1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Virtio SCSI HBA driver 4 * 5 * Copyright IBM Corp. 2010 6 * Copyright Red Hat, Inc. 2011 7 * 8 * Authors: 9 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> 10 * Paolo Bonzini <pbonzini@redhat.com> 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/module.h> 16 #include <linux/slab.h> 17 #include <linux/mempool.h> 18 #include <linux/interrupt.h> 19 #include <linux/virtio.h> 20 #include <linux/virtio_ids.h> 21 #include <linux/virtio_config.h> 22 #include <linux/virtio_scsi.h> 23 #include <linux/cpu.h> 24 #include <linux/blkdev.h> 25 #include <linux/blk-integrity.h> 26 #include <scsi/scsi_host.h> 27 #include <scsi/scsi_device.h> 28 #include <scsi/scsi_cmnd.h> 29 #include <scsi/scsi_tcq.h> 30 #include <scsi/scsi_devinfo.h> 31 #include <linux/seqlock.h> 32 #include <linux/blk-mq-virtio.h> 33 34 #include "sd.h" 35 36 #define VIRTIO_SCSI_MEMPOOL_SZ 64 37 #define VIRTIO_SCSI_EVENT_LEN 8 38 #define VIRTIO_SCSI_VQ_BASE 2 39 40 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 struct virtio_scsi_vq req_vqs[]; 94 }; 95 96 static struct kmem_cache *virtscsi_cmd_cache; 97 static mempool_t *virtscsi_cmd_pool; 98 99 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev) 100 { 101 return vdev->priv; 102 } 103 104 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid) 105 { 106 if (resid) 107 scsi_set_resid(sc, min(resid, scsi_bufflen(sc))); 108 } 109 110 /* 111 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done 112 * 113 * Called with vq_lock held. 114 */ 115 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf) 116 { 117 struct virtio_scsi_cmd *cmd = buf; 118 struct scsi_cmnd *sc = cmd->sc; 119 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd; 120 121 dev_dbg(&sc->device->sdev_gendev, 122 "cmd %p response %u status %#02x sense_len %u\n", 123 sc, resp->response, resp->status, resp->sense_len); 124 125 sc->result = resp->status; 126 virtscsi_compute_resid(sc, virtio32_to_cpu(vscsi->vdev, resp->resid)); 127 switch (resp->response) { 128 case VIRTIO_SCSI_S_OK: 129 set_host_byte(sc, DID_OK); 130 break; 131 case VIRTIO_SCSI_S_OVERRUN: 132 set_host_byte(sc, DID_ERROR); 133 break; 134 case VIRTIO_SCSI_S_ABORTED: 135 set_host_byte(sc, DID_ABORT); 136 break; 137 case VIRTIO_SCSI_S_BAD_TARGET: 138 set_host_byte(sc, DID_BAD_TARGET); 139 break; 140 case VIRTIO_SCSI_S_RESET: 141 set_host_byte(sc, DID_RESET); 142 break; 143 case VIRTIO_SCSI_S_BUSY: 144 set_host_byte(sc, DID_BUS_BUSY); 145 break; 146 case VIRTIO_SCSI_S_TRANSPORT_FAILURE: 147 set_host_byte(sc, DID_TRANSPORT_DISRUPTED); 148 break; 149 case VIRTIO_SCSI_S_TARGET_FAILURE: 150 set_host_byte(sc, DID_BAD_TARGET); 151 break; 152 case VIRTIO_SCSI_S_NEXUS_FAILURE: 153 set_status_byte(sc, SAM_STAT_RESERVATION_CONFLICT); 154 break; 155 default: 156 scmd_printk(KERN_WARNING, sc, "Unknown response %d", 157 resp->response); 158 fallthrough; 159 case VIRTIO_SCSI_S_FAILURE: 160 set_host_byte(sc, DID_ERROR); 161 break; 162 } 163 164 WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) > 165 VIRTIO_SCSI_SENSE_SIZE); 166 if (resp->sense_len) { 167 memcpy(sc->sense_buffer, resp->sense, 168 min_t(u32, 169 virtio32_to_cpu(vscsi->vdev, resp->sense_len), 170 VIRTIO_SCSI_SENSE_SIZE)); 171 } 172 173 scsi_done(sc); 174 } 175 176 static void virtscsi_vq_done(struct virtio_scsi *vscsi, 177 struct virtio_scsi_vq *virtscsi_vq, 178 void (*fn)(struct virtio_scsi *vscsi, void *buf)) 179 { 180 void *buf; 181 unsigned int len; 182 unsigned long flags; 183 struct virtqueue *vq = virtscsi_vq->vq; 184 185 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); 186 do { 187 virtqueue_disable_cb(vq); 188 while ((buf = virtqueue_get_buf(vq, &len)) != NULL) 189 fn(vscsi, buf); 190 191 } while (!virtqueue_enable_cb(vq)); 192 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); 193 } 194 195 static void virtscsi_req_done(struct virtqueue *vq) 196 { 197 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 198 struct virtio_scsi *vscsi = shost_priv(sh); 199 int index = vq->index - VIRTIO_SCSI_VQ_BASE; 200 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index]; 201 202 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd); 203 }; 204 205 static void virtscsi_poll_requests(struct virtio_scsi *vscsi) 206 { 207 int i, num_vqs; 208 209 num_vqs = vscsi->num_queues; 210 for (i = 0; i < num_vqs; i++) 211 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i], 212 virtscsi_complete_cmd); 213 } 214 215 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf) 216 { 217 struct virtio_scsi_cmd *cmd = buf; 218 219 if (cmd->comp) 220 complete(cmd->comp); 221 } 222 223 static void virtscsi_ctrl_done(struct virtqueue *vq) 224 { 225 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 226 struct virtio_scsi *vscsi = shost_priv(sh); 227 228 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free); 229 }; 230 231 static void virtscsi_handle_event(struct work_struct *work); 232 233 static int virtscsi_kick_event(struct virtio_scsi *vscsi, 234 struct virtio_scsi_event_node *event_node) 235 { 236 int err; 237 struct scatterlist sg; 238 unsigned long flags; 239 240 INIT_WORK(&event_node->work, virtscsi_handle_event); 241 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event)); 242 243 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags); 244 245 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node, 246 GFP_ATOMIC); 247 if (!err) 248 virtqueue_kick(vscsi->event_vq.vq); 249 250 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags); 251 252 return err; 253 } 254 255 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi) 256 { 257 int i; 258 259 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) { 260 vscsi->event_list[i].vscsi = vscsi; 261 virtscsi_kick_event(vscsi, &vscsi->event_list[i]); 262 } 263 264 return 0; 265 } 266 267 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi) 268 { 269 int i; 270 271 /* Stop scheduling work before calling cancel_work_sync. */ 272 spin_lock_irq(&vscsi->event_vq.vq_lock); 273 vscsi->stop_events = true; 274 spin_unlock_irq(&vscsi->event_vq.vq_lock); 275 276 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) 277 cancel_work_sync(&vscsi->event_list[i].work); 278 } 279 280 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, 281 struct virtio_scsi_event *event) 282 { 283 struct scsi_device *sdev; 284 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 285 unsigned int target = event->lun[1]; 286 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 287 288 switch (virtio32_to_cpu(vscsi->vdev, event->reason)) { 289 case VIRTIO_SCSI_EVT_RESET_RESCAN: 290 if (lun == 0) { 291 scsi_scan_target(&shost->shost_gendev, 0, target, 292 SCAN_WILD_CARD, SCSI_SCAN_INITIAL); 293 } else { 294 scsi_add_device(shost, 0, target, lun); 295 } 296 break; 297 case VIRTIO_SCSI_EVT_RESET_REMOVED: 298 sdev = scsi_device_lookup(shost, 0, target, lun); 299 if (sdev) { 300 scsi_remove_device(sdev); 301 scsi_device_put(sdev); 302 } else { 303 pr_err("SCSI device %d 0 %d %d not found\n", 304 shost->host_no, target, lun); 305 } 306 break; 307 default: 308 pr_info("Unsupported virtio scsi event reason %x\n", event->reason); 309 } 310 } 311 312 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, 313 struct virtio_scsi_event *event) 314 { 315 struct scsi_device *sdev; 316 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 317 unsigned int target = event->lun[1]; 318 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 319 u8 asc = virtio32_to_cpu(vscsi->vdev, event->reason) & 255; 320 u8 ascq = virtio32_to_cpu(vscsi->vdev, event->reason) >> 8; 321 322 sdev = scsi_device_lookup(shost, 0, target, lun); 323 if (!sdev) { 324 pr_err("SCSI device %d 0 %d %d not found\n", 325 shost->host_no, target, lun); 326 return; 327 } 328 329 /* Handle "Parameters changed", "Mode parameters changed", and 330 "Capacity data has changed". */ 331 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) 332 scsi_rescan_device(sdev); 333 334 scsi_device_put(sdev); 335 } 336 337 static int virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi) 338 { 339 struct scsi_device *sdev; 340 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 341 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 342 int result, inquiry_len, inq_result_len = 256; 343 char *inq_result = kmalloc(inq_result_len, GFP_KERNEL); 344 345 if (!inq_result) 346 return -ENOMEM; 347 348 shost_for_each_device(sdev, shost) { 349 inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 350 351 memset(scsi_cmd, 0, sizeof(scsi_cmd)); 352 scsi_cmd[0] = INQUIRY; 353 scsi_cmd[4] = (unsigned char) inquiry_len; 354 355 memset(inq_result, 0, inq_result_len); 356 357 result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, 358 inq_result, inquiry_len, 359 SD_TIMEOUT, SD_MAX_RETRIES, NULL); 360 361 if (result == 0 && inq_result[0] >> 5) { 362 /* PQ indicates the LUN is not attached */ 363 scsi_remove_device(sdev); 364 } else if (result > 0 && host_byte(result) == DID_BAD_TARGET) { 365 /* 366 * If all LUNs of a virtio-scsi device are unplugged 367 * it will respond with BAD TARGET on any INQUIRY 368 * command. 369 * Remove the device in this case as well. 370 */ 371 scsi_remove_device(sdev); 372 } 373 } 374 375 kfree(inq_result); 376 return 0; 377 } 378 379 static void virtscsi_handle_event(struct work_struct *work) 380 { 381 struct virtio_scsi_event_node *event_node = 382 container_of(work, struct virtio_scsi_event_node, work); 383 struct virtio_scsi *vscsi = event_node->vscsi; 384 struct virtio_scsi_event *event = &event_node->event; 385 386 if (event->event & 387 cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { 388 int ret; 389 390 event->event &= ~cpu_to_virtio32(vscsi->vdev, 391 VIRTIO_SCSI_T_EVENTS_MISSED); 392 ret = virtscsi_rescan_hotunplug(vscsi); 393 if (ret) 394 return; 395 scsi_scan_host(virtio_scsi_host(vscsi->vdev)); 396 } 397 398 switch (virtio32_to_cpu(vscsi->vdev, event->event)) { 399 case VIRTIO_SCSI_T_NO_EVENT: 400 break; 401 case VIRTIO_SCSI_T_TRANSPORT_RESET: 402 virtscsi_handle_transport_reset(vscsi, event); 403 break; 404 case VIRTIO_SCSI_T_PARAM_CHANGE: 405 virtscsi_handle_param_change(vscsi, event); 406 break; 407 default: 408 pr_err("Unsupported virtio scsi event %x\n", event->event); 409 } 410 virtscsi_kick_event(vscsi, event_node); 411 } 412 413 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) 414 { 415 struct virtio_scsi_event_node *event_node = buf; 416 417 if (!vscsi->stop_events) 418 queue_work(system_freezable_wq, &event_node->work); 419 } 420 421 static void virtscsi_event_done(struct virtqueue *vq) 422 { 423 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 424 struct virtio_scsi *vscsi = shost_priv(sh); 425 426 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); 427 }; 428 429 static int __virtscsi_add_cmd(struct virtqueue *vq, 430 struct virtio_scsi_cmd *cmd, 431 size_t req_size, size_t resp_size) 432 { 433 struct scsi_cmnd *sc = cmd->sc; 434 struct scatterlist *sgs[6], req, resp; 435 struct sg_table *out, *in; 436 unsigned out_num = 0, in_num = 0; 437 438 out = in = NULL; 439 440 if (sc && sc->sc_data_direction != DMA_NONE) { 441 if (sc->sc_data_direction != DMA_FROM_DEVICE) 442 out = &sc->sdb.table; 443 if (sc->sc_data_direction != DMA_TO_DEVICE) 444 in = &sc->sdb.table; 445 } 446 447 /* Request header. */ 448 sg_init_one(&req, &cmd->req, req_size); 449 sgs[out_num++] = &req; 450 451 /* Data-out buffer. */ 452 if (out) { 453 /* Place WRITE protection SGLs before Data OUT payload */ 454 if (scsi_prot_sg_count(sc)) 455 sgs[out_num++] = scsi_prot_sglist(sc); 456 sgs[out_num++] = out->sgl; 457 } 458 459 /* Response header. */ 460 sg_init_one(&resp, &cmd->resp, resp_size); 461 sgs[out_num + in_num++] = &resp; 462 463 /* Data-in buffer */ 464 if (in) { 465 /* Place READ protection SGLs before Data IN payload */ 466 if (scsi_prot_sg_count(sc)) 467 sgs[out_num + in_num++] = scsi_prot_sglist(sc); 468 sgs[out_num + in_num++] = in->sgl; 469 } 470 471 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); 472 } 473 474 static void virtscsi_kick_vq(struct virtio_scsi_vq *vq) 475 { 476 bool needs_kick; 477 unsigned long flags; 478 479 spin_lock_irqsave(&vq->vq_lock, flags); 480 needs_kick = virtqueue_kick_prepare(vq->vq); 481 spin_unlock_irqrestore(&vq->vq_lock, flags); 482 483 if (needs_kick) 484 virtqueue_notify(vq->vq); 485 } 486 487 /** 488 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it 489 * @vq : the struct virtqueue we're talking about 490 * @cmd : command structure 491 * @req_size : size of the request buffer 492 * @resp_size : size of the response buffer 493 * @kick : whether to kick the virtqueue immediately 494 */ 495 static int virtscsi_add_cmd(struct virtio_scsi_vq *vq, 496 struct virtio_scsi_cmd *cmd, 497 size_t req_size, size_t resp_size, 498 bool kick) 499 { 500 unsigned long flags; 501 int err; 502 bool needs_kick = false; 503 504 spin_lock_irqsave(&vq->vq_lock, flags); 505 err = __virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size); 506 if (!err && kick) 507 needs_kick = virtqueue_kick_prepare(vq->vq); 508 509 spin_unlock_irqrestore(&vq->vq_lock, flags); 510 511 if (needs_kick) 512 virtqueue_notify(vq->vq); 513 return err; 514 } 515 516 static void virtio_scsi_init_hdr(struct virtio_device *vdev, 517 struct virtio_scsi_cmd_req *cmd, 518 struct scsi_cmnd *sc) 519 { 520 cmd->lun[0] = 1; 521 cmd->lun[1] = sc->device->id; 522 cmd->lun[2] = (sc->device->lun >> 8) | 0x40; 523 cmd->lun[3] = sc->device->lun & 0xff; 524 cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc); 525 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; 526 cmd->prio = 0; 527 cmd->crn = 0; 528 } 529 530 #ifdef CONFIG_BLK_DEV_INTEGRITY 531 static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, 532 struct virtio_scsi_cmd_req_pi *cmd_pi, 533 struct scsi_cmnd *sc) 534 { 535 struct request *rq = scsi_cmd_to_rq(sc); 536 struct blk_integrity *bi; 537 538 virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc); 539 540 if (!rq || !scsi_prot_sg_count(sc)) 541 return; 542 543 bi = blk_get_integrity(rq->q->disk); 544 545 if (sc->sc_data_direction == DMA_TO_DEVICE) 546 cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, 547 bio_integrity_bytes(bi, 548 blk_rq_sectors(rq))); 549 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 550 cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, 551 bio_integrity_bytes(bi, 552 blk_rq_sectors(rq))); 553 } 554 #endif 555 556 static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, 557 struct scsi_cmnd *sc) 558 { 559 u32 tag = blk_mq_unique_tag(scsi_cmd_to_rq(sc)); 560 u16 hwq = blk_mq_unique_tag_to_hwq(tag); 561 562 return &vscsi->req_vqs[hwq]; 563 } 564 565 static int virtscsi_queuecommand(struct Scsi_Host *shost, 566 struct scsi_cmnd *sc) 567 { 568 struct virtio_scsi *vscsi = shost_priv(shost); 569 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc); 570 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 571 bool kick; 572 unsigned long flags; 573 int req_size; 574 int ret; 575 576 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 577 578 /* TODO: check feature bit and fail if unsupported? */ 579 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 580 581 dev_dbg(&sc->device->sdev_gendev, 582 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 583 584 cmd->sc = sc; 585 586 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 587 588 #ifdef CONFIG_BLK_DEV_INTEGRITY 589 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 590 virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc); 591 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 592 req_size = sizeof(cmd->req.cmd_pi); 593 } else 594 #endif 595 { 596 virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc); 597 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 598 req_size = sizeof(cmd->req.cmd); 599 } 600 601 kick = (sc->flags & SCMD_LAST) != 0; 602 ret = virtscsi_add_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd), kick); 603 if (ret == -EIO) { 604 cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET; 605 spin_lock_irqsave(&req_vq->vq_lock, flags); 606 virtscsi_complete_cmd(vscsi, cmd); 607 spin_unlock_irqrestore(&req_vq->vq_lock, flags); 608 } else if (ret != 0) { 609 return SCSI_MLQUEUE_HOST_BUSY; 610 } 611 return 0; 612 } 613 614 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 615 { 616 DECLARE_COMPLETION_ONSTACK(comp); 617 int ret = FAILED; 618 619 cmd->comp = ∁ 620 if (virtscsi_add_cmd(&vscsi->ctrl_vq, cmd, 621 sizeof cmd->req.tmf, sizeof cmd->resp.tmf, true) < 0) 622 goto out; 623 624 wait_for_completion(&comp); 625 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 626 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 627 ret = SUCCESS; 628 629 /* 630 * The spec guarantees that all requests related to the TMF have 631 * been completed, but the callback might not have run yet if 632 * we're using independent interrupts (e.g. MSI). Poll the 633 * virtqueues once. 634 * 635 * In the abort case, scsi_done() will do nothing, because the 636 * command timed out and hence SCMD_STATE_COMPLETE has been set. 637 */ 638 virtscsi_poll_requests(vscsi); 639 640 out: 641 mempool_free(cmd, virtscsi_cmd_pool); 642 return ret; 643 } 644 645 static int virtscsi_device_reset(struct scsi_cmnd *sc) 646 { 647 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 648 struct virtio_scsi_cmd *cmd; 649 650 sdev_printk(KERN_INFO, sc->device, "device reset\n"); 651 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 652 if (!cmd) 653 return FAILED; 654 655 memset(cmd, 0, sizeof(*cmd)); 656 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 657 .type = VIRTIO_SCSI_T_TMF, 658 .subtype = cpu_to_virtio32(vscsi->vdev, 659 VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET), 660 .lun[0] = 1, 661 .lun[1] = sc->device->id, 662 .lun[2] = (sc->device->lun >> 8) | 0x40, 663 .lun[3] = sc->device->lun & 0xff, 664 }; 665 return virtscsi_tmf(vscsi, cmd); 666 } 667 668 static int virtscsi_device_alloc(struct scsi_device *sdevice) 669 { 670 /* 671 * Passed through SCSI targets (e.g. with qemu's 'scsi-block') 672 * may have transfer limits which come from the host SCSI 673 * controller or something on the host side other than the 674 * target itself. 675 * 676 * To make this work properly, the hypervisor can adjust the 677 * target's VPD information to advertise these limits. But 678 * for that to work, the guest has to look at the VPD pages, 679 * which we won't do by default if it is an SPC-2 device, even 680 * if it does actually support it. 681 * 682 * So, set the blist to always try to read the VPD pages. 683 */ 684 sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES; 685 686 return 0; 687 } 688 689 690 /** 691 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth 692 * @sdev: Virtscsi target whose queue depth to change 693 * @qdepth: New queue depth 694 */ 695 static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) 696 { 697 struct Scsi_Host *shost = sdev->host; 698 int max_depth = shost->cmd_per_lun; 699 700 return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); 701 } 702 703 static int virtscsi_abort(struct scsi_cmnd *sc) 704 { 705 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 706 struct virtio_scsi_cmd *cmd; 707 708 scmd_printk(KERN_INFO, sc, "abort\n"); 709 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 710 if (!cmd) 711 return FAILED; 712 713 memset(cmd, 0, sizeof(*cmd)); 714 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 715 .type = VIRTIO_SCSI_T_TMF, 716 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 717 .lun[0] = 1, 718 .lun[1] = sc->device->id, 719 .lun[2] = (sc->device->lun >> 8) | 0x40, 720 .lun[3] = sc->device->lun & 0xff, 721 .tag = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc), 722 }; 723 return virtscsi_tmf(vscsi, cmd); 724 } 725 726 static void virtscsi_map_queues(struct Scsi_Host *shost) 727 { 728 struct virtio_scsi *vscsi = shost_priv(shost); 729 int i, qoff; 730 731 for (i = 0, qoff = 0; i < shost->nr_maps; i++) { 732 struct blk_mq_queue_map *map = &shost->tag_set.map[i]; 733 734 map->nr_queues = vscsi->io_queues[i]; 735 map->queue_offset = qoff; 736 qoff += map->nr_queues; 737 738 if (map->nr_queues == 0) 739 continue; 740 741 /* 742 * Regular queues have interrupts and hence CPU affinity is 743 * defined by the core virtio code, but polling queues have 744 * no interrupts so we let the block layer assign CPU affinity. 745 */ 746 if (i == HCTX_TYPE_POLL) 747 blk_mq_map_queues(map); 748 else 749 blk_mq_virtio_map_queues(map, vscsi->vdev, 2); 750 } 751 } 752 753 static int virtscsi_mq_poll(struct Scsi_Host *shost, unsigned int queue_num) 754 { 755 struct virtio_scsi *vscsi = shost_priv(shost); 756 struct virtio_scsi_vq *virtscsi_vq = &vscsi->req_vqs[queue_num]; 757 unsigned long flags; 758 unsigned int len; 759 int found = 0; 760 void *buf; 761 762 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); 763 764 while ((buf = virtqueue_get_buf(virtscsi_vq->vq, &len)) != NULL) { 765 virtscsi_complete_cmd(vscsi, buf); 766 found++; 767 } 768 769 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); 770 771 return found; 772 } 773 774 static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq) 775 { 776 struct virtio_scsi *vscsi = shost_priv(shost); 777 778 virtscsi_kick_vq(&vscsi->req_vqs[hwq]); 779 } 780 781 /* 782 * The host guarantees to respond to each command, although I/O 783 * latencies might be higher than on bare metal. Reset the timer 784 * unconditionally to give the host a chance to perform EH. 785 */ 786 static enum scsi_timeout_action virtscsi_eh_timed_out(struct scsi_cmnd *scmnd) 787 { 788 return SCSI_EH_RESET_TIMER; 789 } 790 791 static const struct scsi_host_template virtscsi_host_template = { 792 .module = THIS_MODULE, 793 .name = "Virtio SCSI HBA", 794 .proc_name = "virtio_scsi", 795 .this_id = -1, 796 .cmd_size = sizeof(struct virtio_scsi_cmd), 797 .queuecommand = virtscsi_queuecommand, 798 .mq_poll = virtscsi_mq_poll, 799 .commit_rqs = virtscsi_commit_rqs, 800 .change_queue_depth = virtscsi_change_queue_depth, 801 .eh_abort_handler = virtscsi_abort, 802 .eh_device_reset_handler = virtscsi_device_reset, 803 .eh_timed_out = virtscsi_eh_timed_out, 804 .slave_alloc = virtscsi_device_alloc, 805 806 .dma_boundary = UINT_MAX, 807 .map_queues = virtscsi_map_queues, 808 .track_queue_depth = 1, 809 }; 810 811 #define virtscsi_config_get(vdev, fld) \ 812 ({ \ 813 __virtio_native_type(struct virtio_scsi_config, fld) __val; \ 814 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 815 __val; \ 816 }) 817 818 #define virtscsi_config_set(vdev, fld, val) \ 819 do { \ 820 __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \ 821 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 822 } while(0) 823 824 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 825 struct virtqueue *vq) 826 { 827 spin_lock_init(&virtscsi_vq->vq_lock); 828 virtscsi_vq->vq = vq; 829 } 830 831 static void virtscsi_remove_vqs(struct virtio_device *vdev) 832 { 833 /* Stop all the virtqueues. */ 834 virtio_reset_device(vdev); 835 vdev->config->del_vqs(vdev); 836 } 837 838 static int virtscsi_init(struct virtio_device *vdev, 839 struct virtio_scsi *vscsi) 840 { 841 int err; 842 u32 i; 843 u32 num_vqs, num_poll_vqs, num_req_vqs; 844 vq_callback_t **callbacks; 845 const char **names; 846 struct virtqueue **vqs; 847 struct irq_affinity desc = { .pre_vectors = 2 }; 848 849 num_req_vqs = vscsi->num_queues; 850 num_vqs = num_req_vqs + VIRTIO_SCSI_VQ_BASE; 851 vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL); 852 callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *), 853 GFP_KERNEL); 854 names = kmalloc_array(num_vqs, sizeof(char *), GFP_KERNEL); 855 856 if (!callbacks || !vqs || !names) { 857 err = -ENOMEM; 858 goto out; 859 } 860 861 num_poll_vqs = min_t(unsigned int, virtscsi_poll_queues, 862 num_req_vqs - 1); 863 vscsi->io_queues[HCTX_TYPE_DEFAULT] = num_req_vqs - num_poll_vqs; 864 vscsi->io_queues[HCTX_TYPE_READ] = 0; 865 vscsi->io_queues[HCTX_TYPE_POLL] = num_poll_vqs; 866 867 dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n", 868 vscsi->io_queues[HCTX_TYPE_DEFAULT], 869 vscsi->io_queues[HCTX_TYPE_READ], 870 vscsi->io_queues[HCTX_TYPE_POLL]); 871 872 callbacks[0] = virtscsi_ctrl_done; 873 callbacks[1] = virtscsi_event_done; 874 names[0] = "control"; 875 names[1] = "event"; 876 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs - num_poll_vqs; i++) { 877 callbacks[i] = virtscsi_req_done; 878 names[i] = "request"; 879 } 880 881 for (; i < num_vqs; i++) { 882 callbacks[i] = NULL; 883 names[i] = "request_poll"; 884 } 885 886 /* Discover virtqueues and write information to configuration. */ 887 err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); 888 if (err) 889 goto out; 890 891 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 892 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 893 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 894 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 895 vqs[i]); 896 897 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 898 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 899 900 err = 0; 901 902 out: 903 kfree(names); 904 kfree(callbacks); 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); 929 930 num_targets = virtscsi_config_get(vdev, max_target) + 1; 931 932 shost = scsi_host_alloc(&virtscsi_host_template, 933 struct_size(vscsi, req_vqs, num_queues)); 934 if (!shost) 935 return -ENOMEM; 936 937 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 938 shost->sg_tablesize = sg_elems; 939 shost->nr_maps = 1; 940 vscsi = shost_priv(shost); 941 vscsi->vdev = vdev; 942 vscsi->num_queues = num_queues; 943 vdev->priv = shost; 944 945 err = virtscsi_init(vdev, vscsi); 946 if (err) 947 goto virtscsi_init_failed; 948 949 if (vscsi->io_queues[HCTX_TYPE_POLL]) 950 shost->nr_maps = HCTX_TYPE_POLL + 1; 951 952 shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq); 953 954 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 955 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 956 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 957 958 /* LUNs > 256 are reported with format 1, so they go in the range 959 * 16640-32767. 960 */ 961 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 962 shost->max_id = num_targets; 963 shost->max_channel = 0; 964 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 965 shost->nr_hw_queues = num_queues; 966 967 #ifdef CONFIG_BLK_DEV_INTEGRITY 968 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 969 int host_prot; 970 971 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 972 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 973 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 974 975 scsi_host_set_prot(shost, host_prot); 976 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 977 } 978 #endif 979 980 err = scsi_add_host(shost, &vdev->dev); 981 if (err) 982 goto scsi_add_host_failed; 983 984 virtio_device_ready(vdev); 985 986 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 987 virtscsi_kick_event_all(vscsi); 988 989 scsi_scan_host(shost); 990 return 0; 991 992 scsi_add_host_failed: 993 vdev->config->del_vqs(vdev); 994 virtscsi_init_failed: 995 scsi_host_put(shost); 996 return err; 997 } 998 999 static void virtscsi_remove(struct virtio_device *vdev) 1000 { 1001 struct Scsi_Host *shost = virtio_scsi_host(vdev); 1002 struct virtio_scsi *vscsi = shost_priv(shost); 1003 1004 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 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 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1032 virtscsi_kick_event_all(vscsi); 1033 1034 return err; 1035 } 1036 #endif 1037 1038 static struct virtio_device_id id_table[] = { 1039 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 1040 { 0 }, 1041 }; 1042 1043 static unsigned int features[] = { 1044 VIRTIO_SCSI_F_HOTPLUG, 1045 VIRTIO_SCSI_F_CHANGE, 1046 #ifdef CONFIG_BLK_DEV_INTEGRITY 1047 VIRTIO_SCSI_F_T10_PI, 1048 #endif 1049 }; 1050 1051 static struct virtio_driver virtio_scsi_driver = { 1052 .feature_table = features, 1053 .feature_table_size = ARRAY_SIZE(features), 1054 .driver.name = KBUILD_MODNAME, 1055 .driver.owner = THIS_MODULE, 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