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