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