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