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 <linux/blk-integrity.h> 26 #include <scsi/scsi_host.h> 27 #include <scsi/scsi_device.h> 28 #include <scsi/scsi_cmnd.h> 29 #include <scsi/scsi_tcq.h> 30 #include <scsi/scsi_devinfo.h> 31 #include <linux/seqlock.h> 32 #include <linux/blk-mq-virtio.h> 33 34 #include "sd.h" 35 36 #define VIRTIO_SCSI_MEMPOOL_SZ 64 37 #define VIRTIO_SCSI_EVENT_LEN 8 38 #define VIRTIO_SCSI_VQ_BASE 2 39 40 /* Command queue element */ 41 struct virtio_scsi_cmd { 42 struct scsi_cmnd *sc; 43 struct completion *comp; 44 union { 45 struct virtio_scsi_cmd_req cmd; 46 struct virtio_scsi_cmd_req_pi cmd_pi; 47 struct virtio_scsi_ctrl_tmf_req tmf; 48 struct virtio_scsi_ctrl_an_req an; 49 } req; 50 union { 51 struct virtio_scsi_cmd_resp cmd; 52 struct virtio_scsi_ctrl_tmf_resp tmf; 53 struct virtio_scsi_ctrl_an_resp an; 54 struct virtio_scsi_event evt; 55 } resp; 56 } ____cacheline_aligned_in_smp; 57 58 struct virtio_scsi_event_node { 59 struct virtio_scsi *vscsi; 60 struct virtio_scsi_event event; 61 struct work_struct work; 62 }; 63 64 struct virtio_scsi_vq { 65 /* Protects vq */ 66 spinlock_t vq_lock; 67 68 struct virtqueue *vq; 69 }; 70 71 /* Driver instance state */ 72 struct virtio_scsi { 73 struct virtio_device *vdev; 74 75 /* Get some buffers ready for event vq */ 76 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN]; 77 78 u32 num_queues; 79 80 struct hlist_node node; 81 82 /* Protected by event_vq lock */ 83 bool stop_events; 84 85 struct virtio_scsi_vq ctrl_vq; 86 struct virtio_scsi_vq event_vq; 87 struct virtio_scsi_vq req_vqs[]; 88 }; 89 90 static struct kmem_cache *virtscsi_cmd_cache; 91 static mempool_t *virtscsi_cmd_pool; 92 93 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev) 94 { 95 return vdev->priv; 96 } 97 98 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid) 99 { 100 if (resid) 101 scsi_set_resid(sc, min(resid, scsi_bufflen(sc))); 102 } 103 104 /* 105 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done 106 * 107 * Called with vq_lock held. 108 */ 109 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf) 110 { 111 struct virtio_scsi_cmd *cmd = buf; 112 struct scsi_cmnd *sc = cmd->sc; 113 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd; 114 115 dev_dbg(&sc->device->sdev_gendev, 116 "cmd %p response %u status %#02x sense_len %u\n", 117 sc, resp->response, resp->status, resp->sense_len); 118 119 sc->result = resp->status; 120 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid)); 121 switch (resp->response) { 122 case VIRTIO_SCSI_S_OK: 123 set_host_byte(sc, DID_OK); 124 break; 125 case VIRTIO_SCSI_S_OVERRUN: 126 set_host_byte(sc, DID_ERROR); 127 break; 128 case VIRTIO_SCSI_S_ABORTED: 129 set_host_byte(sc, DID_ABORT); 130 break; 131 case VIRTIO_SCSI_S_BAD_TARGET: 132 set_host_byte(sc, DID_BAD_TARGET); 133 break; 134 case VIRTIO_SCSI_S_RESET: 135 set_host_byte(sc, DID_RESET); 136 break; 137 case VIRTIO_SCSI_S_BUSY: 138 set_host_byte(sc, DID_BUS_BUSY); 139 break; 140 case VIRTIO_SCSI_S_TRANSPORT_FAILURE: 141 set_host_byte(sc, DID_TRANSPORT_DISRUPTED); 142 break; 143 case VIRTIO_SCSI_S_TARGET_FAILURE: 144 set_host_byte(sc, DID_BAD_TARGET); 145 break; 146 case VIRTIO_SCSI_S_NEXUS_FAILURE: 147 set_status_byte(sc, SAM_STAT_RESERVATION_CONFLICT); 148 break; 149 default: 150 scmd_printk(KERN_WARNING, sc, "Unknown response %d", 151 resp->response); 152 fallthrough; 153 case VIRTIO_SCSI_S_FAILURE: 154 set_host_byte(sc, DID_ERROR); 155 break; 156 } 157 158 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) > 159 VIRTIO_SCSI_SENSE_SIZE); 160 if (resp->sense_len) { 161 memcpy(sc->sense_buffer, resp->sense, 162 min_t(u32, 163 virtio32_to_cpu(vscsi->vdev, resp->sense_len), 164 VIRTIO_SCSI_SENSE_SIZE)); 165 } 166 167 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("Unsupported 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 int 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 if (!inq_result) { 342 kfree(inq_result); 343 return -ENOMEM; 344 } 345 346 shost_for_each_device(sdev, shost) { 347 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 348 349 memset(scsi_cmd, 0, sizeof(scsi_cmd)); 350 scsi_cmd[0] = INQUIRY; 351 scsi_cmd[4] = (unsigned char) inquiry_len; 352 353 memset(inq_result, 0, inq_result_len); 354 355 result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, 356 inq_result, inquiry_len, 357 SD_TIMEOUT, SD_MAX_RETRIES, NULL); 358 359 if (result == 0 && inq_result[0] >> 5) { 360 /* PQ indicates the LUN is not attached */ 361 scsi_remove_device(sdev); 362 } else if (result > 0 && host_byte(result) == DID_BAD_TARGET) { 363 /* 364 * If all LUNs of a virtio-scsi device are unplugged 365 * it will respond with BAD TARGET on any INQUIRY 366 * command. 367 * Remove the device in this case as well. 368 */ 369 scsi_remove_device(sdev); 370 } 371 } 372 373 kfree(inq_result); 374 return 0; 375 } 376 377 static void virtscsi_handle_event(struct work_struct *work) 378 { 379 struct virtio_scsi_event_node *event_node = 380 container_of(work, struct virtio_scsi_event_node, work); 381 struct virtio_scsi *vscsi = event_node->vscsi; 382 struct virtio_scsi_event *event = &event_node->event; 383 384 if (event->event & 385 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { 386 int ret; 387 388 event->event &= ~cpu_to_virtio32(vscsi->vdev, 389 VIRTIO_SCSI_T_EVENTS_MISSED); 390 ret = virtscsi_rescan_hotunplug(vscsi); 391 if (ret) 392 return; 393 scsi_scan_host(virtio_scsi_host(vscsi->vdev)); 394 } 395 396 switch (virtio32_to_cpu(vscsi->vdev, event->event)) { 397 case VIRTIO_SCSI_T_NO_EVENT: 398 break; 399 case VIRTIO_SCSI_T_TRANSPORT_RESET: 400 virtscsi_handle_transport_reset(vscsi, event); 401 break; 402 case VIRTIO_SCSI_T_PARAM_CHANGE: 403 virtscsi_handle_param_change(vscsi, event); 404 break; 405 default: 406 pr_err("Unsupported virtio scsi event %x\n", event->event); 407 } 408 virtscsi_kick_event(vscsi, event_node); 409 } 410 411 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) 412 { 413 struct virtio_scsi_event_node *event_node = buf; 414 415 if (!vscsi->stop_events) 416 queue_work(system_freezable_wq, &event_node->work); 417 } 418 419 static void virtscsi_event_done(struct virtqueue *vq) 420 { 421 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 422 struct virtio_scsi *vscsi = shost_priv(sh); 423 424 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); 425 }; 426 427 static int __virtscsi_add_cmd(struct virtqueue *vq, 428 struct virtio_scsi_cmd *cmd, 429 size_t req_size, size_t resp_size) 430 { 431 struct scsi_cmnd *sc = cmd->sc; 432 struct scatterlist *sgs[6], req, resp; 433 struct sg_table *out, *in; 434 unsigned out_num = 0, in_num = 0; 435 436 out = in = NULL; 437 438 if (sc && sc->sc_data_direction != DMA_NONE) { 439 if (sc->sc_data_direction != DMA_FROM_DEVICE) 440 out = &sc->sdb.table; 441 if (sc->sc_data_direction != DMA_TO_DEVICE) 442 in = &sc->sdb.table; 443 } 444 445 /* Request header. */ 446 sg_init_one(&req, &cmd->req, req_size); 447 sgs[out_num++] = &req; 448 449 /* Data-out buffer. */ 450 if (out) { 451 /* Place WRITE protection SGLs before Data OUT payload */ 452 if (scsi_prot_sg_count(sc)) 453 sgs[out_num++] = scsi_prot_sglist(sc); 454 sgs[out_num++] = out->sgl; 455 } 456 457 /* Response header. */ 458 sg_init_one(&resp, &cmd->resp, resp_size); 459 sgs[out_num + in_num++] = &resp; 460 461 /* Data-in buffer */ 462 if (in) { 463 /* Place READ protection SGLs before Data IN payload */ 464 if (scsi_prot_sg_count(sc)) 465 sgs[out_num + in_num++] = scsi_prot_sglist(sc); 466 sgs[out_num + in_num++] = in->sgl; 467 } 468 469 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); 470 } 471 472 static void virtscsi_kick_vq(struct virtio_scsi_vq *vq) 473 { 474 bool needs_kick; 475 unsigned long flags; 476 477 spin_lock_irqsave(&vq->vq_lock, flags); 478 needs_kick = virtqueue_kick_prepare(vq->vq); 479 spin_unlock_irqrestore(&vq->vq_lock, flags); 480 481 if (needs_kick) 482 virtqueue_notify(vq->vq); 483 } 484 485 /** 486 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it 487 * @vq : the struct virtqueue we're talking about 488 * @cmd : command structure 489 * @req_size : size of the request buffer 490 * @resp_size : size of the response buffer 491 * @kick : whether to kick the virtqueue immediately 492 */ 493 static int virtscsi_add_cmd(struct virtio_scsi_vq *vq, 494 struct virtio_scsi_cmd *cmd, 495 size_t req_size, size_t resp_size, 496 bool kick) 497 { 498 unsigned long flags; 499 int err; 500 bool needs_kick = false; 501 502 spin_lock_irqsave(&vq->vq_lock, flags); 503 err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size); 504 if (!err && kick) 505 needs_kick = virtqueue_kick_prepare(vq->vq); 506 507 spin_unlock_irqrestore(&vq->vq_lock, flags); 508 509 if (needs_kick) 510 virtqueue_notify(vq->vq); 511 return err; 512 } 513 514 static void virtio_scsi_init_hdr(struct virtio_device *vdev, 515 struct virtio_scsi_cmd_req *cmd, 516 struct scsi_cmnd *sc) 517 { 518 cmd->lun[0] = 1; 519 cmd->lun[1] = sc->device->id; 520 cmd->lun[2] = (sc->device->lun >> 8) | 0x40; 521 cmd->lun[3] = sc->device->lun & 0xff; 522 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc); 523 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; 524 cmd->prio = 0; 525 cmd->crn = 0; 526 } 527 528 #ifdef CONFIG_BLK_DEV_INTEGRITY 529 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, 530 struct virtio_scsi_cmd_req_pi *cmd_pi, 531 struct scsi_cmnd *sc) 532 { 533 struct request *rq = scsi_cmd_to_rq(sc); 534 struct blk_integrity *bi; 535 536 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc); 537 538 if (!rq || !scsi_prot_sg_count(sc)) 539 return; 540 541 bi = blk_get_integrity(rq->q->disk); 542 543 if (sc->sc_data_direction == DMA_TO_DEVICE) 544 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, 545 bio_integrity_bytes(bi, 546 blk_rq_sectors(rq))); 547 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 548 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, 549 bio_integrity_bytes(bi, 550 blk_rq_sectors(rq))); 551 } 552 #endif 553 554 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, 555 struct scsi_cmnd *sc) 556 { 557 u32 tag = blk_mq_unique_tag(scsi_cmd_to_rq(sc)); 558 u16 hwq = blk_mq_unique_tag_to_hwq(tag); 559 560 return &vscsi->req_vqs[hwq]; 561 } 562 563 static int virtscsi_queuecommand(struct Scsi_Host *shost, 564 struct scsi_cmnd *sc) 565 { 566 struct virtio_scsi *vscsi = shost_priv(shost); 567 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc); 568 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 569 bool kick; 570 unsigned long flags; 571 int req_size; 572 int ret; 573 574 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 575 576 /* TODO: check feature bit and fail if unsupported? */ 577 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 578 579 dev_dbg(&sc->device->sdev_gendev, 580 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 581 582 cmd->sc = sc; 583 584 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 585 586 #ifdef CONFIG_BLK_DEV_INTEGRITY 587 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 588 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc); 589 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 590 req_size = sizeof(cmd->req.cmd_pi); 591 } else 592 #endif 593 { 594 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc); 595 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 596 req_size = sizeof(cmd->req.cmd); 597 } 598 599 kick = (sc->flags & SCMD_LAST) != 0; 600 ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick); 601 if (ret == -EIO) { 602 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET; 603 spin_lock_irqsave(&req_vq->vq_lock, flags); 604 virtscsi_complete_cmd(vscsi, cmd); 605 spin_unlock_irqrestore(&req_vq->vq_lock, flags); 606 } else if (ret != 0) { 607 return SCSI_MLQUEUE_HOST_BUSY; 608 } 609 return 0; 610 } 611 612 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 613 { 614 DECLARE_COMPLETION_ONSTACK(comp); 615 int ret = FAILED; 616 617 cmd->comp = ∁ 618 if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd, 619 sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0) 620 goto out; 621 622 wait_for_completion(&comp); 623 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 624 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 625 ret = SUCCESS; 626 627 /* 628 * The spec guarantees that all requests related to the TMF have 629 * been completed, but the callback might not have run yet if 630 * we're using independent interrupts (e.g. MSI). Poll the 631 * virtqueues once. 632 * 633 * In the abort case, scsi_done() will do nothing, because the 634 * command timed out and hence SCMD_STATE_COMPLETE has been set. 635 */ 636 virtscsi_poll_requests(vscsi); 637 638 out: 639 mempool_free(cmd, virtscsi_cmd_pool); 640 return ret; 641 } 642 643 static int virtscsi_device_reset(struct scsi_cmnd *sc) 644 { 645 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 646 struct virtio_scsi_cmd *cmd; 647 648 sdev_printk(KERN_INFO, sc->device, "device reset\n"); 649 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 650 if (!cmd) 651 return FAILED; 652 653 memset(cmd, 0, sizeof(*cmd)); 654 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 655 .type = VIRTIO_SCSI_T_TMF, 656 .subtype = cpu_to_virtio32(vscsi->vdev, 657 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET), 658 .lun[0] = 1, 659 .lun[1] = sc->device->id, 660 .lun[2] = (sc->device->lun >> 8) | 0x40, 661 .lun[3] = sc->device->lun & 0xff, 662 }; 663 return virtscsi_tmf(vscsi, cmd); 664 } 665 666 static int virtscsi_device_alloc(struct scsi_device *sdevice) 667 { 668 /* 669 * Passed through SCSI targets (e.g. with qemu's 'scsi-block') 670 * may have transfer limits which come from the host SCSI 671 * controller or something on the host side other than the 672 * target itself. 673 * 674 * To make this work properly, the hypervisor can adjust the 675 * target's VPD information to advertise these limits. But 676 * for that to work, the guest has to look at the VPD pages, 677 * which we won't do by default if it is an SPC-2 device, even 678 * if it does actually support it. 679 * 680 * So, set the blist to always try to read the VPD pages. 681 */ 682 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES; 683 684 return 0; 685 } 686 687 688 /** 689 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth 690 * @sdev: Virtscsi target whose queue depth to change 691 * @qdepth: New queue depth 692 */ 693 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) 694 { 695 struct Scsi_Host *shost = sdev->host; 696 int max_depth = shost->cmd_per_lun; 697 698 return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); 699 } 700 701 static int virtscsi_abort(struct scsi_cmnd *sc) 702 { 703 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 704 struct virtio_scsi_cmd *cmd; 705 706 scmd_printk(KERN_INFO, sc, "abort\n"); 707 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 708 if (!cmd) 709 return FAILED; 710 711 memset(cmd, 0, sizeof(*cmd)); 712 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 713 .type = VIRTIO_SCSI_T_TMF, 714 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 715 .lun[0] = 1, 716 .lun[1] = sc->device->id, 717 .lun[2] = (sc->device->lun >> 8) | 0x40, 718 .lun[3] = sc->device->lun & 0xff, 719 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc), 720 }; 721 return virtscsi_tmf(vscsi, cmd); 722 } 723 724 static void virtscsi_map_queues(struct Scsi_Host *shost) 725 { 726 struct virtio_scsi *vscsi = shost_priv(shost); 727 struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT]; 728 729 blk_mq_virtio_map_queues(qmap, vscsi->vdev, 2); 730 } 731 732 static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq) 733 { 734 struct virtio_scsi *vscsi = shost_priv(shost); 735 736 virtscsi_kick_vq(&vscsi->req_vqs[hwq]); 737 } 738 739 /* 740 * The host guarantees to respond to each command, although I/O 741 * latencies might be higher than on bare metal. Reset the timer 742 * unconditionally to give the host a chance to perform EH. 743 */ 744 static enum scsi_timeout_action virtscsi_eh_timed_out(struct scsi_cmnd *scmnd) 745 { 746 return SCSI_EH_RESET_TIMER; 747 } 748 749 static const struct scsi_host_template virtscsi_host_template = { 750 .module = THIS_MODULE, 751 .name = "Virtio SCSI HBA", 752 .proc_name = "virtio_scsi", 753 .this_id = -1, 754 .cmd_size = sizeof(struct virtio_scsi_cmd), 755 .queuecommand = virtscsi_queuecommand, 756 .commit_rqs = virtscsi_commit_rqs, 757 .change_queue_depth = virtscsi_change_queue_depth, 758 .eh_abort_handler = virtscsi_abort, 759 .eh_device_reset_handler = virtscsi_device_reset, 760 .eh_timed_out = virtscsi_eh_timed_out, 761 .slave_alloc = virtscsi_device_alloc, 762 763 .dma_boundary = UINT_MAX, 764 .map_queues = virtscsi_map_queues, 765 .track_queue_depth = 1, 766 }; 767 768 #define virtscsi_config_get(vdev, fld) \ 769 ({ \ 770 __virtio_native_type(struct virtio_scsi_config, fld) __val; \ 771 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 772 __val; \ 773 }) 774 775 #define virtscsi_config_set(vdev, fld, val) \ 776 do { \ 777 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \ 778 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 779 } while(0) 780 781 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 782 struct virtqueue *vq) 783 { 784 spin_lock_init(&virtscsi_vq->vq_lock); 785 virtscsi_vq->vq = vq; 786 } 787 788 static void virtscsi_remove_vqs(struct virtio_device *vdev) 789 { 790 /* Stop all the virtqueues. */ 791 virtio_reset_device(vdev); 792 vdev->config->del_vqs(vdev); 793 } 794 795 static int virtscsi_init(struct virtio_device *vdev, 796 struct virtio_scsi *vscsi) 797 { 798 int err; 799 u32 i; 800 u32 num_vqs; 801 vq_callback_t **callbacks; 802 const char **names; 803 struct virtqueue **vqs; 804 struct irq_affinity desc = { .pre_vectors = 2 }; 805 806 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; 807 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL); 808 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *), 809 GFP_KERNEL); 810 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL); 811 812 if (!callbacks || !vqs || !names) { 813 err = -ENOMEM; 814 goto out; 815 } 816 817 callbacks[0] = virtscsi_ctrl_done; 818 callbacks[1] = virtscsi_event_done; 819 names[0] = "control"; 820 names[1] = "event"; 821 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { 822 callbacks[i] = virtscsi_req_done; 823 names[i] = "request"; 824 } 825 826 /* Discover virtqueues and write information to configuration. */ 827 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 828 if (err) 829 goto out; 830 831 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 832 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 833 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 834 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 835 vqs[i]); 836 837 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 838 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 839 840 err = 0; 841 842 out: 843 kfree(names); 844 kfree(callbacks); 845 kfree(vqs); 846 if (err) 847 virtscsi_remove_vqs(vdev); 848 return err; 849 } 850 851 static int virtscsi_probe(struct virtio_device *vdev) 852 { 853 struct Scsi_Host *shost; 854 struct virtio_scsi *vscsi; 855 int err; 856 u32 sg_elems, num_targets; 857 u32 cmd_per_lun; 858 u32 num_queues; 859 860 if (!vdev->config->get) { 861 dev_err(&vdev->dev, "%s failure: config access disabled\n", 862 __func__); 863 return -EINVAL; 864 } 865 866 /* We need to know how many queues before we allocate. */ 867 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; 868 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues); 869 870 num_targets = virtscsi_config_get(vdev, max_target) + 1; 871 872 shost = scsi_host_alloc(&virtscsi_host_template, 873 struct_size(vscsi, req_vqs, num_queues)); 874 if (!shost) 875 return -ENOMEM; 876 877 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 878 shost->sg_tablesize = sg_elems; 879 vscsi = shost_priv(shost); 880 vscsi->vdev = vdev; 881 vscsi->num_queues = num_queues; 882 vdev->priv = shost; 883 884 err = virtscsi_init(vdev, vscsi); 885 if (err) 886 goto virtscsi_init_failed; 887 888 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq); 889 890 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 891 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 892 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 893 894 /* LUNs > 256 are reported with format 1, so they go in the range 895 * 16640-32767. 896 */ 897 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 898 shost->max_id = num_targets; 899 shost->max_channel = 0; 900 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 901 shost->nr_hw_queues = num_queues; 902 903 #ifdef CONFIG_BLK_DEV_INTEGRITY 904 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 905 int host_prot; 906 907 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 908 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 909 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 910 911 scsi_host_set_prot(shost, host_prot); 912 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 913 } 914 #endif 915 916 err = scsi_add_host(shost, &vdev->dev); 917 if (err) 918 goto scsi_add_host_failed; 919 920 virtio_device_ready(vdev); 921 922 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 923 virtscsi_kick_event_all(vscsi); 924 925 scsi_scan_host(shost); 926 return 0; 927 928 scsi_add_host_failed: 929 vdev->config->del_vqs(vdev); 930 virtscsi_init_failed: 931 scsi_host_put(shost); 932 return err; 933 } 934 935 static void virtscsi_remove(struct virtio_device *vdev) 936 { 937 struct Scsi_Host *shost = virtio_scsi_host(vdev); 938 struct virtio_scsi *vscsi = shost_priv(shost); 939 940 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 941 virtscsi_cancel_event_work(vscsi); 942 943 scsi_remove_host(shost); 944 virtscsi_remove_vqs(vdev); 945 scsi_host_put(shost); 946 } 947 948 #ifdef CONFIG_PM_SLEEP 949 static int virtscsi_freeze(struct virtio_device *vdev) 950 { 951 virtscsi_remove_vqs(vdev); 952 return 0; 953 } 954 955 static int virtscsi_restore(struct virtio_device *vdev) 956 { 957 struct Scsi_Host *sh = virtio_scsi_host(vdev); 958 struct virtio_scsi *vscsi = shost_priv(sh); 959 int err; 960 961 err = virtscsi_init(vdev, vscsi); 962 if (err) 963 return err; 964 965 virtio_device_ready(vdev); 966 967 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 968 virtscsi_kick_event_all(vscsi); 969 970 return err; 971 } 972 #endif 973 974 static struct virtio_device_id id_table[] = { 975 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 976 { 0 }, 977 }; 978 979 static unsigned int features[] = { 980 VIRTIO_SCSI_F_HOTPLUG, 981 VIRTIO_SCSI_F_CHANGE, 982 #ifdef CONFIG_BLK_DEV_INTEGRITY 983 VIRTIO_SCSI_F_T10_PI, 984 #endif 985 }; 986 987 static struct virtio_driver virtio_scsi_driver = { 988 .feature_table = features, 989 .feature_table_size = ARRAY_SIZE(features), 990 .driver.name = KBUILD_MODNAME, 991 .driver.owner = THIS_MODULE, 992 .id_table = id_table, 993 .probe = virtscsi_probe, 994 #ifdef CONFIG_PM_SLEEP 995 .freeze = virtscsi_freeze, 996 .restore = virtscsi_restore, 997 #endif 998 .remove = virtscsi_remove, 999 }; 1000 1001 static int __init virtio_scsi_init(void) 1002 { 1003 int ret = -ENOMEM; 1004 1005 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); 1006 if (!virtscsi_cmd_cache) { 1007 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); 1008 goto error; 1009 } 1010 1011 1012 virtscsi_cmd_pool = 1013 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, 1014 virtscsi_cmd_cache); 1015 if (!virtscsi_cmd_pool) { 1016 pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); 1017 goto error; 1018 } 1019 ret = register_virtio_driver(&virtio_scsi_driver); 1020 if (ret < 0) 1021 goto error; 1022 1023 return 0; 1024 1025 error: 1026 mempool_destroy(virtscsi_cmd_pool); 1027 virtscsi_cmd_pool = NULL; 1028 kmem_cache_destroy(virtscsi_cmd_cache); 1029 virtscsi_cmd_cache = NULL; 1030 return ret; 1031 } 1032 1033 static void __exit virtio_scsi_fini(void) 1034 { 1035 unregister_virtio_driver(&virtio_scsi_driver); 1036 mempool_destroy(virtscsi_cmd_pool); 1037 kmem_cache_destroy(virtscsi_cmd_cache); 1038 } 1039 module_init(virtio_scsi_init); 1040 module_exit(virtio_scsi_fini); 1041 1042 MODULE_DEVICE_TABLE(virtio, id_table); 1043 MODULE_DESCRIPTION("Virtio SCSI HBA driver"); 1044 MODULE_LICENSE("GPL"); 1045