1 /* 2 * Virtio SCSI HBA driver 3 * 4 * Copyright IBM Corp. 2010 5 * Copyright Red Hat, Inc. 2011 6 * 7 * Authors: 8 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> 9 * Paolo Bonzini <pbonzini@redhat.com> 10 * 11 * This work is licensed under the terms of the GNU GPL, version 2 or later. 12 * See the COPYING file in the top-level directory. 13 * 14 */ 15 16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 17 18 #include <linux/module.h> 19 #include <linux/slab.h> 20 #include <linux/mempool.h> 21 #include <linux/interrupt.h> 22 #include <linux/virtio.h> 23 #include <linux/virtio_ids.h> 24 #include <linux/virtio_config.h> 25 #include <linux/virtio_scsi.h> 26 #include <linux/cpu.h> 27 #include <linux/blkdev.h> 28 #include <scsi/scsi_host.h> 29 #include <scsi/scsi_device.h> 30 #include <scsi/scsi_cmnd.h> 31 #include <scsi/scsi_tcq.h> 32 #include <linux/seqlock.h> 33 #include <linux/blk-mq-virtio.h> 34 35 #define VIRTIO_SCSI_MEMPOOL_SZ 64 36 #define VIRTIO_SCSI_EVENT_LEN 8 37 #define VIRTIO_SCSI_VQ_BASE 2 38 39 /* Command queue element */ 40 struct virtio_scsi_cmd { 41 struct scsi_cmnd *sc; 42 struct completion *comp; 43 union { 44 struct virtio_scsi_cmd_req cmd; 45 struct virtio_scsi_cmd_req_pi cmd_pi; 46 struct virtio_scsi_ctrl_tmf_req tmf; 47 struct virtio_scsi_ctrl_an_req an; 48 } req; 49 union { 50 struct virtio_scsi_cmd_resp cmd; 51 struct virtio_scsi_ctrl_tmf_resp tmf; 52 struct virtio_scsi_ctrl_an_resp an; 53 struct virtio_scsi_event evt; 54 } resp; 55 } ____cacheline_aligned_in_smp; 56 57 struct virtio_scsi_event_node { 58 struct virtio_scsi *vscsi; 59 struct virtio_scsi_event event; 60 struct work_struct work; 61 }; 62 63 struct virtio_scsi_vq { 64 /* Protects vq */ 65 spinlock_t vq_lock; 66 67 struct virtqueue *vq; 68 }; 69 70 /* 71 * Per-target queue state. 72 * 73 * This struct holds the data needed by the queue steering policy. When a 74 * target is sent multiple requests, we need to drive them to the same queue so 75 * that FIFO processing order is kept. However, if a target was idle, we can 76 * choose a queue arbitrarily. In this case the queue is chosen according to 77 * the current VCPU, so the driver expects the number of request queues to be 78 * equal to the number of VCPUs. This makes it easy and fast to select the 79 * queue, and also lets the driver optimize the IRQ affinity for the virtqueues 80 * (each virtqueue's affinity is set to the CPU that "owns" the queue). 81 * 82 * tgt_seq is held to serialize reading and writing req_vq. 83 * 84 * Decrements of reqs are never concurrent with writes of req_vq: before the 85 * decrement reqs will be != 0; after the decrement the virtqueue completion 86 * routine will not use the req_vq so it can be changed by a new request. 87 * Thus they can happen outside the tgt_seq, provided of course we make reqs 88 * an atomic_t. 89 */ 90 struct virtio_scsi_target_state { 91 seqcount_t tgt_seq; 92 93 /* Count of outstanding requests. */ 94 atomic_t reqs; 95 96 /* Currently active virtqueue for requests sent to this target. */ 97 struct virtio_scsi_vq *req_vq; 98 }; 99 100 /* Driver instance state */ 101 struct virtio_scsi { 102 struct virtio_device *vdev; 103 104 /* Get some buffers ready for event vq */ 105 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN]; 106 107 u32 num_queues; 108 109 /* If the affinity hint is set for virtqueues */ 110 bool affinity_hint_set; 111 112 struct hlist_node node; 113 114 /* Protected by event_vq lock */ 115 bool stop_events; 116 117 struct virtio_scsi_vq ctrl_vq; 118 struct virtio_scsi_vq event_vq; 119 struct virtio_scsi_vq req_vqs[]; 120 }; 121 122 static struct kmem_cache *virtscsi_cmd_cache; 123 static mempool_t *virtscsi_cmd_pool; 124 125 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev) 126 { 127 return vdev->priv; 128 } 129 130 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid) 131 { 132 if (!resid) 133 return; 134 135 if (!scsi_bidi_cmnd(sc)) { 136 scsi_set_resid(sc, resid); 137 return; 138 } 139 140 scsi_in(sc)->resid = min(resid, scsi_in(sc)->length); 141 scsi_out(sc)->resid = resid - scsi_in(sc)->resid; 142 } 143 144 /** 145 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done 146 * 147 * Called with vq_lock held. 148 */ 149 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf) 150 { 151 struct virtio_scsi_cmd *cmd = buf; 152 struct scsi_cmnd *sc = cmd->sc; 153 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd; 154 struct virtio_scsi_target_state *tgt = 155 scsi_target(sc->device)->hostdata; 156 157 dev_dbg(&sc->device->sdev_gendev, 158 "cmd %p response %u status %#02x sense_len %u\n", 159 sc, resp->response, resp->status, resp->sense_len); 160 161 sc->result = resp->status; 162 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid)); 163 switch (resp->response) { 164 case VIRTIO_SCSI_S_OK: 165 set_host_byte(sc, DID_OK); 166 break; 167 case VIRTIO_SCSI_S_OVERRUN: 168 set_host_byte(sc, DID_ERROR); 169 break; 170 case VIRTIO_SCSI_S_ABORTED: 171 set_host_byte(sc, DID_ABORT); 172 break; 173 case VIRTIO_SCSI_S_BAD_TARGET: 174 set_host_byte(sc, DID_BAD_TARGET); 175 break; 176 case VIRTIO_SCSI_S_RESET: 177 set_host_byte(sc, DID_RESET); 178 break; 179 case VIRTIO_SCSI_S_BUSY: 180 set_host_byte(sc, DID_BUS_BUSY); 181 break; 182 case VIRTIO_SCSI_S_TRANSPORT_FAILURE: 183 set_host_byte(sc, DID_TRANSPORT_DISRUPTED); 184 break; 185 case VIRTIO_SCSI_S_TARGET_FAILURE: 186 set_host_byte(sc, DID_TARGET_FAILURE); 187 break; 188 case VIRTIO_SCSI_S_NEXUS_FAILURE: 189 set_host_byte(sc, DID_NEXUS_FAILURE); 190 break; 191 default: 192 scmd_printk(KERN_WARNING, sc, "Unknown response %d", 193 resp->response); 194 /* fall through */ 195 case VIRTIO_SCSI_S_FAILURE: 196 set_host_byte(sc, DID_ERROR); 197 break; 198 } 199 200 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) > 201 VIRTIO_SCSI_SENSE_SIZE); 202 if (sc->sense_buffer) { 203 memcpy(sc->sense_buffer, resp->sense, 204 min_t(u32, 205 virtio32_to_cpu(vscsi->vdev, resp->sense_len), 206 VIRTIO_SCSI_SENSE_SIZE)); 207 if (resp->sense_len) 208 set_driver_byte(sc, DRIVER_SENSE); 209 } 210 211 sc->scsi_done(sc); 212 213 atomic_dec(&tgt->reqs); 214 } 215 216 static void virtscsi_vq_done(struct virtio_scsi *vscsi, 217 struct virtio_scsi_vq *virtscsi_vq, 218 void (*fn)(struct virtio_scsi *vscsi, void *buf)) 219 { 220 void *buf; 221 unsigned int len; 222 unsigned long flags; 223 struct virtqueue *vq = virtscsi_vq->vq; 224 225 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); 226 do { 227 virtqueue_disable_cb(vq); 228 while ((buf = virtqueue_get_buf(vq, &len)) != NULL) 229 fn(vscsi, buf); 230 231 if (unlikely(virtqueue_is_broken(vq))) 232 break; 233 } while (!virtqueue_enable_cb(vq)); 234 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); 235 } 236 237 static void virtscsi_req_done(struct virtqueue *vq) 238 { 239 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 240 struct virtio_scsi *vscsi = shost_priv(sh); 241 int index = vq->index - VIRTIO_SCSI_VQ_BASE; 242 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index]; 243 244 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd); 245 }; 246 247 static void virtscsi_poll_requests(struct virtio_scsi *vscsi) 248 { 249 int i, num_vqs; 250 251 num_vqs = vscsi->num_queues; 252 for (i = 0; i < num_vqs; i++) 253 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i], 254 virtscsi_complete_cmd); 255 } 256 257 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf) 258 { 259 struct virtio_scsi_cmd *cmd = buf; 260 261 if (cmd->comp) 262 complete(cmd->comp); 263 } 264 265 static void virtscsi_ctrl_done(struct virtqueue *vq) 266 { 267 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 268 struct virtio_scsi *vscsi = shost_priv(sh); 269 270 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free); 271 }; 272 273 static void virtscsi_handle_event(struct work_struct *work); 274 275 static int virtscsi_kick_event(struct virtio_scsi *vscsi, 276 struct virtio_scsi_event_node *event_node) 277 { 278 int err; 279 struct scatterlist sg; 280 unsigned long flags; 281 282 INIT_WORK(&event_node->work, virtscsi_handle_event); 283 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event)); 284 285 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags); 286 287 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node, 288 GFP_ATOMIC); 289 if (!err) 290 virtqueue_kick(vscsi->event_vq.vq); 291 292 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags); 293 294 return err; 295 } 296 297 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi) 298 { 299 int i; 300 301 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) { 302 vscsi->event_list[i].vscsi = vscsi; 303 virtscsi_kick_event(vscsi, &vscsi->event_list[i]); 304 } 305 306 return 0; 307 } 308 309 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi) 310 { 311 int i; 312 313 /* Stop scheduling work before calling cancel_work_sync. */ 314 spin_lock_irq(&vscsi->event_vq.vq_lock); 315 vscsi->stop_events = true; 316 spin_unlock_irq(&vscsi->event_vq.vq_lock); 317 318 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) 319 cancel_work_sync(&vscsi->event_list[i].work); 320 } 321 322 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, 323 struct virtio_scsi_event *event) 324 { 325 struct scsi_device *sdev; 326 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 327 unsigned int target = event->lun[1]; 328 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 329 330 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) { 331 case VIRTIO_SCSI_EVT_RESET_RESCAN: 332 scsi_add_device(shost, 0, target, lun); 333 break; 334 case VIRTIO_SCSI_EVT_RESET_REMOVED: 335 sdev = scsi_device_lookup(shost, 0, target, lun); 336 if (sdev) { 337 scsi_remove_device(sdev); 338 scsi_device_put(sdev); 339 } else { 340 pr_err("SCSI device %d 0 %d %d not found\n", 341 shost->host_no, target, lun); 342 } 343 break; 344 default: 345 pr_info("Unsupport virtio scsi event reason %x\n", event->reason); 346 } 347 } 348 349 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, 350 struct virtio_scsi_event *event) 351 { 352 struct scsi_device *sdev; 353 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 354 unsigned int target = event->lun[1]; 355 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 356 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255; 357 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8; 358 359 sdev = scsi_device_lookup(shost, 0, target, lun); 360 if (!sdev) { 361 pr_err("SCSI device %d 0 %d %d not found\n", 362 shost->host_no, target, lun); 363 return; 364 } 365 366 /* Handle "Parameters changed", "Mode parameters changed", and 367 "Capacity data has changed". */ 368 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) 369 scsi_rescan_device(&sdev->sdev_gendev); 370 371 scsi_device_put(sdev); 372 } 373 374 static void virtscsi_handle_event(struct work_struct *work) 375 { 376 struct virtio_scsi_event_node *event_node = 377 container_of(work, struct virtio_scsi_event_node, work); 378 struct virtio_scsi *vscsi = event_node->vscsi; 379 struct virtio_scsi_event *event = &event_node->event; 380 381 if (event->event & 382 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { 383 event->event &= ~cpu_to_virtio32(vscsi->vdev, 384 VIRTIO_SCSI_T_EVENTS_MISSED); 385 scsi_scan_host(virtio_scsi_host(vscsi->vdev)); 386 } 387 388 switch (virtio32_to_cpu(vscsi->vdev, event->event)) { 389 case VIRTIO_SCSI_T_NO_EVENT: 390 break; 391 case VIRTIO_SCSI_T_TRANSPORT_RESET: 392 virtscsi_handle_transport_reset(vscsi, event); 393 break; 394 case VIRTIO_SCSI_T_PARAM_CHANGE: 395 virtscsi_handle_param_change(vscsi, event); 396 break; 397 default: 398 pr_err("Unsupport virtio scsi event %x\n", event->event); 399 } 400 virtscsi_kick_event(vscsi, event_node); 401 } 402 403 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) 404 { 405 struct virtio_scsi_event_node *event_node = buf; 406 407 if (!vscsi->stop_events) 408 queue_work(system_freezable_wq, &event_node->work); 409 } 410 411 static void virtscsi_event_done(struct virtqueue *vq) 412 { 413 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 414 struct virtio_scsi *vscsi = shost_priv(sh); 415 416 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); 417 }; 418 419 /** 420 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue 421 * @vq : the struct virtqueue we're talking about 422 * @cmd : command structure 423 * @req_size : size of the request buffer 424 * @resp_size : size of the response buffer 425 */ 426 static int virtscsi_add_cmd(struct virtqueue *vq, 427 struct virtio_scsi_cmd *cmd, 428 size_t req_size, size_t resp_size) 429 { 430 struct scsi_cmnd *sc = cmd->sc; 431 struct scatterlist *sgs[6], req, resp; 432 struct sg_table *out, *in; 433 unsigned out_num = 0, in_num = 0; 434 435 out = in = NULL; 436 437 if (sc && sc->sc_data_direction != DMA_NONE) { 438 if (sc->sc_data_direction != DMA_FROM_DEVICE) 439 out = &scsi_out(sc)->table; 440 if (sc->sc_data_direction != DMA_TO_DEVICE) 441 in = &scsi_in(sc)->table; 442 } 443 444 /* Request header. */ 445 sg_init_one(&req, &cmd->req, req_size); 446 sgs[out_num++] = &req; 447 448 /* Data-out buffer. */ 449 if (out) { 450 /* Place WRITE protection SGLs before Data OUT payload */ 451 if (scsi_prot_sg_count(sc)) 452 sgs[out_num++] = scsi_prot_sglist(sc); 453 sgs[out_num++] = out->sgl; 454 } 455 456 /* Response header. */ 457 sg_init_one(&resp, &cmd->resp, resp_size); 458 sgs[out_num + in_num++] = &resp; 459 460 /* Data-in buffer */ 461 if (in) { 462 /* Place READ protection SGLs before Data IN payload */ 463 if (scsi_prot_sg_count(sc)) 464 sgs[out_num + in_num++] = scsi_prot_sglist(sc); 465 sgs[out_num + in_num++] = in->sgl; 466 } 467 468 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); 469 } 470 471 static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq, 472 struct virtio_scsi_cmd *cmd, 473 size_t req_size, size_t resp_size) 474 { 475 unsigned long flags; 476 int err; 477 bool needs_kick = false; 478 479 spin_lock_irqsave(&vq->vq_lock, flags); 480 err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size); 481 if (!err) 482 needs_kick = virtqueue_kick_prepare(vq->vq); 483 484 spin_unlock_irqrestore(&vq->vq_lock, flags); 485 486 if (needs_kick) 487 virtqueue_notify(vq->vq); 488 return err; 489 } 490 491 static void virtio_scsi_init_hdr(struct virtio_device *vdev, 492 struct virtio_scsi_cmd_req *cmd, 493 struct scsi_cmnd *sc) 494 { 495 cmd->lun[0] = 1; 496 cmd->lun[1] = sc->device->id; 497 cmd->lun[2] = (sc->device->lun >> 8) | 0x40; 498 cmd->lun[3] = sc->device->lun & 0xff; 499 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc); 500 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; 501 cmd->prio = 0; 502 cmd->crn = 0; 503 } 504 505 #ifdef CONFIG_BLK_DEV_INTEGRITY 506 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, 507 struct virtio_scsi_cmd_req_pi *cmd_pi, 508 struct scsi_cmnd *sc) 509 { 510 struct request *rq = sc->request; 511 struct blk_integrity *bi; 512 513 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc); 514 515 if (!rq || !scsi_prot_sg_count(sc)) 516 return; 517 518 bi = blk_get_integrity(rq->rq_disk); 519 520 if (sc->sc_data_direction == DMA_TO_DEVICE) 521 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, 522 blk_rq_sectors(rq) * 523 bi->tuple_size); 524 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 525 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, 526 blk_rq_sectors(rq) * 527 bi->tuple_size); 528 } 529 #endif 530 531 static int virtscsi_queuecommand(struct virtio_scsi *vscsi, 532 struct virtio_scsi_vq *req_vq, 533 struct scsi_cmnd *sc) 534 { 535 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 536 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 537 unsigned long flags; 538 int req_size; 539 int ret; 540 541 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 542 543 /* TODO: check feature bit and fail if unsupported? */ 544 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 545 546 dev_dbg(&sc->device->sdev_gendev, 547 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 548 549 memset(cmd, 0, sizeof(*cmd)); 550 cmd->sc = sc; 551 552 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 553 554 #ifdef CONFIG_BLK_DEV_INTEGRITY 555 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 556 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc); 557 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 558 req_size = sizeof(cmd->req.cmd_pi); 559 } else 560 #endif 561 { 562 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc); 563 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 564 req_size = sizeof(cmd->req.cmd); 565 } 566 567 ret = virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd)); 568 if (ret == -EIO) { 569 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET; 570 spin_lock_irqsave(&req_vq->vq_lock, flags); 571 virtscsi_complete_cmd(vscsi, cmd); 572 spin_unlock_irqrestore(&req_vq->vq_lock, flags); 573 } else if (ret != 0) { 574 return SCSI_MLQUEUE_HOST_BUSY; 575 } 576 return 0; 577 } 578 579 static int virtscsi_queuecommand_single(struct Scsi_Host *sh, 580 struct scsi_cmnd *sc) 581 { 582 struct virtio_scsi *vscsi = shost_priv(sh); 583 struct virtio_scsi_target_state *tgt = 584 scsi_target(sc->device)->hostdata; 585 586 atomic_inc(&tgt->reqs); 587 return virtscsi_queuecommand(vscsi, &vscsi->req_vqs[0], sc); 588 } 589 590 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, 591 struct scsi_cmnd *sc) 592 { 593 u32 tag = blk_mq_unique_tag(sc->request); 594 u16 hwq = blk_mq_unique_tag_to_hwq(tag); 595 596 return &vscsi->req_vqs[hwq]; 597 } 598 599 static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi, 600 struct virtio_scsi_target_state *tgt) 601 { 602 struct virtio_scsi_vq *vq; 603 unsigned long flags; 604 u32 queue_num; 605 606 local_irq_save(flags); 607 if (atomic_inc_return(&tgt->reqs) > 1) { 608 unsigned long seq; 609 610 do { 611 seq = read_seqcount_begin(&tgt->tgt_seq); 612 vq = tgt->req_vq; 613 } while (read_seqcount_retry(&tgt->tgt_seq, seq)); 614 } else { 615 /* no writes can be concurrent because of atomic_t */ 616 write_seqcount_begin(&tgt->tgt_seq); 617 618 /* keep previous req_vq if a reader just arrived */ 619 if (unlikely(atomic_read(&tgt->reqs) > 1)) { 620 vq = tgt->req_vq; 621 goto unlock; 622 } 623 624 queue_num = smp_processor_id(); 625 while (unlikely(queue_num >= vscsi->num_queues)) 626 queue_num -= vscsi->num_queues; 627 tgt->req_vq = vq = &vscsi->req_vqs[queue_num]; 628 unlock: 629 write_seqcount_end(&tgt->tgt_seq); 630 } 631 local_irq_restore(flags); 632 633 return vq; 634 } 635 636 static int virtscsi_queuecommand_multi(struct Scsi_Host *sh, 637 struct scsi_cmnd *sc) 638 { 639 struct virtio_scsi *vscsi = shost_priv(sh); 640 struct virtio_scsi_target_state *tgt = 641 scsi_target(sc->device)->hostdata; 642 struct virtio_scsi_vq *req_vq; 643 644 if (shost_use_blk_mq(sh)) 645 req_vq = virtscsi_pick_vq_mq(vscsi, sc); 646 else 647 req_vq = virtscsi_pick_vq(vscsi, tgt); 648 649 return virtscsi_queuecommand(vscsi, req_vq, sc); 650 } 651 652 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 653 { 654 DECLARE_COMPLETION_ONSTACK(comp); 655 int ret = FAILED; 656 657 cmd->comp = ∁ 658 if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd, 659 sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0) 660 goto out; 661 662 wait_for_completion(&comp); 663 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 664 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 665 ret = SUCCESS; 666 667 /* 668 * The spec guarantees that all requests related to the TMF have 669 * been completed, but the callback might not have run yet if 670 * we're using independent interrupts (e.g. MSI). Poll the 671 * virtqueues once. 672 * 673 * In the abort case, sc->scsi_done will do nothing, because 674 * the block layer must have detected a timeout and as a result 675 * REQ_ATOM_COMPLETE has been set. 676 */ 677 virtscsi_poll_requests(vscsi); 678 679 out: 680 mempool_free(cmd, virtscsi_cmd_pool); 681 return ret; 682 } 683 684 static int virtscsi_device_reset(struct scsi_cmnd *sc) 685 { 686 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 687 struct virtio_scsi_cmd *cmd; 688 689 sdev_printk(KERN_INFO, sc->device, "device reset\n"); 690 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 691 if (!cmd) 692 return FAILED; 693 694 memset(cmd, 0, sizeof(*cmd)); 695 cmd->sc = sc; 696 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 697 .type = VIRTIO_SCSI_T_TMF, 698 .subtype = cpu_to_virtio32(vscsi->vdev, 699 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET), 700 .lun[0] = 1, 701 .lun[1] = sc->device->id, 702 .lun[2] = (sc->device->lun >> 8) | 0x40, 703 .lun[3] = sc->device->lun & 0xff, 704 }; 705 return virtscsi_tmf(vscsi, cmd); 706 } 707 708 /** 709 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth 710 * @sdev: Virtscsi target whose queue depth to change 711 * @qdepth: New queue depth 712 */ 713 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) 714 { 715 struct Scsi_Host *shost = sdev->host; 716 int max_depth = shost->cmd_per_lun; 717 718 return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); 719 } 720 721 static int virtscsi_abort(struct scsi_cmnd *sc) 722 { 723 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 724 struct virtio_scsi_cmd *cmd; 725 726 scmd_printk(KERN_INFO, sc, "abort\n"); 727 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 728 if (!cmd) 729 return FAILED; 730 731 memset(cmd, 0, sizeof(*cmd)); 732 cmd->sc = sc; 733 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 734 .type = VIRTIO_SCSI_T_TMF, 735 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 736 .lun[0] = 1, 737 .lun[1] = sc->device->id, 738 .lun[2] = (sc->device->lun >> 8) | 0x40, 739 .lun[3] = sc->device->lun & 0xff, 740 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc), 741 }; 742 return virtscsi_tmf(vscsi, cmd); 743 } 744 745 static int virtscsi_target_alloc(struct scsi_target *starget) 746 { 747 struct Scsi_Host *sh = dev_to_shost(starget->dev.parent); 748 struct virtio_scsi *vscsi = shost_priv(sh); 749 750 struct virtio_scsi_target_state *tgt = 751 kmalloc(sizeof(*tgt), GFP_KERNEL); 752 if (!tgt) 753 return -ENOMEM; 754 755 seqcount_init(&tgt->tgt_seq); 756 atomic_set(&tgt->reqs, 0); 757 tgt->req_vq = &vscsi->req_vqs[0]; 758 759 starget->hostdata = tgt; 760 return 0; 761 } 762 763 static void virtscsi_target_destroy(struct scsi_target *starget) 764 { 765 struct virtio_scsi_target_state *tgt = starget->hostdata; 766 kfree(tgt); 767 } 768 769 static int virtscsi_map_queues(struct Scsi_Host *shost) 770 { 771 struct virtio_scsi *vscsi = shost_priv(shost); 772 773 return blk_mq_virtio_map_queues(&shost->tag_set, vscsi->vdev, 2); 774 } 775 776 static struct scsi_host_template virtscsi_host_template_single = { 777 .module = THIS_MODULE, 778 .name = "Virtio SCSI HBA", 779 .proc_name = "virtio_scsi", 780 .this_id = -1, 781 .cmd_size = sizeof(struct virtio_scsi_cmd), 782 .queuecommand = virtscsi_queuecommand_single, 783 .change_queue_depth = virtscsi_change_queue_depth, 784 .eh_abort_handler = virtscsi_abort, 785 .eh_device_reset_handler = virtscsi_device_reset, 786 787 .can_queue = 1024, 788 .dma_boundary = UINT_MAX, 789 .use_clustering = ENABLE_CLUSTERING, 790 .target_alloc = virtscsi_target_alloc, 791 .target_destroy = virtscsi_target_destroy, 792 .track_queue_depth = 1, 793 }; 794 795 static struct scsi_host_template virtscsi_host_template_multi = { 796 .module = THIS_MODULE, 797 .name = "Virtio SCSI HBA", 798 .proc_name = "virtio_scsi", 799 .this_id = -1, 800 .cmd_size = sizeof(struct virtio_scsi_cmd), 801 .queuecommand = virtscsi_queuecommand_multi, 802 .change_queue_depth = virtscsi_change_queue_depth, 803 .eh_abort_handler = virtscsi_abort, 804 .eh_device_reset_handler = virtscsi_device_reset, 805 806 .can_queue = 1024, 807 .dma_boundary = UINT_MAX, 808 .use_clustering = ENABLE_CLUSTERING, 809 .target_alloc = virtscsi_target_alloc, 810 .target_destroy = virtscsi_target_destroy, 811 .map_queues = virtscsi_map_queues, 812 .track_queue_depth = 1, 813 }; 814 815 #define virtscsi_config_get(vdev, fld) \ 816 ({ \ 817 typeof(((struct virtio_scsi_config *)0)->fld) __val; \ 818 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 819 __val; \ 820 }) 821 822 #define virtscsi_config_set(vdev, fld, val) \ 823 do { \ 824 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \ 825 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 826 } while(0) 827 828 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 829 struct virtqueue *vq) 830 { 831 spin_lock_init(&virtscsi_vq->vq_lock); 832 virtscsi_vq->vq = vq; 833 } 834 835 static void virtscsi_remove_vqs(struct virtio_device *vdev) 836 { 837 /* Stop all the virtqueues. */ 838 vdev->config->reset(vdev); 839 vdev->config->del_vqs(vdev); 840 } 841 842 static int virtscsi_init(struct virtio_device *vdev, 843 struct virtio_scsi *vscsi) 844 { 845 int err; 846 u32 i; 847 u32 num_vqs; 848 vq_callback_t **callbacks; 849 const char **names; 850 struct virtqueue **vqs; 851 struct irq_affinity desc = { .pre_vectors = 2 }; 852 853 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; 854 vqs = kmalloc(num_vqs * sizeof(struct virtqueue *), GFP_KERNEL); 855 callbacks = kmalloc(num_vqs * sizeof(vq_callback_t *), GFP_KERNEL); 856 names = kmalloc(num_vqs * sizeof(char *), GFP_KERNEL); 857 858 if (!callbacks || !vqs || !names) { 859 err = -ENOMEM; 860 goto out; 861 } 862 863 callbacks[0] = virtscsi_ctrl_done; 864 callbacks[1] = virtscsi_event_done; 865 names[0] = "control"; 866 names[1] = "event"; 867 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { 868 callbacks[i] = virtscsi_req_done; 869 names[i] = "request"; 870 } 871 872 /* Discover virtqueues and write information to configuration. */ 873 err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names, 874 &desc); 875 if (err) 876 goto out; 877 878 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 879 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 880 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 881 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 882 vqs[i]); 883 884 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 885 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 886 887 err = 0; 888 889 out: 890 kfree(names); 891 kfree(callbacks); 892 kfree(vqs); 893 if (err) 894 virtscsi_remove_vqs(vdev); 895 return err; 896 } 897 898 static int virtscsi_probe(struct virtio_device *vdev) 899 { 900 struct Scsi_Host *shost; 901 struct virtio_scsi *vscsi; 902 int err; 903 u32 sg_elems, num_targets; 904 u32 cmd_per_lun; 905 u32 num_queues; 906 struct scsi_host_template *hostt; 907 908 if (!vdev->config->get) { 909 dev_err(&vdev->dev, "%s failure: config access disabled\n", 910 __func__); 911 return -EINVAL; 912 } 913 914 /* We need to know how many queues before we allocate. */ 915 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; 916 917 num_targets = virtscsi_config_get(vdev, max_target) + 1; 918 919 if (num_queues == 1) 920 hostt = &virtscsi_host_template_single; 921 else 922 hostt = &virtscsi_host_template_multi; 923 924 shost = scsi_host_alloc(hostt, 925 sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues); 926 if (!shost) 927 return -ENOMEM; 928 929 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 930 shost->sg_tablesize = sg_elems; 931 vscsi = shost_priv(shost); 932 vscsi->vdev = vdev; 933 vscsi->num_queues = num_queues; 934 vdev->priv = shost; 935 936 err = virtscsi_init(vdev, vscsi); 937 if (err) 938 goto virtscsi_init_failed; 939 940 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 941 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 942 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 943 944 /* LUNs > 256 are reported with format 1, so they go in the range 945 * 16640-32767. 946 */ 947 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 948 shost->max_id = num_targets; 949 shost->max_channel = 0; 950 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 951 shost->nr_hw_queues = num_queues; 952 953 #ifdef CONFIG_BLK_DEV_INTEGRITY 954 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 955 int host_prot; 956 957 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 958 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 959 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 960 961 scsi_host_set_prot(shost, host_prot); 962 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 963 } 964 #endif 965 966 err = scsi_add_host(shost, &vdev->dev); 967 if (err) 968 goto scsi_add_host_failed; 969 970 virtio_device_ready(vdev); 971 972 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 973 virtscsi_kick_event_all(vscsi); 974 975 scsi_scan_host(shost); 976 return 0; 977 978 scsi_add_host_failed: 979 vdev->config->del_vqs(vdev); 980 virtscsi_init_failed: 981 scsi_host_put(shost); 982 return err; 983 } 984 985 static void virtscsi_remove(struct virtio_device *vdev) 986 { 987 struct Scsi_Host *shost = virtio_scsi_host(vdev); 988 struct virtio_scsi *vscsi = shost_priv(shost); 989 990 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 991 virtscsi_cancel_event_work(vscsi); 992 993 scsi_remove_host(shost); 994 virtscsi_remove_vqs(vdev); 995 scsi_host_put(shost); 996 } 997 998 #ifdef CONFIG_PM_SLEEP 999 static int virtscsi_freeze(struct virtio_device *vdev) 1000 { 1001 virtscsi_remove_vqs(vdev); 1002 return 0; 1003 } 1004 1005 static int virtscsi_restore(struct virtio_device *vdev) 1006 { 1007 struct Scsi_Host *sh = virtio_scsi_host(vdev); 1008 struct virtio_scsi *vscsi = shost_priv(sh); 1009 int err; 1010 1011 err = virtscsi_init(vdev, vscsi); 1012 if (err) 1013 return err; 1014 1015 virtio_device_ready(vdev); 1016 1017 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1018 virtscsi_kick_event_all(vscsi); 1019 1020 return err; 1021 } 1022 #endif 1023 1024 static struct virtio_device_id id_table[] = { 1025 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 1026 { 0 }, 1027 }; 1028 1029 static unsigned int features[] = { 1030 VIRTIO_SCSI_F_HOTPLUG, 1031 VIRTIO_SCSI_F_CHANGE, 1032 #ifdef CONFIG_BLK_DEV_INTEGRITY 1033 VIRTIO_SCSI_F_T10_PI, 1034 #endif 1035 }; 1036 1037 static struct virtio_driver virtio_scsi_driver = { 1038 .feature_table = features, 1039 .feature_table_size = ARRAY_SIZE(features), 1040 .driver.name = KBUILD_MODNAME, 1041 .driver.owner = THIS_MODULE, 1042 .id_table = id_table, 1043 .probe = virtscsi_probe, 1044 #ifdef CONFIG_PM_SLEEP 1045 .freeze = virtscsi_freeze, 1046 .restore = virtscsi_restore, 1047 #endif 1048 .remove = virtscsi_remove, 1049 }; 1050 1051 static int __init init(void) 1052 { 1053 int ret = -ENOMEM; 1054 1055 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); 1056 if (!virtscsi_cmd_cache) { 1057 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); 1058 goto error; 1059 } 1060 1061 1062 virtscsi_cmd_pool = 1063 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, 1064 virtscsi_cmd_cache); 1065 if (!virtscsi_cmd_pool) { 1066 pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); 1067 goto error; 1068 } 1069 ret = register_virtio_driver(&virtio_scsi_driver); 1070 if (ret < 0) 1071 goto error; 1072 1073 return 0; 1074 1075 error: 1076 if (virtscsi_cmd_pool) { 1077 mempool_destroy(virtscsi_cmd_pool); 1078 virtscsi_cmd_pool = NULL; 1079 } 1080 if (virtscsi_cmd_cache) { 1081 kmem_cache_destroy(virtscsi_cmd_cache); 1082 virtscsi_cmd_cache = NULL; 1083 } 1084 return ret; 1085 } 1086 1087 static void __exit fini(void) 1088 { 1089 unregister_virtio_driver(&virtio_scsi_driver); 1090 mempool_destroy(virtscsi_cmd_pool); 1091 kmem_cache_destroy(virtscsi_cmd_cache); 1092 } 1093 module_init(init); 1094 module_exit(fini); 1095 1096 MODULE_DEVICE_TABLE(virtio, id_table); 1097 MODULE_DESCRIPTION("Virtio SCSI HBA driver"); 1098 MODULE_LICENSE("GPL"); 1099