drivers/nvme/target/passthru.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * NVMe Over Fabrics Target Passthrough command implementation.
   4  *
   5  * Copyright (c) 2017-2018 Western Digital Corporation or its
   6  * affiliates.
   7  * Copyright (c) 2019-2020, Eideticom Inc.
   8  *
   9  */
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11 #include <linux/module.h>
  12
  13 #include "../host/nvme.h"
  14 #include "nvmet.h"
  15
  16 MODULE_IMPORT_NS(NVME_TARGET_PASSTHRU);
  17
  18 /*
  19  * xarray to maintain one passthru subsystem per nvme controller.
  20  */
  21 static DEFINE_XARRAY(passthru_subsystems);
  22
  23 static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req)
  24 {
  25         struct nvmet_ctrl *ctrl = req->sq->ctrl;
  26         struct nvme_ctrl *pctrl = ctrl->subsys->passthru_ctrl;
  27         u16 status = NVME_SC_SUCCESS;
  28         struct nvme_id_ctrl *id;
  29         int max_hw_sectors;
  30         int page_shift;
  31
  32         id = kzalloc(sizeof(*id), GFP_KERNEL);
  33         if (!id)
  34                 return NVME_SC_INTERNAL;
  35
  36         status = nvmet_copy_from_sgl(req, 0, id, sizeof(*id));
  37         if (status)
  38                 goto out_free;
  39
  40         id->cntlid = cpu_to_le16(ctrl->cntlid);
  41         id->ver = cpu_to_le32(ctrl->subsys->ver);
  42
  43         /*
  44          * The passthru NVMe driver may have a limit on the number of segments
  45          * which depends on the host's memory fragementation. To solve this,
  46          * ensure mdts is limited to the pages equal to the number of segments.
  47          */
  48         max_hw_sectors = min_not_zero(pctrl->max_segments << (PAGE_SHIFT - 9),
  49                                       pctrl->max_hw_sectors);
  50
  51         /*
  52          * nvmet_passthru_map_sg is limitted to using a single bio so limit
  53          * the mdts based on BIO_MAX_PAGES as well
  54          */
  55         max_hw_sectors = min_not_zero(BIO_MAX_PAGES << (PAGE_SHIFT - 9),
  56                                       max_hw_sectors);
  57
  58         page_shift = NVME_CAP_MPSMIN(ctrl->cap) + 12;
  59
  60         id->mdts = ilog2(max_hw_sectors) + 9 - page_shift;
  61
  62         id->acl = 3;
  63         /*
  64          * We export aerl limit for the fabrics controller, update this when
  65          * passthru based aerl support is added.
  66          */
  67         id->aerl = NVMET_ASYNC_EVENTS - 1;
  68
  69         /* emulate kas as most of the PCIe ctrl don't have a support for kas */
  70         id->kas = cpu_to_le16(NVMET_KAS);
  71
  72         /* don't support host memory buffer */
  73         id->hmpre = 0;
  74         id->hmmin = 0;
  75
  76         id->sqes = min_t(__u8, ((0x6 << 4) | 0x6), id->sqes);
  77         id->cqes = min_t(__u8, ((0x4 << 4) | 0x4), id->cqes);
  78         id->maxcmd = cpu_to_le16(NVMET_MAX_CMD);
  79
  80         /* don't support fuse commands */
  81         id->fuses = 0;
  82
  83         id->sgls = cpu_to_le32(1 << 0); /* we always support SGLs */
  84         if (ctrl->ops->flags & NVMF_KEYED_SGLS)
  85                 id->sgls |= cpu_to_le32(1 << 2);
  86         if (req->port->inline_data_size)
  87                 id->sgls |= cpu_to_le32(1 << 20);
  88
  89         /*
  90          * When passsthru controller is setup using nvme-loop transport it will
  91          * export the passthru ctrl subsysnqn (PCIe NVMe ctrl) and will fail in
  92          * the nvme/host/core.c in the nvme_init_subsystem()->nvme_active_ctrl()
  93          * code path with duplicate ctr subsynqn. In order to prevent that we
  94          * mask the passthru-ctrl subsysnqn with the target ctrl subsysnqn.
  95          */
  96         memcpy(id->subnqn, ctrl->subsysnqn, sizeof(id->subnqn));
  97
  98         /* use fabric id-ctrl values */
  99         id->ioccsz = cpu_to_le32((sizeof(struct nvme_command) +
 100                                 req->port->inline_data_size) / 16);
 101         id->iorcsz = cpu_to_le32(sizeof(struct nvme_completion) / 16);
 102
 103         id->msdbd = ctrl->ops->msdbd;
 104
 105         /* Support multipath connections with fabrics */
 106         id->cmic |= 1 << 1;
 107
 108         /* Disable reservations, see nvmet_parse_passthru_io_cmd() */
 109         id->oncs &= cpu_to_le16(~NVME_CTRL_ONCS_RESERVATIONS);
 110
 111         status = nvmet_copy_to_sgl(req, 0, id, sizeof(struct nvme_id_ctrl));
 112
 113 out_free:
 114         kfree(id);
 115         return status;
 116 }
 117
 118 static u16 nvmet_passthru_override_id_ns(struct nvmet_req *req)
 119 {
 120         u16 status = NVME_SC_SUCCESS;
 121         struct nvme_id_ns *id;
 122         int i;
 123
 124         id = kzalloc(sizeof(*id), GFP_KERNEL);
 125         if (!id)
 126                 return NVME_SC_INTERNAL;
 127
 128         status = nvmet_copy_from_sgl(req, 0, id, sizeof(struct nvme_id_ns));
 129         if (status)
 130                 goto out_free;
 131
 132         for (i = 0; i < (id->nlbaf + 1); i++)
 133                 if (id->lbaf[i].ms)
 134                         memset(&id->lbaf[i], 0, sizeof(id->lbaf[i]));
 135
 136         id->flbas = id->flbas & ~(1 << 4);
 137
 138         /*
 139          * Presently the NVMEof target code does not support sending
 140          * metadata, so we must disable it here. This should be updated
 141          * once target starts supporting metadata.
 142          */
 143         id->mc = 0;
 144
 145         status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
 146
 147 out_free:
 148         kfree(id);
 149         return status;
 150 }
 151
 152 static void nvmet_passthru_execute_cmd_work(struct work_struct *w)
 153 {
 154         struct nvmet_req *req = container_of(w, struct nvmet_req, p.work);
 155         struct request *rq = req->p.rq;
 156         u16 status;
 157
 158         nvme_execute_passthru_rq(rq);
 159
 160         status = nvme_req(rq)->status;
 161         if (status == NVME_SC_SUCCESS &&
 162             req->cmd->common.opcode == nvme_admin_identify) {
 163                 switch (req->cmd->identify.cns) {
 164                 case NVME_ID_CNS_CTRL:
 165                         nvmet_passthru_override_id_ctrl(req);
 166                         break;
 167                 case NVME_ID_CNS_NS:
 168                         nvmet_passthru_override_id_ns(req);
 169                         break;
 170                 }
 171         }
 172
 173         req->cqe->result = nvme_req(rq)->result;
 174         nvmet_req_complete(req, status);
 175         blk_mq_free_request(rq);
 176 }
 177
 178 static void nvmet_passthru_req_done(struct request *rq,
 179                                     blk_status_t blk_status)
 180 {
 181         struct nvmet_req *req = rq->end_io_data;
 182
 183         req->cqe->result = nvme_req(rq)->result;
 184         nvmet_req_complete(req, nvme_req(rq)->status);
 185         blk_mq_free_request(rq);
 186 }
 187
 188 static int nvmet_passthru_map_sg(struct nvmet_req *req, struct request *rq)
 189 {
 190         struct scatterlist *sg;
 191         int op_flags = 0;
 192         struct bio *bio;
 193         int i, ret;
 194
 195         if (req->sg_cnt > BIO_MAX_PAGES)
 196                 return -EINVAL;
 197
 198         if (req->cmd->common.opcode == nvme_cmd_flush)
 199                 op_flags = REQ_FUA;
 200         else if (nvme_is_write(req->cmd))
 201                 op_flags = REQ_SYNC | REQ_IDLE;
 202
 203         bio = bio_alloc(GFP_KERNEL, req->sg_cnt);
 204         bio->bi_end_io = bio_put;
 205         bio->bi_opf = req_op(rq) | op_flags;
 206
 207         for_each_sg(req->sg, sg, req->sg_cnt, i) {
 208                 if (bio_add_pc_page(rq->q, bio, sg_page(sg), sg->length,
 209                                     sg->offset) < sg->length) {
 210                         bio_put(bio);
 211                         return -EINVAL;
 212                 }
 213         }
 214
 215         ret = blk_rq_append_bio(rq, &bio);
 216         if (unlikely(ret)) {
 217                 bio_put(bio);
 218                 return ret;
 219         }
 220
 221         return 0;
 222 }
 223
 224 static void nvmet_passthru_execute_cmd(struct nvmet_req *req)
 225 {
 226         struct nvme_ctrl *ctrl = nvmet_req_passthru_ctrl(req);
 227         struct request_queue *q = ctrl->admin_q;
 228         struct nvme_ns *ns = NULL;
 229         struct request *rq = NULL;
 230         u32 effects;
 231         u16 status;
 232         int ret;
 233
 234         if (likely(req->sq->qid != 0)) {
 235                 u32 nsid = le32_to_cpu(req->cmd->common.nsid);
 236
 237                 ns = nvme_find_get_ns(ctrl, nsid);
 238                 if (unlikely(!ns)) {
 239                         pr_err("failed to get passthru ns nsid:%u\n", nsid);
 240                         status = NVME_SC_INVALID_NS | NVME_SC_DNR;
 241                         goto out;
 242                 }
 243
 244                 q = ns->queue;
 245         }
 246
 247         rq = nvme_alloc_request(q, req->cmd, 0);
 248         if (IS_ERR(rq)) {
 249                 status = NVME_SC_INTERNAL;
 250                 goto out_put_ns;
 251         }
 252
 253         if (req->sg_cnt) {
 254                 ret = nvmet_passthru_map_sg(req, rq);
 255                 if (unlikely(ret)) {
 256                         status = NVME_SC_INTERNAL;
 257                         goto out_put_req;
 258                 }
 259         }
 260
 261         /*
 262          * If a command needs post-execution fixups, or there are any
 263          * non-trivial effects, make sure to execute the command synchronously
 264          * in a workqueue so that nvme_passthru_end gets called.
 265          */
 266         effects = nvme_command_effects(ctrl, ns, req->cmd->common.opcode);
 267         if (req->p.use_workqueue ||
 268             (effects & ~(NVME_CMD_EFFECTS_CSUPP | NVME_CMD_EFFECTS_LBCC))) {
 269                 INIT_WORK(&req->p.work, nvmet_passthru_execute_cmd_work);
 270                 req->p.rq = rq;
 271                 schedule_work(&req->p.work);
 272         } else {
 273                 rq->end_io_data = req;
 274                 blk_execute_rq_nowait(rq->q, ns ? ns->disk : NULL, rq, 0,
 275                                       nvmet_passthru_req_done);
 276         }
 277
 278         if (ns)
 279                 nvme_put_ns(ns);
 280
 281         return;
 282
 283 out_put_req:
 284         blk_mq_free_request(rq);
 285 out_put_ns:
 286         if (ns)
 287                 nvme_put_ns(ns);
 288 out:
 289         nvmet_req_complete(req, status);
 290 }
 291
 292 /*
 293  * We need to emulate set host behaviour to ensure that any requested
 294  * behaviour of the target's host matches the requested behaviour
 295  * of the device's host and fail otherwise.
 296  */
 297 static void nvmet_passthru_set_host_behaviour(struct nvmet_req *req)
 298 {
 299         struct nvme_ctrl *ctrl = nvmet_req_passthru_ctrl(req);
 300         struct nvme_feat_host_behavior *host;
 301         u16 status = NVME_SC_INTERNAL;
 302         int ret;
 303
 304         host = kzalloc(sizeof(*host) * 2, GFP_KERNEL);
 305         if (!host)
 306                 goto out_complete_req;
 307
 308         ret = nvme_get_features(ctrl, NVME_FEAT_HOST_BEHAVIOR, 0,
 309                                 host, sizeof(*host), NULL);
 310         if (ret)
 311                 goto out_free_host;
 312
 313         status = nvmet_copy_from_sgl(req, 0, &host[1], sizeof(*host));
 314         if (status)
 315                 goto out_free_host;
 316
 317         if (memcmp(&host[0], &host[1], sizeof(host[0]))) {
 318                 pr_warn("target host has requested different behaviour from the local host\n");
 319                 status = NVME_SC_INTERNAL;
 320         }
 321
 322 out_free_host:
 323         kfree(host);
 324 out_complete_req:
 325         nvmet_req_complete(req, status);
 326 }
 327
 328 static u16 nvmet_setup_passthru_command(struct nvmet_req *req)
 329 {
 330         req->p.use_workqueue = false;
 331         req->execute = nvmet_passthru_execute_cmd;
 332         return NVME_SC_SUCCESS;
 333 }
 334
 335 u16 nvmet_parse_passthru_io_cmd(struct nvmet_req *req)
 336 {
 337         /* Reject any commands with non-sgl flags set (ie. fused commands) */
 338         if (req->cmd->common.flags & ~NVME_CMD_SGL_ALL)
 339                 return NVME_SC_INVALID_FIELD;
 340
 341         switch (req->cmd->common.opcode) {
 342         case nvme_cmd_resv_register:
 343         case nvme_cmd_resv_report:
 344         case nvme_cmd_resv_acquire:
 345         case nvme_cmd_resv_release:
 346                 /*
 347                  * Reservations cannot be supported properly because the
 348                  * underlying device has no way of differentiating different
 349                  * hosts that connect via fabrics. This could potentially be
 350                  * emulated in the future if regular targets grow support for
 351                  * this feature.
 352                  */
 353                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 354         }
 355
 356         return nvmet_setup_passthru_command(req);
 357 }
 358
 359 /*
 360  * Only features that are emulated or specifically allowed in the list  are
 361  * passed down to the controller. This function implements the allow list for
 362  * both get and set features.
 363  */
 364 static u16 nvmet_passthru_get_set_features(struct nvmet_req *req)
 365 {
 366         switch (le32_to_cpu(req->cmd->features.fid)) {
 367         case NVME_FEAT_ARBITRATION:
 368         case NVME_FEAT_POWER_MGMT:
 369         case NVME_FEAT_LBA_RANGE:
 370         case NVME_FEAT_TEMP_THRESH:
 371         case NVME_FEAT_ERR_RECOVERY:
 372         case NVME_FEAT_VOLATILE_WC:
 373         case NVME_FEAT_WRITE_ATOMIC:
 374         case NVME_FEAT_AUTO_PST:
 375         case NVME_FEAT_TIMESTAMP:
 376         case NVME_FEAT_HCTM:
 377         case NVME_FEAT_NOPSC:
 378         case NVME_FEAT_RRL:
 379         case NVME_FEAT_PLM_CONFIG:
 380         case NVME_FEAT_PLM_WINDOW:
 381         case NVME_FEAT_HOST_BEHAVIOR:
 382         case NVME_FEAT_SANITIZE:
 383         case NVME_FEAT_VENDOR_START ... NVME_FEAT_VENDOR_END:
 384                 return nvmet_setup_passthru_command(req);
 385
 386         case NVME_FEAT_ASYNC_EVENT:
 387                 /* There is no support for forwarding ASYNC events */
 388         case NVME_FEAT_IRQ_COALESCE:
 389         case NVME_FEAT_IRQ_CONFIG:
 390                 /* The IRQ settings will not apply to the target controller */
 391         case NVME_FEAT_HOST_MEM_BUF:
 392                 /*
 393                  * Any HMB that's set will not be passed through and will
 394                  * not work as expected
 395                  */
 396         case NVME_FEAT_SW_PROGRESS:
 397                 /*
 398                  * The Pre-Boot Software Load Count doesn't make much
 399                  * sense for a target to export
 400                  */
 401         case NVME_FEAT_RESV_MASK:
 402         case NVME_FEAT_RESV_PERSIST:
 403                 /* No reservations, see nvmet_parse_passthru_io_cmd() */
 404         default:
 405                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 406         }
 407 }
 408
 409 u16 nvmet_parse_passthru_admin_cmd(struct nvmet_req *req)
 410 {
 411         /* Reject any commands with non-sgl flags set (ie. fused commands) */
 412         if (req->cmd->common.flags & ~NVME_CMD_SGL_ALL)
 413                 return NVME_SC_INVALID_FIELD;
 414
 415         /*
 416          * Passthru all vendor specific commands
 417          */
 418         if (req->cmd->common.opcode >= nvme_admin_vendor_start)
 419                 return nvmet_setup_passthru_command(req);
 420
 421         switch (req->cmd->common.opcode) {
 422         case nvme_admin_async_event:
 423                 req->execute = nvmet_execute_async_event;
 424                 return NVME_SC_SUCCESS;
 425         case nvme_admin_keep_alive:
 426                 /*
 427                  * Most PCIe ctrls don't support keep alive cmd, we route keep
 428                  * alive to the non-passthru mode. In future please change this
 429                  * code when PCIe ctrls with keep alive support available.
 430                  */
 431                 req->execute = nvmet_execute_keep_alive;
 432                 return NVME_SC_SUCCESS;
 433         case nvme_admin_set_features:
 434                 switch (le32_to_cpu(req->cmd->features.fid)) {
 435                 case NVME_FEAT_ASYNC_EVENT:
 436                 case NVME_FEAT_KATO:
 437                 case NVME_FEAT_NUM_QUEUES:
 438                 case NVME_FEAT_HOST_ID:
 439                         req->execute = nvmet_execute_set_features;
 440                         return NVME_SC_SUCCESS;
 441                 case NVME_FEAT_HOST_BEHAVIOR:
 442                         req->execute = nvmet_passthru_set_host_behaviour;
 443                         return NVME_SC_SUCCESS;
 444                 default:
 445                         return nvmet_passthru_get_set_features(req);
 446                 }
 447                 break;
 448         case nvme_admin_get_features:
 449                 switch (le32_to_cpu(req->cmd->features.fid)) {
 450                 case NVME_FEAT_ASYNC_EVENT:
 451                 case NVME_FEAT_KATO:
 452                 case NVME_FEAT_NUM_QUEUES:
 453                 case NVME_FEAT_HOST_ID:
 454                         req->execute = nvmet_execute_get_features;
 455                         return NVME_SC_SUCCESS;
 456                 default:
 457                         return nvmet_passthru_get_set_features(req);
 458                 }
 459                 break;
 460         case nvme_admin_identify:
 461                 switch (req->cmd->identify.cns) {
 462                 case NVME_ID_CNS_CTRL:
 463                         req->execute = nvmet_passthru_execute_cmd;
 464                         req->p.use_workqueue = true;
 465                         return NVME_SC_SUCCESS;
 466                 case NVME_ID_CNS_CS_CTRL:
 467                         switch (req->cmd->identify.csi) {
 468                         case NVME_CSI_ZNS:
 469                                 req->execute = nvmet_passthru_execute_cmd;
 470                                 req->p.use_workqueue = true;
 471                                 return NVME_SC_SUCCESS;
 472                         }
 473                         return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 474                 case NVME_ID_CNS_NS:
 475                         req->execute = nvmet_passthru_execute_cmd;
 476                         req->p.use_workqueue = true;
 477                         return NVME_SC_SUCCESS;
 478                 case NVME_ID_CNS_CS_NS:
 479                         switch (req->cmd->identify.csi) {
 480                         case NVME_CSI_ZNS:
 481                                 req->execute = nvmet_passthru_execute_cmd;
 482                                 req->p.use_workqueue = true;
 483                                 return NVME_SC_SUCCESS;
 484                         }
 485                         return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 486                 default:
 487                         return nvmet_setup_passthru_command(req);
 488                 }
 489         case nvme_admin_get_log_page:
 490                 return nvmet_setup_passthru_command(req);
 491         default:
 492                 /* Reject commands not in the allowlist above */
 493                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 494         }
 495 }
 496
 497 int nvmet_passthru_ctrl_enable(struct nvmet_subsys *subsys)
 498 {
 499         struct nvme_ctrl *ctrl;
 500         struct file *file;
 501         int ret = -EINVAL;
 502         void *old;
 503
 504         mutex_lock(&subsys->lock);
 505         if (!subsys->passthru_ctrl_path)
 506                 goto out_unlock;
 507         if (subsys->passthru_ctrl)
 508                 goto out_unlock;
 509
 510         if (subsys->nr_namespaces) {
 511                 pr_info("cannot enable both passthru and regular namespaces for a single subsystem");
 512                 goto out_unlock;
 513         }
 514
 515         file = filp_open(subsys->passthru_ctrl_path, O_RDWR, 0);
 516         if (IS_ERR(file)) {
 517                 ret = PTR_ERR(file);
 518                 goto out_unlock;
 519         }
 520
 521         ctrl = nvme_ctrl_from_file(file);
 522         if (!ctrl) {
 523                 pr_err("failed to open nvme controller %s\n",
 524                        subsys->passthru_ctrl_path);
 525
 526                 goto out_put_file;
 527         }
 528
 529         old = xa_cmpxchg(&passthru_subsystems, ctrl->cntlid, NULL,
 530                          subsys, GFP_KERNEL);
 531         if (xa_is_err(old)) {
 532                 ret = xa_err(old);
 533                 goto out_put_file;
 534         }
 535
 536         if (old)
 537                 goto out_put_file;
 538
 539         subsys->passthru_ctrl = ctrl;
 540         subsys->ver = ctrl->vs;
 541
 542         if (subsys->ver < NVME_VS(1, 2, 1)) {
 543                 pr_warn("nvme controller version is too old: %llu.%llu.%llu, advertising 1.2.1\n",
 544                         NVME_MAJOR(subsys->ver), NVME_MINOR(subsys->ver),
 545                         NVME_TERTIARY(subsys->ver));
 546                 subsys->ver = NVME_VS(1, 2, 1);
 547         }
 548         nvme_get_ctrl(ctrl);
 549         __module_get(subsys->passthru_ctrl->ops->module);
 550         ret = 0;
 551
 552 out_put_file:
 553         filp_close(file, NULL);
 554 out_unlock:
 555         mutex_unlock(&subsys->lock);
 556         return ret;
 557 }
 558
 559 static void __nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys)
 560 {
 561         if (subsys->passthru_ctrl) {
 562                 xa_erase(&passthru_subsystems, subsys->passthru_ctrl->cntlid);
 563                 module_put(subsys->passthru_ctrl->ops->module);
 564                 nvme_put_ctrl(subsys->passthru_ctrl);
 565         }
 566         subsys->passthru_ctrl = NULL;
 567         subsys->ver = NVMET_DEFAULT_VS;
 568 }
 569
 570 void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys)
 571 {
 572         mutex_lock(&subsys->lock);
 573         __nvmet_passthru_ctrl_disable(subsys);
 574         mutex_unlock(&subsys->lock);
 575 }
 576
 577 void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys)
 578 {
 579         mutex_lock(&subsys->lock);
 580         __nvmet_passthru_ctrl_disable(subsys);
 581         mutex_unlock(&subsys->lock);
 582         kfree(subsys->passthru_ctrl_path);
 583 }