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