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 */ 38struct 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 55struct virtio_scsi_event_node { 56 struct virtio_scsi *vscsi; 57 struct virtio_scsi_event event; 58 struct work_struct work; 59}; 60 61struct 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 */ 88struct 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 */ 99struct 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 121static struct kmem_cache *virtscsi_cmd_cache; 122static mempool_t *virtscsi_cmd_pool; 123 124static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev) 125{ 126 return vdev->priv; 127} 128 129static 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 */ 148static 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 215static 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 236static 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 246static 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 256static 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 264static 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 272static void virtscsi_handle_event(struct work_struct *work); 273 274static 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 296static 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 308static 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 321static 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 348static 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 373static 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 402static 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 410static 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 */ 425static 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 470static 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 490static 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 504static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, 505 struct virtio_scsi_cmd_req_pi *cmd_pi, 506 struct scsi_cmnd *sc) 507{ 508 struct request *rq = sc->request; 509 struct blk_integrity *bi; 510 511 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc); 512 513 if (!rq || !scsi_prot_sg_count(sc)) 514 return; 515 516 bi = blk_get_integrity(rq->rq_disk); 517 518 if (sc->sc_data_direction == DMA_TO_DEVICE) 519 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, 520 blk_rq_sectors(rq) * 521 bi->tuple_size); 522 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 523 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, 524 blk_rq_sectors(rq) * 525 bi->tuple_size); 526} 527 528static int virtscsi_queuecommand(struct virtio_scsi *vscsi, 529 struct virtio_scsi_vq *req_vq, 530 struct scsi_cmnd *sc) 531{ 532 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 533 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 534 int req_size; 535 536 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 537 538 /* TODO: check feature bit and fail if unsupported? */ 539 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 540 541 dev_dbg(&sc->device->sdev_gendev, 542 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 543 544 memset(cmd, 0, sizeof(*cmd)); 545 cmd->sc = sc; 546 547 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 548 549 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 550 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc); 551 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 552 req_size = sizeof(cmd->req.cmd_pi); 553 } else { 554 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc); 555 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 556 req_size = sizeof(cmd->req.cmd); 557 } 558 559 if (virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd)) != 0) 560 return SCSI_MLQUEUE_HOST_BUSY; 561 return 0; 562} 563 564static int virtscsi_queuecommand_single(struct Scsi_Host *sh, 565 struct scsi_cmnd *sc) 566{ 567 struct virtio_scsi *vscsi = shost_priv(sh); 568 struct virtio_scsi_target_state *tgt = 569 scsi_target(sc->device)->hostdata; 570 571 atomic_inc(&tgt->reqs); 572 return virtscsi_queuecommand(vscsi, &vscsi->req_vqs[0], sc); 573} 574 575static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, 576 struct scsi_cmnd *sc) 577{ 578 u32 tag = blk_mq_unique_tag(sc->request); 579 u16 hwq = blk_mq_unique_tag_to_hwq(tag); 580 581 return &vscsi->req_vqs[hwq]; 582} 583 584static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi, 585 struct virtio_scsi_target_state *tgt) 586{ 587 struct virtio_scsi_vq *vq; 588 unsigned long flags; 589 u32 queue_num; 590 591 local_irq_save(flags); 592 if (atomic_inc_return(&tgt->reqs) > 1) { 593 unsigned long seq; 594 595 do { 596 seq = read_seqcount_begin(&tgt->tgt_seq); 597 vq = tgt->req_vq; 598 } while (read_seqcount_retry(&tgt->tgt_seq, seq)); 599 } else { 600 /* no writes can be concurrent because of atomic_t */ 601 write_seqcount_begin(&tgt->tgt_seq); 602 603 /* keep previous req_vq if a reader just arrived */ 604 if (unlikely(atomic_read(&tgt->reqs) > 1)) { 605 vq = tgt->req_vq; 606 goto unlock; 607 } 608 609 queue_num = smp_processor_id(); 610 while (unlikely(queue_num >= vscsi->num_queues)) 611 queue_num -= vscsi->num_queues; 612 tgt->req_vq = vq = &vscsi->req_vqs[queue_num]; 613 unlock: 614 write_seqcount_end(&tgt->tgt_seq); 615 } 616 local_irq_restore(flags); 617 618 return vq; 619} 620 621static int virtscsi_queuecommand_multi(struct Scsi_Host *sh, 622 struct scsi_cmnd *sc) 623{ 624 struct virtio_scsi *vscsi = shost_priv(sh); 625 struct virtio_scsi_target_state *tgt = 626 scsi_target(sc->device)->hostdata; 627 struct virtio_scsi_vq *req_vq; 628 629 if (shost_use_blk_mq(sh)) 630 req_vq = virtscsi_pick_vq_mq(vscsi, sc); 631 else 632 req_vq = virtscsi_pick_vq(vscsi, tgt); 633 634 return virtscsi_queuecommand(vscsi, req_vq, sc); 635} 636 637static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 638{ 639 DECLARE_COMPLETION_ONSTACK(comp); 640 int ret = FAILED; 641 642 cmd->comp = ∁ 643 if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd, 644 sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0) 645 goto out; 646 647 wait_for_completion(&comp); 648 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 649 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 650 ret = SUCCESS; 651 652 /* 653 * The spec guarantees that all requests related to the TMF have 654 * been completed, but the callback might not have run yet if 655 * we're using independent interrupts (e.g. MSI). Poll the 656 * virtqueues once. 657 * 658 * In the abort case, sc->scsi_done will do nothing, because 659 * the block layer must have detected a timeout and as a result 660 * REQ_ATOM_COMPLETE has been set. 661 */ 662 virtscsi_poll_requests(vscsi); 663 664out: 665 mempool_free(cmd, virtscsi_cmd_pool); 666 return ret; 667} 668 669static int virtscsi_device_reset(struct scsi_cmnd *sc) 670{ 671 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 672 struct virtio_scsi_cmd *cmd; 673 674 sdev_printk(KERN_INFO, sc->device, "device reset\n"); 675 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 676 if (!cmd) 677 return FAILED; 678 679 memset(cmd, 0, sizeof(*cmd)); 680 cmd->sc = sc; 681 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 682 .type = VIRTIO_SCSI_T_TMF, 683 .subtype = cpu_to_virtio32(vscsi->vdev, 684 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET), 685 .lun[0] = 1, 686 .lun[1] = sc->device->id, 687 .lun[2] = (sc->device->lun >> 8) | 0x40, 688 .lun[3] = sc->device->lun & 0xff, 689 }; 690 return virtscsi_tmf(vscsi, cmd); 691} 692 693/** 694 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth 695 * @sdev: Virtscsi target whose queue depth to change 696 * @qdepth: New queue depth 697 */ 698static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) 699{ 700 struct Scsi_Host *shost = sdev->host; 701 int max_depth = shost->cmd_per_lun; 702 703 return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); 704} 705 706static int virtscsi_abort(struct scsi_cmnd *sc) 707{ 708 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 709 struct virtio_scsi_cmd *cmd; 710 711 scmd_printk(KERN_INFO, sc, "abort\n"); 712 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 713 if (!cmd) 714 return FAILED; 715 716 memset(cmd, 0, sizeof(*cmd)); 717 cmd->sc = sc; 718 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 719 .type = VIRTIO_SCSI_T_TMF, 720 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 721 .lun[0] = 1, 722 .lun[1] = sc->device->id, 723 .lun[2] = (sc->device->lun >> 8) | 0x40, 724 .lun[3] = sc->device->lun & 0xff, 725 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc), 726 }; 727 return virtscsi_tmf(vscsi, cmd); 728} 729 730static int virtscsi_target_alloc(struct scsi_target *starget) 731{ 732 struct Scsi_Host *sh = dev_to_shost(starget->dev.parent); 733 struct virtio_scsi *vscsi = shost_priv(sh); 734 735 struct virtio_scsi_target_state *tgt = 736 kmalloc(sizeof(*tgt), GFP_KERNEL); 737 if (!tgt) 738 return -ENOMEM; 739 740 seqcount_init(&tgt->tgt_seq); 741 atomic_set(&tgt->reqs, 0); 742 tgt->req_vq = &vscsi->req_vqs[0]; 743 744 starget->hostdata = tgt; 745 return 0; 746} 747 748static void virtscsi_target_destroy(struct scsi_target *starget) 749{ 750 struct virtio_scsi_target_state *tgt = starget->hostdata; 751 kfree(tgt); 752} 753 754static struct scsi_host_template virtscsi_host_template_single = { 755 .module = THIS_MODULE, 756 .name = "Virtio SCSI HBA", 757 .proc_name = "virtio_scsi", 758 .this_id = -1, 759 .cmd_size = sizeof(struct virtio_scsi_cmd), 760 .queuecommand = virtscsi_queuecommand_single, 761 .change_queue_depth = virtscsi_change_queue_depth, 762 .eh_abort_handler = virtscsi_abort, 763 .eh_device_reset_handler = virtscsi_device_reset, 764 765 .can_queue = 1024, 766 .dma_boundary = UINT_MAX, 767 .use_clustering = ENABLE_CLUSTERING, 768 .target_alloc = virtscsi_target_alloc, 769 .target_destroy = virtscsi_target_destroy, 770 .track_queue_depth = 1, 771}; 772 773static struct scsi_host_template virtscsi_host_template_multi = { 774 .module = THIS_MODULE, 775 .name = "Virtio SCSI HBA", 776 .proc_name = "virtio_scsi", 777 .this_id = -1, 778 .cmd_size = sizeof(struct virtio_scsi_cmd), 779 .queuecommand = virtscsi_queuecommand_multi, 780 .change_queue_depth = virtscsi_change_queue_depth, 781 .eh_abort_handler = virtscsi_abort, 782 .eh_device_reset_handler = virtscsi_device_reset, 783 784 .can_queue = 1024, 785 .dma_boundary = UINT_MAX, 786 .use_clustering = ENABLE_CLUSTERING, 787 .target_alloc = virtscsi_target_alloc, 788 .target_destroy = virtscsi_target_destroy, 789 .track_queue_depth = 1, 790}; 791 792#define virtscsi_config_get(vdev, fld) \ 793 ({ \ 794 typeof(((struct virtio_scsi_config *)0)->fld) __val; \ 795 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 796 __val; \ 797 }) 798 799#define virtscsi_config_set(vdev, fld, val) \ 800 do { \ 801 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \ 802 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 803 } while(0) 804 805static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) 806{ 807 int i; 808 int cpu; 809 810 /* In multiqueue mode, when the number of cpu is equal 811 * to the number of request queues, we let the qeueues 812 * to be private to one cpu by setting the affinity hint 813 * to eliminate the contention. 814 */ 815 if ((vscsi->num_queues == 1 || 816 vscsi->num_queues != num_online_cpus()) && affinity) { 817 if (vscsi->affinity_hint_set) 818 affinity = false; 819 else 820 return; 821 } 822 823 if (affinity) { 824 i = 0; 825 for_each_online_cpu(cpu) { 826 virtqueue_set_affinity(vscsi->req_vqs[i].vq, cpu); 827 i++; 828 } 829 830 vscsi->affinity_hint_set = true; 831 } else { 832 for (i = 0; i < vscsi->num_queues; i++) { 833 if (!vscsi->req_vqs[i].vq) 834 continue; 835 836 virtqueue_set_affinity(vscsi->req_vqs[i].vq, -1); 837 } 838 839 vscsi->affinity_hint_set = false; 840 } 841} 842 843static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) 844{ 845 get_online_cpus(); 846 __virtscsi_set_affinity(vscsi, affinity); 847 put_online_cpus(); 848} 849 850static int virtscsi_cpu_callback(struct notifier_block *nfb, 851 unsigned long action, void *hcpu) 852{ 853 struct virtio_scsi *vscsi = container_of(nfb, struct virtio_scsi, nb); 854 switch(action) { 855 case CPU_ONLINE: 856 case CPU_ONLINE_FROZEN: 857 case CPU_DEAD: 858 case CPU_DEAD_FROZEN: 859 __virtscsi_set_affinity(vscsi, true); 860 break; 861 default: 862 break; 863 } 864 return NOTIFY_OK; 865} 866 867static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 868 struct virtqueue *vq) 869{ 870 spin_lock_init(&virtscsi_vq->vq_lock); 871 virtscsi_vq->vq = vq; 872} 873 874static void virtscsi_remove_vqs(struct virtio_device *vdev) 875{ 876 struct Scsi_Host *sh = virtio_scsi_host(vdev); 877 struct virtio_scsi *vscsi = shost_priv(sh); 878 879 virtscsi_set_affinity(vscsi, false); 880 881 /* Stop all the virtqueues. */ 882 vdev->config->reset(vdev); 883 884 vdev->config->del_vqs(vdev); 885} 886 887static int virtscsi_init(struct virtio_device *vdev, 888 struct virtio_scsi *vscsi) 889{ 890 int err; 891 u32 i; 892 u32 num_vqs; 893 vq_callback_t **callbacks; 894 const char **names; 895 struct virtqueue **vqs; 896 897 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; 898 vqs = kmalloc(num_vqs * sizeof(struct virtqueue *), GFP_KERNEL); 899 callbacks = kmalloc(num_vqs * sizeof(vq_callback_t *), GFP_KERNEL); 900 names = kmalloc(num_vqs * sizeof(char *), GFP_KERNEL); 901 902 if (!callbacks || !vqs || !names) { 903 err = -ENOMEM; 904 goto out; 905 } 906 907 callbacks[0] = virtscsi_ctrl_done; 908 callbacks[1] = virtscsi_event_done; 909 names[0] = "control"; 910 names[1] = "event"; 911 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { 912 callbacks[i] = virtscsi_req_done; 913 names[i] = "request"; 914 } 915 916 /* Discover virtqueues and write information to configuration. */ 917 err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names); 918 if (err) 919 goto out; 920 921 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 922 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 923 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 924 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 925 vqs[i]); 926 927 virtscsi_set_affinity(vscsi, true); 928 929 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 930 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 931 932 err = 0; 933 934out: 935 kfree(names); 936 kfree(callbacks); 937 kfree(vqs); 938 if (err) 939 virtscsi_remove_vqs(vdev); 940 return err; 941} 942 943static int virtscsi_probe(struct virtio_device *vdev) 944{ 945 struct Scsi_Host *shost; 946 struct virtio_scsi *vscsi; 947 int err, host_prot; 948 u32 sg_elems, num_targets; 949 u32 cmd_per_lun; 950 u32 num_queues; 951 struct scsi_host_template *hostt; 952 953 if (!vdev->config->get) { 954 dev_err(&vdev->dev, "%s failure: config access disabled\n", 955 __func__); 956 return -EINVAL; 957 } 958 959 /* We need to know how many queues before we allocate. */ 960 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; 961 962 num_targets = virtscsi_config_get(vdev, max_target) + 1; 963 964 if (num_queues == 1) 965 hostt = &virtscsi_host_template_single; 966 else 967 hostt = &virtscsi_host_template_multi; 968 969 shost = scsi_host_alloc(hostt, 970 sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues); 971 if (!shost) 972 return -ENOMEM; 973 974 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 975 shost->sg_tablesize = sg_elems; 976 vscsi = shost_priv(shost); 977 vscsi->vdev = vdev; 978 vscsi->num_queues = num_queues; 979 vdev->priv = shost; 980 981 err = virtscsi_init(vdev, vscsi); 982 if (err) 983 goto virtscsi_init_failed; 984 985 vscsi->nb.notifier_call = &virtscsi_cpu_callback; 986 err = register_hotcpu_notifier(&vscsi->nb); 987 if (err) { 988 pr_err("registering cpu notifier failed\n"); 989 goto scsi_add_host_failed; 990 } 991 992 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 993 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 994 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 995 996 /* LUNs > 256 are reported with format 1, so they go in the range 997 * 16640-32767. 998 */ 999 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 1000 shost->max_id = num_targets; 1001 shost->max_channel = 0; 1002 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 1003 shost->nr_hw_queues = num_queues; 1004 1005 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 1006 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 1007 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 1008 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 1009 1010 scsi_host_set_prot(shost, host_prot); 1011 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 1012 } 1013 1014 err = scsi_add_host(shost, &vdev->dev); 1015 if (err) 1016 goto scsi_add_host_failed; 1017 1018 virtio_device_ready(vdev); 1019 1020 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1021 virtscsi_kick_event_all(vscsi); 1022 1023 scsi_scan_host(shost); 1024 return 0; 1025 1026scsi_add_host_failed: 1027 vdev->config->del_vqs(vdev); 1028virtscsi_init_failed: 1029 scsi_host_put(shost); 1030 return err; 1031} 1032 1033static void virtscsi_remove(struct virtio_device *vdev) 1034{ 1035 struct Scsi_Host *shost = virtio_scsi_host(vdev); 1036 struct virtio_scsi *vscsi = shost_priv(shost); 1037 1038 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1039 virtscsi_cancel_event_work(vscsi); 1040 1041 scsi_remove_host(shost); 1042 1043 unregister_hotcpu_notifier(&vscsi->nb); 1044 1045 virtscsi_remove_vqs(vdev); 1046 scsi_host_put(shost); 1047} 1048 1049#ifdef CONFIG_PM_SLEEP 1050static int virtscsi_freeze(struct virtio_device *vdev) 1051{ 1052 struct Scsi_Host *sh = virtio_scsi_host(vdev); 1053 struct virtio_scsi *vscsi = shost_priv(sh); 1054 1055 unregister_hotcpu_notifier(&vscsi->nb); 1056 virtscsi_remove_vqs(vdev); 1057 return 0; 1058} 1059 1060static int virtscsi_restore(struct virtio_device *vdev) 1061{ 1062 struct Scsi_Host *sh = virtio_scsi_host(vdev); 1063 struct virtio_scsi *vscsi = shost_priv(sh); 1064 int err; 1065 1066 err = virtscsi_init(vdev, vscsi); 1067 if (err) 1068 return err; 1069 1070 err = register_hotcpu_notifier(&vscsi->nb); 1071 if (err) { 1072 vdev->config->del_vqs(vdev); 1073 return err; 1074 } 1075 1076 virtio_device_ready(vdev); 1077 1078 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1079 virtscsi_kick_event_all(vscsi); 1080 1081 return err; 1082} 1083#endif 1084 1085static struct virtio_device_id id_table[] = { 1086 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 1087 { 0 }, 1088}; 1089 1090static unsigned int features[] = { 1091 VIRTIO_SCSI_F_HOTPLUG, 1092 VIRTIO_SCSI_F_CHANGE, 1093 VIRTIO_SCSI_F_T10_PI, 1094}; 1095 1096static struct virtio_driver virtio_scsi_driver = { 1097 .feature_table = features, 1098 .feature_table_size = ARRAY_SIZE(features), 1099 .driver.name = KBUILD_MODNAME, 1100 .driver.owner = THIS_MODULE, 1101 .id_table = id_table, 1102 .probe = virtscsi_probe, 1103#ifdef CONFIG_PM_SLEEP 1104 .freeze = virtscsi_freeze, 1105 .restore = virtscsi_restore, 1106#endif 1107 .remove = virtscsi_remove, 1108}; 1109 1110static int __init init(void) 1111{ 1112 int ret = -ENOMEM; 1113 1114 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); 1115 if (!virtscsi_cmd_cache) { 1116 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); 1117 goto error; 1118 } 1119 1120 1121 virtscsi_cmd_pool = 1122 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, 1123 virtscsi_cmd_cache); 1124 if (!virtscsi_cmd_pool) { 1125 pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); 1126 goto error; 1127 } 1128 ret = register_virtio_driver(&virtio_scsi_driver); 1129 if (ret < 0) 1130 goto error; 1131 1132 return 0; 1133 1134error: 1135 if (virtscsi_cmd_pool) { 1136 mempool_destroy(virtscsi_cmd_pool); 1137 virtscsi_cmd_pool = NULL; 1138 } 1139 if (virtscsi_cmd_cache) { 1140 kmem_cache_destroy(virtscsi_cmd_cache); 1141 virtscsi_cmd_cache = NULL; 1142 } 1143 return ret; 1144} 1145 1146static void __exit fini(void) 1147{ 1148 unregister_virtio_driver(&virtio_scsi_driver); 1149 mempool_destroy(virtscsi_cmd_pool); 1150 kmem_cache_destroy(virtscsi_cmd_cache); 1151} 1152module_init(init); 1153module_exit(fini); 1154 1155MODULE_DEVICE_TABLE(virtio, id_table); 1156MODULE_DESCRIPTION("Virtio SCSI HBA driver"); 1157MODULE_LICENSE("GPL"); 1158