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