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