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