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 } else if (host_byte(result) == DID_BAD_TARGET) { 354 /* 355 * If all LUNs of a virtio-scsi device are unplugged 356 * it will respond with BAD TARGET on any INQUIRY 357 * command. 358 * Remove the device in this case as well. 359 */ 360 scsi_remove_device(sdev); 361 } 362 } 363 364 kfree(inq_result); 365 } 366 367 static void virtscsi_handle_event(struct work_struct *work) 368 { 369 struct virtio_scsi_event_node *event_node = 370 container_of(work, struct virtio_scsi_event_node, work); 371 struct virtio_scsi *vscsi = event_node->vscsi; 372 struct virtio_scsi_event *event = &event_node->event; 373 374 if (event->event & 375 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { 376 event->event &= ~cpu_to_virtio32(vscsi->vdev, 377 VIRTIO_SCSI_T_EVENTS_MISSED); 378 virtscsi_rescan_hotunplug(vscsi); 379 scsi_scan_host(virtio_scsi_host(vscsi->vdev)); 380 } 381 382 switch (virtio32_to_cpu(vscsi->vdev, event->event)) { 383 case VIRTIO_SCSI_T_NO_EVENT: 384 break; 385 case VIRTIO_SCSI_T_TRANSPORT_RESET: 386 virtscsi_handle_transport_reset(vscsi, event); 387 break; 388 case VIRTIO_SCSI_T_PARAM_CHANGE: 389 virtscsi_handle_param_change(vscsi, event); 390 break; 391 default: 392 pr_err("Unsupport virtio scsi event %x\n", event->event); 393 } 394 virtscsi_kick_event(vscsi, event_node); 395 } 396 397 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) 398 { 399 struct virtio_scsi_event_node *event_node = buf; 400 401 if (!vscsi->stop_events) 402 queue_work(system_freezable_wq, &event_node->work); 403 } 404 405 static void virtscsi_event_done(struct virtqueue *vq) 406 { 407 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 408 struct virtio_scsi *vscsi = shost_priv(sh); 409 410 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); 411 }; 412 413 static int __virtscsi_add_cmd(struct virtqueue *vq, 414 struct virtio_scsi_cmd *cmd, 415 size_t req_size, size_t resp_size) 416 { 417 struct scsi_cmnd *sc = cmd->sc; 418 struct scatterlist *sgs[6], req, resp; 419 struct sg_table *out, *in; 420 unsigned out_num = 0, in_num = 0; 421 422 out = in = NULL; 423 424 if (sc && sc->sc_data_direction != DMA_NONE) { 425 if (sc->sc_data_direction != DMA_FROM_DEVICE) 426 out = &sc->sdb.table; 427 if (sc->sc_data_direction != DMA_TO_DEVICE) 428 in = &sc->sdb.table; 429 } 430 431 /* Request header. */ 432 sg_init_one(&req, &cmd->req, req_size); 433 sgs[out_num++] = &req; 434 435 /* Data-out buffer. */ 436 if (out) { 437 /* Place WRITE protection SGLs before Data OUT payload */ 438 if (scsi_prot_sg_count(sc)) 439 sgs[out_num++] = scsi_prot_sglist(sc); 440 sgs[out_num++] = out->sgl; 441 } 442 443 /* Response header. */ 444 sg_init_one(&resp, &cmd->resp, resp_size); 445 sgs[out_num + in_num++] = &resp; 446 447 /* Data-in buffer */ 448 if (in) { 449 /* Place READ protection SGLs before Data IN payload */ 450 if (scsi_prot_sg_count(sc)) 451 sgs[out_num + in_num++] = scsi_prot_sglist(sc); 452 sgs[out_num + in_num++] = in->sgl; 453 } 454 455 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); 456 } 457 458 static void virtscsi_kick_vq(struct virtio_scsi_vq *vq) 459 { 460 bool needs_kick; 461 unsigned long flags; 462 463 spin_lock_irqsave(&vq->vq_lock, flags); 464 needs_kick = virtqueue_kick_prepare(vq->vq); 465 spin_unlock_irqrestore(&vq->vq_lock, flags); 466 467 if (needs_kick) 468 virtqueue_notify(vq->vq); 469 } 470 471 /** 472 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it 473 * @vq : the struct virtqueue we're talking about 474 * @cmd : command structure 475 * @req_size : size of the request buffer 476 * @resp_size : size of the response buffer 477 * @kick : whether to kick the virtqueue immediately 478 */ 479 static int virtscsi_add_cmd(struct virtio_scsi_vq *vq, 480 struct virtio_scsi_cmd *cmd, 481 size_t req_size, size_t resp_size, 482 bool kick) 483 { 484 unsigned long flags; 485 int err; 486 bool needs_kick = false; 487 488 spin_lock_irqsave(&vq->vq_lock, flags); 489 err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size); 490 if (!err && kick) 491 needs_kick = virtqueue_kick_prepare(vq->vq); 492 493 spin_unlock_irqrestore(&vq->vq_lock, flags); 494 495 if (needs_kick) 496 virtqueue_notify(vq->vq); 497 return err; 498 } 499 500 static void virtio_scsi_init_hdr(struct virtio_device *vdev, 501 struct virtio_scsi_cmd_req *cmd, 502 struct scsi_cmnd *sc) 503 { 504 cmd->lun[0] = 1; 505 cmd->lun[1] = sc->device->id; 506 cmd->lun[2] = (sc->device->lun >> 8) | 0x40; 507 cmd->lun[3] = sc->device->lun & 0xff; 508 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc); 509 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; 510 cmd->prio = 0; 511 cmd->crn = 0; 512 } 513 514 #ifdef CONFIG_BLK_DEV_INTEGRITY 515 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, 516 struct virtio_scsi_cmd_req_pi *cmd_pi, 517 struct scsi_cmnd *sc) 518 { 519 struct request *rq = sc->request; 520 struct blk_integrity *bi; 521 522 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc); 523 524 if (!rq || !scsi_prot_sg_count(sc)) 525 return; 526 527 bi = blk_get_integrity(rq->rq_disk); 528 529 if (sc->sc_data_direction == DMA_TO_DEVICE) 530 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, 531 bio_integrity_bytes(bi, 532 blk_rq_sectors(rq))); 533 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 534 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, 535 bio_integrity_bytes(bi, 536 blk_rq_sectors(rq))); 537 } 538 #endif 539 540 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, 541 struct scsi_cmnd *sc) 542 { 543 u32 tag = blk_mq_unique_tag(sc->request); 544 u16 hwq = blk_mq_unique_tag_to_hwq(tag); 545 546 return &vscsi->req_vqs[hwq]; 547 } 548 549 static int virtscsi_queuecommand(struct Scsi_Host *shost, 550 struct scsi_cmnd *sc) 551 { 552 struct virtio_scsi *vscsi = shost_priv(shost); 553 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc); 554 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 555 bool kick; 556 unsigned long flags; 557 int req_size; 558 int ret; 559 560 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 561 562 /* TODO: check feature bit and fail if unsupported? */ 563 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 564 565 dev_dbg(&sc->device->sdev_gendev, 566 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 567 568 cmd->sc = sc; 569 570 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 571 572 #ifdef CONFIG_BLK_DEV_INTEGRITY 573 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 574 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc); 575 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 576 req_size = sizeof(cmd->req.cmd_pi); 577 } else 578 #endif 579 { 580 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc); 581 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 582 req_size = sizeof(cmd->req.cmd); 583 } 584 585 kick = (sc->flags & SCMD_LAST) != 0; 586 ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick); 587 if (ret == -EIO) { 588 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET; 589 spin_lock_irqsave(&req_vq->vq_lock, flags); 590 virtscsi_complete_cmd(vscsi, cmd); 591 spin_unlock_irqrestore(&req_vq->vq_lock, flags); 592 } else if (ret != 0) { 593 return SCSI_MLQUEUE_HOST_BUSY; 594 } 595 return 0; 596 } 597 598 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 599 { 600 DECLARE_COMPLETION_ONSTACK(comp); 601 int ret = FAILED; 602 603 cmd->comp = ∁ 604 if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd, 605 sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0) 606 goto out; 607 608 wait_for_completion(&comp); 609 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 610 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 611 ret = SUCCESS; 612 613 /* 614 * The spec guarantees that all requests related to the TMF have 615 * been completed, but the callback might not have run yet if 616 * we're using independent interrupts (e.g. MSI). Poll the 617 * virtqueues once. 618 * 619 * In the abort case, sc->scsi_done will do nothing, because 620 * the block layer must have detected a timeout and as a result 621 * REQ_ATOM_COMPLETE has been set. 622 */ 623 virtscsi_poll_requests(vscsi); 624 625 out: 626 mempool_free(cmd, virtscsi_cmd_pool); 627 return ret; 628 } 629 630 static int virtscsi_device_reset(struct scsi_cmnd *sc) 631 { 632 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 633 struct virtio_scsi_cmd *cmd; 634 635 sdev_printk(KERN_INFO, sc->device, "device reset\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 = cpu_to_virtio32(vscsi->vdev, 644 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET), 645 .lun[0] = 1, 646 .lun[1] = sc->device->id, 647 .lun[2] = (sc->device->lun >> 8) | 0x40, 648 .lun[3] = sc->device->lun & 0xff, 649 }; 650 return virtscsi_tmf(vscsi, cmd); 651 } 652 653 static int virtscsi_device_alloc(struct scsi_device *sdevice) 654 { 655 /* 656 * Passed through SCSI targets (e.g. with qemu's 'scsi-block') 657 * may have transfer limits which come from the host SCSI 658 * controller or something on the host side other than the 659 * target itself. 660 * 661 * To make this work properly, the hypervisor can adjust the 662 * target's VPD information to advertise these limits. But 663 * for that to work, the guest has to look at the VPD pages, 664 * which we won't do by default if it is an SPC-2 device, even 665 * if it does actually support it. 666 * 667 * So, set the blist to always try to read the VPD pages. 668 */ 669 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES; 670 671 return 0; 672 } 673 674 675 /** 676 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth 677 * @sdev: Virtscsi target whose queue depth to change 678 * @qdepth: New queue depth 679 */ 680 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) 681 { 682 struct Scsi_Host *shost = sdev->host; 683 int max_depth = shost->cmd_per_lun; 684 685 return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); 686 } 687 688 static int virtscsi_abort(struct scsi_cmnd *sc) 689 { 690 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 691 struct virtio_scsi_cmd *cmd; 692 693 scmd_printk(KERN_INFO, sc, "abort\n"); 694 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 695 if (!cmd) 696 return FAILED; 697 698 memset(cmd, 0, sizeof(*cmd)); 699 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 700 .type = VIRTIO_SCSI_T_TMF, 701 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 702 .lun[0] = 1, 703 .lun[1] = sc->device->id, 704 .lun[2] = (sc->device->lun >> 8) | 0x40, 705 .lun[3] = sc->device->lun & 0xff, 706 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc), 707 }; 708 return virtscsi_tmf(vscsi, cmd); 709 } 710 711 static int virtscsi_map_queues(struct Scsi_Host *shost) 712 { 713 struct virtio_scsi *vscsi = shost_priv(shost); 714 struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT]; 715 716 return blk_mq_virtio_map_queues(qmap, vscsi->vdev, 2); 717 } 718 719 static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq) 720 { 721 struct virtio_scsi *vscsi = shost_priv(shost); 722 723 virtscsi_kick_vq(&vscsi->req_vqs[hwq]); 724 } 725 726 /* 727 * The host guarantees to respond to each command, although I/O 728 * latencies might be higher than on bare metal. Reset the timer 729 * unconditionally to give the host a chance to perform EH. 730 */ 731 static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd) 732 { 733 return BLK_EH_RESET_TIMER; 734 } 735 736 static struct scsi_host_template virtscsi_host_template = { 737 .module = THIS_MODULE, 738 .name = "Virtio SCSI HBA", 739 .proc_name = "virtio_scsi", 740 .this_id = -1, 741 .cmd_size = sizeof(struct virtio_scsi_cmd), 742 .queuecommand = virtscsi_queuecommand, 743 .commit_rqs = virtscsi_commit_rqs, 744 .change_queue_depth = virtscsi_change_queue_depth, 745 .eh_abort_handler = virtscsi_abort, 746 .eh_device_reset_handler = virtscsi_device_reset, 747 .eh_timed_out = virtscsi_eh_timed_out, 748 .slave_alloc = virtscsi_device_alloc, 749 750 .dma_boundary = UINT_MAX, 751 .map_queues = virtscsi_map_queues, 752 .track_queue_depth = 1, 753 }; 754 755 #define virtscsi_config_get(vdev, fld) \ 756 ({ \ 757 __virtio_native_type(struct virtio_scsi_config, fld) __val; \ 758 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 759 __val; \ 760 }) 761 762 #define virtscsi_config_set(vdev, fld, val) \ 763 do { \ 764 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \ 765 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 766 } while(0) 767 768 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 769 struct virtqueue *vq) 770 { 771 spin_lock_init(&virtscsi_vq->vq_lock); 772 virtscsi_vq->vq = vq; 773 } 774 775 static void virtscsi_remove_vqs(struct virtio_device *vdev) 776 { 777 /* Stop all the virtqueues. */ 778 vdev->config->reset(vdev); 779 vdev->config->del_vqs(vdev); 780 } 781 782 static int virtscsi_init(struct virtio_device *vdev, 783 struct virtio_scsi *vscsi) 784 { 785 int err; 786 u32 i; 787 u32 num_vqs; 788 vq_callback_t **callbacks; 789 const char **names; 790 struct virtqueue **vqs; 791 struct irq_affinity desc = { .pre_vectors = 2 }; 792 793 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; 794 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL); 795 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *), 796 GFP_KERNEL); 797 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL); 798 799 if (!callbacks || !vqs || !names) { 800 err = -ENOMEM; 801 goto out; 802 } 803 804 callbacks[0] = virtscsi_ctrl_done; 805 callbacks[1] = virtscsi_event_done; 806 names[0] = "control"; 807 names[1] = "event"; 808 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { 809 callbacks[i] = virtscsi_req_done; 810 names[i] = "request"; 811 } 812 813 /* Discover virtqueues and write information to configuration. */ 814 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 815 if (err) 816 goto out; 817 818 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 819 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 820 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 821 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 822 vqs[i]); 823 824 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 825 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 826 827 err = 0; 828 829 out: 830 kfree(names); 831 kfree(callbacks); 832 kfree(vqs); 833 if (err) 834 virtscsi_remove_vqs(vdev); 835 return err; 836 } 837 838 static int virtscsi_probe(struct virtio_device *vdev) 839 { 840 struct Scsi_Host *shost; 841 struct virtio_scsi *vscsi; 842 int err; 843 u32 sg_elems, num_targets; 844 u32 cmd_per_lun; 845 u32 num_queues; 846 847 if (!vdev->config->get) { 848 dev_err(&vdev->dev, "%s failure: config access disabled\n", 849 __func__); 850 return -EINVAL; 851 } 852 853 /* We need to know how many queues before we allocate. */ 854 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; 855 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues); 856 857 num_targets = virtscsi_config_get(vdev, max_target) + 1; 858 859 shost = scsi_host_alloc(&virtscsi_host_template, 860 struct_size(vscsi, req_vqs, num_queues)); 861 if (!shost) 862 return -ENOMEM; 863 864 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 865 shost->sg_tablesize = sg_elems; 866 vscsi = shost_priv(shost); 867 vscsi->vdev = vdev; 868 vscsi->num_queues = num_queues; 869 vdev->priv = shost; 870 871 err = virtscsi_init(vdev, vscsi); 872 if (err) 873 goto virtscsi_init_failed; 874 875 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq); 876 877 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 878 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 879 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 880 881 /* LUNs > 256 are reported with format 1, so they go in the range 882 * 16640-32767. 883 */ 884 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 885 shost->max_id = num_targets; 886 shost->max_channel = 0; 887 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 888 shost->nr_hw_queues = num_queues; 889 890 #ifdef CONFIG_BLK_DEV_INTEGRITY 891 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 892 int host_prot; 893 894 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 895 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 896 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 897 898 scsi_host_set_prot(shost, host_prot); 899 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 900 } 901 #endif 902 903 err = scsi_add_host(shost, &vdev->dev); 904 if (err) 905 goto scsi_add_host_failed; 906 907 virtio_device_ready(vdev); 908 909 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 910 virtscsi_kick_event_all(vscsi); 911 912 scsi_scan_host(shost); 913 return 0; 914 915 scsi_add_host_failed: 916 vdev->config->del_vqs(vdev); 917 virtscsi_init_failed: 918 scsi_host_put(shost); 919 return err; 920 } 921 922 static void virtscsi_remove(struct virtio_device *vdev) 923 { 924 struct Scsi_Host *shost = virtio_scsi_host(vdev); 925 struct virtio_scsi *vscsi = shost_priv(shost); 926 927 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 928 virtscsi_cancel_event_work(vscsi); 929 930 scsi_remove_host(shost); 931 virtscsi_remove_vqs(vdev); 932 scsi_host_put(shost); 933 } 934 935 #ifdef CONFIG_PM_SLEEP 936 static int virtscsi_freeze(struct virtio_device *vdev) 937 { 938 virtscsi_remove_vqs(vdev); 939 return 0; 940 } 941 942 static int virtscsi_restore(struct virtio_device *vdev) 943 { 944 struct Scsi_Host *sh = virtio_scsi_host(vdev); 945 struct virtio_scsi *vscsi = shost_priv(sh); 946 int err; 947 948 err = virtscsi_init(vdev, vscsi); 949 if (err) 950 return err; 951 952 virtio_device_ready(vdev); 953 954 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 955 virtscsi_kick_event_all(vscsi); 956 957 return err; 958 } 959 #endif 960 961 static struct virtio_device_id id_table[] = { 962 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 963 { 0 }, 964 }; 965 966 static unsigned int features[] = { 967 VIRTIO_SCSI_F_HOTPLUG, 968 VIRTIO_SCSI_F_CHANGE, 969 #ifdef CONFIG_BLK_DEV_INTEGRITY 970 VIRTIO_SCSI_F_T10_PI, 971 #endif 972 }; 973 974 static struct virtio_driver virtio_scsi_driver = { 975 .feature_table = features, 976 .feature_table_size = ARRAY_SIZE(features), 977 .driver.name = KBUILD_MODNAME, 978 .driver.owner = THIS_MODULE, 979 .id_table = id_table, 980 .probe = virtscsi_probe, 981 #ifdef CONFIG_PM_SLEEP 982 .freeze = virtscsi_freeze, 983 .restore = virtscsi_restore, 984 #endif 985 .remove = virtscsi_remove, 986 }; 987 988 static int __init init(void) 989 { 990 int ret = -ENOMEM; 991 992 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); 993 if (!virtscsi_cmd_cache) { 994 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); 995 goto error; 996 } 997 998 999 virtscsi_cmd_pool = 1000 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, 1001 virtscsi_cmd_cache); 1002 if (!virtscsi_cmd_pool) { 1003 pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); 1004 goto error; 1005 } 1006 ret = register_virtio_driver(&virtio_scsi_driver); 1007 if (ret < 0) 1008 goto error; 1009 1010 return 0; 1011 1012 error: 1013 mempool_destroy(virtscsi_cmd_pool); 1014 virtscsi_cmd_pool = NULL; 1015 kmem_cache_destroy(virtscsi_cmd_cache); 1016 virtscsi_cmd_cache = NULL; 1017 return ret; 1018 } 1019 1020 static void __exit fini(void) 1021 { 1022 unregister_virtio_driver(&virtio_scsi_driver); 1023 mempool_destroy(virtscsi_cmd_pool); 1024 kmem_cache_destroy(virtscsi_cmd_cache); 1025 } 1026 module_init(init); 1027 module_exit(fini); 1028 1029 MODULE_DEVICE_TABLE(virtio, id_table); 1030 MODULE_DESCRIPTION("Virtio SCSI HBA driver"); 1031 MODULE_LICENSE("GPL"); 1032