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_TARGET_FAILURE); 145 break; 146 case VIRTIO_SCSI_S_NEXUS_FAILURE: 147 set_host_byte(sc, DID_NEXUS_FAILURE); 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 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("Unsupported 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 = scsi_cmd_to_rq(sc); 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(scsi_cmd_to_rq(sc)); 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, scsi_done() will do nothing, because the 624 * command timed out and hence SCMD_STATE_COMPLETE has been set. 625 */ 626 virtscsi_poll_requests(vscsi); 627 628 out: 629 mempool_free(cmd, virtscsi_cmd_pool); 630 return ret; 631 } 632 633 static int virtscsi_device_reset(struct scsi_cmnd *sc) 634 { 635 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 636 struct virtio_scsi_cmd *cmd; 637 638 sdev_printk(KERN_INFO, sc->device, "device reset\n"); 639 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 640 if (!cmd) 641 return FAILED; 642 643 memset(cmd, 0, sizeof(*cmd)); 644 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 645 .type = VIRTIO_SCSI_T_TMF, 646 .subtype = cpu_to_virtio32(vscsi->vdev, 647 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET), 648 .lun[0] = 1, 649 .lun[1] = sc->device->id, 650 .lun[2] = (sc->device->lun >> 8) | 0x40, 651 .lun[3] = sc->device->lun & 0xff, 652 }; 653 return virtscsi_tmf(vscsi, cmd); 654 } 655 656 static int virtscsi_device_alloc(struct scsi_device *sdevice) 657 { 658 /* 659 * Passed through SCSI targets (e.g. with qemu's 'scsi-block') 660 * may have transfer limits which come from the host SCSI 661 * controller or something on the host side other than the 662 * target itself. 663 * 664 * To make this work properly, the hypervisor can adjust the 665 * target's VPD information to advertise these limits. But 666 * for that to work, the guest has to look at the VPD pages, 667 * which we won't do by default if it is an SPC-2 device, even 668 * if it does actually support it. 669 * 670 * So, set the blist to always try to read the VPD pages. 671 */ 672 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES; 673 674 return 0; 675 } 676 677 678 /** 679 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth 680 * @sdev: Virtscsi target whose queue depth to change 681 * @qdepth: New queue depth 682 */ 683 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) 684 { 685 struct Scsi_Host *shost = sdev->host; 686 int max_depth = shost->cmd_per_lun; 687 688 return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); 689 } 690 691 static int virtscsi_abort(struct scsi_cmnd *sc) 692 { 693 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 694 struct virtio_scsi_cmd *cmd; 695 696 scmd_printk(KERN_INFO, sc, "abort\n"); 697 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 698 if (!cmd) 699 return FAILED; 700 701 memset(cmd, 0, sizeof(*cmd)); 702 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 703 .type = VIRTIO_SCSI_T_TMF, 704 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 705 .lun[0] = 1, 706 .lun[1] = sc->device->id, 707 .lun[2] = (sc->device->lun >> 8) | 0x40, 708 .lun[3] = sc->device->lun & 0xff, 709 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc), 710 }; 711 return virtscsi_tmf(vscsi, cmd); 712 } 713 714 static int virtscsi_map_queues(struct Scsi_Host *shost) 715 { 716 struct virtio_scsi *vscsi = shost_priv(shost); 717 struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT]; 718 719 return blk_mq_virtio_map_queues(qmap, vscsi->vdev, 2); 720 } 721 722 static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq) 723 { 724 struct virtio_scsi *vscsi = shost_priv(shost); 725 726 virtscsi_kick_vq(&vscsi->req_vqs[hwq]); 727 } 728 729 /* 730 * The host guarantees to respond to each command, although I/O 731 * latencies might be higher than on bare metal. Reset the timer 732 * unconditionally to give the host a chance to perform EH. 733 */ 734 static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd) 735 { 736 return BLK_EH_RESET_TIMER; 737 } 738 739 static struct scsi_host_template virtscsi_host_template = { 740 .module = THIS_MODULE, 741 .name = "Virtio SCSI HBA", 742 .proc_name = "virtio_scsi", 743 .this_id = -1, 744 .cmd_size = sizeof(struct virtio_scsi_cmd), 745 .queuecommand = virtscsi_queuecommand, 746 .commit_rqs = virtscsi_commit_rqs, 747 .change_queue_depth = virtscsi_change_queue_depth, 748 .eh_abort_handler = virtscsi_abort, 749 .eh_device_reset_handler = virtscsi_device_reset, 750 .eh_timed_out = virtscsi_eh_timed_out, 751 .slave_alloc = virtscsi_device_alloc, 752 753 .dma_boundary = UINT_MAX, 754 .map_queues = virtscsi_map_queues, 755 .track_queue_depth = 1, 756 }; 757 758 #define virtscsi_config_get(vdev, fld) \ 759 ({ \ 760 __virtio_native_type(struct virtio_scsi_config, fld) __val; \ 761 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 762 __val; \ 763 }) 764 765 #define virtscsi_config_set(vdev, fld, val) \ 766 do { \ 767 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \ 768 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 769 } while(0) 770 771 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 772 struct virtqueue *vq) 773 { 774 spin_lock_init(&virtscsi_vq->vq_lock); 775 virtscsi_vq->vq = vq; 776 } 777 778 static void virtscsi_remove_vqs(struct virtio_device *vdev) 779 { 780 /* Stop all the virtqueues. */ 781 vdev->config->reset(vdev); 782 vdev->config->del_vqs(vdev); 783 } 784 785 static int virtscsi_init(struct virtio_device *vdev, 786 struct virtio_scsi *vscsi) 787 { 788 int err; 789 u32 i; 790 u32 num_vqs; 791 vq_callback_t **callbacks; 792 const char **names; 793 struct virtqueue **vqs; 794 struct irq_affinity desc = { .pre_vectors = 2 }; 795 796 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; 797 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL); 798 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *), 799 GFP_KERNEL); 800 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL); 801 802 if (!callbacks || !vqs || !names) { 803 err = -ENOMEM; 804 goto out; 805 } 806 807 callbacks[0] = virtscsi_ctrl_done; 808 callbacks[1] = virtscsi_event_done; 809 names[0] = "control"; 810 names[1] = "event"; 811 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { 812 callbacks[i] = virtscsi_req_done; 813 names[i] = "request"; 814 } 815 816 /* Discover virtqueues and write information to configuration. */ 817 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 818 if (err) 819 goto out; 820 821 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 822 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 823 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 824 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 825 vqs[i]); 826 827 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 828 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 829 830 err = 0; 831 832 out: 833 kfree(names); 834 kfree(callbacks); 835 kfree(vqs); 836 if (err) 837 virtscsi_remove_vqs(vdev); 838 return err; 839 } 840 841 static int virtscsi_probe(struct virtio_device *vdev) 842 { 843 struct Scsi_Host *shost; 844 struct virtio_scsi *vscsi; 845 int err; 846 u32 sg_elems, num_targets; 847 u32 cmd_per_lun; 848 u32 num_queues; 849 850 if (!vdev->config->get) { 851 dev_err(&vdev->dev, "%s failure: config access disabled\n", 852 __func__); 853 return -EINVAL; 854 } 855 856 /* We need to know how many queues before we allocate. */ 857 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; 858 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues); 859 860 num_targets = virtscsi_config_get(vdev, max_target) + 1; 861 862 shost = scsi_host_alloc(&virtscsi_host_template, 863 struct_size(vscsi, req_vqs, num_queues)); 864 if (!shost) 865 return -ENOMEM; 866 867 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 868 shost->sg_tablesize = sg_elems; 869 vscsi = shost_priv(shost); 870 vscsi->vdev = vdev; 871 vscsi->num_queues = num_queues; 872 vdev->priv = shost; 873 874 err = virtscsi_init(vdev, vscsi); 875 if (err) 876 goto virtscsi_init_failed; 877 878 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq); 879 880 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 881 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 882 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 883 884 /* LUNs > 256 are reported with format 1, so they go in the range 885 * 16640-32767. 886 */ 887 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 888 shost->max_id = num_targets; 889 shost->max_channel = 0; 890 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 891 shost->nr_hw_queues = num_queues; 892 893 #ifdef CONFIG_BLK_DEV_INTEGRITY 894 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 895 int host_prot; 896 897 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 898 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 899 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 900 901 scsi_host_set_prot(shost, host_prot); 902 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 903 } 904 #endif 905 906 err = scsi_add_host(shost, &vdev->dev); 907 if (err) 908 goto scsi_add_host_failed; 909 910 virtio_device_ready(vdev); 911 912 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 913 virtscsi_kick_event_all(vscsi); 914 915 scsi_scan_host(shost); 916 return 0; 917 918 scsi_add_host_failed: 919 vdev->config->del_vqs(vdev); 920 virtscsi_init_failed: 921 scsi_host_put(shost); 922 return err; 923 } 924 925 static void virtscsi_remove(struct virtio_device *vdev) 926 { 927 struct Scsi_Host *shost = virtio_scsi_host(vdev); 928 struct virtio_scsi *vscsi = shost_priv(shost); 929 930 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 931 virtscsi_cancel_event_work(vscsi); 932 933 scsi_remove_host(shost); 934 virtscsi_remove_vqs(vdev); 935 scsi_host_put(shost); 936 } 937 938 #ifdef CONFIG_PM_SLEEP 939 static int virtscsi_freeze(struct virtio_device *vdev) 940 { 941 virtscsi_remove_vqs(vdev); 942 return 0; 943 } 944 945 static int virtscsi_restore(struct virtio_device *vdev) 946 { 947 struct Scsi_Host *sh = virtio_scsi_host(vdev); 948 struct virtio_scsi *vscsi = shost_priv(sh); 949 int err; 950 951 err = virtscsi_init(vdev, vscsi); 952 if (err) 953 return err; 954 955 virtio_device_ready(vdev); 956 957 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 958 virtscsi_kick_event_all(vscsi); 959 960 return err; 961 } 962 #endif 963 964 static struct virtio_device_id id_table[] = { 965 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 966 { 0 }, 967 }; 968 969 static unsigned int features[] = { 970 VIRTIO_SCSI_F_HOTPLUG, 971 VIRTIO_SCSI_F_CHANGE, 972 #ifdef CONFIG_BLK_DEV_INTEGRITY 973 VIRTIO_SCSI_F_T10_PI, 974 #endif 975 }; 976 977 static struct virtio_driver virtio_scsi_driver = { 978 .feature_table = features, 979 .feature_table_size = ARRAY_SIZE(features), 980 .suppress_used_validation = true, 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