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   1// SPDX-License-Identifier: GPL-2.0+
   2/*******************************************************************************
   3 * Vhost kernel TCM fabric driver for virtio SCSI initiators
   4 *
   5 * (C) Copyright 2010-2013 Datera, Inc.
   6 * (C) Copyright 2010-2012 IBM Corp.
   7 *
   8 * Authors: Nicholas A. Bellinger <nab@daterainc.com>
   9 *          Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
  10 ****************************************************************************/
  11
  12#include <linux/module.h>
  13#include <linux/moduleparam.h>
  14#include <generated/utsrelease.h>
  15#include <linux/utsname.h>
  16#include <linux/init.h>
  17#include <linux/slab.h>
  18#include <linux/kthread.h>
  19#include <linux/types.h>
  20#include <linux/string.h>
  21#include <linux/configfs.h>
  22#include <linux/ctype.h>
  23#include <linux/compat.h>
  24#include <linux/eventfd.h>
  25#include <linux/fs.h>
  26#include <linux/vmalloc.h>
  27#include <linux/miscdevice.h>
  28#include <asm/unaligned.h>
  29#include <scsi/scsi_common.h>
  30#include <scsi/scsi_proto.h>
  31#include <target/target_core_base.h>
  32#include <target/target_core_fabric.h>
  33#include <linux/vhost.h>
  34#include <linux/virtio_scsi.h>
  35#include <linux/llist.h>
  36#include <linux/bitmap.h>
  37
  38#include "vhost.h"
  39
  40#define VHOST_SCSI_VERSION  "v0.1"
  41#define VHOST_SCSI_NAMELEN 256
  42#define VHOST_SCSI_MAX_CDB_SIZE 32
  43#define VHOST_SCSI_PREALLOC_SGLS 2048
  44#define VHOST_SCSI_PREALLOC_UPAGES 2048
  45#define VHOST_SCSI_PREALLOC_PROT_SGLS 2048
  46
  47/* Max number of requests before requeueing the job.
  48 * Using this limit prevents one virtqueue from starving others with
  49 * request.
  50 */
  51#define VHOST_SCSI_WEIGHT 256
  52
  53struct vhost_scsi_inflight {
  54	/* Wait for the flush operation to finish */
  55	struct completion comp;
  56	/* Refcount for the inflight reqs */
  57	struct kref kref;
  58};
  59
  60struct vhost_scsi_cmd {
  61	/* Descriptor from vhost_get_vq_desc() for virt_queue segment */
  62	int tvc_vq_desc;
  63	/* virtio-scsi initiator task attribute */
  64	int tvc_task_attr;
  65	/* virtio-scsi response incoming iovecs */
  66	int tvc_in_iovs;
  67	/* virtio-scsi initiator data direction */
  68	enum dma_data_direction tvc_data_direction;
  69	/* Expected data transfer length from virtio-scsi header */
  70	u32 tvc_exp_data_len;
  71	/* The Tag from include/linux/virtio_scsi.h:struct virtio_scsi_cmd_req */
  72	u64 tvc_tag;
  73	/* The number of scatterlists associated with this cmd */
  74	u32 tvc_sgl_count;
  75	u32 tvc_prot_sgl_count;
  76	/* Saved unpacked SCSI LUN for vhost_scsi_target_queue_cmd() */
  77	u32 tvc_lun;
  78	/* Pointer to the SGL formatted memory from virtio-scsi */
  79	struct scatterlist *tvc_sgl;
  80	struct scatterlist *tvc_prot_sgl;
  81	struct page **tvc_upages;
  82	/* Pointer to response header iovec */
  83	struct iovec *tvc_resp_iov;
  84	/* Pointer to vhost_scsi for our device */
  85	struct vhost_scsi *tvc_vhost;
  86	/* Pointer to vhost_virtqueue for the cmd */
  87	struct vhost_virtqueue *tvc_vq;
  88	/* Pointer to vhost nexus memory */
  89	struct vhost_scsi_nexus *tvc_nexus;
  90	/* The TCM I/O descriptor that is accessed via container_of() */
  91	struct se_cmd tvc_se_cmd;
  92	/* Copy of the incoming SCSI command descriptor block (CDB) */
  93	unsigned char tvc_cdb[VHOST_SCSI_MAX_CDB_SIZE];
  94	/* Sense buffer that will be mapped into outgoing status */
  95	unsigned char tvc_sense_buf[TRANSPORT_SENSE_BUFFER];
  96	/* Completed commands list, serviced from vhost worker thread */
  97	struct llist_node tvc_completion_list;
  98	/* Used to track inflight cmd */
  99	struct vhost_scsi_inflight *inflight;
 100};
 101
 102struct vhost_scsi_nexus {
 103	/* Pointer to TCM session for I_T Nexus */
 104	struct se_session *tvn_se_sess;
 105};
 106
 107struct vhost_scsi_tpg {
 108	/* Vhost port target portal group tag for TCM */
 109	u16 tport_tpgt;
 110	/* Used to track number of TPG Port/Lun Links wrt to explict I_T Nexus shutdown */
 111	int tv_tpg_port_count;
 112	/* Used for vhost_scsi device reference to tpg_nexus, protected by tv_tpg_mutex */
 113	int tv_tpg_vhost_count;
 114	/* Used for enabling T10-PI with legacy devices */
 115	int tv_fabric_prot_type;
 116	/* list for vhost_scsi_list */
 117	struct list_head tv_tpg_list;
 118	/* Used to protect access for tpg_nexus */
 119	struct mutex tv_tpg_mutex;
 120	/* Pointer to the TCM VHost I_T Nexus for this TPG endpoint */
 121	struct vhost_scsi_nexus *tpg_nexus;
 122	/* Pointer back to vhost_scsi_tport */
 123	struct vhost_scsi_tport *tport;
 124	/* Returned by vhost_scsi_make_tpg() */
 125	struct se_portal_group se_tpg;
 126	/* Pointer back to vhost_scsi, protected by tv_tpg_mutex */
 127	struct vhost_scsi *vhost_scsi;
 128	struct list_head tmf_queue;
 129};
 130
 131struct vhost_scsi_tport {
 132	/* SCSI protocol the tport is providing */
 133	u8 tport_proto_id;
 134	/* Binary World Wide unique Port Name for Vhost Target port */
 135	u64 tport_wwpn;
 136	/* ASCII formatted WWPN for Vhost Target port */
 137	char tport_name[VHOST_SCSI_NAMELEN];
 138	/* Returned by vhost_scsi_make_tport() */
 139	struct se_wwn tport_wwn;
 140};
 141
 142struct vhost_scsi_evt {
 143	/* event to be sent to guest */
 144	struct virtio_scsi_event event;
 145	/* event list, serviced from vhost worker thread */
 146	struct llist_node list;
 147};
 148
 149enum {
 150	VHOST_SCSI_VQ_CTL = 0,
 151	VHOST_SCSI_VQ_EVT = 1,
 152	VHOST_SCSI_VQ_IO = 2,
 153};
 154
 155/* Note: can't set VIRTIO_F_VERSION_1 yet, since that implies ANY_LAYOUT. */
 156enum {
 157	VHOST_SCSI_FEATURES = VHOST_FEATURES | (1ULL << VIRTIO_SCSI_F_HOTPLUG) |
 158					       (1ULL << VIRTIO_SCSI_F_T10_PI)
 159};
 160
 161#define VHOST_SCSI_MAX_TARGET	256
 162#define VHOST_SCSI_MAX_IO_VQ	1024
 163#define VHOST_SCSI_MAX_EVENT	128
 164
 165static unsigned vhost_scsi_max_io_vqs = 128;
 166module_param_named(max_io_vqs, vhost_scsi_max_io_vqs, uint, 0644);
 167MODULE_PARM_DESC(max_io_vqs, "Set the max number of IO virtqueues a vhost scsi device can support. The default is 128. The max is 1024.");
 168
 169struct vhost_scsi_virtqueue {
 170	struct vhost_virtqueue vq;
 171	/*
 172	 * Reference counting for inflight reqs, used for flush operation. At
 173	 * each time, one reference tracks new commands submitted, while we
 174	 * wait for another one to reach 0.
 175	 */
 176	struct vhost_scsi_inflight inflights[2];
 177	/*
 178	 * Indicate current inflight in use, protected by vq->mutex.
 179	 * Writers must also take dev mutex and flush under it.
 180	 */
 181	int inflight_idx;
 182	struct vhost_scsi_cmd *scsi_cmds;
 183	struct sbitmap scsi_tags;
 184	int max_cmds;
 185};
 186
 187struct vhost_scsi {
 188	/* Protected by vhost_scsi->dev.mutex */
 189	struct vhost_scsi_tpg **vs_tpg;
 190	char vs_vhost_wwpn[TRANSPORT_IQN_LEN];
 191
 192	struct vhost_dev dev;
 193	struct vhost_scsi_virtqueue *vqs;
 194	unsigned long *compl_bitmap;
 195	struct vhost_scsi_inflight **old_inflight;
 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
 207struct vhost_scsi_tmf {
 208	struct vhost_work vwork;
 209	struct vhost_scsi_tpg *tpg;
 210	struct vhost_scsi *vhost;
 211	struct vhost_scsi_virtqueue *svq;
 212	struct list_head queue_entry;
 213
 214	struct se_cmd se_cmd;
 215	u8 scsi_resp;
 216	struct vhost_scsi_inflight *inflight;
 217	struct iovec resp_iov;
 218	int in_iovs;
 219	int vq_desc;
 220};
 221
 222/*
 223 * Context for processing request and control queue operations.
 224 */
 225struct vhost_scsi_ctx {
 226	int head;
 227	unsigned int out, in;
 228	size_t req_size, rsp_size;
 229	size_t out_size, in_size;
 230	u8 *target, *lunp;
 231	void *req;
 232	struct iov_iter out_iter;
 233};
 234
 235/* Global spinlock to protect vhost_scsi TPG list for vhost IOCTL access */
 236static DEFINE_MUTEX(vhost_scsi_mutex);
 237static LIST_HEAD(vhost_scsi_list);
 238
 239static void vhost_scsi_done_inflight(struct kref *kref)
 240{
 241	struct vhost_scsi_inflight *inflight;
 242
 243	inflight = container_of(kref, struct vhost_scsi_inflight, kref);
 244	complete(&inflight->comp);
 245}
 246
 247static void vhost_scsi_init_inflight(struct vhost_scsi *vs,
 248				    struct vhost_scsi_inflight *old_inflight[])
 249{
 250	struct vhost_scsi_inflight *new_inflight;
 251	struct vhost_virtqueue *vq;
 252	int idx, i;
 253
 254	for (i = 0; i < vs->dev.nvqs;  i++) {
 255		vq = &vs->vqs[i].vq;
 256
 257		mutex_lock(&vq->mutex);
 258
 259		/* store old infight */
 260		idx = vs->vqs[i].inflight_idx;
 261		if (old_inflight)
 262			old_inflight[i] = &vs->vqs[i].inflights[idx];
 263
 264		/* setup new infight */
 265		vs->vqs[i].inflight_idx = idx ^ 1;
 266		new_inflight = &vs->vqs[i].inflights[idx ^ 1];
 267		kref_init(&new_inflight->kref);
 268		init_completion(&new_inflight->comp);
 269
 270		mutex_unlock(&vq->mutex);
 271	}
 272}
 273
 274static struct vhost_scsi_inflight *
 275vhost_scsi_get_inflight(struct vhost_virtqueue *vq)
 276{
 277	struct vhost_scsi_inflight *inflight;
 278	struct vhost_scsi_virtqueue *svq;
 279
 280	svq = container_of(vq, struct vhost_scsi_virtqueue, vq);
 281	inflight = &svq->inflights[svq->inflight_idx];
 282	kref_get(&inflight->kref);
 283
 284	return inflight;
 285}
 286
 287static void vhost_scsi_put_inflight(struct vhost_scsi_inflight *inflight)
 288{
 289	kref_put(&inflight->kref, vhost_scsi_done_inflight);
 290}
 291
 292static int vhost_scsi_check_true(struct se_portal_group *se_tpg)
 293{
 294	return 1;
 295}
 296
 297static int vhost_scsi_check_false(struct se_portal_group *se_tpg)
 298{
 299	return 0;
 300}
 301
 302static char *vhost_scsi_get_fabric_wwn(struct se_portal_group *se_tpg)
 303{
 304	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
 305				struct vhost_scsi_tpg, se_tpg);
 306	struct vhost_scsi_tport *tport = tpg->tport;
 307
 308	return &tport->tport_name[0];
 309}
 310
 311static u16 vhost_scsi_get_tpgt(struct se_portal_group *se_tpg)
 312{
 313	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
 314				struct vhost_scsi_tpg, se_tpg);
 315	return tpg->tport_tpgt;
 316}
 317
 318static int vhost_scsi_check_prot_fabric_only(struct se_portal_group *se_tpg)
 319{
 320	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
 321				struct vhost_scsi_tpg, se_tpg);
 322
 323	return tpg->tv_fabric_prot_type;
 324}
 325
 326static u32 vhost_scsi_tpg_get_inst_index(struct se_portal_group *se_tpg)
 327{
 328	return 1;
 329}
 330
 331static void vhost_scsi_release_cmd_res(struct se_cmd *se_cmd)
 332{
 333	struct vhost_scsi_cmd *tv_cmd = container_of(se_cmd,
 334				struct vhost_scsi_cmd, tvc_se_cmd);
 335	struct vhost_scsi_virtqueue *svq = container_of(tv_cmd->tvc_vq,
 336				struct vhost_scsi_virtqueue, vq);
 337	struct vhost_scsi_inflight *inflight = tv_cmd->inflight;
 338	int i;
 339
 340	if (tv_cmd->tvc_sgl_count) {
 341		for (i = 0; i < tv_cmd->tvc_sgl_count; i++)
 342			put_page(sg_page(&tv_cmd->tvc_sgl[i]));
 343	}
 344	if (tv_cmd->tvc_prot_sgl_count) {
 345		for (i = 0; i < tv_cmd->tvc_prot_sgl_count; i++)
 346			put_page(sg_page(&tv_cmd->tvc_prot_sgl[i]));
 347	}
 348
 349	sbitmap_clear_bit(&svq->scsi_tags, se_cmd->map_tag);
 350	vhost_scsi_put_inflight(inflight);
 351}
 352
 353static void vhost_scsi_release_tmf_res(struct vhost_scsi_tmf *tmf)
 354{
 355	struct vhost_scsi_tpg *tpg = tmf->tpg;
 356	struct vhost_scsi_inflight *inflight = tmf->inflight;
 357
 358	mutex_lock(&tpg->tv_tpg_mutex);
 359	list_add_tail(&tpg->tmf_queue, &tmf->queue_entry);
 360	mutex_unlock(&tpg->tv_tpg_mutex);
 361	vhost_scsi_put_inflight(inflight);
 362}
 363
 364static void vhost_scsi_release_cmd(struct se_cmd *se_cmd)
 365{
 366	if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) {
 367		struct vhost_scsi_tmf *tmf = container_of(se_cmd,
 368					struct vhost_scsi_tmf, se_cmd);
 369
 370		vhost_work_queue(&tmf->vhost->dev, &tmf->vwork);
 371	} else {
 372		struct vhost_scsi_cmd *cmd = container_of(se_cmd,
 373					struct vhost_scsi_cmd, tvc_se_cmd);
 374		struct vhost_scsi *vs = cmd->tvc_vhost;
 375
 376		llist_add(&cmd->tvc_completion_list, &vs->vs_completion_list);
 377		vhost_work_queue(&vs->dev, &vs->vs_completion_work);
 378	}
 379}
 380
 381static u32 vhost_scsi_sess_get_index(struct se_session *se_sess)
 382{
 383	return 0;
 384}
 385
 386static int vhost_scsi_write_pending(struct se_cmd *se_cmd)
 387{
 388	/* Go ahead and process the write immediately */
 389	target_execute_cmd(se_cmd);
 390	return 0;
 391}
 392
 393static void vhost_scsi_set_default_node_attrs(struct se_node_acl *nacl)
 394{
 395	return;
 396}
 397
 398static int vhost_scsi_get_cmd_state(struct se_cmd *se_cmd)
 399{
 400	return 0;
 401}
 402
 403static int vhost_scsi_queue_data_in(struct se_cmd *se_cmd)
 404{
 405	transport_generic_free_cmd(se_cmd, 0);
 406	return 0;
 407}
 408
 409static int vhost_scsi_queue_status(struct se_cmd *se_cmd)
 410{
 411	transport_generic_free_cmd(se_cmd, 0);
 412	return 0;
 413}
 414
 415static void vhost_scsi_queue_tm_rsp(struct se_cmd *se_cmd)
 416{
 417	struct vhost_scsi_tmf *tmf = container_of(se_cmd, struct vhost_scsi_tmf,
 418						  se_cmd);
 419
 420	tmf->scsi_resp = se_cmd->se_tmr_req->response;
 421	transport_generic_free_cmd(&tmf->se_cmd, 0);
 422}
 423
 424static void vhost_scsi_aborted_task(struct se_cmd *se_cmd)
 425{
 426	return;
 427}
 428
 429static void vhost_scsi_free_evt(struct vhost_scsi *vs, struct vhost_scsi_evt *evt)
 430{
 431	vs->vs_events_nr--;
 432	kfree(evt);
 433}
 434
 435static struct vhost_scsi_evt *
 436vhost_scsi_allocate_evt(struct vhost_scsi *vs,
 437		       u32 event, u32 reason)
 438{
 439	struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 440	struct vhost_scsi_evt *evt;
 441
 442	if (vs->vs_events_nr > VHOST_SCSI_MAX_EVENT) {
 443		vs->vs_events_missed = true;
 444		return NULL;
 445	}
 446
 447	evt = kzalloc(sizeof(*evt), GFP_KERNEL);
 448	if (!evt) {
 449		vq_err(vq, "Failed to allocate vhost_scsi_evt\n");
 450		vs->vs_events_missed = true;
 451		return NULL;
 452	}
 453
 454	evt->event.event = cpu_to_vhost32(vq, event);
 455	evt->event.reason = cpu_to_vhost32(vq, reason);
 456	vs->vs_events_nr++;
 457
 458	return evt;
 459}
 460
 461static int vhost_scsi_check_stop_free(struct se_cmd *se_cmd)
 462{
 463	return target_put_sess_cmd(se_cmd);
 464}
 465
 466static void
 467vhost_scsi_do_evt_work(struct vhost_scsi *vs, struct vhost_scsi_evt *evt)
 468{
 469	struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 470	struct virtio_scsi_event *event = &evt->event;
 471	struct virtio_scsi_event __user *eventp;
 472	unsigned out, in;
 473	int head, ret;
 474
 475	if (!vhost_vq_get_backend(vq)) {
 476		vs->vs_events_missed = true;
 477		return;
 478	}
 479
 480again:
 481	vhost_disable_notify(&vs->dev, vq);
 482	head = vhost_get_vq_desc(vq, vq->iov,
 483			ARRAY_SIZE(vq->iov), &out, &in,
 484			NULL, NULL);
 485	if (head < 0) {
 486		vs->vs_events_missed = true;
 487		return;
 488	}
 489	if (head == vq->num) {
 490		if (vhost_enable_notify(&vs->dev, vq))
 491			goto again;
 492		vs->vs_events_missed = true;
 493		return;
 494	}
 495
 496	if ((vq->iov[out].iov_len != sizeof(struct virtio_scsi_event))) {
 497		vq_err(vq, "Expecting virtio_scsi_event, got %zu bytes\n",
 498				vq->iov[out].iov_len);
 499		vs->vs_events_missed = true;
 500		return;
 501	}
 502
 503	if (vs->vs_events_missed) {
 504		event->event |= cpu_to_vhost32(vq, VIRTIO_SCSI_T_EVENTS_MISSED);
 505		vs->vs_events_missed = false;
 506	}
 507
 508	eventp = vq->iov[out].iov_base;
 509	ret = __copy_to_user(eventp, event, sizeof(*event));
 510	if (!ret)
 511		vhost_add_used_and_signal(&vs->dev, vq, head, 0);
 512	else
 513		vq_err(vq, "Faulted on vhost_scsi_send_event\n");
 514}
 515
 516static void vhost_scsi_evt_work(struct vhost_work *work)
 517{
 518	struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
 519					vs_event_work);
 520	struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 521	struct vhost_scsi_evt *evt, *t;
 522	struct llist_node *llnode;
 523
 524	mutex_lock(&vq->mutex);
 525	llnode = llist_del_all(&vs->vs_event_list);
 526	llist_for_each_entry_safe(evt, t, llnode, list) {
 527		vhost_scsi_do_evt_work(vs, evt);
 528		vhost_scsi_free_evt(vs, evt);
 529	}
 530	mutex_unlock(&vq->mutex);
 531}
 532
 533/* Fill in status and signal that we are done processing this command
 534 *
 535 * This is scheduled in the vhost work queue so we are called with the owner
 536 * process mm and can access the vring.
 537 */
 538static void vhost_scsi_complete_cmd_work(struct vhost_work *work)
 539{
 540	struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
 541					vs_completion_work);
 542	struct virtio_scsi_cmd_resp v_rsp;
 543	struct vhost_scsi_cmd *cmd, *t;
 544	struct llist_node *llnode;
 545	struct se_cmd *se_cmd;
 546	struct iov_iter iov_iter;
 547	int ret, vq;
 548
 549	bitmap_zero(vs->compl_bitmap, vs->dev.nvqs);
 550	llnode = llist_del_all(&vs->vs_completion_list);
 551	llist_for_each_entry_safe(cmd, t, llnode, tvc_completion_list) {
 552		se_cmd = &cmd->tvc_se_cmd;
 553
 554		pr_debug("%s tv_cmd %p resid %u status %#02x\n", __func__,
 555			cmd, se_cmd->residual_count, se_cmd->scsi_status);
 556
 557		memset(&v_rsp, 0, sizeof(v_rsp));
 558		v_rsp.resid = cpu_to_vhost32(cmd->tvc_vq, se_cmd->residual_count);
 559		/* TODO is status_qualifier field needed? */
 560		v_rsp.status = se_cmd->scsi_status;
 561		v_rsp.sense_len = cpu_to_vhost32(cmd->tvc_vq,
 562						 se_cmd->scsi_sense_length);
 563		memcpy(v_rsp.sense, cmd->tvc_sense_buf,
 564		       se_cmd->scsi_sense_length);
 565
 566		iov_iter_init(&iov_iter, ITER_DEST, cmd->tvc_resp_iov,
 567			      cmd->tvc_in_iovs, sizeof(v_rsp));
 568		ret = copy_to_iter(&v_rsp, sizeof(v_rsp), &iov_iter);
 569		if (likely(ret == sizeof(v_rsp))) {
 570			struct vhost_scsi_virtqueue *q;
 571			vhost_add_used(cmd->tvc_vq, cmd->tvc_vq_desc, 0);
 572			q = container_of(cmd->tvc_vq, struct vhost_scsi_virtqueue, vq);
 573			vq = q - vs->vqs;
 574			__set_bit(vq, vs->compl_bitmap);
 575		} else
 576			pr_err("Faulted on virtio_scsi_cmd_resp\n");
 577
 578		vhost_scsi_release_cmd_res(se_cmd);
 579	}
 580
 581	vq = -1;
 582	while ((vq = find_next_bit(vs->compl_bitmap, vs->dev.nvqs, vq + 1))
 583		< vs->dev.nvqs)
 584		vhost_signal(&vs->dev, &vs->vqs[vq].vq);
 585}
 586
 587static struct vhost_scsi_cmd *
 588vhost_scsi_get_cmd(struct vhost_virtqueue *vq, struct vhost_scsi_tpg *tpg,
 589		   unsigned char *cdb, u64 scsi_tag, u16 lun, u8 task_attr,
 590		   u32 exp_data_len, int data_direction)
 591{
 592	struct vhost_scsi_virtqueue *svq = container_of(vq,
 593					struct vhost_scsi_virtqueue, vq);
 594	struct vhost_scsi_cmd *cmd;
 595	struct vhost_scsi_nexus *tv_nexus;
 596	struct scatterlist *sg, *prot_sg;
 597	struct iovec *tvc_resp_iov;
 598	struct page **pages;
 599	int tag;
 600
 601	tv_nexus = tpg->tpg_nexus;
 602	if (!tv_nexus) {
 603		pr_err("Unable to locate active struct vhost_scsi_nexus\n");
 604		return ERR_PTR(-EIO);
 605	}
 606
 607	tag = sbitmap_get(&svq->scsi_tags);
 608	if (tag < 0) {
 609		pr_err("Unable to obtain tag for vhost_scsi_cmd\n");
 610		return ERR_PTR(-ENOMEM);
 611	}
 612
 613	cmd = &svq->scsi_cmds[tag];
 614	sg = cmd->tvc_sgl;
 615	prot_sg = cmd->tvc_prot_sgl;
 616	pages = cmd->tvc_upages;
 617	tvc_resp_iov = cmd->tvc_resp_iov;
 618	memset(cmd, 0, sizeof(*cmd));
 619	cmd->tvc_sgl = sg;
 620	cmd->tvc_prot_sgl = prot_sg;
 621	cmd->tvc_upages = pages;
 622	cmd->tvc_se_cmd.map_tag = tag;
 623	cmd->tvc_tag = scsi_tag;
 624	cmd->tvc_lun = lun;
 625	cmd->tvc_task_attr = task_attr;
 626	cmd->tvc_exp_data_len = exp_data_len;
 627	cmd->tvc_data_direction = data_direction;
 628	cmd->tvc_nexus = tv_nexus;
 629	cmd->inflight = vhost_scsi_get_inflight(vq);
 630	cmd->tvc_resp_iov = tvc_resp_iov;
 631
 632	memcpy(cmd->tvc_cdb, cdb, VHOST_SCSI_MAX_CDB_SIZE);
 633
 634	return cmd;
 635}
 636
 637/*
 638 * Map a user memory range into a scatterlist
 639 *
 640 * Returns the number of scatterlist entries used or -errno on error.
 641 */
 642static int
 643vhost_scsi_map_to_sgl(struct vhost_scsi_cmd *cmd,
 644		      struct iov_iter *iter,
 645		      struct scatterlist *sgl,
 646		      bool write)
 647{
 648	struct page **pages = cmd->tvc_upages;
 649	struct scatterlist *sg = sgl;
 650	ssize_t bytes;
 651	size_t offset;
 652	unsigned int npages = 0;
 653
 654	bytes = iov_iter_get_pages2(iter, pages, LONG_MAX,
 655				VHOST_SCSI_PREALLOC_UPAGES, &offset);
 656	/* No pages were pinned */
 657	if (bytes <= 0)
 658		return bytes < 0 ? bytes : -EFAULT;
 659
 660	while (bytes) {
 661		unsigned n = min_t(unsigned, PAGE_SIZE - offset, bytes);
 662		sg_set_page(sg++, pages[npages++], n, offset);
 663		bytes -= n;
 664		offset = 0;
 665	}
 666	return npages;
 667}
 668
 669static int
 670vhost_scsi_calc_sgls(struct iov_iter *iter, size_t bytes, int max_sgls)
 671{
 672	int sgl_count = 0;
 673
 674	if (!iter || !iter->iov) {
 675		pr_err("%s: iter->iov is NULL, but expected bytes: %zu"
 676		       " present\n", __func__, bytes);
 677		return -EINVAL;
 678	}
 679
 680	sgl_count = iov_iter_npages(iter, 0xffff);
 681	if (sgl_count > max_sgls) {
 682		pr_err("%s: requested sgl_count: %d exceeds pre-allocated"
 683		       " max_sgls: %d\n", __func__, sgl_count, max_sgls);
 684		return -EINVAL;
 685	}
 686	return sgl_count;
 687}
 688
 689static int
 690vhost_scsi_iov_to_sgl(struct vhost_scsi_cmd *cmd, bool write,
 691		      struct iov_iter *iter,
 692		      struct scatterlist *sg, int sg_count)
 693{
 694	struct scatterlist *p = sg;
 695	int ret;
 696
 697	while (iov_iter_count(iter)) {
 698		ret = vhost_scsi_map_to_sgl(cmd, iter, sg, write);
 699		if (ret < 0) {
 700			while (p < sg) {
 701				struct page *page = sg_page(p++);
 702				if (page)
 703					put_page(page);
 704			}
 705			return ret;
 706		}
 707		sg += ret;
 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_target_queue_cmd(struct vhost_scsi_cmd *cmd)
 776{
 777	struct se_cmd *se_cmd = &cmd->tvc_se_cmd;
 778	struct vhost_scsi_nexus *tv_nexus;
 779	struct scatterlist *sg_ptr, *sg_prot_ptr = NULL;
 780
 781	/* FIXME: BIDI operation */
 782	if (cmd->tvc_sgl_count) {
 783		sg_ptr = cmd->tvc_sgl;
 784
 785		if (cmd->tvc_prot_sgl_count)
 786			sg_prot_ptr = cmd->tvc_prot_sgl;
 787		else
 788			se_cmd->prot_pto = true;
 789	} else {
 790		sg_ptr = NULL;
 791	}
 792	tv_nexus = cmd->tvc_nexus;
 793
 794	se_cmd->tag = 0;
 795	target_init_cmd(se_cmd, tv_nexus->tvn_se_sess, &cmd->tvc_sense_buf[0],
 796			cmd->tvc_lun, cmd->tvc_exp_data_len,
 797			vhost_scsi_to_tcm_attr(cmd->tvc_task_attr),
 798			cmd->tvc_data_direction, TARGET_SCF_ACK_KREF);
 799
 800	if (target_submit_prep(se_cmd, cmd->tvc_cdb, sg_ptr,
 801			       cmd->tvc_sgl_count, NULL, 0, sg_prot_ptr,
 802			       cmd->tvc_prot_sgl_count, GFP_KERNEL))
 803		return;
 804
 805	target_queue_submission(se_cmd);
 806}
 807
 808static void
 809vhost_scsi_send_bad_target(struct vhost_scsi *vs,
 810			   struct vhost_virtqueue *vq,
 811			   int head, unsigned out)
 812{
 813	struct virtio_scsi_cmd_resp __user *resp;
 814	struct virtio_scsi_cmd_resp rsp;
 815	int ret;
 816
 817	memset(&rsp, 0, sizeof(rsp));
 818	rsp.response = VIRTIO_SCSI_S_BAD_TARGET;
 819	resp = vq->iov[out].iov_base;
 820	ret = __copy_to_user(resp, &rsp, sizeof(rsp));
 821	if (!ret)
 822		vhost_add_used_and_signal(&vs->dev, vq, head, 0);
 823	else
 824		pr_err("Faulted on virtio_scsi_cmd_resp\n");
 825}
 826
 827static int
 828vhost_scsi_get_desc(struct vhost_scsi *vs, struct vhost_virtqueue *vq,
 829		    struct vhost_scsi_ctx *vc)
 830{
 831	int ret = -ENXIO;
 832
 833	vc->head = vhost_get_vq_desc(vq, vq->iov,
 834				     ARRAY_SIZE(vq->iov), &vc->out, &vc->in,
 835				     NULL, NULL);
 836
 837	pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n",
 838		 vc->head, vc->out, vc->in);
 839
 840	/* On error, stop handling until the next kick. */
 841	if (unlikely(vc->head < 0))
 842		goto done;
 843
 844	/* Nothing new?  Wait for eventfd to tell us they refilled. */
 845	if (vc->head == vq->num) {
 846		if (unlikely(vhost_enable_notify(&vs->dev, vq))) {
 847			vhost_disable_notify(&vs->dev, vq);
 848			ret = -EAGAIN;
 849		}
 850		goto done;
 851	}
 852
 853	/*
 854	 * Get the size of request and response buffers.
 855	 * FIXME: Not correct for BIDI operation
 856	 */
 857	vc->out_size = iov_length(vq->iov, vc->out);
 858	vc->in_size = iov_length(&vq->iov[vc->out], vc->in);
 859
 860	/*
 861	 * Copy over the virtio-scsi request header, which for a
 862	 * ANY_LAYOUT enabled guest may span multiple iovecs, or a
 863	 * single iovec may contain both the header + outgoing
 864	 * WRITE payloads.
 865	 *
 866	 * copy_from_iter() will advance out_iter, so that it will
 867	 * point at the start of the outgoing WRITE payload, if
 868	 * DMA_TO_DEVICE is set.
 869	 */
 870	iov_iter_init(&vc->out_iter, ITER_SOURCE, vq->iov, vc->out, vc->out_size);
 871	ret = 0;
 872
 873done:
 874	return ret;
 875}
 876
 877static int
 878vhost_scsi_chk_size(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc)
 879{
 880	if (unlikely(vc->in_size < vc->rsp_size)) {
 881		vq_err(vq,
 882		       "Response buf too small, need min %zu bytes got %zu",
 883		       vc->rsp_size, vc->in_size);
 884		return -EINVAL;
 885	} else if (unlikely(vc->out_size < vc->req_size)) {
 886		vq_err(vq,
 887		       "Request buf too small, need min %zu bytes got %zu",
 888		       vc->req_size, vc->out_size);
 889		return -EIO;
 890	}
 891
 892	return 0;
 893}
 894
 895static int
 896vhost_scsi_get_req(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc,
 897		   struct vhost_scsi_tpg **tpgp)
 898{
 899	int ret = -EIO;
 900
 901	if (unlikely(!copy_from_iter_full(vc->req, vc->req_size,
 902					  &vc->out_iter))) {
 903		vq_err(vq, "Faulted on copy_from_iter_full\n");
 904	} else if (unlikely(*vc->lunp != 1)) {
 905		/* virtio-scsi spec requires byte 0 of the lun to be 1 */
 906		vq_err(vq, "Illegal virtio-scsi lun: %u\n", *vc->lunp);
 907	} else {
 908		struct vhost_scsi_tpg **vs_tpg, *tpg;
 909
 910		vs_tpg = vhost_vq_get_backend(vq);	/* validated at handler entry */
 911
 912		tpg = READ_ONCE(vs_tpg[*vc->target]);
 913		if (unlikely(!tpg)) {
 914			vq_err(vq, "Target 0x%x does not exist\n", *vc->target);
 915		} else {
 916			if (tpgp)
 917				*tpgp = tpg;
 918			ret = 0;
 919		}
 920	}
 921
 922	return ret;
 923}
 924
 925static u16 vhost_buf_to_lun(u8 *lun_buf)
 926{
 927	return ((lun_buf[2] << 8) | lun_buf[3]) & 0x3FFF;
 928}
 929
 930static void
 931vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 932{
 933	struct vhost_scsi_tpg **vs_tpg, *tpg;
 934	struct virtio_scsi_cmd_req v_req;
 935	struct virtio_scsi_cmd_req_pi v_req_pi;
 936	struct vhost_scsi_ctx vc;
 937	struct vhost_scsi_cmd *cmd;
 938	struct iov_iter in_iter, prot_iter, data_iter;
 939	u64 tag;
 940	u32 exp_data_len, data_direction;
 941	int ret, prot_bytes, i, c = 0;
 942	u16 lun;
 943	u8 task_attr;
 944	bool t10_pi = vhost_has_feature(vq, VIRTIO_SCSI_F_T10_PI);
 945	void *cdb;
 946
 947	mutex_lock(&vq->mutex);
 948	/*
 949	 * We can handle the vq only after the endpoint is setup by calling the
 950	 * VHOST_SCSI_SET_ENDPOINT ioctl.
 951	 */
 952	vs_tpg = vhost_vq_get_backend(vq);
 953	if (!vs_tpg)
 954		goto out;
 955
 956	memset(&vc, 0, sizeof(vc));
 957	vc.rsp_size = sizeof(struct virtio_scsi_cmd_resp);
 958
 959	vhost_disable_notify(&vs->dev, vq);
 960
 961	do {
 962		ret = vhost_scsi_get_desc(vs, vq, &vc);
 963		if (ret)
 964			goto err;
 965
 966		/*
 967		 * Setup pointers and values based upon different virtio-scsi
 968		 * request header if T10_PI is enabled in KVM guest.
 969		 */
 970		if (t10_pi) {
 971			vc.req = &v_req_pi;
 972			vc.req_size = sizeof(v_req_pi);
 973			vc.lunp = &v_req_pi.lun[0];
 974			vc.target = &v_req_pi.lun[1];
 975		} else {
 976			vc.req = &v_req;
 977			vc.req_size = sizeof(v_req);
 978			vc.lunp = &v_req.lun[0];
 979			vc.target = &v_req.lun[1];
 980		}
 981
 982		/*
 983		 * Validate the size of request and response buffers.
 984		 * Check for a sane response buffer so we can report
 985		 * early errors back to the guest.
 986		 */
 987		ret = vhost_scsi_chk_size(vq, &vc);
 988		if (ret)
 989			goto err;
 990
 991		ret = vhost_scsi_get_req(vq, &vc, &tpg);
 992		if (ret)
 993			goto err;
 994
 995		ret = -EIO;	/* bad target on any error from here on */
 996
 997		/*
 998		 * Determine data_direction by calculating the total outgoing
 999		 * iovec sizes + incoming iovec sizes vs. virtio-scsi request +
1000		 * response headers respectively.
1001		 *
1002		 * For DMA_TO_DEVICE this is out_iter, which is already pointing
1003		 * to the right place.
1004		 *
1005		 * For DMA_FROM_DEVICE, the iovec will be just past the end
1006		 * of the virtio-scsi response header in either the same
1007		 * or immediately following iovec.
1008		 *
1009		 * Any associated T10_PI bytes for the outgoing / incoming
1010		 * payloads are included in calculation of exp_data_len here.
1011		 */
1012		prot_bytes = 0;
1013
1014		if (vc.out_size > vc.req_size) {
1015			data_direction = DMA_TO_DEVICE;
1016			exp_data_len = vc.out_size - vc.req_size;
1017			data_iter = vc.out_iter;
1018		} else if (vc.in_size > vc.rsp_size) {
1019			data_direction = DMA_FROM_DEVICE;
1020			exp_data_len = vc.in_size - vc.rsp_size;
1021
1022			iov_iter_init(&in_iter, ITER_DEST, &vq->iov[vc.out], vc.in,
1023				      vc.rsp_size + exp_data_len);
1024			iov_iter_advance(&in_iter, vc.rsp_size);
1025			data_iter = in_iter;
1026		} else {
1027			data_direction = DMA_NONE;
1028			exp_data_len = 0;
1029		}
1030		/*
1031		 * If T10_PI header + payload is present, setup prot_iter values
1032		 * and recalculate data_iter for vhost_scsi_mapal() mapping to
1033		 * host scatterlists via get_user_pages_fast().
1034		 */
1035		if (t10_pi) {
1036			if (v_req_pi.pi_bytesout) {
1037				if (data_direction != DMA_TO_DEVICE) {
1038					vq_err(vq, "Received non zero pi_bytesout,"
1039						" but wrong data_direction\n");
1040					goto err;
1041				}
1042				prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesout);
1043			} else if (v_req_pi.pi_bytesin) {
1044				if (data_direction != DMA_FROM_DEVICE) {
1045					vq_err(vq, "Received non zero pi_bytesin,"
1046						" but wrong data_direction\n");
1047					goto err;
1048				}
1049				prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin);
1050			}
1051			/*
1052			 * Set prot_iter to data_iter and truncate it to
1053			 * prot_bytes, and advance data_iter past any
1054			 * preceeding prot_bytes that may be present.
1055			 *
1056			 * Also fix up the exp_data_len to reflect only the
1057			 * actual data payload length.
1058			 */
1059			if (prot_bytes) {
1060				exp_data_len -= prot_bytes;
1061				prot_iter = data_iter;
1062				iov_iter_truncate(&prot_iter, prot_bytes);
1063				iov_iter_advance(&data_iter, prot_bytes);
1064			}
1065			tag = vhost64_to_cpu(vq, v_req_pi.tag);
1066			task_attr = v_req_pi.task_attr;
1067			cdb = &v_req_pi.cdb[0];
1068			lun = vhost_buf_to_lun(v_req_pi.lun);
1069		} else {
1070			tag = vhost64_to_cpu(vq, v_req.tag);
1071			task_attr = v_req.task_attr;
1072			cdb = &v_req.cdb[0];
1073			lun = vhost_buf_to_lun(v_req.lun);
1074		}
1075		/*
1076		 * Check that the received CDB size does not exceeded our
1077		 * hardcoded max for vhost-scsi, then get a pre-allocated
1078		 * cmd descriptor for the new virtio-scsi tag.
1079		 *
1080		 * TODO what if cdb was too small for varlen cdb header?
1081		 */
1082		if (unlikely(scsi_command_size(cdb) > VHOST_SCSI_MAX_CDB_SIZE)) {
1083			vq_err(vq, "Received SCSI CDB with command_size: %d that"
1084				" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1085				scsi_command_size(cdb), VHOST_SCSI_MAX_CDB_SIZE);
1086				goto err;
1087		}
1088		cmd = vhost_scsi_get_cmd(vq, tpg, cdb, tag, lun, task_attr,
1089					 exp_data_len + prot_bytes,
1090					 data_direction);
1091		if (IS_ERR(cmd)) {
1092			vq_err(vq, "vhost_scsi_get_cmd failed %ld\n",
1093			       PTR_ERR(cmd));
1094			goto err;
1095		}
1096		cmd->tvc_vhost = vs;
1097		cmd->tvc_vq = vq;
1098		for (i = 0; i < vc.in ; i++)
1099			cmd->tvc_resp_iov[i] = vq->iov[vc.out + i];
1100		cmd->tvc_in_iovs = vc.in;
1101
1102		pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",
1103			 cmd->tvc_cdb[0], cmd->tvc_lun);
1104		pr_debug("cmd: %p exp_data_len: %d, prot_bytes: %d data_direction:"
1105			 " %d\n", cmd, exp_data_len, prot_bytes, data_direction);
1106
1107		if (data_direction != DMA_NONE) {
1108			if (unlikely(vhost_scsi_mapal(cmd, prot_bytes,
1109						      &prot_iter, exp_data_len,
1110						      &data_iter))) {
1111				vq_err(vq, "Failed to map iov to sgl\n");
1112				vhost_scsi_release_cmd_res(&cmd->tvc_se_cmd);
1113				goto err;
1114			}
1115		}
1116		/*
1117		 * Save the descriptor from vhost_get_vq_desc() to be used to
1118		 * complete the virtio-scsi request in TCM callback context via
1119		 * vhost_scsi_queue_data_in() and vhost_scsi_queue_status()
1120		 */
1121		cmd->tvc_vq_desc = vc.head;
1122		vhost_scsi_target_queue_cmd(cmd);
1123		ret = 0;
1124err:
1125		/*
1126		 * ENXIO:  No more requests, or read error, wait for next kick
1127		 * EINVAL: Invalid response buffer, drop the request
1128		 * EIO:    Respond with bad target
1129		 * EAGAIN: Pending request
1130		 */
1131		if (ret == -ENXIO)
1132			break;
1133		else if (ret == -EIO)
1134			vhost_scsi_send_bad_target(vs, vq, vc.head, vc.out);
1135	} while (likely(!vhost_exceeds_weight(vq, ++c, 0)));
1136out:
1137	mutex_unlock(&vq->mutex);
1138}
1139
1140static void
1141vhost_scsi_send_tmf_resp(struct vhost_scsi *vs, struct vhost_virtqueue *vq,
1142			 int in_iovs, int vq_desc, struct iovec *resp_iov,
1143			 int tmf_resp_code)
1144{
1145	struct virtio_scsi_ctrl_tmf_resp rsp;
1146	struct iov_iter iov_iter;
1147	int ret;
1148
1149	pr_debug("%s\n", __func__);
1150	memset(&rsp, 0, sizeof(rsp));
1151	rsp.response = tmf_resp_code;
1152
1153	iov_iter_init(&iov_iter, ITER_DEST, resp_iov, in_iovs, sizeof(rsp));
1154
1155	ret = copy_to_iter(&rsp, sizeof(rsp), &iov_iter);
1156	if (likely(ret == sizeof(rsp)))
1157		vhost_add_used_and_signal(&vs->dev, vq, vq_desc, 0);
1158	else
1159		pr_err("Faulted on virtio_scsi_ctrl_tmf_resp\n");
1160}
1161
1162static void vhost_scsi_tmf_resp_work(struct vhost_work *work)
1163{
1164	struct vhost_scsi_tmf *tmf = container_of(work, struct vhost_scsi_tmf,
1165						  vwork);
1166	int resp_code;
1167
1168	if (tmf->scsi_resp == TMR_FUNCTION_COMPLETE)
1169		resp_code = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
1170	else
1171		resp_code = VIRTIO_SCSI_S_FUNCTION_REJECTED;
1172
1173	vhost_scsi_send_tmf_resp(tmf->vhost, &tmf->svq->vq, tmf->in_iovs,
1174				 tmf->vq_desc, &tmf->resp_iov, resp_code);
1175	vhost_scsi_release_tmf_res(tmf);
1176}
1177
1178static void
1179vhost_scsi_handle_tmf(struct vhost_scsi *vs, struct vhost_scsi_tpg *tpg,
1180		      struct vhost_virtqueue *vq,
1181		      struct virtio_scsi_ctrl_tmf_req *vtmf,
1182		      struct vhost_scsi_ctx *vc)
1183{
1184	struct vhost_scsi_virtqueue *svq = container_of(vq,
1185					struct vhost_scsi_virtqueue, vq);
1186	struct vhost_scsi_tmf *tmf;
1187
1188	if (vhost32_to_cpu(vq, vtmf->subtype) !=
1189	    VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET)
1190		goto send_reject;
1191
1192	if (!tpg->tpg_nexus || !tpg->tpg_nexus->tvn_se_sess) {
1193		pr_err("Unable to locate active struct vhost_scsi_nexus for LUN RESET.\n");
1194		goto send_reject;
1195	}
1196
1197	mutex_lock(&tpg->tv_tpg_mutex);
1198	if (list_empty(&tpg->tmf_queue)) {
1199		pr_err("Missing reserve TMF. Could not handle LUN RESET.\n");
1200		mutex_unlock(&tpg->tv_tpg_mutex);
1201		goto send_reject;
1202	}
1203
1204	tmf = list_first_entry(&tpg->tmf_queue, struct vhost_scsi_tmf,
1205			       queue_entry);
1206	list_del_init(&tmf->queue_entry);
1207	mutex_unlock(&tpg->tv_tpg_mutex);
1208
1209	tmf->tpg = tpg;
1210	tmf->vhost = vs;
1211	tmf->svq = svq;
1212	tmf->resp_iov = vq->iov[vc->out];
1213	tmf->vq_desc = vc->head;
1214	tmf->in_iovs = vc->in;
1215	tmf->inflight = vhost_scsi_get_inflight(vq);
1216
1217	if (target_submit_tmr(&tmf->se_cmd, tpg->tpg_nexus->tvn_se_sess, NULL,
1218			      vhost_buf_to_lun(vtmf->lun), NULL,
1219			      TMR_LUN_RESET, GFP_KERNEL, 0,
1220			      TARGET_SCF_ACK_KREF) < 0) {
1221		vhost_scsi_release_tmf_res(tmf);
1222		goto send_reject;
1223	}
1224
1225	return;
1226
1227send_reject:
1228	vhost_scsi_send_tmf_resp(vs, vq, vc->in, vc->head, &vq->iov[vc->out],
1229				 VIRTIO_SCSI_S_FUNCTION_REJECTED);
1230}
1231
1232static void
1233vhost_scsi_send_an_resp(struct vhost_scsi *vs,
1234			struct vhost_virtqueue *vq,
1235			struct vhost_scsi_ctx *vc)
1236{
1237	struct virtio_scsi_ctrl_an_resp rsp;
1238	struct iov_iter iov_iter;
1239	int ret;
1240
1241	pr_debug("%s\n", __func__);
1242	memset(&rsp, 0, sizeof(rsp));	/* event_actual = 0 */
1243	rsp.response = VIRTIO_SCSI_S_OK;
1244
1245	iov_iter_init(&iov_iter, ITER_DEST, &vq->iov[vc->out], vc->in, sizeof(rsp));
1246
1247	ret = copy_to_iter(&rsp, sizeof(rsp), &iov_iter);
1248	if (likely(ret == sizeof(rsp)))
1249		vhost_add_used_and_signal(&vs->dev, vq, vc->head, 0);
1250	else
1251		pr_err("Faulted on virtio_scsi_ctrl_an_resp\n");
1252}
1253
1254static void
1255vhost_scsi_ctl_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
1256{
1257	struct vhost_scsi_tpg *tpg;
1258	union {
1259		__virtio32 type;
1260		struct virtio_scsi_ctrl_an_req an;
1261		struct virtio_scsi_ctrl_tmf_req tmf;
1262	} v_req;
1263	struct vhost_scsi_ctx vc;
1264	size_t typ_size;
1265	int ret, c = 0;
1266
1267	mutex_lock(&vq->mutex);
1268	/*
1269	 * We can handle the vq only after the endpoint is setup by calling the
1270	 * VHOST_SCSI_SET_ENDPOINT ioctl.
1271	 */
1272	if (!vhost_vq_get_backend(vq))
1273		goto out;
1274
1275	memset(&vc, 0, sizeof(vc));
1276
1277	vhost_disable_notify(&vs->dev, vq);
1278
1279	do {
1280		ret = vhost_scsi_get_desc(vs, vq, &vc);
1281		if (ret)
1282			goto err;
1283
1284		/*
1285		 * Get the request type first in order to setup
1286		 * other parameters dependent on the type.
1287		 */
1288		vc.req = &v_req.type;
1289		typ_size = sizeof(v_req.type);
1290
1291		if (unlikely(!copy_from_iter_full(vc.req, typ_size,
1292						  &vc.out_iter))) {
1293			vq_err(vq, "Faulted on copy_from_iter tmf type\n");
1294			/*
1295			 * The size of the response buffer depends on the
1296			 * request type and must be validated against it.
1297			 * Since the request type is not known, don't send
1298			 * a response.
1299			 */
1300			continue;
1301		}
1302
1303		switch (vhost32_to_cpu(vq, v_req.type)) {
1304		case VIRTIO_SCSI_T_TMF:
1305			vc.req = &v_req.tmf;
1306			vc.req_size = sizeof(struct virtio_scsi_ctrl_tmf_req);
1307			vc.rsp_size = sizeof(struct virtio_scsi_ctrl_tmf_resp);
1308			vc.lunp = &v_req.tmf.lun[0];
1309			vc.target = &v_req.tmf.lun[1];
1310			break;
1311		case VIRTIO_SCSI_T_AN_QUERY:
1312		case VIRTIO_SCSI_T_AN_SUBSCRIBE:
1313			vc.req = &v_req.an;
1314			vc.req_size = sizeof(struct virtio_scsi_ctrl_an_req);
1315			vc.rsp_size = sizeof(struct virtio_scsi_ctrl_an_resp);
1316			vc.lunp = &v_req.an.lun[0];
1317			vc.target = NULL;
1318			break;
1319		default:
1320			vq_err(vq, "Unknown control request %d", v_req.type);
1321			continue;
1322		}
1323
1324		/*
1325		 * Validate the size of request and response buffers.
1326		 * Check for a sane response buffer so we can report
1327		 * early errors back to the guest.
1328		 */
1329		ret = vhost_scsi_chk_size(vq, &vc);
1330		if (ret)
1331			goto err;
1332
1333		/*
1334		 * Get the rest of the request now that its size is known.
1335		 */
1336		vc.req += typ_size;
1337		vc.req_size -= typ_size;
1338
1339		ret = vhost_scsi_get_req(vq, &vc, &tpg);
1340		if (ret)
1341			goto err;
1342
1343		if (v_req.type == VIRTIO_SCSI_T_TMF)
1344			vhost_scsi_handle_tmf(vs, tpg, vq, &v_req.tmf, &vc);
1345		else
1346			vhost_scsi_send_an_resp(vs, vq, &vc);
1347err:
1348		/*
1349		 * ENXIO:  No more requests, or read error, wait for next kick
1350		 * EINVAL: Invalid response buffer, drop the request
1351		 * EIO:    Respond with bad target
1352		 * EAGAIN: Pending request
1353		 */
1354		if (ret == -ENXIO)
1355			break;
1356		else if (ret == -EIO)
1357			vhost_scsi_send_bad_target(vs, vq, vc.head, vc.out);
1358	} while (likely(!vhost_exceeds_weight(vq, ++c, 0)));
1359out:
1360	mutex_unlock(&vq->mutex);
1361}
1362
1363static void vhost_scsi_ctl_handle_kick(struct vhost_work *work)
1364{
1365	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1366						poll.work);
1367	struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1368
1369	pr_debug("%s: The handling func for control queue.\n", __func__);
1370	vhost_scsi_ctl_handle_vq(vs, vq);
1371}
1372
1373static void
1374vhost_scsi_send_evt(struct vhost_scsi *vs,
1375		   struct vhost_scsi_tpg *tpg,
1376		   struct se_lun *lun,
1377		   u32 event,
1378		   u32 reason)
1379{
1380	struct vhost_scsi_evt *evt;
1381
1382	evt = vhost_scsi_allocate_evt(vs, event, reason);
1383	if (!evt)
1384		return;
1385
1386	if (tpg && lun) {
1387		/* TODO: share lun setup code with virtio-scsi.ko */
1388		/*
1389		 * Note: evt->event is zeroed when we allocate it and
1390		 * lun[4-7] need to be zero according to virtio-scsi spec.
1391		 */
1392		evt->event.lun[0] = 0x01;
1393		evt->event.lun[1] = tpg->tport_tpgt;
1394		if (lun->unpacked_lun >= 256)
1395			evt->event.lun[2] = lun->unpacked_lun >> 8 | 0x40 ;
1396		evt->event.lun[3] = lun->unpacked_lun & 0xFF;
1397	}
1398
1399	llist_add(&evt->list, &vs->vs_event_list);
1400	vhost_work_queue(&vs->dev, &vs->vs_event_work);
1401}
1402
1403static void vhost_scsi_evt_handle_kick(struct vhost_work *work)
1404{
1405	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1406						poll.work);
1407	struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1408
1409	mutex_lock(&vq->mutex);
1410	if (!vhost_vq_get_backend(vq))
1411		goto out;
1412
1413	if (vs->vs_events_missed)
1414		vhost_scsi_send_evt(vs, NULL, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
1415out:
1416	mutex_unlock(&vq->mutex);
1417}
1418
1419static void vhost_scsi_handle_kick(struct vhost_work *work)
1420{
1421	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
1422						poll.work);
1423	struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
1424
1425	vhost_scsi_handle_vq(vs, vq);
1426}
1427
1428/* Callers must hold dev mutex */
1429static void vhost_scsi_flush(struct vhost_scsi *vs)
1430{
1431	int i;
1432
1433	/* Init new inflight and remember the old inflight */
1434	vhost_scsi_init_inflight(vs, vs->old_inflight);
1435
1436	/*
1437	 * The inflight->kref was initialized to 1. We decrement it here to
1438	 * indicate the start of the flush operation so that it will reach 0
1439	 * when all the reqs are finished.
1440	 */
1441	for (i = 0; i < vs->dev.nvqs; i++)
1442		kref_put(&vs->old_inflight[i]->kref, vhost_scsi_done_inflight);
1443
1444	/* Flush both the vhost poll and vhost work */
1445	vhost_dev_flush(&vs->dev);
1446
1447	/* Wait for all reqs issued before the flush to be finished */
1448	for (i = 0; i < vs->dev.nvqs; i++)
1449		wait_for_completion(&vs->old_inflight[i]->comp);
1450}
1451
1452static void vhost_scsi_destroy_vq_cmds(struct vhost_virtqueue *vq)
1453{
1454	struct vhost_scsi_virtqueue *svq = container_of(vq,
1455					struct vhost_scsi_virtqueue, vq);
1456	struct vhost_scsi_cmd *tv_cmd;
1457	unsigned int i;
1458
1459	if (!svq->scsi_cmds)
1460		return;
1461
1462	for (i = 0; i < svq->max_cmds; i++) {
1463		tv_cmd = &svq->scsi_cmds[i];
1464
1465		kfree(tv_cmd->tvc_sgl);
1466		kfree(tv_cmd->tvc_prot_sgl);
1467		kfree(tv_cmd->tvc_upages);
1468		kfree(tv_cmd->tvc_resp_iov);
1469	}
1470
1471	sbitmap_free(&svq->scsi_tags);
1472	kfree(svq->scsi_cmds);
1473	svq->scsi_cmds = NULL;
1474}
1475
1476static int vhost_scsi_setup_vq_cmds(struct vhost_virtqueue *vq, int max_cmds)
1477{
1478	struct vhost_scsi_virtqueue *svq = container_of(vq,
1479					struct vhost_scsi_virtqueue, vq);
1480	struct vhost_scsi_cmd *tv_cmd;
1481	unsigned int i;
1482
1483	if (svq->scsi_cmds)
1484		return 0;
1485
1486	if (sbitmap_init_node(&svq->scsi_tags, max_cmds, -1, GFP_KERNEL,
1487			      NUMA_NO_NODE, false, true))
1488		return -ENOMEM;
1489	svq->max_cmds = max_cmds;
1490
1491	svq->scsi_cmds = kcalloc(max_cmds, sizeof(*tv_cmd), GFP_KERNEL);
1492	if (!svq->scsi_cmds) {
1493		sbitmap_free(&svq->scsi_tags);
1494		return -ENOMEM;
1495	}
1496
1497	for (i = 0; i < max_cmds; i++) {
1498		tv_cmd = &svq->scsi_cmds[i];
1499
1500		tv_cmd->tvc_sgl = kcalloc(VHOST_SCSI_PREALLOC_SGLS,
1501					  sizeof(struct scatterlist),
1502					  GFP_KERNEL);
1503		if (!tv_cmd->tvc_sgl) {
1504			pr_err("Unable to allocate tv_cmd->tvc_sgl\n");
1505			goto out;
1506		}
1507
1508		tv_cmd->tvc_upages = kcalloc(VHOST_SCSI_PREALLOC_UPAGES,
1509					     sizeof(struct page *),
1510					     GFP_KERNEL);
1511		if (!tv_cmd->tvc_upages) {
1512			pr_err("Unable to allocate tv_cmd->tvc_upages\n");
1513			goto out;
1514		}
1515
1516		tv_cmd->tvc_resp_iov = kcalloc(UIO_MAXIOV,
1517					       sizeof(struct iovec),
1518					       GFP_KERNEL);
1519		if (!tv_cmd->tvc_resp_iov) {
1520			pr_err("Unable to allocate tv_cmd->tvc_resp_iov\n");
1521			goto out;
1522		}
1523
1524		tv_cmd->tvc_prot_sgl = kcalloc(VHOST_SCSI_PREALLOC_PROT_SGLS,
1525					       sizeof(struct scatterlist),
1526					       GFP_KERNEL);
1527		if (!tv_cmd->tvc_prot_sgl) {
1528			pr_err("Unable to allocate tv_cmd->tvc_prot_sgl\n");
1529			goto out;
1530		}
1531	}
1532	return 0;
1533out:
1534	vhost_scsi_destroy_vq_cmds(vq);
1535	return -ENOMEM;
1536}
1537
1538/*
1539 * Called from vhost_scsi_ioctl() context to walk the list of available
1540 * vhost_scsi_tpg with an active struct vhost_scsi_nexus
1541 *
1542 *  The lock nesting rule is:
1543 *    vhost_scsi_mutex -> vs->dev.mutex -> tpg->tv_tpg_mutex -> vq->mutex
1544 */
1545static int
1546vhost_scsi_set_endpoint(struct vhost_scsi *vs,
1547			struct vhost_scsi_target *t)
1548{
1549	struct se_portal_group *se_tpg;
1550	struct vhost_scsi_tport *tv_tport;
1551	struct vhost_scsi_tpg *tpg;
1552	struct vhost_scsi_tpg **vs_tpg;
1553	struct vhost_virtqueue *vq;
1554	int index, ret, i, len;
1555	bool match = false;
1556
1557	mutex_lock(&vhost_scsi_mutex);
1558	mutex_lock(&vs->dev.mutex);
1559
1560	/* Verify that ring has been setup correctly. */
1561	for (index = 0; index < vs->dev.nvqs; ++index) {
1562		/* Verify that ring has been setup correctly. */
1563		if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1564			ret = -EFAULT;
1565			goto out;
1566		}
1567	}
1568
1569	len = sizeof(vs_tpg[0]) * VHOST_SCSI_MAX_TARGET;
1570	vs_tpg = kzalloc(len, GFP_KERNEL);
1571	if (!vs_tpg) {
1572		ret = -ENOMEM;
1573		goto out;
1574	}
1575	if (vs->vs_tpg)
1576		memcpy(vs_tpg, vs->vs_tpg, len);
1577
1578	list_for_each_entry(tpg, &vhost_scsi_list, tv_tpg_list) {
1579		mutex_lock(&tpg->tv_tpg_mutex);
1580		if (!tpg->tpg_nexus) {
1581			mutex_unlock(&tpg->tv_tpg_mutex);
1582			continue;
1583		}
1584		if (tpg->tv_tpg_vhost_count != 0) {
1585			mutex_unlock(&tpg->tv_tpg_mutex);
1586			continue;
1587		}
1588		tv_tport = tpg->tport;
1589
1590		if (!strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1591			if (vs->vs_tpg && vs->vs_tpg[tpg->tport_tpgt]) {
1592				mutex_unlock(&tpg->tv_tpg_mutex);
1593				ret = -EEXIST;
1594				goto undepend;
1595			}
1596			/*
1597			 * In order to ensure individual vhost-scsi configfs
1598			 * groups cannot be removed while in use by vhost ioctl,
1599			 * go ahead and take an explicit se_tpg->tpg_group.cg_item
1600			 * dependency now.
1601			 */
1602			se_tpg = &tpg->se_tpg;
1603			ret = target_depend_item(&se_tpg->tpg_group.cg_item);
1604			if (ret) {
1605				pr_warn("target_depend_item() failed: %d\n", ret);
1606				mutex_unlock(&tpg->tv_tpg_mutex);
1607				goto undepend;
1608			}
1609			tpg->tv_tpg_vhost_count++;
1610			tpg->vhost_scsi = vs;
1611			vs_tpg[tpg->tport_tpgt] = tpg;
1612			match = true;
1613		}
1614		mutex_unlock(&tpg->tv_tpg_mutex);
1615	}
1616
1617	if (match) {
1618		memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn,
1619		       sizeof(vs->vs_vhost_wwpn));
1620
1621		for (i = VHOST_SCSI_VQ_IO; i < vs->dev.nvqs; i++) {
1622			vq = &vs->vqs[i].vq;
1623			if (!vhost_vq_is_setup(vq))
1624				continue;
1625
1626			ret = vhost_scsi_setup_vq_cmds(vq, vq->num);
1627			if (ret)
1628				goto destroy_vq_cmds;
1629		}
1630
1631		for (i = 0; i < vs->dev.nvqs; i++) {
1632			vq = &vs->vqs[i].vq;
1633			mutex_lock(&vq->mutex);
1634			vhost_vq_set_backend(vq, vs_tpg);
1635			vhost_vq_init_access(vq);
1636			mutex_unlock(&vq->mutex);
1637		}
1638		ret = 0;
1639	} else {
1640		ret = -EEXIST;
1641	}
1642
1643	/*
1644	 * Act as synchronize_rcu to make sure access to
1645	 * old vs->vs_tpg is finished.
1646	 */
1647	vhost_scsi_flush(vs);
1648	kfree(vs->vs_tpg);
1649	vs->vs_tpg = vs_tpg;
1650	goto out;
1651
1652destroy_vq_cmds:
1653	for (i--; i >= VHOST_SCSI_VQ_IO; i--) {
1654		if (!vhost_vq_get_backend(&vs->vqs[i].vq))
1655			vhost_scsi_destroy_vq_cmds(&vs->vqs[i].vq);
1656	}
1657undepend:
1658	for (i = 0; i < VHOST_SCSI_MAX_TARGET; i++) {
1659		tpg = vs_tpg[i];
1660		if (tpg) {
1661			tpg->tv_tpg_vhost_count--;
1662			target_undepend_item(&tpg->se_tpg.tpg_group.cg_item);
1663		}
1664	}
1665	kfree(vs_tpg);
1666out:
1667	mutex_unlock(&vs->dev.mutex);
1668	mutex_unlock(&vhost_scsi_mutex);
1669	return ret;
1670}
1671
1672static int
1673vhost_scsi_clear_endpoint(struct vhost_scsi *vs,
1674			  struct vhost_scsi_target *t)
1675{
1676	struct se_portal_group *se_tpg;
1677	struct vhost_scsi_tport *tv_tport;
1678	struct vhost_scsi_tpg *tpg;
1679	struct vhost_virtqueue *vq;
1680	bool match = false;
1681	int index, ret, i;
1682	u8 target;
1683
1684	mutex_lock(&vhost_scsi_mutex);
1685	mutex_lock(&vs->dev.mutex);
1686	/* Verify that ring has been setup correctly. */
1687	for (index = 0; index < vs->dev.nvqs; ++index) {
1688		if (!vhost_vq_access_ok(&vs->vqs[index].vq)) {
1689			ret = -EFAULT;
1690			goto err_dev;
1691		}
1692	}
1693
1694	if (!vs->vs_tpg) {
1695		ret = 0;
1696		goto err_dev;
1697	}
1698
1699	for (i = 0; i < VHOST_SCSI_MAX_TARGET; i++) {
1700		target = i;
1701		tpg = vs->vs_tpg[target];
1702		if (!tpg)
1703			continue;
1704
1705		mutex_lock(&tpg->tv_tpg_mutex);
1706		tv_tport = tpg->tport;
1707		if (!tv_tport) {
1708			ret = -ENODEV;
1709			goto err_tpg;
1710		}
1711
1712		if (strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
1713			pr_warn("tv_tport->tport_name: %s, tpg->tport_tpgt: %hu"
1714				" does not match t->vhost_wwpn: %s, t->vhost_tpgt: %hu\n",
1715				tv_tport->tport_name, tpg->tport_tpgt,
1716				t->vhost_wwpn, t->vhost_tpgt);
1717			ret = -EINVAL;
1718			goto err_tpg;
1719		}
1720		tpg->tv_tpg_vhost_count--;
1721		tpg->vhost_scsi = NULL;
1722		vs->vs_tpg[target] = NULL;
1723		match = true;
1724		mutex_unlock(&tpg->tv_tpg_mutex);
1725		/*
1726		 * Release se_tpg->tpg_group.cg_item configfs dependency now
1727		 * to allow vhost-scsi WWPN se_tpg->tpg_group shutdown to occur.
1728		 */
1729		se_tpg = &tpg->se_tpg;
1730		target_undepend_item(&se_tpg->tpg_group.cg_item);
1731	}
1732	if (match) {
1733		for (i = 0; i < vs->dev.nvqs; i++) {
1734			vq = &vs->vqs[i].vq;
1735			mutex_lock(&vq->mutex);
1736			vhost_vq_set_backend(vq, NULL);
1737			mutex_unlock(&vq->mutex);
1738		}
1739		/* Make sure cmds are not running before tearing them down. */
1740		vhost_scsi_flush(vs);
1741
1742		for (i = 0; i < vs->dev.nvqs; i++) {
1743			vq = &vs->vqs[i].vq;
1744			vhost_scsi_destroy_vq_cmds(vq);
1745		}
1746	}
1747	/*
1748	 * Act as synchronize_rcu to make sure access to
1749	 * old vs->vs_tpg is finished.
1750	 */
1751	vhost_scsi_flush(vs);
1752	kfree(vs->vs_tpg);
1753	vs->vs_tpg = NULL;
1754	WARN_ON(vs->vs_events_nr);
1755	mutex_unlock(&vs->dev.mutex);
1756	mutex_unlock(&vhost_scsi_mutex);
1757	return 0;
1758
1759err_tpg:
1760	mutex_unlock(&tpg->tv_tpg_mutex);
1761err_dev:
1762	mutex_unlock(&vs->dev.mutex);
1763	mutex_unlock(&vhost_scsi_mutex);
1764	return ret;
1765}
1766
1767static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
1768{
1769	struct vhost_virtqueue *vq;
1770	int i;
1771
1772	if (features & ~VHOST_SCSI_FEATURES)
1773		return -EOPNOTSUPP;
1774
1775	mutex_lock(&vs->dev.mutex);
1776	if ((features & (1 << VHOST_F_LOG_ALL)) &&
1777	    !vhost_log_access_ok(&vs->dev)) {
1778		mutex_unlock(&vs->dev.mutex);
1779		return -EFAULT;
1780	}
1781
1782	for (i = 0; i < vs->dev.nvqs; i++) {
1783		vq = &vs->vqs[i].vq;
1784		mutex_lock(&vq->mutex);
1785		vq->acked_features = features;
1786		mutex_unlock(&vq->mutex);
1787	}
1788	mutex_unlock(&vs->dev.mutex);
1789	return 0;
1790}
1791
1792static int vhost_scsi_open(struct inode *inode, struct file *f)
1793{
1794	struct vhost_scsi *vs;
1795	struct vhost_virtqueue **vqs;
1796	int r = -ENOMEM, i, nvqs = vhost_scsi_max_io_vqs;
1797
1798	vs = kvzalloc(sizeof(*vs), GFP_KERNEL);
1799	if (!vs)
1800		goto err_vs;
1801
1802	if (nvqs > VHOST_SCSI_MAX_IO_VQ) {
1803		pr_err("Invalid max_io_vqs of %d. Using %d.\n", nvqs,
1804		       VHOST_SCSI_MAX_IO_VQ);
1805		nvqs = VHOST_SCSI_MAX_IO_VQ;
1806	} else if (nvqs == 0) {
1807		pr_err("Invalid max_io_vqs of %d. Using 1.\n", nvqs);
1808		nvqs = 1;
1809	}
1810	nvqs += VHOST_SCSI_VQ_IO;
1811
1812	vs->compl_bitmap = bitmap_alloc(nvqs, GFP_KERNEL);
1813	if (!vs->compl_bitmap)
1814		goto err_compl_bitmap;
1815
1816	vs->old_inflight = kmalloc_array(nvqs, sizeof(*vs->old_inflight),
1817					 GFP_KERNEL | __GFP_ZERO);
1818	if (!vs->old_inflight)
1819		goto err_inflight;
1820
1821	vs->vqs = kmalloc_array(nvqs, sizeof(*vs->vqs),
1822				GFP_KERNEL | __GFP_ZERO);
1823	if (!vs->vqs)
1824		goto err_vqs;
1825
1826	vqs = kmalloc_array(nvqs, sizeof(*vqs), GFP_KERNEL);
1827	if (!vqs)
1828		goto err_local_vqs;
1829
1830	vhost_work_init(&vs->vs_completion_work, vhost_scsi_complete_cmd_work);
1831	vhost_work_init(&vs->vs_event_work, vhost_scsi_evt_work);
1832
1833	vs->vs_events_nr = 0;
1834	vs->vs_events_missed = false;
1835
1836	vqs[VHOST_SCSI_VQ_CTL] = &vs->vqs[VHOST_SCSI_VQ_CTL].vq;
1837	vqs[VHOST_SCSI_VQ_EVT] = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1838	vs->vqs[VHOST_SCSI_VQ_CTL].vq.handle_kick = vhost_scsi_ctl_handle_kick;
1839	vs->vqs[VHOST_SCSI_VQ_EVT].vq.handle_kick = vhost_scsi_evt_handle_kick;
1840	for (i = VHOST_SCSI_VQ_IO; i < nvqs; i++) {
1841		vqs[i] = &vs->vqs[i].vq;
1842		vs->vqs[i].vq.handle_kick = vhost_scsi_handle_kick;
1843	}
1844	vhost_dev_init(&vs->dev, vqs, nvqs, UIO_MAXIOV,
1845		       VHOST_SCSI_WEIGHT, 0, true, NULL);
1846
1847	vhost_scsi_init_inflight(vs, NULL);
1848
1849	f->private_data = vs;
1850	return 0;
1851
1852err_local_vqs:
1853	kfree(vs->vqs);
1854err_vqs:
1855	kfree(vs->old_inflight);
1856err_inflight:
1857	bitmap_free(vs->compl_bitmap);
1858err_compl_bitmap:
1859	kvfree(vs);
1860err_vs:
1861	return r;
1862}
1863
1864static int vhost_scsi_release(struct inode *inode, struct file *f)
1865{
1866	struct vhost_scsi *vs = f->private_data;
1867	struct vhost_scsi_target t;
1868
1869	mutex_lock(&vs->dev.mutex);
1870	memcpy(t.vhost_wwpn, vs->vs_vhost_wwpn, sizeof(t.vhost_wwpn));
1871	mutex_unlock(&vs->dev.mutex);
1872	vhost_scsi_clear_endpoint(vs, &t);
1873	vhost_dev_stop(&vs->dev);
1874	vhost_dev_cleanup(&vs->dev);
1875	kfree(vs->dev.vqs);
1876	kfree(vs->vqs);
1877	kfree(vs->old_inflight);
1878	bitmap_free(vs->compl_bitmap);
1879	kvfree(vs);
1880	return 0;
1881}
1882
1883static long
1884vhost_scsi_ioctl(struct file *f,
1885		 unsigned int ioctl,
1886		 unsigned long arg)
1887{
1888	struct vhost_scsi *vs = f->private_data;
1889	struct vhost_scsi_target backend;
1890	void __user *argp = (void __user *)arg;
1891	u64 __user *featurep = argp;
1892	u32 __user *eventsp = argp;
1893	u32 events_missed;
1894	u64 features;
1895	int r, abi_version = VHOST_SCSI_ABI_VERSION;
1896	struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
1897
1898	switch (ioctl) {
1899	case VHOST_SCSI_SET_ENDPOINT:
1900		if (copy_from_user(&backend, argp, sizeof backend))
1901			return -EFAULT;
1902		if (backend.reserved != 0)
1903			return -EOPNOTSUPP;
1904
1905		return vhost_scsi_set_endpoint(vs, &backend);
1906	case VHOST_SCSI_CLEAR_ENDPOINT:
1907		if (copy_from_user(&backend, argp, sizeof backend))
1908			return -EFAULT;
1909		if (backend.reserved != 0)
1910			return -EOPNOTSUPP;
1911
1912		return vhost_scsi_clear_endpoint(vs, &backend);
1913	case VHOST_SCSI_GET_ABI_VERSION:
1914		if (copy_to_user(argp, &abi_version, sizeof abi_version))
1915			return -EFAULT;
1916		return 0;
1917	case VHOST_SCSI_SET_EVENTS_MISSED:
1918		if (get_user(events_missed, eventsp))
1919			return -EFAULT;
1920		mutex_lock(&vq->mutex);
1921		vs->vs_events_missed = events_missed;
1922		mutex_unlock(&vq->mutex);
1923		return 0;
1924	case VHOST_SCSI_GET_EVENTS_MISSED:
1925		mutex_lock(&vq->mutex);
1926		events_missed = vs->vs_events_missed;
1927		mutex_unlock(&vq->mutex);
1928		if (put_user(events_missed, eventsp))
1929			return -EFAULT;
1930		return 0;
1931	case VHOST_GET_FEATURES:
1932		features = VHOST_SCSI_FEATURES;
1933		if (copy_to_user(featurep, &features, sizeof features))
1934			return -EFAULT;
1935		return 0;
1936	case VHOST_SET_FEATURES:
1937		if (copy_from_user(&features, featurep, sizeof features))
1938			return -EFAULT;
1939		return vhost_scsi_set_features(vs, features);
1940	default:
1941		mutex_lock(&vs->dev.mutex);
1942		r = vhost_dev_ioctl(&vs->dev, ioctl, argp);
1943		/* TODO: flush backend after dev ioctl. */
1944		if (r == -ENOIOCTLCMD)
1945			r = vhost_vring_ioctl(&vs->dev, ioctl, argp);
1946		mutex_unlock(&vs->dev.mutex);
1947		return r;
1948	}
1949}
1950
1951static const struct file_operations vhost_scsi_fops = {
1952	.owner          = THIS_MODULE,
1953	.release        = vhost_scsi_release,
1954	.unlocked_ioctl = vhost_scsi_ioctl,
1955	.compat_ioctl	= compat_ptr_ioctl,
1956	.open           = vhost_scsi_open,
1957	.llseek		= noop_llseek,
1958};
1959
1960static struct miscdevice vhost_scsi_misc = {
1961	MISC_DYNAMIC_MINOR,
1962	"vhost-scsi",
1963	&vhost_scsi_fops,
1964};
1965
1966static int __init vhost_scsi_register(void)
1967{
1968	return misc_register(&vhost_scsi_misc);
1969}
1970
1971static void vhost_scsi_deregister(void)
1972{
1973	misc_deregister(&vhost_scsi_misc);
1974}
1975
1976static char *vhost_scsi_dump_proto_id(struct vhost_scsi_tport *tport)
1977{
1978	switch (tport->tport_proto_id) {
1979	case SCSI_PROTOCOL_SAS:
1980		return "SAS";
1981	case SCSI_PROTOCOL_FCP:
1982		return "FCP";
1983	case SCSI_PROTOCOL_ISCSI:
1984		return "iSCSI";
1985	default:
1986		break;
1987	}
1988
1989	return "Unknown";
1990}
1991
1992static void
1993vhost_scsi_do_plug(struct vhost_scsi_tpg *tpg,
1994		  struct se_lun *lun, bool plug)
1995{
1996
1997	struct vhost_scsi *vs = tpg->vhost_scsi;
1998	struct vhost_virtqueue *vq;
1999	u32 reason;
2000
2001	if (!vs)
2002		return;
2003
2004	mutex_lock(&vs->dev.mutex);
2005
2006	if (plug)
2007		reason = VIRTIO_SCSI_EVT_RESET_RESCAN;
2008	else
2009		reason = VIRTIO_SCSI_EVT_RESET_REMOVED;
2010
2011	vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
2012	mutex_lock(&vq->mutex);
2013	if (vhost_has_feature(vq, VIRTIO_SCSI_F_HOTPLUG))
2014		vhost_scsi_send_evt(vs, tpg, lun,
2015				   VIRTIO_SCSI_T_TRANSPORT_RESET, reason);
2016	mutex_unlock(&vq->mutex);
2017	mutex_unlock(&vs->dev.mutex);
2018}
2019
2020static void vhost_scsi_hotplug(struct vhost_scsi_tpg *tpg, struct se_lun *lun)
2021{
2022	vhost_scsi_do_plug(tpg, lun, true);
2023}
2024
2025static void vhost_scsi_hotunplug(struct vhost_scsi_tpg *tpg, struct se_lun *lun)
2026{
2027	vhost_scsi_do_plug(tpg, lun, false);
2028}
2029
2030static int vhost_scsi_port_link(struct se_portal_group *se_tpg,
2031			       struct se_lun *lun)
2032{
2033	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2034				struct vhost_scsi_tpg, se_tpg);
2035	struct vhost_scsi_tmf *tmf;
2036
2037	tmf = kzalloc(sizeof(*tmf), GFP_KERNEL);
2038	if (!tmf)
2039		return -ENOMEM;
2040	INIT_LIST_HEAD(&tmf->queue_entry);
2041	vhost_work_init(&tmf->vwork, vhost_scsi_tmf_resp_work);
2042
2043	mutex_lock(&vhost_scsi_mutex);
2044
2045	mutex_lock(&tpg->tv_tpg_mutex);
2046	tpg->tv_tpg_port_count++;
2047	list_add_tail(&tmf->queue_entry, &tpg->tmf_queue);
2048	mutex_unlock(&tpg->tv_tpg_mutex);
2049
2050	vhost_scsi_hotplug(tpg, lun);
2051
2052	mutex_unlock(&vhost_scsi_mutex);
2053
2054	return 0;
2055}
2056
2057static void vhost_scsi_port_unlink(struct se_portal_group *se_tpg,
2058				  struct se_lun *lun)
2059{
2060	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2061				struct vhost_scsi_tpg, se_tpg);
2062	struct vhost_scsi_tmf *tmf;
2063
2064	mutex_lock(&vhost_scsi_mutex);
2065
2066	mutex_lock(&tpg->tv_tpg_mutex);
2067	tpg->tv_tpg_port_count--;
2068	tmf = list_first_entry(&tpg->tmf_queue, struct vhost_scsi_tmf,
2069			       queue_entry);
2070	list_del(&tmf->queue_entry);
2071	kfree(tmf);
2072	mutex_unlock(&tpg->tv_tpg_mutex);
2073
2074	vhost_scsi_hotunplug(tpg, lun);
2075
2076	mutex_unlock(&vhost_scsi_mutex);
2077}
2078
2079static ssize_t vhost_scsi_tpg_attrib_fabric_prot_type_store(
2080		struct config_item *item, const char *page, size_t count)
2081{
2082	struct se_portal_group *se_tpg = attrib_to_tpg(item);
2083	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2084				struct vhost_scsi_tpg, se_tpg);
2085	unsigned long val;
2086	int ret = kstrtoul(page, 0, &val);
2087
2088	if (ret) {
2089		pr_err("kstrtoul() returned %d for fabric_prot_type\n", ret);
2090		return ret;
2091	}
2092	if (val != 0 && val != 1 && val != 3) {
2093		pr_err("Invalid vhost_scsi fabric_prot_type: %lu\n", val);
2094		return -EINVAL;
2095	}
2096	tpg->tv_fabric_prot_type = val;
2097
2098	return count;
2099}
2100
2101static ssize_t vhost_scsi_tpg_attrib_fabric_prot_type_show(
2102		struct config_item *item, char *page)
2103{
2104	struct se_portal_group *se_tpg = attrib_to_tpg(item);
2105	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2106				struct vhost_scsi_tpg, se_tpg);
2107
2108	return sprintf(page, "%d\n", tpg->tv_fabric_prot_type);
2109}
2110
2111CONFIGFS_ATTR(vhost_scsi_tpg_attrib_, fabric_prot_type);
2112
2113static struct configfs_attribute *vhost_scsi_tpg_attrib_attrs[] = {
2114	&vhost_scsi_tpg_attrib_attr_fabric_prot_type,
2115	NULL,
2116};
2117
2118static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
2119				const char *name)
2120{
2121	struct vhost_scsi_nexus *tv_nexus;
2122
2123	mutex_lock(&tpg->tv_tpg_mutex);
2124	if (tpg->tpg_nexus) {
2125		mutex_unlock(&tpg->tv_tpg_mutex);
2126		pr_debug("tpg->tpg_nexus already exists\n");
2127		return -EEXIST;
2128	}
2129
2130	tv_nexus = kzalloc(sizeof(*tv_nexus), GFP_KERNEL);
2131	if (!tv_nexus) {
2132		mutex_unlock(&tpg->tv_tpg_mutex);
2133		pr_err("Unable to allocate struct vhost_scsi_nexus\n");
2134		return -ENOMEM;
2135	}
2136	/*
2137	 * Since we are running in 'demo mode' this call with generate a
2138	 * struct se_node_acl for the vhost_scsi struct se_portal_group with
2139	 * the SCSI Initiator port name of the passed configfs group 'name'.
2140	 */
2141	tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg, 0, 0,
2142					TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
2143					(unsigned char *)name, tv_nexus, NULL);
2144	if (IS_ERR(tv_nexus->tvn_se_sess)) {
2145		mutex_unlock(&tpg->tv_tpg_mutex);
2146		kfree(tv_nexus);
2147		return -ENOMEM;
2148	}
2149	tpg->tpg_nexus = tv_nexus;
2150
2151	mutex_unlock(&tpg->tv_tpg_mutex);
2152	return 0;
2153}
2154
2155static int vhost_scsi_drop_nexus(struct vhost_scsi_tpg *tpg)
2156{
2157	struct se_session *se_sess;
2158	struct vhost_scsi_nexus *tv_nexus;
2159
2160	mutex_lock(&tpg->tv_tpg_mutex);
2161	tv_nexus = tpg->tpg_nexus;
2162	if (!tv_nexus) {
2163		mutex_unlock(&tpg->tv_tpg_mutex);
2164		return -ENODEV;
2165	}
2166
2167	se_sess = tv_nexus->tvn_se_sess;
2168	if (!se_sess) {
2169		mutex_unlock(&tpg->tv_tpg_mutex);
2170		return -ENODEV;
2171	}
2172
2173	if (tpg->tv_tpg_port_count != 0) {
2174		mutex_unlock(&tpg->tv_tpg_mutex);
2175		pr_err("Unable to remove TCM_vhost I_T Nexus with"
2176			" active TPG port count: %d\n",
2177			tpg->tv_tpg_port_count);
2178		return -EBUSY;
2179	}
2180
2181	if (tpg->tv_tpg_vhost_count != 0) {
2182		mutex_unlock(&tpg->tv_tpg_mutex);
2183		pr_err("Unable to remove TCM_vhost I_T Nexus with"
2184			" active TPG vhost count: %d\n",
2185			tpg->tv_tpg_vhost_count);
2186		return -EBUSY;
2187	}
2188
2189	pr_debug("TCM_vhost_ConfigFS: Removing I_T Nexus to emulated"
2190		" %s Initiator Port: %s\n", vhost_scsi_dump_proto_id(tpg->tport),
2191		tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
2192
2193	/*
2194	 * Release the SCSI I_T Nexus to the emulated vhost Target Port
2195	 */
2196	target_remove_session(se_sess);
2197	tpg->tpg_nexus = NULL;
2198	mutex_unlock(&tpg->tv_tpg_mutex);
2199
2200	kfree(tv_nexus);
2201	return 0;
2202}
2203
2204static ssize_t vhost_scsi_tpg_nexus_show(struct config_item *item, char *page)
2205{
2206	struct se_portal_group *se_tpg = to_tpg(item);
2207	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2208				struct vhost_scsi_tpg, se_tpg);
2209	struct vhost_scsi_nexus *tv_nexus;
2210	ssize_t ret;
2211
2212	mutex_lock(&tpg->tv_tpg_mutex);
2213	tv_nexus = tpg->tpg_nexus;
2214	if (!tv_nexus) {
2215		mutex_unlock(&tpg->tv_tpg_mutex);
2216		return -ENODEV;
2217	}
2218	ret = snprintf(page, PAGE_SIZE, "%s\n",
2219			tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
2220	mutex_unlock(&tpg->tv_tpg_mutex);
2221
2222	return ret;
2223}
2224
2225static ssize_t vhost_scsi_tpg_nexus_store(struct config_item *item,
2226		const char *page, size_t count)
2227{
2228	struct se_portal_group *se_tpg = to_tpg(item);
2229	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2230				struct vhost_scsi_tpg, se_tpg);
2231	struct vhost_scsi_tport *tport_wwn = tpg->tport;
2232	unsigned char i_port[VHOST_SCSI_NAMELEN], *ptr, *port_ptr;
2233	int ret;
2234	/*
2235	 * Shutdown the active I_T nexus if 'NULL' is passed..
2236	 */
2237	if (!strncmp(page, "NULL", 4)) {
2238		ret = vhost_scsi_drop_nexus(tpg);
2239		return (!ret) ? count : ret;
2240	}
2241	/*
2242	 * Otherwise make sure the passed virtual Initiator port WWN matches
2243	 * the fabric protocol_id set in vhost_scsi_make_tport(), and call
2244	 * vhost_scsi_make_nexus().
2245	 */
2246	if (strlen(page) >= VHOST_SCSI_NAMELEN) {
2247		pr_err("Emulated NAA Sas Address: %s, exceeds"
2248				" max: %d\n", page, VHOST_SCSI_NAMELEN);
2249		return -EINVAL;
2250	}
2251	snprintf(&i_port[0], VHOST_SCSI_NAMELEN, "%s", page);
2252
2253	ptr = strstr(i_port, "naa.");
2254	if (ptr) {
2255		if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
2256			pr_err("Passed SAS Initiator Port %s does not"
2257				" match target port protoid: %s\n", i_port,
2258				vhost_scsi_dump_proto_id(tport_wwn));
2259			return -EINVAL;
2260		}
2261		port_ptr = &i_port[0];
2262		goto check_newline;
2263	}
2264	ptr = strstr(i_port, "fc.");
2265	if (ptr) {
2266		if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
2267			pr_err("Passed FCP Initiator Port %s does not"
2268				" match target port protoid: %s\n", i_port,
2269				vhost_scsi_dump_proto_id(tport_wwn));
2270			return -EINVAL;
2271		}
2272		port_ptr = &i_port[3]; /* Skip over "fc." */
2273		goto check_newline;
2274	}
2275	ptr = strstr(i_port, "iqn.");
2276	if (ptr) {
2277		if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
2278			pr_err("Passed iSCSI Initiator Port %s does not"
2279				" match target port protoid: %s\n", i_port,
2280				vhost_scsi_dump_proto_id(tport_wwn));
2281			return -EINVAL;
2282		}
2283		port_ptr = &i_port[0];
2284		goto check_newline;
2285	}
2286	pr_err("Unable to locate prefix for emulated Initiator Port:"
2287			" %s\n", i_port);
2288	return -EINVAL;
2289	/*
2290	 * Clear any trailing newline for the NAA WWN
2291	 */
2292check_newline:
2293	if (i_port[strlen(i_port)-1] == '\n')
2294		i_port[strlen(i_port)-1] = '\0';
2295
2296	ret = vhost_scsi_make_nexus(tpg, port_ptr);
2297	if (ret < 0)
2298		return ret;
2299
2300	return count;
2301}
2302
2303CONFIGFS_ATTR(vhost_scsi_tpg_, nexus);
2304
2305static struct configfs_attribute *vhost_scsi_tpg_attrs[] = {
2306	&vhost_scsi_tpg_attr_nexus,
2307	NULL,
2308};
2309
2310static struct se_portal_group *
2311vhost_scsi_make_tpg(struct se_wwn *wwn, const char *name)
2312{
2313	struct vhost_scsi_tport *tport = container_of(wwn,
2314			struct vhost_scsi_tport, tport_wwn);
2315
2316	struct vhost_scsi_tpg *tpg;
2317	u16 tpgt;
2318	int ret;
2319
2320	if (strstr(name, "tpgt_") != name)
2321		return ERR_PTR(-EINVAL);
2322	if (kstrtou16(name + 5, 10, &tpgt) || tpgt >= VHOST_SCSI_MAX_TARGET)
2323		return ERR_PTR(-EINVAL);
2324
2325	tpg = kzalloc(sizeof(*tpg), GFP_KERNEL);
2326	if (!tpg) {
2327		pr_err("Unable to allocate struct vhost_scsi_tpg");
2328		return ERR_PTR(-ENOMEM);
2329	}
2330	mutex_init(&tpg->tv_tpg_mutex);
2331	INIT_LIST_HEAD(&tpg->tv_tpg_list);
2332	INIT_LIST_HEAD(&tpg->tmf_queue);
2333	tpg->tport = tport;
2334	tpg->tport_tpgt = tpgt;
2335
2336	ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
2337	if (ret < 0) {
2338		kfree(tpg);
2339		return NULL;
2340	}
2341	mutex_lock(&vhost_scsi_mutex);
2342	list_add_tail(&tpg->tv_tpg_list, &vhost_scsi_list);
2343	mutex_unlock(&vhost_scsi_mutex);
2344
2345	return &tpg->se_tpg;
2346}
2347
2348static void vhost_scsi_drop_tpg(struct se_portal_group *se_tpg)
2349{
2350	struct vhost_scsi_tpg *tpg = container_of(se_tpg,
2351				struct vhost_scsi_tpg, se_tpg);
2352
2353	mutex_lock(&vhost_scsi_mutex);
2354	list_del(&tpg->tv_tpg_list);
2355	mutex_unlock(&vhost_scsi_mutex);
2356	/*
2357	 * Release the virtual I_T Nexus for this vhost TPG
2358	 */
2359	vhost_scsi_drop_nexus(tpg);
2360	/*
2361	 * Deregister the se_tpg from TCM..
2362	 */
2363	core_tpg_deregister(se_tpg);
2364	kfree(tpg);
2365}
2366
2367static struct se_wwn *
2368vhost_scsi_make_tport(struct target_fabric_configfs *tf,
2369		     struct config_group *group,
2370		     const char *name)
2371{
2372	struct vhost_scsi_tport *tport;
2373	char *ptr;
2374	u64 wwpn = 0;
2375	int off = 0;
2376
2377	/* if (vhost_scsi_parse_wwn(name, &wwpn, 1) < 0)
2378		return ERR_PTR(-EINVAL); */
2379
2380	tport = kzalloc(sizeof(*tport), GFP_KERNEL);
2381	if (!tport) {
2382		pr_err("Unable to allocate struct vhost_scsi_tport");
2383		return ERR_PTR(-ENOMEM);
2384	}
2385	tport->tport_wwpn = wwpn;
2386	/*
2387	 * Determine the emulated Protocol Identifier and Target Port Name
2388	 * based on the incoming configfs directory name.
2389	 */
2390	ptr = strstr(name, "naa.");
2391	if (ptr) {
2392		tport->tport_proto_id = SCSI_PROTOCOL_SAS;
2393		goto check_len;
2394	}
2395	ptr = strstr(name, "fc.");
2396	if (ptr) {
2397		tport->tport_proto_id = SCSI_PROTOCOL_FCP;
2398		off = 3; /* Skip over "fc." */
2399		goto check_len;
2400	}
2401	ptr = strstr(name, "iqn.");
2402	if (ptr) {
2403		tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
2404		goto check_len;
2405	}
2406
2407	pr_err("Unable to locate prefix for emulated Target Port:"
2408			" %s\n", name);
2409	kfree(tport);
2410	return ERR_PTR(-EINVAL);
2411
2412check_len:
2413	if (strlen(name) >= VHOST_SCSI_NAMELEN) {
2414		pr_err("Emulated %s Address: %s, exceeds"
2415			" max: %d\n", name, vhost_scsi_dump_proto_id(tport),
2416			VHOST_SCSI_NAMELEN);
2417		kfree(tport);
2418		return ERR_PTR(-EINVAL);
2419	}
2420	snprintf(&tport->tport_name[0], VHOST_SCSI_NAMELEN, "%s", &name[off]);
2421
2422	pr_debug("TCM_VHost_ConfigFS: Allocated emulated Target"
2423		" %s Address: %s\n", vhost_scsi_dump_proto_id(tport), name);
2424
2425	return &tport->tport_wwn;
2426}
2427
2428static void vhost_scsi_drop_tport(struct se_wwn *wwn)
2429{
2430	struct vhost_scsi_tport *tport = container_of(wwn,
2431				struct vhost_scsi_tport, tport_wwn);
2432
2433	pr_debug("TCM_VHost_ConfigFS: Deallocating emulated Target"
2434		" %s Address: %s\n", vhost_scsi_dump_proto_id(tport),
2435		tport->tport_name);
2436
2437	kfree(tport);
2438}
2439
2440static ssize_t
2441vhost_scsi_wwn_version_show(struct config_item *item, char *page)
2442{
2443	return sprintf(page, "TCM_VHOST fabric module %s on %s/%s"
2444		"on "UTS_RELEASE"\n", VHOST_SCSI_VERSION, utsname()->sysname,
2445		utsname()->machine);
2446}
2447
2448CONFIGFS_ATTR_RO(vhost_scsi_wwn_, version);
2449
2450static struct configfs_attribute *vhost_scsi_wwn_attrs[] = {
2451	&vhost_scsi_wwn_attr_version,
2452	NULL,
2453};
2454
2455static const struct target_core_fabric_ops vhost_scsi_ops = {
2456	.module				= THIS_MODULE,
2457	.fabric_name			= "vhost",
2458	.max_data_sg_nents		= VHOST_SCSI_PREALLOC_SGLS,
2459	.tpg_get_wwn			= vhost_scsi_get_fabric_wwn,
2460	.tpg_get_tag			= vhost_scsi_get_tpgt,
2461	.tpg_check_demo_mode		= vhost_scsi_check_true,
2462	.tpg_check_demo_mode_cache	= vhost_scsi_check_true,
2463	.tpg_check_demo_mode_write_protect = vhost_scsi_check_false,
2464	.tpg_check_prod_mode_write_protect = vhost_scsi_check_false,
2465	.tpg_check_prot_fabric_only	= vhost_scsi_check_prot_fabric_only,
2466	.tpg_get_inst_index		= vhost_scsi_tpg_get_inst_index,
2467	.release_cmd			= vhost_scsi_release_cmd,
2468	.check_stop_free		= vhost_scsi_check_stop_free,
2469	.sess_get_index			= vhost_scsi_sess_get_index,
2470	.sess_get_initiator_sid		= NULL,
2471	.write_pending			= vhost_scsi_write_pending,
2472	.set_default_node_attributes	= vhost_scsi_set_default_node_attrs,
2473	.get_cmd_state			= vhost_scsi_get_cmd_state,
2474	.queue_data_in			= vhost_scsi_queue_data_in,
2475	.queue_status			= vhost_scsi_queue_status,
2476	.queue_tm_rsp			= vhost_scsi_queue_tm_rsp,
2477	.aborted_task			= vhost_scsi_aborted_task,
2478	/*
2479	 * Setup callers for generic logic in target_core_fabric_configfs.c
2480	 */
2481	.fabric_make_wwn		= vhost_scsi_make_tport,
2482	.fabric_drop_wwn		= vhost_scsi_drop_tport,
2483	.fabric_make_tpg		= vhost_scsi_make_tpg,
2484	.fabric_drop_tpg		= vhost_scsi_drop_tpg,
2485	.fabric_post_link		= vhost_scsi_port_link,
2486	.fabric_pre_unlink		= vhost_scsi_port_unlink,
2487
2488	.tfc_wwn_attrs			= vhost_scsi_wwn_attrs,
2489	.tfc_tpg_base_attrs		= vhost_scsi_tpg_attrs,
2490	.tfc_tpg_attrib_attrs		= vhost_scsi_tpg_attrib_attrs,
2491};
2492
2493static int __init vhost_scsi_init(void)
2494{
2495	int ret = -ENOMEM;
2496
2497	pr_debug("TCM_VHOST fabric module %s on %s/%s"
2498		" on "UTS_RELEASE"\n", VHOST_SCSI_VERSION, utsname()->sysname,
2499		utsname()->machine);
2500
2501	ret = vhost_scsi_register();
2502	if (ret < 0)
2503		goto out;
2504
2505	ret = target_register_template(&vhost_scsi_ops);
2506	if (ret < 0)
2507		goto out_vhost_scsi_deregister;
2508
2509	return 0;
2510
2511out_vhost_scsi_deregister:
2512	vhost_scsi_deregister();
2513out:
2514	return ret;
2515};
2516
2517static void vhost_scsi_exit(void)
2518{
2519	target_unregister_template(&vhost_scsi_ops);
2520	vhost_scsi_deregister();
2521};
2522
2523MODULE_DESCRIPTION("VHOST_SCSI series fabric driver");
2524MODULE_ALIAS("tcm_vhost");
2525MODULE_LICENSE("GPL");
2526module_init(vhost_scsi_init);
2527module_exit(vhost_scsi_exit);