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 int out = 0, in = 0;
 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                 if (unlikely(!copy_from_iter_full(req, req_size, &out_iter))) {
 926                         vq_err(vq, "Faulted on copy_from_iter\n");
 927                         vhost_scsi_send_bad_target(vs, vq, head, out);
 928                         continue;
 929                 }
 930                 /* virtio-scsi spec requires byte 0 of the lun to be 1 */
 931                 if (unlikely(*lunp != 1)) {
 932                         vq_err(vq, "Illegal virtio-scsi lun: %u\n", *lunp);
 933                         vhost_scsi_send_bad_target(vs, vq, head, out);
 934                         continue;
 935                 }
 936
 937                 tpg = ACCESS_ONCE(vs_tpg[*target]);
 938                 if (unlikely(!tpg)) {
 939                         /* Target does not exist, fail the request */
 940                         vhost_scsi_send_bad_target(vs, vq, head, out);
 941                         continue;
 942                 }
 943                 /*
 944                  * Determine data_direction by calculating the total outgoing
 945                  * iovec sizes + incoming iovec sizes vs. virtio-scsi request +
 946                  * response headers respectively.
 947                  *
 948                  * For DMA_TO_DEVICE this is out_iter, which is already pointing
 949                  * to the right place.
 950                  *
 951                  * For DMA_FROM_DEVICE, the iovec will be just past the end
 952                  * of the virtio-scsi response header in either the same
 953                  * or immediately following iovec.
 954                  *
 955                  * Any associated T10_PI bytes for the outgoing / incoming
 956                  * payloads are included in calculation of exp_data_len here.
 957                  */
 958                 prot_bytes = 0;
 959
 960                 if (out_size > req_size) {
 961                         data_direction = DMA_TO_DEVICE;
 962                         exp_data_len = out_size - req_size;
 963                         data_iter = out_iter;
 964                 } else if (in_size > rsp_size) {
 965                         data_direction = DMA_FROM_DEVICE;
 966                         exp_data_len = in_size - rsp_size;
 967
 968                         iov_iter_init(&in_iter, READ, &vq->iov[out], in,
 969                                       rsp_size + exp_data_len);
 970                         iov_iter_advance(&in_iter, rsp_size);
 971                         data_iter = in_iter;
 972                 } else {
 973                         data_direction = DMA_NONE;
 974                         exp_data_len = 0;
 975                 }
 976                 /*
 977                  * If T10_PI header + payload is present, setup prot_iter values
 978                  * and recalculate data_iter for vhost_scsi_mapal() mapping to
 979                  * host scatterlists via get_user_pages_fast().
 980                  */
 981                 if (t10_pi) {
 982                         if (v_req_pi.pi_bytesout) {
 983                                 if (data_direction != DMA_TO_DEVICE) {
 984                                         vq_err(vq, "Received non zero pi_bytesout,"
 985                                                 " but wrong data_direction\n");
 986                                         vhost_scsi_send_bad_target(vs, vq, head, out);
 987                                         continue;
 988                                 }
 989                                 prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesout);
 990                         } else if (v_req_pi.pi_bytesin) {
 991                                 if (data_direction != DMA_FROM_DEVICE) {
 992                                         vq_err(vq, "Received non zero pi_bytesin,"
 993                                                 " but wrong data_direction\n");
 994                                         vhost_scsi_send_bad_target(vs, vq, head, out);
 995                                         continue;
 996                                 }
 997                                 prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin);
 998                         }
 999                         /*
1000                          * Set prot_iter to data_iter, and advance past any
1001                          * preceeding prot_bytes that may be present.
1002                          *
1003                          * Also fix up the exp_data_len to reflect only the
1004                          * actual data payload length.
1005                          */
1006                         if (prot_bytes) {
1007                                 exp_data_len -= prot_bytes;
1008                                 prot_iter = data_iter;
1009                                 iov_iter_advance(&data_iter, prot_bytes);
1010                         }
1011                         tag = vhost64_to_cpu(vq, v_req_pi.tag);
1012                         task_attr = v_req_pi.task_attr;
1013                         cdb = &v_req_pi.cdb[0];
1014                         lun = ((v_req_pi.lun[2] << 8) | v_req_pi.lun[3]) & 0x3FFF;
1015                 } else {
1016                         tag = vhost64_to_cpu(vq, v_req.tag);
1017                         task_attr = v_req.task_attr;
1018                         cdb = &v_req.cdb[0];
1019                         lun = ((v_req.lun[2] << 8) | v_req.lun[3]) & 0x3FFF;
1020                 }
1021                 /*
1022                  * Check that the received CDB size does not exceeded our
1023                  * hardcoded max for vhost-scsi, then get a pre-allocated
1024                  * cmd descriptor for the new virtio-scsi tag.
1025                  *
1026                  * TODO what if cdb was too small for varlen cdb header?
1027                  */
1028                 if (unlikely(scsi_command_size(cdb) > VHOST_SCSI_MAX_CDB_SIZE)) {
1029                         vq_err(vq, "Received SCSI CDB with command_size: %d that"
1030                                 " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1031                                 scsi_command_size(cdb), VHOST_SCSI_MAX_CDB_SIZE);
1032                         vhost_scsi_send_bad_target(vs, vq, head, out);
1033                         continue;
1034                 }
1035                 cmd = vhost_scsi_get_tag(vq, tpg, cdb, tag, lun, task_attr,
1036                                          exp_data_len + prot_bytes,
1037                                          data_direction);
1038                 if (IS_ERR(cmd)) {
1039                         vq_err(vq, "vhost_scsi_get_tag failed %ld\n",
1040                                PTR_ERR(cmd));
1041                         vhost_scsi_send_bad_target(vs, vq, head, out);
1042                         continue;
1043                 }
1044                 cmd->tvc_vhost = vs;
1045                 cmd->tvc_vq = vq;
1046                 cmd->tvc_resp_iov = vq->iov[out];
1047                 cmd->tvc_in_iovs = in;
1048
1049                 pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",
1050                          cmd->tvc_cdb[0], cmd->tvc_lun);
1051                 pr_debug("cmd: %p exp_data_len: %d, prot_bytes: %d data_direction:"
1052                          " %d\n", cmd, exp_data_len, prot_bytes, data_direction);
1053
1054                 if (data_direction != DMA_NONE) {
1055                         ret = vhost_scsi_mapal(cmd,
1056                                                prot_bytes, &prot_iter,
1057                                                exp_data_len, &data_iter);
1058                         if (unlikely(ret)) {
1059                                 vq_err(vq, "Failed to map iov to sgl\n");
1060                                 vhost_scsi_release_cmd(&cmd->tvc_se_cmd);
1061                                 vhost_scsi_send_bad_target(vs, vq, head, out);
1062                                 continue;
1063                         }
1064                 }
1065                 /*
1066                  * Save the descriptor from vhost_get_vq_desc() to be used to
1067                  * complete the virtio-scsi request in TCM callback context via
1068                  * vhost_scsi_queue_data_in() and vhost_scsi_queue_status()
1069                  */
1070                 cmd->tvc_vq_desc = head;
1071                 /*
1072                  * Dispatch cmd descriptor for cmwq execution in process
1073                  * context provided by vhost_scsi_workqueue.  This also ensures
1074                  * cmd is executed on the same kworker CPU as this vhost
1075                  * thread to gain positive L2 cache locality effects.
1076                  */
1077                 INIT_WORK(&cmd->work, vhost_scsi_submission_work);
1078                 queue_work(vhost_scsi_workqueue, &cmd->work);
1079         }
1080 out:
1081         mutex_unlock(&vq->mutex);
1082 }
1083
1084 static void vhost_scsi_ctl_handle_kick(struct vhost_work *work)
1085 {
1086         pr_debug("%s: The handling func for control queue.\n", __func__);
1087 }
1088
1089 static void
1090 vhost_scsi_send_evt(struct vhost_scsi *vs,
1091                    struct vhost_scsi_tpg *tpg,
1092                    struct se_lun *lun,
1093                    u32 event,
1094                    u32 reason)
1095 {
1096         struct vhost_scsi_evt *evt;
1097
1098         evt = vhost_scsi_allocate_evt(vs, event, reason);
1099         if (!evt)
1100                 return;
1101
1102         if (tpg && lun) {
1103                 /* TODO: share lun setup code with virtio-scsi.ko */
1104                 /*
1105                  * Note: evt->event is zeroed when we allocate it and
1106                  * lun[4-7] need to be zero according to virtio-scsi spec.
1107                  */
1108                 evt->event.lun[0] = 0x01;
1109                 evt->event.lun[1] = tpg->tport_tpgt;
1110                 if (lun->unpacked_lun >= 256)
1111                         evt->event.lun[2] = lun->unpacked_lun >> 8 | 0x40 ;
1112                 evt->event.lun[3] = lun->unpacked_lun & 0xFF;
1113         }
1114
1115         llist_add(&evt->list, &vs->vs_event_list);
1116         vhost_work_queue(&vs->dev, &vs->vs_event_work);
1117 }
1118
1119 static void vhost_scsi_evt_handle_kick(struct vhost_work *work)
1120 {
1121         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1122                                                 poll.work);
1123         struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1124
1125         mutex_lock(&vq->mutex);
1126         if (!vq->private_data)
1127                 goto out;
1128
1129         if (vs->vs_events_missed)
1130                 vhost_scsi_send_evt(vs, NULL, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
1131 out:
1132         mutex_unlock(&vq->mutex);
1133 }
1134
1135 static void vhost_scsi_handle_kick(struct vhost_work *work)
1136 {
1137         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1138                                                 poll.work);
1139         struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1140
1141         vhost_scsi_handle_vq(vs, vq);
1142 }
1143
1144 static void vhost_scsi_flush_vq(struct vhost_scsi *vs, int index)
1145 {
1146         vhost_poll_flush(&vs->vqs[index].vq.poll);
1147 }
1148
1149 /* Callers must hold dev mutex */
1150 static void vhost_scsi_flush(struct vhost_scsi *vs)
1151 {
1152         struct vhost_scsi_inflight *old_inflight[VHOST_SCSI_MAX_VQ];
1153         int i;
1154
1155         /* Init new inflight and remember the old inflight */
1156         vhost_scsi_init_inflight(vs, old_inflight);
1157
1158         /*
1159          * The inflight->kref was initialized to 1. We decrement it here to
1160          * indicate the start of the flush operation so that it will reach 0
1161          * when all the reqs are finished.
1162          */
1163         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1164                 kref_put(&old_inflight[i]->kref, vhost_scsi_done_inflight);
1165
1166         /* Flush both the vhost poll and vhost work */
1167         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1168                 vhost_scsi_flush_vq(vs, i);
1169         vhost_work_flush(&vs->dev, &vs->vs_completion_work);
1170         vhost_work_flush(&vs->dev, &vs->vs_event_work);
1171
1172         /* Wait for all reqs issued before the flush to be finished */
1173         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1174                 wait_for_completion(&old_inflight[i]->comp);
1175 }
1176
1177 /*
1178  * Called from vhost_scsi_ioctl() context to walk the list of available
1179  * vhost_scsi_tpg with an active struct vhost_scsi_nexus
1180  *
1181  *  The lock nesting rule is:
1182  *    vhost_scsi_mutex -> vs->dev.mutex -> tpg->tv_tpg_mutex -> vq->mutex
1183  */
1184 static int
1185 vhost_scsi_set_endpoint(struct vhost_scsi *vs,
1186                         struct vhost_scsi_target *t)
1187 {
1188         struct se_portal_group *se_tpg;
1189         struct vhost_scsi_tport *tv_tport;
1190         struct vhost_scsi_tpg *tpg;
1191         struct vhost_scsi_tpg **vs_tpg;
1192         struct vhost_virtqueue *vq;
1193         int index, ret, i, len;
1194         bool match = false;
1195
1196         mutex_lock(&vhost_scsi_mutex);
1197         mutex_lock(&vs->dev.mutex);
1198
1199         /* Verify that ring has been setup correctly. */
1200         for (index = 0; index < vs->dev.nvqs; ++index) {
1201                 /* Verify that ring has been setup correctly. */
1202                 if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1203                         ret = -EFAULT;
1204                         goto out;
1205                 }
1206         }
1207
1208         len = sizeof(vs_tpg[0]) * VHOST_SCSI_MAX_TARGET;
1209         vs_tpg = kzalloc(len, GFP_KERNEL);
1210         if (!vs_tpg) {
1211                 ret = -ENOMEM;
1212                 goto out;
1213         }
1214         if (vs->vs_tpg)
1215                 memcpy(vs_tpg, vs->vs_tpg, len);
1216
1217         list_for_each_entry(tpg, &vhost_scsi_list, tv_tpg_list) {
1218                 mutex_lock(&tpg->tv_tpg_mutex);
1219                 if (!tpg->tpg_nexus) {
1220                         mutex_unlock(&tpg->tv_tpg_mutex);
1221                         continue;
1222                 }
1223                 if (tpg->tv_tpg_vhost_count != 0) {
1224                         mutex_unlock(&tpg->tv_tpg_mutex);
1225                         continue;
1226                 }
1227                 tv_tport = tpg->tport;
1228
1229                 if (!strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1230                         if (vs->vs_tpg && vs->vs_tpg[tpg->tport_tpgt]) {
1231                                 kfree(vs_tpg);
1232                                 mutex_unlock(&tpg->tv_tpg_mutex);
1233                                 ret = -EEXIST;
1234                                 goto out;
1235                         }
1236                         /*
1237                          * In order to ensure individual vhost-scsi configfs
1238                          * groups cannot be removed while in use by vhost ioctl,
1239                          * go ahead and take an explicit se_tpg->tpg_group.cg_item
1240                          * dependency now.
1241                          */
1242                         se_tpg = &tpg->se_tpg;
1243                         ret = target_depend_item(&se_tpg->tpg_group.cg_item);
1244                         if (ret) {
1245                                 pr_warn("configfs_depend_item() failed: %d\n", ret);
1246                                 kfree(vs_tpg);
1247                                 mutex_unlock(&tpg->tv_tpg_mutex);
1248                                 goto out;
1249                         }
1250                         tpg->tv_tpg_vhost_count++;
1251                         tpg->vhost_scsi = vs;
1252                         vs_tpg[tpg->tport_tpgt] = tpg;
1253                         smp_mb__after_atomic();
1254                         match = true;
1255                 }
1256                 mutex_unlock(&tpg->tv_tpg_mutex);
1257         }
1258
1259         if (match) {
1260                 memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn,
1261                        sizeof(vs->vs_vhost_wwpn));
1262                 for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1263                         vq = &vs->vqs[i].vq;
1264                         mutex_lock(&vq->mutex);
1265                         vq->private_data = vs_tpg;
1266                         vhost_vq_init_access(vq);
1267                         mutex_unlock(&vq->mutex);
1268                 }
1269                 ret = 0;
1270         } else {
1271                 ret = -EEXIST;
1272         }
1273
1274         /*
1275          * Act as synchronize_rcu to make sure access to
1276          * old vs->vs_tpg is finished.
1277          */
1278         vhost_scsi_flush(vs);
1279         kfree(vs->vs_tpg);
1280         vs->vs_tpg = vs_tpg;
1281
1282 out:
1283         mutex_unlock(&vs->dev.mutex);
1284         mutex_unlock(&vhost_scsi_mutex);
1285         return ret;
1286 }
1287
1288 static int
1289 vhost_scsi_clear_endpoint(struct vhost_scsi *vs,
1290                           struct vhost_scsi_target *t)
1291 {
1292         struct se_portal_group *se_tpg;
1293         struct vhost_scsi_tport *tv_tport;
1294         struct vhost_scsi_tpg *tpg;
1295         struct vhost_virtqueue *vq;
1296         bool match = false;
1297         int index, ret, i;
1298         u8 target;
1299
1300         mutex_lock(&vhost_scsi_mutex);
1301         mutex_lock(&vs->dev.mutex);
1302         /* Verify that ring has been setup correctly. */
1303         for (index = 0; index < vs->dev.nvqs; ++index) {
1304                 if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1305                         ret = -EFAULT;
1306                         goto err_dev;
1307                 }
1308         }
1309
1310         if (!vs->vs_tpg) {
1311                 ret = 0;
1312                 goto err_dev;
1313         }
1314
1315         for (i = 0; i < VHOST_SCSI_MAX_TARGET; i++) {
1316                 target = i;
1317                 tpg = vs->vs_tpg[target];
1318                 if (!tpg)
1319                         continue;
1320
1321                 mutex_lock(&tpg->tv_tpg_mutex);
1322                 tv_tport = tpg->tport;
1323                 if (!tv_tport) {
1324                         ret = -ENODEV;
1325                         goto err_tpg;
1326                 }
1327
1328                 if (strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1329                         pr_warn("tv_tport->tport_name: %s, tpg->tport_tpgt: %hu"
1330                                 " does not match t->vhost_wwpn: %s, t->vhost_tpgt: %hu\n",
1331                                 tv_tport->tport_name, tpg->tport_tpgt,
1332                                 t->vhost_wwpn, t->vhost_tpgt);
1333                         ret = -EINVAL;
1334                         goto err_tpg;
1335                 }
1336                 tpg->tv_tpg_vhost_count--;
1337                 tpg->vhost_scsi = NULL;
1338                 vs->vs_tpg[target] = NULL;
1339                 match = true;
1340                 mutex_unlock(&tpg->tv_tpg_mutex);
1341                 /*
1342                  * Release se_tpg->tpg_group.cg_item configfs dependency now
1343                  * to allow vhost-scsi WWPN se_tpg->tpg_group shutdown to occur.
1344                  */
1345                 se_tpg = &tpg->se_tpg;
1346                 target_undepend_item(&se_tpg->tpg_group.cg_item);
1347         }
1348         if (match) {
1349                 for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1350                         vq = &vs->vqs[i].vq;
1351                         mutex_lock(&vq->mutex);
1352                         vq->private_data = NULL;
1353                         mutex_unlock(&vq->mutex);
1354                 }
1355         }
1356         /*
1357          * Act as synchronize_rcu to make sure access to
1358          * old vs->vs_tpg is finished.
1359          */
1360         vhost_scsi_flush(vs);
1361         kfree(vs->vs_tpg);
1362         vs->vs_tpg = NULL;
1363         WARN_ON(vs->vs_events_nr);
1364         mutex_unlock(&vs->dev.mutex);
1365         mutex_unlock(&vhost_scsi_mutex);
1366         return 0;
1367
1368 err_tpg:
1369         mutex_unlock(&tpg->tv_tpg_mutex);
1370 err_dev:
1371         mutex_unlock(&vs->dev.mutex);
1372         mutex_unlock(&vhost_scsi_mutex);
1373         return ret;
1374 }
1375
1376 static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
1377 {
1378         struct vhost_virtqueue *vq;
1379         int i;
1380
1381         if (features & ~VHOST_SCSI_FEATURES)
1382                 return -EOPNOTSUPP;
1383
1384         mutex_lock(&vs->dev.mutex);
1385         if ((features & (1 << VHOST_F_LOG_ALL)) &&
1386             !vhost_log_access_ok(&vs->dev)) {
1387                 mutex_unlock(&vs->dev.mutex);
1388                 return -EFAULT;
1389         }
1390
1391         for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1392                 vq = &vs->vqs[i].vq;
1393                 mutex_lock(&vq->mutex);
1394                 vq->acked_features = features;
1395                 mutex_unlock(&vq->mutex);
1396         }
1397         mutex_unlock(&vs->dev.mutex);
1398         return 0;
1399 }
1400
1401 static int vhost_scsi_open(struct inode *inode, struct file *f)
1402 {
1403         struct vhost_scsi *vs;
1404         struct vhost_virtqueue **vqs;
1405         int r = -ENOMEM, i;
1406
1407         vs = kzalloc(sizeof(*vs), GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
1408         if (!vs) {
1409                 vs = vzalloc(sizeof(*vs));
1410                 if (!vs)
1411                         goto err_vs;
1412         }
1413
1414         vqs = kmalloc(VHOST_SCSI_MAX_VQ * sizeof(*vqs), GFP_KERNEL);
1415         if (!vqs)
1416                 goto err_vqs;
1417
1418         vhost_work_init(&vs->vs_completion_work, vhost_scsi_complete_cmd_work);
1419         vhost_work_init(&vs->vs_event_work, vhost_scsi_evt_work);
1420
1421         vs->vs_events_nr = 0;
1422         vs->vs_events_missed = false;
1423
1424         vqs[VHOST_SCSI_VQ_CTL] = &vs->vqs[VHOST_SCSI_VQ_CTL].vq;
1425         vqs[VHOST_SCSI_VQ_EVT] = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1426         vs->vqs[VHOST_SCSI_VQ_CTL].vq.handle_kick = vhost_scsi_ctl_handle_kick;
1427         vs->vqs[VHOST_SCSI_VQ_EVT].vq.handle_kick = vhost_scsi_evt_handle_kick;
1428         for (i = VHOST_SCSI_VQ_IO; i < VHOST_SCSI_MAX_VQ; i++) {
1429                 vqs[i] = &vs->vqs[i].vq;
1430                 vs->vqs[i].vq.handle_kick = vhost_scsi_handle_kick;
1431         }
1432         vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ);
1433
1434         vhost_scsi_init_inflight(vs, NULL);
1435
1436         f->private_data = vs;
1437         return 0;
1438
1439 err_vqs:
1440         kvfree(vs);
1441 err_vs:
1442         return r;
1443 }
1444
1445 static int vhost_scsi_release(struct inode *inode, struct file *f)
1446 {
1447         struct vhost_scsi *vs = f->private_data;
1448         struct vhost_scsi_target t;
1449
1450         mutex_lock(&vs->dev.mutex);
1451         memcpy(t.vhost_wwpn, vs->vs_vhost_wwpn, sizeof(t.vhost_wwpn));
1452         mutex_unlock(&vs->dev.mutex);
1453         vhost_scsi_clear_endpoint(vs, &t);
1454         vhost_dev_stop(&vs->dev);
1455         vhost_dev_cleanup(&vs->dev, false);
1456         /* Jobs can re-queue themselves in evt kick handler. Do extra flush. */
1457         vhost_scsi_flush(vs);
1458         kfree(vs->dev.vqs);
1459         kvfree(vs);
1460         return 0;
1461 }
1462
1463 static long
1464 vhost_scsi_ioctl(struct file *f,
1465                  unsigned int ioctl,
1466                  unsigned long arg)
1467 {
1468         struct vhost_scsi *vs = f->private_data;
1469         struct vhost_scsi_target backend;
1470         void __user *argp = (void __user *)arg;
1471         u64 __user *featurep = argp;
1472         u32 __user *eventsp = argp;
1473         u32 events_missed;
1474         u64 features;
1475         int r, abi_version = VHOST_SCSI_ABI_VERSION;
1476         struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1477
1478         switch (ioctl) {
1479         case VHOST_SCSI_SET_ENDPOINT:
1480                 if (copy_from_user(&backend, argp, sizeof backend))
1481                         return -EFAULT;
1482                 if (backend.reserved != 0)
1483                         return -EOPNOTSUPP;
1484
1485                 return vhost_scsi_set_endpoint(vs, &backend);
1486         case VHOST_SCSI_CLEAR_ENDPOINT:
1487                 if (copy_from_user(&backend, argp, sizeof backend))
1488                         return -EFAULT;
1489                 if (backend.reserved != 0)
1490                         return -EOPNOTSUPP;
1491
1492                 return vhost_scsi_clear_endpoint(vs, &backend);
1493         case VHOST_SCSI_GET_ABI_VERSION:
1494                 if (copy_to_user(argp, &abi_version, sizeof abi_version))
1495                         return -EFAULT;
1496                 return 0;
1497         case VHOST_SCSI_SET_EVENTS_MISSED:
1498                 if (get_user(events_missed, eventsp))
1499                         return -EFAULT;
1500                 mutex_lock(&vq->mutex);
1501                 vs->vs_events_missed = events_missed;
1502                 mutex_unlock(&vq->mutex);
1503                 return 0;
1504         case VHOST_SCSI_GET_EVENTS_MISSED:
1505                 mutex_lock(&vq->mutex);
1506                 events_missed = vs->vs_events_missed;
1507                 mutex_unlock(&vq->mutex);
1508                 if (put_user(events_missed, eventsp))
1509                         return -EFAULT;
1510                 return 0;
1511         case VHOST_GET_FEATURES:
1512                 features = VHOST_SCSI_FEATURES;
1513                 if (copy_to_user(featurep, &features, sizeof features))
1514                         return -EFAULT;
1515                 return 0;
1516         case VHOST_SET_FEATURES:
1517                 if (copy_from_user(&features, featurep, sizeof features))
1518                         return -EFAULT;
1519                 return vhost_scsi_set_features(vs, features);
1520         default:
1521                 mutex_lock(&vs->dev.mutex);
1522                 r = vhost_dev_ioctl(&vs->dev, ioctl, argp);
1523                 /* TODO: flush backend after dev ioctl. */
1524                 if (r == -ENOIOCTLCMD)
1525                         r = vhost_vring_ioctl(&vs->dev, ioctl, argp);
1526                 mutex_unlock(&vs->dev.mutex);
1527                 return r;
1528         }
1529 }
1530
1531 #ifdef CONFIG_COMPAT
1532 static long vhost_scsi_compat_ioctl(struct file *f, unsigned int ioctl,
1533                                 unsigned long arg)
1534 {
1535         return vhost_scsi_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
1536 }
1537 #endif
1538
1539 static const struct file_operations vhost_scsi_fops = {
1540         .owner          = THIS_MODULE,
1541         .release        = vhost_scsi_release,
1542         .unlocked_ioctl = vhost_scsi_ioctl,
1543 #ifdef CONFIG_COMPAT
1544         .compat_ioctl   = vhost_scsi_compat_ioctl,
1545 #endif
1546         .open           = vhost_scsi_open,
1547         .llseek         = noop_llseek,
1548 };
1549
1550 static struct miscdevice vhost_scsi_misc = {
1551         MISC_DYNAMIC_MINOR,
1552         "vhost-scsi",
1553         &vhost_scsi_fops,
1554 };
1555
1556 static int __init vhost_scsi_register(void)
1557 {
1558         return misc_register(&vhost_scsi_misc);
1559 }
1560
1561 static void vhost_scsi_deregister(void)
1562 {
1563         misc_deregister(&vhost_scsi_misc);
1564 }
1565
1566 static char *vhost_scsi_dump_proto_id(struct vhost_scsi_tport *tport)
1567 {
1568         switch (tport->tport_proto_id) {
1569         case SCSI_PROTOCOL_SAS:
1570                 return "SAS";
1571         case SCSI_PROTOCOL_FCP:
1572                 return "FCP";
1573         case SCSI_PROTOCOL_ISCSI:
1574                 return "iSCSI";
1575         default:
1576                 break;
1577         }
1578
1579         return "Unknown";
1580 }
1581
1582 static void
1583 vhost_scsi_do_plug(struct vhost_scsi_tpg *tpg,
1584                   struct se_lun *lun, bool plug)
1585 {
1586
1587         struct vhost_scsi *vs = tpg->vhost_scsi;
1588         struct vhost_virtqueue *vq;
1589         u32 reason;
1590
1591         if (!vs)
1592                 return;
1593
1594         mutex_lock(&vs->dev.mutex);
1595
1596         if (plug)
1597                 reason = VIRTIO_SCSI_EVT_RESET_RESCAN;
1598         else
1599                 reason = VIRTIO_SCSI_EVT_RESET_REMOVED;
1600
1601         vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1602         mutex_lock(&vq->mutex);
1603         if (vhost_has_feature(vq, VIRTIO_SCSI_F_HOTPLUG))
1604                 vhost_scsi_send_evt(vs, tpg, lun,
1605                                    VIRTIO_SCSI_T_TRANSPORT_RESET, reason);
1606         mutex_unlock(&vq->mutex);
1607         mutex_unlock(&vs->dev.mutex);
1608 }
1609
1610 static void vhost_scsi_hotplug(struct vhost_scsi_tpg *tpg, struct se_lun *lun)
1611 {
1612         vhost_scsi_do_plug(tpg, lun, true);
1613 }
1614
1615 static void vhost_scsi_hotunplug(struct vhost_scsi_tpg *tpg, struct se_lun *lun)
1616 {
1617         vhost_scsi_do_plug(tpg, lun, false);
1618 }
1619
1620 static int vhost_scsi_port_link(struct se_portal_group *se_tpg,
1621                                struct se_lun *lun)
1622 {
1623         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1624                                 struct vhost_scsi_tpg, se_tpg);
1625
1626         mutex_lock(&vhost_scsi_mutex);
1627
1628         mutex_lock(&tpg->tv_tpg_mutex);
1629         tpg->tv_tpg_port_count++;
1630         mutex_unlock(&tpg->tv_tpg_mutex);
1631
1632         vhost_scsi_hotplug(tpg, lun);
1633
1634         mutex_unlock(&vhost_scsi_mutex);
1635
1636         return 0;
1637 }
1638
1639 static void vhost_scsi_port_unlink(struct se_portal_group *se_tpg,
1640                                   struct se_lun *lun)
1641 {
1642         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1643                                 struct vhost_scsi_tpg, se_tpg);
1644
1645         mutex_lock(&vhost_scsi_mutex);
1646
1647         mutex_lock(&tpg->tv_tpg_mutex);
1648         tpg->tv_tpg_port_count--;
1649         mutex_unlock(&tpg->tv_tpg_mutex);
1650
1651         vhost_scsi_hotunplug(tpg, lun);
1652
1653         mutex_unlock(&vhost_scsi_mutex);
1654 }
1655
1656 static void vhost_scsi_free_cmd_map_res(struct se_session *se_sess)
1657 {
1658         struct vhost_scsi_cmd *tv_cmd;
1659         unsigned int i;
1660
1661         if (!se_sess->sess_cmd_map)
1662                 return;
1663
1664         for (i = 0; i < VHOST_SCSI_DEFAULT_TAGS; i++) {
1665                 tv_cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[i];
1666
1667                 kfree(tv_cmd->tvc_sgl);
1668                 kfree(tv_cmd->tvc_prot_sgl);
1669                 kfree(tv_cmd->tvc_upages);
1670         }
1671 }
1672
1673 static ssize_t vhost_scsi_tpg_attrib_fabric_prot_type_store(
1674                 struct config_item *item, const char *page, size_t count)
1675 {
1676         struct se_portal_group *se_tpg = attrib_to_tpg(item);
1677         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1678                                 struct vhost_scsi_tpg, se_tpg);
1679         unsigned long val;
1680         int ret = kstrtoul(page, 0, &val);
1681
1682         if (ret) {
1683                 pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
1684                 return ret;
1685         }
1686         if (val != 0 && val != 1 && val != 3) {
1687                 pr_err("Invalid vhost_scsi fabric_prot_type: %lu\n", val);
1688                 return -EINVAL;
1689         }
1690         tpg->tv_fabric_prot_type = val;
1691
1692         return count;
1693 }
1694
1695 static ssize_t vhost_scsi_tpg_attrib_fabric_prot_type_show(
1696                 struct config_item *item, char *page)
1697 {
1698         struct se_portal_group *se_tpg = attrib_to_tpg(item);
1699         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1700                                 struct vhost_scsi_tpg, se_tpg);
1701
1702         return sprintf(page, "%d\n", tpg->tv_fabric_prot_type);
1703 }
1704
1705 CONFIGFS_ATTR(vhost_scsi_tpg_attrib_, fabric_prot_type);
1706
1707 static struct configfs_attribute *vhost_scsi_tpg_attrib_attrs[] = {
1708         &vhost_scsi_tpg_attrib_attr_fabric_prot_type,
1709         NULL,
1710 };
1711
1712 static int vhost_scsi_nexus_cb(struct se_portal_group *se_tpg,
1713                                struct se_session *se_sess, void *p)
1714 {
1715         struct vhost_scsi_cmd *tv_cmd;
1716         unsigned int i;
1717
1718         for (i = 0; i < VHOST_SCSI_DEFAULT_TAGS; i++) {
1719                 tv_cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[i];
1720
1721                 tv_cmd->tvc_sgl = kzalloc(sizeof(struct scatterlist) *
1722                                         VHOST_SCSI_PREALLOC_SGLS, GFP_KERNEL);
1723                 if (!tv_cmd->tvc_sgl) {
1724                         pr_err("Unable to allocate tv_cmd->tvc_sgl\n");
1725                         goto out;
1726                 }
1727
1728                 tv_cmd->tvc_upages = kzalloc(sizeof(struct page *) *
1729                                 VHOST_SCSI_PREALLOC_UPAGES, GFP_KERNEL);
1730                 if (!tv_cmd->tvc_upages) {
1731                         pr_err("Unable to allocate tv_cmd->tvc_upages\n");
1732                         goto out;
1733                 }
1734
1735                 tv_cmd->tvc_prot_sgl = kzalloc(sizeof(struct scatterlist) *
1736                                 VHOST_SCSI_PREALLOC_PROT_SGLS, GFP_KERNEL);
1737                 if (!tv_cmd->tvc_prot_sgl) {
1738                         pr_err("Unable to allocate tv_cmd->tvc_prot_sgl\n");
1739                         goto out;
1740                 }
1741         }
1742         return 0;
1743 out:
1744         vhost_scsi_free_cmd_map_res(se_sess);
1745         return -ENOMEM;
1746 }
1747
1748 static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
1749                                 const char *name)
1750 {
1751         struct vhost_scsi_nexus *tv_nexus;
1752
1753         mutex_lock(&tpg->tv_tpg_mutex);
1754         if (tpg->tpg_nexus) {
1755                 mutex_unlock(&tpg->tv_tpg_mutex);
1756                 pr_debug("tpg->tpg_nexus already exists\n");
1757                 return -EEXIST;
1758         }
1759
1760         tv_nexus = kzalloc(sizeof(struct vhost_scsi_nexus), GFP_KERNEL);
1761         if (!tv_nexus) {
1762                 mutex_unlock(&tpg->tv_tpg_mutex);
1763                 pr_err("Unable to allocate struct vhost_scsi_nexus\n");
1764                 return -ENOMEM;
1765         }
1766         /*
1767          * Since we are running in 'demo mode' this call with generate a
1768          * struct se_node_acl for the vhost_scsi struct se_portal_group with
1769          * the SCSI Initiator port name of the passed configfs group 'name'.
1770          */
1771         tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg,
1772                                         VHOST_SCSI_DEFAULT_TAGS,
1773                                         sizeof(struct vhost_scsi_cmd),
1774                                         TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
1775                                         (unsigned char *)name, tv_nexus,
1776                                         vhost_scsi_nexus_cb);
1777         if (IS_ERR(tv_nexus->tvn_se_sess)) {
1778                 mutex_unlock(&tpg->tv_tpg_mutex);
1779                 kfree(tv_nexus);
1780                 return -ENOMEM;
1781         }
1782         tpg->tpg_nexus = tv_nexus;
1783
1784         mutex_unlock(&tpg->tv_tpg_mutex);
1785         return 0;
1786 }
1787
1788 static int vhost_scsi_drop_nexus(struct vhost_scsi_tpg *tpg)
1789 {
1790         struct se_session *se_sess;
1791         struct vhost_scsi_nexus *tv_nexus;
1792
1793         mutex_lock(&tpg->tv_tpg_mutex);
1794         tv_nexus = tpg->tpg_nexus;
1795         if (!tv_nexus) {
1796                 mutex_unlock(&tpg->tv_tpg_mutex);
1797                 return -ENODEV;
1798         }
1799
1800         se_sess = tv_nexus->tvn_se_sess;
1801         if (!se_sess) {
1802                 mutex_unlock(&tpg->tv_tpg_mutex);
1803                 return -ENODEV;
1804         }
1805
1806         if (tpg->tv_tpg_port_count != 0) {
1807                 mutex_unlock(&tpg->tv_tpg_mutex);
1808                 pr_err("Unable to remove TCM_vhost I_T Nexus with"
1809                         " active TPG port count: %d\n",
1810                         tpg->tv_tpg_port_count);
1811                 return -EBUSY;
1812         }
1813
1814         if (tpg->tv_tpg_vhost_count != 0) {
1815                 mutex_unlock(&tpg->tv_tpg_mutex);
1816                 pr_err("Unable to remove TCM_vhost I_T Nexus with"
1817                         " active TPG vhost count: %d\n",
1818                         tpg->tv_tpg_vhost_count);
1819                 return -EBUSY;
1820         }
1821
1822         pr_debug("TCM_vhost_ConfigFS: Removing I_T Nexus to emulated"
1823                 " %s Initiator Port: %s\n", vhost_scsi_dump_proto_id(tpg->tport),
1824                 tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1825
1826         vhost_scsi_free_cmd_map_res(se_sess);
1827         /*
1828          * Release the SCSI I_T Nexus to the emulated vhost Target Port
1829          */
1830         transport_deregister_session(tv_nexus->tvn_se_sess);
1831         tpg->tpg_nexus = NULL;
1832         mutex_unlock(&tpg->tv_tpg_mutex);
1833
1834         kfree(tv_nexus);
1835         return 0;
1836 }
1837
1838 static ssize_t vhost_scsi_tpg_nexus_show(struct config_item *item, char *page)
1839 {
1840         struct se_portal_group *se_tpg = to_tpg(item);
1841         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1842                                 struct vhost_scsi_tpg, se_tpg);
1843         struct vhost_scsi_nexus *tv_nexus;
1844         ssize_t ret;
1845
1846         mutex_lock(&tpg->tv_tpg_mutex);
1847         tv_nexus = tpg->tpg_nexus;
1848         if (!tv_nexus) {
1849                 mutex_unlock(&tpg->tv_tpg_mutex);
1850                 return -ENODEV;
1851         }
1852         ret = snprintf(page, PAGE_SIZE, "%s\n",
1853                         tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1854         mutex_unlock(&tpg->tv_tpg_mutex);
1855
1856         return ret;
1857 }
1858
1859 static ssize_t vhost_scsi_tpg_nexus_store(struct config_item *item,
1860                 const char *page, size_t count)
1861 {
1862         struct se_portal_group *se_tpg = to_tpg(item);
1863         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1864                                 struct vhost_scsi_tpg, se_tpg);
1865         struct vhost_scsi_tport *tport_wwn = tpg->tport;
1866         unsigned char i_port[VHOST_SCSI_NAMELEN], *ptr, *port_ptr;
1867         int ret;
1868         /*
1869          * Shutdown the active I_T nexus if 'NULL' is passed..
1870          */
1871         if (!strncmp(page, "NULL", 4)) {
1872                 ret = vhost_scsi_drop_nexus(tpg);
1873                 return (!ret) ? count : ret;
1874         }
1875         /*
1876          * Otherwise make sure the passed virtual Initiator port WWN matches
1877          * the fabric protocol_id set in vhost_scsi_make_tport(), and call
1878          * vhost_scsi_make_nexus().
1879          */
1880         if (strlen(page) >= VHOST_SCSI_NAMELEN) {
1881                 pr_err("Emulated NAA Sas Address: %s, exceeds"
1882                                 " max: %d\n", page, VHOST_SCSI_NAMELEN);
1883                 return -EINVAL;
1884         }
1885         snprintf(&i_port[0], VHOST_SCSI_NAMELEN, "%s", page);
1886
1887         ptr = strstr(i_port, "naa.");
1888         if (ptr) {
1889                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1890                         pr_err("Passed SAS Initiator Port %s does not"
1891                                 " match target port protoid: %s\n", i_port,
1892                                 vhost_scsi_dump_proto_id(tport_wwn));
1893                         return -EINVAL;
1894                 }
1895                 port_ptr = &i_port[0];
1896                 goto check_newline;
1897         }
1898         ptr = strstr(i_port, "fc.");
1899         if (ptr) {
1900                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1901                         pr_err("Passed FCP Initiator Port %s does not"
1902                                 " match target port protoid: %s\n", i_port,
1903                                 vhost_scsi_dump_proto_id(tport_wwn));
1904                         return -EINVAL;
1905                 }
1906                 port_ptr = &i_port[3]; /* Skip over "fc." */
1907                 goto check_newline;
1908         }
1909         ptr = strstr(i_port, "iqn.");
1910         if (ptr) {
1911                 if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1912                         pr_err("Passed iSCSI Initiator Port %s does not"
1913                                 " match target port protoid: %s\n", i_port,
1914                                 vhost_scsi_dump_proto_id(tport_wwn));
1915                         return -EINVAL;
1916                 }
1917                 port_ptr = &i_port[0];
1918                 goto check_newline;
1919         }
1920         pr_err("Unable to locate prefix for emulated Initiator Port:"
1921                         " %s\n", i_port);
1922         return -EINVAL;
1923         /*
1924          * Clear any trailing newline for the NAA WWN
1925          */
1926 check_newline:
1927         if (i_port[strlen(i_port)-1] == '\n')
1928                 i_port[strlen(i_port)-1] = '\0';
1929
1930         ret = vhost_scsi_make_nexus(tpg, port_ptr);
1931         if (ret < 0)
1932                 return ret;
1933
1934         return count;
1935 }
1936
1937 CONFIGFS_ATTR(vhost_scsi_tpg_, nexus);
1938
1939 static struct configfs_attribute *vhost_scsi_tpg_attrs[] = {
1940         &vhost_scsi_tpg_attr_nexus,
1941         NULL,
1942 };
1943
1944 static struct se_portal_group *
1945 vhost_scsi_make_tpg(struct se_wwn *wwn,
1946                    struct config_group *group,
1947                    const char *name)
1948 {
1949         struct vhost_scsi_tport *tport = container_of(wwn,
1950                         struct vhost_scsi_tport, tport_wwn);
1951
1952         struct vhost_scsi_tpg *tpg;
1953         u16 tpgt;
1954         int ret;
1955
1956         if (strstr(name, "tpgt_") != name)
1957                 return ERR_PTR(-EINVAL);
1958         if (kstrtou16(name + 5, 10, &tpgt) || tpgt >= VHOST_SCSI_MAX_TARGET)
1959                 return ERR_PTR(-EINVAL);
1960
1961         tpg = kzalloc(sizeof(struct vhost_scsi_tpg), GFP_KERNEL);
1962         if (!tpg) {
1963                 pr_err("Unable to allocate struct vhost_scsi_tpg");
1964                 return ERR_PTR(-ENOMEM);
1965         }
1966         mutex_init(&tpg->tv_tpg_mutex);
1967         INIT_LIST_HEAD(&tpg->tv_tpg_list);
1968         tpg->tport = tport;
1969         tpg->tport_tpgt = tpgt;
1970
1971         ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
1972         if (ret < 0) {
1973                 kfree(tpg);
1974                 return NULL;
1975         }
1976         mutex_lock(&vhost_scsi_mutex);
1977         list_add_tail(&tpg->tv_tpg_list, &vhost_scsi_list);
1978         mutex_unlock(&vhost_scsi_mutex);
1979
1980         return &tpg->se_tpg;
1981 }
1982
1983 static void vhost_scsi_drop_tpg(struct se_portal_group *se_tpg)
1984 {
1985         struct vhost_scsi_tpg *tpg = container_of(se_tpg,
1986                                 struct vhost_scsi_tpg, se_tpg);
1987
1988         mutex_lock(&vhost_scsi_mutex);
1989         list_del(&tpg->tv_tpg_list);
1990         mutex_unlock(&vhost_scsi_mutex);
1991         /*
1992          * Release the virtual I_T Nexus for this vhost TPG
1993          */
1994         vhost_scsi_drop_nexus(tpg);
1995         /*
1996          * Deregister the se_tpg from TCM..
1997          */
1998         core_tpg_deregister(se_tpg);
1999         kfree(tpg);
2000 }
2001
2002 static struct se_wwn *
2003 vhost_scsi_make_tport(struct target_fabric_configfs *tf,
2004                      struct config_group *group,
2005                      const char *name)
2006 {
2007         struct vhost_scsi_tport *tport;
2008         char *ptr;
2009         u64 wwpn = 0;
2010         int off = 0;
2011
2012         /* if (vhost_scsi_parse_wwn(name, &wwpn, 1) < 0)
2013                 return ERR_PTR(-EINVAL); */
2014
2015         tport = kzalloc(sizeof(struct vhost_scsi_tport), GFP_KERNEL);
2016         if (!tport) {
2017                 pr_err("Unable to allocate struct vhost_scsi_tport");
2018                 return ERR_PTR(-ENOMEM);
2019         }
2020         tport->tport_wwpn = wwpn;
2021         /*
2022          * Determine the emulated Protocol Identifier and Target Port Name
2023          * based on the incoming configfs directory name.
2024          */
2025         ptr = strstr(name, "naa.");
2026         if (ptr) {
2027                 tport->tport_proto_id = SCSI_PROTOCOL_SAS;
2028                 goto check_len;
2029         }
2030         ptr = strstr(name, "fc.");
2031         if (ptr) {
2032                 tport->tport_proto_id = SCSI_PROTOCOL_FCP;
2033                 off = 3; /* Skip over "fc." */
2034                 goto check_len;
2035         }
2036         ptr = strstr(name, "iqn.");
2037         if (ptr) {
2038                 tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
2039                 goto check_len;
2040         }
2041
2042         pr_err("Unable to locate prefix for emulated Target Port:"
2043                         " %s\n", name);
2044         kfree(tport);
2045         return ERR_PTR(-EINVAL);
2046
2047 check_len:
2048         if (strlen(name) >= VHOST_SCSI_NAMELEN) {
2049                 pr_err("Emulated %s Address: %s, exceeds"
2050                         " max: %d\n", name, vhost_scsi_dump_proto_id(tport),
2051                         VHOST_SCSI_NAMELEN);
2052                 kfree(tport);
2053                 return ERR_PTR(-EINVAL);
2054         }
2055         snprintf(&tport->tport_name[0], VHOST_SCSI_NAMELEN, "%s", &name[off]);
2056
2057         pr_debug("TCM_VHost_ConfigFS: Allocated emulated Target"
2058                 " %s Address: %s\n", vhost_scsi_dump_proto_id(tport), name);
2059
2060         return &tport->tport_wwn;
2061 }
2062
2063 static void vhost_scsi_drop_tport(struct se_wwn *wwn)
2064 {
2065         struct vhost_scsi_tport *tport = container_of(wwn,
2066                                 struct vhost_scsi_tport, tport_wwn);
2067
2068         pr_debug("TCM_VHost_ConfigFS: Deallocating emulated Target"
2069                 " %s Address: %s\n", vhost_scsi_dump_proto_id(tport),
2070                 tport->tport_name);
2071
2072         kfree(tport);
2073 }
2074
2075 static ssize_t
2076 vhost_scsi_wwn_version_show(struct config_item *item, char *page)
2077 {
2078         return sprintf(page, "TCM_VHOST fabric module %s on %s/%s"
2079                 "on "UTS_RELEASE"\n", VHOST_SCSI_VERSION, utsname()->sysname,
2080                 utsname()->machine);
2081 }
2082
2083 CONFIGFS_ATTR_RO(vhost_scsi_wwn_, version);
2084
2085 static struct configfs_attribute *vhost_scsi_wwn_attrs[] = {
2086         &vhost_scsi_wwn_attr_version,
2087         NULL,
2088 };
2089
2090 static const struct target_core_fabric_ops vhost_scsi_ops = {
2091         .module                         = THIS_MODULE,
2092         .name                           = "vhost",
2093         .get_fabric_name                = vhost_scsi_get_fabric_name,
2094         .tpg_get_wwn                    = vhost_scsi_get_fabric_wwn,
2095         .tpg_get_tag                    = vhost_scsi_get_tpgt,
2096         .tpg_check_demo_mode            = vhost_scsi_check_true,
2097         .tpg_check_demo_mode_cache      = vhost_scsi_check_true,
2098         .tpg_check_demo_mode_write_protect = vhost_scsi_check_false,
2099         .tpg_check_prod_mode_write_protect = vhost_scsi_check_false,
2100         .tpg_check_prot_fabric_only     = vhost_scsi_check_prot_fabric_only,
2101         .tpg_get_inst_index             = vhost_scsi_tpg_get_inst_index,
2102         .release_cmd                    = vhost_scsi_release_cmd,
2103         .check_stop_free                = vhost_scsi_check_stop_free,
2104         .sess_get_index                 = vhost_scsi_sess_get_index,
2105         .sess_get_initiator_sid         = NULL,
2106         .write_pending                  = vhost_scsi_write_pending,
2107         .write_pending_status           = vhost_scsi_write_pending_status,
2108         .set_default_node_attributes    = vhost_scsi_set_default_node_attrs,
2109         .get_cmd_state                  = vhost_scsi_get_cmd_state,
2110         .queue_data_in                  = vhost_scsi_queue_data_in,
2111         .queue_status                   = vhost_scsi_queue_status,
2112         .queue_tm_rsp                   = vhost_scsi_queue_tm_rsp,
2113         .aborted_task                   = vhost_scsi_aborted_task,
2114         /*
2115          * Setup callers for generic logic in target_core_fabric_configfs.c
2116          */
2117         .fabric_make_wwn                = vhost_scsi_make_tport,
2118         .fabric_drop_wwn                = vhost_scsi_drop_tport,
2119         .fabric_make_tpg                = vhost_scsi_make_tpg,
2120         .fabric_drop_tpg                = vhost_scsi_drop_tpg,
2121         .fabric_post_link               = vhost_scsi_port_link,
2122         .fabric_pre_unlink              = vhost_scsi_port_unlink,
2123
2124         .tfc_wwn_attrs                  = vhost_scsi_wwn_attrs,
2125         .tfc_tpg_base_attrs             = vhost_scsi_tpg_attrs,
2126         .tfc_tpg_attrib_attrs           = vhost_scsi_tpg_attrib_attrs,
2127 };
2128
2129 static int __init vhost_scsi_init(void)
2130 {
2131         int ret = -ENOMEM;
2132
2133         pr_debug("TCM_VHOST fabric module %s on %s/%s"
2134                 " on "UTS_RELEASE"\n", VHOST_SCSI_VERSION, utsname()->sysname,
2135                 utsname()->machine);
2136
2137         /*
2138          * Use our own dedicated workqueue for submitting I/O into
2139          * target core to avoid contention within system_wq.
2140          */
2141         vhost_scsi_workqueue = alloc_workqueue("vhost_scsi", 0, 0);
2142         if (!vhost_scsi_workqueue)
2143                 goto out;
2144
2145         ret = vhost_scsi_register();
2146         if (ret < 0)
2147                 goto out_destroy_workqueue;
2148
2149         ret = target_register_template(&vhost_scsi_ops);
2150         if (ret < 0)
2151                 goto out_vhost_scsi_deregister;
2152
2153         return 0;
2154
2155 out_vhost_scsi_deregister:
2156         vhost_scsi_deregister();
2157 out_destroy_workqueue:
2158         destroy_workqueue(vhost_scsi_workqueue);
2159 out:
2160         return ret;
2161 };
2162
2163 static void vhost_scsi_exit(void)
2164 {
2165         target_unregister_template(&vhost_scsi_ops);
2166         vhost_scsi_deregister();
2167         destroy_workqueue(vhost_scsi_workqueue);
2168 };
2169
2170 MODULE_DESCRIPTION("VHOST_SCSI series fabric driver");
2171 MODULE_ALIAS("tcm_vhost");
2172 MODULE_LICENSE("GPL");
2173 module_init(vhost_scsi_init);
2174 module_exit(vhost_scsi_exit);