allocated emulated Target"
1967                 " %s Address: %s\n", tcm_vhost_dump_proto_id(tport), name);
1968
1969         return &tport->tport_wwn;
1970 }
1971
1972 static void tcm_vhost_drop_tport(struct se_wwn *wwn)
1973 {
1974         struct tcm_vhost_tport *tport = container_of(wwn,
1975                                 struct tcm_vhost_tport, tport_wwn);
1976
1977         pr_debug("TCM_VHost_ConfigFS: Deallocating emulated Target"
1978                 " %s Address: %s\n", tcm_vhost_dump_proto_id(tport),
1979                 tport->tport_name);
1980
1981         kfree(tport);
1982 }
1983
1984 static ssize_t tcm_vhost_wwn_show_attr_version(
1985         struct target_fabric_configfs *tf,
1986         char *page)
1987 {
1988         return sprintf(page, "TCM_VHOST fabric module %s on %s/%s"
1989                 "on "UTS_RELEASE"\n", TCM_VHOST_VERSION, utsname()->sysname,
1990                 utsname()->machine);
1991 }
1992
1993 TF_WWN_ATTR_RO(tcm_vhost, version);
1994
1995 static struct configfs_attribute *tcm_vhost_wwn_attrs[] = {
1996         &tcm_vhost_wwn_version.attr,
1997         NULL,
1998 };
1999
2000 static struct target_core_fabric_ops tcm_vhost_ops = {
2001         .get_fabric_name                = tcm_vhost_get_fabric_name,
2002         .get_fabric_proto_ident         = tcm_vhost_get_fabric_proto_ident,
2003         .tpg_get_wwn                    = tcm_vhost_get_fabric_wwn,
2004         .tpg_get_tag                    = tcm_vhost_get_tag,
2005         .tpg_get_default_depth          = tcm_vhost_get_default_depth,
2006         .tpg_get_pr_transport_id        = tcm_vhost_get_pr_transport_id,
2007         .tpg_get_pr_transport_id_len    = tcm_vhost_get_pr_transport_id_len,
2008         .tpg_parse_pr_out_transport_id  = tcm_vhost_parse_pr_out_transport_id,
2009         .tpg_check_demo_mode            = tcm_vhost_check_true,
2010         .tpg_check_demo_mode_cache      = tcm_vhost_check_true,
2011         .tpg_check_demo_mode_write_protect = tcm_vhost_check_false,
2012         .tpg_check_prod_mode_write_protect = tcm_vhost_check_false,
2013         .tpg_alloc_fabric_acl           = tcm_vhost_alloc_fabric_acl,
2014         .tpg_release_fabric_acl         = tcm_vhost_release_fabric_acl,
2015         .tpg_get_inst_index             = tcm_vhost_tpg_get_inst_index,
2016         .release_cmd                    = tcm_vhost_release_cmd,
2017         .check_stop_free                = vhost_scsi_check_stop_free,
2018         .shutdown_session               = tcm_vhost_shutdown_session,
2019         .close_session                  = tcm_vhost_close_session,
2020         .sess_get_index                 = tcm_vhost_sess_get_index,
2021         .sess_get_initiator_sid         = NULL,
2022         .write_pending                  = tcm_vhost_write_pending,
2023         .write_pending_status           = tcm_vhost_write_pending_status,
2024         .set_default_node_attributes    = tcm_vhost_set_default_node_attrs,
2025         .get_task_tag                   = tcm_vhost_get_task_tag,
2026         .get_cmd_state                  = tcm_vhost_get_cmd_state,
2027         .queue_data_in                  = tcm_vhost_queue_data_in,
2028         .queue_status                   = tcm_vhost_queue_status,
2029         .queue_tm_rsp                   = tcm_vhost_queue_tm_rsp,
2030         /*
2031          * Setup callers for generic logic in target_core_fabric_configfs.c
2032          */
2033         .fabric_make_wwn                = tcm_vhost_make_tport,
2034         .fabric_drop_wwn                = tcm_vhost_drop_tport,
2035         .fabric_make_tpg                = tcm_vhost_make_tpg,
2036         .fabric_drop_tpg                = tcm_vhost_drop_tpg,
2037         .fabric_post_link               = tcm_vhost_port_link,
2038         .fabric_pre_unlink              = tcm_vhost_port_unlink,
2039         .fabric_make_np                 = NULL,
2040         .fabric_drop_np                 = NULL,
2041         .fabric_make_nodeacl            = tcm_vhost_make_nodeacl,
2042         .fabric_drop_nodeacl            = tcm_vhost_drop_nodeacl,
2043 };
2044
2045 static int tcm_vhost_register_configfs(void)
2046 {
2047         struct target_fabric_configfs *fabric;
2048         int ret;
2049
2050         pr_debug("TCM_VHOST fabric module %s on %s/%s"
2051                 " on "UTS_RELEASE"\n", TCM_VHOST_VERSION, utsname()->sysname,
2052                 utsname()->machine);
2053         /*
2054          * Register the top level struct config_item_type with TCM core
2055          */
2056         fabric = target_fabric_configfs_init(THIS_MODULE, "vhost");
2057         if (IS_ERR(fabric)) {
2058                 pr_err("target_fabric_configfs_init() failed\n");
2059                 return PTR_ERR(fabric);
2060         }
2061         /*
2062          * Setup fabric->tf_ops from our local tcm_vhost_ops
2063          */
2064         fabric->tf_ops = tcm_vhost_ops;
2065         /*
2066          * Setup default attribute lists for various fabric->tf_cit_tmpl
2067          */
2068         TF_CIT_TMPL(fabric)->tfc_wwn_cit.ct_attrs = tcm_vhost_wwn_attrs;
2069         TF_CIT_TMPL(fabric)->tfc_tpg_base_cit.ct_attrs = tcm_vhost_tpg_attrs;
2070         TF_CIT_TMPL(fabric)->tfc_tpg_attrib_cit.ct_attrs = NULL;
2071         TF_CIT_TMPL(fabric)->tfc_tpg_param_cit.ct_attrs = NULL;
2072         TF_CIT_TMPL(fabric)->tfc_tpg_np_base_cit.ct_attrs = NULL;
2073         TF_CIT_TMPL(fabric)->tfc_tpg_nacl_base_cit.ct_attrs = NULL;
2074         TF_CIT_TMPL(fabric)->tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
2075         TF_CIT_TMPL(fabric)->tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
2076         TF_CIT_TMPL(fabric)->tfc_tpg_nacl_param_cit.ct_attrs = NULL;
2077         /*
2078          * Register the fabric for use within TCM
2079          */
2080         ret = target_fabric_configfs_register(fabric);
2081         if (ret < 0) {
2082                 pr_err("target_fabric_configfs_register() failed"
2083                                 " for TCM_VHOST\n");
2084                 return ret;
2085         }
2086         /*
2087          * Setup our local pointer to *fabric
2088          */
2089         tcm_vhost_fabric_configfs = fabric;
2090         pr_debug("TCM_VHOST[0] - Set fabric -> tcm_vhost_fabric_configfs\n");
2091         return 0;
2092 };
2093
2094 static void tcm_vhost_deregister_configfs(void)
2095 {
2096         if (!tcm_vhost_fabric_configfs)
2097                 return;
2098
2099         target_fabric_configfs_deregister(tcm_vhost_fabric_configfs);
2100         tcm_vhost_fabric_configfs = NULL;
2101         pr_debug("TCM_VHOST[0] - Cleared tcm_vhost_fabric_configfs\n");
2102 };
2103
2104 static int __init tcm_vhost_init(void)
2105 {
2106         int ret = -ENOMEM;
2107         /*
2108          * Use our own dedicated workqueue for submitting I/O into
2109          * target core to avoid contention within system_wq.
2110          */
2111         tcm_vhost_workqueue = alloc_workqueue("tcm_vhost", 0, 0);
2112         if (!tcm_vhost_workqueue)
2113                 goto out;
2114
2115         ret = vhost_scsi_register();
2116         if (ret < 0)
2117                 goto out_destroy_workqueue;
2118
2119         ret = tcm_vhost_register_configfs();
2120         if (ret < 0)
2121                 goto out_vhost_scsi_deregister;
2122
2123         return 0;
2124
2125 out_vhost_scsi_deregister:
2126         vhost_scsi_deregister();
2127 out_destroy_workqueue:
2128         destroy_workqueue(tcm_vhost_workqueue);
2129 out:
2130         return ret;
2131 };
2132
2133 static void tcm_vhost_exit(void)
2134 {
2135         tcm_vhost_deregister_configfs();
2136         vhost_scsi_deregister();
2137         destroy_workqueue(tcm_vhost_workqueue);
2138 };
2139
2140 MODULE_DESCRIPTION("VHOST_SCSI series fabric driver");
2141 MODULE_ALIAS("tcm_vhost");
2142 MODULE_LICENSE("GPL");
2143 module_init(tcm_vhost_init);
2144 module_exit(tcm_vhost_exit);