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/virtio.h> 22 #include <linux/virtio_ids.h> 23 #include <linux/virtio_config.h> 24 #include <linux/virtio_scsi.h> 25 #include <linux/cpu.h> 26 #include <linux/blkdev.h> 27 #include <scsi/scsi_host.h> 28 #include <scsi/scsi_device.h> 29 #include <scsi/scsi_cmnd.h> 30 #include <scsi/scsi_tcq.h> 31 #include <linux/seqlock.h> 32 33 #define VIRTIO_SCSI_MEMPOOL_SZ 64 34 #define VIRTIO_SCSI_EVENT_LEN 8 35 #define VIRTIO_SCSI_VQ_BASE 2 36 37 /* Command queue element */ 38 struct virtio_scsi_cmd { 39 struct scsi_cmnd *sc; 40 struct completion *comp; 41 union { 42 struct virtio_scsi_cmd_req cmd; 43 struct virtio_scsi_cmd_req_pi cmd_pi; 44 struct virtio_scsi_ctrl_tmf_req tmf; 45 struct virtio_scsi_ctrl_an_req an; 46 } req; 47 union { 48 struct virtio_scsi_cmd_resp cmd; 49 struct virtio_scsi_ctrl_tmf_resp tmf; 50 struct virtio_scsi_ctrl_an_resp an; 51 struct virtio_scsi_event evt; 52 } resp; 53 } ____cacheline_aligned_in_smp; 54 55 struct virtio_scsi_event_node { 56 struct virtio_scsi *vscsi; 57 struct virtio_scsi_event event; 58 struct work_struct work; 59 }; 60 61 struct virtio_scsi_vq { 62 /* Protects vq */ 63 spinlock_t vq_lock; 64 65 struct virtqueue *vq; 66 }; 67 68 /* 69 * Per-target queue state. 70 * 71 * This struct holds the data needed by the queue steering policy. When a 72 * target is sent multiple requests, we need to drive them to the same queue so 73 * that FIFO processing order is kept. However, if a target was idle, we can 74 * choose a queue arbitrarily. In this case the queue is chosen according to 75 * the current VCPU, so the driver expects the number of request queues to be 76 * equal to the number of VCPUs. This makes it easy and fast to select the 77 * queue, and also lets the driver optimize the IRQ affinity for the virtqueues 78 * (each virtqueue's affinity is set to the CPU that "owns" the queue). 79 * 80 * tgt_seq is held to serialize reading and writing req_vq. 81 * 82 * Decrements of reqs are never concurrent with writes of req_vq: before the 83 * decrement reqs will be != 0; after the decrement the virtqueue completion 84 * routine will not use the req_vq so it can be changed by a new request. 85 * Thus they can happen outside the tgt_seq, provided of course we make reqs 86 * an atomic_t. 87 */ 88 struct virtio_scsi_target_state { 89 seqcount_t tgt_seq; 90 91 /* Count of outstanding requests. */ 92 atomic_t reqs; 93 94 /* Currently active virtqueue for requests sent to this target. */ 95 struct virtio_scsi_vq *req_vq; 96 }; 97 98 /* Driver instance state */ 99 struct virtio_scsi { 100 struct virtio_device *vdev; 101 102 /* Get some buffers ready for event vq */ 103 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN]; 104 105 u32 num_queues; 106 107 /* If the affinity hint is set for virtqueues */ 108 bool affinity_hint_set; 109 110 /* CPU hotplug notifier */ 111 struct notifier_block nb; 112 113 /* Protected by event_vq lock */ 114 bool stop_events; 115 116 struct virtio_scsi_vq ctrl_vq; 117 struct virtio_scsi_vq event_vq; 118 struct virtio_scsi_vq req_vqs[]; 119 }; 120 121 static struct kmem_cache *virtscsi_cmd_cache; 122 static mempool_t *virtscsi_cmd_pool; 123 124 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev) 125 { 126 return vdev->priv; 127 } 128 129 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid) 130 { 131 if (!resid) 132 return; 133 134 if (!scsi_bidi_cmnd(sc)) { 135 scsi_set_resid(sc, resid); 136 return; 137 } 138 139 scsi_in(sc)->resid = min(resid, scsi_in(sc)->length); 140 scsi_out(sc)->resid = resid - scsi_in(sc)->resid; 141 } 142 143 /** 144 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done 145 * 146 * Called with vq_lock held. 147 */ 148 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf) 149 { 150 struct virtio_scsi_cmd *cmd = buf; 151 struct scsi_cmnd *sc = cmd->sc; 152 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd; 153 struct virtio_scsi_target_state *tgt = 154 scsi_target(sc->device)->hostdata; 155 156 dev_dbg(&sc->device->sdev_gendev, 157 "cmd %p response %u status %#02x sense_len %u\n", 158 sc, resp->response, resp->status, resp->sense_len); 159 160 sc->result = resp->status; 161 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid)); 162 switch (resp->response) { 163 case VIRTIO_SCSI_S_OK: 164 set_host_byte(sc, DID_OK); 165 break; 166 case VIRTIO_SCSI_S_OVERRUN: 167 set_host_byte(sc, DID_ERROR); 168 break; 169 case VIRTIO_SCSI_S_ABORTED: 170 set_host_byte(sc, DID_ABORT); 171 break; 172 case VIRTIO_SCSI_S_BAD_TARGET: 173 set_host_byte(sc, DID_BAD_TARGET); 174 break; 175 case VIRTIO_SCSI_S_RESET: 176 set_host_byte(sc, DID_RESET); 177 break; 178 case VIRTIO_SCSI_S_BUSY: 179 set_host_byte(sc, DID_BUS_BUSY); 180 break; 181 case VIRTIO_SCSI_S_TRANSPORT_FAILURE: 182 set_host_byte(sc, DID_TRANSPORT_DISRUPTED); 183 break; 184 case VIRTIO_SCSI_S_TARGET_FAILURE: 185 set_host_byte(sc, DID_TARGET_FAILURE); 186 break; 187 case VIRTIO_SCSI_S_NEXUS_FAILURE: 188 set_host_byte(sc, DID_NEXUS_FAILURE); 189 break; 190 default: 191 scmd_printk(KERN_WARNING, sc, "Unknown response %d", 192 resp->response); 193 /* fall through */ 194 case VIRTIO_SCSI_S_FAILURE: 195 set_host_byte(sc, DID_ERROR); 196 break; 197 } 198 199 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) > 200 VIRTIO_SCSI_SENSE_SIZE); 201 if (sc->sense_buffer) { 202 memcpy(sc->sense_buffer, resp->sense, 203 min_t(u32, 204 virtio32_to_cpu(vscsi->vdev, resp->sense_len), 205 VIRTIO_SCSI_SENSE_SIZE)); 206 if (resp->sense_len) 207 set_driver_byte(sc, DRIVER_SENSE); 208 } 209 210 sc->scsi_done(sc); 211 212 atomic_dec(&tgt->reqs); 213 } 214 215 static void virtscsi_vq_done(struct virtio_scsi *vscsi, 216 struct virtio_scsi_vq *virtscsi_vq, 217 void (*fn)(struct virtio_scsi *vscsi, void *buf)) 218 { 219 void *buf; 220 unsigned int len; 221 unsigned long flags; 222 struct virtqueue *vq = virtscsi_vq->vq; 223 224 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); 225 do { 226 virtqueue_disable_cb(vq); 227 while ((buf = virtqueue_get_buf(vq, &len)) != NULL) 228 fn(vscsi, buf); 229 230 if (unlikely(virtqueue_is_broken(vq))) 231 break; 232 } while (!virtqueue_enable_cb(vq)); 233 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); 234 } 235 236 static void virtscsi_req_done(struct virtqueue *vq) 237 { 238 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 239 struct virtio_scsi *vscsi = shost_priv(sh); 240 int index = vq->index - VIRTIO_SCSI_VQ_BASE; 241 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index]; 242 243 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd); 244 }; 245 246 static void virtscsi_poll_requests(struct virtio_scsi *vscsi) 247 { 248 int i, num_vqs; 249 250 num_vqs = vscsi->num_queues; 251 for (i = 0; i < num_vqs; i++) 252 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i], 253 virtscsi_complete_cmd); 254 } 255 256 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf) 257 { 258 struct virtio_scsi_cmd *cmd = buf; 259 260 if (cmd->comp) 261 complete_all(cmd->comp); 262 } 263 264 static void virtscsi_ctrl_done(struct virtqueue *vq) 265 { 266 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 267 struct virtio_scsi *vscsi = shost_priv(sh); 268 269 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free); 270 }; 271 272 static void virtscsi_handle_event(struct work_struct *work); 273 274 static int virtscsi_kick_event(struct virtio_scsi *vscsi, 275 struct virtio_scsi_event_node *event_node) 276 { 277 int err; 278 struct scatterlist sg; 279 unsigned long flags; 280 281 INIT_WORK(&event_node->work, virtscsi_handle_event); 282 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event)); 283 284 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags); 285 286 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node, 287 GFP_ATOMIC); 288 if (!err) 289 virtqueue_kick(vscsi->event_vq.vq); 290 291 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags); 292 293 return err; 294 } 295 296 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi) 297 { 298 int i; 299 300 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) { 301 vscsi->event_list[i].vscsi = vscsi; 302 virtscsi_kick_event(vscsi, &vscsi->event_list[i]); 303 } 304 305 return 0; 306 } 307 308 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi) 309 { 310 int i; 311 312 /* Stop scheduling work before calling cancel_work_sync. */ 313 spin_lock_irq(&vscsi->event_vq.vq_lock); 314 vscsi->stop_events = true; 315 spin_unlock_irq(&vscsi->event_vq.vq_lock); 316 317 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) 318 cancel_work_sync(&vscsi->event_list[i].work); 319 } 320 321 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, 322 struct virtio_scsi_event *event) 323 { 324 struct scsi_device *sdev; 325 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 326 unsigned int target = event->lun[1]; 327 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 328 329 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) { 330 case VIRTIO_SCSI_EVT_RESET_RESCAN: 331 scsi_add_device(shost, 0, target, lun); 332 break; 333 case VIRTIO_SCSI_EVT_RESET_REMOVED: 334 sdev = scsi_device_lookup(shost, 0, target, lun); 335 if (sdev) { 336 scsi_remove_device(sdev); 337 scsi_device_put(sdev); 338 } else { 339 pr_err("SCSI device %d 0 %d %d not found\n", 340 shost->host_no, target, lun); 341 } 342 break; 343 default: 344 pr_info("Unsupport virtio scsi event reason %x\n", event->reason); 345 } 346 } 347 348 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, 349 struct virtio_scsi_event *event) 350 { 351 struct scsi_device *sdev; 352 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 353 unsigned int target = event->lun[1]; 354 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 355 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255; 356 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8; 357 358 sdev = scsi_device_lookup(shost, 0, target, lun); 359 if (!sdev) { 360 pr_err("SCSI device %d 0 %d %d not found\n", 361 shost->host_no, target, lun); 362 return; 363 } 364 365 /* Handle "Parameters changed", "Mode parameters changed", and 366 "Capacity data has changed". */ 367 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) 368 scsi_rescan_device(&sdev->sdev_gendev); 369 370 scsi_device_put(sdev); 371 } 372 373 static void virtscsi_handle_event(struct work_struct *work) 374 { 375 struct virtio_scsi_event_node *event_node = 376 container_of(work, struct virtio_scsi_event_node, work); 377 struct virtio_scsi *vscsi = event_node->vscsi; 378 struct virtio_scsi_event *event = &event_node->event; 379 380 if (event->event & 381 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { 382 event->event &= ~cpu_to_virtio32(vscsi->vdev, 383 VIRTIO_SCSI_T_EVENTS_MISSED); 384 scsi_scan_host(virtio_scsi_host(vscsi->vdev)); 385 } 386 387 switch (virtio32_to_cpu(vscsi->vdev, event->event)) { 388 case VIRTIO_SCSI_T_NO_EVENT: 389 break; 390 case VIRTIO_SCSI_T_TRANSPORT_RESET: 391 virtscsi_handle_transport_reset(vscsi, event); 392 break; 393 case VIRTIO_SCSI_T_PARAM_CHANGE: 394 virtscsi_handle_param_change(vscsi, event); 395 break; 396 default: 397 pr_err("Unsupport virtio scsi event %x\n", event->event); 398 } 399 virtscsi_kick_event(vscsi, event_node); 400 } 401 402 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) 403 { 404 struct virtio_scsi_event_node *event_node = buf; 405 406 if (!vscsi->stop_events) 407 queue_work(system_freezable_wq, &event_node->work); 408 } 409 410 static void virtscsi_event_done(struct virtqueue *vq) 411 { 412 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 413 struct virtio_scsi *vscsi = shost_priv(sh); 414 415 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); 416 }; 417 418 /** 419 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue 420 * @vq : the struct virtqueue we're talking about 421 * @cmd : command structure 422 * @req_size : size of the request buffer 423 * @resp_size : size of the response buffer 424 */ 425 static int virtscsi_add_cmd(struct virtqueue *vq, 426 struct virtio_scsi_cmd *cmd, 427 size_t req_size, size_t resp_size) 428 { 429 struct scsi_cmnd *sc = cmd->sc; 430 struct scatterlist *sgs[6], req, resp; 431 struct sg_table *out, *in; 432 unsigned out_num = 0, in_num = 0; 433 434 out = in = NULL; 435 436 if (sc && sc->sc_data_direction != DMA_NONE) { 437 if (sc->sc_data_direction != DMA_FROM_DEVICE) 438 out = &scsi_out(sc)->table; 439 if (sc->sc_data_direction != DMA_TO_DEVICE) 440 in = &scsi_in(sc)->table; 441 } 442 443 /* Request header. */ 444 sg_init_one(&req, &cmd->req, req_size); 445 sgs[out_num++] = &req; 446 447 /* Data-out buffer. */ 448 if (out) { 449 /* Place WRITE protection SGLs before Data OUT payload */ 450 if (scsi_prot_sg_count(sc)) 451 sgs[out_num++] = scsi_prot_sglist(sc); 452 sgs[out_num++] = out->sgl; 453 } 454 455 /* Response header. */ 456 sg_init_one(&resp, &cmd->resp, resp_size); 457 sgs[out_num + in_num++] = &resp; 458 459 /* Data-in buffer */ 460 if (in) { 461 /* Place READ protection SGLs before Data IN payload */ 462 if (scsi_prot_sg_count(sc)) 463 sgs[out_num + in_num++] = scsi_prot_sglist(sc); 464 sgs[out_num + in_num++] = in->sgl; 465 } 466 467 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); 468 } 469 470 static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq, 471 struct virtio_scsi_cmd *cmd, 472 size_t req_size, size_t resp_size) 473 { 474 unsigned long flags; 475 int err; 476 bool needs_kick = false; 477 478 spin_lock_irqsave(&vq->vq_lock, flags); 479 err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size); 480 if (!err) 481 needs_kick = virtqueue_kick_prepare(vq->vq); 482 483 spin_unlock_irqrestore(&vq->vq_lock, flags); 484 485 if (needs_kick) 486 virtqueue_notify(vq->vq); 487 return err; 488 } 489 490 static void virtio_scsi_init_hdr(struct virtio_device *vdev, 491 struct virtio_scsi_cmd_req *cmd, 492 struct scsi_cmnd *sc) 493 { 494 cmd->lun[0] = 1; 495 cmd->lun[1] = sc->device->id; 496 cmd->lun[2] = (sc->device->lun >> 8) | 0x40; 497 cmd->lun[3] = sc->device->lun & 0xff; 498 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc); 499 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; 500 cmd->prio = 0; 501 cmd->crn = 0; 502 } 503 504 #ifdef CONFIG_BLK_DEV_INTEGRITY 505 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, 506 struct virtio_scsi_cmd_req_pi *cmd_pi, 507 struct scsi_cmnd *sc) 508 { 509 struct request *rq = sc->request; 510 struct blk_integrity *bi; 511 512 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc); 513 514 if (!rq || !scsi_prot_sg_count(sc)) 515 return; 516 517 bi = blk_get_integrity(rq->rq_disk); 518 519 if (sc->sc_data_direction == DMA_TO_DEVICE) 520 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, 521 blk_rq_sectors(rq) * 522 bi->tuple_size); 523 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 524 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, 525 blk_rq_sectors(rq) * 526 bi->tuple_size); 527 } 528 #endif 529 530 static int virtscsi_queuecommand(struct virtio_scsi *vscsi, 531 struct virtio_scsi_vq *req_vq, 532 struct scsi_cmnd *sc) 533 { 534 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 535 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 536 int req_size; 537 538 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 539 540 /* TODO: check feature bit and fail if unsupported? */ 541 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 542 543 dev_dbg(&sc->device->sdev_gendev, 544 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 545 546 memset(cmd, 0, sizeof(*cmd)); 547 cmd->sc = sc; 548 549 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 550 551 #ifdef CONFIG_BLK_DEV_INTEGRITY 552 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 553 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc); 554 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 555 req_size = sizeof(cmd->req.cmd_pi); 556 } else 557 #endif 558 { 559 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc); 560 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 561 req_size = sizeof(cmd->req.cmd); 562 } 563 564 if (virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd)) != 0) 565 return SCSI_MLQUEUE_HOST_BUSY; 566 return 0; 567 } 568 569 static int virtscsi_queuecommand_single(struct Scsi_Host *sh, 570 struct scsi_cmnd *sc) 571 { 572 struct virtio_scsi *vscsi = shost_priv(sh); 573 struct virtio_scsi_target_state *tgt = 574 scsi_target(sc->device)->hostdata; 575 576 atomic_inc(&tgt->reqs); 577 return virtscsi_queuecommand(vscsi, &vscsi->req_vqs[0], sc); 578 } 579 580 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, 581 struct scsi_cmnd *sc) 582 { 583 u32 tag = blk_mq_unique_tag(sc->request); 584 u16 hwq = blk_mq_unique_tag_to_hwq(tag); 585 586 return &vscsi->req_vqs[hwq]; 587 } 588 589 static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi, 590 struct virtio_scsi_target_state *tgt) 591 { 592 struct virtio_scsi_vq *vq; 593 unsigned long flags; 594 u32 queue_num; 595 596 local_irq_save(flags); 597 if (atomic_inc_return(&tgt->reqs) > 1) { 598 unsigned long seq; 599 600 do { 601 seq = read_seqcount_begin(&tgt->tgt_seq); 602 vq = tgt->req_vq; 603 } while (read_seqcount_retry(&tgt->tgt_seq, seq)); 604 } else { 605 /* no writes can be concurrent because of atomic_t */ 606 write_seqcount_begin(&tgt->tgt_seq); 607 608 /* keep previous req_vq if a reader just arrived */ 609 if (unlikely(atomic_read(&tgt->reqs) > 1)) { 610 vq = tgt->req_vq; 611 goto unlock; 612 } 613 614 queue_num = smp_processor_id(); 615 while (unlikely(queue_num >= vscsi->num_queues)) 616 queue_num -= vscsi->num_queues; 617 tgt->req_vq = vq = &vscsi->req_vqs[queue_num]; 618 unlock: 619 write_seqcount_end(&tgt->tgt_seq); 620 } 621 local_irq_restore(flags); 622 623 return vq; 624 } 625 626 static int virtscsi_queuecommand_multi(struct Scsi_Host *sh, 627 struct scsi_cmnd *sc) 628 { 629 struct virtio_scsi *vscsi = shost_priv(sh); 630 struct virtio_scsi_target_state *tgt = 631 scsi_target(sc->device)->hostdata; 632 struct virtio_scsi_vq *req_vq; 633 634 if (shost_use_blk_mq(sh)) 635 req_vq = virtscsi_pick_vq_mq(vscsi, sc); 636 else 637 req_vq = virtscsi_pick_vq(vscsi, tgt); 638 639 return virtscsi_queuecommand(vscsi, req_vq, sc); 640 } 641 642 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 643 { 644 DECLARE_COMPLETION_ONSTACK(comp); 645 int ret = FAILED; 646 647 cmd->comp = ∁ 648 if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd, 649 sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0) 650 goto out; 651 652 wait_for_completion(&comp); 653 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 654 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 655 ret = SUCCESS; 656 657 /* 658 * The spec guarantees that all requests related to the TMF have 659 * been completed, but the callback might not have run yet if 660 * we're using independent interrupts (e.g. MSI). Poll the 661 * virtqueues once. 662 * 663 * In the abort case, sc->scsi_done will do nothing, because 664 * the block layer must have detected a timeout and as a result 665 * REQ_ATOM_COMPLETE has been set. 666 */ 667 virtscsi_poll_requests(vscsi); 668 669 out: 670 mempool_free(cmd, virtscsi_cmd_pool); 671 return ret; 672 } 673 674 static int virtscsi_device_reset(struct scsi_cmnd *sc) 675 { 676 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 677 struct virtio_scsi_cmd *cmd; 678 679 sdev_printk(KERN_INFO, sc->device, "device reset\n"); 680 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 681 if (!cmd) 682 return FAILED; 683 684 memset(cmd, 0, sizeof(*cmd)); 685 cmd->sc = sc; 686 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 687 .type = VIRTIO_SCSI_T_TMF, 688 .subtype = cpu_to_virtio32(vscsi->vdev, 689 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET), 690 .lun[0] = 1, 691 .lun[1] = sc->device->id, 692 .lun[2] = (sc->device->lun >> 8) | 0x40, 693 .lun[3] = sc->device->lun & 0xff, 694 }; 695 return virtscsi_tmf(vscsi, cmd); 696 } 697 698 /** 699 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth 700 * @sdev: Virtscsi target whose queue depth to change 701 * @qdepth: New queue depth 702 */ 703 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) 704 { 705 struct Scsi_Host *shost = sdev->host; 706 int max_depth = shost->cmd_per_lun; 707 708 return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); 709 } 710 711 static int virtscsi_abort(struct scsi_cmnd *sc) 712 { 713 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 714 struct virtio_scsi_cmd *cmd; 715 716 scmd_printk(KERN_INFO, sc, "abort\n"); 717 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 718 if (!cmd) 719 return FAILED; 720 721 memset(cmd, 0, sizeof(*cmd)); 722 cmd->sc = sc; 723 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 724 .type = VIRTIO_SCSI_T_TMF, 725 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 726 .lun[0] = 1, 727 .lun[1] = sc->device->id, 728 .lun[2] = (sc->device->lun >> 8) | 0x40, 729 .lun[3] = sc->device->lun & 0xff, 730 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc), 731 }; 732 return virtscsi_tmf(vscsi, cmd); 733 } 734 735 static int virtscsi_target_alloc(struct scsi_target *starget) 736 { 737 struct Scsi_Host *sh = dev_to_shost(starget->dev.parent); 738 struct virtio_scsi *vscsi = shost_priv(sh); 739 740 struct virtio_scsi_target_state *tgt = 741 kmalloc(sizeof(*tgt), GFP_KERNEL); 742 if (!tgt) 743 return -ENOMEM; 744 745 seqcount_init(&tgt->tgt_seq); 746 atomic_set(&tgt->reqs, 0); 747 tgt->req_vq = &vscsi->req_vqs[0]; 748 749 starget->hostdata = tgt; 750 return 0; 751 } 752 753 static void virtscsi_target_destroy(struct scsi_target *starget) 754 { 755 struct virtio_scsi_target_state *tgt = starget->hostdata; 756 kfree(tgt); 757 } 758 759 static struct scsi_host_template virtscsi_host_template_single = { 760 .module = THIS_MODULE, 761 .name = "Virtio SCSI HBA", 762 .proc_name = "virtio_scsi", 763 .this_id = -1, 764 .cmd_size = sizeof(struct virtio_scsi_cmd), 765 .queuecommand = virtscsi_queuecommand_single, 766 .change_queue_depth = virtscsi_change_queue_depth, 767 .eh_abort_handler = virtscsi_abort, 768 .eh_device_reset_handler = virtscsi_device_reset, 769 770 .can_queue = 1024, 771 .dma_boundary = UINT_MAX, 772 .use_clustering = ENABLE_CLUSTERING, 773 .target_alloc = virtscsi_target_alloc, 774 .target_destroy = virtscsi_target_destroy, 775 .track_queue_depth = 1, 776 }; 777 778 static struct scsi_host_template virtscsi_host_template_multi = { 779 .module = THIS_MODULE, 780 .name = "Virtio SCSI HBA", 781 .proc_name = "virtio_scsi", 782 .this_id = -1, 783 .cmd_size = sizeof(struct virtio_scsi_cmd), 784 .queuecommand = virtscsi_queuecommand_multi, 785 .change_queue_depth = virtscsi_change_queue_depth, 786 .eh_abort_handler = virtscsi_abort, 787 .eh_device_reset_handler = virtscsi_device_reset, 788 789 .can_queue = 1024, 790 .dma_boundary = UINT_MAX, 791 .use_clustering = ENABLE_CLUSTERING, 792 .target_alloc = virtscsi_target_alloc, 793 .target_destroy = virtscsi_target_destroy, 794 .track_queue_depth = 1, 795 }; 796 797 #define virtscsi_config_get(vdev, fld) \ 798 ({ \ 799 typeof(((struct virtio_scsi_config *)0)->fld) __val; \ 800 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 801 __val; \ 802 }) 803 804 #define virtscsi_config_set(vdev, fld, val) \ 805 do { \ 806 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \ 807 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 808 } while(0) 809 810 static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) 811 { 812 int i; 813 int cpu; 814 815 /* In multiqueue mode, when the number of cpu is equal 816 * to the number of request queues, we let the qeueues 817 * to be private to one cpu by setting the affinity hint 818 * to eliminate the contention. 819 */ 820 if ((vscsi->num_queues == 1 || 821 vscsi->num_queues != num_online_cpus()) && affinity) { 822 if (vscsi->affinity_hint_set) 823 affinity = false; 824 else 825 return; 826 } 827 828 if (affinity) { 829 i = 0; 830 for_each_online_cpu(cpu) { 831 virtqueue_set_affinity(vscsi->req_vqs[i].vq, cpu); 832 i++; 833 } 834 835 vscsi->affinity_hint_set = true; 836 } else { 837 for (i = 0; i < vscsi->num_queues; i++) { 838 if (!vscsi->req_vqs[i].vq) 839 continue; 840 841 virtqueue_set_affinity(vscsi->req_vqs[i].vq, -1); 842 } 843 844 vscsi->affinity_hint_set = false; 845 } 846 } 847 848 static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) 849 { 850 get_online_cpus(); 851 __virtscsi_set_affinity(vscsi, affinity); 852 put_online_cpus(); 853 } 854 855 static int virtscsi_cpu_callback(struct notifier_block *nfb, 856 unsigned long action, void *hcpu) 857 { 858 struct virtio_scsi *vscsi = container_of(nfb, struct virtio_scsi, nb); 859 switch(action) { 860 case CPU_ONLINE: 861 case CPU_ONLINE_FROZEN: 862 case CPU_DEAD: 863 case CPU_DEAD_FROZEN: 864 __virtscsi_set_affinity(vscsi, true); 865 break; 866 default: 867 break; 868 } 869 return NOTIFY_OK; 870 } 871 872 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 873 struct virtqueue *vq) 874 { 875 spin_lock_init(&virtscsi_vq->vq_lock); 876 virtscsi_vq->vq = vq; 877 } 878 879 static void virtscsi_remove_vqs(struct virtio_device *vdev) 880 { 881 struct Scsi_Host *sh = virtio_scsi_host(vdev); 882 struct virtio_scsi *vscsi = shost_priv(sh); 883 884 virtscsi_set_affinity(vscsi, false); 885 886 /* Stop all the virtqueues. */ 887 vdev->config->reset(vdev); 888 889 vdev->config->del_vqs(vdev); 890 } 891 892 static int virtscsi_init(struct virtio_device *vdev, 893 struct virtio_scsi *vscsi) 894 { 895 int err; 896 u32 i; 897 u32 num_vqs; 898 vq_callback_t **callbacks; 899 const char **names; 900 struct virtqueue **vqs; 901 902 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; 903 vqs = kmalloc(num_vqs * sizeof(struct virtqueue *), GFP_KERNEL); 904 callbacks = kmalloc(num_vqs * sizeof(vq_callback_t *), GFP_KERNEL); 905 names = kmalloc(num_vqs * sizeof(char *), GFP_KERNEL); 906 907 if (!callbacks || !vqs || !names) { 908 err = -ENOMEM; 909 goto out; 910 } 911 912 callbacks[0] = virtscsi_ctrl_done; 913 callbacks[1] = virtscsi_event_done; 914 names[0] = "control"; 915 names[1] = "event"; 916 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { 917 callbacks[i] = virtscsi_req_done; 918 names[i] = "request"; 919 } 920 921 /* Discover virtqueues and write information to configuration. */ 922 err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names); 923 if (err) 924 goto out; 925 926 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 927 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 928 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 929 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 930 vqs[i]); 931 932 virtscsi_set_affinity(vscsi, true); 933 934 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 935 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 936 937 err = 0; 938 939 out: 940 kfree(names); 941 kfree(callbacks); 942 kfree(vqs); 943 if (err) 944 virtscsi_remove_vqs(vdev); 945 return err; 946 } 947 948 static int virtscsi_probe(struct virtio_device *vdev) 949 { 950 struct Scsi_Host *shost; 951 struct virtio_scsi *vscsi; 952 int err; 953 u32 sg_elems, num_targets; 954 u32 cmd_per_lun; 955 u32 num_queues; 956 struct scsi_host_template *hostt; 957 958 if (!vdev->config->get) { 959 dev_err(&vdev->dev, "%s failure: config access disabled\n", 960 __func__); 961 return -EINVAL; 962 } 963 964 /* We need to know how many queues before we allocate. */ 965 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; 966 967 num_targets = virtscsi_config_get(vdev, max_target) + 1; 968 969 if (num_queues == 1) 970 hostt = &virtscsi_host_template_single; 971 else 972 hostt = &virtscsi_host_template_multi; 973 974 shost = scsi_host_alloc(hostt, 975 sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues); 976 if (!shost) 977 return -ENOMEM; 978 979 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 980 shost->sg_tablesize = sg_elems; 981 vscsi = shost_priv(shost); 982 vscsi->vdev = vdev; 983 vscsi->num_queues = num_queues; 984 vdev->priv = shost; 985 986 err = virtscsi_init(vdev, vscsi); 987 if (err) 988 goto virtscsi_init_failed; 989 990 vscsi->nb.notifier_call = &virtscsi_cpu_callback; 991 err = register_hotcpu_notifier(&vscsi->nb); 992 if (err) { 993 pr_err("registering cpu notifier failed\n"); 994 goto scsi_add_host_failed; 995 } 996 997 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 998 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 999 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 1000 1001 /* LUNs > 256 are reported with format 1, so they go in the range 1002 * 16640-32767. 1003 */ 1004 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 1005 shost->max_id = num_targets; 1006 shost->max_channel = 0; 1007 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 1008 shost->nr_hw_queues = num_queues; 1009 1010 #ifdef CONFIG_BLK_DEV_INTEGRITY 1011 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 1012 int host_prot; 1013 1014 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 1015 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 1016 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 1017 1018 scsi_host_set_prot(shost, host_prot); 1019 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 1020 } 1021 #endif 1022 1023 err = scsi_add_host(shost, &vdev->dev); 1024 if (err) 1025 goto scsi_add_host_failed; 1026 1027 virtio_device_ready(vdev); 1028 1029 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1030 virtscsi_kick_event_all(vscsi); 1031 1032 scsi_scan_host(shost); 1033 return 0; 1034 1035 scsi_add_host_failed: 1036 vdev->config->del_vqs(vdev); 1037 virtscsi_init_failed: 1038 scsi_host_put(shost); 1039 return err; 1040 } 1041 1042 static void virtscsi_remove(struct virtio_device *vdev) 1043 { 1044 struct Scsi_Host *shost = virtio_scsi_host(vdev); 1045 struct virtio_scsi *vscsi = shost_priv(shost); 1046 1047 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1048 virtscsi_cancel_event_work(vscsi); 1049 1050 scsi_remove_host(shost); 1051 1052 unregister_hotcpu_notifier(&vscsi->nb); 1053 1054 virtscsi_remove_vqs(vdev); 1055 scsi_host_put(shost); 1056 } 1057 1058 #ifdef CONFIG_PM_SLEEP 1059 static int virtscsi_freeze(struct virtio_device *vdev) 1060 { 1061 struct Scsi_Host *sh = virtio_scsi_host(vdev); 1062 struct virtio_scsi *vscsi = shost_priv(sh); 1063 1064 unregister_hotcpu_notifier(&vscsi->nb); 1065 virtscsi_remove_vqs(vdev); 1066 return 0; 1067 } 1068 1069 static int virtscsi_restore(struct virtio_device *vdev) 1070 { 1071 struct Scsi_Host *sh = virtio_scsi_host(vdev); 1072 struct virtio_scsi *vscsi = shost_priv(sh); 1073 int err; 1074 1075 err = virtscsi_init(vdev, vscsi); 1076 if (err) 1077 return err; 1078 1079 err = register_hotcpu_notifier(&vscsi->nb); 1080 if (err) { 1081 vdev->config->del_vqs(vdev); 1082 return err; 1083 } 1084 1085 virtio_device_ready(vdev); 1086 1087 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1088 virtscsi_kick_event_all(vscsi); 1089 1090 return err; 1091 } 1092 #endif 1093 1094 static struct virtio_device_id id_table[] = { 1095 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 1096 { 0 }, 1097 }; 1098 1099 static unsigned int features[] = { 1100 VIRTIO_SCSI_F_HOTPLUG, 1101 VIRTIO_SCSI_F_CHANGE, 1102 #ifdef CONFIG_BLK_DEV_INTEGRITY 1103 VIRTIO_SCSI_F_T10_PI, 1104 #endif 1105 }; 1106 1107 static struct virtio_driver virtio_scsi_driver = { 1108 .feature_table = features, 1109 .feature_table_size = ARRAY_SIZE(features), 1110 .driver.name = KBUILD_MODNAME, 1111 .driver.owner = THIS_MODULE, 1112 .id_table = id_table, 1113 .probe = virtscsi_probe, 1114 #ifdef CONFIG_PM_SLEEP 1115 .freeze = virtscsi_freeze, 1116 .restore = virtscsi_restore, 1117 #endif 1118 .remove = virtscsi_remove, 1119 }; 1120 1121 static int __init init(void) 1122 { 1123 int ret = -ENOMEM; 1124 1125 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); 1126 if (!virtscsi_cmd_cache) { 1127 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); 1128 goto error; 1129 } 1130 1131 1132 virtscsi_cmd_pool = 1133 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, 1134 virtscsi_cmd_cache); 1135 if (!virtscsi_cmd_pool) { 1136 pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); 1137 goto error; 1138 } 1139 ret = register_virtio_driver(&virtio_scsi_driver); 1140 if (ret < 0) 1141 goto error; 1142 1143 return 0; 1144 1145 error: 1146 if (virtscsi_cmd_pool) { 1147 mempool_destroy(virtscsi_cmd_pool); 1148 virtscsi_cmd_pool = NULL; 1149 } 1150 if (virtscsi_cmd_cache) { 1151 kmem_cache_destroy(virtscsi_cmd_cache); 1152 virtscsi_cmd_cache = NULL; 1153 } 1154 return ret; 1155 } 1156 1157 static void __exit fini(void) 1158 { 1159 unregister_virtio_driver(&virtio_scsi_driver); 1160 mempool_destroy(virtscsi_cmd_pool); 1161 kmem_cache_destroy(virtscsi_cmd_cache); 1162 } 1163 module_init(init); 1164 module_exit(fini); 1165 1166 MODULE_DEVICE_TABLE(virtio, id_table); 1167 MODULE_DESCRIPTION("Virtio SCSI HBA driver"); 1168 MODULE_LICENSE("GPL"); 1169