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/vmalloc.h>
  39 #include <linux/miscdevice.h>
  40 #include <asm/unaligned.h>
  41 #include <scsi/scsi_common.h>
  42 #include <scsi/scsi_proto.h>
  43 #include <target/target_core_base.h>
  44 #include <target/target_core_fabric.h>
  45 #include <linux/vhost.h>
  46 #include <linux/virtio_scsi.h>
  47 #include <linux/llist.h>
  48 #include <linux/bitmap.h>
  49
  50 #include "vhost.h"
  51
  52 #define VHOST_SCSI_VERSION  "v0.1"
  53 #define VHOST_SCSI_NAMELEN 256
  54 #define VHOST_SCSI_MAX_CDB_SIZE 32
  55 #define VHOST_SCSI_DEFAULT_TAGS 256
  56 #define VHOST_SCSI_PREALLOC_SGLS 2048
  57 #define VHOST_SCSI_PREALLOC_UPAGES 2048
  58 #define VHOST_SCSI_PREALLOC_PROT_SGLS 2048
  59
  60 /* Max number of requests before requeueing the job.
  61  * Using this limit prevents one virtqueue from starving others with
  62  * request.
  63  */
  64 #define VHOST_SCSI_WEIGHT 256
  65
  66 struct vhost_scsi_inflight {
  67         /* Wait for the flush operation to finish */
  68         struct completion comp;
  69         /* Refcount for the inflight reqs */
  70         struct kref kref;
  71 };
  72
  73 struct vhost_scsi_cmd {
  74         /* Descriptor from vhost_get_vq_desc() for virt_queue segment */
  75         int tvc_vq_desc;
  76         /* virtio-scsi initiator task attribute */
  77         int tvc_task_attr;
  78         /* virtio-scsi response incoming iovecs */
  79         int tvc_in_iovs;
  80         /* virtio-scsi initiator data direction */
  81         enum dma_data_direction tvc_data_direction;
  82         /* Expected data transfer length from virtio-scsi header */
  83         u32 tvc_exp_data_len;
  84         /* The Tag from include/linux/virtio_scsi.h:struct virtio_scsi_cmd_req */
  85         u64 tvc_tag;
  86         /* The number of scatterlists associated with this cmd */
  87         u32 tvc_sgl_count;
  88         u32 tvc_prot_sgl_count;
  89         /* Saved unpacked SCSI LUN for vhost_scsi_submission_work() */
  90         u32 tvc_lun;
  91         /* Pointer to the SGL formatted memory from virtio-scsi */
  92         struct scatterlist *tvc_sgl;
  93         struct scatterlist *tvc_prot_sgl;
  94         struct page **tvc_upages;
  95         /* Pointer to response header iovec */
  96         struct iovec tvc_resp_iov;
  97         /* Pointer to vhost_scsi for our device */
  98         struct vhost_scsi *tvc_vhost;
  99         /* Pointer to vhost_virtqueue for the cmd */
 100         struct vhost_virtqueue *tvc_vq;
 101         /* Pointer to vhost nexus memory */
 102         struct vhost_scsi_nexus *tvc_nexus;
 103         /* The TCM I/O descriptor that is accessed via container_of() */
 104         struct se_cmd tvc_se_cmd;
 105         /* work item used for cmwq dispatch to vhost_scsi_submission_work() */
 106         struct work_struct work;
 107         /* Copy of the incoming SCSI command descriptor block (CDB) */
 108         unsigned char tvc_cdb[VHOST_SCSI_MAX_CDB_SIZE];
 109         /* Sense buffer that will be mapped into outgoing status */
 110         unsigned char tvc_sense_buf[TRANSPORT_SENSE_BUFFER];
 111         /* Completed commands list, serviced from vhost worker thread */
 112         struct llist_node tvc_completion_list;
 113         /* Used to track inflight cmd */
 114         struct vhost_scsi_inflight *inflight;
 115 };
 116
 117 struct vhost_scsi_nexus {
 118         /* Pointer to TCM session for I_T Nexus */
 119         struct se_session *tvn_se_sess;
 120 };
 121
 122 struct vhost_scsi_tpg {
 123         /* Vhost port target portal group tag for TCM */
 124         u16 tport_tpgt;
 125         /* Used to track number of TPG Port/Lun Links wrt to explict I_T Nexus shutdown */
 126         int tv_tpg_port_count;
 127         /* Used for vhost_scsi device reference to tpg_nexus, protected by tv_tpg_mutex */
 128         int tv_tpg_vhost_count;
 129         /* Used for enabling T10-PI with legacy devices */
 130         int tv_fabric_prot_type;
 131         /* list for vhost_scsi_list */
 132         struct list_head tv_tpg_list;
 133         /* Used to protect access for tpg_nexus */
 134         struct mutex tv_tpg_mutex;
 135         /* Pointer to the TCM VHost I_T Nexus for this TPG endpoint */
 136         struct vhost_scsi_nexus *tpg_nexus;
 137         /* Pointer back to vhost_scsi_tport */
 138         struct vhost_scsi_tport *tport;
 139         /* Returned by vhost_scsi_make_tpg() */
 140         struct se_portal_group se_tpg;
 141         /* Pointer back to vhost_scsi, protected by tv_tpg_mutex */
 142         struct vhost_scsi *vhost_scsi;
 143 };
 144
 145 struct vhost_scsi_tport {
 146         /* SCSI protocol the tport is providing */
 147         u8 tport_proto_id;
 148         /* Binary World Wide unique Port Name for Vhost Target port */
 149         u64 tport_wwpn;
 150         /* ASCII formatted WWPN for Vhost Target port */
 151         char tport_name[VHOST_SCSI_NAMELEN];
 152         /* Returned by vhost_scsi_make_tport() */
 153         struct se_wwn tport_wwn;
 154 };
 155
 156 struct vhost_scsi_evt {
 157         /* event to be sent to guest */
 158         struct virtio_scsi_event event;
 159         /* event list, serviced from vhost worker thread */
 160         struct llist_node list;
 161 };
 162
 163 enum {
 164         VHOST_SCSI_VQ_CTL = 0,
 165         VHOST_SCSI_VQ_EVT = 1,
 166         VHOST_SCSI_VQ_IO = 2,
 167 };
 168
 169 /* Note: can't set VIRTIO_F_VERSION_1 yet, since that implies ANY_LAYOUT. */
 170 enum {
 171         VHOST_SCSI_FEATURES = VHOST_FEATURES | (1ULL << VIRTIO_SCSI_F_HOTPLUG) |
 172                                                (1ULL << VIRTIO_SCSI_F_T10_PI)
 173 };
 174
 175 #define VHOST_SCSI_MAX_TARGET   256
 176 #define VHOST_SCSI_MAX_VQ       128
 177 #define VHOST_SCSI_MAX_EVENT    128
 178
 179 struct vhost_scsi_virtqueue {
 180         struct vhost_virtqueue vq;
 181         /*
 182          * Reference counting for inflight reqs, used for flush operation. At
 183          * each time, one reference tracks new commands submitted, while we
 184          * wait for another one to reach 0.
 185          */
 186         struct vhost_scsi_inflight inflights[2];
 187         /*
 188          * Indicate current inflight in use, protected by vq->mutex.
 189          * Writers must also take dev mutex and flush under it.
 190          */
 191         int inflight_idx;
 192 };
 193
 194 struct vhost_scsi {
 195         /* Protected by vhost_scsi->dev.mutex */
 196         struct vhost_scsi_tpg **vs_tpg;
 197         char vs_vhost_wwpn[TRANSPORT_IQN_LEN];
 198
 199         struct vhost_dev dev;
 200         struct vhost_scsi_virtqueue vqs[VHOST_SCSI_MAX_VQ];
 201
 202         struct vhost_work vs_completion_work; /* cmd completion work item */
 203         struct llist_head vs_completion_list; /* cmd completion queue */
 204
 205         struct vhost_work vs_event_work; /* evt injection work item */
 206         struct llist_head vs_event_list; /* evt injection queue */
 207
 208         bool vs_events_missed; /* any missed events, protected by vq->mutex */
 209         int vs_events_nr; /* num of pending events, protected by vq->mutex */
 210 };
 211
 212 /*
 213  * Context for processing request and control queue operations.
 214  */
 215 struct vhost_scsi_ctx {
 216         int head;
 217         unsigned int out, in;
 218         size_t req_size, rsp_size;
 219         size_t out_size, in_size;
 220         u8 *target, *lunp;
 221         void *req;
 222         struct iov_iter out_iter;
 223 };
 224
 225 static struct workqueue_struct *vhost_scsi_workqueue;
 226
 227 /* Global spinlock to protect vhost_scsi TPG list for vhost IOCTL access */
 228 static DEFINE_MUTEX(vhost_scsi_mutex);
 229 static LIST_HEAD(vhost_scsi_list);
 230
 231 static void vhost_scsi_done_inflight(struct kref *kref)
 232 {
 233         struct vhost_scsi_inflight *inflight;
 234
 235         inflight = container_of(kref, struct vhost_scsi_inflight, kref);
 236         complete(&inflight->comp);
 237 }
 238
 239 static void vhost_scsi_init_inflight(struct vhost_scsi *vs,
 240                                     struct vhost_scsi_inflight *old_inflight[])
 241 {
 242         struct vhost_scsi_inflight *new_inflight;
 243         struct vhost_virtqueue *vq;
 244         int idx, i;
 245
 246         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
 247                 vq = &vs->vqs[i].vq;
 248
 249                 mutex_lock(&vq->mutex);
 250
 251                 /* store old infight */
 252                 idx = vs->vqs[i].inflight_idx;
 253                 if (old_inflight)
 254                         old_inflight[i] = &vs->vqs[i].inflights[idx];
 255
 256                 /* setup new infight */
 257                 vs->vqs[i].inflight_idx = idx ^ 1;
 258                 new_inflight = &vs->vqs[i].inflights[idx ^ 1];
 259                 kref_init(&new_inflight->kref);
 260                 init_completion(&new_inflight->comp);
 261
 262                 mutex_unlock(&vq->mutex);
 263         }
 264 }
 265
 266 static struct vhost_scsi_inflight *
 267 vhost_scsi_get_inflight(struct vhost_virtqueue *vq)
 268 {
 269         struct vhost_scsi_inflight *inflight;
 270         struct vhost_scsi_virtqueue *svq;
 271
 272         svq = container_of(vq, struct vhost_scsi_virtqueue, vq);
 273         inflight = &svq->inflights[svq->inflight_idx];
 274         kref_get(&inflight->kref);
 275
 276         return inflight;
 277 }
 278
 279 static void vhost_scsi_put_inflight(struct vhost_scsi_inflight *inflight)
 280 {
 281         kref_put(&inflight->kref, vhost_scsi_done_inflight);
 282 }
 283
 284 static int vhost_scsi_check_true(struct se_portal_group *se_tpg)
 285 {
 286         return 1;
 287 }
 288
 289 static int vhost_scsi_check_false(struct se_portal_group *se_tpg)
 290 {
 291         return 0;
 292 }
 293
 294 static char *vhost_scsi_get_fabric_wwn(struct se_portal_group *se_tpg)
 295 {
 296         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
 297                                 struct vhost_scsi_tpg, se_tpg);
 298         struct vhost_scsi_tport *tport = tpg->tport;
 299
 300         return &tport->tport_name[0];
 301 }
 302
 303 static u16 vhost_scsi_get_tpgt(struct se_portal_group *se_tpg)
 304 {
 305         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
 306                                 struct vhost_scsi_tpg, se_tpg);
 307         return tpg->tport_tpgt;
 308 }
 309
 310 static int vhost_scsi_check_prot_fabric_only(struct se_portal_group *se_tpg)
 311 {
 312         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
 313                                 struct vhost_scsi_tpg, se_tpg);
 314
 315         return tpg->tv_fabric_prot_type;
 316 }
 317
 318 static u32 vhost_scsi_tpg_get_inst_index(struct se_portal_group *se_tpg)
 319 {
 320         return 1;
 321 }
 322
 323 static void vhost_scsi_release_cmd(struct se_cmd *se_cmd)
 324 {
 325         struct vhost_scsi_cmd *tv_cmd = container_of(se_cmd,
 326                                 struct vhost_scsi_cmd, tvc_se_cmd);
 327         struct se_session *se_sess = tv_cmd->tvc_nexus->tvn_se_sess;
 328         int i;
 329
 330         if (tv_cmd->tvc_sgl_count) {
 331                 for (i = 0; i < tv_cmd->tvc_sgl_count; i++)
 332                         put_page(sg_page(&tv_cmd->tvc_sgl[i]));
 333         }
 334         if (tv_cmd->tvc_prot_sgl_count) {
 335                 for (i = 0; i < tv_cmd->tvc_prot_sgl_count; i++)
 336                         put_page(sg_page(&tv_cmd->tvc_prot_sgl[i]));
 337         }
 338
 339         vhost_scsi_put_inflight(tv_cmd->inflight);
 340         target_free_tag(se_sess, se_cmd);
 341 }
 342
 343 static u32 vhost_scsi_sess_get_index(struct se_session *se_sess)
 344 {
 345         return 0;
 346 }
 347
 348 static int vhost_scsi_write_pending(struct se_cmd *se_cmd)
 349 {
 350         /* Go ahead and process the write immediately */
 351         target_execute_cmd(se_cmd);
 352         return 0;
 353 }
 354
 355 static void vhost_scsi_set_default_node_attrs(struct se_node_acl *nacl)
 356 {
 357         return;
 358 }
 359
 360 static int vhost_scsi_get_cmd_state(struct se_cmd *se_cmd)
 361 {
 362         return 0;
 363 }
 364
 365 static void vhost_scsi_complete_cmd(struct vhost_scsi_cmd *cmd)
 366 {
 367         struct vhost_scsi *vs = cmd->tvc_vhost;
 368
 369         llist_add(&cmd->tvc_completion_list, &vs->vs_completion_list);
 370
 371         vhost_work_queue(&vs->dev, &vs->vs_completion_work);
 372 }
 373
 374 static int vhost_scsi_queue_data_in(struct se_cmd *se_cmd)
 375 {
 376         struct vhost_scsi_cmd *cmd = container_of(se_cmd,
 377                                 struct vhost_scsi_cmd, tvc_se_cmd);
 378         vhost_scsi_complete_cmd(cmd);
 379         return 0;
 380 }
 381
 382 static int vhost_scsi_queue_status(struct se_cmd *se_cmd)
 383 {
 384         struct vhost_scsi_cmd *cmd = container_of(se_cmd,
 385                                 struct vhost_scsi_cmd, tvc_se_cmd);
 386         vhost_scsi_complete_cmd(cmd);
 387         return 0;
 388 }
 389
 390 static void vhost_scsi_queue_tm_rsp(struct se_cmd *se_cmd)
 391 {
 392         return;
 393 }
 394
 395 static void vhost_scsi_aborted_task(struct se_cmd *se_cmd)
 396 {
 397         return;
 398 }
 399
 400 static void vhost_scsi_free_evt(struct vhost_scsi *vs, struct vhost_scsi_evt *evt)
 401 {
 402         vs->vs_events_nr--;
 403         kfree(evt);
 404 }
 405
 406 static struct vhost_scsi_evt *
 407 vhost_scsi_allocate_evt(struct vhost_scsi *vs,
 408                        u32 event, u32 reason)
 409 {
 410         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 411         struct vhost_scsi_evt *evt;
 412
 413         if (vs->vs_events_nr > VHOST_SCSI_MAX_EVENT) {
 414                 vs->vs_events_missed = true;
 415                 return NULL;
 416         }
 417
 418         evt = kzalloc(sizeof(*evt), GFP_KERNEL);
 419         if (!evt) {
 420                 vq_err(vq, "Failed to allocate vhost_scsi_evt\n");
 421                 vs->vs_events_missed = true;
 422                 return NULL;
 423         }
 424
 425         evt->event.event = cpu_to_vhost32(vq, event);
 426         evt->event.reason = cpu_to_vhost32(vq, reason);
 427         vs->vs_events_nr++;
 428
 429         return evt;
 430 }
 431
 432 static void vhost_scsi_free_cmd(struct vhost_scsi_cmd *cmd)
 433 {
 434         struct se_cmd *se_cmd = &cmd->tvc_se_cmd;
 435
 436         /* TODO locking against target/backend threads? */
 437         transport_generic_free_cmd(se_cmd, 0);
 438
 439 }
 440
 441 static int vhost_scsi_check_stop_free(struct se_cmd *se_cmd)
 442 {
 443         return target_put_sess_cmd(se_cmd);
 444 }
 445
 446 static void
 447 vhost_scsi_do_evt_work(struct vhost_scsi *vs, struct vhost_scsi_evt *evt)
 448 {
 449         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 450         struct virtio_scsi_event *event = &evt->event;
 451         struct virtio_scsi_event __user *eventp;
 452         unsigned out, in;
 453         int head, ret;
 454
 455         if (!vq->private_data) {
 456                 vs->vs_events_missed = true;
 457                 return;
 458         }
 459
 460 again:
 461         vhost_disable_notify(&vs->dev, vq);
 462         head = vhost_get_vq_desc(vq, vq->iov,
 463                         ARRAY_SIZE(vq->iov), &out, &in,
 464                         NULL, NULL);
 465         if (head < 0) {
 466                 vs->vs_events_missed = true;
 467                 return;
 468         }
 469         if (head == vq->num) {
 470                 if (vhost_enable_notify(&vs->dev, vq))
 471                         goto again;
 472                 vs->vs_events_missed = true;
 473                 return;
 474         }
 475
 476         if ((vq->iov[out].iov_len != sizeof(struct virtio_scsi_event))) {
 477                 vq_err(vq, "Expecting virtio_scsi_event, got %zu bytes\n",
 478                                 vq->iov[out].iov_len);
 479                 vs->vs_events_missed = true;
 480                 return;
 481         }
 482
 483         if (vs->vs_events_missed) {
 484                 event->event |= cpu_to_vhost32(vq, VIRTIO_SCSI_T_EVENTS_MISSED);
 485                 vs->vs_events_missed = false;
 486         }
 487
 488         eventp = vq->iov[out].iov_base;
 489         ret = __copy_to_user(eventp, event, sizeof(*event));
 490         if (!ret)
 491                 vhost_add_used_and_signal(&vs->dev, vq, head, 0);
 492         else
 493                 vq_err(vq, "Faulted on vhost_scsi_send_event\n");
 494 }
 495
 496 static void vhost_scsi_evt_work(struct vhost_work *work)
 497 {
 498         struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
 499                                         vs_event_work);
 500         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 501         struct vhost_scsi_evt *evt, *t;
 502         struct llist_node *llnode;
 503
 504         mutex_lock(&vq->mutex);
 505         llnode = llist_del_all(&vs->vs_event_list);
 506         llist_for_each_entry_safe(evt, t, llnode, list) {
 507                 vhost_scsi_do_evt_work(vs, evt);
 508                 vhost_scsi_free_evt(vs, evt);
 509         }
 510         mutex_unlock(&vq->mutex);
 511 }
 512
 513 /* Fill in status and signal that we are done processing this command
 514  *
 515  * This is scheduled in the vhost work queue so we are called with the owner
 516  * process mm and can access the vring.
 517  */
 518 static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
 519 {
 520         struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
 521                                         vs_completion_work);
 522         DECLARE_BITMAP(signal, VHOST_SCSI_MAX_VQ);
 523         struct virtio_scsi_cmd_resp v_rsp;
 524         struct vhost_scsi_cmd *cmd, *t;
 525         struct llist_node *llnode;
 526         struct se_cmd *se_cmd;
 527         struct iov_iter iov_iter;
 528         int ret, vq;
 529
 530         bitmap_zero(signal, VHOST_SCSI_MAX_VQ);
 531         llnode = llist_del_all(&vs->vs_completion_list);
 532         llist_for_each_entry_safe(cmd, t, llnode, tvc_completion_list) {
 533                 se_cmd = &cmd->tvc_se_cmd;
 534
 535                 pr_debug("%s tv_cmd %p resid %u status %#02x\n", __func__,
 536                         cmd, se_cmd->residual_count, se_cmd->scsi_status);
 537
 538                 memset(&v_rsp, 0, sizeof(v_rsp));
 539                 v_rsp.resid = cpu_to_vhost32(cmd->tvc_vq, se_cmd->residual_count);
 540                 /* TODO is status_qualifier field needed? */
 541                 v_rsp.status = se_cmd->scsi_status;
 542                 v_rsp.sense_len = cpu_to_vhost32(cmd->tvc_vq,
 543                                                  se_cmd->scsi_sense_length);
 544                 memcpy(v_rsp.sense, cmd->tvc_sense_buf,
 545                        se_cmd->scsi_sense_length);
 546
 547                 iov_iter_init(&iov_iter, READ, &cmd->tvc_resp_iov,
 548                               cmd->tvc_in_iovs, sizeof(v_rsp));
 549                 ret = copy_to_iter(&v_rsp, sizeof(v_rsp), &iov_iter);
 550                 if (likely(ret == sizeof(v_rsp))) {
 551                         struct vhost_scsi_virtqueue *q;
 552                         vhost_add_used(cmd->tvc_vq, cmd->tvc_vq_desc, 0);
 553                         q = container_of(cmd->tvc_vq, struct vhost_scsi_virtqueue, vq);
 554                         vq = q - vs->vqs;
 555                         __set_bit(vq, signal);
 556                 } else
 557                         pr_err("Faulted on virtio_scsi_cmd_resp\n");
 558
 559                 vhost_scsi_free_cmd(cmd);
 560         }
 561
 562         vq = -1;
 563         while ((vq = find_next_bit(signal, VHOST_SCSI_MAX_VQ, vq + 1))
 564                 < VHOST_SCSI_MAX_VQ)
 565                 vhost_signal(&vs->dev, &vs->vqs[vq].vq);
 566 }
 567
 568 static struct vhost_scsi_cmd *
 569 vhost_scsi_get_tag(struct vhost_virtqueue *vq, struct vhost_scsi_tpg *tpg,
 570                    unsigned char *cdb, u64 scsi_tag, u16 lun, u8 task_attr,
 571                    u32 exp_data_len, int data_direction)
 572 {
 573         struct vhost_scsi_cmd *cmd;
 574         struct vhost_scsi_nexus *tv_nexus;
 575         struct se_session *se_sess;
 576         struct scatterlist *sg, *prot_sg;
 577         struct page **pages;
 578         int tag, cpu;
 579
 580         tv_nexus = tpg->tpg_nexus;
 581         if (!tv_nexus) {
 582                 pr_err("Unable to locate active struct vhost_scsi_nexus\n");
 583                 return ERR_PTR(-EIO);
 584         }
 585         se_sess = tv_nexus->tvn_se_sess;
 586
 587         tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
 588         if (tag < 0) {
 589                 pr_err("Unable to obtain tag for vhost_scsi_cmd\n");
 590                 return ERR_PTR(-ENOMEM);
 591         }
 592
 593         cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[tag];
 594         sg = cmd->tvc_sgl;
 595         prot_sg = cmd->tvc_prot_sgl;
 596         pages = cmd->tvc_upages;
 597         memset(cmd, 0, sizeof(*cmd));
 598         cmd->tvc_sgl = sg;
 599         cmd->tvc_prot_sgl = prot_sg;
 600         cmd->tvc_upages = pages;
 601         cmd->tvc_se_cmd.map_tag = tag;
 602         cmd->tvc_se_cmd.map_cpu = cpu;
 603         cmd->tvc_tag = scsi_tag;
 604         cmd->tvc_lun = lun;
 605         cmd->tvc_task_attr = task_attr;
 606         cmd->tvc_exp_data_len = exp_data_len;
 607         cmd->tvc_data_direction = data_direction;
 608         cmd->tvc_nexus = tv_nexus;
 609         cmd->inflight = vhost_scsi_get_inflight(vq);
 610
 611         memcpy(cmd->tvc_cdb, cdb, VHOST_SCSI_MAX_CDB_SIZE);
 612
 613         return cmd;
 614 }
 615
 616 /*
 617  * Map a user memory range into a scatterlist
 618  *
 619  * Returns the number of scatterlist entries used or -errno on error.
 620  */
 621 static int
 622 vhost_scsi_map_to_sgl(struct vhost_scsi_cmd *cmd,
 623                       struct iov_iter *iter,
 624                       struct scatterlist *sgl,
 625                       bool write)
 626 {
 627         struct page **pages = cmd->tvc_upages;
 628         struct scatterlist *sg = sgl;
 629         ssize_t bytes;
 630         size_t offset;
 631         unsigned int npages = 0;
 632
 633         bytes = iov_iter_get_pages(iter, pages, LONG_MAX,
 634                                 VHOST_SCSI_PREALLOC_UPAGES, &offset);
 635         /* No pages were pinned */
 636         if (bytes <= 0)
 637                 return bytes < 0 ? bytes : -EFAULT;
 638
 639         iov_iter_advance(iter, bytes);
 640
 641         while (bytes) {
 642                 unsigned n = min_t(unsigned, PAGE_SIZE - offset, bytes);
 643                 sg_set_page(sg++, pages[npages++], n, offset);
 644                 bytes -= n;
 645                 offset = 0;
 646         }
 647         return npages;
 648 }
 649
 650 static int
 651 vhost_scsi_calc_sgls(struct iov_iter *iter, size_t bytes, int max_sgls)
 652 {
 653         int sgl_count = 0;
 654
 655         if (!iter || !iter->iov) {
 656                 pr_err("%s: iter->iov is NULL, but expected bytes: %zu"
 657                        " present\n", __func__, bytes);
 658                 return -EINVAL;
 659         }
 660
 661         sgl_count = iov_iter_npages(iter, 0xffff);
 662         if (sgl_count > max_sgls) {
 663                 pr_err("%s: requested sgl_count: %d exceeds pre-allocated"
 664                        " max_sgls: %d\n", __func__, sgl_count, max_sgls);
 665                 return -EINVAL;
 666         }
 667         return sgl_count;
 668 }
 669
 670 static int
 671 vhost_scsi_iov_to_sgl(struct vhost_scsi_cmd *cmd, bool write,
 672                       struct iov_iter *iter,
 673                       struct scatterlist *sg, int sg_count)
 674 {
 675         struct scatterlist *p = sg;
 676         int ret;
 677
 678         while (iov_iter_count(iter)) {
 679                 ret = vhost_scsi_map_to_sgl(cmd, iter, sg, write);
 680                 if (ret < 0) {
 681                         while (p < sg) {
 682                                 struct page *page = sg_page(p++);
 683                                 if (page)
 684                                         put_page(page);
 685                         }
 686                         return ret;
 687                 }
 688                 sg += ret;
 689         }
 690         return 0;
 691 }
 692
 693 static int
 694 vhost_scsi_mapal(struct vhost_scsi_cmd *cmd,
 695                  size_t prot_bytes, struct iov_iter *prot_iter,
 696                  size_t data_bytes, struct iov_iter *data_iter)
 697 {
 698         int sgl_count, ret;
 699         bool write = (cmd->tvc_data_direction == DMA_FROM_DEVICE);
 700
 701         if (prot_bytes) {
 702                 sgl_count = vhost_scsi_calc_sgls(prot_iter, prot_bytes,
 703                                                  VHOST_SCSI_PREALLOC_PROT_SGLS);
 704                 if (sgl_count < 0)
 705                         return sgl_count;
 706
 707                 sg_init_table(cmd->tvc_prot_sgl, sgl_count);
 708                 cmd->tvc_prot_sgl_count = sgl_count;
 709                 pr_debug("%s prot_sg %p prot_sgl_count %u\n", __func__,
 710                          cmd->tvc_prot_sgl, cmd->tvc_prot_sgl_count);
 711
 712                 ret = vhost_scsi_iov_to_sgl(cmd, write, prot_iter,
 713                                             cmd->tvc_prot_sgl,
 714                                             cmd->tvc_prot_sgl_count);
 715                 if (ret < 0) {
 716                         cmd->tvc_prot_sgl_count = 0;
 717                         return ret;
 718                 }
 719         }
 720         sgl_count = vhost_scsi_calc_sgls(data_iter, data_bytes,
 721                                          VHOST_SCSI_PREALLOC_SGLS);
 722         if (sgl_count < 0)
 723                 return sgl_count;
 724
 725         sg_init_table(cmd->tvc_sgl, sgl_count);
 726         cmd->tvc_sgl_count = sgl_count;
 727         pr_debug("%s data_sg %p data_sgl_count %u\n", __func__,
 728                   cmd->tvc_sgl, cmd->tvc_sgl_count);
 729
 730         ret = vhost_scsi_iov_to_sgl(cmd, write, data_iter,
 731                                     cmd->tvc_sgl, cmd->tvc_sgl_count);
 732         if (ret < 0) {
 733                 cmd->tvc_sgl_count = 0;
 734                 return ret;
 735         }
 736         return 0;
 737 }
 738
 739 static int vhost_scsi_to_tcm_attr(int attr)
 740 {
 741         switch (attr) {
 742         case VIRTIO_SCSI_S_SIMPLE:
 743                 return TCM_SIMPLE_TAG;
 744         case VIRTIO_SCSI_S_ORDERED:
 745                 return TCM_ORDERED_TAG;
 746         case VIRTIO_SCSI_S_HEAD:
 747                 return TCM_HEAD_TAG;
 748         case VIRTIO_SCSI_S_ACA:
 749                 return TCM_ACA_TAG;
 750         default:
 751                 break;
 752         }
 753         return TCM_SIMPLE_TAG;
 754 }
 755
 756 static void vhost_scsi_submission_work(struct work_struct *work)
 757 {
 758         struct vhost_scsi_cmd *cmd =
 759                 container_of(work, struct vhost_scsi_cmd, work);
 760         struct vhost_scsi_nexus *tv_nexus;
 761         struct se_cmd *se_cmd = &cmd->tvc_se_cmd;
 762         struct scatterlist *sg_ptr, *sg_prot_ptr = NULL;
 763         int rc;
 764
 765         /* FIXME: BIDI operation */
 766         if (cmd->tvc_sgl_count) {
 767                 sg_ptr = cmd->tvc_sgl;
 768
 769                 if (cmd->tvc_prot_sgl_count)
 770                         sg_prot_ptr = cmd->tvc_prot_sgl;
 771                 else
 772                         se_cmd->prot_pto = true;
 773         } else {
 774                 sg_ptr = NULL;
 775         }
 776         tv_nexus = cmd->tvc_nexus;
 777
 778         se_cmd->tag = 0;
 779         rc = target_submit_cmd_map_sgls(se_cmd, tv_nexus->tvn_se_sess,
 780                         cmd->tvc_cdb, &cmd->tvc_sense_buf[0],
 781                         cmd->tvc_lun, cmd->tvc_exp_data_len,
 782                         vhost_scsi_to_tcm_attr(cmd->tvc_task_attr),
 783                         cmd->tvc_data_direction, TARGET_SCF_ACK_KREF,
 784                         sg_ptr, cmd->tvc_sgl_count, NULL, 0, sg_prot_ptr,
 785                         cmd->tvc_prot_sgl_count);
 786         if (rc < 0) {
 787                 transport_send_check_condition_and_sense(se_cmd,
 788                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
 789                 transport_generic_free_cmd(se_cmd, 0);
 790         }
 791 }
 792
 793 static void
 794 vhost_scsi_send_bad_target(struct vhost_scsi *vs,
 795                            struct vhost_virtqueue *vq,
 796                            int head, unsigned out)
 797 {
 798         struct virtio_scsi_cmd_resp __user *resp;
 799         struct virtio_scsi_cmd_resp rsp;
 800         int ret;
 801
 802         memset(&rsp, 0, sizeof(rsp));
 803         rsp.response = VIRTIO_SCSI_S_BAD_TARGET;
 804         resp = vq->iov[out].iov_base;
 805         ret = __copy_to_user(resp, &rsp, sizeof(rsp));
 806         if (!ret)
 807                 vhost_add_used_and_signal(&vs->dev, vq, head, 0);
 808         else
 809                 pr_err("Faulted on virtio_scsi_cmd_resp\n");
 810 }
 811
 812 static int
 813 vhost_scsi_get_desc(struct vhost_scsi *vs, struct vhost_virtqueue *vq,
 814                     struct vhost_scsi_ctx *vc)
 815 {
 816         int ret = -ENXIO;
 817
 818         vc->head = vhost_get_vq_desc(vq, vq->iov,
 819                                      ARRAY_SIZE(vq->iov), &vc->out, &vc->in,
 820                                      NULL, NULL);
 821
 822         pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n",
 823                  vc->head, vc->out, vc->in);
 824
 825         /* On error, stop handling until the next kick. */
 826         if (unlikely(vc->head < 0))
 827                 goto done;
 828
 829         /* Nothing new?  Wait for eventfd to tell us they refilled. */
 830         if (vc->head == vq->num) {
 831                 if (unlikely(vhost_enable_notify(&vs->dev, vq))) {
 832                         vhost_disable_notify(&vs->dev, vq);
 833                         ret = -EAGAIN;
 834                 }
 835                 goto done;
 836         }
 837
 838         /*
 839          * Get the size of request and response buffers.
 840          * FIXME: Not correct for BIDI operation
 841          */
 842         vc->out_size = iov_length(vq->iov, vc->out);
 843         vc->in_size = iov_length(&vq->iov[vc->out], vc->in);
 844
 845         /*
 846          * Copy over the virtio-scsi request header, which for a
 847          * ANY_LAYOUT enabled guest may span multiple iovecs, or a
 848          * single iovec may contain both the header + outgoing
 849          * WRITE payloads.
 850          *
 851          * copy_from_iter() will advance out_iter, so that it will
 852          * point at the start of the outgoing WRITE payload, if
 853          * DMA_TO_DEVICE is set.
 854          */
 855         iov_iter_init(&vc->out_iter, WRITE, vq->iov, vc->out, vc->out_size);
 856         ret = 0;
 857
 858 done:
 859         return ret;
 860 }
 861
 862 static int
 863 vhost_scsi_chk_size(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc)
 864 {
 865         if (unlikely(vc->in_size < vc->rsp_size)) {
 866                 vq_err(vq,
 867                        "Response buf too small, need min %zu bytes got %zu",
 868                        vc->rsp_size, vc->in_size);
 869                 return -EINVAL;
 870         } else if (unlikely(vc->out_size < vc->req_size)) {
 871                 vq_err(vq,
 872                        "Request buf too small, need min %zu bytes got %zu",
 873                        vc->req_size, vc->out_size);
 874                 return -EIO;
 875         }
 876
 877         return 0;
 878 }
 879
 880 static int
 881 vhost_scsi_get_req(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc,
 882                    struct vhost_scsi_tpg **tpgp)
 883 {
 884         int ret = -EIO;
 885
 886         if (unlikely(!copy_from_iter_full(vc->req, vc->req_size,
 887                                           &vc->out_iter))) {
 888                 vq_err(vq, "Faulted on copy_from_iter_full\n");
 889         } else if (unlikely(*vc->lunp != 1)) {
 890                 /* virtio-scsi spec requires byte 0 of the lun to be 1 */
 891                 vq_err(vq, "Illegal virtio-scsi lun: %u\n", *vc->lunp);
 892         } else {
 893                 struct vhost_scsi_tpg **vs_tpg, *tpg;
 894
 895                 vs_tpg = vq->private_data;      /* validated at handler entry */
 896
 897                 tpg = READ_ONCE(vs_tpg[*vc->target]);
 898                 if (unlikely(!tpg)) {
 899                         vq_err(vq, "Target 0x%x does not exist\n", *vc->target);
 900                 } else {
 901                         if (tpgp)
 902                                 *tpgp = tpg;
 903                         ret = 0;
 904                 }
 905         }
 906
 907         return ret;
 908 }
 909
 910 static void
 911 vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 912 {
 913         struct vhost_scsi_tpg **vs_tpg, *tpg;
 914         struct virtio_scsi_cmd_req v_req;
 915         struct virtio_scsi_cmd_req_pi v_req_pi;
 916         struct vhost_scsi_ctx vc;
 917         struct vhost_scsi_cmd *cmd;
 918         struct iov_iter in_iter, prot_iter, data_iter;
 919         u64 tag;
 920         u32 exp_data_len, data_direction;
 921         int ret, prot_bytes, c = 0;
 922         u16 lun;
 923         u8 task_attr;
 924         bool t10_pi = vhost_has_feature(vq, VIRTIO_SCSI_F_T10_PI);
 925         void *cdb;
 926
 927         mutex_lock(&vq->mutex);
 928         /*
 929          * We can handle the vq only after the endpoint is setup by calling the
 930          * VHOST_SCSI_SET_ENDPOINT ioctl.
 931          */
 932         vs_tpg = vq->private_data;
 933         if (!vs_tpg)
 934                 goto out;
 935
 936         memset(&vc, 0, sizeof(vc));
 937         vc.rsp_size = sizeof(struct virtio_scsi_cmd_resp);
 938
 939         vhost_disable_notify(&vs->dev, vq);
 940
 941         do {
 942                 ret = vhost_scsi_get_desc(vs, vq, &vc);
 943                 if (ret)
 944                         goto err;
 945
 946                 /*
 947                  * Setup pointers and values based upon different virtio-scsi
 948                  * request header if T10_PI is enabled in KVM guest.
 949                  */
 950                 if (t10_pi) {
 951                         vc.req = &v_req_pi;
 952                         vc.req_size = sizeof(v_req_pi);
 953                         vc.lunp = &v_req_pi.lun[0];
 954                         vc.target = &v_req_pi.lun[1];
 955                 } else {
 956                         vc.req = &v_req;
 957                         vc.req_size = sizeof(v_req);
 958                         vc.lunp = &v_req.lun[0];
 959                         vc.target = &v_req.lun[1];
 960                 }
 961
 962                 /*
 963                  * Validate the size of request and response buffers.
 964                  * Check for a sane response buffer so we can report
 965                  * early errors back to the guest.
 966                  */
 967                 ret = vhost_scsi_chk_size(vq, &vc);
 968                 if (ret)
 969                         goto err;
 970
 971                 ret = vhost_scsi_get_req(vq, &vc, &tpg);
 972                 if (ret)
 973                         goto err;
 974
 975                 ret = -EIO;     /* bad target on any error from here on */
 976
 977                 /*
 978                  * Determine data_direction by calculating the total outgoing
 979                  * iovec sizes + incoming iovec sizes vs. virtio-scsi request +
 980                  * response headers respectively.
 981                  *
 982                  * For DMA_TO_DEVICE this is out_iter, which is already pointing
 983                  * to the right place.
 984                  *
 985                  * For DMA_FROM_DEVICE, the iovec will be just past the end
 986                  * of the virtio-scsi response header in either the same
 987                  * or immediately following iovec.
 988                  *
 989                  * Any associated T10_PI bytes for the outgoing / incoming
 990                  * payloads are included in calculation of exp_data_len here.
 991                  */
 992                 prot_bytes = 0;
 993
 994                 if (vc.out_size > vc.req_size) {
 995                         data_direction = DMA_TO_DEVICE;
 996                         exp_data_len = vc.out_size - vc.req_size;
 997                         data_iter = vc.out_iter;
 998                 } else if (vc.in_size > vc.rsp_size) {
 999                         data_direction = DMA_FROM_DEVICE;
1000                         exp_data_len = vc.in_size - vc.rsp_size;
1001
1002                         iov_iter_init(&in_iter, READ, &vq->iov[vc.out], vc.in,
1003                                       vc.rsp_size + exp_data_len);
1004                         iov_iter_advance(&in_iter, vc.rsp_size);
1005                         data_iter = in_iter;
1006                 } else {
1007                         data_direction = DMA_NONE;
1008                         exp_data_len = 0;
1009                 }
1010                 /*
1011                  * If T10_PI header + payload is present, setup prot_iter values
1012                  * and recalculate data_iter for vhost_scsi_mapal() mapping to
1013                  * host scatterlists via get_user_pages_fast().
1014                  */
1015                 if (t10_pi) {
1016                         if (v_req_pi.pi_bytesout) {
1017                                 if (data_direction != DMA_TO_DEVICE) {
1018                                         vq_err(vq, "Received non zero pi_bytesout,"
1019                                                 " but wrong data_direction\n");
1020                                         goto err;
1021                                 }
1022                                 prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesout);
1023                         } else if (v_req_pi.pi_bytesin) {
1024                                 if (data_direction != DMA_FROM_DEVICE) {
1025                                         vq_err(vq, "Received non zero pi_bytesin,"
1026                                                 " but wrong data_direction\n");
1027                                         goto err;
1028                                 }
1029                                 prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin);
1030                         }
1031                         /*
1032                          * Set prot_iter to data_iter and truncate it to
1033                          * prot_bytes, and advance data_iter past any
1034                          * preceeding prot_bytes that may be present.
1035                          *
1036                          * Also fix up the exp_data_len to reflect only the
1037                          * actual data payload length.
1038                          */
1039                         if (prot_bytes) {
1040                                 exp_data_len -= prot_bytes;
1041                                 prot_iter = data_iter;
1042                                 iov_iter_truncate(&prot_iter, prot_bytes);
1043                                 iov_iter_advance(&data_iter, prot_bytes);
1044                         }
1045                         tag = vhost64_to_cpu(vq, v_req_pi.tag);
1046                         task_attr = v_req_pi.task_attr;
1047                         cdb = &v_req_pi.cdb[0];
1048                         lun = ((v_req_pi.lun[2] << 8) | v_req_pi.lun[3]) & 0x3FFF;
1049                 } else {
1050                         tag = vhost64_to_cpu(vq, v_req.tag);
1051                         task_attr = v_req.task_attr;
1052                         cdb = &v_req.cdb[0];
1053                         lun = ((v_req.lun[2] << 8) | v_req.lun[3]) & 0x3FFF;
1054                 }
1055                 /*
1056                  * Check that the received CDB size does not exceeded our
1057                  * hardcoded max for vhost-scsi, then get a pre-allocated
1058                  * cmd descriptor for the new virtio-scsi tag.
1059                  *
1060                  * TODO what if cdb was too small for varlen cdb header?
1061                  */
1062                 if (unlikely(scsi_command_size(cdb) > VHOST_SCSI_MAX_CDB_SIZE)) {
1063                         vq_err(vq, "Received SCSI CDB with command_size: %d that"
1064                                 " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1065                                 scsi_command_size(cdb), VHOST_SCSI_MAX_CDB_SIZE);
1066                                 goto err;
1067                 }
1068                 cmd = vhost_scsi_get_tag(vq, tpg, cdb, tag, lun, task_attr,
1069                                          exp_data_len + prot_bytes,
1070                                          data_direction);
1071                 if (IS_ERR(cmd)) {
1072                         vq_err(vq, "vhost_scsi_get_tag failed %ld\n",
1073                                PTR_ERR(cmd));
1074                         goto err;
1075                 }
1076                 cmd->tvc_vhost = vs;
1077                 cmd->tvc_vq = vq;
1078                 cmd->tvc_resp_iov = vq->iov[vc.out];
1079                 cmd->tvc_in_iovs = vc.in;
1080
1081                 pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",
1082                          cmd->tvc_cdb[0], cmd->tvc_lun);
1083                 pr_debug("cmd: %p exp_data_len: %d, prot_bytes: %d data_direction:"
1084                          " %d\n", cmd, exp_data_len, prot_bytes, data_direction);
1085
1086                 if (data_direction != DMA_NONE) {
1087                         if (unlikely(vhost_scsi_mapal(cmd, prot_bytes,
1088                                                       &prot_iter, exp_data_len,
1089                                                       &data_iter))) {
1090                                 vq_err(vq, "Failed to map iov to sgl\n");
1091                                 vhost_scsi_release_cmd(&cmd->tvc_se_cmd);
1092                                 goto err;
1093                         }
1094                 }
1095                 /*
1096                  * Save the descriptor from vhost_get_vq_desc() to be used to
1097                  * complete the virtio-scsi request in TCM callback context via
1098                  * vhost_scsi_queue_data_in() and vhost_scsi_queue_status()
1099                  */
1100                 cmd->tvc_vq_desc = vc.head;
1101                 /*
1102                  * Dispatch cmd descriptor for cmwq execution in process
1103                  * context provided by vhost_scsi_workqueue.  This also ensures
1104                  * cmd is executed on the same kworker CPU as this vhost
1105                  * thread to gain positive L2 cache locality effects.
1106                  */
1107                 INIT_WORK(&cmd->work, vhost_scsi_submission_work);
1108                 queue_work(vhost_scsi_workqueue, &cmd->work);
1109                 ret = 0;
1110 err:
1111                 /*
1112                  * ENXIO:  No more requests, or read error, wait for next kick
1113                  * EINVAL: Invalid response buffer, drop the request
1114                  * EIO:    Respond with bad target
1115                  * EAGAIN: Pending request
1116                  */
1117                 if (ret == -ENXIO)
1118                         break;
1119                 else if (ret == -EIO)
1120                         vhost_scsi_send_bad_target(vs, vq, vc.head, vc.out);
1121         } while (likely(!vhost_exceeds_weight(vq, ++c, 0)));
1122 out:
1123         mutex_unlock(&vq->mutex);
1124 }
1125
1126 static void
1127 vhost_scsi_send_tmf_reject(struct vhost_scsi *vs,
1128                            struct vhost_virtqueue *vq,
1129                            struct vhost_scsi_ctx *vc)
1130 {
1131         struct virtio_scsi_ctrl_tmf_resp rsp;
1132         struct iov_iter iov_iter;
1133         int ret;
1134
1135         pr_debug("%s\n", __func__);
1136         memset(&rsp, 0, sizeof(rsp));
1137         rsp.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
1138
1139         iov_iter_init(&iov_iter, READ, &vq->iov[vc->out], vc->in, sizeof(rsp));
1140
1141         ret = copy_to_iter(&rsp, sizeof(rsp), &iov_iter);
1142         if (likely(ret == sizeof(rsp)))
1143                 vhost_add_used_and_signal(&vs->dev, vq, vc->head, 0);
1144         else
1145                 pr_err("Faulted on virtio_scsi_ctrl_tmf_resp\n");
1146 }
1147
1148 static void
1149 vhost_scsi_send_an_resp(struct vhost_scsi *vs,
1150                         struct vhost_virtqueue *vq,
1151                         struct vhost_scsi_ctx *vc)
1152 {
1153         struct virtio_scsi_ctrl_an_resp rsp;
1154         struct iov_iter iov_iter;
1155         int ret;
1156
1157         pr_debug("%s\n", __func__);
1158         memset(&rsp, 0, sizeof(rsp));   /* event_actual = 0 */
1159         rsp.response = VIRTIO_SCSI_S_OK;
1160
1161         iov_iter_init(&iov_iter, READ, &vq->iov[vc->out], vc->in, sizeof(rsp));
1162
1163         ret = copy_to_iter(&rsp, sizeof(rsp), &iov_iter);
1164         if (likely(ret == sizeof(rsp)))
1165                 vhost_add_used_and_signal(&vs->dev, vq, vc->head, 0);
1166         else
1167                 pr_err("Faulted on virtio_scsi_ctrl_an_resp\n");
1168 }
1169
1170 static void
1171 vhost_scsi_ctl_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
1172 {
1173         union {
1174                 __virtio32 type;
1175                 struct virtio_scsi_ctrl_an_req an;
1176                 struct virtio_scsi_ctrl_tmf_req tmf;
1177         } v_req;
1178         struct vhost_scsi_ctx vc;
1179         size_t typ_size;
1180         int ret, c = 0;
1181
1182         mutex_lock(&vq->mutex);
1183         /*
1184          * We can handle the vq only after the endpoint is setup by calling the
1185          * VHOST_SCSI_SET_ENDPOINT ioctl.
1186          */
1187         if (!vq->private_data)
1188                 goto out;
1189
1190         memset(&vc, 0, sizeof(vc));
1191
1192         vhost_disable_notify(&vs->dev, vq);
1193
1194         do {
1195                 ret = vhost_scsi_get_desc(vs, vq, &vc);
1196                 if (ret)
1197                         goto err;
1198
1199                 /*
1200                  * Get the request type first in order to setup
1201                  * other parameters dependent on the type.
1202                  */
1203                 vc.req = &v_req.type;
1204                 typ_size = sizeof(v_req.type);
1205
1206                 if (unlikely(!copy_from_iter_full(vc.req, typ_size,
1207                                                   &vc.out_iter))) {
1208                         vq_err(vq, "Faulted on copy_from_iter tmf type\n");
1209                         /*
1210                          * The size of the response buffer depends on the
1211                          * request type and must be validated against it.
1212                          * Since the request type is not known, don't send
1213                          * a response.
1214                          */
1215                         continue;
1216                 }
1217
1218                 switch (v_req.type) {
1219                 case VIRTIO_SCSI_T_TMF:
1220                         vc.req = &v_req.tmf;
1221                         vc.req_size = sizeof(struct virtio_scsi_ctrl_tmf_req);
1222                         vc.rsp_size = sizeof(struct virtio_scsi_ctrl_tmf_resp);
1223                         vc.lunp = &v_req.tmf.lun[0];
1224                         vc.target = &v_req.tmf.lun[1];
1225                         break;
1226                 case VIRTIO_SCSI_T_AN_QUERY:
1227                 case VIRTIO_SCSI_T_AN_SUBSCRIBE:
1228                         vc.req = &v_req.an;
1229                         vc.req_size = sizeof(struct virtio_scsi_ctrl_an_req);
1230                         vc.rsp_size = sizeof(struct virtio_scsi_ctrl_an_resp);
1231                         vc.lunp = &v_req.an.lun[0];
1232                         vc.target = NULL;
1233                         break;
1234                 default:
1235                         vq_err(vq, "Unknown control request %d", v_req.type);
1236                         continue;
1237                 }
1238
1239                 /*
1240                  * Validate the size of request and response buffers.
1241                  * Check for a sane response buffer so we can report
1242                  * early errors back to the guest.
1243                  */
1244                 ret = vhost_scsi_chk_size(vq, &vc);
1245                 if (ret)
1246                         goto err;
1247
1248                 /*
1249                  * Get the rest of the request now that its size is known.
1250                  */
1251                 vc.req += typ_size;
1252                 vc.req_size -= typ_size;
1253
1254                 ret = vhost_scsi_get_req(vq, &vc, NULL);
1255                 if (ret)
1256                         goto err;
1257
1258                 if (v_req.type == VIRTIO_SCSI_T_TMF)
1259                         vhost_scsi_send_tmf_reject(vs, vq, &vc);
1260                 else
1261                         vhost_scsi_send_an_resp(vs, vq, &vc);
1262 err:
1263                 /*
1264                  * ENXIO:  No more requests, or read error, wait for next kick
1265                  * EINVAL: Invalid response buffer, drop the request
1266                  * EIO:    Respond with bad target
1267                  * EAGAIN: Pending request
1268                  */
1269                 if (ret == -ENXIO)
1270                         break;
1271                 else if (ret == -EIO)
1272                         vhost_scsi_send_bad_target(vs, vq, vc.head, vc.out);
1273         } while (likely(!vhost_exceeds_weight(vq, ++c, 0)));
1274 out:
1275         mutex_unlock(&vq->mutex);
1276 }
1277
1278 static void vhost_scsi_ctl_handle_kick(struct vhost_work *work)
1279 {
1280         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1281                                                 poll.work);
1282         struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1283
1284         pr_debug("%s: The handling func for control queue.\n", __func__);
1285         vhost_scsi_ctl_handle_vq(vs, vq);
1286 }
1287
1288 static void
1289 vhost_scsi_send_evt(struct vhost_scsi *vs,
1290                    struct vhost_scsi_tpg *tpg,
1291                    struct se_lun *lun,
1292                    u32 event,
1293                    u32 reason)
1294 {
1295         struct vhost_scsi_evt *evt;
1296
1297         evt = vhost_scsi_allocate_evt(vs, event, reason);
1298         if (!evt)
1299                 return;
1300
1301         if (tpg && lun) {
1302                 /* TODO: share lun setup code with virtio-scsi.ko */
1303                 /*
1304                  * Note: evt->event is zeroed when we allocate it and
1305                  * lun[4-7] need to be zero according to virtio-scsi spec.
1306                  */
1307                 evt->event.lun[0] = 0x01;
1308                 evt->event.lun[1] = tpg->tport_tpgt;
1309                 if (lun->unpacked_lun >= 256)
1310                         evt->event.lun[2] = lun->unpacked_lun >> 8 | 0x40 ;
1311                 evt->event.lun[3] = lun->unpacked_lun & 0xFF;
1312         }
1313
1314         llist_add(&evt->list, &vs->vs_event_list);
1315         vhost_work_queue(&vs->dev, &vs->vs_event_work);
1316 }
1317
1318 static void vhost_scsi_evt_handle_kick(struct vhost_work *work)
1319 {
1320         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1321                                                 poll.work);
1322         struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1323
1324         mutex_lock(&vq->mutex);
1325         if (!vq->private_data)
1326                 goto out;
1327
1328         if (vs->vs_events_missed)
1329                 vhost_scsi_send_evt(vs, NULL, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
1330 out:
1331         mutex_unlock(&vq->mutex);
1332 }
1333
1334 static void vhost_scsi_handle_kick(struct vhost_work *work)
1335 {
1336         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1337                                                 poll.work);
1338         struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1339
1340         vhost_scsi_handle_vq(vs, vq);
1341 }
1342
1343 static void vhost_scsi_flush_vq(struct vhost_scsi *vs, int index)
1344 {
1345         vhost_poll_flush(&vs->vqs[index].vq.poll);
1346 }
1347
1348 /* Callers must hold dev mutex */
1349 static void vhost_scsi_flush(struct vhost_scsi *vs)
1350 {
1351         struct vhost_scsi_inflight *old_inflight[VHOST_SCSI_MAX_VQ];
1352         int i;
1353
1354         /* Init new inflight and remember the old inflight */
1355         vhost_scsi_init_inflight(vs, old_inflight);
1356
1357         /*
1358          * The inflight->kref was initialized to 1. We decrement it here to
1359          * indicate the start of the flush operation so that it will reach 0
1360          * when all the reqs are finished.
1361          */
1362         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1363                 kref_put(&old_inflight[i]->kref, vhost_scsi_done_inflight);
1364
1365         /* Flush both the vhost poll and vhost work */
1366         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1367                 vhost_scsi_flush_vq(vs, i);
1368         vhost_work_flush(&vs->dev, &vs->vs_completion_work);
1369         vhost_work_flush(&vs->dev, &vs->vs_event_work);
1370
1371         /* Wait for all reqs issued before the flush to be finished */
1372         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1373                 wait_for_completion(&old_inflight[i]->comp);
1374 }
1375
1376 /*
1377  * Called from vhost_scsi_ioctl() context to walk the list of available
1378  * vhost_scsi_tpg with an active struct vhost_scsi_nexus
1379  *
1380  *  The lock nesting rule is:
1381  *    vhost_scsi_mutex -> vs->dev.mutex -> tpg->tv_tpg_mutex -> vq->mutex
1382  */
1383 static int
1384 vhost_scsi_set_endpoint(struct vhost_scsi *vs,
1385                         struct vhost_scsi_target *t)
1386 {
1387         struct se_portal_group *se_tpg;
1388         struct vhost_scsi_tport *tv_tport;
1389         struct vhost_scsi_tpg *tpg;
1390         struct vhost_scsi_tpg **vs_tpg;
1391         struct vhost_virtqueue *vq;
1392         int index, ret, i, len;
1393         bool match = false;
1394
1395         mutex_lock(&vhost_scsi_mutex);
1396         mutex_lock(&vs->dev.mutex);
1397
1398         /* Verify that ring has been setup correctly. */
1399         for (index = 0; index < vs->dev.nvqs; ++index) {
1400                 /* Verify that ring has been setup correctly. */
1401                 if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1402                         ret = -EFAULT;
1403                         goto out;
1404                 }
1405         }
1406
1407         len = sizeof(vs_tpg[0]) * VHOST_SCSI_MAX_TARGET;
1408         vs_tpg = kzalloc(len, GFP_KERNEL);
1409         if (!vs_tpg) {
1410                 ret = -ENOMEM;
1411                 goto out;
1412         }
1413         if (vs->vs_tpg)
1414                 memcpy(vs_tpg, vs->vs_tpg, len);
1415
1416         list_for_each_entry(tpg, &vhost_scsi_list, tv_tpg_list) {
1417                 mutex_lock(&tpg->tv_tpg_mutex);
1418                 if (!tpg->tpg_nexus) {
1419                         mutex_unlock(&tpg->tv_tpg_mutex);
1420                         continue;
1421                 }
1422                 if (tpg->tv_tpg_vhost_count != 0) {
1423                         mutex_unlock(&tpg->tv_tpg_mutex);
1424                         continue;
1425                 }
1426                 tv_tport = tpg->tport;
1427
1428                 if (!strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1429                         if (vs->vs_tpg && vs->vs_tpg[tpg->tport_tpgt]) {
1430                                 kfree(vs_tpg);
1431                                 mutex_unlock(&tpg->tv_tpg_mutex);
1432                                 ret = -EEXIST;
1433                                 goto out;
1434                         }
1435                         /*
1436                          * In order to ensure individual vhost-scsi configfs
1437                          * groups cannot be removed while in use by vhost ioctl,
1438                          * go ahead and take an explicit se_tpg->tpg_group.cg_item
1439                          * dependency now.
1440                          */
1441                         se_tpg = &tpg->se_tpg;
1442                         ret = target_depend_item(&se_tpg->tpg_group.cg_item);
1443                         if (ret) {
1444                                 pr_warn("target_depend_item() failed: %d\n", ret);
1445                                 kfree(vs_tpg);
1446                                 mutex_unlock(&tpg->tv_tpg_mutex);
1447                                 goto out;
1448                         }
1449                         tpg->tv_tpg_vhost_count++;
1450                         tpg->vhost_scsi = vs;
1451                         vs_tpg[tpg->tport_tpgt] = tpg;
1452                         match = true;
1453                 }
1454                 mutex_unlock(&tpg->tv_tpg_mutex);
1455         }
1456
1457         if (match) {
1458                 memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn,
1459                        sizeof(vs->vs_vhost_wwpn));
1460                 for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1461                         vq = &vs->vqs[i].vq;
1462                         mutex_lock(&vq->mutex);
1463                         vq->private_data = vs_tpg;
1464                         vhost_vq_init_access(vq);
1465                         mutex_unlock(&vq->mutex);
1466                 }
1467                 ret = 0;
1468         } else {
1469                 ret = -EEXIST;
1470         }
1471
1472         /*
1473          * Act as synchronize_rcu to make sure access to
1474          * old vs->vs_tpg is finished.
1475          */
1476         vhost_scsi_flush(vs);
1477         kfree(vs->vs_tpg);
1478         vs->vs_tpg = vs_tpg;
1479
1480 out:
1481         mutex_unlock(&vs->dev.mutex);
1482         mutex_unlock(&vhost_scsi_mutex);
1483         return ret;
1484 }
1485
1486 static int
1487 vhost_scsi_clear_endpoint(struct vhost_scsi *vs,
1488                           struct vhost_scsi_target *t)
1489 {
1490         struct se_portal_group *se_tpg;
1491         struct vhost_scsi_tport *tv_tport;
1492         struct vhost_scsi_tpg *tpg;
1493         struct vhost_virtqueue *vq;
1494         bool match = false;
1495         int index, ret, i;
1496         u8 target;
1497
1498         mutex_lock(&vhost_scsi_mutex);
1499         mutex_lock(&vs->dev.mutex);
1500         /* Verify that ring has been setup correctly. */
1501         for (index = 0; index < vs->dev.nvqs; ++index) {
1502                 if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1503                         ret = -EFAULT;
1504                         goto err_dev;
1505                 }
1506         }
1507
1508         if (!vs->vs_tpg) {
1509                 ret = 0;
1510                 goto err_dev;
1511         }
1512
1513         for (i = 0; i < VHOST_SCSI_MAX_TARGET; i++) {
1514                 target = i;
1515                 tpg = vs->vs_tpg[target];
1516                 if (!tpg)
1517                         continue;
1518
1519                 mutex_lock(&tpg->tv_tpg_mutex);
1520                 tv_tport = tpg->tport;
1521                 if (!tv_tport) {
1522                         ret = -ENODEV;
1523                         goto err_tpg;
1524                 }
1525
1526                 if (strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1527                         pr_warn("tv_tport->tport_name: %s, tpg->tport_tpgt: %hu"
1528                                 " does not match t->vhost_wwpn: %s, t->vhost_tpgt: %hu\n",
1529                                 tv_tport->tport_name, tpg->tport_tpgt,
1530                                 t->vhost_wwpn, t->vhost_tpgt);
1531                         ret = -EINVAL;
1532                         goto err_tpg;
1533                 }
1534                 tpg->tv_tpg_vhost_count--;
1535                 tpg->vhost_scsi = NULL;
1536                 vs->vs_tpg[target] = NULL;
1537                 match = true;
1538                 mutex_unlock(&tpg->tv_tpg_mutex);
1539                 /*
1540                  * Release se_tpg->tpg_group.cg_item configfs dependency now
1541                  * to allow vhost-scsi WWPN se_tpg->tpg_group shutdown to occur.
1542                  */
1543                 se_tpg = &tpg->se_tpg;
1544                 target_undepend_item(&se_tpg->tpg_group.cg_item);
1545         }
1546         if (match) {
1547                 for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1548                         vq = &vs->vqs[i].vq;
1549                         mutex_lock(&vq->mutex);
1550                         vq->private_data = NULL;
1551                         mutex_unlock(&vq->mutex);
1552                 }
1553         }
1554         /*
1555          * Act as synchronize_rcu to make sure access to
1556          * old vs->vs_tpg is finished.
1557          */
1558         vhost_scsi_flush(vs);
1559         kfree(vs->vs_tpg);
1560         vs->vs_tpg = NULL;
1561         WARN_ON(vs->vs_events_nr);
1562         mutex_unlock(&vs->dev.mutex);
1563         mutex_unlock(&vhost_scsi_mutex);
1564         return 0;
1565
1566 err_tpg:
1567         mutex_unlock(&tpg->tv_tpg_mutex);
1568 err_dev:
1569         mutex_unlock(&vs->dev.mutex);
1570         mutex_unlock(&vhost_scsi_mutex);
1571         return ret;
1572 }
1573
1574 static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
1575 {
1576         struct vhost_virtqueue *vq;
1577         int i;
1578
1579         if (features & ~VHOST_SCSI_FEATURES)
1580                 return -EOPNOTSUPP;
1581
1582         mutex_lock(&vs->dev.mutex);
1583         if ((features & (1 << VHOST_F_LOG_ALL)) &&
1584             !vhost_log_access_ok(&vs->dev)) {
1585                 mutex_unlock(&vs->dev.mutex);
1586                 return -EFAULT;
1587         }
1588
1589         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1590                 vq = &vs->vqs[i].vq;
1591                 mutex_lock(&vq->mutex);
1592                 vq->acked_features = features;
1593                 mutex_unlock(&vq->mutex);
1594         }
1595         mutex_unlock(&vs->dev.mutex);
1596         return 0;
1597 }
1598
1599 static int vhost_scsi_open(struct inode *inode, struct file *f)
1600 {
1601         struct vhost_scsi *vs;
1602         struct vhost_virtqueue **vqs;
1603         int r = -ENOMEM, i;
1604
1605         vs = kzalloc(sizeof(*vs), GFP_KERNEL | __GFP_NOWARN | __GFP_RETRY_MAYFAIL);
1606         if (!vs) {
1607                 vs = vzalloc(sizeof(*vs));
1608                 if (!vs)
1609                         goto err_vs;
1610         }
1611
1612         vqs = kmalloc_array(VHOST_SCSI_MAX_VQ, sizeof(*vqs), GFP_KERNEL);
1613         if (!vqs)
1614                 goto err_vqs;
1615
1616         vhost_work_init(&vs->vs_completion_work, vhost_scsi_complete_cmd_work);
1617         vhost_work_init(&vs->vs_event_work, vhost_scsi_evt_work);
1618
1619         vs->vs_events_nr = 0;
1620         vs->vs_events_missed = false;
1621
1622         vqs[VHOST_SCSI_VQ_CTL] = &vs->vqs[VHOST_SCSI_VQ_CTL].vq;
1623         vqs[VHOST_SCSI_VQ_EVT] = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1624         vs->vqs[VHOST_SCSI_VQ_CTL].vq.handle_kick = vhost_scsi_ctl_handle_kick;
1625         vs->vqs[VHOST_SCSI_VQ_EVT].vq.handle_kick = vhost_scsi_evt_handle_kick;
1626         for (i = VHOST_SCSI_VQ_IO; i < VHOST_SCSI_MAX_VQ; i++) {
1627                 vqs[i] = &vs->vqs[i].vq;
1628                 vs->vqs[i].vq.handle_kick = vhost_scsi_handle_kick;
1629         }
1630         vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ, UIO_MAXIOV,
1631                        VHOST_SCSI_WEIGHT, 0);
1632
1633         vhost_scsi_init_inflight(vs, NULL);
1634
1635         f->private_data = vs;
1636         return 0;
1637
1638 err_vqs:
1639         kvfree(vs);
1640 err_vs:
1641         return r;
1642 }
1643
1644 static int vhost_scsi_release(struct inode *inode, struct file *f)
1645 {
1646         struct vhost_scsi *vs = f->private_data;
1647         struct vhost_scsi_target t;
1648
1649         mutex_lock(&vs->dev.mutex);
1650         memcpy(t.vhost_wwpn, vs->vs_vhost_wwpn, sizeof(t.vhost_wwpn));
1651         mutex_unlock(&vs->dev.mutex);
1652         vhost_scsi_clear_endpoint(vs, &t);
1653         vhost_dev_stop(&vs->dev);
1654         vhost_dev_cleanup(&vs->dev);
1655         /* Jobs can re-queue themselves in evt kick handler. Do extra flush. */
1656         vhost_scsi_flush(vs);
1657         kfree(vs->dev.vqs);
1658         kvfree(vs);
1659         return 0;
1660 }
1661
1662 static long
1663 vhost_scsi_ioctl(struct file *f,
1664                  unsigned int ioctl,
1665                  unsigned long arg)
1666 {
1667         struct vhost_scsi *vs = f->private_data;
1668         struct vhost_scsi_target backend;
1669         void __user *argp = (void __user *)arg;
1670         u64 __user *featurep = argp;
1671         u32 __user *eventsp = argp;
1672         u32 events_missed;
1673         u64 features;
1674         int r, abi_version = VHOST_SCSI_ABI_VERSION;
1675         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1676
1677         switch (ioctl) {
1678         case VHOST_SCSI_SET_ENDPOINT:
1679                 if (copy_from_user(&backend, argp, sizeof backend))
1680                         return -EFAULT;
1681                 if (backend.reserved != 0)
1682                         return -EOPNOTSUPP;
1683
1684                 return vhost_scsi_set_endpoint(vs, &backend);
1685         case VHOST_SCSI_CLEAR_ENDPOINT:
1686                 if (copy_from_user(&backend, argp, sizeof backend))
1687                         return -EFAULT;
1688                 if (backend.reserved != 0)
1689                         return -EOPNOTSUPP;
1690
1691                 return vhost_scsi_clear_endpoint(vs, &backend);
1692         case VHOST_SCSI_GET_ABI_VERSION:
1693                 if (copy_to_user(argp, &abi_version, sizeof abi_version))
1694                         return -EFAULT;
1695                 return 0;
1696         case VHOST_SCSI_SET_EVENTS_MISSED:
1697                 if (get_user(events_missed, eventsp))
1698                         return -EFAULT;
1699                 mutex_lock(&vq->mutex);
1700                 vs->vs_events_missed = events_missed;
1701                 mutex_unlock(&vq->mutex);
1702                 return 0;
1703         case VHOST_SCSI_GET_EVENTS_MISSED:
1704                 mutex_lock(&vq->mutex);
1705                 events_missed = vs->vs_events_missed;
1706                 mutex_unlock(&vq->mutex);
1707                 if (put_user(events_missed, eventsp))
1708                         return -EFAULT;
1709                 return 0;
1710         case VHOST_GET_FEATURES:
1711                 features = VHOST_SCSI_FEATURES;
1712                 if (copy_to_user(featurep, &features, sizeof features))
1713                         return -EFAULT;
1714                 return 0;
1715         case VHOST_SET_FEATURES:
1716                 if (copy_from_user(&features, featurep, sizeof features))
1717                         return -EFAULT;
1718                 return vhost_scsi_set_features(vs, features);
1719         default:
1720                 mutex_lock(&vs->dev.mutex);
1721                 r = vhost_dev_ioctl(&vs->dev, ioctl, argp);
1722                 /* TODO: flush backend after dev ioctl. */
1723                 if (r == -ENOIOCTLCMD)
1724                         r = vhost_vring_ioctl(&vs->dev, ioctl, argp);
1725                 mutex_unlock(&vs->dev.mutex);
1726                 return r;
1727         }
1728 }
1729
1730 static const struct file_operations vhost_scsi_fops = {
1731         .owner          = THIS_MODULE,
1732         .release        = vhost_scsi_release,
1733         .unlocked_ioctl = vhost_scsi_ioctl,
1734         .compat_ioctl   = compat_ptr_ioctl,
1735         .open           = vhost_scsi_open,
1736         .llseek         = noop_llseek,
1737 };
1738
1739 static struct miscdevice vhost_scsi_misc = {
1740         MISC_DYNAMIC_MINOR,
1741         "vhost-scsi",
1742         &vhost_scsi_fops,
1743 };
1744
1745 static int __init vhost_scsi_register(void)
1746 {
1747         return misc_register(&vhost_scsi_misc);
1748 }
1749
1750 static void vhost_scsi_deregister(void)
1751 {
1752         misc_deregister(&vhost_scsi_misc);
1753 }
1754
1755 static char *vhost_scsi_dump_proto_id(struct vhost_scsi_tport *tport)
1756 {
1757         switch (tport->tport_proto_id) {
1758         case SCSI_PROTOCOL_SAS:
1759                 return "SAS";
1760         case SCSI_PROTOCOL_FCP:
1761                 return "FCP";
1762         case SCSI_PROTOCOL_ISCSI:
1763                 return "iSCSI";
1764         default:
1765                 break;
1766         }
1767
1768         return "Unknown";
1769 }
1770
1771 static void
1772 vhost_scsi_do_plug(struct vhost_scsi_tpg *tpg,
1773                   struct se_lun *lun, bool plug)
1774 {
1775
1776         struct vhost_scsi *vs = tpg->vhost_scsi;
1777         struct vhost_virtqueue *vq;
1778         u32 reason;
1779
1780         if (!vs)
1781                 return;
1782
1783         mutex_lock(&vs->dev.mutex);
1784
1785         if (plug)
1786                 reason = VIRTIO_SCSI_EVT_RESET_RESCAN;
1787         else
1788                 reason = VIRTIO_SCSI_EVT_RESET_REMOVED;
1789
1790         vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1791         mutex_lock(&vq->mutex);
1792         if (vhost_has_feature(vq, VIRTIO_SCSI_F_HOTPLUG))
1793                 vhost_scsi_send_evt(vs, tpg, lun,
1794                                    VIRTIO_SCSI_T_TRANSPORT_RESET, reason);
1795         mutex_unlock(&vq->mutex);
1796         mutex_unlock(&vs->dev.mutex);
1797 }
1798
1799 static void vhost_scsi_hotplug(struct vhost_scsi_tpg *tpg, struct se_lun *lun)
1800 {
1801         vhost_scsi_do_plug(tpg, lun, true);
1802 }
1803
1804 static void vhost_scsi_hotunplug(struct vhost_scsi_tpg *tpg, struct se_lun *lun)
1805 {
1806         vhost_scsi_do_plug(tpg, lun, false);
1807 }
1808
1809 static int vhost_scsi_port_link(struct se_portal_group *se_tpg,
1810                                struct se_lun *lun)
1811 {
1812         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1813                                 struct vhost_scsi_tpg, se_tpg);
1814
1815         mutex_lock(&vhost_scsi_mutex);
1816
1817         mutex_lock(&tpg->tv_tpg_mutex);
1818         tpg->tv_tpg_port_count++;
1819         mutex_unlock(&tpg->tv_tpg_mutex);
1820
1821         vhost_scsi_hotplug(tpg, lun);
1822
1823         mutex_unlock(&vhost_scsi_mutex);
1824
1825         return 0;
1826 }
1827
1828 static void vhost_scsi_port_unlink(struct se_portal_group *se_tpg,
1829                                   struct se_lun *lun)
1830 {
1831         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1832                                 struct vhost_scsi_tpg, se_tpg);
1833
1834         mutex_lock(&vhost_scsi_mutex);
1835
1836         mutex_lock(&tpg->tv_tpg_mutex);
1837         tpg->tv_tpg_port_count--;
1838         mutex_unlock(&tpg->tv_tpg_mutex);
1839
1840         vhost_scsi_hotunplug(tpg, lun);
1841
1842         mutex_unlock(&vhost_scsi_mutex);
1843 }
1844
1845 static void vhost_scsi_free_cmd_map_res(struct se_session *se_sess)
1846 {
1847         struct vhost_scsi_cmd *tv_cmd;
1848         unsigned int i;
1849
1850         if (!se_sess->sess_cmd_map)
1851                 return;
1852
1853         for (i = 0; i < VHOST_SCSI_DEFAULT_TAGS; i++) {
1854                 tv_cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[i];
1855
1856                 kfree(tv_cmd->tvc_sgl);
1857                 kfree(tv_cmd->tvc_prot_sgl);
1858                 kfree(tv_cmd->tvc_upages);
1859         }
1860 }
1861
1862 static ssize_t vhost_scsi_tpg_attrib_fabric_prot_type_store(
1863                 struct config_item *item, const char *page, size_t count)
1864 {
1865         struct se_portal_group *se_tpg = attrib_to_tpg(item);
1866         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1867                                 struct vhost_scsi_tpg, se_tpg);
1868         unsigned long val;
1869         int ret = kstrtoul(page, 0, &val);
1870
1871         if (ret) {
1872                 pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
1873                 return ret;
1874         }
1875         if (val != 0 && val != 1 && val != 3) {
1876                 pr_err("Invalid vhost_scsi fabric_prot_type: %lu\n", val);
1877                 return -EINVAL;
1878         }
1879         tpg->tv_fabric_prot_type = val;
1880
1881         return count;
1882 }
1883
1884 static ssize_t vhost_scsi_tpg_attrib_fabric_prot_type_show(
1885                 struct config_item *item, char *page)
1886 {
1887         struct se_portal_group *se_tpg = attrib_to_tpg(item);
1888         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1889                                 struct vhost_scsi_tpg, se_tpg);
1890
1891         return sprintf(page, "%d\n", tpg->tv_fabric_prot_type);
1892 }
1893
1894 CONFIGFS_ATTR(vhost_scsi_tpg_attrib_, fabric_prot_type);
1895
1896 static struct configfs_attribute *vhost_scsi_tpg_attrib_attrs[] = {
1897         &vhost_scsi_tpg_attrib_attr_fabric_prot_type,
1898         NULL,
1899 };
1900
1901 static int vhost_scsi_nexus_cb(struct se_portal_group *se_tpg,
1902                                struct se_session *se_sess, void *p)
1903 {
1904         struct vhost_scsi_cmd *tv_cmd;
1905         unsigned int i;
1906
1907         for (i = 0; i < VHOST_SCSI_DEFAULT_TAGS; i++) {
1908                 tv_cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[i];
1909
1910                 tv_cmd->tvc_sgl = kcalloc(VHOST_SCSI_PREALLOC_SGLS,
1911                                           sizeof(struct scatterlist),
1912                                           GFP_KERNEL);
1913                 if (!tv_cmd->tvc_sgl) {
1914                         pr_err("Unable to allocate tv_cmd->tvc_sgl\n");
1915                         goto out;
1916                 }
1917
1918                 tv_cmd->tvc_upages = kcalloc(VHOST_SCSI_PREALLOC_UPAGES,
1919                                              sizeof(struct page *),
1920                                              GFP_KERNEL);
1921                 if (!tv_cmd->tvc_upages) {
1922                         pr_err("Unable to allocate tv_cmd->tvc_upages\n");
1923                         goto out;
1924                 }
1925
1926                 tv_cmd->tvc_prot_sgl = kcalloc(VHOST_SCSI_PREALLOC_PROT_SGLS,
1927                                                sizeof(struct scatterlist),
1928                                                GFP_KERNEL);
1929                 if (!tv_cmd->tvc_prot_sgl) {
1930                         pr_err("Unable to allocate tv_cmd->tvc_prot_sgl\n");
1931                         goto out;
1932                 }
1933         }
1934         return 0;
1935 out:
1936         vhost_scsi_free_cmd_map_res(se_sess);
1937         return -ENOMEM;
1938 }
1939
1940 static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
1941                                 const char *name)
1942 {
1943         struct vhost_scsi_nexus *tv_nexus;
1944
1945         mutex_lock(&tpg->tv_tpg_mutex);
1946         if (tpg->tpg_nexus) {
1947                 mutex_unlock(&tpg->tv_tpg_mutex);
1948                 pr_debug("tpg->tpg_nexus already exists\n");
1949                 return -EEXIST;
1950         }
1951
1952         tv_nexus = kzalloc(sizeof(*tv_nexus), GFP_KERNEL);
1953         if (!tv_nexus) {
1954                 mutex_unlock(&tpg->tv_tpg_mutex);
1955                 pr_err("Unable to allocate struct vhost_scsi_nexus\n");
1956                 return -ENOMEM;
1957         }
1958         /*
1959          * Since we are running in 'demo mode' this call with generate a
1960          * struct se_node_acl for the vhost_scsi struct se_portal_group with
1961          * the SCSI Initiator port name of the passed configfs group 'name'.
1962          */
1963         tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg,
1964                                         VHOST_SCSI_DEFAULT_TAGS,
1965                                         sizeof(struct vhost_scsi_cmd),
1966                                         TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
1967                                         (unsigned char *)name, tv_nexus,
1968                                         vhost_scsi_nexus_cb);
1969         if (IS_ERR(tv_nexus->tvn_se_sess)) {
1970                 mutex_unlock(&tpg->tv_tpg_mutex);
1971                 kfree(tv_nexus);
1972                 return -ENOMEM;
1973         }
1974         tpg->tpg_nexus = tv_nexus;
1975
1976         mutex_unlock(&tpg->tv_tpg_mutex);
1977         return 0;
1978 }
1979
1980 static int vhost_scsi_drop_nexus(struct vhost_scsi_tpg *tpg)
1981 {
1982         struct se_session *se_sess;
1983         struct vhost_scsi_nexus *tv_nexus;
1984
1985         mutex_lock(&tpg->tv_tpg_mutex);
1986         tv_nexus = tpg->tpg_nexus;
1987         if (!tv_nexus) {
1988                 mutex_unlock(&tpg->tv_tpg_mutex);
1989                 return -ENODEV;
1990         }
1991
1992         se_sess = tv_nexus->tvn_se_sess;
1993         if (!se_sess) {
1994                 mutex_unlock(&tpg->tv_tpg_mutex);
1995                 return -ENODEV;
1996         }
1997
1998         if (tpg->tv_tpg_port_count != 0) {
1999                 mutex_unlock(&tpg->tv_tpg_mutex);
2000                 pr_err("Unable to remove TCM_vhost I_T Nexus with"
2001                         " active TPG port count: %d\n",
2002                         tpg->tv_tpg_port_count);
2003                 return -EBUSY;
2004         }
2005
2006         if (tpg->tv_tpg_vhost_count != 0) {
2007                 mutex_unlock(&tpg->tv_tpg_mutex);
2008                 pr_err("Unable to remove TCM_vhost I_T Nexus with"
2009                         " active TPG vhost count: %d\n",
2010                         tpg->tv_tpg_vhost_count);
2011                 return -EBUSY;
2012         }
2013
2014         pr_debug("TCM_vhost_ConfigFS: Removing I_T Nexus to emulated"
2015                 " %s Initiator Port: %s\n", vhost_scsi_dump_proto_id(tpg->tport),
2016                 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
2017
2018         vhost_scsi_free_cmd_map_res(se_sess);
2019         /*
2020          * Release the SCSI I_T Nexus to the emulated vhost Target Port
2021          */
2022         target_remove_session(se_sess);
2023         tpg->tpg_nexus = NULL;
2024         mutex_unlock(&tpg->tv_tpg_mutex);
2025
2026         kfree(tv_nexus);
2027         return 0;
2028 }
2029
2030 static ssize_t vhost_scsi_tpg_nexus_show(struct config_item *item, char *page)
2031 {
2032         struct se_portal_group *se_tpg = to_tpg(item);
2033         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2034                                 struct vhost_scsi_tpg, se_tpg);
2035         struct vhost_scsi_nexus *tv_nexus;
2036         ssize_t ret;
2037
2038         mutex_lock(&tpg->tv_tpg_mutex);
2039         tv_nexus = tpg->tpg_nexus;
2040         if (!tv_nexus) {
2041                 mutex_unlock(&tpg->tv_tpg_mutex);
2042                 return -ENODEV;
2043         }
2044         ret = snprintf(page, PAGE_SIZE, "%s\n",
2045                         tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
2046         mutex_unlock(&tpg->tv_tpg_mutex);
2047
2048         return ret;
2049 }
2050
2051 static ssize_t vhost_scsi_tpg_nexus_store(struct config_item *item,
2052                 const char *page, size_t count)
2053 {
2054         struct se_portal_group *se_tpg = to_tpg(item);
2055         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2056                                 struct vhost_scsi_tpg, se_tpg);
2057         struct vhost_scsi_tport *tport_wwn = tpg->tport;
2058         unsigned char i_port[VHOST_SCSI_NAMELEN], *ptr, *port_ptr;
2059         int ret;
2060         /*
2061          * Shutdown the active I_T nexus if 'NULL' is passed..
2062          */
2063         if (!strncmp(page, "NULL", 4)) {
2064                 ret = vhost_scsi_drop_nexus(tpg);
2065                 return (!ret) ? count : ret;
2066         }
2067         /*
2068          * Otherwise make sure the passed virtual Initiator port WWN matches
2069          * the fabric protocol_id set in vhost_scsi_make_tport(), and call
2070          * vhost_scsi_make_nexus().
2071          */
2072         if (strlen(page) >= VHOST_SCSI_NAMELEN) {
2073                 pr_err("Emulated NAA Sas Address: %s, exceeds"
2074                                 " max: %d\n", page, VHOST_SCSI_NAMELEN);
2075                 return -EINVAL;
2076         }
2077         snprintf(&i_port[0], VHOST_SCSI_NAMELEN, "%s", page);
2078
2079         ptr = strstr(i_port, "naa.");
2080         if (ptr) {
2081                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
2082                         pr_err("Passed SAS Initiator Port %s does not"
2083                                 " match target port protoid: %s\n", i_port,
2084                                 vhost_scsi_dump_proto_id(tport_wwn));
2085                         return -EINVAL;
2086                 }
2087                 port_ptr = &i_port[0];
2088                 goto check_newline;
2089         }
2090         ptr = strstr(i_port, "fc.");
2091         if (ptr) {
2092                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
2093                         pr_err("Passed FCP Initiator Port %s does not"
2094                                 " match target port protoid: %s\n", i_port,
2095                                 vhost_scsi_dump_proto_id(tport_wwn));
2096                         return -EINVAL;
2097                 }
2098                 port_ptr = &i_port[3]; /* Skip over "fc." */
2099                 goto check_newline;
2100         }
2101         ptr = strstr(i_port, "iqn.");
2102         if (ptr) {
2103                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
2104                         pr_err("Passed iSCSI Initiator Port %s does not"
2105                                 " match target port protoid: %s\n", i_port,
2106                                 vhost_scsi_dump_proto_id(tport_wwn));
2107                         return -EINVAL;
2108                 }
2109                 port_ptr = &i_port[0];
2110                 goto check_newline;
2111         }
2112         pr_err("Unable to locate prefix for emulated Initiator Port:"
2113                         " %s\n", i_port);
2114         return -EINVAL;
2115         /*
2116          * Clear any trailing newline for the NAA WWN
2117          */
2118 check_newline:
2119         if (i_port[strlen(i_port)-1] == '\n')
2120                 i_port[strlen(i_port)-1] = '\0';
2121
2122         ret = vhost_scsi_make_nexus(tpg, port_ptr);
2123         if (ret < 0)
2124                 return ret;
2125
2126         return count;
2127 }
2128
2129 CONFIGFS_ATTR(vhost_scsi_tpg_, nexus);
2130
2131 static struct configfs_attribute *vhost_scsi_tpg_attrs[] = {
2132         &vhost_scsi_tpg_attr_nexus,
2133         NULL,
2134 };
2135
2136 static struct se_portal_group *
2137 vhost_scsi_make_tpg(struct se_wwn *wwn, const char *name)
2138 {
2139         struct vhost_scsi_tport *tport = container_of(wwn,
2140                         struct vhost_scsi_tport, tport_wwn);
2141
2142         struct vhost_scsi_tpg *tpg;
2143         u16 tpgt;
2144         int ret;
2145
2146         if (strstr(name, "tpgt_") != name)
2147                 return ERR_PTR(-EINVAL);
2148         if (kstrtou16(name + 5, 10, &tpgt) || tpgt >= VHOST_SCSI_MAX_TARGET)
2149                 return ERR_PTR(-EINVAL);
2150
2151         tpg = kzalloc(sizeof(*tpg), GFP_KERNEL);
2152         if (!tpg) {
2153                 pr_err("Unable to allocate struct vhost_scsi_tpg");
2154                 return ERR_PTR(-ENOMEM);
2155         }
2156         mutex_init(&tpg->tv_tpg_mutex);
2157         INIT_LIST_HEAD(&tpg->tv_tpg_list);
2158         tpg->tport = tport;
2159         tpg->tport_tpgt = tpgt;
2160
2161         ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
2162         if (ret < 0) {
2163                 kfree(tpg);
2164                 return NULL;
2165         }
2166         mutex_lock(&vhost_scsi_mutex);
2167         list_add_tail(&tpg->tv_tpg_list, &vhost_scsi_list);
2168         mutex_unlock(&vhost_scsi_mutex);
2169
2170         return &tpg->se_tpg;
2171 }
2172
2173 static void vhost_scsi_drop_tpg(struct se_portal_group *se_tpg)
2174 {
2175         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2176                                 struct vhost_scsi_tpg, se_tpg);
2177
2178         mutex_lock(&vhost_scsi_mutex);
2179         list_del(&tpg->tv_tpg_list);
2180         mutex_unlock(&vhost_scsi_mutex);
2181         /*
2182          * Release the virtual I_T Nexus for this vhost TPG
2183          */
2184         vhost_scsi_drop_nexus(tpg);
2185         /*
2186          * Deregister the se_tpg from TCM..
2187          */
2188         core_tpg_deregister(se_tpg);
2189         kfree(tpg);
2190 }
2191
2192 static struct se_wwn *
2193 vhost_scsi_make_tport(struct target_fabric_configfs *tf,
2194                      struct config_group *group,
2195                      const char *name)
2196 {
2197         struct vhost_scsi_tport *tport;
2198         char *ptr;
2199         u64 wwpn = 0;
2200         int off = 0;
2201
2202         /* if (vhost_scsi_parse_wwn(name, &wwpn, 1) < 0)
2203                 return ERR_PTR(-EINVAL); */
2204
2205         tport = kzalloc(sizeof(*tport), GFP_KERNEL);
2206         if (!tport) {
2207                 pr_err("Unable to allocate struct vhost_scsi_tport");
2208                 return ERR_PTR(-ENOMEM);
2209         }
2210         tport->tport_wwpn = wwpn;
2211         /*
2212          * Determine the emulated Protocol Identifier and Target Port Name
2213          * based on the incoming configfs directory name.
2214          */
2215         ptr = strstr(name, "naa.");
2216         if (ptr) {
2217                 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
2218                 goto check_len;
2219         }
2220         ptr = strstr(name, "fc.");
2221         if (ptr) {
2222                 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
2223                 off = 3; /* Skip over "fc." */
2224                 goto check_len;
2225         }
2226         ptr = strstr(name, "iqn.");
2227         if (ptr) {
2228                 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
2229                 goto check_len;
2230         }
2231
2232         pr_err("Unable to locate prefix for emulated Target Port:"
2233                         " %s\n", name);
2234         kfree(tport);
2235         return ERR_PTR(-EINVAL);
2236
2237 check_len:
2238         if (strlen(name) >= VHOST_SCSI_NAMELEN) {
2239                 pr_err("Emulated %s Address: %s, exceeds"
2240                         " max: %d\n", name, vhost_scsi_dump_proto_id(tport),
2241                         VHOST_SCSI_NAMELEN);
2242                 kfree(tport);
2243                 return ERR_PTR(-EINVAL);
2244         }
2245         snprintf(&tport->tport_name[0], VHOST_SCSI_NAMELEN, "%s", &name[off]);
2246
2247         pr_debug("TCM_VHost_ConfigFS: Allocated emulated Target"
2248                 " %s Address: %s\n", vhost_scsi_dump_proto_id(tport), name);
2249
2250         return &tport->tport_wwn;
2251 }
2252
2253 static void vhost_scsi_drop_tport(struct se_wwn *wwn)
2254 {
2255         struct vhost_scsi_tport *tport = container_of(wwn,
2256                                 struct vhost_scsi_tport, tport_wwn);
2257
2258         pr_debug("TCM_VHost_ConfigFS: Deallocating emulated Target"
2259                 " %s Address: %s\n", vhost_scsi_dump_proto_id(tport),
2260                 tport->tport_name);
2261
2262         kfree(tport);
2263 }
2264
2265 static ssize_t
2266 vhost_scsi_wwn_version_show(struct config_item *item, char *page)
2267 {
2268         return sprintf(page, "TCM_VHOST fabric module %s on %s/%s"
2269                 "on "UTS_RELEASE"\n", VHOST_SCSI_VERSION, utsname()->sysname,
2270                 utsname()->machine);
2271 }
2272
2273 CONFIGFS_ATTR_RO(vhost_scsi_wwn_, version);
2274
2275 static struct configfs_attribute *vhost_scsi_wwn_attrs[] = {
2276         &vhost_scsi_wwn_attr_version,
2277         NULL,
2278 };
2279
2280 static const struct target_core_fabric_ops vhost_scsi_ops = {
2281         .module                         = THIS_MODULE,
2282         .fabric_name                    = "vhost",
2283         .tpg_get_wwn                    = vhost_scsi_get_fabric_wwn,
2284         .tpg_get_tag                    = vhost_scsi_get_tpgt,
2285         .tpg_check_demo_mode            = vhost_scsi_check_true,
2286         .tpg_check_demo_mode_cache      = vhost_scsi_check_true,
2287         .tpg_check_demo_mode_write_protect = vhost_scsi_check_false,
2288         .tpg_check_prod_mode_write_protect = vhost_scsi_check_false,
2289         .tpg_check_prot_fabric_only     = vhost_scsi_check_prot_fabric_only,
2290         .tpg_get_inst_index             = vhost_scsi_tpg_get_inst_index,
2291         .release_cmd                    = vhost_scsi_release_cmd,
2292         .check_stop_free                = vhost_scsi_check_stop_free,
2293         .sess_get_index                 = vhost_scsi_sess_get_index,
2294         .sess_get_initiator_sid         = NULL,
2295         .write_pending                  = vhost_scsi_write_pending,
2296         .set_default_node_attributes    = vhost_scsi_set_default_node_attrs,
2297         .get_cmd_state                  = vhost_scsi_get_cmd_state,
2298         .queue_data_in                  = vhost_scsi_queue_data_in,
2299         .queue_status                   = vhost_scsi_queue_status,
2300         .queue_tm_rsp                   = vhost_scsi_queue_tm_rsp,
2301         .aborted_task                   = vhost_scsi_aborted_task,
2302         /*
2303          * Setup callers for generic logic in target_core_fabric_configfs.c
2304          */
2305         .fabric_make_wwn                = vhost_scsi_make_tport,
2306         .fabric_drop_wwn                = vhost_scsi_drop_tport,
2307         .fabric_make_tpg                = vhost_scsi_make_tpg,
2308         .fabric_drop_tpg                = vhost_scsi_drop_tpg,
2309         .fabric_post_link               = vhost_scsi_port_link,
2310         .fabric_pre_unlink              = vhost_scsi_port_unlink,
2311
2312         .tfc_wwn_attrs                  = vhost_scsi_wwn_attrs,
2313         .tfc_tpg_base_attrs             = vhost_scsi_tpg_attrs,
2314         .tfc_tpg_attrib_attrs           = vhost_scsi_tpg_attrib_attrs,
2315 };
2316
2317 static int __init vhost_scsi_init(void)
2318 {
2319         int ret = -ENOMEM;
2320
2321         pr_debug("TCM_VHOST fabric module %s on %s/%s"
2322                 " on "UTS_RELEASE"\n", VHOST_SCSI_VERSION, utsname()->sysname,
2323                 utsname()->machine);
2324
2325         /*
2326          * Use our own dedicated workqueue for submitting I/O into
2327          * target core to avoid contention within system_wq.
2328          */
2329         vhost_scsi_workqueue = alloc_workqueue("vhost_scsi", 0, 0);
2330         if (!vhost_scsi_workqueue)
2331                 goto out;
2332
2333         ret = vhost_scsi_register();
2334         if (ret < 0)
2335                 goto out_destroy_workqueue;
2336
2337         ret = target_register_template(&vhost_scsi_ops);
2338         if (ret < 0)
2339                 goto out_vhost_scsi_deregister;
2340
2341         return 0;
2342
2343 out_vhost_scsi_deregister:
2344         vhost_scsi_deregister();
2345 out_destroy_workqueue:
2346         destroy_workqueue(vhost_scsi_workqueue);
2347 out:
2348         return ret;
2349 };
2350
2351 static void vhost_scsi_exit(void)
2352 {
2353         target_unregister_template(&vhost_scsi_ops);
2354         vhost_scsi_deregister();
2355         destroy_workqueue(vhost_scsi_workqueue);
2356 };
2357
2358 MODULE_DESCRIPTION("VHOST_SCSI series fabric driver");
2359 MODULE_ALIAS("tcm_vhost");
2360 MODULE_LICENSE("GPL");
2361 module_init(vhost_scsi_init);
2362 module_exit(vhost_scsi_exit);