1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Virtio SCSI HBA driver 4 * 5 * Copyright IBM Corp. 2010 6 * Copyright Red Hat, Inc. 2011 7 * 8 * Authors: 9 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> 10 * Paolo Bonzini <pbonzini@redhat.com> 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/module.h> 16 #include <linux/slab.h> 17 #include <linux/mempool.h> 18 #include <linux/interrupt.h> 19 #include <linux/virtio.h> 20 #include <linux/virtio_ids.h> 21 #include <linux/virtio_config.h> 22 #include <linux/virtio_scsi.h> 23 #include <linux/cpu.h> 24 #include <linux/blkdev.h> 25 #include <scsi/scsi_host.h> 26 #include <scsi/scsi_device.h> 27 #include <scsi/scsi_cmnd.h> 28 #include <scsi/scsi_tcq.h> 29 #include <scsi/scsi_devinfo.h> 30 #include <linux/seqlock.h> 31 #include <linux/blk-mq-virtio.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 /* Driver instance state */ 69 struct virtio_scsi { 70 struct virtio_device *vdev; 71 72 /* Get some buffers ready for event vq */ 73 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN]; 74 75 u32 num_queues; 76 77 struct hlist_node node; 78 79 /* Protected by event_vq lock */ 80 bool stop_events; 81 82 struct virtio_scsi_vq ctrl_vq; 83 struct virtio_scsi_vq event_vq; 84 struct virtio_scsi_vq req_vqs[]; 85 }; 86 87 static struct kmem_cache *virtscsi_cmd_cache; 88 static mempool_t *virtscsi_cmd_pool; 89 90 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev) 91 { 92 return vdev->priv; 93 } 94 95 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid) 96 { 97 if (resid) 98 scsi_set_resid(sc, resid); 99 } 100 101 /** 102 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done 103 * 104 * Called with vq_lock held. 105 */ 106 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf) 107 { 108 struct virtio_scsi_cmd *cmd = buf; 109 struct scsi_cmnd *sc = cmd->sc; 110 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd; 111 112 dev_dbg(&sc->device->sdev_gendev, 113 "cmd %p response %u status %#02x sense_len %u\n", 114 sc, resp->response, resp->status, resp->sense_len); 115 116 sc->result = resp->status; 117 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid)); 118 switch (resp->response) { 119 case VIRTIO_SCSI_S_OK: 120 set_host_byte(sc, DID_OK); 121 break; 122 case VIRTIO_SCSI_S_OVERRUN: 123 set_host_byte(sc, DID_ERROR); 124 break; 125 case VIRTIO_SCSI_S_ABORTED: 126 set_host_byte(sc, DID_ABORT); 127 break; 128 case VIRTIO_SCSI_S_BAD_TARGET: 129 set_host_byte(sc, DID_BAD_TARGET); 130 break; 131 case VIRTIO_SCSI_S_RESET: 132 set_host_byte(sc, DID_RESET); 133 break; 134 case VIRTIO_SCSI_S_BUSY: 135 set_host_byte(sc, DID_BUS_BUSY); 136 break; 137 case VIRTIO_SCSI_S_TRANSPORT_FAILURE: 138 set_host_byte(sc, DID_TRANSPORT_DISRUPTED); 139 break; 140 case VIRTIO_SCSI_S_TARGET_FAILURE: 141 set_host_byte(sc, DID_TARGET_FAILURE); 142 break; 143 case VIRTIO_SCSI_S_NEXUS_FAILURE: 144 set_host_byte(sc, DID_NEXUS_FAILURE); 145 break; 146 default: 147 scmd_printk(KERN_WARNING, sc, "Unknown response %d", 148 resp->response); 149 /* fall through */ 150 case VIRTIO_SCSI_S_FAILURE: 151 set_host_byte(sc, DID_ERROR); 152 break; 153 } 154 155 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) > 156 VIRTIO_SCSI_SENSE_SIZE); 157 if (sc->sense_buffer) { 158 memcpy(sc->sense_buffer, resp->sense, 159 min_t(u32, 160 virtio32_to_cpu(vscsi->vdev, resp->sense_len), 161 VIRTIO_SCSI_SENSE_SIZE)); 162 if (resp->sense_len) 163 set_driver_byte(sc, DRIVER_SENSE); 164 } 165 166 sc->scsi_done(sc); 167 } 168 169 static void virtscsi_vq_done(struct virtio_scsi *vscsi, 170 struct virtio_scsi_vq *virtscsi_vq, 171 void (*fn)(struct virtio_scsi *vscsi, void *buf)) 172 { 173 void *buf; 174 unsigned int len; 175 unsigned long flags; 176 struct virtqueue *vq = virtscsi_vq->vq; 177 178 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); 179 do { 180 virtqueue_disable_cb(vq); 181 while ((buf = virtqueue_get_buf(vq, &len)) != NULL) 182 fn(vscsi, buf); 183 184 if (unlikely(virtqueue_is_broken(vq))) 185 break; 186 } while (!virtqueue_enable_cb(vq)); 187 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); 188 } 189 190 static void virtscsi_req_done(struct virtqueue *vq) 191 { 192 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 193 struct virtio_scsi *vscsi = shost_priv(sh); 194 int index = vq->index - VIRTIO_SCSI_VQ_BASE; 195 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index]; 196 197 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd); 198 }; 199 200 static void virtscsi_poll_requests(struct virtio_scsi *vscsi) 201 { 202 int i, num_vqs; 203 204 num_vqs = vscsi->num_queues; 205 for (i = 0; i < num_vqs; i++) 206 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i], 207 virtscsi_complete_cmd); 208 } 209 210 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf) 211 { 212 struct virtio_scsi_cmd *cmd = buf; 213 214 if (cmd->comp) 215 complete(cmd->comp); 216 } 217 218 static void virtscsi_ctrl_done(struct virtqueue *vq) 219 { 220 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 221 struct virtio_scsi *vscsi = shost_priv(sh); 222 223 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free); 224 }; 225 226 static void virtscsi_handle_event(struct work_struct *work); 227 228 static int virtscsi_kick_event(struct virtio_scsi *vscsi, 229 struct virtio_scsi_event_node *event_node) 230 { 231 int err; 232 struct scatterlist sg; 233 unsigned long flags; 234 235 INIT_WORK(&event_node->work, virtscsi_handle_event); 236 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event)); 237 238 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags); 239 240 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node, 241 GFP_ATOMIC); 242 if (!err) 243 virtqueue_kick(vscsi->event_vq.vq); 244 245 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags); 246 247 return err; 248 } 249 250 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi) 251 { 252 int i; 253 254 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) { 255 vscsi->event_list[i].vscsi = vscsi; 256 virtscsi_kick_event(vscsi, &vscsi->event_list[i]); 257 } 258 259 return 0; 260 } 261 262 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi) 263 { 264 int i; 265 266 /* Stop scheduling work before calling cancel_work_sync. */ 267 spin_lock_irq(&vscsi->event_vq.vq_lock); 268 vscsi->stop_events = true; 269 spin_unlock_irq(&vscsi->event_vq.vq_lock); 270 271 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) 272 cancel_work_sync(&vscsi->event_list[i].work); 273 } 274 275 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, 276 struct virtio_scsi_event *event) 277 { 278 struct scsi_device *sdev; 279 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 280 unsigned int target = event->lun[1]; 281 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 282 283 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) { 284 case VIRTIO_SCSI_EVT_RESET_RESCAN: 285 scsi_add_device(shost, 0, target, lun); 286 break; 287 case VIRTIO_SCSI_EVT_RESET_REMOVED: 288 sdev = scsi_device_lookup(shost, 0, target, lun); 289 if (sdev) { 290 scsi_remove_device(sdev); 291 scsi_device_put(sdev); 292 } else { 293 pr_err("SCSI device %d 0 %d %d not found\n", 294 shost->host_no, target, lun); 295 } 296 break; 297 default: 298 pr_info("Unsupport virtio scsi event reason %x\n", event->reason); 299 } 300 } 301 302 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, 303 struct virtio_scsi_event *event) 304 { 305 struct scsi_device *sdev; 306 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 307 unsigned int target = event->lun[1]; 308 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 309 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255; 310 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8; 311 312 sdev = scsi_device_lookup(shost, 0, target, lun); 313 if (!sdev) { 314 pr_err("SCSI device %d 0 %d %d not found\n", 315 shost->host_no, target, lun); 316 return; 317 } 318 319 /* Handle "Parameters changed", "Mode parameters changed", and 320 "Capacity data has changed". */ 321 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) 322 scsi_rescan_device(&sdev->sdev_gendev); 323 324 scsi_device_put(sdev); 325 } 326 327 static void virtscsi_handle_event(struct work_struct *work) 328 { 329 struct virtio_scsi_event_node *event_node = 330 container_of(work, struct virtio_scsi_event_node, work); 331 struct virtio_scsi *vscsi = event_node->vscsi; 332 struct virtio_scsi_event *event = &event_node->event; 333 334 if (event->event & 335 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { 336 event->event &= ~cpu_to_virtio32(vscsi->vdev, 337 VIRTIO_SCSI_T_EVENTS_MISSED); 338 scsi_scan_host(virtio_scsi_host(vscsi->vdev)); 339 } 340 341 switch (virtio32_to_cpu(vscsi->vdev, event->event)) { 342 case VIRTIO_SCSI_T_NO_EVENT: 343 break; 344 case VIRTIO_SCSI_T_TRANSPORT_RESET: 345 virtscsi_handle_transport_reset(vscsi, event); 346 break; 347 case VIRTIO_SCSI_T_PARAM_CHANGE: 348 virtscsi_handle_param_change(vscsi, event); 349 break; 350 default: 351 pr_err("Unsupport virtio scsi event %x\n", event->event); 352 } 353 virtscsi_kick_event(vscsi, event_node); 354 } 355 356 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) 357 { 358 struct virtio_scsi_event_node *event_node = buf; 359 360 if (!vscsi->stop_events) 361 queue_work(system_freezable_wq, &event_node->work); 362 } 363 364 static void virtscsi_event_done(struct virtqueue *vq) 365 { 366 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 367 struct virtio_scsi *vscsi = shost_priv(sh); 368 369 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); 370 }; 371 372 /** 373 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue 374 * @vq : the struct virtqueue we're talking about 375 * @cmd : command structure 376 * @req_size : size of the request buffer 377 * @resp_size : size of the response buffer 378 */ 379 static int virtscsi_add_cmd(struct virtqueue *vq, 380 struct virtio_scsi_cmd *cmd, 381 size_t req_size, size_t resp_size) 382 { 383 struct scsi_cmnd *sc = cmd->sc; 384 struct scatterlist *sgs[6], req, resp; 385 struct sg_table *out, *in; 386 unsigned out_num = 0, in_num = 0; 387 388 out = in = NULL; 389 390 if (sc && sc->sc_data_direction != DMA_NONE) { 391 if (sc->sc_data_direction != DMA_FROM_DEVICE) 392 out = &sc->sdb.table; 393 if (sc->sc_data_direction != DMA_TO_DEVICE) 394 in = &sc->sdb.table; 395 } 396 397 /* Request header. */ 398 sg_init_one(&req, &cmd->req, req_size); 399 sgs[out_num++] = &req; 400 401 /* Data-out buffer. */ 402 if (out) { 403 /* Place WRITE protection SGLs before Data OUT payload */ 404 if (scsi_prot_sg_count(sc)) 405 sgs[out_num++] = scsi_prot_sglist(sc); 406 sgs[out_num++] = out->sgl; 407 } 408 409 /* Response header. */ 410 sg_init_one(&resp, &cmd->resp, resp_size); 411 sgs[out_num + in_num++] = &resp; 412 413 /* Data-in buffer */ 414 if (in) { 415 /* Place READ protection SGLs before Data IN payload */ 416 if (scsi_prot_sg_count(sc)) 417 sgs[out_num + in_num++] = scsi_prot_sglist(sc); 418 sgs[out_num + in_num++] = in->sgl; 419 } 420 421 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); 422 } 423 424 static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq, 425 struct virtio_scsi_cmd *cmd, 426 size_t req_size, size_t resp_size) 427 { 428 unsigned long flags; 429 int err; 430 bool needs_kick = false; 431 432 spin_lock_irqsave(&vq->vq_lock, flags); 433 err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size); 434 if (!err) 435 needs_kick = virtqueue_kick_prepare(vq->vq); 436 437 spin_unlock_irqrestore(&vq->vq_lock, flags); 438 439 if (needs_kick) 440 virtqueue_notify(vq->vq); 441 return err; 442 } 443 444 static void virtio_scsi_init_hdr(struct virtio_device *vdev, 445 struct virtio_scsi_cmd_req *cmd, 446 struct scsi_cmnd *sc) 447 { 448 cmd->lun[0] = 1; 449 cmd->lun[1] = sc->device->id; 450 cmd->lun[2] = (sc->device->lun >> 8) | 0x40; 451 cmd->lun[3] = sc->device->lun & 0xff; 452 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc); 453 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; 454 cmd->prio = 0; 455 cmd->crn = 0; 456 } 457 458 #ifdef CONFIG_BLK_DEV_INTEGRITY 459 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, 460 struct virtio_scsi_cmd_req_pi *cmd_pi, 461 struct scsi_cmnd *sc) 462 { 463 struct request *rq = sc->request; 464 struct blk_integrity *bi; 465 466 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc); 467 468 if (!rq || !scsi_prot_sg_count(sc)) 469 return; 470 471 bi = blk_get_integrity(rq->rq_disk); 472 473 if (sc->sc_data_direction == DMA_TO_DEVICE) 474 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, 475 bio_integrity_bytes(bi, 476 blk_rq_sectors(rq))); 477 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 478 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, 479 bio_integrity_bytes(bi, 480 blk_rq_sectors(rq))); 481 } 482 #endif 483 484 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, 485 struct scsi_cmnd *sc) 486 { 487 u32 tag = blk_mq_unique_tag(sc->request); 488 u16 hwq = blk_mq_unique_tag_to_hwq(tag); 489 490 return &vscsi->req_vqs[hwq]; 491 } 492 493 static int virtscsi_queuecommand(struct Scsi_Host *shost, 494 struct scsi_cmnd *sc) 495 { 496 struct virtio_scsi *vscsi = shost_priv(shost); 497 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc); 498 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 499 unsigned long flags; 500 int req_size; 501 int ret; 502 503 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 504 505 /* TODO: check feature bit and fail if unsupported? */ 506 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 507 508 dev_dbg(&sc->device->sdev_gendev, 509 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 510 511 cmd->sc = sc; 512 513 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 514 515 #ifdef CONFIG_BLK_DEV_INTEGRITY 516 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 517 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc); 518 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 519 req_size = sizeof(cmd->req.cmd_pi); 520 } else 521 #endif 522 { 523 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc); 524 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 525 req_size = sizeof(cmd->req.cmd); 526 } 527 528 ret = virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd)); 529 if (ret == -EIO) { 530 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET; 531 spin_lock_irqsave(&req_vq->vq_lock, flags); 532 virtscsi_complete_cmd(vscsi, cmd); 533 spin_unlock_irqrestore(&req_vq->vq_lock, flags); 534 } else if (ret != 0) { 535 return SCSI_MLQUEUE_HOST_BUSY; 536 } 537 return 0; 538 } 539 540 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 541 { 542 DECLARE_COMPLETION_ONSTACK(comp); 543 int ret = FAILED; 544 545 cmd->comp = ∁ 546 if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd, 547 sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0) 548 goto out; 549 550 wait_for_completion(&comp); 551 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 552 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 553 ret = SUCCESS; 554 555 /* 556 * The spec guarantees that all requests related to the TMF have 557 * been completed, but the callback might not have run yet if 558 * we're using independent interrupts (e.g. MSI). Poll the 559 * virtqueues once. 560 * 561 * In the abort case, sc->scsi_done will do nothing, because 562 * the block layer must have detected a timeout and as a result 563 * REQ_ATOM_COMPLETE has been set. 564 */ 565 virtscsi_poll_requests(vscsi); 566 567 out: 568 mempool_free(cmd, virtscsi_cmd_pool); 569 return ret; 570 } 571 572 static int virtscsi_device_reset(struct scsi_cmnd *sc) 573 { 574 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 575 struct virtio_scsi_cmd *cmd; 576 577 sdev_printk(KERN_INFO, sc->device, "device reset\n"); 578 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 579 if (!cmd) 580 return FAILED; 581 582 memset(cmd, 0, sizeof(*cmd)); 583 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 584 .type = VIRTIO_SCSI_T_TMF, 585 .subtype = cpu_to_virtio32(vscsi->vdev, 586 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET), 587 .lun[0] = 1, 588 .lun[1] = sc->device->id, 589 .lun[2] = (sc->device->lun >> 8) | 0x40, 590 .lun[3] = sc->device->lun & 0xff, 591 }; 592 return virtscsi_tmf(vscsi, cmd); 593 } 594 595 static int virtscsi_device_alloc(struct scsi_device *sdevice) 596 { 597 /* 598 * Passed through SCSI targets (e.g. with qemu's 'scsi-block') 599 * may have transfer limits which come from the host SCSI 600 * controller or something on the host side other than the 601 * target itself. 602 * 603 * To make this work properly, the hypervisor can adjust the 604 * target's VPD information to advertise these limits. But 605 * for that to work, the guest has to look at the VPD pages, 606 * which we won't do by default if it is an SPC-2 device, even 607 * if it does actually support it. 608 * 609 * So, set the blist to always try to read the VPD pages. 610 */ 611 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES; 612 613 return 0; 614 } 615 616 617 /** 618 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth 619 * @sdev: Virtscsi target whose queue depth to change 620 * @qdepth: New queue depth 621 */ 622 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) 623 { 624 struct Scsi_Host *shost = sdev->host; 625 int max_depth = shost->cmd_per_lun; 626 627 return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); 628 } 629 630 static int virtscsi_abort(struct scsi_cmnd *sc) 631 { 632 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 633 struct virtio_scsi_cmd *cmd; 634 635 scmd_printk(KERN_INFO, sc, "abort\n"); 636 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 637 if (!cmd) 638 return FAILED; 639 640 memset(cmd, 0, sizeof(*cmd)); 641 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 642 .type = VIRTIO_SCSI_T_TMF, 643 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 644 .lun[0] = 1, 645 .lun[1] = sc->device->id, 646 .lun[2] = (sc->device->lun >> 8) | 0x40, 647 .lun[3] = sc->device->lun & 0xff, 648 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc), 649 }; 650 return virtscsi_tmf(vscsi, cmd); 651 } 652 653 static int virtscsi_map_queues(struct Scsi_Host *shost) 654 { 655 struct virtio_scsi *vscsi = shost_priv(shost); 656 struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT]; 657 658 return blk_mq_virtio_map_queues(qmap, vscsi->vdev, 2); 659 } 660 661 /* 662 * The host guarantees to respond to each command, although I/O 663 * latencies might be higher than on bare metal. Reset the timer 664 * unconditionally to give the host a chance to perform EH. 665 */ 666 static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd) 667 { 668 return BLK_EH_RESET_TIMER; 669 } 670 671 static struct scsi_host_template virtscsi_host_template = { 672 .module = THIS_MODULE, 673 .name = "Virtio SCSI HBA", 674 .proc_name = "virtio_scsi", 675 .this_id = -1, 676 .cmd_size = sizeof(struct virtio_scsi_cmd), 677 .queuecommand = virtscsi_queuecommand, 678 .change_queue_depth = virtscsi_change_queue_depth, 679 .eh_abort_handler = virtscsi_abort, 680 .eh_device_reset_handler = virtscsi_device_reset, 681 .eh_timed_out = virtscsi_eh_timed_out, 682 .slave_alloc = virtscsi_device_alloc, 683 684 .dma_boundary = UINT_MAX, 685 .map_queues = virtscsi_map_queues, 686 .track_queue_depth = 1, 687 .force_blk_mq = 1, 688 }; 689 690 #define virtscsi_config_get(vdev, fld) \ 691 ({ \ 692 typeof(((struct virtio_scsi_config *)0)->fld) __val; \ 693 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 694 __val; \ 695 }) 696 697 #define virtscsi_config_set(vdev, fld, val) \ 698 do { \ 699 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \ 700 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 701 } while(0) 702 703 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 704 struct virtqueue *vq) 705 { 706 spin_lock_init(&virtscsi_vq->vq_lock); 707 virtscsi_vq->vq = vq; 708 } 709 710 static void virtscsi_remove_vqs(struct virtio_device *vdev) 711 { 712 /* Stop all the virtqueues. */ 713 vdev->config->reset(vdev); 714 vdev->config->del_vqs(vdev); 715 } 716 717 static int virtscsi_init(struct virtio_device *vdev, 718 struct virtio_scsi *vscsi) 719 { 720 int err; 721 u32 i; 722 u32 num_vqs; 723 vq_callback_t **callbacks; 724 const char **names; 725 struct virtqueue **vqs; 726 struct irq_affinity desc = { .pre_vectors = 2 }; 727 728 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; 729 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL); 730 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *), 731 GFP_KERNEL); 732 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL); 733 734 if (!callbacks || !vqs || !names) { 735 err = -ENOMEM; 736 goto out; 737 } 738 739 callbacks[0] = virtscsi_ctrl_done; 740 callbacks[1] = virtscsi_event_done; 741 names[0] = "control"; 742 names[1] = "event"; 743 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { 744 callbacks[i] = virtscsi_req_done; 745 names[i] = "request"; 746 } 747 748 /* Discover virtqueues and write information to configuration. */ 749 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 750 if (err) 751 goto out; 752 753 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 754 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 755 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 756 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 757 vqs[i]); 758 759 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 760 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 761 762 err = 0; 763 764 out: 765 kfree(names); 766 kfree(callbacks); 767 kfree(vqs); 768 if (err) 769 virtscsi_remove_vqs(vdev); 770 return err; 771 } 772 773 static int virtscsi_probe(struct virtio_device *vdev) 774 { 775 struct Scsi_Host *shost; 776 struct virtio_scsi *vscsi; 777 int err; 778 u32 sg_elems, num_targets; 779 u32 cmd_per_lun; 780 u32 num_queues; 781 782 if (!vdev->config->get) { 783 dev_err(&vdev->dev, "%s failure: config access disabled\n", 784 __func__); 785 return -EINVAL; 786 } 787 788 /* We need to know how many queues before we allocate. */ 789 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; 790 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues); 791 792 num_targets = virtscsi_config_get(vdev, max_target) + 1; 793 794 shost = scsi_host_alloc(&virtscsi_host_template, 795 struct_size(vscsi, req_vqs, num_queues)); 796 if (!shost) 797 return -ENOMEM; 798 799 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 800 shost->sg_tablesize = sg_elems; 801 vscsi = shost_priv(shost); 802 vscsi->vdev = vdev; 803 vscsi->num_queues = num_queues; 804 vdev->priv = shost; 805 806 err = virtscsi_init(vdev, vscsi); 807 if (err) 808 goto virtscsi_init_failed; 809 810 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq); 811 812 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 813 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 814 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 815 816 /* LUNs > 256 are reported with format 1, so they go in the range 817 * 16640-32767. 818 */ 819 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 820 shost->max_id = num_targets; 821 shost->max_channel = 0; 822 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 823 shost->nr_hw_queues = num_queues; 824 825 #ifdef CONFIG_BLK_DEV_INTEGRITY 826 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 827 int host_prot; 828 829 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 830 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 831 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 832 833 scsi_host_set_prot(shost, host_prot); 834 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 835 } 836 #endif 837 838 err = scsi_add_host(shost, &vdev->dev); 839 if (err) 840 goto scsi_add_host_failed; 841 842 virtio_device_ready(vdev); 843 844 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 845 virtscsi_kick_event_all(vscsi); 846 847 scsi_scan_host(shost); 848 return 0; 849 850 scsi_add_host_failed: 851 vdev->config->del_vqs(vdev); 852 virtscsi_init_failed: 853 scsi_host_put(shost); 854 return err; 855 } 856 857 static void virtscsi_remove(struct virtio_device *vdev) 858 { 859 struct Scsi_Host *shost = virtio_scsi_host(vdev); 860 struct virtio_scsi *vscsi = shost_priv(shost); 861 862 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 863 virtscsi_cancel_event_work(vscsi); 864 865 scsi_remove_host(shost); 866 virtscsi_remove_vqs(vdev); 867 scsi_host_put(shost); 868 } 869 870 #ifdef CONFIG_PM_SLEEP 871 static int virtscsi_freeze(struct virtio_device *vdev) 872 { 873 virtscsi_remove_vqs(vdev); 874 return 0; 875 } 876 877 static int virtscsi_restore(struct virtio_device *vdev) 878 { 879 struct Scsi_Host *sh = virtio_scsi_host(vdev); 880 struct virtio_scsi *vscsi = shost_priv(sh); 881 int err; 882 883 err = virtscsi_init(vdev, vscsi); 884 if (err) 885 return err; 886 887 virtio_device_ready(vdev); 888 889 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 890 virtscsi_kick_event_all(vscsi); 891 892 return err; 893 } 894 #endif 895 896 static struct virtio_device_id id_table[] = { 897 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 898 { 0 }, 899 }; 900 901 static unsigned int features[] = { 902 VIRTIO_SCSI_F_HOTPLUG, 903 VIRTIO_SCSI_F_CHANGE, 904 #ifdef CONFIG_BLK_DEV_INTEGRITY 905 VIRTIO_SCSI_F_T10_PI, 906 #endif 907 }; 908 909 static struct virtio_driver virtio_scsi_driver = { 910 .feature_table = features, 911 .feature_table_size = ARRAY_SIZE(features), 912 .driver.name = KBUILD_MODNAME, 913 .driver.owner = THIS_MODULE, 914 .id_table = id_table, 915 .probe = virtscsi_probe, 916 #ifdef CONFIG_PM_SLEEP 917 .freeze = virtscsi_freeze, 918 .restore = virtscsi_restore, 919 #endif 920 .remove = virtscsi_remove, 921 }; 922 923 static int __init init(void) 924 { 925 int ret = -ENOMEM; 926 927 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); 928 if (!virtscsi_cmd_cache) { 929 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); 930 goto error; 931 } 932 933 934 virtscsi_cmd_pool = 935 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, 936 virtscsi_cmd_cache); 937 if (!virtscsi_cmd_pool) { 938 pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); 939 goto error; 940 } 941 ret = register_virtio_driver(&virtio_scsi_driver); 942 if (ret < 0) 943 goto error; 944 945 return 0; 946 947 error: 948 if (virtscsi_cmd_pool) { 949 mempool_destroy(virtscsi_cmd_pool); 950 virtscsi_cmd_pool = NULL; 951 } 952 if (virtscsi_cmd_cache) { 953 kmem_cache_destroy(virtscsi_cmd_cache); 954 virtscsi_cmd_cache = NULL; 955 } 956 return ret; 957 } 958 959 static void __exit fini(void) 960 { 961 unregister_virtio_driver(&virtio_scsi_driver); 962 mempool_destroy(virtscsi_cmd_pool); 963 kmem_cache_destroy(virtscsi_cmd_cache); 964 } 965 module_init(init); 966 module_exit(fini); 967 968 MODULE_DEVICE_TABLE(virtio, id_table); 969 MODULE_DESCRIPTION("Virtio SCSI HBA driver"); 970 MODULE_LICENSE("GPL"); 971