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 <scsi/scsi_host.h> 26 #include <scsi/scsi_device.h> 27 #include <scsi/scsi_cmnd.h> 28 #include <scsi/scsi_tcq.h> 29 #include <scsi/scsi_devinfo.h> 30 #include <linux/seqlock.h> 31 #include <linux/blk-mq-virtio.h> 32 33 #include "sd.h" 34 35 #define VIRTIO_SCSI_MEMPOOL_SZ 64 36 #define VIRTIO_SCSI_EVENT_LEN 8 37 #define VIRTIO_SCSI_VQ_BASE 2 38 39 /* Command queue element */ 40 struct virtio_scsi_cmd { 41 struct scsi_cmnd *sc; 42 struct completion *comp; 43 union { 44 struct virtio_scsi_cmd_req cmd; 45 struct virtio_scsi_cmd_req_pi cmd_pi; 46 struct virtio_scsi_ctrl_tmf_req tmf; 47 struct virtio_scsi_ctrl_an_req an; 48 } req; 49 union { 50 struct virtio_scsi_cmd_resp cmd; 51 struct virtio_scsi_ctrl_tmf_resp tmf; 52 struct virtio_scsi_ctrl_an_resp an; 53 struct virtio_scsi_event evt; 54 } resp; 55 } ____cacheline_aligned_in_smp; 56 57 struct virtio_scsi_event_node { 58 struct virtio_scsi *vscsi; 59 struct virtio_scsi_event event; 60 struct work_struct work; 61 }; 62 63 struct virtio_scsi_vq { 64 /* Protects vq */ 65 spinlock_t vq_lock; 66 67 struct virtqueue *vq; 68 }; 69 70 /* Driver instance state */ 71 struct virtio_scsi { 72 struct virtio_device *vdev; 73 74 /* Get some buffers ready for event vq */ 75 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN]; 76 77 u32 num_queues; 78 79 struct hlist_node node; 80 81 /* Protected by event_vq lock */ 82 bool stop_events; 83 84 struct virtio_scsi_vq ctrl_vq; 85 struct virtio_scsi_vq event_vq; 86 struct virtio_scsi_vq req_vqs[]; 87 }; 88 89 static struct kmem_cache *virtscsi_cmd_cache; 90 static mempool_t *virtscsi_cmd_pool; 91 92 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev) 93 { 94 return vdev->priv; 95 } 96 97 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid) 98 { 99 if (resid) 100 scsi_set_resid(sc, min(resid, scsi_bufflen(sc))); 101 } 102 103 /* 104 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done 105 * 106 * Called with vq_lock held. 107 */ 108 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf) 109 { 110 struct virtio_scsi_cmd *cmd = buf; 111 struct scsi_cmnd *sc = cmd->sc; 112 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd; 113 114 dev_dbg(&sc->device->sdev_gendev, 115 "cmd %p response %u status %#02x sense_len %u\n", 116 sc, resp->response, resp->status, resp->sense_len); 117 118 sc->result = resp->status; 119 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid)); 120 switch (resp->response) { 121 case VIRTIO_SCSI_S_OK: 122 set_host_byte(sc, DID_OK); 123 break; 124 case VIRTIO_SCSI_S_OVERRUN: 125 set_host_byte(sc, DID_ERROR); 126 break; 127 case VIRTIO_SCSI_S_ABORTED: 128 set_host_byte(sc, DID_ABORT); 129 break; 130 case VIRTIO_SCSI_S_BAD_TARGET: 131 set_host_byte(sc, DID_BAD_TARGET); 132 break; 133 case VIRTIO_SCSI_S_RESET: 134 set_host_byte(sc, DID_RESET); 135 break; 136 case VIRTIO_SCSI_S_BUSY: 137 set_host_byte(sc, DID_BUS_BUSY); 138 break; 139 case VIRTIO_SCSI_S_TRANSPORT_FAILURE: 140 set_host_byte(sc, DID_TRANSPORT_DISRUPTED); 141 break; 142 case VIRTIO_SCSI_S_TARGET_FAILURE: 143 set_host_byte(sc, DID_TARGET_FAILURE); 144 break; 145 case VIRTIO_SCSI_S_NEXUS_FAILURE: 146 set_host_byte(sc, DID_NEXUS_FAILURE); 147 break; 148 default: 149 scmd_printk(KERN_WARNING, sc, "Unknown response %d", 150 resp->response); 151 fallthrough; 152 case VIRTIO_SCSI_S_FAILURE: 153 set_host_byte(sc, DID_ERROR); 154 break; 155 } 156 157 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) > 158 VIRTIO_SCSI_SENSE_SIZE); 159 if (resp->sense_len) { 160 memcpy(sc->sense_buffer, resp->sense, 161 min_t(u32, 162 virtio32_to_cpu(vscsi->vdev, resp->sense_len), 163 VIRTIO_SCSI_SENSE_SIZE)); 164 } 165 166 sc->scsi_done(sc); 167 } 168 169 static void virtscsi_vq_done(struct virtio_scsi *vscsi, 170 struct virtio_scsi_vq *virtscsi_vq, 171 void (*fn)(struct virtio_scsi *vscsi, void *buf)) 172 { 173 void *buf; 174 unsigned int len; 175 unsigned long flags; 176 struct virtqueue *vq = virtscsi_vq->vq; 177 178 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); 179 do { 180 virtqueue_disable_cb(vq); 181 while ((buf = virtqueue_get_buf(vq, &len)) != NULL) 182 fn(vscsi, buf); 183 184 if (unlikely(virtqueue_is_broken(vq))) 185 break; 186 } while (!virtqueue_enable_cb(vq)); 187 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); 188 } 189 190 static void virtscsi_req_done(struct virtqueue *vq) 191 { 192 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 193 struct virtio_scsi *vscsi = shost_priv(sh); 194 int index = vq->index - VIRTIO_SCSI_VQ_BASE; 195 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index]; 196 197 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd); 198 }; 199 200 static void virtscsi_poll_requests(struct virtio_scsi *vscsi) 201 { 202 int i, num_vqs; 203 204 num_vqs = vscsi->num_queues; 205 for (i = 0; i < num_vqs; i++) 206 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i], 207 virtscsi_complete_cmd); 208 } 209 210 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf) 211 { 212 struct virtio_scsi_cmd *cmd = buf; 213 214 if (cmd->comp) 215 complete(cmd->comp); 216 } 217 218 static void virtscsi_ctrl_done(struct virtqueue *vq) 219 { 220 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 221 struct virtio_scsi *vscsi = shost_priv(sh); 222 223 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free); 224 }; 225 226 static void virtscsi_handle_event(struct work_struct *work); 227 228 static int virtscsi_kick_event(struct virtio_scsi *vscsi, 229 struct virtio_scsi_event_node *event_node) 230 { 231 int err; 232 struct scatterlist sg; 233 unsigned long flags; 234 235 INIT_WORK(&event_node->work, virtscsi_handle_event); 236 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event)); 237 238 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags); 239 240 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node, 241 GFP_ATOMIC); 242 if (!err) 243 virtqueue_kick(vscsi->event_vq.vq); 244 245 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags); 246 247 return err; 248 } 249 250 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi) 251 { 252 int i; 253 254 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) { 255 vscsi->event_list[i].vscsi = vscsi; 256 virtscsi_kick_event(vscsi, &vscsi->event_list[i]); 257 } 258 259 return 0; 260 } 261 262 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi) 263 { 264 int i; 265 266 /* Stop scheduling work before calling cancel_work_sync. */ 267 spin_lock_irq(&vscsi->event_vq.vq_lock); 268 vscsi->stop_events = true; 269 spin_unlock_irq(&vscsi->event_vq.vq_lock); 270 271 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) 272 cancel_work_sync(&vscsi->event_list[i].work); 273 } 274 275 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, 276 struct virtio_scsi_event *event) 277 { 278 struct scsi_device *sdev; 279 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 280 unsigned int target = event->lun[1]; 281 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 282 283 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) { 284 case VIRTIO_SCSI_EVT_RESET_RESCAN: 285 if (lun == 0) { 286 scsi_scan_target(&shost->shost_gendev, 0, target, 287 SCAN_WILD_CARD, SCSI_SCAN_INITIAL); 288 } else { 289 scsi_add_device(shost, 0, target, lun); 290 } 291 break; 292 case VIRTIO_SCSI_EVT_RESET_REMOVED: 293 sdev = scsi_device_lookup(shost, 0, target, lun); 294 if (sdev) { 295 scsi_remove_device(sdev); 296 scsi_device_put(sdev); 297 } else { 298 pr_err("SCSI device %d 0 %d %d not found\n", 299 shost->host_no, target, lun); 300 } 301 break; 302 default: 303 pr_info("Unsupported virtio scsi event reason %x\n", event->reason); 304 } 305 } 306 307 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, 308 struct virtio_scsi_event *event) 309 { 310 struct scsi_device *sdev; 311 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 312 unsigned int target = event->lun[1]; 313 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 314 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255; 315 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8; 316 317 sdev = scsi_device_lookup(shost, 0, target, lun); 318 if (!sdev) { 319 pr_err("SCSI device %d 0 %d %d not found\n", 320 shost->host_no, target, lun); 321 return; 322 } 323 324 /* Handle "Parameters changed", "Mode parameters changed", and 325 "Capacity data has changed". */ 326 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) 327 scsi_rescan_device(&sdev->sdev_gendev); 328 329 scsi_device_put(sdev); 330 } 331 332 static void virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi) 333 { 334 struct scsi_device *sdev; 335 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 336 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 337 int result, inquiry_len, inq_result_len = 256; 338 char *inq_result = kmalloc(inq_result_len, GFP_KERNEL); 339 340 shost_for_each_device(sdev, shost) { 341 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 342 343 memset(scsi_cmd, 0, sizeof(scsi_cmd)); 344 scsi_cmd[0] = INQUIRY; 345 scsi_cmd[4] = (unsigned char) inquiry_len; 346 347 memset(inq_result, 0, inq_result_len); 348 349 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 350 inq_result, inquiry_len, NULL, 351 SD_TIMEOUT, SD_MAX_RETRIES, NULL); 352 353 if (result == 0 && inq_result[0] >> 5) { 354 /* PQ indicates the LUN is not attached */ 355 scsi_remove_device(sdev); 356 } else if (result > 0 && host_byte(result) == DID_BAD_TARGET) { 357 /* 358 * If all LUNs of a virtio-scsi device are unplugged 359 * it will respond with BAD TARGET on any INQUIRY 360 * command. 361 * Remove the device in this case as well. 362 */ 363 scsi_remove_device(sdev); 364 } 365 } 366 367 kfree(inq_result); 368 } 369 370 static void virtscsi_handle_event(struct work_struct *work) 371 { 372 struct virtio_scsi_event_node *event_node = 373 container_of(work, struct virtio_scsi_event_node, work); 374 struct virtio_scsi *vscsi = event_node->vscsi; 375 struct virtio_scsi_event *event = &event_node->event; 376 377 if (event->event & 378 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { 379 event->event &= ~cpu_to_virtio32(vscsi->vdev, 380 VIRTIO_SCSI_T_EVENTS_MISSED); 381 virtscsi_rescan_hotunplug(vscsi); 382 scsi_scan_host(virtio_scsi_host(vscsi->vdev)); 383 } 384 385 switch (virtio32_to_cpu(vscsi->vdev, event->event)) { 386 case VIRTIO_SCSI_T_NO_EVENT: 387 break; 388 case VIRTIO_SCSI_T_TRANSPORT_RESET: 389 virtscsi_handle_transport_reset(vscsi, event); 390 break; 391 case VIRTIO_SCSI_T_PARAM_CHANGE: 392 virtscsi_handle_param_change(vscsi, event); 393 break; 394 default: 395 pr_err("Unsupported virtio scsi event %x\n", event->event); 396 } 397 virtscsi_kick_event(vscsi, event_node); 398 } 399 400 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) 401 { 402 struct virtio_scsi_event_node *event_node = buf; 403 404 if (!vscsi->stop_events) 405 queue_work(system_freezable_wq, &event_node->work); 406 } 407 408 static void virtscsi_event_done(struct virtqueue *vq) 409 { 410 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 411 struct virtio_scsi *vscsi = shost_priv(sh); 412 413 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); 414 }; 415 416 static int __virtscsi_add_cmd(struct virtqueue *vq, 417 struct virtio_scsi_cmd *cmd, 418 size_t req_size, size_t resp_size) 419 { 420 struct scsi_cmnd *sc = cmd->sc; 421 struct scatterlist *sgs[6], req, resp; 422 struct sg_table *out, *in; 423 unsigned out_num = 0, in_num = 0; 424 425 out = in = NULL; 426 427 if (sc && sc->sc_data_direction != DMA_NONE) { 428 if (sc->sc_data_direction != DMA_FROM_DEVICE) 429 out = &sc->sdb.table; 430 if (sc->sc_data_direction != DMA_TO_DEVICE) 431 in = &sc->sdb.table; 432 } 433 434 /* Request header. */ 435 sg_init_one(&req, &cmd->req, req_size); 436 sgs[out_num++] = &req; 437 438 /* Data-out buffer. */ 439 if (out) { 440 /* Place WRITE protection SGLs before Data OUT payload */ 441 if (scsi_prot_sg_count(sc)) 442 sgs[out_num++] = scsi_prot_sglist(sc); 443 sgs[out_num++] = out->sgl; 444 } 445 446 /* Response header. */ 447 sg_init_one(&resp, &cmd->resp, resp_size); 448 sgs[out_num + in_num++] = &resp; 449 450 /* Data-in buffer */ 451 if (in) { 452 /* Place READ protection SGLs before Data IN payload */ 453 if (scsi_prot_sg_count(sc)) 454 sgs[out_num + in_num++] = scsi_prot_sglist(sc); 455 sgs[out_num + in_num++] = in->sgl; 456 } 457 458 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); 459 } 460 461 static void virtscsi_kick_vq(struct virtio_scsi_vq *vq) 462 { 463 bool needs_kick; 464 unsigned long flags; 465 466 spin_lock_irqsave(&vq->vq_lock, flags); 467 needs_kick = virtqueue_kick_prepare(vq->vq); 468 spin_unlock_irqrestore(&vq->vq_lock, flags); 469 470 if (needs_kick) 471 virtqueue_notify(vq->vq); 472 } 473 474 /** 475 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it 476 * @vq : the struct virtqueue we're talking about 477 * @cmd : command structure 478 * @req_size : size of the request buffer 479 * @resp_size : size of the response buffer 480 * @kick : whether to kick the virtqueue immediately 481 */ 482 static int virtscsi_add_cmd(struct virtio_scsi_vq *vq, 483 struct virtio_scsi_cmd *cmd, 484 size_t req_size, size_t resp_size, 485 bool kick) 486 { 487 unsigned long flags; 488 int err; 489 bool needs_kick = false; 490 491 spin_lock_irqsave(&vq->vq_lock, flags); 492 err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size); 493 if (!err && kick) 494 needs_kick = virtqueue_kick_prepare(vq->vq); 495 496 spin_unlock_irqrestore(&vq->vq_lock, flags); 497 498 if (needs_kick) 499 virtqueue_notify(vq->vq); 500 return err; 501 } 502 503 static void virtio_scsi_init_hdr(struct virtio_device *vdev, 504 struct virtio_scsi_cmd_req *cmd, 505 struct scsi_cmnd *sc) 506 { 507 cmd->lun[0] = 1; 508 cmd->lun[1] = sc->device->id; 509 cmd->lun[2] = (sc->device->lun >> 8) | 0x40; 510 cmd->lun[3] = sc->device->lun & 0xff; 511 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc); 512 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; 513 cmd->prio = 0; 514 cmd->crn = 0; 515 } 516 517 #ifdef CONFIG_BLK_DEV_INTEGRITY 518 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, 519 struct virtio_scsi_cmd_req_pi *cmd_pi, 520 struct scsi_cmnd *sc) 521 { 522 struct request *rq = scsi_cmd_to_rq(sc); 523 struct blk_integrity *bi; 524 525 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc); 526 527 if (!rq || !scsi_prot_sg_count(sc)) 528 return; 529 530 bi = blk_get_integrity(rq->rq_disk); 531 532 if (sc->sc_data_direction == DMA_TO_DEVICE) 533 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, 534 bio_integrity_bytes(bi, 535 blk_rq_sectors(rq))); 536 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 537 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, 538 bio_integrity_bytes(bi, 539 blk_rq_sectors(rq))); 540 } 541 #endif 542 543 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, 544 struct scsi_cmnd *sc) 545 { 546 u32 tag = blk_mq_unique_tag(scsi_cmd_to_rq(sc)); 547 u16 hwq = blk_mq_unique_tag_to_hwq(tag); 548 549 return &vscsi->req_vqs[hwq]; 550 } 551 552 static int virtscsi_queuecommand(struct Scsi_Host *shost, 553 struct scsi_cmnd *sc) 554 { 555 struct virtio_scsi *vscsi = shost_priv(shost); 556 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc); 557 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 558 bool kick; 559 unsigned long flags; 560 int req_size; 561 int ret; 562 563 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 564 565 /* TODO: check feature bit and fail if unsupported? */ 566 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 567 568 dev_dbg(&sc->device->sdev_gendev, 569 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 570 571 cmd->sc = sc; 572 573 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 574 575 #ifdef CONFIG_BLK_DEV_INTEGRITY 576 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 577 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc); 578 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 579 req_size = sizeof(cmd->req.cmd_pi); 580 } else 581 #endif 582 { 583 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc); 584 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 585 req_size = sizeof(cmd->req.cmd); 586 } 587 588 kick = (sc->flags & SCMD_LAST) != 0; 589 ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick); 590 if (ret == -EIO) { 591 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET; 592 spin_lock_irqsave(&req_vq->vq_lock, flags); 593 virtscsi_complete_cmd(vscsi, cmd); 594 spin_unlock_irqrestore(&req_vq->vq_lock, flags); 595 } else if (ret != 0) { 596 return SCSI_MLQUEUE_HOST_BUSY; 597 } 598 return 0; 599 } 600 601 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 602 { 603 DECLARE_COMPLETION_ONSTACK(comp); 604 int ret = FAILED; 605 606 cmd->comp = ∁ 607 if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd, 608 sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0) 609 goto out; 610 611 wait_for_completion(&comp); 612 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 613 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 614 ret = SUCCESS; 615 616 /* 617 * The spec guarantees that all requests related to the TMF have 618 * been completed, but the callback might not have run yet if 619 * we're using independent interrupts (e.g. MSI). Poll the 620 * virtqueues once. 621 * 622 * In the abort case, sc->scsi_done will do nothing, because 623 * the block layer must have detected a timeout and as a result 624 * REQ_ATOM_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 .driver.name = KBUILD_MODNAME, 981 .driver.owner = THIS_MODULE, 982 .id_table = id_table, 983 .probe = virtscsi_probe, 984 #ifdef CONFIG_PM_SLEEP 985 .freeze = virtscsi_freeze, 986 .restore = virtscsi_restore, 987 #endif 988 .remove = virtscsi_remove, 989 }; 990 991 static int __init init(void) 992 { 993 int ret = -ENOMEM; 994 995 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); 996 if (!virtscsi_cmd_cache) { 997 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); 998 goto error; 999 } 1000 1001 1002 virtscsi_cmd_pool = 1003 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, 1004 virtscsi_cmd_cache); 1005 if (!virtscsi_cmd_pool) { 1006 pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); 1007 goto error; 1008 } 1009 ret = register_virtio_driver(&virtio_scsi_driver); 1010 if (ret < 0) 1011 goto error; 1012 1013 return 0; 1014 1015 error: 1016 mempool_destroy(virtscsi_cmd_pool); 1017 virtscsi_cmd_pool = NULL; 1018 kmem_cache_destroy(virtscsi_cmd_cache); 1019 virtscsi_cmd_cache = NULL; 1020 return ret; 1021 } 1022 1023 static void __exit fini(void) 1024 { 1025 unregister_virtio_driver(&virtio_scsi_driver); 1026 mempool_destroy(virtscsi_cmd_pool); 1027 kmem_cache_destroy(virtscsi_cmd_cache); 1028 } 1029 module_init(init); 1030 module_exit(fini); 1031 1032 MODULE_DEVICE_TABLE(virtio, id_table); 1033 MODULE_DESCRIPTION("Virtio SCSI HBA driver"); 1034 MODULE_LICENSE("GPL"); 1035