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 #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 u32 vhost_scsi_sess_get_index(struct se_session *se_sess)
 337 {
 338         return 0;
 339 }
 340
 341 static int vhost_scsi_write_pending(struct se_cmd *se_cmd)
 342 {
 343         /* Go ahead and process the write immediately */
 344         target_execute_cmd(se_cmd);
 345         return 0;
 346 }
 347
 348 static int vhost_scsi_write_pending_status(struct se_cmd *se_cmd)
 349 {
 350         return 0;
 351 }
 352
 353 static void vhost_scsi_set_default_node_attrs(struct se_node_acl *nacl)
 354 {
 355         return;
 356 }
 357
 358 static int vhost_scsi_get_cmd_state(struct se_cmd *se_cmd)
 359 {
 360         return 0;
 361 }
 362
 363 static void vhost_scsi_complete_cmd(struct vhost_scsi_cmd *cmd)
 364 {
 365         struct vhost_scsi *vs = cmd->tvc_vhost;
 366
 367         llist_add(&cmd->tvc_completion_list, &vs->vs_completion_list);
 368
 369         vhost_work_queue(&vs->dev, &vs->vs_completion_work);
 370 }
 371
 372 static int vhost_scsi_queue_data_in(struct se_cmd *se_cmd)
 373 {
 374         struct vhost_scsi_cmd *cmd = container_of(se_cmd,
 375                                 struct vhost_scsi_cmd, tvc_se_cmd);
 376         vhost_scsi_complete_cmd(cmd);
 377         return 0;
 378 }
 379
 380 static int vhost_scsi_queue_status(struct se_cmd *se_cmd)
 381 {
 382         struct vhost_scsi_cmd *cmd = container_of(se_cmd,
 383                                 struct vhost_scsi_cmd, tvc_se_cmd);
 384         vhost_scsi_complete_cmd(cmd);
 385         return 0;
 386 }
 387
 388 static void vhost_scsi_queue_tm_rsp(struct se_cmd *se_cmd)
 389 {
 390         return;
 391 }
 392
 393 static void vhost_scsi_aborted_task(struct se_cmd *se_cmd)
 394 {
 395         return;
 396 }
 397
 398 static void vhost_scsi_free_evt(struct vhost_scsi *vs, struct vhost_scsi_evt *evt)
 399 {
 400         vs->vs_events_nr--;
 401         kfree(evt);
 402 }
 403
 404 static struct vhost_scsi_evt *
 405 vhost_scsi_allocate_evt(struct vhost_scsi *vs,
 406                        u32 event, u32 reason)
 407 {
 408         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 409         struct vhost_scsi_evt *evt;
 410
 411         if (vs->vs_events_nr > VHOST_SCSI_MAX_EVENT) {
 412                 vs->vs_events_missed = true;
 413                 return NULL;
 414         }
 415
 416         evt = kzalloc(sizeof(*evt), GFP_KERNEL);
 417         if (!evt) {
 418                 vq_err(vq, "Failed to allocate vhost_scsi_evt\n");
 419                 vs->vs_events_missed = true;
 420                 return NULL;
 421         }
 422
 423         evt->event.event = cpu_to_vhost32(vq, event);
 424         evt->event.reason = cpu_to_vhost32(vq, reason);
 425         vs->vs_events_nr++;
 426
 427         return evt;
 428 }
 429
 430 static void vhost_scsi_free_cmd(struct vhost_scsi_cmd *cmd)
 431 {
 432         struct se_cmd *se_cmd = &cmd->tvc_se_cmd;
 433
 434         /* TODO locking against target/backend threads? */
 435         transport_generic_free_cmd(se_cmd, 0);
 436
 437 }
 438
 439 static int vhost_scsi_check_stop_free(struct se_cmd *se_cmd)
 440 {
 441         return target_put_sess_cmd(se_cmd);
 442 }
 443
 444 static void
 445 vhost_scsi_do_evt_work(struct vhost_scsi *vs, struct vhost_scsi_evt *evt)
 446 {
 447         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 448         struct virtio_scsi_event *event = &evt->event;
 449         struct virtio_scsi_event __user *eventp;
 450         unsigned out, in;
 451         int head, ret;
 452
 453         if (!vq->private_data) {
 454                 vs->vs_events_missed = true;
 455                 return;
 456         }
 457
 458 again:
 459         vhost_disable_notify(&vs->dev, vq);
 460         head = vhost_get_vq_desc(vq, vq->iov,
 461                         ARRAY_SIZE(vq->iov), &out, &in,
 462                         NULL, NULL);
 463         if (head < 0) {
 464                 vs->vs_events_missed = true;
 465                 return;
 466         }
 467         if (head == vq->num) {
 468                 if (vhost_enable_notify(&vs->dev, vq))
 469                         goto again;
 470                 vs->vs_events_missed = true;
 471                 return;
 472         }
 473
 474         if ((vq->iov[out].iov_len != sizeof(struct virtio_scsi_event))) {
 475                 vq_err(vq, "Expecting virtio_scsi_event, got %zu bytes\n",
 476                                 vq->iov[out].iov_len);
 477                 vs->vs_events_missed = true;
 478                 return;
 479         }
 480
 481         if (vs->vs_events_missed) {
 482                 event->event |= cpu_to_vhost32(vq, VIRTIO_SCSI_T_EVENTS_MISSED);
 483                 vs->vs_events_missed = false;
 484         }
 485
 486         eventp = vq->iov[out].iov_base;
 487         ret = __copy_to_user(eventp, event, sizeof(*event));
 488         if (!ret)
 489                 vhost_add_used_and_signal(&vs->dev, vq, head, 0);
 490         else
 491                 vq_err(vq, "Faulted on vhost_scsi_send_event\n");
 492 }
 493
 494 static void vhost_scsi_evt_work(struct vhost_work *work)
 495 {
 496         struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
 497                                         vs_event_work);
 498         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 499         struct vhost_scsi_evt *evt;
 500         struct llist_node *llnode;
 501
 502         mutex_lock(&vq->mutex);
 503         llnode = llist_del_all(&vs->vs_event_list);
 504         while (llnode) {
 505                 evt = llist_entry(llnode, struct vhost_scsi_evt, list);
 506                 llnode = llist_next(llnode);
 507                 vhost_scsi_do_evt_work(vs, evt);
 508                 vhost_scsi_free_evt(vs, evt);
 509         }
 510         mutex_unlock(&vq->mutex);
 511 }
 512
 513 /* Fill in status and signal that we are done processing this command
 514  *
 515  * This is scheduled in the vhost work queue so we are called with the owner
 516  * process mm and can access the vring.
 517  */
 518 static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
 519 {
 520         struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
 521                                         vs_completion_work);
 522         DECLARE_BITMAP(signal, VHOST_SCSI_MAX_VQ);
 523         struct virtio_scsi_cmd_resp v_rsp;
 524         struct vhost_scsi_cmd *cmd;
 525         struct llist_node *llnode;
 526         struct se_cmd *se_cmd;
 527         struct iov_iter iov_iter;
 528         int ret, vq;
 529
 530         bitmap_zero(signal, VHOST_SCSI_MAX_VQ);
 531         llnode = llist_del_all(&vs->vs_completion_list);
 532         while (llnode) {
 533                 cmd = llist_entry(llnode, struct vhost_scsi_cmd,
 534                                      tvc_completion_list);
 535                 llnode = llist_next(llnode);
 536                 se_cmd = &cmd->tvc_se_cmd;
 537
 538                 pr_debug("%s tv_cmd %p resid %u status %#02x\n", __func__,
 539                         cmd, se_cmd->residual_count, se_cmd->scsi_status);
 540
 541                 memset(&v_rsp, 0, sizeof(v_rsp));
 542                 v_rsp.resid = cpu_to_vhost32(cmd->tvc_vq, se_cmd->residual_count);
 543                 /* TODO is status_qualifier field needed? */
 544                 v_rsp.status = se_cmd->scsi_status;
 545                 v_rsp.sense_len = cpu_to_vhost32(cmd->tvc_vq,
 546                                                  se_cmd->scsi_sense_length);
 547                 memcpy(v_rsp.sense, cmd->tvc_sense_buf,
 548                        se_cmd->scsi_sense_length);
 549
 550                 iov_iter_init(&iov_iter, READ, &cmd->tvc_resp_iov,
 551                               cmd->tvc_in_iovs, sizeof(v_rsp));
 552                 ret = copy_to_iter(&v_rsp, sizeof(v_rsp), &iov_iter);
 553                 if (likely(ret == sizeof(v_rsp))) {
 554                         struct vhost_scsi_virtqueue *q;
 555                         vhost_add_used(cmd->tvc_vq, cmd->tvc_vq_desc, 0);
 556                         q = container_of(cmd->tvc_vq, struct vhost_scsi_virtqueue, vq);
 557                         vq = q - vs->vqs;
 558                         __set_bit(vq, signal);
 559                 } else
 560                         pr_err("Faulted on virtio_scsi_cmd_resp\n");
 561
 562                 vhost_scsi_free_cmd(cmd);
 563         }
 564
 565         vq = -1;
 566         while ((vq = find_next_bit(signal, VHOST_SCSI_MAX_VQ, vq + 1))
 567                 < VHOST_SCSI_MAX_VQ)
 568                 vhost_signal(&vs->dev, &vs->vqs[vq].vq);
 569 }
 570
 571 static struct vhost_scsi_cmd *
 572 vhost_scsi_get_tag(struct vhost_virtqueue *vq, struct vhost_scsi_tpg *tpg,
 573                    unsigned char *cdb, u64 scsi_tag, u16 lun, u8 task_attr,
 574                    u32 exp_data_len, int data_direction)
 575 {
 576         struct vhost_scsi_cmd *cmd;
 577         struct vhost_scsi_nexus *tv_nexus;
 578         struct se_session *se_sess;
 579         struct scatterlist *sg, *prot_sg;
 580         struct page **pages;
 581         int tag;
 582
 583         tv_nexus = tpg->tpg_nexus;
 584         if (!tv_nexus) {
 585                 pr_err("Unable to locate active struct vhost_scsi_nexus\n");
 586                 return ERR_PTR(-EIO);
 587         }
 588         se_sess = tv_nexus->tvn_se_sess;
 589
 590         tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
 591         if (tag < 0) {
 592                 pr_err("Unable to obtain tag for vhost_scsi_cmd\n");
 593                 return ERR_PTR(-ENOMEM);
 594         }
 595
 596         cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[tag];
 597         sg = cmd->tvc_sgl;
 598         prot_sg = cmd->tvc_prot_sgl;
 599         pages = cmd->tvc_upages;
 600         memset(cmd, 0, sizeof(struct vhost_scsi_cmd));
 601
 602         cmd->tvc_sgl = sg;
 603         cmd->tvc_prot_sgl = prot_sg;
 604         cmd->tvc_upages = pages;
 605         cmd->tvc_se_cmd.map_tag = tag;
 606         cmd->tvc_tag = scsi_tag;
 607         cmd->tvc_lun = lun;
 608         cmd->tvc_task_attr = task_attr;
 609         cmd->tvc_exp_data_len = exp_data_len;
 610         cmd->tvc_data_direction = data_direction;
 611         cmd->tvc_nexus = tv_nexus;
 612         cmd->inflight = vhost_scsi_get_inflight(vq);
 613
 614         memcpy(cmd->tvc_cdb, cdb, VHOST_SCSI_MAX_CDB_SIZE);
 615
 616         return cmd;
 617 }
 618
 619 /*
 620  * Map a user memory range into a scatterlist
 621  *
 622  * Returns the number of scatterlist entries used or -errno on error.
 623  */
 624 static int
 625 vhost_scsi_map_to_sgl(struct vhost_scsi_cmd *cmd,
 626                       void __user *ptr,
 627                       size_t len,
 628                       struct scatterlist *sgl,
 629                       bool write)
 630 {
 631         unsigned int npages = 0, offset, nbytes;
 632         unsigned int pages_nr = iov_num_pages(ptr, len);
 633         struct scatterlist *sg = sgl;
 634         struct page **pages = cmd->tvc_upages;
 635         int ret, i;
 636
 637         if (pages_nr > VHOST_SCSI_PREALLOC_UPAGES) {
 638                 pr_err("vhost_scsi_map_to_sgl() pages_nr: %u greater than"
 639                        " preallocated VHOST_SCSI_PREALLOC_UPAGES: %u\n",
 640                         pages_nr, VHOST_SCSI_PREALLOC_UPAGES);
 641                 return -ENOBUFS;
 642         }
 643
 644         ret = get_user_pages_fast((unsigned long)ptr, pages_nr, write, pages);
 645         /* No pages were pinned */
 646         if (ret < 0)
 647                 goto out;
 648         /* Less pages pinned than wanted */
 649         if (ret != pages_nr) {
 650                 for (i = 0; i < ret; i++)
 651                         put_page(pages[i]);
 652                 ret = -EFAULT;
 653                 goto out;
 654         }
 655
 656         while (len > 0) {
 657                 offset = (uintptr_t)ptr & ~PAGE_MASK;
 658                 nbytes = min_t(unsigned int, PAGE_SIZE - offset, len);
 659                 sg_set_page(sg, pages[npages], nbytes, offset);
 660                 ptr += nbytes;
 661                 len -= nbytes;
 662                 sg++;
 663                 npages++;
 664         }
 665
 666 out:
 667         return ret;
 668 }
 669
 670 static int
 671 vhost_scsi_calc_sgls(struct iov_iter *iter, size_t bytes, int max_sgls)
 672 {
 673         int sgl_count = 0;
 674
 675         if (!iter || !iter->iov) {
 676                 pr_err("%s: iter->iov is NULL, but expected bytes: %zu"
 677                        " present\n", __func__, bytes);
 678                 return -EINVAL;
 679         }
 680
 681         sgl_count = iov_iter_npages(iter, 0xffff);
 682         if (sgl_count > max_sgls) {
 683                 pr_err("%s: requested sgl_count: %d exceeds pre-allocated"
 684                        " max_sgls: %d\n", __func__, sgl_count, max_sgls);
 685                 return -EINVAL;
 686         }
 687         return sgl_count;
 688 }
 689
 690 static int
 691 vhost_scsi_iov_to_sgl(struct vhost_scsi_cmd *cmd, bool write,
 692                       struct iov_iter *iter,
 693                       struct scatterlist *sg, int sg_count)
 694 {
 695         size_t off = iter->iov_offset;
 696         int i, ret;
 697
 698         for (i = 0; i < iter->nr_segs; i++) {
 699                 void __user *base = iter->iov[i].iov_base + off;
 700                 size_t len = iter->iov[i].iov_len - off;
 701
 702                 ret = vhost_scsi_map_to_sgl(cmd, base, len, sg, write);
 703                 if (ret < 0) {
 704                         for (i = 0; i < sg_count; i++) {
 705                                 struct page *page = sg_page(&sg[i]);
 706                                 if (page)
 707                                         put_page(page);
 708                         }
 709                         return ret;
 710                 }
 711                 sg += ret;
 712                 off = 0;
 713         }
 714         return 0;
 715 }
 716
 717 static int
 718 vhost_scsi_mapal(struct vhost_scsi_cmd *cmd,
 719                  size_t prot_bytes, struct iov_iter *prot_iter,
 720                  size_t data_bytes, struct iov_iter *data_iter)
 721 {
 722         int sgl_count, ret;
 723         bool write = (cmd->tvc_data_direction == DMA_FROM_DEVICE);
 724
 725         if (prot_bytes) {
 726                 sgl_count = vhost_scsi_calc_sgls(prot_iter, prot_bytes,
 727                                                  VHOST_SCSI_PREALLOC_PROT_SGLS);
 728                 if (sgl_count < 0)
 729                         return sgl_count;
 730
 731                 sg_init_table(cmd->tvc_prot_sgl, sgl_count);
 732                 cmd->tvc_prot_sgl_count = sgl_count;
 733                 pr_debug("%s prot_sg %p prot_sgl_count %u\n", __func__,
 734                          cmd->tvc_prot_sgl, cmd->tvc_prot_sgl_count);
 735
 736                 ret = vhost_scsi_iov_to_sgl(cmd, write, prot_iter,
 737                                             cmd->tvc_prot_sgl,
 738                                             cmd->tvc_prot_sgl_count);
 739                 if (ret < 0) {
 740                         cmd->tvc_prot_sgl_count = 0;
 741                         return ret;
 742                 }
 743         }
 744         sgl_count = vhost_scsi_calc_sgls(data_iter, data_bytes,
 745                                          VHOST_SCSI_PREALLOC_SGLS);
 746         if (sgl_count < 0)
 747                 return sgl_count;
 748
 749         sg_init_table(cmd->tvc_sgl, sgl_count);
 750         cmd->tvc_sgl_count = sgl_count;
 751         pr_debug("%s data_sg %p data_sgl_count %u\n", __func__,
 752                   cmd->tvc_sgl, cmd->tvc_sgl_count);
 753
 754         ret = vhost_scsi_iov_to_sgl(cmd, write, data_iter,
 755                                     cmd->tvc_sgl, cmd->tvc_sgl_count);
 756         if (ret < 0) {
 757                 cmd->tvc_sgl_count = 0;
 758                 return ret;
 759         }
 760         return 0;
 761 }
 762
 763 static int vhost_scsi_to_tcm_attr(int attr)
 764 {
 765         switch (attr) {
 766         case VIRTIO_SCSI_S_SIMPLE:
 767                 return TCM_SIMPLE_TAG;
 768         case VIRTIO_SCSI_S_ORDERED:
 769                 return TCM_ORDERED_TAG;
 770         case VIRTIO_SCSI_S_HEAD:
 771                 return TCM_HEAD_TAG;
 772         case VIRTIO_SCSI_S_ACA:
 773                 return TCM_ACA_TAG;
 774         default:
 775                 break;
 776         }
 777         return TCM_SIMPLE_TAG;
 778 }
 779
 780 static void vhost_scsi_submission_work(struct work_struct *work)
 781 {
 782         struct vhost_scsi_cmd *cmd =
 783                 container_of(work, struct vhost_scsi_cmd, work);
 784         struct vhost_scsi_nexus *tv_nexus;
 785         struct se_cmd *se_cmd = &cmd->tvc_se_cmd;
 786         struct scatterlist *sg_ptr, *sg_prot_ptr = NULL;
 787         int rc;
 788
 789         /* FIXME: BIDI operation */
 790         if (cmd->tvc_sgl_count) {
 791                 sg_ptr = cmd->tvc_sgl;
 792
 793                 if (cmd->tvc_prot_sgl_count)
 794                         sg_prot_ptr = cmd->tvc_prot_sgl;
 795                 else
 796                         se_cmd->prot_pto = true;
 797         } else {
 798                 sg_ptr = NULL;
 799         }
 800         tv_nexus = cmd->tvc_nexus;
 801
 802         se_cmd->tag = 0;
 803         rc = target_submit_cmd_map_sgls(se_cmd, tv_nexus->tvn_se_sess,
 804                         cmd->tvc_cdb, &cmd->tvc_sense_buf[0],
 805                         cmd->tvc_lun, cmd->tvc_exp_data_len,
 806                         vhost_scsi_to_tcm_attr(cmd->tvc_task_attr),
 807                         cmd->tvc_data_direction, TARGET_SCF_ACK_KREF,
 808                         sg_ptr, cmd->tvc_sgl_count, NULL, 0, sg_prot_ptr,
 809                         cmd->tvc_prot_sgl_count);
 810         if (rc < 0) {
 811                 transport_send_check_condition_and_sense(se_cmd,
 812                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
 813                 transport_generic_free_cmd(se_cmd, 0);
 814         }
 815 }
 816
 817 static void
 818 vhost_scsi_send_bad_target(struct vhost_scsi *vs,
 819                            struct vhost_virtqueue *vq,
 820                            int head, unsigned out)
 821 {
 822         struct virtio_scsi_cmd_resp __user *resp;
 823         struct virtio_scsi_cmd_resp rsp;
 824         int ret;
 825
 826         memset(&rsp, 0, sizeof(rsp));
 827         rsp.response = VIRTIO_SCSI_S_BAD_TARGET;
 828         resp = vq->iov[out].iov_base;
 829         ret = __copy_to_user(resp, &rsp, sizeof(rsp));
 830         if (!ret)
 831                 vhost_add_used_and_signal(&vs->dev, vq, head, 0);
 832         else
 833                 pr_err("Faulted on virtio_scsi_cmd_resp\n");
 834 }
 835
 836 static void
 837 vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 838 {
 839         struct vhost_scsi_tpg **vs_tpg, *tpg;
 840         struct virtio_scsi_cmd_req v_req;
 841         struct virtio_scsi_cmd_req_pi v_req_pi;
 842         struct vhost_scsi_cmd *cmd;
 843         struct iov_iter out_iter, in_iter, prot_iter, data_iter;
 844         u64 tag;
 845         u32 exp_data_len, data_direction;
 846         unsigned out, in;
 847         int head, ret, prot_bytes;
 848         size_t req_size, rsp_size = sizeof(struct virtio_scsi_cmd_resp);
 849         size_t out_size, in_size;
 850         u16 lun;
 851         u8 *target, *lunp, task_attr;
 852         bool t10_pi = vhost_has_feature(vq, VIRTIO_SCSI_F_T10_PI);
 853         void *req, *cdb;
 854
 855         mutex_lock(&vq->mutex);
 856         /*
 857          * We can handle the vq only after the endpoint is setup by calling the
 858          * VHOST_SCSI_SET_ENDPOINT ioctl.
 859          */
 860         vs_tpg = vq->private_data;
 861         if (!vs_tpg)
 862                 goto out;
 863
 864         vhost_disable_notify(&vs->dev, vq);
 865
 866         for (;;) {
 867                 head = vhost_get_vq_desc(vq, vq->iov,
 868                                          ARRAY_SIZE(vq->iov), &out, &in,
 869                                          NULL, NULL);
 870                 pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n",
 871                          head, out, in);
 872                 /* On error, stop handling until the next kick. */
 873                 if (unlikely(head < 0))
 874                         break;
 875                 /* Nothing new?  Wait for eventfd to tell us they refilled. */
 876                 if (head == vq->num) {
 877                         if (unlikely(vhost_enable_notify(&vs->dev, vq))) {
 878                                 vhost_disable_notify(&vs->dev, vq);
 879                                 continue;
 880                         }
 881                         break;
 882                 }
 883                 /*
 884                  * Check for a sane response buffer so we can report early
 885                  * errors back to the guest.
 886                  */
 887                 if (unlikely(vq->iov[out].iov_len < rsp_size)) {
 888                         vq_err(vq, "Expecting at least virtio_scsi_cmd_resp"
 889                                 " size, got %zu bytes\n", vq->iov[out].iov_len);
 890                         break;
 891                 }
 892                 /*
 893                  * Setup pointers and values based upon different virtio-scsi
 894                  * request header if T10_PI is enabled in KVM guest.
 895                  */
 896                 if (t10_pi) {
 897                         req = &v_req_pi;
 898                         req_size = sizeof(v_req_pi);
 899                         lunp = &v_req_pi.lun[0];
 900                         target = &v_req_pi.lun[1];
 901                 } else {
 902                         req = &v_req;
 903                         req_size = sizeof(v_req);
 904                         lunp = &v_req.lun[0];
 905                         target = &v_req.lun[1];
 906                 }
 907                 /*
 908                  * FIXME: Not correct for BIDI operation
 909                  */
 910                 out_size = iov_length(vq->iov, out);
 911                 in_size = iov_length(&vq->iov[out], in);
 912
 913                 /*
 914                  * Copy over the virtio-scsi request header, which for a
 915                  * ANY_LAYOUT enabled guest may span multiple iovecs, or a
 916                  * single iovec may contain both the header + outgoing
 917                  * WRITE payloads.
 918                  *
 919                  * copy_from_iter() will advance out_iter, so that it will
 920                  * point at the start of the outgoing WRITE payload, if
 921                  * DMA_TO_DEVICE is set.
 922                  */
 923                 iov_iter_init(&out_iter, WRITE, vq->iov, out, out_size);
 924
 925                 ret = copy_from_iter(req, req_size, &out_iter);
 926                 if (unlikely(ret != req_size)) {
 927                         vq_err(vq, "Faulted on copy_from_iter\n");
 928                         vhost_scsi_send_bad_target(vs, vq, head, out);
 929                         continue;
 930                 }
 931                 /* virtio-scsi spec requires byte 0 of the lun to be 1 */
 932                 if (unlikely(*lunp != 1)) {
 933                         vq_err(vq, "Illegal virtio-scsi lun: %u\n", *lunp);
 934                         vhost_scsi_send_bad_target(vs, vq, head, out);
 935                         continue;
 936                 }
 937
 938                 tpg = ACCESS_ONCE(vs_tpg[*target]);
 939                 if (unlikely(!tpg)) {
 940                         /* Target does not exist, fail the request */
 941                         vhost_scsi_send_bad_target(vs, vq, head, out);
 942                         continue;
 943                 }
 944                 /*
 945                  * Determine data_direction by calculating the total outgoing
 946                  * iovec sizes + incoming iovec sizes vs. virtio-scsi request +
 947                  * response headers respectively.
 948                  *
 949                  * For DMA_TO_DEVICE this is out_iter, which is already pointing
 950                  * to the right place.
 951                  *
 952                  * For DMA_FROM_DEVICE, the iovec will be just past the end
 953                  * of the virtio-scsi response header in either the same
 954                  * or immediately following iovec.
 955                  *
 956                  * Any associated T10_PI bytes for the outgoing / incoming
 957                  * payloads are included in calculation of exp_data_len here.
 958                  */
 959                 prot_bytes = 0;
 960
 961                 if (out_size > req_size) {
 962                         data_direction = DMA_TO_DEVICE;
 963                         exp_data_len = out_size - req_size;
 964                         data_iter = out_iter;
 965                 } else if (in_size > rsp_size) {
 966                         data_direction = DMA_FROM_DEVICE;
 967                         exp_data_len = in_size - rsp_size;
 968
 969                         iov_iter_init(&in_iter, READ, &vq->iov[out], in,
 970                                       rsp_size + exp_data_len);
 971                         iov_iter_advance(&in_iter, rsp_size);
 972                         data_iter = in_iter;
 973                 } else {
 974                         data_direction = DMA_NONE;
 975                         exp_data_len = 0;
 976                 }
 977                 /*
 978                  * If T10_PI header + payload is present, setup prot_iter values
 979                  * and recalculate data_iter for vhost_scsi_mapal() mapping to
 980                  * host scatterlists via get_user_pages_fast().
 981                  */
 982                 if (t10_pi) {
 983                         if (v_req_pi.pi_bytesout) {
 984                                 if (data_direction != DMA_TO_DEVICE) {
 985                                         vq_err(vq, "Received non zero pi_bytesout,"
 986                                                 " but wrong data_direction\n");
 987                                         vhost_scsi_send_bad_target(vs, vq, head, out);
 988                                         continue;
 989                                 }
 990                                 prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesout);
 991                         } else if (v_req_pi.pi_bytesin) {
 992                                 if (data_direction != DMA_FROM_DEVICE) {
 993                                         vq_err(vq, "Received non zero pi_bytesin,"
 994                                                 " but wrong data_direction\n");
 995                                         vhost_scsi_send_bad_target(vs, vq, head, out);
 996                                         continue;
 997                                 }
 998                                 prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin);
 999                         }
1000                         /*
1001                          * Set prot_iter to data_iter, and advance past any
1002                          * preceeding prot_bytes that may be present.
1003                          *
1004                          * Also fix up the exp_data_len to reflect only the
1005                          * actual data payload length.
1006                          */
1007                         if (prot_bytes) {
1008                                 exp_data_len -= prot_bytes;
1009                                 prot_iter = data_iter;
1010                                 iov_iter_advance(&data_iter, prot_bytes);
1011                         }
1012                         tag = vhost64_to_cpu(vq, v_req_pi.tag);
1013                         task_attr = v_req_pi.task_attr;
1014                         cdb = &v_req_pi.cdb[0];
1015                         lun = ((v_req_pi.lun[2] << 8) | v_req_pi.lun[3]) & 0x3FFF;
1016                 } else {
1017                         tag = vhost64_to_cpu(vq, v_req.tag);
1018                         task_attr = v_req.task_attr;
1019                         cdb = &v_req.cdb[0];
1020                         lun = ((v_req.lun[2] << 8) | v_req.lun[3]) & 0x3FFF;
1021                 }
1022                 /*
1023                  * Check that the received CDB size does not exceeded our
1024                  * hardcoded max for vhost-scsi, then get a pre-allocated
1025                  * cmd descriptor for the new virtio-scsi tag.
1026                  *
1027                  * TODO what if cdb was too small for varlen cdb header?
1028                  */
1029                 if (unlikely(scsi_command_size(cdb) > VHOST_SCSI_MAX_CDB_SIZE)) {
1030                         vq_err(vq, "Received SCSI CDB with command_size: %d that"
1031                                 " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1032                                 scsi_command_size(cdb), VHOST_SCSI_MAX_CDB_SIZE);
1033                         vhost_scsi_send_bad_target(vs, vq, head, out);
1034                         continue;
1035                 }
1036                 cmd = vhost_scsi_get_tag(vq, tpg, cdb, tag, lun, task_attr,
1037                                          exp_data_len + prot_bytes,
1038                                          data_direction);
1039                 if (IS_ERR(cmd)) {
1040                         vq_err(vq, "vhost_scsi_get_tag failed %ld\n",
1041                                PTR_ERR(cmd));
1042                         vhost_scsi_send_bad_target(vs, vq, head, out);
1043                         continue;
1044                 }
1045                 cmd->tvc_vhost = vs;
1046                 cmd->tvc_vq = vq;
1047                 cmd->tvc_resp_iov = vq->iov[out];
1048                 cmd->tvc_in_iovs = in;
1049
1050                 pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",
1051                          cmd->tvc_cdb[0], cmd->tvc_lun);
1052                 pr_debug("cmd: %p exp_data_len: %d, prot_bytes: %d data_direction:"
1053                          " %d\n", cmd, exp_data_len, prot_bytes, data_direction);
1054
1055                 if (data_direction != DMA_NONE) {
1056                         ret = vhost_scsi_mapal(cmd,
1057                                                prot_bytes, &prot_iter,
1058                                                exp_data_len, &data_iter);
1059                         if (unlikely(ret)) {
1060                                 vq_err(vq, "Failed to map iov to sgl\n");
1061                                 vhost_scsi_release_cmd(&cmd->tvc_se_cmd);
1062                                 vhost_scsi_send_bad_target(vs, vq, head, out);
1063                                 continue;
1064                         }
1065                 }
1066                 /*
1067                  * Save the descriptor from vhost_get_vq_desc() to be used to
1068                  * complete the virtio-scsi request in TCM callback context via
1069                  * vhost_scsi_queue_data_in() and vhost_scsi_queue_status()
1070                  */
1071                 cmd->tvc_vq_desc = head;
1072                 /*
1073                  * Dispatch cmd descriptor for cmwq execution in process
1074                  * context provided by vhost_scsi_workqueue.  This also ensures
1075                  * cmd is executed on the same kworker CPU as this vhost
1076                  * thread to gain positive L2 cache locality effects.
1077                  */
1078                 INIT_WORK(&cmd->work, vhost_scsi_submission_work);
1079                 queue_work(vhost_scsi_workqueue, &cmd->work);
1080         }
1081 out:
1082         mutex_unlock(&vq->mutex);
1083 }
1084
1085 static void vhost_scsi_ctl_handle_kick(struct vhost_work *work)
1086 {
1087         pr_debug("%s: The handling func for control queue.\n", __func__);
1088 }
1089
1090 static void
1091 vhost_scsi_send_evt(struct vhost_scsi *vs,
1092                    struct vhost_scsi_tpg *tpg,
1093                    struct se_lun *lun,
1094                    u32 event,
1095                    u32 reason)
1096 {
1097         struct vhost_scsi_evt *evt;
1098
1099         evt = vhost_scsi_allocate_evt(vs, event, reason);
1100         if (!evt)
1101                 return;
1102
1103         if (tpg && lun) {
1104                 /* TODO: share lun setup code with virtio-scsi.ko */
1105                 /*
1106                  * Note: evt->event is zeroed when we allocate it and
1107                  * lun[4-7] need to be zero according to virtio-scsi spec.
1108                  */
1109                 evt->event.lun[0] = 0x01;
1110                 evt->event.lun[1] = tpg->tport_tpgt;
1111                 if (lun->unpacked_lun >= 256)
1112                         evt->event.lun[2] = lun->unpacked_lun >> 8 | 0x40 ;
1113                 evt->event.lun[3] = lun->unpacked_lun & 0xFF;
1114         }
1115
1116         llist_add(&evt->list, &vs->vs_event_list);
1117         vhost_work_queue(&vs->dev, &vs->vs_event_work);
1118 }
1119
1120 static void vhost_scsi_evt_handle_kick(struct vhost_work *work)
1121 {
1122         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1123                                                 poll.work);
1124         struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1125
1126         mutex_lock(&vq->mutex);
1127         if (!vq->private_data)
1128                 goto out;
1129
1130         if (vs->vs_events_missed)
1131                 vhost_scsi_send_evt(vs, NULL, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
1132 out:
1133         mutex_unlock(&vq->mutex);
1134 }
1135
1136 static void vhost_scsi_handle_kick(struct vhost_work *work)
1137 {
1138         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1139                                                 poll.work);
1140         struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1141
1142         vhost_scsi_handle_vq(vs, vq);
1143 }
1144
1145 static void vhost_scsi_flush_vq(struct vhost_scsi *vs, int index)
1146 {
1147         vhost_poll_flush(&vs->vqs[index].vq.poll);
1148 }
1149
1150 /* Callers must hold dev mutex */
1151 static void vhost_scsi_flush(struct vhost_scsi *vs)
1152 {
1153         struct vhost_scsi_inflight *old_inflight[VHOST_SCSI_MAX_VQ];
1154         int i;
1155
1156         /* Init new inflight and remember the old inflight */
1157         vhost_scsi_init_inflight(vs, old_inflight);
1158
1159         /*
1160          * The inflight->kref was initialized to 1. We decrement it here to
1161          * indicate the start of the flush operation so that it will reach 0
1162          * when all the reqs are finished.
1163          */
1164         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1165                 kref_put(&old_inflight[i]->kref, vhost_scsi_done_inflight);
1166
1167         /* Flush both the vhost poll and vhost work */
1168         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1169                 vhost_scsi_flush_vq(vs, i);
1170         vhost_work_flush(&vs->dev, &vs->vs_completion_work);
1171         vhost_work_flush(&vs->dev, &vs->vs_event_work);
1172
1173         /* Wait for all reqs issued before the flush to be finished */
1174         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1175                 wait_for_completion(&old_inflight[i]->comp);
1176 }
1177
1178 /*
1179  * Called from vhost_scsi_ioctl() context to walk the list of available
1180  * vhost_scsi_tpg with an active struct vhost_scsi_nexus
1181  *
1182  *  The lock nesting rule is:
1183  *    vhost_scsi_mutex -> vs->dev.mutex -> tpg->tv_tpg_mutex -> vq->mutex
1184  */
1185 static int
1186 vhost_scsi_set_endpoint(struct vhost_scsi *vs,
1187                         struct vhost_scsi_target *t)
1188 {
1189         struct se_portal_group *se_tpg;
1190         struct vhost_scsi_tport *tv_tport;
1191         struct vhost_scsi_tpg *tpg;
1192         struct vhost_scsi_tpg **vs_tpg;
1193         struct vhost_virtqueue *vq;
1194         int index, ret, i, len;
1195         bool match = false;
1196
1197         mutex_lock(&vhost_scsi_mutex);
1198         mutex_lock(&vs->dev.mutex);
1199
1200         /* Verify that ring has been setup correctly. */
1201         for (index = 0; index < vs->dev.nvqs; ++index) {
1202                 /* Verify that ring has been setup correctly. */
1203                 if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1204                         ret = -EFAULT;
1205                         goto out;
1206                 }
1207         }
1208
1209         len = sizeof(vs_tpg[0]) * VHOST_SCSI_MAX_TARGET;
1210         vs_tpg = kzalloc(len, GFP_KERNEL);
1211         if (!vs_tpg) {
1212                 ret = -ENOMEM;
1213                 goto out;
1214         }
1215         if (vs->vs_tpg)
1216                 memcpy(vs_tpg, vs->vs_tpg, len);
1217
1218         list_for_each_entry(tpg, &vhost_scsi_list, tv_tpg_list) {
1219                 mutex_lock(&tpg->tv_tpg_mutex);
1220                 if (!tpg->tpg_nexus) {
1221                         mutex_unlock(&tpg->tv_tpg_mutex);
1222                         continue;
1223                 }
1224                 if (tpg->tv_tpg_vhost_count != 0) {
1225                         mutex_unlock(&tpg->tv_tpg_mutex);
1226                         continue;
1227                 }
1228                 tv_tport = tpg->tport;
1229
1230                 if (!strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1231                         if (vs->vs_tpg && vs->vs_tpg[tpg->tport_tpgt]) {
1232                                 kfree(vs_tpg);
1233                                 mutex_unlock(&tpg->tv_tpg_mutex);
1234                                 ret = -EEXIST;
1235                                 goto out;
1236                         }
1237                         /*
1238                          * In order to ensure individual vhost-scsi configfs
1239                          * groups cannot be removed while in use by vhost ioctl,
1240                          * go ahead and take an explicit se_tpg->tpg_group.cg_item
1241                          * dependency now.
1242                          */
1243                         se_tpg = &tpg->se_tpg;
1244                         ret = target_depend_item(&se_tpg->tpg_group.cg_item);
1245                         if (ret) {
1246                                 pr_warn("configfs_depend_item() failed: %d\n", ret);
1247                                 kfree(vs_tpg);
1248                                 mutex_unlock(&tpg->tv_tpg_mutex);
1249                                 goto out;
1250                         }
1251                         tpg->tv_tpg_vhost_count++;
1252                         tpg->vhost_scsi = vs;
1253                         vs_tpg[tpg->tport_tpgt] = tpg;
1254                         smp_mb__after_atomic();
1255                         match = true;
1256                 }
1257                 mutex_unlock(&tpg->tv_tpg_mutex);
1258         }
1259
1260         if (match) {
1261                 memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn,
1262                        sizeof(vs->vs_vhost_wwpn));
1263                 for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1264                         vq = &vs->vqs[i].vq;
1265                         mutex_lock(&vq->mutex);
1266                         vq->private_data = vs_tpg;
1267                         vhost_vq_init_access(vq);
1268                         mutex_unlock(&vq->mutex);
1269                 }
1270                 ret = 0;
1271         } else {
1272                 ret = -EEXIST;
1273         }
1274
1275         /*
1276          * Act as synchronize_rcu to make sure access to
1277          * old vs->vs_tpg is finished.
1278          */
1279         vhost_scsi_flush(vs);
1280         kfree(vs->vs_tpg);
1281         vs->vs_tpg = vs_tpg;
1282
1283 out:
1284         mutex_unlock(&vs->dev.mutex);
1285         mutex_unlock(&vhost_scsi_mutex);
1286         return ret;
1287 }
1288
1289 static int
1290 vhost_scsi_clear_endpoint(struct vhost_scsi *vs,
1291                           struct vhost_scsi_target *t)
1292 {
1293         struct se_portal_group *se_tpg;
1294         struct vhost_scsi_tport *tv_tport;
1295         struct vhost_scsi_tpg *tpg;
1296         struct vhost_virtqueue *vq;
1297         bool match = false;
1298         int index, ret, i;
1299         u8 target;
1300
1301         mutex_lock(&vhost_scsi_mutex);
1302         mutex_lock(&vs->dev.mutex);
1303         /* Verify that ring has been setup correctly. */
1304         for (index = 0; index < vs->dev.nvqs; ++index) {
1305                 if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1306                         ret = -EFAULT;
1307                         goto err_dev;
1308                 }
1309         }
1310
1311         if (!vs->vs_tpg) {
1312                 ret = 0;
1313                 goto err_dev;
1314         }
1315
1316         for (i = 0; i < VHOST_SCSI_MAX_TARGET; i++) {
1317                 target = i;
1318                 tpg = vs->vs_tpg[target];
1319                 if (!tpg)
1320                         continue;
1321
1322                 mutex_lock(&tpg->tv_tpg_mutex);
1323                 tv_tport = tpg->tport;
1324                 if (!tv_tport) {
1325                         ret = -ENODEV;
1326                         goto err_tpg;
1327                 }
1328
1329                 if (strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1330                         pr_warn("tv_tport->tport_name: %s, tpg->tport_tpgt: %hu"
1331                                 " does not match t->vhost_wwpn: %s, t->vhost_tpgt: %hu\n",
1332                                 tv_tport->tport_name, tpg->tport_tpgt,
1333                                 t->vhost_wwpn, t->vhost_tpgt);
1334                         ret = -EINVAL;
1335                         goto err_tpg;
1336                 }
1337                 tpg->tv_tpg_vhost_count--;
1338                 tpg->vhost_scsi = NULL;
1339                 vs->vs_tpg[target] = NULL;
1340                 match = true;
1341                 mutex_unlock(&tpg->tv_tpg_mutex);
1342                 /*
1343                  * Release se_tpg->tpg_group.cg_item configfs dependency now
1344                  * to allow vhost-scsi WWPN se_tpg->tpg_group shutdown to occur.
1345                  */
1346                 se_tpg = &tpg->se_tpg;
1347                 target_undepend_item(&se_tpg->tpg_group.cg_item);
1348         }
1349         if (match) {
1350                 for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1351                         vq = &vs->vqs[i].vq;
1352                         mutex_lock(&vq->mutex);
1353                         vq->private_data = NULL;
1354                         mutex_unlock(&vq->mutex);
1355                 }
1356         }
1357         /*
1358          * Act as synchronize_rcu to make sure access to
1359          * old vs->vs_tpg is finished.
1360          */
1361         vhost_scsi_flush(vs);
1362         kfree(vs->vs_tpg);
1363         vs->vs_tpg = NULL;
1364         WARN_ON(vs->vs_events_nr);
1365         mutex_unlock(&vs->dev.mutex);
1366         mutex_unlock(&vhost_scsi_mutex);
1367         return 0;
1368
1369 err_tpg:
1370         mutex_unlock(&tpg->tv_tpg_mutex);
1371 err_dev:
1372         mutex_unlock(&vs->dev.mutex);
1373         mutex_unlock(&vhost_scsi_mutex);
1374         return ret;
1375 }
1376
1377 static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
1378 {
1379         struct vhost_virtqueue *vq;
1380         int i;
1381
1382         if (features & ~VHOST_SCSI_FEATURES)
1383                 return -EOPNOTSUPP;
1384
1385         mutex_lock(&vs->dev.mutex);
1386         if ((features & (1 << VHOST_F_LOG_ALL)) &&
1387             !vhost_log_access_ok(&vs->dev)) {
1388                 mutex_unlock(&vs->dev.mutex);
1389                 return -EFAULT;
1390         }
1391
1392         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1393                 vq = &vs->vqs[i].vq;
1394                 mutex_lock(&vq->mutex);
1395                 vq->acked_features = features;
1396                 mutex_unlock(&vq->mutex);
1397         }
1398         mutex_unlock(&vs->dev.mutex);
1399         return 0;
1400 }
1401
1402 static int vhost_scsi_open(struct inode *inode, struct file *f)
1403 {
1404         struct vhost_scsi *vs;
1405         struct vhost_virtqueue **vqs;
1406         int r = -ENOMEM, i;
1407
1408         vs = kzalloc(sizeof(*vs), GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
1409         if (!vs) {
1410                 vs = vzalloc(sizeof(*vs));
1411                 if (!vs)
1412                         goto err_vs;
1413         }
1414
1415         vqs = kmalloc(VHOST_SCSI_MAX_VQ * sizeof(*vqs), GFP_KERNEL);
1416         if (!vqs)
1417                 goto err_vqs;
1418
1419         vhost_work_init(&vs->vs_completion_work, vhost_scsi_complete_cmd_work);
1420         vhost_work_init(&vs->vs_event_work, vhost_scsi_evt_work);
1421
1422         vs->vs_events_nr = 0;
1423         vs->vs_events_missed = false;
1424
1425         vqs[VHOST_SCSI_VQ_CTL] = &vs->vqs[VHOST_SCSI_VQ_CTL].vq;
1426         vqs[VHOST_SCSI_VQ_EVT] = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1427         vs->vqs[VHOST_SCSI_VQ_CTL].vq.handle_kick = vhost_scsi_ctl_handle_kick;
1428         vs->vqs[VHOST_SCSI_VQ_EVT].vq.handle_kick = vhost_scsi_evt_handle_kick;
1429         for (i = VHOST_SCSI_VQ_IO; i < VHOST_SCSI_MAX_VQ; i++) {
1430                 vqs[i] = &vs->vqs[i].vq;
1431                 vs->vqs[i].vq.handle_kick = vhost_scsi_handle_kick;
1432         }
1433         vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ);
1434
1435         vhost_scsi_init_inflight(vs, NULL);
1436
1437         f->private_data = vs;
1438         return 0;
1439
1440 err_vqs:
1441         kvfree(vs);
1442 err_vs:
1443         return r;
1444 }
1445
1446 static int vhost_scsi_release(struct inode *inode, struct file *f)
1447 {
1448         struct vhost_scsi *vs = f->private_data;
1449         struct vhost_scsi_target t;
1450
1451         mutex_lock(&vs->dev.mutex);
1452         memcpy(t.vhost_wwpn, vs->vs_vhost_wwpn, sizeof(t.vhost_wwpn));
1453         mutex_unlock(&vs->dev.mutex);
1454         vhost_scsi_clear_endpoint(vs, &t);
1455         vhost_dev_stop(&vs->dev);
1456         vhost_dev_cleanup(&vs->dev, false);
1457         /* Jobs can re-queue themselves in evt kick handler. Do extra flush. */
1458         vhost_scsi_flush(vs);
1459         kfree(vs->dev.vqs);
1460         kvfree(vs);
1461         return 0;
1462 }
1463
1464 static long
1465 vhost_scsi_ioctl(struct file *f,
1466                  unsigned int ioctl,
1467                  unsigned long arg)
1468 {
1469         struct vhost_scsi *vs = f->private_data;
1470         struct vhost_scsi_target backend;
1471         void __user *argp = (void __user *)arg;
1472         u64 __user *featurep = argp;
1473         u32 __user *eventsp = argp;
1474         u32 events_missed;
1475         u64 features;
1476         int r, abi_version = VHOST_SCSI_ABI_VERSION;
1477         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1478
1479         switch (ioctl) {
1480         case VHOST_SCSI_SET_ENDPOINT:
1481                 if (copy_from_user(&backend, argp, sizeof backend))
1482                         return -EFAULT;
1483                 if (backend.reserved != 0)
1484                         return -EOPNOTSUPP;
1485
1486                 return vhost_scsi_set_endpoint(vs, &backend);
1487         case VHOST_SCSI_CLEAR_ENDPOINT:
1488                 if (copy_from_user(&backend, argp, sizeof backend))
1489                         return -EFAULT;
1490                 if (backend.reserved != 0)
1491                         return -EOPNOTSUPP;
1492
1493                 return vhost_scsi_clear_endpoint(vs, &backend);
1494         case VHOST_SCSI_GET_ABI_VERSION:
1495                 if (copy_to_user(argp, &abi_version, sizeof abi_version))
1496                         return -EFAULT;
1497                 return 0;
1498         case VHOST_SCSI_SET_EVENTS_MISSED:
1499                 if (get_user(events_missed, eventsp))
1500                         return -EFAULT;
1501                 mutex_lock(&vq->mutex);
1502                 vs->vs_events_missed = events_missed;
1503                 mutex_unlock(&vq->mutex);
1504                 return 0;
1505         case VHOST_SCSI_GET_EVENTS_MISSED:
1506                 mutex_lock(&vq->mutex);
1507                 events_missed = vs->vs_events_missed;
1508                 mutex_unlock(&vq->mutex);
1509                 if (put_user(events_missed, eventsp))
1510                         return -EFAULT;
1511                 return 0;
1512         case VHOST_GET_FEATURES:
1513                 features = VHOST_SCSI_FEATURES;
1514                 if (copy_to_user(featurep, &features, sizeof features))
1515                         return -EFAULT;
1516                 return 0;
1517         case VHOST_SET_FEATURES:
1518                 if (copy_from_user(&features, featurep, sizeof features))
1519                         return -EFAULT;
1520                 return vhost_scsi_set_features(vs, features);
1521         default:
1522                 mutex_lock(&vs->dev.mutex);
1523                 r = vhost_dev_ioctl(&vs->dev, ioctl, argp);
1524                 /* TODO: flush backend after dev ioctl. */
1525                 if (r == -ENOIOCTLCMD)
1526                         r = vhost_vring_ioctl(&vs->dev, ioctl, argp);
1527                 mutex_unlock(&vs->dev.mutex);
1528                 return r;
1529         }
1530 }
1531
1532 #ifdef CONFIG_COMPAT
1533 static long vhost_scsi_compat_ioctl(struct file *f, unsigned int ioctl,
1534                                 unsigned long arg)
1535 {
1536         return vhost_scsi_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
1537 }
1538 #endif
1539
1540 static const struct file_operations vhost_scsi_fops = {
1541         .owner          = THIS_MODULE,
1542         .release        = vhost_scsi_release,
1543         .unlocked_ioctl = vhost_scsi_ioctl,
1544 #ifdef CONFIG_COMPAT
1545         .compat_ioctl   = vhost_scsi_compat_ioctl,
1546 #endif
1547         .open           = vhost_scsi_open,
1548         .llseek         = noop_llseek,
1549 };
1550
1551 static struct miscdevice vhost_scsi_misc = {
1552         MISC_DYNAMIC_MINOR,
1553         "vhost-scsi",
1554         &vhost_scsi_fops,
1555 };
1556
1557 static int __init vhost_scsi_register(void)
1558 {
1559         return misc_register(&vhost_scsi_misc);
1560 }
1561
1562 static void vhost_scsi_deregister(void)
1563 {
1564         misc_deregister(&vhost_scsi_misc);
1565 }
1566
1567 static char *vhost_scsi_dump_proto_id(struct vhost_scsi_tport *tport)
1568 {
1569         switch (tport->tport_proto_id) {
1570         case SCSI_PROTOCOL_SAS:
1571                 return "SAS";
1572         case SCSI_PROTOCOL_FCP:
1573                 return "FCP";
1574         case SCSI_PROTOCOL_ISCSI:
1575                 return "iSCSI";
1576         default:
1577                 break;
1578         }
1579
1580         return "Unknown";
1581 }
1582
1583 static void
1584 vhost_scsi_do_plug(struct vhost_scsi_tpg *tpg,
1585                   struct se_lun *lun, bool plug)
1586 {
1587
1588         struct vhost_scsi *vs = tpg->vhost_scsi;
1589         struct vhost_virtqueue *vq;
1590         u32 reason;
1591
1592         if (!vs)
1593                 return;
1594
1595         mutex_lock(&vs->dev.mutex);
1596
1597         if (plug)
1598                 reason = VIRTIO_SCSI_EVT_RESET_RESCAN;
1599         else
1600                 reason = VIRTIO_SCSI_EVT_RESET_REMOVED;
1601
1602         vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1603         mutex_lock(&vq->mutex);
1604         if (vhost_has_feature(vq, VIRTIO_SCSI_F_HOTPLUG))
1605                 vhost_scsi_send_evt(vs, tpg, lun,
1606                                    VIRTIO_SCSI_T_TRANSPORT_RESET, reason);
1607         mutex_unlock(&vq->mutex);
1608         mutex_unlock(&vs->dev.mutex);
1609 }
1610
1611 static void vhost_scsi_hotplug(struct vhost_scsi_tpg *tpg, struct se_lun *lun)
1612 {
1613         vhost_scsi_do_plug(tpg, lun, true);
1614 }
1615
1616 static void vhost_scsi_hotunplug(struct vhost_scsi_tpg *tpg, struct se_lun *lun)
1617 {
1618         vhost_scsi_do_plug(tpg, lun, false);
1619 }
1620
1621 static int vhost_scsi_port_link(struct se_portal_group *se_tpg,
1622                                struct se_lun *lun)
1623 {
1624         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1625                                 struct vhost_scsi_tpg, se_tpg);
1626
1627         mutex_lock(&vhost_scsi_mutex);
1628
1629         mutex_lock(&tpg->tv_tpg_mutex);
1630         tpg->tv_tpg_port_count++;
1631         mutex_unlock(&tpg->tv_tpg_mutex);
1632
1633         vhost_scsi_hotplug(tpg, lun);
1634
1635         mutex_unlock(&vhost_scsi_mutex);
1636
1637         return 0;
1638 }
1639
1640 static void vhost_scsi_port_unlink(struct se_portal_group *se_tpg,
1641                                   struct se_lun *lun)
1642 {
1643         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1644                                 struct vhost_scsi_tpg, se_tpg);
1645
1646         mutex_lock(&vhost_scsi_mutex);
1647
1648         mutex_lock(&tpg->tv_tpg_mutex);
1649         tpg->tv_tpg_port_count--;
1650         mutex_unlock(&tpg->tv_tpg_mutex);
1651
1652         vhost_scsi_hotunplug(tpg, lun);
1653
1654         mutex_unlock(&vhost_scsi_mutex);
1655 }
1656
1657 static void vhost_scsi_free_cmd_map_res(struct se_session *se_sess)
1658 {
1659         struct vhost_scsi_cmd *tv_cmd;
1660         unsigned int i;
1661
1662         if (!se_sess->sess_cmd_map)
1663                 return;
1664
1665         for (i = 0; i < VHOST_SCSI_DEFAULT_TAGS; i++) {
1666                 tv_cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[i];
1667
1668                 kfree(tv_cmd->tvc_sgl);
1669                 kfree(tv_cmd->tvc_prot_sgl);
1670                 kfree(tv_cmd->tvc_upages);
1671         }
1672 }
1673
1674 static ssize_t vhost_scsi_tpg_attrib_fabric_prot_type_store(
1675                 struct config_item *item, const char *page, size_t count)
1676 {
1677         struct se_portal_group *se_tpg = attrib_to_tpg(item);
1678         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1679                                 struct vhost_scsi_tpg, se_tpg);
1680         unsigned long val;
1681         int ret = kstrtoul(page, 0, &val);
1682
1683         if (ret) {
1684                 pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
1685                 return ret;
1686         }
1687         if (val != 0 && val != 1 && val != 3) {
1688                 pr_err("Invalid vhost_scsi fabric_prot_type: %lu\n", val);
1689                 return -EINVAL;
1690         }
1691         tpg->tv_fabric_prot_type = val;
1692
1693         return count;
1694 }
1695
1696 static ssize_t vhost_scsi_tpg_attrib_fabric_prot_type_show(
1697                 struct config_item *item, char *page)
1698 {
1699         struct se_portal_group *se_tpg = attrib_to_tpg(item);
1700         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1701                                 struct vhost_scsi_tpg, se_tpg);
1702
1703         return sprintf(page, "%d\n", tpg->tv_fabric_prot_type);
1704 }
1705
1706 CONFIGFS_ATTR(vhost_scsi_tpg_attrib_, fabric_prot_type);
1707
1708 static struct configfs_attribute *vhost_scsi_tpg_attrib_attrs[] = {
1709         &vhost_scsi_tpg_attrib_attr_fabric_prot_type,
1710         NULL,
1711 };
1712
1713 static int vhost_scsi_nexus_cb(struct se_portal_group *se_tpg,
1714                                struct se_session *se_sess, void *p)
1715 {
1716         struct vhost_scsi_cmd *tv_cmd;
1717         unsigned int i;
1718
1719         for (i = 0; i < VHOST_SCSI_DEFAULT_TAGS; i++) {
1720                 tv_cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[i];
1721
1722                 tv_cmd->tvc_sgl = kzalloc(sizeof(struct scatterlist) *
1723                                         VHOST_SCSI_PREALLOC_SGLS, GFP_KERNEL);
1724                 if (!tv_cmd->tvc_sgl) {
1725                         pr_err("Unable to allocate tv_cmd->tvc_sgl\n");
1726                         goto out;
1727                 }
1728
1729                 tv_cmd->tvc_upages = kzalloc(sizeof(struct page *) *
1730                                 VHOST_SCSI_PREALLOC_UPAGES, GFP_KERNEL);
1731                 if (!tv_cmd->tvc_upages) {
1732                         pr_err("Unable to allocate tv_cmd->tvc_upages\n");
1733                         goto out;
1734                 }
1735
1736                 tv_cmd->tvc_prot_sgl = kzalloc(sizeof(struct scatterlist) *
1737                                 VHOST_SCSI_PREALLOC_PROT_SGLS, GFP_KERNEL);
1738                 if (!tv_cmd->tvc_prot_sgl) {
1739                         pr_err("Unable to allocate tv_cmd->tvc_prot_sgl\n");
1740                         goto out;
1741                 }
1742         }
1743         return 0;
1744 out:
1745         vhost_scsi_free_cmd_map_res(se_sess);
1746         return -ENOMEM;
1747 }
1748
1749 static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
1750                                 const char *name)
1751 {
1752         struct se_portal_group *se_tpg;
1753         struct vhost_scsi_nexus *tv_nexus;
1754
1755         mutex_lock(&tpg->tv_tpg_mutex);
1756         if (tpg->tpg_nexus) {
1757                 mutex_unlock(&tpg->tv_tpg_mutex);
1758                 pr_debug("tpg->tpg_nexus already exists\n");
1759                 return -EEXIST;
1760         }
1761         se_tpg = &tpg->se_tpg;
1762
1763         tv_nexus = kzalloc(sizeof(struct vhost_scsi_nexus), GFP_KERNEL);
1764         if (!tv_nexus) {
1765                 mutex_unlock(&tpg->tv_tpg_mutex);
1766                 pr_err("Unable to allocate struct vhost_scsi_nexus\n");
1767                 return -ENOMEM;
1768         }
1769         /*
1770          * Since we are running in 'demo mode' this call with generate a
1771          * struct se_node_acl for the vhost_scsi struct se_portal_group with
1772          * the SCSI Initiator port name of the passed configfs group 'name'.
1773          */
1774         tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg,
1775                                         VHOST_SCSI_DEFAULT_TAGS,
1776                                         sizeof(struct vhost_scsi_cmd),
1777                                         TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
1778                                         (unsigned char *)name, tv_nexus,
1779                                         vhost_scsi_nexus_cb);
1780         if (IS_ERR(tv_nexus->tvn_se_sess)) {
1781                 mutex_unlock(&tpg->tv_tpg_mutex);
1782                 kfree(tv_nexus);
1783                 return -ENOMEM;
1784         }
1785         tpg->tpg_nexus = tv_nexus;
1786
1787         mutex_unlock(&tpg->tv_tpg_mutex);
1788         return 0;
1789 }
1790
1791 static int vhost_scsi_drop_nexus(struct vhost_scsi_tpg *tpg)
1792 {
1793         struct se_session *se_sess;
1794         struct vhost_scsi_nexus *tv_nexus;
1795
1796         mutex_lock(&tpg->tv_tpg_mutex);
1797         tv_nexus = tpg->tpg_nexus;
1798         if (!tv_nexus) {
1799                 mutex_unlock(&tpg->tv_tpg_mutex);
1800                 return -ENODEV;
1801         }
1802
1803         se_sess = tv_nexus->tvn_se_sess;
1804         if (!se_sess) {
1805                 mutex_unlock(&tpg->tv_tpg_mutex);
1806                 return -ENODEV;
1807         }
1808
1809         if (tpg->tv_tpg_port_count != 0) {
1810                 mutex_unlock(&tpg->tv_tpg_mutex);
1811                 pr_err("Unable to remove TCM_vhost I_T Nexus with"
1812                         " active TPG port count: %d\n",
1813                         tpg->tv_tpg_port_count);
1814                 return -EBUSY;
1815         }
1816
1817         if (tpg->tv_tpg_vhost_count != 0) {
1818                 mutex_unlock(&tpg->tv_tpg_mutex);
1819                 pr_err("Unable to remove TCM_vhost I_T Nexus with"
1820                         " active TPG vhost count: %d\n",
1821                         tpg->tv_tpg_vhost_count);
1822                 return -EBUSY;
1823         }
1824
1825         pr_debug("TCM_vhost_ConfigFS: Removing I_T Nexus to emulated"
1826                 " %s Initiator Port: %s\n", vhost_scsi_dump_proto_id(tpg->tport),
1827                 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1828
1829         vhost_scsi_free_cmd_map_res(se_sess);
1830         /*
1831          * Release the SCSI I_T Nexus to the emulated vhost Target Port
1832          */
1833         transport_deregister_session(tv_nexus->tvn_se_sess);
1834         tpg->tpg_nexus = NULL;
1835         mutex_unlock(&tpg->tv_tpg_mutex);
1836
1837         kfree(tv_nexus);
1838         return 0;
1839 }
1840
1841 static ssize_t vhost_scsi_tpg_nexus_show(struct config_item *item, char *page)
1842 {
1843         struct se_portal_group *se_tpg = to_tpg(item);
1844         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1845                                 struct vhost_scsi_tpg, se_tpg);
1846         struct vhost_scsi_nexus *tv_nexus;
1847         ssize_t ret;
1848
1849         mutex_lock(&tpg->tv_tpg_mutex);
1850         tv_nexus = tpg->tpg_nexus;
1851         if (!tv_nexus) {
1852                 mutex_unlock(&tpg->tv_tpg_mutex);
1853                 return -ENODEV;
1854         }
1855         ret = snprintf(page, PAGE_SIZE, "%s\n",
1856                         tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1857         mutex_unlock(&tpg->tv_tpg_mutex);
1858
1859         return ret;
1860 }
1861
1862 static ssize_t vhost_scsi_tpg_nexus_store(struct config_item *item,
1863                 const char *page, size_t count)
1864 {
1865         struct se_portal_group *se_tpg = to_tpg(item);
1866         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1867                                 struct vhost_scsi_tpg, se_tpg);
1868         struct vhost_scsi_tport *tport_wwn = tpg->tport;
1869         unsigned char i_port[VHOST_SCSI_NAMELEN], *ptr, *port_ptr;
1870         int ret;
1871         /*
1872          * Shutdown the active I_T nexus if 'NULL' is passed..
1873          */
1874         if (!strncmp(page, "NULL", 4)) {
1875                 ret = vhost_scsi_drop_nexus(tpg);
1876                 return (!ret) ? count : ret;
1877         }
1878         /*
1879          * Otherwise make sure the passed virtual Initiator port WWN matches
1880          * the fabric protocol_id set in vhost_scsi_make_tport(), and call
1881          * vhost_scsi_make_nexus().
1882          */
1883         if (strlen(page) >= VHOST_SCSI_NAMELEN) {
1884                 pr_err("Emulated NAA Sas Address: %s, exceeds"
1885                                 " max: %d\n", page, VHOST_SCSI_NAMELEN);
1886                 return -EINVAL;
1887         }
1888         snprintf(&i_port[0], VHOST_SCSI_NAMELEN, "%s", page);
1889
1890         ptr = strstr(i_port, "naa.");
1891         if (ptr) {
1892                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1893                         pr_err("Passed SAS Initiator Port %s does not"
1894                                 " match target port protoid: %s\n", i_port,
1895                                 vhost_scsi_dump_proto_id(tport_wwn));
1896                         return -EINVAL;
1897                 }
1898                 port_ptr = &i_port[0];
1899                 goto check_newline;
1900         }
1901         ptr = strstr(i_port, "fc.");
1902         if (ptr) {
1903                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1904                         pr_err("Passed FCP Initiator Port %s does not"
1905                                 " match target port protoid: %s\n", i_port,
1906                                 vhost_scsi_dump_proto_id(tport_wwn));
1907                         return -EINVAL;
1908                 }
1909                 port_ptr = &i_port[3]; /* Skip over "fc." */
1910                 goto check_newline;
1911         }
1912         ptr = strstr(i_port, "iqn.");
1913         if (ptr) {
1914                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1915                         pr_err("Passed iSCSI Initiator Port %s does not"
1916                                 " match target port protoid: %s\n", i_port,
1917                                 vhost_scsi_dump_proto_id(tport_wwn));
1918                         return -EINVAL;
1919                 }
1920                 port_ptr = &i_port[0];
1921                 goto check_newline;
1922         }
1923         pr_err("Unable to locate prefix for emulated Initiator Port:"
1924                         " %s\n", i_port);
1925         return -EINVAL;
1926         /*
1927          * Clear any trailing newline for the NAA WWN
1928          */
1929 check_newline:
1930         if (i_port[strlen(i_port)-1] == '\n')
1931                 i_port[strlen(i_port)-1] = '\0';
1932
1933         ret = vhost_scsi_make_nexus(tpg, port_ptr);
1934         if (ret < 0)
1935                 return ret;
1936
1937         return count;
1938 }
1939
1940 CONFIGFS_ATTR(vhost_scsi_tpg_, nexus);
1941
1942 static struct configfs_attribute *vhost_scsi_tpg_attrs[] = {
1943         &vhost_scsi_tpg_attr_nexus,
1944         NULL,
1945 };
1946
1947 static struct se_portal_group *
1948 vhost_scsi_make_tpg(struct se_wwn *wwn,
1949                    struct config_group *group,
1950                    const char *name)
1951 {
1952         struct vhost_scsi_tport *tport = container_of(wwn,
1953                         struct vhost_scsi_tport, tport_wwn);
1954
1955         struct vhost_scsi_tpg *tpg;
1956         u16 tpgt;
1957         int ret;
1958
1959         if (strstr(name, "tpgt_") != name)
1960                 return ERR_PTR(-EINVAL);
1961         if (kstrtou16(name + 5, 10, &tpgt) || tpgt >= VHOST_SCSI_MAX_TARGET)
1962                 return ERR_PTR(-EINVAL);
1963
1964         tpg = kzalloc(sizeof(struct vhost_scsi_tpg), GFP_KERNEL);
1965         if (!tpg) {
1966                 pr_err("Unable to allocate struct vhost_scsi_tpg");
1967                 return ERR_PTR(-ENOMEM);
1968         }
1969         mutex_init(&tpg->tv_tpg_mutex);
1970         INIT_LIST_HEAD(&tpg->tv_tpg_list);
1971         tpg->tport = tport;
1972         tpg->tport_tpgt = tpgt;
1973
1974         ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
1975         if (ret < 0) {
1976                 kfree(tpg);
1977                 return NULL;
1978         }
1979         mutex_lock(&vhost_scsi_mutex);
1980         list_add_tail(&tpg->tv_tpg_list, &vhost_scsi_list);
1981         mutex_unlock(&vhost_scsi_mutex);
1982
1983         return &tpg->se_tpg;
1984 }
1985
1986 static void vhost_scsi_drop_tpg(struct se_portal_group *se_tpg)
1987 {
1988         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1989                                 struct vhost_scsi_tpg, se_tpg);
1990
1991         mutex_lock(&vhost_scsi_mutex);
1992         list_del(&tpg->tv_tpg_list);
1993         mutex_unlock(&vhost_scsi_mutex);
1994         /*
1995          * Release the virtual I_T Nexus for this vhost TPG
1996          */
1997         vhost_scsi_drop_nexus(tpg);
1998         /*
1999          * Deregister the se_tpg from TCM..
2000          */
2001         core_tpg_deregister(se_tpg);
2002         kfree(tpg);
2003 }
2004
2005 static struct se_wwn *
2006 vhost_scsi_make_tport(struct target_fabric_configfs *tf,
2007                      struct config_group *group,
2008                      const char *name)
2009 {
2010         struct vhost_scsi_tport *tport;
2011         char *ptr;
2012         u64 wwpn = 0;
2013         int off = 0;
2014
2015         /* if (vhost_scsi_parse_wwn(name, &wwpn, 1) < 0)
2016                 return ERR_PTR(-EINVAL); */
2017
2018         tport = kzalloc(sizeof(struct vhost_scsi_tport), GFP_KERNEL);
2019         if (!tport) {
2020                 pr_err("Unable to allocate struct vhost_scsi_tport");
2021                 return ERR_PTR(-ENOMEM);
2022         }
2023         tport->tport_wwpn = wwpn;
2024         /*
2025          * Determine the emulated Protocol Identifier and Target Port Name
2026          * based on the incoming configfs directory name.
2027          */
2028         ptr = strstr(name, "naa.");
2029         if (ptr) {
2030                 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
2031                 goto check_len;
2032         }
2033         ptr = strstr(name, "fc.");
2034         if (ptr) {
2035                 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
2036                 off = 3; /* Skip over "fc." */
2037                 goto check_len;
2038         }
2039         ptr = strstr(name, "iqn.");
2040         if (ptr) {
2041                 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
2042                 goto check_len;
2043         }
2044
2045         pr_err("Unable to locate prefix for emulated Target Port:"
2046                         " %s\n", name);
2047         kfree(tport);
2048         return ERR_PTR(-EINVAL);
2049
2050 check_len:
2051         if (strlen(name) >= VHOST_SCSI_NAMELEN) {
2052                 pr_err("Emulated %s Address: %s, exceeds"
2053                         " max: %d\n", name, vhost_scsi_dump_proto_id(tport),
2054                         VHOST_SCSI_NAMELEN);
2055                 kfree(tport);
2056                 return ERR_PTR(-EINVAL);
2057         }
2058         snprintf(&tport->tport_name[0], VHOST_SCSI_NAMELEN, "%s", &name[off]);
2059
2060         pr_debug("TCM_VHost_ConfigFS: Allocated emulated Target"
2061                 " %s Address: %s\n", vhost_scsi_dump_proto_id(tport), name);
2062
2063         return &tport->tport_wwn;
2064 }
2065
2066 static void vhost_scsi_drop_tport(struct se_wwn *wwn)
2067 {
2068         struct vhost_scsi_tport *tport = container_of(wwn,
2069                                 struct vhost_scsi_tport, tport_wwn);
2070
2071         pr_debug("TCM_VHost_ConfigFS: Deallocating emulated Target"
2072                 " %s Address: %s\n", vhost_scsi_dump_proto_id(tport),
2073                 tport->tport_name);
2074
2075         kfree(tport);
2076 }
2077
2078 static ssize_t
2079 vhost_scsi_wwn_version_show(struct config_item *item, char *page)
2080 {
2081         return sprintf(page, "TCM_VHOST fabric module %s on %s/%s"
2082                 "on "UTS_RELEASE"\n", VHOST_SCSI_VERSION, utsname()->sysname,
2083                 utsname()->machine);
2084 }
2085
2086 CONFIGFS_ATTR_RO(vhost_scsi_wwn_, version);
2087
2088 static struct configfs_attribute *vhost_scsi_wwn_attrs[] = {
2089         &vhost_scsi_wwn_attr_version,
2090         NULL,
2091 };
2092
2093 static struct target_core_fabric_ops vhost_scsi_ops = {
2094         .module                         = THIS_MODULE,
2095         .name                           = "vhost",
2096         .get_fabric_name                = vhost_scsi_get_fabric_name,
2097         .tpg_get_wwn                    = vhost_scsi_get_fabric_wwn,
2098         .tpg_get_tag                    = vhost_scsi_get_tpgt,
2099         .tpg_check_demo_mode            = vhost_scsi_check_true,
2100         .tpg_check_demo_mode_cache      = vhost_scsi_check_true,
2101         .tpg_check_demo_mode_write_protect = vhost_scsi_check_false,
2102         .tpg_check_prod_mode_write_protect = vhost_scsi_check_false,
2103         .tpg_check_prot_fabric_only     = vhost_scsi_check_prot_fabric_only,
2104         .tpg_get_inst_index             = vhost_scsi_tpg_get_inst_index,
2105         .release_cmd                    = vhost_scsi_release_cmd,
2106         .check_stop_free                = vhost_scsi_check_stop_free,
2107         .sess_get_index                 = vhost_scsi_sess_get_index,
2108         .sess_get_initiator_sid         = NULL,
2109         .write_pending                  = vhost_scsi_write_pending,
2110         .write_pending_status           = vhost_scsi_write_pending_status,
2111         .set_default_node_attributes    = vhost_scsi_set_default_node_attrs,
2112         .get_cmd_state                  = vhost_scsi_get_cmd_state,
2113         .queue_data_in                  = vhost_scsi_queue_data_in,
2114         .queue_status                   = vhost_scsi_queue_status,
2115         .queue_tm_rsp                   = vhost_scsi_queue_tm_rsp,
2116         .aborted_task                   = vhost_scsi_aborted_task,
2117         /*
2118          * Setup callers for generic logic in target_core_fabric_configfs.c
2119          */
2120         .fabric_make_wwn                = vhost_scsi_make_tport,
2121         .fabric_drop_wwn                = vhost_scsi_drop_tport,
2122         .fabric_make_tpg                = vhost_scsi_make_tpg,
2123         .fabric_drop_tpg                = vhost_scsi_drop_tpg,
2124         .fabric_post_link               = vhost_scsi_port_link,
2125         .fabric_pre_unlink              = vhost_scsi_port_unlink,
2126
2127         .tfc_wwn_attrs                  = vhost_scsi_wwn_attrs,
2128         .tfc_tpg_base_attrs             = vhost_scsi_tpg_attrs,
2129         .tfc_tpg_attrib_attrs           = vhost_scsi_tpg_attrib_attrs,
2130 };
2131
2132 static int __init vhost_scsi_init(void)
2133 {
2134         int ret = -ENOMEM;
2135
2136         pr_debug("TCM_VHOST fabric module %s on %s/%s"
2137                 " on "UTS_RELEASE"\n", VHOST_SCSI_VERSION, utsname()->sysname,
2138                 utsname()->machine);
2139
2140         /*
2141          * Use our own dedicated workqueue for submitting I/O into
2142          * target core to avoid contention within system_wq.
2143          */
2144         vhost_scsi_workqueue = alloc_workqueue("vhost_scsi", 0, 0);
2145         if (!vhost_scsi_workqueue)
2146                 goto out;
2147
2148         ret = vhost_scsi_register();
2149         if (ret < 0)
2150                 goto out_destroy_workqueue;
2151
2152         ret = target_register_template(&vhost_scsi_ops);
2153         if (ret < 0)
2154                 goto out_vhost_scsi_deregister;
2155
2156         return 0;
2157
2158 out_vhost_scsi_deregister:
2159         vhost_scsi_deregister();
2160 out_destroy_workqueue:
2161         destroy_workqueue(vhost_scsi_workqueue);
2162 out:
2163         return ret;
2164 };
2165
2166 static void vhost_scsi_exit(void)
2167 {
2168         target_unregister_template(&vhost_scsi_ops);
2169         vhost_scsi_deregister();
2170         destroy_workqueue(vhost_scsi_workqueue);
2171 };
2172
2173 MODULE_DESCRIPTION("VHOST_SCSI series fabric driver");
2174 MODULE_ALIAS("tcm_vhost");
2175 MODULE_LICENSE("GPL");
2176 module_init(vhost_scsi_init);
2177 module_exit(vhost_scsi_exit);