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 #include "sd.h" 34 35 #define VIRTIO_SCSI_MEMPOOL_SZ 64 36 #define VIRTIO_SCSI_EVENT_LEN 8 37 #define VIRTIO_SCSI_VQ_BASE 2 38 39 /* Command queue element */ 40 struct virtio_scsi_cmd { 41 struct scsi_cmnd *sc; 42 struct completion *comp; 43 union { 44 struct virtio_scsi_cmd_req cmd; 45 struct virtio_scsi_cmd_req_pi cmd_pi; 46 struct virtio_scsi_ctrl_tmf_req tmf; 47 struct virtio_scsi_ctrl_an_req an; 48 } req; 49 union { 50 struct virtio_scsi_cmd_resp cmd; 51 struct virtio_scsi_ctrl_tmf_resp tmf; 52 struct virtio_scsi_ctrl_an_resp an; 53 struct virtio_scsi_event evt; 54 } resp; 55 } ____cacheline_aligned_in_smp; 56 57 struct virtio_scsi_event_node { 58 struct virtio_scsi *vscsi; 59 struct virtio_scsi_event event; 60 struct work_struct work; 61 }; 62 63 struct virtio_scsi_vq { 64 /* Protects vq */ 65 spinlock_t vq_lock; 66 67 struct virtqueue *vq; 68 }; 69 70 /* Driver instance state */ 71 struct virtio_scsi { 72 struct virtio_device *vdev; 73 74 /* Get some buffers ready for event vq */ 75 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN]; 76 77 u32 num_queues; 78 79 struct hlist_node node; 80 81 /* Protected by event_vq lock */ 82 bool stop_events; 83 84 struct virtio_scsi_vq ctrl_vq; 85 struct virtio_scsi_vq event_vq; 86 struct virtio_scsi_vq req_vqs[]; 87 }; 88 89 static struct kmem_cache *virtscsi_cmd_cache; 90 static mempool_t *virtscsi_cmd_pool; 91 92 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev) 93 { 94 return vdev->priv; 95 } 96 97 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid) 98 { 99 if (resid) 100 scsi_set_resid(sc, resid); 101 } 102 103 /** 104 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done 105 * 106 * Called with vq_lock held. 107 */ 108 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf) 109 { 110 struct virtio_scsi_cmd *cmd = buf; 111 struct scsi_cmnd *sc = cmd->sc; 112 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd; 113 114 dev_dbg(&sc->device->sdev_gendev, 115 "cmd %p response %u status %#02x sense_len %u\n", 116 sc, resp->response, resp->status, resp->sense_len); 117 118 sc->result = resp->status; 119 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid)); 120 switch (resp->response) { 121 case VIRTIO_SCSI_S_OK: 122 set_host_byte(sc, DID_OK); 123 break; 124 case VIRTIO_SCSI_S_OVERRUN: 125 set_host_byte(sc, DID_ERROR); 126 break; 127 case VIRTIO_SCSI_S_ABORTED: 128 set_host_byte(sc, DID_ABORT); 129 break; 130 case VIRTIO_SCSI_S_BAD_TARGET: 131 set_host_byte(sc, DID_BAD_TARGET); 132 break; 133 case VIRTIO_SCSI_S_RESET: 134 set_host_byte(sc, DID_RESET); 135 break; 136 case VIRTIO_SCSI_S_BUSY: 137 set_host_byte(sc, DID_BUS_BUSY); 138 break; 139 case VIRTIO_SCSI_S_TRANSPORT_FAILURE: 140 set_host_byte(sc, DID_TRANSPORT_DISRUPTED); 141 break; 142 case VIRTIO_SCSI_S_TARGET_FAILURE: 143 set_host_byte(sc, DID_TARGET_FAILURE); 144 break; 145 case VIRTIO_SCSI_S_NEXUS_FAILURE: 146 set_host_byte(sc, DID_NEXUS_FAILURE); 147 break; 148 default: 149 scmd_printk(KERN_WARNING, sc, "Unknown response %d", 150 resp->response); 151 /* fall through */ 152 case VIRTIO_SCSI_S_FAILURE: 153 set_host_byte(sc, DID_ERROR); 154 break; 155 } 156 157 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) > 158 VIRTIO_SCSI_SENSE_SIZE); 159 if (sc->sense_buffer) { 160 memcpy(sc->sense_buffer, resp->sense, 161 min_t(u32, 162 virtio32_to_cpu(vscsi->vdev, resp->sense_len), 163 VIRTIO_SCSI_SENSE_SIZE)); 164 if (resp->sense_len) 165 set_driver_byte(sc, DRIVER_SENSE); 166 } 167 168 sc->scsi_done(sc); 169 } 170 171 static void virtscsi_vq_done(struct virtio_scsi *vscsi, 172 struct virtio_scsi_vq *virtscsi_vq, 173 void (*fn)(struct virtio_scsi *vscsi, void *buf)) 174 { 175 void *buf; 176 unsigned int len; 177 unsigned long flags; 178 struct virtqueue *vq = virtscsi_vq->vq; 179 180 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); 181 do { 182 virtqueue_disable_cb(vq); 183 while ((buf = virtqueue_get_buf(vq, &len)) != NULL) 184 fn(vscsi, buf); 185 186 if (unlikely(virtqueue_is_broken(vq))) 187 break; 188 } while (!virtqueue_enable_cb(vq)); 189 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); 190 } 191 192 static void virtscsi_req_done(struct virtqueue *vq) 193 { 194 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 195 struct virtio_scsi *vscsi = shost_priv(sh); 196 int index = vq->index - VIRTIO_SCSI_VQ_BASE; 197 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index]; 198 199 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd); 200 }; 201 202 static void virtscsi_poll_requests(struct virtio_scsi *vscsi) 203 { 204 int i, num_vqs; 205 206 num_vqs = vscsi->num_queues; 207 for (i = 0; i < num_vqs; i++) 208 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i], 209 virtscsi_complete_cmd); 210 } 211 212 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf) 213 { 214 struct virtio_scsi_cmd *cmd = buf; 215 216 if (cmd->comp) 217 complete(cmd->comp); 218 } 219 220 static void virtscsi_ctrl_done(struct virtqueue *vq) 221 { 222 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 223 struct virtio_scsi *vscsi = shost_priv(sh); 224 225 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free); 226 }; 227 228 static void virtscsi_handle_event(struct work_struct *work); 229 230 static int virtscsi_kick_event(struct virtio_scsi *vscsi, 231 struct virtio_scsi_event_node *event_node) 232 { 233 int err; 234 struct scatterlist sg; 235 unsigned long flags; 236 237 INIT_WORK(&event_node->work, virtscsi_handle_event); 238 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event)); 239 240 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags); 241 242 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node, 243 GFP_ATOMIC); 244 if (!err) 245 virtqueue_kick(vscsi->event_vq.vq); 246 247 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags); 248 249 return err; 250 } 251 252 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi) 253 { 254 int i; 255 256 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) { 257 vscsi->event_list[i].vscsi = vscsi; 258 virtscsi_kick_event(vscsi, &vscsi->event_list[i]); 259 } 260 261 return 0; 262 } 263 264 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi) 265 { 266 int i; 267 268 /* Stop scheduling work before calling cancel_work_sync. */ 269 spin_lock_irq(&vscsi->event_vq.vq_lock); 270 vscsi->stop_events = true; 271 spin_unlock_irq(&vscsi->event_vq.vq_lock); 272 273 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) 274 cancel_work_sync(&vscsi->event_list[i].work); 275 } 276 277 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, 278 struct virtio_scsi_event *event) 279 { 280 struct scsi_device *sdev; 281 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 282 unsigned int target = event->lun[1]; 283 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 284 285 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) { 286 case VIRTIO_SCSI_EVT_RESET_RESCAN: 287 scsi_add_device(shost, 0, target, lun); 288 break; 289 case VIRTIO_SCSI_EVT_RESET_REMOVED: 290 sdev = scsi_device_lookup(shost, 0, target, lun); 291 if (sdev) { 292 scsi_remove_device(sdev); 293 scsi_device_put(sdev); 294 } else { 295 pr_err("SCSI device %d 0 %d %d not found\n", 296 shost->host_no, target, lun); 297 } 298 break; 299 default: 300 pr_info("Unsupport virtio scsi event reason %x\n", event->reason); 301 } 302 } 303 304 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, 305 struct virtio_scsi_event *event) 306 { 307 struct scsi_device *sdev; 308 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 309 unsigned int target = event->lun[1]; 310 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 311 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255; 312 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8; 313 314 sdev = scsi_device_lookup(shost, 0, target, lun); 315 if (!sdev) { 316 pr_err("SCSI device %d 0 %d %d not found\n", 317 shost->host_no, target, lun); 318 return; 319 } 320 321 /* Handle "Parameters changed", "Mode parameters changed", and 322 "Capacity data has changed". */ 323 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) 324 scsi_rescan_device(&sdev->sdev_gendev); 325 326 scsi_device_put(sdev); 327 } 328 329 static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi) 330 { 331 struct scsi_device *sdev; 332 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 333 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 334 int result, inquiry_len, inq_result_len = 256; 335 char *inq_result = kmalloc(inq_result_len, GFP_KERNEL); 336 337 shost_for_each_device(sdev, shost) { 338 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 339 340 memset(scsi_cmd, 0, sizeof(scsi_cmd)); 341 scsi_cmd[0] = INQUIRY; 342 scsi_cmd[4] = (unsigned char) inquiry_len; 343 344 memset(inq_result, 0, inq_result_len); 345 346 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 347 inq_result, inquiry_len, NULL, 348 SD_TIMEOUT, SD_MAX_RETRIES, NULL); 349 350 if (result == 0 && inq_result[0] >> 5) { 351 /* PQ indicates the LUN is not attached */ 352 scsi_remove_device(sdev); 353 } 354 } 355 356 kfree(inq_result); 357 } 358 359 static void virtscsi_handle_event(struct work_struct *work) 360 { 361 struct virtio_scsi_event_node *event_node = 362 container_of(work, struct virtio_scsi_event_node, work); 363 struct virtio_scsi *vscsi = event_node->vscsi; 364 struct virtio_scsi_event *event = &event_node->event; 365 366 if (event->event & 367 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { 368 event->event &= ~cpu_to_virtio32(vscsi->vdev, 369 VIRTIO_SCSI_T_EVENTS_MISSED); 370 virtscsi_rescan_hotunplug(vscsi); 371 scsi_scan_host(virtio_scsi_host(vscsi->vdev)); 372 } 373 374 switch (virtio32_to_cpu(vscsi->vdev, event->event)) { 375 case VIRTIO_SCSI_T_NO_EVENT: 376 break; 377 case VIRTIO_SCSI_T_TRANSPORT_RESET: 378 virtscsi_handle_transport_reset(vscsi, event); 379 break; 380 case VIRTIO_SCSI_T_PARAM_CHANGE: 381 virtscsi_handle_param_change(vscsi, event); 382 break; 383 default: 384 pr_err("Unsupport virtio scsi event %x\n", event->event); 385 } 386 virtscsi_kick_event(vscsi, event_node); 387 } 388 389 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) 390 { 391 struct virtio_scsi_event_node *event_node = buf; 392 393 if (!vscsi->stop_events) 394 queue_work(system_freezable_wq, &event_node->work); 395 } 396 397 static void virtscsi_event_done(struct virtqueue *vq) 398 { 399 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 400 struct virtio_scsi *vscsi = shost_priv(sh); 401 402 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); 403 }; 404 405 static int __virtscsi_add_cmd(struct virtqueue *vq, 406 struct virtio_scsi_cmd *cmd, 407 size_t req_size, size_t resp_size) 408 { 409 struct scsi_cmnd *sc = cmd->sc; 410 struct scatterlist *sgs[6], req, resp; 411 struct sg_table *out, *in; 412 unsigned out_num = 0, in_num = 0; 413 414 out = in = NULL; 415 416 if (sc && sc->sc_data_direction != DMA_NONE) { 417 if (sc->sc_data_direction != DMA_FROM_DEVICE) 418 out = &sc->sdb.table; 419 if (sc->sc_data_direction != DMA_TO_DEVICE) 420 in = &sc->sdb.table; 421 } 422 423 /* Request header. */ 424 sg_init_one(&req, &cmd->req, req_size); 425 sgs[out_num++] = &req; 426 427 /* Data-out buffer. */ 428 if (out) { 429 /* Place WRITE protection SGLs before Data OUT payload */ 430 if (scsi_prot_sg_count(sc)) 431 sgs[out_num++] = scsi_prot_sglist(sc); 432 sgs[out_num++] = out->sgl; 433 } 434 435 /* Response header. */ 436 sg_init_one(&resp, &cmd->resp, resp_size); 437 sgs[out_num + in_num++] = &resp; 438 439 /* Data-in buffer */ 440 if (in) { 441 /* Place READ protection SGLs before Data IN payload */ 442 if (scsi_prot_sg_count(sc)) 443 sgs[out_num + in_num++] = scsi_prot_sglist(sc); 444 sgs[out_num + in_num++] = in->sgl; 445 } 446 447 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); 448 } 449 450 static void virtscsi_kick_vq(struct virtio_scsi_vq *vq) 451 { 452 bool needs_kick; 453 unsigned long flags; 454 455 spin_lock_irqsave(&vq->vq_lock, flags); 456 needs_kick = virtqueue_kick_prepare(vq->vq); 457 spin_unlock_irqrestore(&vq->vq_lock, flags); 458 459 if (needs_kick) 460 virtqueue_notify(vq->vq); 461 } 462 463 /** 464 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it 465 * @vq : the struct virtqueue we're talking about 466 * @cmd : command structure 467 * @req_size : size of the request buffer 468 * @resp_size : size of the response buffer 469 * @kick : whether to kick the virtqueue immediately 470 */ 471 static int virtscsi_add_cmd(struct virtio_scsi_vq *vq, 472 struct virtio_scsi_cmd *cmd, 473 size_t req_size, size_t resp_size, 474 bool kick) 475 { 476 unsigned long flags; 477 int err; 478 bool needs_kick = false; 479 480 spin_lock_irqsave(&vq->vq_lock, flags); 481 err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size); 482 if (!err && kick) 483 needs_kick = virtqueue_kick_prepare(vq->vq); 484 485 spin_unlock_irqrestore(&vq->vq_lock, flags); 486 487 if (needs_kick) 488 virtqueue_notify(vq->vq); 489 return err; 490 } 491 492 static void virtio_scsi_init_hdr(struct virtio_device *vdev, 493 struct virtio_scsi_cmd_req *cmd, 494 struct scsi_cmnd *sc) 495 { 496 cmd->lun[0] = 1; 497 cmd->lun[1] = sc->device->id; 498 cmd->lun[2] = (sc->device->lun >> 8) | 0x40; 499 cmd->lun[3] = sc->device->lun & 0xff; 500 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc); 501 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; 502 cmd->prio = 0; 503 cmd->crn = 0; 504 } 505 506 #ifdef CONFIG_BLK_DEV_INTEGRITY 507 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, 508 struct virtio_scsi_cmd_req_pi *cmd_pi, 509 struct scsi_cmnd *sc) 510 { 511 struct request *rq = sc->request; 512 struct blk_integrity *bi; 513 514 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc); 515 516 if (!rq || !scsi_prot_sg_count(sc)) 517 return; 518 519 bi = blk_get_integrity(rq->rq_disk); 520 521 if (sc->sc_data_direction == DMA_TO_DEVICE) 522 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, 523 bio_integrity_bytes(bi, 524 blk_rq_sectors(rq))); 525 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 526 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, 527 bio_integrity_bytes(bi, 528 blk_rq_sectors(rq))); 529 } 530 #endif 531 532 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, 533 struct scsi_cmnd *sc) 534 { 535 u32 tag = blk_mq_unique_tag(sc->request); 536 u16 hwq = blk_mq_unique_tag_to_hwq(tag); 537 538 return &vscsi->req_vqs[hwq]; 539 } 540 541 static int virtscsi_queuecommand(struct Scsi_Host *shost, 542 struct scsi_cmnd *sc) 543 { 544 struct virtio_scsi *vscsi = shost_priv(shost); 545 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc); 546 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 547 bool kick; 548 unsigned long flags; 549 int req_size; 550 int ret; 551 552 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 553 554 /* TODO: check feature bit and fail if unsupported? */ 555 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 556 557 dev_dbg(&sc->device->sdev_gendev, 558 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 559 560 cmd->sc = sc; 561 562 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 563 564 #ifdef CONFIG_BLK_DEV_INTEGRITY 565 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 566 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc); 567 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 568 req_size = sizeof(cmd->req.cmd_pi); 569 } else 570 #endif 571 { 572 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc); 573 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 574 req_size = sizeof(cmd->req.cmd); 575 } 576 577 kick = (sc->flags & SCMD_LAST) != 0; 578 ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick); 579 if (ret == -EIO) { 580 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET; 581 spin_lock_irqsave(&req_vq->vq_lock, flags); 582 virtscsi_complete_cmd(vscsi, cmd); 583 spin_unlock_irqrestore(&req_vq->vq_lock, flags); 584 } else if (ret != 0) { 585 return SCSI_MLQUEUE_HOST_BUSY; 586 } 587 return 0; 588 } 589 590 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 591 { 592 DECLARE_COMPLETION_ONSTACK(comp); 593 int ret = FAILED; 594 595 cmd->comp = ∁ 596 if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd, 597 sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0) 598 goto out; 599 600 wait_for_completion(&comp); 601 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 602 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 603 ret = SUCCESS; 604 605 /* 606 * The spec guarantees that all requests related to the TMF have 607 * been completed, but the callback might not have run yet if 608 * we're using independent interrupts (e.g. MSI). Poll the 609 * virtqueues once. 610 * 611 * In the abort case, sc->scsi_done will do nothing, because 612 * the block layer must have detected a timeout and as a result 613 * REQ_ATOM_COMPLETE has been set. 614 */ 615 virtscsi_poll_requests(vscsi); 616 617 out: 618 mempool_free(cmd, virtscsi_cmd_pool); 619 return ret; 620 } 621 622 static int virtscsi_device_reset(struct scsi_cmnd *sc) 623 { 624 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 625 struct virtio_scsi_cmd *cmd; 626 627 sdev_printk(KERN_INFO, sc->device, "device reset\n"); 628 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 629 if (!cmd) 630 return FAILED; 631 632 memset(cmd, 0, sizeof(*cmd)); 633 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 634 .type = VIRTIO_SCSI_T_TMF, 635 .subtype = cpu_to_virtio32(vscsi->vdev, 636 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET), 637 .lun[0] = 1, 638 .lun[1] = sc->device->id, 639 .lun[2] = (sc->device->lun >> 8) | 0x40, 640 .lun[3] = sc->device->lun & 0xff, 641 }; 642 return virtscsi_tmf(vscsi, cmd); 643 } 644 645 static int virtscsi_device_alloc(struct scsi_device *sdevice) 646 { 647 /* 648 * Passed through SCSI targets (e.g. with qemu's 'scsi-block') 649 * may have transfer limits which come from the host SCSI 650 * controller or something on the host side other than the 651 * target itself. 652 * 653 * To make this work properly, the hypervisor can adjust the 654 * target's VPD information to advertise these limits. But 655 * for that to work, the guest has to look at the VPD pages, 656 * which we won't do by default if it is an SPC-2 device, even 657 * if it does actually support it. 658 * 659 * So, set the blist to always try to read the VPD pages. 660 */ 661 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES; 662 663 return 0; 664 } 665 666 667 /** 668 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth 669 * @sdev: Virtscsi target whose queue depth to change 670 * @qdepth: New queue depth 671 */ 672 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) 673 { 674 struct Scsi_Host *shost = sdev->host; 675 int max_depth = shost->cmd_per_lun; 676 677 return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); 678 } 679 680 static int virtscsi_abort(struct scsi_cmnd *sc) 681 { 682 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 683 struct virtio_scsi_cmd *cmd; 684 685 scmd_printk(KERN_INFO, sc, "abort\n"); 686 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 687 if (!cmd) 688 return FAILED; 689 690 memset(cmd, 0, sizeof(*cmd)); 691 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 692 .type = VIRTIO_SCSI_T_TMF, 693 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 694 .lun[0] = 1, 695 .lun[1] = sc->device->id, 696 .lun[2] = (sc->device->lun >> 8) | 0x40, 697 .lun[3] = sc->device->lun & 0xff, 698 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc), 699 }; 700 return virtscsi_tmf(vscsi, cmd); 701 } 702 703 static int virtscsi_map_queues(struct Scsi_Host *shost) 704 { 705 struct virtio_scsi *vscsi = shost_priv(shost); 706 struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT]; 707 708 return blk_mq_virtio_map_queues(qmap, vscsi->vdev, 2); 709 } 710 711 static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq) 712 { 713 struct virtio_scsi *vscsi = shost_priv(shost); 714 715 virtscsi_kick_vq(&vscsi->req_vqs[hwq]); 716 } 717 718 /* 719 * The host guarantees to respond to each command, although I/O 720 * latencies might be higher than on bare metal. Reset the timer 721 * unconditionally to give the host a chance to perform EH. 722 */ 723 static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd) 724 { 725 return BLK_EH_RESET_TIMER; 726 } 727 728 static struct scsi_host_template virtscsi_host_template = { 729 .module = THIS_MODULE, 730 .name = "Virtio SCSI HBA", 731 .proc_name = "virtio_scsi", 732 .this_id = -1, 733 .cmd_size = sizeof(struct virtio_scsi_cmd), 734 .queuecommand = virtscsi_queuecommand, 735 .commit_rqs = virtscsi_commit_rqs, 736 .change_queue_depth = virtscsi_change_queue_depth, 737 .eh_abort_handler = virtscsi_abort, 738 .eh_device_reset_handler = virtscsi_device_reset, 739 .eh_timed_out = virtscsi_eh_timed_out, 740 .slave_alloc = virtscsi_device_alloc, 741 742 .dma_boundary = UINT_MAX, 743 .map_queues = virtscsi_map_queues, 744 .track_queue_depth = 1, 745 }; 746 747 #define virtscsi_config_get(vdev, fld) \ 748 ({ \ 749 __virtio_native_type(struct virtio_scsi_config, fld) __val; \ 750 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 751 __val; \ 752 }) 753 754 #define virtscsi_config_set(vdev, fld, val) \ 755 do { \ 756 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \ 757 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 758 } while(0) 759 760 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 761 struct virtqueue *vq) 762 { 763 spin_lock_init(&virtscsi_vq->vq_lock); 764 virtscsi_vq->vq = vq; 765 } 766 767 static void virtscsi_remove_vqs(struct virtio_device *vdev) 768 { 769 /* Stop all the virtqueues. */ 770 vdev->config->reset(vdev); 771 vdev->config->del_vqs(vdev); 772 } 773 774 static int virtscsi_init(struct virtio_device *vdev, 775 struct virtio_scsi *vscsi) 776 { 777 int err; 778 u32 i; 779 u32 num_vqs; 780 vq_callback_t **callbacks; 781 const char **names; 782 struct virtqueue **vqs; 783 struct irq_affinity desc = { .pre_vectors = 2 }; 784 785 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; 786 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL); 787 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *), 788 GFP_KERNEL); 789 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL); 790 791 if (!callbacks || !vqs || !names) { 792 err = -ENOMEM; 793 goto out; 794 } 795 796 callbacks[0] = virtscsi_ctrl_done; 797 callbacks[1] = virtscsi_event_done; 798 names[0] = "control"; 799 names[1] = "event"; 800 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { 801 callbacks[i] = virtscsi_req_done; 802 names[i] = "request"; 803 } 804 805 /* Discover virtqueues and write information to configuration. */ 806 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 807 if (err) 808 goto out; 809 810 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 811 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 812 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 813 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 814 vqs[i]); 815 816 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 817 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 818 819 err = 0; 820 821 out: 822 kfree(names); 823 kfree(callbacks); 824 kfree(vqs); 825 if (err) 826 virtscsi_remove_vqs(vdev); 827 return err; 828 } 829 830 static int virtscsi_probe(struct virtio_device *vdev) 831 { 832 struct Scsi_Host *shost; 833 struct virtio_scsi *vscsi; 834 int err; 835 u32 sg_elems, num_targets; 836 u32 cmd_per_lun; 837 u32 num_queues; 838 839 if (!vdev->config->get) { 840 dev_err(&vdev->dev, "%s failure: config access disabled\n", 841 __func__); 842 return -EINVAL; 843 } 844 845 /* We need to know how many queues before we allocate. */ 846 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; 847 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues); 848 849 num_targets = virtscsi_config_get(vdev, max_target) + 1; 850 851 shost = scsi_host_alloc(&virtscsi_host_template, 852 struct_size(vscsi, req_vqs, num_queues)); 853 if (!shost) 854 return -ENOMEM; 855 856 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 857 shost->sg_tablesize = sg_elems; 858 vscsi = shost_priv(shost); 859 vscsi->vdev = vdev; 860 vscsi->num_queues = num_queues; 861 vdev->priv = shost; 862 863 err = virtscsi_init(vdev, vscsi); 864 if (err) 865 goto virtscsi_init_failed; 866 867 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq); 868 869 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 870 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 871 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 872 873 /* LUNs > 256 are reported with format 1, so they go in the range 874 * 16640-32767. 875 */ 876 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 877 shost->max_id = num_targets; 878 shost->max_channel = 0; 879 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 880 shost->nr_hw_queues = num_queues; 881 882 #ifdef CONFIG_BLK_DEV_INTEGRITY 883 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 884 int host_prot; 885 886 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 887 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 888 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 889 890 scsi_host_set_prot(shost, host_prot); 891 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 892 } 893 #endif 894 895 err = scsi_add_host(shost, &vdev->dev); 896 if (err) 897 goto scsi_add_host_failed; 898 899 virtio_device_ready(vdev); 900 901 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 902 virtscsi_kick_event_all(vscsi); 903 904 scsi_scan_host(shost); 905 return 0; 906 907 scsi_add_host_failed: 908 vdev->config->del_vqs(vdev); 909 virtscsi_init_failed: 910 scsi_host_put(shost); 911 return err; 912 } 913 914 static void virtscsi_remove(struct virtio_device *vdev) 915 { 916 struct Scsi_Host *shost = virtio_scsi_host(vdev); 917 struct virtio_scsi *vscsi = shost_priv(shost); 918 919 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 920 virtscsi_cancel_event_work(vscsi); 921 922 scsi_remove_host(shost); 923 virtscsi_remove_vqs(vdev); 924 scsi_host_put(shost); 925 } 926 927 #ifdef CONFIG_PM_SLEEP 928 static int virtscsi_freeze(struct virtio_device *vdev) 929 { 930 virtscsi_remove_vqs(vdev); 931 return 0; 932 } 933 934 static int virtscsi_restore(struct virtio_device *vdev) 935 { 936 struct Scsi_Host *sh = virtio_scsi_host(vdev); 937 struct virtio_scsi *vscsi = shost_priv(sh); 938 int err; 939 940 err = virtscsi_init(vdev, vscsi); 941 if (err) 942 return err; 943 944 virtio_device_ready(vdev); 945 946 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 947 virtscsi_kick_event_all(vscsi); 948 949 return err; 950 } 951 #endif 952 953 static struct virtio_device_id id_table[] = { 954 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 955 { 0 }, 956 }; 957 958 static unsigned int features[] = { 959 VIRTIO_SCSI_F_HOTPLUG, 960 VIRTIO_SCSI_F_CHANGE, 961 #ifdef CONFIG_BLK_DEV_INTEGRITY 962 VIRTIO_SCSI_F_T10_PI, 963 #endif 964 }; 965 966 static struct virtio_driver virtio_scsi_driver = { 967 .feature_table = features, 968 .feature_table_size = ARRAY_SIZE(features), 969 .driver.name = KBUILD_MODNAME, 970 .driver.owner = THIS_MODULE, 971 .id_table = id_table, 972 .probe = virtscsi_probe, 973 #ifdef CONFIG_PM_SLEEP 974 .freeze = virtscsi_freeze, 975 .restore = virtscsi_restore, 976 #endif 977 .remove = virtscsi_remove, 978 }; 979 980 static int __init init(void) 981 { 982 int ret = -ENOMEM; 983 984 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); 985 if (!virtscsi_cmd_cache) { 986 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); 987 goto error; 988 } 989 990 991 virtscsi_cmd_pool = 992 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, 993 virtscsi_cmd_cache); 994 if (!virtscsi_cmd_pool) { 995 pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); 996 goto error; 997 } 998 ret = register_virtio_driver(&virtio_scsi_driver); 999 if (ret < 0) 1000 goto error; 1001 1002 return 0; 1003 1004 error: 1005 if (virtscsi_cmd_pool) { 1006 mempool_destroy(virtscsi_cmd_pool); 1007 virtscsi_cmd_pool = NULL; 1008 } 1009 if (virtscsi_cmd_cache) { 1010 kmem_cache_destroy(virtscsi_cmd_cache); 1011 virtscsi_cmd_cache = NULL; 1012 } 1013 return ret; 1014 } 1015 1016 static void __exit fini(void) 1017 { 1018 unregister_virtio_driver(&virtio_scsi_driver); 1019 mempool_destroy(virtscsi_cmd_pool); 1020 kmem_cache_destroy(virtscsi_cmd_cache); 1021 } 1022 module_init(init); 1023 module_exit(fini); 1024 1025 MODULE_DEVICE_TABLE(virtio, id_table); 1026 MODULE_DESCRIPTION("Virtio SCSI HBA driver"); 1027 MODULE_LICENSE("GPL"); 1028