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 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 if (lun == 0) { 288 scsi_scan_target(&shost->shost_gendev, 0, target, 289 SCAN_WILD_CARD, SCSI_SCAN_INITIAL); 290 } else { 291 scsi_add_device(shost, 0, target, lun); 292 } 293 break; 294 case VIRTIO_SCSI_EVT_RESET_REMOVED: 295 sdev = scsi_device_lookup(shost, 0, target, lun); 296 if (sdev) { 297 scsi_remove_device(sdev); 298 scsi_device_put(sdev); 299 } else { 300 pr_err("SCSI device %d 0 %d %d not found\n", 301 shost->host_no, target, lun); 302 } 303 break; 304 default: 305 pr_info("Unsupport virtio scsi event reason %x\n", event->reason); 306 } 307 } 308 309 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, 310 struct virtio_scsi_event *event) 311 { 312 struct scsi_device *sdev; 313 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 314 unsigned int target = event->lun[1]; 315 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 316 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255; 317 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8; 318 319 sdev = scsi_device_lookup(shost, 0, target, lun); 320 if (!sdev) { 321 pr_err("SCSI device %d 0 %d %d not found\n", 322 shost->host_no, target, lun); 323 return; 324 } 325 326 /* Handle "Parameters changed", "Mode parameters changed", and 327 "Capacity data has changed". */ 328 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) 329 scsi_rescan_device(&sdev->sdev_gendev); 330 331 scsi_device_put(sdev); 332 } 333 334 static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi) 335 { 336 struct scsi_device *sdev; 337 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 338 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 339 int result, inquiry_len, inq_result_len = 256; 340 char *inq_result = kmalloc(inq_result_len, GFP_KERNEL); 341 342 shost_for_each_device(sdev, shost) { 343 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 344 345 memset(scsi_cmd, 0, sizeof(scsi_cmd)); 346 scsi_cmd[0] = INQUIRY; 347 scsi_cmd[4] = (unsigned char) inquiry_len; 348 349 memset(inq_result, 0, inq_result_len); 350 351 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 352 inq_result, inquiry_len, NULL, 353 SD_TIMEOUT, SD_MAX_RETRIES, NULL); 354 355 if (result == 0 && inq_result[0] >> 5) { 356 /* PQ indicates the LUN is not attached */ 357 scsi_remove_device(sdev); 358 } else if (host_byte(result) == DID_BAD_TARGET) { 359 /* 360 * If all LUNs of a virtio-scsi device are unplugged 361 * it will respond with BAD TARGET on any INQUIRY 362 * command. 363 * Remove the device in this case as well. 364 */ 365 scsi_remove_device(sdev); 366 } 367 } 368 369 kfree(inq_result); 370 } 371 372 static void virtscsi_handle_event(struct work_struct *work) 373 { 374 struct virtio_scsi_event_node *event_node = 375 container_of(work, struct virtio_scsi_event_node, work); 376 struct virtio_scsi *vscsi = event_node->vscsi; 377 struct virtio_scsi_event *event = &event_node->event; 378 379 if (event->event & 380 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { 381 event->event &= ~cpu_to_virtio32(vscsi->vdev, 382 VIRTIO_SCSI_T_EVENTS_MISSED); 383 virtscsi_rescan_hotunplug(vscsi); 384 scsi_scan_host(virtio_scsi_host(vscsi->vdev)); 385 } 386 387 switch (virtio32_to_cpu(vscsi->vdev, event->event)) { 388 case VIRTIO_SCSI_T_NO_EVENT: 389 break; 390 case VIRTIO_SCSI_T_TRANSPORT_RESET: 391 virtscsi_handle_transport_reset(vscsi, event); 392 break; 393 case VIRTIO_SCSI_T_PARAM_CHANGE: 394 virtscsi_handle_param_change(vscsi, event); 395 break; 396 default: 397 pr_err("Unsupport virtio scsi event %x\n", event->event); 398 } 399 virtscsi_kick_event(vscsi, event_node); 400 } 401 402 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) 403 { 404 struct virtio_scsi_event_node *event_node = buf; 405 406 if (!vscsi->stop_events) 407 queue_work(system_freezable_wq, &event_node->work); 408 } 409 410 static void virtscsi_event_done(struct virtqueue *vq) 411 { 412 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 413 struct virtio_scsi *vscsi = shost_priv(sh); 414 415 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); 416 }; 417 418 static int __virtscsi_add_cmd(struct virtqueue *vq, 419 struct virtio_scsi_cmd *cmd, 420 size_t req_size, size_t resp_size) 421 { 422 struct scsi_cmnd *sc = cmd->sc; 423 struct scatterlist *sgs[6], req, resp; 424 struct sg_table *out, *in; 425 unsigned out_num = 0, in_num = 0; 426 427 out = in = NULL; 428 429 if (sc && sc->sc_data_direction != DMA_NONE) { 430 if (sc->sc_data_direction != DMA_FROM_DEVICE) 431 out = &sc->sdb.table; 432 if (sc->sc_data_direction != DMA_TO_DEVICE) 433 in = &sc->sdb.table; 434 } 435 436 /* Request header. */ 437 sg_init_one(&req, &cmd->req, req_size); 438 sgs[out_num++] = &req; 439 440 /* Data-out buffer. */ 441 if (out) { 442 /* Place WRITE protection SGLs before Data OUT payload */ 443 if (scsi_prot_sg_count(sc)) 444 sgs[out_num++] = scsi_prot_sglist(sc); 445 sgs[out_num++] = out->sgl; 446 } 447 448 /* Response header. */ 449 sg_init_one(&resp, &cmd->resp, resp_size); 450 sgs[out_num + in_num++] = &resp; 451 452 /* Data-in buffer */ 453 if (in) { 454 /* Place READ protection SGLs before Data IN payload */ 455 if (scsi_prot_sg_count(sc)) 456 sgs[out_num + in_num++] = scsi_prot_sglist(sc); 457 sgs[out_num + in_num++] = in->sgl; 458 } 459 460 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); 461 } 462 463 static void virtscsi_kick_vq(struct virtio_scsi_vq *vq) 464 { 465 bool needs_kick; 466 unsigned long flags; 467 468 spin_lock_irqsave(&vq->vq_lock, flags); 469 needs_kick = virtqueue_kick_prepare(vq->vq); 470 spin_unlock_irqrestore(&vq->vq_lock, flags); 471 472 if (needs_kick) 473 virtqueue_notify(vq->vq); 474 } 475 476 /** 477 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it 478 * @vq : the struct virtqueue we're talking about 479 * @cmd : command structure 480 * @req_size : size of the request buffer 481 * @resp_size : size of the response buffer 482 * @kick : whether to kick the virtqueue immediately 483 */ 484 static int virtscsi_add_cmd(struct virtio_scsi_vq *vq, 485 struct virtio_scsi_cmd *cmd, 486 size_t req_size, size_t resp_size, 487 bool kick) 488 { 489 unsigned long flags; 490 int err; 491 bool needs_kick = false; 492 493 spin_lock_irqsave(&vq->vq_lock, flags); 494 err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size); 495 if (!err && kick) 496 needs_kick = virtqueue_kick_prepare(vq->vq); 497 498 spin_unlock_irqrestore(&vq->vq_lock, flags); 499 500 if (needs_kick) 501 virtqueue_notify(vq->vq); 502 return err; 503 } 504 505 static void virtio_scsi_init_hdr(struct virtio_device *vdev, 506 struct virtio_scsi_cmd_req *cmd, 507 struct scsi_cmnd *sc) 508 { 509 cmd->lun[0] = 1; 510 cmd->lun[1] = sc->device->id; 511 cmd->lun[2] = (sc->device->lun >> 8) | 0x40; 512 cmd->lun[3] = sc->device->lun & 0xff; 513 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc); 514 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; 515 cmd->prio = 0; 516 cmd->crn = 0; 517 } 518 519 #ifdef CONFIG_BLK_DEV_INTEGRITY 520 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, 521 struct virtio_scsi_cmd_req_pi *cmd_pi, 522 struct scsi_cmnd *sc) 523 { 524 struct request *rq = sc->request; 525 struct blk_integrity *bi; 526 527 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc); 528 529 if (!rq || !scsi_prot_sg_count(sc)) 530 return; 531 532 bi = blk_get_integrity(rq->rq_disk); 533 534 if (sc->sc_data_direction == DMA_TO_DEVICE) 535 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, 536 bio_integrity_bytes(bi, 537 blk_rq_sectors(rq))); 538 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 539 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, 540 bio_integrity_bytes(bi, 541 blk_rq_sectors(rq))); 542 } 543 #endif 544 545 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, 546 struct scsi_cmnd *sc) 547 { 548 u32 tag = blk_mq_unique_tag(sc->request); 549 u16 hwq = blk_mq_unique_tag_to_hwq(tag); 550 551 return &vscsi->req_vqs[hwq]; 552 } 553 554 static int virtscsi_queuecommand(struct Scsi_Host *shost, 555 struct scsi_cmnd *sc) 556 { 557 struct virtio_scsi *vscsi = shost_priv(shost); 558 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc); 559 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 560 bool kick; 561 unsigned long flags; 562 int req_size; 563 int ret; 564 565 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 566 567 /* TODO: check feature bit and fail if unsupported? */ 568 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 569 570 dev_dbg(&sc->device->sdev_gendev, 571 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 572 573 cmd->sc = sc; 574 575 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 576 577 #ifdef CONFIG_BLK_DEV_INTEGRITY 578 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 579 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc); 580 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 581 req_size = sizeof(cmd->req.cmd_pi); 582 } else 583 #endif 584 { 585 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc); 586 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 587 req_size = sizeof(cmd->req.cmd); 588 } 589 590 kick = (sc->flags & SCMD_LAST) != 0; 591 ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick); 592 if (ret == -EIO) { 593 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET; 594 spin_lock_irqsave(&req_vq->vq_lock, flags); 595 virtscsi_complete_cmd(vscsi, cmd); 596 spin_unlock_irqrestore(&req_vq->vq_lock, flags); 597 } else if (ret != 0) { 598 return SCSI_MLQUEUE_HOST_BUSY; 599 } 600 return 0; 601 } 602 603 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 604 { 605 DECLARE_COMPLETION_ONSTACK(comp); 606 int ret = FAILED; 607 608 cmd->comp = ∁ 609 if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd, 610 sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0) 611 goto out; 612 613 wait_for_completion(&comp); 614 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 615 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 616 ret = SUCCESS; 617 618 /* 619 * The spec guarantees that all requests related to the TMF have 620 * been completed, but the callback might not have run yet if 621 * we're using independent interrupts (e.g. MSI). Poll the 622 * virtqueues once. 623 * 624 * In the abort case, sc->scsi_done will do nothing, because 625 * the block layer must have detected a timeout and as a result 626 * REQ_ATOM_COMPLETE has been set. 627 */ 628 virtscsi_poll_requests(vscsi); 629 630 out: 631 mempool_free(cmd, virtscsi_cmd_pool); 632 return ret; 633 } 634 635 static int virtscsi_device_reset(struct scsi_cmnd *sc) 636 { 637 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 638 struct virtio_scsi_cmd *cmd; 639 640 sdev_printk(KERN_INFO, sc->device, "device reset\n"); 641 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 642 if (!cmd) 643 return FAILED; 644 645 memset(cmd, 0, sizeof(*cmd)); 646 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 647 .type = VIRTIO_SCSI_T_TMF, 648 .subtype = cpu_to_virtio32(vscsi->vdev, 649 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET), 650 .lun[0] = 1, 651 .lun[1] = sc->device->id, 652 .lun[2] = (sc->device->lun >> 8) | 0x40, 653 .lun[3] = sc->device->lun & 0xff, 654 }; 655 return virtscsi_tmf(vscsi, cmd); 656 } 657 658 static int virtscsi_device_alloc(struct scsi_device *sdevice) 659 { 660 /* 661 * Passed through SCSI targets (e.g. with qemu's 'scsi-block') 662 * may have transfer limits which come from the host SCSI 663 * controller or something on the host side other than the 664 * target itself. 665 * 666 * To make this work properly, the hypervisor can adjust the 667 * target's VPD information to advertise these limits. But 668 * for that to work, the guest has to look at the VPD pages, 669 * which we won't do by default if it is an SPC-2 device, even 670 * if it does actually support it. 671 * 672 * So, set the blist to always try to read the VPD pages. 673 */ 674 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES; 675 676 return 0; 677 } 678 679 680 /** 681 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth 682 * @sdev: Virtscsi target whose queue depth to change 683 * @qdepth: New queue depth 684 */ 685 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) 686 { 687 struct Scsi_Host *shost = sdev->host; 688 int max_depth = shost->cmd_per_lun; 689 690 return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); 691 } 692 693 static int virtscsi_abort(struct scsi_cmnd *sc) 694 { 695 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 696 struct virtio_scsi_cmd *cmd; 697 698 scmd_printk(KERN_INFO, sc, "abort\n"); 699 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 700 if (!cmd) 701 return FAILED; 702 703 memset(cmd, 0, sizeof(*cmd)); 704 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 705 .type = VIRTIO_SCSI_T_TMF, 706 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 707 .lun[0] = 1, 708 .lun[1] = sc->device->id, 709 .lun[2] = (sc->device->lun >> 8) | 0x40, 710 .lun[3] = sc->device->lun & 0xff, 711 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc), 712 }; 713 return virtscsi_tmf(vscsi, cmd); 714 } 715 716 static int virtscsi_map_queues(struct Scsi_Host *shost) 717 { 718 struct virtio_scsi *vscsi = shost_priv(shost); 719 struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT]; 720 721 return blk_mq_virtio_map_queues(qmap, vscsi->vdev, 2); 722 } 723 724 static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq) 725 { 726 struct virtio_scsi *vscsi = shost_priv(shost); 727 728 virtscsi_kick_vq(&vscsi->req_vqs[hwq]); 729 } 730 731 /* 732 * The host guarantees to respond to each command, although I/O 733 * latencies might be higher than on bare metal. Reset the timer 734 * unconditionally to give the host a chance to perform EH. 735 */ 736 static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd) 737 { 738 return BLK_EH_RESET_TIMER; 739 } 740 741 static struct scsi_host_template virtscsi_host_template = { 742 .module = THIS_MODULE, 743 .name = "Virtio SCSI HBA", 744 .proc_name = "virtio_scsi", 745 .this_id = -1, 746 .cmd_size = sizeof(struct virtio_scsi_cmd), 747 .queuecommand = virtscsi_queuecommand, 748 .commit_rqs = virtscsi_commit_rqs, 749 .change_queue_depth = virtscsi_change_queue_depth, 750 .eh_abort_handler = virtscsi_abort, 751 .eh_device_reset_handler = virtscsi_device_reset, 752 .eh_timed_out = virtscsi_eh_timed_out, 753 .slave_alloc = virtscsi_device_alloc, 754 755 .dma_boundary = UINT_MAX, 756 .map_queues = virtscsi_map_queues, 757 .track_queue_depth = 1, 758 }; 759 760 #define virtscsi_config_get(vdev, fld) \ 761 ({ \ 762 __virtio_native_type(struct virtio_scsi_config, fld) __val; \ 763 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 764 __val; \ 765 }) 766 767 #define virtscsi_config_set(vdev, fld, val) \ 768 do { \ 769 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \ 770 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 771 } while(0) 772 773 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 774 struct virtqueue *vq) 775 { 776 spin_lock_init(&virtscsi_vq->vq_lock); 777 virtscsi_vq->vq = vq; 778 } 779 780 static void virtscsi_remove_vqs(struct virtio_device *vdev) 781 { 782 /* Stop all the virtqueues. */ 783 vdev->config->reset(vdev); 784 vdev->config->del_vqs(vdev); 785 } 786 787 static int virtscsi_init(struct virtio_device *vdev, 788 struct virtio_scsi *vscsi) 789 { 790 int err; 791 u32 i; 792 u32 num_vqs; 793 vq_callback_t **callbacks; 794 const char **names; 795 struct virtqueue **vqs; 796 struct irq_affinity desc = { .pre_vectors = 2 }; 797 798 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; 799 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL); 800 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *), 801 GFP_KERNEL); 802 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL); 803 804 if (!callbacks || !vqs || !names) { 805 err = -ENOMEM; 806 goto out; 807 } 808 809 callbacks[0] = virtscsi_ctrl_done; 810 callbacks[1] = virtscsi_event_done; 811 names[0] = "control"; 812 names[1] = "event"; 813 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { 814 callbacks[i] = virtscsi_req_done; 815 names[i] = "request"; 816 } 817 818 /* Discover virtqueues and write information to configuration. */ 819 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 820 if (err) 821 goto out; 822 823 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 824 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 825 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 826 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 827 vqs[i]); 828 829 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 830 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 831 832 err = 0; 833 834 out: 835 kfree(names); 836 kfree(callbacks); 837 kfree(vqs); 838 if (err) 839 virtscsi_remove_vqs(vdev); 840 return err; 841 } 842 843 static int virtscsi_probe(struct virtio_device *vdev) 844 { 845 struct Scsi_Host *shost; 846 struct virtio_scsi *vscsi; 847 int err; 848 u32 sg_elems, num_targets; 849 u32 cmd_per_lun; 850 u32 num_queues; 851 852 if (!vdev->config->get) { 853 dev_err(&vdev->dev, "%s failure: config access disabled\n", 854 __func__); 855 return -EINVAL; 856 } 857 858 /* We need to know how many queues before we allocate. */ 859 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; 860 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues); 861 862 num_targets = virtscsi_config_get(vdev, max_target) + 1; 863 864 shost = scsi_host_alloc(&virtscsi_host_template, 865 struct_size(vscsi, req_vqs, num_queues)); 866 if (!shost) 867 return -ENOMEM; 868 869 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 870 shost->sg_tablesize = sg_elems; 871 vscsi = shost_priv(shost); 872 vscsi->vdev = vdev; 873 vscsi->num_queues = num_queues; 874 vdev->priv = shost; 875 876 err = virtscsi_init(vdev, vscsi); 877 if (err) 878 goto virtscsi_init_failed; 879 880 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq); 881 882 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 883 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 884 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 885 886 /* LUNs > 256 are reported with format 1, so they go in the range 887 * 16640-32767. 888 */ 889 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 890 shost->max_id = num_targets; 891 shost->max_channel = 0; 892 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 893 shost->nr_hw_queues = num_queues; 894 895 #ifdef CONFIG_BLK_DEV_INTEGRITY 896 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 897 int host_prot; 898 899 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 900 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 901 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 902 903 scsi_host_set_prot(shost, host_prot); 904 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 905 } 906 #endif 907 908 err = scsi_add_host(shost, &vdev->dev); 909 if (err) 910 goto scsi_add_host_failed; 911 912 virtio_device_ready(vdev); 913 914 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 915 virtscsi_kick_event_all(vscsi); 916 917 scsi_scan_host(shost); 918 return 0; 919 920 scsi_add_host_failed: 921 vdev->config->del_vqs(vdev); 922 virtscsi_init_failed: 923 scsi_host_put(shost); 924 return err; 925 } 926 927 static void virtscsi_remove(struct virtio_device *vdev) 928 { 929 struct Scsi_Host *shost = virtio_scsi_host(vdev); 930 struct virtio_scsi *vscsi = shost_priv(shost); 931 932 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 933 virtscsi_cancel_event_work(vscsi); 934 935 scsi_remove_host(shost); 936 virtscsi_remove_vqs(vdev); 937 scsi_host_put(shost); 938 } 939 940 #ifdef CONFIG_PM_SLEEP 941 static int virtscsi_freeze(struct virtio_device *vdev) 942 { 943 virtscsi_remove_vqs(vdev); 944 return 0; 945 } 946 947 static int virtscsi_restore(struct virtio_device *vdev) 948 { 949 struct Scsi_Host *sh = virtio_scsi_host(vdev); 950 struct virtio_scsi *vscsi = shost_priv(sh); 951 int err; 952 953 err = virtscsi_init(vdev, vscsi); 954 if (err) 955 return err; 956 957 virtio_device_ready(vdev); 958 959 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 960 virtscsi_kick_event_all(vscsi); 961 962 return err; 963 } 964 #endif 965 966 static struct virtio_device_id id_table[] = { 967 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 968 { 0 }, 969 }; 970 971 static unsigned int features[] = { 972 VIRTIO_SCSI_F_HOTPLUG, 973 VIRTIO_SCSI_F_CHANGE, 974 #ifdef CONFIG_BLK_DEV_INTEGRITY 975 VIRTIO_SCSI_F_T10_PI, 976 #endif 977 }; 978 979 static struct virtio_driver virtio_scsi_driver = { 980 .feature_table = features, 981 .feature_table_size = ARRAY_SIZE(features), 982 .driver.name = KBUILD_MODNAME, 983 .driver.owner = THIS_MODULE, 984 .id_table = id_table, 985 .probe = virtscsi_probe, 986 #ifdef CONFIG_PM_SLEEP 987 .freeze = virtscsi_freeze, 988 .restore = virtscsi_restore, 989 #endif 990 .remove = virtscsi_remove, 991 }; 992 993 static int __init init(void) 994 { 995 int ret = -ENOMEM; 996 997 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); 998 if (!virtscsi_cmd_cache) { 999 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); 1000 goto error; 1001 } 1002 1003 1004 virtscsi_cmd_pool = 1005 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, 1006 virtscsi_cmd_cache); 1007 if (!virtscsi_cmd_pool) { 1008 pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); 1009 goto error; 1010 } 1011 ret = register_virtio_driver(&virtio_scsi_driver); 1012 if (ret < 0) 1013 goto error; 1014 1015 return 0; 1016 1017 error: 1018 mempool_destroy(virtscsi_cmd_pool); 1019 virtscsi_cmd_pool = NULL; 1020 kmem_cache_destroy(virtscsi_cmd_cache); 1021 virtscsi_cmd_cache = NULL; 1022 return ret; 1023 } 1024 1025 static void __exit fini(void) 1026 { 1027 unregister_virtio_driver(&virtio_scsi_driver); 1028 mempool_destroy(virtscsi_cmd_pool); 1029 kmem_cache_destroy(virtscsi_cmd_cache); 1030 } 1031 module_init(init); 1032 module_exit(fini); 1033 1034 MODULE_DEVICE_TABLE(virtio, id_table); 1035 MODULE_DESCRIPTION("Virtio SCSI HBA driver"); 1036 MODULE_LICENSE("GPL"); 1037