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