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 fallthrough; 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 set_status_byte(sc, SAM_STAT_CHECK_CONDITION); 165 } 166 167 sc->scsi_done(sc); 168 } 169 170 static void virtscsi_vq_done(struct virtio_scsi *vscsi, 171 struct virtio_scsi_vq *virtscsi_vq, 172 void (*fn)(struct virtio_scsi *vscsi, void *buf)) 173 { 174 void *buf; 175 unsigned int len; 176 unsigned long flags; 177 struct virtqueue *vq = virtscsi_vq->vq; 178 179 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); 180 do { 181 virtqueue_disable_cb(vq); 182 while ((buf = virtqueue_get_buf(vq, &len)) != NULL) 183 fn(vscsi, buf); 184 185 if (unlikely(virtqueue_is_broken(vq))) 186 break; 187 } while (!virtqueue_enable_cb(vq)); 188 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); 189 } 190 191 static void virtscsi_req_done(struct virtqueue *vq) 192 { 193 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 194 struct virtio_scsi *vscsi = shost_priv(sh); 195 int index = vq->index - VIRTIO_SCSI_VQ_BASE; 196 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index]; 197 198 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd); 199 }; 200 201 static void virtscsi_poll_requests(struct virtio_scsi *vscsi) 202 { 203 int i, num_vqs; 204 205 num_vqs = vscsi->num_queues; 206 for (i = 0; i < num_vqs; i++) 207 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i], 208 virtscsi_complete_cmd); 209 } 210 211 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf) 212 { 213 struct virtio_scsi_cmd *cmd = buf; 214 215 if (cmd->comp) 216 complete(cmd->comp); 217 } 218 219 static void virtscsi_ctrl_done(struct virtqueue *vq) 220 { 221 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 222 struct virtio_scsi *vscsi = shost_priv(sh); 223 224 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free); 225 }; 226 227 static void virtscsi_handle_event(struct work_struct *work); 228 229 static int virtscsi_kick_event(struct virtio_scsi *vscsi, 230 struct virtio_scsi_event_node *event_node) 231 { 232 int err; 233 struct scatterlist sg; 234 unsigned long flags; 235 236 INIT_WORK(&event_node->work, virtscsi_handle_event); 237 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event)); 238 239 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags); 240 241 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node, 242 GFP_ATOMIC); 243 if (!err) 244 virtqueue_kick(vscsi->event_vq.vq); 245 246 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags); 247 248 return err; 249 } 250 251 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi) 252 { 253 int i; 254 255 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) { 256 vscsi->event_list[i].vscsi = vscsi; 257 virtscsi_kick_event(vscsi, &vscsi->event_list[i]); 258 } 259 260 return 0; 261 } 262 263 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi) 264 { 265 int i; 266 267 /* Stop scheduling work before calling cancel_work_sync. */ 268 spin_lock_irq(&vscsi->event_vq.vq_lock); 269 vscsi->stop_events = true; 270 spin_unlock_irq(&vscsi->event_vq.vq_lock); 271 272 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) 273 cancel_work_sync(&vscsi->event_list[i].work); 274 } 275 276 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, 277 struct virtio_scsi_event *event) 278 { 279 struct scsi_device *sdev; 280 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 281 unsigned int target = event->lun[1]; 282 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 283 284 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) { 285 case VIRTIO_SCSI_EVT_RESET_RESCAN: 286 if (lun == 0) { 287 scsi_scan_target(&shost->shost_gendev, 0, target, 288 SCAN_WILD_CARD, SCSI_SCAN_INITIAL); 289 } else { 290 scsi_add_device(shost, 0, target, lun); 291 } 292 break; 293 case VIRTIO_SCSI_EVT_RESET_REMOVED: 294 sdev = scsi_device_lookup(shost, 0, target, lun); 295 if (sdev) { 296 scsi_remove_device(sdev); 297 scsi_device_put(sdev); 298 } else { 299 pr_err("SCSI device %d 0 %d %d not found\n", 300 shost->host_no, target, lun); 301 } 302 break; 303 default: 304 pr_info("Unsupport virtio scsi event reason %x\n", event->reason); 305 } 306 } 307 308 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, 309 struct virtio_scsi_event *event) 310 { 311 struct scsi_device *sdev; 312 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 313 unsigned int target = event->lun[1]; 314 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 315 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255; 316 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8; 317 318 sdev = scsi_device_lookup(shost, 0, target, lun); 319 if (!sdev) { 320 pr_err("SCSI device %d 0 %d %d not found\n", 321 shost->host_no, target, lun); 322 return; 323 } 324 325 /* Handle "Parameters changed", "Mode parameters changed", and 326 "Capacity data has changed". */ 327 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) 328 scsi_rescan_device(&sdev->sdev_gendev); 329 330 scsi_device_put(sdev); 331 } 332 333 static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi) 334 { 335 struct scsi_device *sdev; 336 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 337 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 338 int result, inquiry_len, inq_result_len = 256; 339 char *inq_result = kmalloc(inq_result_len, GFP_KERNEL); 340 341 shost_for_each_device(sdev, shost) { 342 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 343 344 memset(scsi_cmd, 0, sizeof(scsi_cmd)); 345 scsi_cmd[0] = INQUIRY; 346 scsi_cmd[4] = (unsigned char) inquiry_len; 347 348 memset(inq_result, 0, inq_result_len); 349 350 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 351 inq_result, inquiry_len, NULL, 352 SD_TIMEOUT, SD_MAX_RETRIES, NULL); 353 354 if (result == 0 && inq_result[0] >> 5) { 355 /* PQ indicates the LUN is not attached */ 356 scsi_remove_device(sdev); 357 } else if (result > 0 && host_byte(result) == DID_BAD_TARGET) { 358 /* 359 * If all LUNs of a virtio-scsi device are unplugged 360 * it will respond with BAD TARGET on any INQUIRY 361 * command. 362 * Remove the device in this case as well. 363 */ 364 scsi_remove_device(sdev); 365 } 366 } 367 368 kfree(inq_result); 369 } 370 371 static void virtscsi_handle_event(struct work_struct *work) 372 { 373 struct virtio_scsi_event_node *event_node = 374 container_of(work, struct virtio_scsi_event_node, work); 375 struct virtio_scsi *vscsi = event_node->vscsi; 376 struct virtio_scsi_event *event = &event_node->event; 377 378 if (event->event & 379 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { 380 event->event &= ~cpu_to_virtio32(vscsi->vdev, 381 VIRTIO_SCSI_T_EVENTS_MISSED); 382 virtscsi_rescan_hotunplug(vscsi); 383 scsi_scan_host(virtio_scsi_host(vscsi->vdev)); 384 } 385 386 switch (virtio32_to_cpu(vscsi->vdev, event->event)) { 387 case VIRTIO_SCSI_T_NO_EVENT: 388 break; 389 case VIRTIO_SCSI_T_TRANSPORT_RESET: 390 virtscsi_handle_transport_reset(vscsi, event); 391 break; 392 case VIRTIO_SCSI_T_PARAM_CHANGE: 393 virtscsi_handle_param_change(vscsi, event); 394 break; 395 default: 396 pr_err("Unsupport virtio scsi event %x\n", event->event); 397 } 398 virtscsi_kick_event(vscsi, event_node); 399 } 400 401 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) 402 { 403 struct virtio_scsi_event_node *event_node = buf; 404 405 if (!vscsi->stop_events) 406 queue_work(system_freezable_wq, &event_node->work); 407 } 408 409 static void virtscsi_event_done(struct virtqueue *vq) 410 { 411 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 412 struct virtio_scsi *vscsi = shost_priv(sh); 413 414 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); 415 }; 416 417 static int __virtscsi_add_cmd(struct virtqueue *vq, 418 struct virtio_scsi_cmd *cmd, 419 size_t req_size, size_t resp_size) 420 { 421 struct scsi_cmnd *sc = cmd->sc; 422 struct scatterlist *sgs[6], req, resp; 423 struct sg_table *out, *in; 424 unsigned out_num = 0, in_num = 0; 425 426 out = in = NULL; 427 428 if (sc && sc->sc_data_direction != DMA_NONE) { 429 if (sc->sc_data_direction != DMA_FROM_DEVICE) 430 out = &sc->sdb.table; 431 if (sc->sc_data_direction != DMA_TO_DEVICE) 432 in = &sc->sdb.table; 433 } 434 435 /* Request header. */ 436 sg_init_one(&req, &cmd->req, req_size); 437 sgs[out_num++] = &req; 438 439 /* Data-out buffer. */ 440 if (out) { 441 /* Place WRITE protection SGLs before Data OUT payload */ 442 if (scsi_prot_sg_count(sc)) 443 sgs[out_num++] = scsi_prot_sglist(sc); 444 sgs[out_num++] = out->sgl; 445 } 446 447 /* Response header. */ 448 sg_init_one(&resp, &cmd->resp, resp_size); 449 sgs[out_num + in_num++] = &resp; 450 451 /* Data-in buffer */ 452 if (in) { 453 /* Place READ protection SGLs before Data IN payload */ 454 if (scsi_prot_sg_count(sc)) 455 sgs[out_num + in_num++] = scsi_prot_sglist(sc); 456 sgs[out_num + in_num++] = in->sgl; 457 } 458 459 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); 460 } 461 462 static void virtscsi_kick_vq(struct virtio_scsi_vq *vq) 463 { 464 bool needs_kick; 465 unsigned long flags; 466 467 spin_lock_irqsave(&vq->vq_lock, flags); 468 needs_kick = virtqueue_kick_prepare(vq->vq); 469 spin_unlock_irqrestore(&vq->vq_lock, flags); 470 471 if (needs_kick) 472 virtqueue_notify(vq->vq); 473 } 474 475 /** 476 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it 477 * @vq : the struct virtqueue we're talking about 478 * @cmd : command structure 479 * @req_size : size of the request buffer 480 * @resp_size : size of the response buffer 481 * @kick : whether to kick the virtqueue immediately 482 */ 483 static int virtscsi_add_cmd(struct virtio_scsi_vq *vq, 484 struct virtio_scsi_cmd *cmd, 485 size_t req_size, size_t resp_size, 486 bool kick) 487 { 488 unsigned long flags; 489 int err; 490 bool needs_kick = false; 491 492 spin_lock_irqsave(&vq->vq_lock, flags); 493 err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size); 494 if (!err && kick) 495 needs_kick = virtqueue_kick_prepare(vq->vq); 496 497 spin_unlock_irqrestore(&vq->vq_lock, flags); 498 499 if (needs_kick) 500 virtqueue_notify(vq->vq); 501 return err; 502 } 503 504 static void virtio_scsi_init_hdr(struct virtio_device *vdev, 505 struct virtio_scsi_cmd_req *cmd, 506 struct scsi_cmnd *sc) 507 { 508 cmd->lun[0] = 1; 509 cmd->lun[1] = sc->device->id; 510 cmd->lun[2] = (sc->device->lun >> 8) | 0x40; 511 cmd->lun[3] = sc->device->lun & 0xff; 512 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc); 513 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; 514 cmd->prio = 0; 515 cmd->crn = 0; 516 } 517 518 #ifdef CONFIG_BLK_DEV_INTEGRITY 519 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, 520 struct virtio_scsi_cmd_req_pi *cmd_pi, 521 struct scsi_cmnd *sc) 522 { 523 struct request *rq = sc->request; 524 struct blk_integrity *bi; 525 526 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc); 527 528 if (!rq || !scsi_prot_sg_count(sc)) 529 return; 530 531 bi = blk_get_integrity(rq->rq_disk); 532 533 if (sc->sc_data_direction == DMA_TO_DEVICE) 534 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, 535 bio_integrity_bytes(bi, 536 blk_rq_sectors(rq))); 537 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 538 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, 539 bio_integrity_bytes(bi, 540 blk_rq_sectors(rq))); 541 } 542 #endif 543 544 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, 545 struct scsi_cmnd *sc) 546 { 547 u32 tag = blk_mq_unique_tag(sc->request); 548 u16 hwq = blk_mq_unique_tag_to_hwq(tag); 549 550 return &vscsi->req_vqs[hwq]; 551 } 552 553 static int virtscsi_queuecommand(struct Scsi_Host *shost, 554 struct scsi_cmnd *sc) 555 { 556 struct virtio_scsi *vscsi = shost_priv(shost); 557 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc); 558 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 559 bool kick; 560 unsigned long flags; 561 int req_size; 562 int ret; 563 564 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 565 566 /* TODO: check feature bit and fail if unsupported? */ 567 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 568 569 dev_dbg(&sc->device->sdev_gendev, 570 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 571 572 cmd->sc = sc; 573 574 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 575 576 #ifdef CONFIG_BLK_DEV_INTEGRITY 577 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 578 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc); 579 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 580 req_size = sizeof(cmd->req.cmd_pi); 581 } else 582 #endif 583 { 584 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc); 585 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 586 req_size = sizeof(cmd->req.cmd); 587 } 588 589 kick = (sc->flags & SCMD_LAST) != 0; 590 ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick); 591 if (ret == -EIO) { 592 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET; 593 spin_lock_irqsave(&req_vq->vq_lock, flags); 594 virtscsi_complete_cmd(vscsi, cmd); 595 spin_unlock_irqrestore(&req_vq->vq_lock, flags); 596 } else if (ret != 0) { 597 return SCSI_MLQUEUE_HOST_BUSY; 598 } 599 return 0; 600 } 601 602 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 603 { 604 DECLARE_COMPLETION_ONSTACK(comp); 605 int ret = FAILED; 606 607 cmd->comp = ∁ 608 if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd, 609 sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0) 610 goto out; 611 612 wait_for_completion(&comp); 613 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 614 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 615 ret = SUCCESS; 616 617 /* 618 * The spec guarantees that all requests related to the TMF have 619 * been completed, but the callback might not have run yet if 620 * we're using independent interrupts (e.g. MSI). Poll the 621 * virtqueues once. 622 * 623 * In the abort case, sc->scsi_done will do nothing, because 624 * the block layer must have detected a timeout and as a result 625 * REQ_ATOM_COMPLETE has been set. 626 */ 627 virtscsi_poll_requests(vscsi); 628 629 out: 630 mempool_free(cmd, virtscsi_cmd_pool); 631 return ret; 632 } 633 634 static int virtscsi_device_reset(struct scsi_cmnd *sc) 635 { 636 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 637 struct virtio_scsi_cmd *cmd; 638 639 sdev_printk(KERN_INFO, sc->device, "device reset\n"); 640 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 641 if (!cmd) 642 return FAILED; 643 644 memset(cmd, 0, sizeof(*cmd)); 645 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 646 .type = VIRTIO_SCSI_T_TMF, 647 .subtype = cpu_to_virtio32(vscsi->vdev, 648 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET), 649 .lun[0] = 1, 650 .lun[1] = sc->device->id, 651 .lun[2] = (sc->device->lun >> 8) | 0x40, 652 .lun[3] = sc->device->lun & 0xff, 653 }; 654 return virtscsi_tmf(vscsi, cmd); 655 } 656 657 static int virtscsi_device_alloc(struct scsi_device *sdevice) 658 { 659 /* 660 * Passed through SCSI targets (e.g. with qemu's 'scsi-block') 661 * may have transfer limits which come from the host SCSI 662 * controller or something on the host side other than the 663 * target itself. 664 * 665 * To make this work properly, the hypervisor can adjust the 666 * target's VPD information to advertise these limits. But 667 * for that to work, the guest has to look at the VPD pages, 668 * which we won't do by default if it is an SPC-2 device, even 669 * if it does actually support it. 670 * 671 * So, set the blist to always try to read the VPD pages. 672 */ 673 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES; 674 675 return 0; 676 } 677 678 679 /** 680 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth 681 * @sdev: Virtscsi target whose queue depth to change 682 * @qdepth: New queue depth 683 */ 684 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) 685 { 686 struct Scsi_Host *shost = sdev->host; 687 int max_depth = shost->cmd_per_lun; 688 689 return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); 690 } 691 692 static int virtscsi_abort(struct scsi_cmnd *sc) 693 { 694 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 695 struct virtio_scsi_cmd *cmd; 696 697 scmd_printk(KERN_INFO, sc, "abort\n"); 698 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 699 if (!cmd) 700 return FAILED; 701 702 memset(cmd, 0, sizeof(*cmd)); 703 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 704 .type = VIRTIO_SCSI_T_TMF, 705 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 706 .lun[0] = 1, 707 .lun[1] = sc->device->id, 708 .lun[2] = (sc->device->lun >> 8) | 0x40, 709 .lun[3] = sc->device->lun & 0xff, 710 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc), 711 }; 712 return virtscsi_tmf(vscsi, cmd); 713 } 714 715 static int virtscsi_map_queues(struct Scsi_Host *shost) 716 { 717 struct virtio_scsi *vscsi = shost_priv(shost); 718 struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT]; 719 720 return blk_mq_virtio_map_queues(qmap, vscsi->vdev, 2); 721 } 722 723 static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq) 724 { 725 struct virtio_scsi *vscsi = shost_priv(shost); 726 727 virtscsi_kick_vq(&vscsi->req_vqs[hwq]); 728 } 729 730 /* 731 * The host guarantees to respond to each command, although I/O 732 * latencies might be higher than on bare metal. Reset the timer 733 * unconditionally to give the host a chance to perform EH. 734 */ 735 static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd) 736 { 737 return BLK_EH_RESET_TIMER; 738 } 739 740 static struct scsi_host_template virtscsi_host_template = { 741 .module = THIS_MODULE, 742 .name = "Virtio SCSI HBA", 743 .proc_name = "virtio_scsi", 744 .this_id = -1, 745 .cmd_size = sizeof(struct virtio_scsi_cmd), 746 .queuecommand = virtscsi_queuecommand, 747 .commit_rqs = virtscsi_commit_rqs, 748 .change_queue_depth = virtscsi_change_queue_depth, 749 .eh_abort_handler = virtscsi_abort, 750 .eh_device_reset_handler = virtscsi_device_reset, 751 .eh_timed_out = virtscsi_eh_timed_out, 752 .slave_alloc = virtscsi_device_alloc, 753 754 .dma_boundary = UINT_MAX, 755 .map_queues = virtscsi_map_queues, 756 .track_queue_depth = 1, 757 }; 758 759 #define virtscsi_config_get(vdev, fld) \ 760 ({ \ 761 __virtio_native_type(struct virtio_scsi_config, fld) __val; \ 762 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 763 __val; \ 764 }) 765 766 #define virtscsi_config_set(vdev, fld, val) \ 767 do { \ 768 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \ 769 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 770 } while(0) 771 772 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 773 struct virtqueue *vq) 774 { 775 spin_lock_init(&virtscsi_vq->vq_lock); 776 virtscsi_vq->vq = vq; 777 } 778 779 static void virtscsi_remove_vqs(struct virtio_device *vdev) 780 { 781 /* Stop all the virtqueues. */ 782 vdev->config->reset(vdev); 783 vdev->config->del_vqs(vdev); 784 } 785 786 static int virtscsi_init(struct virtio_device *vdev, 787 struct virtio_scsi *vscsi) 788 { 789 int err; 790 u32 i; 791 u32 num_vqs; 792 vq_callback_t **callbacks; 793 const char **names; 794 struct virtqueue **vqs; 795 struct irq_affinity desc = { .pre_vectors = 2 }; 796 797 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; 798 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL); 799 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *), 800 GFP_KERNEL); 801 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL); 802 803 if (!callbacks || !vqs || !names) { 804 err = -ENOMEM; 805 goto out; 806 } 807 808 callbacks[0] = virtscsi_ctrl_done; 809 callbacks[1] = virtscsi_event_done; 810 names[0] = "control"; 811 names[1] = "event"; 812 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { 813 callbacks[i] = virtscsi_req_done; 814 names[i] = "request"; 815 } 816 817 /* Discover virtqueues and write information to configuration. */ 818 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 819 if (err) 820 goto out; 821 822 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 823 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 824 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 825 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 826 vqs[i]); 827 828 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 829 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 830 831 err = 0; 832 833 out: 834 kfree(names); 835 kfree(callbacks); 836 kfree(vqs); 837 if (err) 838 virtscsi_remove_vqs(vdev); 839 return err; 840 } 841 842 static int virtscsi_probe(struct virtio_device *vdev) 843 { 844 struct Scsi_Host *shost; 845 struct virtio_scsi *vscsi; 846 int err; 847 u32 sg_elems, num_targets; 848 u32 cmd_per_lun; 849 u32 num_queues; 850 851 if (!vdev->config->get) { 852 dev_err(&vdev->dev, "%s failure: config access disabled\n", 853 __func__); 854 return -EINVAL; 855 } 856 857 /* We need to know how many queues before we allocate. */ 858 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; 859 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues); 860 861 num_targets = virtscsi_config_get(vdev, max_target) + 1; 862 863 shost = scsi_host_alloc(&virtscsi_host_template, 864 struct_size(vscsi, req_vqs, num_queues)); 865 if (!shost) 866 return -ENOMEM; 867 868 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 869 shost->sg_tablesize = sg_elems; 870 vscsi = shost_priv(shost); 871 vscsi->vdev = vdev; 872 vscsi->num_queues = num_queues; 873 vdev->priv = shost; 874 875 err = virtscsi_init(vdev, vscsi); 876 if (err) 877 goto virtscsi_init_failed; 878 879 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq); 880 881 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 882 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 883 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 884 885 /* LUNs > 256 are reported with format 1, so they go in the range 886 * 16640-32767. 887 */ 888 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 889 shost->max_id = num_targets; 890 shost->max_channel = 0; 891 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 892 shost->nr_hw_queues = num_queues; 893 894 #ifdef CONFIG_BLK_DEV_INTEGRITY 895 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 896 int host_prot; 897 898 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 899 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 900 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 901 902 scsi_host_set_prot(shost, host_prot); 903 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 904 } 905 #endif 906 907 err = scsi_add_host(shost, &vdev->dev); 908 if (err) 909 goto scsi_add_host_failed; 910 911 virtio_device_ready(vdev); 912 913 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 914 virtscsi_kick_event_all(vscsi); 915 916 scsi_scan_host(shost); 917 return 0; 918 919 scsi_add_host_failed: 920 vdev->config->del_vqs(vdev); 921 virtscsi_init_failed: 922 scsi_host_put(shost); 923 return err; 924 } 925 926 static void virtscsi_remove(struct virtio_device *vdev) 927 { 928 struct Scsi_Host *shost = virtio_scsi_host(vdev); 929 struct virtio_scsi *vscsi = shost_priv(shost); 930 931 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 932 virtscsi_cancel_event_work(vscsi); 933 934 scsi_remove_host(shost); 935 virtscsi_remove_vqs(vdev); 936 scsi_host_put(shost); 937 } 938 939 #ifdef CONFIG_PM_SLEEP 940 static int virtscsi_freeze(struct virtio_device *vdev) 941 { 942 virtscsi_remove_vqs(vdev); 943 return 0; 944 } 945 946 static int virtscsi_restore(struct virtio_device *vdev) 947 { 948 struct Scsi_Host *sh = virtio_scsi_host(vdev); 949 struct virtio_scsi *vscsi = shost_priv(sh); 950 int err; 951 952 err = virtscsi_init(vdev, vscsi); 953 if (err) 954 return err; 955 956 virtio_device_ready(vdev); 957 958 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 959 virtscsi_kick_event_all(vscsi); 960 961 return err; 962 } 963 #endif 964 965 static struct virtio_device_id id_table[] = { 966 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 967 { 0 }, 968 }; 969 970 static unsigned int features[] = { 971 VIRTIO_SCSI_F_HOTPLUG, 972 VIRTIO_SCSI_F_CHANGE, 973 #ifdef CONFIG_BLK_DEV_INTEGRITY 974 VIRTIO_SCSI_F_T10_PI, 975 #endif 976 }; 977 978 static struct virtio_driver virtio_scsi_driver = { 979 .feature_table = features, 980 .feature_table_size = ARRAY_SIZE(features), 981 .driver.name = KBUILD_MODNAME, 982 .driver.owner = THIS_MODULE, 983 .id_table = id_table, 984 .probe = virtscsi_probe, 985 #ifdef CONFIG_PM_SLEEP 986 .freeze = virtscsi_freeze, 987 .restore = virtscsi_restore, 988 #endif 989 .remove = virtscsi_remove, 990 }; 991 992 static int __init init(void) 993 { 994 int ret = -ENOMEM; 995 996 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); 997 if (!virtscsi_cmd_cache) { 998 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); 999 goto error; 1000 } 1001 1002 1003 virtscsi_cmd_pool = 1004 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, 1005 virtscsi_cmd_cache); 1006 if (!virtscsi_cmd_pool) { 1007 pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); 1008 goto error; 1009 } 1010 ret = register_virtio_driver(&virtio_scsi_driver); 1011 if (ret < 0) 1012 goto error; 1013 1014 return 0; 1015 1016 error: 1017 mempool_destroy(virtscsi_cmd_pool); 1018 virtscsi_cmd_pool = NULL; 1019 kmem_cache_destroy(virtscsi_cmd_cache); 1020 virtscsi_cmd_cache = NULL; 1021 return ret; 1022 } 1023 1024 static void __exit fini(void) 1025 { 1026 unregister_virtio_driver(&virtio_scsi_driver); 1027 mempool_destroy(virtscsi_cmd_pool); 1028 kmem_cache_destroy(virtscsi_cmd_cache); 1029 } 1030 module_init(init); 1031 module_exit(fini); 1032 1033 MODULE_DEVICE_TABLE(virtio, id_table); 1034 MODULE_DESCRIPTION("Virtio SCSI HBA driver"); 1035 MODULE_LICENSE("GPL"); 1036