linux/drivers/vhost/scsi.c
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   1/*******************************************************************************
   2 * Vhost kernel TCM fabric driver for virtio SCSI initiators
   3 *
   4 * (C) Copyright 2010-2012 RisingTide Systems LLC.
   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@risingtidesystems.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/miscdevice.h>
  39#include <asm/unaligned.h>
  40#include <scsi/scsi.h>
  41#include <scsi/scsi_tcq.h>
  42#include <target/target_core_base.h>
  43#include <target/target_core_fabric.h>
  44#include <target/target_core_fabric_configfs.h>
  45#include <target/target_core_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
  52#include "vhost.c"
  53#include "vhost.h"
  54
  55#define TCM_VHOST_VERSION  "v0.1"
  56#define TCM_VHOST_NAMELEN 256
  57#define TCM_VHOST_MAX_CDB_SIZE 32
  58
  59struct vhost_scsi_inflight {
  60        /* Wait for the flush operation to finish */
  61        struct completion comp;
  62        /* Refcount for the inflight reqs */
  63        struct kref kref;
  64};
  65
  66struct tcm_vhost_cmd {
  67        /* Descriptor from vhost_get_vq_desc() for virt_queue segment */
  68        int tvc_vq_desc;
  69        /* virtio-scsi initiator task attribute */
  70        int tvc_task_attr;
  71        /* virtio-scsi initiator data direction */
  72        enum dma_data_direction tvc_data_direction;
  73        /* Expected data transfer length from virtio-scsi header */
  74        u32 tvc_exp_data_len;
  75        /* The Tag from include/linux/virtio_scsi.h:struct virtio_scsi_cmd_req */
  76        u64 tvc_tag;
  77        /* The number of scatterlists associated with this cmd */
  78        u32 tvc_sgl_count;
  79        /* Saved unpacked SCSI LUN for tcm_vhost_submission_work() */
  80        u32 tvc_lun;
  81        /* Pointer to the SGL formatted memory from virtio-scsi */
  82        struct scatterlist *tvc_sgl;
  83        /* Pointer to response */
  84        struct virtio_scsi_cmd_resp __user *tvc_resp;
  85        /* Pointer to vhost_scsi for our device */
  86        struct vhost_scsi *tvc_vhost;
  87        /* Pointer to vhost_virtqueue for the cmd */
  88        struct vhost_virtqueue *tvc_vq;
  89        /* Pointer to vhost nexus memory */
  90        struct tcm_vhost_nexus *tvc_nexus;
  91        /* The TCM I/O descriptor that is accessed via container_of() */
  92        struct se_cmd tvc_se_cmd;
  93        /* work item used for cmwq dispatch to tcm_vhost_submission_work() */
  94        struct work_struct work;
  95        /* Copy of the incoming SCSI command descriptor block (CDB) */
  96        unsigned char tvc_cdb[TCM_VHOST_MAX_CDB_SIZE];
  97        /* Sense buffer that will be mapped into outgoing status */
  98        unsigned char tvc_sense_buf[TRANSPORT_SENSE_BUFFER];
  99        /* Completed commands list, serviced from vhost worker thread */
 100        struct llist_node tvc_completion_list;
 101        /* Used to track inflight cmd */
 102        struct vhost_scsi_inflight *inflight;
 103};
 104
 105struct tcm_vhost_nexus {
 106        /* Pointer to TCM session for I_T Nexus */
 107        struct se_session *tvn_se_sess;
 108};
 109
 110struct tcm_vhost_nacl {
 111        /* Binary World Wide unique Port Name for Vhost Initiator port */
 112        u64 iport_wwpn;
 113        /* ASCII formatted WWPN for Sas Initiator port */
 114        char iport_name[TCM_VHOST_NAMELEN];
 115        /* Returned by tcm_vhost_make_nodeacl() */
 116        struct se_node_acl se_node_acl;
 117};
 118
 119struct vhost_scsi;
 120struct tcm_vhost_tpg {
 121        /* Vhost port target portal group tag for TCM */
 122        u16 tport_tpgt;
 123        /* Used to track number of TPG Port/Lun Links wrt to explict I_T Nexus shutdown */
 124        int tv_tpg_port_count;
 125        /* Used for vhost_scsi device reference to tpg_nexus, protected by tv_tpg_mutex */
 126        int tv_tpg_vhost_count;
 127        /* list for tcm_vhost_list */
 128        struct list_head tv_tpg_list;
 129        /* Used to protect access for tpg_nexus */
 130        struct mutex tv_tpg_mutex;
 131        /* Pointer to the TCM VHost I_T Nexus for this TPG endpoint */
 132        struct tcm_vhost_nexus *tpg_nexus;
 133        /* Pointer back to tcm_vhost_tport */
 134        struct tcm_vhost_tport *tport;
 135        /* Returned by tcm_vhost_make_tpg() */
 136        struct se_portal_group se_tpg;
 137        /* Pointer back to vhost_scsi, protected by tv_tpg_mutex */
 138        struct vhost_scsi *vhost_scsi;
 139};
 140
 141struct tcm_vhost_tport {
 142        /* SCSI protocol the tport is providing */
 143        u8 tport_proto_id;
 144        /* Binary World Wide unique Port Name for Vhost Target port */
 145        u64 tport_wwpn;
 146        /* ASCII formatted WWPN for Vhost Target port */
 147        char tport_name[TCM_VHOST_NAMELEN];
 148        /* Returned by tcm_vhost_make_tport() */
 149        struct se_wwn tport_wwn;
 150};
 151
 152struct tcm_vhost_evt {
 153        /* event to be sent to guest */
 154        struct virtio_scsi_event event;
 155        /* event list, serviced from vhost worker thread */
 156        struct llist_node list;
 157};
 158
 159enum {
 160        VHOST_SCSI_VQ_CTL = 0,
 161        VHOST_SCSI_VQ_EVT = 1,
 162        VHOST_SCSI_VQ_IO = 2,
 163};
 164
 165enum {
 166        VHOST_SCSI_FEATURES = VHOST_FEATURES | (1ULL << VIRTIO_SCSI_F_HOTPLUG)
 167};
 168
 169#define VHOST_SCSI_MAX_TARGET   256
 170#define VHOST_SCSI_MAX_VQ       128
 171#define VHOST_SCSI_MAX_EVENT    128
 172
 173struct vhost_scsi_virtqueue {
 174        struct vhost_virtqueue vq;
 175        /*
 176         * Reference counting for inflight reqs, used for flush operation. At
 177         * each time, one reference tracks new commands submitted, while we
 178         * wait for another one to reach 0.
 179         */
 180        struct vhost_scsi_inflight inflights[2];
 181        /*
 182         * Indicate current inflight in use, protected by vq->mutex.
 183         * Writers must also take dev mutex and flush under it.
 184         */
 185        int inflight_idx;
 186};
 187
 188struct vhost_scsi {
 189        /* Protected by vhost_scsi->dev.mutex */
 190        struct tcm_vhost_tpg **vs_tpg;
 191        char vs_vhost_wwpn[TRANSPORT_IQN_LEN];
 192
 193        struct vhost_dev dev;
 194        struct vhost_scsi_virtqueue vqs[VHOST_SCSI_MAX_VQ];
 195
 196        struct vhost_work vs_completion_work; /* cmd completion work item */
 197        struct llist_head vs_completion_list; /* cmd completion queue */
 198
 199        struct vhost_work vs_event_work; /* evt injection work item */
 200        struct llist_head vs_event_list; /* evt injection queue */
 201
 202        bool vs_events_missed; /* any missed events, protected by vq->mutex */
 203        int vs_events_nr; /* num of pending events, protected by vq->mutex */
 204};
 205
 206/* Local pointer to allocated TCM configfs fabric module */
 207static struct target_fabric_configfs *tcm_vhost_fabric_configfs;
 208
 209static struct workqueue_struct *tcm_vhost_workqueue;
 210
 211/* Global spinlock to protect tcm_vhost TPG list for vhost IOCTL access */
 212static DEFINE_MUTEX(tcm_vhost_mutex);
 213static LIST_HEAD(tcm_vhost_list);
 214
 215static int iov_num_pages(struct iovec *iov)
 216{
 217        return (PAGE_ALIGN((unsigned long)iov->iov_base + iov->iov_len) -
 218               ((unsigned long)iov->iov_base & PAGE_MASK)) >> PAGE_SHIFT;
 219}
 220
 221void tcm_vhost_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
 229static void tcm_vhost_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
 256static struct vhost_scsi_inflight *
 257tcm_vhost_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
 269static void tcm_vhost_put_inflight(struct vhost_scsi_inflight *inflight)
 270{
 271        kref_put(&inflight->kref, tcm_vhost_done_inflight);
 272}
 273
 274static int tcm_vhost_check_true(struct se_portal_group *se_tpg)
 275{
 276        return 1;
 277}
 278
 279static int tcm_vhost_check_false(struct se_portal_group *se_tpg)
 280{
 281        return 0;
 282}
 283
 284static char *tcm_vhost_get_fabric_name(void)
 285{
 286        return "vhost";
 287}
 288
 289static u8 tcm_vhost_get_fabric_proto_ident(struct se_portal_group *se_tpg)
 290{
 291        struct tcm_vhost_tpg *tpg = container_of(se_tpg,
 292                                struct tcm_vhost_tpg, se_tpg);
 293        struct tcm_vhost_tport *tport = tpg->tport;
 294
 295        switch (tport->tport_proto_id) {
 296        case SCSI_PROTOCOL_SAS:
 297                return sas_get_fabric_proto_ident(se_tpg);
 298        case SCSI_PROTOCOL_FCP:
 299                return fc_get_fabric_proto_ident(se_tpg);
 300        case SCSI_PROTOCOL_ISCSI:
 301                return iscsi_get_fabric_proto_ident(se_tpg);
 302        default:
 303                pr_err("Unknown tport_proto_id: 0x%02x, using"
 304                        " SAS emulation\n", tport->tport_proto_id);
 305                break;
 306        }
 307
 308        return sas_get_fabric_proto_ident(se_tpg);
 309}
 310
 311static char *tcm_vhost_get_fabric_wwn(struct se_portal_group *se_tpg)
 312{
 313        struct tcm_vhost_tpg *tpg = container_of(se_tpg,
 314                                struct tcm_vhost_tpg, se_tpg);
 315        struct tcm_vhost_tport *tport = tpg->tport;
 316
 317        return &tport->tport_name[0];
 318}
 319
 320static u16 tcm_vhost_get_tag(struct se_portal_group *se_tpg)
 321{
 322        struct tcm_vhost_tpg *tpg = container_of(se_tpg,
 323                                struct tcm_vhost_tpg, se_tpg);
 324        return tpg->tport_tpgt;
 325}
 326
 327static u32 tcm_vhost_get_default_depth(struct se_portal_group *se_tpg)
 328{
 329        return 1;
 330}
 331
 332static u32 tcm_vhost_get_pr_transport_id(struct se_portal_group *se_tpg,
 333        struct se_node_acl *se_nacl,
 334        struct t10_pr_registration *pr_reg,
 335        int *format_code,
 336        unsigned char *buf)
 337{
 338        struct tcm_vhost_tpg *tpg = container_of(se_tpg,
 339                                struct tcm_vhost_tpg, se_tpg);
 340        struct tcm_vhost_tport *tport = tpg->tport;
 341
 342        switch (tport->tport_proto_id) {
 343        case SCSI_PROTOCOL_SAS:
 344                return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 345                                        format_code, buf);
 346        case SCSI_PROTOCOL_FCP:
 347                return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 348                                        format_code, buf);
 349        case SCSI_PROTOCOL_ISCSI:
 350                return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 351                                        format_code, buf);
 352        default:
 353                pr_err("Unknown tport_proto_id: 0x%02x, using"
 354                        " SAS emulation\n", tport->tport_proto_id);
 355                break;
 356        }
 357
 358        return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 359                        format_code, buf);
 360}
 361
 362static u32 tcm_vhost_get_pr_transport_id_len(struct se_portal_group *se_tpg,
 363        struct se_node_acl *se_nacl,
 364        struct t10_pr_registration *pr_reg,
 365        int *format_code)
 366{
 367        struct tcm_vhost_tpg *tpg = container_of(se_tpg,
 368                                struct tcm_vhost_tpg, se_tpg);
 369        struct tcm_vhost_tport *tport = tpg->tport;
 370
 371        switch (tport->tport_proto_id) {
 372        case SCSI_PROTOCOL_SAS:
 373                return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 374                                        format_code);
 375        case SCSI_PROTOCOL_FCP:
 376                return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 377                                        format_code);
 378        case SCSI_PROTOCOL_ISCSI:
 379                return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 380                                        format_code);
 381        default:
 382                pr_err("Unknown tport_proto_id: 0x%02x, using"
 383                        " SAS emulation\n", tport->tport_proto_id);
 384                break;
 385        }
 386
 387        return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 388                        format_code);
 389}
 390
 391static char *tcm_vhost_parse_pr_out_transport_id(struct se_portal_group *se_tpg,
 392        const char *buf,
 393        u32 *out_tid_len,
 394        char **port_nexus_ptr)
 395{
 396        struct tcm_vhost_tpg *tpg = container_of(se_tpg,
 397                                struct tcm_vhost_tpg, se_tpg);
 398        struct tcm_vhost_tport *tport = tpg->tport;
 399
 400        switch (tport->tport_proto_id) {
 401        case SCSI_PROTOCOL_SAS:
 402                return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 403                                        port_nexus_ptr);
 404        case SCSI_PROTOCOL_FCP:
 405                return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 406                                        port_nexus_ptr);
 407        case SCSI_PROTOCOL_ISCSI:
 408                return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 409                                        port_nexus_ptr);
 410        default:
 411                pr_err("Unknown tport_proto_id: 0x%02x, using"
 412                        " SAS emulation\n", tport->tport_proto_id);
 413                break;
 414        }
 415
 416        return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 417                        port_nexus_ptr);
 418}
 419
 420static struct se_node_acl *tcm_vhost_alloc_fabric_acl(
 421        struct se_portal_group *se_tpg)
 422{
 423        struct tcm_vhost_nacl *nacl;
 424
 425        nacl = kzalloc(sizeof(struct tcm_vhost_nacl), GFP_KERNEL);
 426        if (!nacl) {
 427                pr_err("Unable to allocate struct tcm_vhost_nacl\n");
 428                return NULL;
 429        }
 430
 431        return &nacl->se_node_acl;
 432}
 433
 434static void tcm_vhost_release_fabric_acl(struct se_portal_group *se_tpg,
 435        struct se_node_acl *se_nacl)
 436{
 437        struct tcm_vhost_nacl *nacl = container_of(se_nacl,
 438                        struct tcm_vhost_nacl, se_node_acl);
 439        kfree(nacl);
 440}
 441
 442static u32 tcm_vhost_tpg_get_inst_index(struct se_portal_group *se_tpg)
 443{
 444        return 1;
 445}
 446
 447static void tcm_vhost_release_cmd(struct se_cmd *se_cmd)
 448{
 449        return;
 450}
 451
 452static int tcm_vhost_shutdown_session(struct se_session *se_sess)
 453{
 454        return 0;
 455}
 456
 457static void tcm_vhost_close_session(struct se_session *se_sess)
 458{
 459        return;
 460}
 461
 462static u32 tcm_vhost_sess_get_index(struct se_session *se_sess)
 463{
 464        return 0;
 465}
 466
 467static int tcm_vhost_write_pending(struct se_cmd *se_cmd)
 468{
 469        /* Go ahead and process the write immediately */
 470        target_execute_cmd(se_cmd);
 471        return 0;
 472}
 473
 474static int tcm_vhost_write_pending_status(struct se_cmd *se_cmd)
 475{
 476        return 0;
 477}
 478
 479static void tcm_vhost_set_default_node_attrs(struct se_node_acl *nacl)
 480{
 481        return;
 482}
 483
 484static u32 tcm_vhost_get_task_tag(struct se_cmd *se_cmd)
 485{
 486        return 0;
 487}
 488
 489static int tcm_vhost_get_cmd_state(struct se_cmd *se_cmd)
 490{
 491        return 0;
 492}
 493
 494static void vhost_scsi_complete_cmd(struct tcm_vhost_cmd *tv_cmd)
 495{
 496        struct vhost_scsi *vs = tv_cmd->tvc_vhost;
 497
 498        llist_add(&tv_cmd->tvc_completion_list, &vs->vs_completion_list);
 499
 500        vhost_work_queue(&vs->dev, &vs->vs_completion_work);
 501}
 502
 503static int tcm_vhost_queue_data_in(struct se_cmd *se_cmd)
 504{
 505        struct tcm_vhost_cmd *tv_cmd = container_of(se_cmd,
 506                                struct tcm_vhost_cmd, tvc_se_cmd);
 507        vhost_scsi_complete_cmd(tv_cmd);
 508        return 0;
 509}
 510
 511static int tcm_vhost_queue_status(struct se_cmd *se_cmd)
 512{
 513        struct tcm_vhost_cmd *tv_cmd = container_of(se_cmd,
 514                                struct tcm_vhost_cmd, tvc_se_cmd);
 515        vhost_scsi_complete_cmd(tv_cmd);
 516        return 0;
 517}
 518
 519static int tcm_vhost_queue_tm_rsp(struct se_cmd *se_cmd)
 520{
 521        return 0;
 522}
 523
 524static void tcm_vhost_free_evt(struct vhost_scsi *vs, struct tcm_vhost_evt *evt)
 525{
 526        vs->vs_events_nr--;
 527        kfree(evt);
 528}
 529
 530static struct tcm_vhost_evt *tcm_vhost_allocate_evt(struct vhost_scsi *vs,
 531        u32 event, u32 reason)
 532{
 533        struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 534        struct tcm_vhost_evt *evt;
 535
 536        if (vs->vs_events_nr > VHOST_SCSI_MAX_EVENT) {
 537                vs->vs_events_missed = true;
 538                return NULL;
 539        }
 540
 541        evt = kzalloc(sizeof(*evt), GFP_KERNEL);
 542        if (!evt) {
 543                vq_err(vq, "Failed to allocate tcm_vhost_evt\n");
 544                vs->vs_events_missed = true;
 545                return NULL;
 546        }
 547
 548        evt->event.event = event;
 549        evt->event.reason = reason;
 550        vs->vs_events_nr++;
 551
 552        return evt;
 553}
 554
 555static void vhost_scsi_free_cmd(struct tcm_vhost_cmd *tv_cmd)
 556{
 557        struct se_cmd *se_cmd = &tv_cmd->tvc_se_cmd;
 558
 559        /* TODO locking against target/backend threads? */
 560        transport_generic_free_cmd(se_cmd, 1);
 561
 562        if (tv_cmd->tvc_sgl_count) {
 563                u32 i;
 564                for (i = 0; i < tv_cmd->tvc_sgl_count; i++)
 565                        put_page(sg_page(&tv_cmd->tvc_sgl[i]));
 566
 567                kfree(tv_cmd->tvc_sgl);
 568        }
 569
 570        tcm_vhost_put_inflight(tv_cmd->inflight);
 571
 572        kfree(tv_cmd);
 573}
 574
 575static void tcm_vhost_do_evt_work(struct vhost_scsi *vs,
 576        struct tcm_vhost_evt *evt)
 577{
 578        struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 579        struct virtio_scsi_event *event = &evt->event;
 580        struct virtio_scsi_event __user *eventp;
 581        unsigned out, in;
 582        int head, ret;
 583
 584        if (!vq->private_data) {
 585                vs->vs_events_missed = true;
 586                return;
 587        }
 588
 589again:
 590        vhost_disable_notify(&vs->dev, vq);
 591        head = vhost_get_vq_desc(&vs->dev, vq, vq->iov,
 592                        ARRAY_SIZE(vq->iov), &out, &in,
 593                        NULL, NULL);
 594        if (head < 0) {
 595                vs->vs_events_missed = true;
 596                return;
 597        }
 598        if (head == vq->num) {
 599                if (vhost_enable_notify(&vs->dev, vq))
 600                        goto again;
 601                vs->vs_events_missed = true;
 602                return;
 603        }
 604
 605        if ((vq->iov[out].iov_len != sizeof(struct virtio_scsi_event))) {
 606                vq_err(vq, "Expecting virtio_scsi_event, got %zu bytes\n",
 607                                vq->iov[out].iov_len);
 608                vs->vs_events_missed = true;
 609                return;
 610        }
 611
 612        if (vs->vs_events_missed) {
 613                event->event |= VIRTIO_SCSI_T_EVENTS_MISSED;
 614                vs->vs_events_missed = false;
 615        }
 616
 617        eventp = vq->iov[out].iov_base;
 618        ret = __copy_to_user(eventp, event, sizeof(*event));
 619        if (!ret)
 620                vhost_add_used_and_signal(&vs->dev, vq, head, 0);
 621        else
 622                vq_err(vq, "Faulted on tcm_vhost_send_event\n");
 623}
 624
 625static void tcm_vhost_evt_work(struct vhost_work *work)
 626{
 627        struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
 628                                        vs_event_work);
 629        struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 630        struct tcm_vhost_evt *evt;
 631        struct llist_node *llnode;
 632
 633        mutex_lock(&vq->mutex);
 634        llnode = llist_del_all(&vs->vs_event_list);
 635        while (llnode) {
 636                evt = llist_entry(llnode, struct tcm_vhost_evt, list);
 637                llnode = llist_next(llnode);
 638                tcm_vhost_do_evt_work(vs, evt);
 639                tcm_vhost_free_evt(vs, evt);
 640        }
 641        mutex_unlock(&vq->mutex);
 642}
 643
 644/* Fill in status and signal that we are done processing this command
 645 *
 646 * This is scheduled in the vhost work queue so we are called with the owner
 647 * process mm and can access the vring.
 648 */
 649static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
 650{
 651        struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
 652                                        vs_completion_work);
 653        DECLARE_BITMAP(signal, VHOST_SCSI_MAX_VQ);
 654        struct virtio_scsi_cmd_resp v_rsp;
 655        struct tcm_vhost_cmd *tv_cmd;
 656        struct llist_node *llnode;
 657        struct se_cmd *se_cmd;
 658        int ret, vq;
 659
 660        bitmap_zero(signal, VHOST_SCSI_MAX_VQ);
 661        llnode = llist_del_all(&vs->vs_completion_list);
 662        while (llnode) {
 663                tv_cmd = llist_entry(llnode, struct tcm_vhost_cmd,
 664                                     tvc_completion_list);
 665                llnode = llist_next(llnode);
 666                se_cmd = &tv_cmd->tvc_se_cmd;
 667
 668                pr_debug("%s tv_cmd %p resid %u status %#02x\n", __func__,
 669                        tv_cmd, se_cmd->residual_count, se_cmd->scsi_status);
 670
 671                memset(&v_rsp, 0, sizeof(v_rsp));
 672                v_rsp.resid = se_cmd->residual_count;
 673                /* TODO is status_qualifier field needed? */
 674                v_rsp.status = se_cmd->scsi_status;
 675                v_rsp.sense_len = se_cmd->scsi_sense_length;
 676                memcpy(v_rsp.sense, tv_cmd->tvc_sense_buf,
 677                       v_rsp.sense_len);
 678                ret = copy_to_user(tv_cmd->tvc_resp, &v_rsp, sizeof(v_rsp));
 679                if (likely(ret == 0)) {
 680                        struct vhost_scsi_virtqueue *q;
 681                        vhost_add_used(tv_cmd->tvc_vq, tv_cmd->tvc_vq_desc, 0);
 682                        q = container_of(tv_cmd->tvc_vq, struct vhost_scsi_virtqueue, vq);
 683                        vq = q - vs->vqs;
 684                        __set_bit(vq, signal);
 685                } else
 686                        pr_err("Faulted on virtio_scsi_cmd_resp\n");
 687
 688                vhost_scsi_free_cmd(tv_cmd);
 689        }
 690
 691        vq = -1;
 692        while ((vq = find_next_bit(signal, VHOST_SCSI_MAX_VQ, vq + 1))
 693                < VHOST_SCSI_MAX_VQ)
 694                vhost_signal(&vs->dev, &vs->vqs[vq].vq);
 695}
 696
 697static struct tcm_vhost_cmd *vhost_scsi_allocate_cmd(
 698        struct vhost_virtqueue *vq,
 699        struct tcm_vhost_tpg *tv_tpg,
 700        struct virtio_scsi_cmd_req *v_req,
 701        u32 exp_data_len,
 702        int data_direction)
 703{
 704        struct tcm_vhost_cmd *tv_cmd;
 705        struct tcm_vhost_nexus *tv_nexus;
 706
 707        tv_nexus = tv_tpg->tpg_nexus;
 708        if (!tv_nexus) {
 709                pr_err("Unable to locate active struct tcm_vhost_nexus\n");
 710                return ERR_PTR(-EIO);
 711        }
 712
 713        tv_cmd = kzalloc(sizeof(struct tcm_vhost_cmd), GFP_ATOMIC);
 714        if (!tv_cmd) {
 715                pr_err("Unable to allocate struct tcm_vhost_cmd\n");
 716                return ERR_PTR(-ENOMEM);
 717        }
 718        tv_cmd->tvc_tag = v_req->tag;
 719        tv_cmd->tvc_task_attr = v_req->task_attr;
 720        tv_cmd->tvc_exp_data_len = exp_data_len;
 721        tv_cmd->tvc_data_direction = data_direction;
 722        tv_cmd->tvc_nexus = tv_nexus;
 723        tv_cmd->inflight = tcm_vhost_get_inflight(vq);
 724
 725        return tv_cmd;
 726}
 727
 728/*
 729 * Map a user memory range into a scatterlist
 730 *
 731 * Returns the number of scatterlist entries used or -errno on error.
 732 */
 733static int vhost_scsi_map_to_sgl(struct scatterlist *sgl,
 734        unsigned int sgl_count, struct iovec *iov, int write)
 735{
 736        unsigned int npages = 0, pages_nr, offset, nbytes;
 737        struct scatterlist *sg = sgl;
 738        void __user *ptr = iov->iov_base;
 739        size_t len = iov->iov_len;
 740        struct page **pages;
 741        int ret, i;
 742
 743        pages_nr = iov_num_pages(iov);
 744        if (pages_nr > sgl_count)
 745                return -ENOBUFS;
 746
 747        pages = kmalloc(pages_nr * sizeof(struct page *), GFP_KERNEL);
 748        if (!pages)
 749                return -ENOMEM;
 750
 751        ret = get_user_pages_fast((unsigned long)ptr, pages_nr, write, pages);
 752        /* No pages were pinned */
 753        if (ret < 0)
 754                goto out;
 755        /* Less pages pinned than wanted */
 756        if (ret != pages_nr) {
 757                for (i = 0; i < ret; i++)
 758                        put_page(pages[i]);
 759                ret = -EFAULT;
 760                goto out;
 761        }
 762
 763        while (len > 0) {
 764                offset = (uintptr_t)ptr & ~PAGE_MASK;
 765                nbytes = min_t(unsigned int, PAGE_SIZE - offset, len);
 766                sg_set_page(sg, pages[npages], nbytes, offset);
 767                ptr += nbytes;
 768                len -= nbytes;
 769                sg++;
 770                npages++;
 771        }
 772
 773out:
 774        kfree(pages);
 775        return ret;
 776}
 777
 778static int vhost_scsi_map_iov_to_sgl(struct tcm_vhost_cmd *tv_cmd,
 779        struct iovec *iov, unsigned int niov, int write)
 780{
 781        int ret;
 782        unsigned int i;
 783        u32 sgl_count;
 784        struct scatterlist *sg;
 785
 786        /*
 787         * Find out how long sglist needs to be
 788         */
 789        sgl_count = 0;
 790        for (i = 0; i < niov; i++)
 791                sgl_count += iov_num_pages(&iov[i]);
 792
 793        /* TODO overflow checking */
 794
 795        sg = kmalloc(sizeof(tv_cmd->tvc_sgl[0]) * sgl_count, GFP_ATOMIC);
 796        if (!sg)
 797                return -ENOMEM;
 798        pr_debug("%s sg %p sgl_count %u is_err %d\n", __func__,
 799               sg, sgl_count, !sg);
 800        sg_init_table(sg, sgl_count);
 801
 802        tv_cmd->tvc_sgl = sg;
 803        tv_cmd->tvc_sgl_count = sgl_count;
 804
 805        pr_debug("Mapping %u iovecs for %u pages\n", niov, sgl_count);
 806        for (i = 0; i < niov; i++) {
 807                ret = vhost_scsi_map_to_sgl(sg, sgl_count, &iov[i], write);
 808                if (ret < 0) {
 809                        for (i = 0; i < tv_cmd->tvc_sgl_count; i++)
 810                                put_page(sg_page(&tv_cmd->tvc_sgl[i]));
 811                        kfree(tv_cmd->tvc_sgl);
 812                        tv_cmd->tvc_sgl = NULL;
 813                        tv_cmd->tvc_sgl_count = 0;
 814                        return ret;
 815                }
 816
 817                sg += ret;
 818                sgl_count -= ret;
 819        }
 820        return 0;
 821}
 822
 823static void tcm_vhost_submission_work(struct work_struct *work)
 824{
 825        struct tcm_vhost_cmd *tv_cmd =
 826                container_of(work, struct tcm_vhost_cmd, work);
 827        struct tcm_vhost_nexus *tv_nexus;
 828        struct se_cmd *se_cmd = &tv_cmd->tvc_se_cmd;
 829        struct scatterlist *sg_ptr, *sg_bidi_ptr = NULL;
 830        int rc, sg_no_bidi = 0;
 831
 832        if (tv_cmd->tvc_sgl_count) {
 833                sg_ptr = tv_cmd->tvc_sgl;
 834/* FIXME: Fix BIDI operation in tcm_vhost_submission_work() */
 835#if 0
 836                if (se_cmd->se_cmd_flags & SCF_BIDI) {
 837                        sg_bidi_ptr = NULL;
 838                        sg_no_bidi = 0;
 839                }
 840#endif
 841        } else {
 842                sg_ptr = NULL;
 843        }
 844        tv_nexus = tv_cmd->tvc_nexus;
 845
 846        rc = target_submit_cmd_map_sgls(se_cmd, tv_nexus->tvn_se_sess,
 847                        tv_cmd->tvc_cdb, &tv_cmd->tvc_sense_buf[0],
 848                        tv_cmd->tvc_lun, tv_cmd->tvc_exp_data_len,
 849                        tv_cmd->tvc_task_attr, tv_cmd->tvc_data_direction,
 850                        0, sg_ptr, tv_cmd->tvc_sgl_count,
 851                        sg_bidi_ptr, sg_no_bidi);
 852        if (rc < 0) {
 853                transport_send_check_condition_and_sense(se_cmd,
 854                                TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
 855                transport_generic_free_cmd(se_cmd, 0);
 856        }
 857}
 858
 859static void vhost_scsi_send_bad_target(struct vhost_scsi *vs,
 860        struct vhost_virtqueue *vq, int head, unsigned out)
 861{
 862        struct virtio_scsi_cmd_resp __user *resp;
 863        struct virtio_scsi_cmd_resp rsp;
 864        int ret;
 865
 866        memset(&rsp, 0, sizeof(rsp));
 867        rsp.response = VIRTIO_SCSI_S_BAD_TARGET;
 868        resp = vq->iov[out].iov_base;
 869        ret = __copy_to_user(resp, &rsp, sizeof(rsp));
 870        if (!ret)
 871                vhost_add_used_and_signal(&vs->dev, vq, head, 0);
 872        else
 873                pr_err("Faulted on virtio_scsi_cmd_resp\n");
 874}
 875
 876static void vhost_scsi_handle_vq(struct vhost_scsi *vs,
 877        struct vhost_virtqueue *vq)
 878{
 879        struct tcm_vhost_tpg **vs_tpg;
 880        struct virtio_scsi_cmd_req v_req;
 881        struct tcm_vhost_tpg *tv_tpg;
 882        struct tcm_vhost_cmd *tv_cmd;
 883        u32 exp_data_len, data_first, data_num, data_direction;
 884        unsigned out, in, i;
 885        int head, ret;
 886        u8 target;
 887
 888        /*
 889         * We can handle the vq only after the endpoint is setup by calling the
 890         * VHOST_SCSI_SET_ENDPOINT ioctl.
 891         *
 892         * TODO: Check that we are running from vhost_worker which acts
 893         * as read-side critical section for vhost kind of RCU.
 894         * See the comments in struct vhost_virtqueue in drivers/vhost/vhost.h
 895         */
 896        vs_tpg = rcu_dereference_check(vq->private_data, 1);
 897        if (!vs_tpg)
 898                return;
 899
 900        mutex_lock(&vq->mutex);
 901        vhost_disable_notify(&vs->dev, vq);
 902
 903        for (;;) {
 904                head = vhost_get_vq_desc(&vs->dev, vq, vq->iov,
 905                                        ARRAY_SIZE(vq->iov), &out, &in,
 906                                        NULL, NULL);
 907                pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n",
 908                                        head, out, in);
 909                /* On error, stop handling until the next kick. */
 910                if (unlikely(head < 0))
 911                        break;
 912                /* Nothing new?  Wait for eventfd to tell us they refilled. */
 913                if (head == vq->num) {
 914                        if (unlikely(vhost_enable_notify(&vs->dev, vq))) {
 915                                vhost_disable_notify(&vs->dev, vq);
 916                                continue;
 917                        }
 918                        break;
 919                }
 920
 921/* FIXME: BIDI operation */
 922                if (out == 1 && in == 1) {
 923                        data_direction = DMA_NONE;
 924                        data_first = 0;
 925                        data_num = 0;
 926                } else if (out == 1 && in > 1) {
 927                        data_direction = DMA_FROM_DEVICE;
 928                        data_first = out + 1;
 929                        data_num = in - 1;
 930                } else if (out > 1 && in == 1) {
 931                        data_direction = DMA_TO_DEVICE;
 932                        data_first = 1;
 933                        data_num = out - 1;
 934                } else {
 935                        vq_err(vq, "Invalid buffer layout out: %u in: %u\n",
 936                                        out, in);
 937                        break;
 938                }
 939
 940                /*
 941                 * Check for a sane resp buffer so we can report errors to
 942                 * the guest.
 943                 */
 944                if (unlikely(vq->iov[out].iov_len !=
 945                                        sizeof(struct virtio_scsi_cmd_resp))) {
 946                        vq_err(vq, "Expecting virtio_scsi_cmd_resp, got %zu"
 947                                " bytes\n", vq->iov[out].iov_len);
 948                        break;
 949                }
 950
 951                if (unlikely(vq->iov[0].iov_len != sizeof(v_req))) {
 952                        vq_err(vq, "Expecting virtio_scsi_cmd_req, got %zu"
 953                                " bytes\n", vq->iov[0].iov_len);
 954                        break;
 955                }
 956                pr_debug("Calling __copy_from_user: vq->iov[0].iov_base: %p,"
 957                        " len: %zu\n", vq->iov[0].iov_base, sizeof(v_req));
 958                ret = __copy_from_user(&v_req, vq->iov[0].iov_base,
 959                                sizeof(v_req));
 960                if (unlikely(ret)) {
 961                        vq_err(vq, "Faulted on virtio_scsi_cmd_req\n");
 962                        break;
 963                }
 964
 965                /* Extract the tpgt */
 966                target = v_req.lun[1];
 967                tv_tpg = ACCESS_ONCE(vs_tpg[target]);
 968
 969                /* Target does not exist, fail the request */
 970                if (unlikely(!tv_tpg)) {
 971                        vhost_scsi_send_bad_target(vs, vq, head, out);
 972                        continue;
 973                }
 974
 975                exp_data_len = 0;
 976                for (i = 0; i < data_num; i++)
 977                        exp_data_len += vq->iov[data_first + i].iov_len;
 978
 979                tv_cmd = vhost_scsi_allocate_cmd(vq, tv_tpg, &v_req,
 980                                        exp_data_len, data_direction);
 981                if (IS_ERR(tv_cmd)) {
 982                        vq_err(vq, "vhost_scsi_allocate_cmd failed %ld\n",
 983                                        PTR_ERR(tv_cmd));
 984                        goto err_cmd;
 985                }
 986                pr_debug("Allocated tv_cmd: %p exp_data_len: %d, data_direction"
 987                        ": %d\n", tv_cmd, exp_data_len, data_direction);
 988
 989                tv_cmd->tvc_vhost = vs;
 990                tv_cmd->tvc_vq = vq;
 991                tv_cmd->tvc_resp = vq->iov[out].iov_base;
 992
 993                /*
 994                 * Copy in the recieved CDB descriptor into tv_cmd->tvc_cdb
 995                 * that will be used by tcm_vhost_new_cmd_map() and down into
 996                 * target_setup_cmd_from_cdb()
 997                 */
 998                memcpy(tv_cmd->tvc_cdb, v_req.cdb, TCM_VHOST_MAX_CDB_SIZE);
 999                /*
1000                 * Check that the recieved CDB size does not exceeded our
1001                 * hardcoded max for tcm_vhost
1002                 */
1003                /* TODO what if cdb was too small for varlen cdb header? */
1004                if (unlikely(scsi_command_size(tv_cmd->tvc_cdb) >
1005                                        TCM_VHOST_MAX_CDB_SIZE)) {
1006                        vq_err(vq, "Received SCSI CDB with command_size: %d that"
1007                                " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1008                                scsi_command_size(tv_cmd->tvc_cdb),
1009                                TCM_VHOST_MAX_CDB_SIZE);
1010                        goto err_free;
1011                }
1012                tv_cmd->tvc_lun = ((v_req.lun[2] << 8) | v_req.lun[3]) & 0x3FFF;
1013
1014                pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",
1015                        tv_cmd->tvc_cdb[0], tv_cmd->tvc_lun);
1016
1017                if (data_direction != DMA_NONE) {
1018                        ret = vhost_scsi_map_iov_to_sgl(tv_cmd,
1019                                        &vq->iov[data_first], data_num,
1020                                        data_direction == DMA_TO_DEVICE);
1021                        if (unlikely(ret)) {
1022                                vq_err(vq, "Failed to map iov to sgl\n");
1023                                goto err_free;
1024                        }
1025                }
1026
1027                /*
1028                 * Save the descriptor from vhost_get_vq_desc() to be used to
1029                 * complete the virtio-scsi request in TCM callback context via
1030                 * tcm_vhost_queue_data_in() and tcm_vhost_queue_status()
1031                 */
1032                tv_cmd->tvc_vq_desc = head;
1033                /*
1034                 * Dispatch tv_cmd descriptor for cmwq execution in process
1035                 * context provided by tcm_vhost_workqueue.  This also ensures
1036                 * tv_cmd is executed on the same kworker CPU as this vhost
1037                 * thread to gain positive L2 cache locality effects..
1038                 */
1039                INIT_WORK(&tv_cmd->work, tcm_vhost_submission_work);
1040                queue_work(tcm_vhost_workqueue, &tv_cmd->work);
1041        }
1042
1043        mutex_unlock(&vq->mutex);
1044        return;
1045
1046err_free:
1047        vhost_scsi_free_cmd(tv_cmd);
1048err_cmd:
1049        vhost_scsi_send_bad_target(vs, vq, head, out);
1050        mutex_unlock(&vq->mutex);
1051}
1052
1053static void vhost_scsi_ctl_handle_kick(struct vhost_work *work)
1054{
1055        pr_debug("%s: The handling func for control queue.\n", __func__);
1056}
1057
1058static void tcm_vhost_send_evt(struct vhost_scsi *vs, struct tcm_vhost_tpg *tpg,
1059        struct se_lun *lun, u32 event, u32 reason)
1060{
1061        struct tcm_vhost_evt *evt;
1062
1063        evt = tcm_vhost_allocate_evt(vs, event, reason);
1064        if (!evt)
1065                return;
1066
1067        if (tpg && lun) {
1068                /* TODO: share lun setup code with virtio-scsi.ko */
1069                /*
1070                 * Note: evt->event is zeroed when we allocate it and
1071                 * lun[4-7] need to be zero according to virtio-scsi spec.
1072                 */
1073                evt->event.lun[0] = 0x01;
1074                evt->event.lun[1] = tpg->tport_tpgt & 0xFF;
1075                if (lun->unpacked_lun >= 256)
1076                        evt->event.lun[2] = lun->unpacked_lun >> 8 | 0x40 ;
1077                evt->event.lun[3] = lun->unpacked_lun & 0xFF;
1078        }
1079
1080        llist_add(&evt->list, &vs->vs_event_list);
1081        vhost_work_queue(&vs->dev, &vs->vs_event_work);
1082}
1083
1084static void vhost_scsi_evt_handle_kick(struct vhost_work *work)
1085{
1086        struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1087                                                poll.work);
1088        struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1089
1090        mutex_lock(&vq->mutex);
1091        if (!vq->private_data)
1092                goto out;
1093
1094        if (vs->vs_events_missed)
1095                tcm_vhost_send_evt(vs, NULL, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
1096out:
1097        mutex_unlock(&vq->mutex);
1098}
1099
1100static void vhost_scsi_handle_kick(struct vhost_work *work)
1101{
1102        struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1103                                                poll.work);
1104        struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1105
1106        vhost_scsi_handle_vq(vs, vq);
1107}
1108
1109static void vhost_scsi_flush_vq(struct vhost_scsi *vs, int index)
1110{
1111        vhost_poll_flush(&vs->vqs[index].vq.poll);
1112}
1113
1114/* Callers must hold dev mutex */
1115static void vhost_scsi_flush(struct vhost_scsi *vs)
1116{
1117        struct vhost_scsi_inflight *old_inflight[VHOST_SCSI_MAX_VQ];
1118        int i;
1119
1120        /* Init new inflight and remember the old inflight */
1121        tcm_vhost_init_inflight(vs, old_inflight);
1122
1123        /*
1124         * The inflight->kref was initialized to 1. We decrement it here to
1125         * indicate the start of the flush operation so that it will reach 0
1126         * when all the reqs are finished.
1127         */
1128        for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1129                kref_put(&old_inflight[i]->kref, tcm_vhost_done_inflight);
1130
1131        /* Flush both the vhost poll and vhost work */
1132        for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1133                vhost_scsi_flush_vq(vs, i);
1134        vhost_work_flush(&vs->dev, &vs->vs_completion_work);
1135        vhost_work_flush(&vs->dev, &vs->vs_event_work);
1136
1137        /* Wait for all reqs issued before the flush to be finished */
1138        for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
1139                wait_for_completion(&old_inflight[i]->comp);
1140}
1141
1142/*
1143 * Called from vhost_scsi_ioctl() context to walk the list of available
1144 * tcm_vhost_tpg with an active struct tcm_vhost_nexus
1145 *
1146 *  The lock nesting rule is:
1147 *    tcm_vhost_mutex -> vs->dev.mutex -> tpg->tv_tpg_mutex -> vq->mutex
1148 */
1149static int vhost_scsi_set_endpoint(
1150        struct vhost_scsi *vs,
1151        struct vhost_scsi_target *t)
1152{
1153        struct tcm_vhost_tport *tv_tport;
1154        struct tcm_vhost_tpg *tv_tpg;
1155        struct tcm_vhost_tpg **vs_tpg;
1156        struct vhost_virtqueue *vq;
1157        int index, ret, i, len;
1158        bool match = false;
1159
1160        mutex_lock(&tcm_vhost_mutex);
1161        mutex_lock(&vs->dev.mutex);
1162
1163        /* Verify that ring has been setup correctly. */
1164        for (index = 0; index < vs->dev.nvqs; ++index) {
1165                /* Verify that ring has been setup correctly. */
1166                if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1167                        ret = -EFAULT;
1168                        goto out;
1169                }
1170        }
1171
1172        len = sizeof(vs_tpg[0]) * VHOST_SCSI_MAX_TARGET;
1173        vs_tpg = kzalloc(len, GFP_KERNEL);
1174        if (!vs_tpg) {
1175                ret = -ENOMEM;
1176                goto out;
1177        }
1178        if (vs->vs_tpg)
1179                memcpy(vs_tpg, vs->vs_tpg, len);
1180
1181        list_for_each_entry(tv_tpg, &tcm_vhost_list, tv_tpg_list) {
1182                mutex_lock(&tv_tpg->tv_tpg_mutex);
1183                if (!tv_tpg->tpg_nexus) {
1184                        mutex_unlock(&tv_tpg->tv_tpg_mutex);
1185                        continue;
1186                }
1187                if (tv_tpg->tv_tpg_vhost_count != 0) {
1188                        mutex_unlock(&tv_tpg->tv_tpg_mutex);
1189                        continue;
1190                }
1191                tv_tport = tv_tpg->tport;
1192
1193                if (!strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1194                        if (vs->vs_tpg && vs->vs_tpg[tv_tpg->tport_tpgt]) {
1195                                kfree(vs_tpg);
1196                                mutex_unlock(&tv_tpg->tv_tpg_mutex);
1197                                ret = -EEXIST;
1198                                goto out;
1199                        }
1200                        tv_tpg->tv_tpg_vhost_count++;
1201                        tv_tpg->vhost_scsi = vs;
1202                        vs_tpg[tv_tpg->tport_tpgt] = tv_tpg;
1203                        smp_mb__after_atomic_inc();
1204                        match = true;
1205                }
1206                mutex_unlock(&tv_tpg->tv_tpg_mutex);
1207        }
1208
1209        if (match) {
1210                memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn,
1211                       sizeof(vs->vs_vhost_wwpn));
1212                for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1213                        vq = &vs->vqs[i].vq;
1214                        /* Flushing the vhost_work acts as synchronize_rcu */
1215                        mutex_lock(&vq->mutex);
1216                        rcu_assign_pointer(vq->private_data, vs_tpg);
1217                        vhost_init_used(vq);
1218                        mutex_unlock(&vq->mutex);
1219                }
1220                ret = 0;
1221        } else {
1222                ret = -EEXIST;
1223        }
1224
1225        /*
1226         * Act as synchronize_rcu to make sure access to
1227         * old vs->vs_tpg is finished.
1228         */
1229        vhost_scsi_flush(vs);
1230        kfree(vs->vs_tpg);
1231        vs->vs_tpg = vs_tpg;
1232
1233out:
1234        mutex_unlock(&vs->dev.mutex);
1235        mutex_unlock(&tcm_vhost_mutex);
1236        return ret;
1237}
1238
1239static int vhost_scsi_clear_endpoint(
1240        struct vhost_scsi *vs,
1241        struct vhost_scsi_target *t)
1242{
1243        struct tcm_vhost_tport *tv_tport;
1244        struct tcm_vhost_tpg *tv_tpg;
1245        struct vhost_virtqueue *vq;
1246        bool match = false;
1247        int index, ret, i;
1248        u8 target;
1249
1250        mutex_lock(&tcm_vhost_mutex);
1251        mutex_lock(&vs->dev.mutex);
1252        /* Verify that ring has been setup correctly. */
1253        for (index = 0; index < vs->dev.nvqs; ++index) {
1254                if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1255                        ret = -EFAULT;
1256                        goto err_dev;
1257                }
1258        }
1259
1260        if (!vs->vs_tpg) {
1261                ret = 0;
1262                goto err_dev;
1263        }
1264
1265        for (i = 0; i < VHOST_SCSI_MAX_TARGET; i++) {
1266                target = i;
1267                tv_tpg = vs->vs_tpg[target];
1268                if (!tv_tpg)
1269                        continue;
1270
1271                mutex_lock(&tv_tpg->tv_tpg_mutex);
1272                tv_tport = tv_tpg->tport;
1273                if (!tv_tport) {
1274                        ret = -ENODEV;
1275                        goto err_tpg;
1276                }
1277
1278                if (strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1279                        pr_warn("tv_tport->tport_name: %s, tv_tpg->tport_tpgt: %hu"
1280                                " does not match t->vhost_wwpn: %s, t->vhost_tpgt: %hu\n",
1281                                tv_tport->tport_name, tv_tpg->tport_tpgt,
1282                                t->vhost_wwpn, t->vhost_tpgt);
1283                        ret = -EINVAL;
1284                        goto err_tpg;
1285                }
1286                tv_tpg->tv_tpg_vhost_count--;
1287                tv_tpg->vhost_scsi = NULL;
1288                vs->vs_tpg[target] = NULL;
1289                match = true;
1290                mutex_unlock(&tv_tpg->tv_tpg_mutex);
1291        }
1292        if (match) {
1293                for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
1294                        vq = &vs->vqs[i].vq;
1295                        /* Flushing the vhost_work acts as synchronize_rcu */
1296                        mutex_lock(&vq->mutex);
1297                        rcu_assign_pointer(vq->private_data, NULL);
1298                        mutex_unlock(&vq->mutex);
1299                }
1300        }
1301        /*
1302         * Act as synchronize_rcu to make sure access to
1303         * old vs->vs_tpg is finished.
1304         */
1305        vhost_scsi_flush(vs);
1306        kfree(vs->vs_tpg);
1307        vs->vs_tpg = NULL;
1308        WARN_ON(vs->vs_events_nr);
1309        mutex_unlock(&vs->dev.mutex);
1310        mutex_unlock(&tcm_vhost_mutex);
1311        return 0;
1312
1313err_tpg:
1314        mutex_unlock(&tv_tpg->tv_tpg_mutex);
1315err_dev:
1316        mutex_unlock(&vs->dev.mutex);
1317        mutex_unlock(&tcm_vhost_mutex);
1318        return ret;
1319}
1320
1321static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
1322{
1323        if (features & ~VHOST_SCSI_FEATURES)
1324                return -EOPNOTSUPP;
1325
1326        mutex_lock(&vs->dev.mutex);
1327        if ((features & (1 << VHOST_F_LOG_ALL)) &&
1328            !vhost_log_access_ok(&vs->dev)) {
1329                mutex_unlock(&vs->dev.mutex);
1330                return -EFAULT;
1331        }
1332        vs->dev.acked_features = features;
1333        smp_wmb();
1334        vhost_scsi_flush(vs);
1335        mutex_unlock(&vs->dev.mutex);
1336        return 0;
1337}
1338
1339static int vhost_scsi_open(struct inode *inode, struct file *f)
1340{
1341        struct vhost_scsi *s;
1342        struct vhost_virtqueue **vqs;
1343        int r, i;
1344
1345        s = kzalloc(sizeof(*s), GFP_KERNEL);
1346        if (!s)
1347                return -ENOMEM;
1348
1349        vqs = kmalloc(VHOST_SCSI_MAX_VQ * sizeof(*vqs), GFP_KERNEL);
1350        if (!vqs) {
1351                kfree(s);
1352                return -ENOMEM;
1353        }
1354
1355        vhost_work_init(&s->vs_completion_work, vhost_scsi_complete_cmd_work);
1356        vhost_work_init(&s->vs_event_work, tcm_vhost_evt_work);
1357
1358        s->vs_events_nr = 0;
1359        s->vs_events_missed = false;
1360
1361        vqs[VHOST_SCSI_VQ_CTL] = &s->vqs[VHOST_SCSI_VQ_CTL].vq;
1362        vqs[VHOST_SCSI_VQ_EVT] = &s->vqs[VHOST_SCSI_VQ_EVT].vq;
1363        s->vqs[VHOST_SCSI_VQ_CTL].vq.handle_kick = vhost_scsi_ctl_handle_kick;
1364        s->vqs[VHOST_SCSI_VQ_EVT].vq.handle_kick = vhost_scsi_evt_handle_kick;
1365        for (i = VHOST_SCSI_VQ_IO; i < VHOST_SCSI_MAX_VQ; i++) {
1366                vqs[i] = &s->vqs[i].vq;
1367                s->vqs[i].vq.handle_kick = vhost_scsi_handle_kick;
1368        }
1369        r = vhost_dev_init(&s->dev, vqs, VHOST_SCSI_MAX_VQ);
1370
1371        tcm_vhost_init_inflight(s, NULL);
1372
1373        if (r < 0) {
1374                kfree(vqs);
1375                kfree(s);
1376                return r;
1377        }
1378
1379        f->private_data = s;
1380        return 0;
1381}
1382
1383static int vhost_scsi_release(struct inode *inode, struct file *f)
1384{
1385        struct vhost_scsi *s = f->private_data;
1386        struct vhost_scsi_target t;
1387
1388        mutex_lock(&s->dev.mutex);
1389        memcpy(t.vhost_wwpn, s->vs_vhost_wwpn, sizeof(t.vhost_wwpn));
1390        mutex_unlock(&s->dev.mutex);
1391        vhost_scsi_clear_endpoint(s, &t);
1392        vhost_dev_stop(&s->dev);
1393        vhost_dev_cleanup(&s->dev, false);
1394        /* Jobs can re-queue themselves in evt kick handler. Do extra flush. */
1395        vhost_scsi_flush(s);
1396        kfree(s->dev.vqs);
1397        kfree(s);
1398        return 0;
1399}
1400
1401static long vhost_scsi_ioctl(struct file *f, unsigned int ioctl,
1402                                unsigned long arg)
1403{
1404        struct vhost_scsi *vs = f->private_data;
1405        struct vhost_scsi_target backend;
1406        void __user *argp = (void __user *)arg;
1407        u64 __user *featurep = argp;
1408        u32 __user *eventsp = argp;
1409        u32 events_missed;
1410        u64 features;
1411        int r, abi_version = VHOST_SCSI_ABI_VERSION;
1412        struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1413
1414        switch (ioctl) {
1415        case VHOST_SCSI_SET_ENDPOINT:
1416                if (copy_from_user(&backend, argp, sizeof backend))
1417                        return -EFAULT;
1418                if (backend.reserved != 0)
1419                        return -EOPNOTSUPP;
1420
1421                return vhost_scsi_set_endpoint(vs, &backend);
1422        case VHOST_SCSI_CLEAR_ENDPOINT:
1423                if (copy_from_user(&backend, argp, sizeof backend))
1424                        return -EFAULT;
1425                if (backend.reserved != 0)
1426                        return -EOPNOTSUPP;
1427
1428                return vhost_scsi_clear_endpoint(vs, &backend);
1429        case VHOST_SCSI_GET_ABI_VERSION:
1430                if (copy_to_user(argp, &abi_version, sizeof abi_version))
1431                        return -EFAULT;
1432                return 0;
1433        case VHOST_SCSI_SET_EVENTS_MISSED:
1434                if (get_user(events_missed, eventsp))
1435                        return -EFAULT;
1436                mutex_lock(&vq->mutex);
1437                vs->vs_events_missed = events_missed;
1438                mutex_unlock(&vq->mutex);
1439                return 0;
1440        case VHOST_SCSI_GET_EVENTS_MISSED:
1441                mutex_lock(&vq->mutex);
1442                events_missed = vs->vs_events_missed;
1443                mutex_unlock(&vq->mutex);
1444                if (put_user(events_missed, eventsp))
1445                        return -EFAULT;
1446                return 0;
1447        case VHOST_GET_FEATURES:
1448                features = VHOST_SCSI_FEATURES;
1449                if (copy_to_user(featurep, &features, sizeof features))
1450                        return -EFAULT;
1451                return 0;
1452        case VHOST_SET_FEATURES:
1453                if (copy_from_user(&features, featurep, sizeof features))
1454                        return -EFAULT;
1455                return vhost_scsi_set_features(vs, features);
1456        default:
1457                mutex_lock(&vs->dev.mutex);
1458                r = vhost_dev_ioctl(&vs->dev, ioctl, argp);
1459                /* TODO: flush backend after dev ioctl. */
1460                if (r == -ENOIOCTLCMD)
1461                        r = vhost_vring_ioctl(&vs->dev, ioctl, argp);
1462                mutex_unlock(&vs->dev.mutex);
1463                return r;
1464        }
1465}
1466
1467#ifdef CONFIG_COMPAT
1468static long vhost_scsi_compat_ioctl(struct file *f, unsigned int ioctl,
1469                                unsigned long arg)
1470{
1471        return vhost_scsi_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
1472}
1473#endif
1474
1475static const struct file_operations vhost_scsi_fops = {
1476        .owner          = THIS_MODULE,
1477        .release        = vhost_scsi_release,
1478        .unlocked_ioctl = vhost_scsi_ioctl,
1479#ifdef CONFIG_COMPAT
1480        .compat_ioctl   = vhost_scsi_compat_ioctl,
1481#endif
1482        .open           = vhost_scsi_open,
1483        .llseek         = noop_llseek,
1484};
1485
1486static struct miscdevice vhost_scsi_misc = {
1487        MISC_DYNAMIC_MINOR,
1488        "vhost-scsi",
1489        &vhost_scsi_fops,
1490};
1491
1492static int __init vhost_scsi_register(void)
1493{
1494        return misc_register(&vhost_scsi_misc);
1495}
1496
1497static int vhost_scsi_deregister(void)
1498{
1499        return misc_deregister(&vhost_scsi_misc);
1500}
1501
1502static char *tcm_vhost_dump_proto_id(struct tcm_vhost_tport *tport)
1503{
1504        switch (tport->tport_proto_id) {
1505        case SCSI_PROTOCOL_SAS:
1506                return "SAS";
1507        case SCSI_PROTOCOL_FCP:
1508                return "FCP";
1509        case SCSI_PROTOCOL_ISCSI:
1510                return "iSCSI";
1511        default:
1512                break;
1513        }
1514
1515        return "Unknown";
1516}
1517
1518static void tcm_vhost_do_plug(struct tcm_vhost_tpg *tpg,
1519        struct se_lun *lun, bool plug)
1520{
1521
1522        struct vhost_scsi *vs = tpg->vhost_scsi;
1523        struct vhost_virtqueue *vq;
1524        u32 reason;
1525
1526        if (!vs)
1527                return;
1528
1529        mutex_lock(&vs->dev.mutex);
1530        if (!vhost_has_feature(&vs->dev, VIRTIO_SCSI_F_HOTPLUG)) {
1531                mutex_unlock(&vs->dev.mutex);
1532                return;
1533        }
1534
1535        if (plug)
1536                reason = VIRTIO_SCSI_EVT_RESET_RESCAN;
1537        else
1538                reason = VIRTIO_SCSI_EVT_RESET_REMOVED;
1539
1540        vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1541        mutex_lock(&vq->mutex);
1542        tcm_vhost_send_evt(vs, tpg, lun,
1543                        VIRTIO_SCSI_T_TRANSPORT_RESET, reason);
1544        mutex_unlock(&vq->mutex);
1545        mutex_unlock(&vs->dev.mutex);
1546}
1547
1548static void tcm_vhost_hotplug(struct tcm_vhost_tpg *tpg, struct se_lun *lun)
1549{
1550        tcm_vhost_do_plug(tpg, lun, true);
1551}
1552
1553static void tcm_vhost_hotunplug(struct tcm_vhost_tpg *tpg, struct se_lun *lun)
1554{
1555        tcm_vhost_do_plug(tpg, lun, false);
1556}
1557
1558static int tcm_vhost_port_link(struct se_portal_group *se_tpg,
1559        struct se_lun *lun)
1560{
1561        struct tcm_vhost_tpg *tv_tpg = container_of(se_tpg,
1562                                struct tcm_vhost_tpg, se_tpg);
1563
1564        mutex_lock(&tcm_vhost_mutex);
1565
1566        mutex_lock(&tv_tpg->tv_tpg_mutex);
1567        tv_tpg->tv_tpg_port_count++;
1568        mutex_unlock(&tv_tpg->tv_tpg_mutex);
1569
1570        tcm_vhost_hotplug(tv_tpg, lun);
1571
1572        mutex_unlock(&tcm_vhost_mutex);
1573
1574        return 0;
1575}
1576
1577static void tcm_vhost_port_unlink(struct se_portal_group *se_tpg,
1578        struct se_lun *lun)
1579{
1580        struct tcm_vhost_tpg *tv_tpg = container_of(se_tpg,
1581                                struct tcm_vhost_tpg, se_tpg);
1582
1583        mutex_lock(&tcm_vhost_mutex);
1584
1585        mutex_lock(&tv_tpg->tv_tpg_mutex);
1586        tv_tpg->tv_tpg_port_count--;
1587        mutex_unlock(&tv_tpg->tv_tpg_mutex);
1588
1589        tcm_vhost_hotunplug(tv_tpg, lun);
1590
1591        mutex_unlock(&tcm_vhost_mutex);
1592}
1593
1594static struct se_node_acl *tcm_vhost_make_nodeacl(
1595        struct se_portal_group *se_tpg,
1596        struct config_group *group,
1597        const char *name)
1598{
1599        struct se_node_acl *se_nacl, *se_nacl_new;
1600        struct tcm_vhost_nacl *nacl;
1601        u64 wwpn = 0;
1602        u32 nexus_depth;
1603
1604        /* tcm_vhost_parse_wwn(name, &wwpn, 1) < 0)
1605                return ERR_PTR(-EINVAL); */
1606        se_nacl_new = tcm_vhost_alloc_fabric_acl(se_tpg);
1607        if (!se_nacl_new)
1608                return ERR_PTR(-ENOMEM);
1609
1610        nexus_depth = 1;
1611        /*
1612         * se_nacl_new may be released by core_tpg_add_initiator_node_acl()
1613         * when converting a NodeACL from demo mode -> explict
1614         */
1615        se_nacl = core_tpg_add_initiator_node_acl(se_tpg, se_nacl_new,
1616                                name, nexus_depth);
1617        if (IS_ERR(se_nacl)) {
1618                tcm_vhost_release_fabric_acl(se_tpg, se_nacl_new);
1619                return se_nacl;
1620        }
1621        /*
1622         * Locate our struct tcm_vhost_nacl and set the FC Nport WWPN
1623         */
1624        nacl = container_of(se_nacl, struct tcm_vhost_nacl, se_node_acl);
1625        nacl->iport_wwpn = wwpn;
1626
1627        return se_nacl;
1628}
1629
1630static void tcm_vhost_drop_nodeacl(struct se_node_acl *se_acl)
1631{
1632        struct tcm_vhost_nacl *nacl = container_of(se_acl,
1633                                struct tcm_vhost_nacl, se_node_acl);
1634        core_tpg_del_initiator_node_acl(se_acl->se_tpg, se_acl, 1);
1635        kfree(nacl);
1636}
1637
1638static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tv_tpg,
1639        const char *name)
1640{
1641        struct se_portal_group *se_tpg;
1642        struct tcm_vhost_nexus *tv_nexus;
1643
1644        mutex_lock(&tv_tpg->tv_tpg_mutex);
1645        if (tv_tpg->tpg_nexus) {
1646                mutex_unlock(&tv_tpg->tv_tpg_mutex);
1647                pr_debug("tv_tpg->tpg_nexus already exists\n");
1648                return -EEXIST;
1649        }
1650        se_tpg = &tv_tpg->se_tpg;
1651
1652        tv_nexus = kzalloc(sizeof(struct tcm_vhost_nexus), GFP_KERNEL);
1653        if (!tv_nexus) {
1654                mutex_unlock(&tv_tpg->tv_tpg_mutex);
1655                pr_err("Unable to allocate struct tcm_vhost_nexus\n");
1656                return -ENOMEM;
1657        }
1658        /*
1659         *  Initialize the struct se_session pointer
1660         */
1661        tv_nexus->tvn_se_sess = transport_init_session();
1662        if (IS_ERR(tv_nexus->tvn_se_sess)) {
1663                mutex_unlock(&tv_tpg->tv_tpg_mutex);
1664                kfree(tv_nexus);
1665                return -ENOMEM;
1666        }
1667        /*
1668         * Since we are running in 'demo mode' this call with generate a
1669         * struct se_node_acl for the tcm_vhost struct se_portal_group with
1670         * the SCSI Initiator port name of the passed configfs group 'name'.
1671         */
1672        tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1673                                se_tpg, (unsigned char *)name);
1674        if (!tv_nexus->tvn_se_sess->se_node_acl) {
1675                mutex_unlock(&tv_tpg->tv_tpg_mutex);
1676                pr_debug("core_tpg_check_initiator_node_acl() failed"
1677                                " for %s\n", name);
1678                transport_free_session(tv_nexus->tvn_se_sess);
1679                kfree(tv_nexus);
1680                return -ENOMEM;
1681        }
1682        /*
1683         * Now register the TCM vhost virtual I_T Nexus as active with the
1684         * call to __transport_register_session()
1685         */
1686        __transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
1687                        tv_nexus->tvn_se_sess, tv_nexus);
1688        tv_tpg->tpg_nexus = tv_nexus;
1689
1690        mutex_unlock(&tv_tpg->tv_tpg_mutex);
1691        return 0;
1692}
1693
1694static int tcm_vhost_drop_nexus(struct tcm_vhost_tpg *tpg)
1695{
1696        struct se_session *se_sess;
1697        struct tcm_vhost_nexus *tv_nexus;
1698
1699        mutex_lock(&tpg->tv_tpg_mutex);
1700        tv_nexus = tpg->tpg_nexus;
1701        if (!tv_nexus) {
1702                mutex_unlock(&tpg->tv_tpg_mutex);
1703                return -ENODEV;
1704        }
1705
1706        se_sess = tv_nexus->tvn_se_sess;
1707        if (!se_sess) {
1708                mutex_unlock(&tpg->tv_tpg_mutex);
1709                return -ENODEV;
1710        }
1711
1712        if (tpg->tv_tpg_port_count != 0) {
1713                mutex_unlock(&tpg->tv_tpg_mutex);
1714                pr_err("Unable to remove TCM_vhost I_T Nexus with"
1715                        " active TPG port count: %d\n",
1716                        tpg->tv_tpg_port_count);
1717                return -EBUSY;
1718        }
1719
1720        if (tpg->tv_tpg_vhost_count != 0) {
1721                mutex_unlock(&tpg->tv_tpg_mutex);
1722                pr_err("Unable to remove TCM_vhost I_T Nexus with"
1723                        " active TPG vhost count: %d\n",
1724                        tpg->tv_tpg_vhost_count);
1725                return -EBUSY;
1726        }
1727
1728        pr_debug("TCM_vhost_ConfigFS: Removing I_T Nexus to emulated"
1729                " %s Initiator Port: %s\n", tcm_vhost_dump_proto_id(tpg->tport),
1730                tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1731        /*
1732         * Release the SCSI I_T Nexus to the emulated vhost Target Port
1733         */
1734        transport_deregister_session(tv_nexus->tvn_se_sess);
1735        tpg->tpg_nexus = NULL;
1736        mutex_unlock(&tpg->tv_tpg_mutex);
1737
1738        kfree(tv_nexus);
1739        return 0;
1740}
1741
1742static ssize_t tcm_vhost_tpg_show_nexus(struct se_portal_group *se_tpg,
1743        char *page)
1744{
1745        struct tcm_vhost_tpg *tv_tpg = container_of(se_tpg,
1746                                struct tcm_vhost_tpg, se_tpg);
1747        struct tcm_vhost_nexus *tv_nexus;
1748        ssize_t ret;
1749
1750        mutex_lock(&tv_tpg->tv_tpg_mutex);
1751        tv_nexus = tv_tpg->tpg_nexus;
1752        if (!tv_nexus) {
1753                mutex_unlock(&tv_tpg->tv_tpg_mutex);
1754                return -ENODEV;
1755        }
1756        ret = snprintf(page, PAGE_SIZE, "%s\n",
1757                        tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
1758        mutex_unlock(&tv_tpg->tv_tpg_mutex);
1759
1760        return ret;
1761}
1762
1763static ssize_t tcm_vhost_tpg_store_nexus(struct se_portal_group *se_tpg,
1764        const char *page,
1765        size_t count)
1766{
1767        struct tcm_vhost_tpg *tv_tpg = container_of(se_tpg,
1768                                struct tcm_vhost_tpg, se_tpg);
1769        struct tcm_vhost_tport *tport_wwn = tv_tpg->tport;
1770        unsigned char i_port[TCM_VHOST_NAMELEN], *ptr, *port_ptr;
1771        int ret;
1772        /*
1773         * Shutdown the active I_T nexus if 'NULL' is passed..
1774         */
1775        if (!strncmp(page, "NULL", 4)) {
1776                ret = tcm_vhost_drop_nexus(tv_tpg);
1777                return (!ret) ? count : ret;
1778        }
1779        /*
1780         * Otherwise make sure the passed virtual Initiator port WWN matches
1781         * the fabric protocol_id set in tcm_vhost_make_tport(), and call
1782         * tcm_vhost_make_nexus().
1783         */
1784        if (strlen(page) >= TCM_VHOST_NAMELEN) {
1785                pr_err("Emulated NAA Sas Address: %s, exceeds"
1786                                " max: %d\n", page, TCM_VHOST_NAMELEN);
1787                return -EINVAL;
1788        }
1789        snprintf(&i_port[0], TCM_VHOST_NAMELEN, "%s", page);
1790
1791        ptr = strstr(i_port, "naa.");
1792        if (ptr) {
1793                if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
1794                        pr_err("Passed SAS Initiator Port %s does not"
1795                                " match target port protoid: %s\n", i_port,
1796                                tcm_vhost_dump_proto_id(tport_wwn));
1797                        return -EINVAL;
1798                }
1799                port_ptr = &i_port[0];
1800                goto check_newline;
1801        }
1802        ptr = strstr(i_port, "fc.");
1803        if (ptr) {
1804                if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
1805                        pr_err("Passed FCP Initiator Port %s does not"
1806                                " match target port protoid: %s\n", i_port,
1807                                tcm_vhost_dump_proto_id(tport_wwn));
1808                        return -EINVAL;
1809                }
1810                port_ptr = &i_port[3]; /* Skip over "fc." */
1811                goto check_newline;
1812        }
1813        ptr = strstr(i_port, "iqn.");
1814        if (ptr) {
1815                if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
1816                        pr_err("Passed iSCSI Initiator Port %s does not"
1817                                " match target port protoid: %s\n", i_port,
1818                                tcm_vhost_dump_proto_id(tport_wwn));
1819                        return -EINVAL;
1820                }
1821                port_ptr = &i_port[0];
1822                goto check_newline;
1823        }
1824        pr_err("Unable to locate prefix for emulated Initiator Port:"
1825                        " %s\n", i_port);
1826        return -EINVAL;
1827        /*
1828         * Clear any trailing newline for the NAA WWN
1829         */
1830check_newline:
1831        if (i_port[strlen(i_port)-1] == '\n')
1832                i_port[strlen(i_port)-1] = '\0';
1833
1834        ret = tcm_vhost_make_nexus(tv_tpg, port_ptr);
1835        if (ret < 0)
1836                return ret;
1837
1838        return count;
1839}
1840
1841TF_TPG_BASE_ATTR(tcm_vhost, nexus, S_IRUGO | S_IWUSR);
1842
1843static struct configfs_attribute *tcm_vhost_tpg_attrs[] = {
1844        &tcm_vhost_tpg_nexus.attr,
1845        NULL,
1846};
1847
1848static struct se_portal_group *tcm_vhost_make_tpg(struct se_wwn *wwn,
1849        struct config_group *group,
1850        const char *name)
1851{
1852        struct tcm_vhost_tport *tport = container_of(wwn,
1853                        struct tcm_vhost_tport, tport_wwn);
1854
1855        struct tcm_vhost_tpg *tpg;
1856        unsigned long tpgt;
1857        int ret;
1858
1859        if (strstr(name, "tpgt_") != name)
1860                return ERR_PTR(-EINVAL);
1861        if (kstrtoul(name + 5, 10, &tpgt) || tpgt > UINT_MAX)
1862                return ERR_PTR(-EINVAL);
1863
1864        tpg = kzalloc(sizeof(struct tcm_vhost_tpg), GFP_KERNEL);
1865        if (!tpg) {
1866                pr_err("Unable to allocate struct tcm_vhost_tpg");
1867                return ERR_PTR(-ENOMEM);
1868        }
1869        mutex_init(&tpg->tv_tpg_mutex);
1870        INIT_LIST_HEAD(&tpg->tv_tpg_list);
1871        tpg->tport = tport;
1872        tpg->tport_tpgt = tpgt;
1873
1874        ret = core_tpg_register(&tcm_vhost_fabric_configfs->tf_ops, wwn,
1875                                &tpg->se_tpg, tpg, TRANSPORT_TPG_TYPE_NORMAL);
1876        if (ret < 0) {
1877                kfree(tpg);
1878                return NULL;
1879        }
1880        mutex_lock(&tcm_vhost_mutex);
1881        list_add_tail(&tpg->tv_tpg_list, &tcm_vhost_list);
1882        mutex_unlock(&tcm_vhost_mutex);
1883
1884        return &tpg->se_tpg;
1885}
1886
1887static void tcm_vhost_drop_tpg(struct se_portal_group *se_tpg)
1888{
1889        struct tcm_vhost_tpg *tpg = container_of(se_tpg,
1890                                struct tcm_vhost_tpg, se_tpg);
1891
1892        mutex_lock(&tcm_vhost_mutex);
1893        list_del(&tpg->tv_tpg_list);
1894        mutex_unlock(&tcm_vhost_mutex);
1895        /*
1896         * Release the virtual I_T Nexus for this vhost TPG
1897         */
1898        tcm_vhost_drop_nexus(tpg);
1899        /*
1900         * Deregister the se_tpg from TCM..
1901         */
1902        core_tpg_deregister(se_tpg);
1903        kfree(tpg);
1904}
1905
1906static struct se_wwn *tcm_vhost_make_tport(struct target_fabric_configfs *tf,
1907        struct config_group *group,
1908        const char *name)
1909{
1910        struct tcm_vhost_tport *tport;
1911        char *ptr;
1912        u64 wwpn = 0;
1913        int off = 0;
1914
1915        /* if (tcm_vhost_parse_wwn(name, &wwpn, 1) < 0)
1916                return ERR_PTR(-EINVAL); */
1917
1918        tport = kzalloc(sizeof(struct tcm_vhost_tport), GFP_KERNEL);
1919        if (!tport) {
1920                pr_err("Unable to allocate struct tcm_vhost_tport");
1921                return ERR_PTR(-ENOMEM);
1922        }
1923        tport->tport_wwpn = wwpn;
1924        /*
1925         * Determine the emulated Protocol Identifier and Target Port Name
1926         * based on the incoming configfs directory name.
1927         */
1928        ptr = strstr(name, "naa.");
1929        if (ptr) {
1930                tport->tport_proto_id = SCSI_PROTOCOL_SAS;
1931                goto check_len;
1932        }
1933        ptr = strstr(name, "fc.");
1934        if (ptr) {
1935                tport->tport_proto_id = SCSI_PROTOCOL_FCP;
1936                off = 3; /* Skip over "fc." */
1937                goto check_len;
1938        }
1939        ptr = strstr(name, "iqn.");
1940        if (ptr) {
1941                tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
1942                goto check_len;
1943        }
1944
1945        pr_err("Unable to locate prefix for emulated Target Port:"
1946                        " %s\n", name);
1947        kfree(tport);
1948        return ERR_PTR(-EINVAL);
1949
1950check_len:
1951        if (strlen(name) >= TCM_VHOST_NAMELEN) {
1952                pr_err("Emulated %s Address: %s, exceeds"
1953                        " max: %d\n", name, tcm_vhost_dump_proto_id(tport),
1954                        TCM_VHOST_NAMELEN);
1955                kfree(tport);
1956                return ERR_PTR(-EINVAL);
1957        }
1958        snprintf(&tport->tport_name[0], TCM_VHOST_NAMELEN, "%s", &name[off]);
1959
1960        pr_debug("TCM_VHost_ConfigFS: Allocated emulated Target"
1961                " %s Address: %s\n", tcm_vhost_dump_proto_id(tport), name);
1962
1963        return &tport->tport_wwn;
1964}
1965
1966static void tcm_vhost_drop_tport(struct se_wwn *wwn)
1967{
1968        struct tcm_vhost_tport *tport = container_of(wwn,
1969                                struct tcm_vhost_tport, tport_wwn);
1970
1971        pr_debug("TCM_VHost_ConfigFS: Deallocating emulated Target"
1972                " %s Address: %s\n", tcm_vhost_dump_proto_id(tport),
1973                tport->tport_name);
1974
1975        kfree(tport);
1976}
1977
1978static ssize_t tcm_vhost_wwn_show_attr_version(
1979        struct target_fabric_configfs *tf,
1980        char *page)
1981{
1982        return sprintf(page, "TCM_VHOST fabric module %s on %s/%s"
1983                "on "UTS_RELEASE"\n", TCM_VHOST_VERSION, utsname()->sysname,
1984                utsname()->machine);
1985}
1986
1987TF_WWN_ATTR_RO(tcm_vhost, version);
1988
1989static struct configfs_attribute *tcm_vhost_wwn_attrs[] = {
1990        &tcm_vhost_wwn_version.attr,
1991        NULL,
1992};
1993
1994static struct target_core_fabric_ops tcm_vhost_ops = {
1995        .get_fabric_name                = tcm_vhost_get_fabric_name,
1996        .get_fabric_proto_ident         = tcm_vhost_get_fabric_proto_ident,
1997        .tpg_get_wwn                    = tcm_vhost_get_fabric_wwn,
1998        .tpg_get_tag                    = tcm_vhost_get_tag,
1999        .tpg_get_default_depth          = tcm_vhost_get_default_depth,
2000        .tpg_get_pr_transport_id        = tcm_vhost_get_pr_transport_id,
2001        .tpg_get_pr_transport_id_len    = tcm_vhost_get_pr_transport_id_len,
2002        .tpg_parse_pr_out_transport_id  = tcm_vhost_parse_pr_out_transport_id,
2003        .tpg_check_demo_mode            = tcm_vhost_check_true,
2004        .tpg_check_demo_mode_cache      = tcm_vhost_check_true,
2005        .tpg_check_demo_mode_write_protect = tcm_vhost_check_false,
2006        .tpg_check_prod_mode_write_protect = tcm_vhost_check_false,
2007        .tpg_alloc_fabric_acl           = tcm_vhost_alloc_fabric_acl,
2008        .tpg_release_fabric_acl         = tcm_vhost_release_fabric_acl,
2009        .tpg_get_inst_index             = tcm_vhost_tpg_get_inst_index,
2010        .release_cmd                    = tcm_vhost_release_cmd,
2011        .shutdown_session               = tcm_vhost_shutdown_session,
2012        .close_session                  = tcm_vhost_close_session,
2013        .sess_get_index                 = tcm_vhost_sess_get_index,
2014        .sess_get_initiator_sid         = NULL,
2015        .write_pending                  = tcm_vhost_write_pending,
2016        .write_pending_status           = tcm_vhost_write_pending_status,
2017        .set_default_node_attributes    = tcm_vhost_set_default_node_attrs,
2018        .get_task_tag                   = tcm_vhost_get_task_tag,
2019        .get_cmd_state                  = tcm_vhost_get_cmd_state,
2020        .queue_data_in                  = tcm_vhost_queue_data_in,
2021        .queue_status                   = tcm_vhost_queue_status,
2022        .queue_tm_rsp                   = tcm_vhost_queue_tm_rsp,
2023        /*
2024         * Setup callers for generic logic in target_core_fabric_configfs.c
2025         */
2026        .fabric_make_wwn                = tcm_vhost_make_tport,
2027        .fabric_drop_wwn                = tcm_vhost_drop_tport,
2028        .fabric_make_tpg                = tcm_vhost_make_tpg,
2029        .fabric_drop_tpg                = tcm_vhost_drop_tpg,
2030        .fabric_post_link               = tcm_vhost_port_link,
2031        .fabric_pre_unlink              = tcm_vhost_port_unlink,
2032        .fabric_make_np                 = NULL,
2033        .fabric_drop_np                 = NULL,
2034        .fabric_make_nodeacl            = tcm_vhost_make_nodeacl,
2035        .fabric_drop_nodeacl            = tcm_vhost_drop_nodeacl,
2036};
2037
2038static int tcm_vhost_register_configfs(void)
2039{
2040        struct target_fabric_configfs *fabric;
2041        int ret;
2042
2043        pr_debug("TCM_VHOST fabric module %s on %s/%s"
2044                " on "UTS_RELEASE"\n", TCM_VHOST_VERSION, utsname()->sysname,
2045                utsname()->machine);
2046        /*
2047         * Register the top level struct config_item_type with TCM core
2048         */
2049        fabric = target_fabric_configfs_init(THIS_MODULE, "vhost");
2050        if (IS_ERR(fabric)) {
2051                pr_err("target_fabric_configfs_init() failed\n");
2052                return PTR_ERR(fabric);
2053        }
2054        /*
2055         * Setup fabric->tf_ops from our local tcm_vhost_ops
2056         */
2057        fabric->tf_ops = tcm_vhost_ops;
2058        /*
2059         * Setup default attribute lists for various fabric->tf_cit_tmpl
2060         */
2061        TF_CIT_TMPL(fabric)->tfc_wwn_cit.ct_attrs = tcm_vhost_wwn_attrs;
2062        TF_CIT_TMPL(fabric)->tfc_tpg_base_cit.ct_attrs = tcm_vhost_tpg_attrs;
2063        TF_CIT_TMPL(fabric)->tfc_tpg_attrib_cit.ct_attrs = NULL;
2064        TF_CIT_TMPL(fabric)->tfc_tpg_param_cit.ct_attrs = NULL;
2065        TF_CIT_TMPL(fabric)->tfc_tpg_np_base_cit.ct_attrs = NULL;
2066        TF_CIT_TMPL(fabric)->tfc_tpg_nacl_base_cit.ct_attrs = NULL;
2067        TF_CIT_TMPL(fabric)->tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
2068        TF_CIT_TMPL(fabric)->tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
2069        TF_CIT_TMPL(fabric)->tfc_tpg_nacl_param_cit.ct_attrs = NULL;
2070        /*
2071         * Register the fabric for use within TCM
2072         */
2073        ret = target_fabric_configfs_register(fabric);
2074        if (ret < 0) {
2075                pr_err("target_fabric_configfs_register() failed"
2076                                " for TCM_VHOST\n");
2077                return ret;
2078        }
2079        /*
2080         * Setup our local pointer to *fabric
2081         */
2082        tcm_vhost_fabric_configfs = fabric;
2083        pr_debug("TCM_VHOST[0] - Set fabric -> tcm_vhost_fabric_configfs\n");
2084        return 0;
2085};
2086
2087static void tcm_vhost_deregister_configfs(void)
2088{
2089        if (!tcm_vhost_fabric_configfs)
2090                return;
2091
2092        target_fabric_configfs_deregister(tcm_vhost_fabric_configfs);
2093        tcm_vhost_fabric_configfs = NULL;
2094        pr_debug("TCM_VHOST[0] - Cleared tcm_vhost_fabric_configfs\n");
2095};
2096
2097static int __init tcm_vhost_init(void)
2098{
2099        int ret = -ENOMEM;
2100        /*
2101         * Use our own dedicated workqueue for submitting I/O into
2102         * target core to avoid contention within system_wq.
2103         */
2104        tcm_vhost_workqueue = alloc_workqueue("tcm_vhost", 0, 0);
2105        if (!tcm_vhost_workqueue)
2106                goto out;
2107
2108        ret = vhost_scsi_register();
2109        if (ret < 0)
2110                goto out_destroy_workqueue;
2111
2112        ret = tcm_vhost_register_configfs();
2113        if (ret < 0)
2114                goto out_vhost_scsi_deregister;
2115
2116        return 0;
2117
2118out_vhost_scsi_deregister:
2119        vhost_scsi_deregister();
2120out_destroy_workqueue:
2121        destroy_workqueue(tcm_vhost_workqueue);
2122out:
2123        return ret;
2124};
2125
2126static void tcm_vhost_exit(void)
2127{
2128        tcm_vhost_deregister_configfs();
2129        vhost_scsi_deregister();
2130        destroy_workqueue(tcm_vhost_workqueue);
2131};
2132
2133MODULE_DESCRIPTION("VHOST_SCSI series fabric driver");
2134MODULE_ALIAS("tcm_vhost");
2135MODULE_LICENSE("GPL");
2136module_init(tcm_vhost_init);
2137module_exit(tcm_vhost_exit);
2138
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