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