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/dma-mapping.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 static unsigned int virtscsi_poll_queues; 41 module_param(virtscsi_poll_queues, uint, 0644); 42 MODULE_PARM_DESC(virtscsi_poll_queues, 43 "The number of dedicated virtqueues for polling I/O"); 44 45 /* Command queue element */ 46 struct virtio_scsi_cmd { 47 struct scsi_cmnd *sc; 48 struct completion *comp; 49 union { 50 struct virtio_scsi_cmd_req cmd; 51 struct virtio_scsi_cmd_req_pi cmd_pi; 52 struct virtio_scsi_ctrl_tmf_req tmf; 53 struct virtio_scsi_ctrl_an_req an; 54 } req; 55 union { 56 struct virtio_scsi_cmd_resp cmd; 57 struct virtio_scsi_ctrl_tmf_resp tmf; 58 struct virtio_scsi_ctrl_an_resp an; 59 struct virtio_scsi_event evt; 60 } resp; 61 } ____cacheline_aligned_in_smp; 62 63 struct virtio_scsi_event_node { 64 struct virtio_scsi *vscsi; 65 struct virtio_scsi_event *event; 66 struct work_struct work; 67 }; 68 69 struct virtio_scsi_vq { 70 /* Protects vq */ 71 spinlock_t vq_lock; 72 73 struct virtqueue *vq; 74 }; 75 76 /* Driver instance state */ 77 struct virtio_scsi { 78 struct virtio_device *vdev; 79 80 /* Get some buffers ready for event vq */ 81 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN]; 82 83 u32 num_queues; 84 int io_queues[HCTX_MAX_TYPES]; 85 86 struct hlist_node node; 87 88 /* Protected by event_vq lock */ 89 bool stop_events; 90 91 struct virtio_scsi_vq ctrl_vq; 92 struct virtio_scsi_vq event_vq; 93 94 __dma_from_device_group_begin(); 95 struct virtio_scsi_event events[VIRTIO_SCSI_EVENT_LEN]; 96 __dma_from_device_group_end(); 97 98 struct virtio_scsi_vq req_vqs[]; 99 }; 100 101 static struct kmem_cache *virtscsi_cmd_cache; 102 static mempool_t *virtscsi_cmd_pool; 103 104 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev) 105 { 106 return vdev->priv; 107 } 108 109 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid) 110 { 111 if (resid) 112 scsi_set_resid(sc, min(resid, scsi_bufflen(sc))); 113 } 114 115 /* 116 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done 117 * 118 * Called with vq_lock held. 119 */ 120 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf) 121 { 122 struct virtio_scsi_cmd *cmd = buf; 123 struct scsi_cmnd *sc = cmd->sc; 124 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd; 125 126 dev_dbg(&sc->device->sdev_gendev, 127 "cmd %p response %u status %#02x sense_len %u\n", 128 sc, resp->response, resp->status, resp->sense_len); 129 130 sc->result = resp->status; 131 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid)); 132 switch (resp->response) { 133 case VIRTIO_SCSI_S_OK: 134 set_host_byte(sc, DID_OK); 135 break; 136 case VIRTIO_SCSI_S_OVERRUN: 137 set_host_byte(sc, DID_ERROR); 138 break; 139 case VIRTIO_SCSI_S_ABORTED: 140 set_host_byte(sc, DID_ABORT); 141 break; 142 case VIRTIO_SCSI_S_BAD_TARGET: 143 set_host_byte(sc, DID_BAD_TARGET); 144 break; 145 case VIRTIO_SCSI_S_RESET: 146 set_host_byte(sc, DID_RESET); 147 break; 148 case VIRTIO_SCSI_S_BUSY: 149 set_host_byte(sc, DID_BUS_BUSY); 150 break; 151 case VIRTIO_SCSI_S_TRANSPORT_FAILURE: 152 set_host_byte(sc, DID_TRANSPORT_DISRUPTED); 153 break; 154 case VIRTIO_SCSI_S_TARGET_FAILURE: 155 set_host_byte(sc, DID_BAD_TARGET); 156 break; 157 case VIRTIO_SCSI_S_NEXUS_FAILURE: 158 set_status_byte(sc, SAM_STAT_RESERVATION_CONFLICT); 159 break; 160 default: 161 scmd_printk(KERN_WARNING, sc, "Unknown response %d", 162 resp->response); 163 fallthrough; 164 case VIRTIO_SCSI_S_FAILURE: 165 set_host_byte(sc, DID_ERROR); 166 break; 167 } 168 169 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) > 170 VIRTIO_SCSI_SENSE_SIZE); 171 if (resp->sense_len) { 172 memcpy(sc->sense_buffer, resp->sense, 173 min_t(u32, 174 virtio32_to_cpu(vscsi->vdev, resp->sense_len), 175 VIRTIO_SCSI_SENSE_SIZE)); 176 } 177 178 scsi_done(sc); 179 } 180 181 static void virtscsi_vq_done(struct virtio_scsi *vscsi, 182 struct virtio_scsi_vq *virtscsi_vq, 183 void (*fn)(struct virtio_scsi *vscsi, void *buf)) 184 { 185 void *buf; 186 unsigned int len; 187 unsigned long flags; 188 struct virtqueue *vq = virtscsi_vq->vq; 189 190 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); 191 do { 192 virtqueue_disable_cb(vq); 193 while ((buf = virtqueue_get_buf(vq, &len)) != NULL) 194 fn(vscsi, buf); 195 196 } while (!virtqueue_enable_cb(vq)); 197 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); 198 } 199 200 static void virtscsi_req_done(struct virtqueue *vq) 201 { 202 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 203 struct virtio_scsi *vscsi = shost_priv(sh); 204 int index = vq->index - VIRTIO_SCSI_VQ_BASE; 205 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index]; 206 207 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd); 208 }; 209 210 static void virtscsi_poll_requests(struct virtio_scsi *vscsi) 211 { 212 int i, num_vqs; 213 214 num_vqs = vscsi->num_queues; 215 for (i = 0; i < num_vqs; i++) 216 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i], 217 virtscsi_complete_cmd); 218 } 219 220 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf) 221 { 222 struct virtio_scsi_cmd *cmd = buf; 223 224 if (cmd->comp) 225 complete(cmd->comp); 226 } 227 228 static void virtscsi_ctrl_done(struct virtqueue *vq) 229 { 230 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 231 struct virtio_scsi *vscsi = shost_priv(sh); 232 233 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free); 234 }; 235 236 static void virtscsi_handle_event(struct work_struct *work); 237 238 static int virtscsi_kick_event(struct virtio_scsi *vscsi, 239 struct virtio_scsi_event_node *event_node) 240 { 241 int err; 242 struct scatterlist sg; 243 unsigned long flags; 244 245 INIT_WORK(&event_node->work, virtscsi_handle_event); 246 sg_init_one(&sg, event_node->event, sizeof(struct virtio_scsi_event)); 247 248 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags); 249 250 err = virtqueue_add_inbuf_cache_clean(vscsi->event_vq.vq, &sg, 1, event_node, 251 GFP_ATOMIC); 252 if (!err) 253 virtqueue_kick(vscsi->event_vq.vq); 254 255 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags); 256 257 return err; 258 } 259 260 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi) 261 { 262 int i; 263 264 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) { 265 vscsi->event_list[i].vscsi = vscsi; 266 vscsi->event_list[i].event = &vscsi->events[i]; 267 virtscsi_kick_event(vscsi, &vscsi->event_list[i]); 268 } 269 270 return 0; 271 } 272 273 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi) 274 { 275 int i; 276 277 /* Stop scheduling work before calling cancel_work_sync. */ 278 spin_lock_irq(&vscsi->event_vq.vq_lock); 279 vscsi->stop_events = true; 280 spin_unlock_irq(&vscsi->event_vq.vq_lock); 281 282 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) 283 cancel_work_sync(&vscsi->event_list[i].work); 284 } 285 286 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, 287 struct virtio_scsi_event *event) 288 { 289 struct scsi_device *sdev; 290 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 291 unsigned int target = event->lun[1]; 292 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 293 294 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) { 295 case VIRTIO_SCSI_EVT_RESET_RESCAN: 296 if (lun == 0) { 297 scsi_scan_target(&shost->shost_gendev, 0, target, 298 SCAN_WILD_CARD, SCSI_SCAN_INITIAL); 299 } else { 300 scsi_add_device(shost, 0, target, lun); 301 } 302 break; 303 case VIRTIO_SCSI_EVT_RESET_REMOVED: 304 sdev = scsi_device_lookup(shost, 0, target, lun); 305 if (sdev) { 306 scsi_remove_device(sdev); 307 scsi_device_put(sdev); 308 } else { 309 pr_err("SCSI device %d 0 %d %d not found\n", 310 shost->host_no, target, lun); 311 } 312 break; 313 default: 314 pr_info("Unsupported virtio scsi event reason %x\n", event->reason); 315 } 316 } 317 318 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, 319 struct virtio_scsi_event *event) 320 { 321 struct scsi_device *sdev; 322 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 323 unsigned int target = event->lun[1]; 324 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 325 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255; 326 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8; 327 328 sdev = scsi_device_lookup(shost, 0, target, lun); 329 if (!sdev) { 330 pr_err("SCSI device %d 0 %d %d not found\n", 331 shost->host_no, target, lun); 332 return; 333 } 334 335 /* Handle "Parameters changed", "Mode parameters changed", and 336 "Capacity data has changed". */ 337 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) 338 scsi_rescan_device(sdev); 339 340 scsi_device_put(sdev); 341 } 342 343 static int virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi) 344 { 345 struct scsi_device *sdev; 346 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 347 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 348 int result, inquiry_len, inq_result_len = 256; 349 char *inq_result = kmalloc(inq_result_len, GFP_KERNEL); 350 351 if (!inq_result) 352 return -ENOMEM; 353 354 shost_for_each_device(sdev, shost) { 355 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 356 357 memset(scsi_cmd, 0, sizeof(scsi_cmd)); 358 scsi_cmd[0] = INQUIRY; 359 scsi_cmd[4] = (unsigned char) inquiry_len; 360 361 memset(inq_result, 0, inq_result_len); 362 363 result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, 364 inq_result, inquiry_len, 365 SD_TIMEOUT, SD_MAX_RETRIES, NULL); 366 367 if (result == 0 && inq_result[0] >> 5) { 368 /* PQ indicates the LUN is not attached */ 369 scsi_remove_device(sdev); 370 } else if (result > 0 && host_byte(result) == DID_BAD_TARGET) { 371 /* 372 * If all LUNs of a virtio-scsi device are unplugged 373 * it will respond with BAD TARGET on any INQUIRY 374 * command. 375 * Remove the device in this case as well. 376 */ 377 scsi_remove_device(sdev); 378 } 379 } 380 381 kfree(inq_result); 382 return 0; 383 } 384 385 static void virtscsi_handle_event(struct work_struct *work) 386 { 387 struct virtio_scsi_event_node *event_node = 388 container_of(work, struct virtio_scsi_event_node, work); 389 struct virtio_scsi *vscsi = event_node->vscsi; 390 struct virtio_scsi_event *event = event_node->event; 391 392 if (event->event & 393 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { 394 int ret; 395 396 event->event &= ~cpu_to_virtio32(vscsi->vdev, 397 VIRTIO_SCSI_T_EVENTS_MISSED); 398 ret = virtscsi_rescan_hotunplug(vscsi); 399 if (ret) 400 return; 401 scsi_scan_host(virtio_scsi_host(vscsi->vdev)); 402 } 403 404 switch (virtio32_to_cpu(vscsi->vdev, event->event)) { 405 case VIRTIO_SCSI_T_NO_EVENT: 406 break; 407 case VIRTIO_SCSI_T_TRANSPORT_RESET: 408 virtscsi_handle_transport_reset(vscsi, event); 409 break; 410 case VIRTIO_SCSI_T_PARAM_CHANGE: 411 virtscsi_handle_param_change(vscsi, event); 412 break; 413 default: 414 pr_err("Unsupported virtio scsi event %x\n", event->event); 415 } 416 virtscsi_kick_event(vscsi, event_node); 417 } 418 419 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) 420 { 421 struct virtio_scsi_event_node *event_node = buf; 422 423 if (!vscsi->stop_events) 424 queue_work(system_freezable_wq, &event_node->work); 425 } 426 427 static void virtscsi_event_done(struct virtqueue *vq) 428 { 429 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 430 struct virtio_scsi *vscsi = shost_priv(sh); 431 432 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); 433 }; 434 435 static int __virtscsi_add_cmd(struct virtqueue *vq, 436 struct virtio_scsi_cmd *cmd, 437 size_t req_size, size_t resp_size) 438 { 439 struct scsi_cmnd *sc = cmd->sc; 440 struct scatterlist *sgs[6], req, resp; 441 struct sg_table *out, *in; 442 unsigned out_num = 0, in_num = 0; 443 444 out = in = NULL; 445 446 if (sc && sc->sc_data_direction != DMA_NONE) { 447 if (sc->sc_data_direction != DMA_FROM_DEVICE) 448 out = &sc->sdb.table; 449 if (sc->sc_data_direction != DMA_TO_DEVICE) 450 in = &sc->sdb.table; 451 } 452 453 /* Request header. */ 454 sg_init_one(&req, &cmd->req, req_size); 455 sgs[out_num++] = &req; 456 457 /* Data-out buffer. */ 458 if (out) { 459 /* Place WRITE protection SGLs before Data OUT payload */ 460 if (scsi_prot_sg_count(sc)) 461 sgs[out_num++] = scsi_prot_sglist(sc); 462 sgs[out_num++] = out->sgl; 463 } 464 465 /* Response header. */ 466 sg_init_one(&resp, &cmd->resp, resp_size); 467 sgs[out_num + in_num++] = &resp; 468 469 /* Data-in buffer */ 470 if (in) { 471 /* Place READ protection SGLs before Data IN payload */ 472 if (scsi_prot_sg_count(sc)) 473 sgs[out_num + in_num++] = scsi_prot_sglist(sc); 474 sgs[out_num + in_num++] = in->sgl; 475 } 476 477 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); 478 } 479 480 static void virtscsi_kick_vq(struct virtio_scsi_vq *vq) 481 { 482 bool needs_kick; 483 unsigned long flags; 484 485 spin_lock_irqsave(&vq->vq_lock, flags); 486 needs_kick = virtqueue_kick_prepare(vq->vq); 487 spin_unlock_irqrestore(&vq->vq_lock, flags); 488 489 if (needs_kick) 490 virtqueue_notify(vq->vq); 491 } 492 493 /** 494 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it 495 * @vq : the struct virtqueue we're talking about 496 * @cmd : command structure 497 * @req_size : size of the request buffer 498 * @resp_size : size of the response buffer 499 * @kick : whether to kick the virtqueue immediately 500 */ 501 static int virtscsi_add_cmd(struct virtio_scsi_vq *vq, 502 struct virtio_scsi_cmd *cmd, 503 size_t req_size, size_t resp_size, 504 bool kick) 505 { 506 unsigned long flags; 507 int err; 508 bool needs_kick = false; 509 510 spin_lock_irqsave(&vq->vq_lock, flags); 511 err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size); 512 if (!err && kick) 513 needs_kick = virtqueue_kick_prepare(vq->vq); 514 515 spin_unlock_irqrestore(&vq->vq_lock, flags); 516 517 if (needs_kick) 518 virtqueue_notify(vq->vq); 519 return err; 520 } 521 522 static void virtio_scsi_init_hdr(struct virtio_device *vdev, 523 struct virtio_scsi_cmd_req *cmd, 524 struct scsi_cmnd *sc) 525 { 526 cmd->lun[0] = 1; 527 cmd->lun[1] = sc->device->id; 528 cmd->lun[2] = (sc->device->lun >> 8) | 0x40; 529 cmd->lun[3] = sc->device->lun & 0xff; 530 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc); 531 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; 532 cmd->prio = 0; 533 cmd->crn = 0; 534 } 535 536 #ifdef CONFIG_BLK_DEV_INTEGRITY 537 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, 538 struct virtio_scsi_cmd_req_pi *cmd_pi, 539 struct scsi_cmnd *sc) 540 { 541 struct request *rq = scsi_cmd_to_rq(sc); 542 struct blk_integrity *bi; 543 544 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc); 545 546 if (!rq || !scsi_prot_sg_count(sc)) 547 return; 548 549 bi = blk_get_integrity(rq->q->disk); 550 551 if (sc->sc_data_direction == DMA_TO_DEVICE) 552 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, 553 bio_integrity_bytes(bi, 554 blk_rq_sectors(rq))); 555 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 556 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, 557 bio_integrity_bytes(bi, 558 blk_rq_sectors(rq))); 559 } 560 #endif 561 562 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, 563 struct scsi_cmnd *sc) 564 { 565 u32 tag = blk_mq_unique_tag(scsi_cmd_to_rq(sc)); 566 u16 hwq = blk_mq_unique_tag_to_hwq(tag); 567 568 return &vscsi->req_vqs[hwq]; 569 } 570 571 static enum scsi_qc_status virtscsi_queuecommand(struct Scsi_Host *shost, 572 struct scsi_cmnd *sc) 573 { 574 struct virtio_scsi *vscsi = shost_priv(shost); 575 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc); 576 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 577 bool kick; 578 unsigned long flags; 579 int req_size; 580 int ret; 581 582 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 583 584 /* TODO: check feature bit and fail if unsupported? */ 585 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 586 587 dev_dbg(&sc->device->sdev_gendev, 588 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 589 590 cmd->sc = sc; 591 592 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 593 594 #ifdef CONFIG_BLK_DEV_INTEGRITY 595 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 596 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc); 597 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 598 req_size = sizeof(cmd->req.cmd_pi); 599 } else 600 #endif 601 { 602 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc); 603 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 604 req_size = sizeof(cmd->req.cmd); 605 } 606 607 kick = (sc->flags & SCMD_LAST) != 0; 608 ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick); 609 if (ret == -EIO) { 610 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET; 611 spin_lock_irqsave(&req_vq->vq_lock, flags); 612 virtscsi_complete_cmd(vscsi, cmd); 613 spin_unlock_irqrestore(&req_vq->vq_lock, flags); 614 } else if (ret != 0) { 615 return SCSI_MLQUEUE_HOST_BUSY; 616 } 617 return 0; 618 } 619 620 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 621 { 622 DECLARE_COMPLETION_ONSTACK(comp); 623 int ret = FAILED; 624 625 cmd->comp = ∁ 626 if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd, 627 sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0) 628 goto out; 629 630 wait_for_completion(&comp); 631 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 632 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 633 ret = SUCCESS; 634 635 /* 636 * The spec guarantees that all requests related to the TMF have 637 * been completed, but the callback might not have run yet if 638 * we're using independent interrupts (e.g. MSI). Poll the 639 * virtqueues once. 640 * 641 * In the abort case, scsi_done() will do nothing, because the 642 * command timed out and hence SCMD_STATE_COMPLETE has been set. 643 */ 644 virtscsi_poll_requests(vscsi); 645 646 out: 647 mempool_free(cmd, virtscsi_cmd_pool); 648 return ret; 649 } 650 651 static int virtscsi_device_reset(struct scsi_cmnd *sc) 652 { 653 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 654 struct virtio_scsi_cmd *cmd; 655 656 sdev_printk(KERN_INFO, sc->device, "device reset\n"); 657 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 658 if (!cmd) 659 return FAILED; 660 661 memset(cmd, 0, sizeof(*cmd)); 662 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 663 .type = VIRTIO_SCSI_T_TMF, 664 .subtype = cpu_to_virtio32(vscsi->vdev, 665 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET), 666 .lun[0] = 1, 667 .lun[1] = sc->device->id, 668 .lun[2] = (sc->device->lun >> 8) | 0x40, 669 .lun[3] = sc->device->lun & 0xff, 670 }; 671 return virtscsi_tmf(vscsi, cmd); 672 } 673 674 static int virtscsi_device_alloc(struct scsi_device *sdevice) 675 { 676 /* 677 * Passed through SCSI targets (e.g. with qemu's 'scsi-block') 678 * may have transfer limits which come from the host SCSI 679 * controller or something on the host side other than the 680 * target itself. 681 * 682 * To make this work properly, the hypervisor can adjust the 683 * target's VPD information to advertise these limits. But 684 * for that to work, the guest has to look at the VPD pages, 685 * which we won't do by default if it is an SPC-2 device, even 686 * if it does actually support it. 687 * 688 * So, set the blist to always try to read the VPD pages. 689 */ 690 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES; 691 692 return 0; 693 } 694 695 696 /** 697 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth 698 * @sdev: Virtscsi target whose queue depth to change 699 * @qdepth: New queue depth 700 */ 701 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) 702 { 703 struct Scsi_Host *shost = sdev->host; 704 int max_depth = shost->cmd_per_lun; 705 706 return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); 707 } 708 709 static int virtscsi_abort(struct scsi_cmnd *sc) 710 { 711 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 712 struct virtio_scsi_cmd *cmd; 713 714 scmd_printk(KERN_INFO, sc, "abort\n"); 715 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 716 if (!cmd) 717 return FAILED; 718 719 memset(cmd, 0, sizeof(*cmd)); 720 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 721 .type = VIRTIO_SCSI_T_TMF, 722 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 723 .lun[0] = 1, 724 .lun[1] = sc->device->id, 725 .lun[2] = (sc->device->lun >> 8) | 0x40, 726 .lun[3] = sc->device->lun & 0xff, 727 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc), 728 }; 729 return virtscsi_tmf(vscsi, cmd); 730 } 731 732 static void virtscsi_map_queues(struct Scsi_Host *shost) 733 { 734 struct virtio_scsi *vscsi = shost_priv(shost); 735 int i, qoff; 736 737 for (i = 0, qoff = 0; i < shost->nr_maps; i++) { 738 struct blk_mq_queue_map *map = &shost->tag_set.map[i]; 739 740 map->nr_queues = vscsi->io_queues[i]; 741 map->queue_offset = qoff; 742 qoff += map->nr_queues; 743 744 if (map->nr_queues == 0) 745 continue; 746 747 /* 748 * Regular queues have interrupts and hence CPU affinity is 749 * defined by the core virtio code, but polling queues have 750 * no interrupts so we let the block layer assign CPU affinity. 751 */ 752 if (i == HCTX_TYPE_POLL) 753 blk_mq_map_queues(map); 754 else 755 blk_mq_map_hw_queues(map, &vscsi->vdev->dev, 2); 756 } 757 } 758 759 static int virtscsi_mq_poll(struct Scsi_Host *shost, unsigned int queue_num) 760 { 761 struct virtio_scsi *vscsi = shost_priv(shost); 762 struct virtio_scsi_vq *virtscsi_vq = &vscsi->req_vqs[queue_num]; 763 unsigned long flags; 764 unsigned int len; 765 int found = 0; 766 void *buf; 767 768 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); 769 770 while ((buf = virtqueue_get_buf(virtscsi_vq->vq, &len)) != NULL) { 771 virtscsi_complete_cmd(vscsi, buf); 772 found++; 773 } 774 775 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); 776 777 return found; 778 } 779 780 static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq) 781 { 782 struct virtio_scsi *vscsi = shost_priv(shost); 783 784 virtscsi_kick_vq(&vscsi->req_vqs[hwq]); 785 } 786 787 /* 788 * The host guarantees to respond to each command, although I/O 789 * latencies might be higher than on bare metal. Reset the timer 790 * unconditionally to give the host a chance to perform EH. 791 */ 792 static enum scsi_timeout_action virtscsi_eh_timed_out(struct scsi_cmnd *scmnd) 793 { 794 return SCSI_EH_RESET_TIMER; 795 } 796 797 static const struct scsi_host_template virtscsi_host_template = { 798 .module = THIS_MODULE, 799 .name = "Virtio SCSI HBA", 800 .proc_name = "virtio_scsi", 801 .this_id = -1, 802 .cmd_size = sizeof(struct virtio_scsi_cmd), 803 .queuecommand = virtscsi_queuecommand, 804 .mq_poll = virtscsi_mq_poll, 805 .commit_rqs = virtscsi_commit_rqs, 806 .change_queue_depth = virtscsi_change_queue_depth, 807 .eh_abort_handler = virtscsi_abort, 808 .eh_device_reset_handler = virtscsi_device_reset, 809 .eh_timed_out = virtscsi_eh_timed_out, 810 .sdev_init = virtscsi_device_alloc, 811 812 .dma_boundary = UINT_MAX, 813 .map_queues = virtscsi_map_queues, 814 .track_queue_depth = 1, 815 }; 816 817 #define virtscsi_config_get(vdev, fld) \ 818 ({ \ 819 __virtio_native_type(struct virtio_scsi_config, fld) __val; \ 820 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 821 __val; \ 822 }) 823 824 #define virtscsi_config_set(vdev, fld, val) \ 825 do { \ 826 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \ 827 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 828 } while(0) 829 830 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 831 struct virtqueue *vq) 832 { 833 spin_lock_init(&virtscsi_vq->vq_lock); 834 virtscsi_vq->vq = vq; 835 } 836 837 static void virtscsi_remove_vqs(struct virtio_device *vdev) 838 { 839 /* Stop all the virtqueues. */ 840 virtio_reset_device(vdev); 841 vdev->config->del_vqs(vdev); 842 } 843 844 static int virtscsi_init(struct virtio_device *vdev, 845 struct virtio_scsi *vscsi) 846 { 847 int err; 848 u32 i; 849 u32 num_vqs, num_poll_vqs, num_req_vqs; 850 struct virtqueue_info *vqs_info; 851 struct virtqueue **vqs; 852 struct irq_affinity desc = { .pre_vectors = 2 }; 853 854 num_req_vqs = vscsi->num_queues; 855 num_vqs = num_req_vqs + VIRTIO_SCSI_VQ_BASE; 856 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL); 857 vqs_info = kcalloc(num_vqs, sizeof(*vqs_info), GFP_KERNEL); 858 859 if (!vqs || !vqs_info) { 860 err = -ENOMEM; 861 goto out; 862 } 863 864 num_poll_vqs = min_t(unsigned int, virtscsi_poll_queues, 865 num_req_vqs - 1); 866 vscsi->io_queues[HCTX_TYPE_DEFAULT] = num_req_vqs - num_poll_vqs; 867 vscsi->io_queues[HCTX_TYPE_READ] = 0; 868 vscsi->io_queues[HCTX_TYPE_POLL] = num_poll_vqs; 869 870 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n", 871 vscsi->io_queues[HCTX_TYPE_DEFAULT], 872 vscsi->io_queues[HCTX_TYPE_READ], 873 vscsi->io_queues[HCTX_TYPE_POLL]); 874 875 vqs_info[0].callback = virtscsi_ctrl_done; 876 vqs_info[0].name = "control"; 877 vqs_info[1].callback = virtscsi_event_done; 878 vqs_info[1].name = "event"; 879 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs - num_poll_vqs; i++) { 880 vqs_info[i].callback = virtscsi_req_done; 881 vqs_info[i].name = "request"; 882 } 883 884 for (; i < num_vqs; i++) 885 vqs_info[i].name = "request_poll"; 886 887 /* Discover virtqueues and write information to configuration. */ 888 err = virtio_find_vqs(vdev, num_vqs, vqs, vqs_info, &desc); 889 if (err) 890 goto out; 891 892 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 893 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 894 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 895 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 896 vqs[i]); 897 898 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 899 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 900 901 err = 0; 902 903 out: 904 kfree(vqs_info); 905 kfree(vqs); 906 if (err) 907 virtscsi_remove_vqs(vdev); 908 return err; 909 } 910 911 static int virtscsi_probe(struct virtio_device *vdev) 912 { 913 struct Scsi_Host *shost; 914 struct virtio_scsi *vscsi; 915 int err; 916 u32 sg_elems, num_targets; 917 u32 cmd_per_lun; 918 u32 num_queues; 919 920 if (!vdev->config->get) { 921 dev_err(&vdev->dev, "%s failure: config access disabled\n", 922 __func__); 923 return -EINVAL; 924 } 925 926 /* We need to know how many queues before we allocate. */ 927 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; 928 num_queues = min_t(unsigned int, nr_cpu_ids, num_queues); 929 num_queues = blk_mq_num_possible_queues(num_queues); 930 931 num_targets = virtscsi_config_get(vdev, max_target) + 1; 932 933 shost = scsi_host_alloc(&virtscsi_host_template, 934 struct_size(vscsi, req_vqs, num_queues)); 935 if (!shost) 936 return -ENOMEM; 937 938 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 939 shost->sg_tablesize = sg_elems; 940 shost->nr_maps = 1; 941 vscsi = shost_priv(shost); 942 vscsi->vdev = vdev; 943 vscsi->num_queues = num_queues; 944 vdev->priv = shost; 945 946 err = virtscsi_init(vdev, vscsi); 947 if (err) 948 goto virtscsi_init_failed; 949 950 if (vscsi->io_queues[HCTX_TYPE_POLL]) 951 shost->nr_maps = HCTX_TYPE_POLL + 1; 952 953 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq); 954 955 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 956 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 957 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 958 959 /* LUNs > 256 are reported with format 1, so they go in the range 960 * 16640-32767. 961 */ 962 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 963 shost->max_id = num_targets; 964 shost->max_channel = 0; 965 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 966 shost->nr_hw_queues = num_queues; 967 968 #ifdef CONFIG_BLK_DEV_INTEGRITY 969 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 970 int host_prot; 971 972 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 973 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 974 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 975 976 scsi_host_set_prot(shost, host_prot); 977 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 978 } 979 #endif 980 981 err = scsi_add_host(shost, &vdev->dev); 982 if (err) 983 goto scsi_add_host_failed; 984 985 virtio_device_ready(vdev); 986 987 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 988 virtscsi_kick_event_all(vscsi); 989 990 scsi_scan_host(shost); 991 return 0; 992 993 scsi_add_host_failed: 994 vdev->config->del_vqs(vdev); 995 virtscsi_init_failed: 996 scsi_host_put(shost); 997 return err; 998 } 999 1000 static void virtscsi_remove(struct virtio_device *vdev) 1001 { 1002 struct Scsi_Host *shost = virtio_scsi_host(vdev); 1003 struct virtio_scsi *vscsi = shost_priv(shost); 1004 1005 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1006 virtscsi_cancel_event_work(vscsi); 1007 1008 scsi_remove_host(shost); 1009 virtscsi_remove_vqs(vdev); 1010 scsi_host_put(shost); 1011 } 1012 1013 #ifdef CONFIG_PM_SLEEP 1014 static int virtscsi_freeze(struct virtio_device *vdev) 1015 { 1016 virtscsi_remove_vqs(vdev); 1017 return 0; 1018 } 1019 1020 static int virtscsi_restore(struct virtio_device *vdev) 1021 { 1022 struct Scsi_Host *sh = virtio_scsi_host(vdev); 1023 struct virtio_scsi *vscsi = shost_priv(sh); 1024 int err; 1025 1026 err = virtscsi_init(vdev, vscsi); 1027 if (err) 1028 return err; 1029 1030 virtio_device_ready(vdev); 1031 1032 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1033 virtscsi_kick_event_all(vscsi); 1034 1035 return err; 1036 } 1037 #endif 1038 1039 static struct virtio_device_id id_table[] = { 1040 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 1041 { 0 }, 1042 }; 1043 1044 static unsigned int features[] = { 1045 VIRTIO_SCSI_F_HOTPLUG, 1046 VIRTIO_SCSI_F_CHANGE, 1047 #ifdef CONFIG_BLK_DEV_INTEGRITY 1048 VIRTIO_SCSI_F_T10_PI, 1049 #endif 1050 }; 1051 1052 static struct virtio_driver virtio_scsi_driver = { 1053 .feature_table = features, 1054 .feature_table_size = ARRAY_SIZE(features), 1055 .driver.name = KBUILD_MODNAME, 1056 .id_table = id_table, 1057 .probe = virtscsi_probe, 1058 #ifdef CONFIG_PM_SLEEP 1059 .freeze = virtscsi_freeze, 1060 .restore = virtscsi_restore, 1061 #endif 1062 .remove = virtscsi_remove, 1063 }; 1064 1065 static int __init virtio_scsi_init(void) 1066 { 1067 int ret = -ENOMEM; 1068 1069 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); 1070 if (!virtscsi_cmd_cache) { 1071 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); 1072 goto error; 1073 } 1074 1075 1076 virtscsi_cmd_pool = 1077 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, 1078 virtscsi_cmd_cache); 1079 if (!virtscsi_cmd_pool) { 1080 pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); 1081 goto error; 1082 } 1083 ret = register_virtio_driver(&virtio_scsi_driver); 1084 if (ret < 0) 1085 goto error; 1086 1087 return 0; 1088 1089 error: 1090 mempool_destroy(virtscsi_cmd_pool); 1091 virtscsi_cmd_pool = NULL; 1092 kmem_cache_destroy(virtscsi_cmd_cache); 1093 virtscsi_cmd_cache = NULL; 1094 return ret; 1095 } 1096 1097 static void __exit virtio_scsi_fini(void) 1098 { 1099 unregister_virtio_driver(&virtio_scsi_driver); 1100 mempool_destroy(virtscsi_cmd_pool); 1101 kmem_cache_destroy(virtscsi_cmd_cache); 1102 } 1103 module_init(virtio_scsi_init); 1104 module_exit(virtio_scsi_fini); 1105 1106 MODULE_DEVICE_TABLE(virtio, id_table); 1107 MODULE_DESCRIPTION("Virtio SCSI HBA driver"); 1108 MODULE_LICENSE("GPL"); 1109